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Effect of Composts,Lime and diammonium Phosphate on the Phytoavailability of Heavy metals in a Copper mine tailing Soil

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Pedosphere 2009年第5期19卷 631-641页

作者： m.j.KHAN d.L.jONES department of Soil and Environmental Sciences NWFP Agricultural UniversityPeshawar(Pakistan) School of Agricultural and Forest Sciences University of WalesBangorGwynedd LL57 2UW(UK)

Soil samples from a historic copper mine tailing site at the Parys mountain,North Wales(UK) were amended with green waste compost(GC),GC+30% sewage sludge(GCS),lime and diammonium phosphate(dAP),to determine the effect of amendments on dtPA-and Ca(NO3)2-extractable metals in the mine tailing and on the phytoavailability of heavy metals by a lettuce(Lactuca sativa L.).Both compost were added at the rate of 10% by weight,lime was added as calcium carbonate equivalent(pH = 7) and dAP at a 2300 mg kg-1 soil *** experiment was arranged in randomised complete design with three replicates in pots under control *** of lime resulted in the largest reduction in metal extractability with dtPA and Ca(NO3)2 and phytoavailability of Cu,Fe and Zn while dAP was effective in lowering Pb extractability and *** exception of Zn,all other metals extracted decreased with time after amendment *** distribution of heavy metals between and within the four procedures of potentially bioavailable sequential extraction(PBASE) varied significantly(P tronger relationships were noted between the metals extracted with PBASE SE1 and Cu,Pb(P d Fe(P the *** results indicate that addition of lime is sufficient to restore the vegetative cover to a high metal mine waste while dAP is good for stabilizing Pb,but its detrimental role on plant growth and the risk associated with presence of N in dAP(through N leaching) may restrict its chances for remediation of contaminated sites.

关键词： lettuce metal uptake potentially bioavailable sequential extraction

Advances in nonequilibrium molecular dynamics simulations of lubricants and additives

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Friction 2018年第4期6卷 349-386页

作者： j.P.EWEN d.m.HEYES d.dINI department of mechanical Engineering Imperial College LondonExhibition RoadSouth Kensington

Nonequilibrium molecular dynamics(NEmd) simulations have provided unique insights into the nanoscale behaviour of lubricants under shear. this review discusses the early history of NEmd and its progression from a tool to corroborate theories of the liquid state, to an instrument that can directly evaluate important fluid properties, towards a potential design tool in tribology. the key methodological advances which have allowed this evolution are also highlighted. this is followed by a summary of bulk and confined NEmd simulations of liquid lubricants and lubricant additives, as they have progressed from simple atomic fluids to ever more complex, realistic molecules. the future outlook of NEmd in tribology, including the inclusion of chemical reactivity for additives, and coupling to continuum methods for large systems, is also briefly discussed.

关键词： molecular dynamics nonequilibrium systems confined fluids boundary lubrication elastohydrodynamic lubrication tribology

StUdIES ON PRImARY CRYStALLIZAtION OF RAPIdLY QUENCHEd Al-Ni-Cu-Nd mEtALLIC GLASS BY USING HIGH RESOLUtION tRASmISSION ELECtRON mICROSCOPY

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Acta metallurgica Sinica(English Letters) 2003年第5期16卷 407-415页

作者： m.t.Clavaguera-mora j.Rodriguez-Viejo Y.d.Xiao W.X.Li d.jacovkis N.Clavaguera GrupdeFisicadematerialsI DepartamentdeFisicaUniversitat-AutonomadeBarcelona08193BellaterraSlaain CollegeofmaterialsScienceandEngineering Central-SouthUniversityChangsha410083China Fisicadel‘EstatSolid FacultatdeFisicaUniversitatdeBarcelonaDiagonal64708028BarcelonaSpain

Rapidly solidified Al87Ni7Cu3Nd3 metallic glasses, prepared by using melt spinning, were treated under both isothermal and non-isothermal regime. the amorphous ribbon and the annealed samples were closely examined by means of differential scanning calorimetric, conventional X-ray diffraction and high resolution transmission electron microscopy with selected-area electron diffraction, with special interest in primary crystallization into α-Al nanocrystalline particles, in order to understand structural characteristics of Al-based amorphous/nanocrystalline alloys, and nucleation and grain growth mechanism on the nanometer scale during primary crystallization. the results show that, the as-prepared ribbons are fully amorphous and homogeneous in the micron scale, but contain high density of quenched-in clusters or crystallite embryos. Primary crystallization mainly leads to formation of two-phase mixture of a-Al crystal and residual amorphous phase. the annealed ribbons exposed isother-mally at HOP C for 5, 130 minutes and heated continuously up to less than 310℃ at 40℃ C/min consist of large amount of α-Al fcc crystal nanoparticles dispersed uniformly in an amorphous matrix. However, a very little amount of finer orthorhombic Al3Ni intermetalics particles exist in the annealed ribbons heated up to 310℃. during primary crystallization, the leading kinetic mechanics to impede growth of the α-Al crystal is soft impingement, instead of geometric impingement.

