Hydrogen slush density reference system

A hydrogen slush density reference system was designed for calibration of field-type instruments and/or transfer standards. The device is based on the buoyancy principle of Archimedes. The solids are weighed in a low-mass container so arranged that solids and container are buoyed by triple-point liquid hydrogen during the weighing process. Several types of hydrogen slush density transducers were developed and tested for possible use as transfer standards. The most successful transducers found were those which depend on change in dielectric constant, after which the Clausius-Mossotti function is used to relate dielectric constant and density

Predicting the severity of the grass pollen season and the effect of climate change in Northwest Europe

Allergic rhinitis is an inflammation in the nose caused by overreaction of the immune system to allergens in the air. Managing allergic rhinitis symptoms is challenging and requires timely intervention. The following are major questions often posed by those with allergic rhinitis: How should I prepare for the forthcoming season? How will the season's severity develop over the years? No country yet provides clear guidance addressing these questions. We propose two previously unexplored approaches for forecasting the severity of the grass pollen season on the basis of statistical and mechanistic models. The results suggest annual severity is largely governed by preseasonal meteorological conditions. The mechanistic model suggests climate change will increase the season severity by up to 60%, in line with experimental chamber studies. These models can be used as forecasting tools for advising individuals with hay fever and health care professionals how to prepare for the grass pollen season

Habitat Associations of Fish Species of Greatest Conservation Need at Multiple Spatial Scales in Wadeable Iowa Streams

Fish and habitat data were collected from 84 wadeable stream reaches in the Mississippi River drainage of Iowa to predict the occurrences of seven fish species of greatest conservation need and to identify the relative importance of habitat variables measured at small (e.g., depth, velocity, and substrate) and large (e.g., stream order, elevation, and gradient) scales in terms of their influence on species occurrences. Multiple logistic regression analysis was used to predict fish species occurrences, starting with all possible combinations of variables (5 large-scale variables, 13 small-scale variables, and all 18 variables) but limiting the final models to a maximum of five variables. Akaike’s information criterion was used to rank candidate models, weight model parameters, and calculate model-averaged predictions. On average, the correct classification rate (CCR = 80%) and Cohen’s kappa (κ = 0.59) were greatest for multiple-scale models (i.e., those including both large-scale and small-scale variables), intermediate for small-scale models (CCR = 75%; κ = 0.49), and lowest for large-scale models (CCR = 73%; κ = 0.44). The occurrence of each species was associated with a unique combination of large-scale and small-scale variables. Our results support the necessity of understanding factors that constrain the distribution of fishes across spatial scales to ensure that management decisions and actions occur at the appropriate scale

Ultrafast-ultrafine probing of high-speed electrical waveforms using a scanning force microscope with photoconductive gating

Picosecond photoconductivity in low-temperature-grown GaAs (LT GaAs) has been used to provide temporal resolution both in rigid probes and in scanning force microscope probes. This article reviews the fabrication and use of such probes. 2.5 ps temporal resolution and few microvolts sensitivity are obtained at arbitrary points on circuits with a spatial definition of 100 nm. Rigid probes are tested in application to analogue and digital circuits. As an alternative to electron beam testing, scanning force probes are applied to in situ imaging and waveform measurement. Finally, the use of time-resolved waveform analysis with scanning-force microscopy probes with semiconductor laser sources is demonstrated.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43337/1/11082_2004_Article_BF00820152.pd

Dakota Gold®-brand dried distiller’s grains with solubles in finishing cattle diets: a preharvest strategy against acid resistant Escherichia coli and coliforms?

Trial 1. Finishing beef heifers (345 head) were used in a 153-day finishing trial to evaluate the effects of feeding six levels of Dakota Gold®-brand dried distiller’s grains with solubles (DDGS): 0%, 15%, 30%, 45%, 60%, 75% (dry basis), on the number of acid resistant E. coli and coliforms. Fecal grab samples were taken on day 65 and day 100, 2 and 20 hours after feeding, and were analyzed for acid resistant E. coli and total coliforms, as well as pH and VFA. There was a significant linear increase in fecal pH with increased DDGS at both 2 and 20 hours post-feeding (P<0.05). Total coliforms and acid resistant E. coli at 2 and 20 hours postfeeding were not affected by dietary treatment (P>0.05). Total fecal VFAs were not affected by dietary treatment or hour sampled after feeding (P>0.05) Trial 2. Trial 2 was conducted on ruminally fistulated Jersey steers (18 head) using three levels of DDGS (0%, 30%, 75%). Rumen and fecal grab samples were taken after 4-week adaptation periods on three occasions after every animal had been on each level of the diet and had been sampled. Fecal and rumen samples were taken 2, 4, 6, 8, 12,18, and 24 hours post-feeding. Both fecal and rumen pH were unaffected by dietary treatment, yet an hour effect was noted. Dietary treatment had no effect (P>0.05) on E. coli or total coliforms cultured from rumen fluid or feces

Combinations of wet corn gluten feed and steam-flaked corn in finishing cattle diets: effects on acid-resistant E. Coli and coliforms, VFA Profiles and pH

Finishing beef steers (615 head) were used in a 152-day experiment to evaluate the effects of feeding 80:0, 60:30 or 30:60 ratios (dry basis) of steam-flaked corn and wet corn gluten feed (WCGF, 30WCGF, 60WCGF) on acid-resistant E. coli and coliforms. On days 114 to 118 ruminal and fecal samples were collected from 180 steers and analyzed for pH, VFA, and total and acid-resistant Escherichia coli (E. coli) and coliforms. Ruminal (P=0.13) and fecal (P=0.10) VFA tended to decrease linearly as CGF increased. Consequently, there was a corresponding numerical linear increase in ruminal pH and a significant linear increase in fecal pH (P<0.05). Total and acid-resistant E. coli and coliforms, however, were not affected (P>0.10) by dietary treatment

Analysis of the energy weighted angular correlations in hadronic e e annihilations at 22 and 34 GeV

CELLO Collaboration.SIGLEDEGerman

The influence of fragmentation models on the determination of the strong coupling constant in e e annihilation into hadrons

CELLO collaborationSIGLEDEGerman