Lowering of thickness of boron-doped microcrystalline hydrogenated silicon film by seeding technique

By using a seeding technique it has been possible to reduce the thickness of p-μc-Si:H film to 230 Å, with an improved electrical conductivity (0.93 S cm⁻¹) and lower optical absorption compared to those of conventional p-μc-Si:H layers without a seed layer, for use at the tunnel junction and as the top layer of a double junction n–i–p structured a-Si solar cell. Undoped-μc-Si:H has been used as the seed layer. The layers were prepared by the radio frequency plasma-enhanced chemical vapour deposition (RF-PECVD) method (13.56 MHz) at 40 mW/cm² rf power density and low substrate temperature (200 °C). The ultrathin seed layer (30 Å) enhances the growth of microcrystallinity of the p-type μc-Si:H film as confirmed by the results of transmission electron microscopy (TEM) analysis and Raman spectroscopy.     

Storage and affinity properties of Murraya koenigii trypsin inhibitor

The Murraya Koenigii trypsin inhibitor was found to be the major protein component of the seed extract. The quantity of protein was determined to be approximately 20% of total protein extracted by simple buffer extraction. During different stages of seed development after flowering, the protein concentrations were found to be 5.27, 5.5, 8.5, 18.8 and 20% in 7, 19, 25, 37 and 55 days, respectively. During seed germination, protein degradations were observed from 20% to 12, 7 and 2% in 13, 16 and 22 days, respectively. This inhibitor, earlier purified using ion-exchange and gel filtration chromatography, was purified in single step by affinity column, using Cibacron blue 3GA, with substantial increase in yield. In partial internal sequencing by MALDI-TOF-TOF, six peptides of varying length, totalling 98 amino acid residues, exhibited similarities to the sequences from protease inhibitors, storage proteins and homeodomain-like proteins.     

Implicit Spatial Contextual Learning in Healthy Aging.

Three experiments investigated the aging of implicit spatial and spatiotemporal context learning in 2 tasks. In contextual cuing, people learn to use repeated spatial configurations to facilitate search for a target, whereas in higher order serial learning, they learn to use subtle sequence regularities to respond more quickly and accurately to a series of events. Results reveal a dissociation; overall contextual cuing is spared in healthy aging, whereas higher order sequence learning is impaired in the same individuals. This finding suggests that these 2 forms of implicit learning rely on different neural substrates that age differently; the results are also consistent with recent evidence that fronto-striatal circuits are particularly susceptible to decline in health aging. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Enhanced Biocompatibility of Porous Nitinol

Porous Nitinol (PNT) has found vast applications in the medical industry as interbody fusion devices, synthetic bone grafts, etc. However, the tendency of the PNT to corrode is anticipated to be greater as compared to solid nitinol since there is a larger surface area in contact with body fluids. In such cases, surface preparation is known to play a major role in a material’s biocompatibility. In an effort to check the effect of surface treatments on the in vitro corrosion properties of PNT, in this investigation, they were subjected to different surface treatments such as boiling in water, dry heating, and passivation. The localized corrosion resistance of alloys before and after each treatment was evaluated in phosphate buffer saline solution (PBS) using cyclic polarization tests in accordance with ASTM F 2129-08.     

Development of catalytic activity protocol for electrochemical reduction of carbon dioxide to value added products

Utilization of carbon dioxide for the production of value added products is a challenging task. Electrochemical reduction of carbon dioxide is one of the most promising techniques to convert the carbon dioxide into value added products. However, the development and selection of a suitable electrocatalyst is not so straightforward. The main problems are non-selectivity of the electrocatalyst toward CO₂ reduction, simultaneous hydrogen evolution reaction, and low efficiency of the process. To overcome these problems, many electrocatalysts have been studied and reported in the literature. However, there is no effective guideline to screen the electrocatalysts in a quick and simple way. Moreover, it is found that the method used for the screening of electrocatalyst is not accurate and has anomalies. Therefore, in this paper, a simple and quick protocol based on half-cell tests is proposed. The method provides a first-hand prediction about the electrochemical activity of an electrocatalyst toward electrochemical reduction of carbon dioxide. The protocol was validated and compared along with confirming the results by product analysis of the electrochemical reduction of CO₂ using full electrochemical reactor. The method was found satisfactory for the preliminary screening of electrocatalyst to reduce carbon dioxide electrochemically.     

