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.
The research aims to study the importance of applying lean accounting techniques and the tools and methods they contain, the most important of which is the “value path costs” technique and its impact on rationalizing and controlling costs, as well as reducing production costs in general and reducing quality costs in a way Special by reducing or eliminating waste and waste in both time and resources and meeting customer requirements. In order to achieve this goal, the researcher relied on the application of lean accounting tools by obtaining data related to the mill, in addition to that, the information obtained as a result of field coexistence in the mill and being able to view the records of the mill in the research sample. From the
... Show MoreIraq suffers from lack of water resources supply because the headwaters of the rivers located outside its borders and the influence of upstream countries on the quantities of flowing water, in addition to the increase of pressure on available water as a result of population increase and not adopting the principle of rationalization where misuse and wastage and lack of strategic vision to treat and manage water use in accordance with the economic implications fall. This is reflected fallout on water security and subsequently on national and food security, while the issue of using water resources is development top priority in different countries in the world because of the importance of water effect on the security of indivi
... Show MoreObesity is a disease describe a case of excessive accumulation of body fats. Obesity is linked to the morbidity of human health, such as the development of hypertension. The study designed to investigate the levels of glucose, urea, creatinine, and lipid profile parameters in sera of obese female and hypertensive obese female. The study included 90 subjects who divided onto three groups equally, in which they are healthy control, normotensive obese, and hypertensive obese. A significant elevation (P<0.01) has observed in the level of glucose, urea, creatinine, triglycerides (TGs), cholesterol, LDL-C, and VLDL-C in obese females compared with control, yet only TGs and VLDL-C were si
The article discusses political discourse as a communicative space of modern politics in the context of the anthropocentric paradigm. The following components of the political discourse have been outlined: the character of the subject and that of the addressee, genres of oral and written speech, the opposition of monologue and dialogue, the functions, the amount of information among the genres, the aim of speech.
Summary Kidney transplantation is widely performed nowadays as an optimal treatment of end stage kidney diseases. Complications such as stenosis in graft renal arteries anastomosis may occur. Different suturing techniques are available for renal artery anastomosis. We aimed to compare the incidence of renal artery stenosis of the transplanted kidney when two suture techniques (continuous or interrupted) used for renal artery anastomosis. Therefore, a retrospectively comparative study was conducted on 44 patients managed with kidney transplantation during the years 2009-2011. Patients assigned into two groups; first group included 20 patients namely, continuous suture group, and the second group included 24 patients in whom the allograft art
... Show MoreThe objective of this work was to analyze the involvement of AhR in bone metabolism using a rat model of experimental osteoporosis and to analyze the mechanisms behind its activity. Rats were assigned randomly to the subsequent groups; Control, received no treatment; ovariectomized (OVX) rats; Sham; Sham+RES received resveratrol; OVX+RES and OVX+CH received AhR’s antagonist, CH223191 (CH); and finally OVX+CHR group received both AhR antagonist along with resveratrol. Resveratrol and AhR antagonist treatment started 7 days after surgery and continued to 45 days. The serum of osteocalcin (OC) and Ca+2 was measured by ELISA and spectrophotometer, respectively. X-ray was used to estimate bone density of rats. In molecular levels,
... Show MoreThe purpose of the research is to identify the role of Islamic banks in facing the financial crisis in Iraq for the period 2012-2014, and highlight the various factors that contributed to the emergence of the financial crisis, as well as to identify the problems and challenges facing the Islamic banking business in Iraq and identify the reasons and find appropriate solutions, And the development of treatments to avoid the occurrence of such problems and overcome them. The main findings of the research are as follows,Islamic banks (the sample of the study) were affected by the global financial crisis indirectly, as the financial crisis turned into an economic crisis affecting the real economy, because the activity of Islamic banks is more
... Show MoreThis article explores the role of talk shows in setting the public's agenda regarding political mobilization in Iraq. The researcher designed a questionnaire that contains both closed and open-ended questions to allow respondents to express their opinions more freely.
The researcher chose a phased purposive sample consisting of 294 respondents. The data was then subjected to analysis and verification using the Statistical Package for the Social Sciences (SPSS).
Background: The present work investigated the profile and biodiversity of the pathogenic streptococci species isolated from local and imported mozzarella soft cheese in Baghdad City from October 2022 to January 2023. The study aimed to examine the molecular characterization of 16Sr RNA gene in some streptococcus species isolates from mozzarella soft cheese in Baghdad city Methods: From 50 samples, 8 isolates in all were found and identified based on the VITEK, molecular, and sequencing of the 16SrRNA gene. The eight isolates represented Lactococcus cremoris. Streptococcus alactolyticus, Streptococcus sanguinis, and Streptococcus thoraltensis. The isolates were subjected to conventional PCR and electrophoresis to detect the 16SrRNA gene usi
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