Radio and X-ray burst from PSR 0950+08     

M. R. Deshpande  Hari Om Vats  Harish Chandra  P. Janardhan  A. D. Bobra  G. D. Vyas 《Astrophysics and Space Science》1994,218(2):249-265

This article describes in detail a burst from PSR 0950+08 on July 29, 1992. This event was observed by two radio telescopes (separated by ~ 200 km) operating at 103 MHz. There exists a very convincing indirect evidence that at the same time the pulsar also emitted large X-ray flux. The X-ray flux during the event compares with that during a solar X-ray flare. During the event the Sun was extraordinarily quiet as the solar X-ray flux 3 · 10^–7 W/m² only was observed. The cause for the burst is quite unknown and may be complex. However, a possibility of accretion of a comet-like object by pulsar may provide reasonable explanation of the observations. These results open some interesting questions about the pulsar physics.  相似文献   

Erratum to: Seasonal discharge and chemical flux variations of rivers flowing into the Bayhead canal of Durban Harbour,South Africa     

Kavandren Moodley  Srinivasan Pillay  Keshia Pather  Hari Ballabh 《中国地球化学学报》2016,35(4):354-354

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Policy without politics: technocratic control of climate change adaptation policy making in Nepal     

Hemant R. Ojha  Sharad Ghimire  Adam Pain  Andrea Nightingale  Dil B. Khatri  Hari Dhungana 《Climate Policy》2016,16(4):415-433

As developing countries around the world formulate policies to address climate change, concerns remain as to whether the voices of those most exposed to climate risk are represented in those policies. Developing countries face significant challenges for contextualizing global-scale scientific research into national political dynamics and downscaling global frameworks to sub-national levels, where the most affected are presumed to live. This article critiques the ways in which the politics of representation and climate science are framed and pursued in the process of climate policy development, and contributes to an understanding of the relative effectiveness of globally framed, generic policy mechanisms in vulnerable and politically volatile contexts. Based on this analysis, it also outlines opportunities for the possibility of improving climate policy processes to contest technocratic framing and generic international adaptation solutions.

Policy relevance

Nepal's position as one of the countries most at risk from climate change in the Himalayas has spurred significant international support to craft climate policy responses over the past few years. Focusing on the National Adaptation Programme of Action (NAPA) and the Climate Change Policy, this article examines the extent to which internationally and scientifically framed climate policy in Nepal recognizes the unfolding political mobilizations around the demand for a representative state and equitable adaptation to climate risks. This is particularly important in Nepal, where political unrest in the post-conflict transition after the end of the civil war in 2006 has focused around struggles over representation for those historically on the political margins. Arguing that vulnerability to climate risk is produced in conjunction with social and political conditions, and that not everyone in the same locality is equally vulnerable, we demonstrate the multi-faceted nature of the politics of representation for climate policy making in Nepal. However, so far, this policy making has primarily been shaped through a technocratic framing that avoids political contestations and downplays the demand for inclusive and deliberative processes. Based on this analysis, we identify the need for a flexible, contextually grounded, and multi-scalar approach to political representation while also emphasizing the need for downscaling climate science that can inform policy development and implementation to achieve fair and effective adaptation to climate change.  相似文献   

Mineralogical composition and ash geochemistry of raw and beneficiated high sulfur coals     

Binoy K. Saikia  Banashree Mahanta  Upendra N. Gupta  Om P. Sahu  Prasenjit Saikia  Bimala P. Baruah 《Journal of the Geological Society of India》2016,88(3):339-349

