21 research outputs found

    Intelligent Optimization Systems for MaintenanceScheduling of Power Plant Generators

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    This paper presents a Genetic Algorithm (GA) and Ant-Colony (AC) optimization model for power plant generators’ maintenance scheduling. Maintenance scheduling of power plant generators is essential for ensuring the reliability and economic operation of a power system. Proper maintenance scheduling prolongs the shelf life of the generators and prevents unexpected failures. To reduce the cost and duration of generator maintenance, these models are built with various constants, fitness functions, and objective functions. The Analytical Hierarchy Process (AHP), a decision-making tool, is implemented to aid the researcher in prioritizing and re-ranking the maintenance activities from the most important to the least. The intelligent optimization models are developed using MATLAB and the developed intelligent algorithms are tested on a case study in a coal power plant located at minjung, Perak, Malaysia. The power plant is owned and operated by Tenaga Nasional Berhad (TNB), the electric utility company in peninsular Malaysia. The results show that GA outperforms ACO since it reduces maintenance costs by 39.78% and maintenance duration by 60%. The study demonstrates that the proposed optimization method is effective in reducing maintenance time and cost while also optimizing power plant operation

    Towards Wind Energy-based Charging Stations: A Review of Optimization Methods

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    Due to the growing importance of renewable sources in sustainable energy systems, the strategic deployment of robust optimization techniques plays a crucial role in the design of Electric Vehicle Charging Stations (EVCSs). These stations need to smoothly incorporate renewable sources, ensuring optimal energy utilization. This study provides a comprehensive overview of the methodologies and approaches employed in the enhancement of wind energy based EVCSs. The aim is to discern the most efficacious techniques for optimizing charging stations. Researchers engage diverse strategies and methodologies in the realm of sizing and optimization, encompassing a spectrum of algorithmic implementations and software solutions. Evidently, each algorithm or software application bears distinctive merits and demerits. Singular reliance on a solitary algorithm or software for charging utility optimization is discerned to be potentially limiting. The investigation reveals that achieving better results in Electric Vehicle Charging Station (EVCS) optimization is facilitated by the collaborative use of multiple algorithms like GA, PSO, and ACO, among others, or software tools like Homer or RETScreen

    Delamination-and electromigration-related failures in solar panels—a review

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    The reliability of photovoltaic (PV) modules operating under various weather conditions attracts the manufacturer’s concern since several studies reveal a degradation rate higher than 0.8% per year for the silicon-based technology and reached up to 2.76% per year in a harsh climate. The lifetime of the PV modules is decreased because of numerous degradation modes. Electromigration and delamination are two failure modes that play a significant role in PV modules’ output power losses. The correlations of these two phenomena are not sufficiently explained and understood like other failures such as corrosion and potential-induced degradation. Therefore, in this review, we attempt to elaborate on the correlation and the influence of delamination and electromigration on PV module components such as metallization and organic materials to ensure the reliability of the PV modules. Moreover, the effects, causes, and the sites that tend to face these failures, particularly the silicon solar cells, are explained in detail. Elsewhere, the factors of aging vary as the temperature and humidity change from one country to another. Hence, accelerated tests and the standards used to perform the aging test for PV modules have been covered in this review

    A Novel Quinazoline Inhibits Hsp90 Protein, EGFR and Induces Apoptosis in Leukemia Cells

