Interpolation formula for the electrical conductivity of nonideal plasmas

On the basis of a quantum-statistical approach to the electrical conductivity of nonideal plasmas we derive analytical results in the classical low-density regime, in the degenerate Born limit, and for the contribution of the Debye-Onsager relaxation effect. These explicit results are used to construct an improved interpolation formula of the electrical conductivity valid in a wide range of temperature and density which allows to compare with available experimental data of nonideal plasmas.Comment: 7 pages, 1 tabl

The causes for geographical variations in OS187/OS186 at the Cretaceous-Tertiary boundary

Researchers at Yale has approached the problem of the osmium isotopic composition of marine deposits formed in contact with both oxidized and reduced bottom waters. The measured (187) Os/(186) Os ratios of modern bulk sediment can be explained using mixing equations involving continental detrital, volcaniclastic, cosmogenic and hydrogeneous components. These studies show that sediments deposited under reducing marine conditions contain a hydrogenous component which is enriched in Re and has a radiogenic (187) Os/(186) Os ratio. The presence of such a hydrogenous component in the marine fish clay at Stevns Klint can account for the elevation of its (187) Os/(186) Os ration above the expected meteoritic value. Mass balance considerations require the Re/Os ratio of the phase precipitated from the terminal Cretaceous sea at Stevns Klint to have been about one tenth the value observed in contemporary deposits in the Black Sea, assuming Re has not been lost (or Os gained) subsequent to precipitation. In continental sections, the elevation of the (187) Os/(186) Os ratio in boundary layers may be due to precipitation from continental waters of crustally-derived radiogenic osmium either contemporaneous with the meteoritic (or mantle) osmium deposition or later during diagenesis

Effect of Length of Feeding Period on Performance of British and Exotic Crossbred Yearling Heifers

Seventy-two heifers were fed for 47, 61 and 75 days to determine the optimum feeding period for exotic cross and black baldy heifers. Average daily gains and feed conversions of the heifers were similar among treatments. Carcass weight, quality grade and yield grade increased with time on feed. Fat thickness, quality grade and yield grade increased faster for the black baldy heifers. Cost per pound of gain was similar for all treatments. The optimum weight at which to slaughter the black baldy yearling heifers appeared to be between 1000 and 1050 lb., both from a quality and economic view point. The optimum weight for slaughtering the exotic cross heifers was apparently not reached, as the last slaughter group was still gaining rapidly and efficiently with little increase in condition. The limited research conducted in this study indicates that a producer with mixed lots of cattle needs to be aware of the weight at which different types of cattle reach optimum condition. The feeder has greater flexibility in marketing the larger framed exotic cross type cattle as compared to the relatively smaller framed English breeds

Report on a visit to Indonesia to conduct a review of the post harvest fisheries sector

A review of post-harvest fisheries in Indonesia was undertaken for the Overseas Development Administration, by a fisheries technologist, a biologist, and an economist, during a five week visit in June and July 1988. The terms of reference were: to review post-harvest fisheries and donors' activities in the sector, and to identify a strategy for future ODA inputs. The marine fishery is the most important in terms of value, followed by tambak aquaculture (mostly shrimps and milkfish), and the inland capture fishery. Most of the harvest is sold in the domestic market as wet fish, dried fish, and pindang (fish cooked in brine). Exports of frozen shrimp, from the tambaks and the marine fishery, are becoming increasingly important. Additionally, there are exports of wet fish on ice to Singapore. The team considered that the greatest problem facing the sector is overfishing of the South Java Sea, resulting in operational fishing grounds being located at an ever increasing distance from the main markets on Java. This poses a challenge to resource management, both pre- and post-harvest. The former requiring resource surveys, and the latter, the identification of low-cost improvements to on-board handling, to ensure the supply of fish to Java's predominantly low income population. A study encompassing these aspects is proposed by the EC in collaboration with France; ODNRI, in consultation with ODA HO, will liase with the French technical agency (ORSTOM) to determine whether complementary inputs from ODNRI would be useful. A second area in which action is proposed is in reducing losses from insect infestation of sun-dried fish. Dried fish is an important protein source for low-income groups in Indonesia, and an area in which ODA could make an effective contribution. The use of household insecticides on drying fish in Indonesia has been widely publicised and the practice banned. The problem persists though, and the team recommends a follow-up programme to an existing project. The existing project has provided training to the staff of provincial quality control laboratories in loss assessment and reduction, including the use of a safe (and approved) insecticide - Minawet. Financial analysis of the use of Minawet and adoption trials will be undertaken during the final stages of the existing project. Subject to satisfactory results from these, a large-scale extension project is proposed, aimed at adoption of Minawet by fish processors. An additional element will be the provision of the necessary training and equipment in pesticide residue analysis, for the National Centre for Quality Control and Fish Processing

Feeding Value of Pro-Sil Treated High-Moisture Ground Ear Corn with Two Groups of Crossbred Heifers

Pro-Sil, an ammonia-molasses-mineral suspension, has been shown to be a highly effective commercial additive for corn silage in studies at SDSU and other midwest universities. When added to corn silage at the time of ensiling, this product stimulates beneficial fermentation and increases the crude protein content of the silage, thereby reducing or eliminating the need for protein supplementation at the time of feeding. While Pro-Sil has been thoroughly tested with whole plant corn silage, no research has been conducted with ensiled high-moisture ear corn (HMEC). Since the crude protein content of HMEC is low compared to the needs of feedlot cattle, research is needed to evaluate economical methods of boosting the level of this critical nutrient. Thus, the major objective of this initial study was to compare the feedlot performance of cattle fed Pro-Sil treated HMEC or regular HMEC mixed with either a control or a urea-based protein supplement at the time of feeding. Both types of HMEC were ensiled in a plastic Silopress bag to examine the effectiveness of this storage method with HMEC. The relative performance of exotic and British crossbred yearling heifers was also studied in this trial