80,944 research outputs found
Recommended from our members
Studies on the toxicity of Vacor (RH-787) on the reproductive biology of Rattus rattus rufescens
Vacor (RH-787), a relatively new rodenticide, was evaluated for the control of Rattus rattus rufescens. The symptoms of paralysis in hind limbs were observed after feeding it to rodents. The susceptibility to this rodenticide in Rattus rattus increased with the increase in its concentration. Experimental observations revealed that RH-787 bait with 0.0125% concentration affects the reproductive biology of the rats. Bait with 0.025% Vacor proved sublethal and within 5 days 70% mortality was observed, while 100% mortality was observed when rats were fed with 0.05% Vaco
Study of non-equilibrium transport phenomena
Nonequilibrium phenomena due to real gas effects are very important features of low density hypersonic flows. The shock shape and emitted nonequilibrium radiation are identified as the bulk flow behavior parameters which are very sensitive to the nonequilibrium phenomena. These parameters can be measured in shock tubes, shock tunnels, and ballistic ranges and used to test the accuracy of computational fluid dynamic (CFD) codes. Since the CDF codes, by necessity, are based on multi-temperature models, it is also desirable to measure various temperatures, most importantly, the vibrational temperature. The CFD codes would require high temperature rate constants, which are not available at present. Experiments conducted at the NASA Electric Arc-driven Shock Tube (EAST) facility reveal that radiation from steel contaminants overwhelm the radiation from the test gas. For the measurement of radiation and the chemical parameters, further investigation and then appropriate modifications of the EAST facility are required
A possible correspondence between Ricci identities and Dirac equations in the Newman-Penrose formalism: towards an understanding of gravity induced collapse of the wave-function?
It is well-known that in the Newman-Penrose formalism the Riemann tensor can
be expressed as a set of eighteen complex first-order equations, in terms of
the twelve spin coefficients, known as Ricci identities. The Ricci tensor
herein is determined via the Einstein equations. It is also known that the
Dirac equation in a curved spacetime can be written in the Newman-Penrose
formalism as a set of four first-order coupled equations for the spinor
components of the wave-function. In the present article we suggest that it
might be possible to think of the Dirac equations in the N-P formalism as a
special case of the Ricci identities, after an appropriate identification of
the four Dirac spinor components with four of the spin coefficients, provided
torsion is included in the connection, and after a suitable generalization of
the energy-momentum tensor. We briefly comment on similarities with the
Einstein-Cartan-Sciama-Kibble theory. The motivation for this study is to take
some very preliminary steps towards developing a rigorous description of the
hypothesis that dynamical collapse of the wave-function during a quantum
measurement is caused by gravity.Comment: v2. 30 pages. Additional discussion in Sections IV and V. References
added. To appear in Gen. Rel. Gra
No Modes left behind: Capturing the data distribution effectively using GANs
Generative adversarial networks (GANs) while being very versatile in
realistic image synthesis, still are sensitive to the input distribution. Given
a set of data that has an imbalance in the distribution, the networks are
susceptible to missing modes and not capturing the data distribution. While
various methods have been tried to improve training of GANs, these have not
addressed the challenges of covering the full data distribution. Specifically,
a generator is not penalized for missing a mode. We show that these are
therefore still susceptible to not capturing the full data distribution.
In this paper, we propose a simple approach that combines an encoder based
objective with novel loss functions for generator and discriminator that
improves the solution in terms of capturing missing modes. We validate that the
proposed method results in substantial improvements through its detailed
analysis on toy and real datasets. The quantitative and qualitative results
demonstrate that the proposed method improves the solution for the problem of
missing modes and improves training of GANs.Comment: accepted to AAAI 2018 conferenc
Finite Blocklength Rates over a Fading Channel with CSIT and CSIR
In this work, we obtain lower and upper bounds on the maximal transmission
rate at a given codeword length , average probability of error
and power constraint , over a finite valued, block fading additive
white Gaussian noise (AWGN) channel with channel state information (CSI) at the
transmitter and the receiver. These bounds characterize deviation of the finite
blocklength coding rates from the channel capacity which is in turn achieved by
the water filling power allocation across time. The bounds obtained also
characterize the rate enhancement possible due to the CSI at the transmitter in
the finite blocklength regime. The results are further elucidated via numerical
examples.Comment: 10 pages, 2 figures, results for finite valued fading states, typos
corrected, proofs elaborated, lower bound under short term power constraint
improve
Radiative neutralino production in low energy supersymmetric Models. II. The case of beam polarization
We study the production of the lightest neutralinos in the radiative process
in low energy supersymmetric
models for the International Linear Collider energies with longitudinally
polarized electron and positron beams. For this purpose we consider the case of
nonminimal supersymmetric standard model as well as the case of minimal
supersymmetric standard model. At the first stage of a linear collider, with
GeV, the radiative production of the lightest neutralinos may
be a viable channel to study supersymmetric partners of the Standard Model
particles, especially if the other supersymmetric particles are too heavy to to
be pair-produced. We consider in detail the effect of beam polarization on the
production cross section. We compare and contrast the dependence of the signal
cross section on the parameters of the neutralino sector of the nonminimal and
minimal supersymmetric standard model when the electron and positron beams are
longitudinally polarized. In order to assess the feasibility of experimentally
observing the radiative neutralino production process, we consider the
background to this process coming from the Standard Model process with longitudinally polarized electron and positron beams.
We also consider the supersymmetric background to the radiative neutralino
production process coming from the radiative production of the scalar partners
of the neutrinos (sneutrinos) ,
with longitudinally polarized beams. This process can be a a background to the
radiative neutralino production when the sneutrinos decay invisibly.Comment: 20 pages, 16 figures, 13 tables; latex problem fixe
- …