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%.
Background: Hypothyroidism is a decrease in the production of the thyroid hormones and leads to gland dysfunction. Ashwagandha extract was used as an ayurvedic treatment and supposed to be as antihypothyroidism agent.
Objectives: to investigate the impact of ashwagandha (Ash) extract on propylthiouracil (PTU)-induced hypothyroidism in rats.
Subjects and Methods: The rats were divided into three groups, control group, PTU (hypothyroid) group (6mg/kg/day by oral route), PTU (6mg/kg/day by oral route) +Ash (50mg/kg/day by oral route) treated group. All treatment continued for
... Show Moreيعد الكيمياء من العلوم المهمة التي تدرس في جميع مراحل التعليم الاساسي ومراحل التعليم العالي في كليات (الزراعة ، العلوم ، الصيدلة ، التربية الاساسية ، الطب ، طب الاسنان ، الطب البيطري) لأنها تدخل في الكثير من مفاصل الحياة اليومية وما لها من تأثير في تقدم المجتمعات من الناحية الصناعية والاقتصادية حيث تدخل الكيمياء في الصناعات الغذائية ، والصناعات الدوائية او صناعة الاقمشة والزراعة وتطوير الثروة الحيوانية عن ط
... Show MoreWhite and black chia seeds were used in some food products, such us gluten –free biscuits processing by using rice flour and chia seeds (white and black) with these amonths 112.5, 74.25, 56.25, 27.5 g with 27.5g of quinoa seeds for treatments 1, 2, 3 and 4 respectively, and comparison sensitively with the control treatment which has no additions including the appearance and homogenization of the product, surface cracks, softness, taste and flavor, core color and the specific volume, some microbiological tests were performed for biscuit product after storage for 4 months at 30 and 50°C including bacterial total count and fungal and yeast count, results showed that there weren’t any observation of bacteria or yeast or fungal growth at
... Show Moreيختلف دور العلاقات العامة (PR) وأهميتها من مجتمع إلى آخر، تبعاً لاختلاف ثقافات هذه المجتمعات عموماً, ولاختلاف القيم الأخلاقية المعمول بها من ممارسيها في منظمات هذه المجتمعات, فالعلاقات العامة في المجتمعات المتقدمة وبعض الدول النامية قد خطت خطوات جبارة ووصلت إلى مرحلة المساهمة في التخطيط الاستراتيجي وعملية اتخاذ القرار, في إطار التزام إداراتها بقيم ومعايير أخلاقية محددة لممارسيها, وبالمقابل نجد أن تطبيقها في
... Show MoreAbstract
The research study about the empowerment as an independent variable, in which details include (training and improvement, incentives, information sharing, trust, and delegation), has also focused on the performance of the service organization as a dependent variable in all dimensions which include (improve work efficiency, building the core competencies, focus on the beneficiary of the service, increasing the feeling of satisfaction of the employees, and the organizational support commitment). The research has been based on the opinions of a chosen sample of 75 service officers of the Ministry of Interior who work at the General Directorate of Traffic. The research problem has been identified by t
... Show MoreThe research discusses one of the most critical issues of corporate finance which is related to asset utilization efficiency. Researchers used internal growth rate as independent variable (Proxy of asset utilization efficiency) and sustainable growth rate-dependent variable (proxy of stockholders wealth). According to these two variables, researchers formulate major hypotheses (There is no significant effect of internal growth rate on sustainable growth rate), as well as two sub-hypotheses, examine the components of major variables. Sample of Iraqi industrial companies which listed in the Iraqi stock exchange selected to test and examine main hypotheses. Result of simple and multiple regressions explain there is a significant effect of i
... Show MorePrayer It is the second pillar of Islam, which is what Allaah erases sins, the Prophet, peace be upon him say: "Do you see if the river at the door of you wash it every day five, what it says: it keeps dirt," they said, does not keep the dirt something, He said: «That is like the five daily prayers, Allaah erases sins", Bukhari (1/112), and the places and times supervised thanks to worship them, was to pray at the three mosques (the Grand Mosque and the Prophet's Mosque and the Al-Aqsa Mosque) private virtue from the rest of the mosques and this virtue include the obligatory prayers and Voluntary Prayers
The purpose of this research is to investigate the events and events that took place after the death of Imam Musa al-Kadhim (peace be upon him) and the role of Ahmad ibn Musa (peace be upon him) in the succession of Imam al-Rida (peace be upon him). Will the writer attempt to answer the question about the role