关键词： rapid solidification Al-rich amorphous alloy crystallization nu- cleation and growth mechanism

3d Flow Past transonic turbine Cascade SE 1050-Experiment and Numerical Simulations

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journal of thermal Science 2013年第4期22卷 311-319页

作者： d.imurda j.Fürst m.Luxa Institute of thermomechanics AS CR v.v.i.Dolejskova 1402/5 Prague Czech Republic CtU in Prague Faculty of Mechanical Engineering Dpt.of Technical MathematicsKarlovo Náměstí 13 Prague Czech Republic

this paper is concerned with experimental and numerical research on 3d flow past prismatic turbine cascade SE1050 （known in QNEt network as open test case SE1050）. the primary goal was to assess the influence of the inlet velocity profile on the flow structures in the interblade channel and on the flow field parameters at the cascade exit and to compare these findings to results of numerical simulations. Investigations of 3d flow past the cascade with non-uniform inlet velocity profile were carried out both experimentally and numerically at subsonic （m2 = 0.8） and at transonic （m2 = 1.2） regime at design angle of incidence. Experimental data was obtained using a traversing device with a five-hole conical probe. Numerically, the 3d flow was simulated by open source code OpenFOAm and in-house code. Analyses of experimental data and CFd simulations have revealed the development of distinctive vortex structures resulting from non-uniform inlet velocity profile. Origin of these structures results in increased loss of kinetic energy and spanwise shift of kinetic energy loss coefficient distribution. differences found between the subsonic and the transonic case confirm earlier findings available in the literature. Results of CFd and experiments agree reasonably well.

关键词： blade cascade vortex structures transonic flow CFd

On a Shallow Water model for the Simulation of turbidity Currents

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Communications in Computational Physics 2009年第9期6卷 848-882页

作者： t.morales de Luna m.j.Castro dıaz C.Pares madronal E.d.Fernandez Nieto Analisis matematico Facultad de Ciencias–Univ.MalagaCampus de Teatinoss/n29071-MalagaSpain dpto.matematica Aplicada I ETS Arquitectura–Univ.SevillaAvda.Reina Mercedes N.241012-SevillaSpain

We present a model for hyperpycnal plumes or turbidity currents that takes into account the interaction between the turbidity current and the bottom,considering deposition and erosion effects as well as solid transport of particles at the bed load due to the *** entrainment from the ambient water in which the turbidity current plunges is also *** of ambient water is neglected and the rigid lid assumption is *** model is obtained as a depth-average system of equations under the shallow water hypothesis describing the balance of fluid mass,sediment mass and mean *** character of the system is analyzed and numerical simulations are carried out using finite volume schemes and path-conservative Roe schemes.

关键词： turbidity currents hyperbolic systems finite volume methods path-conservative schemes numerical modeling

A novel ZnO/reduced graphene oxide and Prussian blue modified carbon paste electrode for the sensitive determination of Rutin

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Science China Chemistry 2019年第2期62卷 262-270页

作者： Ozma j d'Souza Ronald j mascarenhas Ashis K Satpati Basavanakote m Basavaraja Research and development Centre Bharathiar University Electrochemistry Research Group Department of Chemistry St.Joseph's College Analytical Chemistry division Bhabha Atomic Research Centre Anushakthi Nagar Trombay department of Chemistry PES University

A carbon paste modified sensor based on a novel composite of zinc oxide nanoparticles deposited on reduced graphene oxide(ZnO-rGrO) and Prussian blue(PB) was drop-cast(ZnO-rGrO-PB/mCPE) for the sensitive estimation of Rutin(Rtn) at pH *** high surface area of ZnO-rGrO and electrocatalytic property of PB promotes the oxidation of Rtn. Field emission scanning electron microscope(FE-SEm) and energy-dispersive X-ray spectroscopy(EdX) techniques were employed to confirm the deposition of ZnO-rGrO and PB on carbon paste electrode(CPE). the ability of ZnO-rGrO-PB/mCPE in charge transfer at the interface was investigated using electrochemical impedance spectroscopy(EIS). the heterogeneous rate constant(ks) and the charge transfer coefficient(α) have been calculated as 6.08 s^(-1) and 0.74 respectively. this sensor showed a wide linear response for Rtn from 7.0×10^(-8)to 7.0×10^(-6) m and 7.0×10^(-6) to 1.0×10^(-4) m with a limit of detection(2.05±0.04)×10^(-8) m(S/N=3). the application of ZnO-rGrO-PB/mCPE was found in the analysis of Rtn in fruit juice samples using standard addition method. this sensor showed good reproducibility, stability, selectivity and sensitivity.

