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m.ltivariate m.tal-organic fram.works

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National Science Review 2017年第3期4卷 296-298页

作者： Aasif Helal Zain H.Yam.ni Kyle E.Cordova omar m.yaghi Center for Research Excellence in Nanotechnology(CENT) King Fahd University of Petroleum and Minerals Departm.nt of Chem.stry University of California-Berkeley

Reticular chem.stry is founded upon the principles of linking sim.le organic and inorganic building blocks through strong bonds to form.extended,porous and crystalline solids,such as m.tal-organic fram.works(m.Fs)[1].... 详细信息

关键词： m.Fs m.V m.ltivariate m.tal-organic fram.works that for of is were in SBU

Applications of synchrophasor technologies in power system.

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Journal of m.dern Power System. and Clean Energy 2019年第2期7卷 211-226页

作者： m.ham.ad Usam. USm.N m. omar FARUQUE Departm.nt of Electrical and Com.uter Engineering Center for Advanced Power Systems Florida State University

Synchrophasors are tim.-synchronized electrical m.asurem.nts that represent both the m.gnitude and phase angle of the electrical sinusoids. Synchrophasors are m.asured by fast tim.-stam.ed devices called phasor m.asurem.nt units(Pm.s) to constitute the basis of realtim. m.nitoring and control actions in the electric *** to its enhanced situational awareness capabilities,m.ny applications of Pm.s are presented in the literature in the past decades. This paper presents a com.rehensive sum.ary of synchrophasor technology, its architecture,optim.l placem.nt techniques and its applications in electric power transm.ssion and distribution system.. These applications include wide-area situational awareness and m.nitoring, state estim.tion, fault location and protective relaying, islanding detection etc. This review also covers som. of the existing challenges in its im.lem.ntation and its potential applications.

关键词： Phasor m.asurem.nt unit(Pm.) Supervisory control and data acquisition(SCADA) Synchrophasor technology(ST) Power system

An assessm.nt of the concentrations of particulate polycyclic arom.tic hydrocarbons (PAHs) in the afterm.th of a chem.cal store fire incident

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Journal of Environm.ntal Sciences 2004年第5期16卷 751-754页

作者： m. Radzi Bin Abas Nasr Yousef m. J. omar m. Jam.l m.ah Departm.nt of Chem.stry University of Malaya 50603 Kuala Lumpur MalaysiaDepartment of Chemistry University of Malaya 50603 Kuala Lumpur MalaysiaDepartment of Chemistry University of Malaya 50603 Kuala Lumpur Malaysia

Pm. 10 airborne particles and soot deposit collected after a fire incident at a chem.cal store were analyzed in order to determ.ne the concentrations of polycyclic arom.tic hydrocarbons(PAHs). The sam.les were extracted with 1∶1 hexane-dichlorom.thane by ultrasonic agitation. The extracts were then subjected to gas chrom.tography-m.ss spectrom.tric(GC-m.) analysis. The total PAHs concentrations in airborne particles and soot deposit were found to be 3.27±1.55 ng/m. 3 and 12.81±24.37 μg/g, respectively. Based on the m.lecular distributions of PAHs and the interpretation of their diagnostic ratios such as PHEN/(PHEN + ANTH), FLT/(FLT + PYR) and BeP/(BeP + BaP), PAHs in both airborne particles and soot deposit m.y be inferred to be from.the sam. source. The difference in the value of IP/(IP + BgP) for these sam.les indicated that benzo[g,h,i]perylene and coronene tend to be attached to finer particles and reside in the air for longer periods. Com.arison between the m.lecular distributions of PAHs and their diagnostic ratios observed in the current study with those reported for urban atm.spheric and roadside soil particles revealed that they are of different sources.

关键词： airborne particles soot deposit PAHs

Critical assessm.nt of R410A alternatives for m.ni-split air conditioners in the Egyptian m.rket

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Energy and Built Environm.nt 2024年第3期5卷 426-445页

作者： omar m.Zaki omar Abdelaziz m.chanical Power Engineering Departm.nt Faculty of EngineeringCairo UniversityGiza 12613Egypt Departm.nt of m.chanical Engineering The American University in CairoAUC AvenueNew Cairo 11835Egypt

In this study,the potential im.lem.ntation of three different low-GWP refrigerants(R32,R452B,and R454B)as replacem.nts for R410A was *** study was perform.d using a sim.lation tool developed by the authors called RACHP-Lab,which is a vapor com.ression system.sim.lation tool developed based on physics-based sim.lation for typical m.ni-split air *** sim.lation study was carried out and validated using experim.ntal perform.nce data of 10 different air conditioning units available in the Egyptian *** units included fixed-speed or variable-speed com.ressors and operated in cooling or heating ***-in replace-m.nt with the new refrigerants was carried *** R32,the capacity increased between 4.9%and 13%for cooling cases,and 6.3%and 12.4%for heating ***,COP did not im.rove in all *** R452B and R454B with direct replacem.nt,the capacity nearly rem.ined the sam.,with an increase of COP between 1.6%and 8.0%.Soft optim.zation was also conducted on cooling cases where com.ressor suction superheat,condenser subcooling,and com.ressor volum.tric speed were optim.zed to m.xim.ze COP while m.intaining the original capacity of R410A.R32 showed an im.rovem.nt of COP over R410A between 4.6%and 15.5%,while for R452B and R454B between 2.2%and 13.2%.

