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Transport Properties of K_xV_2O_5·nH_2O Nanocrystalline Films

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Journal of Materials Science & Technology 2011年第10期27卷 865-872页

作者： A.A.Bahgat H.A.Mady A.S.abdel Moghny A.S.abd-Rabo Samia e.Negm Department of Physics Faculty of ScienceAl-Azhar University

Five different compositions of KxV2O5-nH2O （where prepared by the sol-gel process. electrical conductiv x=0.00, 0.0017, 0.0049, 0.0064 and 0.0091 mol） were ty and thermoelectric power were measured parallel to the substrate surface in the temperature range of 300-480 K. The electrical conductivity showed that all samples were semiconductors and that conductivity increased with increasing K content. The conductivity of the present system was primarily determined by hopping carrier mobility. The carrier density was evaluated as well. The conduction was confirmed to obey non-adiabatic small polaron hopping. The thermoelectric power or Seebeck effect, increased with increasing K ions content. The results obtained indicated that an n-type semiconducting behavior within the temperature range was investigated.

关键词： Vanadium pentoxide xerogel Nanocrystalline film electrical conductivity Small polaron hopping

Neoproterozoic Tectonic events of egypt

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Acta Geologica Sinica(english edition) 2021年第4期95卷 1366-1405页

作者： Mohamed abd eL-WAHeD Zakaria HAMIMI Geology Department Faculty of ScienceTanta UniversityTanta 31527Egypt Department of Geology Faulty of ScienceBen ha UniversityBenha 13518Egypt

The egyptian Nubian Shield(eNS)represents the northwestern part of the Arabian-Nubian Shield and the northern extension of the east African *** eNS is regarded as being formed due to northward-directed escape *** is characterized by mild accretion and suture zones dominated by major strike-slip zones with a commonly sinistral sense of movement;some shear zones display a dextral sense of *** is dominated by gneisses and migmatites in the south,arc volcaniclastic metasediments and highly dismembered ophiolites in the central parts,whereas its northern part is dominated by late-to post-tectonic *** southern Sinai,the Neoproterozoic rocks are grouped into four complexes,namely Feiran–Solaf,Sa’al–Zaghra,Kid and *** eNS ophiolites were formed between 730–750 Ma,mainly in a supra-subduction zone *** eNS has undergone a Neoproterozoic deformation history involving three successive phases:(1)early N–S shortening phase(D1),(2)Syn-accretionary phase(D2)and(3)Post-accretionary phase(D3).The initial island-arc stage(780–730 Ma)is a N–S shortening phase initiated by collision between the eastern Desert tectonic terrane to the north with both the Gebeit and Gabgaba terranes to the south(830–720 Ma).During the arc-splitting and back-arc spreading stage(730–620),voluminous syn-tectonic granitoids intruded into the eNS(750–610 Ma).The e–W-directed compressional/transpressional phase(620–450 Ma)led to the overall uplift of the central part of the eNS and consequently the development and exhumation of the core complexes in oblique convergent *** e–W intense shortening deformation resulted also in the formation of NW-and Ne-striking sinistral and dextral strike-slip shear zones,*** latest periods of the e–W-directed compressional/transpressional regime were characterized by deposition of the molasse-type Hammamat Sediments unconformably over the Dokhan Volcanics,or interbedded with *** combined thrusting,folding and sin

关键词： Neoproterozoic deformation N–S shortening syn-accretionary phase post-accretionary phase egyptian Nubian Shield

Physico-analytical Studies on Salicylaldehyde Thiosemicarbazone Complexes

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Journal of Materials Science & Technology 1998年第5期14卷 434-440页

作者： Abo el Fetoh, S.H. abd el-Kareem, A.T. Wassel, M.A. eid, A.e. Faculty of Girls-Ain Shams University Egypt National Research Centre Egypt Faculty of Science El-Menoufia University Egypt Faculty of Science Al-Azhar University Egypt

The complexes of salicylaldehyde thiosemicarbazone with Pd, Cu and Ru were prepared. The prepared complexes were characterized by spectroscopic, element and thermal analyses and D.C. conductivity measurements. The antimicrobial activity of all the prepared compounds against gram-positive, gram-negative and fungi was studied. From these studies, it has been obtained that the ligand is bonded to the metals through O, N and S, but to palladium in [Pd (H//2L//2)] Cl//2 only through N and O. Biological studies confirm that the organic effect on both gram-positive and gram-negative bacteria is very weak and their complexes have no effect on fungi, but Cu-complex has strong influence on both types of bacteria. (edited author abstract) 22 Refs.

