Phase-change materials (PCMs) have a remarkable potential for use as efficient energy storage means. However, their poor response rates during energy storage and retrieval modes require the use of heat transfer enhancers to combat these limitations. This research marks the first attempt to explore the potential of dimple-shaped fins for the enhancement of PCM thermal response in a shell-and-tube casing. Fin arrays with different dimensions and diverse distribution patterns were designed and studied to assess the effect of modifying the fin geometric parameters and distribution patterns in various spatial zones of the physical domain. The results indicate that increasing the number of dimple fins in the range of 8–32 results in faster heat storage rates by up to 8.7% faster than they would be without the dimple fins. Further improvements of approximately 1.4, 1.2, 1.1, and 1.0% can be obtained by optimizing the position of the first fin section, the spacing between other fin sections, the fin spacing based on the aromatic algorithm, and the use of the staggered fin distribution. The heat storage rate is improved by almost 12% for the best case compared with that of the no-fin case.
This paper present a study about effect of the random phase and expansion of the scale sampling factors to improve the monochrome image hologram and compared it with previous produced others. Matlab software is used to synthesize and reconstruction hologram.
The recent development in statistics has made statistical distributions the focus of researchers in the process of compensating for some distribution parameters with fixed values and obtaining a new distribution, in this study, the distribution of Kumaraswamy was studied from the constant distributions of the two parameters. The characteristics of the distribution were discussed through the presentation of the probability density function (p.d.f), the cumulative distribution function (c.d.f.), the ratio of r, the reliability function and the hazard function. The parameters of the Kumaraswamy distribution were estimated using MLE, ME, LSEE by using the simulation method for different sampling sizes and using preli
... Show MoreThe present work included study of the effects of weather conditions such as solar radiation and ambient temperature on solar panels (monocrystalline 30 Watts) via proposed mathematical model, MATLAB_Simulation was used by scripts file to create a special code to solve the mathematical model , The latter is single –diode model (Five parameter) ,Where the effect of ambient temperature and solar radiation on the output of the solar panel was studied, the Newton Raphson method was used to find the output current of the solar panel and plot P-V ,I-V curves, the performance of the PV was determined at Standard Test Condition (STC) (1000W/m2)and a comparison between theoretical and experimental results were done .The best efficiency
... Show MoreEgypt and Ethiopia have connected in a strong relation as there are historical facts that
deepen these relations, one of these is Egypt's cooperation in establishing the first economic
and financial banking system in Ethiopia.
Beside the religious relation between The Egyptian and Ethiopian churches the Nile River is
considered one of the effective connections
That strong then the relations as it leads to some tension between the two countries because
Ethiopia believes that Egypt seeks to control the river tries to build its project over the Blue
Nile means a threat to the Ethiopian national security.
The tension continues even after the revolution of 25th of January 2011because the Nahda
dam which is a clear t
The aim of this study is to investigate the feasibility of underground storage of gas in Um El-Radhuma formation /Ratawi field. This formation is an aquifer consisting of a high permeable dolomitebeds overlain by impermeable anhydrite bed of Rus formation. Interactive petrophysics (IP), Petrel REand Eclipse 100 softwares were used to conduct a well log interpretation, build a reservoir simulationmodel and predict the reservoir behavior during storage respectively. A black oil, three dimensionaland two phase fluid model has been used. The results showed that the upper part of Um El-Radhumaformation is suitable for underground gas storage, because of the seal of its cap rock and capability ofreserving gas in the reservoir. It was foun
... Show MoreObjective: To evaluate knowledge towards smoking and its relationship with lung cancer among members of
Baghdad Nursing College.
Methodology: The study comprised 100 affiliates from the College of Nursing/ University of Baghdad that
included students, teaching staff and employees. All data was collected through a structured questionnaire
prepared by the National Cancer Research Center which were answered during a scientific symposium
organized by the center on lung Cancer Awareness in March 2016.The data were analyzed by using the SPSS,
version 22
Results: The age of the respondents ranged from (19-64 years); 76% were females and only 4% were smokers.
The results showed that the mean score for the level of knowled
The treatment of migraine headache targets the neurovascular mechanism and involves the use of serotonin receptor antagonists. Some of these drugs are used for the treatment of acute attacks; while others are effective as prophylactic measures to decrease the duration and frequency of attacks. Pizotifen, a 5-HTA antagonist, is one of the prophylactic drugs for which the clinical use resulted in low outcomes in reducing migraine symptoms. Melatonin, a serotonin derived neurohormone, was reported to exert many functions like sleep induction, anti-inflammatory, neurovascular regulation, cytoprotection and modulation of neurotransmitter release. In the view of the involvement of serotonin in the pathophysiology of migraine a
... Show MoreComparative taxonomic study has been compeleted for the species of the. genus Centaurium Hill. of Iraq. So the morphological characters were studied comparatively for the first time form Iraqi materials. Stems, leaves ,infloresences and reproductive organs characters were a good taxonomic importance. Geographical distrtribution has been done for the species of the genus in addition to the environment information. The results were presented with schedules, tables, maps and micrographs. Taxonomic key for the species separation was also presented.