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.
كانت المجالس وما ا زلت تعقد فػي البيػوت او الػدواويف الرسػمية ينػاقش فيهػا المجتمعػوف امػوره الخاصػػة والعامػػة وقػػد اخػػذت هػػذ المجػػالس عمػػ عاتقهػػا نشػػر عمػو العممػػا والقصائد الشعرية والاخبار السياسية والفكاهية وكاف يحضرها مختمؼ ش ا رئح المجتمع ساعدت هػذ المجػالس عمػ حفػظ التػ ا رث العربػي الاسػلامي مػف مثُػؿ وقػي خمقيػة لكػف بسبب الفػتف المذهبيػة التػي سػادت المجتمػع فػي القػرف الخػامس الهجػري
... Show Moreيهدف البحث الى دراسة مسالة مهمة اجتماعية ذات طابع اسري يعني بالاهتمام بالطفل من ناحية العناية والرعاية حين افتراق الابوين
It is certain that thepsychologicalunity, is awidespread status among individuals of the human race, to the extent that it became -in fact- the unlimited presenttruth in our daily lives,in all cases it found in all stages of life, which is generally considered
an essential access to understand all the psychological phenomena, and that any defects or problems that could hinder the individual from achieving its natural social interaction, may lead him to enter the circle of social and psychological disorders, if not find a proper guidance and understanding his needs and problems,naturally , if we want to give the employee a safe environment so he can be psychological and socially a
... Show MorePhonetics has close relevance with Musicology; in this study I decided explaining the interlinkages and harmony between Phonetics and Musicology. Linguists preceded philosophers in an attempt to link Phonetics with Musicology; the 1st serious attempt to link Phonetics with Musicology was done by Ibn Jeny (Dead 392 IC), but the real attempt is found with Farabi through his book under title Al Musiqa Al Kabeer, he defined music and link it with tune and relation between melody and tone, This is the same as pointed out by Ikhwan Al Safa who followed the doctrine of al-Farabi, their attention was with music and link it with phoneme, as they made music independent science, and they created special mathematics rules for it. Melody in music can
... Show MoreThe aim of the present study was to distinguish between healthy children and those with epilepsy by electroencephalography (EEG). Two biomarkers including Hurst exponents (H) and Tsallis entropy (TE) were used to investigate the background activity of EEG of 10 healthy children and 10 with epilepsy. EEG artifacts were removed using Savitzky-Golay (SG) filter. As it hypothesize, there was a significant changes in irregularity and complexity in epileptic EEG in comparison with healthy control subjects using t-test (p< 0.05). The increasing in complexity changes were observed in H and TE results of epileptic subjects make them suggested EEG biomarker associated with epilepsy and a reliable tool for detection and identification of this di
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Quranic readings at Imam Razi In his explanation (Unseen keys)
تتراوح ضريبة الارض ما بين 10%من المحصول (الشعير ) و 40 -50 من الخراج
as important aspects emerged related to the management of the caliphate and how it was transferred, and the clarification of the political trends and transformations at the end of their lives. In addition, how the Rightly Guided
Imam Sajjad was interested for the development of individual realization faith when individual being an important element among the component of society He asserted the development of the spirit of tolerance and the removal of intolerance and fulfillment of the promise Also,
In this research a proposed technique is used to enhance the frame difference technique performance for extracting moving objects in video file. One of the most effective factors in performance dropping is noise existence, which may cause incorrect moving objects identification. Therefore it was necessary to find a way to diminish this noise effect. Traditional Average and Median spatial filters can be used to handle such situations. But here in this work the focus is on utilizing spectral domain through using Fourier and Wavelet transformations in order to decrease this noise effect. Experiments and statistical features (Entropy, Standard deviation) proved that these transformations can stand to overcome such problems in an elegant way.
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