Due to the potential cost saving and minimal temperature stratification, the energy storage based on phase-change materials (PCMs) can be a reliable approach for decoupling energy demand from immediate supply availability. However, due to their high heat resistance, these materials necessitate the introduction of enhancing additives, such as expanded surfaces and fins, to enable their deployment in more widespread thermal and energy storage applications. This study reports on how circular fins with staggered distribution and variable orientations can be employed for addressing the low thermal response rates in a PCM (Paraffin RT-35) triple-tube heat exchanger consisting of two heat-transfer fluids flow in opposites directions through the inner and the outer tubes. Various configurations, dimensions, and orientations of the circular fins at different flow conditions of the heat-transfer fluid were numerically examined and optimized using an experimentally validated computational fluid-dynamic model. The results show that the melting rate, compared with the base case of finless, can be improved by 88% and the heat charging rate by 34%, when the fin orientation is downward–upward along the left side and the right side of the PCM shell. The results also show that there is a benefit if longer fins with smaller thicknesses are adopted in the vertical direction of the storage unit. This benefit helps natural convection to play a greater role, resulting in higher melting rates. Changing the fins’ dimensions from (thickness × length) 2 × 7.071 mm2 to 0.55 × 25.76 mm2 decreases the melting time by 22% and increases the heat charging rate by 9.6%. This study has also confirmed the importance of selecting the suitable values of Reynolds numbers and the inlet temperatures of the heat-transfer fluid for optimizing the melting enhancement potential of circular fins with downward–upward fin orientations.
Praise be to God, Lord of the worlds, and peace and blessings be upon our master Muhammad and his family and companions as follows:
This research examines altruism in the Noble Qur’an objectively. The altruism is a word that permeates selection, preference, presentation, types of gifts, and all other material and moral virtues. It is the highest level of generosity and generosity, provided that the consent of God Almighty is enriched on the consent of others, and that greatness arises in it, and that creation affects On yourself in what does not deprive you of a religion, and it does not cut you off on a path, because the praiseworthy altruism is only in relation to souls, not the disgraced altruism tha
Socio-scientific issues provide a great platform to both engage students in scientific topics and assess their understanding of scientific concepts. Nancy R. Singer, Amy Lannin, Maha Kareem, William Romine, and Katie Kline report on the STEM Literacy Project, a three-year National Science Foundation grant that aimed to improve STEM teachers’ knowledge and integration of literacy in their classrooms. They describe teachers’ professional learning, scenario-based assessments and other strategies they incorporated in their STEM classrooms, and how writing enables students to understand real-world issues.
يتنامى يوما بعد يوم استخدام السيارات وتتعاضم اعدادها ، فهذا هو عصر السرعة، وخاصة في مجال النقل والمواصلات، والتي تتحقق باستخدام وسائل النقل المختلفة ومن بينها السيارات، وبالتالي اصبحت هذه الوسيلة ضرورية لتحقيق هذه السرعة ومن ضرورات الحياة في انجاز الاعمال.
وتتبارى مصانع السيارات فيما بينها لانتاج انواع السيارات بمواصفات عالية من المتانة والامان والراحة، وفي ذات الوقت اصبحت هندسة الطرق
... Show MoreBecause it is obligatory for every Muslim to pay attention to the jurisprudence of his religion in order to achieve goodness thereby
He is guided to the paths of light.
One of the most important topics of Islamic jurisprudence is marriage. Because it relates to the life of every member of society, the engagement is one of the prerequisites for marriage, and whatever is related to what is important is important. It also contains many matters and details, so we wanted to write a study in it that understands its tasks so that the Muslim is aware of his religion.
And let him stay away from situations and customs that contradict our true religion. We have adopted approved books that are widely circulated among the majo
... Show MoreThe eloquence assemblage, as it is appeared in this research, is the most prominent terms that
accompany the art. It includes the whole artworkand it does not stop at the borders of the
construction, but also extends to the material presented in this or that work. It means the
discovery of all that essential in the material presented and it is far away from what is
accidental and fleeting. Moreover, it is the type of pressure of the poetic status and the
familiarity with the material flowing subconsciously. It means that the clever poet masters his
language alongside with his discernment and intelligence framed by fast-witted. The semantic
assemblage within the technical construction means focusing on what embodies t
The present study tackles the scientific model and the mechanisms of operating in the formation of the image of the artistic work to create a scene that cares for the aesthetic decoration through raw and techniques and employing them to express the aesthetic values that care for what is not familiar and deviation from the familiar in the visual exhibition and the care for the employment of the technical abilities, lighting, and sound as well as the employment of multiple materials. The research presents the objectives of his study in the exhibition hall of Natural History Museum (University of Baghdad) to create an aesthetic and expressive state at the same time. Then, in the theoretical framework the researcher traces the experiments of
... Show MoreRenewal is generally considered an urgent requirement of life, and a section of its continuation, because renewal means that life exists and continues, and just as renewal is in life, renewal is in science, and in this research the issue of renewal in the science of interpretation, and showed through research that renewal in This science was an urgent demand throughout the Islamic ages, as the research showed the necessity of renewal in the material of interpretation, its method and methods, and the researcher presented the opinions of schools about renewal in the interpretation of the Noble Qur’an inferred by living models that refer to their owners.
<p>The speech act of request is face-threatening by nature and an inappropriate request can cause offence to the hearer, particularly when s/he has higher authority (Economidou-Kogetsidis, 2011). E-mail is frequently used to facilitate communication between student and professor in Iraq. Iraqi EFL (English as a foreign language) learners face pragmatic difficulty in making proper requests to individuals of higher authority via e-mail. Some studies have been conducted on Arab EFL learners to uncover the pragmatic behaviour of these learners in real-life requests using elicited data. This research fills a gap in Inter-language Pragmatics (ILP) literature in that it investigates the use of academic request in three diverse imposi
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