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31.
Shipra Shah Dharam Prakash Sharma Nazir A. Pala Priyanka Tripathi Munesh Kumar 《山地科学学报》2014,11(4):959-966
The present study was conducted in Solan Forest Division of Himachal Pradesh covering an area of about 57,158 ha. The aim was to estimate and assess the temporal change in carbon stock of the Chil Working Circle, in two forest ranges of the Division, Solan and Dharampur, over the period of 1956-2011. The inventory data of the working plans of Solan Forest Division from 1956-1957, 1984-1985 and 2002- 2003 were used in the present study while field data for biomass estimation was collected for the year 2011. The results showed a declining trend in carbon stock over 1956-1984 period, however, an increasing trend over 1984-2002 was observed, which showed a further increase for the period 2002-2011. These fluctuating trends in the forest carbon stock can be related to increasing anthropogenic pressure on forests and the subsequent introduction of a ban on green felling envisaging efficient forest management, both of which affect the forest carbon pool significantly. 相似文献
32.
Algorithms are derived for constructing five dimensional Kaluza-Klein cosmological space-times in the presence of a perfect fluid source in the framework of f(R,T) gravity theory proposed by Harko et al. (Phys. Rev. D 84:024020, 2011). Starting from the solution of Reddy et al. (Int. J. Theor. Phys 51:3222-3227, 2012b) some classes of new solutions are generated which correspond to accelerating models of the Universe. The physical and kinematical behaviors of the models are studied. 相似文献
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34.
Characterizing spatial variability of soil properties in salt affected coastal India using geostatistics and kriging 总被引:2,自引:0,他引:2
35.
Priyanka Ghosh 《Computers and Geotechnics》2009,36(1-2):342-351
This paper presents the pseudo-dynamic analysis to determine the seismic vertical uplift capacity of a horizontal strip anchor using upper bound limit analysis. However, in the literature, the pseudo-static approach was used by few researchers to compute the seismic vertical pullout resistance, where the real dynamic nature of earthquake accelerations cannot be considered. Under the seismic conditions, the values of the unit weight component of uplift factor fγE are determined for different magnitudes of soil friction angle, soil amplification, embedment ratio and seismic acceleration coefficients both in the horizontal and vertical directions. It is observed that the uplift factor fγE decreases significantly with the increase in seismic accelerations and amplification but increases with the increase in embedment ratio. The results are compared with the existing values in the literature and the significance of the present methodology for designing the horizontal strip anchor is discussed. In presence of vertical earthquake acceleration and amplification of vibration, the present values of fγE compare reasonably well with the existing pseudo-static values obtained by modifying the horizontal acceleration coefficient. 相似文献
36.
Seismic active earth pressure on walls with bilinear backface using pseudo-dynamic approach 总被引:2,自引:0,他引:2
This paper presents a study on the seismic active earth pressure behind a rigid cantilever retaining wall with bilinear backface using pseudo-dynamic approach. The wall has sudden change in inclination along its depth and a planar failure surface has been considered behind the retaining wall. The effects of a wide range of parameters like soil friction angle, wall inclination, wall friction angle, amplification of vibration, variation of shear modulus, and horizontal and vertical seismic accelerations on the active earth pressure have been explored in the present study. Unlike the Mononobe-Okabe method, which incorporates pseudo-static analysis, the present analysis predicts a nonlinear variation of active earth pressure along the wall. The results have been compared with the existing values in the literature. 相似文献
37.
Priyanka Ghosh 《Geographical review》2015,105(4):429-440
The Sundarban Biosphere Reserve in West Bengal, India, is part of the largest mangrove forest ecosystem in the world. The reserve is a world heritage site and the last refuge for the endangered Bengal tiger at a crucial time when global climate change threatens their existence. The mangrove ecosystem and wildlife conservation have become the priority for the state government of West Bengal. However, in becoming so, the state government imposes restrictions on catching fish in the core and buffer areas of the biosphere reserve, which intensify fishermen's everyday resource‐access struggles in the mangrove forest. This paper examines the conflict between local fishermen and conservation needs, broadening the understanding of human‐environment relationships in the Sundarbans region of India. 相似文献
38.
This note shows a study on the seismic passive earth pressure behind a non-vertical cantilever retaining wall using pseudo-dynamic
approach. A composite failure surface comprising of an arc of the logarithmic spiral near the wall and a straight line in
the planar shear zone near the ground, has been considered behind the retaining wall. The effects of soil friction angle,
wall inclination, wall friction angle, amplification of vibration, horizontal and vertical earthquake acceleration on the
passive earth pressure have been explored in this study. The results available in the literature for passive pressure, on
the basis of pseudo-static analysis are found to predict the passive resistance on the conservative side and the assumption
of a planar failure surface is found to overestimate the passive resistance for higher wall friction. An attempt has been
made in the present study to overcome both the limitations simultaneously. The present results are compared with the existing
values in the literature and found a reasonable match among the values. 相似文献
39.
Priyanka Tripathi G. Parthasarathy S. Masood Ahmad O. P. Pandey 《International Journal of Earth Sciences》2012,101(5):1385-1395
We report here for the first time geochemical, mineralogical and stable carbon and oxygen isotopic data on the crystalline basement rocks of the 1993 Killari earthquake region of Maharashtra (India), which is covered by a thick suite of Deccan volcanics. Our results revealed the hitherto unknown amphibolite–granulite nature of the 2.5?Ga basement, which contains 2.00–2.28?wt% of CO2. The stable carbon (δ13C) and oxygen (δ18O) isotopic measurements on carbonates separated from two basement samples KIL-13 (440.5?m depth) and KIL-20 (499.6?m depth) collected from the KLR-1 borehole drilled in the epicentral region showed the respective values of ?6.23 and ?6.22‰ versus PDB for δ13C and 7.94 and 8.11‰ versus SMOW for δ18O. The samples plot in the primary igneous carbonatite field, indicating the mantle origin of the carbonates, derived through the process of mantle metasomatism from the deep mantle carbon reservoir. This would suggest large-scale crust-mantle thermal fluid interaction beneath the Killari seismogenic region, which is characterized by massive upwarping of the high-velocity mafic crust and retrograde metamorphism. 相似文献