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Copper-Induced Changes in the Urea Uptake and Urease Activity in the Cyanobacteria Anabaena doliolum and Anacystis nidulans:Interaction With sulphur Containing Amino Acids

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biomedical and Environmental sciences 1995年第2期8卷 158-163页

作者： s.singh b.b.singh 等 DepartmentofMicrobiology NorthMaharashtraUniversityJalgaon－425001India DepartmentofMicrobiology Nor

Copper-induced changes in the urea uptake and urease activity have been investigated in the cyanobacteria Anabaena doliolum and Anacystis nidulans. Copper, at and above 5 μmol/L concentration, inhibited urea uptake and urease activity systems in both the cyanobacteria in a concentration dependent manner. However, the urea uptake and urease activity systems in A. nidulans appeared slightly more tolerant to copper than that of ***. The inhibitory effect of copper on urea uptake and urease activity was mitigated by sulphur containing amino acids (cystine and cysteine), however, methionine could not do so, indicating the involvement of sulfhydryl (-sH) groups in the assimilation of urea in cyanobacteria

关键词： Activity HEPEs Copper-Induced Changes in the Urea Uptake and Urease Activity in the Cyanobacteria Anabaena doliolum and Anacystis nidulans

Analytical solution of the blast Wave Problem in a Non-Ideal Gas

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Chinese Physics Letters 2011年第11期28卷 152-154页

作者： L.P.singh s.D.Ram D.b.singh Department of Applied Mathematics Institute of TechnologyBanaras Hindu UniversityVaranasi-221005India

An analytical approach is used to construct the exact solution of the blast wave problem with generalized geometries in a non-ideal *** is assumed that the density ahead of the shock front varies according to a power of distance from the source of the blast ***,an analytical expression for the total energy in a non-ideal medium is derived.

关键词： wave analytical assumed

separation of hematite from banded hematite jasper(bHJ) by magnetic coating

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Journal of Central south University 2015年第2期22卷 437-444页

作者： subhashree singh H.sahoo s.s.Rath b.b.Palei b.Das CsIR-Institute of Minerals and Materials Technology

The separation of iron oxide from banded hematite jasper(bHJ) assaying 47.8% Fe, 25.6% si O2 and 2.30%Al2O3 using selective magnetic coating was studied. Characterization studies of the low grade ore indicate that besides hematite and goethite,jasper, a microcrystalline form of quartzite, is the major impurity associated with this ore. beneficiation by conventional magnetic separation technique could yield a magnetic concentrate containing 60.8% Fe with 51% Fe recovery. In order to enhance the recovery of the iron oxide minerals, fine magnetite, colloidal magnetite and oleate colloidal magnetite were used as the coating material. When subjected to magnetic separation, the coated ore produces an iron concentrate containing 60.2% Fe with an enhanced recovery of56%. The AFM studies indicate that the coagulation of hematite particles with the oleate colloidal magnetite facilitates the higher recovery of iron particles from the low grade bHJ iron ore under appropriate conditions.

关键词： banded hematite jasper ore selective coating oleate colloidal magnetite magnetic separation atomic force microscopy

Utilization of alkali-activated copper slag as binder in concrete

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Frontiers of structural and Civil Engineering 2021年第3期15卷 773-780页

作者： Jagmeet singh s P singh Department of Civil Engineering Dr.B R Ambedkar National Institute of TechnologyJalandhar144011India

This study was focused on developing concrete using alkali-activated copper slag(AACs)as a *** properties of alkali-activated copper slag concrete(AACsC)were compared with portland cement concrete(PCC).Different AACsC mixes were prepared with varying Na_(2)O dosage(6%and 8%of the binder by weight)and curing *** products in AACsC were retrieved using Fourier-transform infrared spectroscopy(FTIR)and X-ray powder diffraction(XRD)*** test results indicate that the workability of AACsC was lesser than that of *** AACsC mix with 6%Na_(2)O dosage has exhibited similar mechanical properties as that of *** mechanical properties of AACsC were higher than PCC when 8%of Na_(2)O dosage was *** curing was effective to upgrade the strength properties of AACsC at an early age of curing,but at a later age mechanical properties of ambient cured and heat-cured AACsC were *** hydration products of AACsC were not identified in XRD patterns,whereas,in FTIR spectra of AACsC some alkali-activated reaction products were *** AACsC mixes were found to be more sustainable than *** has been concluded that AACsC can be produced similarly to that of PCC and ambient curing is sufficient.

