364 research outputs found
Inversion of low-frequency subsurface data in a finite-depth ocean
AbstractLet:[▿2+k2+k2v(x)]u=−δ(x−y) in L=R2 × [0,h],u= 0 at x3 = 0, ux3 = 0 at x3 = h, u(x,y,k) satisfies the limiting absorption principle. Letu(x,y,k) be known for all x,y∈ P ≔ {x:x3 = d}, where 0< d<h is a small fixed number (subsurface data), and allk∈ (0,k0),k0 > 0 is a small number. These data determine v(x) uniquely and an analytical procedure is given for finding v(x) given the above data. It is assumed that v(x), the inhomogeneity in the refraction coefficient (of the ocean of depth h), is an arbitrary compactly supported square integrable function
Using Tau Polarization for Charged Higgs Boson and SUSY Searches at LHC
The polarization can be easily measured at LHC in the 1-prong hadronic
decay channel by measuring what fraction of the -jet momentum is
carried by the charged track. A simple cut requiring this fraction to be >0.8
retains most of the polarization of +1 -jet signal while
suppressing the polarization of -1 -jet background and practically
eliminating the fake background. This can be utilized to extract the
charged Higgs signal. It can be also utilized to extract the SUSY signal in the
stau NLSP region, and in particular the stau co-annihilaton region.Comment: 8 pages, 9 figures; Fig.8 and Fig.9 are replaced, published in
"Physics at the Large Hadron Collider", A Platinum Jubilee Special Issue of
the Indian National Science Academy, Springer (2009) p 20
Rice-fish-vegetable integrated farming: towards a sustainable ecosystem
An outline is given of procedures to take in order to adopt an integrated rice-fish-vegetable farming system in India. Vegetables, which are cultivated in the dikes of the system, may include Luffa acutangula, Vigna unguiculata and Phaseolus vulgaris . When the water depth of the field rises to 30-40 cm, fish fingerlings (Puntius javanicus, Cyprinus carpio and Labeo rohita ) and prawn juveniles (Macrobranchium rosenbergii ) may be stocked. The advantages of such a system are listed and include year round employment opportunities for the farm family and improved farm family income and nutrition
Nuclear Half-Lives for Alpha Radioactivity of Elements with 100 Z 130
Theoretical estimates for the half lives of about 1700 isotopes of heavy
elements with Z from 100 to 130 are tabulated using theoretical Q-values. The
quantum mechanical tunneling probabilities are calculated within a WKB
framework using microscopic nuclear potentials. The microscopic nucleus-nucleus
potentials are obtained by folding the densities of interacting nuclei with a
density dependent M3Y (DDM3Y) effective nucleon-nucleon interaction. The
alpha-decay half lives calculated in this formalism using the experimental
Q-values were found to be in good agreement over a wide range of experimental
data spanning about twenty orders of magnitude. The theoretical Q-values used
for the present calculations are extracted from three different mass estimates
viz. Myers-Swiatecki [MS], Muntian-Hofmann-Patyk-Sobiczewski [M] and
Koura-Tachibana-Uno-Yamada [KUTY].Comment: 57 pages, 2 tables, 1 figur
Cluster radioactivity in very heavy nuclei: a new perspective
Exotic cluster decay of very heavy nuclei is studied using the microscopic
nuclear potentials obtained by folding density dependent M3Y effective
interaction with the densities of the cluster and the daughter nuclei. The
microscopic nuclear potential, Coulomb interaction and the centrifugal barrier
arising out of spin-parity conservation are used to obtain the potential
between the cluster and the daughter nuclei. Half life values are calculated in
the WKB framework and the preformation factors are extracted. The latter values
are seen to have only a very weak dependence on the mass of the emitted
cluster.Comment: 4 pages including 2 table
Greenberger-Horne-Zeilinger nonlocality for continuous variable systems
As a development of our previous work, this paper is concerned with the
Greenberger-Horne-Zeilinger (GHZ) nonlocality for continuous variable cases.
