In plane stress analysis

An investigation of the blowing up of UK numerical results for the inplane stress calculations for silicon ribbon is presented. The inplane stress that exists in a thin plate is governed by two general equations of equilibrium and compatibility

Provisional list of parasites occurring on Fundulus spp

In recent years interest in the utilization of fishes, particularly marine species, as experimental animals has increased. In the search for species amenable to this use, many investigators have chosen the hardy euryhaline species belonging to the genus Fundulus. In the course of holding these animals under restricted laboratory conditions, problems involving parasitization have developed. In the summer of 1964, workers at our Institute experienced great difficulty in maintaining Fundulus in captivity, and large numbers of experimental animals died. Examination of these fish revealed them to be heavily infested with monogenetic trematodes (mostly gyrodactylids, a few dactylogyrids). Inasmuch as severe cases of parasitism could well effect experimental results and render interpretation difficult, it is important that rnlationships between experimental animals and their parasites be recognized and dealt with. It is hoped that this provisional list of symbionts of the fundulid cyprinidonts will be of help in this regard. The following lists of parasites and bibliographic data have been compiled from monographic works, check-lists and various papers in the pertinent fields. Additional records from the researches of workers at this Institute are reported

BIOPHYSICAL SIMULATION IN SUPPORT OF CROP PRODUCTION DECISIONS: A CASE STUDY IN THE BLACKLANDS REGION OF TEXAS

Economic feasibility of Texas Blacklands corn production in relation to sorghum, wheat, and cotton is studied. Biophysical simulation generated yield data are integrated with an economic decision model using quadratic programming. Given the various scenarios analyzed, corn is economically feasible for the Blacklands. A crop mix of half corn and half cotton production is selected under risk neutrality with wheat entering if risk aversion is present. Corn and grain sorghum production are highly substitutable. Profit effects attributed to changing corn planting dates are more pronounced than profit changes resulting from altering corn population or maturity class.Crop Production/Industries,

RISK AND MARKET PARTICIPANT BEHAVIOR IN THE U.S. SLAUGHTER-CATTLE MARKET

Incomplete information generates uncertainty for market participants in the slaughter-cattle market. Buyer and seller behavior in the presence of that uncertainty is examined. Statistically significant risk premiums are charged by packers when buying slaughter cattle on either a live- or dressed-weight basis compared to buying on a grade-and-yield basis. Pratt-Arrow risk-aversion coefficients are calculated for buyers and these remain constant over all marketing methods. Sellers market cattle under all three marketing methods, suggesting producersÂ’' attitudes toward risk (risk-aversion coefficients) vary.Risk and Uncertainty,

Stress and buckling analysis

An analysis is presented of elastic stress and buckling behavior due to thermal stresses in silicon ribbon. Thermal profiles for reducing stresses and improving flatness in wide ribbon are discussed

High-severity wildfire leads to multi-decadal impacts on soil biogeochemistry in mixed-conifer forests.

During the past century, systematic wildfire suppression has decreased fire frequency and increased fire severity in the western United States of America. While this has resulted in large ecological changes aboveground such as altered tree species composition and increased forest density, little is known about the long-term, belowground implications of altered, ecologically novel, fire regimes, especially on soil biological processes. To better understand the long-term implications of ecologically novel, high-severity fire, we used a 44-yr high-severity fire chronosequence in the Sierra Nevada where forests were historically adapted to frequent, low-severity fire, but were fire suppressed for at least 70 yr. High-severity fire in the Sierra Nevada resulted in a long-term (44 +yr) decrease (>50%, P < 0.05) in soil extracellular enzyme activities, basal microbial respiration (56-72%, P < 0.05), and organic carbon (>50%, P < 0.05) in the upper 5 cm compared to sites that had not been burned for at least 115 yr. However, nitrogen (N) processes were only affected in the most recent fire site (4 yr post-fire). Net nitrification increased by over 600% in the most recent fire site (P < 0.001), but returned to similar levels as the unburned control in the 13-yr site. Contrary to previous studies, we did not find a consistent effect of plant cover type on soil biogeochemical processes in mid-successional (10-50 yr) forest soils. Rather, the 44-yr reduction in soil organic carbon (C) quantity correlated positively with dampened C cycling processes. Our results show the drastic and long-term implication of ecologically novel, high-severity fire on soil biogeochemistry and underscore the need for long-term fire ecological experiments

Stress-strain analysis of silicon ribbon

Temperature profiles for silicon ribbon are presented. Ribbon dislocations and elastic stress are discussed. Ribbon quality is important for the ribbon's function as a solar cell

Improved strain-wire flowmeter has fast response time

Strain-sensitive resistance wires in a Wheatstone bridge arrangement form the sensing element of a flowmeter. The change in resistance of the wires is measured as a function of stream velocity. Thus the electrical output is a measure of both rapidly varying and steady fluid-flow rates