Deposition of yttria-stabilized zirconia buffer layer on Si and its suitability for Y-Ba-Cu-O thin films

The deposition of yttria-stabilized zirconia (YSZ) as buffer layer on (100) silicon has been studied by rf sputtering with a view to subsequently preparing superconducting films of YBa₂Cu₃O _x on it. As-deposited films were found to be (100) oriented. The thermal mismatch and reaction between Si and YSZ at high temperatures were found to give rise to cracks in the films. Grain growth of buffer layer on annealing helped in the formation of superconducting phase.     

Finite element analysis of toughening for a particle‐reinforced composite

An axisymmetric spherical cell is used to quantitatively predict the toughening of a glass particle‐reinforced 2,2‐bis[4(2‐hydroxy‐3 methacryloyloxypropyloxy)‐phenyl]propane/triethylene glycol dimethacrylate (BisGMA/TEGDMA) polymer composite. The effect of a novel interphase consisting of ultrahigh molecular weight polyethylene, and residual stresses on composite toughness is studied. Results show that the fracture toughness of the composite increases with increasing interphase thickness, while the Young's modulus is not reduced significantly if the interphase thickness is less than 10% of the particle diameter. The negative strain originating from the curing process reduces fracture toughness, while an imagined positive strain increases fracture toughness significantly. POLYM COMPOS., 27:360–367, 2006. © 2006 Society of Plastics Engineers     

Seismic Behavior of CFT Column and Steel Pile Footings

In this study, two column and pile-footing models consisting of concrete-filled steel tube (CFT) columns, reinforced concrete footings, and steel H-piles were designed and constructed at approximately one-fifth scale. The experimental differences between the two models were in the design details of the CFT column-to-footing connections. One connection consisted of welded studs, and the other used a base plate and stiffeners. The two models were tested in a vertical cantilever condition with cyclic horizontal forces and a constant axial load applied to the top of the column. The model footings were supported on 16 model steel H-piles simulating the pile foundation. Under imposed horizontal displacement, the two models with different CFT-to-pile-cap connection details demonstrated satisfactory cyclic behavior, with the development of full plastic hinges at the bottom of the columns. Strut-and-tie modeling analysis was carried out to show the force-resisting mechanism in the reinforced concrete footing. The study also validated a new design detail for the anchorage of steel H-piles to pile caps.     

Response surface optimisation of extraction of antioxidants from strawberry fruit, and lipid peroxidation inhibitory potential of the fruit extract in cooked chicken patties

BACKGROUND: Strawberries contain high levels of antioxidants and have beneficial effects against oxidative stress‐mediated diseases, such as cancer. They contain multiple phenolic compounds, which contribute to their biological properties. Hence, a study was carried out to optimise the extraction of antioxidants and evaluate the antioxidant potential of strawberry fruit extract (SE) in cooked chicken patties during refrigerated storage. The activity of SE was compared with that of butylhydroxytoluene (BHT). RESULTS: The effect of solvent type (MeOH and EtOH), concentration (0–70%) of EtOH in the system, temperature (30–60 °C), and time (30–150 min) on DPPH^?‐scavenging activity of SE was investigated. Response surface methodology was used to estimate the optimum extraction conditions for each parameter. The maximum predicted DPPH^? scavenging under the optimised conditions (100% MeOH, 30 °C, 150 min) was 43% at 1 mg SE mL^?1. Freshly prepared chicken patties were treated with 5% and 10% SE and 2% BHT, and stored aerobically at 4 °C for 6 days. SE had no influence (P < 0.05) on any of the sensory attributes of the patties. The values of thiobarbituric acid reactive substances reduced significantly (P < 0.05) from 2.47 mg in control patties to 0.312 mg and 0.432 mg malonaldehyde kg^?1 sample in 5‐SE and 10‐SE patties, respectively, on the day 6 of storage. CONCLUSION: The optimised model depicted MeOH at 30 °C with an extended time of 150 min as the optimum settings for extraction of compounds from strawberry that had the scavenging activity. The study shows that the extraction of natural antioxidants from strawberry can be improved by optimising several key extraction parameters. SE also acted as an effective antioxidant and suppressed lipid peroxidation in cooked chicken patties. Copyright © 2011 Society of Chemical Industry     

Effect of silane coupling agent on vulcanization,network structure,polymer-filler interaction,physical properties and failure mode of mica-filled styrene-butadiene rubber

Physical properties of composites from mica and styrene-butadiene rubber (SBR) have been studied with special reference to the effect of silane coupling agent (A-174) in the compound. Tensile and tear properties increase with the addition of mica. The increase of tensile properties in more pronounced in the case of silane-treated mica. Silane treatment also raises the volume fraction of rubber in solvent-swollen rubber vulcanizate. Attempts have been made to correlate the changes in properties with the network structure of rubber. In order to understand the mechanism of failure, tensile fracture surfaces have been examined by scanning electron microscopy (SEM). The fractographs have been correlated with the strength and type of failure of these composites. The observed values of viscosity (rheometric) correspond to the calculated values from existing theory based on the hydrodynamic model of dispersed particles in a fluid medium.     

Mutual phase stabilization of aluminium phosphate and titania in AlPO4-TiO2 binary system

Crystallization behaviour of amorphous aluminium phosphate (AlPO₄) and titania (TiO₂) in a mixed system of the two (5:1) has been reviewed in the light of our recent results. The polymorphous aluminium phosphate in such a binary system grows exclusively in a single phase over a temperature range 500–1150°C. The phase is reported to have a tridymite-like structure belonging to orthorhombic system with cell parametersa=9·638±0·0019,b=8·664±0·0017 andc=18·280±0036Å. Titania in the system preferentially retains its anatase phase morphology up to a temperature (950°C) well beyond its normal anatase → rutile transformation temperature showing a phenomenon of stabilization of this phase in such mixture. An interfacial reaction mechanism that can explain the observed phenomenon of mutual phase stabilization has been discussed and implications of this result towards the use of such technique for stabilization of various polymorphous compounds in a single phase has been pointed out.     

Chrysamine-G, a lipophilic analogue of Congo red, inhibits A beta-induced toxicity in PC12 cells

Increasing evidence suggests that deposition of amyloid-beta (A beta) peptide leads to neurodegeneration in Alzheimer's disease. Congo red, a histologic dye that binds to amyloid has previously been shown to diminish the toxic effects of A beta in cell culture. Since Congo red is too highly charged to enter the brain in significant quantities, a lipophilic derivative, Chrysamine-G, was tested for the ability to attenuate A beta[25-35]-induced toxicity in PC12 cells using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Chrysamine-G showed a concentration-dependent inhibition of A beta[25-35]-induced toxicity. This protective effect became significant at 0.2 microM, a concentration very close to the Ki for Chrysamine-G binding to synthetic A beta (0.37 microM). A decarboxy derivative of Chrysamine-G, which does not bind to A beta, also did not protect against A beta-induced toxicity. The protective effects of Chrysamine-G may relate to its ability to bind directly to A beta and may involve other post-binding effects as well.