The discussion is based on the introduction of a pseudospin operator, which has
the same algebra as the Pauli operator, for each of the modes of a light
field. Then the Bell-CHSH (Clauser, Horne, Shimony and Holt) inequality is
presented for the modes, each of which has a continuous degree of freedom.
Following Mermin's argument, it is demonstrated that for -mode
parity-entangled GHZ states (in an infinite-dimensional Hilbert space) of the
light field, the contradictions between quantum mechanics and local realism
grow exponentially with , similarly to the usual -spin cases.Comment: RevTEX; comments are welcomed; new version with minor change
Some anisotropic universes in the presence of imperfect fluid coupling with spatial curvature
We consider Bianchi VI spacetime, which also can be reduced to Bianchi types
VI0-V-III-I. We initially consider the most general form of the energy-momentum
tensor which yields anisotropic stress and heat flow. We then derive an
energy-momentum tensor that couples with the spatial curvature in a way so as
to cancel out the terms that arise due to the spatial curvature in the
evolution equations of the Einstein field equations. We obtain exact solutions
for the universes indefinetly expanding with constant mean deceleration
parameter. The solutions are beriefly discussed for each Bianchi type. The
dynamics of the models and fluid are examined briefly, and the models that can
approach to isotropy are determined. We conclude that even if the observed
universe is almost isotropic, this does not necessarily imply the isotropy of
the fluid (e.g., dark energy) affecting the evolution of the universe within
the context of general relativity.Comment: 17 pages, no figures; to appear in International Journal of
Theoretical Physics; in this version (which is more concise) an equation
added, some references updated and adde
Star Models with Dark Energy
We have constructed star models consisting of four parts: (i) a homogeneous
inner core with anisotropic pressure (ii) an infinitesimal thin shell
separating the core and the envelope; (iii) an envelope of inhomogeneous
density and isotropic pressure; (iv) an infinitesimal thin shell matching the
envelope boundary and the exterior Schwarzschild spacetime. We have analyzed
all the energy conditions for the core, envelope and the two thin shells. We
have found that, in order to have static solutions, at least one of the regions
must be constituted by dark energy. The results show that there is no physical
reason to have a superior limit for the mass of these objects but for the ratio
of mass and radius.Comment: 20 pages, 1 figure, references and some comments added, typos
corrected, in press GR
Recent developments in unconventional superconductivity theory
The review of recent developments in the unconventional superconductivity
theory is given. In the fist part I consider the physical origin of the Kerr
rotation polarization of light reflected from the surface of superconducting
. Then the comparison of magneto-optical responses in
superconductors with orbital and spin spontaneous magnetization is presented.
The latter result is applied to the estimation of the magneto-optical
properties of neutral superfluids with spontaneous magnetization. The second
part is devoted to the natural optical activity or gyrotropy properties of
noncentrosymmetric metals in their normal and superconducting states. The
temperature behavior of the gyrotropy coefficient is compared with the
temperature behavior of paramagnetic susceptibility determining the noticeable
increase of the paramagnetic limiting field in noncentrosymmetric
superconductors. In the last chapter I describe the order parameter and the
symmetry of superconducting state in the itinerant ferromagnet with
orthorhombic symmetry. Finally the Josephson coupling between two adjacent
ferromagnet superconducting domains is discussed.Comment: 15 page
Decision-Making Ontology for Information System Engineering
International audienceInformation Systems (IS) engineering (ISE) processes contain steps where decisions must be made. Moreover, the growing role of IS in organizations involves requirements for ISE such as quality, cost and time. Considering these aspects implies that the number of researches dealing with decision-making (DM) in ISE increasingly grows. As DM becomes widespread in the ISE field, it is necessary to build a representation, shared between researchers and practitioners, of DM concepts and their relations with DM problems in ISE. In this paper, we present a DM ontology which aims at formalizing DM knowledge. Its goal is to enhance DM and to support DM activities in ISE. This ontology is illustrated within the requirements engineering field
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