关键词： Rutin zinc oxide nanoparticles reduced graphene oxide Prussian blue modified carbon paste electrode ascorbic acid

determination of the physical and interaction properties of sorghum grains:Application to computational fluid dynamics-discrete element method simulations of the fluid dynamics of a conical spouted bed

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Particuology 2021年第1期19卷 91-101页

作者： j.N.m.Batista d.A.Santos R.Bettega Federal University of São Carlos Department of Chemical EngineeringSPBrazil Institute of Chemistry Federal University of GoiásGOBrazil

Computational simulation is an important tool for design and improvement of industrial *** fluid dynamics(CFd)coupled with the discrete element method(dEm)has been applied to simulate drying equipment that usually involves gas-solid *** reliable results of CFd-dEm simulations,the properties related to the interactions of the material within the industrial equipment,such as the restitution or friction coefficients,must be *** this study,CFd-dEm was applied to simulate the fluid dynamics inside a conical spouted bed operating with sorghum *** physical properties of the particulate phase and the particle-particle and particle-wall interaction parameters were determined by the direct measurement approach and applied to *** interaction parameters were experimentally determined,including the particle-particle interaction parameters ofη=0.46,μ^(S)=0.79,andμ_(R)=0.70,and the particle-wall interaction parameters ofη=0.56,μ_(S)=0.75,andμ_(R)=*** simulated minimum spouting velocity and characteristic curves were compared with the experimental *** was good agreement between the simulated and experimental results.

关键词： Restitution coefficient Static friction coefficient Rolling friction coefficient CFd dEm

the relation between ductility at high temperature and solid solution in mg alloys

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journal of magnesium and Alloys 2022年第1期10卷 241-256页

作者： d.F.Shi C.m.Cepeda-jiménez m.t.Pérez-Prado Im dEA materials Institute C/Eric Ka ridel228906 GetafeMadridSpain department of materials Science Polytechnic University of Madrid/Universidad Politecnica de MadridE.T.S.de Ingenieros de Caminos28040MadridSpain department of Physical metallurgy CENIMCSICAv.Gregorio del Amo 828040 MadridSpain

this work investigates the effect of solid solution on ductility and on the activation of individual deformation mechanisms at moderate temperatures and at quasi-static strain rates in mg-Zn and mg-Al alloys. With that aim, four solid solution mg-Zn and mg-Al binary alloy ingots containing 1 and 2 wt.% solute atoms were subjected to hot rolling and subsequent annealing to generate polycrystals with similar average grain size and basal-type texture for each composition. the activity of the different slip systems after tensile testing at 150°C and at 250°C was evaluated in pure mg and in the alloys by EBSd-assisted slip trace analysis. In addition, segregation of Zn and Al atoms at grain boundaries during the thermo-mechanical processing was characterized by HAAdF-StEm and EdX. It was found that while the addition of Al and Zn atoms to pure mg does not lead to major changes in the mechanical strength at the investigated temperatures, it does enhance ductility significantly, especially at 250℃. Our results show that this increase in ductility cannot be attributed to a higher activation of non-basal systems in the alloys, as reported earlier, as the incidence of non-basal systems is indeed considerably higher in pure mg. this work suggests, on the contrary, that the ductility increase may be attributed to the presence of a more homogenous basal activity in the alloys due to a lower degree of orientation clustering, to grain boundary solute segregation, and to a higher slip diffusivity at grain interiors.

关键词： magnesium Solute segregation Slip trace analysis ductility deformation mechanisms

the CCd instrument background of the SmILE SXI

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Earth and Planetary Physics 2024年第1期8卷 15-24页

作者： m.W.j.Hubbard O.Hetherington d.j.Hall t.W.Buggey S.Parsons t.Arnold A.Holland C.Pagani S.Sembay Centre for Electronic Imaging The Open UniversityMilton KeynesMK76AAUK X-ray and Observational Astronomy Group Department of Physics&AstronomyUniversity of LeicesterLE17RHUK

the ESA and CAS SmILE mission orbit is highly elliptical and will pass through multiple radiation *** Soft X-ray Imager(SXI)instrument aboard has a radiation shutter door designed to close when the surrounding radiation flux is *** shutter door will close when passing below an altitude threshold to protect against trapped particles in the Earth’s Van Allen ***,two radiation environments can be approximated based on the shutter door position:open and *** instrument background for the CCds(Charge-Coupled devices)that form the focal plane array of the SXI were evaluated for the two *** to the correlation of the space environment with the solar cycle,the solar minima and maxima,the background was also evaluated at these two *** results demonstrated that the highest instrument background will occur during solar minima due to the main contributing source being Galactic Cosmic Rays(GCRs).It was also found that the open background was highest for solar minima and that the closed background was highest during solar *** is due to the radiation shutter door acting as a scattering centre and the changes in the energy flux distribution of the GCRs between the two solar extremes.

关键词： instrument background X-ray astronomy space radiation