On the role of the thermal treatment of sulfided Rh/CNT catalysts applied in the oxygen reduction reaction

Low loading sulfided rhodium catalysts supported on carbon nanotubes (CNTs) were prepared from RhCl₃ by deposition–precipitation using hydrogen peroxide, followed by an exposure to hydrogen sulfide and an additional thermal treatment in the range from 400 °C to 900 °C. Hydrogen sulfide was generated online from hydrogen and sulfur vapor over molybdenum disulfide as catalyst. By elemental analysis, the Rh loading of the prepared catalysts was found to be 1.4–1.8 wt%. Morphology and composition of the resulting catalysts were characterized by X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM and TEM), and X-ray photoelectron spectroscopy (XPS). Nanoparticles were found to be highly dispersed on the CNTs with an average diameter as small as 1.0 nm determined by TEM. Sintering occurred during heat treatments at 650 °C and 900 °C in helium, as evidenced by XRD, TEM, and XPS. The treatment with hydrogen sulfide significantly enhanced the activity of the supported rhodium catalysts for the oxygen reduction reaction (ORR) in hydrochloric acid, as determined by rotating disc electrode measurements. The sulfided catalyst annealed at 650 °C with a particle size of about 2.5 ± 1.0 nm showed the best performance for the ORR, which is discussed based on the presence of a more stable rhodium sulfide layer on the metallic rhodium particles.     

Role of bismuth oxide as a reinforcer on gamma shielding ability of unsaturated polyester based polymer composites

Unsaturated Polyester resin is reinforced with Bi₂O₃ up to 60% filler weight. The effect of bismuth oxide on gamma shielding ability of the composites is studied in terms of attenuation parameters using Ba‐133, Cs‐137, and Co‐60 gamma ray sources. The results reveal that, the shielding property of the composite material increases with increase in the filler concentration and decreases with energy. The HVL, TVL, and relaxation length of the composites are found to decrease with increase in the filler concentration. It is found that, the shielding ability of 60% filled polymer composite is comparable to that of barite at low energy. The above polymer composite performs well at all energies and can act as an excellent gamma radiation shield for low energies and also proved to be light weight when compared to the conventional shielding materials. Thus, the gamma shielding ability of the UP resin is enhanced due to the addition of Bi₂O₃. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44657.     

Impact of low lignin containing brown midrib sorghum mutants to harness biohydrogen production using mixed anaerobic consortia

Three low lignin containing bmr 3 derivatives, namely DRT 07K1, DRT 07K6 and DRT 07K15 developed through backcrossing were used along with the parent, bmr 3 source mutant (IS 21888) for evaluation of biohydrogen production. Results demonstrated that biohydrogen production varied amongst bmr derivatives under similar fermentation conditions. Significant negative correlation was observed between lignin content and fermentative biohydrogen production. All bmr derivatives with lower lignin content produced higher levels of biohydrogen compared to source bmr 3 (IS 21888) which has more lignin content. The maximum and a minimum biohydrogen production observed was 72 and 50 ml/g Total Volatile Solids (TVS) for the DRT 07K6 bmr3 derivative and bmr 3 (IS 21888) respectively. Acetate and butyrate were accounted >85% of volatile fatty acids, indicating acid type fermentations. Statistical analysis revealed that all bmr mutant derivatives with respect to source differ significantly in cumulative biohydrogen production, plant height, grain yield and lignin content. Biohydrogen production from biomass associated at least two different levels, one at lignin entanglement another at the polymeric nature of cellulose and hemicellulose. Further studies are necessary to determine the effect of biomass structure associated with different bmr traits on the microbial growth and biohydrogen production rate.     

