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Behavior of ring footing resting on reinforced sand subjected to eccentric-inclined loading

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Journal of Rock Mechanics and Geotechnical Engineering 2018年第2期10卷 347-357页

作者： Vaibhav Sharma arvind Kumar Dr.B.R.Ambedkar National Institute of Technology Jalandhar144011India

Ring footings are suitable for the structures like tall transmission towers, chimneys, silos and oil *** types of structures are susceptible to horizontal loads(wind load) in addition to their dead *** the literature, very little or no effort has been made to study the effect of ring footing resting on reinforced sand when subjected to eccentric, inclined and/or eccentric-inclined loadings. This paper aims to study the behavior of ring footing resting on loose sand and/or compacted randomly distributed fiberreinforced sand(RDFS) when subjected to eccentric(0 B, 0.05 B and 0.1 B, where B is the outer diameter of ring footing), inclined(0°,5°,10°, 15°,-5°,-10° and-15°)and eccentric-inclined loadings by using a finite element(FE) software PLAXIS 3 D. The behavior of ring footing is studied by using a dimensionless factor called reduction factor(RF). The numerical model used in the PLAXIS 3 D has been validated by conducting model plate load tests. Moreover, an empirical expression using regression analysis has been presented which will be helpful in plotting a load-settlement curve for the ring footing.

关键词： Soil reinforcement Ring footing Numerical method Randomly distributed fibers Load inclination Load eccentricity Model tests Reduction factor(RF)

Structural,vibrational and magnetic properties of Ti substituted bulk hematite:-Fe_(2-x)Ti_(x)O_(3)

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Journal of Advanced Ceramics 2014年第4期3卷 269-277页

作者： Dinesh VARSHNEY arvind YOGI Materials Science Laboratory School of PhysicsVigyan BhawanDevi Ahilya UniversityKhandwa Road CampusIndore 452001India School of Physics Indian Institute of Science Education and ResearchThiruvananthapuram 695016India

Ti doped hematitea-Fe_(2-x)Ti_(x)O_(3)(x=0.0,0.0206 and 0.0344)samples are synthesized using solid-state ceramic route *** phase and corundum(Al_(2)O_(3))type structure is revealed from the X-ray diffraction(XRD)*** substitution of Ti at Fe site,all Raman active modes are shifted to higher wave *** additional feature of Eu(LO)mode at about 660 cm^(-1)is *** E_(u) mode frequency is decreased and pronounced systematically as a function of Ti doping,and it reaches a value of 658 cm^(-1)for x=*** coercivity Hc(remanence M_(r))for x=0.0,0.0206 and 0.0344 are determined to be 995 Oe(0.44 emu/mg),1404 Oe(0.00019 emu/mg)and 2023 Oe(0.00016 emu/mg),*** larger coercivity for Ti doped samples can be attributed to their enhanced shape and magneto-crystalline *** observed isomer shift(d)from room temperature Mössbauer data clearly shows the presence of ferric(Fe^(3+))and Ti^(4+)ordering ofa-Fe_(2-x)Ti_(x)O_(3)for x=0.0344.

关键词： magnetic materials X-ray diffraction(XRD) Raman spectra Mössbauer spectroscopy

Magnetic and structural properties of pure and Cr-doped haematite:α-Fe_(2-x)Cr_(x)O_(3)(0≤x≤1)

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Journal of Advanced Ceramics 2013年第4期2卷 360-369页

作者： arvind YOGI Dinesh VARSHNEY Materials Science Laboratory School of PhysicsVigyan BhawanDevi Ahilya UniversityKhandwa Road CampusIndore 452001India School of Physics Indian Institute of Science Education and ResearchThiruvananthapuram 695016India

Solid-state ceramic technique route is used for synthesizing Cr-doped haematiteaα-Fe_(2-x)Cr_(x)O_(3)(x=0,0.125,0.50 and 1)*** phase and corundum(Al2O_(3))type structure is revealed from the X-ray diffraction(XRD)*** Raman spectra ofαa-Fe_(2-x)Cr_(x)O_(3)illustrate seven phonon *** substitution of Cr(x=0,0.125,0.50 and 1)at Fe site,all Raman active modes are shifted to higher wave *** coercivity and remanence of Cr-doped haematites increase as x *** increased coercivity and remanence for Cr-doped samples can be attributed to their enhanced shape and magneto-crystalline *** observed isomer shiftδdvalues from room-temperature Mössbauer data clearly show the presence of ferric(Fe^(3+))and Cr^(3+)ions illustrating strong ferromagnetic ordering up to x=0.125 inaα-Fe_(2-x)Cr_(x)O_(3)haematite and weak ferromagnetic ordering foraα-Fe2-xCrxO_(3)(x>0.125)haematites.

