The increasing demand in the diverse device applications of transparent conducting oxides （TCOs） requires synthesis of new TCOs of n- or p-type conductivity. This article is about materials engineering of ZnO-SnO2- ...The increasing demand in the diverse device applications of transparent conducting oxides （TCOs） requires synthesis of new TCOs of n- or p-type conductivity. This article is about materials engineering of ZnO-SnO2- In2O3-Ga2O3 to synthesize powders of the quaternary compound Zn2-xSn1-xlnxGaxO4-δ in the stoichiometry of x = 0.2, 0.3, and 0.4 by solid state reaction at 1275℃. Lattice parameters were determined by X-ray diffraction （XRD） technique and solubility of In3＋ and Ga3＋ in spinel Zn2SnO4 was found at 1275℃. The solubility limit of In3＋ and Ga3＋ in Zn2SnO4 is found at below x = 0.4. The optical transmittance approximated by the UV-Vis reflectance spectra showed excellent characteristics while optical band gap was consistent across 3.2 eV with slight decrease along increasing x value. Carrier mobility of the species was considerably higher than the older versions of zinc stannate spinel co-substitutions whereas the carrier concentrations were moderate.展开更多
In order to obtain highly conductive polymer gel electrolytes for electrochemical devices, Poly (vinylidene fluoride) (PVdF) based gel electrolytes namely (100–x)PVdF + xNH4SCN electrolyte system has been synthesized...In order to obtain highly conductive polymer gel electrolytes for electrochemical devices, Poly (vinylidene fluoride) (PVdF) based gel electrolytes namely (100–x)PVdF + xNH4SCN electrolyte system has been synthesized by solution cast technique and characterized by XRD, DSC, IR, SEM and electrical measurements. IR study of gel electrolytes shows interaction of PVdF matrix and dopant salt with prominence of α-phase. This result is also well supported by XRD and DSC studies. The electrolytes are electrochemically stable within ± 1.5 V. The optimum bulk electrical conductivity for 90PVdF + 10NH4SCN electrolyte has been found to be ~ 2.5 × 10–2 S●cm–1. Dielectric relaxation behavior shows low frequency dispersion and αc-related relaxation peak is observed in loss spectra. Polarization behavior of gel electrolyte shows ionic nature of charge transport (Tion. > 0.90). The temperature dependent conductivity shows VTF behavior.展开更多
The complexity of plant cell walls impedes the conversion of cellulosic biomass to sugars. Pretreatment becomes a necessity to increase the digestibility of biomass. An in-depth understanding of the structure and unde...The complexity of plant cell walls impedes the conversion of cellulosic biomass to sugars. Pretreatment becomes a necessity to increase the digestibility of biomass. An in-depth understanding of the structure and underlying mechanisms governing deconstruction process is important. In the present study, the comprehensive investigation of morphological and structural changes in corn stover and sugarcane bagasse following ionic liquids dissolution and alkaline extraction was done using Fourier transform infrared spectroscopy, Thermogravimetric analysis, Confocal scanning laser microscopy, Atomic force microscopy and Dynamic light scattering studies. Both the substrates were pretreated with ILs 1-ethyl-3-methylimidazolium acetate and 1-butyl-3-methylimidazolium acetate followed by alkaline extraction. The pronounced changes such as lignin, hemicelluloses removal and decreased cellulose crystallinity after the pretreatments lead to the structural transformation of matrix polymers. The enzymatic hydrolysis showed 90% theoretical sugar yield in case of sugarcane bagasse and 80% in corn stover following synergistically combined pretreatments.展开更多
Charge-transfer (CT) complex of o-toluidine (o-tol) with the π-acceptor tetrachloro-p-benzoquinone (p-chloranil; CHL) has been synthesized and characterized, along with the products of the elimination reaction of o-t...Charge-transfer (CT) complex of o-toluidine (o-tol) with the π-acceptor tetrachloro-p-benzoquinone (p-chloranil; CHL) has been synthesized and characterized, along with the products of the elimination reaction of o-toluidine (o-tol) with 2,3-dichloro-5,6dicyano-p-benzoquinone (DDQ) and 7,7,8,8-tetracyanoquinodimethane (TCNQ). Their properties and structures have been investigated using electronic absorption and IR spectroscopy as well as elemental analyses of the isolated compounds. The o-tol/p-CHL CT complex is shown to consist of a CHL radical anion and o-tol + radical cation. The formations of all three compounds result in the appearance of new UV-Vis spectral bands that peaked in intensity at a stoichiometric ratio of 1 : 1. 1 H-NMR and mass spectra were used to confirm the formation of the o-tol/DDQ and o-tol/TCNQ products. The new 7,8-dicyano-7′,8′-o-toluidilequinodimethane and 2,3-dichloro-5-cyano-6-o-toluidil-p-benzoquinone products resulted from the rapid reaction of o-tol with TCNQ and DDQ, respectively. Thermogravimetric studies showed that the CT-complex decomposes in three steps whereas the new compounds decompose in a single step. Thermodynamic parameters were computed from the thermal decomposition data.展开更多
In order to study the nephropathy associated with experimental streptozotocin diabetes, serial functional and ultrastructural studies were done in insulin-treated (Group T), untreated (Group D) diabetic Wistar rats an...In order to study the nephropathy associated with experimental streptozotocin diabetes, serial functional and ultrastructural studies were done in insulin-treated (Group T), untreated (Group D) diabetic Wistar rats and normal controls on d 3, d 8, d 14 and d 28 of diabetes. The ratio of kidney weight to the body weight (KW/BW) and mean glomerular diameter (MGD) in diabetes rats at varying durations were increased as compared with those in control animals, but an increase of KW/BW and MGD in Group D was more marked than in Group T. The creatinine clearance (Ccr) and total urinary protein excretion rate (TUPER) were increased in Group D end T, but the increase in TUPER appeared later in Group T than in Group D. Enlargement of epithelial cells, disappearance of folds on their surface and widening of foot processes were observed after 3 d of diabetes. After 14 d of diabetes, increased basement membrane-like material in the mesangium was found. Morphologically an increase in glomerular size, expanded foot processes with ball-like terminal expansions, thickened basement membrane were observed.展开更多
文摘The increasing demand in the diverse device applications of transparent conducting oxides （TCOs） requires synthesis of new TCOs of n- or p-type conductivity. This article is about materials engineering of ZnO-SnO2- In2O3-Ga2O3 to synthesize powders of the quaternary compound Zn2-xSn1-xlnxGaxO4-δ in the stoichiometry of x = 0.2, 0.3, and 0.4 by solid state reaction at 1275℃. Lattice parameters were determined by X-ray diffraction （XRD） technique and solubility of In3＋ and Ga3＋ in spinel Zn2SnO4 was found at 1275℃. The solubility limit of In3＋ and Ga3＋ in Zn2SnO4 is found at below x = 0.4. The optical transmittance approximated by the UV-Vis reflectance spectra showed excellent characteristics while optical band gap was consistent across 3.2 eV with slight decrease along increasing x value. Carrier mobility of the species was considerably higher than the older versions of zinc stannate spinel co-substitutions whereas the carrier concentrations were moderate.
