An efficient resampling reliability approach was developed to consider the effect of statistical uncertainties in input properties arising due to insufficient data when estimating the reliability of rock slopes and tu...An efficient resampling reliability approach was developed to consider the effect of statistical uncertainties in input properties arising due to insufficient data when estimating the reliability of rock slopes and tunnels.This approach considers the effect of uncertainties in both distribution parameters(mean and standard deviation)and types of input properties.Further,the approach was generalized to make it capable of analyzing complex problems with explicit/implicit performance functions(PFs),single/multiple PFs,and correlated/non-correlated input properties.It couples resampling statistical tool,i.e.jackknife,with advanced reliability tools like Latin hypercube sampling(LHS),Sobol’s global sensitivity,moving least square-response surface method(MLS-RSM),and Nataf’s transformation.The developed approach was demonstrated for four cases encompassing different types.Results were compared with a recently developed bootstrap-based resampling reliability approach.The results show that the approach is accurate and significantly efficient compared with the bootstrap-based approach.The proposed approach reflects the effect of statistical uncertainties of input properties by estimating distributions/confidence intervals of reliability index/probability of failure(s)instead of their fixed-point estimates.Further,sufficiently accurate results were obtained by considering uncertainties in distribution parameters only and ignoring those in distribution types.展开更多
A simple one step, reproducible, synthesis route for carbon nanotubes was proposed. No external catalyst was used for the synthesis. These nanotubes were obtained after decomposition of acetone at 650 ℃ in a speciall...A simple one step, reproducible, synthesis route for carbon nanotubes was proposed. No external catalyst was used for the synthesis. These nanotubes were obtained after decomposition of acetone at 650 ℃ in a specially designed autoclave. The pressure generated due to decomposition of acetone played a vital role in the synthesis. The X-ray diffraction pattern and transmission electron microscopy of the sample showed that the diameter of nanotubes is in the range of 3-14 nm. The thermo gravimetric analysis showed 3% weight loss below 500 ℃; the content of amorphous carbon is very less. The growth mechanism of CNTs was also proposed in the present paper.展开更多
Immunotherapy is rapidly evolving secondary to the advent of newer immunotherapeutic agents and increasing approval of the current agents by the United States Food and Drug Administration to treat a wide spectrum of c...Immunotherapy is rapidly evolving secondary to the advent of newer immunotherapeutic agents and increasing approval of the current agents by the United States Food and Drug Administration to treat a wide spectrum of cancers.Immunotherapeutic agents have gained immense popularity due to their tumorspecific action.Immunotherapy is slowly transforming into a separate therapeutic entity,and the fifth pillar of management for cancers alongside surgery,radiotherapy,chemotherapy,and targeted therapy.However,like any therapeutic entity it has its own adverse effects.With the increasing use of immunotherapeutic agents,it is vital for physicians to acquaint themselves with these adverse effects.The aim of this review is to investigate the common systemic adverse effects and toxicities associated with the use of different classes of immunotherapeutic agents.We provide an overview of potential adverse effects and toxicities associated with different classes of immunotherapeutic agents organized by organ systems,as well as an extensive discussion of the current recommendations for treatment and clinical trial data.As we continue to see increasing usage of these agents in clinical practice,it is vital for physicians to familiarize themselves with these effects.展开更多
Abstract The severe acute respiratory syndrome coronavirus 2(coronavirus disease 2019,COVID-19)pandemic has placed a tremendous burden on healthcare systems globally.Therapeutics for treatment of the virus are extreme...Abstract The severe acute respiratory syndrome coronavirus 2(coronavirus disease 2019,COVID-19)pandemic has placed a tremendous burden on healthcare systems globally.Therapeutics for treatment of the virus are extremely inconsistent due to the lack of time evaluating drug efficacy in clinical trials.Currently,there is a deficiency of published literature that comprehensively discusses all therapeutics being considered for the treatment of COVID-19.A review of the literature was performed for articles related to therapeutics and clinical trials in the context of the current COVID-19 pandemic.We used PubMed,Google Scholar,and Clinicaltrials.gov to search for articles relative to the topic of interest.We used the following keywords:“COVID-19”,“therapeutics”,“clinical trials”,“treatment”,“FDA”,“ICU”,“mortality”,and“management”.In addition,searches through the references of retrieved articles was also performed.In this paper,we have elaborated on the therapeutic strategies that have been hypothesized or trialed todate,the mechanism of action of each therapeutic,the clinical trials finished or inprocess that support the use of each therapeutic,and the adverse effects associated with each therapeutic.Currently,there is no treatment that has been proven to provide significant benefit in reducing morbidity and mortality.There are many clinical trials for numerous different therapeutic agents currently underway.By looking back and measuring successful strategies from previous pandemics in addition to carrying out ongoing research,we provide ourselves with the greatest opportunity to find treatments that are beneficial.展开更多
Amongst several biometric traits,Vein pattern biometric has drawn much attention among researchers and diverse users.It gains its importance due to its difficulty in reproduction and inherent security advantages.Many ...Amongst several biometric traits,Vein pattern biometric has drawn much attention among researchers and diverse users.It gains its importance due to its difficulty in reproduction and inherent security advantages.Many research papers have dealt with the topic of new generation biometric solutions such as iris and vein biometrics.However,most implementations have been based on small datasets due to the difficulties in obtaining samples.In this paper,a deeper study has been conducted on previously suggested methods based on Convolutional Neural Networks(CNN)using a larger dataset.Also,modifications are suggested for implementation using ensemble methods.Ensembles were used to reduce training time and cost by training multiple weak classifiers instead of a single,strong classifier.Classifiers used were CNN,Random Forest and Logistic Regression.An inexpensive and robust data acquisition system was also developed for obtaining the dataset.The obtained result shows an improved accuracy of 96.77%using ensemble method instead of dealing with a single classifier.展开更多
Traditional global sensitivity analysis(GSA)neglects the epistemic uncertainties associated with the probabilistic characteristics(i.e.type of distribution type and its parameters)of input rock properties emanating du...Traditional global sensitivity analysis(GSA)neglects the epistemic uncertainties associated with the probabilistic characteristics(i.e.type of distribution type and its parameters)of input rock properties emanating due to the small size of datasets while mapping the relative importance of properties to the model response.This paper proposes an augmented Bayesian multi-model inference(BMMI)coupled with GSA methodology(BMMI-GSA)to address this issue by estimating the imprecision in the momentindependent sensitivity indices of rock structures arising from the small size of input data.The methodology employs BMMI to quantify the epistemic uncertainties associated with model type and parameters of input properties.The estimated uncertainties are propagated in estimating imprecision in moment-independent Borgonovo’s indices by employing a reweighting approach on candidate probabilistic models.The proposed methodology is showcased for a rock slope prone to stress-controlled failure in the Himalayan region of India.The proposed methodology was superior to the conventional GSA(neglects all epistemic uncertainties)and Bayesian coupled GSA(B-GSA)(neglects model uncertainty)due to its capability to incorporate the uncertainties in both model type and parameters of properties.Imprecise Borgonovo’s indices estimated via proposed methodology provide the confidence intervals of the sensitivity indices instead of their fixed-point estimates,which makes the user more informed in the data collection efforts.Analyses performed with the varying sample sizes suggested that the uncertainties in sensitivity indices reduce significantly with the increasing sample sizes.The accurate importance ranking of properties was only possible via samples of large sizes.Further,the impact of the prior knowledge in terms of prior ranges and distributions was significant;hence,any related assumption should be made carefully.展开更多
The height of total entropy(S)for a magnetic refrigerant material is essentially concerned with the magnetic and structural transitions.However,the participation of such transitions in layered materials is not well un...The height of total entropy(S)for a magnetic refrigerant material is essentially concerned with the magnetic and structural transitions.However,the participation of such transitions in layered materials is not well understood.Therefore,the purpose of this work is to investigate the interplay between double layer lattice with their single perovskite counterpart,to achieve optimal magnetocaloric performance.A series of self-doped Pr_(1.4+x)Sr_(1.6-x)Mn_(2)O_(7)(0.0≤x≤0.5)Ruddlesden-Popper(R-P)perovskite have been prepared through the solid-state sintering method.With increasing the Pr-stoichiometry,the lattice faults have increased and the double layer lattice dramatically disintegrates into single perovskite structure.Due to the reduction of bilayer R-P phase into single perovskite the spin crossover occurs from weak bilayer(T=304 K)interactions towards the strong three-dimensional(T=308 K)interactions respectively.This series consistently develops thermomagnetic irreversibility in zero-field cooled(ZFC)-field cooled(FC)magnetization,which is indicative of a spin-glass state.The glassy nature has been ascribed collectively to the lattice strain produced because of dislocations and to an antiferromagnetic phase segregated at the surface.The maximum value of temperature average entropy change(TEC)and adiabatic temperature(ΔT)has enhanced nearly by 4 folds from 0.53 J kg^(-1)K^(-1),0.59 K(for x=0.0)up to 1.85 J kg^(-1)K^(-1),10 K(for x=0.5)at 2.5 T,respectively.Additionally,the room temperature relative cooling power has improved from 26.94 J/kg up to 77.84 J/kg with an applied field of 2.5 T.Our findings in this work suggest that the controlled reduction of double layer lattice into single perovskite and/or existence of both phases simultaneously in bilayer R-P manganites may be very effective in obtaining the desirable characteristics of magnetocaloric effects.展开更多
Linear Discriminant Analysis （LDA） is one of the principal techniques used in face recognition systems. LDA is well-known scheme for feature extraction and dimension reduction. It provides improved performance over ...Linear Discriminant Analysis （LDA） is one of the principal techniques used in face recognition systems. LDA is well-known scheme for feature extraction and dimension reduction. It provides improved performance over the standard Principal Component Analysis （PCA） method of face recognition by introducing the concept of classes and distance between classes. This paper provides an overview of PCA, the various variants of LDA and their basic drawbacks. The paper also has proposed a development over classical LDA, i.e., LDA using wavelets transform approach that enhances performance as regards accuracy and time complexity. Experiments on ORL face database clearly demonstrate this and the graphical comparison of the algorithms clearly showcases the improved recognition rate in case of the proposed algorithm.展开更多
The ongoing outbreak of severe acute respiratory syndrome coronavirus-2[SARSCoV-2,or coronavirus disease 2019(COVID-19)]was declared a pandemic by the World Health Organization on March 11,2020.Worldwide,more than 65 ...The ongoing outbreak of severe acute respiratory syndrome coronavirus-2[SARSCoV-2,or coronavirus disease 2019(COVID-19)]was declared a pandemic by the World Health Organization on March 11,2020.Worldwide,more than 65 million people have been infected with this SARS-CoV-2 virus,and over 1.5 million people have died due to the viral illness.Although a tremendous amount of medical progress has been made since its inception,there continues to be ongoing research regarding the pathophysiology,treatments,and vaccines.While a vast majority of those infected develop only mild to moderate symptoms,about 5%of people have severe forms of infection resulting in respiratory failure,myocarditis,septic shock,or multi-organ failure.Despite maximal cardiopulmonary support and invasive mechanical ventilation,mortality remains high.Extracorporeal membrane oxygenation(ECMO)remains a valid treatment option when maximal conventional strategies fail.Utilization of ECMO in the pandemic is challenging from both resource allocation and ethical standpoints.This article reviews the rationale behind its use,current status of utilization,and future considerations for ECMO in critically ill COVID-19 patients.展开更多
Silver nanowire films are promising alternatives to tin-doped indium oxide(ITO)films as transparent conductive electrodes.In this paper,we report the use of vacuum filtration and a polydimethylsiloxane(PDMS)-assisted ...Silver nanowire films are promising alternatives to tin-doped indium oxide(ITO)films as transparent conductive electrodes.In this paper,we report the use of vacuum filtration and a polydimethylsiloxane(PDMS)-assisted transfer printing technique to fabricate silver nanowire films on both rigid and flexible substrates,bringing advantages such as the capability of patterned transfer,the best performance among various ITO alternatives(10Ω/sq at 85%transparency),and good adhesion to the underlying substrate,thus eliminating the previously reported adhesion problem.In addition,our method also allows the preparation of high quality patterned films of silver nanowires with different line widths and shapes in a matter of few minutes,making it a scalable process.Furthermore,use of an anodized aluminum oxide(AAO)membrane in the transfer process allows annealing of nanowire films at moderately high temperature to obtain films with extremely high conductivity and good transparency.Using this transfer technique,we obtained silver nanowire films on a flexible polyethylene terephthalate(PET)substrate with a transparency of 85%,a sheet resistance of 10Ω/sq,with good mechanical flexibility.Detailed analysis revealed that the Ag nanowire network exhibits two-dimensional percolation behavior with good agreement between experimentally observed and theoretically predicted values of critical volume。展开更多
There is a new public health catastrophe forbidding the world.With the advent and spread of 2019 novel coro-navirus(2019-nCoV).Learning from the experiences of various countries and the World Health Organization(WHO)g...There is a new public health catastrophe forbidding the world.With the advent and spread of 2019 novel coro-navirus(2019-nCoV).Learning from the experiences of various countries and the World Health Organization(WHO)guidelines,social distancing,use of sanitizers,thermal screening,quarantining,and provision of lock-down in the cities being the effective measure that can contain the spread of the pandemic.Though complete lockdown helps in containing the spread,it generates complexity by breaking the economic activity chain.Besides,laborers,farmers,and workers may lose their daily earnings.Owing to these detrimental effects,the government has to open the lockdown strategically.Prediction of the COVID-19 spread and analyzing when the cases would stop increasing helps in developing a strategy.An attempt is made in this paper to predict the time after which the number of new cases stops rising,considering the strong implementation of lockdown conditions using three different techniques such as Decision Tree,Support Vector Machine,and Gaussian Process Regression algorithm are used to project the number of cases.Thus,the projections are used in identifying inflection points,which would help in planning the easing of lockdown in a few of the areas strategically.The criticality in a region is evaluated using the criticality index(CI),which is proposed by authors in one of the past of research works.This research work is made available in a dashboard to enable the decision-makers to combat the pandemic.展开更多
An augmented methodology is developed to estimate the reliability of deep excavations along spatially variable massive rock masses using the cohesion weakening friction strengthening(CWFS)model.Sensitive parameters of...An augmented methodology is developed to estimate the reliability of deep excavations along spatially variable massive rock masses using the cohesion weakening friction strengthening(CWFS)model.Sensitive parameters of the CWFS model were initially identified using Sobol’s global sensitivity analysis based on their influence on the displacements and excavation damage zone around excavations.The probability of failure was estimated by performing Mont–Carlo Simulations on random finite difference models of excavations generated via MATLAB-FLAC2D coupling,considering the spatial variation of these sensitive parameters.Spatial variation was modeled by generating anisotropic random fields of sensitive CWFS parameters via the recently developed Fourier series method and updated correlations suggested by Walton(2019).The proposed methodology was demonstrated for a proposed deep nuclear waste repository to be located in Canada.Results from the developed methodology were systematically compared with those of traditional reliability(ignoring spatial variation)and deterministic methods(ignoring uncertainty).Although the developed methodology was computationally complex,it was judged to be the most realistic due to the realistic consideration of heterogeneous distributions of rock properties.Traditional methodologies underestimate/overestimate the excavation performance due to negligence of uncertainty and spatial variability.Finally,a parametric analysis was performed using developed methodology by varying the initial friction angle,scale of fluctuations(SOFs)and dilation angle.The effect of initial friction angle was observed to be more pronounced on the probability of failures as compared to SOFs and dilation angle.Similar observations were made related to the excavation damage zone(EDZ)development quantified using yield area ratio.展开更多
Due to their unique activation modes,small organic molecule catalysts(organocatalysts)have proved their potential in facilitating the remote functionalizations of unsaturated acceptors with extended conjugation.The or...Due to their unique activation modes,small organic molecule catalysts(organocatalysts)have proved their potential in facilitating the remote functionalizations of unsaturated acceptors with extended conjugation.The organocatalytic 1,6-addition reaction involving the attack of nucleophiles on the δ-carbon of the α,β,γ,δ-unsaturated acceptors has emerged as an excellent strategy to create a stereocenter at the δ-site with high regio-and stereo-control.Organocatalysis has also opened the window for developing complex domino reactions involving the 1,6-addition step.Tremendous advancement has been accomplished in the organocatalytic asymmetric 1,6-addition and related domino reactions for the stereocontrolled synthesis of complex molecular structures bearing multiple stereocenters.This review article summarizes the significant advancement in stereoselective domino reactions involving 1,6-addition as a critical step.展开更多
Globally,microalgae are gaining attention due to their high nutritional value and broad application in the pharmaceutical,nutraceutical,food,cosmetics,bio-fertilizer,and biofuel industries.Microalgal-based foods have ...Globally,microalgae are gaining attention due to their high nutritional value and broad application in the pharmaceutical,nutraceutical,food,cosmetics,bio-fertilizer,and biofuel industries.Microalgal-based foods have been shown a positive impact on human health by acting as antioxidants,antimicrobials,anti-inflammatory agents,and antiviral agents.Scale-up,production cost,and safety issues are the significant challenges in microalgae product commercialization.However,various techniques have been developed to overcome these challenges and to produce microalgae bio-products in a high amount and make them safe for human and animals use.Recently,multiple techniques such as metabolic and genetic engineering have emerged to overcome these limitations.The present review focused on the application of these engineering tools to improve biomass yield and nutrient quality in microalgae.However,these tools are proved to be very effective in enhancing the nutrients in microalgae.Limited success has been achieved to improve the quality at the industrial level.展开更多
文摘An efficient resampling reliability approach was developed to consider the effect of statistical uncertainties in input properties arising due to insufficient data when estimating the reliability of rock slopes and tunnels.This approach considers the effect of uncertainties in both distribution parameters(mean and standard deviation)and types of input properties.Further,the approach was generalized to make it capable of analyzing complex problems with explicit/implicit performance functions(PFs),single/multiple PFs,and correlated/non-correlated input properties.It couples resampling statistical tool,i.e.jackknife,with advanced reliability tools like Latin hypercube sampling(LHS),Sobol’s global sensitivity,moving least square-response surface method(MLS-RSM),and Nataf’s transformation.The developed approach was demonstrated for four cases encompassing different types.Results were compared with a recently developed bootstrap-based resampling reliability approach.The results show that the approach is accurate and significantly efficient compared with the bootstrap-based approach.The proposed approach reflects the effect of statistical uncertainties of input properties by estimating distributions/confidence intervals of reliability index/probability of failure(s)instead of their fixed-point estimates.Further,sufficiently accurate results were obtained by considering uncertainties in distribution parameters only and ignoring those in distribution types.
基金Council of Scientific and Industrial Research(CSIR)India,for providing financial assistance
文摘A simple one step, reproducible, synthesis route for carbon nanotubes was proposed. No external catalyst was used for the synthesis. These nanotubes were obtained after decomposition of acetone at 650 ℃ in a specially designed autoclave. The pressure generated due to decomposition of acetone played a vital role in the synthesis. The X-ray diffraction pattern and transmission electron microscopy of the sample showed that the diameter of nanotubes is in the range of 3-14 nm. The thermo gravimetric analysis showed 3% weight loss below 500 ℃; the content of amorphous carbon is very less. The growth mechanism of CNTs was also proposed in the present paper.
文摘Immunotherapy is rapidly evolving secondary to the advent of newer immunotherapeutic agents and increasing approval of the current agents by the United States Food and Drug Administration to treat a wide spectrum of cancers.Immunotherapeutic agents have gained immense popularity due to their tumorspecific action.Immunotherapy is slowly transforming into a separate therapeutic entity,and the fifth pillar of management for cancers alongside surgery,radiotherapy,chemotherapy,and targeted therapy.However,like any therapeutic entity it has its own adverse effects.With the increasing use of immunotherapeutic agents,it is vital for physicians to acquaint themselves with these adverse effects.The aim of this review is to investigate the common systemic adverse effects and toxicities associated with the use of different classes of immunotherapeutic agents.We provide an overview of potential adverse effects and toxicities associated with different classes of immunotherapeutic agents organized by organ systems,as well as an extensive discussion of the current recommendations for treatment and clinical trial data.As we continue to see increasing usage of these agents in clinical practice,it is vital for physicians to familiarize themselves with these effects.
文摘Abstract The severe acute respiratory syndrome coronavirus 2(coronavirus disease 2019,COVID-19)pandemic has placed a tremendous burden on healthcare systems globally.Therapeutics for treatment of the virus are extremely inconsistent due to the lack of time evaluating drug efficacy in clinical trials.Currently,there is a deficiency of published literature that comprehensively discusses all therapeutics being considered for the treatment of COVID-19.A review of the literature was performed for articles related to therapeutics and clinical trials in the context of the current COVID-19 pandemic.We used PubMed,Google Scholar,and Clinicaltrials.gov to search for articles relative to the topic of interest.We used the following keywords:“COVID-19”,“therapeutics”,“clinical trials”,“treatment”,“FDA”,“ICU”,“mortality”,and“management”.In addition,searches through the references of retrieved articles was also performed.In this paper,we have elaborated on the therapeutic strategies that have been hypothesized or trialed todate,the mechanism of action of each therapeutic,the clinical trials finished or inprocess that support the use of each therapeutic,and the adverse effects associated with each therapeutic.Currently,there is no treatment that has been proven to provide significant benefit in reducing morbidity and mortality.There are many clinical trials for numerous different therapeutic agents currently underway.By looking back and measuring successful strategies from previous pandemics in addition to carrying out ongoing research,we provide ourselves with the greatest opportunity to find treatments that are beneficial.
文摘Amongst several biometric traits,Vein pattern biometric has drawn much attention among researchers and diverse users.It gains its importance due to its difficulty in reproduction and inherent security advantages.Many research papers have dealt with the topic of new generation biometric solutions such as iris and vein biometrics.However,most implementations have been based on small datasets due to the difficulties in obtaining samples.In this paper,a deeper study has been conducted on previously suggested methods based on Convolutional Neural Networks(CNN)using a larger dataset.Also,modifications are suggested for implementation using ensemble methods.Ensembles were used to reduce training time and cost by training multiple weak classifiers instead of a single,strong classifier.Classifiers used were CNN,Random Forest and Logistic Regression.An inexpensive and robust data acquisition system was also developed for obtaining the dataset.The obtained result shows an improved accuracy of 96.77%using ensemble method instead of dealing with a single classifier.
文摘Traditional global sensitivity analysis(GSA)neglects the epistemic uncertainties associated with the probabilistic characteristics(i.e.type of distribution type and its parameters)of input rock properties emanating due to the small size of datasets while mapping the relative importance of properties to the model response.This paper proposes an augmented Bayesian multi-model inference(BMMI)coupled with GSA methodology(BMMI-GSA)to address this issue by estimating the imprecision in the momentindependent sensitivity indices of rock structures arising from the small size of input data.The methodology employs BMMI to quantify the epistemic uncertainties associated with model type and parameters of input properties.The estimated uncertainties are propagated in estimating imprecision in moment-independent Borgonovo’s indices by employing a reweighting approach on candidate probabilistic models.The proposed methodology is showcased for a rock slope prone to stress-controlled failure in the Himalayan region of India.The proposed methodology was superior to the conventional GSA(neglects all epistemic uncertainties)and Bayesian coupled GSA(B-GSA)(neglects model uncertainty)due to its capability to incorporate the uncertainties in both model type and parameters of properties.Imprecise Borgonovo’s indices estimated via proposed methodology provide the confidence intervals of the sensitivity indices instead of their fixed-point estimates,which makes the user more informed in the data collection efforts.Analyses performed with the varying sample sizes suggested that the uncertainties in sensitivity indices reduce significantly with the increasing sample sizes.The accurate importance ranking of properties was only possible via samples of large sizes.Further,the impact of the prior knowledge in terms of prior ranges and distributions was significant;hence,any related assumption should be made carefully.
基金the National Research Foundation of Korea grant the Korean government(No.2018R1D1A1B07046937)。
文摘The height of total entropy(S)for a magnetic refrigerant material is essentially concerned with the magnetic and structural transitions.However,the participation of such transitions in layered materials is not well understood.Therefore,the purpose of this work is to investigate the interplay between double layer lattice with their single perovskite counterpart,to achieve optimal magnetocaloric performance.A series of self-doped Pr_(1.4+x)Sr_(1.6-x)Mn_(2)O_(7)(0.0≤x≤0.5)Ruddlesden-Popper(R-P)perovskite have been prepared through the solid-state sintering method.With increasing the Pr-stoichiometry,the lattice faults have increased and the double layer lattice dramatically disintegrates into single perovskite structure.Due to the reduction of bilayer R-P phase into single perovskite the spin crossover occurs from weak bilayer(T=304 K)interactions towards the strong three-dimensional(T=308 K)interactions respectively.This series consistently develops thermomagnetic irreversibility in zero-field cooled(ZFC)-field cooled(FC)magnetization,which is indicative of a spin-glass state.The glassy nature has been ascribed collectively to the lattice strain produced because of dislocations and to an antiferromagnetic phase segregated at the surface.The maximum value of temperature average entropy change(TEC)and adiabatic temperature(ΔT)has enhanced nearly by 4 folds from 0.53 J kg^(-1)K^(-1),0.59 K(for x=0.0)up to 1.85 J kg^(-1)K^(-1),10 K(for x=0.5)at 2.5 T,respectively.Additionally,the room temperature relative cooling power has improved from 26.94 J/kg up to 77.84 J/kg with an applied field of 2.5 T.Our findings in this work suggest that the controlled reduction of double layer lattice into single perovskite and/or existence of both phases simultaneously in bilayer R-P manganites may be very effective in obtaining the desirable characteristics of magnetocaloric effects.