关键词： Metallorganic polymers

Modeling the initiation of sediment motion under a wide range of flow conditions using a Geno-Mamdani Fuzzy Inference System method

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International Journal of Sediment Research 2020年第5期35卷 467-483页

作者： Hussein Bizimana abdüsselam Altunkaynak Hydraulics Division Faculty of Civil EngineeringIstanbul Technical University

The current study introduces a novel approach to estimate the incipient motion of sediments under a wide range of flow regimes by developing a fuzzy model with a fuzzy-band that refers to a transition from weak motion to general motion of *** partial sediment entrainment is defined by fuzzy sets considering the uncertainty related to the individual ratio of inertia to viscous forces which is the definition of shear Reynolds *** the current study,the Mamdani Fuzzy Inference System（Mamdani FIS） is used to develop a comprehensive fuzzy model of the incipient motion of *** Mamdani FIS has a shortcoming regarding the training of the fuzzy *** estimate the dimensionless shear stress,a new method is developed by combining a genetic algorithm with the fuzzy approach which is named the Geno-Mamdani Fuzzy Inference System（GMFIS） *** performance of the GMFIS model is evaluated using experimental data by considering root mean square error（RMSe）,NashSutcliffe coefficient of efficiency（Ce）,degree of robustness（Dr）,and concordance coefficient（CC） as evaluation *** GMFIS model performed very well based on the RMSe,Ce,Dr,and CC values and satisfactorily represented the three types of incipient ***,a new range of fuzzy,dimensionless,critical shear stress values is established in all flow conditions from weak to general sediment entrainment.

关键词： Incipient motion Dimensionless shear stress Shear Reynolds number Fuzzy logic Genetic algorithms Sediment

Performance of the Aluminide Coating of SomeLow Alloy Steels

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Journal of Materials Science & Technology 1997年第6期13卷 462-466页

作者： H.M.Soliman and M.e.abd e1-Azim(Metallurgy Dept., Atomic energy Authority, Cairo, egypt ) Metallurgy Dept. Atomic Energy Authority Cairo Egypt

Two low alloy steels 0.5Cr-0.5Mo-0.25V and H85 were pack-aluminized at 900°for 4 h by using Fe-Al powder mixture containing 48% Fe, 20.6% Al- 29.4% Al2O3 and 2% NH4Cl by weight. The microhardness and oxidation resistance at 900℃ of the aluminide coatings were studied. It was found that pack-aluminizing improves the microhardness of the 0.5Cro.5Mo-0.25V steel while it reduces the microhardness of the H85 steel. Pack aluminizing highly improves the oxidation resistance after 20h exposure at 900℃ in air for the investigated steels.

关键词： Cr Performance of the Aluminide Coating of SomeLow Alloy Steels

exact solutions of stochastic fractional Korteweg de–Vries equation with conformable derivatives

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Chinese Physics B 2020年第3期29卷 62-69页

作者： Hossam A.Ghany abd-Allah Hyder M Zakarya King Khalid University College of ScienceDepartment of MathematicsP.O.Box 900461413AbhaSaudi Arabia Department of engineering Mathematics and Physics Faculty of EngineeringAl-Azhar University11371CairoEgypt Department of Mathematics Helwan UniversitySawah Street(11282)CairoEgypt Department of Mathematics Faculty of ScienceAl-Azhar University71524AssiutEgypt

We deal with the Wick-type stochastic fractional Korteweg de–Vries(KdV) equation with conformable *** the aid of the exp-function method, white noise theory, and Hermite transform, we produce a novel set of exact soliton and periodic wave solutions to the fractional KdV equation with conformable derivatives. With the help of inverse Hermite transform, we get stochastic soliton and periodic wave solutions of the Wick-type stochastic fractional KdV equation with conformable derivatives. eventually, by an application example, we show how the stochastic solutions can be given as Brownian motion functional solutions.

关键词： Korteweg de–Vries(KdV)equation conformable derivative stochastic Brownian motion expfunction method

Cancelable Speaker Identification System Based on Optical-Like encryption Algorithms

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Computer Systems Science & engineering 2022年第10期43卷 87-102页

作者： Safaa el-Gazar Walid el-Shafai Ghada el-Banby Hesham F.A.Hamed Gerges M.Salama mohamme. abd-e.naby Fathi e.abd el-Samie Department of electrical engineering Faculty of EngineeringEgyptian-Russian UniversityCairoEgypt Department of electronics and electrical Communications engineering Faculty of Electronic EngineeringMenoufia UniversityMenouf32952Egypt Security engineering Laboratory Department of Computer SciencePrince Sultan UniversityRiyadh11586Saudi Arabia Department of Industrial electronics and Control engineering Faculty of Electronic EngineeringMenoufia UniversityMenouf32952Egypt Department of Computer engineering College of Computers and Information TechnologyTaif UniversityTaif21944Saudi Arabia Department of Information Technology College of Computer and Information SciencesPrincess Nourah Bint Abdulrahman UniversityRiyadh84428Saudi Arabia

