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Experimental and mathematical modeling of Cr(Ⅵ) removal using nano-magnetic Fe3O4-coated perlite from the liquid phase

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Chinese Journal of Chemical Engineering 2020年第6期28卷 1582-1590页

作者： Ismail m.Ahmed mostafa m.hamed Sayed S.metwally Chemistry Department College of ScienceJouf UniversitySkakaSaudi Arabia Hot Laboratories and Waste management Center Atomic Energy Authority13759 CairoEgypt

modification of perlite using nano-magnetic iron oxide was implemented to produce nano-magneticFe3O4-coated perlite composite(Fe3O4/Perlite).The prepared composite was characterized using Scanning Electron microscopy,Fourier-Transform Infrared spectroscopy and Powder X-ray *** potentiality of both perlite and Fe3O4/Perlite composite to eliminate Cr(VI)from the environmentally relevant water was *** influence of main factors which could affect the adsorption was studied including;pH of medium,shaking time and Cr(VI)ions *** experimental outcome demonstrated that the modification of perlite by nano-magnetic Fe3O4 showed a significantly enhanced Cr(VI)removal efficiency relative to that of unmodified *** the kinetic studies,the experimental data fitted well with the pseudo-second-order ***,it proposes that Langmuir isotherm is more adequate than the Freundlich isotherm for both perlite and modified *** results recommended that Fe3O4/Perlite composite had a great potential as an economic and efficient adsorbent of Cr(VI)from contaminated water,which has huge application potential.

关键词： Nano-magnetic Composite Kinetics Isotherm Perlite Adsorption

Simple and sensitive method for the determination of trace amounts of thorium using a benzoquinone derivative

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Nuclear Science and Techniques 2019年第5期30卷 22-31页

作者： mostafa m.hamed Refaat F.Aglan Hot Laboratories and Waste management Center Atomic Energy Authority of Egypt

A novel simple, sensitive, rapid, direct, and spectrophotometry-based procedure was investigated to determine Th(IV) at trace amounts. The new method is based on Th(IV) chelation with 3,6-dichloro-2,5-dihydroxy-l,4-benzoquinone(DDBQ). The reagent reacts with Th(IV) in 0.1 m HCl to form an orange 1:2 complex. The stability constant value is 6.62×10~4 for the Th(IV)complex. The Th(IV)-DDBQ obtained shows one peak with a maximum at about 346 nm. The chelate forms immediately and the absorbance remains stable for over24 h. Beer's law was obeyed in the concentration range0–10 μg mL^(-1). The molar absorptivity and Sandell's sensitivity were 4.4×10~4 L mol^(-1)cm^(-1) and 0.0053 μg cm^(-2), respectively. Different analytical parameters were tested in detail. Interfering ion(cations and anions) effects were tested. methods for Th(IV) determination by second and third-derivative spectrophotometry were also introduced at about 344 and 341 nm, respectively. These two derivative orders offer the feature of sensitivity without the necessity for solvent extraction,heating, or pre-concentration steps. Finally, the methods were successfully utilized for Th(IV) determination in monazite, environmental water, and wastewater samples.

关键词： Th(IV) determination p-benzoquinone derivative Spectrophotometry

Vibration suppression in multi-tool ultrasonic machining to multi-external and parametric excitations

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Acta mechanica Sinica 2009年第3期25卷 403-415页

作者： m.m.Kamel W.A.A.El-Ganaini Y.S.hamed Department of Engineering mathematics Faculty of Electronic EngineeringMenoufiya University

Ultrasonic machining （USm） is of particular interest for the machining of non-conductive, brittle materials such as engineering ceramics. In this paper, a multi-tool technique is used in USm to reduce the vibration in the tool holder and have reasonable amplitude for the tools. This can be done via dynamic absorbers. The coupling of four nonlinear oscillators of the tool holder and tools representing ultrasonic cutting process are investigated. This leads to a four-degree-of-freedom system subjected to multi-external and multi-parametric excitation forces. The aim of this work is to control the tool holder behavior at simultaneous primary, sub-harmonic and internal resonance condition. multiple scale perturbation method is used to obtain the solution up to the second order approximations. The different resonance cases are reported and studied numerically. The stability of the system is investigated by using both phase-plane and frequency response techniques. The effects of the different parameters of the tools on the system behavior are studied numerically. Comparison with the available published work is reported.