文摘Linear Discriminant Analysis （LDA） is one of the principal techniques used in face recognition systems. LDA is well-known scheme for feature extraction and dimension reduction. It provides improved performance over the standard Principal Component Analysis （PCA） method of face recognition by introducing the concept of classes and distance between classes. This paper provides an overview of PCA, the various variants of LDA and their basic drawbacks. The paper also has proposed a development over classical LDA, i.e., LDA using wavelets transform approach that enhances performance as regards accuracy and time complexity. Experiments on ORL face database clearly demonstrate this and the graphical comparison of the algorithms clearly showcases the improved recognition rate in case of the proposed algorithm.
文摘The ongoing outbreak of severe acute respiratory syndrome coronavirus-2[SARSCoV-2,or coronavirus disease 2019(COVID-19)]was declared a pandemic by the World Health Organization on March 11,2020.Worldwide,more than 65 million people have been infected with this SARS-CoV-2 virus,and over 1.5 million people have died due to the viral illness.Although a tremendous amount of medical progress has been made since its inception,there continues to be ongoing research regarding the pathophysiology,treatments,and vaccines.While a vast majority of those infected develop only mild to moderate symptoms,about 5%of people have severe forms of infection resulting in respiratory failure,myocarditis,septic shock,or multi-organ failure.Despite maximal cardiopulmonary support and invasive mechanical ventilation,mortality remains high.Extracorporeal membrane oxygenation(ECMO)remains a valid treatment option when maximal conventional strategies fail.Utilization of ECMO in the pandemic is challenging from both resource allocation and ethical standpoints.This article reviews the rationale behind its use,current status of utilization,and future considerations for ECMO in critically ill COVID-19 patients.
基金funded by the U.S.Department of Energy,Office of Science and Office of Basic Energy Sciences under Award No.DE-SC0001013.
文摘Silver nanowire films are promising alternatives to tin-doped indium oxide(ITO)films as transparent conductive electrodes.In this paper,we report the use of vacuum filtration and a polydimethylsiloxane(PDMS)-assisted transfer printing technique to fabricate silver nanowire films on both rigid and flexible substrates,bringing advantages such as the capability of patterned transfer,the best performance among various ITO alternatives(10Ω/sq at 85%transparency),and good adhesion to the underlying substrate,thus eliminating the previously reported adhesion problem.In addition,our method also allows the preparation of high quality patterned films of silver nanowires with different line widths and shapes in a matter of few minutes,making it a scalable process.Furthermore,use of an anodized aluminum oxide(AAO)membrane in the transfer process allows annealing of nanowire films at moderately high temperature to obtain films with extremely high conductivity and good transparency.Using this transfer technique,we obtained silver nanowire films on a flexible polyethylene terephthalate(PET)substrate with a transparency of 85%,a sheet resistance of 10Ω/sq,with good mechanical flexibility.Detailed analysis revealed that the Ag nanowire network exhibits two-dimensional percolation behavior with good agreement between experimentally observed and theoretically predicted values of critical volume。
文摘There is a new public health catastrophe forbidding the world.With the advent and spread of 2019 novel coro-navirus(2019-nCoV).Learning from the experiences of various countries and the World Health Organization(WHO)guidelines,social distancing,use of sanitizers,thermal screening,quarantining,and provision of lock-down in the cities being the effective measure that can contain the spread of the pandemic.Though complete lockdown helps in containing the spread,it generates complexity by breaking the economic activity chain.Besides,laborers,farmers,and workers may lose their daily earnings.Owing to these detrimental effects,the government has to open the lockdown strategically.Prediction of the COVID-19 spread and analyzing when the cases would stop increasing helps in developing a strategy.An attempt is made in this paper to predict the time after which the number of new cases stops rising,considering the strong implementation of lockdown conditions using three different techniques such as Decision Tree,Support Vector Machine,and Gaussian Process Regression algorithm are used to project the number of cases.Thus,the projections are used in identifying inflection points,which would help in planning the easing of lockdown in a few of the areas strategically.The criticality in a region is evaluated using the criticality index(CI),which is proposed by authors in one of the past of research works.This research work is made available in a dashboard to enable the decision-makers to combat the pandemic.
