Pumice stone supported titanium dioxide for removal of pathogen in drinking water and recalcitrant in wastewater

Bactericidal and organic degradation effects of TiO₂ on pumice stone are described in this paper. Immobilization of TiO₂ on pumice stone is easy and efficient method to obtain photocatalytic reactions without the problem of filtration. Pumice stone is soft and available as pellets that can be used in pellets fixed (with cement or poly carbonate) on a slanting plank/glass by coating the preformed TiO₂ over the pellets using simple paint brush for applying the photo catalyst. The treatment of inactivation of bacteria especially E. coli existing in real river waters and also different model organic substrate degradations like acid orange-7, resorcinol, 4, 6-dinitro-o-cresol, 4-nitrotoluene-2-sulfonicacid, isoproturan are studied. Furthermore, TiO₂ over pumice stone loaded in a multi tube reactor gave similar results for the disinfection and detoxification studies.     

Unsteady mixed convection flow of a thermomicropolar fluid on a long thin vertical cylinder

The unsteady laminar mixed convection boundary layer flow of a thermomicropolar fluid over a long thin vertical cylinder has been studied when the free stream velocity varies with time. The coupled nonlinear partial differential equations with three independent variables governing the flow have been solved numerically using an implicit finite difference scheme in combination with the quasilinearization technique. The results show that the buoyancy, curvature and suction parameters, in general, enhance the skin friction, heat transfer and gradient of microrotation, but the effect of injection is just opposite. The skin friction and heat transfer for the micropolar fluid are considerably less than those for the Newtonian fluids. The effect of microrotation parameter is appreciable only on the microrotation gradient. The effect of the Prandtl number is appreciable on the skin friction, heat transfer and gradient of microtation.     

Microwave assisted synthesis,spectroscopic, thermal,and antifungal studies of some lanthanide（Ⅲ） complexes with a heterocyclic bishydrazone

A bishydrazone formed by the condensation of isatinmonohydrazone and salicylaldehyde reacted with lanthanide（Ⅲ） chloride to form complexes of the type [Ln（HISA）2Cl3], where, Ln=La（Ⅲ）, Ce（Ⅲ）, Pr（Ⅲ）, Nd（Ⅲ）, Sm（Ⅲ）, Eu（Ⅲ）, or Gd（Ⅲ） and HISA= [（2-hydroxybenzaldehyde）-3-isatin]bishydrazone. Both reactions were carried out under microwave conditions. The ligand and the metal complexes were characterized on the basis of elemental analysis, molar conductance, magnetic susceptibility measurements, UV visible, infrared, far infrared, and proton NMR spectral data. The ligand acted as neutral tridentate, coordinating through the carbonyl oxygen, azomethine nitrogen, and phenolic oxygen without deprotonation. The ligand and lanthanum（Ⅲ） complex were subjected to X-ray diffraction studies. The X-ray diffraction pattern of ligand exhibited its crystalline nature and that of the lanthanum（Ⅲ） complex indicated its amorphous character. The thermal decomposition behaviour of the complex, [La（HISA）2Cl3], was examined in the temperature range of 40-800 ℃ using TG, DTG, and DTA. The ligand and the metal complexes were screened for their antifungal activities.     

Polymer-derived β-SiAlON:Eu2+ phosphors

A series of β-SiAlON:Eu²⁺ phosphors were synthesized from single-source precursors, perhydropolysilazane chemically modified with Al(OCH(CH₃)₂)₃, AlCl₃, and EuCl₂. The single-source precursors were converted to β-SiAlON:Eu²⁺ phosphors by pyrolysis under flowing N₂ or NH₃ at 1000°C, followed by heat treatment at 1800°C under an N₂ gas pressure at 980 kPa. By varying the molar ratio of the chemical modifiers, β-SiAlON:Eu²⁺ with the compositions close to the theoretical ones expressed as Si_6−zAl_zO_z−2yN_8−z+2y:yEu²⁺ were synthesized, where the z values and Eu²⁺ contents were controlled in the ranges of .44–.78 and .35–1.48 mol%, respectively. The polymer-derived β-SiAlON:Eu²⁺ phosphors exhibited green emission under excitation at 460 nm attributed to the 4f⁷–4f⁶(7f³)5d¹ transition of dopant Eu²⁺. High-angle annular dark-field-scanning transmission microscopy analysis confirmed that the doped-Eu²⁺ existed interstitially within the channels along the c axis of host β-SiAlON. Compared with the conventional powder metallurgy route, the polymer-derived ceramic route in this study offers some advantages in the grain growth of host β-SiAlON and photoluminescence properties in terms of green emission intensity under excitation at 460 nm, and the highest intensity was achieved for the polymer-derived β-SiAlON:Eu²⁺ with z = .64 and .37 mol% Eu²⁺.     

