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.
هذا البحث يتحدى الافتراض القائل أن العراق بعد عام 2003 يجب دراسته بمعزل عن ديناميات التي سبقت عام 2003، اذ تبرهن هذه الدراسة على ان الشعبوية هي احدى الديناميات التي تمظهرت بصورة شعبوية استبدادية في النظام الديكتاتوري، نظرًا لأنه كان زعيم حزب علماني وعربي على نطاق واسع، لكنه استخدم الدين والقومية بشكل استراتيجي وانتقائي في ظروف معينة، مما خلق سياق الشعبوية الحديثة. الموجة الثانية هي الشعبوية العرقية والطائف
... Show MoreThe research addressed the problem of widows that increased recently enormously. The researcher also referred to the perspective of Islam that gave a significant attention for both widows and orphans as powerless groups. Some straightforward example were presented to reflect the actual difficulties that encounter these groups as well as the author proposed number of appropriate ways that mitigate their psychological and physical sufferings such as: the provision of convenience jobs, and the legislation of rule that save their rights. Moreover, the researcher addressed the importance of marrying widows and what these challenges that encounter polygamy in Arab societies, the advantages and disadvantages of polygamy, and discussing all the
... Show MoreThe current research (violence in contemporary Iraqi drawing) study the nature of the manifestations of violence, Kdoual effective in technical text and give these functions of the images have multiple connotations psychological symbolism, and has read the text in the light of the impact of the Iraqi social reality after the recent occupation of events and to study the impact of this stage on Iraqi contemporary painting, and this research consists of three chapters included the first chapter defines the research problem, which is illustrated through the following questions which are real problems require study and research .
Is constitute an objective treatment of the Academy of artistic representations of a phenomenon in the for
... Show MoreCinema 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 MoreThe contemporary ideas were characterized by the abundance and diversity of their knowledge, human and conceptual production, the strategy is both a general and a detailed framework covering all design disciplines both inside and outside the field of architecture. From here, many of these terraces emerged from fields outside the field of architecture, but soon moved to form an important nerve within the field of architecture. Hence the need to define a more comprehensive framework for studying one of the concepts that can frame the framework, namely the concept of "Alliteration", and its adoption as an architectural design strategy aimed at giving the resulting form a feature of rhetoric. So the research highlighted the
... Show MoreThe development of better tools for diagnosis and more accurate prognosis of cancer includes the search for biomarkers; molecules whose presence, absence or change in quantity or structure is associated with a particular tumour or prognosis/therapeutic outcome. While biomarkers need not be functionally relevant, if cell survival, then they could also provide new targets for therapeutic drugs. In recent years attention has been applied to a group of proteins known as cancer testis antigens (CT antigens) [1]. These proteins are products of genes whose expression was normally confined to the testis, yet they are expressed in tumour cells. CT genes are bound to serve a wide array of roles in the testes, which have many highly differentiated cel
... Show MoreThe aim of this paper is to prove some results for equivalence of moduli of smoothnes in approximation theory , we used a"non uniform" modulus of smoothness and the weighted Ditzian –Totik moduli of smoothness in by spline functions ,several results are obtained .For example , it shown that ,for any the inequality , is satisfied ,finally, similar result for chebyshev partition and weighted Ditzian –Totik moduli of smoothness are also obtained.
This 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
... Show MoreThe super good artist, and its leading role experience detailed instrumental in the birth of the modern Iraqi drawing because of the represented technical personal super good in leading production Iraqi drawing since the early forties. If taken Excellence professional to experience the artist compared to the experiences of other pioneers and strengthened, the stylistic diversity through metaphors Different presented by the super good so that covered the period from romantic to Impressionism through schools drawing expressionism and cubism space, and therefore the heritage and the richness of diversity stylistic high to experience the good represents documentation required by contemporary Iraqi formation history, so the researcher found t
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