基金supported by the Initiation Research Grant from Indian Institute of Technology Kanpur,India.
文摘An augmented methodology is developed to estimate the reliability of deep excavations along spatially variable massive rock masses using the cohesion weakening friction strengthening(CWFS)model.Sensitive parameters of the CWFS model were initially identified using Sobol’s global sensitivity analysis based on their influence on the displacements and excavation damage zone around excavations.The probability of failure was estimated by performing Mont–Carlo Simulations on random finite difference models of excavations generated via MATLAB-FLAC2D coupling,considering the spatial variation of these sensitive parameters.Spatial variation was modeled by generating anisotropic random fields of sensitive CWFS parameters via the recently developed Fourier series method and updated correlations suggested by Walton(2019).The proposed methodology was demonstrated for a proposed deep nuclear waste repository to be located in Canada.Results from the developed methodology were systematically compared with those of traditional reliability(ignoring spatial variation)and deterministic methods(ignoring uncertainty).Although the developed methodology was computationally complex,it was judged to be the most realistic due to the realistic consideration of heterogeneous distributions of rock properties.Traditional methodologies underestimate/overestimate the excavation performance due to negligence of uncertainty and spatial variability.Finally,a parametric analysis was performed using developed methodology by varying the initial friction angle,scale of fluctuations(SOFs)and dilation angle.The effect of initial friction angle was observed to be more pronounced on the probability of failures as compared to SOFs and dilation angle.Similar observations were made related to the excavation damage zone(EDZ)development quantified using yield area ratio.
基金financial support from the Council of Scientific and Industrial Research(CSIR),India(File No.:02(0422)/21/EMR-Ⅱ)the Indian Institute of Technology Jammu for providing Seed Grant(File No.:SG0002)to establish the independent research groupthe Indian Institute of Technology Jammu for the fellowships.
文摘Due to their unique activation modes,small organic molecule catalysts(organocatalysts)have proved their potential in facilitating the remote functionalizations of unsaturated acceptors with extended conjugation.The organocatalytic 1,6-addition reaction involving the attack of nucleophiles on the δ-carbon of the α,β,γ,δ-unsaturated acceptors has emerged as an excellent strategy to create a stereocenter at the δ-site with high regio-and stereo-control.Organocatalysis has also opened the window for developing complex domino reactions involving the 1,6-addition step.Tremendous advancement has been accomplished in the organocatalytic asymmetric 1,6-addition and related domino reactions for the stereocontrolled synthesis of complex molecular structures bearing multiple stereocenters.This review article summarizes the significant advancement in stereoselective domino reactions involving 1,6-addition as a critical step.
文摘Globally,microalgae are gaining attention due to their high nutritional value and broad application in the pharmaceutical,nutraceutical,food,cosmetics,bio-fertilizer,and biofuel industries.Microalgal-based foods have been shown a positive impact on human health by acting as antioxidants,antimicrobials,anti-inflammatory agents,and antiviral agents.Scale-up,production cost,and safety issues are the significant challenges in microalgae product commercialization.However,various techniques have been developed to overcome these challenges and to produce microalgae bio-products in a high amount and make them safe for human and animals use.Recently,multiple techniques such as metabolic and genetic engineering have emerged to overcome these limitations.The present review focused on the application of these engineering tools to improve biomass yield and nutrient quality in microalgae.However,these tools are proved to be very effective in enhancing the nutrients in microalgae.Limited success has been achieved to improve the quality at the industrial level.