关键词： magnetic materials X-ray diffraction(XRD) Raman spectra Mössbauer spectroscopy

Performance evaluation of cement-stabilized pond ash-rice husk ashclay mixture as a highway construction material

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Journal of Rock Mechanics and Geotechnical Engineering 2017年第1期9卷 159-169页

作者： Deepak Gupta arvind Kumar Department of Civil Engineering National Institute of Technology (NIT) Jalandhar India

This paper reports the results of an investigation carried out on clay soil stabilized with pond ash(PA),rice husk ash(RHA) and cement. Modified Proctor compaction tests were performed in order to investigate the compaction behavior of clay, and California bearing ratio(CBR) tests were performed to determine the strength characteristics of clay. For evaluation purpose, the specimens containing different amounts of admixtures were prepared. Clay was replaced with PA and RHA at a dosage of 30%e45% and5%e20%, respectively. The influence of stabilizer types and dosages on mechanical properties of clay was evaluated. In order to study the surface morphology and crystallization characteristics of the soil samples, scanning electron microscopy(SEM) and X-ray diffraction(XRD) analyses were carried out,respectively. The results obtained indicated a decrease in the maximum dry density(MDD) and a simultaneous increase in the optimum moisture content(OMC) with the addition of PA and *** linear regression analysis(MLRA) showed that the predicted values of CBR tests are in good agreement with the experimental values. Developed stabilized soil mixtures showed satisfactory strength and can be used for construction of embankments and stabilization of sub-grade soil. The use of locally available soils, PA, RHA, and cement in the production of stabilized soils for such applications can provide sustainability for the local construction industry.

关键词： California bearing ratio(CBR) Pond ash(PA) Rice husk ash(RHA) Optimum moisture content(OMC) Maximum dry density(MDD)

Charmonia and bottomonia in asymmetric magnetized hot nuclear matter

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Chinese Physics C 2019年第12期43卷 141-158页

作者： Rajesh Kumar arvind Kumar Department of Physics Dr.B R Ambedkar National Institute of Technology Jalandhar

We investigate the mass-shift of P-wave charmonium(χc0,χc1),and S and P-wave bottomonium(ηb,■,χb0,andχb1)states in magnetized hot asymmetric nuclear matter using the unification of QCD sum rules(QCDSR)and the chiral S U(3)*** QCDSR,we use two approaches,i.e.,the moment sum rule and the Borel sum *** magnetic field induced scalar gluon condensateand the twist-2 gluon operatorcalculated in the chiral S U(3)model are utilised in QCD sum rules to calculate the in-medium mass-shift of the above *** attractive mass-shift of these mesons is observed,which is more sensitive to magnetic field in the high density regime for charmonium,however less so for *** results may be helpful to understand the decay of higher quarkonium states to the lower quarkonium states in asymmetric heavy ion collision experiments.

关键词： heavy mesons hot and dense matter finite magnetic field QCD sum rules chiral model

Comparative study of different hydro-dynamic flow in microbial fuel cell stacks

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Chinese Journal of Chemical Engineering 2021年第4期34卷 423-430页

作者： Suransh Jain arvind Kumar Mungray Chemical Engineering Department Sardar Vallabhbhai National Institute of TechnologySurat 395007India

This work has investigated the scaleup potential of microbial fuel cells(MFCs)under stacking *** was done in batch mode and continuous *** feeding mode stacks were operated in electrical series(S)and parallel(P)*** feeding mode stacks were kept in electrically parallel mode with different hydrodynamic *** two continuous stacks were connected hydrodynamically in series(*** Dependent;PD)and parallel(*** Independent;PID)*** performance of the continuous stacks was evaluated on the basis of COD consumption rate,power generation and coulombic *** obtained highest power(0.47 mW)which was approximately 3.6 times that of PD configuration(0.13 mW).The rate of COD consumption was also highest in PID stack(3091.75 mg·L^(-1)·d ^(-1)).Coulombic efficiency of the PID stack was 14.26%which was approximately 292.8%of the PD *** results confirmed that the parallel electrical connection hybridized with the independent hydrodynamic flow gives the best possible results when working with stacking of MFCs.

