Abstract Nanosized spherical copper particle embedded on oxide matrix (Cunp-Cu2O/SiO2) is synthes... more Abstract Nanosized spherical copper particle embedded on oxide matrix (Cunp-Cu2O/SiO2) is synthesized from a low cost chalcopyrite concentrate. The concentrate is reduced by hydrogen at 1323 K, followed by acid leaching to produce Cunp-Cu2O/SiO2. Powder X-ray diffraction confirms the formation of metallic copper as the principal phase along with oxides of silicon and copper. The weight fractions of Cu, SiO2 and Cu2O are 0.565(8), 0.203(2) and 0.232 (3) respectively, as obtained from a three-phase Rietveld refinement. The diameter of copper spheres, rooted on silica, as observed in transmission electron microscopy, is ranging between 4 and 34 nm. Spectroscopic studies, especially Raman spectra, confirm the occurrence of Cu2O. Raman active 2nd overtone at 219 cm−1 appears as the most intense peak. Contribution of SiO2 is clear in Fourier transform infrared spectra. A broad band between 1000 and 1100 cm−1, more specifically at 1080 cm−1 occurs due to Si–O–Si asymmetric stretches. The presence of Cu2O causes photoluminescence peaks to appear in the visible region, corresponding to energy gaps of 0.9 and 1 eV, which indicate the existence of two donor levels below the conduction band. Broad absorption wavelength in the ultraviolet–visible absorption spectra in visible region and low band gap energy of 1.4 eV indicate the possibility of Cunp-Cu2O/SiO2 to be an excellent photocatalytic material. The composite's photocatalytic performance as it is directly derived from the concentrate is quite promising under solar light irradiation. Bromophenol blue (BB) degradation efficiency is 71.26% in 90 min, the photocatalytic kinetics rate is 0.01447 min−1. Characterizations of Cunp-Cu2O/SiO2 as the recycled photocatalyst confirm its photocatalytic stability.
Respiratory infections by RNA viruses are one of the major burdens on global health and economy. ... more Respiratory infections by RNA viruses are one of the major burdens on global health and economy. Viruses like influenza or coronaviruses can be transmitted through respiratory droplets or contamina...
IOP Conference Series: Materials Science and Engineering, 2018
Bulk graphitic carbon nitride (g-C 3 N 4) is synthesized by thermal decomposition of urea and use... more Bulk graphitic carbon nitride (g-C 3 N 4) is synthesized by thermal decomposition of urea and used as an adsorbent for gadolinium ion (Gd 3+) from aqueous solution. Adsorption capacity of g-C 3 N 4 is found to be influenced by initial Gd 3+ concentration, solution pH and contact time. Adsorbed Gd 3+ is separated from g-C 3 N 4 by ultracentrifuge. Initial and Gd ion accumulated g-C 3 N 4 adsorbent are characterized by X-ray diffraction technique (XRD) for phase identification, UV-visible and Fourier transform infrared (FTIR) spectroscopy for adsorption characteristics and optical property, scanning electron microscopy (SEM) for morphological behaviour along with energy dispersive X-ray spectroscopy (EDS) for elemental study. HNO 3 (0.1M), NaOH (0.1M) and de-ionized water are used for desorption and around 97% quantitative recovery of Gd ion is observed.
International Journal of Minerals, Metallurgy, and Materials, 2015
The structural and morphological characterizations of a chalcopyrite concentrate, collected from ... more The structural and morphological characterizations of a chalcopyrite concentrate, collected from the Indian Copper Complex, Ghatshila, India, were carried out by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The concentrate powder was composed mainly of free chalcopyrite and low quartz in about 3:1 weight ratio. The particle size was about 100 µm. Spectroscopic studies (FTIR, Raman, UV-visible) of the concentrate supported the XRD findings, and also revealed a marginal oxidation of the sulfide phase. The energy band gap of the sulfide was found to be 3.4 eV. Differential thermal analysis and thermogravimetry of the concentrate showed a decomposition of chalcopyrite at 658 K with an activation energy of 208 kJ⋅mol −1 , and two successive structural changes of silica at 848 K and 1145 K.