关键词： Control Stability Ultrasonic machining (USm)

Cooling enhancement of planar-balanced magnetron cathode

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Nuclear Science and Techniques 2017年第8期28卷 69-74页

作者： m'hamed Salhi Seddik El Hak Abaidia Brahim mohamedi Sofiane Laouar Centre de Recherche Nucleaire de Birine B.P. 18017200 Ain-Oussera Algeria Unite de Recherche mPE Faculte des Sciences de l'Ingenieur Universite M'hamed Bougarra de Boumerdes 35000 Boumerdes Algeria

In physical vapor deposition on a magnetron cathode, temperature of sensitive components must be kept under threshold limit, so as to ensure the cathode reliability,the process reproducibility, and the best quality of thin *** can be achieved by an adequate design to enhance the dissipation of heat generated at the cathode. In this paper,temperature distribution and streamlines velocity of the cathode coolant inside a cathode magnetron are analyzed by using CFD solver ANSYS FLUENT in the single-phase method in combination with k–e standards turbulent *** results show that the design is appropriate under the calculation parameters, and for high heat densities some improvements are necessary to enhance heat dissipation and keep temperature under the threshold limit.

关键词：阴极冷却强化磁控平衡平面物理气相沉积 FLUENT 温度分布

An economic analysis of Iranian petroleum contract

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Petroleum Science 2020年第5期17卷 1451-1461页

作者： Fazel m.Farimani Xiaoyi mu hamed Sahebhonar Ali Taherifard Sharif Policy Research Institute Sharif University of TechnologyTehranIran Center for Energy Petroleum Mineral Law and PolicyUniversity of DundeeDundeeUK Sobhan Institute for Energy Studies TehranIran Sobhan Institute for Energy Studies Imam Sadiq UniversityTehranIran

Following three generations of buyback contracts,the new model of Iranian petroleum contracts(IPC) was introduced by the Iranian cabinet to incentivize investments in the *** paper analyzes the fiscal terms of the contract with technical information from one of the candidate fields for *** financial simulation shows that,in general,the IPC resembles more a service contract than a production sharing contract as the contractor's take is relatively low—below 5% across different scenarios of crude oil ***,the IPC is progressive in that as the overall profitability of the project improves the government takes an increasing share of the economic *** results are confirmed in a sensitivity analysis of each party's profitability and takes on oil price,CAPEX,OPEX and the fee.

关键词： Iranian petroleum contract(IPC) Fiscal regime Government take Progressive Petroleum rent

Utilization of iron oxide bearing pellets waste for preparing hard and soft ferromagnetic glass ceramics

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Journal of Advanced Ceramics 2014年第4期3卷 259-268页

作者： Salwa A.m.ABDEL-HAmEED Ibrahim m.hamed Nehal A.ERFAN Glass Research Department National Research CenterDokkiCairoEgypt Chemical Engineering Department Faculty of EngineeringMinia UniversityMiniaEgyp

About 8%of the imported iron oxide pellets burdens to Egypt are *** this paper,broken pellets waste(BPW)is used as raw material for the preparation of hard magnetic glass ceramics(HmGC)as well as soft magnetic glass ceramics(SmGC).About 54 wt%and 37 wt%of BPW are used to prepare SmGC and HmGC,*** thermal analysis(DTA)reveals two broad exothermic peaks for HmGC at 591℃and 697℃,whereas one exothermic peak at 820℃is detected for SmGC.X-ray diffraction(XRD)shows the crystallization of hematite as the sol phase in BPW,and meanwhile,Zn-ferrite and Ba-hexaferrite are identified in SmGC and HmGC,*** electron microscopy(TEm)reveals the crystallization of nanosize particles of~20 nm for SmGC and~12 nm for *** scanning magnetometer(VSm)reveals an increase in saturation magnetization from~1 emu/g for BPW to~77 emu/g for SmGC and 21 emu/g for HmGC.

