Pulse Profile Rule in Laser Heating of Opaque Targets in Air

A theoretical model is developed to determine time evolution of temperature at the surface of an opaque target placed in air for cases characterized by the formation of laser supported absorption waves (LSAW) plasmas. The model takes into account the power temporal variation throughout an incident laser pulse, (i.e. pulse shape, or simply: pulse profile).Three proposed profiles are employed and results are compared with the square pulse approximation of a constant power

Psychological Security And Self-Efficacy Among Syrian Refugee Students Inside And Outside The Camps

The present study aimed to identify the degree of psychological security and self-efficacy among the Syrian refugee students inside and outside the camps. The sample consisted of 600 students from Syrian refugees inside and outside the camps in the second semester of the academic year 2014-2015. Scales for psychological security and self- efficacy were implemented to answer the study questions. Results indicated low degree of psychological security for Syrian refugee students inside the camps but moderate for those outside the camps. The results also showed low degree of self-efficacy among Syrian refugee students inside and outside the camps. The results indicated also statistically significant correlation between psychological security and self- efficacy

An attempt to understand complexity in a government digital transformation project

Digital transformation projects will become one of the dominating tools for mastering digital transformation in governments. Studies show that such projects are complex undertakings and increasingly difficult to manage. The purpose of the paper is to provide a better understanding of the factors that cause complexity in government digital transformation projects. The authors use an in-depth case study approach to investigate factors of complexity in an ongoing digital transformation project. The results indicate that complexity in this project is rooted in dynamic relationships between multiple dimensions of organization, technologies, and innovation. The authors conclude that when organizational structuring, the introduction of new technology, and efforts to innovate and create added value for citizens and businesses operate in tandem, the pervasive complexity associated with delivering government digital transformation projects becomes increasingly difficult to manage

أثر الخلاف في القياس على الأصل المحصور بعدد بين المُثبِتين والنّافيـن على الفـروع الفقهيّـة - دراسة أصولية تطبيقية- The Impact of Disagreement in Qiyas (analoyg) on the Origin Limited to a Number Between the Proven and the Negative on the Fiqh Branches “An applied fundamentalist study”

ملخص هذا البحث المُعنون بـ أثر الخلاف في القياس على الأصل المحصور بعدد بين المُثبِتين والنّافين على الفروع الفقهيَّة دراسة أصولية تطبيقية ، يتطرَّق بالدِّراسة المعمَّقة لمسألة أصوليّة ذات أثر بالغ في الفروع الفقهيّة، وهي ما كان الأصل محصورًا بعدد معيَّن كأربع أو خمس ونحو ذلك، فهل يمنع ذلك من القياس عليه عن طريق تعدية حكمه إلى فروع مسكوت عنها، تشترك مع الأصل المنطوق به في علة الحُكم ومناطه أم لا؟ وذلك من خلال الحديث عن التعريف بمصطلحات البحث (القياس، الأصل، المحصور)، وذكر العلاقة بين القاعدة وبعض القواعد القريبة، وبيان خلاف الأصوليّين في حكم القياس على الأصل المحصور بعدد، وأثر الاختلاف فيها على عدد من الفروع الفقهية، فُصِّلت في صفحات هذا البحث، وقد توصَّل الباحث إلى القول: إنّ الأصلَ المحصورَ بعددٍ معيّن يجوز القياسُ عليه، كما أوصى بتوجيه عناية الباحثين بالكتابة في الربط بين القواعد الأصوليّة والمسائل الفقهيّة؛ لضبط عملية الاجتهاد. كلمات مفتاحية: القياس، الأصل، العدد المحصور، الفروع الفقهيّة. The Impact of Disagreement in Qiyas (analoyg) on the Origin Limited to a Number Between the Proven and the Negative on the Fiqh Branches “An applied fundamentalist study” Abstract This research is entitled “The Impact of Disagreement in Measurement on the Origin Limited to a Number Between the Proven and the Negative on the Fiqh Branches An applied fundamentalist study”, it deals with an in-depth study of a fundamental issue that has a profound impact on the branches of jurisprudence that is, if the original is limited to a specific number, such as four or five, and so on, does that prevent it from being compared to it by transcending its ruling to branches that are silent about it that share with the original utterance in the reason for the ruling and its implications, or not? And that is by talking about the definition of the search terms (measurement, origin, confined), and the statement of the fundamentalists’ disagreement in the rule of analogy on the origin limited to a number, and the impact of the difference in them on a number of jurisprudential branches that are detailed in the pages of this research. The researcher came to the saying: that the origin that is limited to a certain number may be measured against, as he recommended directing researchers’ attention to writing in linking the fundamental rules and jurisprudence issues; To adjust for the process of ijtihad. Keywords: Measurement, Origin, Limited number, Jurisprudence branches

Mechanical properties of old concrete—UHPFC interface

The uniqueness of Ultra-High Performance Fiber Concrete (UHPFC) is its extremely low porosity gives its low permeability and high durability, making it potentially suitable for rehabilitation and retrofitting reinforced concrete structures or for use as a new construction material. This experimental study was performed to assess the bond strength between UHPFC as a repair material and Normal Concrete (NC) substrate as an old material; split tensile strength and slant shear tests were performed to quantify the bond strength in indirect tension and shear respectively, also the correlation between split tensile strength and slant shear were studied. The result showed that UHPFC has been cured by steam, gives high bond strength at the early age of the repair process, and interacts well with the surface of NC, as a result the failure occurred mostly in the NC substrate. A good correlation between the slant shear test results and the split tensile test results has been observed

Effect of different curing conditions on the mechanical properties of UHPFC

(Received: Match 20, 2013; Accepted in Revised Form: June 22, 2013) Abstract: Ultra-High Performance Fiber Concrete (UHPFC) is a new class of concrete. Because of its distinguished mechanical properties, UHPFC is considered as an ideal alternative material for use in developing new structural solutions. This paper discusses on influence of different curing conditions on mechanical properties of UHPFC. An experimental program was performed to study the mechanical properties of UHPFC which were cured under six different curing conditions. Test results indicated that steam and boil curing methods showed a promising performance particularly at early age of curing compared to other type of curing

Effect of high temperature on the mechanical properties of basalt fibre self-compacting concrete as an overlay material

Basalt fibres are modern inorganic concrete fibres, fabricated by melting the basalt rock. These fibres exhibited remarkable resistance to elevated temperatures in comparison with other manufactured fibres. Thus, when the impact of fire is the main consideration, basalt fibres are favoured in the construction of concrete buildings. In this study, the effects of basalt fibres on the workability of fresh self-compacting concrete (SCC) were measured using slump flow, J-ring flow, V-funnel flow and L-box height ratio. The properties of hardened concrete such as compressive strength, splitting strength, modulus of elasticity, flexural strength, and Poisson's ratio were examined at temperatures between 25 °C and 500 °C. Also, the bond strength between the basalt fibre SCC as an overlay material and a normal concrete substrate was analysed at elevated temperatures. The interfacial surface between the concrete parts of the hybrid samples was roughened in different ways to determine the best roughening mode, which induced high slant shear strength of concrete under fire. The experimental results revealed that increasing the temperature up to 500 °C reduced the tensile and compressive strengths of SCC by over 20%. The optimum slant shear strength of hybrid concrete under fire was achieved by roughening the interfacial surface through the sandblasting method. © 2020 Elsevier Lt