文摘In order to obtain highly conductive polymer gel electrolytes for electrochemical devices, Poly (vinylidene fluoride) (PVdF) based gel electrolytes namely (100–x)PVdF + xNH4SCN electrolyte system has been synthesized by solution cast technique and characterized by XRD, DSC, IR, SEM and electrical measurements. IR study of gel electrolytes shows interaction of PVdF matrix and dopant salt with prominence of α-phase. This result is also well supported by XRD and DSC studies. The electrolytes are electrochemically stable within ± 1.5 V. The optimum bulk electrical conductivity for 90PVdF + 10NH4SCN electrolyte has been found to be ~ 2.5 × 10–2 S●cm–1. Dielectric relaxation behavior shows low frequency dispersion and αc-related relaxation peak is observed in loss spectra. Polarization behavior of gel electrolyte shows ionic nature of charge transport (Tion. > 0.90). The temperature dependent conductivity shows VTF behavior.
文摘The complexity of plant cell walls impedes the conversion of cellulosic biomass to sugars. Pretreatment becomes a necessity to increase the digestibility of biomass. An in-depth understanding of the structure and underlying mechanisms governing deconstruction process is important. In the present study, the comprehensive investigation of morphological and structural changes in corn stover and sugarcane bagasse following ionic liquids dissolution and alkaline extraction was done using Fourier transform infrared spectroscopy, Thermogravimetric analysis, Confocal scanning laser microscopy, Atomic force microscopy and Dynamic light scattering studies. Both the substrates were pretreated with ILs 1-ethyl-3-methylimidazolium acetate and 1-butyl-3-methylimidazolium acetate followed by alkaline extraction. The pronounced changes such as lignin, hemicelluloses removal and decreased cellulose crystallinity after the pretreatments lead to the structural transformation of matrix polymers. The enzymatic hydrolysis showed 90% theoretical sugar yield in case of sugarcane bagasse and 80% in corn stover following synergistically combined pretreatments.
文摘Charge-transfer (CT) complex of o-toluidine (o-tol) with the π-acceptor tetrachloro-p-benzoquinone (p-chloranil; CHL) has been synthesized and characterized, along with the products of the elimination reaction of o-toluidine (o-tol) with 2,3-dichloro-5,6dicyano-p-benzoquinone (DDQ) and 7,7,8,8-tetracyanoquinodimethane (TCNQ). Their properties and structures have been investigated using electronic absorption and IR spectroscopy as well as elemental analyses of the isolated compounds. The o-tol/p-CHL CT complex is shown to consist of a CHL radical anion and o-tol + radical cation. The formations of all three compounds result in the appearance of new UV-Vis spectral bands that peaked in intensity at a stoichiometric ratio of 1 : 1. 1 H-NMR and mass spectra were used to confirm the formation of the o-tol/DDQ and o-tol/TCNQ products. The new 7,8-dicyano-7′,8′-o-toluidilequinodimethane and 2,3-dichloro-5-cyano-6-o-toluidil-p-benzoquinone products resulted from the rapid reaction of o-tol with TCNQ and DDQ, respectively. Thermogravimetric studies showed that the CT-complex decomposes in three steps whereas the new compounds decompose in a single step. Thermodynamic parameters were computed from the thermal decomposition data.
文摘In order to study the nephropathy associated with experimental streptozotocin diabetes, serial functional and ultrastructural studies were done in insulin-treated (Group T), untreated (Group D) diabetic Wistar rats and normal controls on d 3, d 8, d 14 and d 28 of diabetes. The ratio of kidney weight to the body weight (KW/BW) and mean glomerular diameter (MGD) in diabetes rats at varying durations were increased as compared with those in control animals, but an increase of KW/BW and MGD in Group D was more marked than in Group T. The creatinine clearance (Ccr) and total urinary protein excretion rate (TUPER) were increased in Group D end T, but the increase in TUPER appeared later in Group T than in Group D. Enlargement of epithelial cells, disappearance of folds on their surface and widening of foot processes were observed after 3 d of diabetes. After 14 d of diabetes, increased basement membrane-like material in the mesangium was found. Morphologically an increase in glomerular size, expanded foot processes with ball-like terminal expansions, thickened basement membrane were observed.