An Indian magnetite ore from the Nagaland region was characterized by powder X-ray diffraction, s... more An Indian magnetite ore from the Nagaland region was characterized by powder X-ray diffraction, spectroscopies (ultraviolet-visible and Raman), high temperature magnetization and thermal analysis. A Rietveld refinement of the diffraction data revealed that the principal phase present in the sample is magnetite with partial substitution of Fe with Mg (mainly) and Cr, leading to the chemical formula of MgCr0.2Fe1.8O4. The UV-visible spectra of the sample in MeCN solution showed three distinct peaks. The lower region bands are due to metal-oxygen charge transitions and the other band is for d-d transition of iron. Raman spectral study at room temperature gave four characteristics bands of magnetite. The sample underwent a magnetic transition at high temperature and the thermomagnetization curve shows hysteresis during cooling cycle which indicates the possibility of first order structural transition at high temperature. The thermal property of the concentrate was studied by differentia...
ABSTRACT The structural and morphological characterizations of a chalcopyrite concentrate, collec... more ABSTRACT The structural and morphological characterizations of a chalcopyrite concentrate, collected from the Indian Copper Complex, Ghatshila, India, were carried out by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The concentrate powder was composed mainly of free chalcopyrite and low quartz in about 3:1 weight ratio. The particle size was about 100 μm. Spectroscopic studies (FTIR, Raman, UV-visible) of the concentrate supported the XRD findings, and also revealed a marginal oxidation of the sulfide phase. The energy band gap of the sulfide was found to be 3.4 eV. Differential thermal analysis and thermogravimetry of the concentrate showed a decomposition of chalcopyrite at 658 K with an activation energy of 208 kJ·mol−1, and two successive structural changes of silica at 848 K and 1145 K.
Respiratory infections by RNA viruses are one of the major burdens upon global health and economy... more Respiratory infections by RNA viruses are one of the major burdens upon global health and economy. Viruses like influenza or coronaviruses can be transmitted through respiratory droplets or contaminated surfaces. An effective antiviral coating can decrease the viability of the virus particles in the outside environment significantly, hence reducing their transmission rate. In this work, we have screened a series of nanoparticles and their composites for antiviral activity using Nano Luciferase based highly sensitive influenza A reporter virus. Using this screening system, we have identified copper-graphene (Cu-Gr) nanocomposite shows strong antiviral activity. Extensive material and biological characterization of the nanocomposite suggested a unique metal oxide embedded graphene sheet architecture that can inactivate the virion particles only within 30 minutes of pre-incubation and subsequently interferes with the entry of these virion particles into the host cell. This ultimately r...
In actual situation decision-making is rather dynamic process and not static. It varies with the ... more In actual situation decision-making is rather dynamic process and not static. It varies with the continuous changing environment. In reality the value of decision making attitude depends upon decision maker’s personal choice. Under such circumstances decision making attitude behaves as a variable that may yield different results. A decision maker (DM) has to choose one alternative, which must be the best option. Multi-criteria decision making (MCDM) is applied to preferable decisions among available classified alternatives by multiple attributes. In the present research work selection of CNC lathe is done by applying Technique for order performance by similarity to ideal solution (TOPSIS). Weights are assigned to the different criteria by entropy method. The alternatives are ranked and best selection is made. Finally sensitivity is carried out in order to justify the proposed selection methodology by MATLAB programming arrangement.
Manufacturing processes can be broadly divided into two groups and they are primary manufacturing... more Manufacturing processes can be broadly divided into two groups and they are primary manufacturing processes and secondary manufacturing processes. The former ones provide basic shape and size to the material as per designer‘s requirement. Casting, forming, powder metallurgy are such processes to name a few. Secondary manufacturing processes provide the final shape and size with tighter control on dimension, surface characteristics etc. Material removal processes are mainly the secondary manufacturing processes. Material removal processes once again can be divided into mainly two groups and they are ―Conventional Machining Processes‖ and ―Non-Traditional Manufacturing Processes‖. Conventional Machining Processes mostly remove material in the form of chips by applying forces on the work material with a wedge shaped cutting tool that is harder than the work material under machining condition. Such forces induce plastic deformation within the work piece leading to shear deformation alon...
