Search Results - (Author, Cooperation:S. Ojha)
-
1Latest Papers from Table of Contents or Articles in PressJ. S. Kargel ; G. J. Leonard ; D. H. Shugar ; U. K. Haritashya ; A. Bevington ; E. J. Fielding ; K. Fujita ; M. Geertsema ; E. S. Miles ; J. Steiner ; E. Anderson ; S. Bajracharya ; G. W. Bawden ; D. F. Breashears ; A. Byers ; B. Collins ; M. R. Dhital ; A. Donnellan ; T. L. Evans ; M. L. Geai ; M. T. Glasscoe ; D. Green ; D. R. Gurung ; R. Heijenk ; A. Hilborn ; K. Hudnut ; C. Huyck ; W. W. Immerzeel ; J. Liming ; R. Jibson ; A. Kaab ; N. R. Khanal ; D. Kirschbaum ; P. D. Kraaijenbrink ; D. Lamsal ; L. Shiyin ; L. Mingyang ; D. McKinney ; N. K. Nahirnick ; N. Zhuotong ; S. Ojha ; J. Olsenholler ; T. H. Painter ; M. Pleasants ; K. C. Pratima ; Q. I. Yuan ; B. H. Raup ; D. Regmi ; D. R. Rounce ; A. Sakai ; S. Donghui ; J. M. Shea ; A. B. Shrestha ; A. Shukla ; D. Stumm ; M. van der Kooij ; K. Voss ; W. Xin ; B. Weihs ; D. Wolfe ; W. Lizong ; Y. Xiaojun ; M. R. Yoder ; N. Young
American Association for the Advancement of Science (AAAS)
Published 2015Staff ViewPublication Date: 2015-12-18Publisher: American Association for the Advancement of Science (AAAS)Print ISSN: 0036-8075Electronic ISSN: 1095-9203Topics: BiologyChemistry and PharmacologyComputer ScienceMedicineNatural Sciences in GeneralPhysicsKeywords: Disasters/*prevention & control ; Earthquakes/*mortality ; Environmental Monitoring/*methods ; Floods ; Humans ; Lakes ; Landslides/*mortality ; Nepal ; Safety Management/*methods ; Satellite ImageryPublished by: -
2Articles: DFG German National LicensesChoudhury, P. K. ; Khastgir, P. ; Ojha, S. P. ; Singh, L. K.
[S.l.] : American Institute of Physics (AIP)
Published 1992Staff ViewISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: An analytical study of a waveguide with two parabolic cylindrical surfaces separating the guiding region of refractive index n1 from two cladding regions of common refractive index n2 with n1(approximately-greater-than)n2 is presented. The cutoff conditions for modes are derived as equations containing trigonometric functions. The modes show a bunching tendency instead of well-defined discreteness, and several mode bunches occur because the distance of separation between the two interfaces does not remain constant but continues to increase as one moves away from the region near the vertices of the parabolas. Unlike the planar waveguide, a nonzero cutoff is deduced which may be attributed to the curvature of the boundaries, and the flare.Type of Medium: Electronic ResourceURL: -
3Articles: DFG German National LicensesStaff View
ISSN: 0042-207XSource: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision MechanicsPhysicsType of Medium: Electronic ResourceURL: -
4Articles: DFG German National LicensesStaff View
ISSN: 0042-207XSource: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision MechanicsPhysicsType of Medium: Electronic ResourceURL: -
5Articles: DFG German National LicensesStaff View
ISSN: 1572-946XSource: Springer Online Journal Archives 1860-2000Topics: PhysicsNotes: Abstract The self-similar model of a shock wave, produced on account of an instantaneous release of energy in an inhomogeneous self-gravitating gaseous mass, has been discussed with the help of equations of motion and equilibrium conditions. The disturbances are headed by a shock of variable strength. The variation of velocity density, pressure, and mass have been discussed for the different values of strength of the shock.Type of Medium: Electronic ResourceURL: -
6Articles: DFG German National LicensesStaff View
ISSN: 1572-946XSource: Springer Online Journal Archives 1860-2000Topics: PhysicsNotes: Abstract Similarity solutions for one-dimensional unsteady isothermal flow of a perfect gas behind a magnetogasdynamic shock wave including the effects of thermal radiation has been investigated in a uniform thin atmosphere. The flow is caused by an expanding piston and the total energy of the flow is assumed to be constant. Radiation pressure and energy have been neglected in comparison to radiation heat flux and the gas is assumed to be grey and opaque.Type of Medium: Electronic ResourceURL: -
7Articles: DFG German National LicensesStaff View
