Generally the a.c. conductivity shows a power law in frequency s () where the exponent s ≤ 1. As the frequency goes to zero the conductivity become frequency independent. The a.c. conductivity was studied for the Ge1-xSex thin films to see how the selenium contents affect the permittivity and the permeability for the Ge1-x Sex. The thin films prepared by thermal evaporation at room temperature and under vacuum (~2 x10-5toor) using Edward coating unit model 306A. From the relation between ln conductivity and ln w, the effect of selenium contents in Ge1-x Sex thin films on the exponent value, the relaxation time and the maximum barrier height. An algebric fitting method for circles and circular arcs was used to find the permittivity and the permeability from cole-cole diagram, and to see how the selenium content affects these parameter values of Ge1-x Sex thin films. It was clear that there were direct proportions between the selenium content in the Ge1-x Sex structure and each of the following factors: The exponent S, the barrier height, and the permittivity. It was also possible to note the presence of inverse proportion between the selenium content in the Ge1-x Sex structure and each of the polarizability and the charge carrier relaxation time.
In this work, a convex lens concentrating solar collector is designed and manufactured locally by using 10 convex lenses (concentrator) of a diameter 10cm and one Copper absorber tube of a diameter 12.5mm and 1mm in thickness 1m length. Two axes manual Tracking system also constructed to track the sun continuously in two directions. The experiments are made on 17th of May 2015 in climatic conditions of Baghdad. The experimental data are fed to a computer program to solve the thermal performing equation, to find efficiency and actual useful energy. Then this data is used in numerical CFD software for three different absorber diameters (12.5 mm, 18.75 mm and 25 mm). From the results that obtained the maximum the
... Show Moreتتمثل مشكلة الدراسة في الصعوبات التي يواجهها طلاب اللغة الإنجليزية كلغة أجنبية في تعلم وإتقان المتلازمات اللفظية. تهدف هذا الدراسة تهدف إلى تحديد أثر استخدام تقنية المسرد الاملائي على معرفة المتلازمات اللفظية لدى الطلاب. ولتحقيق أهداف هذا البحث والتحقق من فرضياته تم اختيار عينة عشوائية مكونة من (60) طالبة من كلية اللغة الإنجليزية للسنة الثانية باستخدام كتاب الفهم القرائي المقرر للمستوى الثاني في قسم الل
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This study was conducted in the plant protection department/ College of Agriculture/ University of Baghdad to evaluate the efficiency of physical agents ozone, ultraviolet radiation, microwave for destroying afla produced in corn seeds. An isolate af A.flavus producing Aflatoxin B1 was obtained from plant protection dept. college of Agric. University of Baghdad. Results showed destroy toxin AFLA B1 the effect of radiation microwave in the media of Japex degree 80 and 100 co 57.14% and 85.71%, respectively, and for 20 sec, compared to the treatment comparison 0.00% as found significant differences were apparent between transactions and the treatment of comparison, as and notes the existence of a significant dif
... Show MoreBackground: Odontogenisis is a complex process controlled by dynamic and reciprocal interactions that regulated by various molecules. Thymosin β4 is a small bioactive peptide with wide spectrum biological effects on much cell types. The present study was designed to highlight the effect of synthetic exogenous Tβ4 on developing dental tissue of the upper central teeth of rats, by histological examination and immunohistochemical evaluation of TGFβ1. Materials and method: Thirty six Albino Wister pregnant rat 18control group received intraperitoneal injection of normal saline and the others are experimental group received 50µg/300µl of Tβ4 injection. The animals were sacrificed at periods 16th and 18th day I.U.L and one day p
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An experiment was conducted to study how SAE 50 engine oil contaminated with diesel fuel affects engine performance. The engine oil was contaminated with diesel fuel at concentrations of 0%, 1%, and 3%. The following performance characteristics were studied: brake-specific fuel consumption, brake thermal efficiency, friction power, and exhaust gas temperature. Each treatment was tested three times. The three treatments (0%, 1%, and 3%) were analyzed statistically with a one-way ANOVA model at the 5% probability level to determine if the three treatments produced significant differences in engine performance. The statistical results showed that there were significant differences in engine performance metrics among the three treatments. The 3
... Show MoreSpecial exercises in individual games are an important pillar in learning their basic skills. The aim of the research is to prepare special exercises using tools and their effect on learning the skill of landing with Salto backward tucked to stand - knowing the effect of special exercises using tools and their effect on learning the skill of landing with Salto backward tucked to stand on the horizontal bar. Either the research assumes the existence of significant differences in the pre- and post-tests in learning the skill of landing with Salto backward tucked to stand on the horizontal bar in favor of the post-test. The researchers used the experimental method with a single sample design to suit the research problem, as the researc
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In this paper Alx Ga1-x As:H films have been prepared by using new deposition method based on combination of flash- thermal evaporation technique. The thickness of our samples was about 300nm. The Al concentration was altered within the 0 x 40.
The results of X- ray diffraction analysis (XRD) confirmed the amorphous structure of all AlXGa1-x As:H films with x 40 and annealing temperature (Ta)<200°C. the temperature dependence of the DC conductivity GDC with various Al content has been measured for AlXGa1-x As:H films.
We have found that the thermal activation energy Ea depends of Al content and Ta, thus the value of Ea were approximately equal to half the value of optical gap.
Abstract
The aim of the current research is to identify the Effect of the alternative evaluation strategy on the achievement of fourth-grade female students in the subject of biology. The researchers adopted the zero hypothesis to prove the research objectives, which is there is no statistically significant difference at the level (0.05) between the average scores of the experimental group who study according to the alternative evaluation strategy and the average scores of the control group who study in accordance with the traditional method. The researchers selected the experimental partial adjustment design of the experimental and control groups with the post-test. The researchers intentionally selected (Al-fed
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The current research aims to identify the effect of the idea filtering strategy on the achievement of second-intermediate school female students in science. The two researchers adopted the experimental method and the experimental design with partial control in the two groups (experimental group and control group). The two researchers applied the research experience to a sample of students of the second intermediate grade in the school Martyrs of (Jiser Al Aimma for Girls) affiliated with the Baghdad Education Directorate / Rusafa /1 for the academic year (2021/2022), which was chosen intentionally. The number of female students in the research sample was (70) students, with (35) students for the ex
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