The power generation of solar photovoltaic (PV) technology is being implemented in every nation worldwide due to its environmentally clean characteristics. Therefore, PV technology is significantly growing in the present applications and usage of PV power systems. Despite the strength of the PV arrays in power systems, the arrays remain susceptible to certain faults. An effective supply requires economic returns, the security of the equipment and humans, precise fault identification, diagnosis, and interruption tools. Meanwhile, the faults in unidentified arc lead to serious fire hazards to commercial, residential, and utility-scale PV systems. To ensure secure and dependable distribution of electricity, the detection of such hazards is crucial in the early phases of the distribution. In this paper, a detailed review of modern approaches for the identification of DC arc faults in PV is presented. In addition, a thorough comparison is performed between various DC arc-fault models, characteristics, and approaches used for the identification of the faults.
Missing data is one of the problems that may occur in regression models. This problem is usually handled by deletion mechanism available in statistical software. This method reduces statistical inference values because deletion affects sample size. In this paper, Expectation Maximization algorithm (EM), Multicycle-Expectation-Conditional Maximization algorithm (MC-ECM), Expectation-Conditional Maximization Either (ECME), and Recurrent Neural Networks (RNN) are used to estimate multiple regression models when explanatory variables have some missing values. Experimental dataset were generated using Visual Basic programming language with missing values of explanatory variables according to a missing mechanism at random general pattern and s
... Show MoreIn this paper, we have investigated some of the most recent energy efficient routing protocols for wireless body area networks. This technology has seen advancements in recent times where wireless sensors are injected in the human body to sense and measure body parameters like temperature, heartbeat and glucose level. These tiny wireless sensors gather body data information and send it over a wireless network to the base station. The data measurements are examined by the doctor or physician and the suitable cure is suggested. The whole communication is done through routing protocols in a network environment. Routing protocol consumes energy while helping non-stop communic
... Show MoreThe 2D imaging survey was carried out using Wenner-Schlumberger array through (11) 2D survey lines distributed within and out of Abu-Jir fault zone, Southwest of Karbala City, central Iraq. The aim is to delineate subsurface fractures density. The total length of each 2D survey line is (600m.) with the unit electrode spacing (a) equals to (10m.).The results showed two types of fractures zones. The first type is formed by dissolution process of carbonate rocks, while the second fractures zone is formed from tectonic movements, and it includes two types of fractures system, oblique and vertical fractures.
This study includes comparison between subsurface fracture density within and out of Abu- Jir fault zone. This comparison showed that
The Polarographic study of the interaction between ascorbic acid and Ni+2 was carried out at dropping mercury electrode [DME] . This study included the determination of the kinetic parameters (kfh ,n) and thermodynamic parameters such as enthalpy change (H), free energy change (G) and entropy change (S) of Ni+2 complexes with ascorbic acid in 0.1 M KCl solution over the temperature rang of (294-309)K. The electrode processes were irreversible and diffusion controlled.
The extrasolar planets in the vicinity of stars are expected to be bright enough
and are very difficult to be observed by direct detection. The problem is attributed to
the side loops of the star that created due to the telescope diffraction processing.
Several methods have been suggested in the literatures are being capable to detect
exoplanet at a separation angle of 4λ/D and at a contrast ratio of 10-10. These
methods are more than one parameter function and imposing limitations on the inner
working distance. New simple method based on a circular aperture combined with a
third power Gaussian function is suggested. The parameters of this function are then
optimized based on obtaining a minimum inner working dis
Four different spectrophotometric methods are used in this study for the determination of Sulfamethoxazole and sulfanilamide drugs in pharmaceutical compounds, synthetic samples, and in their pure forms. The work comprises four chapters which are shown in the following: Chapter One: Includes a brief for Ultraviolet-Visible (UV-VIS) Absorption spectroscopy, antibacterial drugs and sulfonamides with some methods for their determination. The chapter lists two methods for optimization; univariate method and multivariate method. The later includes different types, two of these were mentioned; simplex method and design of experiment method. Chapter Two: Includes reaction of the two studied drugs with sodium nitrite and hydrochloric acid for diazo
... Show MoreA study of the effects of the discharge (sputtering) currents (60-75 mA) and the thickness of copper target (0.037, 0.055 and 0.085 mm) on the prepared samples was performed. These samples were deposited with pure copper on a glass substrate using dc magnetron sputtering with a magnetic flux density of 150 gauss at the center. The effects of these two parameters were studied on the height, diameter, and size of the deposition copper grains as well as the roughness of surface samples using atomic force microscopy (AFM).The results of this study showed that it is possible to control the specifications of copper grains by changing the discharge currents and the thickness of the target material. The increase in discharge curre
... Show MoreAbstract
In this work, pure Polypyrrole (PPy) and Polypyrrole (PPy)/Graphene (GN) was synthesized by in-situ polymerization in different weight percentages (0.1, 0.3, 0.5, 1, 3 and 5 wt.% (g)) of GN nano particles using chemical oxidation method at room temperature. The FTIR, SEM and electrical properties were studies for the nano composites. The result show that when concentration of GN Nano particle increase, the electrical conductivity increased and the graphene sheets were merging to form a continuous area of the GN through the polypyrrole base material. The FTIR spectra shows that the characteristics absorption peaks of polypyrrole that is, 1546.80, 1463.87 and 3400.27 cm-1(stretching vibration in the pyrrol
... Show MoreSo far, APT (Advanced Persistent Threats) is a constant concern for information security. Despite that, many approaches have been used in order to detect APT attacks, such as change controlling, sandboxing and network traffic analysis. However, success of 100% couldn’t be achieved. Current studies have illustrated that APTs adopt many complex techniques to evade all detection types. This paper describes and analyzes APT problems by analyzing the most common techniques, tools and pathways used by attackers. In addition, it highlights the weaknesses and strengths of the existing security solutions that have been used since the threat was identified in 2006 until 2019. Furthermore, this research proposes a new framework that can be u
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