Interaction of H_2 and O_2 on platinum (111)

Abstract Unavailabl

Amino Acid Supplementation of Opaque-2 Corn for Growing Pigs

Protein needs and amino acid requirements are of major interest in the swine industry today. A considerable amount of research has been conducted on these subjects and more is sure to follow. Amino acid content and balance are now being recognized as more important factors in swine nutrition than total protein alone. Recently, the development of opaque-2 corn with higher amounts of lysine and tryptophan than normal corn has stimulated interest in its presence in simplified diets to supply the amino acid needs of swine. Performance of pigs fed opaque-2 corn has generally been superior to that of pigs fed normal corn. Although opaque-2 corn is inadequate as the only source of amino acids in a growing pig diet, it may, with proper supplementation, prove to be a practical and economical base for swine diets. Data suggest that pigs require less supplemental protein when fed opaque-2 corn than when fed normal corn. The purpose of the research presented herein was to study the adequacy of the essential amino acids lysine, methionine, tryptophan, threonine, and isoleucine in opaque-2 corn diets for young pigs. Rate of gain, feed efficiency, and plasma amino acid levels were criteria used to evaluate the diets

A Method for Reducing the Severity of Epidemics by Allocating Vaccines According to Centrality

One long-standing question in epidemiological research is how best to allocate limited amounts of vaccine or similar preventative measures in order to minimize the severity of an epidemic. Much of the literature on the problem of vaccine allocation has focused on influenza epidemics and used mathematical models of epidemic spread to determine the effectiveness of proposed methods. Our work applies computational models of epidemics to the problem of geographically allocating a limited number of vaccines within several Texas counties. We developed a graph-based, stochastic model for epidemics that is based on the SEIR model, and tested vaccine allocation methods based on multiple centrality measures. This approach provides an alternative method for addressing the vaccine allocation problem, which can be combined with more conventional approaches to yield more effective epidemic suppression strategies. We found that allocation methods based on in-degree and inverse betweenness centralities tended to be the most effective at containing epidemics.Comment: 10 pages, accepted to ACM BCB 201

Measurements and Prediction of Thermal Contact Resistance across Coated Joints

An integrated experimental and numerical investigation of the thermal contact resistance across two nominally flat, coated metallic engineering surfaces in contact is presented. The model consists of a surface deformation computation, which determines the actual contact area and number of contacting asperities at a joint, and a constriction resistance analysis, which determines the constriction resistance through each individual contacting asperity. Predictions from the model are validated against experiments conducted for the purpose. The experiments are performed according to a “design of experiments” approach and evaluated using statistical regression. Three substrates (copper, brass, and aluminum) and three coatings (silver, nickel, and tin) are considered with a variety of coating thicknesses and substrate roughnesses. The contact load is also varied. The experimental measurements show that the best choice of a coating for contact resistance mitigation depends on the substrate material and roughness, and it cannot be prescribed in general. A regression equation developed for the experimental results offers a useful tool for the design of coated contacts. The measured results agree well with predicted values from the numerical model, especially in cases of a rough substrate or hard coating

Biostratigraphic and magnetostratigraphic synthesis of the Celebes and Sulu Seas, Leg 124

During ODP Leg 124, late middle Eocene to Quaternary sediment sequences were recovered from 13 holes drilled at five sites in the Celebes and Sulu basins. Paleomagnetic measurements and biostratigraphic studies using calcareous nannofossils, planktonic and benthic foraminifers, radiolarians, and diatoms were completed and summarized here. Two Neogene sediment sections recovered in the Sulu Basin yielded excellent core recoveries and magnetic reversal records, allowing direct magnetobiostratigraphic correlations for the Pliocene and Quaternary at Site 768 and for the middle Miocene to Quaternary at Site 769. The interpolated ages of biohorizons are not consistent between sites and only a few of them are in good agreement with previous calibrations. The differences may be the results of redeposition by turbidity currents and selective dissolution of key fossils

Evaluating the Usability of a Multilingual Passphrase Policy

The literature shows that users struggle to generate secure passwords. This has led to systems administrators implementing password expiry policies that burden and frustrate users. This study explores the security and usability of a multilingual passphrase policy, as multilingualism has the potential to enhance security. A total of 224 participants were invited to participate in an experiment to generate and recall short passwords and multilingual passphrases. The findings of this study show that, although a multilingual passphrase policy made passphrase generation slightly more difficult, its use motivated users to generate unique memorable passphrases. Arguably, repeated use of passphrases promotes memorability and cognitive fluency. Furthermore, the multilingual passphrases in this study proved to be stronger than those reported in the literature