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مزج الامواج في المضخم البصري شبه الموصل
Wave - Mixing in Semiconductor Optical Amplifiers
الصفحات الاولى:
مكان الجامعة:
ذي قار
اللغة:
الانكليزية
الجامعة:
جامعة ذي قار - كلية العلوم - قسم الفيزياء
الدرجة:
ماجستير
الموضوع الدقيق:
اشباه الموصلات
السنة:
2017
الموضوع العام:
علوم الفيزياء
اسم المشرف:
احمد حمود فليح
اسم المؤلف:
ريام حسين علي
👁 مشاهدة
دراسة امكانية استخدام طاقة الرياح لانتاج الكهرباء في مدينة السماوة
A Study of Possibility of Using the Wind Energy to Produce the Electricity in Samawa City |
الصفحات الاولى:
مكان الجامعة:
ذي قار
اللغة:
الانكليزية
الجامعة:
جامعة ذي قار - كلية العلوم - قسم الفيزياء
الدرجة:
ماجستير
الموضوع الدقيق:
الفيزياء
السنة:
2017
الموضوع العام:
علوم الفيزياء
اسم المشرف:
عبد الكريم مهدي صالح
اسم المؤلف:
مها حاتم كامل
👁 مشاهدة
تشخيص تصلب الشرايين باستخدام معالجة الصور الرقمية
The Diagnosis of Atherosclerosis Using Digital Image Processing
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 themes of science that needs to be searched because it has a direct impact on human existence. Medical Physics is one of the branches of the Physics Department that deals with the interest of providing theoretical or scientific foundations which had the aims to provide scientific services in the medical field. The subject of the medical image processing is one of the applications of this section. It aims to increase the efficiency of medical diagnostic systems to provide an integrated diagnostic system that works to distinguish a heart disease and atherosclerosis.This study depends on medical images that were obtained from patients in Nasiriyah Heart Center. Where thesis focus on images for arteries feeding heart muscle for Infected patients and other healthy. Set of operations were performed on these images derived from work areas and the separation arteries of these areas from the rest of unimportant information within the image To be brought into the neural network, the use of 110 image to train the network 60 and 50 were used for the test.The next step is to count the number of qualities for each image after it has been extracted artery of the image by making some operations on this image .The proposed system has proven successful in the conduct of the diagnostic process through the results obtained on the ratio of 100% in the training phase and 92% in the testing phase
الصفحات الاولى:
مكان الجامعة:
ذي قار
اللغة:
الانكليزية
الجامعة:
جامعة ذي قار - كلية العلوم - قسم الفيزياء
الدرجة:
ماجستير
الموضوع الدقيق:
الفيزياء
السنة:
2016
الموضوع العام:
علوم الفيزياء
اسم المشرف:
حازم باقر طاهر العلي
اسم المؤلف:
عبد الكريم صكر كمر
👁 مشاهدة
دراسة وتحضير خلية شمسية صبغية ذات تركيب صلب باستخدام صبغة نوع D146 ثنائي اوكسيد التيتانيوم كانود وانابيب الكاربون النانوية متعدد الجدار ككاثود
Study and Preparation of Solid State Dye Sensitized Solar Cell using D149 as a dye ,TiO2 Nanoparticles as a Photo anode and MWCNTs as a Counter Electrode
المستخلص:
The dye sensitized solar cell (DSSC) is one of the photochemical electric cells, which consists of the photo electrode, dye, electrolyte, and the counter electrode. The advantage of DSSC is the low cost of the solar energy conversion into electricity because of inexpensive materials and the relative ease of the fabrication processes. In this work, titanium dioxide (TiO2) films as a photo electrode were prepared from anatas titanium Oxid (TiO2) nanoparticles and deposited by doctor blade method on fluorine doped tin oxide (FTO)coated glass substrates. After the process of deposition that including the prepared samples in the oven, the temperature raises from room temperature (R.T) to set up to around 400°C. Half an hour later, the temperature started to decrease to reach theroom temperature (R.T) . Multi - walled carbon nanotubes (MWCNT)used as a counter electrode instead of platinum(Pt),where prepared by spray pyrolysis technique (SPT) at 300°C,10 sec as spraying time ,and 60 sec stopped time. In the next step, Preparing the dye solution at room temperature then placed TiO2 electrode in the dye solution for 24 hours in the dark .The last step is collecting two electrodes one over the other leads to build a solar cell. Then a mixture electrolyte about(0.6 M 1 - methyl - 3 propoylimidazolium iodide (PMII) + 0.1 M LiI )is dipped onto the surfaces of both (FTO glass/TiO2NP/D149/PMII and MWCNTs/FTO)glasses .The thickness about (400nm) and the films are prepared under various deposition conditions in order to understand the effect of the temperature on the cell properties and to specify the optimum condition. X - ray diffraction (XRD), scanning electron microscope (SEM) are used for the structural analysis.Raman scattering spectrum used to determine the type of material CNTs used for DSSCs fabrication , Fourier