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    The objective of the first part of this study was to investigate the Hsp90 protein possible activ ity of a novel quinazoline Her2/ EGFR inhibitor (Co mpound No. 1: 4-(2-(4-Oxo-2-thio xo-1,4-d ihydroquinazolin-3(2H)yl)ethyl)benzenesulfonamide) p reviously synthesized by a collaborating group. Heat shock protein 90 (Hsp90) has a central ro le in regulation of several client proteins involved in cancers [1,2]. Several Hsp90 inhibitors of the natural or synthetic origin d isplayed potent anticancer activity [3,4]. Accordingly, Hsp90 emerged as an attractive target in the design of anticancer agents. To evaluate the binding mode of compound No. 1 into the ATPase site of Hsp90, a co mparative mo lecular docking study was performed using AutoDock 4.2. The results of this studywas compared with that of the co-crystallized ligand (ATI-13387X, Onalespib). The energy minimization process of the chemical structures of No. 1 was done following our previous report [5]. The results of the docking study revealed that No. 1 fit n icely into the ATPase site, and it displayed a binding free energy (Gb) of-7.21 kcal/ mo l and inhibition constant (Ki) of 5.19 µM to Hsp90, co mpared to Gb of-7.90 kcal/ mol and Ki of 1.62 µM for ATI-13387X. Furthermore, to confirm this result, the surface plasmon resonance (SPR) was devised to test the Hsp90 inhibition activity of No.1, wh ich was 51 nM co mpared to Rad icico l and 17AA G (1.8 nM, and 360 nM; respectively). Overall, co mpound No. 1 exh ibited pro mising Hsp90 inhib iting activity. The second part of the study focused on the effect of No. 1, Dinaciclib and their co mbinationsin HL-60 leukemia cells. The comb ination showed synergistic EGFR inhib ition effect in HL-60 cells. Moreover, No. 1, Dinaciclib and their combination caused a significant increase in the Sub-G1 co mpared to control and doxorubicin (24h), at the expense of S and G2/M cell cycle phases. Cyclin D3, was consequently inhibited by each of the two drugs, and synergistically by their comb ination in HL-60 cells. Furthermore, each of the two drugs downregulated Survivin, wh ich was synergistically inhib ited by the co mbination. In conclusion, co mpound No.1, Dinaciclib and their comb inations showed synergestic EGFR inhibit ion; and pro-apoptoticeffect in HL-60 cells.This project was funded by the deanship of scientific research, Umm Alqura University, KSA (DSR: 15-M ED-3-1-0060). Keywords: Novel quinazoline EGFR inhi bi tor, Hs p90 protein, Leukemi a cells

    The approach of value innovation towards superior performance, competitive advantage, and sustainable growth: A systematic literature review

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    The value innovation strategy of pursuing differentiation and low cost has diverged and correlated with various notions and perspectives, which adds complexity and ambiguity to the current knowledge of value innovation. Thus, this study uses a systematic literature review methodology to identify key scientific contributions to the field of value innovation by providing a structured reliable overview of the current knowledge. This study aims to integrate the findings of previous research on value innovation to identify where conclusions converge and diverge and highlight emerging trends and gaps in the literature. This study seeks to answer the research question, “How can value innovation be an approach for superior performance, competitive advantage, or sustainable growth?” In this context, results are achieved through analyzing and synthesizing 73 empirical articles on value innovation literature published from 1997 to January 2021. Particularly, this study contributes to the extant literature by providing an integrative framework that summarizes the literature findings and addressing thematic classifications of the value innovation process. This study also helps further improve research on value innovation by identifying gaps and suggesting a conceptual model to mitigate those gaps

    The effect of value innovation in the superior performance and sustainable growth of telecommunications sector : Mediation effect of customer satisfaction and loyalty

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    The telecommunications industry has recognized innovation as the key to growth and survival. Globalization, liberalization, and privatization, the terms most commonly associated with this sector, have resulted in fierce competition, making it more difficult for telecommunications firms to increase their market share and, as a result, their customer base, sales volume, and, ultimately, profits. The new success strategy is differentiation through innovation, with the aim of breaking out of the competition and creating an uncontested market. This can be accomplished by providing high-value, innovative services that result in customer satisfaction and promote customer loyalty. The primary goal of this study was to create and validate a conceptual model of value innovation and its impact on firm performance and long-term growth by examining the mediation effect of customer satisfaction and loyalty. The empirical analysis results were based on 304 respondents who completed a paper-based survey provided to employees of Yemeni mobile service providers using a convenience non-probability sampling technique. SmartPLS 3 was used to test the hypothesized relationships using partial least squares structural equation modeling (PLS-PM). As a result, the findings empirically validated the theoretical research model, confirming the importance of the value innovation approach to achieving company performance and long-term growth by promoting customer satisfaction and loyalty. Finally, we have provided a discussion of the study’s theoretical contributions, managerial implications, and future research directions

