العلم العراقي
عرض: 25 50 75 100 النتائج

نتائج البحث: 75 من أصل 41,289

تشفير الكلام بالاعتماد على دوال الفوضى المتعددة كمولد مفاتيح A Proposed Speech Scrambling Based on Multi Chaotic Maps as key Generators

اسم المؤلف: حسين علي اسماعيل
اسم المشرف: ستار بدر سدخان المالكي
الموضوع العام: علوم الحاسبات
السنة: 2017
الموضوع الدقيق: برمجيات
الدرجة: ماجستير
الجامعة: جامعة بابل - كلية تكنولوجيا المعلومات - قسم البرامجيات
اللغة: الانكليزية
مكان الجامعة: بابل
الصفحات الاولى:
المستخلص: تشفير الكلام هو عملية جعل خاصية المفهومية المتبقية للكلام واطئة, بالتالي يجعل من الصعب فهم الكلام من قبل المتنصت او المهاجم. وبسبب التطور السريع والكبير الذي وقع في نظم الاتصالات تسبب في زيادة المشاكل التي تهتم بالخصوصية وامن المعلومات، لذلك تطلب من الباحثين تطوير خوارزميات التشفير لحماية البيانات بحيث تكون الخوارزمية اكثر امنا، واحدة من هذه البيانات هو البيانات صوت التي يتم ارسالها من خلال القناة عامة المعرضة الى نوعين من المشاكل الضجيج بالاضافة الى تتنصت.نظرية الفوضى هي واحدة من اهم النظريات المستخدمة في الترميز ذلك لانها تمتلك خصائص مناسبة للتشفير، حيث انها تحقق خاصيتي الانتشار والارتباك, اللتان تعتبران من الخصائص المهمة في علم التشفير. في بحثي تم استخدام مفهوم الدوال الفوضى الهجينة كما مولدات مفاتيح لتغيير معالم الخطاب، حيث كان الهدف من استخدام مفهوم هجين من الخرائط الفوضى بدلا من استخدام دالة الفوضوية واحد هو زيادة تعقيد النظام المقترح. في هذه الرسالة تم استخدام خمسة دوال الفوضوية تشمل (Logistic, Henon, Lorenz, Chen, Standard) ، حيث تم استخدام مزيج من الدوال الفوضوية المختلفة لانتاج فيض من المفتاح الثنائي الذي يمتاز بمساحة مفتاح عالية واكثر عشوائيا وكذلك يقلل المفهوم المتبقية للكلام عند استخدامه لتشفير الكلام. وتوضح النتائج ان العشوائية باستخدام المعهد الوطني للمعاييروالتكنولوجيا (NIST) مثل التردد احادي بت = 0.0586 لدالة لورينز واحدة والتردد احادي بت = 0.0113 لدالة تشن واحدة ، في حين ان التردد احادي بت = 0.7665 لدوال لورينز وتشن مع بعضهما، بالتالي نلاحظ زيادة في العشوائية.المفهومية المتبقية باستخدام مقياس الطيف القطعي لنسبة اشارة المعلومات للضوضاء (SSNR) - 16.9729= لدالة لورينز واحدة وSSNR =16.9432 - لدالة تشن واحدة بينما SSNR = 17.3716 - دوال لورينز تشن مع بعضها، بالتالي نلاحظ ان المفهومية المتبقية فيد انخفضت. كذلك مساحة المفتاح = 2^360 لدالة لورزنز وتشن معا بينما مساحة المفتاح = 2^180 لدالة تشن واحدة ومساحة المفتاح = 2^180 لدالة لورنز واحدة. الظروف الابتدائية والمتغيرات تمثل مفاتيح النظام. تم الحصول على نتائج جيدة مقارنة مع دالة فوضوية واحدة. | Speech scrambling is the process of making low residual unintelligible of speech. So, it will make difficult for understanding it by eavesdrops or attackers. Due to the rapid and great developments that have been taking place in communication systems causing increased problems that are interesting to the privacy and security of the information, so they ask the researchers to develop encryption algorithms for protecting the data to become more secure. One of this data is voice data that sends through the public channel to be exposed to noise in addition to eavesdrops.Chaos theory is one of the most important theories used in cryptography because it possesses suitable properties for encryption. These properties can be used for investigating diffusion and confusion properties, which is one of the important characteristics in cryptography. In this thesis, the concept of hybrid chaotic maps has been used as generator of keys to scramble speech. The objective has been used the concept of hybrid of chaotic maps instead of using single chaotic map so as increase the complexity of the proposed system. This thesis has used five chaotic maps as generators of keys including (Logistic, Henon, Lorenz, Chen, Standard) maps. It uses of combination of two different chaotic maps for production random keystream bits that have large of the key space, more randomness and achieving low residual intelligibility for speech. The results explain that randomness by using National Institute of Standards and Technology (NIST) tests such as the frequency mono - bit =0.0586 for Lorenz map alone and the frequency mono - bit = 0.0113 for chen map alone, while frequency mono - bit =0.7665 for Lorenz and Chen, thus they observe an increase in randomness. The residual intelligibility using Segmental Spectral Signal to Noise Ratio measure (SSNR) = - 16.9729 for Lorenz map alone and SSNR = - 16.9432 for Chen map alone while SSNR = - 17.3716 for Lorenz and chen maps, thus they observe an low residual intelligibility of speech. The key space = 2^360 for Lorenz and chen maps togethers while key space =2^180 for Chen map alone and key space = 2^180 for Lorenz map alone, the parameters and initial conditions of map represent secret keys in system. It has got better and successful results compared with single chaotic map

تمييز حركة الكائن المفرد اعتمادا على نظرية تاكوشي للامثلية ومجموعة الخام للتصنيف Single Object Motion Categorization Based on Taguchi Method Optimization and Rough Set Classification

اسم المؤلف: عادل عباس مجيد الربيعي
اسم المشرف: اسراء هادي علي الشمري
الموضوع العام: علوم الحاسبات
السنة: 2017
الموضوع الدقيق: علوم الحاسبات
الدرجة: دكتوراه
الجامعة: جامعة بابل - كلية تكنولوجيا المعلومات - قسم البرامجيات
اللغة: الانكليزية
مكان الجامعة: بابل
الصفحات الاولى:
المستخلص: تعتبر انظمة التتبع الفيديوية ذات اهمية كبيرة في عالمنا الحديث. لاعتبارها احد الفروع الهامة من علوم الحاسوب التي تتعامل مع عدة مواضيع مثل الامن، الطبية، القضائية او الطب الشرعي، الرياضة وغيرها من المجالات الحيوية والحياتية الاخرى.ان المشكلة الاساسية التي تم تناولها ودراستها في بحثنا هذا كيفية الكشف عن حركة الاجسام او الاشخاص والتركيز لايجاد نوع وشكل الحركة للاجسام في الافلام.الحصول على معلومات اضافية من الفيديو ادت الى تجميع بعض الافكار لبرهنة او دحض بعض الحقائق. وكذلك ايجاد الدوال المناسبة لها والتي تمثل نوع الحركة للجسم، حيث تم استخلاص الصفات المهمة لمسار الجسم مع تحديد وزن كل صفة وهذا مما يؤدي تقليل الزمن المستهلك في تطبيقات التعقب الفديوي. تم استخدام طرق الرياضيات الحديثة لغرض تصنيف الحركات المتنوعة والمتشابهة في الشكل للاجسام التي يتم تعقبها بالاعتماد على قاعدة بيانات ذات مقاييس عالمية. هناك الكثير من التحديات التي تواجه عملية تعقب الاهداف المتحركة، مثل فصل الجسم او الهدف عن خلفية المشهد، نحن نستخدم طريقة محدثة من الرسم البياني التراكمي لبناء قالب للمشهد الخلفي. بعد ايجاد مسار الجسم نحن نختار عدد من الصفات الملائمة مثل (الازاحة، السرعة، الفرق في الطول، الميل) لغرض تحديد شكل وطبيعة حركة الجسم.في بحثتا هذا استخدمنا ثلاث طرق وقارنا بينها (الميل، الانحدار، وصف فورير) لحركة الاجسام لكي نحدد شكل الحركة (مستقيم، دائرة، قوس، بيضوي، متذبذب، حرف اس ....الخ) واستنتجنا ان طريقة الميل هي الافضل من حيث الزمن المستهلك وغير مكلفة حسابيا. في مرحلة الامثلية التي تعتبر جزء مهم في انظمة التعقب الفيديوي، وظفنا نظرية تاكوشي لتحديد الاعلى وزنا لافضل خاصية من الخواص المستخلصة مما يؤدي لتقليل الزمن المستهلك في التطبيقات. لتصنيف انواع عديدة من حركة الاشخاص نحن نعتمد على موديل مجموعة الخام لبناء نظام المعلومات وعدد من القواعد لتمييز شكل الحركات المتداخلة مثل (الانحناء، رفع اليد والساق في نفس المكان، القفز مع الحركة، القفز في نفس المكان، الركض، الحركة الجانبية، القفز بقدم واحدة، المشي، الحركة الموجية) في عملية التصنيف. في النهاية، للكشف عن البحث وما يتضمنه من تجارب يمكن متابعة الفصل الثاني والثالث بشكل مفصل علما ان وثوقية النظام بلغت بحدود 93% بعد اجراء الكثير من التجارب بالاعتماد على قاعدة بيانات قياسية تسمى "ويزمان | Video tracking systems (VTS) is a matter of interest in this modern world, because it regarded as one of important branches of computer science which deals with several subjects such as security, medical, judicial or forensic, sports and other vital fields of life.The main problem that has been addressed, studied and analyzed in this thesis is how can detect and recognize objects (persons) motions? farther more this work was concentrated on finding the shape and form of a movement of person or objects in a video. Getting additional information from a video will enable the author to sum the ideas in order to prove or disprove some facts. For instance, finding and manipulating the trajectory of object and mathematical models used in analyzing. Finding the suitable functions which represent types of objects’ motions, extract important features of trajectory object’s moving, in order to find optima features by determine the weight of each features. This reduce the consume time in video tracking application. Using the modern mathematical models to classify object motion and determine the types and form of them. This is based on standard database (Weizmann). There are some difficulties facing the process of tracking moving targets such as separate the object or target from the background of scene. In order to build a background template model which is used an upgrade accumulative histogram technique.Finding the trajectory of object, and selecting a number of appropriate motion attributes such as (displacement, velocity, differences in length and slope), enable us to determine the form and the nature of the motion object movement.In this work three methods “Slope, Regression and Fourier descriptors” have been studied, and a comparison among them was made, and determines the shape of the movement (straight line, circle, arc, ellipse, oscillating, S - shaped…etc.) was detected. It was found, that the slope method was the best in terms of consumed time or computationally inexpensive.The optimization stage regards a core part of a video tracking, specified Taguchi method have been used in this work in order to assign in high value of weight for best features extraction and it has reduced the consumption of analysis time.The classification of persons motion depends on rough set model to implement information system and number of rules in distinguishing forms of overlapping movements types such as to (bend, jack, jump, pjump, run , side, skip, walk and wave). In the end, the detection of this work implicitly tested in chapter two and chapter three. Thesis reliability up to 93% after a lot of testing based on the standards database is called “Weizmann”.

توليد مفتاح امن باستخدام شبكة بتري Secure Key Generation Using Petri Net

اسم المؤلف: رند عبد الواحد محمد علي البير
اسم المشرف: حسين عطية لفتة الخالدي
الموضوع العام: علوم الحاسبات
السنة: 2017
الموضوع الدقيق: برمجيات
الدرجة: ماجستير
الجامعة: جامعة بابل - كلية العلوم - قسم البرامجيات
اللغة: الانكليزية
مكان الجامعة: بابل
الصفحات الاولى:
المستخلص: التشفير هو العلم الذي يهتم بحماية المعلومات المهمة من الاشخاص الغير مخولين . تكون عملية التشفير بالتشفير التدفقي على بت بت من النص الصريح عن طريق عملية xor مع مفتاح التشفير. ولذك اهم جزء بالتشفير التدفقي هو عملية توليد المفتاح. يعتمد النظام المقترح على مجموعة متكونة من اربعه شبكات بتري ملونة وشبكة بتري عادية لتوليد مفتاح معقد شبه عشوائي. تمتلك البتري نت موديل مثالي لتوليد مفتاح معقد طويل. يتطلب هذا النظام مفتاح قصير ذا طول ۱۲۸بت كقيمة ابتدائية متفق عليها من قبل الطرفين المرسل والمستقبل لتكون التاشير الابتدائي لشبكات البتري الملونة . يختلف الناتج المتولد من كل شبكات البتري الملونة من وقت الى اخر بالاعتماد على انتقال القيم بين عقد الشبكة والتي تختلف من واحدة الى اخرى. تزيد عملية ربط شبكات البتري الملونة مع شبكة بتري عاديه من اللاخطية للمفتاح المتولد .استخدمت عملية الترميز الرمادي واعادة ترتيب النص الصريح في النظام المقترح من اجل زيادة امن النص المشفر المتولد. استخدمت في هذه الاطروحة الاختبارات الاحصائية لقياس عشوائية المفتاح المتولد والكشف عن نقاط ضعفه. وقد بينت هذه الاختبارات ان المفتاح المتولد باستخدام شبكة بتري يمتلك عشوائية جيدة. | Cryptography is the science of protecting the important information from an unauthorized people. Stream cipher encrypted one individual bit of a plaintext message at a time by XOR operation with the key stream, therefore an important part of stream cipher is key generation.The proposed system bases on a combination of four coloured petri nets and one ordinary petri net to generate secure pseudo random key, Petri net has a perfect model to generate complex key sequence. This system requires (128 bits) initial short key shared between the sender and the receiver by a secure channel to be an initial marking for CPNs and the output of them are different from one time to another depending on the firing of different types of transitions. Connecting the CPNs with ordinary petri net increase the nonlinearity of the generated key. The system also consists of two operation gray coding and permutation operation to increase the security of the generated cipher text.In this thesis ,the statistical tests are used to measure the randomness quality of a key generator and to detect its weaknesses. These statistical tests show that the key generated using petri net has good randomnes

ازالة الضوضاء من الصور باستخدام تقنية الانصهار معتمدا على معاملات تحويل المويجة المتقطعة Image Denoising Using Fusion Technique Based on DWT Coefficient

اسم المؤلف: رسل حيدر جاسم
اسم المشرف: اسراء هادي علي الشمري
الموضوع العام: علوم الحاسبات
السنة: 2017
الموضوع الدقيق: علوم الحاسبات
الدرجة: ماجستير
الجامعة: جامعة بابل - كلية العلوم - قسم علوم الحاسبات
اللغة: الانكليزية
مكان الجامعة: بابل
الصفحات الاولى:
المستخلص: الضوضاء هو عبارة عن معلومات غير مرغوب فيها في الصورة التي تدهورت اثناء عملية النقل او استحصال الصورة. ان اثار الضوضاء يقلل من وضوح الصورة. عملية ازالة الضوضاء من الصورة يسهل من عملية المعالجة. ان مشكلة ازالة الضوضاء في المجال المكاني تعمل على تنعيم البيانات بالاضافة الى تنعيم الحواف. لهذا السبب استخدمت ازالة الضوضاء عن طريق المويجة باستخدام المجال الترددي التي تعمل في المحافظة على الخصائص المهمة للصورة والحواف بالاضافة الى ازالة الضوضاء من الصور لكن تبقى مشكلة فقدان بعض المعلومات المهمة للصورة وتكوين صورة اقل وضوحا. تلعب طريقة انصهار الصور في الوقت الحاضر التي هي احدى انواع تكنولوجيا المعلومات المتكاملة دورا هاما في العديد من المجالات وتكوين صورة ذات نوعية عالية . الهدف من انصهار الصورة هو مزج المعلومات من صور عديدة بالاضافة الى حفظ المعلومات الهامة الموجودة في الصور الاصلية واستعادة جودة الصورة بناءا على مقياس نسبة الاشارة الى الضوضاء. يتالف النظام المقترح من اربع مراحل رئيسية هي تحويل المويجة المتقطعة ،ازالة الضوضاء باستخدام المويجة ،مرحلة الانصهار ومعكوس تحويل المويجة المتقطعة. في البداية تم تطبيق تحويل المويجة المتقطعة على مجموعة من الصور بنفس الحجم والمنظر مع استخدام المستوى الثاني من تحليل المويجة ومن ثم تطبيق احد تقنيات ازالة الضوضاء باستخدام التعتيبب على اجزاء معاملات المويجة وليس على الصورة باكملها من خلال استخدام قيمة عتبة لمعامل التفصيل ومقارنتها مع معاملات المويجة حيث تم استخدام العتبة الناعمة والصلبة مع عتبات الشامله وبايز حيث تتم مقارنة كل جزء من اجزاء الصورة مع الاجزاء المقابلة لصورة اخرى لاختيار الجزء الذي يحتوي على اقل ضوضاء. بعد ذلك يتم اختيار الاجزاء المثالية التي تحتوي على اعلى قيمة نسبة الاشارة الى الضوضاء من صور مختلفة لتكوين الصورة المنصهرة . والمرحلة الاخيرة هو تطبيق معكوس تحويل المويجة المتقطعة على الصورة المنصهرة لتحويلها من المجال الترددي الى المجال المكاني للحصول على الصورة الناتجة.الصورة الناتجة هي الصورة الجديدة التي تكون اكثر ملاءمة لرؤية الانسان والادراك الالي واظهرت نتائج هذا التطبيق ان طريقة العتبة الناعمة لازالة الضوضاء تعطي نتائج افضل من العتبة الصعبة بناءا على المقياس المستخدم. يعتبر النظام المقترح غير مناسب لدمج صورتين لان نسبة الاشارة الى الضوضاء للصورة الاولى والثانية تكون متساوبة. ان تطبيق الصور الضبابية على نفس النظام المقترح لايعطي نتائج مرضية في المجال الترددي حول دمج الاجزاء المثالية للصورة ولهذا السبب تم تطبيق الصور الضبابية في المجال المكاني مع مرحلة الانصهار باستخدام التصفية العكسية والتي اعطت نتائج جيدة للصورة الناتجة . الصور التي تم استخدامها في الرسالة هي صور رمادية ذات ابعاد مختلفة مع استخدام انواع مختلفة من الضوضاء. تم تنفيذ النظام المقترح باستخدام لغة برمجة (فيجوال ستوديو2012 ) vb.net. | The noise is unwanted information in image that is corrupted during its transmission or acquisition. The noise effects reduce the effectiveness of vision. Removing noise from the image eases the processing. The problem of the noise removal in the spatial domain is smoothing the data and the edges. Wavelet denoising is the process noise removal using wavelet in frequency domain. Therefore, it uses in keeping on the edges of the image, preventing types of noises and keeping the significant features of image, but this problem causes a loss in some of important information of image and produces image less visually. In the present time, image fusion is considered as one of types of integrated technology information, it plays a significant role in several domains and production of high quality images. The goal of image fusion is blending information from several images, also it is fusing and keeping all the significant visual information that is existed in original images and restoration the image quality that is based on PSNR and SNR measures. The proposed system includes four main stages are a discrete wavelet transform (DWT), denoising wavelet, fusion stage and inverse discrete wavelet transform (IDWT). In the beginning, discreet wavelet transform applies on the set of images of the same scene and size with two decomposition level. Then is performing the denoising wavelet hard and soft thresholding on sub band of image and is not the whole it, it is achieved by threshold value (universal and bayes thresholds) for detail sub bands and compare it with wavelet coefficient. After that is selecting the optimal sub band that contain less noise based on PSNR and SNR values for different images to form the fused image. Finally, apply IDWT process to convert the fused image from frequency domain to spatial domain and is obtained the resulted image. The resulted image is a new image which is more appropriate for human vision and machine perception .The results of the application show soft thresholding method is better than of hard thresholding that is based on higher PSNR value and image visually. The proposed system is unsuccessful for fusion two images, because PSNR value of one image and another image is same. The blur images applying on same proposed don't give satisfying results in the frequency domain about fused the optimal sub bands, therefore; it is applied in the spatial domain with fusion process by using inverse filtering and getting on the good results. The images are utilized in this thesis are gray images that different dimensions with using different types of noise as (salt &pepper, gaussian, Poisson and speckle) and the proposed system is performed using visual basic.net 2012 programing language.

خوارزهية التوجيه الهجينة لاتصاللات الماكنة مع ملكنة Hybriid Routiing Allgoriithm for Machiine to Machiine Communiicatiion

اسم المؤلف: باسم جميل علي
اسم المشرف: سعد طالب حسون الجبوري
الموضوع العام: علوم الحاسبات
السنة: 2017
الموضوع الدقيق: علوم الحاسبات
الدرجة: دكتوراه
الجامعة: جامعة بابل - كلية العلوم - قسم علوم الحاسبات
اللغة: الانكليزية
مكان الجامعة: بابل
الصفحات الاولى:
المستخلص: The wireless communication devices have witnessed rapid growth in the recent years. Such growth and its useful applications led to the appearance of new applications known as "machine - to - machine" (M2M) communications. M2M plays a big role in finding the best hopeful explanation to change the current and the future smart widespread requests. Most of the smart wireless devices may perform as servers, collection of data and/or delivering the data at real time to users in a certain collaborative fashion.M2M communication domain consists of a huge number of tiny nodes and gateway (or sink) that are suffer from suffer from resource constrains like power limitation, storage capacity, radio limitation, data processing, etc.. Thus, it is necessary to find methods to increase node's lifetime as long as possible and consequently the overall sensor network. M2M devices consume considerable amount of energy due to communication process comparing to other process. This process depends on message size and the distance between the sender and the recipient. Thus reducing the packet size and finding a low energy aware routing procedure is necessary to save nodes energy.This thesis adopted compressed sensing (CS) as a modern data compression technique, modified Gossip algorithm as a flat protocol and introduced hybrid Gossip based low energy adaptive clustering hierarchy (LEACH) protocols as a new hybrid routing algorithm. CS combined with LEACH protocol named LEACHCS and the results that are reported from LEACHCS showed that the communication process can be improved in term of the channel bandwidth (B.W) utilization, increasing network throughput and saving node's communication energy.Gossip data aggregation technique is a biologically inspired paradigm of contagion inspired from behavior of the disease infection process. Its procedure is based on the help of neighboring nodes and employs the randomization technique to form a chain of the intermediary nodes (route). The modification of Gossip based on the selection operation of the next node hop. This thesis introduced three versions of modifying Gossip : a) Modify Gossip named (DGossip), in which a chain of intermediary nodes can be formed according to the relative node's energy and relative nodes displacement to the sink instance of randomization technique in the original Gossip. b) The formation of intermediary nodes based on the relative energy of neighbor nodes and nearest node to the source node called EN_Gossip. c) A hybrid of EN_Gossip and EL_Gossip named ENL_Gossip is introduced as a new version. In ENL_Gossip, a chain of intermediary nodes is collected through alternating use of both EN_Gossip first then EL_Gossip starting from the source node till reached the sink.The results showed that the DGossip is significantly better than others in term of the average remaining energy of network and latency time (in terms of number of hops), while ENL_gossip outperforms the others in term of network's live time.A new hybrid algorithm is proposed which combined Gossip as a bio - inspired technique with LEACH as a hierarchical multi - hop routing algorithm called LEACHGossip algorithm. This algorithm uses LEACH for clustering configuration purpose, while Gossip applies for each CH (or normal node) that is away (do m) from the sink (or from its associated CH). The simulation results proved that it outperforms LEACH about more times in terms of congestion between CHs and BS, node still alive and energy saving. Thus, the above mentioned procedures can be considered as efficient communication protocols for M2M communication networks in term of energy saving.

