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خصائص نقل الالكترون العابر لانظمة نقاط كمية متعددة == Transient Electron Transport Properties of Multiple Quantum Dots Systems

Author name: حسه ابراهيم عسكر
Supervisor name: شاكر ابراهيم عيسى
General topic: Physics
Specific topic: Electronics Physics
Degree: Master
University: University Of Basrah - College Of Education For Pure Sciences - Department Of Laser Physics
Language: Arabic
University location: Basrah
First pages:
Abstract: We presented a theoretical study for the electron transportcharacteristic, within a system of multi - quantum dots coupled tothe three metallic leads (right lead as an electron reservoir andtwo left leads as an electron source). We take into account twoarrangements for the scattering regions, one composed of twoquantum dots and the other is composed of four quantum dots.The study concentrated on the system parameters that has itseffect on the characteristic of the electron transfer process andhow these characteristic are affect by the number of the quantumdots in the scattering region in the both arrangements for thescattering regions.The theoretical formulism depends on the one - electron model.Where, we assigning a single effective level for each quantumdots and by taking the effects of the leads continuum levels intoaccount which are show within the wide band gap approximationto produce an imaginary quantity add to the energy levels of thequantum dots, representing the broadening in each effectivelevels.The related basic equation of motion for all the correspondinglevels eigen function probability amplitudes are solvedanalytically by using Laplace transform technique. We calculatethe occupation probability for the right lead, the instantaneouscurrent and the average instantaneous current that passes throughthe right lead.Our calculated results for the time - dependent dynamical electrontransfer offered a general features that takes into account thefollowing effects :  Energy levels position changes with respect to the leadFermi level. A suitable applied bais voltage on the right and left leads. Changes of the coupling amount among the quantum dots levels and in between them and the leads levels. Change of the leads temperatureThe characteristic of the time - dependent charge transport in the system are shown through the relation between the average instantaneous current passes the right lead and the applied baisvoltage, which we show as follow :  For the case of the scattering region arrangement that compose of two quantum dots it is an Ohmic behavior. For the case of the scattering region arrangement that compose of four quantum dots it is a non - linear (non - Ohmic) behavior.

قياس تركيز غاز الرادون والثورون في المنازل والمستشفيات والمراكز الصحية في محافظة البصرة العراق

Author name: حسام نجم عبود
Supervisor name: عيسى جاسم محمد الخليفة
General topic: Physics
Specific topic: Physics
Degree: Doctorate
University: University Of Basrah - College Of Education For Pure Sciences - Department Of Laser Physics
Language: Arabic
University location: Basrah
First pages:

دراسة نظرية لبعض العوامل المؤثرة في سلوك دالة الموجة المستخدمة في تكثيف بوز اينشتاين

Author name: ايمان عبد الرضا موحي المالكي
Supervisor name: نوري حسين نور الهاشمي
General topic: Physics
Specific topic: Physics
Degree: Master
University: University Of Basrah - College Of Education For Pure Sciences - Department Of Laser Physics
Language: Arabic
University location: Basrah
First pages:
Abstract: This study entails some of the theoretical characteristics of Bose - Einstein intensification of the ideal gas properties, since the wave function behavior has been studied and analysed according to the effect three types of external potentials trapping that are used in the production Bose - Einstein condensation which are (harmonic potential, optical lattice potential , and double well potential) that have been used as individual or overlapping potentials, and the value of the non - linear has been confirmed according to fixed values in the whole study in order to the study the effect of the other elements. The effect anisotropy AL has been studied according to the behavior of the wave function and the distribution potential where the harmonic potential has individually at first, than it has been overlapped with the optical lattice potential in order to study this factor. Furthermore,the effect of this factor has been explained due to the distribution potential, function wave and relation type between the factor itself, chemical potential and energy. Additionally, we have used the intertwined harmonic potential with the optical lattice to study the effect of optical lattice potential factor q after confirming the harmonic potential AL at certain values, with exposition of it's effect the wave function behavior and distribution of potential with explanation to the nature of the relation between the chemical potential and energy with this factor. In addition to that, we have studied the influence of the center of double well potential coefficient A on the nature and behavior of the wave function and potential, and the nature of the relationship between this factor and chemical potential and energy. Noting the effect of these factors on the behavior of the wave function and the distribution of potential, therefore it has effect in Bose - Einstein condensation production.

