139 research outputs found
Understanding the bulk electronic structure of Ca1-xSrxVO3
We investigate the electronic structure of Ca1-xSrxVO3 using careful
state-of-the-art experiments and calculations. Photoemission spectra using
synchrotron radiation reveal a hitherto unnoticed polarization dependence of
the photoemission matrix elements for the surface component leading to a
substantial suppression of its intensity. Bulk spectra extracted with the help
of experimentally determined electron escape depth and estimated suppression of
surface contributions resolve outstanding puzzles concerning the electronic
structure in Ca1-xSrxVO3.Comment: 4 pages including 3 figure
Antidepressant effect of atypical antipsychotic ziprasidone in albino rats
Background: Depression is a common psychiatric illness but conventional antidepressants are often shows unpredictable response. Pharmacological profiles of many atypical antipsychotics have potential antidepressant effect. Ziprasidone is an atypical antidepressant with 5HT1A agonistic activity and 5HT1D, 5HT2A and D2 receptors antagonistic activity. It’s a potential candidate for evaluating possible antidepressant activity.Methods: Behavioural despair test are widely used for evaluation of potential antidepressant molecule. Tail suspension test is a variant of behavioural despair test. Healthy male Wistar albino rat 18 in number and weighing between of 150-200 grams were divided in 3 groups with 6 rats in each group. Group A was treated with 0.9% Normal Saline, Group B with Fluoxetine and Group C with Ziprasidone for 28 days. Tail suspension test was done on day 0, 7, 14, 21 and 28 days.Results: In comparison to Normal saline both the drugs shows significant antidepressant activity after 28 days of treatment. While antidepressant activity of fluoxetine started to appear from day 7; that of ziprasidone started to appear from 14th day.Conclusions: Ziprasidone can be suitable candidate for clinical trials of Major Depressive Disorders not responding to conventional antidepressant.
Mixed-layer characteristics as related to the monsoon climate of New Delhi, India
Annual variations of mixed-layer characteristics at New Delhi, India have been studied for a weak monsoon (1987) and a strong monsoon (1988) year. In the weak monsoon year (1987), the maximum mixing depthh max was found to have a value of around 3000 m during the pre-monsoon, less than 2000 m during the summer monsoon, around 2000 m during the post-monsoon, and less than 1000 m in the winter season. For the strong monsoon year (1988),h max values were less than 1987 values for comparable periods throughout the year. The seasonal and yearly differences ofh max were explained by the surface energy balance and potential temperature gradient γ at a time close to sunrise. According to the spatial patterns of γ obtained by an objective analysis of the 850 to 700 hPa layers. mixed-layer characteristics obtained at New Delhi are representative of the north and central regions of India
Band Structure of Topological Insulator BiSbTe1.25Se1.75
We present our angle resolved photoelectron spectroscopy (ARPES) and density
functional theory results on quaternary topological insulator (TI)
BiSbTe1.25Se1.75 (BSTS) confirming the non-trivial topology of the surface
state bands (SSBs) in this compound. We find that the SSBs, which are are
sensitive to the atomic composition of the terminating surface have a partial
3D character. Our detailed study of the band bending (BB) effects shows that in
BSTS the Dirac point (DP) shifts by more than two times compared to that in
Bi2Se3 to reach the saturation. The stronger BB in BSTS could be due to the
difference in screening of the surface charges. From momentum density curves
(MDCs) of the ARPES data we obtained an energy dispersion relation showing the
warping strength of the Fermi surface in BSTS to be intermediate between those
found in Bi2Se3 and Bi2Te3 and also to be tunable by controlling the ratio of
chalcogen/pnictogen atoms. Our experiments also reveal that the nature of the
BB effects are highly sensitive to the exposure of the fresh surface to various
gas species. These findings have important implications in the tuning of DP in
TIs for technological applications
A microspectroscopic study of the electronic homogeneity of ordered and disordered Sr2FeMoO6
Besides a drastic reduction in saturation magnetization of disordered
Sr2FeMoO6 compared to highly ordered samples, magnetizations as a function of
the temperature for different disordered samples may also show qualitatively
different behaviors. We investigate the origin of such diversity by performing
spatially resolved photoemission spectroscopy on various disordered samples.
Our results establish that extensive electronic inhomogeneity, arising most
probably from an underlying chemical inhomogeneity in disordered samples is
responsible for the observed magnetic inhomogeneity. It is further pointed out
that these inhomogeneities are connected with composition fluctuations of the
type Sr2Fe1+xMo1-xO6 with Fe-rich (x>0) and Mo-rich (x<0) regions.Comment: 14 pages, 4 figure
MIXED-LAYER CHARACTERISTICS AS RELATED TO THE MONSOON CLIMATE OF NEW DELHI, INDIA
Abstract. Annual variations of mixed-layer characteristics at New Delhi, India have been studied for a weak monsoon (1987) and a strong monsoon (1988) year. In the weak monsoon year (1987), the maximum mixing depth hma x was found to have a value of around 3000 m during the pre-monsoon, less than 2000 m during the summer monsoon, around 2000 m during the post-monsoon, and less than 1000 m in the winter season. For the strong monsoon year (1988), hmax values were Jess than 1987 values for comparable periods throughout the year. The seasonal and yearly differences of h~ax were explained by the surface energy balance and potential temperature gradient y at a time close to sunrise. According to the spatial patterns of 7 obtained by an objective analysis of the 850 to 700 hPa layers, mixed-layer characteristics obtained at New Delhi are representative of the north and central regions of India
Effect of monsoon on coastal fish diversity of Goa: an example from the gillnet fishery
The dynamics of fauna in coastal ecosystems are influenced by seasonal patterns in the oceanographic environment. It is well known that the monsoon along south-west coast of India influences the movement and spawning of fishes. Thus, they have direct effect on the richness, abundance and evenness of fish diversity in the ecosystem. This study investigates how the monsoon affects the commercial gillnet fishery along the coast of Goa. Fishing experiments were conducted in popular gillnet fishing grounds and the temporal pattern in diversity indices between October 2013 and September 2014 was assessed. A total of 124 fish species (40 families), 16 crustacean species (4 families) and 9 molluscan species (8 families) were recorded. The species diversity was found to be significantly different during the monsoon season and the species abundance distribution followed a geometric series during this period indicating signs of ecosystem perturbations. The economic and biological aspects of gillnet fishing in relation to the monsoon season in Goa are also discussed
Diffuse reflectance spectroscopy: diagnostic accuracy of a non-invasive screening technique for early detection of malignant changes in the oral cavity
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