Enhanced Photovoltaic Performance of PEDOT:PSS/Si Heterojunction Solar Cell with ZnO BSF Layer: A Simulation Study using SCAPS-1D

Silicon - Here, we report an enhanced photovoltaic (PV) performance including open circuit voltage (Voc), short circuit current (Jsc), fill factor (FF) and power conversion efficiency (PCE) of...     

Synthesis and characterization of ruthenium dioxide nanostructures

We report the synthesis of ruthenium dioxide (RuO₂) nanostructures by thermal evaporation of RuO₂ powder. RuO₂ nanostructures of different shapes were synthesized at various concentration, flow rate, and pressure of oxygen. At a constant pressure of 3 torr of flowing oxygen, polygonal prism-like RuO₂ nanorods with flat tips were grown at an O₂ flow rate of 100 sccm; club-shaped nanorods with obelisk tip were formed at 300 and 600 sccm, and hollow rods with square tip were formed at 1800 sccm. A mixture of O₂ and Ar at a total flow rate of 600 sccm led to the formation of short club-shaped nanorods indicating the suppression effect of Ar on the growth of nanorods. The pressure also had a significant effect on the formation of RuO₂ nanostructures, at a fixed flow rate of 600 sccm of O₂, a pressure of 3 torr resulted in the growth of club-shaped RuO₂ nanorods, while high pressures of 380 and 760 torr resulted in the formation of both linear club-shaped and pine tree-like hierarchical RuO₂ nanorods. X-ray diffraction and transmission electron microscopy analysis indicated the formation of tetragonal phase of RuO₂ with high crystallinity. A density functional calculation on RuO₂, RuO₃, and RuO₄ was performed to help to explain the experimental results.     

An improved decision feedback equalization using a priori information

This paper addresses the exhaustive computational complexity of the maximum‐a‐posteriori equalizer and the inefficiency of the conventional decision feedback equalizer (DFE) algorithm in iterative equalization, especially when the higher‐level modulation is used with severely distorted Inter Symbol Interference channels. The new method proposed here improves the bit error rate (BER) performance by computing the extra metric r_n+1 using the feedback symbols from previous iteration and combining it with a priori information of the symbols. After each iteration, the hard‐detected symbols are saved in the memory as a priori data for next iteration. We verified the proposed algorithm for Binary Phase Shift Keying and 8‐phase shift keying modulation. The promising simulation results show that the BER performance given by the proposed low complexity DFE algorithm improved dramatically throughout the iterations when the conventional DFE has only insignificant improvement in the process of iterative equalization. Copyright © 2009 John Wiley & Sons, Ltd.     

Chemopreventive Effect of Different Ratios of Fish Oil and Corn Oil in Experimental Colon Carcinogenesis

n-3 Polyunsaturated fatty acids (PUFA) have a chemopreventive effect while n-6 PUFA promote carcinogenesis. The effect of these essential fatty acids may be related to oxidative stress. Therefore, the study was designed to evaluate the effect of different ratios of fish oil (FO) and corn oil (CO) in the prevention of colon cancer. Male Wistar rats were divided into control, dimethylhydrazine dihydrochloride (DMH) treated, FO + CO (1:1) and FO + CO (2.5:1). All the groups, except the control received a weekly injection of DMH for 4 weeks. The animals were sacrificed either 48 h later (initiation phase) or kept for 16 weeks (post initiation phase). DMH treatment in the initiation phase animals showed mild to moderate inflammation, decreased ROS and TrxR activity, increased antioxidants, apoptosis and ACF multiplicity. The post initiation study showed severe inflammation with hyperplasia, increased ACF multiplicity and ROS levels, a decrease in antioxidants and apoptosis. The FO + CO (1:1) treated animals showed severe inflammation, a decrease in ROS, an increase in antioxidants and apoptosis in the initiation phase. FO + CO (1:1) in the post initiation phase and FO + CO (2.5:1) in the initiation showed mild inflammation, increased ROS, apoptosis and decreased antioxidants. There was a decrease in ACF multiplicity and ROS levels, increased antioxidants and apoptosis in the post initiation phase study. The present study suggests that FO has a dose- and time-dependent chemopreventive effect in colon cancer mediated through oxidative stress and apoptosis.     

Quality Mapping and Positioning of Sev—A Deep Fat Fried Snack

“Sev,” savory prepared from chickpea flour is a popular snack item for its appealing flavor and texture. Mapping and positioning of market samples consisting different varieties like Small (S1, S2, S3), Medium (M1, M2, M3), and Big (B1, B2, B3, B4) were carried out using principal component analysis. Samples were subjected to sensory profiling resulting in small variety samples were crisper compared to other varieties. Texture measurement indicated breaking strength was higher in big variety samples. Color analysis showed significant difference in L*, a*, and b* values. Principal component analysis results indicated that S1 and S2 were associated with crispness, uniform texture, and typical fried oil aroma. Commercially available sev samples were significantly different in their quality parameters, which was indicated by the study. Study showed that small variety (S3) had the highest overall quality among all the samples, which also had high sensory scores for crispness.