5,670 research outputs found
Evolution of electromagnetic and Dirac perturbations around a black hole in Horava gravity
The evolution of electromagnetic and Dirac perturbations in the spacetime
geometry of Kehagias-Sfetsos(KS) black hole in the deformed Horava-Lifshitz(HL)
gravity is investigated and the associated quasinormal modes are evaluated
using time domain integration and WKB methods. We find a considerable deviation
in the nature of field evolution in HL theory from that in the Schwarzschild
spacetime and QNMs region extends over a longer time in HL theory before the
power-law tail decay begins. The dependence of the field evolution on the HL
parameter are studied. In the time domain picture we find that the
length of QNM region increases with . But the late time decay of field
follows the same power-law tail behavior as in the case of Schwarzschild black
hole.Comment: The article was fully rewritten, references added, to appear in MPL
The Theology of Self-Surrender in the Writings of E. Stanley Jones
This thesis seeks to grapple with one of the most crucial issues confronting Christian theology today, namely, what to make of the insights and discoveries of the newer disciplines of psychology, psychoanalysis, psychiatry, psychotherapy, etc. For a while psychology proceeded as though theology did not exist or as though it were a remnant of the superstitions of a previous age. However, in recent years psychological practitioners outside the church have shown somewhat greater interest in the religious life of their patients and in the role of religious life of their patients and in the role of religious life and practice in mental health and illness.
Both Christianity and psychology describe in considerable detail the distortions of human existence under the pressures of anxiety and estrangement. Both seek the transformation of the personality rather than the mere suppression of symptoms. These two disciplines, therefore, cannot remain aloof from each other. While retaining their respective and distinctive roles, they must become allies.
The basic purpose of this investigation has been to make a critical appraisal of E. Stanley Jones\u27 concept of conversion from a theological and psychological frame of reference. Both the field of psychology and theology are extremely sensitive. Yet, in the popular writings of one of the most outstanding writers of our generation, that of E. Stanley Jones\u27, these two disciplines converge
Anomalous Defects and Their Quantized Transverse Conductivities
Using a description of defects in solids in terms of three-dimensional
gravity, we study the propagation of electrons in the background of
disclinations and screw dislocations. We study the situations where there are
bound states that are effectively localized on the defect and hence can be
described in terms of an effective 1+1 dimensional field theory for the low
energy excitations. In the case of screw dislocations, we find that these
excitations are chiral and can be described by an effective field theory of
chiral fermions. Fermions of both chirality occur even for a given direction of
the magnetic field. The ``net'' chirality of the system however is not always
the same for a given direction of the magnetic field, but changes from one sign
of the chirality through zero to the other sign as the Fermi momentum or the
magnitude of the magnetic flux is varied. On coupling to an external
electromagnetic field, the latter becomes anomalous, and predicts novel
conduction properties for these materials.Comment: New material added. ReVTeX , 31 pgs., 4 figs.(uses epsf
Formal geometric quantisation for proper actions
Published online: 23 April 2015We define formal geometric quantisation for proper Hamiltonian actions by possibly noncompact groups on possibly noncompact, prequantised symplectic manifolds, generalising work of Weitsman and Paradan. We study the functorial properties of this version of formal geometric quantisation, and relate it to a recent result by the authors via a version of the shifting trick. For (pre)symplectic manifolds of a certain form, quantisation commutes with reduction, in the sense that formal quantisation equals a more direct version of quantisation.Peter Hochs, Varghese Matha
Far Field Deposition Of Scoured Regolith Resulting From Lunar Landings
As a lunar lander approaches a dusty surface, the plume from the descent engine impinges on the ground, entraining loose regolith into a high velocity dust spray. Without the inhibition of a background atmosphere, the entrained regolith can travel many kilometers from the landing site. In this work, we simulate the flow field from the throat of the descent engine nozzle to where the dust grains impact the surface many kilometers away. The near field is either continuum or marginally rarefied and is simulated via a loosely coupled hybrid DSMC - Navier Stokes (DPLR) solver. Regions of two-phase and polydisperse granular flows are solved via DSMC. The far field deposition is obtained by using a staged calculation, where the first stages are in the near field where the flow is quasi-steady and the outer stages are unsteady. A realistic landing trajectory is approximated by a set of discrete hovering altitudes which range from 20m to 3m. The dust and gas motions are fully coupled using an interaction model that conserves mass, momentum, and energy statistically and inelastic collisions between dust particles are also accounted for. Simulations of a 4 engine configuration are also examined, and the erosion rates as well as near field particle fluxes are discussed.Astronom
Transition to the ultimate regime in two-dimensional Rayleigh-B\'enard convection
The possible transition to the so-called ultimate regime, wherein both the
bulk and the boundary layers are turbulent, has been an outstanding issue in
thermal convection, since the seminal work by Kraichnan [Phys. Fluids 5, 1374
(1962)]. Yet, when this transition takes place and how the local flow induces
it is not fully understood. Here, by performing two-dimensional simulations of
Rayleigh-B\'enard turbulence covering six decades in Rayleigh number Ra up to
for Prandtl number Pr , for the first time in numerical
simulations we find the transition to the ultimate regime, namely at
. We reveal how the emission of thermal plumes enhances
the global heat transport, leading to a steeper increase of the Nusselt number
than the classical Malkus scaling [Proc.
R. Soc. London A 225, 196 (1954)]. Beyond the transition, the mean velocity
profiles are logarithmic throughout, indicating turbulent boundary layers. In
contrast, the temperature profiles are only locally logarithmic, namely within
the regions where plumes are emitted, and where the local Nusselt number has an
effective scaling , corresponding to the
effective scaling in the ultimate regime.Comment: 6 pages, 4figure
Efficient Fair Queueing using Deficit Round Robin
Fair queuing is a technique that allows each flow passing through a network device to have fair share of network resources. previous schemes for fair queuing that achieved nearly perfect fairness were expensive to implement: specifically, the work required to process a packet in these schemes was O(log(n)), where n is the number of active flows. This is expensive at high speeds. On the other hand, cheaper approximations of fair queuing that have been reported in the literature exhibit unfair behavior. In this paper, we describe a new approximation of fair queuing, that we call Deficit Round Robin. Our scheme achieves nearly perfect fairness in terms of throughput, requires only O(1) work to process a packet, and is simple enough to implement in hardware. Deficit Round Robin is also applicable to other scheduling problems where servicing cannot be broken up into smaller units
Identification of Escherichia coli from potable water sources of Durg-Bhilai, Chhattisgarh (India), using 16S rRNA gene sequence Analysis
Potable water sources mainly municipal water and ground water (from tube wells) were studied for the presence of multidrug resistant pathogenic Escherichia coli. A total of 11 isolates were obtained, eight from municipal water and three from tube well water. Antibiotic resistance analysis (ARA) showed that only two strains named EcPH2 and EcPul2 isolated from municipal tap waters were multidrug resistant (MDR). The strains were characterized using 16S ribosomal RNA gene sequencing. Phylogenetic analysis and similarity search showed isolate EcPH2 had 98% similarity and EcPul2 had 94% similarity to E. coli. The 16S rRNA sequences were submitted to Genbank with accession no. KC254645, KC254646 for isolate EcPH2 and isolate EcPul2 respectively
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