This study explores,for the first time,the influence of various C1 gases,such as methane(CH_(4)),carbon dioxide(CO_(2)),and biogas(CH4+CO_(2)),on catalytic pyrolysis of plastic waste(polypropylene)to evaluate their po...This study explores,for the first time,the influence of various C1 gases,such as methane(CH_(4)),carbon dioxide(CO_(2)),and biogas(CH4+CO_(2)),on catalytic pyrolysis of plastic waste(polypropylene)to evaluate their potential in producing aromatic hydrocarbons.Also,this study used the 0.5 wt%,1 wt%,3 wt%,and 5 wt%Ga-modified ZSM-5 catalyst and its reduction-oxidation processed catalysts owing to their promising catalytic properties.According to the results,the highest yield(39.5 wt%)of BTEX(benzene,toluene,xylene,and ethylbenzene)was achieved under CH4 over RO-GHZ(1)catalyst among all tested conditions.The reduction-oxidation process not only promotes a significant reduction of the Ga-size but also induces its diffusion inside the pore,compared to GHZ(1).This leads to the formation of highly active GaO^(+)ionic species,balancing the Lewis/Brönsted ratio,thereby accelerating the aromatization reaction.The effect of Ga loading on the RO-GHZ catalyst was also evaluated systematically,which showed a negative impact on the BTEX yield owing to the lowering in the concentration of active GaO+species.A detailed catalyst characterization supports the experimental results well.展开更多
A qualitative analysis of the diameter of the spherical head of a long positive Jet streamer above thundercloud is presented in this paper under uniform atmospheric condition for streamers of less than 7 km length. In...A qualitative analysis of the diameter of the spherical head of a long positive Jet streamer above thundercloud is presented in this paper under uniform atmospheric condition for streamers of less than 7 km length. In this study, an attempt is made to replicate laboratory-based point electrode discharge model for jet streamers originating above the thunderclouds. In laboratory conditions, it is not possible to produce huge electrode potentials which could be the reason that the streamers generated under the controlled lab environment have diameter of the order of only a few centimeter and length of a few millimeter. On the other hand, the thunderclouds carry huge electrical charges, for example 50 C, which can produce huge electrical potentials of the order of several hundred MeV. Such huge potential can act as the potential of a point electrode which may be capable of producing very large and thicker streamers above the thunderclouds. So, a leader mechanism of streamer initiation is assumed in calculations as the tip of conducting leader channel can act as point electrode carrying huge cloud potential to generate large streamers. It is found in this study that as the streamer moves larger distance away from the electrode (leader tip), the diameter of the streamer head decreases. Higher the potential of the electrode (leader tip), thicker is the streamer and more slowly the diameter decreases. Also, it is also found in our calculations that for higher electrode (leader tip) potential lower is the altitude of initiation of streamers.展开更多
Mycobacterium avium subsp. paratuberculosis causes chronic inflammation of the intestine known as Johne’s disease (JD) in domestic and wild ruminants including primates. MAP has also been associated with inflammatory...Mycobacterium avium subsp. paratuberculosis causes chronic inflammation of the intestine known as Johne’s disease (JD) in domestic and wild ruminants including primates. MAP has also been associated with inflammatory bowel disease (IBD) so called Crohn’s disease (CD) of human beings, which is incurable even after surgery. By virtue of the pasteurization resistant power, high endemicity of the infection in animals continues to be the permanent source of infection to human population. High bio-burden of MAP in wide range of biotic (animal hosts including human beings) and abiotic environment in each and every country where it has been investigated, serves a reminder about the survival abilities of the MAP in diverse range of environmental conditions. Ability of the MAP to evade immune system of the host and the temporal events during infection of the macro-phages, is an area of major concern and research activities as the pattern of distribution are quiet different from those of other pathogenic intracellular organisms. Moreover, the organism can survive over a wide range of environmental conditions such as high and low environmental temperatures, pasteurization, low pH, and high salt concentration etc. This superior survival efficiency from environmental degradation and dormancy within host allows the pathogen to be available for causing disease and pathogenicity in animals and human beings, when conditions are favorable. Perusal of literature reveal that, despite the availability of whole genome sequence of MAP, a very little is known about the replication, persistence and survival mechanisms of this pathogen. Therefore, this review tries to address the survival mechanisms of Mycobacterium avium subspecies paratuberculosis in the different host species and adverse environmental conditions in order to allow designing of more rational diagnostic and control procedures.展开更多