Biometric authentication is a rapidly growing trend that is gaining increasing attention in the last *** achieves safe access to systems using biometrics instead of the traditional *** utilization of a biometric in its original format makes it usable only ***,a cancelable biometric template should be used,so that it can be replaced when it is *** biometrics aims to enhance the security and privacy of biometric *** encryption is an efficient technique to be used in order to generate cancelable biometric *** this paper,a highly-secure encryption algorithm is proposed to ensure secure biometric data in verification *** considered biometric in this paper is the speech *** speech signal is transformed into its ***,the spectrogram is encrypted using two cascaded optical encryption *** first algorithm is the Optical Scanning Holography(OSH)for its efficiency as an encryption *** OSH encrypted spectrogram is encrypted using Double Random Phase encoding(DRPe)by implementing two Random Phase Masks(RPMs).After the two cascaded optical encryption algorithms,the cancelable template is *** verification is implemented through correlation estimation between enrolled and test templates in their encrypted *** the correlation value is larger than a threshold value,the user is *** threshold value can be determined from the genuine and imposter correlation distribution curves as the midpoint between the two *** implementation of optical encryption is adopted using its software rather than the optical *** efficiency of the proposed cancelable biometric algorithm is illustrated by the simulation *** can improve the biometric data security without deteriorating the recognition *** results give close-to-zero This values for the equal error Rate(eeR)and close-to-one values for the Area under Receiver Operator Charact

关键词： Cancelable biometrics spectrogram OSH DRPe eeR AROC

Comprehensive evaluation and sensitivity analysis of regeneration energy for acid gas removal plant using single and activated-methyl diethanolamine solvents

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Chinese Journal of Chemical engineering 2020年第6期28卷 1684-1693页

作者： Ammar Ali abd Samah Zaki Naji Ahmed Barifcani Water Resources engineering College Al-Qasim Green UniversityBabylonIraq Petroleum engineering Department Kerbala UniversityKerbalaIraq Chemical engineering Department Curtin University of TechnologyPerthAustralia.

The absorption of acid gas using reactive amines is among the most widely used types of capturing ***,the absorption process requires intensive energy expenditure majorly in the solvent regeneration *** study simultaneously evaluated the regeneration energy of MDeA and PZ/MDeA solvents in terms of heat of absorption,sensible heat,and vaporization *** Hysys version 8.8 simulation tool is applied to model the full acid gas removal plant for the chemical absorption *** new energy balance technique presents around the absorption and desorption columns to bring a new perspective of energy distribution in the capturing of acid gas *** analysis of regeneration energy and its three contributors is performed at several operation parameters such as absorber and stripper pressures,lean amine circulation rate,solvent concentration,reflux ratio,and CO2 and H2 S *** results show that the heat of absorption of PZ/MDeA system is higher than that for MDeA system for the same operating *** sensible heat is the main contributor in the required regeneration energy of MDeA solvent *** simulation results have been validated against data taken from real plant and *** product specifications of our simulation corroborate with real plant data in an excellent approach;additionally,the profile temperature of the absorber and the stripper columns are in good agreement with *** overall results highlight the direction of the effects of each parameter on the heat of absorption,sensible heat,and vaporization heat.

关键词： Heat of absorption Sensible heat Vaporization heat Regeneration energy Acid gases capturing Piperazine Activated-Methyl diethanolamine

Pack Aluminizing of Copper

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Journal of Materials Science & Technology 1997年第2期13卷 127-132页

作者： M.e.abd el-Azim H.M.Soliman (Metallurgy Dept., Atomic energy Authority Cairo, egypt) Metallurgy Dept. Atomic Energy Authority Cairo Egypt

Aluminizing of Cu by a pack cementation process was performed to improve its surface *** effect of variation of pack aluminizing temperature from 800 to 900℃ and aluminizing time from 1 to 6 h on the microstructure and the thickness of the aluminide coating of Cu was investigated. Pack aluminizing of Cu significantly improved the microhardness and the oxidation resistance. The microhardness was increased about seven times and the oxidation resistance,after 96 h exposure in air at 900℃, was extremely increased ten times by aluminizing Cu at 900℃ for 3 h.

关键词： VHN Pack Aluminizing of Copper