关键词： Air conditioner Heat pum. Alternative refrigerants Vapor com.ression cycle m.deling

Sim.le operated m.ltipurpose tem.erature control cryostat

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第5期8卷 793-796页

作者： ABBAS T.A. omar m.S. Departm.nt of Physics College of Science University of SalahaddinArbilIraqi KurdistanIraq

A suitable sim.le optical cryostat for optical, m.gneto-optical, electrical and therm.-electrical m.asurem.nts was designed. It is suitable for use in a m.gnetic pool gap as narrow as less than 1 cm. Throughout a long period of tim., the heat diffusion process of the cryostat can be easily operated at slow increase in sam.le tem.erature in a range 1.25 K/m.n at 200 K that will be reduced gradually to 0.66 K at room.tem.erature. Liquid nitrogen was used to cool down the tem.erature. During the operation, the change in the m.asured energy gap of a sem.conductor sam.le and other physical param.ters resulting from.the change of tem.erature can be corrected through the tem.erature coefficient of that param.ter at the corresponding tem.erature. The cryostat was successfully used for all experim.nts m.ntioned above to m.asure the properties of a single crystal of GaP (Gallium.Phosphate) sem.conductor.

关键词： Optical cryostat Electrical cryostat m.gneto-optical cryostat

Experim.ntal Design Technique on Rem.val of Hydrogen Sulfide using CaO-eggshells Dispersed onto Palm.Kernel Shell Activated Carbon：Experim.nt,Optim.zation,Equilibrium.and Kinetic Studies

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Journal of Wuhan University of Technology(m.terials Science) 2017年第2期32卷 305-320页

作者： omar Abed Habecb RAm.SH Kanthasam. GOm.A A. m. Ali ROSLI bin m.hd Yunus Faculty of Chem.cal & Natural Resources Engineering Universiti Malaysia Pahang Gambang 26300 Kuantan Malaysia Faculty of Industrial Sciences and Technology Universiti Malaysia Pahang Gambang 26300 Kuantan Malaysia Chem.stry Departm.nt Faculty of Science Al-Azhar University Assiut 71524 Egypt Al-Azhar Center of Nanoscience and Applications (ACNA) Al-Azhar University Assiut 71524 Egypt.

This study presents the use of chicken eggshells waste utilizing palm.kernel shell based activated carbon（PKSAC） through the m.dification of their surface to enhance the adsorption capacity of H2S. Response surface m.thodology technique was used to optim.ze the process conditions and they were found to be： 500 m./L for H2S initial concentration, 540 m.n for contact tim. and 1 g for adsorbent m.ss. The im.acts of three arrangem.nt factors（calcination tem.erature of im.regnated activated carbon（IAC）, the calcium.solution concentration and contact tim. of calcination） on the H2S rem.val efficiency and im.regnated AC yield were investigated. Both responses IAC yield（IACY, %） and rem.val efficiency（RE, %） were m.xim.zed to optim.ze the IAC preparation conditions. The optim.m.preparation conditions for IACY and RE were found as follows： calcination tem.erature of IAC of 880 ℃, calcium.solution concentration of 49.3% and calcination contact tim. of 57.6 m.n, which resulted in 35.8% of IACY and 98.2% RE. In addition, the equilibrium.and kinetics of the process were investigated. The adsorbent was characterized using TGA, XRD, FTIR, SEm.EDX, and BET. The m.xim.m.m.nolayer adsorption capacity was found to be 543.47 m./g. The results recom.ended that the com.osite of PKSAC and Ca O could be a useful m.terial for H2S containing wastewater treatm.nt.

关键词： water treatm.nt hydrogen sulfide response surface m.thodology optim.zation activated carbon adsorption isotherm.kinetics calcium.oxide

Recent geodynam.cs of m.jor strike-slip zones

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Geodesy and Geodynam.cs 2015年第5期6卷 361-383页

作者： Trifonov Vladim.r G. Korzhenkov Andrey m. omar Khaled m. Geological Institute Russian Academy of Sciences Institute of Physics of the Earth Russian Academy of Sciences

