298 research outputs found
Effects of Molybdenum Supplementation on Performance of Forageâfed SteersReceiving Highâsulfur Water
There has been onâgoing research in the area of the consumption of highâsulfur (S) water by steers grazing rangeland as well as forageâfed steers in a feedlot setting. During the summer of 2009, a trial was conducted on the effects of highâS water in finishing steers supplemented with molybdenum (Mo). The main purpose of the research was to gather data that may aid in the formulation of a supplement to counteract the negative effects of highâS water consumed by ruminant livestock species in areas where sulfur concentration in water sources is a risk to animal health and performance. The specific focus of this trial was to determine whether the feeding of supplemental Mo would improve animal health and performance by decreasing the formation of hydrogen sulfide gas (H2S) in the rumen. Yearling steers (n=96) were used for a 56âd trial. The trial consisted of 3 treatment groups; a lowâS water group and two highâS water groups. One highâS water treatment group received the same pellet that the lowâS group was given and the other highâS water treatment group received a pellet with supplemental Mo included. Rumen gas cap H2S was collected on d â1, 29 and 57. Weights were recorded on d â2, â1, 29, 56 and 57. There were no differences between treatments in water intake (P= 0.719), but feed intake was reduced in the steers receiving the supplemental Mo (P \u3c 0.001). There was a significant difference in ruminal H2S due to treatment (P= 0.014), with higher ruminal H2S in the steers receiving the supplemental Mo. Steers receiving the Mo supplement had lower ADG than steers in the other treatments (P= 0.009). Throughout the duration of the trial, two steers were removed from the trial due to advanced symptoms of sulfurâinduced PEM (sPEM) from the highâS treatment with no supplemental M
Product consistency testing of three reference glasses in stainless steel and perfluoroalkoxy resin vessels
Because of their chemical durability, silicate glasses have been proposed and researched since the mid-1950s as a medium for incorporating high-level radioactive waste (HLW) generated from processing of nuclear materials. A number of different waste forms were evaluated and ranked in the early 1980s; durability (leach resistance) was the highest weighted factor. Borosilicate glass was rated the best waste form available for incorporation of HLW. Four different types of vessels and three different glasses were used to study the possible effect of vessel composition on durability test results from the Production Consistency Test (PCT). The vessels were 45-m 304 stainless steel vessels, 150-m 304 L stainless steel vessels, and 60-m perfluoroalkoxy (PFA) fluoropolymer resin vessels. The three glasses were the Environmental Assessment glass manufactured by Corning Incorporated and supplied by Westinghouse Savannah River company, and West Valley Nuclear Services reference glasses 5 and 6, manufactured and supplied by Catholic University of America. Within experimental error, no differences were found in durability test results using the 3 different glasses in the 304L stainless steel or PFA fluoropolymer resin vessels over the seven-day test period
Recommended from our members
Product consistency testing of three reference glasses in stainless steel and perfluoroalkoxy resin vessels
Because of their chemical durability, silicate glasses have been proposed and researched since the mid-1950s as a medium for incorporating high-level radioactive waste (HLW) generated from processing of nuclear materials. A number of different waste forms were evaluated and ranked in the early 1980s; durability (leach resistance) was the highest weighted factor. Borosilicate glass was rated the best waste form available for incorporation of HLW. Four different types of vessels and three different glasses were used to study the possible effect of vessel composition on durability test results from the Production Consistency Test (PCT). The vessels were 45-m 304 stainless steel vessels, 150-m 304 L stainless steel vessels, and 60-m perfluoroalkoxy (PFA) fluoropolymer resin vessels. The three glasses were the Environmental Assessment glass manufactured by Corning Incorporated and supplied by Westinghouse Savannah River company, and West Valley Nuclear Services reference glasses 5 and 6, manufactured and supplied by Catholic University of America. Within experimental error, no differences were found in durability test results using the 3 different glasses in the 304L stainless steel or PFA fluoropolymer resin vessels over the seven-day test period
Vortex Plastic Flow, , Deep in the Bose Glass and Mott-Insulator Regimes
We present simulations of flux-gradient-driven superconducting vortices
interacting with strong columnar pinning defects as an external field is
quasi-statically swept from zero through a matching field . We
analyze several measurable quantities, including the local flux density , magnetization , critical current , and the
individual vortex flow paths. We find a significant change in the behavior of
these quantities as the local flux density crosses , and quantify it
for many microscopic pinning parameters. Further, we find that for a given pin
density can be enhanced by maximizing the distance between the pins
for .Comment: 4 pages, 4 PostScript Figure
Copper Supplementation of Grazing Yearling Steers Supplemented withMolybdenum While Consuming Highâsulfur Water