Coal is one of the most available energy sources on earth. The mineralogical and geo-chemical aspects of coals are of prime importance for their utilization. The mineralogical composition, ash chemistry, and ash fusion temperature (AFT) ranges of raw and beneficiated coals are investigated in this paper. Further, the mineral matter transformation during the beneficiation processes viz. by oxidative desulfurization; alkali extraction and ultrasonication along with the relationship of the ash fusion temperature (AFT) ranges with the ash components in the coal are discussed. The major oxides present in the coal and beneficiated coal ashes include Fe₂O₃, Al₂O₃, SiO₂, CaO, and MgO, which significantly affect the ash fusion temperature ranges. Initial deformation temperature (IDT) changes with the ash components and, increases with the increase in the Fe₂O₃ content in coal ash. With increasing concentrations of both Al₂O₃ and SiO₂, the initial deformation temperature (IDT) also increases. The increasing and decreasing nature of the initial deformation temperature (IDT) observed is also dependent upon the CaO and MgO contents. XRD analysis of the coal samples revealed significant changes in mineral matter contents with the types of beneficiation processes adopted for coal. The minerals like chlorite, illite, montmorillonite, pyrite, calcite, aragonite, and alumina have been removed during the beneficiation processes. The FTIR spectra also indicate the presence of minerals like gypsum (G), calcite (C) aragonite (Ar), quartz (Q) and kaolinite (K) in the raw coal and their subsequent removal after the beneficiation processes.  相似文献   

Utilization of high-resolution EGM2008 gravity data for geological exploration over the Singhbhum-Orissa Craton,India     

S.K. Pal  T.J. Majumdar  Vipin Kumar Pathak  Satya Narayan  Ujjawal Kumar  Om Prakash Goswami 《国际地球制图》2016,31(7):783-802

High-resolution EIGEN6C4 and EGM2008 Bouguer gravity data of 2190 degree spherical harmonic over the Singhbhum-Orissa Craton, India, have been generated from the International Centre for Global Earth Models. The Bouguer gravity anomaly difference maps of (i) in situ and EIGEN6C4, (ii) in situ and EGM2008 and iii) EIGEN6C4 and EGM2008 of the study area are compared. It reveals that EIGEN6C4 has lesser systematic error than EGM2008. However, from different profile plots of Bouguer gravity, east–west horizontal derivative and north–south horizontal derivative anomalies of the in situ, EIGEN6C4 and EGM2008, it is observed that most of the signatures of lithounits and geological structural elements are delineated very well by EGM2008 and match 94–98% with those of EIGEN6C4. Further, the Bouguer gravity, east–west horizontal derivative and north–south horizontal derivative anomalies of EGM2008 data over the study area have been used effectively for identifying various lithounits and geological structural elements.  相似文献   

Estimation of structural vulnerability for flooding using geospatial tools in the rural area of Orissa,India     

Praveen K. Thakur  Sreyasi Maiti  Nanette C. Kingma  V. Hari Prasad  S. P. Aggarwal  Ashutosh Bhardwaj 《Natural Hazards》2012,61(2):501-520

Vulnerability assessment of natural disasters is a crucial input for risk assessment and management. In the light of increasing frequency of disasters, societies must become more disaster resilient. This research tries to contribute to this aim. For risk assessment, insight is needed into the hazard, the elements at risk and their vulnerabilities. This study focused on the estimation of structural vulnerability due to flood for a number of structural elements at risk in the rural area of Orissa, India (Kendrapara), using a community-based approach together with geospatial analysis tools. Sixty-three households were interviewed about the 2003 floods in 11 villages and 166 elements at risk (buildings) were identified. Two main structural types were identified in the study area, and their vulnerability curves were made by plotting the relationships between flood depth and vulnerability for each structural type. The vulnerability ranges from 0 (no damage) to 1 (collapse/total damage). Structural type-1 is characterized by mud wall/floor material and a roof of paddy straw, and structural type-2 is characterized by reinforced cement concrete (RCC) walls/floor and a RCC roof. The results indicate that structural type-1 is most vulnerable for flooding. Besides flood depth, flood duration is also of major importance. Houses from structural type-1 were totally collapsed after 3 days of inundation. Damage of the houses of structural type-2 began after 10 days of inundation.  相似文献   

Circular Polarization Characteristics of South Polar Lunar Craters using Chandrayaan-1 Mini-SAR and LRO Mini-RF     