transform infrared spectroscopy (FTIR) used for description as an analysis for system chemical structure of the atoms. UV and visible spectra have been recorded as a function of wavelength in the range (200 - 1000 nm) in order to study the optical properties such as reflectance, energy gap of allowed and forbidden direct transitions, extinction coefficient, refractive index, and dielectric constant in real and imaginary parts. It has been found that all the investigated parameters are affected by the sensitizer dye in the visible region of the spectrum .Finally I - V characteristic curves of the fabricated cell were measured and studied, this cell shows highest photovoltaic performances to date as Solid state dye sensitive solar cells
الصفحات الاولى:
مكان الجامعة:
ذي قار
اللغة:
الانكليزية
الجامعة:
جامعة ذي قار - كلية العلوم - قسم الفيزياء
الدرجة:
ماجستير
الموضوع الدقيق:
فيزياء الطاقة الشمسية
السنة:
2017
الموضوع العام:
علوم الفيزياء
اسم المشرف:
سامر مهدي عبد المحسن
اسم المؤلف:
ايات عبد علي كطان
👁 مشاهدة
الاستقرارية البصرية في زوج من التراكيب النقط الكمية
Optical Stability in Double Quantum Dot Structures
الصفحات الاولى:
مكان الجامعة:
ذي قار
اللغة:
الانكليزية
الجامعة:
جامعة ذي قار - كلية العلوم - قسم الفيزياء
الدرجة:
ماجستير
الموضوع الدقيق:
فيزياء الليزر والكهروبصريات
السنة:
2017
الموضوع العام:
علوم الفيزياء
اسم المشرف:
امين حبيب السيد جاسم
اسم المؤلف:
نرمين عبد الخالق كامل
👁 مشاهدة
التحقق من اداء منظومة ليزر التحويل السلبي لعامل النوعية المقترنة بوسط رامان
Investigation of Laser system performance of passive Q - switching with intracavity Raman medium
المستخلص:
The performance of passive Q - switching with intracavity laser system to generate high power pulses have been investigated .The considered laser system consists of Nd : YVO4 , Cr4+ : YAG, and BaWO4 as a active medium, saturable absorber material, and Raman medium respectively to generate high power pulses . A computer program has been employed to solve the rate equations which are simulates the system performance numerically by Rung - Kutta - Fehelberg method. So, the results of the numerical solution have been utiliza to calculate the photons losses behavior in order to study the effects of these losses in the system performance.Raman spontaneous scattering factor ( ) sp k effect on high power pulses characteristics has been studied. There is a small increasing in the duration of the passive Q - switching pulse and stability in duration of stokes pulse when the factor ( ) sp k become high value. According to the current study, the reason of this behaviour is related to the small increasing in the falling time of passive Q - switching pulse and the semi stability in the falling time of passive Q - switching pulse . So, the mentioned aspect demonstrates the increasing in the pulses energy. The study explain that as an outcome high density of the pulses photons .Also the study shows the power of pulses is increasing with Raman spontaneous scattering factor value.In the study aspect which concern the losses behaviour in term of Raman spontaneous scattering factor, the study shows that the decreasing in the final value of total photon loss with Raman spontaneous scattering factor. The study related that to decreasing which occur in the density number of the ground state of SAM ions , that lead to decrement in its absorption activity, this is dominators of the increment in the excited stateof SAM absorption activity according to the difference values ofabsorption cross sections of levels.Output coupler mirror reflectivity on Raman laser pulse characteristics has been studied, the study illustrate that the broadening in the duration of Raman laser pulse whenever the value of output coupler reflectivity at Raman photons ( ) R R increases, the study explains that related to the broadening in the falling time of the pulse. Concerning the pulse energy, the study demonstrates the increase which occurs in the energy of Raman laser pulse with increase of the output coupler reflectivity at Raman photons ( ) R R , the study related that to increase in the photons density. A according that mentioned the study illustrate the increase in the power of Raman laser pulse with the increase of the output coupler reflectivity at Raman photons ( ) R R .Finally, the study arrives to concludes that the passive Q - switching laser system of Nd : YVO4, Cr : YAG, with intracavity Raman medium (BaWO4) crystals which takes into account characterized by compatible performance to obtain high power pulses. So, the Raman media which are distinguished by high spontaneous scattering factor are more efficient to realization high power Raman laser pulses. In addition, the quality factor of resonator is found tobe proportional with the spontaneous scattering factor of Raman medium.
