Sol–gel derived nanocrystalline CeO2–TiO2 coatings for electrochromic windows

Mixed CeO₂–TiO₂ coatings synthesized by sol–gel spin coating process using mixed organic–inorganic Ti(OC₃H₇)₄ and CeCl₃·7H₂O precursors with different Ce/Ti mole ratios were investigated by a wide range of characterization techniques. The attempts were directed towards achieving coatings with high transparency in the visible region and good electrochemical properties. Elucidation of the structural and optical features of the films yielded information on the aspects relevant to their usage in transmissive electrochromic devices. The films have been found to exhibit properties for counter electrode in electrochromic smart windows in which they are able to retain their transparency under charge insertion, high enough for practical uses. The high optical modulation and fastest switching for WO₃ film in the device configuration with the Ce/Ti (1:1) film is interpreted in terms of conducive microstructural changes induced by addition of TiO₂ in an amount equivalent to CeO₂.     

Green fire retardant finishing and combined dyeing of proteinous wool fabric

Flame retardancy was imparted to a scoured and bleached, proteinous woollen textile by using banana pseudostem sap, an ecofriendly waste agricultural product, at different pH levels. The flame retardancy characteristics of both the control and the treated fabrics were analysed in terms of the limiting oxygen index and the vertical flammability measurement. Thermal degradation and fire retardancy mechanisms were studied using thermogravimetry, scanning electron microscopy, and energy dispersive X‐ray analysis. Moreover, the charring mechanism of both the control and the banana‐pseudostem‐sap‐treated fabrics with varying pH was analysed and reported in detail. The wool fabric was also dyed with CI Acid Blue 25 using banana pseudostem sap as well as water as the medium. The fabric dyed with the banana pseudostem sap medium at pH 5.5 showed more colour exhaustion, colour strength, and thermal stability compared with the control wool fabric. The mechanism by which superior fire retardancy and colour strength are imparted to the woollen textile by the application of banana pseudostem sap is proposed.     

Receptor-mediated endocytosis of IL-8: a fluorescent microscopic evidence and implication of the process in ligand-induced biological response in human neutrophils

Interleukin 8 (IL-8), a neurophil-activating and chemotactic cytokine, is known to play a key role in the pathogenesis of a large number of neutrophil-driven inflammatory diseases. Although the cytokine is rapidly internalized at 37 degrees C with its receptors, there was no direct evidence for the ligand-induced endocytosis of the receptor or that of the interaction of receptor ligand complex at 37 degrees C. As a result, our understanding about the regulation of Il-8 induced biological response is very limited. In the present study, using FITC-IL-8 conjugate as a probe, we have demonstrated the time- and temperature-dependent endocytosis of IL-8 under fluorescent microscope. We have also shown that the bright fluorescent light on the surface of neutrophils gradually disappears and it becomes almost dark after 120 min of incubation. Monodansyl cadaverine (MDC, 900 microM), however, was found to retain the fluorescent light of FITC coupled with Il-8 on the cells. MDC and ouabain (2.5 mM) can inhibit the ligand induced endocytosis by 76% and 96%, respectively, compared to control. With respect to control, IL-8 induced biological responses e.g. IL-8 directed migration, intracellular Ca2+ release and superoxide release are significantly reduced by 77%, 94% and 76%, respectively, in presence of MDC. The study presents a direct visual evidence of the time and temperature-dependent receptor-mediated endocytosis of IL-8 which is inhibited by MDC and ouabain. This information is useful for understanding the ligand receptor interaction at 37 degrees C and may be useful for developing anti-inflammatory agents against IL-8.     

Performance evaluation of a fluid temperature-compensated single sensor constant temperature anemometer

The performance of a hot-wire anemometer configuration is affected by variation in the fluid temperature. The classical temperature compensation techniques in such anemometers employ two sensors. The performance of a temperature-compensated hot-wire anemometer configuration, using a single sensor alternating between two operating temperatures, and proposed for constant fluid velocity, is investigated under conditions of time-varying fluid velocity. The measurement error introduced is quantified and can be practically eliminated using a low-pass digital filter.     

Yield point behavior in extruded aluminum rod

The microstructure of aluminum, extruded under industrial conditions at 250°C has been investigated in relation to the purity of the billet. Electron microscopy was used to observe the substructure and Kikuchi diffraction techniques were used to measure boundary angles and thus distinguish between recrystallization and repolygonization for samples of two different purities (99.7 pct Al and 99.99 pct Al) extruded under identical conditions. High tensile flow stresses of about 8000 to 9000 psi (55 to 62 MN/m²) were observed in specimens taken from the first sections of the high purity extrusion. These high strength levels were attributed to the presence of fine microstructure. When small recrystallized grains (0.5 to 2.0 μm diam) were present a yield drop was observed. This phenomenon is associated with the condition where nearly all the dislocations are likely to be immobile. The absence of a yield point in the 99.7 pct purity aluminum extruded under the same conditions as the 99.99 pct purity aluminum is due to the existence of fine subgrains instead of the fine recrystallized structure. A small yield point in 99.7 pct aluminum was induced by subsequent heat treatment resulting in the formation of small recrystallized grains of similar character to those in the higher purity extrusion. Formerly Research Assistant, Department of Mechanical Engineering, University of Waterloo, Waterloo, Ontario.     

Electrocoagulation of methylene blue and eosin yellowish using mild steel electrodes

The paper presents the study of electrocoagulation (EC) of aqueous dye solutions of two different industrial dyes in a batch stirred cell. Experiments were carried out with 200 mg/l individual concentration of methylene blue (MB) and eosin yellowish (EY) in presence of NaCl as electrolyte. Effect of operating time and current density on the decolorization of dye solutions, reduction of chemical oxygen demand (COD) and variation in conductivity, pH during treatment has been studied. Small difference between color diminution and COD reduction has been found with the progress of treatment. First-order rate equation for dye removal has been developed from the experimental results. Sludge formation during EC and problems associated with this solid waste generation and disposal has been assessed. Energy consumption in KWh/m(3) with reduction of COD (kg) during treatment has been reported. Electric power consumption of 1.5 KWh reduces 0.21 and 0.11 kg COD from 0.24 and 0.14 kg of initial COD for MB and EY, respectively, starting from 200 mg/l dye concentration.     

Characterisation and functional properties of proteins of some Indian chickpea (Cicer arietinum) cultivars

BACKGROUND: Chickpea (Cicer arietinum L.) proteins have received attention during recent years owing to their higher biological values and better functional ingredients than oilseed proteins. In this study the composition, fractionation, electrophoretic behaviour and functional properties of five chickpea protein concentrates were determined. RESULTS: The chickpea proteins contained 15.9–54.8 g kg^?1 albumin, 48.9–154.1 g kg^?1 globulin, 39.2–76.5 g kg^?1 glutelin and traces of prolamin. Electrophoresis of the various fractions revealed that albumin and globulin were made up of sub‐units of different molecular weights ranging from 7 to 96 kDa. Water and oil absorption of the protein concentrates varied from 1.15 to 2.75 g g^?1 and from 2.60 to 5.65 g g^?1 respectively. Foaming capacity and foam stability of the protein concentrates were good and improved with the addition of salt (10 g L^?1 NaCl) or sugar (100 g L^?1 sucrose) at both isoelectric and neutral pH. Emulsifying capacity and emulsion stability of the protein concentrates were good and excellent respectively. CONCLUSION: Protein concentrates prepared from chickpeas have potential use in food formulations owing to their good emulsifying/foaming and water/oil‐binding capacities. Copyright © 2008 Society of Chemical Industry