In this work, an experimental analysis is made to predict the thermal performance of the natural-convection phenomenon from a heated vertical externally finned-tube to surrounding air through an open-ended enclosure. Two different configurations of longitudinal rectangular fin namely, continuous and interrupted are utilized with constant thickness, different numbers, and different heights are extended radially on the outer surface of a heated tube. The tube is heated electrically from inner surface with five varied power input magnitudes. The effect of fins configuration, fins number, fins height, and heat flux of the inner tube surface on the thermal performance of natural convection have been studied and analyzed experimentally. Obtained results show that the tube with twelve interrupted longitudinal fins gives the best natural-convection thermal performance in terms of average Nusselt number, about 20% greater than that for the tube with continuous fins. Experimental correlations to predict the average Nusselt number for the heated tubes with continuous and interrupted longitudinal fins are proposed. The present data are compared to previous study and good convergence is noticed.
The primary objective of the present research is to diagnose the most mportant imensions of quality of work life in a sample of individuals working in the Northern Gas Filling Company in Nynawa. The study sample consisted of 140 employees of the Northern Region Filling Company in even ,Through a questionnaire prepared for this purpose. The study concluded that there are five main factors that are considered to be measure of the quality of working life and are based on their importance: Empowerment, organizational health, internal work environment, motivation, development and training of workers. The study recommended that the organization should payattentio
... Show Moreمن الضروري اجراء تحليل الحساسية للمشاريع الاستثمارية التي يتبناها القطاع العام أو الخاص وذلك لسببين ، الاول هو تضمين عامل المخاطرة واللاتاكد عند تقييم المشروع من الناحية الاقتصادية ، حيث لابد من يكون نسبة مخاطرة وعدم تاكد عند تقييم أي مشروع لمجابهة احداث المستقبل الغير متوقعة ، الثاني المنافسة الشديدة بين المنتجات المحلية والمستوردة ، حيث ان تحليل الحساسية يعطينا صورة عن مدى حساسية القيمة الحالية
... Show Moreان الهدف من هذا البحث هو تحليل كتاب الفيزياء للصف الخامس العلمي للمرحلة الاعدادية في ضوء معايير تصميم وانتاج الانفوجرافيك. ويتم التحقق من هدف البحث من خلال الاجابة عن الاسئلة الاتية: ما هي المعايير التي يمكن في ضوئها تقويم كتاب الفيزياءلصف الخامس العلمي؟ ما النسبة الواجب توافرها لمعايير تصميم وانتاج الانفوجرافيك في كتاب الفيزياء لصف الخامس العلمي؟ ما مدى توفر معايير تصميم وانتاج الانفوجرافيك في كتاب الفيزي
... Show MoreThe field of translation studies is full of different types of social, economic, political, and literary translations as well as other types related to the life of the human being which are several, but the translation of the grammatical aspects is considered one of the important tasks that both of the translator and interpreter have to take in consideration, so as to get an translation so perfect and so correct as much as possible. One of the grammatical aspects that we have to know how to be translated correctly is the relative pronouns. And it’s about the relative pronouns translation from Spanish to Arabic turns my research work.
In this research, I will consider how to be translated the relat
... Show MoreThis study examines the dynamic relationship between stock market and economic activity in the United States to verify the possibility of using financial indicators to monitor the turning points in the expected path of future economic activity. Has been used methodology (Johansen - Juselius) for the Co-integration and causal (Granger) to test the relationship between the (S & P 500 , DJ) index and gross domestic product (GDP) in the United States for the period
(1960-2009). The results of the analysis revealed the existence of a causal relationship duplex (two-way) between the variables mentioned. which means the possibility of the use stock market indicators to pre
The main goal of the current research is to know -Environmental problems included in the content of the two science books (chemistry units) for intermediate stage
A list of environmental problems had been prepared and consisting of (8) main areas which are (air and atmosphere pollution, water pollution, soil pollution, energy, disturbance of biodiversity and environmental balance, waste management, food and medicinal pollution, investment of mineral wealth). Of which (60) sub-problems, at that time the researcher analyzed the two science books (two chemistry units) for the intermediate stage of the academic year (2020-2021) in light of the list that was prepared, and the validity and consisten
... Show MoreThe aim of the research is to identify the imaginative thinking skills included in the content of the chemistry textbook for fifth-grade students in biological sciences at the preparatory stage, which is approved by the Ministry of Education, General Directorate of Curricula in the academic year 2020-2021. To achieve the objective of the study, the researcher depends on the previous studies in the field and content of imaginative thinking skills for preparing a list of skills that includes (3) essential skills and (11) sub-skills and (28) items related to all skills. The researcher adopted the analytical descriptive approach because of its appropriation of the goals of the research. Then the researcher analyzed the content of the book de
... Show MoreThe current research aims to identify the extent to which cognitive economics skills are included in the content of the chemistry textbook for the third intermediate grade, and the research sample was represented in the chemistry textbook for the third intermediate grade. A list of knowledge economy skills was prepared (6) main skills (basic skills, communication skills, thinking skills, work skills Group, information-gathering skill, behavioral skills (and (20) sub-skills) (reading, writing, operations, computer skills and employability, oral expression and written communication, dialogue, persuasion, influence and arousal, analysis, problem-solving, decision-making, suggestions and hypotheses and employing them. Controlling, directing
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