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Moustafa Abdelrahman Moustafa(무스타파 압델라흐만 무스타파),Choong-koo Chang(장중구) 대한전기학회 2020 전기학회논문지 Vol.69 No.1
Cascading failure is the main mechanism of large blackouts in electrical power systems; this paper analyzes a cascading failure in Hanbit nuclear power plant unit (2) caused by a circuit breaker (CB) operation failure. This malfunction has been expanded to the loss of offsite power (LOOP). In this study, current practices are reviewed and then the methodologies of how to mitigate cascading failures in protection power systems are introduced. A description of the implementation-as a key solution-of the IEC61850 GOOSE message, together with zone selectivity interlocking was described. In consideration of ZSI blocking time, attention should be paid to all contributing factors such as circuit breaker tripping time, relay responding time and communications traveling time in the communication network. The aim of this paper is to establish the influence of cascading failure in NPP electrical protection power system and propose preventive actions of this failures. Finally, the expected advantages and challenges are elaborated.
Preventing cascading failure of electric power protection systems in nuclear power plant
Moustafa, Moustafa Abdelrahman Mohamed Mohamed,Chang, Choong-koo Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.1
Cascading failure is the main cause of large blackouts in electrical power systems; this paper analyzes a cascading failure in Hanbit nuclear power plant unit two (2) caused by a circuit breaker (CB) operation failure. This malfunction has been expanded to the loss of offsite power (LOOP). In this study, current practices are reviewed and then the methodologies of how to prevent cascading failures in protection power systems are introduced. An overview on the implementation of IEC61850 GOOSE messaging-based zone selective interlocking (ZSI) scheme as key solution is proposed. In consideration of ZSI blocking time, all influencing factors such as circuit breaker opening time, relay I/O response time and messages travelling time in the communication network should be taken into account. The purpose of this paper is to elaborate on the effect of cascading failure in NPP electrical power protection system and propose preventive actions for this failures. Finally, the expected advantages and challenges are elaborated.
Ahmed H. Moustafa(Ahmed H. Moustafa ),Heba F. Pasha(Heba F. Pasha ),Manar A. Abas(Manar A. Abas ),Adel M. Aboregela(Adel M. Aboregela ) 대한해부학회 2023 Anatomy & Cell Biology Vol.56 No.1
Thioacetamide (TAA) exposure and hepatitis C virus infection are usually associated with renal dysfunction. Sofosbuvir (SFV) and daclatasvir (DAC) drugs combination has great value in the treatment of hepatitis C. The study aimed to identify the nephrotoxic effects of TAA and to evaluate the ameliorative role of SFV and DAC in this condition. Forty-eight adult male albino rats were divided into eight groups and received saline (control), SFV, DAC, SFV+DAC, TAA, TAA+SFV, TAA+DAC and TAA+SFV+DAC for eight weeks. Kidney and blood samples were retrieved and processed for histological (Hematoxylin and Eosin and Masson’s trichrome), immunohistochemical (α-smooth muscle actin), and biochemical analysis (urea, creatinine, total protein, albumin, malondialdehyde, reduced glutathione, superoxide dismutase, and tumor necrosis factor-α). Examination revealed marked destruction of renal tubules on exposure to TAA with either hypertrophy or atrophy of glomeruli, increase in collagen deposition, and wide expression of α-smooth muscle actin. Also, significant disturbance in kidney functions, oxidative stress markers, and tumor necrosis factor-α. Supplementation with either SFV or DAC produced mild improvement in the tissue and laboratory markers. Moreover, the combination of both drugs greatly refined the pathology induced by TAA at the cellular and laboratory levels. However, there are still significant differences when compared to the control. In conclusion, SFV and DAC combination partially but greatly ameliorated the renal damage induced by TAA which might be enhanced with further supplementations to give new hope for those with nephropathy associated with hepatitis.
Abbassy Moustafa A.,Khalifa Moustafa A.,Nassar Atef M. K.,El-Deen Eman E. Nour,Salim Yehia M. 한국독성학회 2021 Toxicological Research Vol.37 No.4
Levels of organochlorine pesticides (OCPs) residues in tilapia fish and their health risk associated with the consumption of fish from Edko lake, Egypt were determined. The quick, easy, cheap, effective, rugged, and safe method (QuEChERS) was used for extraction and clean-up of 18 OCPs residues from fish followed by GC-ECD and GC-ITD analytical tools were employed for identification of OPs. Out of the 18 OCPs, only heptachlorepoxide, p,p-DDE, dieldrin, p,p-DDD, and endrin ketone were detected in muscles of fish with concentrations of 0.1144, 0.2119, 0.4352, 0.1196, and 0.1323 μg/Kg bw, respectively. Results of the risk assessment calculations showed that dieldrin had a health risk index of more than one. This means that there was a health risk to adults associated with the consumption of fish. On the other hand, heptachlorepoxide, p,p-DDE, p,p-DDD, and endrin ketone did not show any direct health risk. Contamination of fish, collected from Edko lake in Egypt, with residues of OCPs might pose health implications if fish were consumed fresh.
