The effects of T-shaped fins on the improvement of phase change materials (PCM) melting are numerically investigated in vertical triple-tube storage containment. The PCM is held in the middle pipe of a triple-pipe heat exchanger while the heat transfer fluid flows through the internal and external pipes. The dimension effects of the T-shaped fins on the melting process of the PCM are investigated to determine the optimum case. Results indicate that while using T-shaped fins improves the melting performance of the PCM, the improvement potential is mainly governed by the fin’s body rather than the head. Hence, the proposed T-shaped fin did not noticeably improve melting at the bottom of the PCM domain; additionally, a flat fin is added to the optimal case (Added-Fin case) and compared to the No-Fin, Uniform-Fin, and Optimum T-shaped Fin cases (no added fin). The analysis shows that the total heat storage rate of the Added-Fin case increased by 141.7%, 58.8%, and 47.6% compared with the No-Fin, Uniform-Fin, and the Optimum T-shaped Fin cases, respectively. Furthermore, the total melting time for the Added-Fin case was 1882 s and decreased by 59.6%, 38.4%, and 33.6% compared with those of the No-Fin, Uniform-Fin, and the Optimum T-shaped Fin (Optimum) cases, respectively.
DBN Rashid, 2012 - Cited by 2
Leishmania species are the causative agent of a tropical disease known as leishmaniasis. Previous studies on the old world species Leishmania major, showed that the amastigotes form which resides inside the macrophage of the vertebrate host, utilize host’s sphingolipids for survival and proliferation. In this study, gene expression of serine palmitoyltransferase (SPT) subunit two (MmLCB2) of the mouse macrophage cell line (RAW264.7), which is the first enzyme in the de novo sphingolipid biosynthesis, was detected in both infected and non-infected macrophages. This was detected under condition where available sphingolipid was reduced, with the new world species Leishmania mexicana. Results of qPCR analysis showed that there was no differen
... Show MoreA field experiment was carried out in the province of Najaf - al ashraf using two types of blue-green algae( Anabaena circinalis and Oscillaoria lymentica) which have been isolated and diagnosed in the laboratories of the department of plant protection / ministry of agriculture in Iraq with the compost( palm fronds ) manufacturer locally and by 1 ml : 10 g of organic matter within one month of cuddling and using a single level of humidity is 1 : 2 (water : organic matter). Randomized complete block design RCBD to see the effect of use it as a single or mix in the productivity of rice crop Yasamin cultivar where it was noted that it is equipped with a dynamic composting of organic matter leads to the analysis of organic material and incre
... Show MoreIn Australia, most of the existing buildings were designed before the release of the Australian standard for earthquake actions in 2007. Therefore, many existing buildings in Australia lack adequate seismic design, and their seismic performance must be assessed. The recent earthquake that struck Mansfield, Victoria near Melbourne elevated the need to produce fragility curves for existing reinforced concrete (RC) buildings in Australia. Fragility curves are frequently utilized to assess buildings’ seismic performance and it is defined as the demand probability surpassing capacity at a given intensity level. Numerous factors can influence the results of the fragility assessment of RC buildings. Among the most important factors that can affe
... Show MoreAllergic Rhinitis (AR) is a chronic immune system inflammation that occurs when the body overreacts to antigens in the environment (triggers) and produces a variety of symptoms in the nasal mucosa and paranasal sinuses due to the release of many interleukins and cytokines.
We investigated the influence of the allergen on serum levels of TNF-α and Total IgE in patients with AR and their function in initiating allergic rhinitis in Iraqi petrol station workers in Baghdad. One hundred individuals with allergic
... Show MoreBackground: Pyle`s disease is a distinct skeletal dysplasia with defective metaphyseal modeling and Erlenmeyer-flask deformity of tubular bones.
Objectives: Clinical implications in five reported cases with mechanical bone properties different from normal bones were presented. One patient with Genu-valgum deformity had corrective osteotomy done with internal fixation showing osteotomy healing and sustained deformity correction with more than twelve years of follow up. Two patients presented with fractures and angular malalignment with abundant callus .The other two had insufficiency fractures due to repetitive low energy activities.
Results: Patients with Pyle`s disease have less than normal mechanical bone
Abstract
This study aims to identify the most prominent factors that lead to bullying of students with intellectual disabilities in primary and middle schools from the perspectives of special education teachers. A quantitative descriptive approach was utilized. A questionnaire was used as a tool for data collection. The sample consisted of (72) male and female teachers from the Asir region in the Kingdom of Saudi Arabia. The results revealed the most prominent factors that lead to bullying as follows: factors associated with the school and its policies, factors associated with peers, factors associated with students with intellectual disabilities, and factors associated with general education teachers. The findin
... Show MoreEffect of antioxidants (vitamins C and E) (500mg/kg) was studied on function of testes in albino mice treated with hexavalent chromium (1000ppm). The results showed that exposure to hexavalent chromium caused a significant decrease in body weights, without changes in weight of testes, seminal vesicles and prostate. A significant decrease was observed in the percentage of dead sperms, sperms abnormalities, diameter of seminiferous tubules and the number of leydig cells. Degenerative changes and necrosis were observed in the lumen of seminiferous tubules. Treatment of hexavalent chromium-exposed mice with vitamin C caused improvement in weights and characters of sperms and improvement of the tissue of seminiferous tubules. Tre
... Show Morethis research aims to identify the impact of teaching with ana logies in collection of chemistry students grade average.And direction in order to verify to the zero hypothesis has been formulated and validated,The researcher conducted experiment lasted a full semester as experimental design was chosen (exactly)two equal one pilot and another officer.The research community has been selected one of intentional Middle School of the Education Directorate in B aghdad Karkh second either search sample consisted of (68) students from second grade average (34 ) Students for each group randomly selected research groups was equal to the following variables (lifetime months,parent of first grade chemistry degrees average test informat
... Show MoreThe current research seeks to know the difficulties in memorizing literary texts with fourth grade students from teachers’ point of view of and students
The research contains a community of (10,870) students from schools affiliated to the Directorate of Karkh, second and the number of schools for boys and girls (79) School and the number of teachers (349) who are specialized in teaching Arabic language to fourth grade preparatory students and there was a section of a randomly sample of each of the students, teachers and schools .
Some actions which can be listed below:-The survey which was done by the researcher for the views of the two samples from teachers and students as the number of teachers covered in this research (20) and