Because of the interesting and multifunctional properties,recently,ZnO nanostructures are considered as excellent material for fabrication of highly sensitive and selective gas sensors.Thus,ZnO nanomaterials are widel...Because of the interesting and multifunctional properties,recently,ZnO nanostructures are considered as excellent material for fabrication of highly sensitive and selective gas sensors.Thus,ZnO nanomaterials are widely used to fabricate efficient gas sensors for the detection of various hazardous and toxic gases.The presented review article is focusing on the recent developments of NO2gas sensors based on ZnO nanomaterials.The review presents the general introduction of some metal oxide nanomaterials for gas sensing application and finally focusing on the structure of ZnO and its gas sensing mechanisms.Basic gas sensing characteristics such as gas response,response time,recovery time,selectivity,detection limit,stability and recyclability,etc are also discussed in this article.Further,the utilization of various ZnO nanomaterials such as nanorods,nanowires,nano-micro flowers,quantum dots,thin films and nanosheets,etc for the fabrication of NO2gas sensors are also presented.Moreover,various factors such as NO2concentrations,annealing temperature,ZnO morphologies and particle sizes,relative humidity,operating temperatures which are affecting the NO2gas sensing properties are discussed in this review.Finally,the review article is concluded and future directions are presented.展开更多
The various methods for microwave processing of materials exhibit numerous advantages,such as short processing times,high yield,expanded reaction conditions,high reproducibility,and high purity of products.Microwave-a...The various methods for microwave processing of materials exhibit numerous advantages,such as short processing times,high yield,expanded reaction conditions,high reproducibility,and high purity of products.Microwave-assisted synthesis strategies have been widely adopted for the preparation of highperformance graphene-based materials for supercapacitor electrodes.Metal oxides,mixed metal oxides,metal hydroxides,layered double hydroxides,carbon nanotubes and conducting polymers are some of the main materials which have been added to graphene derivatives for advanced composite/hybrid electrodes.This review article first provides a brief introduction and an overview of microwave heating and its advantages for processing graphene-based electrode materials.After that,a systematic survey of recently published research on microwave irradiation-assisted processing is presented,focusing on:(i)transformation of graphite/graphite oxide into graphene/graphene oxide by exfoliation and reduction;(ii)formation of graphene derivatives in various liquid and gaseous media;(iii)modification of graphene derivatives with various metal oxides/hydroxides,carbon nanotubes,and conducting polymers for use in supercapacitors.Major challenges and future perspectives for microwave-assisted processing of graphene-based materials for cutting-edge supercapacitor electrode applications are also summarized in the conclusion.展开更多
Non-enzymatic biosensors based on mixed transition metal oxides are deemed as the most promising devices due to their high sensitivity,selectivity,wide concentration range,low detection limits,and excellent recyclabil...Non-enzymatic biosensors based on mixed transition metal oxides are deemed as the most promising devices due to their high sensitivity,selectivity,wide concentration range,low detection limits,and excellent recyclability.Spinel NiCo2O4 mixed oxides have drawn considerable attention recently due to their outstanding advantages including large specific surface area,high permeability,short electron,and ion diffusion pathways.Because of the rapid development of non-enzyme biosensors,the current state of methods for synthesis of pure and composite/hybrid NiCo2P4 materials and their subsequent electrochemical biosensing applications are systematically and comprehensively reviewed herein.Comparative analysis reveals better electrochemical sensing of bioanalytes by one-dimensional and two-dimensional NiCo2O4 nano-/microstructures than other morphologies.Better biosensing efficiency of NiCo2O4 as compared to corresponding individual metal oxides,viz.NiO and Co3O4,is attributed to the close intrinsic-state redox couples of Ni3+/Ni2+(0.58 V/0.49 V) and Co3+/Co2+(0.53 V/0.51 V).Biosensing performance of NiCo2O4 is also significantly improved by making the composites of NiCo2O4 with conducting carbonaceous materials like graphene,reduced graphene oxide,carbon nanotubes(single and multi-walled),carbon nanofibers;conducting polymers like polypyrrole(PPy),polyaniline(PANI);metal oxides NiO,Co3O4,SnO2,MnO2;and metals like Au,Pd,etc.Various factors affecting the morphologies and biosensing parameters of the nano-/microstructured NiCo2O4 are also highlighted.Finally,some drawbacks and future perspectives related to this promising field are outlined.展开更多
