Neutron irradiation effect on SiPMs up to Φneq\Phi_{neq} = 5 ×\times 1014^{14} cm−2^{-2}

Silicon Photo-Multipliers (SiPM) are becoming the photo-detector of choice for increasingly more particle detection applications, from fundamental physics to medical and societal applications. One major consideration for their use at high-luminosity colliders is the radiation damage induced by hadrons, which leads to a dramatic increase of the dark count rate. KETEK SiPMs have been exposed to various fluences of reactor neutrons up to $\Phi_{neq}$ = 5$\times$10$^{14}$ cm$^{-2}$ (1 MeV equivalent neutrons). Results from the I-V, and C-V measurements for temperatures between $-$30$^\circ$C and $+$30$^\circ$C are presented. We propose a new method to quantify the effect of radiation damage on the SiPM performance. Using the measured dark current the single pixel occupation probability as a function of temperature and excess voltage is determined. From the pixel occupation probability the operating conditions for given requirements can be optimized. The method is qualitatively verified using current measurements with the SiPM illuminated by blue LED light

Design, development and evaluation of Stanford/Ames Extra-Vehicular Activity (EVA) prehensors

A summary is given of progress to date on work proposed in 1983 and continued in 1985, including design iterations on three different types of manually powered prehensors, construction of functional mockups of each and culminating in detailed drawings and specifications for suit-compatible sealed units for testing under realistic conditions

Design, development and evaluation of Stanford/Ames EVA prehensors

Space Station operations and maintenance are expected to make unprecedented demands on astronaut EVA. With Space Station expected to operate with an 8 to 10 psi atmosphere (4 psi for Shuttle operations), the effectivness of pressurized gloves is called into doubt at the same time that EVA activity levels are to be increased. To address the need for more frequent and complex EVA missions and also to extend the dexterity, duration, and safety of EVA astronauts, NASA Ames and Stanford University have an ongoing cooperative agreement to explore and compare alternatives. This is the final Stanford/Ames report on manually powered Prehensors, each of which consists of a shroud forming a pressure enclosure around the astronaut's hand, and a linkage system to transfer the motions and forces of the hand to mechanical digits attached to the shroud. All prehensors are intended for attachment to a standard wrist coupling, as found on the AX-5 hard suit prototype, so that realistic tests can be performed under normal and reduced gravity as simulated by water flotation

New Facilities

This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440

Producer Opinions on Antibiotic Use in the Beef Industry

Antibiotic use in the beef industry is of increasing interest to consumers and has become a point of discussion for producers, veterinarians, and professional scientists in recent years. With the vast amount of information available on the internet and social media, consumers are becoming more knowledgeable about beef production practices and the use of antibiotics in the food animal industries. Furthermore, scientists have devoted a large amount of time and money to research to investigate consumer opinions and perspectives about management practices used in food animal production. However, many of these investigations fail to include the opinions and perspectives of the producers who raise these animals. Therefore, the objective of this survey was to explore producer practices and opinions on antibiotic use and antibiotic resistance in the beef industry

A Survey of Dry Processed Corn Particle Size and Fecal Starch in Midwestern U.S. Feedlots

Optimizing grain processing practices in cattle feeding operations is critical to reaching maximum feed utilization efficiency. An increased degree of grain processing has consistently shown improved dry matter and starch digestibility; however, it exists with conflicting results on improving performance in finishing cattle. These inconsistencies are likely due to diet composition, such as roughage and co-product level, that could offset the effects of reduced particle size on rate of fermentation thus reducing the risk of digestive dysfunction. Finishing diets are commonly formulated with processed grain to increase utilization of starch and improve animal performance. Processing methods including steam-flaking, grinding, or dry-rolling improve total tract starch digestibility compared with that of whole grain. When dry-rolling corn for finishing cattle, recommendations often suggest that grain be coarsely processed, or cracked to prevent production of an excessive quantity of fine material that could potentially result in an increased rate of fermentation, reduced rumen pH, and digestive disturbances. However, previous research has reported that inclusion of dried distillers grains in finishing diets may influence optimal grain processing method. Grinding corn to a finer particle size when the grain is fed in combination with distillers grains may result in improved total tract starch utilization without causing reduced ruminal pH and digestive disturbances. The objective of this survey was to provide the feedlot industry with an indication of average particle size distribution from current manufacturing practices of dry processed corn, fecal starch content, and co-product and roughage inclusion levels in Midwestern feedlots

