This paper presents the effect of relativistic and ponderomotive nonlinearity on cross-focusing of two intense laser beams in a collisionless and unmagnetized plasma. It should be noted here that while considering the self-focusing due to relativistic electron mass variation, the electron ponderomotive density depression in the channel may also be important. Therefore/these two nonlinearties may simultaneously affect the self-focusing process. These nonlinearities depend not only on the intensity of one laser but also on the second laser. Therefore, one laser beam affects the dynamics of the second beam and hence the process of cross-focusing takes place. The electric field amplitude of the excited electron plasma wave (EPW) has been calculated. Comparison of the theory with the recent experimental observations has also been presented.
The experiment was carried out in the green house of botanical garden belong to Department of Biology/College of Education for Pure Science Ibn AL-Haitham, University of Baghdad for growing season 2017-2018 to evaluate effect of lead stress with concentrations (0, 50, 100, 150) mg.L -1 and Selenium concentrations (0, 15, 30) mg.L-1 on growth of dill plant using pots. The experiment was designed according to completely randomized design (CRD) with three replications. Result indicated that dill plants subjected to lead stress with height concentrations caused decrease in plant parameters (plant height, no. of branches. plant-1, root length, shoot dry weight, the content of nitrogen, phosphorus and potassium, protein concentration, no. of umbe
... Show More؛ ١٨his study male and female albino mice werdministr^d doses of alkaloid and phenolic extracts of Allium cepa at doses of( 25 ,50,100, 200) mg / kg of( body weight). males and females were divided into four groups and each croup comprised mice were injected intra^ritonially daily for one week and orally ٢٠٢ one month . After which animals were killed and the serum was separated for biochemical analysis (total blood suger, total protein , otal cholesterol). Results showed significant decrease ( p< 0,05) in the total blood suger and total cholesterol on the serum of both males and females and significant increase( p< 0,05) in the total serum protein of both males and females of the two types of injection and oral administr
... Show MoreIn this paper, the effect of temperature on the charge transfer rate of dye (N3) in contact with ZnS semiconductors is discussed and studied when electrons move from the excited N3 dye to the conduction band of ZnS based on quantum shift theory. In a heterogeneous system, the energy levels are assumed to be continuous, and the N3-ZnS system is surrounded by a variety of polar solvent media. The transition energy of the N3/ZnS heterojunction was calculated using seven different solvents at room temperature, considering the refractive index and dielectric constant of the solvents and the ZnS semiconductor, respectively. The charge-transport reaction rate was calculated over different te
In this research TiO2 nano-powder was prepared by a spray pyrolysis technique and then adds to the TiO2 powder with particle size (0.523 μm) in ratio (0, 5, 10, 15 at %) atomic percentage, and then deposition of the mixture on the stainless steel 316 L substrate in order to use in medical and industrial applications.
Structure properties including x-ray diffraction (XRD) and scanning electron microscope (SEM0, also some of mechanical properties and the effect of thermal annealing in different temperature have been studied. The results show that the particle size of a prepared nano-powder was 50 up to 75 nm from SEM, and the crystal structure of the powders (original and nano powder) was rutile with tetragonal cell. An improvement in
The research dealt with the impact of reinsurance on the financial surplus of the National Insurance Company by focusing on reinsurance in the marine insurance / merchandise branch. The aim of this research was to show the impact of reinsurance indicators (reinsurance ratios, retention ratios, commission rates earned) on reinsurance operations Data on the research variables were collected based on the inductive and deductive approach in the analysis of information for the financial reports of the National Insurance Company of the Marine Insurance Branch and the insurance portfolio (goods) for the period from 2010 to 2017, and for the purpose of obtaining results was used M a number of statistical methods commensurate with the nature of t
... Show Moreتعد الديمقراطية من أهم المواضيع التي عنيت بها الفلسفة فهي مثار نقاش بين الفلاسفة ورجال الفكر والسياسة، إذ تعود الجذور الأولى لفكرة الديمقراطية إلى الفلاسفة اليونان لكن تبلورها لم يتأتى إلا مع فلاسفة العقد الاجتماعي والتي تقوم على فلسفة الذات المؤسسة على فكرة العقد الاجتماعي الذي ينتقل الإفراد بموجبة إلى الحالة المدنية لكن هذا الطرح لقي تفنيدا في الفكر السياسي المعاصر وهو ما حاول يورغن هابرماس التأسيس له من
... Show MoreIbn al-Haytham is the pioneer of optics, which is a science that had described optics circumstances. Optics or landscape science as it was known by the Arab and Muslim scientists at the time when is a science known as the conditions of sighters in their quantity and quality as the proximity and distance from the beholder , the different forms , conditions and what mediate between the beholder and the microscopes , to explain useful knowledge of what obscures the sight of the conditions of sighters and is used to measure the space Distant criminality and mirrors.
Ibn al-Haitham wrote his famous book The Book of Mirrors and studied mistakes adopted the m
... Show MoreExperts of Psychology and education emphasized that childhood is one of the most important stages in the formation of human personality, and the most influential in his public life, especially the stage in which he lives within his family, which must provide him with the requirements of healthy growth of physical, emotional, moral and social. Emotional-social connection of the child to his family, is especially important in determining the characteristics of his social character, in accordance with the norms and values prevailing in society. This requires the child to be cared for and cared for, and to deal with him in a healthy social manner. So as to achieve positive growth and harmony in the process of social control in internal
... Show Moreخضع فن التمثيل وتقنياته في العصر الحديث لانعطافات عديدة ومختلفة وجوهرية في بنيته العامة والخاصة لاسيما وان المنظرين والمخرجين والممثلين المحدثين على تماس وعلى حراك في خلق حساسية أدائية جديدة تنسجم ولغة العصر وحاجاته وإشكاله وأنماطه منطلقين في تنظير اتهم وتطبيقاتهم من نظم والسلوك البشري الخارجي والداخلي والاستفادة من ميادين الفنون الأدائية الأخرى كالرقص وفن البهلوان والمهرج والسيرك فضلا"عن استعارته الخ
... Show MoreThe research aims at:
1 - Detection of the degree of social values (truthfulness, honesty, cooperation) of the
primary first class students who compose members of the research sample in general.
2 - Are there significant differences at the level (0,05%) between the average degree of
members of the research sample in the values (truthfulness, honesty, cooperation) among
students enrolled and not enrolled in kindergarten and in general.
3 - Are there significant differences at the level (0,05%) between the mean scores of
individuals in the sample values (truthfulness, honesty, cooperation) in the light of two
variables: A - Gender (male / female), b - enrolled and not enrolled in kindergarten.
Having in mind that