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.
Language is a gift from God to His servants, as it is a tool of communication, rather it is a tool of life, and without it, life cannot be straight and complete.
A language is a kind of substitution. A vocal disorder that may be a disease of speech, and it is one of the obstacles caused by organic and congenital causes, perhaps the common one is genetic.If we separate between lisping in children and separating it from what happens in adults, we find that lisping in children may have psychological causes as well as other ones, this is what we will show in this research.
Attention is one of the mental processes of knowledge that play an important role in the life of the individual in general and the child's life, in particular, the child relates to the external environment through its interaction with it, to achieve the adjustment with his environment and harmony with his community.
Much ness and multiplicity of information sources make the child need to scan and exploration to provide the appropriate response by handling sensory stimuli involving the discovery of stimulus and receive it by sensory devices then pay attention to it and realizing and storing it in memory and restoring it in the next positio
... Show Moreأهمية البحث والحاجة اليه :
الحمد لله رب العالمين القائل (( وانك لعلى خلق عظيم )) (سورة القام :4) وصلى الله وسلم وبارك على نبينا محمد القائل " انما بعثت لأتمم مكارم الاخلاق " مسند احم: رقم الحديث 8595.
ان الاهتمام بالمشكلات السلوكية من اهم ركائن التربية والتعليم وتأتي تأتي اهميتها من ان التعيم يعين التغيير في سلوك الفرد نحو الافضل تحت تأثير الظروف والخبرات والمعارف والمهارات ال
... Show MoreThere are a lot of takes care of the legacy of the household (p) and from different Islamic sects, where draw works several dealt biography Zahra Virgin (p) was research deals with male workbooks that were classified for girlfriend (p) since the second century AH, which is my father Mkhnf, Lot bin Yahya bin Said Azdi (d. 157 AH / 773 AD) the first class
Objectives: To determine the effectiveness of physical education program on the domains of the university
students attitudes of physical activity and health, physical activity and mental health, physical activity and nutrition
toward physical fitness.
Methodology: A quasi-experimental design is carried out throughout the present study with the application of
test-retest approach through the period from February 3rd 2013 to June 30th 2013. The study is conducted on
purposive sample of(40) Undergraduate Students at the College of Science University of Baghdad . The sample is
Consisted of (20) males and (20) females. Questionnaire of two main parts, Personal and demographic
information and students' attitudes about phys
Abstract:
The hotel sector is one of the most vital sectors exposed to risks, and the authorities concerned with control must take their active and influential role in putting the hotel sector on the right track and compatible with the internationally approved approaches, and the importance of auditing the performance of the hotel sector in light of the (Covid-19) pandemic is embodied in the fact that it gives a clear and realistic picture to the management and regulatory bodies about the performance and activities of this sector and the shortcomings and deviations that must be addressed, and also helps government decision makers to ob
... Show MoreAbstract:
This research aims to know the reflection of selection of employees strategy dimensions ( selection of employees strategy standards, procedures selection of employees strategy , efficiency based on a selection of employees strategy) on human capital (knowledge, skills, abilities) in a sample of Lecturers consists of (Deans and assistants and heads of departments) in ( Baghdad University) included nine colleges and university president as total sample size (54), which represent almost 50% of the total research community of 116, was used in the light of the objectives of the research descriptive and analytical approach, has been a resolution main tool for data collection as well as the interview p
... Show MoreAbstract
A surface fitting model is developed based on calorimeter data for two famous brands of household compressors. Correlation equations of ten coefficient polynomials were found as a function of refrigerant saturating and evaporating temperatures in range of (-35℃ to -10℃) using Matlab software for cooling capacity, power consumption, and refrigerant mass flow rate.
Additional correlations equations for these variables as a quick choice selection for a proper compressor use at ASHRAE standard that cover a range of swept volume range (2.24-11.15) cm3.
The result indicated that these surface fitting models are accurate with in ± 15% for 72 compressors model of cooling cap
... Show MoreBackground: Phosphodiesterase-5 (PDE-5) inhibitorsrestore nitric oxide (NO) signaling and may reducecirculating inflammatory markers, and improve metabolicparameters through a number of mechanisms. Dailyadministration of the PDE-5 inhibitor, tadalafil (TAD) mayattenuate inflammation; improve fasting plasma glucose andtriglyceride levels and body weight. This study aims toevaluate the efficacy of low dose PDE-5 inhibitor, tadalafil(TAD) in controlling dysglycemia and body weight in obesediabetic men.Methods: Forty obese men with type 2 diabetes aged 30-50years incorporated in this study, all with A1c of 7-8.5%,attending obesity unit in AL-Kindy college of medicine.Weight, height, BMI, FPG, A1c, cholesterol, TG, HDL andLDL measured for all
... Show MoreThe study aimed to explaining the concepts of water footprint and virtual water and how these two concepts could use to achieve water savings at the local level to meet the water supply deficit in Iraq, which is expected to increase in the coming years and influence of that on food security in Iraq by using these concepts when drawing production, irrigated and import plans in Iraq. The study aimed to studying the water footprint and virtual water and their impact on the foreign trade for wheat and rice crops during the period 2000-2022 and estimating the most important indicators of virtual water and the water footprint of the study crops due to the importance of these criteria in det