    Deep-learning-based approach for Iraqi and Malaysian vehicle license plate recognition

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    Recognizing vehicle plate numbers is a key step towards implementing the legislation on traffic and reducing the number of daily traffic accidents. Although machine learning has advanced considerably, the recognition of license plates remains an obstacle, particularly in countries whose plate numbers are written in different languages or blended with Latin alphabets. This paper introduces a recognition system for Arabic and Latin alphabet license plates using a deep-learning-based approach in conjugation with data collected from two specific countries: Iraq and Malaysia. The system under study is proposed to detect, segment, and recognize vehicle plate numbers. Moreover, Iraqi and Malaysian plates were used to compare these processes. A total of 404 Iraqi images and 681 Malaysian images were tested and used for the proposed techniques. The evaluation took place under various atmospheric environments, including fog, different contrasts, dirt, different colours, and distortion problems. The proposed approach showed an average recognition rate of 85.56% and 88.86% on Iraqi and Malaysian datasets, respectively. Thus, this evidences that the deep-learning-based method outperforms other state-of-the-art methods as it can successfully detect plate numbers regardless of the deterioration level of image quality

    Electrical equipment incipient faults simulation using electromagnetic field emission

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    Predicting failures of electrical equipment is an increasingly important topic in wide range of settings including industry as well as household appliances. The protection from failures can be achieved through early preventive actions while faults are in early stages. Identification of such incipient faults needs a thorough study and understanding of their patterns. Several methods exist for collecting necessary incipient fault data for further analysis and extraction of those patterns. One approach is to use the Electromagnetic Fields (EMF) emission from electrical equipment as a signature of incipient fault. However, this parameter requires conducting measurements to capture the EMF emission from equipment experiencing one or more incipient faults, which might require interrupting or damaging the equipment or parts of it, potentially leading to hazardous consequences. Another method is to design an antenna that generates faulty signals like those of equipment experiencing real incipient faults. However, this method requires detailed knowledge about the faults and the EMF emission propagation mechanism and is not in favor due to cost and design complexity. Hence, in this paper, we propose to simulate incipient faults based on a derived model of the EMF emission of a normal operating equipment. To generate the simulated signals, the coefficients of the model transfer function are systematically varied to yield different incipient fault patterns. The results are validated with two measured incipient faults, namely, inverter and winding faults and it was found that the correlation between the simulated and actual faults was significant which indicates that this method is viable as another source of data for incipient fault analysis

    Power Quality Assessment of Grid-Connected PV System in Compliance with the Recent Integration Requirements

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    The generation and integration of photovoltaic power plants (PVPPs) into the utility grid have increased dramatically over the past two decades. In this sense, and to ensure a high quality of the PVPPs generated power as well as a contribution on the power system security and stability, some of the new power quality requirements imposed by different grid codes and standards in order to regulate the installation of PVPPs and ensure the grid stability. This study aims to investigate the recent integration requirements including voltage sag, voltage flicker, harmonics, voltage unbalance, and frequency variation. Additionally, compliance controls and methods to fulfill these requirements are developed. In line with this, a large-scale three-phase grid-connected PVPP is designed. A modified inverter controller without the use of any extra device is designed to mitigate the sage incidence and achieve the low-voltage ride-through requirement. It can efficiently operate at normal conditions and once sag or faults are detected, it can change the mode of operation and inject a reactive current based on the sag depth. A dynamic voltage regulator and its controller are also designed to control the voltage flicker, fluctuation, and unbalance at the point of common coupling between the PVPP and the grid. The voltage and current harmonics are reduced below the specified limits using proper design and a RLC filter. The obtained results show that the proposed controller fulfilled the recent standard requirements in mitigating power quality (PQ) events. Thus, this study can increase the effort towards the development of smooth PVPP integration by optimizing the design, operation and control strategies towards high PQ and green electricity
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