35,235 research outputs found
Nuclear Breathing Mode in the Relativistic Mean Field Theory
The breathing-mode giant monopole resonance is studied within the framework
of the relativistic mean-field (RMF) theory. Using a broad range of parameter
sets, an analysis of constrained incompressibility and excitation energy of
isoscalar monopole states in finite nuclei is performed. It is shown that the
non-linear scalar self-interaction and the resulting surface properties
influence the breathing-mode considerably. It is observed that dynamical
surface properties respond differently in the RMF theory than in the Skyrme
approach. A comparison is made with the incompressibility derived from the
semi-infinite nuclear matter and with constrained nonrelativistic Skyrme
Hartree-Fock calculaions.Comment: Latex (12 pages) and 3 figures (available upon request) J. Phys. G
(in press
A New Parameterization for the Lagrangian Density of Relativistic Mean Field Theory
A new parameterization for an effective non-linear Lagrangian density of
relativistic mean field (RMF) theory is proposed, which is able to provide an
excellent description not only for the properties of stable nuclei but also for
those far from the valley of beta-stability. In addition recently measured
superdeformed mimima in the Hg-region are reproduced with high accuracy.Comment: 8 pages, Latex, 1 ps figur
Birefringence analysis of multilayer leaky cladding optical fibre
We analyse a multilayer leaky cladding (MLC) fibre using the finite element
method and study the effect of the MLC on the bending loss and birefringence of
two types of structures: (i) a circular core large-mode-area structure and (ii)
an elliptical-small-core structure. In a large-mode-area structure, we verify
that the multilayer leaky cladding strongly discriminates against higher order
modes to achieve single-mode operation, the fibre shows negligible
birefringence, and the bending loss of the fibre is low for bending radii
larger than 10 cm. In the elliptical-small-core structure we show that the MLC
reduces the birefringence of the fibre. This prevents the structure from
becoming birefringent in case of any departures from circular geometry. The
study should be useful in the designs of MLC fibres for various applications
including high power amplifiers, gain flattening of fibre amplifiers and
dispersion compensation.Comment: 18 page
Branching ratios of Bc Meson Decaying to Pseudoscalar and Axial-Vector Mesons
We study Cabibbo-Kobayashi-Maskawa (CKM) favored weak decays of Bc mesons in
the Isgur-Scora-Grinstein-Wise (ISGW) quark model. We present a detailed
analysis of the Bc meson decaying to a pseudoscalar meson (P) and an
axial-vector meson (A). We also give the form factors involving transition in
the ISGW II framework and consequently, predict the branching ratios of decays.Comment: 19 pages,7 table
Synthesis of biologically active compounds of agricultural interest
A practical approach for the chiral synthesis of propargyl alcohols and hydroxyvinyl chlorides, making use of base induced elimination of chiral 2,3-epoxy chlorides is described and their utility in the synthesis of octadecenoids, viz., (S)-coriolic acid (I) and (S)-l5,16-didehydrocoriolic acid (V) the self-defensive substances in rice plant against rice blast disease, is discussed
Generalized q-Deformed Symplectic sp(4) Algebra for Multi-shell Applications
A multi-shell generalization of a fermion representation of the q-deformed
compact symplectic sp_q(4) algebra is introduced. An analytic form for the
action of two or more generators of the Sp_q(4) symmetry on the basis states is
determined and the result used to derive formulae for the overlap between
number preserving states as well as for matrix elements of a model Hamiltonian.
A second-order operator in the generators of Sp_q(4) is identified that is
diagonal in the basis set and that reduces to the Casimir invariant of the
sp(4) algebra in the non-deformed limit of the theory. The results can be used
in nuclear structure applications to calculate beta-decay transition
probabilities and to provide for a description of pairing and higher-order
interactions in systems with nucleons occupying more than a single-j orbital.Comment: 10 page
ICRISAT pests monitoring and surveillance at a glance and weather based forewarning models for chickpea and pigeonpea Helicoverpa armigera
The extreme climate events and narrowing crop diversity are encouraging epidemics of agricultural pest and diseases (P&D) incidences and accounts for 40 per cent crop losses globally each year. These changes in the ecosystem promotes the disruption in the geographical synchronization of pests and beneficial insects as well as increases damage potentials of new invasive pests. Therefore, constant surveillance and monitoring of pest distribution are essential to take control measures timely. However, the ICRISAT Farm services (FS) and Integrated Crop Management (ICM) of RP-Asia Program have been monitoring and collecting daily field pest surveillance and trap data of the Patancheru campus from 1980s onward. The trend pest incidence in ICRISAT mandate crops (chickpea, pigeonpea, groundnut, pearl millet and sorghum) was decreasing over the years (1980s to 2018). Among the seasons pest’s severity was severe in Kharif followed by Rabi and summer seasons. We tried to develop the weather based forewarning models for Helicoverpa armigera of chickpea and pigeonpea. The bimodal series of Helicoverpa population distribution were recorded the models were developed for pigeonpea [(Y=-1853.60 - 0.19* Z120 + 38.34 Z11 + 0.55 Z131 + 0.052 Z251) with 0.75 r2 value] and pigeonpea/chickpea [(Y=-978.72 + 0.149 Z130 + 0.63 Z131 + 0.17 Z141+ 2.23 Z251) with 0.69 r2 value] at 25-33 and 45-3 standard meteorological weeks (SMW). The accuracy of Helicoverpa incidence and economic threshold levels (ETLs) were cross examined with dates of pest control measure have been initiated. However, validation of these models under progress in the current cropping season
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