Sacred groves preserve a rich religious and socio-cultural heritage of Indian biodiversity from primeval times,due to their values.They act as a bridge between man and nature.Groves help to improve soil quality,replen...Sacred groves preserve a rich religious and socio-cultural heritage of Indian biodiversity from primeval times,due to their values.They act as a bridge between man and nature.Groves help to improve soil quality,replenish water resources and are pivotal for biodiversity conservation of plants and animals including rare,endemic,threatened,vulnerable species and ethnobotanical species.Most of India's sacred groves are associated with a deity or a spiritual being,who protects the grove and local people.Vegetation cover of these groves has traditional ethnobotanical value,especially in the field of ethnomedicine,which accounts for the conservation of groves over the years.Numerous plant species from sacred groves are used according to tradition and culture to prevent or cure various health problems.However,modernisation,industrialisation,increased encroachment and misuse of forest resources increasingly threaten sacred groves.These treasures of nature must be conserved by formulating and applying new laws and policies while creating awareness among people about the value of sacred groves.Toward this aim,we review the distribution,ecological and socio-cultural significance of sacred groves of India and strategies to conserve them.展开更多
A high energy and high yield neutron source is a prime requirement for technological studies related to fusion reactor development. It provides a high-energy neutron environment for small-scale fusion reactor componen...A high energy and high yield neutron source is a prime requirement for technological studies related to fusion reactor development. It provides a high-energy neutron environment for small-scale fusion reactor components research and testing such as tritium breeding, shielding, plasmafacing materials, reaction cross-section data study for fusion materials, etc. Along with ITER participation, the Institute of Plasma Research, India is developing an accelerator-based 14 MeV neutron source with a yield of 10^(12)n s^(-1). The design of the source is based on the deuterium–tritium fusion reaction. The deuterium beam is accelerated and delivered to the tritium target to generate 14 MeV neutrons. The deuterium beam energy and tritium availability in the tritium target are the base parameters of the accelerator-based neutron source design. The paper gives the physics design of the neutron generator facility of the Institute for Plasma Research. It covers the requirements, design basis, and physics parameters of the neutron generator. As per the analytical results generator can produce more than 1 × 10^(12)n s^(-1)with a 110 keV D^(+) ion beam of 10 mA and a minimum 5 Ci tritium target. However, the detailed simulation with the more realistic conditions of deuteron ion interaction with the tritium titanium target shows that the desired results cannot be achieved with 110 keV. The safe limit of the ion energy should be 300 keV as per the simulation. At 300 keV ion energy and 20 mA current, it reaches 1.6 × 10^(12)n s^(-1). Moreover, it was found that to ensure sufficiently long operation time a tritium target of more than 20 Ci should be used. The scope of the neutron source is not limited to the fusion reactor research studies, it is extended to other areas such as medical radioisotopes research, semiconductor devices irradiations, and many more.展开更多
India has proposed the helium-cooled solid breeder blanket concept as a tritium breeding module to be tested in ITER.The module has lithium titanate for tritium breeding and beryllium for neutron multiplication.Beryll...India has proposed the helium-cooled solid breeder blanket concept as a tritium breeding module to be tested in ITER.The module has lithium titanate for tritium breeding and beryllium for neutron multiplication.Beryllium also enhances tritium breeding.A design for the module is prepared for detailed analysis.Neutronic analysis is performed to assess the tritium breeding rate,neutron distribution,and heat distribution in the module.The tritium production distribution in submodules is evaluated to support the tritium transport analysis.The tritium breeding density in the radial direction of the module is also assessed for further optimization of the design.The heat deposition profile of the entire module is generated to support the heat removal circuit design.The estimated neutron spectrum in the radial direction also provides a more in-depth picture of the nuclear interactions inside the material zones.The total tritium produced in the HCSB module is around 13.87 mg per full day of operation of ITER,considering the 400 s ON time and 1400 s dwell time.The estimated nuclear heat load on the entire module is around 474 kW,which will be removed by the high-pressure helium cooling circuit.The heat deposition in the test blanket model(TBM)is huge(around 9 GJ)for an entire day of operation of ITER,which demonstrates the scale of power that can be produced through a fusion reactor blanket.As per the Brayton cycle,it is equivalent to 3.6 GJ of electrical energy.In terms of power production,this would be around 1655 MWh annually.The evaluation is carried out using the MCNP5 Monte Carlo radiation transport code and FEDNL 2.1 nuclear cross section data.The HCSB TBM neutronic performance demonstrates the tritium production capability and high heat deposition.展开更多