تحديد مكان وهوية المتكلم باستخدام تقنية توجيه حزم الاشارة المحسنة

اسم المؤلف: علي يعكوب يوسف
اسم المشرف: حسين عطية لفتة الخالدي
الموضوع العام: علوم الحاسبات
السنة: 2016
الموضوع الدقيق: علوم الحاسبات
الدرجة: دكتوراه
الجامعة: جامعة بابل - كلية العلوم - قسم علوم الحاسبات
اللغة: الانكليزية
مكان الجامعة: بابل
الصفحات الاولى:
المستخلص: Automatic speech recognition (ASR) systems perform well when using a close - talking microphone, However, many environments (Hands - free) where the use of such microphones is undesirable for reasons of convenience. In a hands - free environment, the noise and reverberation degrade the accuracy of recognition. An enhanced approach using microphone array for speaker localization and enhancement of speech signal input to an automatic speech identification system was proposed. The proposed system using enhanced beamforming technique based on Minimum Variance Distortionless Response (MVDR) for speaker localization with multi - microphone arrays. The strongest output beam signal corresponding to selected microphone array, used for the speaker identification. The identification phase based on using Mel Frequency Cepstrum Coefficient MFCC for feature extraction and enhance LBG algorithm for speaker modeling.Speaker identification accuracy in using proposed method were compared with conventional beamforming method, It was found that the higher recognition accuracy than previous approaches, and in experiments using speech signals that were artificially corrupted by additive noise. The proposed system provided a consistent, improvement in recognition accuracy for several experiments in simulation environments. It is also showing the benefit of usingmicrophone array processing. The localization phase evaluated using SNR, showing enhanced ratio after applying enhanced beamforming that estimate speaker location. The results showing localization accuracy 96.8% and 98.1% recognition accuracy where achieved.

نظام توصيات قائم على الويب لانتشار الاوبئة Web - Based Recommender System for Spread Epidemics

اسم المؤلف: حيدر محمد حبيب مجيد
اسم المشرف: نبيل هاشم الاعرجي
الموضوع العام: علوم الحاسبات
السنة: 2016
الموضوع الدقيق: علوم الحاسبات
الدرجة: دكتوراه
الجامعة: جامعة بابل - كلية العلوم - قسم علوم الحاسبات
اللغة: الانكليزية
مكان الجامعة: بابل
الصفحات الاولى:
المستخلص: The usage of Online Social Networks, such as Facebook and Twitterbecomes more and more popular in order to exchange and disseminate news andinformation in real - time. Twitter in particular allows the instant dissemination ofshort messages in the form of microblogs to followers. This dissertation exploresand examine the usage of how social networks, such as the microblogging toolTwitter, can help in the detection of spreading epidemics and reducing time delaybetween the emergence of disease and report sick to the health authorities suchas World Health Organization (WHO).Text classification has been used to classify the patients and non - patients(positive / negative). Sentiment Analysis (SA) and Linear Support VectorClassifier (LSVC) have been applied in the classification patients. In thisdissertation, four diseases have examined. Diseases that have most similarity intheir symptoms have been taken in order to classify patients based on theirsymptoms by applying a recommendation system techniques. Symptoms - basedHealthcare Recommender System is new approach in this work. It uses patientsymptominstead of user - item in traditional Collaborative Recommender System.Collaborative Filtering (CF) has been applied in order to recommend whichdisease the patient may has. CF shows an indicator that users on Social Networkshave not enough knowledge to mention all symptoms for specific disease, that’sled to classify patients to more than one disease according to common symptomsthat mentioned by patients.Geolocation of users that classified as patients has been extracted in orderto recommend health authorities that there is a certain area might has a beginningof spread disease. An implicit geocoding of users has been extracted by usingGoogle Maps Geocoding API to avoid neglecting those who don’t have explicitgeolocation.IISuspected areas has been weighted by computing a Confidence Factor(cFactor) of Tweet source whatever it comes from mobile or desktop. cFactorhelp in reducing time consuming into 29% of collecting and processing data.Weighted and Geographic Symptoms - based Recommender (WGSR) model hasbeen created detect, classify and visualize patients on the map.The accuracy of WGSR model reached to %94 in the classification andmore than %80 with the real reports of World Health Organization (WHO) whichrefers as a very good and can be improved for better results.

تطوير ادوات جديدة في نظام مودل Developing New Tools in Moodle System

اسم المؤلف: نهلة فليح حساني الشويلي
اسم المشرف: كاظم حسن كبان الابراهيمي
الموضوع العام: علوم الحاسبات
السنة: 2017
الموضوع الدقيق: علوم الحاسبات
الدرجة: ماجستير
الجامعة: جامعة ذي قار - كلية التربية للعلوم الصرفة - قسم الحاسبات
اللغة: الانكليزية
مكان الجامعة: ذي قار
الصفحات الاولى:
المستخلص: E - learning is the use of IT in learning and teaching. This usage improved the quality of learning and teaching through facilitating access to resources and remote collaboration among teachers and students. E - Learning makes it easier to create and distribute learning materials, independently of geographical or time limits. It allows students to exchange information and participation in activities.There are many systems (software) development for management of E - learning (LMS). These systems provide tools for simulation the traditional learning, development and support the electronic learning.LMS provides many tools to create, manage the examination, evaluate the grades and spread question types.The general aim of this thesis is to develop the LMS that has been increasingly used having widespread in E - Learning in many countries. This system is "Moodle" which designed to supporting electronic learning.Moodle system is not satisfying conditions of the traditional exam copybook that is used in examination committees in Iraqi universities in terms of security and accuracy."Single view" report in Moodle system allows the teacher to edit grades of "Quiz" activities.Moodle system not provided question type in which the answering method is done through selecting word from a given text; this idea is a suggested product for the development of Moodle website in 2014 and doesn't have solution yet.In this thesis, we proposed three main proposals : 1. Development of Moodle system to use it in the examinations in Iraqi Universities through designing and implementation of new module named "Teacher view" to provide "The Electronic Exam Copybook" which simulated the traditional exam copybook that is used in the examination committees in these universities for assessment of student's answers. It also presents documentation of detailed information about student's attempt on examination and calculates the student's grades. This "Electronic Exam Copybook" satisfies all conditions of the traditional exam copybook in terms of security and accuracy. Also, the proposed module provides students' results in English and Arabic languages and manual of this module.2. Overcome of the weakness in "Single view" report in Moodle system.3. Development of Moodle system through designing and implementation of a new question type called "Highlight words" in this system. The idea of answering method to this question type is highlight word from a given clickable text.We used the following requirements to design and implement the proposals tools in this thesis : 32 bit windows7 operating system, 2.30 GHz Core i3 processor, router device, WAMP server, Moodle system (version 2.9) in English language, Mozilla Firefox web browser, Macromedia Dreamweaver 8 and First object XML Editor software

تصنيف اورام الدماغ باستخدام الشبكات العصبية الاصطناعية

اسم المؤلف: نور حيدر داخل
اسم المشرف: حازم باقر طاهر العلي
الموضوع العام: علوم الحاسبات
السنة: 2017
الموضوع الدقيق: علوم الحاسبات
الدرجة: ماجستير
الجامعة: جامعة ذي قار - كلية التربية للعلوم الصرفة - قسم الحاسبات
اللغة: الانكليزية
مكان الجامعة: ذي قار
الصفحات الاولى:
المستخلص: Accelerating the pace of scientific progress and that focus in the field of human service requirements is to provide daily health and service. Health aspect is one of the most important things of science that needs to be develop it because it has an important effect on human life. Medical imaging has become one of the most important factors in the treatment of human health. A large amount of information and data can be obtained about disease by different methods of Images acquisition techniques same like Magnetic Resonance Imaging (MRI), Computed Tomography (CT).The purpose of this thesis is to discover a way to detect the brain is to suggest a system to diagnose the brain whether it is normal or abnormal (contains a tumor) by using artificial neural network technology which contain many steps. The first step of detecting the brain tumor system is the input image to the system as digital data.The processing is the second step, which includes reducing noise and removing impurities of the brain image. So as the noise is removed by using median filter and wiener filter. After processing (filtration) image segmentation. Feature extraction is the techniques that is used to measure of difference properties of image segments, given the specific features as input to the artificial neural network classified (ANN).Seeded classified databases are due to the two types of brain image, (normal or abnormal).Samples have taken from a group of patients in AL - Husain Teaching Hospital disparate ages and both ganders, which was 100 samples ,80 of them were training samples and 20 were tested .The proposed system has proven successful of the diagnostic through the results obtained on the ratio of (100% in the training phase) and (100% in the testing phase

تسريع ضغط الصور الكسوري باستخدام تقنيات مطورة Fast Fractal Image Compression using Adaptive Techniques

اسم المؤلف: حيدر عباس محسن
اسم المشرف: حازم باقر طاهر العلي
الموضوع العام: علوم الحاسبات
السنة: 2016
الموضوع الدقيق: علوم الحاسبات
الدرجة: ماجستير
الجامعة: جامعة ذي قار - كلية التربية للعلوم الصرفة - قسم الحاسبات
اللغة: الانكليزية
مكان الجامعة: ذي قار
الصفحات الاولى:
المستخلص: Fractal Image Compression (FIC) is one of the lossy techniques. In order for fractal compression image to be encoded is partitioned into non - overlapping blocks called ranges. From this range pool creates a new array called domain pool, the data of domain is array produced from taking an average of every four (2x2) adjacent elements in the range array, the domain is divided into overlapping blocks. Each block in range pool should be matched with every large number of blocks in the domain pool in order to find minimum error and recorded its best IFS approximate. The decoder process applies the determined IFS transformations on any initial image, and the process is repeated many times until reaching the attractor. In this thesis, it presents reducing the long encoding time of FIC without making significant sacrifice in the quality. In addition to the traditional fractal compression method, four IFS coding methods have been tested.The first method is speed up encoding phase by using moment features of the domain blocks with threshold , this method it compute the moment features of domain blocks only , during the matching process, compares the ratio factor of domain block with threshold, then compute the scaling (s), offset (o) coefficients and minimum error between range and domain blocks, and storing the optimal IFS coding , the results of this method with lenna image (4x4) block size, (the encoding time = 50.29 sec), (compression ration= 4.57 ) ,(PSNR=24.04), (RTR=33.42 ). The second method is speed up encoding phase by using the entropy technique of the domain blocks only , during the matching process, compares entropy value of domain block with threshold, and storing optimal IFS coding , the results of lenna image(4x4) block size, (the encoding time = 95.47sec), (compression ration= 4.47 ) ,(PSNR= 24.08) and (RTR= 17.60) . In the third method it merges the entropy technique with moment features of domain blocks only , during the matching process, compares entropy value and moments ratio factor of domain blocks with threshold and storing IFC coding, the compression results of lenna image (4x4)block size , (encoding time = 100.90 sec), (compression ration=4.47) ,(PSNR= 24.11) and (RTR=16.66) , the flaw in this method is the encoding time of 16x16 partitioning more than 4x4 and 8x8 partitioning. In the fourth method speed up encoding phase by use moment features of the range and domain blocks, in this method it computes the moment features of range and domain blocks, during the matching process, if the moments ratio factor of range and domain blocks are equal then compute scale(s),offset(o) and error (R) .storing best IFS coding. the results of lenna image(4x4) (encoding time = 114.02 sec), (compression ration= 4.47) ,(PSNR= 24.43), (RTR=14.74), the flaw in this method is the encoding time of 16x16 partitioning more than 4x4 and 8x8 partitioning. Matlab R2008a was used as a program to designed and implemented to achieve the coding and testing tasks. The environment used for our tests is a single PC with processor (core i3 CPU 2.53GHz) and 4.00 GB RAM .

خوارزمية موازنة الاحمال المقترحة في الحوسبة السحابية A Proposed Load Balancing Algorithm in Cloud Computing

اسم المؤلف: اطياف ضاري برغش
اسم المشرف: خلدون ابراهيم عارف
الموضوع العام: علوم الحاسبات
السنة: 2017
الموضوع الدقيق: علوم الحاسبات
الدرجة: ماجستير
الجامعة: جامعة ذي قار - كلية التربية للعلوم الصرفة - قسم الحاسبات
اللغة: الانكليزية
مكان الجامعة: ذي قار
الصفحات الاولى:
المستخلص: Cloud computing considers an important paradigm that provides services and dynamic virtual resources to the consumers over the internet.One of the main challenges and important fields for research in the cloud computing environment is load balancing. So the main goal of this thesis is to establish an effective load balancing algorithm for task scheduling. In cloud computing environment, the demands are executed into the virtual machines (VMs) and in the execution, it must be avoided a situation some of the resources are under loaded states while there are resources overloaded or heavy while achieving less the execution time of the tasks andresponse time. In this thesis, we present the Load Balancing Decision Algorithm (LBDA) which aims to achieve load balancing for reducing the : Total completion time (Makespan), Response time and Total execution time of tasks in cloud computing environment.The mechanism of LBDA is based on three functions, first : calculating the virtual machine capacity, virtual machine load then determining VM states (Under loaded, Balance, High balance, Overloaded) based on comparing VM capacity, VM load and using three thresholds : threshold upper; threshold fair; and threshold lower. Second : estimating the time required to complete executing the task in each VM. Finally, making a decision to distribute the tasks among the VMs based on VM state and task time required. Where checked task time required into VMs under states and selecting the fastest VM, when there are more than one VMs have the same time to complete a task, LBDA assigns a task to VMs which has the largest capacity. When all VMs become (Balance or High balance) states, the tasks are distributed between VMs depending on the fastest execution. The proposed LBDA was compared with Max - Min, Shortest Job First and Round Robin algorithms. We applied many experiments with various VMs’ capacity and : A different number of tasks on a different number of VMs, The same number of tasks on a different number of VMs, and A different number of tasks on a different number of VMs.The performance evaluation results implemented in cloudsim toolkit 3.0.3 and the experiments demonstrate that our proposed LBDA outperformed to other algorithms by reducing the completion time of tasks, response time, andtotal execution time of tasks.

مخطط يربط المفتاح بالقياسات الحيوية لحماية انظمة المعلومات A Biometric Key Binding Scheme for Information Systems Protection

اسم المؤلف: ابرار خلف الشريفي
اسم المشرف: كاظم مهدي الموسوي كاظم حسن الابراهيمي
الموضوع العام: علوم الحاسبات
السنة: 2016
الموضوع الدقيق: علوم الحاسبات
الدرجة: ماجستير
الجامعة: جامعة ذي قار - كلية التربية للعلوم الصرفة - قسم الحاسبات
اللغة: الانكليزية
مكان الجامعة: ذي قار
الصفحات الاولى:
المستخلص: Cryptosystems becomes an increasingly important feature as the most reliable tool in network and information security. However, while there are many forms of cryptosystems exist today a weak link of all systems is the secure management of the cryptographic key. And as a result of the growing interests in biometrics a new field of research has emerged, which is called "biometric cryptosystems". Within biometric cryptosystems the advantages of biometric authentication are introduced to generic cryptographic key management systems to enhance security.This work proposes a scheme to bind a cryptographic key with the face biometric by combining correlation filters based biometric recognition with a biometric key binding scheme with providing the variation tolerance, discrimination and security which are the most important requirements that apply to a cryptographic key retrieval using a biometric. In the proposed scheme the cryptographic key is generated independently of user's face image using Pseudo - Noise generator to produce a unique and long enough key (128 bits) for each user then this key is linked to the face image only through a secure block of data known as the 'protected record'. The correct key will only be derived via the interaction of this protected record with the correct user's face image during a live authentication process. The resultant key may be used in a system as cryptographic key or as a personal identification number (PIN) to overcome the need to carry, store, or remember keys for cryptosystems or any other application that are used (PIN).The proposed scheme performance has evaluated using FACE 94 facial database. The performance rate reached to 100% which is a perfect result for practical applications. The proposed scheme is implemented using (MATLAB 2008). It is executed for testing purpose on computer with processor of 1.80 GHZ dual core, i3 under Microsoft Windows 7 operating system.

Secure Email Message Using Genetic Algorithm - Based Elliptic Curve Cryptography Systems

اسم المؤلف: محمد حسن حالوب
اسم المشرف: Haider M. Abdul - Nabi
الموضوع العام: علوم الحاسبات
السنة: 2018
الموضوع الدقيق: علوم الحاسبات
الدرجة: ماجستير
الجامعة: جامعة البصرة - كلية العلوم
اللغة: الانكليزية
مكان الجامعة: البصرة
الصفحات الاولى:
المستخلص: Email is a service for exchanged messages between group of people (sender and receiver) using communication network. Nowadays people, companies, and business sectors are using email in the official communications. There are a lot of threats on the email service and the most importantly one is the eavesdropping. Some email messages are very important and must have a level of security during exchange of them.The current study uses hash function to add data integrity by applying Secure Hash Algorithm - 1(SHA - 1). This study uses Elliptic Curve Digital Signature Algorithm to add authentication and non - repudiation to the email message sender.Encrypt of an email message is a solution to overcome the eavesdropping. Hence, the attacker can obtain the email message but cannot read it without the key. The encryption algorithm, which is used, is Elliptic Curve Cryptography. This algorithm has a strong encryption, high level of security, and small key size compared to the RSA algorithm.The contributions of this thesis are : proposes a new method based on genetic algorithm to select the most effective parameters of the Elliptic Curve Cryptography (a,b); and proposes four encryption methods : updated symmetric Elliptic Curve Cryptography, modified Menzes - Vanston Elliptic Curve Cryptography, hybrid symmetric and asymmetric Elliptic Curve Cryptography, and hybrid Menzes - Vanston Elliptic Curve Cryptography and AlGamal Elliptic Curve Cryptography.The proposed methods are compared against previous techniques. It is found that these methods outperform the previous techniques in terms of the encryption/decryption processing time and the level of security.

Robust and High Capacity Data Hiding System Using Error Correcting Codes

اسم المؤلف: نداء حسن عباس
اسم المشرف: منذر التكريتي قاسم زيدان
الموضوع العام: علوم الحاسبات
الموضوع الدقيق: علوم الحاسبات
اللغة: الانكليزية
الصفحات الاولى:
المستخلص: اقترح هذا البحث تقنية متينة لاخفاء العلامة المائية والتي نستطيع ان نعالج من خلالها كمية كبيرة من البيانات مثل الصور ذات التدرج الرصاصي.لقد تم تحقيق موازنة بين كمية البيانات المخبئة وبين نوعية الصورة الحاوية للعلامة المائية.تهدف الخوارزمية الى جعل المتطفل يخفق في الوصول الى مكان المعلومات داخل الصورة وذلك من خلال التوزيع العشوائي لمكونات العلامة على كل الصورة. تم تطبيق الخوارزمية في مجال تحويل المويجة (Wavelet Transform) لما لهذا التحويل من فوائد عديدة والتي يمكن استغلالها في كبس الصور وكذلك في التطبيقات العملية للعلامة المائية. لقد تم تنفيذ البحث ايضا بطريقة جديدة وذلك باستخدام شفر تصحيح الخطا لتجاوز مشكلة فقدان البيانات اثناء عملية الكبس والكبس الاضافي الفاقد للبيانات. لقد تم استرجاع الصورة المخفية بشكل تام والنتائج العملية كانت مقنعة بسبب تشابه الصورة الاصلية مع الصورة الحاوية للعلامة المائية وصمود ومتانة العلامة امام الكبس الاضافي. اشارت النتائج العملية بعدم وجود تشويهات مرئية في الصورة المسترجعة حتى بعد 5 % من الكبس الاظافي علاوة على تعقيد اسلوب محاولة كشف العلامة. هذا يشير بان نظام العلامة المائية مقاوم اكثر الى هجمات الضغط ذو الخسارة العالية. | In this research, a robust watermarking system for images is proposed. The proposed scheme can handle a significantly large quantity of data such as gray scale images. A trade - off between the quantity of hidden data and the quality of the watermarked image had been achieved. The proposed algorithm aims to mislead the intruder and prevent the detection of the watermark due to the random distribution of the signature image on the entire image. The algorithm is applied in the wavelet transform domain. The wavelet transform has a number of advantages over other transforms that can be exploited for both image compression and watermarking applications. Therefore, it had been found that it is imperative to consider the wavelet transform domain for watermarking applications.1. Due to the lossy compression, some parts of the watermarking will be lost. For that the algorithm had been implemented with the new proposed approach using error correcting codes skill to overcome this drawback. The impact of different codeword lengths of BCH code is also investigated. The BCH code is effective against burst error. This approach has been compared with the case of embedding without using error correcting codes and satisfactory results were achieved, as the watermarked image was visually similar to the original. Experimental results indicated that are no visible distortions in the watermarked image, and the recovered signature is similar to the original signature even after 5% JPEG lossy compression quality factor. This indicates that the watermark system is more resistant to lossy compression attacks (JPEG).

معادلة تجريبية لتخمين سرعة ترسيب الجسيمات لجو مدينة بغداد EMPIRICAL RELATION TO ESTIMATE PARTICLE DEPOSITION VELOCITY OVER BAGHDAD CITY

اسم المؤلف: هبة سعد حسن
اسم المشرف: منعم حكيم خلف الجبوري
الموضوع العام: علوم الجو
السنة: 2015
الموضوع الدقيق: علوم الجو
الدرجة: ماجستير
الجامعة: الجامعة المستنصرية - كلية العلوم - قسم علوم الجو
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: ان الهدف من هذا البحث هو انشاء وتصميم نموذج رياضي لحساب سرعة ترسيب الجسيمات فوق مدينة بغداد وبستخدام قياسات لسرعة الرياح ودرجة الحرارة بالقرب من سطح الارض وعلى ارتفاع 20 متر. لقد بينت النتائج ان سرعة الترسيب تتناسب طرديا مع انصاف اقطار الجسيمات الكبيرة والتي هي اكبر من 1.5 مايكرومتر بسبب تاثير الجاذبية عليها, اما بالنسبة للجسيمات الصغيرة التي اقطارها اقل من 0.1 مايكرومتر تتناسب سرعة ترسيبها عكسيا مع انصاف اقطار هذه الجسيمات لكون تاثير الجاذبية عليها معدوم. اما بالنسبة للجسيمات التي تترواح انصاف اقطارها من 0.1 الى 1.5 مايكرومتر يحصل فيها ثبوت بسبب الوصول الى السرعة الحدية. وكذالك يمكن ان نستنتج ان اعلى قيمة لسرعة الترسيب تحدث في حالة الظروف المستقره واقل قيمة تكون في الظروف الغير مستقرة وفي الوسط حالة التعادل وهذا ينطبق مع الطبيعة الفيزيائية لميكانيكية الاستقرار في الغلاف الجوي وكذالك يمكن ان نستنتج من خلال الحسابات ان هنالك علاقة طردية مابين سرعة الترسيب والسرعة الاحتكاكية ولكنها تختلف باختلاف احجام الجسمات لكل حالات الاستقراريه ففي المديات الحجمية من 0.01 الى 0.3 مايكرومتر هنالك زيادة تناقصية لسرعة الترسيب مع زيادة السرعة الاحتكاكية حتى الثبوت عند المديات الحجمية من 0.3 الى 1 مايكرومتر بحيث يكون هنالك عدم تاثير لزيادة السرعة الاحتكاكية على سرعة الترسيب وبعد هذا المدى الحجمي والذي هوا 1 مايكرومتر هنالك علاقة طردية تزايدية لسرعة الترسيب مع زيادة السرعة الاحتكاكية حتى المدى الحجمي 30 مايكرومتر. اما بالنسبة لطول الخشونه فان تاثيرها يظهر فقط في حالة الاستقرار وعدم الاستقرار الجوي وهذا التاثير يكون قليل على سرعة الترسيب وتقريبا متساوي في كلا الحالتين حيث ان الزيادة في طول الخشونه تؤدي الى الزيادة في سرعة الترسيب. اما العلاقة مابين سرعة الترسيب وسرعة الرياح فهي علاقة عكسية زيادة سرعة الرياح سوف تعرقل من نزول الجسيمات وبالتالي تقلليل سرعة الترسيب وهذا التاثير يظهر فقط على الجسيمات الكبيرة الاكبر من 5 مايكرومتر. واخيرا تاثير درجة الحرارة الذي يدخل للموديل عن طريق الحركة البروانية فانه يكون قليل جدا ويهمل هذا التغير حيث وضع في الموديل تغير في درجة الحرارة من صفر الى 50 درجة سليزية ولم يحث سوى تغيير طفيف جدا وهذا لكل حالات الاستقرارية المتعادلة والمستقرة والغير مستقرة | AbstractThe aim of this research to make and design mathematical model and empirical relation for calculate deposition velocity of particles above Baghdad city by using data of wind speed and temperatures near the earth surface at the high 20 m. Result indicate deposition velocity have a direct relation with the large particles which have half diameters more than 1.5 micrometers because the effect of gravity on it, for the small particles the half diameters less than 0.1 micrometers have inverse relation with deposition velocity because the effect of gravity on it is neglected, As for particles has a half diameters from 0.1 to 1.5 micrometers there will be fix state because the reach to terminal velocity. also we will discover that high value deposition velocity will be happen in the case of stability, and the low value in the case of instability, and in the middle will be neutral and this similar to the physics natural of the mechanical saturation in the atmosphere. also will be cover from the calculation there is a direct relation between deposition velocity and friction velocity but they are different with the particles volume for all case of stability, in the volume range from 0.01 to 0. 3 micrometers there is decreasing in deposition velocity with increasing of friction velocity until fixation at the volume range from 0. 3 to 1 micrometers until there is no effect for the increase friction velocity on the deposition velocity, after this volume range 1 micrometers there is direct increase deposition velocity with increase friction velocity until range volume 30 micrometers . As for Roughness length the effect appears only in the case of stabile and unstable and this effect will be less on the deposition velocity and nearly equal in both case, because the increase in roughness length lead to increase deposition velocity. The relation between deposition velocity and wind speed the inverse relation, the increase of wind speed will prevent particles fall are lead to minimize deposition velocity and this effect appears only on the particles size more than 5 micrometers. Finally the effect of temperature appears in the model from the browin motion will be very latter and neglected this change, inter in this model change of temperature from 0 to 5 C0 there was a very later change and that for all case of stability ( stable, unstable and neutral).

