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: Normal Left Ventricular systolic function is present in nearly 50% of patients with congestive heart failure, the majority of such patients have systemic hypertension. Recent studies have demonstrated Left Ventricular dyssynchrony among patients with heart failure and normal systolic function. The co-existence between Left Ventricular dyssynchrony and hypertension with normal systolic function (with no clinical evidence of heart failure) is less well understood.
Objective:
To assess the Left Ventricular dyssynchrony among hypertensive patients with normal systolic function by using Tissue doppler imaging.To find out the associations between the LV dyssynchrony and other global
... Show MoreBackground: Patients with chronic kidney
disease have different grades of sensorineural
deafness .
Objective: To study the incidence of
sensorineural hearing loss and possible contributing
factors in patients with chronic kidney disease.
Methods: A total of 100 patients with chronic
kidney disease were studied. All of them were
males. 92 of them were on regular haemodialysis
programme. Only 8 patients were on conservative
management the age range of the study patients was
18-40 year patients were divided into three groups
according to age. All patients were assessed
clinically and were evaluated by audiometry , and
analysis was made on bone conduction threshold
.The mean follow up period was 2
Background: Both bladder cancer and schistosomiasis are endemic in Egypt. The former has a unique epidemiological pattern, which has been linked to bladder infestation by Schistosoma. The last decades have witnessed a great reduction in the infection rate of schistosomiasis and a decline in the incidence and changes in the patterns of bladder cancer. Whether these changes are linked to each other or a co-incidence is a subject of investigations.
Method: Literature on epidemiological data of bladder cancer and Schistosoma in Egypt was searched for in Medline, Scopus, PubMed, and Google Scholar. Furthermore, a hand search for literature and reports released by the Egyptian government and involved agencies was perfo
... Show MoreABSTRACT: BACKGROUND: The main goal of facelift surgery is to reduce the effect of aging by reposition of face soft tissue in to more youthful orientation. There are many methods for SMAS plication which had different design and vector of pull. AIM OF STUDY: To evaluate the effectiveness and longitivity of 7 shaped SMAS plication in facelift. PATIENT AND METHODS: From January 2020 to march 2021, 10 female patients with age (45-60) years were presented with facial sagging, those patients were subjected to subcutaneous facelift with 7 shaped SMAS plication with fat greft in Al-Shaheed Ghazi Al-Harri Hospital and Baghdad burn medical center at Baghdad medical complex. RESULTS: The average follow up period was 6 to 12 months. The mean operative
... Show MoreBackground: Polycystic ovary syndrome (PCOS) is a common endocrine disorder in women of reproductive age with primary manifestations of infertility, menstrual dysfunction and clinical or biochemical hyperandrogenism (hirsutism, acne and elevated androgen). Adiponectin is the most abundant adipokine. It has insulin-sensitizing, anti-atherogenic, and antiinflammatory actions.Objective: Low adiponectin levels in women with PCOS have been largely attributed to obesity which is common among these patients. Therefore, the aim of this study was to measure adiponectin levels in normal weight women with PCOS and its contribution to development of disease.Subjects and Methods: Fifty two (52) women were included in this study with age ra
... Show MoreBackground: The prevalence of both obesity & diabetes are increasing all over the world & more in women. They have a negative impact not only on morbidity & mortality but also on quality of life.
Objectives: To assess the HRQoL with a specific comparison between obese & normal weight among wo
... Show MoreBackground: Patients with decompensated cirrhosis are often given therapeutic and prophylactic drugs. Polypharmacy raises both the likelihood of prescription errors and the complications associated with drugs. Clinical pharmacists are excellent at recognizing, addressing, and preventing clinically significant drug-related problems.
Objectives: Identification types of pharmacist interventions to address drug-related problems in patients with decompensated cirrhosis and assess the acceptance/implementation of these recommendations. And identify patient factors associated with accepting pharmacist recommend
... Show MoreBreast cancer (BC) is the most commonly diagnosed cancer in women. The metabolism of iron is closely regulated by hepcidin which exerts its action by interacting with a ferroportin.
The aim of the present study was to assess the alterations in the levels of some serum biomarkers that have a role in iron homeostasis (hepcidin and ferroportin) in addition to hematological parameters (hemoglobin, leukocyte and platelets count) in different stages of BC.
This study included 66 women with BC. The patients were categorized as follows : group 1 includes :22 patients with stage I disease ,group 2 includes: 22 patients with stage II disease ,and group 3 include: 22 patients with stage III disease .Group 4 includes :22 appare
... Show MoreCo-crystals are new solid forms of drugs that could resolve more than one problem associated with drugs formulations like solubility, stability, bioavailability, mechanical and tableting properties. A preliminary theoretical study for estimating the possible bonding between the co-crystal components (paracetamol and naproxen) was performed using the ChemOffice program. The results revealed a high possibility for bonding between paracetamol and naproxen and indicated the ability of molecular mechanics study to predict the co-crystal design.
In this work, four different methods were used for the preparation of three different ratios 1:1, 2:1, and 1:2 of paracetamol:naproxen co-crystals. The four
... Show MoreBackground. Alopecia areata (AA) is a common form of noncicatricial hair loss of unknown cause, affecting 0.1-0.2% of the general population. Most evidence supports the hypothesis that it is disease of the hair follicle of autoimmune nature mediated by T-cells, with important cytokine role. Objective of the Study. The objective of this study is to study the association and changes in serum levels of interleukin-15 (IL-15) and tumor necrosis factor-α (TNF-α) in patients with AA in relation to the type, activity, and disease duration. Patients and Methods. Thirty-eight patients with AA and 22 individuals without the disease as controls were enrolled in this case-controlled study conducted in the Department of Dermatology in the Al-K
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