The nonlinear refractive index and the nonlinear absorption coefficient of unmodified and functional poly(methyl methacrylate) PMMA films were studied before and after the addition of the filler by the z-scan technique, using a Q-switched Nd:YAG laser at two wavelengths: 532 nm and 1064 nm, and at three input energies (13, 33 and 53) mJ. Both linear and nonlinear refractive indices and absorption coefficients of polymer films were studied by using UV-VIS spectrophotometer. The results show that the creation of functional PMMA from unmodified PMMA will increase the nonlinear optical properties in the functional PMMA/copper matrix more than in the unmodified PMMA/copper matrix. Hence, the functional PMMA appears promising as a useful third-order nonlinear material. The nonlinear refractive index is directly proportional to the input intensity and directly proportional to the increase in the concentration of the filler, while the nonlinear absorption coefficient is inversely proportional to the input energy and inversely proportional to the increase in the concentration of the filler. The nonlinear effect is more enhanced at the 532 nm wavelength than at 1064 nm..
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تضمن البحث دراسة تأثير بعض مركبات قواعد شيف الجديدة على فعالية أنزيم الكولين استريز في مصل دم الإنسان وقد لوحظ بأن المركبات المستعملة تسبب تنشيط فعالية الانزيم وباستعمال تراكيز مختلفة من هذه المركبات ودراسة نوع التثبيط اظهرت النتائج المستحصله من رسم line weaver Burk ان التثبيط يكون غير تنافسي وكانت النسبه المئوية التثبيط بهذه المركبات تتراوح بين (38.44-87.16(%
تعد ظاهرة الارهاب المتزايدة في العالم من اخطر اشكال التهديدات الامنية التي تواجة الدول لانها تستهدف في جانب مهم منها امن واستقرارومستقبل مجتمعاتها لاسيما اذا جمع الفعل الارهابي بين مطامع واهداف القوى الخارجية التي لا تريد استخدام ادواتها المباشرة وانما بالاعتماد على محركات في خلق الازمات داخل الدول المستهدفة
... Show Moreتهدف هذه الدراسة إلى التعرف على تأثير المؤشرات الفسيولوجية على أداء الرياضيين في العاب المضرب (التنس، الريشة الطائرة، وتنس الطاولة)، مع التركيز على الجوانب المتعلقة بنظام الطاقة، الجهاز التنفسي، الدورة الدموية، والجهاز العصبي. تعتمد هذه الألعاب بشكل كبير على التوافق بين الأنظمة الفسيولوجية المختلفة لتحقيق الأداء الأمثل في التنس،بعبارة اخرى "التوافق بين الأنظمة الفسيولوجية المختلفة لتحقيق الأداء الأمثل ف
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Electrochemical Grinding (ECG) process is a mechanically assisted electrochemical process for material processing. The process is able to successfully machine electrically conducting harder materials at faster rate with improved surface finish and dimensional control. This research studies the effect of applied current, electrolyte concentration, spindle speed and the gap between workpiece and tool on hardness and material removal rate during electrochemical grinding for stainless steel 316. The characteristic features of the electrochemical grinding process are explored through Taguchi-design-based experimental studies. The better hardness can be obtained at 10 A of the current, 150 g/l of the electrolyte concentration, 0.3 mm of gap an
... Show MoreMost studies indicated that the values of atmospheric variables have changed from their general rates due to pollution or global warming etc. Hence, the research indicates the changes of direct solar radiation values over a whole century i.e. from 1900 to 2000 depending on registered data for four cities, namely (Mosul - Baghdad - Rutba - Basra. Moreover, attemptsto correlate the direct solar radiation with the temperature values have been recorded over that period. The results showed that there is a decreasing pattern of radiation quantities over time throughout the study period, where the value of direct radiation over the city of Baghdad 5550 w/m2 was recorded in the year 1900, but this ratio decreased cle
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The issue of Palestinian prisoners inside the prisons of the Israeli occupation is considered
a humanitarian issue par excellence، as it affects every Palestinian family as a
result of the absence of a husband، wife or son.
Almost no Palestinian house is vacant without one or more prisoners، and even women،
children and the elderly are not spared from these arrests.
The problem of the study was to identify the role of public relations in the Ministry
of Detainees and Ex-Prisoners Affairs in educating the Palestinian public about the
issue of prisoners، the nature of this role and the means used to bring support and
solidarity with this important and sensitive issue through the applied study on the
employee
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The physical, mechanical, electrical and thermal properties containing (Viscosity, curing, adhesion force, Tensile strength, Lap shear strength, Resistively, Electrical conductivity and flammability) of adhesive material that prepared from Nitrocellulose reinforced with graphite particles and aluminum streat. A comparison is made between the properties of adhesive material with varying percentage of graphite powder (0%, 25%, 30%, 35%, 40%) to find out the effect of reinforcement on the adhesive material. The ability of property an electrical was studied through the measurement of conductivity a function of temperature varying. The results of comparison have clearly shown that the increasing of conten
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