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11.
R. K. Kaul C. L. Bhat M. L. Sapru M. K. Kaul 《Journal of Astrophysics and Astronomy》1994,15(1):95-102
The weather-imageries from the INSAT group of satellites provide reliable and concurrent multistation cloud-cover data — an important input for a proper selection of an observatory site for optical, infra-red and γ-ray astronomy work. Using these data, it is shown that Gurushikar, Mt. Abu, promises to be an excellent site for setting up the proposed GRACE facility for high-sensitivity Gamma-Ray Astrophysics Cerenkov Experiments. 相似文献
12.
Snowmelt makes an essential component of the hydrological system of Kashmir Himalayas. The present study was carried out to examine the status of Snow Cover Area (SCA) using Moderate Resolution Imaging Spectroradiometer (MODIS) 8-day Snow Cover Product between 2000 and 2016. The intra- and inter-annual variability in SCA and in meteorological parameters was observed and various statistical tests were used to study the interrelationship. Results of statistical analysis indicate decrease in maximum temperature (?0.05 °C/year) and minimum temperatures (?0.02 °C/year) while rise in precipitation (19.13 mm/year). It also showed an increase in annual mean SCA (43.5 sq km) during the study period. The analysis was also carried out on a seasonal basis. The results revealed that in Kashmir Himalayas, climate plays a dominating role in controlling the SCA. The results depict the short-term fluctuations in SCA and show the magnitude of change between two successive values being very large in SCA. 相似文献
13.
W. M. Yan R. N. Manchester G. Hobbs W. van Straten J. E. Reynolds N. Wang M. Bailes N. D. R. Bhat S. Burke-Spolaor D. J. Champion A. Chaudhary W. A. Coles A. W. Hotan J. Khoo S. Oslowski J. M. Sarkissian D. R. B. Yardley 《Astrophysics and Space Science》2011,335(2):485-498
We report on variations in the mean position angle of the 20 millisecond pulsars being observed as part of the Parkes Pulsar Timing Array (PPTA) project. It is found that the observed variations are dominated by changes in the Faraday rotation occurring in the Earth??s ionosphere. Two ionospheric models are used to correct for the ionospheric contribution and it is found that one based on the International Reference Ionosphere gave the best results. Little or no significant long-term variation in interstellar RM was found with limits typically about 0.1 rad?m?2?yr?1 in absolute value. In a few cases, apparently significant RM variations over timescales of a few 100 days or more were seen. These are unlikely to be due to localised magnetised regions crossing the line of sight since the implied magnetic fields are too high. Most probably they are statistical fluctuations due to random spatial and temporal variations in the interstellar electron density and magnetic field along the line of sight. 相似文献
14.
Abstract Laboratory tests were conducted on compacted marine sediments to study the effect of salt concentration of permeating fluid on its permeability characteristics. Deep sea sediment samples were collected from water depths varying from 3700 to 4500 m off Mauritius coast. Liquid limit and plasticity index varied widely from 45 to 75 and 10 to 35, respectively. Permeability was found at different void ratios with distilled water and 0.2, 0.4, and 0.8 N NaCl solutions as permeating fluid. It was found that permeability increases with an increase in salt concentration for a given void ratio. This is explained by diffused double layer theory. Also, the rate of increase in permeability decreases with increase in salt concentration. The effect of salt concentration seemed to be less at higher void ratios. 相似文献
15.
16.
Mahdi S. Sheraz Dhekale B. S. Jan Rukhsana Bhat M. Anwar Hussain Ashaq Jehangir Intikhab Aalum Sofi Najeebul Rehman Ahmed Latief Qureshi Asif M. Iqbal Aezum Aziz Mujtaba Bangroo Shabir A. Wani Owais Ali Bahar F. A. Mishra S. K. 《Theoretical and Applied Climatology》2022,149(1-2):727-741
Theoretical and Applied Climatology - Analysis of climatic variables is important for the detection and attribution of climate change trends and has received considerable attention from researchers... 相似文献
17.
A. Talib K. N. Gaur A. K. Sisodia Bilal A. Bhat Roohi Irshad 《Journal of the Geological Society of India》2012,80(5):667-675
A foraminiferal assemblage comprising 30 species dominated by the family Vaginulinidae is recovered from the Chari Formation exposed at Keera Dome, Kutch. The paper presents a systematic account of eight species, reported for the first time form the Indian region. Preliminary interpretations regarding age and palaeoenvironment are drawn on the basis of the recovered foraminiferal assemblage. The assemblage supports a Callovian to Oxfordian age for the studied sequence. A near shore, open marine environment ranging from mid to outer shelf is interpreted on the basis of the foraminiferal assemblage. 相似文献
18.
Sanjeev P. Deshpande K. V. Radhakrishnan U. Gopalakrishna Bhat 《Journal of the Indian Society of Remote Sensing》2011,39(4):547-554
The technique of predicting Potential Fishing Zone using satellite derived sea surface temperature and chlorophyll is becoming
an important aspect for the fishermen. In the present study an attempt has been made to compare fish density/catch per unit
effort in the areas predicted by Satellite imagery and available to fishermen via electronic display boards at the fish landing
centers of Uttara Kannada district, Karnataka with those of non predicted areas. Direct and Indirect validation was done.
Direct method means comparing the catch using fishing vessels simultaneously in the notified region with that of catch from
non notified region. And in indirect method by comparing catch data from landing centers on notified days with that of non
notified days. Direct validation off Karwar showed that catch was significantly higher in notified (PFZ) area with high densities
as compared to non notified (non PFZ) regions. When comparisons of landing center data of Karwar, Tadadi and Bhatkal are done
it is evident that in all the centers during the period under study, higher catches were observed on notified days than non
notified days except in Bhatkal centre in 2009–10. There by validating the accuracy of PFZ predictions and economic gains
to fishermen. 相似文献
19.
20.
Fatigue reliability analysis of deep water rigid marine risers associated with Morison-type wave loading 总被引:1,自引:0,他引:1
Muddassir Nazir Faisal Khan Paul Amyotte 《Stochastic Environmental Research and Risk Assessment (SERRA)》2008,22(3):379-390
This work presents a simple and efficient framework for the fatigue reliability assessment of a vertical top-tensioned rigid
riser. The fatigue damage response is considered as a narrow-band Gaussian stationary random process with a zero mean for
the short-term behavior of a riser. Non-linearity in a response associated with Morison-type wave loading is accounted for
by using a factor, which is the ratio of expected damage according to a non-linear probability distribution to the expected
damage according to a linear method of analysis. Long-term non-stationary response is obtained by summing up a large number
of short-term stationary responses. Uncertainties associated with both the strength and stress parts of the limit state function
are quantified by a lognormal distribution. A closed form reliability analysis is carried out, which is based on the limit
state function formulated in terms of Miner’s cumulative damage rule. The results thus obtained are compared with the well-documented
lognormal format of reliability analysis based on time to fatigue failure. The validity of using the lognormal hazard rate
function in predicting the fatigue life is discussed. A Monte Carlo simulation technique is also used as a reliability assessment
method. A simple algorithm is used to reduce the uncertainty associated with direct sampling at small probability of failure
values and a small number of simulations. Simulation results are compared with closed form solutions. A worked example is
included to show the practical riser design problem based on reliability analysis. 相似文献