关键词： magnetic materials nanostructure pellets waste

Heat transfer analysis in the flow of Walters' B fluid with a convective boundary condition

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Chinese Physics B 2014年第8期23卷 382-388页

作者： T.Hayat Sadia Asad m.mustafa hamed H.Alsulami Department of mathematics Quaid-i-Azam University 45320 Department of mathematics Faculty of Science King Abdulaziz University School of Natural Sciences National University of Science and Technology (NUST)

Radiative heat transfer in the steady two-dimensional flow of Walters＇ B fluid with a non-uniform heat source/sink is investigated. An incompressible fluid is bounded by a stretching porous surface. The convective boundary condition is used for the thermal boundary layer problem. The relevant equations are first simplified under usual boundary layer assumptions and then transformed into a similar form by suitable transformations. Explicit series solutions of velocity and temperature are derived by the homotopy analysis method （HAm）. The dimensionless velocity and temperature gradients at the wall are calculated and discussed.

关键词： Walters' B fluid heat source/sink convective boundary condition analytic solution

Photocatalytic Synthesis of Gold Nanoparticles Using Preyssler Acid and Their Photocatalytic Activity

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催化学报 2011年第6期32卷 978-982页

作者： Ali AYATI Ali AHmADPOUR Fatemeh F.BAmOHARRAm majid m.HERAVI hamed RASHIDI Department of Chemical Engineering Ferdowsi University of Mashhad Department of Chemistry School of SciencesIslamic Azad University Department of Chemistry School of SciencesAlzahra University

Preyssler acid H14[NaP5W30O110] was used as reducing agent and stabilizer for the synthesis of gold nanoparticles by photolysis of Au(III)/Preyssler acid/propan-2-ol *** acid plays both the role of transferring electrons from propan-2-ol to Au(III) and stabilizing the ***-2-ol was used as sacrificial reagent for the photoformation of reduced Preyssler *** nanoparticles (Au NPs) were characterized by UV-Vis spectroscopy,transmission electron microscopy (TEm),and particle size distribution (PSD) *** synthesized Au NPs had a uniform hexagonal morphology and their size was about 17 *** catalytic performance of these NPs for photodegradation of methyl orange (meO) was investigated in aqueous ***-Vis studies showed that Au NPs can catalyze photodegradation of this azo *** pseudo-first-order rate constants were also calculated for this reaction.

关键词：固体超强碱氧化钙硝酸钾氧化铝氧化锆氢氧化钾硝酸钙

Distribution of central corneal thickness and intraocular pressure in emmetropic eyes of healthy children of Palestine: a representative cross-sectional study

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International Journal of Ophthalmology(English edition) 2019年第3期12卷 496-503页

作者： hamed Tm Alkhodari Department of Optometry Faculty of Health Sciences Islamic University of Gaza

AIm: To determine the distributions of central corneal thickness(CCT) and intraocular pressure(IOP) in emmetropic eyes of healthy children of ***: This representative cross sectional study included a total of 1156 eyes from 578 healthy school children aged 7-15 y. Inclusion criteria included emmetropia, no previous history of ocular or systemic diseases, no previous history of contact lens use, and the availability of both eyes. CCT and IOP were measured using ultrasound pachymeter and Goldmann applanation tonometer, respectively. The relationship of the results with age and gender was ***: The mean age of school children was 11.13±2.8 y. mean CCT was 542.2±37.4 and 544.3±39.2 μm for right and left eyes, respectively. mean IOP was 12.5±2.2 and 12.3±2.2 mm Hg for right and left eyes, respectively. A positive correlation was observed between CCT and IOP of the right eye(P0.05). There were significant differences in mean CCT and IOP between right and left eyes(P=0.004, P=0.001, respectively).CONCLUSION: A population profile of CCT and IOP is established in Palestinian children for the first time. mean CCT is comparable to some studies but differ from others. mean IOP is considerably lower than that of majority children of other ethnic groups. Intereye difference of more than 36 μm in CCT, and 5 mm Hg in IOP should prompt evaluation for potential ocular disorders.

关键词： central corneal thickness intraocular pressure intereye asymmetry Goldmann applanation tonometer ultrasound pachymeter