103 research outputs found
Marine climate and fisheries scenario of Maharashtra Climcard-4
Marine climate and fisheries scenario of Maharashtra Climcard-
Decay modes of 250No
The Fragment Mass Analyzer at the ATLAS facility has been used to
unambiguously identify the mass number associated with different decay modes of
the nobelium isotopes produced via 204Pb(48Ca,xn)(252-x)No reactions.
Isotopically pure (>99.7%) 204Pb targets were used to reduce background from
more favored reactions on heavier lead isotopes. Two spontaneous fission
half-lives (t_1/2 = 3.7+1.1-0.8 us and 43+22-15 us) were deduced from a total
of 158 fission events. Both decays originate from 250No rather than from
neighboring isotopes as previously suggested. The longer activity most likely
corresponds to a K-isomer in this nucleus. No conclusive evidence for an alpha
branch was observed, resulting in upper limits of 2.1% for the shorter lifetime
and 3.4% for the longer activity.Comment: RevTex4, 10 pages, 5 figures, submitted to PR
Results of rocket measurements of D-region ionization over Thumba in MAP
Under MAP, two rockets were launched from Thumba (8.5 N, 76.8 E) around 1030 hrs Lt with identical payloads on 7 and 10 March 1986 for D region studies. Positive ion densities were measured by spherical probe and Gerdien condenser and electron densities were measured by Langmuir probe and propagation experiments. In both flights a valley in ionization height profile was noticed around 83 km. The density of ionization at this altitude was about 4 x 10(2) cu cm. A detailed positive ion-chemical scheme was used to reproduce the measured ionization height profiles. The density of NO needed to reproduce the valley in ionization at 83 km came around 5 x 10(5) cu cm. A photochemical treatment without diffusion process was found inadequate to explain this value of NO. Calculations showed that the value of vertical eddy diffusion needed to reproduce the value of NO was around 10(6)sq cm/s. Interestingly, the same value of eddy diffusion coefficient was obtained when derived in the manner described by Thrane and his coworkers using only the positive ion current data of spherical probes
Coexisting single-particle excitations and octupole correlations in transitional nucleus
The level structure of the transitional nucleus has been
extended with the addition of around 20 new transitions. The discrepancies
between the placements of several transitions reported in the earlier studies
are resolved. The newly-established negative-parity sequence at low excitation
energies hints at the expected parity-doublet structures in this nucleus. The
properties of the observed simplex bands are compared with that of similar
bands in neighboring nuclei. Since the presence of parity-doublet structures
reflect octupole correlations, theoretical calculations using
reflection-asymmetric triaxial particle rotor model (RAT-PRM) have been
performed. A comparison of the observed features of the simplex bands with the
predictions of the RAT-PRM calculations suggests that
exhibits an intermediate the behavior between the extremes of spherical and
octupole-deformed nuclei. The termination of the simplex bands at intermediate
energies and the structures lying above reflect the dominance of the
single-particle excitations at higher excitation energies.Comment: 15 pages, 16 figure
A review on a deep learning perspective in brain cancer classification
AWorld Health Organization (WHO) Feb 2018 report has recently shown that mortality rate due to brain or central nervous system (CNS) cancer is the highest in the Asian continent. It is of critical importance that cancer be detected earlier so that many of these lives can be saved. Cancer grading is an important aspect for targeted therapy. As cancer diagnosis is highly invasive, time consuming and expensive, there is an immediate requirement to develop a non-invasive, cost-effective and efficient tools for brain cancer characterization and grade estimation. Brain scans using magnetic resonance imaging (MRI), computed tomography (CT), as well as other imaging modalities, are fast and safer methods for tumor detection. In this paper, we tried to summarize the pathophysiology of brain cancer, imaging modalities of brain cancer and automatic computer assisted methods for brain cancer characterization in a machine and deep learning paradigm. Another objective of this paper is to find the current issues in existing engineering methods and also project a future paradigm. Further, we have highlighted the relationship between brain cancer and other brain disorders like stroke, Alzheimer’s, Parkinson’s, andWilson’s disease, leukoriaosis, and other neurological disorders in the context of machine learning and the deep learning paradigm
High-spin spectroscopy in At: Evidence of a 29/2 isomeric state
Yrast and near-yrast states above the known 25/2 isomer in At
are established for the first time. The level scheme is extended up to
47/2 and 6.5 MeV with the addition of about 60 new -ray
transitions. The half-life of the 25/2 isomer is revisited and a value of
= 107.5(9) ns is deduced. Evidence of a hitherto unobserved
29/2 isomer in At is presented. A systematic study of
values for the transitions de-exciting the 29/2 isomer in the neighboring
odd- At isotopes suggests a half-life in the 24 s range for this
state in At. The experimental results are compared with large-scale
shell-model calculations performed using the KHM3Y effective interaction in the
= 50126, = 82184 model space and an overall good agreement is
noted between the theory and the experiment. A qualitative comparison of the
excited states and the isomers with analogous states in neighboring nuclei
provides further insight into the structure of At.Comment: 15 pages, 13 figure
Anomalous isomeric decays in 174Lu as a probe of K-mixing and interactions in deformed nuclei
A Kπ=13+, 280 ns four-quasiparticle isomer in the odd-odd nucleus 174Lu has been identified and characterized. The isomer decays to both Kπ=7+ and Kπ=0+ rotational bands obtained from the parallel and antiparallel coupling of the proton 7/2+[404] and neutron 7/2+[633] orbitals. K mixing caused by particle-rotation coupling explains the anomalously fast transition rates to the 7+ band but those to the 0+ band are caused by a chance degeneracy between the isomer and a collective state, allowing the mixing matrix element for a large K difference to be deduced
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