BACKGROUND Non-alcoholic fatty liver disease(NAFLD)increases the risk of cardiovascular diseases independently of other risk factors.However,data on its effect on cardiovascular outcomes in coronavirus disease 2019(CO...BACKGROUND Non-alcoholic fatty liver disease(NAFLD)increases the risk of cardiovascular diseases independently of other risk factors.However,data on its effect on cardiovascular outcomes in coronavirus disease 2019(COVID-19)hospitalizations with varied obesity levels is scarce.Clinical management and patient care depend on understanding COVID-19 admission results in NAFLD patients with varying obesity levels.AIM To study the in-hospital outcomes in COVID-19 patients with NAFLD by severity of obesity.METHODS COVID-19 hospitalizations with NAFLD were identified using International Classification of Disease-10 CM codes in the 2020 National Inpatient Sample database.Overweight and Obesity Classes Ⅰ,Ⅱ,and Ⅲ(body mass index 30-40)were compared.Major adverse cardiac and cerebrovascular events(MACCE)(all-cause mortality,acute myocardial infarction,cardiac arrest,and stroke)were compared between groups.Multivariable regression analyses adjusted for sociodemographic,hospitalization features,and comorbidities.RESULTS Our analysis comprised 13260 hospitalizations,7.3% of which were overweight,24.3% Class Ⅰ,24.1% Class Ⅱ,and 44.3% Class Ⅲ.Class Ⅲ obesity includes younger patients,blacks,females,diabetics,and hypertensive patients.On multivariable logistic analysis,Class Ⅲ obese patients had higher risks of MACCE,inpatient mortality,and respiratory failure than Class Ⅰ obese patients.Class Ⅱ obesity showed increased risks of MACCE,inpatient mortality,and respiratory failure than Class I,but not significantly.All obesity classes had non-significant risks of MACCE,inpatient mortality,and respiratory failure compared to the overweight group.CONCLUSION Class Ⅲ obese NAFLD COVID-19 patients had a greater risk of adverse outcomes than class Ⅰ.Using the overweight group as the reference,unfavorable outcomes were not significantly different.Morbid obesity had a greater risk of MACCE regardless of the referent group(overweight or Class Ⅰ obese)compared to overweight NAFLD patients admitted with COVID-19.展开更多
Coal is the major source of power in India and world over.Coal mining is an essential industry which has a major role in the economic development of the country.Most major mining activities contribute directly or indi...Coal is the major source of power in India and world over.Coal mining is an essential industry which has a major role in the economic development of the country.Most major mining activities contribute directly or indirectly to air pollution.Coal dust is a major air pollutant which affects the personal working in the mines and also people residing in villages near the mines.Air pollution due to coal particulates can affect human health and cause damages to the environment.Hence effective pollution control mechanisms are needed to keep the pollution levels within permissible levels.The easiest and most common method employed for dust suppression worldwide is sprinkling of water.In majority of mines,water sprinklers are operated manually and can lead to wastage of water due to over sprinkling.It can also prove to be ineffective in dust suppression if sprinkling is not done properly.The paper proposes a system which can be deployed to automate the dust suppressions sprinklers.The system will monitor the concentration of PM_(10) and PM_(2.5) in the air and initiate sprinkling operation when the particulate matter content exceeds preconfigured limits.展开更多
Wire electric discharge machining(WEDM)process is used for precision manufacturing.The accuracy of machining is function of various parameters like current,voltage,wire speed,gap between wire and work piece,wire oscil...Wire electric discharge machining(WEDM)process is used for precision manufacturing.The accuracy of machining is function of various parameters like current,voltage,wire speed,gap between wire and work piece,wire oscillation,work material,wire material,etc.Once the process parameters are selected,it is important that the wire vibrations are less to obtain a good surface finish.Due to the importance of wire vibration in obtaining the surface finish,it is necessary to study the wire vibration.This paper discusses different models of wire vibration presented in the literature and simulates a closed form solution of wire vibration using MATLAB.The transverse vibration of wire is analysed as forced vibration of moving wire with excitation due to the sparks during machining.The resulting partial differential equation is solved by using finite difference method and vibration is also simulated in the finite element package‘ANSYS’.The wire behaviour is investigated under different operating conditions and results of the two methods are展开更多
