Ground Water Monitoring Project for Arkansas, Phase III

This report is composed of two parts. The first part is an interpretation of the pesticide and nitrate data collected in Woodruff County based on samples collected during 1994. Because there is an indication that there were hydrological differences between 1994 and 1995, and because most of the pesticide data is from 1994, this interpretive portion is restricted to 1994 data. Six wells initially sampled in 1994 that contained pesticides had continuing contamination in re-sampling in 1994 and 1995. Part II lists a seventh well in Woodruff County that contained pesticides in February and May of 199

Investment Performance of Public Commodity Pools: 1979 to 1989

This study investigates performance of public commodity pools both as a single randomly-selected pool and a market portfolio of pools over the 1979-1989 period. A market portfolio of public commodity pools provides superior investment performance relative to a randomly-selected pool. However, in general, this study provides no evidence that even a market portfolio of commodity pools is an attractive stand-alone investment. Nevertheless, there is some evidence that public commodity pools may improve the risk-return performance of a stock-bond portfolio. This evidence is conditional on the time period analyzed. Furthermore, a portfolio analysis is conducted using the lower brokerage, management, and incentive fees paid by institutional investors in commodity pools. The analysis reveals a substantial increase in the diversification benefits of adding commodity pools to a stock-bond portfolio. This suggests that the costs of public commodity pools form a significant deterrent to wider inclusion in investment portfolios

Overview of Heat Addition and Efficiency Predictions for an Advanced Stirling Convertor

The U.S. Department of Energy (DOE) and Lockheed Martin Space Systems Company (LMSSC) have been developing the Advanced Stirling Radioisotope Generator (ASRG) for use as a power system for space science missions. This generator would use two high-efficiency Advanced Stirling Convertors (ASCs), developed by Sunpower Inc. and NASA Glenn Research Center (GRC). The ASCs convert thermal energy from a radioisotope heat source into electricity. As part of ground testing of these ASCs, different operating conditions are used to simulate expected mission conditions. These conditions require achieving a particular operating frequency, hot end and cold end temperatures, and specified electrical power output for a given net heat input. Microporous bulk insulation is used in the ground support test hardware to minimize the loss of thermal energy from the electric heat source to the environment. The insulation package is characterized before operation to predict how much heat will be absorbed by the convertor and how much will be lost to the environment during operation. In an effort to validate these predictions, numerous tasks have been performed, which provided a more accurate value for net heat input into the ASCs. This test and modeling effort included: (a) making thermophysical property measurements of test setup materials to provide inputs to the numerical models, (b) acquiring additional test data that was collected during convertor tests to provide numerical models with temperature profiles of the test setup via thermocouple and infrared measurements, (c) using multidimensional numerical models (computational fluid dynamics code) to predict net heat input of an operating convertor, and (d) using validation test hardware to provide direct comparison of numerical results and validate the multidimensional numerical models used to predict convertor net heat input. This effort produced high fidelity ASC net heat input predictions, which were successfully validated using specially designed test hardware enabling measurement of heat transferred through a simulated Stirling cycle. The overall effort and results are discussed

Back-to-back coral bleaching events on isolated atolls in the Coral Sea

Severe bleaching events caused by marine heatwaves over the past four decades have now affected almost every coral reef ecosystem in the world. These recurring events have led to major losses of coral cover, with adverse consequences for tropical reef ecosystems and the people who depend on them. Here, we document two consecutive and widespread coral bleaching events on remote atolls in the Coral Sea in 2016 and 2017. In each year, the proportion of colonies that bleached was strongly related to heat exposure (measured as Degree Heating Weeks, DHW, °C-weeks), depth and coral assemblage structure. Bleaching was more severe at higher DHW exposure, and at sites with a higher proportion of susceptible taxa. Bleaching was also lower at 6 m than at 2 m depth. Despite the severe bleaching in 2016 on reefs in the central section of the Coral Sea Marine Park, total coral cover was not significantly reduced by 2017, suggesting that most bleached corals survived. Moreover, bleaching was less severe in 2017 despite a higher exposure to heat stress. These results indicate that while the isolation of these oceanic reefs provides no refuge from bleaching, low nutrient levels, high wave energy and proximity to cooler deeper waters may make coral on these reefs more resistant to bleaching induced mortality

