The free electron laser is considered one of these important and advanced inventions because it provides a laser beam within various wavelengths of the electromagnetic spectrum. In any laser system device, several parameters must be available on which the efficiency and performance of the laser system are dependent. The Pierce parameter is one of the important parameters in measuring the performance quality of the free electron laser. In this paper, the simulation results were obtained using the MATLAB program to show the important effect of the Pierce parameter on the performance of the free electron laser system. The simulation results showed that the values of the Pierce parameter ranged between (0.01 - 0.03) for the laser beam with long wavelengths, while it ranged between (0.001-0.0001) for the short wavelengths. The results showed an increase in the efficiency values of the free electron laser system with increasing the values of the Pierce parameter, which represents the ratio between the saturation power and the power of the electron; therefore, it can be used as a specific threshold to measure the efficiency of the laser system. Additionally, the simulation of the Pierce parameter has a direct relation to the small signal gain per unit length.
The Aim of this paper is to investigate numerically the simulation of ice melting in one and two dimension using the cell-centered finite volume method. The mathematical model is based on the heat conduction equation associated with a fixed grid, latent heat source approach. The fully implicit time scheme is selected to represent the time discretization. The ice conductivity is chosen
to be the value of the approximated conductivity at the interface between adjacent ice and water control volumes. The predicted temperature distribution, percentage melt fraction, interface location and its velocity is compared with those obtained from the exact analytical solution. A good agreement is obtained when comparing the numerical results of one
An experiment in the semester, the second semester of the academic year (2022-2023), and the data used was not processed (the second test for two independent, inaccurate samples, the Bermon correlation coefficient, and the Spearman correlation coefficient), and the following results were reached: There is a statistically significant difference at the level of ( 0) average, 05) between the third grade who studied the plan for asking cluster questions, and between the average of those who studied the special feature according to the traditional method of selecting achievement, and enjoyed completing the specialization, choosing the experimental group, because the strategy of asking cluster questions is one of the externalities that... Lear
... Show MoreBackground: Sperm motility disorder is an important cause of infertility in male, and one of the causes of reduced motility of the sperm is the disorders of the mitochondria because it provides the required energy for sperm motility, Laser biostimulation or low-level laser therapy has a positive effect on the mitochondria and led to increasing the synthesis of ATP. Method: Twenty fresh human semen samples were used in this research study, each sample was separated into two portions, one was used as control which is not exposed to the laser beam and the other was irradiated with the wavelength of 410 nm diode laser with an output power of 100 mW and an exposure time of 60 seconds, then the measurement of
... Show MoreThe purpose of the study is to analyze the extent of the impact of liquidity as an independent variable on profitability as an intermediate variable and the value of banks listed in the Iraq Stock Exchange as a dependent variable, as the research problem is summarized by the fact that most banks focus on profitability as a phased goal without focusing on maximizing its value as a strategic goal by enhancing the wealth of owners and shareholders. On the long term, the research community is represented by the banks listed on the Iraq Stock Exchange, while the research sample was deliberately chosen, which included three private banks such as Baghdad Commercial Bank, the Iraqi Commercial Bank and the Iraqi Investment Bank, an
... Show MoreAbstract The study aims to clarify the value of auditing economic units and how it can be measured, which is one of the most important challenges to matching the Value Relevance of Accounting Information. The problem of the study was identified with questions that revolve around the extent to which it is possible to measure the value of auditing in Iraqi economic units and the extent to which the value of auditing affects the adequacy of accounting information. Through reviewing the studies discussing this topic, it was found that auditing can provide value through the performance of the auditor and adding value to the economic unit subject to audit. The study recommended the need to study the situational factors of auditing, whether exter
... Show MoreThe research aims to identify the effect of the PQ5R strategy on the achievement of chemistry among fifth-grade science students in government secondary and preparatory schools. Al-Zumar Girls High School was chosen as its students as the research sample affiliated with the Diyala Education Directorate, Diyala Education Department, for the academic year (2023-2024). and Two divisions were chosen from among divisions. The fifth scientific grade was chosen randomly, one of them was the experimental group taught according to the PQ5R strategy, and the other was the control group taught according to the usual method. The equality of the two research groups was verified with a set of variables, which were (chronological age in months, previous a
... Show MoreThe purpose of this study is to investigate the effect of credit risk indicators on the Arab Gulf countries' banks Profitability over the period of 2015 to 2017. The banking credit risk was calculated using non-performing loans ratio affecting banks profitability indicators like net income and by using fixed effect and random effect model analyses, the study found that increasing in non-performing loans ratio will decrease the net income in gulf banks, the study also found that personal loans represent the largest share of loans granted in gulf banks. Also, the study recommends the importance of developing the capabilities of credit departments in commercial banks in dealing with bad loans, and studying the financial statem
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