关键词： binder concrete mechanical properties mineralogy workability

Enhanced cavitation erosion resistance of a friction stir processed high entropy alloy

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International Journal of Minerals,Metallurgy and Materials 2020年第10期27卷 1353-1362页

作者： Rakesh b.Nair H.s.Arora Harpreet singh Grewal surface science and Tribology Lab Department of Mechanical EngineeringShiv Nadar UniversityGautam Buddha NagarUttar Pradesh 203207India

Friction stir processing of an Al0.1CoCrFeNi high entropy alloy(HEA)was performed at controlled cooling conditions(ambient and liquid submerged).Microstructural and mechanical characterization of the processed and as-cast HEAs was evaluated using electron backscatter diffraction,micro-hardness testing and *** under the submerged cooling condition showed elongated grains(10μm)with fine equiaxed grains(2μm)along the boundary compared to the coarser grain(~2 mm)of as-cast *** hardness showed remarkable improvements with four(submerged cooling condition)and three(ambient cooling condition)times that of as-cast HEA(HV^150).The enhanced hardness is attributed to the significant grain refinement in the processed *** erosion behavior was observed for samples using an ultrasonication *** of the HEAs showed better cavitation erosion resistance than the stainless steel *** sample processed under a submerged liquid condition showed approximately 20 and 2 times greater erosion resistance than stainless steel 316L and ascast HEA,*** enhanced erosion resistances of the processed HEAs correlate to their increased hardness,resistance to plasticity,and better yield strength than the as-cast *** surface of the tested samples showed nucleation and pit growth,and plastic deformation of the material followed by fatigue-controlled disintegration as the primary material removal mechanism.

关键词： cavitation erosion microstructure mechanical properties surface engineering

Responses of two cultivars of Trifolium repens L. to ethylene diurea in relation to ambient ozone

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Journal of Environmental sciences 2010年第7期22卷 1096-1103页

作者： shalini singh Dalbir Kaur s.b.Agrawal M.Agrawal Laboratory of Air Pollution and Global Climate Change Department of BotanyBanaras Hindu University

Three ethylene diurea （EDU） concentrations （0, 150 and 300 mg/L） were used to evaluate the negative impact of ozone （O3） on two cultivars of Trifoliurn repens L. cv. Vardan and bundel grown under natural field conditions in a suburban area of Varanasi, India. Mean O3 concentrations varied from 30.3 to 46.6 μg/L during the experimental period. Higher photosynthetic pigments and ascorhic acid concentrations were noticed in both EDU-treated cultivars over non-EDU-treated ones, but a reverse trend was found for lipid peroxidation. Growth parameters and biomass also showed increments under EDU treatment of both cultivars. The ratio of variable fluorescence to maximum fluorescence increased significantly in Vardan but not in bundel upon EDU treatment. Results revealed that EDU concentration of 300 mg/L was more effective to combat the oxidative stress as well as protecting plants from O3 injury symptoms. The test cultivar Vardan is relatively sensitive to O3, thereby can be used as a bioindicator of O3 pollution in areas having higher O3 concentrations. Results also indicated that bundel has more efficient antioxidant defense system than Vardan and hence was more tolerant to O3 stress.

