2,911 research outputs found
K-Total Product Cordial Labelling of Graphs
In this paper we introduce the k-Total Product cordial labelling of graphs. Also we investigate the 3-Total Product cordial labelling behaviour of some standard graphs
Quantized Orbits and Resonant Transport
A tight binding representation of the kicked Harper model is used to obtain
an integrable semiclassical Hamiltonian consisting of degenerate "quantized"
orbits. New orbits appear when renormalized Harper parameters cross integer
multiples of . Commensurability relations between the orbit frequencies
are shown to correlate with the emergence of accelerator modes in the classical
phase space of the original kicked problem. The signature of this resonant
transport is seen in both classical and quantum behavior. An important feature
of our analysis is the emergence of a natural scaling relating classical and
quantum couplings which is necessary for establishing correspondence.Comment: REVTEX document - 8 pages + 3 postscript figures. Submitted to
Phys.Rev.Let
Chemotaxonomic studies on Tragia involucrata Linn.
In the present work a common plant in and around trichy, botanically equated as Tragia involucrata Linn belonging to the family Euphorbiaceae, has been studied from chemotaxonomic point of view. The study explained the identification and characterization of the compounds isolated from this plant. The chloroform extract of T. involucrata L was subjected to FT-IR and GC-MS to identify the compounds present in it. The compounds identified were Ar- Tumerone; 9, 10 Anthracenedione 1,8-dihydroxy-3-methyl; Friedelane-3-one. The therapeutic potentials of the active principles identified were already assessed. Ar-Tumerone was already reported from Curcuma longa L and the antibacterial and wound healing activity of this compound was well established. Chemistry of T. involucrata L reported in this present work can contribute significantly in providing chemical evidence in support of its inclusion in the family Euphorbiaceae and assigning the position to the genus Tragia.© 2009 International Formulae Group. All rights reserved.Keywords: Tragia involucrata, Chemotaxonomic studies, Ar-Tumerone
Tuberculosis awareness among educated public in two cities in Tamil Nadu
A questionnaire on source of information regarding tuberculosis, signs and symptoms, diagnostic
methods, treatment duration and personal and community hygiene relating to tuberculosis, was
administered to 446 students and employees with an educational status of high school certificate and
above.
The main source of information were books and magazines and 86% were aware that the Tuberculosis
germ was the causative agent. Symptoms of Tuberculosis such as cough (85%) and loss of weight
(74%) were well known. Other symptoms suchchest pain (29%), fever (27%) were less known. Sputum
examination as a diagnostic tool was known to 68% while 80% knew about radiograph being used
to diagnose the disease. Cough as a method of spread was known to 91%. In this questionnaire the
duration of treatment was the least known fact. 28% felt that treatment could be stopped if symptoms
disappeared. 16% were aware that the method of sputum disposal was by incineration. The
implications are discussed
Isolation and characterization of the two subpopulations of cells with different lethalities from zajdela ascitic hepatoma
Two distinct subpopulations of cells, light (L-cells) and heavy (H-cells), have been isolated and characterized from a rat ascitic tumor, the Zajdela ascitic hepatoma. These two populations have been separated by Percoll density gradient centrifugation and studied by flow cytofluorimetry. The two populations, in addition to their difference in buoyant densities, show characteristically different profiles for DNA and RNA contents, nonspecific esterase activity, and surface amino group distribution. The DNA distribution in the two types of cells clearly shows that the H-cells are rapidly proliferating while the L-cells are quiescent. Studies on the two groups of cells after colchicine treatment also confirm this conclusion. The H-cell induced tumors kill the host animals rapidly while the L-cell induced tumors regress in about 3 months. The H- and L-cells from the Zajdela tumor form a convenient experimental system to study the marked difference in the progression of tumors induced by these cells, possible differences in gene expression in regressing and nonregressing tumors and the interactions between the subpopulations with a view to delineate molecular events governing tumor progression and tumor heterogeneity
On the complexity of trial and error for constraint satisfaction problems
In 2013 Bei, Chen and Zhang introduced a trial and error model of computing, and applied to some constraint satisfaction problems. In this model the input is hidden by an oracle which, for a candidate assignment, reveals some information about a violated constraint if the assignment is not satisfying. In this paper we initiate a systematic study of constraint satisfaction problems in the trial and error model, by adopting a formal framework for CSPs, and defining several types of revealing oracles. Our main contribution is to develop a transfer theorem for each type of the revealing oracle. To any hidden CSP with a specific type of revealing Oracle, the transfer theorem associates another CSP in the normal setting, such that their complexities are polynomial-time equivalent. This in principle transfers the study of a large class of hidden CSPs to the study of normal CSPs. We apply the transfer theorems to get polynomial-time algorithms or hardness results for several families of concrete problems. (C) 2017 Elsevier Inc. All rights reserved
Surface effects on nanowire transport: numerical investigation using the Boltzmann equation
A direct numerical solution of the steady-state Boltzmann equation in a
cylindrical geometry is reported. Finite-size effects are investigated in large
semiconducting nanowires using the relaxation-time approximation. A nanowire is
modelled as a combination of an interior with local transport parameters
identical to those in the bulk, and a finite surface region across whose width
the carrier density decays radially to zero. The roughness of the surface is
incorporated by using lower relaxation-times there than in the interior.
An argument supported by our numerical results challenges a commonly used
zero-width parametrization of the surface layer. In the non-degenerate limit,
appropriate for moderately doped semiconductors, a finite surface width model
does produce a positive longitudinal magneto-conductance, in agreement with
existing theory. However, the effect is seen to be quite small (a few per cent)
for realistic values of the wire parameters even at the highest practical
magnetic fields. Physical insights emerging from the results are discussed.Comment: 15 pages, 7 figure
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