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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.
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.
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 Abdou Elsyad,Fathi Abo Setta,Ahmed Samir Khirallah 대한치과보철학회 2016 The Journal of Advanced Prosthodontics Vol.8 No.2
PURPOSE The aim of the present study was to evaluate, by means of strain gauge analysis, the effect of different implant angulations on strains around two implants retaining mandibular overdenture with Locator attachments. MATERIALS AND METHODS Four duplicate mandibular acrylic models were constructed. Two implants were inserted in the canine regions using the following degrees of distal inclinations: group I (control); 0°, group II; 10°, group III; 20°, and group IV; 30°. Locator pink attachments were used to connect the overdenture to the implants and Locator red (designed for severely angled implants) was used for group IV (group IVred). For each group, two linear strain gauges were attached at the mesial and distal surfaces of the acrylic resin around each implant. Peri-implant strain was measured on loading and non-loading sides during bilateral and unilateral loading. RESULTS For all groups, the mesial surfaces of the implants at loading and non-loading sides experienced compressive (negative) strains, while the distal implant surfaces showed tensile (positive) strains. Group IV showed the highest strain, followed by group III, group II. Both group I and group IVred showed the lowest strain. The strain gauges at the mesial surface of the loading side recorded the highest strain, and the distal surface at non-loading side showed the lowest strain. Unilateral loading recorded significantly higher strain than bilateral loading. CONCLUSION Peri-implant strains around two implants used to retain mandibular overdentures with Locator attachments increase as distal implant inclination increases, except when red nylon inserts were used.
Moustafa Guellil,Hayat Saidi,Fouad Bourada,Abdelmoumen Anis Bousahla,Abdelouahed Tounsi,Mesfer Mohammad Al-Zahrani,Muzamal Hussain,S. R. Mahmoud 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.38 No.1
In this paper, a higher order shear deformation theory for bending analysis of functionally graded plates resting on Pasternak foundation and under various boundary conditions is exposed. The proposed theory is based on the assumption that porosities can be produced within functionally graded plate which may lead to decline in strength of materials. In this research a novel distribution of porosity according to the thickness of FG plate are supposing. Governing equations of the present theory are derived by employing the virtual work principle, and the closed-form solutions of functionally graded plates have been obtained using Navier solution. Numerical results for deflections and stresses of several types of boundary conditions are presented. The exactitude of the present study is confirmed by comparing the obtained results with those available in the literature. The effects of porosity parameter, slenderness ratio, foundation parameters, power law index and boundary condition types on the deflections and stresses are presented.
Moustafa, Abbas,Takewaki, Izuru Techno-Press 2010 Structural Engineering and Mechanics, An Int'l Jou Vol.34 No.6
Near-fault ground motion with directivity or fling effects is significantly influenced by the rupture mechanism and substantially different from ordinary records. This class of ground motion has large amplitude and long period, exhibits unusual response spectra shapes, possesses high PGV/PGA and PGD/PGA ratios and is best characterized in the velocity and the displacement time-histories. Such ground motion is also characterized by its energy being contained in a single or very few pulses, thus capable of causing severe damage to the structures. This paper investigates the characteristics of near-fault pulse-like ground motions and their implications on the structural responses using new proposed measures, such as, the effective frequency range, the energy rate (in time and frequency domains) and the damage indices. The paper develops also simple mathematical expressions for modeling this class of ground motion and the associated structural responses, thus eliminating numerical integration of the equations of motion. An optimization technique is also developed by using energy concepts and damage indices for modeling this class of ground motion for inelastic structures at sites having limited earthquake data.
Moustafa, M.A,Eisa, H.M,El-Emam, A.A.,Metwally, M.A. The Pharmaceutical Society of Korea 1990 Archives of Pharmacal Research Vol.13 No.2
Certain pyrazolin-5-one and pyrazole derivatives bearing uracil-6-yl or tetrazol-5-yl moiety in position 1 have been synthesized. The anti-inflammatory activity of six representative compounds have been tested and the results are reported.
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.