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%.
Research aims at evaluating the quality of the teaching skills of math teachers in junior high / scientific branch from their point of view.
The researchers prepared for this purpose a quality of teaching skills standards questionnaire, It consisted of 72 items distributed on four axis, The research sample was 200 teachers The researchers used statistical methods: the arithmetic mean, standard deviation, variance test, test Shiva , The results showed a statistically significance difference Attributed to the qualification variable in the second axis (Planning for teaching topics) And the absence of statistical difference function,
... Show MoreThe way used to estimate the fuzzy reliability differs according to the nature of the information of failure time which has been dealt in this research.The information of failure times has no probable distribution to explain it , in addition it has fuzzy quality.The research includes fuzzy reliability estimation of three periods ,the first one from 1986 to 2013,the second one from 2013 to 2033 while the third one from 2033 to 2066 .Four failure time have been chosen to identify the membership function of fuzzy trapezoid represented in the pervious years after taking in consideration the estimation of most researchers, proffional geologists and the technician who is incharge of maintaining of Mosul Dam project. B
... Show Moreتهدف الورقة البحثية الى اعداد مشروع لصناعة مكتبة رقمية للطالب في قسم علوم القران الكريم والتربية االسالمية في كلية التربية ابن رشد للعلوم االنسانية / جامعة بغداد ، اعدت الباحثة استمارة نموذج كوكل تضمنت مجموعة من االسئلة الغرض منها تحديد المؤلفات االساسية التي يحتاجها طالب العلوم االسالمية في دراساته وابحاثه ،واعتمدت الباحثة على المنهج الوصفي اسلوب المسح لجمع البيانات ، ووزعت االستمارة عبر الصفوف االلكترو
... Show MorePerformance measures are a central component of management control system, making good planning and control decisions requires information about how different subunits of organizations have performed. To be effective, performance measures (both financial and nonfinancial) must also motivate managers and employees at all levels of organization to strive to achieve organization goals.
To give aclear picture about performance must be used compound measure, that was best than single measure.
Altman model can be used as a compound performance measure that measures the performance by tied a sum of variables, due to make weight for every variable to reach for performance.
In the light of what is witnessing in the advertising arena of new ways and methods in delivering advertising message to consumers by finding new outlets to communicate with them especially through social networking sites, which became the first choice of advertising companies in order to spread its goods and services. These companies now are relying gradually on celebrities to appear with their products and goods to drive the audience's attention towards them. The thesis aims to find out the attitudes of young people towards the the advertisements that show famous celebrities on social networking sites. The researcher used survey method which aims to record, analyze and interpret the phenomenon after collecting the necessa
... Show Moreتعد ظاهرة الارهاب المتزايدة في العالم من اخطر اشكال التهديدات الامنية التي تواجة الدول لانها تستهدف في جانب مهم منها امن واستقرارومستقبل مجتمعاتها لاسيما اذا جمع الفعل الارهابي بين مطامع واهداف القوى الخارجية التي لا تريد استخدام ادواتها المباشرة وانما بالاعتماد على محركات في خلق الازمات داخل الدول المستهدفة
... Show Moreلقد أدت التطورات العلمية والتقنية وتطبيقاتها العملية في مختلف ميادين الحياة بشكل عام وميدان التربية والتعليم بشكل خاص إلى ظهور تغيرات في البناء التعليمي وطرائق التدريس بصيغتها الحديثة التي تنسجم في مجملها وروح العصر مما دعى المؤسسات التربوية والتعليمية وبإيعاز إلى الباحثين والمهتمين بهذا الميدان الى ضرورة متابعة الاتجاهات الحديثة ونواحي التجديد لمحتوى العملية التعليمية فيما يتعلق بالمجالات المعر
... Show MoreIrak Türk ağızları Azeri Türkçesinin bir uzantısı olarak değerlendirilir.Kerkük Türkçesiyle yazılan edebi ürünler, Irak Türkçesinin tamamını ifade etmek üzere kullanılmaktadır. Zamanın Eli divanı Kerkük Türkçesile yazılan bir eserdir. Bu yüzden bu divanı seçtik ve Irak Türkmen Türkçesi , Osmanlı Türkçesi ve Türkiye Türkçesi dilleri arasında karşılaştırmalı bir inceleme yaptık.
Bu araştırma, Irak Türkmen şairlerinden birisi sayılan Es’at Naib’in şiirleri üzerinde uygulamalı bir çalışmadanoluşmaktadır. Bu çalışmada adı geçen şairin “Zamanın Eli” Divanından bazışiirlerini önce yeni Türkçeye çevirdik vedaha sonra isim ç
... Show Moreتناول هذا البحث عرض وتوثيق المشارکات النسوية العراقية بألعاب القوى في الدورات الرياضية العربية منذ تأسيس اتحاد ألعاب القوى عام 1948م ولغاية عام 2017 م، وکذلک تحليل النتائج المتحققة لهذه المشارکات ومناقش أسباب عدم المشارکة في بعض هذه الدورات ومحاولة الباحثات أن يبينن الدور المتميز للرياضيات العراقيات أسوة بنساء الوطن العربي وإسهامهن الفعال في هذه الدورات من أجل تمثيل، البلد خير تمثيل، وکذلک النهوض بالواقع الر
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