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Assessment of the impact of a 10-MW grid-tied solar system on the Libyan grid in terms of the power-protection system stability

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Clean Energy 2023年第2期7卷 389-407页

作者： Feras Alasali Abdelaziz salah Saidi Naser El-Naily Othman Alsmadi mohamed Khaleel Ibrahim Ghirani Department of Electrical Engineering Faculty of EngineeringThe Hashemite UniversityPO Box 330127Zarqa 13133Jordan Department of Electrical Engineering King Khalid UniversityAbha PO Box 394Abha City 61411Saudi Arabia Universitéde Tunis El Manar Ecole Nationale d’Ingénieurs de TunisLaboratoire des SystèmesÉlectriquesTunisie Electrical Engineering Department College of Electrical and Electronics Technology-BenghaziBenghaziLibya Electrical Engineering Department Faculty of EngineeringThe University of JordanAmmanJordan Aeronautical Engineering Department College of Civil Aviation MisrataLibya

The energy market in Libya is expected to face substantial changes in the next few years:electrical energy consumption will increase by 50% within the next 4 ***,there is a plan to gradually increase renewable energy sources in the power network by 2030 to 30%.Solar photovoltaic(PV)plants will play a significant role in the energy transition and the mix of energy sources in *** article is a study conducted to investigate the challenges of power-flow management and power protection from integrating PV power plants into the Libyan power *** particular,a simulation model is built for the Kufra PV power plant(10 MW)with eight buses to assess the power network performance in terms of power quality such as voltage profile,power losses and ***,the impact of the PV plant on the short-circuit level and the power-protection system is presented under different operating *** fault ride-through(FRT)is operated using standard ambient temperature and a wide range of irradiation intensity,and is verified by using the Libyan grid *** results show that the integration of the PV plant into the grid has a significant impact on the short-circuit level and the FRT over the different fault levels and locations on the *** initial period of the three-phase fault shows that the PV plant will be disconnected from the grid due to a decrease in the root mean square value voltages where the reactive and active power of the grid reach 938 MVAR and 261 MW,*** results show that increasing the fault level will lead to an increase in injecting the active *** work is considered the first extensive investigation into the challenges of modern power-flow management and power protection for the power network system in Libya.

关键词： photovoltaic renewable energy sources power protection voltage profile fault ride-through

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On Two Natural Extensions of n-normality

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Acta Mathematica Sinica,English Series 2023年第6期39卷 1147-1152页

作者： salah MECHERI Faculty of Mathematics and informatics Mohamed El Bachir El Ibrahimi UniversityBordj Bou ArreridjAlgeria

A bounded linear operator T on a complex Hilbert space H is called n-normal if T^(*)T^(n)=T^(n)T^(*).By Fuglede’s theorem T is n-normal if and only if T^(n)is *** k,n∈*** a bounded linear operator T is said to be of typeⅠk-quasi-n-normal if T^(*k){T^(*)T^(n)-T^(n)T^(*)}T^(k)=0,and T is said to be of typeⅡk-quasi-n-normal if T^(*k){T^(*n)T^(n)-T^(n)T^(*n)}T^(k)=0.1-quasi-n-normal is called *** shall show that(1)typeⅠquasi-2-normal and typeⅡquasi-2-normal are different classes;(2)the intersection of the class of typeⅠquasi-2-normal and the class of typeⅡquasi-2-normal is equal to the class of *** also give some examples of type I k-quasi-n-normal and typeⅡ*** also show that Weyl’s theorem holds for this class of operators and every k-quasi-n-normal operator has a non trivial invariant subspace.

关键词： Normal operator n-normal operator invariant subspace

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Risk factors and prognosis of pediatric rhegmatogenous retinal detachment in Egypt:a university hospital based study

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International Journal of Ophthalmology(English edition) 2023年第12期16卷 2034-2040页

作者： mohamed Gaber Eissa Mohamad Amr salah Eddin Abdelhakim Tamer Ahmed Macky Hassan Aly Mortada Department of Ophthalmology Kasr Al Ainy HospitalFaculty of MedicineCairo UniversityCairo 11431Egypt

