Ground subsidence induced by extraction of coal seam belowground brings about changes in surface environment leading to trough and pot-hole subsidence.Pot-hole subsidence is extremely hazardous and does not give any p...Ground subsidence induced by extraction of coal seam belowground brings about changes in surface environment leading to trough and pot-hole subsidence.Pot-hole subsidence is extremely hazardous and does not give any prior indication before its occurrence.In India,several pot-holes have occurred in the coal mines of South Eastern Coalfields Limited triggering the need for in-depth studies.In line with the requirement,literature review and field investigations were conducted to develop an in-depth understanding of various parameters influencing the occurrence of pot-holes.The critical parameters identified were rock to soil ratio,depth to height of extraction ratio,brittleness index of rock and rock density.Risk assessment of pot-hole subsidence has been done by developing an empirical rating approach named as pot-hole subsidence rating(PHSR),involving the critical parameters with suitable corrections for certain structural and mining conditions to obtain corrected PHSR(CPHSR).CPHSR was then applied for all the 34pot-holes studied and it was found that all the pot-holes fall under Class I and Class II category of risk representing a very high to high risk class.An effort was made for the estimation of pot-hole depth utilizing the developed CPHSR in both the development and depillaring cases.The developed approach was found to yield consistent results in pot-hole depth prediction.展开更多
The aim of this study was to analyse the responses to HIV/AIDS in BRICS （Brazil, Russia, India, China and South Africa） countries to determine if they are winning the war on this pandemic. The authors used a compara...The aim of this study was to analyse the responses to HIV/AIDS in BRICS （Brazil, Russia, India, China and South Africa） countries to determine if they are winning the war on this pandemic. The authors used a comparative case study approach and multiple data sources on HIV prevalence, incidence, mortality, and risk factors of HIV. BRICS has 42% of the world＇s population, a total of 11.1 million people living with HIV （PLHIV） and an average HIV prevalence of 2.8%. Overall, there were 11.1 million PLHIV, 739,909 new infections, and 592,786 deaths in BRICS countries in 2012. The magnitude of HIV in BRICS countries was Brazil （.5%）, Russia （1.1%）, India （.3%）, China （.1%）, and South Africa （12.2%）. New infections declined by 30% or more and overall prevalence and deaths also declined in Brazil, India, China, and South Africa. The epidemic has stabilized in Brazil at .6%. Russia has one of the world＇s fastest-growing H1V epidemics, India has the largest burden of HIV in Asia and South Africa has the largest number of PLHIV. During a 10 year period, Russia had a 47% increase in new HIV infections. This suggests that Russia may be losing the battle against HIV at this stage. On the other hand, India and South Africa seem to have turned the corner with declines in HIV infections of 43% and 38% respectively.展开更多
基金Financial support for this work is provided by M/s SECL,CIL,India
文摘Ground subsidence induced by extraction of coal seam belowground brings about changes in surface environment leading to trough and pot-hole subsidence.Pot-hole subsidence is extremely hazardous and does not give any prior indication before its occurrence.In India,several pot-holes have occurred in the coal mines of South Eastern Coalfields Limited triggering the need for in-depth studies.In line with the requirement,literature review and field investigations were conducted to develop an in-depth understanding of various parameters influencing the occurrence of pot-holes.The critical parameters identified were rock to soil ratio,depth to height of extraction ratio,brittleness index of rock and rock density.Risk assessment of pot-hole subsidence has been done by developing an empirical rating approach named as pot-hole subsidence rating(PHSR),involving the critical parameters with suitable corrections for certain structural and mining conditions to obtain corrected PHSR(CPHSR).CPHSR was then applied for all the 34pot-holes studied and it was found that all the pot-holes fall under Class I and Class II category of risk representing a very high to high risk class.An effort was made for the estimation of pot-hole depth utilizing the developed CPHSR in both the development and depillaring cases.The developed approach was found to yield consistent results in pot-hole depth prediction.
文摘The aim of this study was to analyse the responses to HIV/AIDS in BRICS （Brazil, Russia, India, China and South Africa） countries to determine if they are winning the war on this pandemic. The authors used a comparative case study approach and multiple data sources on HIV prevalence, incidence, mortality, and risk factors of HIV. BRICS has 42% of the world＇s population, a total of 11.1 million people living with HIV （PLHIV） and an average HIV prevalence of 2.8%. Overall, there were 11.1 million PLHIV, 739,909 new infections, and 592,786 deaths in BRICS countries in 2012. The magnitude of HIV in BRICS countries was Brazil （.5%）, Russia （1.1%）, India （.3%）, China （.1%）, and South Africa （12.2%）. New infections declined by 30% or more and overall prevalence and deaths also declined in Brazil, India, China, and South Africa. The epidemic has stabilized in Brazil at .6%. Russia has one of the world＇s fastest-growing H1V epidemics, India has the largest burden of HIV in Asia and South Africa has the largest number of PLHIV. During a 10 year period, Russia had a 47% increase in new HIV infections. This suggests that Russia may be losing the battle against HIV at this stage. On the other hand, India and South Africa seem to have turned the corner with declines in HIV infections of 43% and 38% respectively.