ON SOME RECURSION RELATIONS FOR HORN'S HYPERGEOMETRIC FUNCTIONS OF THREE VARIABLES
P. Agarwal,A. SHEHATA,S. I. MOUSTAFA,K. CHAKRABORTY 장전수학회 2021 Proceedings of the Jangjeon mathematical society Vol.24 No.2
The principal aim of this paper to study the recursion formulas for the Horns hypergeometric functions of three variables. Earlier in [Shehata, A.; and Moustafa, S.I. Some new results for Horn's hypergeometric functions Γ1 and Γ2. Journal of Mathematics and Computer Science, (2021), 23 (1), 26{35.], and Pathan et al. [Pathan, M.A.; Shehata, A.; and Moustafa, S.I. Certain new formulas for the Horns hypergeometric functions. Acta Uni- versitatis Apulensis, (2020)] have studied the new results for Horns hypergeometric functions. Motivated by the above works here we will derive some contiguous relation for the families of Horn hypergeometric functions GA, GB, GC, GD and G C of three variables. After that we will establish the differential reclusion relations and differential operators for GA, GB, GC, GD and G* C of three variables, respectively.
Moustafa Y. El-Naggar 한국미생물학회 2007 The journal of microbiology Vol.45 No.3
During a screening program, an actinomycete strain isolated from the Egyptian soil was investigated for its potential to show antimicrobial activity. The identification of this isolate was performed according to spore morphology and cell wall chemo-type, which suggested that this strain is a streptomycete. Further cultural, physiological characteristics and the analysis of the nucleotide sequence of the 16S rRNA gene (1480 bp) of this isolate indicated that this strain is identical to Streptomyces violaceusniger (accession number EF063682) and then designated S. violaceusniger strain HAL64. In its culture supernatant, this organism could produce one major compound strongly inhibits the growth of Gram-positive but the inhibition of Gramnegative indicator bacteria was lower. The antibiotic was separated by silica gel column chromatography and then purified on a sephadex LH-20 column and finally the purity was checked by HPLC. The chemical structure of the purified compound was determined using spectroscopic analyses (molecular formula of C33H32N2O10 and molecular weight of 617.21) and found to be identical to the kosinostatin, a quinocycline antibiotic which is known to be produced by Micromonspora sp. TP-A0468 (Igarashi et al., 2002) and to quinocycline B isolated from Streptomyces aureofaciens (Celmer et al., 1958). Although the antibiotic is known, the newly isolated strain was able to produce the antibiotic as a major product providing an important biotechnological downstream advantage.
Securing the IoT Frontier: Exploring the Limitation and Future Directions in Cybersecurity
Moustafa Abdelrahman Mahmoud Ahmed,Nur Arzilawati Md Yunus The Institute of Internet 2024 International Journal of Internet, Broadcasting an Vol.16 No.2
As the Internet of Things (IoT) continues to permeate every facet of modern life, the imperative to secure this vast and dynamic frontier becomes increasingly paramount. This presents a comprehensive exploration of the challenges and opportunities inherent in safeguarding the interconnected web of IoT devices. The research critically examines the limitations of current cybersecurity measures through an extensive review of diverse topics, including IoT network performance, smart grid security, and the escalating cyber threats against critical infrastructures. A meticulous analysis of research findings underscores the need for enhanced infrastructure and ongoing research to fortify the cybersecurity mechanisms surrounding IoT objects. We underline the imperative of relentless research efforts to parry the advancing threats and leverage the promise of nascent technologies. Our findings affirm the pivotal influence of robust cybersecurity measures in crafting a resiliently connected ecosystem. The paper underscores the importance of ongoing research to address evolving threats and harness the potential of emerging technologies, reaffirming the central role of cybersecurity in shaping a secure interconnected world. In conclusion, the study emphasizes the dynamic and ever-evolving nature of cybersecurity on the IoT frontier. It unveils a complex landscape of challenges, ranging from network performance intricacies to the security concerns of critical infrastructures.
Moustafa Abdelmotaleb 한국행정학회 2020 International Review of Public Administration Vol.25 No.3
This investigation aims to examine themoderating and mediating role of public service motivation (PSM) on the relationship between organizations’ social responsibility (SR) and employee organization engagement (OE). Using a sample of employees working in four public hospitals in Egypt, the study’s hypotheses were tested using structural equation modeling. Results reported in the study indicated the following: a) PSM had a positive influence on employees’ OE; b) PSM mediated the relationship between organizations’ SR and employees’ OE; c) PSM did not moderate the relationship between organizations’ SR and employees’ OE. Overall, the model results into a partial mediation model of PSM. This investigation could be regarded as one of the first studies undertaking analyses of the relationships between organizations’ SR, PSM, and employee engagement. However, further work is still needed to provide a better understanding of the organizational factors that can help instill, nurture, or suppress PSM and employees’ OE in the public sector.
Moustafa, Mohamed A.,El-Emam, Ali A.,Abdelal, Ali M.,Metwally, Mohammed E.S. The Pharmaceutical Society of Korea 1991 Archives of Pharmacal Research Vol.14 No.1
(R) (+) and (S) (-) $4-^2H$-phenytoin have been used as substrates for the determination of the percentage of deuterium retention (NIH shift) after para-hydroxylation of the substrates in rat. By using GC-MS analyses, the percentages of deuterium retention were found to be 69% and 70% for the (R) and (S) phenyl rings, respectively. The results add additional evidence for the involvement of arene oxide in the oxidation of the pro (R) and pro (S) phenyls of phenytoin. The oxidation process of each ring could be mediated by independent enzyme systems, a rapid oxidative enzyme for the pro (S) phenyl and a slow oxidative enzyme for the pro (R) phenyl.