Studies on the Reduction of Radon Plate-Out

The decay of common radioactive gases, such as radon, produces stable isotopes by a sequence of daughter particles with varied half-lives. These daughter particles are a significant source of gamma, neutron, and alpha particle backgrounds that can mimic desired signals in dark matter and neutrinoless double beta decay experiments. In the LUMINA Laboratory at Southern Methodist University (SMU), studies of radon plate-out onto copper samples are conducted using one of XIA's first five UltraLo 1800 alpha counters. We present results from investigations into various mitigation approaches. A custom-built copper holder (in either plastic or metal) has been designed and produced to maximize the copper's exposure to 220Rn. The 220Rn source is a collection of camping lantern mantles. We present the current status of control and experimental methods for addressing radon exposure levels.Comment: 4 pages, 1 figure, Conference Proceedings for Low Radioactivity Techniques 201

COUNTRY-OF-ORIGIN LABELING OF BEEF PRODUCTS: U.S. CONSUMERS' PERCEPTIONS

In 2002, Chicago and Denver consumers were surveyed and participated in an experimental auction to elicit willingness to pay for country-of-origin labeling (COOL) of beef. Survey results indicate the majority of consumers (73%) were willing to pay an 11% and 24% premium for COOL of steak and hamburger, respectively. In the auction, consumers were willing to pay a 19% premium for steak labeled “"U.S.A. Guaranteed: Born and Raised in the U.S.”" Food-safety concerns, preferences for labeling source and origin information, a strong desire to support U.S. producers, and beliefs that U.S. beef was of higher quality were reasons consumers preferred COOL.Consumer/Household Economics,

CONSUMER PREFERENCE FOR DOMESTIC VERSUS INTERNATIONAL BEEF STEAKS

Demand and Price Analysis,

THE VALUE OF BEEF FLAVOR: CONSUMER WILLINGNESS-TO-PAY FOR MARBLING IN BEEF STEAKS

Consumer/Household Economics, Food Consumption/Nutrition/Food Safety,

U.S. Consumers' Willingness to Pay for Flavor and Tenderness in Steaks as Determined with an Experimental Auction

In a study of beef quality, consumers tasted steak samples and participated in an experimental auction to determine their willingness to pay. Steaks differed in marbling, tenderness, country of origin, and aging method. Marbling and tenderness had statistically significant impacts on consumers' palatability ratings for steaks. Tenderness significantly impacted consumers' willingness-to pay values. There appear to be threshold levels of marbling and tenderness, below which consumers discount steaks. Steaks from Australia were rated lower for overall acceptability, and bids were lower than for the U.S. steak samples. Dry-aging methods negatively impacted taste panel ratings and bids.beef, country of origin, experimental auctions, marbling, tenderness, Consumer/Household Economics,

Flavor Relationships among Muscles form the Beef Chuck and Round

This research compared off-flavor notes and the relationship of pH and heme-iron content to off-flavor for different beef muscles. After grading, knuckles and shoulder clods were removed from 16 USDA Choice and 14 USDA Select beef carcasses, vacuum- packaged, and aged for 7 d. The rectus femoris (REC), vastus medalis (VAM), vastus lateralis (VAL), teres major (TER), infraspinatus (INF), and triceps brachii-long head (TRI) were separated, cut into steaks, and frozen (−16°C). Sensory analysis was conducted using a trained taste panel, with steaks grilled to an internal temperature of 65°C. Heme-iron concentration and pH were determined. The INF had lower (P \u3c 0.05) off-flavor intensity ratings and less frequent sour flavor than the other muscles, and the VAL had the most intense (P \u3c 0.05) off-flavor ratings and among the greatest frequency of sour, charred, and oxidized flavors. The frequencies of liver-like, bloody, and rancid flavors were not affected by muscle type. Heme-iron concentration did not differ among muscles. Three USDA Select carcasses had intense off-flavor in the muscles. Liver-like flavor was highly negatively correlated with off-flavor intensity for each of the muscles tested. Muscles rated a 5 or below (on an 8-point rating scale, where 1 = extremely intense off-flavor and 8 = no off-flavor) in off-flavor intensity and identified as liver-like by 30% or more of the panelists were grouped together and compared to normal muscles. Those in the liver-flavored group were less frequently identified as charred, probably because the liver-like flavor was so intense. There were no differences between the 2 groups for sour, metallic, bloody, oxidized, or fatty off-flavor notes. Regression equations containing the linear and quadratic functions of heme-iron concentration, muscle pH, and their interaction were established for the frequency of off-flavor notes within each muscle. The REC, TER, VAL, and VAM showed a relationship between pH, heme iron, and off-flavor intensity (P \u3c 0.05). Liver-like flavor was explained partially by pH and heme iron in the REC, VAM, and VAL (R2 = 0.45 to 0.55; P \u3c 0.05). Few other significant relationships were found. Heme iron and pH were unrelated to metallic, oxidized, or rancid flavors for any of the muscles tested. These data suggest that liver-like off-flavors are specific to individual animals, and that pH and heme iron are not strongly related to off-flavor notes

The History of the Dalat Nuclear Reactor

Undergraduate Research Opportunity Program (UROP)http://deepblue.lib.umich.edu/bitstream/2027.42/116113/1/TheHistoryofthe_Dalat_Nuclear_Reactor.pd

Strongly Variable z=1.48 FeII and MgII Absorption in the Spectra of z=4.05 GRB 060206

We report on the discovery of strongly variable FeII and MgII absorption lines seen at z=1.48 in the spectra of the z=4.05 GRB 060206 obtained between 4.13 to 7.63 hours (observer frame) after the burst. In particular, the FeII line equivalent width (EW) decayed rapidly from 1.72+-0.25 AA to 0.28+-0.21 AA, only to increase to 0.96+-0.21 AA in a later date spectrum. The MgII doublet shows even more complicated evolution: the weaker line of the doublet drops from 2.05+-0.25 AA to 0.92+-0.32 AA, but then more than doubles to 2.47+-0.41 AA in later data. The ratio of the EWs for the MgII doublet is also variable, being closer to 1:1 (saturated regime) when the lines are stronger and becoming closer to 2:1 (unsaturated regime) when the lines are weaker, consistent with expectations based on atomic physics. We have investigated and rejected the possibility of any instrumental or atmospheric effects causing the observed strong variations. Our discovery of clearly variable intervening FeII and MgII lines lends very strong support to their scenario, in which the characteristic size of intervening patches of MgII ``clouds'' is comparable to the GRB beam size, i.e, about 10^16 cm. We discuss various implications of this discovery, including the nature of the MgII absorbers, the physics of GRBs, and measurements of chemical abundances from GRB and quasar absorption lines.Comment: 14 pages, 3 figures, 1 table; ApJ Letters, accepte

Consumer Acceptance and Value of Beef from Various Countries of Origin

To determine consumer acceptance and value of beef from various countries, 12 taste panels were conducted in each of two cities. Two pairs of beef strip steaks were evaluated - domestic versus Australian grass-fed and domestic versus Canadian. Consumers gave significantly higher scores for flavor, tenderness and overall acceptability to domestic steaks compared to Australian grass-fed steaks and Canadian steaks. A significantly higher value also was placed on the domestic samples compared to Australian grass-fed steaks ($3.68/lb versus$2.48/lb) and Canadian steaks ($3.95/lb versus$3.57/lb). U.S. consumers preferred and were willing to pay significantly more for domestic steaks than Australian and Canadian steaks