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1.
Prasanta Kumar Bal Andimuthu Ramachandran Kandasamy Palanivelu Perumal Thirumurugan Rajadurai Geetha Balakrishnan Bhaskaran 《Asia-Pacific Journal of Atmospheric Sciences》2016,52(5):519-519
The author “Bhaski Bhaskaran” and his affiliation “Fujitsu Laboratory of Europe, Middlesex, UK” should be replaced by “Balakrishnan Bhaskaran”, “Fujitsu Laboratories of Europe Limited, Hayes Park, Middlesex, UK”, respectively.The corrected name and affiliation are shown in this erratum. 相似文献
2.
C. Panneerselvam C. Selvaraj K. Jeeva K. U. Nair C. P. Anilkumar S. Gurubaran 《Journal of Earth System Science》2007,116(3):179-186
Surface measurements of the atmospheric electrical parameters like Maxwell current, electric field and conductivity studied
at the Indian station, Maitri (70.75° S, 11.75° E, 117 m above mean sea level), Antarctica, during austral summer have been
analyzed for the years 2001 to 2004. A total of 69 days were selected which satisfied the ‘fairweather’ conditions, i.e.,
days with absence of high winds, drifting or falling snow, clouds, and fog effects. The diurnal variation curve of electric
field and vertical current averaged for 69 fairweather days is a single periodic with a minimum at 03:00 UT and a maximum
near 19:00 UT, which is very similar to the Carnegie curve. The correlation coefficient between these measured parameters
has a high value (more than 0.9) for all the days. During fairweather days the measured current and field variations are similar
and hence it is clear that the conductivity is more or less stable. During magnetically disturbed days, the dawn-dusk potential
drop has clear influences on the diurnal variation and it modifies the conductivity. Apart from the day-to-day variation in
low latitude thunderstorm activity, there are diurnal, seasonal, inter-annual variations in the electric potential and the
currents, as well as solar influences on the measured parameters. This study will help us to examine the impact of solar and
geophysical phenomena like solar flares, geomagnetic storms and substorms on the global electric circuit. 相似文献
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4.
MURUGESAN Vasanthavigar KRISHNARAJ Srinivasamoorthy KANNUSAMY Vijayaragavan SELVARAJ Gopinath SUBRAMANYA Sarma 《地球空间信息科学学报》2011,14(1):17-26
The main objective of the study is to identify groundwater potential zones in Thirumanimuttar basin with an integrated approach using Remote Sensing and geographical information system(GIS).FCC Image of Landsat TM 30 m resolution data and topographic maps has been used to generate thematic maps like geology,geomorphology,lineament and lineament density,drain-age,drainage density,and slope map of the study area.A number of geomorphic units such as Denudational hills,structural hills,Bajadas,Colluvial plain,Pediplain,Deep Pediment and Alluvial plains have been observed.A composite groundwater potential map has been generated as very high,high,medium,low and very low based on the groundwater availability area.The upper,mid-dle and downstream of the basins have been identified as potential zones for groundwater exploration.The regions of lineaments and intersecting lineaments proved for groundwater potential zones.The data generated was validated with field checks and ob-served to be in conformity with the same. 相似文献
5.
K. Jeeva C. Panneerselvam K. U. Nair C. Selvaraj Ajay Dhar B. M. Pathan S. Gurubaran 《Journal of the Geological Society of India》2011,78(3):199-210
The global component of fairweather electricity is subject to special attention to watch the solar-terrestrial effects and
secular changes in climate. It is generally considered that the diurnal variation of atmospheric electricity parameters, if
they are not following the Carnegie pattern, are not representative of the global thunderstorm activity. Some of the results
obtained from Maitri (70°45′54″S, 11°44′03″), are discussed here in context with global thunderstorm activity and space weather
influences. The diurnal pattern of the Potential Gradient and current density strongly deviate from the Carnegie curve. We
have showed that this deviation is not due to the local electrical influence but due to the global thunderstorm activity.
During fairweather condition the parameters are representing the global thunderstorm activity and to some extent they respond
to the upper atmospheric electro dynamic phenomenon. The mean value of the potential gradient (77.7 V/m) and current density
(2.13 pA/m2) well below the expected global mean but close to the value reported from the same location and season in the past years.
The mean conductivity, 3.34 × 10−14 mhom−1, is slightly at higher side and they exhibit a different diurnal trend comparing to the past measurements at this location. 相似文献
6.
The role of biofilm proteins in modulating cyprid metamorphosis is not well understood. In the present investigation this possibility was explored by disrupting biofilm proteins using commercially available protease. The influence of natural biofilm and artificial biofilms of Aeromonas salmonicida salmonicida and Bacillus brevis and their culture supernatants and exopolysaccharides obtained under different nutritional conditions was evaluated. Natural biofilm facilitated cyprid metamorphosis in Balanus amphitrite, whereas monospecies biofilms did not. The treatment of biofilms with protease resulted in a decline in metamorphosis, except in B. brevis, where although metamorphosis was negated initially, it increased with the protease concentration and observation days. As the response of cyprids to exopolysaccharides produced by A. salmonicida salmonicida was dependent on protein concentration, protease treatment resulted in a decrease in metamorphosis, whereas in case of B. brevis biofilms, protease hydrolysis products could be important in providing settlement cues. Thus, biofilm bacterial components play an important role in the cyprid metamorphosis of Balanus amphitrite. 相似文献
7.