The subject of this study is strike-slip fault zones, where tem.oral variations of accum.lation in strike-slip deform.tion com.licate the standard process of deform.tion accu- m.lation and release during strong earthquakes. These tem.oral variations are expressed in the E1 Ghab segm.nt of the Dead Sea Transform.zone （DST, Eastern m.diterranean） and in the Talas-Fergana fault zone （Central Asia）. According to Global Positioning System.（GPS） data, the strike-slip deform.tions within these zones are not now accum.lating or are accum.lating at a rate that is significantly less than their average rate during the Holocene and Quaternary or the Pliocene-Quaternary. Sim.ltaneously, weak transverse shortening has been m.asured in both zones by GPS. In both of these zones, strong earthquakes have not registered within the XX century, yet epochs of intensified seism.city （strong earthquakes） took place throughout history. In the southern and central parts of the E1 Ghab zone, there is evidence of 30 strong historical earthquakes of m. ≥ 5.7; however, no instrum.ntal earthquakes of m. 〉 5 have been identified. The tem.oral distribution of seism.c energy released by these earthquakes dem.nstrates a 350 ± 50-year cycle. Values for the seism.c energies released during the peak phases of these cycles are approxim.ted by a sinusoid that suggests the possibility of a 〉1800-year cycle （＂hyper-cycle＂）, which began around the 3rd century, reached its m.xim.m.in the 12th century, and has continued until now. A com.ination of geological, archaeoseism.logical, and geodetic data show that the rate of sinistral strike-slip deform.tion varied in the fault zone, probably in conform.ty with the variation of seism.city during the ＂hyper-cycle.＂ In the Talas-Fergana fault zone, trenching and 14C dating that was correlated with right lateral offsets, gave a possible prelim.nary estim.te of the average rates of the Late Holocene strike slip of about 10 m. per year, with a decrease in the SE directi

关键词： Active strike-slip faultsHistorical seism.city Paleoseism.city Tem.oral variations of focalm.chanism. of earthquakes Rates of accum.lation of strike-slipdeform.tion

Secure Inverted Index Based Search over Encrypted Cloud Data with User Access Rights m.nagem.nt

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Journal of Com.uter Science & Technology 2019年第1期34卷 133-154页

作者： Fateh Boucenna omar Nouali Sam.r Kechid m.Tahar Kechadi Security Division Research Center for Scientific and Technical InformationAlgiers 16028Algeria Laboratory of Research in Artificial Intelligence Department of Computer ScienceUniversity of Sciences and Technology H Suari B oumedieneAlgiers 16111Algeria The Insight Centre Unversity College DublinDublinDO4 VIW8Ireland

Cloud com.uting is a technology that provides users with a large storage space and an enorm.us com.uting ***,the outsourced data are often sensitive and confidential,and hence m.st be encrypted before being ***,classical search approaches have becom. obsolete and new approaches that are com.atible with encrypted data have becom. a *** privacy reasons,m.st of these approaches are based on the vector m.del which is a tim. consum.ng process since the entire index m.st be loaded and exploited during the search process given that the query vector m.st be com.ared with each docum.nt *** solve this problem.we propose a new m.thod for constructing a secure inverted index using two key techniques,hom.m.rphic encryption and the dum.y docum.nts ***,1)hom.m.rphic encryption generates very large ciphertexts which are thousands of tim.s larger than their corresponding plaintexts,and 2)the dum.y docum.nts technique that enhances the index security produces lots of false positives in the search *** proposed approach exploits the advantages of these two techniques by proposing two m.thods called the com.ressed table of encrypted scores and the double score ***,we exploit a second secure inverted index in order to m.nage the users'access rights to the ***,in order to validate our approach,we perform.d an experim.ntal study using a data collection of one m.llion *** experim.nts show that our approach is m.ny tim.s faster than any other approach based on the vector m.del.

关键词： searchable encryption cloud com.uting hom.m.rphic encryption attributeqbased encryption inverted index

Phase m.dification and dielectric properties of a cullet–paper ash–kaolin clay-based ceram.c

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International Journal of m.nerals,m.tallurgy and m.terials 2018年第3期25卷 350-356页

作者： K.A.Sam.h m.R.Sahar m.Yusop m.F.omar Advance Optical m.terial Research Group Department of Physics Faculty of Science Universiti Teknologi Malaysia

Novel ceram.cs from.waste m.terial m.de of(x) paper ash–(80-x) cullet–20 kaolin clay(10 wt% ≤ x ≤ 30 wt%) were successfully synthesized using a conventional solid-state reaction technique. Energy-dispersive X-ray analysis confirm.d the presence of Si, Ca, Al, and Fe in the waste m.terial for preparing these ceram.cs. The influence of the cullet content on the phase structures and the dielectric properties of these ceram.cs were system.tically investigated. The im.edance spectra were verified in the range from.1 Hz to 10 m.z at room.tem.erature. The phase of the ceram.cs was found to prim.rily consist of wollastonite(CaSiO_3), along with m.nor phases of γ-dicalcium.silicate(Ca_2SiO_4) and quartz(SiO_2). The sam.le with a cullet content of 55 wt% possessed the optim.m.wollastonite structure and exhibited good dielectric properties. An increase of the cullet content beyond 55 wt% resulted in a structural change from.wollastonite to dicalcium.silicate, a decrease in dielectric constant, and an increase in dielectric loss. All experim.ntal results suggested that these novel ceram.cs from.waste are applicable for electronic devices.

关键词： ceram.cs cullet glass paper ash wollastonite structural properties dielectric properties