文摘This study explores,for the first time,the influence of various C1 gases,such as methane(CH_(4)),carbon dioxide(CO_(2)),and biogas(CH4+CO_(2)),on catalytic pyrolysis of plastic waste(polypropylene)to evaluate their potential in producing aromatic hydrocarbons.Also,this study used the 0.5 wt%,1 wt%,3 wt%,and 5 wt%Ga-modified ZSM-5 catalyst and its reduction-oxidation processed catalysts owing to their promising catalytic properties.According to the results,the highest yield(39.5 wt%)of BTEX(benzene,toluene,xylene,and ethylbenzene)was achieved under CH4 over RO-GHZ(1)catalyst among all tested conditions.The reduction-oxidation process not only promotes a significant reduction of the Ga-size but also induces its diffusion inside the pore,compared to GHZ(1).This leads to the formation of highly active GaO^(+)ionic species,balancing the Lewis/Brönsted ratio,thereby accelerating the aromatization reaction.The effect of Ga loading on the RO-GHZ catalyst was also evaluated systematically,which showed a negative impact on the BTEX yield owing to the lowering in the concentration of active GaO+species.A detailed catalyst characterization supports the experimental results well.
文摘A qualitative analysis of the diameter of the spherical head of a long positive Jet streamer above thundercloud is presented in this paper under uniform atmospheric condition for streamers of less than 7 km length. In this study, an attempt is made to replicate laboratory-based point electrode discharge model for jet streamers originating above the thunderclouds. In laboratory conditions, it is not possible to produce huge electrode potentials which could be the reason that the streamers generated under the controlled lab environment have diameter of the order of only a few centimeter and length of a few millimeter. On the other hand, the thunderclouds carry huge electrical charges, for example 50 C, which can produce huge electrical potentials of the order of several hundred MeV. Such huge potential can act as the potential of a point electrode which may be capable of producing very large and thicker streamers above the thunderclouds. So, a leader mechanism of streamer initiation is assumed in calculations as the tip of conducting leader channel can act as point electrode carrying huge cloud potential to generate large streamers. It is found in this study that as the streamer moves larger distance away from the electrode (leader tip), the diameter of the streamer head decreases. Higher the potential of the electrode (leader tip), thicker is the streamer and more slowly the diameter decreases. Also, it is also found in our calculations that for higher electrode (leader tip) potential lower is the altitude of initiation of streamers.
文摘Mycobacterium avium subsp. paratuberculosis causes chronic inflammation of the intestine known as Johne’s disease (JD) in domestic and wild ruminants including primates. MAP has also been associated with inflammatory bowel disease (IBD) so called Crohn’s disease (CD) of human beings, which is incurable even after surgery. By virtue of the pasteurization resistant power, high endemicity of the infection in animals continues to be the permanent source of infection to human population. High bio-burden of MAP in wide range of biotic (animal hosts including human beings) and abiotic environment in each and every country where it has been investigated, serves a reminder about the survival abilities of the MAP in diverse range of environmental conditions. Ability of the MAP to evade immune system of the host and the temporal events during infection of the macro-phages, is an area of major concern and research activities as the pattern of distribution are quiet different from those of other pathogenic intracellular organisms. Moreover, the organism can survive over a wide range of environmental conditions such as high and low environmental temperatures, pasteurization, low pH, and high salt concentration etc. This superior survival efficiency from environmental degradation and dormancy within host allows the pathogen to be available for causing disease and pathogenicity in animals and human beings, when conditions are favorable. Perusal of literature reveal that, despite the availability of whole genome sequence of MAP, a very little is known about the replication, persistence and survival mechanisms of this pathogen. Therefore, this review tries to address the survival mechanisms of Mycobacterium avium subspecies paratuberculosis in the different host species and adverse environmental conditions in order to allow designing of more rational diagnostic and control procedures.