关键词： Microbial fuel cells Waste water Hydro-dynamically independent COD consumption Fuel cell Bioenergy

Does black hole spin play a key role in the FSRQ/BL Lac dichotomy?

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Research in Astronomy and Astrophysics 2016年第4期16卷 7-14页

作者： Debbijoy Bhattacharya Parameswaran Sreekumar Banibrata Mukhopadhyay Ishan tomar Manipal Centre for Natural Sciences Manipal UniversityManipal 576104India Indian Institute of Astrophysics Bangalore 560034India Astronomy and Astrophysics Programme Department of PhysicsIndian Institute of ScienceBangalore 560012India Space Astronomy Group ISRO Satellite CentreKarthik NagarBangalore 560037India

Blazars are characterized by large intensity and spectral variations across the electromagnetic spectrum It is believed that jets emerging from them are almost aligned with the line-of-sight. The major- ity of identified extragalactic sources in γ-ray catalogs of EGRET and Fermi are blazars. Observationally, blazars can be divided into two classes： fiat spectrum radio quasars （FSRQs） and BL Lacs. BL Lacs usually exhibit lower γ-ray luminosity and harder power law spectra at γ-ray energies than FSRQs. We attempt to explain the high energy properties of FSRQs and BL Lacs from Fermi γ-ray space telescope observations. It was argued previously that the difference in accretion rates is mainly responsible for the large mismatch in observed luminosity in ＂7-ray. However, when intrinsic luminosities are derived by correcting for beaming effects, this difference in 7-ray luminosity between the two classes is significantly reduced. In order to ex- plain this difference in intrinsic luminosities, we propose that spin plays an important role in the luminosity distribution dichotomy of BL Lacs and FSRQs. As the outflow power of a blazar increases with increasing spin of a central black hole, we suggest that the spin plays a crucial role in making BL Lac sources low luminous and slow rotators compared to FSRQ sources.

关键词： BL Lacertae objects: general -- quasars: general -- galaxies: jets -- black hole physics --relativistic processes -- gravitation

Impedance and ferroelectric properties of Sr^(2+) modified PZT-PMN ceramics

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International Journal of Minerals,Metallurgy and Materials 2014年第6期21卷 595-603页

作者： arvind Kumar S.K.Mishra Research and Technology Development Centre Sharda University Dr. Harisingh Gour University

Sr^2＋ modified polycrystalline PZT-PMN ceramics were synthesized by a semi-wet route. Impedance spectroscopy studies indicate the bulk and grain boundary effects of PZT-PMN material along with the negative temperature coefficient of resistance. The bulk conductiv-ity exhibits an Arrhenius-type thermally activated hopping process which is supported by the AC conductivity behavior as a function of fre-quency and temperature. It is observed that the remnant polarization increases with an increase in the Sr2＋content in PZT-PMN.

关键词： piezoelectric ceramics ferroelectric materials ferroelectricity electrochemical properties strontium

Effects of Sr^(2+) substitution on the structural, dielectric, and piezoelectric properties of PZT-PMN ceramics

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International Journal of Minerals,Metallurgy and Materials 2014年第2期21卷 175-180页

作者： arvind Kumar S.K. Mishra Research and Technology Development Centre Sharda University

This study described the structural, dielectric, and piezoelectric behavior of Pb1-xSrx[（Zr0.52Ti0.48）0.95（Mn1/3Nb2/3）0.05]O3 ceramics （PSZT-PMN, x=0, 0.025, 0.050, and 0.075）, prepared by a semi-wet route. X-ray diffraction, dielectric, and piezoelectric investigations were carried out to analyze the crystal structure. The relative dielectric constant and dielectric loss were both calculated as the functions of temperature. The room-temperature dielectric constant reaches a maximum for a Sr2＋-modified PZT-PMN ceramic with an x value of 0.050, which corresponds to the morphotropic phase boundary （MPB）. Raman spectroscopy studies also confirm the existence of this MPB for x=0.050. The piezoelectric strain coefficients （d33） value shows a maximum response for this composition. In addition, the phase transition temperature decreases significantly when the Sr2＋concentration increases in the PZT-PMN ceramics.

关键词： ceramic materials strontium substitution structural properties dielectric properties piezoelectricity