AIM:To study and compare the predisposing factors and clinical features of pediatric,adult,and elderly rhegmatogenous retinal detachment(RRD).METHODS:This is an observational analytic crosssectional study in which patients with RRD admitted for surgery during 6mo period were divided into 3 age groups:pediatric(60y).Patients’demographic data,clinical features,RRD predisposing factors/features including myopia(axial length≥26.5 mm),aphakia/pseudophakia,blunt trauma,peripheral retinal degenerations,history of RRD in the fellow eye,and surgical interventions/findings were recorded and ***:Totally 142 patients(142 eyes)were studied:26(18.31%)pediatrics,86(60.56%)adults,and 30(21.13%)*** patients had a significantly higher intraocular pressures and cataracts compared to the other 2 groups(P=0.04).The RRD extent was larger in pediatric group(mostly 4 quadrants)compared to adults and elderly(mostly 2 quadrants),but it was not statistically insignificant(P=0.242).There were not statistically significantly differences in proliferative vitreoretinopathy(PVR)rate,posterior vitreous detachment(PVD)rate,number,site,shape,and size of breaks in three *** three groups had macular detachment in all *** and peripheral retinal degenerations were found to be more significant in adults(P=0.049,P=0.035,respectively),while blunt trauma was higher but insignificant in pediatric eyes(P=0.052).Pars plana vitrectomy(PPV)with silicone oil as a tamponade was the most used surgery in all ***:There are no significant difference in PVR rate in pediatric eyes but a significant higher rate of total *** trauma is more frequent in pediatrics eyes while myopia and/or peripheral retinal degenerations are more frequent in older *** rate of PPV as a choice for surgery is similar among all age groups.

关键词： rhegmatogenous retinal detachment pediatric predisposing factors proliferative vitreoretinopathy peripheral retinal degenerations

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Surfactant-Assisted Poly(lactic acid)/Cellulose Nanocrystal Bionanocomposite for Potential Application in Paper Coating

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Journal of Renewable Materials 2018年第4期6卷 394-401页

作者： Ragab E.Abou-Zeid mohamed A.Diab salah A.A.mohamed Ahmed Salama Hind Abdullah Aljohani kamel Rizq Shoueir Cellulose and Paper Department National Research Centre33 El-Bohouth St.DokkiP.O.12622GizaEgypt Packing and Packaging Materials Department National Research Centre33 El-Bohouth St.DokkiP.O.12622GizaEgypt Tabuk University Chemistry DepartmentCollege of Al WajhAl WajhSaudi Arabia Institute of Nanoscience&Nanotechnology Chemistry departmentKafr Elsheikh University33516 Kafr ElsheikhEgypt

The current article addresses a new strategy for the preparation of polylactic acid/cellulose nanocrystal(PLA/CNCs)nanobiocomposite films with improved structural morphology,mechanical and barrier properties for food packaging *** addition of hexadecyltrimethylammonium bromide(CTAB)and sodium lauryl sulfate(SLS)as cationic and anionic surfactants respectively,was found to play a crucial role in preventing re-aggregation of the CNCs during drying and improving the dispersion of CNCs in the *** coated paper was characterized using mechanical tests,water vapor permeability(WVP),X-ray diffraction(XRD),scanning electron microscopy(SEM)and air *** results showed that the paper coated with PLA containing 7.5%CNCs and 0.15%CTAB based on weight of PLA,gives the highest measured paper properties,where an increase in tensile strength(+133%),Young’s modulus(+309%),tear index(+183%),burst(+60.8)and a decrease in air permeability(−92%)was obtained.

关键词： Cellulose nanocrystal surfactant paper coating mechanical properties air permeability water vapor permeability

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A New Generative Mathematical Model for Coverless Steganography System Based on Image Generation

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Computers, Materials & Continua 2023年第3期74卷 5087-5103页

作者： Al-Hussien Seddik Mohammed salah Gamal Behery Ahmed El-harby Ahmed Ismail Ebada Sokea Teng Yunyoung Nam mohamed Abouhawwash Department of Computer Science Faculty of ScienceMinia UniversityMiniaEgypt Department of Computer Science Faculty of Computers and Artificial IntelligenceDamietta UniversityNew DamiettaEgypt Department of ICT Convergence Soonchunhyang UniversityAsan31538Korea Department of Mathematics Faculty of ScienceMansoura UniversityMansoura35516Egypt Department of Computational Mathematics Scienceand Engineering(CMSE)Michigan State UniversityEast Lansing48824MIUSA

The ability of any steganography system to correctly retrieve the secret message is the primary criterion for measuring its ***,researchers have tried to generate a new natural image driven from only the secret message bits rather than using a cover to embed the secret message within it;this is called the stego *** paper proposes a new secured coverless steganography system using a generative mathematical model based on semi Quick Response(QR)code and maze game image *** system consists of two *** first component contains two processes,encryption process,and hiding *** encryption process encrypts secret message bits in the form of a semi-QR code image whereas the hiding process conceals the pregenerated semi-QR code in the generated maze game *** the other hand,the second component contains two processes,extraction and decryption,which are responsible for extracting the semi-QR code from the maze game image and then retrieving the original secret message from the extracted semi-QR code image,*** results were obtained using the bit error rate(BER)*** results confirmed that the system achieved high hiding capacity,good performance,and a high level of robustness against attackers compared with other coverless steganography methods.