There has been onâgoing research conducted by South Dakota State University in the area of the consumption of highâsulfur (S) water by steers grazing rangeland. During the summer of 2009 a trial was conducted in cooperation with the University of Wyoming on the effects of copper supplementation of grazing pasture steers supplemented with molybdenum (Mo), while drinking highâsulfur water. The main purpose of this experiment was to gather data that may aide in the formulation of a method to counteract the negative effects of highâS water consumed by ruminant livestock species in areas where sulfur concentrations in water sources causes risk to animal health and performance. Yearling steers (n=120) were assigned randomly to 9 replicate groups, 3 replicates of 3 treatments for a 52 d experiment. All groups were provided with highâS water containing on average 2,201 mgâąkgâ1 of sulfate. Additionally, all treatment groups received 100 mgâąkgâ1 of supplemental Mo as an antagonist that would bind excess S. Unfortunately, Mo also binds copper (Cu), indicating that supplemental Cu may be necessary. Therefore treatments differed in level of supplemental copper: treatments 1 through 3 received 0, 75, or 150 mgâąkgâ1 of supplemental Cu, respectively. Prior to the trial, midâtrial and at the conclusion of the trial, ruminal H2S gas cap levels were collected. Animal weights were recorded d â2, â1, 28, 52 and 53. Over the entire course of the experiment there was a significant difference in ADG due to treatment (P\u3c 0.001). There were no differences in water consumption as a result of treatment (P= 0.618). No differences were observed in ruminal H2S due to treatment. No animal losses occurred due to the consumption of highâS water in this trial
Adaptive Mesh Refinement for Characteristic Grids
I consider techniques for Berger-Oliger adaptive mesh refinement (AMR) when
numerically solving partial differential equations with wave-like solutions,
using characteristic (double-null) grids. Such AMR algorithms are naturally
recursive, and the best-known past Berger-Oliger characteristic AMR algorithm,
that of Pretorius & Lehner (J. Comp. Phys. 198 (2004), 10), recurses on
individual "diamond" characteristic grid cells. This leads to the use of
fine-grained memory management, with individual grid cells kept in
2-dimensional linked lists at each refinement level. This complicates the
implementation and adds overhead in both space and time.
Here I describe a Berger-Oliger characteristic AMR algorithm which instead
recurses on null \emph{slices}. This algorithm is very similar to the usual
Cauchy Berger-Oliger algorithm, and uses relatively coarse-grained memory
management, allowing entire null slices to be stored in contiguous arrays in
memory. The algorithm is very efficient in both space and time.
I describe discretizations yielding both 2nd and 4th order global accuracy.
My code implementing the algorithm described here is included in the electronic
supplementary materials accompanying this paper, and is freely available to
other researchers under the terms of the GNU general public license.Comment: 37 pages, 15 figures (40 eps figure files, 8 of them color; all are
viewable ok in black-and-white), 1 mpeg movie, uses Springer-Verlag svjour3
document class, includes C++ source code. Changes from v1: revised in
response to referee comments: many references added, new figure added to
better explain the algorithm, other small changes, C++ code updated to latest
versio
Is there anybody out there? Occupancy of the carnivore guild in a temperate archipelago
Carnivores are important components of ecological communities with wide-ranging effects that vary with carnivore size, natural history, and hunting tactics. Researchers and managers should strive to understand both the presence and distribution of carnivores within their local environment. We studied the carnivore guild in the Apostle Islands, where the distribution and occupancy of carnivores was largely unknown. We monitored 19 islands with 160 functioning camera traps from 2014-2017, from which we collected 203,385 photographs across 49,280 trap nights. We documented 7,291 total wildlife events with 1,970 carnivore events, and detected 10 of the 12 terrestrial carnivores found in Wisconsin. Detection rates for species were generally higher in summer than winter, except for coyotes (Canis latrans) and red foxes (Vulpes vulpes). Finitesample occupancy estimates for carnivores varied across islands, with mean estimated occupancy across islands varying from a high of 0.73 for black bears to a low of 0.21 for gray wolves. Of the potential island biogeography explanatory variables for carnivore occupancy we considered, island size was the most important, followed by distance to the mainland, and then interisland distance. We estimated that terrestrial carnivore species varied in the number of islands they were detected on from 1 island for gray wolves to 13 islands for black bears. Estimated carnivore richness across islands (i.e., the number of carnivores occupying an island) also varied substantively from 1 species on Michigan Island to 10 species on Stockton Island. Island size and connectivity between islands appear important for the persistence of the carnivore community in the Apostle Islands
Closed-Form transformation between geodetic and ellipsoidal coordinates
We present formulas for direct closed-form transformation between geodetic coordinates(Ί, λ, h) and ellipsoidal coordinates (ÎČ, λ, u) for any oblate ellipsoid of revolution.These will be useful for those dealing with ellipsoidal representations of the Earth's gravityfield or other oblate ellipsoidal figures. The numerical stability of the transformations for nearpolarand near-equatorial regions is also considered
- âŠ