Simple, shock-free, quick-release connector - A concept

Connector concept is based on characteristics of friction between sliding surfaces and consists of two packs of foil strips. Advantages of this connector are - separation is smooth and shock-free, and connector can also act as a seal. Equation for computing tensile load-carrying capability is also given

Effect of Whole Beetroot on Muscular Endurance and Power in Powerlifters and Physique Competitors

Nitrate ingestion improves aerobic exercise performance, but the efficacy in resistance training has not been established. The purpose of this study was to investigate whether consuming whole beetroot, as a means to ingest nitrate, had an ergogenic benefit in muscular power and endurance in resistance training in powerlifters and physique competitors. Thirteen men and women (mean ± SE age, 21.2 ± 0.8 y; mass, 83.1 ± 5.9 kg) that had competed in a powerlifting or a physique competition in the previous year were studied in a randomized double blind controlled crossover trial with a seven day washout period. Participants ingested 200g of beetroot or cranberry puree (control) 2.5 hours prior to performing ten sets on the bench press with 50% of their one repetition maximum with each set taken to fatigue. Between each set 120 seconds of rest was given. Heart rate and rate of perceived exertion was measured throughout the protocol and blood pressure was measured prior to the protocol. No differences were found for total repetitions, work, or power output between trials for the ten sets (P\u3e0.05). No differences were found for heart rate or perceived exertion between trials (P\u3e0.05). Systolic blood pressure tended to be lower in the beetroot trial (beetroot, 118 ± 3.3 mmHg; control, 124 ± 4.8 mmHg), but was not statistically significant (P= 0.238). In conclusion, beetroot ingestion did not provide a statistically significant difference in muscular endurance or power in the bench press. Beetroot would not be recommended as an ergogenic aid in these groups under these conditions. It is possible a beetroot loading period is needed to see a greater change in performance

Low cost solar array project 1: Silicon material

The low cost production of silicon by deposition of silicon from a hydrogen/chlorosilane mixture is described. Reactor design, reaction vessel support systems (physical support, power control and heaters, and temperature monitoring systems) and operation of the system are reviewed. Testing of four silicon deposition reactors is described, and test data and consequently derived data are given. An 18% conversion of trichlorosilane to silicon was achieved, but average conversion rates were lower than predicted due to incomplete removal of byproduct gases for recycling and silicon oxide/silicon polymer plugging of the gas outlet. Increasing the number of baffles inside the reaction vessel improved the conversion rate. Plans for further design and process improvements to correct the problems encountered are outlined

Thick silicon growth techniques

Hall mobility measurements on a number of single crystal silicon ribbons grown from graphite dies have shown some ribbons to have mobilities consistent with their resistivities. The behavior of other ribbons appears to be explained by the introduction of impurities of the opposite sign. Growth of a small single crystal silicon ribbon has been achieved from a beryllia dia. Residual internal stresses of the order of 7 to 18,000 psi have been determined to exist in some silicon ribbon, particularly those grown at rates in excess of 1 in./min. Growth experiments have continued toward definition of a configuration and parameters to provide a reasonable yield of single crystal ribbons. High vacuum outgassing of graphite dies and evacuation and backfilling of growth chambers have provided significant improvements in surface quality of ribbons grown from graphite dies

Singular Case of Loss of the Hair

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Sulphate of Manganese in Jaundice

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Cwbr Author Interview: Compelling Images Enhance Narrative Histories: Interview With William C. Davis

William C. Davis is the author or editor of more than 40 books on the Civil War and Southern history, as well as numerous documentary screenplays. He has served as historical consultant on various television and film productions. Davis has twice been nominated for the Pulitzer Prize in history and is currently professor of history at the Virginia Polytechnic Institute and State University. His most recent book, The Civil War in Photographs (Carlton 2002), served as the platform for this interview..

Thick film silicon growth techniques

One inch wide silicon ribbons up to 14 inches long have been produced from graphite dies. Several different techniques have been employed to improve the semiconductor purity of silicon. This has resulted in a general increase in quality although the techniques involved have not been optimized. The power factor of uncoated ribbon solar cells produced for material evaluation has increased to approximately 75% of those evaluation cells made from commercial silicon. The present limitation is believed due to low lifetime. Additional work has continued with new die materials; however, only composite dies of SiO2 and C show significant potential at this time

Ancestral Genes Can Control the Ability of Horizontally Acquired Loci to Confer New Traits

Horizontally acquired genes typically function as autonomous units conferring new abilities when introduced into different species. However, we reasoned that proteins preexisting in an organism might constrain the functionality of a horizontally acquired gene product if it operates on an ancestral pathway. Here, we determine how the horizontally acquired pmrD gene product activates the ancestral PmrA/PmrB two-component system in Salmonella enterica but not in the closely related bacterium Escherichia coli. The Salmonella PmrD protein binds to the phosphorylated PmrA protein (PmrA-P), protecting it from dephosphorylation by the PmrB protein. This results in transcription of PmrA-dependent genes, including those conferring polymyxin B resistance. We now report that the E. coli PmrD protein can activate the PmrA/PmrB system in Salmonella even though it cannot do it in E. coli, suggesting that these two species differ in an additional component controlling PmrA-P levels. We establish that the E. coli PmrB displays higher phosphatase activity towards PmrA-P than the Salmonella PmrB, and we identified a PmrB subdomain responsible for this property. Replacement of the E. coli pmrB gene with the Salmonella homolog was sufficient to render E. coli resistant to polymyxin B under PmrD-inducing conditions. Our findings provide a singular example whereby quantitative differences in the biochemical activities of orthologous ancestral proteins dictate the ability of a horizontally acquired gene product to confer species-specific traits. And they suggest that horizontally acquired genes can potentiate selection at ancestral loci