Urban road dust was collected from Vellore City,Tamil Nadu,India,and analyzed.Scanning electron microscopy(SEM)was used to examine road dust from nine sampling locations in the study region.SEM image analysis was used...Urban road dust was collected from Vellore City,Tamil Nadu,India,and analyzed.Scanning electron microscopy(SEM)was used to examine road dust from nine sampling locations in the study region.SEM image analysis was used to identify various shape factors of collected dust particles.The equivalent spherical diameter of most particles was between 10μm and 30μm.Fine particles had greater concentrations at locations with higher traffic flow.Particles were categorized into four classes based on their shape factors,viz.,spherical,mineral,elongated,or irregular.Spherical particles had the smallest mean equivalent diameter(1.95μm)and mineral particles had the largest diameter(33.3μm).Spherical particles made up the smallest portion of road dust(0-12%)in the study region and mineral particles made up the largest(45-65%).Elongated and irregular particles,each made up 23-30%of road dust.Electron dispersive X-ray spectroscopy analysis was used to identify the elemental composition of dust particles.Spherical particles were mostly from combustion sources and mineral particles were largely of crustal origin.No individual source was found for irregular and elongated particles.Biological debris was the major source of irregular particles.展开更多
Site-specific seismic hazard analysis is crucial for designing earthquake resistance structures,particularly in seismically active regions.Shear wave velocity(V_(S))is a key parameter in such analysis,although the eco...Site-specific seismic hazard analysis is crucial for designing earthquake resistance structures,particularly in seismically active regions.Shear wave velocity(V_(S))is a key parameter in such analysis,although the economy and other factors restrict its direct field measurement in many cases.Various V_(S)-SPT-N correlations are routinely incorporated in seismic hazard analysis to estimate the value of V_(S).However,many uncertainties question the reliability of these estimated V_(S)values.This paper comes up with a statistical approach to take care of such uncertainties involved in V_(S)calculations.The measured SPT-N values from all the critical boreholes were converted into statistical parameters and passed through various correlations to estimate V_(S)at different depths.The effect of different soil layers in the boreholes on the V_(S)estimation was also taken into account.Further,the average shear wave velocity of the top 30 m soil coverV_(S30))is estimated after accounting for various epistemic and aleatoric uncertainties.The scattering nature of the V_(S)values estimated using different V_(S)-N correlations was reduced significantly with the application of the methodology.Study results further clearly demonstrated the potential of the approach to eliminate various uncertainties involved in the estimation of V_(S)30 using general and soil-specific correlations.展开更多
DC microgrids(DCMGs)are made up of a network of sources and loads that are connected by a number of power electronic converters(PECs).The increase in the number of these PECs instigates major concerns in system stabil...DC microgrids(DCMGs)are made up of a network of sources and loads that are connected by a number of power electronic converters(PECs).The increase in the number of these PECs instigates major concerns in system stability.While interconnecting the microgrids to form a cluster,the system stability must be ensured.This paper proposes a novel stepby-step system matrix building(SMB)algorithm to update the system matrix of an existing DCMG cluster when a new microgrid is added to the cluster through a distribution line.The stability of the individual DCMGs and the DCMG cluster is analyzed using the eigenvalue method.Further,the particle swarm optimization(PSO)algorithm is used to retune the controller gains if the newly formed cluster is not stable.The simulation of the DCMG cluster is carried out in MATLAB/Simulink environment to test the proposed algorithm.The results are also validated using the OP4510 real-time simulator(RTS).展开更多
DC microgrids are gaining more attention with the increased penetration of various DC sources such as solar photovoltaic systems, fuel cells, batteries, etc., and DC loads. Due to the rapid integration of these compon...DC microgrids are gaining more attention with the increased penetration of various DC sources such as solar photovoltaic systems, fuel cells, batteries, etc., and DC loads. Due to the rapid integration of these components into the existing power system, the importance of DC microgrids has reached a salient point. Compared with conventional AC systems, DC systems are free from synchronization issues, reactive power control, frequency control, etc., and are more reliable and efficient.However, many challenges need to be addressed for utilizing DC power to its full potential. The absence of natural current zero is a significant issue in protecting DC systems. In addition,the stability of the DC microgrid, which relies on inertia, needs to be considered during system design. Moreover, power quality and communication issues are also significant challenges in DC microgrids. This paper presents a review of various value streams of DC microgrids including architectures, protection schemes, power quality, inertia, communication, and economic operation. In addition, comparisons between different microgrid configurations, the state-of-the-art projects of DC microgrid, and future trends are also set forth for further studies.展开更多
文摘BACKGROUND Non-alcoholic fatty liver disease(NAFLD)increases the risk of cardiovascular diseases independently of other risk factors.However,data on its effect on cardiovascular outcomes in coronavirus disease 2019(COVID-19)hospitalizations with varied obesity levels is scarce.Clinical management and patient care depend on understanding COVID-19 admission results in NAFLD patients with varying obesity levels.AIM To study the in-hospital outcomes in COVID-19 patients with NAFLD by severity of obesity.METHODS COVID-19 hospitalizations with NAFLD were identified using International Classification of Disease-10 CM codes in the 2020 National Inpatient Sample database.Overweight and Obesity Classes Ⅰ,Ⅱ,and Ⅲ(body mass index 30-40)were compared.Major adverse cardiac and cerebrovascular events(MACCE)(all-cause mortality,acute myocardial infarction,cardiac arrest,and stroke)were compared between groups.Multivariable regression analyses adjusted for sociodemographic,hospitalization features,and comorbidities.RESULTS Our analysis comprised 13260 hospitalizations,7.3% of which were overweight,24.3% Class Ⅰ,24.1% Class Ⅱ,and 44.3% Class Ⅲ.Class Ⅲ obesity includes younger patients,blacks,females,diabetics,and hypertensive patients.On multivariable logistic analysis,Class Ⅲ obese patients had higher risks of MACCE,inpatient mortality,and respiratory failure than Class Ⅰ obese patients.Class Ⅱ obesity showed increased risks of MACCE,inpatient mortality,and respiratory failure than Class I,but not significantly.All obesity classes had non-significant risks of MACCE,inpatient mortality,and respiratory failure compared to the overweight group.CONCLUSION Class Ⅲ obese NAFLD COVID-19 patients had a greater risk of adverse outcomes than class Ⅰ.Using the overweight group as the reference,unfavorable outcomes were not significantly different.Morbid obesity had a greater risk of MACCE regardless of the referent group(overweight or Class Ⅰ obese)compared to overweight NAFLD patients admitted with COVID-19.
文摘Coal is the major source of power in India and world over.Coal mining is an essential industry which has a major role in the economic development of the country.Most major mining activities contribute directly or indirectly to air pollution.Coal dust is a major air pollutant which affects the personal working in the mines and also people residing in villages near the mines.Air pollution due to coal particulates can affect human health and cause damages to the environment.Hence effective pollution control mechanisms are needed to keep the pollution levels within permissible levels.The easiest and most common method employed for dust suppression worldwide is sprinkling of water.In majority of mines,water sprinklers are operated manually and can lead to wastage of water due to over sprinkling.It can also prove to be ineffective in dust suppression if sprinkling is not done properly.The paper proposes a system which can be deployed to automate the dust suppressions sprinklers.The system will monitor the concentration of PM_(10) and PM_(2.5) in the air and initiate sprinkling operation when the particulate matter content exceeds preconfigured limits.