تحليل قابلية التنبؤ المناخي للشرق الاوسط باستخدام انموذج ديميتر

اسم المؤلف: نور واثق عبد الكريم الشيخلي
الموضوع العام: علوم الجو
الموضوع الدقيق: علوم الجو
الدرجة: ماجستير
الجامعة: الجامعة المستنصرية - كلية العلوم - قسم علوم الجو
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: في هذه الدراسة استخدمت طريقة نسبة الاشارة لحساب القابلية على التنبؤ المناخ الفصلي . وتعتمد هذه الطريقة على نظام تنبؤ المجموعة Ensemble Prediction System ((EPS . كما تم استخدام نوعين من البيانات الخاصة بالمركز الاوربي للتنبؤ بالطقس المتوسطة المدىEuropean Center For Medium Range Weather Forecast (ECMWF) وهما بيانات ديميتر والبيانات المعادة التحليل ERA - 15. اذ تتكون هذه البيانات من عدة مجاميع Ensembles وكل مجموعة تتكون من عدة افراد Members ،وتعتمد هذه البيانات على ملفات خاصة من اجل فتحها والتعامل معها. ولقد تبين من خلال هذه الدراسة ان القابلية على التنبؤ لانموذج ديميترتكون جيدة للعراق في حالة الارتفاع الجهدي لمستوى 850 hPa ،وللمناطق القريبة من البحر الاحمر خاصة السعودية في حالة درجة الحرارة الجهدية لمستوى 500 hPa. بينما تكون متوسطة في معظم منطقة الشرق الاوسط وتحديدا العراق للارتفاع الجهدي لمستوى 500 hPa ودرجة الحرارة الجهدية لمستوى 850 hPa و500 hPa. كما نجد ان القابلية على التنبؤ لانموذج الـ ERA - 15 تكون متوسطة في معظم منطقة الشرق الاوسط من ضمنها العراق. وان انموذج ديميتر اكثر كفاءة من انموذج الـ ERA - 15 في حساب القابلية على التنبؤ على المستوى الاقليمي regional فضلا عن كفاءته على مستوى العالم Global . | In this study the signal to noise ratio method has been used to count seasonal climate predictability which depend on ensemble prediction system .We use two type of data in this study, which are : Demeter data and Reanalysis of Data ERA - 15 belong to the european center for medium range weather forecast and these data consist of several ensembles, and every ensemble consists of several members. These data depend on special files to facilitate opening and dealing with it. The results show that the predictability for Demeter model is good for Iraq in case of geopotential height at 850 hPa level ,and for red sea regions especially kingdom of saudi arabia ,in case of potential temperature at 500 hPa level. While in the most of middle east regions, the predictability is moderate for potential height at 500 hPa level and potential temperature at 850,500 hPa level. The predictability for ERA - 15 model is found also to be moderate in most of middle east regions especially for Iraq. Finally, Demeter model is more efficient than ERA - 15 model in calculating the predictability for both regional and global regions.

تقييم تاثير التغير المناخي العالمي على درجة حرارة الهواء في العراق باستخدام نماذج المناخ Evaluating of the Impact of Global Climate Change on Air Temperature in Iraq using Climate Models

اسم المؤلف: میلاء محمد كاظم الجبوري
اسم المشرف: قیس جمیل الجمیلي بدور یاسین حمود
الموضوع العام: علوم الجو
السنة: 2014
الموضوع الدقيق: علوم الجو
الدرجة: ماجستير
الجامعة: الجامعة المستنصرية - كلية العلوم - قسم علوم الجو
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: Global warming and climate change refer to an increase in average global temperatures. Natural events and human activities are believed to be contributing to an increase in average global temperatures. This is caused primarily by increases in “greenhouse” gases such as Carbon Dioxide (CO2). The aim of this research is to use simple climate mathematical models to investigate effects of various parameters, functions, and components of the climate system on the temperature rise. Also it aims toward the use of the output of complex climate models to explore the future rise of temperature over Iraq for the 21st century. The results indicated that the increase in diffusivity causes an increase in the heat flux towards the poles causing the temperature to increase in the polar regions and sub polar regions and to decrease in the tropics and subtropics regions. Solar radiation plays a major role in the climate system. It was found that a change of +/˗0.1 of its current value could led the Earth surface to be ice free/totally covered with ice. The results showed that changes in upward longwave radiation can mostly affect polar and sub polar regions. The effect of Hadley cell is to increase the heat flux towards the poles and therefore increasing temperature in these regions and reducing it in the tropics. The results for the simulation of land/ocean combinations for different initial temperatures showed that the combination of most amount of water cover was closest to the initial temperature for all initial temperatures and the combination of most land cover was the farthest distribution from the initial temperature. Analysis of the output of the Intergovernmental Panel on Climate Change (IPCC) models for Iraq showed that global warming will affect Iraq in this century. For the mid - century the temperature will be increased by 0.5 to 2.5 oC and summer months will be the most affected time of the year. The results suggested that by the end of the century temperature will be increased by 3.5 to 4.5 oC and also summer months will be the most affected time of the year. Comparison of the 16 models and three scenarios (B1, A1B and A2) of the IPCC Baghdad showed that for mid - century the scenario B1 gave the lowest increase of temperature for all months, while the scenarios A1B and A2 gives the highest increase of temperature for most of months for all models. For the end of century, it was found that in this period the scenario A2 gives the highest increase of temperature for most of the models, while scenario B1 give the lowest increase temperature for most of models.

Modeling the effect of virtual temperature on take - off and landing operations of aircraft

اسم المؤلف: مهند توفيق امين
اسم المشرف: نعمة محسن لفتة الفتلاوي
الموضوع العام: علوم الجو
السنة: 2014
الموضوع الدقيق: علوم الجو
الدرجة: ماجستير
الجامعة: الجامعة المستنصرية - كلية العلوم - قسم علوم الجو
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: This Thesis focuses on the role of virtual temperature during Take - off and Landing performance, any increase in temperature or altitude means a decrease in the aircraft's optimum performance, so both of high temperature and high elevation airports, an airplane requires more runway to take off. Its rate of climb will be less (during take - off), its approach will be faster (during landing). The increase in temperature leads to a marked increase in radius of turn (during take - off and landing) but a tiny decrease in obstacle angle (during take - off) and a small increase in flare height (during landing).The effect of virtual temperature of five Iraqi airports (Mosul, Erbil, Sulaimaniyha, Baghdad and Basra), and the data base for an extended period was from January 2008 until the month of February 2014. Information was selected for weather report for certain days of the summer season (May, June, July, August and September), where the maximum temperature recorded was 50 ° C for airports Basra and Baghdad, the maximum temperature recorded during the period studied at the Mosul airport,48 ° C at the Erbil airport 44 ° C and Sulaymaniyah airport 43 ° C . Certain days of the winter season (December, January, February) were selected where the minimum temperature recorded the lowest, lowest temperature recorded in Basra airport 6° C, Baghdad airport 2 ° C, Mosul - 1 ° C, Erbil - 2 ° C and Sulaymaniyah - 8° C. The effect of virtual temperature was calculated for five Iraqi airports from comparing the most requirements affect (radius of turn, Distance and stalling velocity) in winter/summer with typical requirement (measured at ISA), the comparing use of actual values and their average during a case study in every airport, icy aerodrome which is considered as an extreme type and calculate its effect in Baghdad and Basra airport. Simulation software program shows us Perfect take - off and landing which are usually preceded by a deliberate planning for approaching the most appropriate velocities. The simulation which was edited is named R.O.T.A.L. (Requirements of Take - off and Landing).This simulation used a set of covering equations programed in visual basic and other programs of medi

تقدير تاخير الانتشار المحتث في اشارات نظام تحديد المواقع العالمي بواسطة المكونات الجوية Estimation propagation delay induced in GPS signals by atmospheric constituents

اسم المؤلف: فايز هلال صالح الزيادي
اسم المشرف: ضياء عزيز بلال
الموضوع العام: علوم الجو
السنة: 2014
الموضوع الدقيق: علوم الجو
الدرجة: ماجستير
الجامعة: الجامعة المستنصرية - كلية العلوم - قسم علوم الجو
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: عندما تنتقل الموجات الراديوية خلال الغلاف الجوي الارضي المتعادل , فان الاشارات الراديوية تتاثر بتغير معامل انكساره بصورة واضحة , والذي يتسبب بصورة ابتدائية في تاخير وصولها , وفي العادة هذا يشير الى التاخير الناتج من التروبوسفير . ان نظام تحديد المواقع العالمي (GPS) هو عبارة عن الملاحة الراديوية الفضائية .ان المستلم في نظام (GPS) يقوم بتزويد معلومات الموقع والوقت الدقيقين ولعدد غير محدد من المستعملين وفي كل الظروف الجوية , نهارا وليلا في اي مكان في العالم . ان (GPS) يستخدم ثلاثة ترددات والتي هي (L1 = 1.57542 GHz) , (L2 = 1.22760 GHz) و(L3 = 1.38105 GHz) . ان الهواء الجاف , بخار الماء , الجسيمات الجوية المائية والجسيمات الاخرى (التراب , الغبار والعوالق الجوية) في الغلاف الجوي تسبب تاخير في انتقال الموجات الراديوية .هذه التاخيرات يجب ان تكون موصوفة بدقة من اجل الحصول على الدقة الاعلى في المسح الارضي والتحسس النائي باستعمال اشارات نظام تحديد المواقع العالمي (GPS) . يركز الجزء العملي بصورة رئيسية على كيفية توضيح ونمذجة تاثيرات المكونات الجوية مثل الجليد , بخار الماء , الاوكسجين , الغيوم , المطر والثلج على ترددات (GPS) (L1 , L2 وL3) . النتائج توضح ان الجزء الحقيقي والجزء الخيالي لمعامل الانكسار المعقد للجليد يتزايد مع الزيادة في درجات الحرارة اما للماء فانها تنخفض مع الزيادة في درجة الحرارة , لكن بصورة عامة فان معامل الانكسار المعقد للماء يكون اعلى منه للجليد . كذلك فان قيم التوهين الناتجة عن قطيرات الغيمة النقية بواسطة رايلي هي اكبر من قيمها الناتجة عن قطرات المطر النقية بواسطة مي للترددات الثلاثة , وهذه القيم تتناقص مع الزيادة في درجة الحرارة وتزداد مع الزيادة في التردد . ان لكل من طيف بخار الماء والاوكسجين منطقتين تمتلكان اعلى قيم للتوهين (ان لكل من طيف بخار الماء والاوكسجين منطقتين تمتلكان اعلى قيم للتوهين ( GHz183 ,GHz 325 لبخار الماء وGHz 60 , GHz 118 للاوكسجين ) . ان تغير الطور التفاوتي (∅∆) في حالة المطر يحصل بواسطة قطرة المطر المفلطحة والتي لها محورين مختلفين وبسبب الاختلاف في تركيز قطرات المطر , ايضا فان (∅∆) لا تعتمد على درجات الحرارة لكنها تزداد مع زيادة التردد حيث تكون قيم (∅∆) deg/km 6 لـ (L1) , deg/km 5 لـ (L2) وdeg/km 5.4 لـ (L3) . بالاضافة الى اعتماد التوهين التفاوتي (∆A) في حالة المطر على شكل قطرة المطر وتركيز القطرات فانه يعتمد على درجة الحرارة والتردد . ان (∅∆) في حالة الثلج تحصل بواسطة الشكل غير المنتظم لجسيم الثلج وتعتمد على درجات الحرارة والتردد . ان (A∆) في حالة الثلج تمتلك قيم واطئة جدا في درجات الحرارة المختلفة والترددات المختلفة | When radio waves propagate through the earth’s neutral atmosphere, the radio signals are affected significantly by the variability of its refractive index, which causes primarily in the delay of the arrival, usually referred to as the tropospheric delay . The Global Positioning System (GPS) is a space - based radio navigation . The GPS system receiver provides exact location and time information for an unlimited number of users in all weather conditions, day and night, anywhere in the world. The GPS uses three frequencies that are (L1 = 1.57542 GHz , L2 = 1.22760 GHz and L3 = 1.38105 GHz) . Dry air, water vapor, hydrometeors and other particulates (sand, dust and aerosols) in the atmosphere introduce radio waves propagation delays. These delays must be properly characterized to achieve the highest accuracy in surveying and atmospheric sensing using Global Positioning System (GPS) signals . This work mainly focuses on the illustration of a model showing the effects of the atmospheric constituents such as ice and snow, water vapor , oxygen , clouds , rain on the GPS frequencies (L1 , L2 and L3) .The results show that the real and imaginary parts of complex refractive index for ice increase with the increase of the temperature and for water decrease with the increase of the temperature , but generally , the complex refractive index of water is higher than that of ice . Also , the attenuation values that are induced by pure cloud droplets by Rayleigh are higher than the attenuation values that are induced by pure water drops by Mie for the three frequencies , and these values decrease with the increase of the temperature and increase with the increase of the frequency . Each of water vapor and oxygen molecules have a small effect on radio waves in troposphere . The differential phase shift (∆∅) in case of rain is caused by the oblate rain drop that is has two different axes ,and because of the difference of the concentration of rain drops, also (∆∅) doesn't depend on the temperature but increase with the increase of the frequency where the values of (∆∅) are 6 deg/km for L1 , 5 deg/km for L2 and 5.4 deg/km for L3 . In case of rain , the differential attenuation (∆A) in addition to depend on the shape and the concentration of drops , it depends on the temperature and the frequency . In case of snow , the (∆∅) caused by the irregular shape of snow particle and depends on the temperature and the frequency . The (∆A) in case of snow has very low values in different temperatures and frequencies

تصميم وتطبيق منظومة تعقيم المياه باستخدام الاشعاع الشمسي Designing and Implementing a Water Disinfection System by Solar Radiation

اسم المؤلف: عبد الوهاب حسين محمد علي العبيدي
اسم المشرف: حسن هاشم سلمان خليل مصطفى خماس
الموضوع العام: علوم الجو
السنة: 2010
الموضوع الدقيق: علوم الجو
الدرجة: دكتوراه
الجامعة: الجامعة المستنصرية - كلية العلوم - قسم علوم الجو
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: تم العمل بهذه الاطروحة لتصميم وتطبيق منظومة عملية تعمل على تعقيم ماء الشرب باستخدام الاشعة الشمسية المتوفرة في قطرنا بشكل واسع، وباقل التكاليف لاستخدامها في البيوت العراقية وخاصة تلك التي تقع في القرى والارياف والمناطق النائية. الخطوة الاولى كانت الاعداد لنظام بسيط لهذه المنظومة، والخطوة الثانية كانت تحضير الحاويات الملائمة لهذه المنظومة وتجهيزها بنماذج الماء الخام(الملوث) وتعريضه للاشعاع الشمسي.لقد تم اجراء اكتر من 25 تجربة لاختبار تاثير مختلف المتغيرات الجوية على عملية تعقيم ماء الشرب باستخدام الاشعاع الشمسي,وتاثير هذه المتغيرات على كفاءة قتل مجموعة البكتريا القولونية، القولونية البرازية والقولونية بالاشعاع الشمسي. هذه المتغيرات هي : درجة الحرارة، الاشعاع الشمسي، الوان حاويات المنظومة، المطر والغيوم والعواصف الرملية. وقد تم مقارنة نتائج هذه التجارب باستخدام الاشعاع الشمسي والحرارة مع نتائج التجارب التي استخدمت فيها الحرارة فقط.وقد كانت نتائج هذه التجارب كما يلي : 1 - ان قيمة الاشعاع الشمسي الساقط على مدينة بغداد للفترة من 22 مايس 2009 ولغاية 4 تموز 2010 ودرجات الحراة المسجلة عن طريق المحطة الانوائية والثرموميتر الموجودعلى سطح المنظومة، كانت طيلة هذه الفترة اعلى من الحد الادنى المطلوب لتعقيم الماء باستخدام الاشعاع الشمسي ,باستثناء ايام الشتاء المحددة بشهري تشرين الثاني وكانون الاول. والمعالجة خلال هذه الفترة كانت تتم عن طريق زيادة الفترة الزمنية لتعريض النموذج للاشعاع من 6 ساعات الى 48 ساعة.2 - اظهرت نتائج التجارب بوضوح تاثير عكورة الماء على عملي التعقيم باستخدام الاشعاع الشمسي,حيث يتم تركيد(ترسيب) الجسيمات الدقيقة العالقة قبل التعريض للاشعاع الشمسي، وبهذه الخطوة يتم التخلص من حولي 90% من العدد الكلي لجميع المجموعات من الكائنات الحية الدقيقة العالقة مع الجسيمات.3 - اظهرت نتائج التجارب الى ان هناك ترابط وتازر بين الاشعاع الشمسي ودرجة الحرارة، واظهرت احدى التجارب في الصيف انه قد تم قتل كل مجموعة البكتريا الموجودة في النموذج 100% يعد التعريض للاشعاع والحرارة معا، الا انه يم يتم الوصول الى هذه النتيجة بتعريض هذا النموذج للحرارة فقط.4 - عندما يكون الجو حارالاانه مصحوبا بعاصفة ترابية فانه لا يتم تعقيم الماء 100% في مثل هذه الظروف، وتكون المعالجة بزيادة الفترة الزمنية لتعريض النموذج من 6 ساعات الى 48 ساعة.5 - تم اجراء العديد من التجارب بعد تغيير الوان حاويات المنظومة واختبار كفاءة قتل البكتيريا بعد تغيير الالوان, وكانت النتائج كالتالي : الازرق(كفاءة عالية)، الاصفر(معتدلة) والاحمر (منخفض)الكفاءة.6 - اتضح من خلال التجارب ان موسم الصيف يظهر فيه اكبر عدد من انواع البكتيريا في نماذج الماء غير المعاملة(غير المعرضة للاشعاع)، اما موسم الشتاء فيكون فيه عدد انواع البكتيريا اقل. | The aim of this thesis is to design and implement a system for disinfecting drinking water by solar radiation with low cost so that it can be used in Iraqi houses, particularly, those located in suburban and rural areas. The steps of system include building the system, preparing the required water containers, collecting the infected water samples and exposing them to solar radiation. More than 25 experiments were conducted to test the effects of several variables on the process of water disinfection by solar radiation and the impact of each of these variables on the efficiency of the inactivation of the total coliform, faecal coliform and E.coli by the solar radiation. These variables include water turbidity, the amount of solar radiation, air temperature, dust storms, cloud formation, and rainfall. These experiments were compared with the inactivation of bacteria by heating (oven) only. Results indicated that the amount of solar radiation incident on Baghdad during the period from 22 March 2009 to 4 July 2010, and temperature recorded by the Weather Station and by the thermometer mount on the system was always more than the threshold value required for the inactivation, except during days of winter months of November and December due to low amount of solar radiation. This was overcome by increasing the time period of exposure to the solar radiation from 6 hours to 48 hours. The results of experiments showed clearly the effect of water turbidity on the disinfection processes by solar radiation. Settling infected water samples before exposing them to solar radiation has inactivated 90% of bacteria. Experiments conducted during summer, when solar radiation values are relatively high showed the percentage of bacteria inactivation was 100%, while disinfection by heat only did not reach that value. The conditions of dust storm occurrence, cloud formation, and fall of rain greatly affect the disinfection processes by solar radiation, since these atmospheric constituents reduces the amount of solar radiation reaching the Earth's surface. Results suggested that under such conditions, exposure time should be increased from 6 to 48 hours. Several experiments were performed to investigate the effect of the containers colors (wavelengths) on the bacteria inactivation. Three colors were selected; those are blue (short wavelength), yellow, and red. Results showed that the blue colored containers have the highest efficiency, yellow containers have moderate efficiency, and red containers have the lowest efficiency. Results also illustrated that infected water samples collected during summer have a larger number of bacteria that those collected during winter.

تنبؤ احصائي لسرع الرياح لمحطات محددة في العراق Statistical Forecasting of Wind Speed for Selected Stations in Iraq

اسم المؤلف: سرى ثامر ناصر
اسم المشرف: بدور ياسين حمود العامري محمد احمد صالح ابو الطيب
الموضوع العام: علوم الجو
السنة: 2014
الموضوع الدقيق: علوم الجو
الدرجة: ماجستير
الجامعة: الجامعة المستنصرية - كلية العلوم - قسم علوم الجو
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: Wind speed is one of the most meteorological variables which has been changing rapidly with time. Due to the properties of wind speed such as non - stationarity, high fluctuations and irregularity. accurate forecasting becomes a challenge because, The wind speed is easily influenced by many factors, such as latitude, altitude, terrain, pressure, temperature. Therefore, The forecasting of the wind speed is important for many environmental, economic and meteorological applications. Due to the difficulties of the physical models and their non - availability, The Box - Jenkins ARIMA model has been used .Because, it is suitable tool to predict the wind speed and can also be used as an effective tool to get the missing data which existing within the time series of monthly mean wind speed. When Box - Jenkins ARIMA model has used, The ARIMA (15,1,10) model has determined as a suitable model for the monthly mean wind speed for studied stations in Iraqi after passing through the four stages of the model that include Identification of The Time Series, Estimation of The Model Parameters, Diagnostic Check of The Residuals and Model Adequacy and finally, The Forecasting. Many of the evaluation criteria have been used to check the accuracy of the best proposed prediction models by lowest values of each MAE and RMSE and MAPE and the highest values of the correlation coefficient (R2) and correlation coefficient (r), which confirmed the preference of ARIMA(15,1,10) for the monthly mean of wind speed but, This model could not applied on the daily mean of wind speed due to difficult in chose one best - fit model for all time series in all regions of Iraq. Because, The large variance of the wind speed during day and night and has not appeared clear correlation in all stations as shown in monthly data. The best solution is to take the difference of the non - stationarity time series from one lag to the next and then analyze this series after reaching to stationarity. The time series of daily wind speed need to take the difference once for the Baghdad station (d = 1) and twice for the Kirkuk station (d = 2) and three times for the Nasiriya station (d = 3) for reaching to stationarity. When ARIMA(15,1,10) model has been used, All the residuals were found within the confidence intervals and The error rate of using MAPE measure has been found near ( 4% ) for all studied stations in Iraq .

