The design, construction and investigation of experimental study of two compound parabolic concentrators (CPCs) with tubular absorber have been presented. The performance of CPCs have been evaluated by using outdoor experimental measurements including the instantaneous thermal efficiency. The two CPCs are tested instantly by holding them on a common structure. Many tests are conducted in the present work by truncating one of them in three different levels. For each truncation the acceptance half angle (θc) was changed. Geometrically, the acceptance half angle for standard CPC is (26o). For the truncation levels for the other CPC 1, 2 and 3 the acceptance half angle were 20o, 26o and 59o, consequently. A significant difference between the instantaneous thermal efficiency of 3.86× CPC (θc=20o) and 2.32× CPC (θc=26o), and between that for 3.61× CPC (θc=26o) and 2.32× CPC (θc=26o). It's noticed that the difference between the instantaneous thermal efficiency of 2.32× CPC (θc=59o) and 2.32× CPC (θc=26o) is small compared with the difference of the first and second cases, the instantaneous thermal efficiency of 2.32× CPC (26o) was higher than those for other three CPCs. The experimental results show that the maximum thermal efficiency of the full 2.32×CPC (26o) is 0.708, the maximum thermal efficiency of the 3.93×CPC (15o), when it's truncated to 3.84× CPC (20o), 3.61× CPC (26o) and 2.32× CPC (59o) are 0.51, 0.52 and 0.66, respectively. As the concentration ratio decreases from (3.93× to 1×), the thermal efficiency, energy losses and optical efficiency increase from (0.47 to 63), (1.58 to 7.2 K.m2/W) and (0.494 to 0.797), respectively.
Energy savings are very common in IoT sensor networks because IoT sensor nodes operate with their own limited battery. The data transmission in the IoT sensor nodes is very costly and consume much of the energy while the energy usage for data processing is considerably lower. There are several energy-saving strategies and principles, mainly dedicated to reducing the transmission of data. Therefore, with minimizing data transfers in IoT sensor networks, can conserve a considerable amount of energy. In this research, a Compression-Based Data Reduction (CBDR) technique was suggested which works in the level of IoT sensor nodes. The CBDR includes two stages of compression, a lossy SAX Quantization stage which reduces the dynamic range of the
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اثر بديع الزمان سعيد النورسي على الفكر الاسلامي المعاصر في تركيا
ت نايبتسلاا ثحابلا مدختسا دقو ,ةيداصتقلاا تادحولا ةميق ىلع انوروك ةحئاج لظ يف يلخادلا قيقدتلا ريثأت ةيداصتقلاا تادحولا فادها قيقحت يف مهسي يلخادلا قيقدتلا نا ثحبلا تاجاتنتسا مها تناكو , ثحبلا تاريغتم نيب ةقلاعلا نايبل رطاخملا ةرادأو اهتءافكو اهتيلعاف نيسحتو قيقدتلا عقوم زيزعت ىلع لمعلا تايصوتلا مها تناكو امك, ةمكوحلا تايلمعو ةباقرلاو قيقحتل رارمتسأب ئراوطلا ططخ ثيدحتو ةبقارمو ةحضاو تازفحم ءاشناو ةلمتحم
... Show MoreSome great families in England had competed for the sake of getting authority and power in England.
This competition turned to be a bloody civil war which extended till 1455 and ended with the victory of Henry Tudor whose judgment in England started from 28th of August 1458, consequently a new dynast which is known as (the Tudor)has established
The research aims to identify the level of functional engagement and hope-based thinking of kindergarten teachers, identify if there is a significant difference in functional engagement and hope-based thinking in terms of specialization and years of service for kindergarten teachers, identify if there is a significant correlation between functional engagement and hope-based thinking of kindergarten teachers. The current research is determined by kindergarten teachers in the Second Rusafa Baghdad Education Directorate for the academic year (2022-2023). In order to achieve the objectives of the research, the researcher prepared a functional engagement scale, which consists of (45) items in three areas: Perceptual and functional engagement
... Show Moreيعد موضوع البرنامج النووي الايراني من الموضوعات التي تحظى بأهمية كبيرة في مجال الدراسات الدولية بشكل عام والدراسات الاستراتيجية بشكل خاص، وذلك لكونه لا يتعلق بمستقبل الجمهورية الاسلامية الايرانية فحسب بل بمستقبل منطقة الشرق الاوسط ولاسيما منطقة الخليج العربي، وهو ذو صله وثيقة بمستقبل انتشار الاسلحة النووية بين دول المنطقة والذي قد يؤدي انتشارها الى حروب اقليمية وقد يوظف فيها هذا النوع من الاسلحة النووية،
... Show Moreاستأثرت ظاهرة هجرة العقول او (الكفاءات العلمية) خلال العقدين الاخيرين باهتمام البلدان المتقدمة والنامية على حد سواء ، وذلك نسبة لاثارها السلبية والايجابية ، على الواقع الاجتماعي والتنموي في الدول المرسلة والمستقبلة ، وزاد الاهتمام بهذه الظاهرة في البلدان النامية لما ينجم عن هجرة العقول من خسارة البلدان المرسلة للموارد البشرية العالية التاهيل ، واللازمة لتحقيق النمو الاقتصادي ذ
... Show Moreعلى الرغم من إن الابداع والمبدعين وخصائصهم العقلية والشخصية تعد من المفاهيم المهمة والشائعة في الحياة بمجالاتها كافة، ففي الوقت الذي نجد فيه العديد من الدراسات والمقالات العربية والاجنبية التي تناولته بشكل او باخر، لكنها جميعها اعتمدت على المقياس الخاص بالتفكير الابداعي لمؤسسه الاول تورانس منذ عام (1967)، متجاهلة التغيير والتطور المعلوماتي ولا سيما في الانترنيت والحاسوب وما افرزه هذا من مفردات شاعت وتداول
... Show MoreThe main purpose of this work is to introduce some types of fuzzy convergence sequences of operators defined on a standard fuzzy normed space (SFN-spaces) and investigate some properties and relationships between these concepts. Firstly, the definition of weak fuzzy convergence sequence in terms of fuzzy bounded linear functional is given. Then the notions of weakly and strongly fuzzy convergence sequences of operators are introduced and essential theorems related to these concepts are proved. In particular, if ( ) is a strongly fuzzy convergent sequence with a limit where linear operator from complete standard fuzzy normed space into a standard fuzzy normed space then belongs to the set of all fuzzy bounded linear operators
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