Probing Correlated Ground States with Microscopic Optical Model for Nucleon Scattering off Doubly-Closed-Shell Nuclei

The RPA long range correlations are known to play a significant role in understanding the depletion of single particle-hole states observed in (e, e') and (e, e'p) measurements. Here the Random Phase Approximation (RPA) theory, implemented using the D1S force is considered for the specific purpose of building correlated ground states and related one-body density matrix elements. These may be implemented and tested in a fully microscopic optical model for NA scattering off doubly-closed-shell nuclei. A method is presented to correct for the correlations overcounting inherent to the RPA formalism. One-body density matrix elements in the uncorrelated (i.e. Hartree-Fock) and correlated (i.e. RPA) ground states are then challenged in proton scattering studies based on the Melbourne microscopic optical model to highlight the role played by the RPA correlations. Effects of such correlations which deplete the nuclear matter at small radial distance (r $<$ 2 fm) and enhance its surface region, are getting more and more sizeable as the incident energy increases. Illustrations are given for proton scattering observables measured up to 201 MeV for the $^{16}$O, $^{40}$Ca, $^{48}$Ca and $^{208}$Pb target nuclei. Handling the RPA correlations systematically improves the agreement between scattering predictions and data for energies higher than 150 MeV.Comment: 20 pages, 7 figure

Differences in Efficacy Between Gamithromycin, Tilmicosin, and Tulathromycin as Metaphylactic Treatments in High Risk Calves for Bovine Respiratory Disease

The cost of Bovine Respiratory Disease to the beef industry due to death, poorer conversions, and therapy is estimated to cost more than $3 billion per year. Identifying and mitigating Bovine Respiratory Disease in cattle can be difficult due to the increased susceptibility for Bovine Respiratory Disease in high risk cattle. One management option to minimize an outbreak of respiratory disease is the use of metaphylaxis, the mass treatment of a group of calves to reduce the incidence and adverse effects of respiratory disease on high risk animals. Criteria used to determine the necessity of metaphylactic treatment against Bovine Respiratory Disease in feedlots can be based on several factors depending on feedlot preference; however, the primary criteria often considered are: a known history of no previous vaccinations, overall appearance of cattle, source of cattle, Bovine Respiratory Disease in calves received from same source previously, long shipping distance, season of the year, and light arrival weight. The objective of this study was to compare the efficacy of treating newly received, highrisk feedlot calves with gamithromycin, tulathromycin, and tilmicosin as metaphylactic treatments on health and performance characteristics

Liver Abscess Severity at Slaughter Does Not Affect Meat Tenderness and Sensory Attributes in Commercially Finished Beef Cattle Fed Without Tylosin Phosphate

Liver abscesses are a significant problem in the United States’ cattle feeding industry, costing the industry an estimated $15.9 million annually in liver condemnation, trim losses, and reduced carcass weights and quality grades. Recent reported incidence rates of liver abscesses at slaughter range from 10 to 20%. Liver abscess incidence may be influenced by a number of factors including: breed, gender, diet, days on feed, cattle type, season, and geographical location. Liver abscesses typically occur secondary to rumen insults caused by acidosis or rumenitis. It has been proposed that pathogens associated with liver abscess formation enter the blood stream through damaged rumen epithelium and are transported to the liver through the portal vein where they cause infection, manifested as liver abscesses. Severe liver abscesses have been linked to reduction in hot carcass weight, dressing percentage, yield grade, longissimus muscle area, and marbling scores of carcasses when compared to those with normal livers. However, the effect of liver abscesses on meat tenderness and sensory attributes has not been previously investigated