تم في هذا البحث استخدام المحفز الجديد المصنع من تحميل دقائق البلاتين النانوية على سطح الصفائح النانوية للكرافين كمحفز ضوئي واختباره لدراسة التجزئة الضوئية لملوثات المياه وازالتها بشكل نهائي من مصادر المياه لما لها من تأثير سلبي على البيئة. حيث تم استخدام صبغة البروموفينول الأزرق كمثال على أحد الملوثات. في البدء تم التأكد من تحضير المحفز بالطريقة المستخدمة في طريقة العمل من خلال تشخيصه باستخدام عدد من التقنيات ومنها تقنية المجهر الالكتروني النافذ عالي الدقة، تقنية طاقة تشتت الاشعة السينية الطيفي عن طريق قياس الامتزاز/ الامتزاز باستخدام غاز النتروجين. كذلك تم قياس المساحة السطحية للمحفز المصنع، بالإضافة الى فحص التركيب الكريستال للمحفز باستخدام تقنية حيود الاشعة السينية. وبعد ان تم التأكد من التركيب النهائي للمحفز الضوئي تضمن الجزء الثاني من العمل دراسة قدرة المحفز المصنع على استخدامه في التجزئة الضوئية لصبغة البروموفينول الأزرق تحت الاشعة فوق البنفسجية حيث تم تحضير عدة تراكيز من صبغة البروموفينول الأزرق، تم تشعيع الصبغة بدون وجود المحفز ووجد بان التجزئة الضوئية لم تكن فعالة وبعد ذلك تم استخدام المحفز مع المحلول المائي للصبغة وبتركيز 15 جزء من المليون وأجريت التجارب باستخدام عدة اوزان من المحفز لتحديد افضل وزن يمكن استخدامه من المحفز في كمية محددة من محلول الصبغة ووجد ان 0.01 غرام من الصبغة لكل 250 ملليتر من المحلول المائي للصبغة هو افضل نسبة يمكن الحصول عليها. كما تم اختبار الوسط للتفاعل في الوسطين الحامضي والقاعدي ووجد ان تفكك الصبغة يزداد بشكل ملحوظ في الوسط القاعدي. تم اقتراح ميكانيكية التفاعل التي بينت ان تكون الجذور الحرة لها دور كبير في مهاجمة الاواصر المزدوجة في الصبغة.
This century is witnessing changes in various fields,which have become a challenge to the enterprises in the contemporary business environment, the most important of which is the importance of measurement and disclosure of the role of knowledge capital in the transition to the knowledge economy, which is no longer the land and labor and physical capital resources the basic. Knowledge-based capital has emerged that provides the enterprise with an area of excellence and enhances its position to achieve competitive advantage. The research tackled the concept, objectives, components and importance of knowledge capital, which is fundamental in knowledge management, creating value added and enhancing competitiveness, as well as an
... Show MoreAbstract As the United Nations approaches its 70th anniversary, the world is going through the most severe accumulation of serious international security failures in recent memory, challenging the UN Security Council’s ability to address them effectively. Over the past four years, crises in Libya, Syria and Ukraine have precipitated a worrisome erosion of great power relations that has complicated Security Council decision making on a number of trouble spots. Its inability to devise consensus responses to the escalating civil war in Syria has been particularly troubling, resulting in the regional spill over into Iraq and the emergence of Islamic State as a new threat to peace in the region and beyond. Meanwhile, the UN’s often under
... Show MoreBackground: Although bleaching is typically considered a safe procedure, various investigations have found minor negative effects and changes in mineral composition. The aim was to Evaluate and compare the efficacy of using Nanohydroxyapatite serum on surface microhardness of enamel surface before and after bleaching with chemically cured Boost bleaching. Material and methods: ten sound human permanent upper and lower premolar teeth were used and their roots were removed 2 mm apically to the cementoenamel junction, the crowns were sectioned mesiodistally into two halves buccal and lingual/palatal, the buccal surface was further subdivided into two halves. The samples were embeded in an acrylic resin, resulting in 30 specimens divide
... Show MoreForward-swept wings were researched and introduced to improve maneuverability, control, and fuel efficiency while reducing drag and they are often used alongside canards, to further enhance their characteristics. In this research, the effects of canard dihedral angles on the wing loading of a forward-swept wing in transonic flow conditions were studied, as the wing loading provides a measure of wing’s efficiency (lift/drag). A generic aircraft model from literatures was selected, simulated, and compared to, using CFD software ANSYS/Fluent where the flow equations were solved to calculate the aerodynamic characteristics. The research was carried at two different Mach numbers, 0.6 and 0.9, for five different canard dihedral angles which tra
... Show MoreIn this study, a three-dimensional finite element analysis using ANSYS 12.1 program had been employed to simulate simply supported reinforced concrete (RC) T-beams with multiple web circular openings subjected to an impact loading. Three design parameters were considered, including size, location and number of the web openings. Twelve models of simply supported RC T-beams were subjected to one point of transient (impact) loading at mid span. Beams were simulated and analysis results were obtained in terms of mid span deflection-time histories and compared with the results of the solid reference one. The maximum mid span deflection is an important index for evaluating damage levels of the RC beams subjected to impact loading. Three experi
... Show MoreThere is an interesting potential for the use of GFRP-pultruded profiles in hybrid GFRP-concrete structural elements, either for new constructions or for the rehabilitation of existing structures. This paper provides experimental and numerical investigations on the flexural performance of reinforced concrete (RC) specimens composite with encased pultruded GFRP I-sections. Five simply supported composite beams were tested in this experimental program to investigate the static flexural behavior of encased GFRP beams with high-strength concrete. Besides, the effect of using shear studs to improve the composite interaction between the GFRP beam and concrete as well as the effect of web stiffeners of GFRP were explored. Encasing the GFRP
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