文摘Wire electric discharge machining(WEDM)process is used for precision manufacturing.The accuracy of machining is function of various parameters like current,voltage,wire speed,gap between wire and work piece,wire oscillation,work material,wire material,etc.Once the process parameters are selected,it is important that the wire vibrations are less to obtain a good surface finish.Due to the importance of wire vibration in obtaining the surface finish,it is necessary to study the wire vibration.This paper discusses different models of wire vibration presented in the literature and simulates a closed form solution of wire vibration using MATLAB.The transverse vibration of wire is analysed as forced vibration of moving wire with excitation due to the sparks during machining.The resulting partial differential equation is solved by using finite difference method and vibration is also simulated in the finite element package‘ANSYS’.The wire behaviour is investigated under different operating conditions and results of the two methods are
文摘Urban road dust was collected from Vellore City,Tamil Nadu,India,and analyzed.Scanning electron microscopy(SEM)was used to examine road dust from nine sampling locations in the study region.SEM image analysis was used to identify various shape factors of collected dust particles.The equivalent spherical diameter of most particles was between 10μm and 30μm.Fine particles had greater concentrations at locations with higher traffic flow.Particles were categorized into four classes based on their shape factors,viz.,spherical,mineral,elongated,or irregular.Spherical particles had the smallest mean equivalent diameter(1.95μm)and mineral particles had the largest diameter(33.3μm).Spherical particles made up the smallest portion of road dust(0-12%)in the study region and mineral particles made up the largest(45-65%).Elongated and irregular particles,each made up 23-30%of road dust.Electron dispersive X-ray spectroscopy analysis was used to identify the elemental composition of dust particles.Spherical particles were mostly from combustion sources and mineral particles were largely of crustal origin.No individual source was found for irregular and elongated particles.Biological debris was the major source of irregular particles.
文摘Site-specific seismic hazard analysis is crucial for designing earthquake resistance structures,particularly in seismically active regions.Shear wave velocity(V_(S))is a key parameter in such analysis,although the economy and other factors restrict its direct field measurement in many cases.Various V_(S)-SPT-N correlations are routinely incorporated in seismic hazard analysis to estimate the value of V_(S).However,many uncertainties question the reliability of these estimated V_(S)values.This paper comes up with a statistical approach to take care of such uncertainties involved in V_(S)calculations.The measured SPT-N values from all the critical boreholes were converted into statistical parameters and passed through various correlations to estimate V_(S)at different depths.The effect of different soil layers in the boreholes on the V_(S)estimation was also taken into account.Further,the average shear wave velocity of the top 30 m soil coverV_(S30))is estimated after accounting for various epistemic and aleatoric uncertainties.The scattering nature of the V_(S)values estimated using different V_(S)-N correlations was reduced significantly with the application of the methodology.Study results further clearly demonstrated the potential of the approach to eliminate various uncertainties involved in the estimation of V_(S)30 using general and soil-specific correlations.
文摘DC microgrids(DCMGs)are made up of a network of sources and loads that are connected by a number of power electronic converters(PECs).The increase in the number of these PECs instigates major concerns in system stability.While interconnecting the microgrids to form a cluster,the system stability must be ensured.This paper proposes a novel stepby-step system matrix building(SMB)algorithm to update the system matrix of an existing DCMG cluster when a new microgrid is added to the cluster through a distribution line.The stability of the individual DCMGs and the DCMG cluster is analyzed using the eigenvalue method.Further,the particle swarm optimization(PSO)algorithm is used to retune the controller gains if the newly formed cluster is not stable.The simulation of the DCMG cluster is carried out in MATLAB/Simulink environment to test the proposed algorithm.The results are also validated using the OP4510 real-time simulator(RTS).
文摘DC microgrids are gaining more attention with the increased penetration of various DC sources such as solar photovoltaic systems, fuel cells, batteries, etc., and DC loads. Due to the rapid integration of these components into the existing power system, the importance of DC microgrids has reached a salient point. Compared with conventional AC systems, DC systems are free from synchronization issues, reactive power control, frequency control, etc., and are more reliable and efficient.However, many challenges need to be addressed for utilizing DC power to its full potential. The absence of natural current zero is a significant issue in protecting DC systems. In addition,the stability of the DC microgrid, which relies on inertia, needs to be considered during system design. Moreover, power quality and communication issues are also significant challenges in DC microgrids. This paper presents a review of various value streams of DC microgrids including architectures, protection schemes, power quality, inertia, communication, and economic operation. In addition, comparisons between different microgrid configurations, the state-of-the-art projects of DC microgrid, and future trends are also set forth for further studies.
