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Experimental approaches and analytical technique for determining heavy metals in fallen dust at ferrosilicon production factory in Edfu, Aswan,Egypt

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2005年第8期6卷 708-718页

作者： SOLTAN m.E rageh h.m rageh N.m AhmED m.E Department of Ch.mistry Faculty of Science at Aswan South Valley UniversityEgypt Department of Chemistry Faculty of Science at Qena South Valley UniversityEgyptDepartment of Chemistry Faculty of Science at Qena South Valley UniversityEgyptDepartment of Environment Egyptian Ferroalloy Edfu AswanEgypt

In this study aimed to evaluate the pollution extent of metals and nonmetals inside and outside the ferrosilicon production factory in Edfu, Aswan, Egypt, raw materials (quartz, cokes, iron oxides), ferrosilicon alloy, silica fume, dust and suspended dust (at different sites) samples were collected from the factory, and fallen dust samples were collected from outside the factory, horizontally (at different sites and different distance and directions) and vertically (at different floors in the selected buildings). Gravimetric methods, X-ray fluorescence (XRF), flame photometer, wide range carbon determinator and atomic absorption spectroscopy tools were used for elements determination. The results indicating that the fallen dust and its element contents on southern factory walls being higher than those on eastern factory walls may be due to the nature of the dusts and effects of wind force and wind direction. Fallen dust levels in different regions outside the factory were found to be affected by the distance, direction and floors. The nature of dust samples was affected by gravity and the suspended dust in different factory units depended on the work capacity and method of handling materials by personnel in different production units. Silica fume was a complicated problem, had dangerous effect against the workers' health, and was characterized by high concentrations of SiO2(90.6%～93.6%) and heavy metals (mn, 420.6×10-6～520.3×10-6; Fe, 2354×10-6～2685×10-6; Co, 80.7×10-6～101.6×10 6 and Ni,5.3× 10-6～6.05× 10-6). The TSP (Total Suspended Particulate) levels in all factory units were higher than the recommended air quality value (70 μg/m3) under Egyptian law. The effect of ferrosilicon factory fallen dust on the surrounding regions decreased with increasing distance between the factory and these regions. The suspended dust samples in the factory units and their components greatly exceeded national and international standards, so health and environmental criteria must be

关键词： Air pollution Dust heavy metals Fallen dust

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Is there more than one stickiness criterion?

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Friction 2023年第6期11卷 1027-1039页

作者： Anle WANG martin h.müSER Department of material Science and Engineering Saarland UniversitySaarbrücken66123Germany INm—Leibniz Institute for New materials Saarbrücken66123Germany

Adhesion between an elastic body and a smooth,rigid substrate can lead to large tensile stresses between ***,most macroscopic objects are microscopically rough,which strongly suppresses adhesion.A fierce debate has unfolded recently as to whether local or global parameters determine the crossover between small and large ***,we report simulations revealing that the dependence of the pull-off force Fn on the surface energyγdoes not only have two regimes of high and low adhesion but up to four *** are related to contacts,which at the moment of rupture consist of(i)the last individual hertzian-shaped contact,in which is linear inγ,(ii)a last meso-scale,individual patches with super-linear scaling,(iii)many isolated contact patches with extremely strong scaling,and(iv)a dominating largest contact patch,for which the pull-off stress is no longer negligible compared to the maximum,microscopic pull-off ***(iii)can be seen as a transition *** is located near the point where the surface energy is half the elastic energy per unit area in conformal contact.A criterion for the transition between regimes(i)and(ii)appears difficult to grasp.

关键词： adhesion pull-off force rough contact stickiness

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Application of shortened heat treatment cycles on A356 automotive brake calipers with respective globular and dendritic microstructures

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Transactions of Nonferrous metals Society of China 2010年第9期20卷 1780-1785页

作者： h.mLLER G.GOVEN DER W.E.STUmPF materials Science and manufacturing Council for Scientific and Industrial Research (CSIR) Department of materials Science and metallurgic al Engineering University of Pretoria

Since the automotive industry has many possible applications for semi-solid metal (SSm)-high-pressure die casting (hPDC) parts, the newly developed heat treatment cycles, as well as the traditional heat treatment cycles, were applied to A356 brake calipers cast using a LK DCC630 hPDC *** hardness measurements at a cross section of the brake calipers were performed, indicating that similar values can be obtained when using the significantly shorter heat treatment ***, the typical tensile properties that can be obtained for SSm-hPDC A356 brake calipers are compared with those manufactured by gravity die *** indicate that the differences in microstructures (globular or dendritic) do not have a noteworthy effect on the heat treatment *** implies that the short heat treatment cycles originally developed for globular SSm-hPDC A356 castings can be successfully applied to dendritic liquid A356 castings too.