Determination of Curcuminoids and Their Degradation Products in Turmeric (<Emphasis Type="Italic">Curcuma longa</Emphasis>) Rhizome Herbal Products by Non-aqueous Capillary Electrophoresis with Photodiode Array Detection

Non-aqueous capillary electrophoresis (NACE) method was optimised for simultaneous determination of major bioactive curcuminoids (CCD) viz., curcumin (CC), desmethoxycurcumin (DC) and bisdesmethoxycurcumin (BC), and some of the degradation products viz., vanillin (VN), vanillic acid (VA), ferulic acid (FA) and 4-hydroxybenzaldehyde (HB) in turmeric milk and herbal products. Separation was achieved using non-aqueous background electrolyte (NA-BGE), consisting of a mixture of sodium tetraborate, sodium hydroxide, methanol and 1-propanol in a single run by capillary electrophoresis (CE). In the present study, a novel ultrasonication-assisted phase separation method (US-PS) was used for extracting the analytes in turmeric milk and the extract was directly injected into the capillary without any pretreatment. High-performance thin layer chromatographic (HPTLC) method for the separation of the analytes was also evaluated on pre-coated silica gel plate. Two different high-performance liquid chromatographic (HPLC) conditions were reported in the literature for the separation of above-mentioned target compounds. The proposed method NACE is simple, fast, convenient and economical.     

Three-dimensional numerical study of heat and mass transfer in fluidized beds with spray nozzle

The numerical computations of temperature and concentration distributions inside a fluidized bed with spray injection in three-dimensions are presented. A continuum model, based on rigorous mass and energy balance equations developed from Nagaiah et al., is used for the three-dimensional simulations. The three-dimensional model equation for nozzle spray is reformulated in comparison to Heinrich. For solving the non-linear partial differential equations with boundary conditions a finite element method is used for space discretization and an implicit Euler method is used for time discretization.The time-dependent behavior of the air humidity, air temperature, degree of wetting, liquid film temperature and particle temperature is presented using two different sets of experimental data. The presented numerical results are validated with the experimental results. Finally, the parallel numerical results are presented using the domain decomposition methods.     

Variations of radon and thoron concentrations in different types of dwellings in Mysore city, India

²²²Rn and ²²⁰Rn, the immediate decay products of radium isotopes,are causative agents of lung cancer. ²²²Rn and ²²⁰Rn concentrationsin houses with different floorings, roofs and walls and in differentrooms of houses have been measured in Mysore city, Karnatakastate, India, using solid-state nuclear track detectors. Theradon and thoron concentrations in dwellings with granite flooringsare found to be higher compared with other types. A correlationbetween the indoor radon concentration and dose in air fromterrestrial gamma radiation is observed.     

Preparation and characterization of lead monoxide filled unsaturated polyester based polymer composites for gamma radiation shielding applications

Particulate polymer composites of Isophthalate based unsaturated polyester resin filled with different concentrations of lead monoxide were prepared. These composites were investigated for physical, thermal, mechanical, and gamma radiation shielding characteristics. The results of density evaluation, microscopic studies, and the radiation shielding properties for gamma rays of energy 0.662 MeV from Cs‐137 point source have been presented in this article. The results show that, the density of the composites was observed to increase with filler loading. The morphological analysis of the composites made using the scanning electron microscope showed that, the lead monoxide particles were observed to disperse uniformly in the polymer matrix with an average inter particle distance of about 10 μm and an average size of about 5.36 μm. The linear attenuation coefficient of the composites was found to increase with increased filler content in the composites. The highest value of 0.206 cm^?1 was found for 50 wt % of lead monoxide. These composites were observed to exhibit excellent % of heaviness and Half value layer in comparison with other conventional materials. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Groundwater Quality Around Mysore,Karnataka, India

Ground water samples were collected in the vicinity of Mysore, Karnataka, India, and were analyzed for inorganic constituents. These analyses were carried out to study changes in ground water quality that may reflect rock-water interactions as the water passes from recharge to discharge zones. Four hydrologic flow regimes were identified in the study area and variations in their ground water chemistry determined. Ground water in this area was classified as either CaHCO 3 or MgHCO 3 type. The anions and cations in these samples showed saturation characteristics of CaCO 3 . The hydrochemical data were modelled using WATEQ4F. The ground waters were oversaturated with respect to calcite and to a lesser extent with dolomite. Sixty percent of the ground water samples had nitrate concentration higher than the World Health Organization (WHO) limit of 45 mgL m 1 , whereas, eighty six percent of the samples had fluoride concentration less than 1.0 mgL m 1 . The concentration of all the trace metals except iron and zinc was close to the detection limit at most of the sampling sites.