The free-radical and ion chemistry of volatile silanes, germanes and phosphines

Progress is reported on: Ion-molecule reactions in SiH{sub 4}-CO mixtures, reactions of OH{sub x}{sup +} and SiH{sub x}{sup +} ions with GeH{sub 4}, infrared multiple phonon decomposition of Si{sub 2}F{sub 6}; disproportionation and combination of GeH{sub 3} radicals, and reactions of SiH{sub 2} with CH{sub 4}. 17 refs., 2 figs., 1 tab. (CBS

Comparison of Grain Sources (Barley, White Corn, and Yellow Corn) for Swine Diets and Their Effects on Meat Quality and Production Traits

Efficient pork production is a necessity for an economically viable swine industry. Number two yellow corn is considered the primary energy source for swine diets in the Midwest. Despite the low protein content, corn is considered one of the most economical feed stuffs available to the swine production system. Barley is a high fiber that has approximately 89% of the energy content of corn. While barley contains a higher protein and amino acid level than corn, animal performance is expected to be depressed due to the high fiber content. Because barley lacks the carotene content that yellow corn possesses, it has been hypothesized that barley-fed pigs will yield higher meat and fat quality that is desired by export markets. White corn was used in this trial to determine its contribution to meat quality and growth traits. An experiment was conducted to evaluate the effect of energy source on performance and carcass traits of pigs. Diet treatments (primary energy source) were: 1) yellow corn, 2) white corn, 3) 1/3 yellow corn, 2/3 white corn, 4) 2/3 yellow corn, 1/3 white corn, 5) barley. Pigs completing the trial were from two sires lines, Duroc (n=500) and Hamp x Duroc (n=499), that were mated to PIC 1055 females. Pigs were randomly allocated to pens based on genetic type and gender using a 2 x 2 x 5 factorial arrangement with two genetic types, two sexes (barrows and gilts) and five treatments. Animals fed these diets differing in energy source did not express a difference in average daily gain, average daily feed intake, feed-to-gain ratio, backfat depth or percent fat free lean. However, barley-fed pigs did have a smaller (p \u3c .05) loin muscle area than pigs fed corn-based diets. Diet did not have an effect on sensory panel traits for tenderness or chewiness and limited differences were observed for juiciness, flavor, and off-flavor. Percentage loin purge, and cooking loss did not differ among diets fed to the pigs with minimal difference noted for color values. Pigs fed barley diets did have lower iodine value content within the subcutaneous fat indicating that the fat is of firmer quality. Results of this trial suggest that barley does not have an advantage in meat quality traits when compared to traditional corn-based diets. Barley does however have a significant impact on the hardness of pork fat, but does not have a significant effect on subjective color values

Role of impact parameter in branching reactions: Chemical accelerator studies of the reaction Xe++CH4→XeCH3 ++H

This is the publisher's version, also available electronically from http://scitation.aip.org/content/aip/journal/jcp/74/9/10.1063/1.441716.Integral reaction cross sections and product velocity distributions have been measured for the ion–molecule reaction Xe+(CH4,H)XeCH3 + over the relative reactant translational energy range of 0.7–5.5 eV by chemical accelerator techniques. The kinematic results indicate that reaction proceeds in a direct manner by a rebound mechanism over the energy range studied, suggesting that this substitution reaction occurs predominantly in small impact parameter collisions. This finding contrasts with the results obtained for the competing reaction, Xe+(CH4,CH3)XeH+, where the strong forward scattering of the XeH+ product indicates that H‐atom abstraction occurs primarily in large impact parameter collisions

Comparison of Grain Sources (Barley, White Corn, and Yellow Corn) for Swine Diets and Their Effect on Production and Carcass Traits

Energy sources differ in content, quality, and availability of nutrients. The objective of this study was to identify and compare differences in production and carcass traits in pigs fed different energy sources. While pigs fed a barley-based diet had a smaller loin muscle area, there was no difference among diets when comparing fat depth or percent fat-free lean. Barley based-diets and a diet containing one-third yellow corn and two-thirds white corn had a lower lean gain per day on test. There was no significant difference in average daily gain or feed-to-gain ratios

Precise determination of the Wtb couplings at LHC

Top pair production at LHC is the ideal place to search for nonstandard Wtb couplings in t -> W b -> l nu b decays. The lb forward-backward asymmetry in the W rest frame is very sensitive to sigma_{mu nu} couplings, and can spot one-loop QCD corrections to the decay vertex with more than 5 sigma statistical significance. We discuss the potential of this asymmetry to signal nonstandard gamma_mu and sigma_{mu nu} couplings and compare with top-antitop spin correlation asymmetries, which have a lower sensitivity. We also briefly summarise the results for Tevatron.Comment: LaTeX, 12 pages, 2 PS figures. One reference added. To be published in PR

Chirality and Symmetry Breaking in a discrete internal Space

In previous papers the permutation group S_4 has been suggested as an ordering scheme for elementary particles, and the appearance of this finite symmetry group was taken as indication for the existence of a discrete inner symmetry space underlying elementary particle interactions. Here it is pointed out that a more suitable choice than the tetrahedral group S_4 is the pyritohedral group A_4 x Z_2 because its vibrational spectrum exhibits exactly the mass multiplet structure of the 3 fermion generations. Furthermore it is noted that the same structure can also be obtained from a primordial symmetry breaking S_4 --> A_4. Since A_4 is a chiral group, while S_4 is achiral, an argument can be given why the chirality of the inner pyritohedral symmetry leads to parity violation of the weak interactions.Comment: 42 pages, 3 table

One-loop N-point equivalence among negative-dimensional, Mellin-Barnes and Feynman parametrization approaches to Feynman integrals

We show that at one-loop order, negative-dimensional, Mellin-Barnes' (MB) and Feynman parametrization (FP) approaches to Feynman loop integrals calculations are equivalent. Starting with a generating functional, for two and then for $N$-point scalar integrals we show how to reobtain MB results, using negative-dimensional and FP techniques. The $N-$point result is valid for different masses, arbitrary exponents of propagators and dimension.Comment: 11 pages, LaTeX. To be published in J.Phys.