关键词： semi-solid metal (SSm) forming heat treatment A356 brake caliper gravity die casting automotive

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Characterization of surface liquid segregation in SSm-hPDC aluminium alloys 7075,2024,6082 and A201

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中国有色金属学会会刊：英文版 2010年第S3期20卷 847-851页

作者： h.mLLER U.A.CURLE E.P.mASUKU materials Science and manufacturing Council for Scientific and Industrial Research(CSIR)PretoriaSouth Africa

The surface liquid segregation(SLS) phenomenon in semi-solid metal-high pressure die casting(SSm-hPDC) plates of 7075,2024,6082 and A201 was investigated by different *** profiles were determined by firstly measuring the ch.mical composition of the surface of the plates using a Thermo Quantris optical emission spectrometer(OES).material was then removed by a grinding process followed by measurement of the amount of material removed and ch.mical *** profiles of the main alloying elements were plotted for the cross-section of the plates in the as-cast and T6(after solution treatment) temper *** hardness profiles from the surface to the centre of the plates were *** samples of cross-sections of the castings were prepared and evaluated using a scanning electron *** results show that surface liquid segregation in SSm-hPDC alloys causes significant differences in properties between the surface and the bulk of these castings in both the F and T6 temper conditions.

关键词： semi-solid metal(SSm) forming alloy 7075 alloy 2024 alloy 6082 alloy A201 surface liquid segregation

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Nitriles in heterocyclic synthesis: studies on ethyl 3-amino-4,4-dicyano-3-butenoate

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Chinese Journal of Ch.mistry 1991年第5期9卷 461-466页

作者： SOLImAN A.Y BAKEER h.m Department of Ch.mistry Faculty of Education Fayoum Cairo University Egypt Department of Chemistry Faculty of Education Fayoum Cairo University Egypt

New polyfunctionally substituted heterocyclic compounds were synthesized from ethyl 3-amino-4, 4-dicyano-3-butenoate (1) as a starting material.

关键词： CI studies on ethyl 3-amino-4,4-dicyano-3-butenoate Nitriles in heterocyclic synthesis

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On the friction and adhesion hysteresis between polymer brushes attached to curved surfaces: Rate and solvation effects

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Friction 2015年第2期3卷 148-160页

作者： Sissi de BEER G.DjuidjéKENmOÉ martin h.mÜSER materials Science and Technology of Polymers MESA+Institute for NanotechnologyUniversity of TwenteP.O.Box 2177500 AE Enschedethe Netherlands Jülich Supercomputing Centre Institute for Advanced Simulation FZ Jülich 52425 JülichGermany Department of Physics Laboratory of Mechanics Faculty of ScienceUniversity of YaoundéP.O.Box 812YaoundéCameroon

Computer simulations of friction between polymer brushes are usually simplified compared to real systems in terms of solvents and *** most simulations,the solvent is only implicit with infinite compressibility and zero *** addition,the model geometries are parallel walls rather than curved or rough as in *** this work,we study the effects of these approximations and more generally the relevance of solvation on dissipation in polymer-brush systems by comparing simulations based on different solvation *** find that the rate dependence of the energy loss during the collision of brush-bearing asperities can be different for explicit and implicit ***,the non-Newtonian rate dependences differ noticeably between normal and transverse motion,i.e.,between head-on and off-center asperity ***,when the two opposing brushes are made immiscible,the friction is dramatically reduced compared to an undersaturated miscible polymer-brush system,irrespective of the sliding direction.

关键词： polymer brushes biomimetic materials molecular dynamics simulation

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Influence of surface liquid segregation on corrosion behavior of semi-solid metal high pressure die cast aluminium alloys

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中国有色金属学会会刊：英文版 2010年第S3期20卷 837-841页

作者： E.P.mASUKU h.mLLER U.A.CURLE P.C.PISTORIUS materials Science and manufacturing Council for Scientific Industrial ResearchPretoriaSouth Africa Department of materials Science and Engineering Carnegie Mellon UniversityPittsburghUSA

The corrosion behavior(in chloride medium) of the surface layer of SSm-hPDC plates of alloys 7075-T6 and 2024-T6 was compared with that of the wrought alloys 7075-T6 and *** testing was performed in deaerated 3.5%NaCl *** separate tests,the open-circuit potential was monitored in aerated 3.5% NaCl for 30 min after *** electroch.mical tests show that there is no significant difference in the pitting potential of the wrought alloys and that of the Cu-enriched surfaces of the SSm-hPDC alloys.