خصائص نقل الالكترون لكيوبت مقترن بترانزستور الالكترون المفرد == The Electron Transport Properties of Qubit Coupled with SET

Author name: ايات طاهر ابراهيم
Supervisor name: جنان مجيد المخ
General topic: Physics
Specific topic: Electronics Physics
Degree: Master
University: University Of Basrah - College Of Education For Pure Sciences - Department Of Laser Physics
Language: Arabic
University location: Basrah
First pages:
Abstract: In this work, the dynamics of electron transport through a system consists of qubit (two coupled quantum dots) electrostatically coupled with single - electron transistor (quantum dot coupled to leads). The time - dependent Hamiltonian, that is used to describe the system energy, includes the electrostatic coupling between the qubit and the single - electron transistor. The time - dependent equations of motion for all the creation and annihilation operators are expressed in Heisenberg representation to derive the differential equations of motion for the quantum dots occupation numbers of the qubit and the single electron transistor, the related equations of motion for the correlation functions and also the formula that calculates the current which tunnels from the left lead to the single - electron transistor quantum dot. The system of equations of motion are treated by using the wide band approximation, and are solved numerically by using six order Runge - Kutta method, where the error is calculated at each step of time. By getting use of the system of differential equations solutions, the qubit and the single - electron transistor quantum dots occupation numbers are calculated as a function of time, in addition to the current that tunnels from the left lead to the single electron transistor quantum dot as a function of time.The main goal of this study in to investigate the effect of the parameters that related to the qubit and the single - electron transistor and their role in determing the electron transport process features through the whole system. These parameters, that are related to the initialization, manipulation and measurement processes, are the qubit and the single electron transistor quantum dots energy levels, the coupling strength between the qubit quantum dots, the electrostatic coupling between thequbit and the single electron transistor in addition to the coupling strength between the single - electron transistor quantum dot and the leads as well as the leads properties such as tempreture and band width. The effects of quantum dots energy levels tuning and the symmetry of the coupling with leads on the electron transport through the system are also investigated.Our study highlights four important physical features that related to the initialization, manipulation and measurement processes, these are : 1. The occupation numbers of the quantum dots of the qubit and the single electron transistor and the current of SET at the final time of measurement.2. The charge accumulation on the qubit quantum dots, at the final time of measurement, on the far - removed quantum dot and the nearest one to the single - electron transistor, that can be controlled by appling bias voltage and gate voltage.3. The determination of the time - current dependence if it follows the dependence of the far - removed or the nearest qubit quantum dot occupation number on time.4. The role of qubit energy levels tunning and the asymmetric coupling with the leads in determining the suitable initialization and manipulation processes get the quantum measurement with high quantum efficiency.

قياس تراكيز الرادون للمستشفيات ,المراكز الصحية والمنازل وقياس البورون في مياه محافظة ذي قار - العراق == Measurements of Radon in Hospitals, Health Centers and Dwelling as well as Boron Measurements in Water of Thiqar Governorate(Iraq)

