The present research had dealt with preparing  bars  with the length of about  (13 cm) and  adiametar  of  (1.5 cm) of composite materials with metal  matrix  represented by (Al-Cu-Mg) alloy cast enforced by (ZrO₂) particles with chosen weight  percentages (1.5, 2.5 ,3.5, 5.5 %). The base  cast and the composite  materials were prepared by casting method by uses vortex  Technique inorder to  fix up (ZrO₂) particles in homogeneous way on  the  base cast. In addition to  that, two main groups of composite materials were prepared depending on the particles size of (ZrO₂) , respectively.       &n

Crystalline silicon (c-Si) has low optical absorption due to its high surface reflection of incident light. Nanotexturing of c-Si which produces black silicon (b-Si) offers a promising solution. In this work, effect of H₂O₂ concentrations towards surface morphological and optical properties of b-Si fabricated by two-step silver-assisted wet chemical etching (Ag-based two-step MACE) for potential photovoltaic (PV) applications is presented. The method involves a 30 s deposition of silver nanoparticles (Ag NPs) in an aqueous solution of AgNO₃:HF (5:6) and an optimized etching in HF:H₂O₂:DI H₂O solution under 0.62 M, 1.85 M, 2.47 M, and 3.7 M concentrations of H₂O<

ملخص البحث

بينت في البحث ماهية الإعجاز القرآني, وتعريف الإعجاز والقرآن,
ومفهوم مصطلح الإعجاز القرآني, ودلائل الإعجاز, ودلائل نبوة محمد صلى
الله عليه وآله وسلم , والقدر المعجز من القرآن, ووجوه إعجاز القرآن,
وأنواع الإعجاز القرآني, ومجموعة من الآيات الكونية

فسيفساء قبة الصخرة دراسة تحليلية

 يَحْمِلُ المشروعُ عنوان "المشروع الرقمي البون لبرديات الموتىDigitales Bonner Totenbuch-Papyrus"، ويمكن الوصول إليه عبر موقعه الرسمي  https://tottenbuch.awk.nrw.deانطلق العمل في هذا المشروع منذ عام 2004م، ويهدف إلى رَصْدِ برديات "كتاب الموتى" الموجودة في متاحف العالم ومكتبات الجامعات والمعاهد الأوروبية، وحَصْرِها رقمياً. يستند هذا المشروع إلى تحالفٍ علمي بين جامعتي كولونيا تأسست عام 1388م، وبون تأسست عام 1818م، وهما من أبرز المؤسسات ال

يعد التحليل العاملي Factor Analysis أحد الأساليب الإحصائية المهمة والتي يصعب تنفيذها يدويا ً أو بالألات الحاسبة الصغيرة لذا لاقى الباحثين صعوبة في إستخدامه في البداية بل كان من المستحيل القيام به ، لذا فالمؤلف قد تناول التحيلي العاملي الاستكشافي لكونه إسلوب إحصائي يستخدم في تحليل البيانات ويتطلب شروطا ً لأستخدامه ودقة في مراعاة هذه الشروط ويتطلب أيضا ً معايير يجب أن يتأكد الباحث من توافرها في البيانات وهذا ما تم ت

Humanity has Suffered Greatly from the Economic crisis and instability, Before the Emergence of the rule of the Capitalist System, However, the reaons were Different. But almost Completely Contradictory. At a time When the Causes of the Crisis was due to the time Factor is the product of failure of productie forces, Bears modern Crises resoled by the progress that is in the embrace of the abundance, and as far as lies in the nature and content of the capitalist system itselfas a system based on the creation of productive capacities in excess unable to accomplish through demand by the chaos of production based,  on the logic of the market on one hand, and the nature of the output and direction. On the other hand the relations

This study presents the effect of laser energy on burning loss of magnesium from the holes' drilled in aluminum alloy 5052. High energy free running pulsed Nd:Glass laser of 300 µs pulse duration has been used to perform the experiments. The laser energy was varied from 1.0 to 8.0 Joules, The drilling processes have been carried out under atmospheric pressure and vacuum inside a specially designed chamber. Microhardness of the blind drilled holes has been investigated .The results indicated that the magnesium loss could be manipulated by adjusting the focusing conditions of the laser beam. Almost, the obtained holes were free of cracks with low taper and low sputter deposition. .The holes performed under atmospheric conditions have high

Atheism is one of the most dangerous absurd doctrines that have swept the world in the modern era. Its strength lies in the bodies that stand behind it and adopt its ideologies which are accompanied by the tremendous media momentum of the theses of its supporters based on scientific and non-scientific levels. And since the denial of the existence of the Creator is the main focus and central point which the atheists based their view towards the universe, life and man, this humble research came to discuss the claim of the existence of the world by pure chance, and try to explain this scientifically through the theory of natural selection and survival of the fittest developed by the English biologist Charles Darwin. The resea