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.
Background: Diabetes mellitus is a common health problem of the world. Iron may be a part of the cause of the disease and its Complications
Objectives: This study was designed to determine the relationship between the levels of iron indices and diabetes mellitus type 2. Type 2
Type of the study: Cross –sectional study.
Methods: diabetes mellitus is clinical condition characterized by hyperglycemia due to the absolute or relative deficiency of insulin. It is also followed by pathological abnormalities like impaired insulin secretion, peripheral insulin resistance, and excessive hepatic glucose production. Although type 2 diabetes mellitus i
... Show MoreWater injection equipments such as pipelines, which are used in the second recovery of oil in the Al-Ahdeb wells, suffer from the corrosion in water during maintaining vacuum deoxygenated tower that used to decrease concentration of the dissolved oxygen gas in the water from 6.2-9.1 ppm to o.5 ppm. This study involved calculation the corrosion rates of the internal surfaces of the
pipelines either during operation of the vacuum unit or when the tower out of operation. Finally, find the solution by one of the following suggestions. In the first suggestion removal of the dissolved O2 from water is achieved by increasing the dosage of the oxygen scavenger (sodium sulphite). The second suggestion involves removing the dissolved O2 from w
IH Abdul-Abbas, QJ Rashid, M RasimYounus, PalArch's Journal of Archaeology of Egypt/Egyptology, 2021 - Cited by 9
The research aims to study the impact of the dimensions of fun in the workplace in achieving internal marketing And knowing the type of relationships That link the dimensions of fun in the workplace With each other, None of the researchers mentioned (to the researcher's knowledge) the link between fun in the workplace and internal marketing From this point of view the main objective is determined, which is to study the effect of fun in the workplace in internal marketing, The research was conducted at Al Salam Public Company for Communications and Information Technology The research community was represented by (308) employees of the aforementioned company , Where a random sample was selected tha
... Show MoreThe subject of education, and since time immemorial, gripe the attention of the religious, intellectual, political, social and economic elites. This attention not only in Iraq, but in different countries in the world. There is a close correlation between the educational level of the societies and the edginess of its rising and advancement in all fields.
In order to achieve the research objectives, the research has been divided into three sections: section I include the historical, scientific, humanitarian evolution of education, starting from the first economic revolution (The Agricultural revolution) through the second economic revolution (The Industrial Revolution) and till the Third Economi
... Show MoreIn-situ gelation is a process of gel formation at the site of application, in which a drug product formulation that exists as a liquid has been transformed into a gel upon contact with body fluids. As a drug delivery agent, the in-situ gel has an advantage of providing sustained release of the drug agent. In-situ gelling liquid suppositories using poloxamer 188 (26-30% W/W) as a suppository base with 10% W/W naproxen were prepared, the gelation temperature of these preparations were measured and they were all above the physiological temperature. Additives such as polyvinylpyrrolidin "PVP" ,hydroxylpropylmethylcellulose "HPMC", sodium alginate and sodium chloride were used in concentration ranging from (0.25-1
... Show MoreThe issue of the Circular Economy is not a new issue to several countries, especially the developed ones. Here in Iraq it is considered newly introduced, despite the few attempts to establish projects that concern recycling most of them were doomed to fail, due to two main reasons: the first one is the financial and administrative corruption widespread in all departments of the country, the second one is the priorities of public spending. It is well known that Iraq was subjected to two major attacks, the ISIS entry attack in 2014 to Iraq. ISIS occupied about a third of Iraqi lands which resulted in a collapse in oil prices, as Iraq depends almost entirely on oil revenues in its budget which is the second attack. This made the Iraqi governme
... Show MoreThe liver is one of the most prominent glands in the digestive system. It crosses vital organs with multiple functions, including the secretion of enzymes, digestion of fats, and secretion of bile. Through histological studies and those interested in them, the tissue structure of the liver is of interest to researchers, and the four samples of Guinea pig Cavia porcellus were taken in this study to know the histological structure and compare it with rodents in particular. and other animals in general. The results of the liver parenchyma were comparable to those of the studied mammals in periods of hepatocytes, Kupffer cells, and sinusoids surrounding the central vein, blood supply, and bile ducts. He did not record differences, eve
... Show More