43 research outputs found

    Radiation characteristic of slots on conducting circular cylindercovered by eccentric dielectric cylinder

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    The radiation characteristics of axial slots on a circular conducting cylinder covered by an eccentric dielectric cylinder are investigated. A dual infinite-series solution based on the boundary-value method is obtained with the aid of the addition theorem of Bessel functions. The dual infinite series involved in the solution is then properly truncated to generate numerical results. Comparison with published data for concentric cylinders shows excellent agreement. Several interesting radiation characteristics corresponding to new geometries of the coated slot cylindrical antenna are presente

    Radiation characteristic of slots on conducting circular cylindercovered by eccentric dielectric cylinder

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    The radiation characteristics of axial slots on a circular conducting cylinder covered by an eccentric dielectric cylinder are investigated. A dual infinite-series solution based on the boundary-value method is obtained with the aid of the addition theorem of Bessel functions. The dual infinite series involved in the solution is then properly truncated to generate numerical results. Comparison with published data for concentric cylinders shows excellent agreement. Several interesting radiation characteristics corresponding to new geometries of the coated slot cylindrical antenna are presente

    Interaction Between Appreciation Doctrine and International Custom

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    Customary law is a dynamic source of international law that forms by various act of international players. Applying of margin of appreciation and its invoking is involved the one that can raise its formation as a customary rule. It has been examined in this research whether states invoking on margin of appreciation before any dispute settlement bodies as a defense and its assessment, will be led to its formation as a customary rule or not. For this purpose, requirements needed to identify customary rule, as well as capabilities and challenges that dispute settlement bodies, in particular ECHR, faces with, to stablish customary rules, has been assessed. by distinguishing between the role of states and dispute settlement bodies, the article concludes that Despite of possibility of its formation, there are certain restrictions and ambiguities for recognizing the content of the margin of appreciation as a customary rule, which international law rules has not yet provided any answer to them

    Liver morbidity among haemodialysis patients negative for manifest HBV and HCV : A hospital-based study in an endemic area

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    Background: End-stage renal disease (ESRD) is an increasing health problem worldwide.  Older age, diabetes mellitus and hypertension, acute kidney damage are among some of the factors that play a role in ESRD. This study aims at exploring liver morbidity (LM) among Egyptian hemodialysis (HD) patients.  Methods: The study included 142 patients free from overt hepatitis B virus (HBV) or  hepatitis C virus (HCV); their data were retrieved from files and all were clinically assessed and tested for liver functions, serological markers and viremia of HCV and HBV. Results: Of 142 eligible HD patients, two seroconverted to overt HCV, and five showed occult HCV. According to the laboratory and ultrasonography (US) data, three patterns of LM were found in 62 (43.7%), non-alcoholic fatty liver disease (NAFLD) in 30 (48.4%), liver fibrosis in 19 (30.6%), and hepatitis in 13 (21%). The mean durations of renal impairment (7.6 ± 5.91), hemodialysis (9 ± 6.1269), and total dialysis sessions (976.26 ± 683.69) were significantly higher in patients with LM compared to others (6.78 ± 4.82, 5.38 ± 3.69, and 699.4 ± 467.1). Alanine aminotransferase (ALT) and Aspartate aminotransferase (AST) levels were elevated in 14 (22.6%) and 13 (21%) of patients with LM. However, the ROC curve revealed ALT and AST cut-off points of 16.5 and 25.5 IU/L to discriminate LM. Conclusion: LM is common among EDRD patients undergoing hemodialysis despite the low levels of ALT and AST. The use of the US and the new lower levels of ALT and AST could improve the screening approach of LM

    High SARS CoV2 antibody-prevalence among health care workers with variable exposure to COVID-19 patients: A cross-sectional university hospital study.

