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.
In Incremental sheet metal forming process, one important step is to produce tool path, an
accurate tool path is one of the main challenge of incremental sheet metal forming
process. Various factors should be considered prior to generation of the tool path i.e.
mechanical properties of sheet metal, the holding mechanism, tool speed, feed rate and
tool size. In this work investigation studies have been carried out to find the different tool
path strategies to control the twist effect in the final product manufactured by single point
incremental sheet metal forming (SPIF), an adaptive tool path strategy was proposed and
examined for several Aluminum conical models. The comparison of the proposed tool path with t
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In this research is to study the influence of the aging heat treatment on the pitting corrosion resistance of martensitic stainless steel (MSS), where a number of specimens from martensitic stainless steel were subjected to solution treatment at 1100 oC for one hour followed by water quenching then aging in the temperatures range (500-750) oC for different holding times (1,5,10,15&20) hr. Accelerated chemical corrosion test and immersion chemical corrosion test were performed on samples after heat treatment. The results of the research showed that the pitting corrosion resistance is significantly affected by the aging temperature. Where found that the aging samples at a temperature of 500 °C have the highest ra
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In this paper, the speed control of the real DC motor is experimentally investigated using nonlinear PID neural network controller. As a simple and fast tuning algorithm, two optimization techniques are used; trial and error method and particle swarm optimization PSO algorithm in order to tune the nonlinear PID neural controller's parameters and to find best speed response of the DC motor. To save time in the real system, a Matlab simulation package is used to carry out these algorithms to tune and find the best values of the nonlinear PID parameters. Then these parameters are used in the designed real time nonlinear PID controller system based on LabVIEW package. Simulation and experimental results are compared with each other and showe
... Show MoreJamal Basha: His Administrative and Political Effort in Baghdad
Phonetics 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 MoreHolly Quran and prophetic sunna is the two main sources for this religion and the formers derived the rules from them directly . the jurisprudent was a scientist in commentary of holly Quran , narrators of prophetic Tradition, jurisprudence and linguistics in the same time. The sciences of commentary , jurisprudence , Tradition and linguistics were integral system without any distinguishing until these sciences started to distinguish in their limits and ranges.
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 MoreImam 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,
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