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81.
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83.
Kumar M. Dinesh Tandon Shubham Bassi Nitin Mohanty Pradipta Kumar Kumar Saurabh Mohandas Manish 《Natural Hazards》2022,110(3):2035-2057
Natural Hazards - Many coastal cities in developing countries are at the risk of flooding due to a progressive increase in the built-up areas and poor management of storm water. The flooding... 相似文献
84.
Natural Hazards - Glacial lakes are rapidly growing in response to climate change and glacier retreat which may lead to catastrophic socio-economic disasters. The failure of moraine-dammed lakes is... 相似文献
85.
The application of piezo-ceramic elements for measuring shear and compression wave velocities in the soil mass is increasing
day-by-day. Depending upon the configuration and polarity, these elements can either be used as benders or extenders, which
can transmit and receive shear and compression waves, respectively. Though, several researchers have successfully employed
these elements for characterizing the soil mass based on the shear and compression wave velocities, determination of the “time
lag” between the input and output waves remains debatable. Even, the existing literature does not clearly present the response
of these elements with respect to the frequency of excitation and the type of the material to be characterized. With this
in view, extensive investigations were made to capture the performance of piezo-ceramic elements by changing their (a) wiring
configuration (i.e., series or parallel) and (b) polarization (i.e., same or opposite) in the compacted soils of different
characteristics (i.e., moisture content, dry density and type of the soil). Details of the methodology are presented in this
paper and special attention has been paid to address various problems (i.e., wave attenuation, crosstalk phenomena, near field
effect and overshooting of transmitting waves) that are associated with signal interpretation and may yield misleading results. 相似文献
86.
Manish K. Purohit K. K. Prajapati R. K. Trivedi 《Journal of the Geological Society of India》2010,76(5):479-484
Re-examination of the outcrop of conjugate of strike-slip faults mapped by Roday et al. (1989) near forest rest house at Hirapur reveals that the main dextral strike-slip fault that strikes N35°E and is a manifestation of the earliest NE-SW trending subhorizontal σ1 that produced extensional reef system in the Bundelkhand massif. Although the change in the stress system though 90° rotation of the principal compressive stress σ1 and σ3 (with σ2 maintaining near vertically) is correct, another point of interest is that the σ1 for the system of faults bisects the obtuse angle between the two sets and not an acute one as required by the brittle failure criterion. The sinistral strike-slip faults were probably formed by rejuvenation of the initial dextral strike-slip faults that were generated when the maximum principal compressive stress was oriented NS. The reversal of fault displacement is seen on all scales in the Bundelkhand massif. The dextral strike-slip fault related to the late stress system was preferentially produced along pre-existing tensile fractures that were generated under NE-SW directed subhorizontal σ1. Some of these fractures were converted into sinistral strike-slip faults under NS directed maximum principal compression acting subhorizontally. 相似文献
87.
R. Nagendra Satish J. Patel Rakesh Deepankar A. N. Reddy 《Journal of the Geological Society of India》2010,76(5):525-532
Well preserved ichnofossils were found in Kulakkalnattam sandstone exposed at Kulakkalnattam stream in Ariyalur area, Cauvery Basin. It consists of infaunal structures of both suspension and deposit feeders. Five ichnofossils are present in a fine to coarse grain sandstone which includes Ophiomorpha, Palaeophycus, Planolites Skolithos, and Thalassinoides. The study infers that ichnofossils Skolithos and Ophiomorpha are infaunal colonization of the suspension feeders in high energy condition in shifting substrate, whereas Thalassinoides and Planolites-Palaeophycus ichnofossils indicate infaunal deposit feeders living at the sediment-sediment interface in low to moderate energy conditions. Furthermore, the abundance and diversity of the trace fossils indicates there was alternatively fluctuations in energy conditions which lead to development of Skolithos and Cruziana ichnofacies type condition during the deposition of Kulkkallanattam sandstone in foreshore-shoreface environments. 相似文献
88.
Manish Tiwari Rengaswamy Ramesh Ravi Bhushan Madavalm S. Sheshshayee Bammidipati L. K. Somayajulu A. J. Timothy Jull George S. Burr 《第四纪科学杂志》2010,25(7):1179-1188
A few studies from the western Arabian Sea indicate that the Indian summer (or southwest) monsoon (ISM), after attaining its maximum intensity at ca. 9 ka, declined during the Holocene, as did insolation. In contrast, earlier and later observations from both the eastern and the western Arabian Sea do not support this inference. Analysis of multiple proxies of productivity in a new sediment core from the western Arabian Sea fails to confirm the earlier, single‐proxy (e.g. abundance of Globigerina bulloides) based, inference of the Holocene weakening of ISM, following insolation. The reason for the observed decreasing trend in foraminiferal abundance – the basis for the earlier inference – could be the favouring of silicate rather than carbonate productivity by the increased ISM wind strength. Although ISM exhibits several multi‐millennial scale fluctuations, there is no evidence from several multi‐proxy data to conclude that it declined during the Holocene; this is consistent with the phase lag analysis of longer time series of monsoon proxies. Thus, on sub‐Milankovitch timescales, ISM did not follow insolation, highlighting the importance of internal feedbacks. A comparison with East Asian summer monsoon (EASM) records suggests that both ISM and EASM varied in unison, implying common forcing factors on such longer timescales. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
89.
Stefanie Wachter Chryssa Kouveliotou Sandeep Patel Don Figer Peter Woods 《Astrophysics and Space Science》2007,308(1-4):67-71
Both Anomalous X-ray Pulsars (AXPs) and Soft Gamma Repeaters (SGRs) are thought to be manifestations of magnetars. However, the specific physical characteristics that differentiate the two classes of objects remain unclear. There is some evidence that the progenitors of these sources and/or the environment in which they form might influence the type of phenomena the resulting magnetar displays. Several of the AXPs appear to be associated with supernova remnants, while embedded clusters of massive stars have been found in the immediate vicinity of some SGRs. Since both AXPs and SGRs are distributed close to the Galactic plane, high extinction makes studies in the optical difficult. We present early results from our Spitzer program aimed at probing the environmental factors that might contribute to the difference in the observed characteristics between AXPs and SGRs. 相似文献
90.
N K Patel T T Medhavy C Patnaik A Hussain 《Journal of the Indian Society of Remote Sensing》1995,23(2):33-39
Microwave sensors having all-weather capabilities provide an opportunity to monitor rice grown in monsoon season. An attempt has been made to identify rice crop using multitemporal ERS-1 SAR data in C-band (5.3 GHz). Data acquired on August 15 (D1), September 19 (D2), October 24 (D3) and November 28 (D4) 1993 were taken. Combinations of data acquired on different dates were used for identification of rice crop. Single-date IRS-1B LISS II data in visible and NIR bands acquired on October 23, 1993 was also used for comparison of estimated rice area. Analysis of the results has shown that a combination of SAR data acquired at the tillering (August), booting (September) and heading (October) stages of rice crop enabled identification and area estimation of rice crop grown under lowland conditions. Single-date SAR data acquired in the month of October was found to be better for identification of rice compared to other dates. 相似文献