Om Prakash Narayan Calla  Shubhra Mathur  Monika Jangid  Kishan Lal Gadri 《Earth, Moon, and Planets》2015,115(1-4):83-100

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Microwave bursts from Jupiter due to K, N, P2 and S fragments     

Hari Om Vats  M. R. Deshpansde  O. P. N. Calla  N. M. Vadher  B. M. Darji  V. Sukumaran 《Earth, Moon, and Planets》1996,73(2):125-132

This article reports the observations of microwave emission from Jupiter during the impact of K, N, P2 and S fragments of the comet Shoemaker-Levy 9. The comparison of microwave bursts intensities produced by these impacts with the impact class and the size of the impactors reveals no correlation. This is in conformity with other observations at microwave frequencies and indicates that the process of burst emission is very complex. The impacts K and N produced three microwave bursts which could possibly be due to further fragmentation of these fragments. The results are discussed in the perspective of synchrotron emission from Jupiter and possible enhancements due to an increase in the radial diffusion coefficient. However, this model does not fully explain the observations.  相似文献   

Processing of Indian Doppler Weather Radar data for mesoscale applications   总被引：1，自引：1，他引：0  

S. K. Roy Bhowmik  Soma Sen Roy  Kuldeep Srivastava  B. Mukhopadhay  S. B. Thampi  Y. K. Reddy  Hari Singh  S. Venkateswarlu  Sourav Adhikary 《Meteorology and Atmospheric Physics》2011,111(3-4):133-147

This paper demonstrates the usefulness of Indian Doppler Weather Radar (DWR) data for nowcasting applications, and assimilation into a mesoscale Numerical Weather Prediction (NWP) model. Warning Decision Support System Integrated Information (WDSS-II) developed by National Severe Storm Laboratory (NSSL) and Advanced Regional Prediction System (ARPS) developed at the Centre for Analysis and Prediction, University of Oklahoma are used for this purpose. The study reveals that the WDSS-II software is capable of detecting and removing anomalous propagation echoes from the Indian DWR data. The software can be used to track storm cells and mesocyclones through successive scans. Radar reflectivity mosaics are created for a land-falling tropical cyclone??Khaimuk of 14 November 2008 over the Bay of Bengal using observations from three DWR stations, namely, Visakhapatnam, Machilipatnam and Chennai. Assimilation of the quality-controlled radar data (DWR, Chennai) of the WDSS-II software in a very high-resolution NWP model (ARPS) has a positive impact for improving mesoscale prediction. This has been demonstrated for a land-falling tropical cyclone Nisha of 27 November 2008 of Tamil Nadu coast. This paper also discusses the optimum scan strategy and networking considerations. This work illustrates an important step of transforming research to operation.  相似文献   

Petrogenesis of gabbro and orthopyroxene gabbro from the Phenai Mata Igneous Complex,Deccan volcanic province: Products of concurrent assimilation and fractional crystallization     

K. R. Hari  N. V. Chalapathi Rao  Vikas Swarnkar 《Journal of the Geological Society of India》2011,78(6):501-509

We report the occurrence of orthopyroxene gabbro from the Phenai Mata Igneous Complex (containing thoeliitic and alkaline rocks) that occur within Deccan Traps. The P-T calculations based on two pyroxene thermometry vary from 8.5±1.0 kbar and 963±39 °C. These gabbroic rocks exhibit high Mg# (0.67 to 0.71). But their primary magma signature can be negated due to their high SiO₂ (> 50 wt %), low Ni (32–35 ppm) and Cr (105–182 ppm) contents. Further, simple fractional crystallization was not responsible for the modification of the magma. Modeling carried out using trace element concentrations revealed that concurrent assimilation and fractional crystallization (AFC) was responsible for the genesis of these rocks. Small pods of magma could have accumulated in the crustal portions and concurrent assimilation and fractional crystallization have taken place in the generation of gabbro and orthopyroxene gabbro in the present study area.  相似文献