Multi-walled carbon nanotubes (CNT) were synthesized by the spray pyrolysis of a mixture of benze... more Multi-walled carbon nanotubes (CNT) were synthesized by the spray pyrolysis of a mixture of benzene (carbon precursor) and ferrocene (precursor for Fe catalyst) on an alumina template in a horizontal tube furnace at 900-1000°C. The concentration of ferrocene in ferrocene-benzene solution, flow rate of argon gas, and temperature were the variables studied to obtain the best reaction condition in terms of the smallness of tube diameter and unidirectionality of the nanotubes. The synthesized material was soaked in a 1:1 HCl solution plus a few drops of concentrated HNO3 in order to remove the impurity iron. Subsequently, the differential thermal (DT) and thermo gravimetric (TG) analyses of the resulting iron-free material revealed the presence of amorphous carbon in it and indicated the temperature for its removal, paving the way for the production of pure CNT. The synthesized CNT was characterized by X-ray diffraction (XRD), electron microscopy (SEM and TEM) and Raman spectroscopy. Th...
Iron was produced by the hydrogen reduction of magnetite ore fines in a thermogravimetric analyze... more Iron was produced by the hydrogen reduction of magnetite ore fines in a thermogravimetric analyzer. Experiments were carried out in the temperature range of 973- 1173K. The other variables studied were hydrogen flow rate (0.1-0.4 l/min), sample bed height (0.25-0.75 cm), hydrogen partial pressure (0.5-1 atm), and particle size (75-180 micron). Phase identification, product morphology and elemental analysis were done by X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy respectively. The results showed that the reduction of magnetite fines took place in two stages: Fe3O4→FeO and FeO→Fe, each of which was controlled by the pore diffusion kinetics. The activation energy was 33 kJ/mol. The percentage removal of oxygen went up to above 60%.
Abstract Nanosized spherical copper particle embedded on oxide matrix (Cunp-Cu2O/SiO2) is synthes... more Abstract Nanosized spherical copper particle embedded on oxide matrix (Cunp-Cu2O/SiO2) is synthesized from a low cost chalcopyrite concentrate. The concentrate is reduced by hydrogen at 1323 K, followed by acid leaching to produce Cunp-Cu2O/SiO2. Powder X-ray diffraction confirms the formation of metallic copper as the principal phase along with oxides of silicon and copper. The weight fractions of Cu, SiO2 and Cu2O are 0.565(8), 0.203(2) and 0.232 (3) respectively, as obtained from a three-phase Rietveld refinement. The diameter of copper spheres, rooted on silica, as observed in transmission electron microscopy, is ranging between 4 and 34 nm. Spectroscopic studies, especially Raman spectra, confirm the occurrence of Cu2O. Raman active 2nd overtone at 219 cm−1 appears as the most intense peak. Contribution of SiO2 is clear in Fourier transform infrared spectra. A broad band between 1000 and 1100 cm−1, more specifically at 1080 cm−1 occurs due to Si–O–Si asymmetric stretches. The presence of Cu2O causes photoluminescence peaks to appear in the visible region, corresponding to energy gaps of 0.9 and 1 eV, which indicate the existence of two donor levels below the conduction band. Broad absorption wavelength in the ultraviolet–visible absorption spectra in visible region and low band gap energy of 1.4 eV indicate the possibility of Cunp-Cu2O/SiO2 to be an excellent photocatalytic material. The composite's photocatalytic performance as it is directly derived from the concentrate is quite promising under solar light irradiation. Bromophenol blue (BB) degradation efficiency is 71.26% in 90 min, the photocatalytic kinetics rate is 0.01447 min−1. Characterizations of Cunp-Cu2O/SiO2 as the recycled photocatalyst confirm its photocatalytic stability.
