Numerous tests are recently conducted to assess vibration's role in accelerating the heat transfer rate in various heat exchangers. In this work, the enhancement of heat transfer by the effect of transfer vibration and inclination angles on the surface of a double pipe heat exchanger experimentally has been investigated. A data acquisition system is applied to record the data of temperatures, flow rates, and frequencies over the tests. A compound technique was adopted, including the application of a set of inclination angles of (0°, 10°, 20°, and 30°) under the effect of frequency of vibration ranging from sub-resonance to over-resonance frequencies. The results showed that the overall heat transfer coefficient enhances by applying the compound technique at all the working fluid's temperatures and flow rate ranges. The maximum increase in overall heat transfer coefficient occurs at an angle of 30° and the resonance frequency. Moreover, the effectiveness of the double pipe heat exchanger gradually expanded when temperature, inclination angles, and vibration amplitude rosed. But the effectiveness value declined as the hot working flow rate increased considerably. Finally, the enhancement factor demonstrated that the combined strategy (vibration frequencies and inclination angles) had been the most effective technique in improving and enhancing heat transfer and was superior to the other ways. Additionally, the extremes improvement in overall heat transfer coefficient, effectiveness, and enhancement factor are 183.4, 191, and 164.4 %. The improvement was situated at the resonance frequency with a 30° inclination angle.
DBNRSK Sayed, Journal of Strategic Research in Social Science (JoSReSS), 2020
The present study aimed to investigate the effect of re-operations engineering business in continuous improvement, as the rapid development of service activities generally private and the great diversity in the goals of its operations and programs of the university and the service has led to the increasing importance of re-operations engineering business as well as continuous improvement so began to study the relationship between the re engineering and continuous improvement of university service, and applied study on a sample of professors from the faculties of administration, economics and law. Find and reach to several conclusions, notably that the preparation of the teaching staff training sessions on how to use modern teaching
... Show MoreThe current research aims to diagnose the role of social responsibility as a contributing factor in enhancing the quality of services provided by the public sector in Iraq, where the research sought to demonstrate the relationship and impact of social responsibility dimensions (economic, legal, moral, and human) on the sector Services related to the electric field in Nineveh governorate because of its importance and its direct relationship with the citizen especially after the end of military operations in the destruction of the electricity sector by a large percentage in the city of Mosul. Nineveh Electricity Distribution Directorate / Center was chosen as a research community including (administrators and staff) of the research
... Show MoreIn this study, Yogurt was dried and milled, then shaked with distilled water to remove the soluble materials, then again dried and milled. Batch experiments were carried out to remove hexavalent chromium from aqueous solutions. Different parameters were optimized such as amount of adsorbent, treatment time, pH and concentration of adsorbate. The concentrations of Cr6+ in solutions are determined by UV-Visible spectrophotometer. Maximum percentage removal of Cr6+ was 82% at pH 2. Two equilibrium adsorption isotherms mechanisms are tested Langmuir and Freundlich, the results showed that the isotherm obeyed to Freundlich isotherm. Kinetic models were applied to the adsorption of Cr6+ ions on the adsorbents, ps
... Show Moreلقد كان حرص المؤلف على إصدار هذا الكتاب نابعا ً من قناعة تامة بأن مجال التقويم والقياس بحاجة إلى كتاب علمي حديث يتناول عرض أدوات الاختبار والقياس والمتمثلة بالصدق والثبات ويتسم بالوضوح في التعبير عن المفاهيم والمصطلحات والأنواع لكل منها ليكون وسيلة مبسطة بأيدي الأساتذة والباحثين وطلبتي الدراسات العليا الماجستير والدكتوراه لإستخراج صدق وثبات الاختبارات والمقاييس بطرق إحصائية متقدمة من خلال إستخدام البرنا
... Show MoreThis study appears GIS techniqueand remote sensing data are matching with the field observation to identify the structural features such as fault segments in the urban area such as the Merawa and Shaqlawa Cities. The use of different types of data such as fault systems, drainage patterns (previously mapped), lineament, and lithological contacts with spatial resolution of 30m was combined through a process of integration and index overlay modeling technique for producing the susceptibility map of fault segments in the study area. GIS spatial overlay technique was used to determine the spatial relationships of all the criteria (factors) and subcriteria (classes) within layers (maps) to classify and map the potential ar
... Show MoreAbstract: Background: Optical biosensors offer excellent properties and methods for detecting bacteria when compared to traditional analytical techniques. It allows direct detection of many biological and chemical materials. Bacteria are found in the human body naturally non-pathogenic and pathologically, as they are found in other living organisms. One of these bacteria is Escherichia coli (E. coli) which are found in the human body in its natural and pathogenic form. E.coli bacteria cause many diseases, including Stomach, intestines, urinary system infections, and others. The aim of this study: is sensing and differentiation between normal flora and pathogenic E.coli. Material and method:
... Show MoreThe present work reports on the performance of three types of nanofiltration membranes in the removal of highly polluting and toxic lead (Pb2+) and cadmium (Cd2+) from single and binary salt aqueous solutions simulating real wastewaters. The effect of the operating variables (pH (5.5-6.5), types of NF membrane and initial ions concentration (10-250 ppm)) on the separation process and water flux was investigated. It was observed that the rejection efficiency increased with increasing pH of solution and decreasing the initial metal ions concentrations. While the flux decreased with increasing pH of solution and increasing initial metal ions concentrations. The maximum rejection of lead and cadmium ion
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