关键词： semi-solid metal(SSm) forming wrought aluminium alloys alloy 7075 alloy 2024 corrosion surface liquid segregation

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Effect of Under Connected Plates on the hydrodynamic Efficiency of the Floating Breakwater

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China Ocean Engineering 2014年第3期28卷 349-362页

作者： A.S.Koraim O.S.rageh Water and Water Structure Engineering Department Faculty of EngineeringZagazig University Irrigation and hydraulics Department Faculty of Engineering El-Mansoura University

In this paper, the hydrodynamic efficiency of a floating breakwater system is experimentally studied by use of physical models. Regular waves with wide ranges of wave heights and periods are tested. The efficiency of the breakwater is presented as a function of the wave transmission, reflection, and energy dissipation coefficients. Different parameters affecting the breakwater efficiency are investigated, e.g. the number of the under connected vertical plates, the length of the mooring wire, and the wave length. It is found that, the transmission coefficient kt decreases with the increase of the relative breakwater width B/L, the number of plates n and the relative wire length l/h, while the reflection coefficient kr takes the opposite trend. Therefore, it is possible to achieve kt values smaller than 0.25 and kr values larger than 0.80 when B/L is larger than 0.25 for the case of l/h-1.5 and n=4. In addition, empirical equations used for estimating the transmission and reflection coefficients are developed by using the dimensionless analysis, regression analysis and measured data and verified by different theoretical and experimental results.

关键词： floating breakwaters vertical plates regular waves transmission reflection energy dissipation

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hydrodynamic Performance of Vertical Porous Structures Under Regular Waves

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China Ocean Engineering 2013年第4期27卷 451-468页

作者： A.S.Koraim O.S.rageh Water and Water Structure Eng. Dept. Faculty of Eng. Zagazig University Irrigation and hydraulics Dept. Faculty of Eng. El-Mansoura University

The hydrodynamic efficiency of the vertical porous structures is investigated under regular waves by use of physical models. The hydrodynamic efficiency of the breakwater is presented in terms of the wave transmission （kt）, reflection （kr） and energy dissipation （ka） coefficients. Different wave and structural parameters affecting the breakwater efficiency are tested. It is found that, the transmission coefficient （kt） decreases with the increase of the relative water depth （h/L）, the wave steepness （hi^L）, the relative breakwater widths （B/L, B/h）, the relative breakwater height （D/h）, and the breakwater porosity （n）. The reflection coefficient （kr） takes the opposite trend of kt when D/h=l.25 and it decreases with the increasing h/L, hJL and B/L when D/h〈1.0. The dissipation coefficient （kd） increases with the increasing h/L, hilL and B/L when D/h〈_l.O and it decreases when D/h=l.25. In which, it is possible to achieve values ofkt smaller than 0.3, k~ larger than 0.5, and kd larger than 0.6 when D/h=1.25, B/h=0.6, h/L〉0.22, B/L〉O. 13, and h/L 〉0.04. Empirical equations are developed for the estimation of the transmission and reflection coefficients. The results of these equations are compared with other experimental and theoretical results and a reasonable agreement is obtained.

关键词： water waves porous breakwaters wave attenuation wave transmission wave reflection wave dissipation

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Influence of elevated Fe,Ni and Cr levels on tensile properties of SSm-hPDC Al-Si-mg alloy F357

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中国有色金属学会会刊：英文版 2010年第S3期20卷 842-846页

作者： h.mLLER W.E.STUmPF P.C.PISTORIUS materials Science and manufacturing Council for Scientific and Industrial Research(CSIR)PretoriaSouth Africa Department of materials Science and metallurgical Engineering University of PretoriaPretoriaSouth Africa Department of materials Science and Engineering Carnegie Mellon UniversityPittsburghUnited States of America

The microstructures and tensile properties of semi-solid metal high pressure die cast(SSm-hPDC) F357 alloys with low and high levels of Fe,Ni and Cr were compared in different temper *** software was used to predict the different intermetallics that can be expected in the alloys,and scanning electron microscopy(SEm) with energy dispersive spectroscopy(EDS) was used to investigate the actual intermetallics that *** influence of these intermetallics on tensile properties was *** results show that lower strength is obtained in the alloy with high Fe,Ni and Cr *** is attributed mainly to the formation of more π-Al8Femg3Si6 phase,which removes strengthening mg atoms from solid ***,the ductility of the high Fe,Ni and Cr levels alloy is decreased significantly due to microcracking of the higher volume fraction π-Al8Femg3Si6 and Al9FeNi *** combination of lower strength and ductility results in a decrease of the quality index of this alloy compared with the alloy with low levels of Fe,Ni and Cr.

关键词： semi-solid metal(SSm) forming alloy F357 heat treatment intermetallics π-Al8Femg3Si6 Al9FeNi β-Al5FeSi

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