Among the different passive techniques heat pipe heat exchanger (HPHE) seems to be the most effective one for energy saving in heating ventilation and air conditioning system (HVAC). The applications for nanofluids with high conductivity are favorable to increase the thermal performance in HPHE. Even though the nanofluid has the higher heat conduction coefficient that dispels more heat theoretically but the higher concentration will make clustering .Clustering is a problem that must be solved before nanofluids can be considered for long-term practical uses. Results showed that the maximum value of relative power is 0.13 mW at nanofluid compared with other concentrations due to the low density of nanofluid at this concentration. For higher concentration, the agglomeration can occur so the scattering of laser light was increased resulting in the decrement of output power. Laser with longer wavelength (650nm) at visible spectral region was more sensing compared with 532 nm laser for low concentration of Ag inside deionized water. The starting sensing powers of 532nm CW diode laser is 0.1W of these concentrations for this type of nanofluid while the ending detection power is 1W.
In our time, not too long ago, the universities of the world have been fast to take care of the study of an innovative type of technical and human studies, called the science of "comparative literature". Comparative research studies have grown and flourished rapidly in response to the demands of both mental and artistic life. This shows the increasing awareness at both the modern national and the international levels in order to develop through connecting with the international intellectual, nental and artistic currents to nurture ethics and originality. Comparative studies show that the beginning of the comparative literature goes back to the time when the Latin literature was connected to the Greek literature and th
... Show MoreThis research is an attempt to study and evaluate the maintenance function at Factory 7 - The State General Company for Leather Industries, and to design a computerized preventive maintenance system to design and to analyze preventive maintenance. To accomplish the objectives of this research, data were gathered and analyzed according to the reliability engineering criteria for the period 2/1– 30/6/2005, then a preventive maintenance plan was designed for each machine of the sample study using the computerized system designed in this research. A Monte Carlo Simulation methodology was used for the purpose of evaluating the performance of the preventive maintenance plan of each machine for one year. The simulation res
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Abstract:
This research aims to compare Bayesian Method and Full Maximum Likelihood to estimate hierarchical Poisson regression model.
The comparison was done by simulation using different sample sizes (n = 30, 60, 120) and different Frequencies (r = 1000, 5000) for the experiments as was the adoption of the Mean Square Error to compare the preference estimation methods and then choose the best way to appreciate model and concluded that hierarchical Poisson regression model that has been appreciated Full Maximum Likelihood Full Maximum Likelihood with sample size (n = 30) is the best to represent the maternal mortality data after it has been reliance value param
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يهدف هذا البحث إلى تأصيل الإستدلال بالقاعدة العقائدية، وبيان ضوابطه، وإبراز نماذج من أهم تطبيقاته المعاصرة، وقد أعتمد مناهج من أهمها المنهج الإستقرائي والمنهج المقارن ، وتناول البحث التعريف لقصص النبوة فى الأديان السماوية ، وعرض بعض الدراسات السابقة التى تناولت نفس الموضوع ، ثم تطرق البحث لذكر نماذج من قصص الأنبياء من الديانات السماوية الثلاث ، وتوصل البحث الى أن الأديان السماوية رغم بعض الإختلاف
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The study aims to identify the common fears of preschool children and their relationship to the approaches to parental treatment in South Al Batinah Governorate from their mother’s point of view. Total of (466) mothers were selected as the study sample. The researcher used the scale of common fear and the scale of parental treatment approaches. The results of the study have shown that the most common fear among the study sample was (the fear of darkness) in the first level with a rate of 75.03%, and in the second level came the item (my child is afraid to sleep alone) by 72.74%, in the third level came to the item (fear of seeing insects) with a rate of 67.59%, and the last one was (the fear of rain) w
... Show Moreتهدف الدراسة الحالية الى استعمال الانموذج اللوجستي ثنائي المعلم في تدريج مقياس الشخصية الافتراضية المتعدد الابعاد لطلبة الجامعة وفقا لنظرية الاستجابة للفقرة، والخروج بتعميم لنتائج البحث والوقوف على الاجراءات العلمية المناسبة وتوفير تطبيق عملي علمي صحيح لاعتمادها من قبل الباحثين. وقد اتبعث الباحثة الاسلوب العلمي من خطوات واجراءات في عملية بناء المقياس حيث حدت ابعاد الشخصية الافتراضية المتمثلة بسبع ابعا
... Show MoreResearch questions start from the fact that what the Arab origins of education indicted . First question are :
- To what extent the subject of assets acquired a specific meaning in the Arabic books and educational subjects ? Is these selections are reflected on the classification of assets and their types ?
- What’s the nature of the content ? .Is there a consistency between the meaning and content ?
- What entrances handling and curriculum approach and tactics are in those books ?
- Is the assets subject introduced within the grade best suited ?
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... Show MoreThis research aimed to evaluate the level of readiness to teach science in the light of the information, media, and technology skills among undergraduate students at the Faculty of Edu-cation, King Khalid University. To achieve this goal, a descriptive and analytical approach was used. A list of readiness to teach science was prepared in the light of Information, media, and technology skills, and in the light of this list, a cognitive test, observation sheet, and attitude scale were prepared to assess readiness to teach science in its three aspects, cognitive, behavioral, and emotional. The sample of the research consisted of (42) students enrolled in field training courses at the sixth, seventh and eighth levels. Research tools were app
... Show MoreThis research discusses the rehabilitation of heritage markets in the historical centers of Islamic Arab cities and their use in the field of cultural tourism as one of the most important tourist attractions and the subsequent revival of the national economy in addition to preserving the urban heritage as these markets part of the historical centers of cities. The research also discusses the preservation of the continuity of heritage markets as a product of cultural heritage value within an integrated framework to preserve the urban heritage in the historic centers of cities. The study then reviews a number of experiences of Arab and Islamic countries in the field of preserving and rehabilitating heritage markets, which qualify them to b
... Show MoreChitinase-3-like 1 protein (YKL-40) is a glycoprotein primarily produced in the arthritic joint and plays a crucial role in inflammatory processes. The aim of the study is to establish the role of YKL-40 as a biomarker for rheumatoid arthritis (RA) compared to proinflammatory biomarkers and disease activity. The study included 58 patients and 18 control. Diseases activity score (DAS-28) and clinical disease activity index (CDAI) were measured. Serum level of YKL-40, tumor necrosis factor-α (TNF-α), interleukin-1B (IL-1β), erythrocyte sedimentation (ESR), rheumatoid factor (RF), C-reactive protein (CRP), and anti-citrullinated protein antibody (ACPA) were assessed. The results showed that the median serum YKL-40 level which was 5.42
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