الصفحات الاولى:
مكان الجامعة:
ذي قار
اللغة:
الانكليزية
الجامعة:
جامعة ذي قار - كلية العلوم - قسم الفيزياء
الدرجة:
ماجستير
الموضوع الدقيق:
الفيزياء
السنة:
2017
الموضوع العام:
علوم الفيزياء
اسم المشرف:
عبد الكريم مهدي صالح النيازي
اسم المؤلف:
سالي باسم كاظم
👁 مشاهدة
استجابة التضمين والضوضاء في قفل الحقن لليزرات التعاقب الكمي
INTENSITY MODULATION RESPONSE AND NOISE IN INJECTION - LOCKING QUANTUM CASCADE LASERS
المستخلص:
In communication field, there are many advantages for using terahertz carriers in optical data transmission along both analog and digital links such as small antenna sizes and large information bandwidth. The optical injection locking is an alternative technique to improve the dynamic properties of QCL light sources. In this technique the frequency and phase of one laser oscillator, known as the slave laser, are locked through the direct coupling to the light injection from another laser oscillator, known as the master laser. In this work, the optical injection locking induced laser dynamics in a QCL is investigated theoretically. The present theoretical analyses are based on the rate equations model that takes into account all carrier relaxation processes as well as the effect of the optical injection locking. The small signal analysis is used to calculate the intensity modulation response and intensity noise in QCL. The present analysis focuses on the effect of carrier relaxation time and the optical injection locking on the dynamic properties in these devices. The results show that the optical injection locking and fast carrier relaxation time can enhance the dynamic properties and decreases noise value and increases the modulation bandwidth in these advanced lasers. The optical injection locking increases the carrier density in active region to suppress the effect of fast carrier scattering to lower state and enhances the stimulated emission. The fast carrier relaxation times decreases the threshold injection current. Also, in optical injection operation, the active region length and linewidth enhancement factor has strong effect on the intensity modulation response and intensity noise.
الصفحات الاولى:
مكان الجامعة:
ذي قار
اللغة:
الانكليزية
الجامعة:
جامعة ذي قار - كلية العلوم - قسم الفيزياء
الدرجة:
ماجستير
الموضوع الدقيق:
الفيزياء
السنة:
2017
الموضوع العام:
علوم الفيزياء
اسم المشرف:
حسين هادي وارد
اسم المؤلف:
اخلاص عبد العالي حسين
👁 مشاهدة
دراسة نظرية لعملية انتقال الالكترون خلال بعض التراكيب النانوية
Theoretical Study of Electron Transport Through Some Nanoelectronic Structures
المستخلص:
The present work is a theoretical study for the electronic properties of the electron transport process throughout some molecular structures. The investigated system is a left lead - donor - molecule - acceptor - right lead. The investigate molecule is one of the following structures (Phenyl, Biphenyl, Triphenyl, Naphthalene, Anthracene and Phenanthrene).A theoretical treatment of steady - state has been presented to express the transmission probability of the electron transport throughout ring structures. The Hamiltonian describing the system is the Anderson - Newns Hamiltonian with neglecting the spin and Coulomb interactions on the system. The treatment easily includes a magnetic flux effect on the transport process for any ring structure. Furthermore, the most important effects, taking into consideration, are quantum interference, gate voltage and bias voltage. The transmission probability is employed to calculate the conductance and electric current.Density functional theory (DFT) has also been used to calculate electronic properties of considered molecules, especially on the energy - band gap and density of states, and the distribution of electronic density (HOMO and LUMO). It has been ensured that all studied systems simulated using Caussian program 09 can be fabricated by utilizing their computed total energy.The quantum interference effect at typical values of magnetic flux was utilized to design quantum logic gates (XNOR gate and NAND gate) and nanoscale rectifier (half - wave rectifier and full - wave rectifier).
الصفحات الاولى:
مكان الجامعة:
ذي قار
اللغة:
الانكليزية
الجامعة:
جامعة ذي قار - كلية العلوم - قسم الفيزياء
الدرجة:
ماجستير
الموضوع الدقيق:
الفيزياء
السنة:
2017
الموضوع العام:
علوم الفيزياء
اسم المشرف:
فلاح حسن حنون
لافي فرج البدري
اسم المؤلف:
محمد عبد الامير عباس
👁 مشاهدة
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