X-rays from supernovae remants 3C 400.2 (≡ G53.7-2.2) and MSH 15-56     

P. C. Agrawal  G. R. Riegler  K. P. Singh 《Astrophysics and Space Science》1983,89(2):279-283

Detection of two new soft X-ray sources and their identification with the supernova remnants (RNRs) 3C400.2 and MSH 15-56, is reported. From the observed X-ray flux in the 0.7–2.0 keV energy range, the X-ray luminosity of 3C400.2 is derived to be in the range of (2.7–5.3)×10³⁵ ergs s^?1 and that of MSH 15-56 in the range of (0.9–1.6)×10³⁵ ergs s^?1. If we use the standard adiabatic shockwave model for the SNR's, an age of ～(1.4–3.2)×10⁴ yr is derived for 3C400.2 whereas MSH 15-56 is found to be younger of an age of (5–10)×10³ yr.  相似文献   

Heat and mass transfer in rotating fluid with Hall current,I     

H. L. Agrawal  P. C. Ram  V. Singh 《Astrophysics and Space Science》1983,96(2):245-254

Hall effects on the hydromagnetic free convection resulting from the combined effects of thermal and mass diffusion of an electrically conducting liquid past an infinite vertical porous plate in a rotating system have been analysed. The expressions for the mean velocity, mean temperature in the boundary layer and the mean skin friction, the mean rate of heat transfer on the plate are derived. The effects of magnetic parameterM, Hall parameterm, Schmidt number Sc, and Ekman numberE on the flow field, are discussed with the help of graphs and tables.  相似文献   

Data modelling for crude oil migration studies using ranking method: a rapid geo-tracer technique for geochemists     

Oluwabamise L. Faboya  Oluwadayo O. Sonibare  Olusola T. Faboya  Utkarsh Agrawal  Zewen Liao  O. Ekundayo 《中国地球化学学报》2018,37(6):901-910

The direction of oil charges within a field in the Niger Delta, Nigeria was determined by the sum of differences ranking method of carbazole concentrations after ascertaining other possible geological constraints on their compositional variations. The principle is that the smaller the sum, the closer the well to the source kitchen. The approach makes use of carbazoles’ interaction with the matrix, which leads to a reduction in their concentration with increasing distance from the source kitchen, allowing prediction of the charging direction. A wide range of compositional variations was observed for C₁ (806.72–2152.90 μg/g) and C₂ (767–2469.72 μg/g) carbazoles within the field. Based on these results, we inferred a filling pathway orientation from west to east. This suggests that the source kitchen—the most promising region for oil exploration—is located in the western part of the oil field.  相似文献   

Evaluation of initiating system by measurement of seismic energy dissipation in surface blasting     

Hemant Agrawal  A. K. Mishra 《Arabian Journal of Geosciences》2018,11(13):345

Enhanced demand for coal and minerals in the country has forced mine operators for mass production through large opencast mines. Heavy blasting and a large amount of explosive use have led to increased environmental problems, which may have potential harm and causes a disturbance. Ground vibrations generated due to blasting operations in mines and quarries are a very important environmental aspect. It is clear that a small amount of total explosive energy is being utilized in blasting for breakage of rock mass, while the rest is being wasted. The amount of energy which is wasted causes various environmental issues such as ground vibrations, air overpressure, and fly rock. Ground vibrations caused by blasting cannot be eliminated entirely, yet they can be minimized as far as possible through a suitable blasting methodology. A considerable amount of work has been done to identify ground vibrations and assess the blast performance regarding the intensity of ground vibrations, i.e., peak particle velocity and frequency spectrum. However, not much research has done into reducing the seismic energy wasted during blasting leading to ground vibrations. In this paper, the blast-induced ground vibrations in three orthogonal directions, i.e., transverse, vertical, and longitudinal, were recorded at different distances using seismographs. An attempt has been made for the estimation of the percentage of explosive energy dissipated in the form of seismic energy with electronic and non-electric (NONEL) initiation system. signal processing techniques with the help of DADiSP software is used to study the same.  相似文献   

Assessment of greenhouse gas emissions from coal and natural gas thermal power plants using life cycle approach   总被引：2，自引：1，他引：1  

K. Kr. Agrawal  S. Jain  A. Kr. Jain  S. Dahiya 《International Journal of Environmental Science and Technology》2014,11(4):1157-1164

The importance of mitigation of climate change due to greenhouse gas (GHG) emissions from various developmental and infrastructure projects has generated interest at global level to reduce environmental impacts. Life cycle assessment may be used as a tool to assess GHG emissions and subsequent environmental impacts resulting from electricity generation from thermal power plants. This study uses life cycle approach for assessing GHG emissions and their impacts due to natural gas combined cycle (NGCC) and imported coal thermal power plants using the IPCC 2001 and Eco-Indicator 99(H) methods in India for the first time. The total GHG emission from the NGCC thermal power plant was 584 g CO₂ eq/kWh electricity generation, whereas in case of imported coal, it was 1,127 g CO₂ eq/kWh electricity generation. This shows that imported coal has nearly ~2 times more impacts when compared to natural gas in terms of global warming potential and human health as disability-adjusted life years from climate change due to GHG emissions such as carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O).  相似文献   

