The purpose of our work is to report a theoretical study of electrons tunneling through semiconductor superlattice (SSL). The (SSL) that we have considered is (GaN/AlGaN) system within the energy range of ε < Vo, ε = Vo and ε > Vo, where Vo is the potential barrier height. The transmission coefficient (TN) was determined using the transfer matrix method. The resonant energies are obtained from the T (E) relation. From such system, we obtained two allowed quasi-levels energy bands for ε < VO and one band for ε VO.
تعد تقنية العقلنة ([i]) تقنية تطويرية للنظام البرلماني تعمل على معالجة الانحرافات التي يمكن ان تحدث لهذا النظام سواء بفعل النظرية او نتيجة للممارسة السياسية، ولعل اول من تحدث بموضوع (البرلمانية المعقلنة) الفقيه الدستوري الروسي الاصل (بوريس ميركن) في فترة مابين الحربين العالميتين (الاولى والثانية) واراد بها تقوية مركز الحكومة لمواجهة البرلمان، وقد اخذ بها واضعوا الق
... Show MoreThis paper aims to improve the voltage profile using the Static Synchronous Compensator (STATCOM) in the power system in the Kurdistan Region for all weak buses. Power System Simulation studied it for Engineers (PSS\E) software version 33.0 to apply the Newton-Raphson (NR) method. All bus voltages were recorded and compared with the Kurdistan region grid index (0.95≤V ≤1.05), simulating the power system and finding the optimal size and suitable location of Static Synchronous Compensator (STATCOM)for bus voltage improvement at the weakest buses. It shows that Soran and New Koya substations are the best placement for adding STATCOM with the sizes 20 MVAR and 40 MVAR. After adding STATCOM with the sizes [20MVAR and 40MV
... Show MoreThe information revolution، the new language has become one for all the peoples of the world through handling and exchange and to participate in all key areas (economic، cultural and scientific) and Accounting episode of this revolution has turned most of the traditional systems (manual) in companies to automated systems، this transformation in the regulations summoned from the auditors that develops their traditional examination automated systems so had to provide tools for auditing help auditors to keep abreast of developments and as a result there is no evidence checksum Local Private audited automated systems came search to provide evidence helps auditors for guidance as part of COBIT، which provides audit procedures Detailed inf
... Show MoreThis study relates to the estimation of a simultaneous equations system for the Tobit model where the dependent variables ( ) are limited, and this will affect the method to choose the good estimator. So, we will use new estimations methods different from the classical methods, which if used in such a case, will produce biased and inconsistent estimators which is (Nelson-Olson) method and Two- Stage limited dependent variables(2SLDV) method to get of estimators that hold characteristics the good estimator .
That is , parameters will be estim
... Show MoreThe study aims to achieve several objectives, including follow-up scientific developments and transformations in the modern concepts of the Holistic Manufacturing System for the purpose of identifying the methods of switching to the entrances of artificial intelligence, and clarifying the mechanism of operation of the genetic algorithm under the Holonic Manufacturing System, to benefit from the advantages of systems and to achieve the maximum savings in time and cost of machines Using the Holistic Manufacturing System method and the Genetic algorithm, which allows for optimal maintenance time and minimizing the total cost, which in turn enables the workers of these machines to control the vacations in th
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Most of the industrial organization in the world became suffering from the problem of the pollution of the poisonous chemicals things, this urged to depend on the principle of the responsible production, because it has the positive role by dealing with these chemical things and to safe the health of the society, due to the main goal of this study is to restrict the role responsible production in accomplishing the system of the environmental management through an actual study in the northern gas company in Kirkuk province, the topic has acquired a big importance bacause there were a limited number of studies and res
... Show MoreThis paper presents a computer simulation model of a thermally activated roof (TAR) to cool a room using cool water from a wet cooling tower. Modeling was achieved using a simplified 1-D resistance-capacitance thermal network (RC model) for an infinite slab. Heat transfer from the cooling pipe network was treated as 2-D heat flow. Only a limited number of nodes were required to obtain reliable results. The use of 6th order RC-thermal model produced a set of ordinary differential equations that were solved using MATLAB - R2012a. The computer program was written to cover all possible initial conditions, material properties, TAR system geometry and hourly solar radiation. The cool water supply was considered time
... Show MoreBackground:
Angiogenesis plays a crucial role in tumorigensis; several reports have described a significant increase in microvessel density (MVD) in colorectal carcinogenesis There are
several methods to measure the angiogenesis in neoplasms, but immunohitochemistry seems to be the mainstay of all. This method enable us to measure the tumor microvessel densities highlighted by using antibodies directed against endothelial cell markers like CD31,CD34 or others; then assessment of MVD by manual count of the number of microvessels in what appears to be the most vascular area of the tumor(called the hot spot) using a protocol described by Weidner et al.Automated cellular imaging system is used to analyze
The calculation of potential earth's surface solar radiation is imperative for analyzing the atmosphere-vegetation-soil interaction process. Therefore, many schemes were introduced with direct (using net radiometer) or indirect (using air temperature or air plus soil temperatures) formulas. Three combinations of factors are known to control the Rn value; the astronomical based factors which determine the general spatial distribution of Rn values, the climatological factors which determine the assigned spatial variation of those values, and the topographical factors that influence climatological factors rates ( i.e. have indirect effects on Rn values).
For Iraq, the ecosystem in
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