تحليل الانماط الزمانية والمكانية للاوزون فوق العراق nalysis of temporal and spatial patterns of ozone over Iraq

اسم المؤلف: زهراء موسى حسن
اسم المشرف: علي محمد عبد الرحمن الصالحي
الموضوع العام: علوم الجو
السنة: 2014
الموضوع الدقيق: علوم الجو
الدرجة: ماجستير
الجامعة: الجامعة المستنصرية - كلية العلوم - قسم علوم الجو
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: onthly and annual values of the total column ozone amount have been analyzed for five locations of Iraq for the period from 1979 to 2012 employing Total ozone Mapping Spectrometer (TOMS) data point and (1o × 1.25o ) grid data, It is found that ozone variation is function of latitude, where the higher values of total ozone column occurs at the northern Iraq which represented by Mosul location, it decreases gradually from northern location (Mosul) passing by middle region locations (Biji, Baghdad and Rutba) to southern location (Basra). The values of Total ozone column start to increase gradually from November to reach its maximum at March then it decreases gradually to reach its minimum values at October. The analysis of the spatial distribution of the monthly average of total ozone column for each month of the year has been made. It is found that the largest of total ozone column amounts occurs systematically over the northern regions during winter whereas in spring and early summer months the maximum values of total ozone column directed to the northwestern regions of the Iraq. Latitudinal gradients in total ozone column are very strong especially during winter, spring and early summer months. The spatiotemporal trend analysis has been made by converting the gridded data from time domain to spatial domain, it is found that the results show that the total ozone column trends was negative during most months of the year, whereas the spatial trend analysis of the second period of study (2005 - 2012) presented positive total ozone column during all months of the year except February and September which presented a negative trends and the overall presented positive trends varied from 0.1 to 2.3 DU / year. Finally the results of the two period trend analysis indicated that the ozonelayer may be responding as expected to the reducing on ozone - depleting substances imposed by the Montreal Protocol.

تاثير درجة حرارة سطح البحر المتوسط على درجة حرارة الهواء السطحية والامطار لبعض المواقع في الشرق الاوسط The effect of Mediterranean Sea surface temperature on air surface temperature and rainfall for some locations in the Middle East

اسم المؤلف: حنين حاكم عبد الرضا عباس
اسم المشرف: منعم حكيم خلف الجبوري
الموضوع العام: علوم الجو
السنة: 2014
الموضوع الدقيق: علوم الجو
الدرجة: دكتوراه
الجامعة: الجامعة المستنصرية - كلية العلوم - قسم علوم الجو
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: درجة حرارة سطح البحر تلعب دور مهم في التغير المناخي لانها تؤثر على درجة حرارة الهواء مباشرة فوق السطح ومعدل التبخر للماء والذي يؤثر بدوره على درجة حرارة الهواء وتكوين الغيوم والامطار. لذلك دراسة درجة حرارة سطح البحر مهمه في حل المشاكل للظواهر الجوية والبحرية ونظام المناخ للارض. يهدف هذا البحث الى دراسة تاثير تغيرات درجة حرارة سطح البحرالابيض المتوسط(SST) على درجة حرارة الهواء السطحية(T2M) والامطار(TP) لمنطقة الشرق الاوسط خلال الفترة .(1980 - 2009) البيانات المستخدمة في هذه الدراسة تم الحصول عليها من المركز الاوربي وتم عمل ثلاث شبكات للمتغيرات لايجاد العلاقة بين SST وT2MوTP ب استخدام طريقتين للتحليل الاحصائي. ففي الجزء الاول من الدراسة تم استخدام طرق التحليل الاحصائي مثل السلاسل الزمنية ومعامل الارتباط, وتم اختيار ثلاث مواقع (نقاط) على الشبكة في البحر المتوسط واربع مناطق في الشرق الاوسط (بغداد, عمان, دمشق, بيروت).النتائج اظهرت ان التغيرات في درجة حرارة سطح البحر لها اكبر قيمة للميل في شهر تموز (0.06) للنقاط الثلاثة واقل قيمة كانت في الفصول الانتقالية, في شهر نيسان كانت (0.01) للنقطتين الاولى والثالثة, في شهرتشرين الاول كانت قيمة الميل (0.04) في النقطة الثالثة. اما اعلى قيمة للميل لدرجة حرارة الهواء السطحية في الشرق الاوسط فكانت في شهر تموز (0.06) في مدينتي بغداد ودمشق وكانت اقل قيمة في شهر نيسان (0.006 - ) في مدينة عمان. بالنسبة لقيمة الميل للامطار فكانت اعلى قيمة في عمان وبيروت (0.3) خلال شهري كانون الاول وشباط على التوالي, واقل قيمة للميل كانت في بغداد (0.27 - ) خلال شهر كانون الاول. بينت النتائج ان درجة حرارة سطح البحر لها اكبر تاثير على درجة حرارة الهواء السطحية في شهر تموز, بسبب ان معامل الارتباط كانت له اعلى قيمة (0.58), (0.48), (0.50), (0.56) للمدن بغداد وعمان ودمشق وبيروت على التوالي خصوصا مع النقطة الاولى. اقل قيمه خصوصا للنقطتين االثانيه والثالثه فكانت في شهر نيسان, (0.007 - ), (0.08 - ), (0.08 - ), (0.08 - ) للمدن بغداد وعمان ودمشق وبيروت على التوالي.ولوحظ انه لاتوجد علاقة بين درجة حرارة سطح البحر والامطار للمناطق الاربع لان معامل الارتباط له قيم قليله في كل المواسم المطرية.في الجزء الثاي من الدراسة فتم استخدام طريقة التحليل بواسطة الدالة التجربيبة المتعامدة (EOF) للتغاير المكاني واخذت اول نمطين للـEOF الاول والثاني (EOF2, EOF1) وطريقة التحليل بواسطة (PC) للتغاير الزمني للنمط الاول (PC1). استخدمت شبكتين للنقاط للبيانات, الاولى تمثل شبكة SST لمنطقة البحر المتوسط والشبكة الثانية تمثل شبكة ((T2M,TP لمنطقة الشرق الاوسط وبقدره تميز 0.50 x 0.50 وقسمت فترة الدراسة الى فترات تمثل كل عشر سنوات.النتائج بينت ان نسبة التغاير المكاني لدرجة حرارة سطح البحر للـEOF1 ودرجة الحرارة السطحية كانت 97% و95% من التغاير الكلي على التوالي , وهذا يشير الى وجود علاقة محتملة بينهم, بينما التغاير المكاني للامطار سجلت اقل قيمة خلال فترة الدراسة.اما التحليل بواسطه التغاير الزمني بواسطه PC للـ SST فقط لوحظ وجود دوره قوية لها عشر قمم كل عشر سنوات من فترة الدراسة. | Sea surface temperature plays an important role in the climate change, because it affects the temperature of the air immediately above the surface, evaporation rate of water, cloud formation and precipitation. Therefore, the study of sea surface temperature is fairly essential for solving many meteorological and oceanographic problems and climate system of the earth. The aim of this thesis is to study the effect of sea surface temperature (SST) variation of Mediterranean Sea on air surface temperature (T2M) and rainfall (TP) in Middle East during the period (1980 - 2009). The data used in this study obtained from the Europe center (ECMWF) and made three grids of the variables in order to determine the relationship between SST and (T2M, TP) by using two statistical analysis methods. In the first part of study, statistical analysis technique used such as time series and correlation coefficient, and select three location (points I,II,III) on the grid of Mediterranean sea and four locations on Middle East (Baghdad, Amman, Damascus, Beirut). The results show that, The variation of SST has the highest value of trend in July (0.06) for the points I, II, III and the lowest value was in the transition season, in April was (0.01) for point I, III, in October was (0.04) for point III. While the highest value of trend for T2M in Middle East was in July (0.06) in Baghdad and Amman city and the lowest value in April ( - 0.006) in Amman city. For the value of trend of rainfall, the highest value was in Amman and Beirut (0.3) in December and February months respectively, and the lowest value of trend was in Baghdad ( - 0.27) in December month. The results show that the SST has the largest impact on T2M in July, because the correlation coefficients has the highest value (0.58), (0.48), (0.50), and (0.56) for Baghdad, Amman, Damascus and Beirut respectively especially for point I. The lowest value of especially for point II, III, in April was ( - 0.07), ( - 0.008), ( - 0.008) and ( - 0.008) for Baghdad, Amman, Damascus and Beirut respectively. And notes there is no relation between SST and TP for the four locations, because the correlation coefficient has small value in all rainfall months. The second part of the study use the Empirical orthogonal function (EOF) for the spatial variance and take the first two EOF (EOF1, EOF2) mode, and principle component analysis (PCA) tool for the temporal variation of (PC1) mode. Two grids of points have been used for the data; the first one represents the SST grid of Mediterranean Sea area and the second one represents the (T2M, TP) grid of Middle East of 0.50 x 0.50 and the period of study divided into periods every 10 years. The results show that the percentage of spatial variation of EOF1 for SST and T2M was 97% and 95% of total variance respectively, that indicate to have possible relationship between them while the spatial variance of TP record the lowest value in the period of study. The analysis made by the temporal variance of PC for SST show it has strong cycle with 10 peaks every 10 years of the period of study.

تاثير البقع الشمسية على بعض المتغيرات المناخية في العراق The Effect of Sunspot Numbers on Some Climate Variability over Iraq

اسم المؤلف: بيداء جعفر حسن
اسم المشرف: عوني ادوار عبد الاحد بدور ياسين حمود
الموضوع العام: علوم الجو
السنة: 2012
الموضوع الدقيق: علوم الجو
الدرجة: دكتوراه
الجامعة: الجامعة المستنصرية - كلية العلوم - قسم علوم الجو
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: ان دراسة العلاقة بين النشاط الشمسي مع المتغيرات المناخية من العلوم المهمة والتي ترتبط ارتباطا مباشرا بالانسان وبيئته . في هذا البحث تم دراسة العلاقة بين النشاط الشمسي (دورة البقع الشمسية) مع بعض العناصر المناخية مثل الامطار ودرجات الحرارة وذلك بالاعتماد على سنين طويلة من الرصدات والبيانات . تم استخدام معاملات الارتباط الخطية لاختبار درجة الارتباط بين اي متغيرين . تم استخدام طريقتين لدراسة هذا البحث : الاولى هي دراسة العلاقة بين الدورات الشمسية (ما يقارب 11دورة شمسية ) مع كل من ظاهرة (NAO و(ENSO وقد تبين بان التغيرات طويلة المدى لل NAO)) تتناسب تناسبا عكسيا مع دورة البقع الشمسية عند نهاية القرن التاسع عشر وبداية القرن العشرين بمعامل ارتباط مقداره (0.65 - ) , بينما كان التناسب طرديا للفترة (1940 - 2010) وبمعامل ارتباط مقداره (0.75) ومن جهة اخرى تم دراسة العلاقة بين ( NAOو(ENSO مع درجات الحرارة والامطار للمحطات الثلاث موصل - بغداد - البصرة وقد تبين بان علاقة ال(NAO) مع درجة الحرارة عالية بشكل عام في الشتاء بينما كانت العلاقة ضعيفة في فصل الصيف للمحطات الثلاث وتقل تلك العلاقة كلما اتجهنا جنوبا . اما علاقة (NAO) مع الامطار كانت متذبذبة بين معاملات ارتباط عالية واخرى واطئة. اما فيما يتعلق بالعلاقة مع ال(ENSO) فهي ضعيفة عموما للمحطات الثلاث. الطريقة الثانية استخدام تقنية Continuous Wavelet Transformation) ) ذو الابعاد الثلاث ( three dimensions)من خلال برنامج MATLAB لمعرفة مدى الدورية periodicity للنشاط الشمسي مع المجموع السنوي للامطار للفترة (1910 - 2000) ومع درجات الحرارة للفترة 1871 - 2008 للعراق. وقد اشارت النتائج الى ان للبقع الشمسية ثلاث فترات periodicity رئيسية 11، 21 و33 سنة ، بينما كان للعناصر الجوية دورات صغيرة (2 - 9 ) سنة بالاضافة الى نفس الدورات اعلاه (11، 21،33 ) سنة. تم تطبيق المتوسط المتحرك moving average طبقا لتلك الدوريات periodicities حيث تبين ان للنشاط الشمسي علاقة جيدة مع الامطار ، بينما كانت علاقة النشاط الشمسي مع درجات الحرارة غير واضحة او متغيرة مع كل من الزمان والمكان | The study of the relation between solar activity with the climate elements is one of the important science which closely related with the human and his environmental. Relationships between solar activity (sunspot cycles) with some climate elements such as precipitation, Air temperature was the primary aim of this thesis, biased on many years of observations and using linear correlation coefficients to examine the relations between two variables. The methods of this research were organized in two domains as follows : The first domain : Studied the relation between solar cycles (for about eleven cycles) with (NAO) and with (ENSO). The main results were the long - term variations of NAO are negatively correlated with sunspot activity at the end of the 19th and the beginning of the 20th century, with a correlation coefficient of ( - 0.65), whereas positively correlated for the period (1940 - 2010), with a correlation coefficient of (0.75), links (NAO and ENSO) with air temperature and precipitation have been also studied for three stations, Mosul, Baghdad and Basra. The main results showed that the NAO is closely correlated with air temperature in winter season (higher than summer) for the three stations, but this correlation relatively decreased toward south of Iraq. The relation between NAO and precipitation was oscillated between high and low correlations. The relations between the ENSO with air temperature and with precipitation were not obvious for the three stations. The second domain : is using continuous wavelet transformation by MATLAB technique. The relations between the solar cycles with annual precipitation for the period (1910 - 2000), air temperature, for the period (1871 - 2008) have been studied for Iraq. The results indicated that the sunspot cycles have three main periods, around 11, 21 and 33 year, while the studied climate elements had small periods (3 - 7) as well as the 11, 21, 33 years. After applying moving average according to the periodicities that found by continuous wavelet transformation, relations between solar cycles were closely related to the annual precipitation. Whereas the correlation of solar activity with air temperature was found to vary with place and time

تاثير شدة الاضطراب على اداء توربين الرياح Effect of Turbulence Intensity on Wind Turbine Performance

اسم المؤلف: باسم عبد السادة محمد الكناني
اسم المشرف: عوني ادوار عبد الاحد محمد احمد صالح
الموضوع العام: علوم الجو
السنة: 2015
الموضوع الدقيق: علوم الجو
الدرجة: دكتوراه
الجامعة: الجامعة المستنصرية - كلية العلوم - قسم علوم الجو
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: The ongoing depleting of oil and gas reserves, combined with the growing concerns about global warming, has made it inevitable to seek alternative resources of energy. To substitute oil produced energy and eventually minimize atmospheric degradation, renewable energy resources have increasingly become attractive and have been widely used. Therefore, this study focuses on one of the most important resources of renewable energy which is wind energy.Wind speed and direction data of Sulaymaniyah Province (airport station) in the north of Iraq in (2012) measured with 10 seconds time interval, were used to calculate wind potential in the site. Wind speed values with 10 seconds time interval are important to calculate wind turbulence intensity. Mean wind speed and standard deviation with (1, 10, and 60 minutes) time intervals were calculated, together with wind speed distribution, wind direction distribution, wind shear, and turbulence intensity; also, the appropriate class of wind turbine was identified.The impact of meteorological parameters (turbulence intensity, and wind shear) on the performance of wind turbine has been calculated using a MATLAB programming language, which was designed and implemented for this study.Results show that the turbulence intensity is the most significant parameter due to its major effects on the useful life time of a wind turbine. In addition, ambient turbulence intensity was determined, and the turbulence generated by wind turbines was calculated, this type of turbulence is called effective turbulence intensity (Ieff). It was found that wind turbine class (C) is a suitable choice to be installed at the study site (Sulaymaniyah airport station).VIAlso, results show that wind shear is a very important concept for wind turbine developers and installers, since a small difference in wind speed can lead to large difference in power output of a wind turbine. This can be achieved either by calculating wind speed at different heights using equivalent wind speed or by calculating wind speed at hub height using power law. It can be concluded that using equivalent wind speed to evaluate the site gives better calculation of mean wind speed available at that site than wind speed calculated at hub height only. In addition, shear exponent calculation as a function of height is more accurate than its assumed constant value (0.14), in power density estimation.Moreover, wind speed data, of Baghdad Province (Al - Mustansiriyah University meteorological station) in the middle of Iraq in (2008) measured with 15 minutes time interval, were used to calculate the characteristic turbulence intensity of small wind turbine, and monthly mean turbulence intensity. It was found that wind turbine class (B) is the best choice in Al - Mustansiriyah University site. In addition, the highest values of monthly mean turbulence intensity at Baghdad (Al - Mustansiriyah University) were obtained during November, and January, while the lowest values were in June, and July.Finally, wind data were analyzed using Weibull distribution function with its parameters (scale and shape), which were calculated using three analytical methods. Results show that the maximum likelihood method (MLM) gives the best calculation for Weibull parameters in both Sulaymaniyah airport and Al - Mustansiriyah University stations.

نمذجة ابذار الغيوم الدافئة بواسطة قطيرات محلول كلوريد الصوديوم Modeling of Warm Cloud Seeding Using NaCl Solution Droplets

اسم المؤلف: اصداف عبد الامیررعید
اسم المشرف: رشید حمود النعیمي قیس جمیل الجمیلي
الموضوع العام: علوم الجو
السنة: 2015
الموضوع الدقيق: علوم الجو
الدرجة: دكتوراه
الجامعة: الجامعة المستنصرية - كلية العلوم - قسم علوم الجو
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: Clouds has a crucial role in the dynamic and thermodynamics of the atmosphere. Precipitation from clouds is of vital importance for human life and activity. Cloud seeding, a form of weather modification, is the attempt to change the amount or type of precipitation that falls from clouds, by dispersing substances into the air that serve as cloud condensation or ice nuclei, which alter the microphysical processes within the cloud. The usual intent is to increase precipitation (rain or snow), but hail and fog suppression are also widely practiced in airports. The aim of this study is to develop and implement a numerical warm cloud models to simulate microphysical processes within clouds and investigate the effects of seeding process on the formation of raindrops. Results of the modeling the effects of solute on the formation of cloud droplets suggested that the super saturation is decreased by solutes and critical super saturation value depends on the activity of the solute. The results also indicated that Urea is the best solute for decreasing super saturation, as compared with other materials. Bulk modeling of warm clouds showed that updraft, fall speed, radius of cloud element, and surface temperature are the most important factors affecting the microphysical processes within the cloud parcel. An increase in these parameters can lead to an increase in the fallout from cloud. Simple model of warm cloud droplet suggested that updraft, initial drop radius, and liquid water content play an important role in the growth of cloud drop and rain formation. Numerical simulation of warm cloud seeding by salt solution showed that growth of most drops depends on seeding density value, the rate of growth of the cloud drop increase with increasing seeding density in a nonlinear way. The results illustrated that the radius of the large drop plays an important role in growth process while very small radius of small droplets has almost negligible effects on the growth process. It was found that rainfall is increased when seeding density is increased from 0 (the case of no seeding). The results also showed there is an optimum value for seeding density that gives the relatively largest amount of rainfall. Beside seeding density, the updraft radius of the cloud plays an important role in the formation of rain. Therefore the proper seeding density to be used depends on the updraft radius of the cloud

دراسة الاشعاع طويل الموجة الخارج فوق العراق باستعمال بيانات AIRS Study of Outgoing Longwave Radiation Over Iraq Using AIRS Data

اسم المؤلف: صفاء عبد الرزاق عبد الحسين
اسم المشرف: علي محمد الصالحي
الموضوع العام: علوم الجو
السنة: 2017
الموضوع الدقيق: علوم الجو
الدرجة: ماجستير
الجامعة: الجامعة المستنصرية - كلية العلوم - قسم علوم الجو
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: Outgoing longwave radiation (OLR) is a thermal energy represents total upward radiation from the Earth - Atmosphere system towards space. Clouds and greenhouses gases trapped and absorb certain wavelengths of OLR and radiated back towards the Earth, this led to adding an amount of heat to the atmosphere. Variation in OLR values would be influenced Earth’s climate system by increasing or decreasing the average temperature of the Earth's surface. The present thesis involves analysis the spatiotemporal distribution of the outgoing longwave radiation (OLR) and developing an OLR estimation models. Dataset acquired from polar orbit satellite Aqua and its instrument the Atmospheric Infrared Sounder (AIRS). The study was carried out using data collected from January 2003 to December 2016 which covered a region [W : 37.5, S : 28.5, E : 49.5, N : 38.5] in a grid of resolution of 1º×1º. The 13 - years data from 2003 to 2015 were used for climatology and for establishing relationships in the developed models, multiple linear regression (MLR) and Artificial Neural Network (ANN)because the suitability of the technique to provide estimates, while the data of the year 2016 was employed to investigate the estimation capacities of these models of monthly - average OLR value in Iraq. The spatiotemporal distribution of monthly averaged values of OLR for 13 years period showed that Winter season have the minimum average values, about (270 15.8) Wm - 2. Start from Spring season OLR levels become increasingly intense and reach (306 16.2) Wm - 2. Summer season became more intense when compared to previous seasons, specifically over the southern parts of Iraq and dominate the highest OLR overall observed average values. These values reached (351 16.2), (360 14.5), (355 12.9) Wm - 2 for June, July and August respectively. As Autumn season start, the reduction of overall average OLR values start. The minimum average values reached in November with a (283.6 12.3) Wm - 2. The results also showed a zonally relationship between OLR and latitude. The spatial variance of OLR values were indicates an indirect zonally relation between OLR and latitude.Different observed meteorological parameters, including (Surface temperature (ST), Relative humidity (RH), and Cloud fraction (CF)) were offered as the input variables for modeling ANN and MLR to get OLR values. For the entire period, these three meteorological parameters were highly correlated (R= 0.980) with measured OLR. Furthermore, satellite data were used in three different locations over Iraq (Mosul, Baghdad and Basrah). Estimations of OLR values were evaluated by using several statistical bases. Comparisons among the three selected cities in test data (the year 2016) showed close agreement between the estimated OLR and measured OLR from AIRS. Mosul city at the north of the study area showed the best statistical performance indicators with the lowest root mean square error (RMSE) of (4.4966 and 1.3853) and highest correlation coefficient (R) of (0.9929 and 0.9993) for the two models (MLR and ANN) respectively, indicating model's efficiency and accuracy. Statistical analysis in term of β (regression constant) showed that surface temperature (1.823 to 2.311) tended to contribute significantly to high OLR values.The estimated results showed a satisfying performance for the ANN model when compared to the MLR model. These results obviously indicate the advantage of using the satellite AIRS data and both of MLR and ANN models to investigate the impact of the atmospheric meteorological parameters on OLR values on cities and country. Finally, the MLR model is used to map the estimated monthly average of OLR over Iraq.

