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.
إن تجسيد الشعراء للجمال واقامته تمثالا مصورا مرئيا ، كان الهدف منه اولا اشاعة جو نفسي مريح في مقدمات قصائد المديح ، فهو الجزء البصري الممتع لمدركات حسية اخرى ترافقه، وأما المرامي الاخرى
ﻓﮭﻲ إﻣﺘﺎع اﻟﻨﻔﺲ إﻣﺎ ﺑﺎﺳﺘﺮﺟﺎع أﺟﻤﻞ ﺻﻮرة أو أﻧﻤﻮذج ﻗﺎﺋﻢ ﻓﻲ اﻟﺬاﻛﺮة، وﺟﻌﻠﮫ ﯾﺤﯿﺎ ﻣﻦ ﺟﺪﯾﺪ ﻟﺪواﻋﻲ اﻟﺤﻨﯿﻦ للاماكن والازمنة الاثيرة . أو الميل للتعبير عن الوعي الجمالي الذي يتصل بموضوع الج
... Show MoreThe research tagged (Digital Collage in Contemporary Art) consisted of four chapters. The first chapter was devoted to the methodological framework of the research. The problem ended with the following questions: How does digital collage represent contemporary art? What is the variable at the level of meaning shifts in composing works according to the digital collage? Was the digital collage a qualitative leap in the path of the aesthetic pattern in art? How does digital collage interfere with contemporary life and societies? It included the aim of the research and its importance, while the second chapter dealt with two topics, the first (reading in the concept of collage), and the second (digital collage). The third chapter was devoted
... Show MoreThe 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 MoreThat water is the lifeblood and without it no life on our planet, he says in the Holy Koran: In the Name of God {{And We made from water every living thing}} truth of God Almighty (the prophets verse 30) The basis of the existence of settlements served human and a source of fresh water close to it easy access to it is used for domestic, agricultural, on a daily basis, even closer look at the map of Iraq to human settlement to find it is a signatory to both sides of the river are thick and less as we moved away from the source of water until they make up a scene like a necklace the river and the stones of cities and settlements served, was the ancient civilizations, countries and capitals Throughout history, choose sites near sour
... Show Moreيتنامى 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 MoreMost real-life situations need some sort of approximation to fit mathematical models. The beauty of using topology in approximation is achieved via obtaining approximation for qualitative subgraphs without coding or using assumption. The aim of this paper is to apply near concepts in the -closure approximation spaces. The basic notions of near approximations are introduced and sufficiently illustrated. Near approximations are considered as mathematical tools to modify the approximations of graphs. Moreover, proved results, examples, and counterexamples are provided.
Cinema has always addressed human issues from diverse perspectives. It covered biographies, philosophy, history, war, and sci-fi. These disciplines promote economic and artistic success. Since the 1930s, cinema has explored sexual transformation. These films have defended homosexuals, explored how homosexuality causes AIDS, and discussed transgenderism for decades. As widely recognised, animated films for adults and children worldwide have included this trend. This study will demonstrate how hormone imbalance affects sexual function. This study, "Promoting Physiological Transformations in Cinema," comprises four chapters: The first chapter (methodological framework) covers the study problem, "What are the foundations and necessities of p
... Show MoreCopulas are simply equivalent structures to joint distribution functions. Then, we propose modified structures that depend on classical probability space and concepts with respect to copulas. Copulas have been presented in equivalent probability measure forms to the classical forms in order to examine any possible modern probabilistic relations. A probability of events was demonstrated as elements of copulas instead of random variables with a knowledge that each probability of an event belongs to [0,1]. Also, some probabilistic constructions have been shown within independent, and conditional probability concepts. A Bay's probability relation and its pro
... Show MoreThis research deals with dialogic submission as one of the most important deliberative topics in the process of linguistic communication between the two sides of the discourse, and therefore we find in this research its concept among the ancient Arabs of grammarians, rhetoric and fundamentalists, and we started with Western linguists as a result of their knowledge of the philosophy of language, and this research was satisfied with the principle of cooperation that came By Grace as the founder of this modern deliberative topic with an attempt to monitor this principle in the prophetic stories and the susceptibility of the stories to this kind of implicit communication, as the prophetic stories included multiple deliberative dimensions of
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