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: Cardiopulmonary resuscitation (CPR) is a technique or procedure that combined chest compression and rescue breathing to maintain enough circulation that prevents brain damage until other essential steps are taken to control the main cause of cardiac and respiratory arrest. The health care personnel should be qualified in the performing of cardiopulmonary resuscitation (CPR) to improve the survival rate of the victims. Therefore; it is necessary to use new methods for learning [1]. Objectives: the study aims to compare the effectiveness of self-instructional teaching strategy and traditional teaching approach on student’s knowledge toward cardiopulmonary resuscitation. Methods: A randomized comparative trial (RCT) design was ca
... Show MoreThis study was carried out in Artificial Insemination Center of Iraq to revealed FMD disease effect on some seminal attributer parameters of 14 imported Holstein bulls divided to three groups according to different reproductive efficiency (four High, five medium and five weak). Results showed that FMD disease had significant (P < 0.05) adverse effect on most seminal attributer parameters, mass, individual motility and sperm concentration / ml during post disease in first of two, four, all months of high, medium and weak semen quality bulls respectively .but semen volume didn’t influenced significantly with this disease. So semen collection should be suspended until resume normal fertility of sperm, after two, four month of high and
... Show MoreBackground: Mothers are considered as the key role in effect on child's dental behavior. So it is important to involve her in oral health promotion program to prevent early childhood dental caries from occurring in early age. Objectives: To identify the knowledge, practice and attitude of mothers about the oral health of their children. And to measure the change in oral hygiene of children aged (4-7) years old after one month of interventional program on their mothers. Type of study: Non-randomized interventional.Methods: Non-randomized interventional study for one month in Al Shaab area in Baghdad to 65 mothers who have children aged (4-7) years .A modified administrated questionnaire is given to assess mothers’ knowledge, practice an
... Show Moreشهد العصر الحالي سرعة فائقة في انتاج وسائل الاتصال لاسيما في حقل الاتصال الاليكتروني وتوضح ذلك عبر الاندماج بين ظاهرة الكم الهائل من المعلومات وتعدد الوسائل الاتصالية وذلك لتحقيق الهدف المنشود لبث الرسالة الاتصالية الا وهو التفاعل من اجل التأثير في الفرد ومن ثم المجتمع ككل , فيما اضحت العلاقات العامة احد العوامل المؤثرة في عملية التغيير الاجتماعي بما تستند اليه من ممارسات تضعها في اطار الوظائف المجتمعية ال
... Show MoreExamination is a form of tax audits which have been done by tax examiner rests with the General Commission for Taxes is responsible for determining the extent to which the amounts subject to tax provided by the holders of admissions with the laws and regulations, taxes. So the tax-examination is the major means of tax administration to make sure the fact that tax revenues generated from the imposition of taxes different kinds of direct and indirect search result, the importance of the role played by the (Department of Control and Internal Audit / Audit Division in charge) in charge of auditing the accounts, which may be Maclvoha clung to their accounts and access to the tax base acceptable to the expensive and fin
... Show MoreSeen in Iraq that the volume of insurance activity in the case of a clear deterioration and a sharp decline in demand for life insurance, because of reluctance by senior members of the Iraqi society on the demand for life insurance. The study was descriptive approach in identifying and addressing variables, namely the (perception of risk need of the individual trends in personal income of the individual insurance awareness of the individual customs and traditions of communal religious belief of the individual age and sex of the individual methods promotional company competitive alternatives to the insurance service life inflation rate service life insurance) indepen
... Show MoreThe problem of the study is concerned with the work of The Iraqi Airways Company in political, economic, and social environment that suffers instability for many years. This has its negative outcomes regarding its decisions of providing services to its markets and customers as a result of the orientations, behavior, and marketing values the company management adopted. The aim of this study is to investigate the marketing philosophy adopted by the management and to identify the extent it suits the materialistic and the human capacities of the company and its current environmental circumstances within the marketing culture common to the thoughts and behaviors of the management and their employees. And in order to achiev
... Show Moreيتناول البحث الاخلال المسبق واثره في تنفيذ الالتزام العقدي على حساب المدين ـ دراسة مقارنة في القوانين المدنية والقانون الانكليزي
يتناول هذا البحث موضوع مهم في تاريخ العراق في العهد الملكي يتمثل في الانقلاب العسكري الذي قام به عدد من قادة الجيش العراقي بقيادة الفريق بكر صدقي رئيس أركان الجيش العراقي سنة 1936م وتم تشكيل حكومة من الانقلابيين استمرت حوالي تسعة أشهر وكتب عنها الكثير بعض هذه الكتابات كانت مع الانقلاب وبعضها كانت ضده وجاء هذا البحث ليسلط الضوء على ألصوره الذهنية التي حاولت ان ترسمها الصحف العراقية في حينها وتم دراسة الموضوعات
... Show Moreيهدف هذا البحث إلى معرفة أثر استخدام دورة التعلم في اكتساب المفاهيم الصرفية واستخلاصها لدى طالبات قسم اللغة العربية بكلية التربية للبنات وقد صيغت فرضيتان مفادهما أن ؛ 1- لا توجد فروق ذات دلالة إحصائية بين متوسط درجات طالبات المجموعة التجريبية اللاتي يدرسن المادة الصرفية في دورة التعلم ومتوسط درجات طالبات المجموعة الضابطة اللاتي يدرسن المادة الصرفية بالطريقة القياسية لاكتساب المفاهيم. 2- لا توجد فروق ذ
... Show More