Application of Approaches of Mass Customization and its effect Competitive Advantages An Analytical Study for Wassit state Company for Textile Industries - Kut Factory

اسم المؤلف: حامد كاظم معن
اسم المشرف: احمد عبد اسماعيل الصفار
الموضوع العام: الادارة والاقتصاد
السنة: 2013
الموضوع الدقيق: ادارة اعمال
الدرجة: ماجستير
الجامعة: الجامعة المستنصرية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: Describe mass customization system as the main of excellence and achieve sustainable competitive advantage and high profitability, also research based on the idea of substantial that the constant change in the needs and desires of customers divers mean intensification of the conflict in the field of competition in the business environment , which generates pressure on companies led to inevitability of the adoption of new technologies and new trends in production , represented by (mass customization system ) in order to achieve competitive advantage thereby increase profits the research was based on two variables interact with each other to form the frame of mind to him , are (mass customization approaches as the depended variable, the research initiate of problem expressed introduced a number of questions aimed at answering her knowledge of the theoretical aspects of these variables being one of the modern application topics , and then diagnosed effect adoption of mass customization in achieving competitive advantage in the wassit state company for textile industries / knitting factory and because of importance of these approaches and the need for adoption at the factory , which achieve thus competitive advantage . The study chapters include theoretical coverage of problem , the researcher depended on information in the literature of subject and accumulated knowledge in this area . As the research include applied aside based on key assumption and sub assumption specialized department including diagnosis of correlation between the mass customization approaches and competitive advantage , while the other section diagnosise singled relationship with the impact of the application of those approaches to achieve competitive advantage. Wassit state company for textile industries - knitting factory was chosen as a site to conduct research and researcher used variant statistical tools of analysis and processing of data and information using statistical system( spss).The research style was a prospective study - analytical being comprehensive analysis style and deep for problem. The researcher reach to the fact that the existence of relations correlation effect between the variables , and researcher presented a set of recommendation s that serv the factory , as if they were taking them based on the conclustions that have been reached , it was most notably the need to adopt factory mass customization a pproaches and need to take to achieve competitive advantage

استقصاء قلف شجرة الكالبتوس كمانع تاكل للفولاذ الكربوني X52 في الاوساط المختلفة للانابيب الناقلة للنفط الخام Investigation The Bark Of Eucalyptus Tree As Corrosion Inhibitor For Carbon Steel X52 In Different Media Of Crude Oil Pipelines

اسم المؤلف: زينب فؤاد حمزة الشريفي
اسم المشرف: كاظم فنطيل السلطاني
الموضوع العام: هندسة الانتاج والمعادن والمواد
السنة: 2017
الموضوع الدقيق: هندسة المعادن
الدرجة: ماجستير
الجامعة: جامعة بابل - كلية هندسة المواد - قسم هندسة المعادن
اللغة: الانكليزية
مكان الجامعة: بابل
الصفحات الاولى:
المستخلص: In the oil and gas industry, the crude oil pipelines which made of low carbon steel suffer from internal corrosion. The corrosion operation is originally related with the presence of the wastewater mixed with the crude oil, especially when it is accompanied by hydrogen sulfide, carbon dioxide, elemental sulfur, inorganic salts, organic acids, and bacteria. Corrosion inhibitors injection in the oilfield is a most common and beneficial method for prevention the pipelines internal corrosion. Because of a high cost and toxic nature of the chemical corrosion inhibitors which used presently in oil industry, it is necessary to promote a less expensive and environmentally acceptable inhibitors, natural plants can be treated as a perfect sources for this purpose.This study investigate the internal corrosion of low carbon steel pipelines in fluid environments, as well as prepare and use natural and locally available plant ( the bark of eucalyptus tree) as a natural corrosion inhibitor, and compared the new inhibitor with a chemical inhibitor used by Missan Oil Company (MOC) in terms of the cost, toxicity, availability and performance.Some experiments were achieved to estimate the performance of a new inhibitor, one of these tests include corrosion measurement by simple immersion in crude oil within and without of inhibitors which added in different amounts 30, 40, 50, and 60 ppm , where the best inhibition efficiencies which get when added the inhibitors in a critical amounts or closest to it, since for the aqueous extract (EB - A) the inhibition efficiency reached (94.4) and (86.71)% at 300 and 323K respectively, and for diethyl ether extract (EB - D) reached (82.87) and (84.6)% at 300 and 323K respectively, while the chemical inhibitor (CRW) which used by MOC reach to (84.21) and (88.73)% at 300 and 323K respectively.optical microscopy examination have been conducted to evaluate the corrosion nature where it show a clear difference in the topography of the immersed samples surface after add the inhibitors at two temperatures.Another tests was achieved to evaluate the corrosion behavior such as potentiostatic polarization and open circuit potential tests in wastewater, since the inhibitor efficiency at 313k reached (88.21)% when add a 60ppm from the EB - A inhibitor to the wastewater in Tafel extrapolation, while it reached (74.91)% when add a 30ppm from the EB - D inhibitor.Several tests was achieved such as FT - IR spectra and using a chemical reagents to detection the presence of many active groups and the presence of tannins, phenols and alkaloids in the Eucalyptus Bark (EB).The results show , that the new corrosion inhibitor is not only equivalent to a chemical inhibitor, but have greatly improvement properties such as : high efficiency , low cost , non - toxic , easily to product, and nonpolluting as compared with chemical inhibitor which is considered toxic and cancering inhibitor.

استقصاء الخواص الفيزيائية والميكانيكية لنحاس الومينا متدرج وظيفيا Investigation Of Physical And Mechanical Properties Of Cu/Al2O3 Functionally Graded Materials

اسم المؤلف: رؤى حاتم كاظم
اسم المشرف: عبد الرحمن كاظم عبد علي
الموضوع العام: هندسة الانتاج والمعادن والمواد
السنة: 2017
الموضوع الدقيق: هندسة المعادن
الدرجة: ماجستير
الجامعة: جامعة بابل - كلية هندسة المواد - قسم هندسة المعادن
اللغة: الانكليزية
مكان الجامعة: بابل
الصفحات الاولى:
المستخلص: One of the most important smart material is the functionally graded materials, which had more increasing attention in different engineering applications.In this study, five - layered stepwise Cu/Al2O3 as functionally graded materials have been prepared from copper powder with five percentage of alumina powder as (5, 10, 20, 30, and 40 Wt%) by using powder metallurgy technique. Mixing of copper (34.32 ?m) and alumina (1.439 ?m) powders for two hours and then several disk sample with dimensions (14mm diameter and 10mm thickness) and cylindrical specimens with (18mm diameter and 27 height) have been compacting at different compacting stresses (550, 650 and 750 MPa). However, sintering of specimens for three hours at 850?C under vacuum about has been achieved.Several physical tests such as porosity, electrical resistance and thermal conductivity, X - ray diffraction, X - ray Fluorescence and Particale size analysis have been achieved. Furthermore, Microstructure and mechanical tests such as hardness, compression, double shear and dry sliding wear have been done for preparing samples from composite and functionally graded material.Numerical modeling using finite element analysis by ANSYS software has been presented for copper/alumina joints and compare with copper/alumina functionally graded materials.From the several experimental results, it is clear that the best compacting pressure was 650 MPa is determined by measuring green density at different compacting pressure, hardness increased with the increasing additive percentage of alumina, hardness resultschange in each layer by producing functionally graded materials (FGM) according to the percentage of the harder constituent (i.e. Al2O3) from 53 to 113 HV at compacting pressure 650 MPa, While the shear strength decreases with alumina increased from 72 MPa for layer one to 28 MPa for layer five at compacting pressure 650 MPa. The Wear rate increases as the time and load is increased. The wear resistance increased with increasing contain of Alumina. Results from the numerical modeling, it is clear that residual thermal stresses gradually decreased from the interface to the edges of functionally graded sample whereas in Copper/Alumina joint there is very high thermal residual stress in the joint interface.

امثلية عمليات اللحام باستخدام مصفوفة التضارب Optimization Of Welding Processes Using Confusion Matrix

اسم المؤلف: حسين خليل برهان
اسم المشرف: حيدر الجبوري
الموضوع العام: هندسة الانتاج والمعادن والمواد
السنة: 2015
الموضوع الدقيق: هندسة المعادن
الدرجة: دبلوم عالي
الجامعة: جامعة بابل - كلية هندسة المواد - قسم هندسة المعادن
اللغة: الانكليزية
مكان الجامعة: بابل
الصفحات الاولى:
المستخلص: Welding is a materials joining process in which two or more parts coalesced at their contacting surfaces by suitable application of heat and/or pressure.The proposed system consist of three stages : - First stage : preparing the actual samples from the previous research. These stage have multi tests (i.e, residual stress, fatigue life, impact energy, hardness and tensile strength) - Second stage : Translated the result of previous stage depending on speed of welding and heat input. The mechanical properties was related to the heat input and the temperature of the processes of welding. The quantity of the heat input was increased when the speed of welding was slow and heat input decrease when the speed of welding was high, this high heat input led to form coarse grain and this led to decrease the mechanical properties.Third stage : generated software system used different types of error measures, this software include two phase, the first phase is to estimate the error between the actual and predicted tests. While the second phase is to verification of the result phase on the person correlation measures, and this phase show high correlation among welding processes. In general these correlation lied from +1. The verification occur base on the measures of confusion matrix, (i.e SSE, MSE, RMSE ,MAPE, MPE and MAE ).The system satisfy the following results (Accuracy equal 84.37%, True positive (TP) equal 86.66 % and Precision equal 96.2% ).

تاثير معدل التبريد على خواص سبيكة Ag - Cu - Sn Effects Of Cooling Rate On Roperties Of (Ag - Cu Sn) Ternary Alloy

اسم المؤلف: جمان حيدر ساجت
اسم المشرف: حيدر حسن جابر جمال الدين
الموضوع العام: هندسة الانتاج والمعادن والمواد
السنة: 2017
الموضوع الدقيق: هندسة المعادن
الدرجة: دبلوم عالي
الجامعة: جامعة بابل - كلية هندسة المواد - قسم هندسة المعادن
اللغة: الانكليزية
مكان الجامعة: بابل
الصفحات الاولى:
المستخلص: Dental fillings is widely used because of good mechanical properties and low cost but also was one of the more fillings topic of discussion and it studied continuously.The objective of this research is studing the effect of the cooling rate on the phases and properties of amalgam. two alloys were prepared by two types of casting (die casting and sand casting) with fixed percentage of tin, copper, silver and zinc for both alloys respectively about (7.5gm, 6.25gm , 10.75gm , 0.5gm).The process done by using an electric furnace in an inert gas atmosphere of argon and alloys thermally treated at a temperature (400C?) for a period of four hours for the purpose of homogenization phases alloys. And then it was studying the microstructure using an optical microscope. And using X - ray diffraction to determine the phases in alloys.The phase evaluation showed that the phases in the amalgam alloy (die alloy) has ? (Ag3Sn) , ? (Cu3Sn), and one other phase ? (Cu6Sn5) and the phases in the amalgam alloy (sand alloy) has ? (Ag3Sn) and ? (Cu3Sn). Then alloys have been converted into powder using a ball mill. The powder was treated thermally output for temperature (100C?) for a period of three hours atmosphere vacuum to remove internal stresses.The amalgam manufactured according to the ADA specification No.1 where he was mixing 0.8gm from each of the mercury and the powder for 30 seconds mined device and then put the dough, resulting in the mold of Teflon and sheds them straining compression amount (14MN / m2) for a period of 85 seconds still stress after that, the sample isextracted from the mold after the half - hour and placed in a glass chamber at a temperature of 37 ± 1C?.Microstructure of the amalgams were studied primarily by x - ray diffraction, optical microscopy.The phase analysis of two amalgams shows two phases; ?1, ?.studied the mechanical properties (tensile, compression, creep, dimensional change, hardness) and the result was that all properties effected with the change of the colling rate.It was conducted two types of corrosion tests are testing the open circuit (OCP) and potentiodynamic polarization in industrial saliva solution at a temperature of 37 ± 1C?.

تاثير اضافة الكالسيوم على البنية المجهرية والخواص الميكانيكية لسبيكة Al - Cu - Mg Effect of Ca Addition On The Microstructure And Mechanical Properties of Al - Cu - Mg Alloys

اسم المؤلف: نور صباح توفيق
اسم المشرف: منذر محمد راضي
الموضوع العام: هندسة الانتاج والمعادن والمواد
السنة: 2014
الموضوع الدقيق: هندسة المعادن
الدرجة: ماجستير
الجامعة: الجامعة التكنولوجية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: في هذه الرسالة تم دراسة تاثير اضافة عنصر الكالسيوم بنسب مختلفة ) 3.0 المجهرية والخواص الميكانيكية لسبيكة) المنيوم - نحاس - مغنيسيوم ( , حيث تم انتاج هذه السبائك باستخدام والتي تتضمن )المعاملة المحلولية, )? السباكة الرملية وعوملت حراريا باستخدام المعاملة ا | In this thesis ,the effect of pure Ca element addition in different percents of (0.3,0.6,0.9%) on the mechanical properties of Al - Cu - Mg alloy were studied.The Alloys were produced using sand casting and heat treated using T6 which involve [solution treatment , quenching , artificial aging ], aging process were carried out at 220? C for different periods of time ranging between (5min to5hr).Also the work involves a study on the effect of Ca addition on both grain size as well as the resulting phases before and after heat treatment, samples were examined using optical microscope, Scanning Electron microscope ,X - Ray diffractometer and image - J to estimate the average grain size.The results of hardness and tensile tests for 0.6% Ca and 4hr aging shows the best response as compared to the other alloys. The hardness and strength values have been changed from (78.29HV)(110.57Mpa) during (30min)at 220?C for non - Ca content alloy to(125.9HV)(164.2Mpa) for 0.6%Ca alloy. X - Ray diffraction , results shows the basic phase that forms is Al2CuMg (S??, S? phase) which is considered as the main strengthening phase in AL alloys, and it was found that Ca addition leads to form (Al4Ca) and (Al2Ca)which delay the alloy response to precipitation hardening by delaying the formation of (S)phase. SEM images showed a large and small dimple structure and broken or cracked Al - Ca compounds particles.This indicates that the fracture was ductile fracture in the Al matrix and brittle in these compounds ,.Also presence of microvoids (porosity) on the fracture surface is formed at the interfaces between Ca compounds and Al matrix enhanced the crack propagation through their center. The presence of the secondary phases precipitates (Al2CuMg ,Al2Ca and Al4Ca) in the fracture surface also contributed to ameliorate the mechanical properties by increasing the bonding of the matrix and reduced the ductility.Also Ca addition in the range of (0.3 - 0.6%) gives rise to grains refining ,While increasing Ca content up 0.9%wt coarsing the grains, which leads to decrease the hardness and tensile strength, From these results the decrease in tensile strength with increasing Ca content over 0.9% seems to be attributed to the reduction in elongation caused by the occurrence of micro porosity due to Ca addition.

تخطيط مسار نقطي خال من الاصطدام لروبوت ممفصل ذا خمس درجات حرية Point - To - Point Free Collision Path Planning of 5 DOF Articulated Robot

اسم المؤلف: محمد عبد الرحمن غفور
اسم المشرف: تحسين فاضل عباس
الموضوع العام: هندسة الانتاج والمعادن والمواد
السنة: 2014
الموضوع الدقيق: هندسة الانتاج
الدرجة: ماجستير
الجامعة: الجامعة التكنولوجية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: ان الهدف الرئيسي من هذا البحث هو ايجاد مسار لمفاصل الروبوت وللماسك النهائي في الروبوت خلال حركة الماسك من نقطة البداية الى نقطة الهدف المراد الوصول اليها خلال حيز مؤتمت بدون الاصطدام مع العوائق الموجودة في بيئة الروبوت اعتمادا على الحل العلوي لاذرع الروب | The main objective of this research is to find a path for the robot joints and gripper from the given start point to the desired goal point without collision with the obstacles which exist in the robot environment depending on the robot links upper solution. This research will investigate the problem of path planning for a 5 axis articulated robot, operating in an environment with obstacles whose boundaries are enveloped by a spherical shape. The path planning approach has been developed in the robot joint space and consists of five phases : The first phase is using Bezier, Hermit, B - spline and NURBS curve techniques considering their control points weight not constant. The second phase is to generate a sufficient number of intermediate points in Cartesian space along those curves. The third phase converts the coordinate of the generated intermediate points from its Cartesian space into joint space and move the robot gripper along the generated path. The fourth phase screens the generated four Bezier, Hermite, B - Spline and NURBS paths in order to choose the best one. The fifth phase is developing the chosen path by using proposed algorithm to improve the selected path.Both forward and inverse kinematics solutions for the robot links using Denavite - Hartenberg representation are important step to determine the manipulator's joint angles and Cartesian coordinates, that assists generating the required path which has been derived in this work.Matlab program has been used as an assistant program to analyze, sketch and implement the algorithms of forward kinematics, inverse kinematics and path planning.This work will not be limited to theoretical studies or simulations, experiments have been run with various tests, on "educational robot" Lab - Volt R5150 to assess which path is the better ability in avoiding the obstacles. The method applies to robots in a fixed and known environment. A number of experiments have been carried out to test the ability of the robot arm to reach its goal without collision It’s found that Bezier curve was the chosen path because it was the better obstacle avoidance and shorter path.

دراسة سلوك البلى الترددي لمواد مركبة ذات اساس من سبيكة المنيوم / sic تحت ظروف الانزلاق الجاف والرطب A Study On The Reciprocating Wear Behavior of Aluminum Alloy / SiC Composites Under Dry And Wet Conditions

اسم المؤلف: عتبة حسين علوان
اسم المشرف: احمد علي اكبر اكبر
الموضوع العام: هندسة الانتاج والمعادن والمواد
السنة: 2014
الموضوع الدقيق: هندسة المعادن
الدرجة: ماجستير
الجامعة: الجامعة التكنولوجية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: تم في هذا البحث دراسة معدل البلى لاحدى سبائك الالمنيوم ((AA2024) (Al - Cu - Mg ومواد مركبة عن طريق تصنيع جهاز بلى ترددي تبعا للمقياس العالمي ( ASTM G133) ذو ترتيبة المسمار على المستوى (Pin on Flat) لمتغيرات مختلفة (الحمل المسلط , النسبة الوزنيه لدقائق كا | In this work the wear rate of one of aluminum alloys (Al - Cu - Mg) (AA 2024) and composite materials, has been studied by manufacturing a reciprocating wear device according to the International Standard (ASTM G 133 Pin on Flat) for different variables (applied load, weight percentage of (SiC) and sliding speed) under dry and wet (lubrication) conditions. Stir casting method has been used to prepare a composite material by using vortex technique to force the particles inside the molten metal (Al - alloy) and to distribute them regularly. The composite materials reinforced with different weight percentages of SiC (3, 6, 9, 12 wt%) are used. The base alloy and composite materials samples were tested to investigate the microstructure, and phases using optical microscope and Vickers hardness, wear rate, and the worn surfaces by using scanning electron microscope (SEM). From the results of microscopic examination it is found that the microstructure of alloy matrix was fine dendrites, in addition to the SiC particles that distributed near homogenously in the alloy matrix. The hardness test results showed that, the increasing of the weight percentage of (SiC) leads to increase the hardness, and the highest value of hardness was found at 12wt% SiC. Also the results showed that the wear rate increases with applied load for all weight percentage of reinforced particles (SiC).With increasing the load, more wear tracks, deep, and closed paths are formed and severe wear happens under dry condition but the lubrication case has less effect than dry case.It was shown that wear rate of both base alloy and composites under various conditions, increases with increasing of applied load and sliding speed but the wear rate decreases with increasing the SiC wt% in composite.Statistical method using software (Minitab 16) was used to study the effect of wear rate for both the base alloy and composite material by using three variables; applied load (X1), silicon carbide proportion (X2), sliding speed (X3), with five levels of each variable. It is concluded that the optimum weight loss under dry case was 0.0014g, The combined effect of variables and the wear rate was obtained and which variable are more influential, as shown in the equation below : D = 0.056703 - 0.002164 X2 - 0.000282 X3+ 0.000017 X1 X3 +0.000010X2 X3 While under lubrication case that the optimum weight loss was 0.0037g and the combined effect of variables and the wear rate was obtained and which variable are more influential, as shown in the equation below : L= 0.009607 + 0.002825 X1 - 0.002375 X2 + 0.001100 X3 + 0.001664 X3 2 + 0.004700 X1 X3 + 0.002700 X2 X3 The applied load (X1) and sliding speed (X3) have the largest effect on wear rate.

السحب العميق المتعدد المراحل للاقداح السداسية Multistage Deep Drawing of Hexagonal Cups

اسم المؤلف: صبيح سلمان داود
اسم المشرف: وليد خالد جواد
الموضوع العام: هندسة الانتاج والمعادن والمواد
السنة: 2014
الموضوع الدقيق: هندسة الانتاج
الدرجة: دكتوراه
الجامعة: الجامعة التكنولوجية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: The aim of this work is to design and manufacturing a multistage (three stages) deep drawing dies to produce cylindrical and hexagonal cups of (43,33.1,26.8)mm diagonal diameter through two methods. The first method by drawing the hexagonal cups directly by using hexagonal orifice die from a flat sheet (blank) of (80mm) diameter and (0.7) mm sheet thickness for (1006 - AISI) hot rolling low carbon steel material.The second method by redrawing a cylindrical cups of (43,33.1,26.8) mm outer diameter (produced previously by a cylindrical orifice die) in to hexagonal orifice die which transform (convert) these cylindrical cups into hexagonal cups of (43,33.1,26.8)mm diagonal diameter.For all stages of drawing hexagonal cups, wall corner radius of die (0.7, 4)mm, with punch and die profile radius of (4 and 8) mm and drawing speed of (50, 200, 500) mm/min were used to study the effect of these parameter on drawing forces, cup wall thickness, strain distribution over the cup wall and surface defect of the cup wall.A commercially finite element soft ware (ANSYS 11.0)was used to perform the numerical simulation for cylindrical and hexagonal cups in three stages of drawing process. A comparison between theoretical (simulation) and experimental results lie within average of (15 - 20%), and the agreement is good in the first stage.The results shown that excessive metal flow ,maximum thinning of cup wall and maximum strain occurred at corner radius of (0.7) mm and at drawing speed of (500mm/min )for hexagonal cup produced directly from flat sheet.The results shown that the best thickness distribution and strain distribution over the cup wall, better cup wall surface (less surface defects) and lowest drawing force was with percentage (63.8%,45.4%,74.1%) respectively occurred when transform (converting) the cylindrical cup into hexagonal cup with wall corner radius of die (Rc= 4)mm in three stages.

دراسة زاوية تعشق العدة في عمليات التفريز Studying Tool Engagement Angle In Milling Process

اسم المؤلف: ليث فاضل شاكر
اسم المشرف: ليث عبد الله محمد
الموضوع العام: هندسة الانتاج والمعادن والمواد
السنة: 2014
الموضوع الدقيق: هندسة الانتاج
الدرجة: ماجستير
الجامعة: الجامعة التكنولوجية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: هذه الاطروحة تعنى بدراسة تاثير زاوية تعشيق العدة بالمشغولة على ستراتيجيات ونتائج عمليات التفريز بالعدد ذات النهايات المسطحة. تم تصميم نموذجين (CAD model) باستخدام برنامج (Solid work 2013) الاول على شكل كونتور خارجي والاخر على شكل بوكيت داخلي وبعد ذلك تم | This work focuses on the effect of controlling tool engagement angle (TEA) on the milling process planning and the results of end milling operations. Two CAD models has been designed by using Solid Work 2013 software, then G - code have been generated and simulated by using Surfcam V5 software with (Fanuc post processing). AL7075 - T6 alloy has been used for its high machinability, dry machining (no coolant) has been done on 3 - axes milling machine (C - tek) available in the University of Technology Training and Workshop Center.Feeds, speeds and other machining parameters (axial and redial depth of cut) have been selected according to machining handbooks recommendations. Machining of workpieces has been accomplished by using two techniques (two types of tool - path), first one was conventional tool - path machining (contour parallel tool - path), and the second was by using TRUEMILL technique (true engagement controlled tool - path) by Surfcam V5. Thirty experiment have been designed, four of them have been failed, ten have been accomplished and the others neglected for reasonable causes as it will be discussed. Finally a comparison between the two techniques has been made focusing on machining time, material removal rate, cutting temperature and surface roughness. The results confirm that TEA control leads to reduce machining time, we have a time reduction in about (80%) for contour machining and (57%) for pocket machining. Cutting heat was under control though the feeds and the axial depths of cut went higher, also by controlling tool engagement angle we skipped the cause of failure of some experiment in conventional tool - path machining. Surface roughness was not that affected by controlling tool engagement angle, the minimum surface roughness in hand is (0.43 µm), it is higher than the best result of a previous work for the same material by 50%.

