In this paper, the characteristics of microstrip monopole antennas are studied firstly in free space. Secondly, the effects of the human body on the studied antenna's performance are investigated for wearable communications. Different patch shapes of microstrip monopole antenna are chosen to operate at two bands: industrial scientific and medical band (ISM) and ultra-wideband (UWB) for wearable applications. The studied antenna consists of a radiating element on one side of the substrate and a partial ground plane on the other side. The antenna is supposed to fabricate on cloth fabric whose relative dielectric constant is Ɛr =1.7. At the same time, the pure copper could be used as the conducting part representing both the radiating monopole and the partial ground plane. The software program of Computer Simulation Technology (CST) for Microwave Studio (MWS) is utilized to simulate the studied antennas. The obtained results have illustrated that in the free space, the proposed antennas of slotted hexagonal, rectangular, and circular shapes can operate from 2-12 GHz and of the bandwidth of 10.31 GHz, 10.19 GHz, and 9.67 GHz, respectively. The hexagonal antenna is selected and proposed to investigate the effects of the human body on its performance. The human body is simulated, and its effects on the performance of the proposed antenna are studied. The reflection coefficient, Voltage Standing Wave Ratio (VSWR), gain, and efficiency are found over that frequency range. The simulated results indicate that the human body effects are significant, and the proposed antenna showed to be a good candidate for wearable communications.
In this research, the mechanism of cracks propagation for epoxy/ chopped carbon fibers composites have been investigated .Carbon fibers (5%, 10%, 15%, and 20%) by weight were used to reinforce epoxy resin. Bending test was carried out to evaluate the flexural strength in order to explain the mechanism of cracks propagation. It was found that, the flexural strength will increase with increasing the percentage weight for carbon fibers. At low stresses, the cracks will state at the lower surface for the specimen. Increasing the stresses will accelerate the speed of cracks until fracture accorded .The path of cracks is changed according to the distributions of carbon fibers
In the present work, the ternary compound MgxZn7-x O7Wurtzoid with variable Zn and Mg contents was analyzed using density functional theory with B3LYP 6-311G**basis set. The electronic and vibrational properties of MgxZn7-xO7 wurtzoids, were investigated, including energy gaps, bond lengths, spectral properties, such like infrared spectra and Raman. IR and Raman spectra were compared with experimental longitudinal optical modes frequency results. The theoretical results agree well with experiments and previous data. It has been found that the energy gap is increasing with the increased Mg concentration, and that the longitudinal optical position exposes a UV shift movement with an increase in the concentration.
One of the most important problems that would continuously face the Higher education organizations is how to improve the service level presented by them, and how this can lead to increase demand for services of this organizations.As this issue has exhausted many organizations pushed some of them to withdraw from the market Because of weaknesses in their services. Here lies the importance of this matter to be given more attention in order to maintain the organization competitive position. According to that, The selection of the research title (The Impact of Quality on the Level of the University Service Request) which seeks to measure the impact of service quality on the level of demand, At a time when world&
... Show MoreThe current specialized research tagged (intellectual and artistic concepts of the cultural context and their impact on contemporary ceramic sculpture) paves the way for the emergence of the context in ceramics active in life, so that this relationship will indicate the development and presence of ceramics or not and the volume of its circulation in the joints of the culture of the Arab recipient. As a result, the researcher collected scientific materials to serve the subject of the research in four chapters: Chapter One (General Methodological Framework) To clarify the problem of the research, the importance of the research to achieve benefit in higher education and education for scholars and teachers, while the research aims to revea
... Show MoreFG Mohammed, HM Al-Dabbas, Science International, 2018 - Cited by 2
A cumulative review with a systematic approach aimed to provide a comparison of studies’ investigating the possible impact of the active form of vitamin D3, calcitriol (CTL), on the tooth movement caused by orthodontic forces (OTM) by evaluating the quality of evidence, based on collating current data from animal model studies, in vivo cell culture studies, and human clinical trials. Methods: A strict systematic review protocol was applied following the application of the International Prospective Register of Systematic Reviews (PROSPERO). A structured search strategy, including main keywords, was defined during detailed search with the application of electronic database systems: Medline/Pubmed, EMBASE, Scopus, Web of Science, and
... Show MoreThe research aims to identify the academic problems of family counseling diploma students at Saudi Universities. In addition, to identify the differences in these problems according to gender, marital status, place of study, academic specialization, and GPA. The sample consisted of (491) students. The researcher has used one questionnaire for academic problems prepared by the researcher. The research revealed the following results: There were academic problems among family counseling diploma students at Saudi Universities, the most problems were related to the systems and administrations of the university, then the field training, the buildings, classrooms and campus facilities, then the academic courses, after that the exams, then
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Knowing the amount of residual stresses and find technological solutions to minimize and control them during the production operation are an important task because great levels of deformation which occurs in single point incremental forming (SPIF), this induce highly non-uniform residual stresses. In this papera propose of a method for multilayer single point incremental forming with change in thickness of the top plate (0.5, 0.7, 0.9) mm and lubrication or material between two plates(polymer, grease, grease with graphite, mos2) to knowing an effect of this method and parameters on residual stresses for the bottom plates. Also compare these results for the
... Show MoreBackground: Postoperative nausea and vomiting (PONV) are one of the most common complaints following laparoscopic cholecystectomy.
Objective: This study was designed to compare the effects of dexamethasone, metoclopramide, and their combination on preventing PONV in patients undergoing laparoscopic cholecystectomy.
Methods: A total of 135 patients enrolled in the study. American Society of Anesthesiologists (ASA) physical status I and II patients were included in this randomized, double blind, placebo-controlled study. Patients were randomly assigned to group A administered 8mg iv dexamethasone, group B received metoclopramide 10 mg, group C received combination of 8mg de
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