Imprints, Vol. 2

Imprints is the official publication for Sigma Tau Delta, the honorary English fraternity. The editors welcome creative works submitted by contributors and also publish winners of the annual T. E. Ferguson Writing Contest. Especially welcome are poems, fiction pieces and essays of no more than 5,000 words in length. At this time we would like to express our gratitude to David Whitescarver, Sigma Tau Delta faculty advisor, for his unrelenting optimism and valuable help in the preparation of this journal

A Computational Methodology for Simulating Thermal Loss Testing of the Advanced Stirling Convertor

Convertor and generator testing is carried out in tests designed to characterize convertor performance when subjected to environments intended to simulate launch and space conditions. The value of net heat input must be known in order to calculate convertor efficiency and to validate convertor performance. Specially designed test hardware was used to verify and validate a two step methodology for the prediction of net heat input. This lessons learned from these simulations have been applied to previous convertor simulations. As heat is supplied to the convertors, electric power is produced and measured. Net heat input to the convertor is one parameter that will contribute to the calculation of efficiency. This parameter is not measured directly. Insulation Loss. Determine the current status of the thermal conductivity of the micro-porous insulation. - Match heat source and hot end temperatures. - Match temperature difference across Kaowool insulatio

Effective mobilities in pseudomorphic Si/SiGe/Si p-channel metal-oxide-semiconductor field-effect transistors with thin silicon capping layers

The room-temperature effective mobilities of pseudomorphic Si/Si0.64Ge0.36/Si p-metal-oxidesemiconductor field effect transistors are reported. The peak mobility in the buried SiGe channel increases with silicon cap thickness. It is argued that SiO2/Si interface roughness is a major source of scattering in these devices, which is attenuated for thicker silicon caps. It is also suggested that segregated Ge in the silicon cap interferes with the oxidation process, leading to increased SiO2/Si interface roughness in the case of thin silicon caps

In vivo and in vitro immune responses against Francisella tularensis vaccines are comparable among Fischer 344 rat substrains

Identifying suitable animal models and standardizing preclinical methods are important for the generation, characterization, and development of new vaccines, including those against Francisella tularensis. Non-human primates represent an important animal model to evaluate tularemia vaccine efficacy, and the use of correlates of vaccine-induced protection may facilitate bridging immune responses from non-human primates to people. However, among small animals, Fischer 344 rats represent a valuable resource for initial studies to evaluate immune responses, to identify correlates of protection, and to screen novel vaccines. In this study, we performed a comparative analysis of three Fischer rat substrains to determine potential differences in immune responses, to evaluate methods used to quantify potential correlates of protection, and to evaluate protection after vaccination. To this end, we took advantage of data previously generated using one of the rat substrains by evaluating two live vaccines, LVS and F. tularensis SchuS4-ΔclpB (ΔclpB). We compared immune responses after primary vaccination, adaptive immune responses upon re-stimulation of leukocytes in vitro, and sensitivity to aerosol challenge. Despite some detectable differences, the results highlight the similarity of immune responses to tularemia vaccines and challenge outcomes between the three substrains, indicating that all offer acceptable and comparable approaches as animal models to study Francisella infection and immunity

Optimizing the post-graduate institutional program evaluation process

Abstract Background Reviewing program educational efforts is an important component of postgraduate medical education program accreditation. The post-graduate review process has evolved over time to include centralized oversight based on accreditation standards. The institutional review process and the impact on participating faculty are topics not well described in the literature. Methods We conducted multiple Plan-Do-Study-Act (PDSA) cycles to identify and implement areas for change to improve productivity in our institutional program review committee. We also conducted one focus group and six in-person interviews with 18 committee members to explore their perspectives on the committee’s evolution. One author (MLL) reviewed the transcripts and performed the initial thematic coding with a PhD level research associate and identified and categorized themes. These themes were confirmed by all participating committee members upon review of a detailed summary. Emergent themes were triangulated with the University of Michigan Medical School’s Admissions Executive Committee (AEC). Results We present an overview of adopted new practices to the educational program evaluation process at the University of Michigan Health System that includes standardization of meetings, inclusion of resident members, development of area content experts, solicitation of committed committee members, transition from paper to electronic committee materials, and focus on continuous improvement. Faculty and resident committee members identified multiple improvement areas including the ability to provide high quality reviews of training programs, personal and professional development, and improved feedback from program trainees. Conclusions A standing committee that utilizes the expertise of a group of committed faculty members and which includes formal resident membership has significant advantages over ad hoc or other organizational structures for program evaluation committees.http://deepblue.lib.umich.edu/bitstream/2027.42/117363/1/12909_2016_Article_586.pd