دراسة تجريبية حول مسحوق حبيبات النحاس ذات الحجم النانوي باستخدام الترسيب الكهربائي المصحوب بالامواج الفوق صوتية Experimental Study of Nanosized Copper Powder Using Sonoelectrodeposition Process

اسم المؤلف: حيدر ياسر ثامر الياسري
اسم المشرف: محمد جاسم كاظم عدنان شمخي جبر
الموضوع العام: هندسة الانتاج والمعادن والمواد
السنة: 2014
الموضوع الدقيق: هندسة المعادن
الدرجة: ماجستير
الجامعة: الجامعة التكنولوجية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: عملية الترسيب او التحليل الكھربائي تعتبر من الطرق التصنيعية الرئيسية التي تستخدم لانتاج مختلف الاشكال والاحجام (ضمن المدى الميكروي) من حبيبات مسحوق معدن النحاس والتي تستخدم لاحقا بواسطة تكنولوجيا المساحيق لانتاج اجزاء محددة. ايضا استخدمت ھذه الطريقة بمد | Electrolytic or electrodeposition process is considered a main way to produce many shapes and sizes (micro range) of copper powder to be used in powder metallurgy process. It is used broadly to deposit copper coatings with nanosized grains, but it is rarely used to produce nanosized particles of copper. Reaching this goal is highly dependent on the optimum design of the parameters of electrodeposition process.This work aims to study the important variables that most affect the electrodeposition process outputs. These variables are : copper sulphate pentahydrate salt concentration CuSO4.5H2O (1, 5.5, and 10) g/l, cathodic current density (12.5, 25 , and 37.5) mA/cm2, ultrasonic (20 KHz frequency) vibration amplitude (5%, 20%, and 35%) from the maximum amplitude (1 ?m), and amount of sulphuric acid H2SO4 (H2SO4 concentration > 97%) in electrodeposition cell (0.05, 0.10, and 0.15) ml/l. The study of effects of these variables is concerned with size of resultant powder particles, also their effect on the purity, morphology, and shapes of particles is studied, and the crystallinity of particles is also covered.The design of experiment (DOE) approach is applied here through Taguchi design of experiments, to manage and analyze the results and study the specific effects of each. The arrangement of variables’ levels is done using the setup of (Taguchi L9).The analysis of experiment tests of the study of electrodeposition process to get copper nanoparticles showed that all variables have effect on the size of resultant copper particles, but in different ways and degrees. The mean particle size of all samples is about 86 nm. It was found that the increasing of concentration of copper sulphate salt (1, 5.5, and 10) g/l had a negative on the increasing the size of copper particles in the range (71, 69, and 117) nm.While the increasing of cathodic current density (12.5, 25 , and 37.5) mA/cm2 had an effect of decreasing the particle size of copper in the range (114, 75, and 68) nm. The case was the same for increasing of amplitude of ultrasonic vibration, where increasing it (5%, 20%, and 35%) caused decreasing in the particle size in the range (97, 92, and 68) nm. And the effect of acid amount (0.05, 0.10, and 0.15) ml/l was multiple because it decreased the particle size first and increased it later in the range (90, 65, and 102) nm. The amount of effect of each variable on the process was calculated using specific equations of Taguchi design. It was found that the current density has the bigger effect (35%) on the resultant particle size (it minimized the size). The salt copper concentration has the second effect (34%) (it maximized the size), and thirdly the acid concentration effect is 19% (it had multiple effect on the size).Finally the ultrasonic vibration has 12% effect (it minimized the size). The optimum values of process parameters that lead to minimum size of the particles were : CuSO4.5H2O concentration = 5.5 g/l, Current density = 37.5 mA/cm2, Ultrasonic amplitude = 35%, H2SO4 concentration = 0.1 ml/l.The SEM photographs were used to examine the morphology of particles. The results show that the shape and morphology widely vary between many modes : from treelike through irregular, angular, or rounded shapes to a wellfaceted truncated octahedron. The forming of well - faceted truncated octahedron copper particles is related strongly to the presence of ultrasonic vibration which plays the role of inhibitor.Energy dispersive spectroscopy (EDS) elemental analysis of copper nanoparticles indicates the high purity of most of samples except the cases where there are traces of oxygen from very thin layer of oxides and/or carbon from residual alcohol.The x - ray diffraction studies reveal that the resulting particles are a crystalline copper element with a face center cubic (FCC) crystal structure.

تطبيق نظام دعم القرار لانشطة الصيانة في مصفى الدورة Application of A Decision Support System For Maintenance Activities In Al - Daura Oil Refinery

اسم المؤلف: مصطفى محمد علي منصور
اسم المشرف: لمياء محمد داود لمى عدنان حميد
الموضوع العام: هندسة الانتاج والمعادن والمواد
السنة: 2014
الموضوع الدقيق: الهندسة الصناعية
الدرجة: ماجستير
الجامعة: الجامعة التكنولوجية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: في ھذا البحث تم دراسة انشطة الصيانة في معمل دھون 3 احد معامل الدھون في مصفى الدورة حيث تم اختيار ھذا المعمل كونھ الاحدث والاكثر انتاجية مقارنة مع المعملين الاخرين وتم اخذ بيانات انشطة الصيانة لمدة عشر اشھر متتاليھ من ايار 2012 ولغاية شباط 2013 علما ان وح | In this research maintenance activities in lube oil factory (3) of Daura refineries is investigated for ten consecutive months from May (2012) to February (2013).This factory is the newest and largest in its capacity compared with lube oil factory (1 and 2). Dewaxing unit produces the greater products compared with other production units in lube oil factory (3). The frequency of breakdowns and type of maintenance were identified, Pareto chart are used to analyze the collected data. Results indicated that %95 of breakdowns of different equipments (pumps, exchangers, compressors, docks, filters, furnaces and towers) are due to mechanical causes, the rest are related to electrical causes.Pareto chart highlights that the most frequent failure for both pumps and exchangers followed by compressors and other equipments of lube oil factory 3.Loss production cost due to maintenance activities was also conducted in this study so as to analyze different aspects of maintenance activities for lube oil factory (3).The total loss in production due to breakdown in the ten months of this study is (99 Billion ID). It is worth’s mentioning that pumps registered the highest losses of production cost due to bad maintenance. Accordingly, decision making for maintenance activities is a multiattribute and decision support system is crucial to signify priorities and definealternatives. ERGO (Latin word meaning "therefore" or Greek word meaning "work", used as a prefix ergo - , for example, in ergonomics and it is generalpurpose decision support system using 35 criterion to choose the best alternatives) is employed so as to evaluate detailed scope and the best of best alternatives. ERGO results indicated that Pumps are the best alternative offered to decision maker to conduct the necessary maintenance ERGO identifies the equipment with the most frequent breakdown indewaxing unit, which causes the greater loss in production cost. Compressors were identified as the highest frequency failure equipment(s). Combining two criteria (frequency of failure and lost production cost) reveals that pumps are the best alternative.

تقليل ضياعات القص في مشكلة قطع الخامات احادية البعد باستخدام نموذج برنامج جاهز Trim Loss Minimization In One - Dimensional Cutting Stock Problem Using A Ready Software Model

اسم المؤلف: سلام قدوري داود
اسم المشرف: سوسن صبيح الزبيدي
الموضوع العام: هندسة الانتاج والمعادن والمواد
السنة: 2014
الموضوع الدقيق: الهندسة الصناعية
الدرجة: ماجستير
الجامعة: الجامعة التكنولوجية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: تعتبر مشكلة قص الخامات واحدة من المشاكـل العملية المهمـة، لذا ركز البحث على دراسة مشكلة قص الخامات احادية البعد بالتفصيل، حيث تم دراسة تصنيف وخصائص وطرق حل هذا النوع من المشاكل بالاضافـة الى اقتراح اسلـوب حـل مناسب لتقليل ضياعات القص الحاصلـة في بيئـة ا | Cutting stock problem is one of the important operation problems. The one dimensional cutting stock problem is considered as obvious problem which should be centered to be solved, so this thesis focuses on studying classification, characteristics and solution methods for this problem, in addition to suggest suitable approach for minimization of the trim losses in actual environment, as it is required to fulfill all of the small required items with different lengths and quantities by cutting the identical large objects which are available as stock. The variety of lengths and quantities of these small required items makes the problem obvious in complexity to fulfill all items with minimization of Integer Linear Programing (ILP) which is aided by Advanced Interactive Multidimensional Modeling System (AIMMS) software used to solve research problems. This software used because that getting of accurate details and speed results for waste amounts, number of used stocks, total and efficient cutting patterns that are generated to getoptimal solutions.Our study has been applied in an actual environment (housing project with 41 building units in Azezeiyah - Wasset) being carried out by Al - Mansour Company of Iraq Ministry of Construction and Housing, where the reinforcement steel (Rebar) with standard length is considered as a backbone component of building structure.These problems have been studied according to different rebar diameter (25 mm, 16 mm, 12 mm, and 10 mm), where each problem is subdivided and solved according to basic building activity designs (foundation, columns, beams, slabs, stairs, balcony, and front arch building entrance), trim losses which were resulting from certain activity design - diameter problem that have lengths longer than required item lengths in the next activity designs are stored and utilized to get optimal stock ratios. The utilization stock ratio which is resulting of suggested solution approach (ILP) for all these one dimensional cutting stock problems has reached (98.53%), while the utilization of used stock in that actual environment got by Al - Mansour Company is lower than this percentage.

تاثير المعاملة بالليزر على مقاومة التاكل للفولاذ المقاوم للصدا نوع 304 Effect of Laser Treatment On Corrosion Resistance of 304 Stainless Steel

اسم المؤلف: زمن عبد الرزاق عبد الوهاب
اسم المشرف: محمد جاسم كاظم سامي ابراهيم جعفر
الموضوع العام: هندسة الانتاج والمعادن والمواد
السنة: 2014
الموضوع الدقيق: هندسة المعادن
الدرجة: ماجستير
الجامعة: الجامعة التكنولوجية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: تعتبر هذه الدراسة بانها محاولة لتحسين مقاومة التاكل للصلب المقاوم للصدا من نوع 304 عن طريق الانصهار السطحى بالليزر. تم استخدام تقنية منحني تافل لتحديد معدلات تاكل الصلب المقاوم للصدا نوع 304 في محلول 3.5? كلوريد الصوديوم عند اربعة حالات مختلفة. الاولى بدو | The present work represents an attempt to improve corrosion resistance of sensitized 304 stainless steel by laser surface melting treatment. Tafel extrapolation technique was used to determine the corrosion rates of stainless steel type 304 in 3.5% NaCl in four conditions. The first condition is as received, the second sensitized microstructures at temperatures 850 oC for one hour, the third condition is treating the stainless steel alloy by laser surface melting (LSM) without sensitization. The fourth condition is studying the effect of LSM on sensitized stainless steel.The main results obtained are expressed in terms of corrosion parameters through electrochemical behavior : E°, I°, E Corr., ICorr., EP., IP, EPit. and IPit.These parameters are strongly dependent on the microstructures of the alloy. The results reveal when the potentials increase, this means that the microstructure becomes thermodynamically more stable and has good corrosion resistance. The above electrochemical parameters for sensitized 304 stainless steel show that localized corrosion rate increases due to precipitation of chromium carbides on grain boundaries and to the sensitization process affecting the phases. The LSM treatment shifts the potential toward noble direction, the corrosion current densities values shift to lower values. Generally, a change in surface hardness shows a microstructure modification in metallic bonds. The comparison of anodic polarization curves indicates that the corrosion rates for laser treated specimens are reduced. Increase in corrosion resistance probably means that most inclusions at the surface have been dissolved in the structure due to melting or alternatively, they are covered by molten materials. An interesting feature is the systematic shift of the pitting potential in the noble region with a laser treatment. This result confirms that the laser treatment can be used successfully to improve the localized corrosion resistance.

المعاملة السطحية بالليزر لحديد الزهر الرمادي باستخدام ليزر (Nd : YAG - Nano Second) Laser Surface Heat Treatment For Gray Cast Iron Using Nano Second Nd : YAG Laser

اسم المؤلف: بلال احمد حبيب
اسم المشرف: رابحة صالح ياسين هجران زين العابدين طعمة
الموضوع العام: هندسة الانتاج والمعادن والمواد
السنة: 2014
الموضوع الدقيق: هندسة المعادن
الدرجة: ماجستير
الجامعة: الجامعة التكنولوجية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: في هذا البحث، تم استخدام تاثير معلمات الليزر لتحسين الخواص السطحية للحديد الزهر الرمادي، وذلك باستخدام جهاز Nd : YAG ليزر بطول موجي nm(1064 (، البعد البؤري cm( 5 ,10,18)، وامد النبظة ns (10). استخدمت طريقة الانصهار السطحي بالليزر في تصليد العينات، الى | In this thesis , the effect of laser parameters is used for perfection of the surface characteristics for gray cast iron , using pulsed Nd : YAG laser with wavelength of (1064nm ).The laser surface glazing and shocking methods have been used in hardening the specimens , besides using the laser energy in treatment of (1.2 J) , pulse duration (10 ns), with different focal length of (5,10,18) cm and used the (air ,water , DMSO) as a active medium. In laser surface engineering the micro hardness, roughness and wear rate examinations deliberated before and after laser treatment. The effect of laser parameters includes : The effect of the pulse repetition rate (P.R.R) , the result shows , thevalue of the micro hardness of work pieces reduced but the variation in the value hardness decreased. For the effect of the medium used (air, water, DMSO) it was found with increasing the water and DMSO high the value of the micro hardness of work piece increased and value of the (loss of weight , wear rate, surface roughness ) reduced. After treatment by laser the amount of loss in weight is less than the loss of weight with the base metal (before the treatment) , so the results reveal an improvement in wear rate after treatment by laser. And for the effect of overlapping technique ,it was found that the best percentage for overlapping technique ratio is 50% for the selected laser energy. The value of micro hardness increased by moving away from the center of the laser strike on the work piece.

الحماية من التاكل لقواعد الاعمدة الكهربائية في الترب ذات المقاومية المنخفضة Corrosion Protection of Electrical Bar Stands In Low Resistivity Soil

اسم المؤلف: اياد نصيف جاسم
اسم المشرف: سامي ابراهيم جعفر الربيعي
الموضوع العام: هندسة الانتاج والمعادن والمواد
السنة: 2014
الموضوع الدقيق: هندسة المعادن
الدرجة: ماجستير
الجامعة: الجامعة التكنولوجية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: يستخدم الفولاذ المغلون في تصنيع الاعمدة الكهربائية لامتلاكه خواص ميكانيكية جيدة ومقاومة تاكل عالية. وتحت الظروف الاعتيادية يعاني العمود من التاكل بعد عدة سنوات من الخدمة.يصنع عمود الكهرباء من فولاذ St - 52 والمطابق للمواصفة DIN الالمانية ويتالف من ثلاثة | Galvanized steel is used in electrical poles because of the good combination of its mechanical properties and the corrosion resistance. Under normal conditions, electrical pole suffered from corrosion after some years in service. Electrical poles, which were made according to Germany standard DIN st.52, consist of three parts; the upper, mid and lower part. This study focuses on the last part because the surrounding soil of electrical pole is more corrosive than the atmospheric environment, which surrounds to other two parts of the electrical pole. Soil resistivity is the one variable that has the greatest influence on corrosion rate. Electrical poles which at buried in low resistivity soils will generally be anode, whereas electrical poles buried in adjacent high resistivity soils will generally low corrosion.The electrolyte in this work was prepared according to the values of Iraqi soil resistivity. Sodium chloride (NaCl) was used in different concentrations of (2, 2.5, 3 and 3.5) wt. %, which are equivalent to 27, 24, 20 and 18 ohm.cm. Two methods were used in this work in order to improve corrosion resistance, the first method galvanizing process in different thicknesses (80, 90,100,110,120 and130) µm and the second method is coating by different types of Iraqi paints (D - 5547) with hardener (H - 1457)and(G - 5532,G - 5533,D - 5542) with hardener(H - 5533) The corrosion rate and corrosion potential of steel increases and decreases with the increase in NaCl wt.% concentration respectively. Corrosion rates (mpy) with coating thickness are achieved as a function of environment in different soil resistivities. The more corrosion resistance occurs at 120 µm galvanized layer. Micro cracks appear at 130 µm galvanized thickness.In this work, two mixed ratios of paint and hardener were used. These ratios are 2 : 1 and 1 : 1. Paint with mixing ratio equal to 2 : 1 of G - 5532 + G 5533and mixing ratio 1 : 1 D 5542 with hardener 5530 gave the more corrosion resistance.The coating thickness has a direct influence on the performance or life of the electrical pole. As the thickness of galvanized layer increases, the life of protection increases until 120 µm. The life of a zinc coating is a linear function of coating weight for any specific environment. The efficiency of coated electrical pole either by galvanization or paint process was a proximately between 94% to 97% and 98% to 99.6% respectively.

سلوك المواد فائقة اللدونة ذات البنية المجهرية الناعمة لسبيكة المغنيسيوم نوع AZ31B والمشكلة بواسطة التشكيل العالي الانفعال Superplastic Behavior of Fine Grained AZ31B Magnesium Alloy Processed By Severe Plastic Deformation

اسم المؤلف: زياد طارق عبد الوهاب
اسم المشرف: ازل رفعت اسماعيل
الموضوع العام: هندسة الانتاج والمعادن والمواد
السنة: 2014
الموضوع الدقيق: هندسة الانتاج
الدرجة: ماجستير
الجامعة: الجامعة التكنولوجية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: Superplastic properties and microstructure evolution of commercial AZ31B magnesium alloy processed by two different severe plastic deformation methods Equal Channel Angular Pressing (ECAP) and Equal Channel Angular Rolling) ECAR) were studied. Samples were tested in tension at temperature of 623 K and strain rate ranging from 2.4×10 - 4 1×10 - 2 s - 1. ECAP die with 10 ×10 mm cross section channel, oblique angle of ?=90° and ?=13° was designed to refine the alloy microstructure at temperature of 473 K using route BC. Application of ECAP showed a remarkable grain refinement for AZ31B Mg alloy from 14.1 to 2.1?m after three ECAP passes. Maximum superplastic elongation of 261% was achieved at 623 K and strain rate of 2.45×10 - 4 s - 1. The measured strain rate sensitivity was m = 0.33 demonstrating that viscous glide control creep was the dominant deformation mechanism. In most investigation used ECAR process, the die temperature was set to room temperature, in order to avoid cracking intermediate annealing was used for AZ31B Mg alloy which has poor formability at room temperature. This is caused by a lack of active slip systems, especially in the <c+a> direction. However, in this study a special isothermal ECAR die capable of operating without intermediate annealing was used to process AZ31B Mg alloy. The ECAR was carried out at 623 K using a die of ?115 ° channel angle and without rotation. Processing by ECAR showed less effect on the microstructure refinement where the grain size was reduced from 10?m to 4.2?m after six ECAR passes. ECAR increases the yield and ultimate stress and decreases the elongation corresponding to increasing the number of ECAR passes, the as - received material exhibits large amount of superplastic elongation compared to ECAR processed specimens. Therefore superplastic behavior of the AZ31B magnesium alloy was evaluated at temperatures 623 K and strain rate ranging from 7.8×10 - 4 s - 1? 1×10 - 2 s - 1. The test showed that maximum elongation of 367% can be achieved at 623 K and strain rate of 7.8×10 - 4 s - 1. The strain rate sensitivity (m) was evaluated by two different methods, uniaxial tensile test on the basis of the true stress true strain curve and by strain - rate jump test. The results show small differences between the two method) m = 0.42 - 0.45), which demonstrate that the grain boundary sliding (GBS) is the dominant deformation mechanism during superplastic test Keywords : Superplasticity. Severe plastic deformation. AZ31B magnesium alloy.

نظام ذكي لتقييم الخشونة السطحية لعملية تشكيل الصفائح التزايدية Intelligent Surface Roughness Evaluation System of Ismf Process

اسم المؤلف: اوس خالد ابراهيم
اسم المشرف: وسام كاظم حمدان
الموضوع العام: هندسة الانتاج والمعادن والمواد
السنة: 2014
الموضوع الدقيق: هندسة الانتاج
الدرجة: ماجستير
الجامعة: الجامعة التكنولوجية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: تعد عملية تشكيل الصفائح التزايدية تقنية حديثة نسبيا لتشكيل الصفائح المعدنية والتي توفر امكانية تصنيع اجزاء معقدة الشكل وذلك باستخدام مكائن التفريز المبرمجة (CNC milling machines) بدون الحاجة الى قوالب خاصة لكل منتج والتي تتطلب وقتا طويلا للتصنيع مقارنة مع | Incremental Sheet Metal Forming (ISMF) is a modern sheet metal forming technology which offers the possibility of manufacturing 3D complex parts of thin sheet metals using the CNC milling machine. The surface quality is a very important aspect in any manufacturing process. Therefore, this study focuses on the surface quality of parts produced by single point incremental forming (SPIF) process. As a consequence, the objective of this study is to control the surface roughness by studying five forming factors, namely; (tool diameter, step size, tool shape, rotational speed and slope angle).In order to evaluate the surface quality, practical experiments for forming pyramid like shapes have been carried out on sheets of aluminum AA1050 with thickness 0.9 mm. As a result, two Adaptive Neuro - Fuzzy Inference systems (ANFISs) are conducted for predicting the surface roughness. The first system depends on the five forming factors as a direct contact estimation method while the second system utilizes contactless parameters (average gray level, standard deviation and mean frequency) that are extracted from the products images using a vision system as a contactless prediction method. A third model is developed using Sugeno Fuzzy Inference System (SFIS) for the evaluation of forming factors by which the surface roughness for a certain slope angle is obtained.Both quantitative and qualitative assessments have been used to explore the effects of the five forming factors on surface quality of parts produced by SPIF process. The ANOVA and MEP results show that the incremental step size and the forming tool shape are the most important factors affecting the surface roughness. These two factors are directly and inversely proportional to the surface roughness respectively. The maximum and minimum surface roughness, which is achieved from all the 24 experiments is (Ra = 4.3 & Ra = 0.18 µm) respectively. As a result, a surface with roughness smaller than the initial roughness of the sheet (0.27 µm) has been obtained. The qualitative assessment reveals that the surface roughness tends to increase towards the part deep.It can be concluded that the image based estimation of roughness using ANFIS is superior in terms of prediction accuracy. This vision system can achieve (97.856%) testing prediction accuracy compared to (85.799%) that is reached by the direct contact estimation of roughness. Conclusions also show that the vision system is capable of predicting the surface roughness of a hyperboloid part as a non - linear shape with prediction deviation (14.411%), thus enabling to evaluate the surface quality of complex parts that cannot be measured by the stylus. It can also be concluded that the SFIS is a successful approach for estimating the forming factors by which the surface roughness for a particular slope angle is obtained.

متغيرات اللحام المثلى بالقوس الكهربائي المغمور باستخدام طريقة تاكوشي Optimizing of Submerged Arc Welding Parameters Using Taguchi Method

اسم المؤلف: هشام جواد كاظم
اسم المشرف: احمد علي اكبر اكبر
الموضوع العام: هندسة الانتاج والمعادن والمواد
السنة: 2014
الموضوع الدقيق: هندسة المعادن
الدرجة: ماجستير
الجامعة: الجامعة التكنولوجية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: اللحام بالقوس الكهربائي المغمور غالبا مايستخدم في الصناعات الثقيلة. يستخدم في هذا النوع من اللحام سلك لحام مستمر يكون معدنن الملئ. االقوس يكون مغمور في مساعد الصهر والذي يتم تغذيته من خلال انبوب في حاوية اعلى سلك اللحام الذي يغذى باستمرار. مساعد الصهر يع | Submerged arc welding (SAW) is often used for heavy industries. The SAW process employs a continuous bare wire electrode that is consumed to produce filler, the arc is submerged in the flux, and the flux is supplied through a funnel located ahead of the filler wire which is fed continuously from a hopper, the flux contributes to deoxidize the base metal, and protect the molten weld metal from atmospheric contaminants In order to achieve best weld quality and good mechanical properties in manufacturing industries which need to be optimized. Selection of appropriate SAW parameters is essential to ensure a predictable weld bead which is important for obtaining high quality welding.Manufacturing industries and training centers often face the problem of selecting appropriate or optimum combinations of input welding parameters for achieving the required weld quality. Three input parameters of SAW were used to weld the steel plates, and four levels for each parameter, and three output response variables were used The experimental work consists of welding of sixteen low carbon steel plates of (AISI 1005) specimen measured 300 mm × 50 mm × 12 mm were submerged arc welded using welding currents (280, 340, 400, 460) amp, voltage (26, 29, 32, 35) volt and welding speeds (3.3, 5, 6.6, 8.3) mm/s This work details the application of Taguchi design to determine the optimal SAW parameters. An effort has been made to study the effect of SAW process parameters (current I, voltage V, speed S) on the bead geometry dimensions (depth of penetration P, bead width W, heat affected zone width w).Signal to noise ratios are computed to determine the optimum parameters. Statistical models have been developed based on multiply regression analysis relating the bead geometry with process parameters. The adequacy and significance of the models were checked by using ANOVA technique, also the models are validated using normal probability plot, and residual versus fit plots.The models were employed easily in form of executed program designed by using Visual Basic 6 software. The objective of such models and designed program is to predict weld bead geometry which enables selecting the desired weld parameters and select the weld bead dimensions. The effect of SAW parameters on heat affected zone and weld metal hardness also has been studied by means of hardness measurements, and grain size measurement using intercept method. Main and interaction effects of the process parameters on bead geometry are presented graphically. The experimental results were analyzed by using Minitab 16 software.It was found that current (280 to 460) amp causes increase in depth of penetration from (1.742 to 3.752) mm and HAZ width (1.222 to 1.512) mm. Bead width increases from (10.99 to 13.13) mm with increase in voltage from (26 to 35) volt and decreases from (12.61 - 11.80) mm with increase in welding speed from (3.3 to 8.3) mm/s. The welding speed and voltage do not affect appreciably the depth of penetration. Also change in weld speed reduces the width of the HAZ from (1.462 to 1.295) mm. The hardness of HAZ reaches maximum value 122.39 HV at the center of HAZ and decreases gradually toward the BM 109.22 HV; also it was found that the executed program is a useful tool used to predict weld bead geometry dimensions from welding parameters for SAW process.

التفريز المبرمج باستخدام ملفات STL Cnc Milling Using Stl Files

اسم المؤلف: نادية سامي حسن
اسم المشرف: ليث عبد الله محمد
الموضوع العام: هندسة الانتاج والمعادن والمواد
السنة: 2014
الموضوع الدقيق: هندسة الانتاج
الدرجة: ماجستير
الجامعة: الجامعة التكنولوجية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: تعد ملفات (STL) من الملفات المهمة في برامج الرسم والتصميم المعان بالحاسوب (CAD) والشائعة الاستخدام حاليا في النمذجة السريعة وانظمة التصنيع المعان بالحاسوب (CAM). يتناول هذا البحث اقتراح وتطوير خوارزميات لقراءة ملفات (STL) واستخلاص السمات الهندسية اللازم | Stereolithography (STL) files are considered very important files in both computer aided drawing and design (CAD) programs and are commonly used now days in both rapid prototyping and computer aided manufacturing (CAM) systems.This thesis proposes and develops algorithms to read (STL) files and extract engineering entities required in CNC milling processes. The proposed algorithms are dependent on some mathematical modeling and manipulations of the engineering model by slicing an (STL) file to many slices and then building the required algorithms to adopt these slices to generate CNC machining paths as G - Code.The proposed system in this work is divided to three parts, in the first part of this thesis an algorithm is proposed to extract engineering object entities to some proposed models based on their (STL) files using Matlab program. The proposed models include cube, cylinder, dome, cone and cavity models. In the second part of this thesis, a slicing algorithm is proposed to enable the slices along the proposed models z - axis to find and navigate the required manufacturing data. UGS CAM program was used also to generate the tool paths and to simulate the machining process and then generate NC part program of the proposed objects (G - Code). The machining process was achieved using 3 - axis CNC milling machine, at spindle speed of (700 rpm) and feed rate (60 mm/min).Finally, the third part of this thesis includes comparing results produced based on both (STL) and (UGS), to achieve the required aim by experimentally comparing both objects surface roughness and evaluate their geometrical variations.According to the experimental results, the objects produced using STL models are clearly have rough surfaces compared with the surfaces produced by UGS with average percentage of 13µm, and according to the geometrical variations experiments, CAD readings are in good agreement with experimental results and confirm the validity of the proposed approach with 4.5mm of shape error.

دراسة مقارنة بين T - spline وNURBS في النمذجة والتشغيل باستخدام ماكنة التفريز المبرمجة Comparison Study of T - Spline And NURBS In Modeling And Machining Using CNC Milling Machine

اسم المؤلف: مهند مصدق جعفر
اسم المشرف: ليث عبد الله محمد
الموضوع العام: هندسة الانتاج والمعادن والمواد
السنة: 2014
الموضوع الدقيق: هندسة الانتاج
الدرجة: ماجستير
الجامعة: الجامعة التكنولوجية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: نمذجة السطوح باستخدام تقنية الـ (T - spline ) تعد من اهم الوسائل المتسخدمة الان في التصميم المعان بالحاسوب (CAD).يهدف البحث الى زيادة الانتاجية من المنتجات المعقدة من خلال تعزيز عملية النمذجة السطحية للمنتج وتعزيز التصنيع باستخدام T - SPLINE للنمذجة السط | Surface modeling utilizing T - spline technique is one of the most important tool now in computer aided design (CAD).ThisThesisaims to increase the productivity of complicated products through enhancing the process of product surface modeling and manufacturing by using T - spline for surface modeling. This method provides the designer with many powerful tools to add details only where necessary on the CAD modeling, create non - rectangular topology of the surface, easily edit complex freeform models, and besides maintaining NURBS (non - uniform rational B - splines) compatibility of the model.ThisThesisuses T - spline for surface modeling and compare it with NURBS modeling to get the best modeling points between the two methods. The comparison will be through surface analysis and manufacturing process.ThisThesisincludes design of two types of models : convex model (bicycle seat) and concave model (longitudinal section of the bottle) for each T - spline surface and NURBS surface using Rhinoceros 5.0 software which has been transformed to UG - NX8.5 software to get the machining process simulation and G - code programs for the models. The models have been machined using 3 - axis vertical CNC machine (C - tek) type.Finally, analysis of surfaces (Environment Map analysis, Zebra analysis, Naked Edges analysis, Gaussian Curvature analysis, data structure analysis, Draft Angle analysis) by Rhinoceros 5.0 software and measurement of the roughness by Pocket Surf equipment and measurement runtime for machining by timer, shows that the T - Splines surfaces typically have (50 - 70%) less geometric data structure [ surfaces , 3d curve , 2d curves , vertices , edges , trims , loops , faces ] than the equivalent NURBS surface, inEnvironment Map analysis, the image of T - Spline surface for the models is reflected moreclearly than a NURBS surface, in Naked Edges analysis, the T - Spline surface for the models has a number of naked edge less than the NURBS surface, in measurement runtime for machining (roughing and finishing), the T - spline surface for the bicycle seat model is machined in (16 minutes) less than machining the NURBS surface, and the T - Spline surface for the longitudinal section of the bottle model is machined in (10 minutes) less than machining the NURBS surface. In measurement of roughness, the T - Spline surface for the bicycle seat model has (2.4861 µm) average (Ra) for patches measured roughness average (Ra), and the NURBS surface has (4.9216 µm) average (Ra) for patches measured roughness average (Ra).

تحليل مسار العدة في عملية التشكيل التزايدية للصفائح المعدنية Analysis of Tool Path In Incremental Sheet Metal Forming Process

اسم المؤلف: ميثم سعد علي
اسم المشرف: وسام كاظم حمدان
الموضوع العام: هندسة الانتاج والمعادن والمواد
السنة: 2014
الموضوع الدقيق: هندسة الانتاج
الدرجة: ماجستير
الجامعة: الجامعة التكنولوجية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: التشكيل التزايدي للصفائح المعدنية هو عملية مرنة للغاية ومتعددة الاستعمالات للتصنيع السريع لاجزاء الصفائح المعدنيه المعقدة حيث تمتلك امكانية التكيف بامتياز مع انظمة التحكم الرقمي بالحاسوب (مكائن التفريز المبرمج CNC) من خلال السيطرة المباشرة على بيانات CAD | Incremental sheet forming (ISMF) is a highly versatile and flexible process for rapid manufacturing of complex sheet metal parts. It has excellent adaptability to computer numerical control (CNC) systems through direct control of CAD data, minimizing the use of specialized tooling and presses. A sheet of metal is formed by a progression of localized plastic deformation using simple forming tool controlled by a CNC machine - tool. The aim of the presented thesis is to investigate the feasibility of incrementally forming of 3D complex shape (like automotive heat shield shape) and the solar cooker shape by Single Point Incremental Forming process without using a dedicated die depending on different tool paths. Six different forming tool paths (unidirectional ZLVTP, bidirectional ZLVTP, FPRTP, ZGZTP, BSLTP and HSLTP) were generated byUnigraphics - NX8 (UGS - NX8) programing system and applied to realize solar cooker shape and automotive heat shield shape. The feasibility investigation and development of automotive heat shield shape is based on three control factors are tool path type, forming tool head shape and the Z - increment (vertical pitch). For each of these factors, levels were tested. The tool head shape and vertical pitch contain their both on two levels while the tool path type on six levels. Hence, 24 experiments applied to realize automotive heat shield shape based on a full factorial design of experiments, and 6 experiments applied to realize solar cooker shape. Hybrid tool paths are tested to explore the applicability these paths in ISMF process. This thesis discussed the impact of tool paths types and other control factors (tool shape and vertical pitch) on the three different quality characteristic namely geometrical accuracy, thickness variation and forming time. The significant of the control factors are explored using two statistical methods are analysis of variance ANOVA and main effect plot. All experiments were carried out on sheets of Aluminum Alloy (AL1070) with thickness 1.5 mm by using 3axis CNC machine. The CNC machine and dial gauge are used to measure dimensional accuracy and final thickness of formed parts respectively. Depending on the results of this work, Helical - Streamline tool path (HSLTP) and follow periphery tool path (FPRTP) are achieved higher geometrical accuracy when forming the solar cooker shape and the automotive heat shield shape respectively. On the other hand, Z Level profile tool path (ZLVTP) is the best tool path to achieve homogeneous thickness distribution and minimum forming time of formed parts. Hybrid tool paths are undesirable in incremental sheet metal forming. The ANOVA results show that all control factors have influence on the accuracy, especially the tool path type. The tool shape and vertical pitch have no influence on the thickness of the formed parts. But, the vertical pitch has major effects on the forming time and accuracy. In contrast, the tool path shape has a great influence on the process implementation.

التحقيق التجريبي والعددي للصفائح الرقيقة المثقوبة تحت الشد Experimental And Numerical Investigations of Thin Tensioned Plates With Holes

اسم المؤلف: ارشد عبد الله راشد
اسم المشرف: كريم محسن يونس
الموضوع العام: هندسة الانتاج والمعادن والمواد
السنة: 2014
الموضوع الدقيق: هندسة الانتاج
الدرجة: ماجستير
الجامعة: الجامعة التكنولوجية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: ان الصفائح المثقوبة تستخدم عالميا في تصنيع الھياكل في التطبيقات الميكانيكية والانشاءات كمثال على ذلك ھياكل الطائرات والتراكيب الطبية ووصلات الربط الخ. ومن المعروف جيدا ان استعمال الثقوب في الھياكل المجھدة تولد اجھادا موقعيا عاليا في منطقة من الثقب تعرف بم | The plates with holes are used in cosmopolitan for manufacturing structures in mechanical and civil engineering applications like aircrafts, medical structures, joint connection applications etc. It is well known that utilizing holes in stressed structures produces highly localized stresses at area of the holes known as the stress concentration area,which leads to reduce the mechanical strength of the structures.The main objective of this study is to investigate the effect of three parameters on the stress concentration factor in plate with two holes having different size holes and subjected to uniaxial tension. The three parameters include firstly, the location of holes when oriented with respect to axis of loading, parallel, transverse and inclined with line of uniaxial tension load at different angles. Secondly, the aspect ratio for the hole size (large to small radius).The last parameter effect is the distance between two holes.Numerical simulation using finite element method for two - dimensional model is developed to determine the maximum value of Von Mises stress with commercial software package ANSYS V.11.The experimental photoelastic technique is carried out on fabricated polycarbonate model loaded in one direction. From the analysis of the results, it is found that the maximum stress concentration factor is at the point tangent to the edge of the hole. The comparison between the finite element method and experimental photoelastic technique results showed the stress concentration factor, which obtained experimentally and with finite element method are congruent, since the maximum variation between the two results is about 7.03% As well as the highest and lowest value of the stress concentration factor equal to 3.1973, 2.0640 at value of angle 60°, 90° respectively.It is recommended from the above conclusions that manipulating the three parameters which effect the stress concentration factor are namely, holes position, size, and distance between two holes on the plate that used in the application will play essential role to reduce the value of stress concentration factor which subsequently crucially minimize or avoid fast failure. This can be translated into saving precious lives preventing money wastage due to structures damage ending into catastrophe.

فحص بلى عدة القطع المعان بالرؤيا الحاسوبية خلال عملية الخراطة Computer Vision Aided Inspection of Cutting Tool Wear In Turning

اسم المؤلف: علي كريم علوان العكيلي
اسم المشرف: علي عبار خليف
الموضوع العام: هندسة الانتاج والمعادن والمواد
السنة: 2014
الموضوع الدقيق: هندسة الانتاج
الدرجة: ماجستير
الجامعة: الجامعة التكنولوجية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: في الوقت الحاضر , تحظى مكائن القطع المبرمجة باھمية كبيرة في المعامل والورش التصنيعية بسبب دقتھا العالية ومرونتھا لكن لسوء الحظ لا تزال ھذه المكائن غير قادرة على التاكد من جودة السطوح المنتجة. الاتجاه نحو اتمتة عمليات القطع سير للحاجة الملحة للحصول على ج | Nowadays, computerized numerically controlled (CNC) machines have high importance in manufacturing factories and workshops due to their high accuracy and flexibility. Unfortunately they still cannot ensure the quality of machined products. The trend towards automation in machining has been driven by the need to maintain high product quality with improving production rate, these improvements can be possible by monitoring and control of machining process. In this research a vision based monitoringsystem was introduced for the on - line direct automated measurement of the cutting tool flank wear width based on a new algorithm on the basis of canny edge detection and morphological operations for the captured images.Twelve specimens were prepared using STARCHIP CNC turning with four cutting speeds (57,98,110 and 125 m/min) and three depths of cut (0.5,1 and 2 mm) and constant feed of (0.04 mm/rev). Maximum and minimum absolute error and error percentage in the maximum flank wear width was (0.058,0.002 mm) (9.7,0.54 %) respectively. The results show the effectiveness of the proposed method in the monitoring of the tool condition.Also, Vision based monitoring system was proposed for the measurement of tool nose wear which have direct interaction with the workpiece during machining. Measurement operation is done by comparing reference and worn tool images; the algorithm is composed of image preprocessing, Otsu thresholding, conforming method for the exact alignment between the two images and image subtraction is performed in order to detect the nose wear area. Morphological opening by reconstruction was used to remove isolated foreground pixels result in due to the quantization errors. The maximum and minimum error percentage in tool nose wear area (6.72,0.48 %) respectively; the experimental results show that nose wear occurs after the flank wear exceeded its maximum standard limit in roughing operations Keywords : tool wear, flank wear, nose wear image processing, automated visual inspection, tool condition monitoring.

دراسة سلوك البلى الانزلاقي الجاف لسبائك المنيوم - 7% سليكون عمليا وباستخدام تقنية تصميم التجارب Studying Dry Sliding Wear Behavior of Al - 7% Si Alloys Using Experimental And DOE Techniques

اسم المؤلف: قاسم سعد عبد الواحد
اسم المشرف: عقيل ظاهر صبحي علي عبار خليف
الموضوع العام: هندسة الانتاج والمعادن والمواد
السنة: 2014
الموضوع الدقيق: هندسة المعادن
الدرجة: ماجستير
الجامعة: الجامعة التكنولوجية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: تعد سبائك الالمنيوم - سليكون والتي تحتوي على التيتانيوم احدى المواد التي تتميز بمقاومتها للبلى كما بينت الدراسات والابحاث العلمية ذلك.في هذا البحث تم صب سبيكة المنيوم - 7% سليكون وبنسب مختلفة من التيتانيوم (0.5 , 1 , 1.5%) وتحت معدلات تبريد مختلفة في قال | Aluminum - silicon alloys that contain Titanium can be considered one of the wear resistant materials and attract several researchers recently.In this work ,Al - 7%Si alloy with different percentages of Ti ( 0.5 , 1 , 1.5% ) was poured under different solidification conditions into the metal mould.All prepared alloys were dry slided under different bearing pressures ( 5 , 10 , 15 , 20 , 25 N ) on the steel counterface surface using pin on disk wear apparatus. Optical microscope and scanning electron microscope (SEM) were used to study the microstructure and determine wear mechanism of Al - Si alloys respectively. On the other hand , X - ray diffraction technique (XRD) was used to determine the phases that were present in the matrix of Al - Si alloys.Microstructural analysis and X - ray diffraction showed that two phases are presented in the matrix of Al - 7%Si alloys.These phases are ? - aluminum and eutectic and three phases are present in the matrix of Al - Si alloys that contains Ti. These phases are ? - aluminum ,eutectic and titanium aluminide Ti9Al23.Significant refinement occurred for ? - aluminum, eutectic and titanium aluminide Ti9Al23 phases when using metallic mould cooled with cold water in comparison with heated and unheated metallic moulds Hardness was increased with increasing Ti percentage and with increasing the severity of solidification condition used.Remarkable changes in the wear rate occurred for Al - Si alloys during dry sliding in which the magnitude of wear rate was dependent on the Ti percentage ,load and solidification condition used.Design of experiment (DOE) was used to optimize the effect of process variables ( load and Ti percentage) on the wear rate under different solidification conditions using computational statistical software (Mintab 16).

تاثير التشكيل على البنية المجهرية وسلوك البلى للمواد المعدنية المتراكبة النانوية Al2O3 / A356 The Role of Forming On Microstructure And Wear Behavior of Metal Nano Composite Al2O3 / A356

اسم المؤلف: مروان باسل حسين
اسم المشرف: نوال عزت عبد اللطيف عقيل ظاهر صبحي
الموضوع العام: هندسة الانتاج والمعادن والمواد
السنة: 2014
الموضوع الدقيق: هندسة المعادن
الدرجة: ماجستير
الجامعة: الجامعة التكنولوجية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: في هذا البحث تم تحضير المواد المركبة النانوية اساس معدني (A356/Al2O3) باستخدام تقنية (rheocasting) ومن ثم تم اجراء عملية التشويه على الساخن عند درجة حرارة °250 م.في البداية تم صهر السبيكة A356 في درجة حرارة °730 م بعدها تم تبريدها الى درجة حرارة الشبه ص | In the present work Al2O3/A356 nano composites have been prepared using rheocasting technique, the nano composites were then processed using hot deformation at 250 °C.Firstly A356 matrix alloy was melted at about 730 °C, the superheated molten alloy was allowed to cool to the semi - solid temperature at 600 °C, then Al2O3 nano - particles with different size (10,20) nm and different weight percentages (1 and 2)%wt were added inside the vortex formed due to stirring , hot deformation carried out with different ratio 30% and 40% at the temperatures of 250 °C and strain rates 0.1 s?1. The produced nano composites samples were characterized using optical and scanning electron microscopy ,X - ray diffraction , hardness test and wear test using pin on disc apparatus. The results of microstructural observations showed that the Al2O3 nano particles cluster mostly near the grain boundaries and form a band surrounding the grain boundaries. The dendritic structure of ? - Al phase is fragmented and the ? grains became more uniform and smaller than their corresponding as - cast 356 alloy. On other hand the microstructures of nano - Al2O3/A356 composites after casting and hot deformation at 250°C, showed modification of ? - Al and Si eutectic. The columnar dendrites ? - Al phase changed to the nearly equiaxed grains or globular morphology. The results of hardness test showed that the nano Al2O3/A356 composite were exhibited higher hardness than the as - cast A356 alloy The nano - composites hardness, increase with increases the size and increases in weight percentage of the Al2O3 nano - particles, and with increasing percentage deformation. The result of wear test showed that the hot deformed nano Al2O3 /A356 composites have greater wear resistance compared with hot deformed A356 alloy. Furthermore, with increasing the particle size and the percentage of Al2O3 nano particles, wear rate will decrease. The results also revealed that the optimal results was achieved at the nano - composites containing 20nm Al2O3 particles after hot deformation with 40%. SEM studies of the worn surface of nano composites showed that the main wear mechanism was oxidative in conjunction with metallic wear.

كلال الدورات المنخفضة في سبيكة المنيوم قابلة للتصليد بالترسيب Low Cycle Fatigue of Precipitation Hardened Aluminum Alloy

اسم المؤلف: سيف خالد محمود
اسم المشرف: ظافر صادق الفتال
الموضوع العام: هندسة الميكانيك
السنة: 2014
الموضوع الدقيق: ميكانيك تطبيقي
الدرجة: ماجستير
الجامعة: الجامعة التكنولوجية - قسم الهندسة الميكانيكية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: لسبائك الالمنيوم عالية المقاومة طيف واسع من التطبيقات من صناعة السيا ا رت الى الصناعات الفضائية.ان السبب الرئيسي وراء النمو السريع للطلب على هذة السبائك هو مزيج من الخواص الفريدة التي جعلت منها واحدة من اكثر الت ا ركيب والمواد الهندسية استعمالا، ولذلك ل | High strength AL - alloys have a wide spectrum of applications from automobile to aerospace industries. The demand for these aluminum alloys grows rapidly because of the unique combination of properties which make them the most versatile of engineering and construction materials. Hence, development of high strength Al - alloys continues to be an important area of research.In this work, the influence of different heat treatments on the mechanical properties and fatigue life under low cycles of wrought 7075 aluminum alloy was experimentally investigated. The heat treatments included peak ageing (T6), over ageing (T73) and annealing (O).The effect of heat treatments on the alloy was explained in terms of their influence on the mechanical properties. The results showed that T73 temper has an ultimate strength of 504.7 MPa and elongation of 12.5%. Peak ageing treatment enhanced the strength by 10.9% and reduced the elongation by 7.2%, while in the annealed condition, the strength was reduced and the elongation was improved by 51.33% and 31.2%, respectively. T6 had the highest hardness followed by T73 and O tempers.The flat fatigue specimens were subjected to constant reverse bending load. The tests were performed at the laboratory environment with a frequency of 23.3 Hz and at a stress ratio (R) of - 1. For each temper, strain - life graphs were obtained for specimens with notches in the form of central cylindrical holes made by drilling. The fatigue resistance of specimens with notches was compared to the results for notch - free specimens. It was observed that the presence of a stress raiser, such as a drilled hole, lowers the fatigue life for all tempers. However, the notch sensitivity of the fatigue life was different for each temper.The fatigue crack growth rate of T73 and annealed temper was investigated, the results showed that T73 treated sample exhibits higher crack growth resistance. Paris` equation was derived for each temper Keywords : LCF. precipitation hardening. 7075 aluminum alloy. fatigue crack growth.

