A paraffin wax and copper foam matrix were used as a thermal energy storage material in the double passes air solar chimney (SC) collector to get ventilation effect through daytime and after sunset. Air SC collector was installed in the south wall of an insulated test room and tested with different working angles (30o, 45o and 60o). Different SC types were used; single pass, double passes flat plate collector and double pass thermal energy storage box collector (TESB). A computational model based on the finite volume method for transient tw dimensional domains was carried out to describe the heat transfer and storage in the thermal energy storage material of collector. Also, equivalent specific heat method was employed to describe the heat storage and release in the mushy zone. Experimental results referred to an increase in thermal conductivity of paraffin wax that supported by copper foam matrix more than ten times. While the ventilation effect was still active for hours after the sun set, depending on the heat storage amount. Maximum ventilation mass flow rate with TESB collector was recorded with value equals to 36.651 kg/hr., when the overall discharge coefficient that was calculated for the system equals to 0.371. Experimental results showed that the best working angle range was 45~60o, and the highest air to the collector approaching temperature appeared to the double passes flat plate collector. Results gave greater heat storage efficiency of (47)% when the maximum solar radiation was 780 W/m2 at 12.00pm, while the energy summation through duration charge time was 18460 kJ. Computational results, depending on the equivalent heat capacity method for heat storage or release from phase change material that supported by copper foam matrix, showed the behavior of paraffin wax melting and solidification situation through periodic for charge and released heat from the solar collector. Also, these results gave agreement approaching the experimental results for the heat storage in the combined heat storage material, with standard error of 16.8%.
يعتبر مفهوم المجتمع المدني من بين سلة المفاهيم التي حملت لوائها واعادت رفعها حركات الموجة الثالثة من الديمقراطية في العالم التي نادت بالتعددية والانتخابات الحرة ...الخ .
Since her early beginning in 1974 in her novel "Les armoires vides", Annie Ernaux writing about life in all its various aspects remained her main goal. This novel gave the earliest signals of what would happen later on in her literary career. Indeed, her works showed abilities of echoing reality, her sufferance and experiences via the use of simple and clear language. Add to this, her writings are to be viewed as an expression of deep felt journey, and a continuous search due to the consequent changes coming out of her identity.
We try here to give an answer to the question about writing as to whether being, to Ernaux herself, a need for the search about her social and feminist identity, or a pure literary work
... Show Moreهدفَ البحث الى التعرف على درجة الاتزان الانفعالي لدى الطلبة، التعرف على الفروق في درجات الإتزان الإنفعالي تبعاً لمتغير النوع (ذكور–إناث) والتعرف على الفروق في درجات الإتزان الإنفعالي تبعا لمتغير المرحلة الدراسية (الاول- الثالث)، من أجل تحقيق أهداف البحث قامت الباحثة إعداد مقياس الإتزان الإنفعالي بالإعتماد على نظرية التحليل النفسي لفرويد، وكان عدد فقرات المقياس بصورة النهائية من (20) فقرة، وطُبق مقياس البحث
... Show MoreSoftware cost management is a significant feature of project management. As such, it needs to be employed in a project or line of work. Software cost management is integral to software development failures, which, in turn, cause software failure. Thus, it is imperative that software development professionals develop their cost management skills to deliver successful software projects. The aim of this study is to examine the impact of cost management success factors with project management factors and three agile methodologies – Extreme Programming (XP), Scrum and Kanban methodologies which are used in the Pakistani software industry. To determine the results, the researchers applied quantitative approach through an extensive survey on
... Show MoreIn The Name of Allah Most Gracious Most Merciful
The reason for choosing this topic was:
First: It is my great love for the Prophet Muhammad, may God’s prayers and peace be upon him, his family, his companions, his followers, the followers of their followers, and the scholars after them until the Day of Judgment.
Secondly: Showing a great jurisprudential figure who has contributed by speaking about important jurisprudential issues in the life of this nation, and bringing out this immortal book to put it in the hands of scholars, so I chose a figure from the followers (may God be pleased with them all).
Third: The study of the jurisprudence of the companions
واقع تدريس السياسة الخارجية في كلية العلوم السياسية - جامعة بغداد
(Abstract)
A man find himself in front of narrative literal productions when he read the title of this paper that deals with specialist , followers of Arabic literal narration productions through the era of Arabic literature in a period arrived to 1500 years. It is strange to present (Narration art in Arabic heritage) , in addition to (Arabic diwan) . This matter introduces us to come back to the past to inspect Arabic narration production , specially that is called (Artistic narration ) which is full ,variety of purposes and goals.
The study aimed at detecting the extent of the practice of students Almtbakan skills crisis to teach in geographical sections of the Colleges of Education Baghdad University. The current research was limited to students in the fourth stage geographical divisions in the Faculties of Education for Girls and Ibn Rushd / Baghdad University for the academic year 2013-2014.
The View Finder methodology of the study and procedures, explaining the method used to obtain the data and information to achieve the goal of the search, and used the questionnaire and the way to achieve the goal of the research, as it was prepared based on the views of the exploratory and literature and previous studies and the experience o
... Show MoreThis search aims to meditate Divan of Hazem Al-Qirtagni his incomplete contiguous and non-contiguous naturalizations are investigated through two interrelated sections, the first is contiguous deficient naturalization and the analysis of phonemic symmetry in the light of syntactic syntax, phonemic (partial) symmetry and semantic difference
تشير الادبيات الى ان العنف قد رافق الانسان منذ بدء الخليقة حتى يومنا هذا، الا ان التطور العلمي والتكنلوجي والسرعة الفائقة في التغيير قد زاد من حجمه، وعدد مثيراته واختلفت نوعيته تبعاً لارتقاء الانسان ( العكيلي، 2000، ص91).
يتسم القرن الحادي والعشرين بظاهرة العنف بشكل عام، حيث لم تسلم منطقة منه، وهذا لا يمثل تهديداً لمنجزات الانسان المادية والاجتماعية فقط، ولكنه يمتد نحو الانسان ذاته. وسلوك الع
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