<p>Photovoltaic (PV) systems are becoming increasingly popular; however, arc faults on the direct current (DC) side are becoming more widespread as a result of the effects of aging as well as the trend toward higher DC voltage levels, posing severe risk to human safety and system stability. The parallel arc faults present higher level of current as compared with the series arc faults, making it more difficult to spot the series arc. In this paper and for the aim of condition monitoring, the features of a DC series arc fault are analyzed by analysing the arc features, performing model’s simulation in PSCAD, and carrying out experimental studies. Various arc models are simulated and investigated; for low current arcs, the heuristic model is used where a set of parameters established. Moreover, the heuristic model’s simulated arc has been shown to be compatible with the experimental data. The features of arc noise in the electrode separation region and steady-arcing states with varied gap widths are investigated. It has been discovered that after an arc fault occurs, arc noise increases, notably in the frequency range below 50 kHz; where this property is useful for detecting DC series arc faults. Besides that, variations in air gap width are more sensitive to frequencies under 5 kHz.</p>
:p>بحثت هذه الدراسة الدور التعليمي لتطبيق (إنستغرام) وإسهامه في تعليم اللغة الإسبانية كلغة أجنبية داخل القاعات الدراسية، من خلال مراجعة لأهم الدراسات الحديثة ذات الصلة. استعرضت الدراسة مفهوم التعليم الرقمي وعلاقته بالابتكار التعليمي، كما ناقشت الخصائص التعليمية التي تجعل من إنستغرام أداة فعالة في تدريس اللغات الأجنبية، مثل التفاعل البصري، والتعليم غير الرسمي، وتعزيز المشاركة والتفاعل بين المتعلمين. وقد
... Show MoreObjective: The purpose of this study was to assess the effectiveness of Vibriophage Universiti Sains Malaysia 8 (VPUSM 8), a bacteriophage that destroys bacteria, in managing the proliferation of Vibrio cholerae, specifically the El Tor serotype, as an alternate therapeutic strategy. Methods: The study entailed subjecting water samples from Kelantan, Malaysia, to reproduce the natural circumstances that promote the growth of V. cholerae. Subsequently, the samples were contaminated with the V. cholerae O1 El Tor Inaba strain and treated using VPUSM 8. The study employed a controlled experimental design, wherein the samples were divided into three groups, each experiencing different treatment methods. Quantifying the number of colony-
... Show MoreIn this study, poly4-(nicotinamido)-4-oxo-2-butenoic acid (PNOE) was prepared by the electro polymerization of 4-(nicotinamido)-4-oxo-2-butenoic acid (NOE) monomer on a 316 stainless steel (St.St) which acts as an anticorrosion coating. Fourier transforms infrared (FTIR), atomic force microscopy (AFM), scanning electron microscopy (SEM), and cyclic voltammetry were used to diagnose the structure and the properties of the prepared polymer layer. The corrosion behavior of the uncoated and coated 316 St.St were evaluated by using an electro chemical polarization technique in 0.2 M hydrochloric acid solution as a corrosive medium at a temperature range of 293 to 323 K. Nano materials, such as nano ZnO and graphene were added in di
... Show MoreBackground: Migraine is one of multiple attack neurological conditions that causes moderate to severe headaches with no defined pathophysiology and few animal models. Aim: Establishing an animal model that reproduces migraine-like action is important in medical research to identify the mechanism underlying this disorder. Additionally, it facilitates the availability and reliability of new models that may act as human surrogate models. Method: Rabbits were divided into four groups. Negative group, migraine group, rizatriptan- nitroglycerin group, and rizatriptan group. The frequency of head scratching and the histopathological changes in the brain, liver, kidney, and heart for groups were evaluated in all groups. Results: T
... Show MoreIn October 2019, Iraq and Lebanon witnessed widespread protests, which aroused the interest of the media, as they began with demands for the provision of services, then escalated with the overthrow of the political system. The researchers chose a satellite channel that represents a direction for a country accused of entering the line of protests. This paper aims to analyze the main bulletin of Al-Alam channel to find out how it deals with the protests in the news. It is classified descriptively, using the survey method and the method of content analysis. The study community was represented by the main news bulletin of Al-Alam channel. The researchers adopted a deliberate sample for the period from 1/10/2019 to
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