Crosslinked Starch Entrapped in Agarose-Beads. An Affinity Matrix for the Preparation of α-D-Mannose/α-D-Glucose Specific Lectins

A simple biospecific affinity matrix like crosslinked starch entrapped in agarose-beads is used for the isolation of α-D-mannose/α-D-glucose specific lectins such as Concanavalin A. pea and lentil. The adsorption capacities of these lectins for crosslinked starch are compared with those of Sephadex G-50. The purified lectins were found to be identical to those obtained by using Sephadex G-50 as an affinity matrix, as judged from their electrophoretic patterns (PAGE - pH 4.5, SDS-PAGE) and hemagglutination of papain treated rabbit erythrocytes.     

Permeability of silicone polymers to hydrogen

Permeability coefficients, P?, for H₂ in 10 different types of silicone polymer membranes were measured in the temperature range of 10.0–55.0°C and at pressures up to 100 psig (～6.8 atm). The values of P? decrease slightly with increasing Δp, the pressure difference across the membranes. The permeability of silicone polymers to H₂ increases with an increase in temperature; the values of the energy of activation for permeation are in the range of 1.4–4.3 kcal/mol. The substitution of different functional groups in the backbone and side chains of silicone polymers has similar effects on the permeability of the polymers to H₂ as observed in earlier studies with other light gases. P? for H₂ decreases with an increase in the bulkiness of the substituted functional groups. The substitution of Si? O bonds with stiffer Si? C bonds in the backbone chains also results in a considerable decrease in permeability.     

Maintenance Improvement Policy to Optimise System Availability

It is necessary to maintain the level of system availability from the point of view of reliable service to consumers. One way of maintaining the required level of system availability is to improve the existing maintenance activity. This paper presents an algorithm to determine the optimal policy for improving existing maintenance activity.     

Optimum coordination of overcurrent relay timing using continuous genetic algorithm

Overcurrent relays (OCR) are the major protection devices in a distribution system. To reduce the power outages, mal-operation of the backup relays should be avoided, and therefore, OCR time coordination in power distribution network is a major concern of protection engineer. The OCR time coordination in ring fed distribution networks is a highly constrained optimization problem. The purpose is to find an optimum relay setting to minimize the time of operation of relays and at the same time, to avoid the mal-operation of relays.This paper presents continuous genetic algorithm (CGA) technique for optimum coordination of OCR in a ring fed distribution system. Constraints are incorporated in the fitness function making use of the penalty method. The CGA is inherently faster than binary genetic algorithm (GA) because the chromosomes do not have to be decoded. Also the CGA gives an advantage of requiring less storage than binary GA.     

Composite polymer electrolyte based on (PEO)6:NaPO3 dispersed with BaTiO3

BACKGROUND: Polymer electrolytes have attracted considerable attention as regards portable solid‐state electrochemical device applications. The present investigation is focused on the characterization of a new Na⁺ ion conducting polymer electrolyte (PEO)₆:NaPO₃ dispersed with 3–10 wt% BaTiO₃ (0.7 µm) fillers. The composite polymer electrolytes (CPEs) were prepared by a solution‐casting method and characterized using various physical measurement techniques. RESULTS: Differential scanning calorimetry results indicate a maximum reduction in the degree of crystallinity of the polymer from 62.6% for uncomplexed poly(ethylene oxide) (PEO) to 27.6% for the CPE with 6 wt% BaTiO₃. This substantiates an enhancement in the amorphous phase of the polymer inferred from X‐ray diffraction and optical micrographs. The CPE dispersed with 6 wt% BaTiO₃ is found to be the best composition exhibiting a maximum ionic conductivity of 1.2 × 10^?6 S cm^?1 at 345 K with cationic transport number (t) of 0.33. CONCLUSIONS: An enhancement in the ionic conductivity of about two orders of magnitude is achieved for the composite electrolytes when compared to filler‐free solid polymer electrolyte. Correlation of the temperature‐dependent conductivity, activation energy for ion migration and transport number enables an understanding of the role played by the fillers in conduction characteristics of the CPEs. Copyright © 2007 Society of Chemical Industry     

Emittance from stagnation temperature study

Variation of stagnation temperature of various coatings kept in an insulated one glass cover box is theoreticall analysed. This shows that it is possible to make an approximate estimate of thermal emittance of the coating of known absorptance from the knowledge of stagnation temperature, ambient temperature and solar insolation. Such estimate of emittance for several black painted, black chrome and structured nickel coated samples are compared with their emittance values obtained from reflectance data.     

Phase-Change Inks

Phase-change, or hot melt, inks aresolid at ambient temperature and liquid at the moment of printing. Such inks contain no volatile solvent to be trapped in ink film or to produce Volatile Organic Compounds (VOC). The phase-change inks found application in non-impact printing technology by either thermal transfer or “solid ink” digital printing. The environmental and health problems caused by inks containing volatile organic compounds, such as toluene, call for new solutions in the rotogravure printing industry. Because of their low VOC content, phase-change inks might be a reasonable solution for gravure printing. College of Engineering and Applied Sciences, Department of Paper and Printing Science and Engineering, Welborn Hall, Kalamazoo, MI 49008-5060.