ISSN: 1432-0681Keywords: Key words weak discontinuity ; wave evolution ; chemically reacting atmosphere ; focusing ; shockSource: Springer Online Journal Archives 1860-2000Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision MechanicsNotes: Summary The growth and decay of a weak discontinuity headed by a singular surface of arbitrary shape in three dimensions is investigated in a chemically reacting atmosphere, in the absence of dissipative mechanisms such as viscosity, diffusion and heat conduction. The combined effects of the disequilibrium due to the chemical reaction and a wave front curvature on the propagation of discontinuities have been examined and discussed. It has been observed that the chemical disequilibrium, with its Arrhenius rate dependence, causes the compression wave to steepen more swiftly that it does in an inert atmosphere. The critical values of the initial discontinuity, and time for shock formation, in cases of diverging and converging waves, have been determined.Type of Medium: Electronic ResourceURL: -
8Articles: DFG German National LicensesStaff View
ISSN: 1432-0681Keywords: weak discontinuity ; wave evolution ; chemically reacting atmosphere ; focusing ; shockSource: Springer Online Journal Archives 1860-2000Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision MechanicsNotes: Summary The growth and decay of a weak discontinuity headed by a singular surface of arbitrary shape in three dimensions is investigated in a chemically reacting atmosphere, in the absence of dissipative mechanisms such as viscosity, diffusion and heat conduction. The combined effects of the disequilibrium due to the chemical reaction and a wave front curvature on the propagation of discontinuities have been examined and discussed. It has been observed that the chemical disequilibrium, with its Arrhenius rate dependence, causes the compression wave to steepen more swiftly that it does in an inert atmosphere. The critical values of the initial discontinuity, and time for shock formation, in cases of diverging and converging waves, have been determined.Type of Medium: Electronic ResourceURL: -
9Articles: DFG German National LicensesStaff View
ISSN: 1420-9136Source: Springer Online Journal Archives 1860-2000Topics: GeosciencesPhysicsNotes: Summary By taking radiative parameters independent of magnetic field, the aim of this paper is to investigate the propagation of spherical shock in self-gravitating conducting gas spheres, such as stars, caused by an instantaneous central explosion of finite amount of energy. Ionisation, dissociation have not been taken into account and the medium is assumed to be a fully perfect gas.Type of Medium: Electronic ResourceURL: -
10Articles: DFG German National LicensesStaff View
ISSN: 1420-9136Source: Springer Online Journal Archives 1860-2000Topics: GeosciencesPhysicsNotes: Summary The growth equation for the pressure shocks as conceived by Thomas and Edstrom (1961), in a thermally and electrically conducting viscous gas has been derived. Ionisation and dissociation have not been taken into account, while the effects of radiation have been considered under the assumption that the radiative parameters are independent of magnetic field. During the course of derivation certain boundary conditions and the well known compatibility conditions established by Thomas (1957) have been used.Type of Medium: Electronic ResourceURL: -
11Articles: DFG German National LicensesStaff View
ISSN: 1572-946XSource: Springer Online Journal Archives 1860-2000Topics: PhysicsNotes: Abstract Similarity solutions describing the flow of a perfect gas behind a strong plane shock wave propagating in an exponentially decreasing atmosphere with radiation heat flux are investigated. The Planck's diffusion approximation has been taken into account to observe the effects of radiation heat flux.Type of Medium: Electronic ResourceURL: -
12Articles: DFG German National LicensesStaff View
ISSN: 1572-946XSource: Springer Online Journal Archives 1860-2000Topics: PhysicsNotes: Abstract A theoretical model of shock-wave propagation has been studied in a heat-conducting and a self-gravitating medium. The effects of magnetic field has been taken into consideration. The shock is strong enough to neglect the ambient gas pressure. The variation of flow variables behind the shock have been investigated numerically.Type of Medium: Electronic ResourceURL: -
13Articles: DFG German National LicensesStaff View
ISSN: 1572-946XSource: Springer Online Journal Archives 1860-2000Topics: PhysicsNotes: Abstract A study has been made of self-similar magnetohydrodynamic spherical shock waves for a rotating atmosphere taking into account the effect of self-gravitation. The energy is assumed to vary with some power of time. A study has been made to investigate the effects of magnetic field in the presence and absence of gravitation. The variation of flow variables is shown in tables for several different cases of physical interest.Type of Medium: Electronic ResourceURL: -