Numerical investigation of the seakeeping behavior of a catamaran advancing in regular head waves 总被引：3，自引：0，他引：3
A numerical study was undertaken in order to assess the capability of an unsteady RANS code to predict the seakeeping characteristics of a high-speed multi-hull vessel in high sea states. Numerical analysis includes evaluation of ship motions, effects of wave steepness on ship response, catamaran natural frequency and added resistance in waves. Computations were performed for the DELFT 372 catamaran by the URANS solver CFDSHIP-Iowa V.4. The code was validated with encouraging results for high ship speeds (0.3≤Fn≤0.75) and high wave amplitudes (0.025≤Ak≤0.1). Comparison with strip theory solutions shows that the RANS method predicts ship motions with higher accuracy and allows the detection of nonlinear effects. Current computations evidence that heave peaks occur at resonance for all Fn, and reach the absolute maximum at Fn=0.75. Maximum pitch occurs at frequencies lower than resonance, for each speed, and absolute maximum occurs at medium Fn=0.6. Maximum added resistance, Raw, was computed at Fn=0.45, which, interestingly, is near the catamaran Fncoincidence. Overall, we found similar results as Simonsen et al. (2008) for KCS containership, though, herein, a multi-hull geometry and higher speeds were tested. Also, our results are useful to further evaluate the exciting forces and their correlation with fe and λ/Lpp. 相似文献
8.
Kandasamy Selvaraj Gopal Parthiban Chen-Tung Arthur Chen Jiann-Yuh Lou 《Continental Shelf Research》2010,30(10-11):1200-1210
Slag material was dumped in two sites off southwestern Taiwan by the China Steel Corporation during 1984–1995. By geochemically analyzing four sediment cores, we investigated the impact of slag on the sediment chemistry. Elemental profiles from the dumping sites show a strong depletion in detrital elements and enrichment in alkaline and redox-sensitive elements, especially for the top ～20 cm of sediments. The relative enrichment factor (EFrel) exhibits wider range for Ca (0.73–13.33), Fe (0.88–3.03), Mg (0.94–9.58) and Mn (1.22–33.30) due to contamination of sediments by slag. Sediment weathering indicators also show a distinct change with lower values in sediments influenced by dumping due to Ca and Sr addition. Higher EFrel for As, Cd and Pb in the top sections of the cores indicate an additional modern/industrial input of these elements since ～1950. Our study suggests that slag dumping may have a localized effect on biogeochemical processes by inducing the diagenetic remobilization of certain elements. 相似文献
9.
Marine gas hydrates, one of the largest methane reservoirs on Earth, may greatly affect the deep sea sedimentary environment and biogeochemistry; however, the carbon geochemistry in gas hydrate-bearing sediments is poorly understood. In this study, we investigated the carbon variables in sediment core 973-3 from the southwestern Taiwan Basin in the South China Sea to understand the effect of environmental factors and archaeal communities on carbon geochemistry. The carbon profiles suggest the methanogenesis with the incerase of dissolved inorganic carbon(DIC) and high total organic carbon(TOC)(mean = 0.46%) originated from terrigenous organic matter(mean δ~(13)C_(TOC) value of-23.6‰) driven by the abundant methanogen ‘Methanosaeta and Methanomicrobiales'. The active anaerobic oxidation of methane is characterized by the increase of DIC and inorganic carbon(IC), and the depleted δ~(13)C_(IC), coupled with the increase of TOC and the decrease of δ~(13)C_(TOC) values owing to the methanotroph ‘Methanosarcinales/ANME' in 430–840 cm. Environmental factors and archaeal communities in core 973-3 are significantly correlated to carbon variables owing to methane production and oxidation. Our results indicate that the carbon geochemical characteristics are obviously responding to the formation and decomposition of gas hydrates. Furthermore, pH, Eh and grain size, and Methanosaeta greatly affect the carbon geochemistry in gas hydrate-associated sediments. 相似文献
10.
Prasanta Kumar Bal Andimuthu Ramachandran Kandasamy Palanivelu Perumal Thirumurugan Rajadurai Geetha Bhaski Bhaskaran 《Asia-Pacific Journal of Atmospheric Sciences》2016,52(4):353-369
This study presents a comprehensive assessment of the possible regional climate change over India by using Providing REgional Climates for Impacts Studies (PRECIS), a regional climate model (RCM) developed by Met Office Hadley Centre in the United Kingdom. The lateral boundary data for the simulations were taken from a sub-set of six members sampled from the Hadley Centre’s 17- member Quantified Uncertainty in Model Projections (QUMP) perturbed physics ensemble. The model was run with 25 km × 25 km resolution from the global climate model (GCM) - HadCM3Q at the emission rate of special report on emission scenarios (SRES) A1B scenarios. Based on the model performance, six member ensembles running over a period of 1970-2100 in each experiment were utilized to predict possible range of variations in the future projections for the periods 2020s (2005-2035), 2050s (2035-2065) and 2080s (2065-2095) with respect to the baseline period (1975-2005). The analyses concentrated on maximum temperature, minimum temperature and rainfall over the region. For the whole India, the projections of maximum temperature from all the six models showed an increase within the range 2.5°C to 4.4°C by end of the century with respect to the present day climate simulations. The annual rainfall projections from all the six models indicated a general increase in rainfall being within the range 15-24%. Mann-Kendall trend test was run on time series data of temperatures and rainfall for the whole India and the results from some of the ensemble members indicated significant increasing trends. Such high resolution climate change information may be useful for the researchers to study the future impacts of climate change in terms of extreme events like floods and droughts and formulate various adaptation strategies for the society to cope with future climate change. 相似文献