التقنية المثلى الحرارية لاعادة تشكيل القرنية اثناء الجراحة الليزرية Thermal Optimization Technique For Corneal Reshaping During Laser Surgery

اسم المؤلف: نبراس حسين عائب
اسم المشرف: خالد احمد الجودي سومر متي ناسي
الموضوع العام: هندسة الميكانيك
السنة: 2014
الموضوع الدقيق: ديناميك موائع
الدرجة: دكتوراه
الجامعة: جامعة بغداد
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: جرى التحقق من التغيير في شكل القرنية حراريا بمساعدة منظومة ليزر لتعويض الاخطاء الانكسارية. شملت الدراسة صياغة نموذج رياضي للمسالة ببعد واحد مع تجارب عملية باستخدام المزدوجات الحرارية والكاميرا الحرارية. كانت درجة الحرارة القصوى المحسوبة من النموذج الرياض | A change in corneal shape assisted by laser system to compensate the refractive errors is investigated thermally. The investigation included a mathematical one dimensional model and experimental work using thermocouples and infrared camera. The maximum th

تحسين اداء التبريد الغشائي لثقوب النفث باستخدام المنحدرات Enhancement of Film Cooling Performance By Using Ramped - Holes Injection

اسم المؤلف: فلاح فاخر حاتم الجابري
اسم المشرف: عاصم حميد يوسف الدراجي قتيبة جميل مهدي الخشالي
الموضوع العام: هندسة الميكانيك
السنة: 2014
الموضوع الدقيق: هندسة الميكانيك
الدرجة: دكتوراه
الجامعة: الجامعة التكنولوجية - قسم الهندسة الميكانيكية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: The effect of introducing ramps with cylindrical and conical holes on the film cooling performance has been investigated numerically and experimentally in the present study. A computational fluid dynamic code (FLUENT) has been used to predict the flow beh

تحليل الانبعاج الاهتزاز لصفائح مركبة طبقية Buckling And Vibration Analysis of Laminated Composite Plates

اسم المؤلف: فراس حميزة تايه
اسم المشرف: Widad I. Majeed
الموضوع العام: هندسة الميكانيك
السنة: 2014
الموضوع الدقيق: هندسة الميكانيك
الدرجة: ماجستير
الجامعة: جامعة بغداد
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: تمت دراسة الاهتزاز الحر والانبعاج للصفائح الرقيقة المركبة المكونة من طبقات المعرضة لاحمال منتظمة, منحنية, وخطية ضمن مستوي الصفيحة باستخدام نظرية الصفائح الطبقية الكلاسيكية (CLPT). ان موضوع هذا العمل هو دراسة صفائح مركبة تحت تاثير احمال انبعاج وايجاد الترد | Free vibration and buckling behavior of laminated composite thin plates subjected to in - plane uniform, parabolic, and linear distributed loads is studied using classical laminated plate theory (CLPT). The object of this work is to carry out a theoretica

تقييم الاداء لمبادل حراري مباشر ثلاثي الاطوار Performance Evaluation of Three Phase Spray Direct Contact Heat Exchanger

اسم المؤلف: فاطمة احمد عبد الخالق
اسم المشرف: Najim A. Jassim
الموضوع العام: هندسة الميكانيك
السنة: 2014
الموضوع الدقيق: هندسة الميكانيك
الدرجة: ماجستير
الجامعة: جامعة بغداد
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: يتناول البحث الحالي دراسة عملية لمبادل حراري مباشر ثلاثي الطور، لنظام (ماء - R11). حيث ان الماء هو الطور المستمر (السائل) وR11 (الغاز - السائل) هو الطور المتشتت. يتكون مقطع الاختبار من عمود اسطواني من الزجاج نوع (Perspex) بقطر داخلي 8 سم وطول 1?2 متر.، ال | The present investigation dealt with experimental study of three - phase direct - contact heat exchanger, for water - R11 system. Whereas water was the continuous phase (liquid) and R11 (liquid - gas) was the dispersed phase. The test section consisted of

تقليل الاعاقة للجريان المضطرب الاحادي والثنائي الطور في الانابيب باستخدام بوليمر نوع CMC Drag Reduction In Single And Two - Phase Turbulent Pipe Flow Using CMC Polymer

اسم المؤلف: عصام مجبل عبد
اسم المشرف: Sabah T. Ahmed
الموضوع العام: هندسة الميكانيك
السنة: 2007
الموضوع الدقيق: قوى حرارية
الدرجة: دكتوراه
الجامعة: الجامعة التكنولوجية - قسم الهندسة الميكانيكية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: ان تقليل الاعاقة ظاهرة فيزيائية تتضح بشكل واضح خلال الجريان المضطرب عند اضافة بوليمر للجريان ذات سلسلة طويلة. ان خاصية السلسلة الطويلة للبوليمر لها فائدة في تكسير الطبقة المتاخمة المتكونة عند سطح الانبوب خلال عملية الجريان. يمكن ان يقسم الجريان الى نوعين | Drag reduction is a physical phenomenon appears through turbulent flow due to polymer additive. The long chain of polymer destroyed the sublayer which normally growing through single and two - phase flows. The flow is divided into Newtonian flow (zero con

تحليل الانبعاج عمليا ونظريا لصفائح رقيقة مركبة طباقيا ذات شق Experimental And Theoretical Buckling Analysis of Cracked Laminated Composite Thin Plates

اسم المؤلف: عزيز درويش مجيد المواش
اسم المشرف: عدنان ناجي جميل
الموضوع العام: هندسة الميكانيك
السنة: 2014
الموضوع الدقيق: هندسة الميكانيك
الدرجة: ماجستير
الجامعة: جامعة بغداد
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: هذا البحث ركز بصورة رئيسية على سلوك الانبعاج للصفائح الرقيقة المركبة طباقيا ذات شق (شق طرفي اوداخلي) والمسلطة عليها احمال ستاتيكية. الاحمال الستاتيكية درست تحليليا وعمليا للصفائح الرقيقة المركبة طباقيا غير متشققة. كذلك درست عدديا وعمليا للصفائح الرق | This present work focused mainly on the buckling behavior of cracked laminated composite thin plates (edge or internal crack) subjected to static loads. The static loads have been studied analytical and experimental analysis for uncracked laminated compos

الخصائص الميكانيكية والبنية المجهرية على امتداد المقطع السميك في سبائك الالمنيوم T6 - 7075 الملحومة بالاحتكاك والمزج Mechanical And Microstructural Properties Along The Thick Section of Friction Stir Welded 7075 - T6 Aluminum Alloy

اسم المؤلف: دينا عبد الجليل رؤوف
اسم المشرف: قاسم محمد دوس
الموضوع العام: هندسة الميكانيك
السنة: 2014
الموضوع الدقيق: التصنيع
الدرجة: ماجستير
الجامعة: جامعة بغداد
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: ان الهدف من هذه الدراسة هو التحقق من امكانية تطبيق لحام الاحتكاك 7075 - ( بسمك ) 25 T بالخلط في وصل سبيكة الالومنيوم ذات المقاومة العالية ) 6 (Single باخرى مماثلة. طبقت العملية بطريقتي اللحام ذو التمريرة المفردة )mm باستخدام ماكنة )Double sided weld( والل | The present work investigates the feasibility of friction stir buttweld of a (25 mm) thickness of the high strength aluminum alloy 7075 - T6. Welds were made in single and double sided by using a conventional milling machine and special profiled tools. Su

تاثير الاهتزاز المسلط على انتقال الحرارة بالحمل الحراري الحر في داخل غرفة مكعبة الشكل Natural Convection Heat Transfer In An Enclosed Vibration Cavity

اسم المؤلف: بيداء خليل خضير
اسم المشرف: عادل محمود صالح قيس عبد الامير الطائي
الموضوع العام: هندسة الميكانيك
السنة: 2014
الموضوع الدقيق: التبريد والتكييف
الدرجة: ماجستير
الجامعة: الجامعة التكنولوجية - قسم الهندسة الميكانيكية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: يقدم هذا البحث دراسة نظرية وعملية لانتقال الحرارة بالحمل الحراري المضطرب لاستقصاء تاثير الاهتزاز المكانيكي الخارجي المسلط على حيز مغلق مكعب الشكل (mm 120* mm 120* mm 120) وفي ظروف الجاذبية الارضية. النسبة باعية (نسبة ارتفاع الحيز الى طوله) تساوي واحد, يست | The theoretical and experimental study has been implemented to elucidate the effect of vertical mechanical vibration at normal gravity on the natural convection in a cubic enclosure (L=120mm) filled with air as working fluid at Rayleigh number 7*?10?^7and

تحليل نموذج للكشف عن التبطين في لوحات الصفائح المركبة Modal Analysis For Delamination Detection In Composite Laminated Plates

اسم المؤلف: باسم جميل حمود
اسم المشرف: نبيل حسن هادي
الموضوع العام: هندسة الميكانيك
السنة: 2014
الموضوع الدقيق: هندسة الميكانيك
الدرجة: ماجستير
الجامعة: جامعة بغداد
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: كشف وتحديد الضرر في الهياكل جزء مهم في مراقبه وتصليح الانظمة الهيكلية اثناء الخدمة، مما اجتذب اهتمامنا نحو دراسه نمذجه وتحليل الاهتزازات للصفائح الهيكلية المتضررة.العيوب التصنيعية تسبب تغير بالخصائص الديناميكية للهياكل والتي تشمل التغير في تردداتها الطبي | Detection and determination of damage in the structures is considered as an important part in watching and repairing of structural systems during the service. The manufacturing defects cause changes in the dynamic characteristics of the structures includi

دراسة سلوك الكلال تحت احمال ثنائية المحور لمادة بوليميرية مدعمة بالالياف عمليا وباستخدام الطرق العددية Investigation of Biaxial Fatigue Behavior of Fiber Reinforced Plastic Using Experimental And Numerical Techniques

اسم المؤلف: ياسر يعرب قحطان
اسم المشرف: محسن جبر جويج شاكر سكران حسن
الموضوع العام: هندسة الميكانيك
السنة: 2014
الموضوع الدقيق: هندسة الميكانيك
الدرجة: دكتوراه
الجامعة: الجامعة التكنولوجية - قسم الهندسة الميكانيكية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: ان البحث الحالي درس عدديا وعمليا تصرف المواد المصنوعة من الياف الكاربون والالياف الزجاجية المدمجة بواسطة المادة الرابطة البوليميرية (ايبوكسي) اثناء الاحمال التكرارية (الكلال) الثنائية المحور (Biaxial) بواسطة تسليط حمل من نوع شد - شد. هذا العمل احتوى على | The present work studied numerically and experimentally the fatigue behavior of carbon fiber reinforced polymer (CFRP) and glass fiber reinforced polymer (GFRP) with different numbers of layers under a biaxial loading of tension - tension. This work inclu

دراسة عددية وتجريبية لاداء توربين - المدخنة الشمسية Numerical And Experimental Study of Turbine - Solar Chimney Performance

اسم المؤلف: عباس جاسم جبير
اسم المشرف: اركان خلخال حسين الطائي وحيد شاتي محمد
الموضوع العام: هندسة الميكانيك
السنة: 2014
الموضوع الدقيق: قوى حرارية
الدرجة: دكتوراه
الجامعة: الجامعة التكنولوجية - قسم الهندسة الميكانيكية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: تم في هذه الدراسة اجراء محاكاة عددية وتقييم اداء محطة المدخنة الشمسية التجريبية في مدينة بغداد. تم نمذجة المحطة باستخدام برنامج Fluent والذي يعمل على اساس العناصر المحددة, وذلك لحل المعادلات الحاكمة (الاستمرارية, Naver - Stockes, الطاقة والاشعاع ) من خلال | Numerical simulation and performance evaluation for pilot plant solar chimney oriented in Baghdad city have been carried out in this work. A finite volume modeling technique is used to cast the governing equations [i.e.,continuity, Naver - stockes, energy

تحسين المواصفات الميكانيكية لسبيكة (Cu - Zn - Al) القادرة على استعادة شكلها بعد التشوه Enhancing The Mechanical Properties of Cu - Zn - Al Shape Memory Alloy

اسم المؤلف: صلاح نوري عبود النعماني
اسم المشرف: ظافر الفتال عبد الواحد راجح
الموضوع العام: هندسة الميكانيك
السنة: 2014
الموضوع الدقيق: هندسة الميكانيك
الدرجة: دكتوراه
الجامعة: الجامعة التكنولوجية - قسم الهندسة الميكانيكية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: ان زيادة الطلب على تطوير بعض المواد لاستخدامها في صناعات الفضاء والصناعات الطبية العسكرية، تتطلب دراسات واسعة النطاق لتعزيز مثل هذه المواد وخاصة السبائك الذكية القادرة على استعادة شكلها. وتلقى سبائك النحاس الذكية اهتماما واسعا نظرا للتطبيقات الهامة وانخفا | The increased demand for the development of certain materials to be used in aerospace, military and medical industries justifies the execution of an extensive investigation to enhance the properties of such materials, especially the shape memory alloys (S

خصائص سبيكة الالمنيوم - سليكون مقواة بدقائق سيراميكية Characteristic Analysis of An Aluminum - Silicon Base Alloy With Nano Particulate Ceramic Reinforcement

اسم المؤلف: رونق احمد محمد
اسم المشرف: ابتهال عبد الرزاق محمود عدنان داود محمد
الموضوع العام: هندسة الميكانيك
السنة: 2014
الموضوع الدقيق: هندسة الميكانيك
الدرجة: دكتوراه
الجامعة: الجامعة التكنولوجية - قسم الهندسة الميكانيكية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: تستخدم سبائك الالمنيوم المتراكبة بدقائق الالومينا سواء كانت مايكروية او نانوية في نطاق واسع في تطبيقات عالية الاداء كالسيارات العسكرية والصناعات الفضائية والكهربائية بسبب امكانية تحسين خواصها الفيزياوية. تم تحضيرسبيكة A332 ثم اضيفت الدقائق المايكروية وال | Aluminium matrix composites (AMC) reinforced with micro and nano - sized Al2O3 particles are widely used for high performance applications, such as automotive, military, aerospace and electrical industries because of their improved physical and mechanical

An Investigation on The Combustion And Emissions Characteristics of (HSDI) Diesel Engine Fueled With Diesel, Biodiesel And Heavy Fuel Oil

اسم المؤلف: حيدر عبد ضهد
اسم المشرف: Ekhlas M. Alfayyadh Mohammed ali Abdulhadi
الموضوع العام: هندسة الميكانيك
السنة: 2014
الموضوع الدقيق: هندسة الميكانيك
الدرجة: دكتوراه
الجامعة: الجامعة التكنولوجية - قسم الهندسة الميكانيكية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: In this study, an investigation was carried out on the combustion, regulated gases emissions, unregulated gases emissions and particulate matter emissions characteristics in a high speed direct injection (HSDI) diesel engine fueled with rapeseed methyl es

تحليل الاجهادات في صفيحة رقيقة تحتوي على شق سطحي معرضة الى حمل صدمة متكرر Stress Analysis In Thin Plate With Surface Crack Subjected To Cyclic Impact Loading

اسم المؤلف: بسام علي احمد
اسم المشرف: فتحي عبد الصاحب الشماع
الموضوع العام: هندسة الميكانيك
السنة: 2014
الموضوع الدقيق: ميكانيك تطبيقي
الدرجة: ماجستير
الجامعة: جامعة بغداد
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: في هذا العمل.. تم دراسة وتحليل الاجهادات وحركة نمو الشق لصفائح رقيقه ومستويه تحتوي على شق سطحي في وسطها ومعرضه لحمل صدمه متكرر ذات سرعه منخفضه ولنوعين من سبائك الالمنيوم (2024,6061). حيث تم استخدام ثلاثة طرق رئيسية : الحل التحليلي وذلك باستخدام النظرية | In this work, the stresses and dynamic crack growth were studied and analyzed in thin flat plate with a surface crack at the center, subjected to cycling low velocity impact loading for two types of aluminum plates (2024, 6061). Three main methods have b

تاثير الفجوة بين مطيار واسطوانة دوارة على اداء المطيار Effect of Gap Between Airfoil And Embedded Rotating Cylinder on Airfoil Performance

اسم المؤلف: مصطفى فالح حسن
اسم المشرف: نجدت نشات عبد الله
الموضوع العام: هندسة الميكانيك
السنة: 2014
الموضوع الدقيق: هندسة الميكانيك
الدرجة: ماجستير
الجامعة: جامعة بغداد
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: هذه الدراسة توضح تاثير الفجوة بين الجناح والاسطوانة الدوارة على اداء الجناح عمليا ونظريا.اعتمدت الدراسة النظرية لجريان ثنائي الابعاد لقيم عدد رينولدز (700,000) بالاعتماد على طول الوتر لجناح متناظر (NACA 0012) وجناح غير تقليدي NACA 0012) يحتوي في مقدمته ع | The present study explores the effect of the gap between the airfoil and a rotating cylinder embedded on leading edge of the airfoil on its aerodynamic performance theoretically and experimentally.Numerically, two - dimensional turbulent flows with Reyno

تكامل منظومة الملاحة INS/DGPS) (لمرحلة هبوط الطائرة Integration of (INS/DGPS) System For Airplane Landing Phase

اسم المؤلف: هدى ناجي عبد الرضا
اسم المشرف: فرج محل محمد سمير عبد الخالق عزيز
الموضوع العام: هندسة الكهرباء والالكترون والاتصالات
السنة: 2014
الموضوع الدقيق: الهندسة الكهروميكانيكية
الدرجة: ماجستير
الجامعة: الجامعة التكنولوجية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: تستخدم على نحو متزايد في )INS( ومنظومة الملاحة )GPS( منظومة تحديد الموقع العالمي مجموعة واسعة من التطبيقات. منظومة تحديد الموقع العالمي هو نظام الملاحة الذي يوفر درجة الاشارات على الاقل )GPS( عالية من دقة تحديد الموقع وتقدير السرعة للمستخدم. يتلقى مستلم م | Global positioning system (GPS) and Inertial Navigation System (INS) are increasingly used for positioning and attitude determination in a wide range of applications. The GPS is a navigation system which provides highly accurate position and velocity esti

تحسين انتقال الحرارة باستخدام الشريط الملتوي Enhancement of Heat Transfer Using Twisted Tape

اسم المؤلف: اسامة ثامر حسين
اسم المشرف: قاسم جبار سليمان
الموضوع العام: هندسة الميكانيك
السنة: 2014
الموضوع الدقيق: هندسة الميكانيك
الدرجة: ماجستير
الجامعة: جامعة النهرين - كلية الهندسة - قسم الهندسة الميكانيكية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: تقنية تحسين انتقال الحرارة تشير الى عدة طرق مستخدمة لزيادة نسبة انتقال الحرارة بدون التاثير على كفاءة المنظومة وھذا التقنية تقسم الى ثلاثه اقسام ھي( نشيط وسلبي والمركب).تم استخدام ثلاث طرق لتعزيز انتقال الحرارة باستخدام مسببات شدة الاضطراب وذلك من اجل زي | Heat transfer enhancement techniques refer to different methods used to increase rate of heat transfer without affecting much the overall performance of the system. These techniques broadly are of three types. passive, active and compound techniques.Thre

التحقيق في ديناميك المرونة الهوائية والكشف عن الشقوق في ريشة توربين رياح متصدعة Investigation Into Dynamic Aeroelasticity And Crack Detection of A Cracked Wind Turbine Blade

اسم المؤلف: فاروق عمر حمدون
اسم المشرف: موفق علي توفيق محمد ادريس ابو طبيخ
الموضوع العام: هندسة الميكانيك
السنة: 2014
الموضوع الدقيق: هندسة الميكانيك
الدرجة: دكتوراه
الجامعة: الجامعة التكنولوجية - قسم الهندسة الميكانيكية
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: يتضمن البحث الحالي جزئين رئيسيين. يبدا الجزء الاول بتطوير نموذج عددي للتحقيق في اثار حجم وموقع الشق على سلوك المرونة الهوائية للريشة في ظل ظروف مختلفة للرياح. تهدف الدراسة الحالية الى ايجاد حل فعال وسريع فيما يتعلق بالتكلفة الحسابية والتعقيد الرياضي المتا | The present research is divided into two parts. The first part starts with developing a numerical model for investigating the effects of crack size and location on the blade aeroelastic behavior under different wind conditions. The purpose of this study i

دراسة وتصميم براد يعمل بالطاقة الشمسية بطريقة الامتزاز المتقطع Study And Design An Intermittent Solar Energy Adsorption Cooler

اسم المؤلف: فاضل عباس عاصي
اسم المشرف: خالد احمد الجودي عصام محمد علي
الموضوع العام: هندسة الميكانيك
السنة: 2014
الموضوع الدقيق: هندسة الميكانيك
الدرجة: ماجستير
الجامعة: جامعة بغداد
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: يركز هذا البحث على واحدة من الطرق المستدامة لخفض الطلب على طاقة التبريد وهو نظام التبريد بالامتزاز المعتمد على الطاقة الشمسية (solar - powered adsorption cooling system), كما تقوم هذه الدراسة بالتحليل النظري والعملي لثلاجة شمسية تعمل بمبدا الامتزاز المتقط | This work is focused on one of the sustainable ways to decrease energy demand for cooling which is the solar - powered adsorption cooling system. This study presents a theoretical and experimental analysis of an intermittent solar assisted adsorption refr

دراسة نظرية وعملية لمقطر شمسي احادي الحوض ذو مادة خزن متغير الطور Theoretical And Experimental Investigation of Single Basin Solar Still With Pcm Storage Medium

اسم المؤلف: ضرغام ابراهيم حسين
اسم المشرف: سعد محسن المشاط
الموضوع العام: هندسة الميكانيك
السنة: 2014
الموضوع الدقيق: قوى حرارية
الدرجة: ماجستير
الجامعة: جامعة بغداد
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: البحث الحالي هو دراسة نظرية وعملية لاداء مقطر شمسي نوع احادي الحوض احادي الميل مع استخدام شمع البرافيين (Paraffin wax ) وحامض الشمع (Stearic acid ) كمواد متغيرة الطور.تم اجراء الدراسة في محافظة ميسان (جنوب العراق خط عرض 31.5? وخط طول 47.8?) لاختبار تاثير | The present work is a theoretical and experimental investigation on the performance of a solar still type single slope single basin with Stearic acid (SA) and Paraffin Wax (PW) as phase change materials (PCM) storage medium.The work was carried out in Mi
1 ... 392 393 394 395 396 ... 551