14Articles: DFG German National LicensesStaff View
ISSN: 1572-946XSource: Springer Online Journal Archives 1860-2000Topics: PhysicsNotes: Abstract The magnetohydrodynamic model of shock waves has been discussed in an atmosphere with gravitation and radiation. The disturbance is headed by a strong shock of increasing density. The medium ahead of the shock is assumed to be inhomogeneous and at rest. Variation of magnetic field radiation flux, and other flow variables are given in tabular form.Type of Medium: Electronic ResourceURL: -
15Articles: DFG German National LicensesStaff View
ISSN: 1572-946XSource: Springer Online Journal Archives 1860-2000Topics: PhysicsNotes: Abstract A model of similarity solution for the propagation of shock waves produced on account of an instantaneous release of energy in an inhomogeneous medium with the effect of radiation has been discussed. The disturbances of the medium are headed by a shock of variable strength. The variations of flow variables have been discussed for the different values of strength of the shock.Type of Medium: Electronic ResourceURL: -
16Articles: DFG German National LicensesStaff View
ISSN: 1572-946XSource: Springer Online Journal Archives 1860-2000Topics: PhysicsNotes: Abstract A theoretical model of shock wave propagation in a self-gravitating radiative magneto-hydrodynamic medium has been studied. The effects of the magnetic field, radiation, and gravitation have been discussed separately. The results discussed depend upon the numerical variations of flow variables behind the shock.Type of Medium: Electronic ResourceURL: -
17Articles: DFG German National LicensesStaff View
ISSN: 1572-946XSource: Springer Online Journal Archives 1860-2000Topics: PhysicsNotes: Abstract Similarity solutions have been obtained for a cylindrical piston advancing with constant speed into a uniform plasma of infinite electrical conductivity and uniform axial magnetic field with heat radiation. The total energy of the expanding wave has been supposed to remain constant. The plasma is assumed to be a perfect grey gas in local thermodynamic equilibrium. To make the discussions less complicated the simplifying assumptions include transparent shock, cool piston neither an emitter nor a reflector and negligible radiation pressure and energy.Type of Medium: Electronic ResourceURL: -
18Articles: DFG German National LicensesStaff View
ISSN: 1572-946XSource: Springer Online Journal Archives 1860-2000Topics: PhysicsNotes: Abstract Similarity solutions for line explosion in a non-uniform self-gravitating medium including the effects of magnetic field radiation flux and neglecting the radiation pressure and energy are investigated. Gas is assumed to be grey and opaque and the shock to be transparent and isothermal.Type of Medium: Electronic ResourceURL: -
19Articles: DFG German National LicensesStaff View
ISSN: 1572-946XSource: Springer Online Journal Archives 1860-2000Topics: PhysicsNotes: Abstract The propagation of weak discontinuities headed by a wavefront and their formation into shock waves are investigated in a thermally-radiative ideal plasma. It is found that all compressive waves grow without bound only if the magnitude of initial discontinuity associated with the wave exceeds a critical value. In particular, the grow and decay of weak discontinuities in plane, cylindrical, and spherical geometries have been discussed and the shock formation distance and time in all these cases have been derived in presence of magnetic field and radiation, separately.Type of Medium: Electronic ResourceURL: -
20Articles: DFG German National LicensesStaff View
ISSN: 1573-4803Source: Springer Online Journal Archives 1860-2000Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision MechanicsNotes: Abstract Hot rolled strips of an HSLA steel containing niobium and vanadium were cold rolled in the range 15 to 80% and annealed for 1 h at various temperatures from 400 to 700 ° C. The response to the amount of deformation and annealing temperature were studied in terms of changes in its hardness, tensile strength and ductility. Hardness and strength were observed to increase while ductility decreased with the amount of deformation. Although annealing of the steel up to 500 ° C did not show significant changes in its mechanical properties, a sharp decrease in hardness and strength and improvement in ductility were observed on annealing the steel at temperatures greater than or equal to 600 ° C. Microstructural studies showed complete recrystallization in the samples subjected to 60% deformation followed by annealing at 600 ° C.Type of Medium: Electronic ResourceURL: