On the SEP of Cooperative Diversity with Opportunistic Relaying

We analyze the exact symbol error probability (SEP) of cooperative diversity with opportunistic amplify-and-forward (AF) relaying. The benefit of this opportunism to the SEP is assessed by comparing with maximal ratio combining of orthogonal multiple AF relay transmissions.     

A device for measuring the equivalent resistance of an energized circuit section

A device for measuring the active resistance of a direct current energized circuit section is described. Owing to the use of up-to-date electronic components, an iteration measurement algorithm, and a sinusoidal signal as a test one, the following performance characteristics have been obtained: the measurement time is <1 s, and the error varies from 0.3 to 2.0% in a 100-Ω to 1-MΩ range and ≤25% in 10-to 100-Ω and 1-to 10-MΩ ranges.     

Cover Picture: UV‐Light‐Induced Swelling and Visible‐Light‐Induced Shrinking of a TiO2‐Containing Redox Gel (Adv. Mater. 9/2007)

Polyacrylate gels containing Ag⁺ and TiO₂ nanoparticles are shown to swell under UV light and shrink under visible light in water. In work reported by Tetsu Tatsuma and co‐workers on p. 1249, the TiO₂ absorbs UV light and reduces the Ag⁺, whereas the deposited Ag absorbs visible light and dissolves itself. These redox reactions change the interactions between the polymer chains and eventually the volume of the gel, as shown on the cover.     

Investigation of the use of ram horn hydrolysate for fungal protein production

Production of the fungus Aspergillus niger NRRL 330 was studied in submerged fermentation with ram horn hydrolysate (RHH) as substrate. The characteristics of RHH have been reported previously. The RHH was enriched by addition of glucose and KH₂PO₄. The effects of kinetic parameters on the biomass yield of the fungus were investigated. The optimal conditions for growth of A niger on RHH were initial pH 6.5, temperature 30 °C, fermentation time 96 h and agitation speed 150 rpm. Under these optimal conditions the initial carbohydrate content of RHH was reduced from 1.52 to 0.2% and the biomass yield was 8.9 g l^?1. The biomass contained about 48.1% protein, 5.2% fat and 9.4% ash (on a dry weight basis). The amino acid content of the biomass was compared with Food and Agricultural Organisation (FAO) and animal feed standards. The protein produced contained all the essential amino acids for animal feed, but the amounts of these amino acids were somewhat lower than those of FAO and soybean reference protein. However, the amino acid composition of the biomass was better than that of animal feed. The results with RHH were also compared with previously reported data on fungal mycelium grown on waste liquor substrate. In conclusion, it was found that RHH could be used as a substrate in the production of fungal protein for use as animal feed. Copyright © 2003 Society of Chemical Industry     

The absence of lipase in cottonseed

Summary Although analyses of free fatty acid fractions obtained from deteriorating cottonseed indicate that they are released by hydrolysis of the glycerides, no lipase could be detected in meals obtained from such seed. Prime cottonseed also was without lipolytic activity (Longenecker and Haley method). The mechanism of the reaction whereby free fatty acids develop in wet seed during storage thus remains obscure. Contribution from the Multiple Fellowship of the Cotton Research Foundation, Mellon Institute, Pittsburgh. Presented in part before the Division of Agricultural and Food Chemistry of the American Chemical Society at Detroit, September, 1940.     

Some Thoughts on the Evolution of Work Teams in Organizations

In this time of flat, team-based and technology-enabled organizations the effectiveness of communication and team leadership practices will be more important than ever before. Therefore, we believe that some of the earlier, time-tested classic works on group dynamics and leadership are worthy of re-reading. We are particularly impressed by how relevant one of the oldest classics, Benne and Sheats' (1948) article on functional roles of group members, remains to this day.