关键词： Trifolium repens ozone oxidative stress ascorbic acid photosynthetic pigments

Influence of magnetic field on wave propagation at liquid-microstretch solid interface

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Applied Mathematics and Mechanics(English Edition) 2011年第5期32卷 595-602页

作者： b.singh Department of Mathematics Post Graduate Government College

The reflection and refraction of a longitudinal wave at an interface between a perfectly conducting nonviscous liquid half-space and a perfectly conducting microstretch elastic solid half-space are studied. The appropriate solutions to the governing equations are obtained in both the half-spaces satisfying the required boundary conditions at the interface to obtain a system of five non-homogeneous equations in the amplitude ratios of various reflected and transmitted waves. The system is solved by a Fortran program of the Gauss elimination method for a particular example of an interface between water and aluminum-epoxy composite. Numerical values of the amplitude ratios are computed for a certain range of the incidence angle both in the presence and absence of an impressed transverse magnetic field. The effects of the presence of the transverse magnetic field on the amplitude ratios of various reflected and transmitted waves are shown graphically.

关键词： microstretch wave propagation reflection and transmission magnetic field

strength and deformation characteristics of steel fibrous concrete beams

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Journal of Zhejiang University-science A(Applied Physics & Engineering) 2007年第2期8卷 257-263页

作者： singh bhupinder singh s.P. KAUsHIK s.K Department of Civil Engineering Indian Institute of Technology Roorkee 247 667 India Department of Civil Engineering National Institute of Technology Jalandhar 144 011 India

The results of an analytical investigation of the flexural behaviour of steel Fibre Reinforced Concrete （sFRC） beams are presented. The complete response of the sFRC beams under displacement controlled static loading was obtained using nonlinear Finite Element （FE） techniques implemented with the help of ATENA 2D soRware. Issues relating to the behaviour of sFRC which have a direct bearing on the FE modelling are discussed with relevance to the software employed for the nonlinear analysis. Constitutive models amenable to numerical analysis for steel fibrous concrete are presented. The structural response throughout the loading regime was captured in terms of the load-deflection behaviour, which in addition to the post-peak response characterized the failure mode of the test beams. The crack patterns at crack initiation and at the end of the tests were also recorded. Experimental results from the specimens of two other investigators were used as control values for this investigation. The response of the specimens of this investigation was evaluated in terms of initial tangent stiffness, peak loads and toughness. Good match was obtained between the results from this investigation and corresponding experimentally obtained values, wherever available. The influence of the fibre content is reflected in the observed trends in peak loads, deflection at peak loads and toughness, which are in broad agreement with known behavioral patterns of sFRC.

关键词： Analysis Deformation strength steel Fibre Reinforced Concrete (sFRC) Toughness

Effect of site amplification on inelastic seismic response

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Earthquake Engineering and Engineering Vibration 2019年第3期18卷 535-554页

作者： Adhikary s singh Y Department of Civil Engineering Visvesvaraya National Institute of Technology Nagpur-440010 Maharashtra India Department of Earthquake Engineering Indian Institute of Technology Roorkee-247667 Uttarakhand India

The available models for eff ective periods of site and structure are reviewed in context of frequency tuning in the inelastic seismic response of soil-structure system. The eff ect of seismic intensity and ductility demand, on the eff ective periods, is investigated, and inelastic site amplifi cation is shown to be strongly correlated to the normalized eff ective period. Two non-dimensional parameters, analogous to the conventional site amplifi cation factors in codes, are defi ned to quantify the inelastic site amplifi cation. It is shown that the inelastic site amplifi cation factor (i.e. ratio of constant ductility spectral ordinates at soil site to those at rock outcrop) is able to represent the site eff ects more clearly, as compared to the inelastic site amplifi cation ratio (i.e. ratio of inelastic spectral ordinates at soil site to the corresponding elastic spectral ordinates at rock outcrop). Further, the peak in the amplifi cation factor corresponding to the eff ective site period diminishes rapidly with increasing ductility demand.

关键词： site amplifi cation normalized response spectra eff ective period inelastic seismic response inelastic site amplifi cation factor