Respiratory infections by RNA viruses are one of the major burdens on global health and economy. ... more Respiratory infections by RNA viruses are one of the major burdens on global health and economy. Viruses like influenza or coronaviruses can be transmitted through respiratory droplets or contamina...
IOP Conference Series: Materials Science and Engineering, 2018
Bulk graphitic carbon nitride (g-C 3 N 4) is synthesized by thermal decomposition of urea and use... more Bulk graphitic carbon nitride (g-C 3 N 4) is synthesized by thermal decomposition of urea and used as an adsorbent for gadolinium ion (Gd 3+) from aqueous solution. Adsorption capacity of g-C 3 N 4 is found to be influenced by initial Gd 3+ concentration, solution pH and contact time. Adsorbed Gd 3+ is separated from g-C 3 N 4 by ultracentrifuge. Initial and Gd ion accumulated g-C 3 N 4 adsorbent are characterized by X-ray diffraction technique (XRD) for phase identification, UV-visible and Fourier transform infrared (FTIR) spectroscopy for adsorption characteristics and optical property, scanning electron microscopy (SEM) for morphological behaviour along with energy dispersive X-ray spectroscopy (EDS) for elemental study. HNO 3 (0.1M), NaOH (0.1M) and de-ionized water are used for desorption and around 97% quantitative recovery of Gd ion is observed.
International Journal of Minerals, Metallurgy, and Materials, 2015
The structural and morphological characterizations of a chalcopyrite concentrate, collected from ... more The structural and morphological characterizations of a chalcopyrite concentrate, collected from the Indian Copper Complex, Ghatshila, India, were carried out by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The concentrate powder was composed mainly of free chalcopyrite and low quartz in about 3:1 weight ratio. The particle size was about 100 µm. Spectroscopic studies (FTIR, Raman, UV-visible) of the concentrate supported the XRD findings, and also revealed a marginal oxidation of the sulfide phase. The energy band gap of the sulfide was found to be 3.4 eV. Differential thermal analysis and thermogravimetry of the concentrate showed a decomposition of chalcopyrite at 658 K with an activation energy of 208 kJ⋅mol −1 , and two successive structural changes of silica at 848 K and 1145 K.
An Indian magnetite ore from the Nagaland region was characterized by powder X-ray diffraction, s... more An Indian magnetite ore from the Nagaland region was characterized by powder X-ray diffraction, spectroscopies (ultraviolet-visible and Raman), high temperature magnetization and thermal analysis. A Rietveld refinement of the diffraction data revealed that the principal phase present in the sample is magnetite with partial substitution of Fe with Mg (mainly) and Cr, leading to the chemical formula of MgCr0.2Fe1.8O4. The UV-visible spectra of the sample in MeCN solution showed three distinct peaks. The lower region bands are due to metal-oxygen charge transitions and the other band is for d-d transition of iron. Raman spectral study at room temperature gave four characteristics bands of magnetite. The sample underwent a magnetic transition at high temperature and the thermomagnetization curve shows hysteresis during cooling cycle which indicates the possibility of first order structural transition at high temperature. The thermal property of the concentrate was studied by differentia...
ABSTRACT The structural and morphological characterizations of a chalcopyrite concentrate, collec... more ABSTRACT The structural and morphological characterizations of a chalcopyrite concentrate, collected from the Indian Copper Complex, Ghatshila, India, were carried out by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The concentrate powder was composed mainly of free chalcopyrite and low quartz in about 3:1 weight ratio. The particle size was about 100 μm. Spectroscopic studies (FTIR, Raman, UV-visible) of the concentrate supported the XRD findings, and also revealed a marginal oxidation of the sulfide phase. The energy band gap of the sulfide was found to be 3.4 eV. Differential thermal analysis and thermogravimetry of the concentrate showed a decomposition of chalcopyrite at 658 K with an activation energy of 208 kJ·mol−1, and two successive structural changes of silica at 848 K and 1145 K.
Respiratory infections by RNA viruses are one of the major burdens upon global health and economy... more Respiratory infections by RNA viruses are one of the major burdens upon global health and economy. Viruses like influenza or coronaviruses can be transmitted through respiratory droplets or contaminated surfaces. An effective antiviral coating can decrease the viability of the virus particles in the outside environment significantly, hence reducing their transmission rate. In this work, we have screened a series of nanoparticles and their composites for antiviral activity using Nano Luciferase based highly sensitive influenza A reporter virus. Using this screening system, we have identified copper-graphene (Cu-Gr) nanocomposite shows strong antiviral activity. Extensive material and biological characterization of the nanocomposite suggested a unique metal oxide embedded graphene sheet architecture that can inactivate the virion particles only within 30 minutes of pre-incubation and subsequently interferes with the entry of these virion particles into the host cell. This ultimately r...
In actual situation decision-making is rather dynamic process and not static. It varies with the ... more In actual situation decision-making is rather dynamic process and not static. It varies with the continuous changing environment. In reality the value of decision making attitude depends upon decision maker’s personal choice. Under such circumstances decision making attitude behaves as a variable that may yield different results. A decision maker (DM) has to choose one alternative, which must be the best option. Multi-criteria decision making (MCDM) is applied to preferable decisions among available classified alternatives by multiple attributes. In the present research work selection of CNC lathe is done by applying Technique for order performance by similarity to ideal solution (TOPSIS). Weights are assigned to the different criteria by entropy method. The alternatives are ranked and best selection is made. Finally sensitivity is carried out in order to justify the proposed selection methodology by MATLAB programming arrangement.
Manufacturing processes can be broadly divided into two groups and they are primary manufacturing... more Manufacturing processes can be broadly divided into two groups and they are primary manufacturing processes and secondary manufacturing processes. The former ones provide basic shape and size to the material as per designer‘s requirement. Casting, forming, powder metallurgy are such processes to name a few. Secondary manufacturing processes provide the final shape and size with tighter control on dimension, surface characteristics etc. Material removal processes are mainly the secondary manufacturing processes. Material removal processes once again can be divided into mainly two groups and they are ―Conventional Machining Processes‖ and ―Non-Traditional Manufacturing Processes‖. Conventional Machining Processes mostly remove material in the form of chips by applying forces on the work material with a wedge shaped cutting tool that is harder than the work material under machining condition. Such forces induce plastic deformation within the work piece leading to shear deformation alon...
Multi-walled carbon nanotubes (CNT) were synthesized by the spray pyrolysis of a mixture of benze... more Multi-walled carbon nanotubes (CNT) were synthesized by the spray pyrolysis of a mixture of benzene (carbon precursor) and ferrocene (precursor for Fe catalyst) on an alumina template in a horizontal tube furnace at 900-1000°C. The concentration of ferrocene in ferrocene-benzene solution, flow rate of argon gas, and temperature were the variables studied to obtain the best reaction condition in terms of the smallness of tube diameter and unidirectionality of the nanotubes. The synthesized material was soaked in a 1:1 HCl solution plus a few drops of concentrated HNO3 in order to remove the impurity iron. Subsequently, the differential thermal (DT) and thermo gravimetric (TG) analyses of the resulting iron-free material revealed the presence of amorphous carbon in it and indicated the temperature for its removal, paving the way for the production of pure CNT. The synthesized CNT was characterized by X-ray diffraction (XRD), electron microscopy (SEM and TEM) and Raman spectroscopy. Th...
Iron was produced by the hydrogen reduction of magnetite ore fines in a thermogravimetric analyze... more Iron was produced by the hydrogen reduction of magnetite ore fines in a thermogravimetric analyzer. Experiments were carried out in the temperature range of 973- 1173K. The other variables studied were hydrogen flow rate (0.1-0.4 l/min), sample bed height (0.25-0.75 cm), hydrogen partial pressure (0.5-1 atm), and particle size (75-180 micron). Phase identification, product morphology and elemental analysis were done by X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy respectively. The results showed that the reduction of magnetite fines took place in two stages: Fe3O4→FeO and FeO→Fe, each of which was controlled by the pore diffusion kinetics. The activation energy was 33 kJ/mol. The percentage removal of oxygen went up to above 60%.
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