Geological and mineralogical study of eclogite and glaucophane schists in the Naga Hills Ophiolite,Northeast India     

Naresh C. Ghose  Om Prakash Agrawal  Nilanjan Chatterjee 《Island Arc》2010,19(2):336-356

A variety of low‐ to high‐pressure metamorphic assemblages occur in the metabasic rocks and metachert in the Upper Cretaceous–Eocene ophiolite belt of the central part of the Naga Hills, an area in the northern sector of the Indo–Myanmar Ranges in the Indo–Eurasian collision zone. The ophiolite suite includes peridotite tectonite containing garnet lherzolite xenoliths, layered ultramafic–mafic cumulates, metabasic rocks, basaltic lava, volcaniclastics, plagiogranite, and pelagic sediments emplaced as dismembered and imbricated bodies at thrust contacts between moderately metamorphosed accretionary rocks/basement (Nimi Formation/Naga Metamorphics) and marine sediments (Disang Flysch). It is overlain by coarse clastic Paleogene sediments of ophiolite‐derived rocks (Jopi/Phokphur Formation). The metabasic rocks, including high‐grade barroisite/glaucophane‐bearing epidote eclogite and glaucophane schist, and low‐grade greenschist and prehnite–clinochlore schist, are associated with lava flows and ultramafic cumulates at the western thrust contact. Chemically, the metabasites show a low‐K tholeiitic affinity that favors derivation from a depleted mantle source as in the case of mid‐ocean ridge basalt. Thermobarometry indicates peak P–T conditions of about 20 kb and 525°C. Retrogression related to uplift is marked by replacement of barroisite and omphacite by glaucophane followed by secondary actinolite, albite, and chlorite formation. A metabasic lens with an eclogite core surrounded by successive layers of glaucophane schist and greenschist provides field evidence of retrogression and uplift. Presence of S‐C mylonite in garnet lherzolite and ‘mica fish’ in glaucophane schist indicates ductile deformation in the shear zone along which the ophiolite was emplaced.  相似文献   

Twin lintel belt in steel for seismic strengthening of brick masonry buildings   总被引：2，自引：1，他引：1  

C.V.R.Murty JayantaDutta S.K.Agrawal 《地震工程与工程振动(英文版)》2004,3(2):215-222

A single-room, single-storey full-scale brick masonry building with precast RC roofing system was tested thric eunder displacement controlled lateral cyclic loading, to assess the effectiveness of the basic repair and seismic strengthening techniques. Initially, the virgin building specimen was loaded laterally to failure, In the second stage, the damaged building was repaired by stitching across the cracks, and tested under the same lateral loading. In the third stage, the twice-damaged structure was repaired once more by stitching and strengthened by twin lintel belt in steel and vertical corner reinforcement,and re-tested. The building strengthened by twin lintel belt in steel showed about 28% higher strength under lateral loading than the virgin building.  相似文献   

Journey through the birth,growth and maturity of X-ray astronomy     

Prahlad Chandra Agrawal 《天文和天体物理学研究(英文版)》2019,(10)

  相似文献   

A synoptic-climatic study of the onset of southwest monsoon over Mumbai   总被引：1，自引：0，他引：1  

Shravan Kumar  Thakur Prasad  Asha Lata Agrawal 《Journal of Earth System Science》1999,108(4):321-326

Surface and upper air synoptic features prevailing at the time of onset of southwest monsoon over Mumbai have been examined for a period of 50 years from 1947 to 1996. These synoptic situations have been found to fall under three broad categories. The study shows that on about 66% of the occasions, the onset of monsoon over Mumbai is caused by low pressure area forming over southeast and east central Arabian Sea as they move northwards, while on 28% of the occasions, the onset is due to the low pressure systems forming over northwest/head Bay of Bengal and their movement towards northwest/west northwest. Based on the findings of the study and the climatological aspects, a criterion for declaring onset over Mumbai has been suggested.  相似文献   

Urban land consolidation: a review of policy and procedures in Indonesia and other Asian countries   总被引：3，自引：0，他引：3  

P. Agrawal 《GeoJournal》1999,49(3):311-322

Many Asian mega-cities are growing rapidly and they face formidable urban problems: unplanned squatter settlements, inadequate infrastructure and basic amenities. Smaller Asian urban areas also need badly the provision of basic infrastructure and facilities. However, efforts to improve are often constrained by either nonavailability of suitable land or its exorbitant cost. Strategies such as land consolidation have shown considerable promise. Implementation of the strategy varies from country to country and from project to project. In general, the land consolidation approach is participatory in nature and places emphasis on in situ development with voluntary contribution of private assets by affected households in need of infrastructure and basic services. However, to make any significant impact of the land consolidation strategy on urban development, financial support from multilateral agencies such as the World Bank is necessary. To enable this it is necessary that the policy and implementation procedures fully conform to the objectives of the World Bank's safeguard policies such as OD 4.30 `Involuntary Resettlement'. This study reviews the land consolidation policies and procedures as applied in several Asian countries in general, and in Indonesia in particular. The objective is to identify the gaps that exist between the policy and procedures and that of the objectives of the World Bank's Policy of Involuntary resettlement and to recommend general policy and procedural guidelines for land consolidation projects that would enable financial support from multilateral agencies such as the World Bank. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献