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%.
The basic goal of human creation is worship, the Almighty stated: { I created the jinn and mankind only to worship Me} Al-Dhariyat 56. The basic worships by which we approach Allah Almighty are the praying and zakat, that they are significant because the praying and zakat mostly come together in numerous Qur’anic verses. Being the praying is a Physical worship while zakat is a financial devotion, they have many educational effects explained by the writer Muhammad Darwaza in his interpretations of these two pillars of Islam that he has chosen them to be the subject of this research
The Stressful Life Events consider one of the important thing in humans life in different period of life even school period, where it is deal with vital period of life which is the youth period that represent the hope and precious resources that nation depend on it in building her civilization, structure anddevelopment ,they are part from the present and whole future .As the great effect of stressful life event on humans , increase the need to put a program about psyching-up which consider one of the modren and effective programs.The aim of current search:1. Measure the level of stressful events at the junior high school studen
... Show MoreReceived several formats historical kings of old Babylonian era carries connotations military as it chronicled the kings of this era Sunni rule work, was in the forefront of those formulas taken from weapons-grade events have the history of years of their rule, and the keenness of the Kings on the industry that weapon and because it is dedicated to the goddess is the weapon of God, and which pulls the Goddess encouragement and an support them in their wars, they think the Iraqis ancient gods be carrying weapons at the forefront of their armies to fight the enemy with them as well as the receipt of a lot of alliances
لم يكن من السهولة على الباحث في مجال التربية والتعليم تحديد مراحل التعليم في العصر العباسي الأخير او وضع فواصل محددة بين تلك المراحل المختلفة من ذلك العصر، لان التعليم آنذاك كان يتميز بالمرونة التي تتيح للتعليم الحرية المطلقة في اختيار نوع الدراسة والمادة الدراسية التي يريد دراستها.
فكانت المساجد والكتاتيب والمجالس العامة والخاصة هي المؤسسات العلمية الاولى للتعليم عند المسلمين في عهد ال
... Show MoreCultivation of the green seaweed Enteromorpha compressa was performed under natural laboratory spring environmental conditions of temperature, light intensity and photoperiod to study the salinity tolerance of this intertidal green macroalga. Cultivation was carried out under artificial seawater (ASW) of different concentrations (18, 35, 53 and 106 g/l sea salt) compared to the control using natural seawater (NSW). Growth rate and pigment content of the cultivated alga were recorded at regular intervals during the experimental duration. Antioxidant activity of the crude ethanolic extract and its fractions (petroleum ether, chloroform, ethyl acetate and acetone) was performed against DPPH radical scavenging assay and compared to
... Show Moreتعد ظاهرة الصراعات ظاهرة قديمة كقدم الوجود البشري وهذا يطبق على المستوى الدولي مما يجعل الدول الصغرى هي ساحة تصفيات كما هو الحال في سوريا مما يجعل الامن الانساني فيها معدوم
The current researsh is aimed to pay attention on concept of human resources hard (Difficult) to manage. Such style of human resourcses has emerged to form anew challenge for busniess organizations.
Management such human resources entails first determing incentives of their behaviour models. Analyzing these models will be important to strategical management of them from work.
In nutshell, this researsh try to recommendation of contemporary literature about future of difficult (hard) human resources management.
Specialized banks provide their banking activities to their customers at interest rates that are determined according to the approved bank policy, which is almost similar to most or most banks. To satisfy the financial desires of customers and at the same time it is a source of the bank's profits, However, these banks have been introduced to new services that they provide with the funds of the Central Bank initiative launched at the beginning of (2016) to address the economic stagnation that befell the country due to the (financial security) crisis that the country faced in 2014. To put forward initiatives amounting to nearly (15) trillion dinars, which were put forward through private commercial and Islamic banks and specialized
... Show Moreيواجه الكثير من الافراد مشكلات في التكيف، خاصة الطلبة الذين ينتقلون من المرحلة الدراسية الثانوية الى المرحلة الجامعية، حيث يرافق هذه البيئة الثقافية الاجتماعية العديد من الضغوط والمواقف التي تحتم على الطالب الوصول الى تكيف مثالي.
ان التعليم الجامعي يوفر مجالات عديدة للتخصص تعمل على تحقيق طموحات الشباب التي تناسب قدراتهم وميولهم واهتماماتهم، وهو بذلك يمثل نوعية من التعليم تختلف عن النم
... Show MoreThe research has designed for studying the relationship between manufacturing strategy and its flexibility under the flexible manufacturing system with their reflection on the competitive environmental performance of the firm. To interpret and tackle the problem, a hypothesis has formulated stating that “ the competitive performance of a firm is interpreted by the manufacturing strategy and flexibility which are derived from the firm and its business strategies under the flexible manufacturing system”. Related literatures with their theoretical dissertations, which enhanced the thoughtful content, have analyzed. An illustrative case study on the flexible manufacturing system at Toyota Motors Corporation working at the g
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