关键词： Coverless steganography data hiding information security QR code maze game

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Wheat Straw Burial Improves Physiological Traits, Yield and Grain Quality of Rice by Regulating Antioxidant System and Nitrogen Assimilation Enzymes under Alternate Wetting and Drying Irrigation

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Rice science 2022年第5期29卷 473-488页

作者： Yousef ALHAJ HAMOUD Hiba SHAGHALEH WANG Ruke Willy Franz GOUERTOUMBO Amar Ali ADAM HAMAD mohamed salah SHETEIWY WANG Zhenchang GUO Xiangping College of Agricultural Science and Engineering Hohai UniversityNanjing 210098China Jiangsu Provincial Key Laboratory for the Chemistry and Utilization of Agro-Forest Biomass College of Chemical EngineeringNanjing Forestry UniversityNanjing 210037China Department of Agronomy Faculty of AgricultureMansoura UniversityMansoura 35516Egypt

Wheat straw burial has great potential to sustain rice production under alternate wetting and drying(AWD)irrigation.A field experiment was conducted with three wheat straw burial treatments,including without straw burial(NSB),with light straw burial of 300 kg/hm^(2)(LSB)and dense straw burial of 800 kg/hm^(2)(DSB),as well as three AWD regimes:alternate wetting/moderate drying(AWMD),alternate wetting/severe drying(AWSD)and alternate wetting/critical drying(AWCD).The rice growth and grain quality were higher in LSB and NSB than those in NSB under the same AWD *** AWMD×DSB treatment resulted in the highest yield,brown rice rate,milled rice rate,amylose content and protein ***,the AWCD×NSB treatment led to the lowest yield,brown rice rate,milled rice rate,amylose content and protein *** active absorption area and nitrate reductase activity of roots were higher in the AWMD×DSB treatment than those in the AWCD×NSB treatment,as the former increased organic carbon and nitrogen contents in the rhizosphere,whereas the latter reduced their *** soluble protein content and glutamine synthetase activity were greater in the AWMD×DSB treatment than those in the AWCD×NSB *** activities of superoxide dismutase and catalase were higher in the AWMD×DSB treatment compared with the AWCD×NSB treatment,leading to the amelioration of oxidative cell injury,as shown by a lower malonaldehyde *** study suggested that farmers should implement AWMD irrigation after leaving the straw residues in the field,followed by deep tillage to improve soil quality and mitigate the drought stress cycles of *** approach can improve rice growth and grain quality and alleviate the problems of disposal of straw residues and water scarcity for sustainable rice production.

关键词： antioxidant enzyme activity wheat straw burial irrigation regime nitrogen uptake Oryza sativa grain quality yield

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Design of adaptive intuitionistic fuzzy controller for synchronisation of uncertain chaotic systems

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CAAI Transactions on Intelligence Technology 2020年第4期5卷 237-246页

作者： mohamed Hamdy salah Helmy mohamed Magdy Department of Industrial Electronics and Control Engineering Faculty of Electronic EngineeringMenoufia UniversityMenouf-32952Egypt Department of Mechatronics Engineering Higher Institute of Engineering and TechnologyEl-Mahalla El-Kobra-31951Egypt

This study presents the synchronisation between two non-linear Lorenz chaotic systems using an adaptive intuitionistic fuzzy controller(AIFC).This problem is solved in the presence of external disturbances and *** classes of Lorenz systems have been formulated one as the master and the other as the *** master and slave systems have different initial *** different initial conditions,both systems *** is called the butterfly effect that rules the behaviour of chaotic *** is chosen as a different method that has not been used before to synchronise the chaotic *** scaling factors of the inputs and the output of the intuitionistic fuzzy controller(IFC)are tuned using the artificial bee colony(ABC)algorithm depending on a specified objective *** IFC stability is studied when it is applied to synchronise the Lorenz *** simulation results achieved to assess the adequacy of the proposed control and to exhibit its dependability to synchronise the Lorenz system.

关键词： function. chaotic specified

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Constraints on the crustal structure beneath the Sinai subplate,SE Mediterranean,from analysis of local and regional travel times

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Geoscience Frontiers 2013年第2期4卷 213-222页

作者： mohamed K.salah Geology Department Faculty of ScienceTanta UniversityTanta 31527Egypt

The Sinai Peninsula has been recognized as a subplate of the African Plate located at the triple junction of the Gulf of Suez rift,the Dead Sea Transform fault,and the Red Sea *** upper and lower crustal structures of this tectonically active,rapidly developing region are yet poorly understood because of many *** this reason,a set of P- and S-wave travel times recorded at 14 seismic stations belonging to the Egyptian National Seismographic Network（ENSN） from 111 local and regional events are analyzed to investigate the crustal structures and the locations of the seismogenic zones beneath central and southern *** the velocity model used for routine earthquake location by ENSN is one-dimensional,the travel-time residuals will show lateral heterogeneity of the velocity structures and unmodeled vertical *** activity is strong along the eastern and southern borders of the study area but low to moderate along the northern boundary and the Gulf of Suez to the *** crustal V_P/V_S ratio is 1.74 from shallow（depth≤10 km） earthquakes and 1.76 from deeper（depth 〉 10 km） crustal *** majority of the regional and local travel-time residuals are positive relative to the Preliminary Reference Earth Model（PREM）,implying that the seismic stations are located above widely distributed,tectonically-induced low-velocity *** low-velocity zones are mostly related to the local crustal faults affecting the sedimentary section and the basement complex as well as the rifting processes prevailing in the northern Red Sea region and the ascending of hot mantle materials along crustal *** delineation of these low-velocity zones and the locations of big crustal earthquakes enable the identification of areas prone to intense seismotectonic activities,which should be excluded from major future development projects and large constructions in central and southern Sinai.

关键词： Crustal structure Sinai Peninsula SE Mediterranean Seismicity Travel-time residuals(TTRs) Crustal V_P/V_S ratio

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Upper crustal structure beneath Southwest Iberia north of the convergent boundary between the Eurasian and African plates

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Geoscience Frontiers 2014年第6期5卷 845-854页

作者： mohamed K.salah Geology Department Faculty of ScienceTanta UniversityTanta 31527Egypt

The 3-D P- and S-wave velocity models of the upper crust beneath Southwest Iberia are determined by inverting arrival time data from local earthquakes using a seismic tomo^raphy method. We used a total of 3085 P- and 2780 S-wave high quality arrival times from 886 local earthquakes recorded by a per- manent seismic network, which is operated by the Institute of Meteorology （IM）, Lisbon, Portugal. The computed P- and S-wave velocities are used to determine the 3-D distributions of Vp/Vs ratio. The 3-D velocity and Vp/Vs ratio images display clear lateral heterogeneities in the study area. Significant veloc- ity variations up to ~6% are revealed in the upper crust beneath Southwest lberia, At 4 km depth, both P- and S-wave velocity take average to high values relative to the initial velocity model, while at 12 km, low P-wave velocities are clearly visible along the coast and in the southern parts. High S-wave velocities at 12 km depth are imaged in the central parts, and average values along the coast; although some scattered patches of low and high S-wave velocities are also revealed. The Vp/Vs rztio is generally high at depths of 4 and 12 km along the coastal parts with some regions of high Vp/Vs ratio in the north at 4 km depth, and low Vp/Vs ratio in the central southern parts at a depth of 12 km, The imaged low velocity and high Vp/Vs ratios are related to the thick saturated and unconsolidated sediments covering the region; whereas the high velocity regions are generally associated with the Mesozoic basement rocks.

关键词： Upper crustal structure Southwest (SW) lberiaLoca Lseismic tomography Crustal Vp/Vs ratio

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A seismological evidence for the northwestward movement of Africa with respect to Iberia from shear-wave splitting

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Geoscience Frontiers 2012年第5期3卷 681-696页

作者： mohamed K.salah Geology Department Faculty of Science Tanta UniversityTanta 31527Egypt

Seismic anisotropy and its main features along the convergent boundary between Africa and Iberia are detected through the analysis of teleseismic shear-wave splitting. Waveform data generated by 95 teleseismic events recorded at 17 broadband stations deployed in the western Mediterranean region are used in the present study. Although the station coverage is not uniform in the Iberian Peninsula and north- west Africa, significant variations in the fast polarization directions and delay times are observed at stations located at different tectonic domains. Fast polarization directions are oriented predominantly NW-SE at most stations which are close to the plate boundary and in central Iberia; being consistent with the absolute plate motion in the region. In the northern part of the Iberian Peninsula, fast velocity direc- tions are oriented nearly E--W; coincident with previous results. Few stations located slightly north of the plate boundary and to the southeast of lberia show E--W to NE-SW fast velocity directions, which may be related to the Alpine Orogeny and the extension direction in lberia. Delay times vary significantly between 0.2 and 1.9 s for individual measurements, reflecting a highly anisotropic structure beneath the recording stations. The relative motion between Africa and lberia represents the main reason for the observed NW-SE orientations of the fast velocity directions. However, different causes of anisotropy have also to be considered to explain the wide range of the splitting pattern observed in the western Mediterranean region. Many geophysical observations such as the low Pn velocity, lower lithospheric Q values, higher heat flow and the presence of high conductive features support the mantle flow in the western Mediterranean, which may contribute and even modify the splitting pattern beneath the studied region.

关键词： Shear-wave splitting Seismic anisotropy Iberian Peninsula Northwest Africa Western Mediterranean

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