Effects of solubility parameter differences among PEG,PVP and CA on the preparation of ultrafiltration membranes: Impacts of solvents and additives on morphology,permeability and fouling performances

The effects of two different hydrophilic additives and two solvents on the membrane morphological structure,permeability property and anti-fouling performances of cellulose acetate (CA) ultrafiltration membranes were investigated.During the phase-inversion process,cellulose acetate was selected as a membrane forming polymer;polyethylene glycol (PEG) and polyvinyl pyrrolidone (PVP) were used as additives;acetone (Ac):N,N-Dimethylacetamide (DMAc) andN,N-Dimethylformamide (DMF) were used as solvents;and deionized (DI) water was used in the coagulation bath.All the prepared membranes were characterized in terms of hydraulic permeability (Pm),membrane resistance,average pore radius,and hydrophilicity.The top surface and crosssectional view of the prepared membranes were also observed by using field emission scanning electron microscopy.Membrane fouling and rejection experimentations were done using a stirred batch-cell filtration set-up.The experimental studies of fouling/rinsing cycles,rejection,and permeate fluxes were used to investigate the effect of PEG and PVP additives and effect of the two solvents on the fabricated membranes using bovine serum albumin (BSA) as a model protein.     

3-substituted 2-phenylimidazo[2,1-b]benzothiazoles: synthesis, anticancer activity, and inhibition of tubulin polymerization

A new series of 3‐substituted 2‐phenylimidazo[2,1‐b]benzothiazoles ( 3 a – h ) were synthesized by C‐arylation of 2‐arylimidazo[2,1‐b]benzothiazoles using palladium acetate as catalyst, and the resulting compounds were evaluated for their anticancer activity. Compounds 3 a , 3 e , and 3 h exhibited good antiproliferative activity, with GI₅₀ values in the range of 0.19–83.1 μM . Compound 3 h showed potent anticancer efficacy against 60 human cancer cell lines, with a mean GI₅₀ value of 0.88 μM . This compound also induced cell‐cycle arrest in the G₂/M phase and inhibited tubulin polymerization followed by activation of caspase‐3 and apoptosis. A high‐throughput tubulin polymerization assay showed that the level of inhibition for compound 3 h is similar to that of combretastatin A‐4. Molecular modeling studies provided a molecular basis for the favorable binding of compounds 3 a , 3 e , and 3 h to the colchicine binding pocket of tubulin.     

Clarification of Stevia extract by ultrafiltration: Selection criteria of the membrane and effects of operating conditions

Clarification of pre-treated Stevia extract using ultrafiltration is presented in this study. Performance of four different ultrafiltration membranes, namely 5, 10, 30 and 100 kDa were investigated in terms of permeate flux and permeate quality, mainly the recovery of Stevioside in the permeate. In this regard, the 30 kDa membrane was found to be most suitable. A systematic set of experiments under steady state were conducted to analyze the effects of the operating conditions, transmembrane pressure drop and stirrer speed on the permeate flux and permeate quality. Steady state was reached in between 8 and 16 min depending on the operating conditions. Steady state was reached earlier at higher stirring speed. A simple resistance in series model was used to quantify the fouling resistance. Membrane resistance was found to be negligible compared to the fouling resistance. It was a strong function of the stirrer speed but remained almost invariant with transmembrane pressure drop. The steady state permeate flux increased with pressure drop as well as the stirrer speed. 45% average recovery of Stevioside was obtained during stirred steady state experiments at lower operating pressures (276 and 414 kPa). At higher operating pressures, recovery of Stevioside in the permeate decreased remarkably.     

Development of antifungal films based on low‐density polyethylene and thyme oil for avocado packaging

Trilayer low‐density polyethylene (LDPE) films were prepared by incorporating varying concentrations of thyme oil, as the antifungal active additive for avocado packaging. A comprehensive thermal, structural, mechanical, and functional characterization of the prepared films was carried out. Thermal stability of the film reduced with the addition of thyme oil in higher concentration, whereas the degree of crystallinity increased upto 2.5 wt % thyme oil loading. The elastic modulus and elongation at break of the films decreased in presence of thyme oil. However, the incorporation of thyme oil did not change the water vapor transmission characteristics of the original film. The antifungal activity of the films was tested against Colletotrichum gloeosporioides causal organism of “anthracnose” postharvest disease in avocados. The results indicated that the films have great potential as antifungal packaging materials for avocado fruits. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43045.     

Performance of superstrate multijunction amorphous silicon-based solar cells using optical layers for current management

The performance of multijunction amorphous silicon-based thin film solar cells has been reported using thin layers of TiO₂ and SiO_x acting as refractive index matching optical layers for different interfaces of the superstrate device structure. Improvement of short-circuit current from the sub-cells of a-Si/μc-Si cells is demonstrated with TiO₂ as anti-reflection layer at TCO/Si interface and SiO_x as intermediate-reflector layer between two sub-cells. An initial efficiency of 11.8% is achieved by applying both the TiO₂ and SiO_x optical layers in a-Si/μc-Si solar cell.