Synthesis and characterization of highly acetylated sago starch

This study was carried out to understand and establish the changes in physicochemical parameters of sago starch after acetylation. Highly substituted starch acetate was prepared by reaction with native sago starch and acetic anhydride in organic solvent. Their formation was confirmed by the titrimetric analysis and FT‐IR. The presence of absorption band in FT‐IR at 1748 cm⁻¹ confirmed the carbonyl group attachment. The thermal behavior of native and acetyl substituted sago starch was investigated using thermo gravimetric analysis (TGA) and DSC. The results reveal that highly substituted starch acetate was more thermally stable as compared to native form. The XRD patterns showed loss of crystalline nature and its transformation into amorphous form. The SEM study suggested that the smooth surfaces of starch granules were changed into fibrous form after acetylation.     

High performance wire‐array silicon solar cells

Nano/micro‐wire silicon solar cells, consisting of wire‐arrays of radial p–n junction structures, are expected to offer performance enhancement at lower costs, using smaller volumes of low carrier lifetime, cheaper silicon. Using inexpensive microsphere‐lithography‐based fabrication that is scalable to large areas, we have demonstrated wire‐array solar cells that outperform the control cell. Key to the design of these cells is the impact of various parameters, such as wire diameter and junction depth, that influences the competing effects of light trapping ability of the wire‐array, quantum efficiency, and series resistance of the resulting device. Using capacitance measurements we can identify two possible types of junction structure in a wire‐array solar cell: radial and planar. We show that the former is the prerequisite for performance‐enhancing wire‐array solar cells. Copyright © 2010 John Wiley & Sons, Ltd.     

Influence of highly dispersible silica filler on the physical properties,tearing energy,and abrasion resistance of tire tread compound

Rubber industry is facing a stiff challenge in the years to come. There are rising price for fossil fuel and shortage of resources. There is more stringent legislation to protect the environment and reduce the emission. Filler plays an important role in imparting useful properties to rubber products. In this article, the effects of new generation filler, on the physical properties, tearing energy, and abrasion resistance were investigated. The new generation filler, highly dispersible silica, has a dibutyl phthalate (DBP) absorption value of more than 180cc 100 g⁻¹, more branched structure and relatively higher amount of small aggregates. Four different loadings of silica (up to 45 phr) were investigated. With increasing filler loading, the tensile strength and modulus at 300% elongation increased and the elongation-at-break decreased. The rebound resilience decreased and tan delta value improved with increasing silica content. The abradability continuously decreased with concomitant increase in the side coefficient force. The fatigue resistance was found to be better at higher silica loading. The silica particles due to its surface structure helps in crack arresting. The abradibility was related to tearing energy, loss modulus, and breaking energy. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47560.     

Temporal response of biochemical and biological sensors with bimodal surface adsorption from a finite sample

Microsystem Technologies - The importance of adsorption-based biochemical/biological sensors in biochemistry and biophysics is paramount. Their temporal response gives information about the...     

Generating a representative keyword subset pertaining to an academic conference series

Scientometrics - The breadth and velocity of innovation has resulted in explosion of research documents day by day. Academic conferences are being arranged worldwide, most of them in regular...     

An approach of feature selection using graph-theoretic heuristic and hill climbing

Pattern Analysis and Applications - Search-based methods that use matrix- or vector-based representations of the dataset are commonly employed to solve the problem of feature selection. These...     

Study of mechanical,thermal, morphological,and process rheology of acrylonitrile styrene acrylate (ASA)/ Na+1 poly(ethylene‐co‐methacrylic acid) ionomer blend

Acrylonitrile–styrene–acrylic (ASA) terpolymer was blended with a sodium neutralized poly (ethylene‐co‐methacrylic acid) ionomer to develop a weather‐resistant ASA with good heat sealing and adhesion properties. Both tensile strengths and modulus were reduced by about 45% with an increase in Na‐ionomer concentration of 50%. The mechanical data were fitted with different models that predict mechanical behavior. The thermal stability was increased with the incorporation of ionomer. The temperature corresponding to 50% mass loss (T_m50) was increased from 400°C (for ASA) to 427°C for 50/50 ASA/Na‐ionomer blend. SEM and AFM micrographs reveal the cone‐shaped microstructure on the ASA matrix surface after a critical Na‐ionomer concentration of 30%. This blend system follows typical non‐Newtonian behavior. The heat sealing performance study with metal was also carried out to investigate the utilization of these blend systems as a protective layer for metal. POLYM. ENG. SCI., 55:1571–1579, 2015. © 2014 Society of Plastics Engineers