Silk-elastinlike protein polymer hydrogels: Influence of monomer sequence on physicochemical properties

Silk-elastinlike protein polymer, SELP-815K, with eight silk and fifteen elastin units and a lysine (K) modified elastin, was genetically engineered with longer silk and elastin units compared to existing hydrogel forming analogs (SELP-415K and SELP-47K). Hydrogels of the three SELPs (with similar MWs) were investigated for their structure-function relationships. Results indicate that equilibrium swelling ratio in these hydrogels is a function of polymer structure, concentration, cure time and ionic strength of media. Swelling was not influenced by the changes in pH. Storage moduli observed by dynamic mechanical analysis and the Debye-Bueche correlation length obtained from small-angle neutron scattering provided structural insight that suggests the cross-linking densities in these hydrogels follow the order SELP-47K > SELP-815K > SELP-415K. These results allude to the importance of the length of elastin blocks in governing the spacing of the cross-linked hydrogel network and that of silk in governing the stiffness of their 3-dimensional structures.     

Effect of reformulated fuel strategy on compression ignition engine compatibility using antioxidant additive and clean Karanja methyl ester

Clean Technologies and Environmental Policy - The present work aims at investigating the compatibility of antioxidant with biodiesel through the tribological assessment of a compression ignition...     

Monodispersed and Stable Nano Copper(0) from Copper‐ Aluminium Hydrotalcite: Importance in C?C Couplings of Deactivated Aryl Chlorides

A simple one‐step approach for the preparation of highly monodispersed nano copper(0) stabilized on alumina [Cu(0)/Al₂O₃] by thermal reduction of copper‐aluminium hydrotalcite (Cu‐Al HT) under a hydrogen atmosphere is described. The transformation of Cu‐Al HT to Cu(0)/Al₂O₃ occurrs via dehydroxylation of divalent and trivalent metal hydroxides and decarboxylation of carbonate anions present in the interlayers of hydrotalcite, as confirmed by XPS, XANES, XRD and TEM analysis. Cu(0)/Al₂O₃ nano composites were used as an efficient catalyst in the C C coupling of deactivated aryl chlorides. The high efficiency and reusability exhibited by Cu(0)/Al₂O₃ outline its potential as an alternative over traditional noble metal‐based catalysts in C C coupling reactions.     

Electrochemical synthesis of ZnO branched submicrorods on carbon fibers and their feasibility for environmental applications

We investigated the structural and optical properties of the hierarchically integrated zinc oxide (ZnO) branched submicrorods on carbon fibers (ZOCF) by scanning/transmission electron microscopy, X-ray diffraction, and photoluminescence (PL) measurements. The ZnO submicrorods were facilely synthesized by an electrochemical deposition method on polyacrylonitrile-based carbon fiber sheets used as a substrate. After coating the ZnO seed layer on the surface of the carbon fibers, ZnO submicrorods were densely grown on the nuclei sites of the seed layer. The prepared ZOCF samples exhibited high crystallinity and good PL properties. A feasibility for environmental application in Pb(II) removal from aqueous solutions was also studied. The ZOCF adsorbent exhibited an excellent maximum adsorption capacity of 245.07 mg g⁻¹, which could be practically used in Pb(II) removal from water. These fabricated ZOCFs are potentially useful for multifunctional and environmental devices.     

Scalable reduction of large datasets to interesting subsets

With a huge amount of RDF data available on the web, the ability to find and access relevant information is crucial. Traditional approaches to storing, querying, and reasoning fall short when faced with web-scale data. We present a system that combines the computational power of large clusters for enabling large-scale reasoning and data access with an efficient data structure for storing and querying the accessed data on a traditional personal computer or other resource-constrained device. We present results of using this system to load the 2009 Billion Triples Challenge dataset, materialize RDFS inferences, extract an “interesting” subset of the data using a large cluster, and further analyze the extracted data using a personal computer, all in the order of tens of minutes.     

Detection of object abandonment using temporal logic

This paper describes a novel framework for a smart threat detection system that uses computer vision to capture, exploit and interpret the temporal flow of events related to the abandonment of an object. Our approach uses contextual information along with an analysis of the causal progression of events to decide whether or not an alarm should be raised. When an unattended object is detected, the system traces it back in time to determine and record who its most likely owner(s) may be. Through subsequent frames, the system searches the scene for the owner and issues an alert if no match is found for the owner over a given period of time. Our algorithm has been successfully tested on two benchmark datasets (PETS 2006 Benchmark Data, 2006; i-LIDS Dataset for AVSS, 2007), and yielded results that are substantially more accurate than similar systems developed by other academic and industrial research groups.     

Charge density and pH effects on polycation adsorption on poly-Si, SiO2, and Si3N4 films and impact on removal during chemical mechanical polishing

The pH-dependent interactions of five aqueous abrasive-free polycationic solutions, all at a concentration of 250 ppm, with poly-Si, SiO(2), and Si(3)N(4) films and IC1000 polishing pads used in chemical mechanical polishing have been investigated and compared with the interaction of poly(diallyldimethyl ammonium chloride) (PDADMAC) that was investigated recently. Three of the polycationic solutions, poly(dimethylamine-co-epichlorohydrin-co-ethylenediamine), poly(allylamine), and poly(ethylene imine) (PEI) enhance poly-Si removal rates (RRs) to the range of about 500 to 600 nm/min at pH 10. In contrast, poly(acrylamide) (PAA) suppressed poly-Si RRs to about 50 nm/min, whereas with a copolymer of PAA and PDADMAC, the RRs were lower than those obtained with PDADMAC but higher than those obtained with PAA. For all the polycationic solutions, the RRs of both SiO(2), and Si(3)N(4) films were ~0 nm/min. These solutions offer a low-defect option for the processing of emerging FinFET devices. The variation in the RR magnitude and dependence on pH among the different polycations is related to the relative charge density of the polycations as well as the films being polished, consistent with ζ potential data. Based on the ζ potential data and earlier published reports, it is suggested that the strong polycation-mediated bridging interactions between the polarized and weakened Si-Si bonds of the poly-Si surface and the polyurethane IC 1000 pad are responsible for the high poly-Si RRs.     

Reduction, aggregation and physicochemical properties of silver nanoparticles in propan-2-ol:cyclohexane mixtures induced by a high energy electron beam

Radiolytic reduction of silver and gold ions and subsequent formation of their aggregates have been studied in propan-2-ol:cyclohexane mixture using pulse radiolysis technique. The silver sol, produced on irradiation of Ag⁺ solution with a train of electron pulses, has been characterized using XRD and TEM. The size of the particles has been found to be in the range of 30-50 nm. The silver sol emit light with a maximum at 340 nm on irradiation with a high energy electron beam. The intensity of emission has been found to decrease with decrease in concentration of Ag particles. Formation of colloidal gold has also been observed on irradiation of NaAuCl₄ solution in propan-2-ol:cyclohexane by train of electron pulses. The particles so formed are oxidized on exposure to air. No light emission has been observed from Au sol.