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    Background: During the COVID-19 pandemic, the pattern of medical services changed to minimize transmission to health care workers (HCWs) or hospitalized patients. Despite the care of COVID-19 patients in a special ward, new cases are accidentally discovered. This study aimed at determining the antibody seroprevalence among asymptomatic HCWs and the associated risks. Methods: The study involved 190 participants, including physicians, nurses, technicians, and administrative staff. All were inquired for sociodemographic, specialty, previous isolation, and previous infection, and their blood was tested for SARS-CoV2 antibody. Results: Of 190 HCWs; 72,1% were females, the mean age was 32.6±7.9 years, 10.5% were smokers, and 15.8% reported co-morbid illness. SARS CoV2 antibodies were found in 68 (35.8%); being IgG, IgM and both IgM and IgG in 47 (69.1%), 10 (14.7%) and 11 (16.2%) participants respectively. The prevalence was higher (47.6%) among HCWs of the COVID unit, [OR=1.7 (95% CI: 0.69-4.3)] and HCWs with previous COVID-19, OR:1.61 (95% CI:0.88-2.94). The prevalence was significantly lower among smokers (p=0.049), OR:0.29 (95% CI:0.08-1.01), and significantly higher in HCWs who recalled cough (p=0.036) OR: 1.97 (95% CI: 1.05-3.69). The likelihood of antibody seropositivity increased in technicians [OR:2.02 (95% CI: 0.92-4.44)], followed by physicians [OR:1.7 (95% CI: 0.7-4.33)] while the odds ratio was low among nurses [OR:0.58 (95% CI: 0.32-1.07). Conclusion: A considerable proportion of antibody positive HCWs had evidence of past SARS CoV2. Provision of adequate personal protective equipment and periodic screening of HCWs are urgently needed to lessen the transmission within the health care settings

    Development of simulation-based testing environment for safety-critical software

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    Recently, a software program has been used in nuclear power plants (NPPs) to digitalize many instrumentation and control systems. To guarantee NPP safety, the reliability of the software used in safety-critical instrumentation and control systems must be quantified and verified with proper test cases and test environment. In this study, a software testing method using a simulation-based software test bed is proposed. The test bed is developed by emulating the microprocessor architecture of the programmable logic controller used in NPP safety-critical applications and capturing its behavior at each machine instruction. The effectiveness of the proposed method is demonstrated via a case study. To represent the possible states of software input and the internal variables that contribute to generating a dedicated safety signal, the software test cases are developed in consideration of the digital characteristics of the target system and the plant dynamics. The method provides a practical way to conduct exhaustive software testing, which can prove the software to be error free and minimize the uncertainty in software reliability quantification. Compared with existing testing methods, it can effectively reduce the software testing effort by emulating the programmable logic controller behavior at the machine level

    Numerical Investigation on Hollow Pultruded Fibre Reinforced Polymer Tube Columns

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    As the axial behaviour of hollow pultruded fibre reinforced polymer (PFRP) profiles is governed by the instability conditions due to the local and global buckling, the determination of the safe load carrying capacity of FRP columns is vital. The compressive performance of PFRP tube depends on many factors such as fibre type, fibre content, and orientation of fibre layers, cross-section, thickness and height of the column member. In this study, concentric compressive testing was conducted using PFRP short columns. Based on the fibre orientation and thickness, the samples were divided into two groups of tubes in a square shape and two groups in a circular shape. The height of columns is designed to keep the slenderness ratio (length/lateral dimension) of 5. The axial behaviour of FRP columns was simulated using STRAND7 finite element software package. The laminate method was followed to define the mechanical properties of the FRP material. Failure was investigated by using the Tsai-Wu failure criterion. The experimental results show that the failure mode of the hollow square tube was either local buckling or corner splitting at the mid-height followed by buckling. Although both types of circular tubes failed in a similar way by crushing one end with high noise, followed by separation of the crushed end into strips, the stiffness and the load capacity of PFRP column was higher for the profiles with fibres oriented close to the axial direction. The numerical results are in close agreement with the peak value of the experimental results. This can be extended to study the effects of all factors that influence the axial behaviour of PFRP columns numerically
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