1,826 research outputs found
Colored Pseudo-Goldstone Bosons and Gauge Boson Pairs
If the electroweak symmetry breaking sector contains colored particles
weighing a few hundred GeV, then they will be copiously produced at a hadron
supercollider. Colored technipions can rescatter into pairs of gauge bosons. As
proposed by Bagger, Dawson, and Valencia, this leads to gauge boson pair rates
far larger than in the standard model. In this note we reconsider this
mechanism, and illustrate it in a model in which the rates can be reliably
calculated. The observation of both an enhanced rate of gauge-boson-pair events
and colored particles would be a signal that the colored particles were
pseudo-Goldstone bosons of symmetry breaking.Comment: 10 pages, 2 figures not include
Photoemission studies of the near Fermi level spectral weight shifts in FeSe1-xTex superconductor
Our valence band photoelectron spectroscopic studies show a temperature
dependent spectral weight transfer near the Fermi level in the Fe-based
superconductor FeSe1-xTex. Using theoretical band structure calculations we
have shown that the weight transfer is due to the temperature induced changes
in the Fe(Se,Te)4 tetrahedra. These structural changes lead to shifts in the
electron occupancy from the xz/yz and x2-y2 orbitals to the 3z2-r2 orbitals
indicating a temperature induced crossover from a metallic state to an Orbital
Selective Mott (OSM) Phase. Our study presents the observation of a temperature
induced crossover to a low temperature OSM phase in the family of Fe
chalcogenides.Comment: 10 pages, 4 figure
Studies on the Accumulation of Chromium in Fenugreek
Studying Cr uptake by Fenugreek, we note that the maximum concentration of Cr takes place in the shells of the pods followed by leaves, stems and seeds in that order. Interestingly, applied higher doses of Cr does not increase accumulation of Cr in the stems, rather Cr content in the stems levels off. However, the maximum dispersal/distribution of Cr taken up is in the leaves
Chromium uptake by Fenugreek
Fenugreek (Trigonella foenum- graecum) is both herb (leaves) and a spice (seed) belonging to the family Fabaceae. Fenugreek leaves and seeds are used in the cuisine of India. Fenugreek also has medicinal value. Fenugreek seeds are known to reduce serum glucose and improve glucose tolerance and hence are prescribed to diabetic patients. In the recent past supplemental Chromium is being prescribed to diabetic patients to activate (increased- insulin binding, insulin receptor number, insulin receptor phosphorylation) insulin. Plants can uptake substantial quantities of toxic metals from contaminated soils if these soils are well ameliorated. 

It is then probable that the medicinal efficacy of Fenugreek in the case of diabetes could be enhanced if it takes up chromium from the soil. Preliminary studies are being conducted to note the chromium uptake by Fenugreek from soils which are applied with potassium dichromate
Axigluons cannot explain the observed top quark forward-backward asymmetry
We study an SU(3)^2 axigluon model introduced by Frampton, Shu, and Wang to
explain the recent Fermilab Tevatron observation of a significant positive
enhancement in the top quark forward-backward asymmetry relative to standard
model predictions. First, we demonstrate that data on neutral B_d-meson mixing
excludes the region of model parameter space where the top asymmetry is
predicted to be the largest. Keeping the gauge couplings below the critical
value that would lead to fermion condensation imposes further limits at large
axigluon mass, while precision electroweak constraints on the model are
relatively mild. Furthermore, by considering an extension to an SU(3)^3 color
group, we demonstrate that embedding the model in an extra-dimensional
framework can only dilute the axigluon effect on the forward-backward
asymmetry. We conclude that axigluon models are unlikely to be the source of
the observed top quark asymmetry.Comment: 12 pages, 7 eps figures included. Minor changes to conform with
published versio
A Rapidly-progressing Outbreak of Cholera in a Shelter-home for Mentally-retarded Females, Amta-II Block, Howrah, West Bengal, India
On 13 May 2010, a cluster of diarrhoeal disease cases was reported among the inmates of a shelter-home for mentally-retarded females in Parbaksi village of Howrah district in West Bengal, India. The outbreak was investigated to identify the aetiological agent and source of infection and to propose recommendations. A suspected case of cholera was defined as an acute onset of >3 loose watery stools in a female resident of the shelter-home since 1 May 2010. The demographic and clinical details were collected from the suspected case-patients, and the outbreak was described by time, place, and person. A retrospective cohort study was conducted to identify the risk factors associated with the illness. Of the 101 inmates, 91 (90%) developed diarrhoea, and three patients died (case fatality−3%). Four of the five stool specimens were positive for Vibrio cholerae O1 Ogawa. Drinking of water from the pond-connected tubewell (adjusted odds ratio=25.7, 95% confidence interval 2.7-236.4) was associated with the illness. Relocation of the pond-connected tubewell away from the groundwater tubewell, colour-coding of the tubewells meant for drinking purposes, and regular disinfection of the tubewells were recommended
An Interconnected Wind Driven SEIG System Using SVPWM Controlled TL Z-Source Inverter Strategy for Off-Shore WECS
This paper discuss about the interconnection of wind driven SEIG for drive applications by using TL Z-source inverter strategy .TL Z-source consists of two coupled inductors having turns ratio γTL and four diodes are used . The wind energy system uses a two Self Excited Induction generator (SEIG) connected parallel in order to increase the reliability. The proposed system components like wind turbine SEIG, rectifier, SVM Controlled TL Z-source inverter, are modeled by matlab Simulink. The maximum power can be extracted and supplied to the load efficiently by using TL Z-source inverter with a proper value of modulation index. The simulation output is analysed experimentally using 500 W experimental setup
Quantum phase transition in a Dp-Dq system
Using the top-down approach, we study intersecting Dp-Dq brane configuration
in string theory and find examples, where there can be a quantum phase
transition at zero temperature induced by the violation of the
Breitenlohner-Freedman (BF) bound at IR, which is done essentially by a
combination of charge density and magnetic fields. In particular, there exists
a Berezinskii-Kosterlitz-Thouless (BKT) type of transition for D3-D5 and D5-D5
systems. The study of the BKT type of transition is initiated by Jensen et al.