Author name: احمد عباس محمد
Supervisor name: عيسى جاسم محمد الخليفة
General topic: Physics
Specific topic: Nuclear and Environmental Physics
Degree: Doctorate
University: University Of Basrah - College Of Education For Pure Sciences - Department Of Laser Physics
Language: English
University location: Basrah
First pages:
Abstract: العمل الحالي يتضمن ثلاث دراسات اجريت جميعها في محافظة ذي قار جنوب العراق, حيث استخدم 976 نموذج فيها.الدراسة الاولى استخدمت 625 نموذج من كاشف الاثر LR 115 Type II جمعت من 40 منزل في كل قضاء , حيث تم قياس مستويات الرادون وخطر الاصابة بسرطان الرئة من خلال الطريقة السلبية . النتائج اظهرة مستويات مرتفعه وخصوصا في المطبخ مقارنتا مع الاماكن الاخرى وذلك بسبب غاز الطبخ والمياه المستعملة. ان المعدل للجرعة المكافئة السنوية للمطبخ تتغير من 2.316±0.172 في الناصرية الى0.759±0.0348 في سوق الشيوخ .اما الدراسة الثانية فقد استخدمت 186 نموذج من كاشف الاثر LR 115 Type IIجمعت من 57 مستشفى ومركز صحي , حيث استعملت الطريقة اعلاه لقياس مستويات الرادون وخطر الاصابة بسرطان الرئة هناك.لقد اظهرت النتائج ان مستويات الرادون في المستشفيات اعلى من نظيرتها في المراكز الصحية. ان اعلى معدل للجرعة المكافئة السنوية للمراكز الصحية 2.504±0.114 mSv/y بينما للمستشفيات3.150±0.091 mSv/y. في كلى الدراستين اعلاه وجد ان اغلب الجرعات الاشعاعية , ليست اعلى من المعدل العالمي 2.4 mSv/y , ولذلك فانها لا تشكل خطرا جديا على المتواجدين.ان الدراسة الثالثة هدفها قياس تراكيز البورون في مياه محافظة ذي قار , حيث ان امدادات المياه تاتي من مصدرين رئيسين وهما نهري دجلة والفرات, حيث جمع 165 نموذج من 55 موقع لثلاثة انواع من المياه (مياه نهر, مياه اسالة , مياه شرب) واستخدمت الطريقة اللونية لقياس تركيز البورون في عينات الماء. ان اعلى التراكيز سجلت لمياه الانهر في قضاء الناصرية 1.729 mg/l , ولمياه الاسالة سجلت في قضاء الجبايش 0.3 mg/l , اما مياه الشرب فسجلت في قضاء الجبايش 0.286mg/l ,حيث النتائج اظهرت كذلك ان نهر الفرات اكثر تلوثا بعنصر البورون وذلك بسبب ان المناطق ذات الكثافة السكانية العالية ,المصانع والمنشات الكبيرة تقع على ضفافه , حيث ان معدل لتراكيز البورون لنهر دجلة 0.244 mg/l , بينما لنهر الفرات 0.794 mg/l . الدراسة الحالية اظهرت ان تراكيز البورون لنهر دجلة ليست اعلى من المعدل العالمي (اقل من 0.5 mg/l) . بشكل عام نتائج نهر الفرات اعلى من المعدل العالمي 0.5 mg/l , ولكنها تبقى ضمن المستويات المنخفضة لتراكيز البورون , حيث حدد الاتحاد الاوربي المستويات المقبولة ب 1.0 mg/L عام 1998 , اما نيوزيلندا فحددته ب 1.4 mg/L. | The present work included three studies carried out in Thiqar Governorate southern of Iraq, where 976 samples has been used .The first study used 625 samples of LR 115 Type II dosimeters where collected from 40 dwelling in each distract, Passive method is used to measure the radon indoor levels and lung cancer risk. The results show higher indoor radon levels and radon effective dose especially in kitchen as compared to other locations. High values of radon activity may be due to use of water and cooking gas in kitchen.The average annual effective dose for kitchen varying from 2.316±0.172 mSv/y recorded in Al Nasiriya district to 0.759±0.0348 mSv/y recorded in Suq AlShyouk district.The second study used 186 samples of LR 115 Type II dosimeters collected from 57 Hospitals and Health centers, also Passive method is used to measure the radon indoor levels and lung cancer risk. The results show that the calculated indoor radon levels and radon effective dose in Hospitals are higher than that in Health Centers.The maximum average annual effective dose in Health Centers is 2.504±0.114 mSv/y , while for Hospitals is 3.150±0.091 mSv/y.In the two studies most of the radiation dose are not higher than the world wide average back ground dose of 2.4 mSv/y and hence they does not pose any serious threat to the occupants.The third study aims is to measure the concentration of boron in waters of Thiqar Governorate (southern of Iraq), the water is supplied from two major sources (Tigris and Euphrates Rivers). 165 samples collected from 55 location for three types of water (rivers water, Tab water, drink water). Colorimetric curcumin method is used to measure the boron concentration in the water samples. The maximum Boron concentrations in Thiqar Governorate for River water (surface water) (1.729 mg/l) in Nasiriya district, Tab water(0.3 mg/l) in Chibiesh district and Drink water (0.286mg/l) in Chibiesh district. The results shown that Euphrates river is more polluted with boron element, because its pass in highly occupied region and meager factories ,facilities lay on it, where Tigris average value 0.244 mg/l,while Euphrates average value 0.794 mg/l.The present work shows most of the boron concentration in Tigris river aren't higher than the world wide back ground <0.5 mg/l. In general Euphrates river results are higher than the world wide back ground, but it's still in the low concentration levels for boron, where the European Union established a value of 1.0 mg/L for boron in 1998 for the quality of water intended for human consumption, also New Zealand has established a drinking water standard for boron of 1.4 mg/L

اللااستقراريات والفوضى في الدوائر الالكترونية

Author name: ابو طالب يوسف عباس عبد الكريم الشامي
Supervisor name: نوري حسين نور الهاشمي | فرات احمد مهدي السيمري
General topic: Physics
Specific topic: Electronics Physics
Degree: Master
University: University Of Basrah - College Of Education For Pure Sciences - Department Of Laser Physics
Language: Arabic
University location: Basrah
First pages: