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PVC nanocomposites for cable insulation with enhanced dielectric properties,partial discharge resistance and mechanical performance

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High Voltage 2020年第4期5卷 463-471页

作者： Nagat M.K.abdel-gawad Adel Z.El Dein Diaa-Eldin A.Mansour Hanaa M.ahmed Mohamed M.F.Darwish Matti Lehtonen Department of Electrical Power and Machines Engineering Faculty of Engineering at ShoubraBenha UniversityCairoEgypt Department of High Voltage Networks Faculty of Energy EngineeringAswan UniversityAswanEgypt High Voltage and Superconductivity Laboratory Department of Electrical Power and Machines EngineeringFaculty of EngineeringTanta UniversityTantaEgypt Department of Mathematics and Engineering Physics Faculty of Engineering at ShoubraBenha UniversityCairoEgypt Department of Electrical Engineering and Automation School of Electrical EngineeringAalto UniversityEspooFinland

The current study aims to develop polyvinyl chloride(PVC)nanocomposites with enhanced electrical and mechanical properties by incorporating titanium oxide(TiO_(2))nanoparticles within PVC *** loading of nanoparticles and different nanoparticle surface states were *** surface states are unfunctionalised,functionalised using vinyl silane and functionalised using amino *** choice of a most suitable surface state was a critical factor that guarantees a good dispersion of nanoparticles and consequently enhances the compatibility between TiO_(2)and PVC *** process followed in the PVC/TiO_(2)nanocomposites preparation,loaded with different wt.%of TiO_(2)nanoparticles,was the solvent *** dielectric properties measured here were the relative permittivity(ɛr),dielectric loss(tanδ),breakdown strength(AC and DC under uniform field)and the internal partial discharges(PDs)within insulation *** measurements have been performed under room temperature and at frequency ranged from 20 to 1.0 ***,the mechanical properties of the samples like elongation,elasticity modulus and tensile strength were also *** silane showed better improvements in both electrical and mechanical performances compared to the amino silane,especially in cases of high weight fractions of TiO_(2).This is because of the improvement in the PVC-TiO_(2)interfacial region arise from the similarity of polarity and surface tension values of vinyl silane with that of PVC matrix and TiO_(2)nanoparticles.

关键词： dielectric insulation resistance

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Synthesis and study the influence of yttrium doping on band structure,optical,non-linear optical and dielectric results for Ca_(12)Al_(14)O_(33) (C12A7) single crystals grown using traveling-solvent floating zone (TSFZ) method

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Chinese Physics B 2022年第1期31卷 626-630页

作者： A.abdel Moez ahmed I.Ali A.Tayel Solid State Physics Department Physical Research DivisionNational Research Centre(NRC)33 El Bohouth StreetDokkiGiza 12622Egypt Basic Science Department Faculty of Faculty of Technology and EducationHelwan UniversityKobry El-QopaCairo 11281Egypt

Ca_(12)Al_(14)O_(33)(C12A7)and Y_(0.02)Ca_(11.98)Al_(14)O_(33)(Y-C12A7)single crystals were grown by using the traveling-solvent floating zone(TSFZ)*** temperature was increased to avoid the bubbles and cracks which may be formed during the preparation of the ingot *** have started with the flux higher than the normal to avoid the bubbles and make good treatment for the solid-liquid *** structures of both Ca_(12)Al_(14)O_(33)(C12A7)and Y_(0.02)Ca_(11.98)Al_(14)O_(33)(Y-C12A7)were studied by using x-ray diffraction(XRD).Optical properties for C12A7 and Y-C12A7 single crystals have been studied in order to determine the optical parameters such as optical energy gap(Eg),refractive index n,oscillating energy(Eo),dispersion energy(Ed),volume energy loss function(VELF),and surface energy loss function(SELF).Finally,a new result for these samples is that the third-order nonlinear optical susceptibility(χ(3))was *** results have been discussed with effect of Y-doping on the C12A7 single crystals for optical and industrial applications.

关键词： syntheses Ca_(12)Al_(14)O_(33)(C12A7)single crystals Y-doping optical parameters dielectric results nonlinear optical susceptibility

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Antifouling evaluation of extracts from Red Sea soft corals against primary biofilm and biofouling

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Asian Pacific Journal of Tropical Biomedicine 2017年第11期7卷 991-997页

作者： Yosry abdel Aziz Soliman ahmed Mohammed Brahim ahmed Hussein Moustafa Mohamed abdel Fattah Hamed Marine Chemistry Lab. Marine Environment DivisionNational Institute of Oceanography and FisheriesSuezEgypt Department of Chemistry Faculty of ScienceZagazig UniversityZagazigEgypt

Objectives: To evaluate antifouling property of extracts from Red Sea soft corals against primary biofilm and ***: Seven species of soft corals Sarcophyton glaucum(a), Sinularia compressa,Sinularia cruciata(a), Heteroxenia fuscescens(a), Sarcophyton glaucum(b), Heteroxenia fuscescens(b) and Sinularia cruciata(b) were chosen to test their extracts as antibacterial and antifouling agents in Eastern Harbour of Alexandria, Mediterranean *** compounds of soft corals were extracted by using methanol and concentrated under vacuum. The residues of extracts were mixed in formulation of inert paint which consisted of rosin, chlorinated rubber and ferrous oxide against micro and macro fouling organisms. The formulated paints were then applied on PVC panels twice by brush,hanged in a steel frame and immersed in Eastern Harbour of Alexandria Mediterranean Sea followed by visual inspection and photographic ***: After 185 days of immersion in seawater, the antifouling results agreed with the antibacterial results where extracts of Sinularia compressa and Heteroxenia fuscescens(b) gave the best activity against marine fouling tubeworms and barnacles. The inhibition activity was correlated with the major functional groups(hydroxyl, amino, carbonyl,aliphatic(fatty acids), C]C of alkene or aromatic rings and CeC l of aryl halides) of the ***: The strong antifouling activity makes them promising candidates for new antifouling additives. After the screening and application of natural organic compounds from soft corals, marine organisms show activity against micro and macro fouling organisms.

关键词： Antibacterial Antifouling Paints Seawater Marine Organisms

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Neutron activation analysis of ceramic tiles and its component and radon exhalation rate

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Journal of Environmental Sciences 2004年第1期16卷 94-99页

作者： A.El-Shershaby A.Sroor F.ahmed A.S.abdel-Haleem Z.abdel Nuclear Physics Laboratory Faculty of WomenAin-Shams UniversityNuclear Physics LaboratoryFaculty of WomenAin-Shams UniversityIonizing Radiation DepartmentNational Institute for StandardsHot Laboratories CenterAtomic Energy AuthorityNuclear Physics LaboratoryFaculty of WomenAin-Shams University Cairo EgyptCairo EgyptGiza EgyptCairo EgyptCairo Egypt

The concentrations of 20 trace elements in several ceramics tiles and ceramic composites used in Egypt were elementally analyzed by neutron activation analysis(NAA) technique. The samples and standard were irradiated with reactor for 4 h(in the Second Research Egyptian Reactor(Et-RR-2)) with thermal neutron flux 5.9×10 13 n/(cm 2·s).The gamma-ray spectra obtained were measured for several times by means of the hyper pure germanium detection system(HPGe). Also a solid state nuclear track detector(SSNTD) CR-39, was used to measure the emanation rate of radon for these samples. The radium concentrations were found to vary from 0.39—3.59 ppm and the emanation rates were found to vary from (0.728—5.688) × 10 -4 kg/(m 2· s).The elemental analysis of the ceramic tiles and ceramic composites have a great importance in assigning the physical properties and in turn the quality of the material.

关键词： ceramic neutron activation analysis(NAA) radon emanation solid state nuclear track detector(SSNTD)

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Field and reverse field solitons in waveoperator nonlinear Schrödinger equation with space-time reverse: Modulation instability

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Communications in Theoretical Physics 2023年第6期75卷 39-50页

作者： H I abdel-gawad Mathematics Department Faculty of Science Cairo University GizaEgypt

The wave-operator nonlinear Schrödinger equation was introduced in the ***,nonlocal space-time reverse complex field equations were also recently *** in this area were focused on employing the inverse scattering method and Darboux ***,we present an approach to find the solutions of the wave-operator nonlinear Schrödinger equation with space and time reverse(W-O-NLSE-STR).It is based on implementing the unified method together with introducing a conventional formulation of the ***,a field and a reverse field may be ***,for deriving the solutions of W-O-NLSE-STR,it is evident to distinguish two cases(when the field and its reverse are interactive or not-interactive).In the non-interactive and interactive cases,exact and approximate solutions are *** both cases,the solutions are evaluated numerically and they are displayed *** is observed that the field exhibits solitons propagating essentially(or mainly)on the negative space variable,while those of the reverse field propagate on the other side(or vice versa).These results are completely novel,and we think that it is an essential behavior that characterizes a complex field system with *** the other hand,they may exhibit right and left cable patterns(or vice versa).It is found that the solutions of the field and its reverse exhibit self-phase modulation by solitary *** the interactive case,the pulses of the field and its reverse propagate in the whole *** analysis of modulation stability shows that,when the field is stable,its reverse is unstable or both are *** holds whenever the polarization of the medium is selfdefocusing.

关键词： wave-operator nonlinear Schrödinger equation space-time reverse unified method

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Dolomite apatite separation by amphoteric collector in presence of bacteria

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Journal of Central South University 2013年第6期20卷 1645-1652页

作者： Elmahdy ahmed El-Mofty Salah abdel-Khalek Mohamed abdel-Khalek Nagui El-MidanyAyman Central Metallurgical Research and Development Institute Mining Petroleum and Metallurgical Engineering DepartmentCairo University

Bioflotation represents one of the growing trends to enhance the selectivity of conventional flotation processes. It utilizes the micro-organisms to replace or to interact with the chemical reagents to increase the gap between surface properties of similar minerals and to enhance the separation selectivity. In this work, dolomite-phosphate separation was investigated using amphoteric collector （dodecyl-N-carboxyethyl-N-hyroxyethyl-imidazoline） in presence of bacteria. Two types of bacteria, Corynebacterium- diphtheriae-intermedius （CDI）, and Pseudomonas aeruginosa （PA）, were used. The collector-bacteria interaction was characterized by Fourier transform infra-red （FTIR）, frothing height and Zeta potential. The results show that the collector-bacteria interaction improves the flotation selectivity. Although, the PA positively affects the separation results, the CDI cannot lower the MgO to less than 1%. A phosphate content of 0.7% MgO and 31.77% P205 with a recovery of 68% at pH 11, 3.0 kg/t amphoteric collector, 4× 10^7 cells of PA is obtained.

关键词： dolomite phosphate amphoteric collector bacteria bio-flotation carbonate minerals

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Self-phase modulation via similariton solutions of the perturbed NLSE Modulation instability and induced self-steepening

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Communications in Theoretical Physics 2022年第8期74卷 41-50页

作者： H I abdel-gawad Department of Mathematics Faculty of Science Cairo University Egypt

The perturbed nonlinear Schrodinger equation(PNLSE)describes the pulse propagation in optical fibers,which results from the interaction of the higher-order dispersion effect,self-steepening(SS)and self-phase modulation(SPM).The challenge between these aforementioned phenomena may lead to a dominant one among *** is worth noticing that the study of modulation instability(MI)leads to the inspection of dominant phenomena(DPh).Indeed,the MI triggers when the coefficient of DPh exceeds a critical value and it may occur that the interaction leads to wave *** PNLSE is currently studied in the literature,mainly on finding traveling wave ***,we are concerned with analyzing the similarity solutions of the *** exact solutions are obtained via introducing similarity transformations and by using the extended unified *** solutions are evaluated numerically and they are shown *** is observed that the intensity of the pulses exhibits self steepening which progresses to shock soliton in ultrashort time(or near t=0).Also,it is found that the real part of the solution exhibits self-phase modulation in *** study of(MI)determines the critical value for the coefficients of SS,SPM,or high dispersivity to occur.

关键词： Perturbed NLSE steepening self–phase modulation extended unified method

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Pedestrian Height Estimation and 3D Reconstruction Using Pixel-resolution Mapping Method Without Special Patterns

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International Journal of Automation and computing 2019年第4期16卷 449-461页

作者： Bing-Xing Wu Suat Utku Ay ahmed abdel-Rahim Department of Electrical and Computer Engineering University of Idaho Moscow 83844-1023 USA Department of Civil Engineering University of Idaho Moscow 83844-1022 USA

Extracting the three-dimensional (3D) information including location and height of a pedestrian is important for vision-based intelligent traffic monitoring systems. This paper tackles the relationship between pixels′ actual size and pixels′ spatial resolution through a new method named pixel-resolution mapping (P-RM). The proposed P-RM method derives the equations for pixels′ spatial resolutions (XY-direction) and object′s height (Z-direction) in the real world, while introducing new tilt angle and mounting height calibration methods that do not require special calibration patterns placed in the real world. Both controlled laboratory and actual world experiments were performed and reported. The tests on 3D mensuration using proposed P-RM method showed overall better than 98.7% accuracy in laboratory environments and better than 96% accuracy in real world pedestrian height estimations. The 3D reconstructed images for measured points were also determined with the proposed P-RM method which shows that the proposed method provides a general algorithm for 3D information extraction.

关键词： Traffic monitoring application spatial resolution pixel-resolution mapping (P-RM) method 3D information pedestrian height estimation

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Characteristics and outcome of newborn admitted with acute bilirubin encephalopathy to a tertiary neonatal intensive care unit

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World Journal of Pediatrics 2019年第1期15卷 42-48页

作者： Nahed Fahmy Helal Eman abdel Ghany abdel Ghany Walaa Alsharany Abuelhamd Amna Yehea ahmed Alradem Department of Pediatrics Faculty of MedicineCairo UniversityCairoEgypt Ministry of Health CairoEgypt

Background Acute bilirubin encephalopathy (ABE) still represents a significant cause of morbidity and mortality throughout the world,especially in developing *** aimed to determine the prevalence of ABE based on the Johnson bilirubininduced neurologic dysfunction (BIND) score and to describe the discharge *** We prospectively studied all newborns ≥ 35 weeks with ABE by evaluating signs of mental sensorium,muscle tone,and cry patterns over 1 *** 12% (81 out of 674) of the newborns admitted for neonatal hyperbilirubinemia had a BIND score > *** admission age was 6 ± 4.1 days;total serum bilirubin (TSB) was 31.2± 10 mg/dL (range 17.5-75.2).Of these newborns,40.7% and 21% had evidence of haemolysis and sepsis,*** mortality was 9.9%;58% of the newborns showed signs of mild-to-moderate BIND at discharge,while 32.1% survived with an apparently normal *** BIND score was significantly correlated with admission TSB (r=0.476,P < 0.001).Similarly,BIND score at discharge was correlated with admission TSB (r=0.442,P < 0.001) and admission BIND score (r =0.888,P < 0.001).The regression model showed that admission TSB (P < 0.001) and maternal illiteracy (P =0.034) were predictors of the BIND score at admission,while admission BIND score was the best indicator of the discharge score (P < 0.001).Conclusions ABE is still a major problem in our *** TSB and maternal illiteracy are good predictors of bilirubin encephalopathy at admission and discharge.

关键词： Bilirubin-induced neurologic dysfunction Bilirubin encephalopathy Kernicterus Neonatal hyperbilirubinemia

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Lightweight Transfer Learning Models for Ultrasound-Guided Classification of COVID-19 Patients

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Computers, Materials & Continua 2021年第11期69卷 2295-2312页

作者： Mohamed Esmail Karar Omar Reyad Mohammed Abd-Elnaby abdel-Haleem abdel-Aty Marwa ahmed Shouman College of Computing and Information Technology Shaqra UniversityShaqra11961Saudi Arabia Department of Industrial Electronics and Control Engineering Faculty of Electronic Engineering(FEE)Menoufia UniversityMenouf32952Egypt Department of Mathematics and Computer Science Faculty of ScienceSohag UniversitySohag82524Egypt Department of Computer Engineering College of Computers and Information TechnologyTaif UniversityTaif21944Saudi Arabia Department of Physics College of SciencesUniversity of BishaBisha61922Saudi Arabia Department of Physics Faculty of ScienceAl-Azhar UniversityAssiut71524Egypt Department of Computer Science and Engineering Faculty of Electronic Engineering(FEE)Menoufia UniversityMenouf32952Egypt

Lightweight deep convolutional neural networks(CNNs)present a good solution to achieve fast and accurate image-guided diagnostic procedures of COVID-19 ***,advantages of portable Ultrasound(US)imaging such as simplicity and safe procedures have attracted many radiologists for scanning suspected COVID-19 *** this paper,a new framework of lightweight deep learning classifiers,namely COVID-LWNet is proposed to identify COVID-19 and pneumonia abnormalities in US *** to traditional deep learning models,lightweight CNNs showed significant performance of real-time vision applications by using mobile devices with limited hardware *** main lightweight deep learning models,namely MobileNets,ShuffleNets,MENet and MnasNet have been proposed to identify the health status of lungs using US *** image dataset(POCUS)was used to validate our proposed COVID-LWNet framework *** classes of infectious COVID-19,bacterial pneumonia,and the healthy lung were investigated in this *** results showed that the performance of our proposed MnasNet classifier achieved the best accuracy score and shortest training time of 99.0%and 647.0 s,*** paper demonstrates the feasibility of using our proposed COVID-LWNet framework as a new mobilebased radiological tool for clinical diagnosis of COVID-19 and other lung diseases.

关键词： Coronavirus medical image processing artificial intelligence ultrasound

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