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.
This study aims at identifying the activation of the role of feminine leaders in educational decision-making in educational administrations in the Northern Borders Province in light of the Kingdom's vision 2030. It also aims to identify what educational leadership is, to study the conceptual framework of the contemporary education decision-making process, and to examine the reality of the problems of feminine leaders in educational decision-making in the educational administrations in the Northern Borders. In addition, it tries to develop a proposed vision to activate the role of feminine leaders in educational decision-making in Educational Administrations in the Northern Borders Province in light of Vision 2030. To achieve the objectiv
... Show MoreMost of the literature on the management and application terkzat waved the last period on large organizations was the negligence of knowledge management in small organizations where research aims to find out knowleddge management, small projects In oxygen Ahli plant in Iraq, and the fact the role of knowledge management in small projects from the standpoint of employees in order to achieve this used production method results. The results showed that knowledge management has a role in the high level of productivity during the years 2010-2013. The results showed that knowledge management has a role in the high level of productivity during the years 2
... Show MoreAbstract The success of the system of government in any country needs to have a handle on the amount of power efficiency , capacity , capability and wisdom, Iraq has gone through since its inception through several stages of time, namely: The first stage: which ran from August 23, 1921 until July 14, 1958 and was ruling monarchy (rule of the royal family) and punishing power of political elites both of them and works access to power without taking into consideration the laws and principles of the Constitution, and as a result of the inability of civilian powers and political parties access to power to grant that army officers regulatory and disciplinary specifications as well as possessing arms and overthrow the rule of the minority coup
... Show MoreBackground: Iron homeostasis is crucial to many physiological functions in the human body, such as cellular activity, erythropoiesis, and the innate immune response. Iron deficiency anemia may occur from obesity's ability to disturb iron homeostasis. Obesity may be seen as a pre-inflammatory condition with mild, ongoing systemic inflammation. Additionally, an increase in hepcidin levels by chronic inflammation causes iron insufficiency in obese people. For this reason, this current experiment is designed to investigate the iron profile and some hematological and inflammatory parameters in obese adults in the Kurdistan region-Iraq.
Subjects and Methods: The cross-sectional study w
... Show MoreDue to the significance of hospital drinking water, a study was done to assess the water in three hospitals in Baghdad (Al-Yarmouk Teaching Hospital, Ibn Sina Hospital, and Ibn-Al-Nafis Hospital) for its nature and quality, compare it to other hospitals in terms of its physical, chemical, and bacterial specifications, and compare it to international standards. According to Iraqi standards from 2009 and WHO standards from 2011, Chemical factors were measured, which included pH, Total Dissolved Solids (TDS), and Calcium Ion (Ca+2). Reported readings are all within acceptable ranges for drinking water. In contrast, turbidity, total hardness (T.H.), chlorides (Cl-), magnesium (Mg+2), the number of aerobic plates (APC), total coliform (T
... Show MoreLogic in the philosophy of ethical behavior in business organizations
The goal of the research is to highlight the role of the governance and its characteristics in increasing the tax outcome by implementing the laws, regulations and annual controls issued annually from the general authority for taxation for the financing of the general treasury of the state, Additional development and economic capacity, As the search shares a view of the governance and its characteristics and its ideas from increasing tax output. The analytical transparent approach was used by adopting the practice of practicalities of the general authority for tax For quotations in the senior cabinet section ,the revealing of the ongoing operations was relied on the revenue for each financial year, The tools adopted in the process of ana
... Show MoreMicroorganisms establish both structural and functional construction in the marine environment, despite scientific advances, the identification of marine bacterial species is still considered as a common challenge in microbiology. Nevertheless, the present study aims to make an effort, although it seems modest, but it could establish a basis for studying the bacterial diversity in the Iraqi marine area, because of what this aspect entails of the poverty of studies related to this aspect in the studied area. The current results show the marine studied area are classified within worming area, where the average temperature ranged from 23.17 to 26.17 ºC. The recorded number of bacteria was increased with temperature increasing (0.210, 0.250
... Show MoreSoil is a crucial component of environment. Total soil analysis may give information about possible enrichment of the soil with heavy metals. Heavy metals, potentially contaminate soils, may have been dumped on the ground. chromium, nickel and cadmium,