In this work, the effects of size, and temperature on the linear and nonlinear optical properties in InGaN/GaN inverse parabolic and triangular quantum wells (IPQW and ITQW) for different concentrations at the well center were theoretically investigated. The indium concentrations at the barriers were fixed to be always xmax = 0.2. The energy levels and their associated wave functions are computed within the effective mass approximation. The expressions of optical properties are obtained analytically by using the compact density-matrix approach. The linear, nonlinear, and total absorption coefficients depending on the In concentrations at the well center are investigated as a function of the incident photon energy for different values of temperature and quantum wells size. The results show that the In concentrations, size and temperature have a significant effect on these optical properties. The positions of the resonance peaks of the absorption coefficients were blue-shifted under increasing indium compositions in the quantum wells (InGaN) and temperature while they were red-shifted with the increase in the thickness of the wells. Moreover, the amplitudes of the resonance peaks were enhanced under the increase of the In composition, the temperature, and the thickness of the quantum wells. The optical absorption in ITQW structure is slightly greater than that in IPQW one.
ABSTRACT The role of specific amino acids namely cysteine, methionine, threonine and asparagine in the protection provided by vamin solution against B-lactam inhibition to E. coli was evaluated in vitro. In minimal medium, Cells were treated with 32 ug/ml of penicillin G, carbencillin, hostacillin, cloxacillin and cephalotin in the presence of specific amino acid supplementations. Deletion of specific amino acids from the media abolished the protection provided by vamin. Threonine was essential for the protection of cells against all tested antibiotics, while cysteine was essential for protection against carbencillin and cephalotin Deletion of methionine or asparagine abolished the protec- tion against carbencillin and to a less extent ce
... Show MoreThere are many studies that discussed the famous museum's graveyards in the Islamic worlds, to study the lives of these figures, there are many difficulties for their studies because the first we need the regularity and history information, and many sciences support, such as in language, geography information.
I am studying the research from Maraqid Al-Maaraf book by Harz Aldeen, the book has large members about the persons have graved in Persian Country in the middle ages, there are more than (30) figures in my study, I have studied every figure in this research depending on the sources and references books.
The current research aims to show the impact of the international auditing standard IAS 540 in reducing income smoothing practices in Iraq. To achieve the objectives of the research, the researcher adopted a questionnaire for a sample of auditors in Iraq. Where 60 forms were distributed and after the questionnaire was retrieved and statistical analysis was done using the SPSS program, The research reached a number of results, the most important of which are: the existence of a statistically significant effect of the application of the international auditing standard IAS 540 in reducing income smoothing practices, The research recommended the necess
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Este estudio muestra una relación comparativa entre literatura y arte, concretamente entre las artes visuales (pintura y cine) y la literatura. Dicho estudio se puede clasificar dentro de los estudios actuales de literatura comparada. El interés por la cuestión viene por la problemática relación entre las dos artes, que tiene una larga tradición que se extiende desde el Ars poetica de Aristóteles hasta la aparición del vanguardismo en el siglo XX. La relación se presenta a través de los colores de las pinturas y los sonidos de las palabras. A los pintores de iconos se les conocía como iconógrafos porque se les consideraba más escritores que pintores. El icono era en realida
... Show MoreThe objective of this study was to investigate the effect of Royal jelly RJ on morphology and motility of mice sperms. Sperms were collected from the cauda region of the epididymis of each 10 mice from the treatment and control groups. Direct activation techniques and evaluation of sperm morphology were carried out. Dhino microscope was used for sperm measurement. The inspection was carried out in Salamatic laboratory for pathological analysis in 2015.The result revealed that all of the sperm function parameters registered significant activation in the treatment group. There was a significant increase in both the percentage of the sperm motility grade A and the progressive motility (A+B) of the treatment gr
... Show MoreThe current work aims to evaluate the association between genetic mutations in thymidylate synthetase (
Purpose: The research aims to diagnose the current availability of knowledge workers characteristics and the role of these characteristics in knowledge acquision in the city of Sulaimaniya Directorate of Electricity, and to identify the differences between personal and occupational characteristics of a sample of research and its impact on the availability of such properties.Design/methodology/approach :to achieve the objectives of the research questionnaire was developed especially for it and then distributed to a sample of engineers and technicians working in the Directorate of Electricity city of Sulaimaniya, where the sample of the research (52) respondents.
Findings: the most important conclusions reached
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The research seeks to determine the nature of audit services, their characteristics and the basic concepts of services marketing audit and definition of the rules and basic dimensions of the marketing audit services through the knowledge of the elements of the marketing mix and test the preferences of customers and auditors of the factors affecting the marketing audit services by selecting a sample of the owners of some of the projects and companies and a sample of auditors has been use the resolution to achieve the objectives of the research where a good question to the owners about the most important factors in your choice of the Audit Office and asked the organization to answer according to the standard trio (very important, a few imp
... Show MoreThe present study aims at answering the following questions:.
1-Which is more effective in enriching students. Vocabulary ,the use of short stories or the traditional way?
2-What extent has the use of short stories an effect upon the students. achievement in vocabulary test?
3- Is there any significant difference between the male and female student of the experimental group in vocabulary achievement test?
 
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Abstract
This study aims to identify the degree to which the first cycle teachers use different feedback patterns in the e-learning system in addition to the differences in the degree of use according to specialization, teaching experience, and in-service training in the field of classroom assessment, as well as the interaction between them. The study sample consisted of (350) female teachers of the first cycle in government schools in Muscat Governorate for the academic year 2020/2021. The study used a questionnaire that contained four different patterns of feedback, which are reinforcement, informative, corrective, and interpretive feedback. The psychometric properties of the que
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