6 research outputs found
Study of ambient air pollutants over Rishikesh at foothills of north-western Indian Himalaya
49-60Air quality parameters measured over Rishikesh city of Uttarakhand, where a large number of visitors and pilgrimage stay and pass by throughout the year are analyzed and studied. Such intensive human activities lead to the impacts and its manifestation on regional scale environment. Due to consistent infrastructure development and the increased vehicular emission due to transport, a large amount of particulate matters is added to the ambient environment and affects the air quality adversely. Here an attempt is made to understand the growth in level of ambient air pollutants through available measurement. In this study particulate matter (PM10), suspended particulate matters (SPMs) and the concentration of gaseous pollutants (SO2 and NO2) from 2011 to 2014 are measured and analyzed. It is observed that concentrations of the pollutants increase during pre-monsoon season as compared to the winter and monsoon seasons. In addition, PM10 and SPM concentrations are found about two times higher than the prescribed national standard. SO2 and NO2 levels are found within the limits as proposed by the Central Pollution Control Board (CPCB) New Delhi, India. A detailed statistical analysis is carried out on the basis of monthly mean values of the observed pollutants. The PM10 exhibits a significant positive correlation with SO2 and NO2 concentrations. In addition, back trajectories show partly long-term transport from North Africa, Saudi Arabia and central Asian region in contributing over the region with local emission that is considered to be the main and direct cause of increasing trend of the pollutants
Abundance and stratification analysis of the CP star HD 103498
Slow rotation and absence of strong mixing processes in atmospheres of
chemically peculiar stars develop ideal conditions for the appearance of
abundance anomalies through the mechanism of microscopic particle diffusion.
This makes these objects look spectroscopically and photometrically different
from their "normal" analogs. As a result, it is often difficult to accurately
determine atmospheric parameters of these stars and special methods are needed
for the consistent analysis of their atmospheres. The main aim of the present
paper is to analyse atmospheric abundance and stratification of chemical
elements in the atmosphere of the chemically peculiar star HD 103498. We find
that two model atmospheres computed with individual and stratified abundances
provide reasonable fit to observed spectroscopic and photometric indicators:
Teff=9300 K, logg=3.5 and Teff=9500K, logg=3.6. It is shown that Mg has a large
abundance gradient in the star's atmosphere with accumulation of Mg ions in the
uppermost atmospheric layers, whereas Si demonstrates opposite behaviour with
accumulation in deep layers. In addition, a detailed non-LTE analysis showed
that none of Mg transitions under consideration is a subject of noticeable
non-LTE effects. Comparing observed photometry transformed to physical units we
estimated the radius of HD 103498 to be between R=(4.56 +/- 0.77)Rsun for
Teff=9300K, logg=3.5 and R=(4.39 +/- 0.75)Rsun for Teff=9500K, logg=3.6 models
respectively. We note that the lack of suitable observations in absolute units
prevents us to uniquely determine the Teff of the star at the current stage of
analysis.Comment: 9 pages, 7 figures and 3 tables, accepted for publication in MNRA
Study of fission track registration efficiency of Îł-irradiated polyester track detector in solution medium
Black carbon aerosols in the ambient air of Gangotri Glacier valley of north-western Himalaya in India
Local Conditions Influencing In Situ Formation of Different Shaped Silver Nanostructures and Subsequent Reorganizations in Ionomer Membrane
Effects of once-weekly exenatide on cardiovascular outcomes in type 2 diabetes
BACKGROUND: The cardiovascular effects of adding once-weekly treatment with exenatide to usual care in patients with type 2 diabetes are unknown. METHODS: We randomly assigned patients with type 2 diabetes, with or without previous cardiovascular disease, to receive subcutaneous injections of extended-release exenatide at a dose of 2 mg or matching placebo once weekly. The primary composite outcome was the first occurrence of death from cardiovascular causes, nonfatal myocardial infarction, or nonfatal stroke. The coprimary hypotheses were that exenatide, administered once weekly, would be noninferior to placebo with respect to safety and superior to placebo with respect to efficacy. RESULTS: In all, 14,752 patients (of whom 10,782 [73.1%] had previous cardiovascular disease) were followed for a median of 3.2 years (interquartile range, 2.2 to 4.4). A primary composite outcome event occurred in 839 of 7356 patients (11.4%; 3.7 events per 100 person-years) in the exenatide group and in 905 of 7396 patients (12.2%; 4.0 events per 100 person-years) in the placebo group (hazard ratio, 0.91; 95% confidence interval [CI], 0.83 to 1.00), with the intention-to-treat analysis indicating that exenatide, administered once weekly, was noninferior to placebo with respect to safety (P<0.001 for noninferiority) but was not superior to placebo with respect to efficacy (P=0.06 for superiority). The rates of death from cardiovascular causes, fatal or nonfatal myocardial infarction, fatal or nonfatal stroke, hospitalization for heart failure, and hospitalization for acute coronary syndrome, and the incidence of acute pancreatitis, pancreatic cancer, medullary thyroid carcinoma, and serious adverse events did not differ significantly between the two groups. CONCLUSIONS: Among patients with type 2 diabetes with or without previous cardiovascular disease, the incidence of major adverse cardiovascular events did not differ significantly between patients who received exenatide and those who received placebo