[Phys. Rev. Lett. {\bf 105}, 041601 (2010) ] for a D3-D5 system with nonzero
charge density and a magnetic field. Here, we show that one can have the BKT
transition for a D3-D5 system even in the absence of charge density but
requires multiple magnetic fields. In this case the field theory lives in 2+1
dimensions, whereas for the D5-D5 type, the transition requires the presence of
both the charge density and magnetic fields and the dual field theory lives on
a 3+1 dimensional spacetime. We also study the D3-D7 system but it does not
show the BKT type of transition.Comment: 1+37 pages; v2 Chern-Simon term for D3-D5 case presented, typos fixed
and a reference added; v3 Minor corrections, Chern-Simon term for D2-D4,
D4-D6, and D5-D7 added, also an appendix and few references added; v4 Journal
versio
The Impact of El Niño/Southern Oscillation on Hydrology and Rice Productivity in the Cauvery Basin, India: Application of the Soil and Water Assessment Tool
AbstractThis study was performed to further understanding of the variations in hydrology and rice crop productivity during different El Niño/Southern Oscillation (ENSO) events in the Cauvery River Basin of Tamil Nadu, India using the Soil and Water Assessment Tool (SWAT). The entire Cauvery Basin was divided into 301 sub-basins and further subdivided into 3,601 Hydrological Response Units (HRU). Based on the National Oceanic and Atmospheric Administration (NOAA) official website, information on El Niño (1972, 1982, 1987, 1991, 1997, 2002 and 2004) and La Niña (1970, 1971, 1973, 1974, 1975, 1988, 1998, 1999 and 2000) years were obtained. The SWAT model was continuously run from 1970 to 2008, and a composite for El Niño, La Niña and normal years was constructed to understand their influence on hydrology and rice crop productivity in the study area. From the analysis, it was clear that an El Niño episode is correlated with rainfall, hydrology and rice productivity in the Cauvery river basin. The validation of the SWAT model indicated the capability of SWAT to accurately predict stream flow and rice productivity. It was evident from the investigation that the quantum of rainfall was more during El Niño years with high inter-annual rainfall variability (809.3mm to 2,366mm) compared with La Niña and normal years. As a result, the soil water recharge, including percolation and soil water availability in the surface layers, was increased in the El Niño years. Simulated rice productivity over 39 years in the Cauvery Basin ranged between 1,137 and 7,865kgha−1 with a mean productivity of 3,955kgha−1. The coefficient of variation in rice productivity was higher during La Niña (21.4%) years compared with El Niño (14.7%) and normal years (14.6%). The mean rice productivity was increased in both El Niño and normal years, indicating the possibility of higher yields than those in La Niña years. An analysis of the hydrological data and rice productivity showed that the risk of failure was low during El Niño years compared with normal or La Niña years. This behavior could be utilized for forecasting rice crop productivity under different ENSO conditions and can provide information for policy makers when deciding on water allocation and import / export policies
Valence band electronic structure of Pd based ternary chalcogenide superconductors
We present a comparative study of the valence band electronic structure of Pd
based ternary chalcogenide superconductors Nb2Pd0.95S5, Ta2Pd0.97S6 and
Ta2Pd0.97Te6 using experimental photoemission spectroscopy and density
functional based theoretical calculations. We observe a qualitatively
similarity between valence band (VB) spectra of Nb2Pd0.95S5 and Ta2Pd0.97S6.
Further, we find a pseudogap feature in Nb2Pd0.95S5 at low temperature, unlike
other two compounds. We have correlated the structural geometry with the
differences in VB spectra of these compounds. The different atomic packing in
these compounds could vary the strength of inter-orbital hybridization among
various atoms which leads to difference in their electronic structure as
clearly observed in our DOS calculations
- …