基金supported by NSTIP strategic technologies programs,number(12-NAN2551-02)in the Kingdom of Saudi Arabia
文摘Because of the interesting and multifunctional properties,recently,ZnO nanostructures are considered as excellent material for fabrication of highly sensitive and selective gas sensors.Thus,ZnO nanomaterials are widely used to fabricate efficient gas sensors for the detection of various hazardous and toxic gases.The presented review article is focusing on the recent developments of NO2gas sensors based on ZnO nanomaterials.The review presents the general introduction of some metal oxide nanomaterials for gas sensing application and finally focusing on the structure of ZnO and its gas sensing mechanisms.Basic gas sensing characteristics such as gas response,response time,recovery time,selectivity,detection limit,stability and recyclability,etc are also discussed in this article.Further,the utilization of various ZnO nanomaterials such as nanorods,nanowires,nano-micro flowers,quantum dots,thin films and nanosheets,etc for the fabrication of NO2gas sensors are also presented.Moreover,various factors such as NO2concentrations,annealing temperature,ZnO morphologies and particle sizes,relative humidity,operating temperatures which are affecting the NO2gas sensing properties are discussed in this review.Finally,the review article is concluded and future directions are presented.
基金Science and Engineering Research Board(SERB),Department of Science&Technology(DST),New Delhi,India for providing research fund under Ramanujan Fellowship/Award(SB/S2/RJN-159/2017)。
文摘The various methods for microwave processing of materials exhibit numerous advantages,such as short processing times,high yield,expanded reaction conditions,high reproducibility,and high purity of products.Microwave-assisted synthesis strategies have been widely adopted for the preparation of highperformance graphene-based materials for supercapacitor electrodes.Metal oxides,mixed metal oxides,metal hydroxides,layered double hydroxides,carbon nanotubes and conducting polymers are some of the main materials which have been added to graphene derivatives for advanced composite/hybrid electrodes.This review article first provides a brief introduction and an overview of microwave heating and its advantages for processing graphene-based electrode materials.After that,a systematic survey of recently published research on microwave irradiation-assisted processing is presented,focusing on:(i)transformation of graphite/graphite oxide into graphene/graphene oxide by exfoliation and reduction;(ii)formation of graphene derivatives in various liquid and gaseous media;(iii)modification of graphene derivatives with various metal oxides/hydroxides,carbon nanotubes,and conducting polymers for use in supercapacitors.Major challenges and future perspectives for microwave-assisted processing of graphene-based materials for cutting-edge supercapacitor electrode applications are also summarized in the conclusion.
文摘Non-enzymatic biosensors based on mixed transition metal oxides are deemed as the most promising devices due to their high sensitivity,selectivity,wide concentration range,low detection limits,and excellent recyclability.Spinel NiCo2O4 mixed oxides have drawn considerable attention recently due to their outstanding advantages including large specific surface area,high permeability,short electron,and ion diffusion pathways.Because of the rapid development of non-enzyme biosensors,the current state of methods for synthesis of pure and composite/hybrid NiCo2P4 materials and their subsequent electrochemical biosensing applications are systematically and comprehensively reviewed herein.Comparative analysis reveals better electrochemical sensing of bioanalytes by one-dimensional and two-dimensional NiCo2O4 nano-/microstructures than other morphologies.Better biosensing efficiency of NiCo2O4 as compared to corresponding individual metal oxides,viz.NiO and Co3O4,is attributed to the close intrinsic-state redox couples of Ni3+/Ni2+(0.58 V/0.49 V) and Co3+/Co2+(0.53 V/0.51 V).Biosensing performance of NiCo2O4 is also significantly improved by making the composites of NiCo2O4 with conducting carbonaceous materials like graphene,reduced graphene oxide,carbon nanotubes(single and multi-walled),carbon nanofibers;conducting polymers like polypyrrole(PPy),polyaniline(PANI);metal oxides NiO,Co3O4,SnO2,MnO2;and metals like Au,Pd,etc.Various factors affecting the morphologies and biosensing parameters of the nano-/microstructured NiCo2O4 are also highlighted.Finally,some drawbacks and future perspectives related to this promising field are outlined.
文摘Sacred groves preserve a rich religious and socio-cultural heritage of Indian biodiversity from primeval times,due to their values.They act as a bridge between man and nature.Groves help to improve soil quality,replenish water resources and are pivotal for biodiversity conservation of plants and animals including rare,endemic,threatened,vulnerable species and ethnobotanical species.Most of India's sacred groves are associated with a deity or a spiritual being,who protects the grove and local people.Vegetation cover of these groves has traditional ethnobotanical value,especially in the field of ethnomedicine,which accounts for the conservation of groves over the years.Numerous plant species from sacred groves are used according to tradition and culture to prevent or cure various health problems.However,modernisation,industrialisation,increased encroachment and misuse of forest resources increasingly threaten sacred groves.These treasures of nature must be conserved by formulating and applying new laws and policies while creating awareness among people about the value of sacred groves.Toward this aim,we review the distribution,ecological and socio-cultural significance of sacred groves of India and strategies to conserve them.
文摘A high energy and high yield neutron source is a prime requirement for technological studies related to fusion reactor development. It provides a high-energy neutron environment for small-scale fusion reactor components research and testing such as tritium breeding, shielding, plasmafacing materials, reaction cross-section data study for fusion materials, etc. Along with ITER participation, the Institute of Plasma Research, India is developing an accelerator-based 14 MeV neutron source with a yield of 10^(12)n s^(-1). The design of the source is based on the deuterium–tritium fusion reaction. The deuterium beam is accelerated and delivered to the tritium target to generate 14 MeV neutrons. The deuterium beam energy and tritium availability in the tritium target are the base parameters of the accelerator-based neutron source design. The paper gives the physics design of the neutron generator facility of the Institute for Plasma Research. It covers the requirements, design basis, and physics parameters of the neutron generator. As per the analytical results generator can produce more than 1 × 10^(12)n s^(-1)with a 110 keV D^(+) ion beam of 10 mA and a minimum 5 Ci tritium target. However, the detailed simulation with the more realistic conditions of deuteron ion interaction with the tritium titanium target shows that the desired results cannot be achieved with 110 keV. The safe limit of the ion energy should be 300 keV as per the simulation. At 300 keV ion energy and 20 mA current, it reaches 1.6 × 10^(12)n s^(-1). Moreover, it was found that to ensure sufficiently long operation time a tritium target of more than 20 Ci should be used. The scope of the neutron source is not limited to the fusion reactor research studies, it is extended to other areas such as medical radioisotopes research, semiconductor devices irradiations, and many more.
文摘India has proposed the helium-cooled solid breeder blanket concept as a tritium breeding module to be tested in ITER.The module has lithium titanate for tritium breeding and beryllium for neutron multiplication.Beryllium also enhances tritium breeding.A design for the module is prepared for detailed analysis.Neutronic analysis is performed to assess the tritium breeding rate,neutron distribution,and heat distribution in the module.The tritium production distribution in submodules is evaluated to support the tritium transport analysis.The tritium breeding density in the radial direction of the module is also assessed for further optimization of the design.The heat deposition profile of the entire module is generated to support the heat removal circuit design.The estimated neutron spectrum in the radial direction also provides a more in-depth picture of the nuclear interactions inside the material zones.The total tritium produced in the HCSB module is around 13.87 mg per full day of operation of ITER,considering the 400 s ON time and 1400 s dwell time.The estimated nuclear heat load on the entire module is around 474 kW,which will be removed by the high-pressure helium cooling circuit.The heat deposition in the test blanket model(TBM)is huge(around 9 GJ)for an entire day of operation of ITER,which demonstrates the scale of power that can be produced through a fusion reactor blanket.As per the Brayton cycle,it is equivalent to 3.6 GJ of electrical energy.In terms of power production,this would be around 1655 MWh annually.The evaluation is carried out using the MCNP5 Monte Carlo radiation transport code and FEDNL 2.1 nuclear cross section data.The HCSB TBM neutronic performance demonstrates the tritium production capability and high heat deposition.
