7,733 research outputs found
Connes-amenability and normal, virtual diagonals for measure algebras, I
We prove that the measure algebra of a locally compact group is
Connes-amenable if and only if is amenable.Comment: 18 pages; some revisions as suggested by the refere
Analysis of advanced optical glass and systems
Optical lens systems performance utilizing optical materials comprising reluctant glass forming compositions was studied. Such special glasses are being explored by NASA/Marshall Space Flight Center (MSFC) researchers utilizing techniques such as containerless processing in space on the MSFC Acoustic Levitation Furnace and on the High Temperature Acoustic Levitation Furnace in the conceptual design phase for the United States Microgravity Laboratory (USML) series of shuttle flights. The application of high refractive index and low dispersive power glasses in optical lens design was investigated. The potential benefits and the impacts to the optical lens design performance were evaluated. The results of the studies revealed that the use of these extraordinary glasses can result in significant optical performance improvements. Recommendations of proposed optical properties for potential new glasses were also made. Applications of these new glasses are discussed, including the impact of high refractive index and low dispersive power, improvements of the system performance by using glasses which are located outside of traditional glass map, and considerations in establishing glass properties beyond conventional glass map limits
A Comparison of Two Methods of Quantifying Mating Success in Low Density Gypsy Moth (Lymantria dispar) Populations
The gypsy moth (Lymantria dispar) is a defoliating pest native to Europe and invasive to North America. The gypsy moth is subject to depressed mating success in low density populations, which may restrict spread of the forest pest. Research focusing on gypsy moth density as it relates to mating behavior has often used counts of males caught in pheromone-baited delta traps as a proxy to estimate the probability of female mating success. The purpose of this project was to determine whether pheromone trap counts provide accurate estimates of female mating success probability, by comparing data gathered from pheromone-baited delta traps to data gathered on mating success of tethered females. To determine the relationship between number of males caught in delta traps and the probability of successful mating, male catch counts in traps were compared to mating success of tethered females in a mass male release experiment. The relationship between delta trap catch of males and female mating success was quantified using a Bayesian framework, which explicitly incorporates uncertainties in the model. Vegetative cover in the study plots was reduced to a single measure through principal components analysis and included as an independent factor in the model. The data suggest that delta traps reduce the male’s ability to find a female by 67%; thus, results garnered from delta trap catch counts tend to underestimate the underlying ability of males to locate and mate with females. Thick understory vegetation further reduced the male’s ability to locate a female, and further reduced the effectiveness of delta traps. Future studies that seek to use counts of males in pheromone-baited traps as a proxy for mating success should consider using an adjustment factor to equate the two methods of quantifying reproductive behavior in the gypsy moth.https://scholarscompass.vcu.edu/uresposters/1271/thumbnail.jp
Role of Implantable Cardioverter Defibrillators in the Treatment of Hypertrophic Cardiomyopathy
Hypertrophic cardiomyopathy (HCM) is an important cardiovascular disease with sudden cardiac death as the most devastating presentation. Implantable cardioverter defibrillators (ICD) are the optimal therapy for prevention of sudden death from ventricular tachycardia or fibrillation of any cause. While there is no controversy with implanting ICDs in patients who have already survived a cardiac arrest, identifying high-risk patients for primary prevention in this disease remains a challenge. Implanting ICDs in patients with HCM is an important clinical consideration since many individuals could achieve normal or near-normal lifespans with this protection
Development summary of a sympathetic discharge CO2 laser for lidar use
A commercial pulsed sympathetic discharge laser has been characterized and modified for use as a potential lidar. This report summarizes the initial findings and modifications made to the baseline system. The new laser performance is then checked with theory and operational results are presented. The laser has inherent mode instability and high chirp. Several solutions were tried and their results are presented
Contamination study
The time dependence of the angular reflectance from molecularly contaminated optical surfaces in the Vacuum Ultraviolet (VUV) is measured. The light scattering measurements are accomplished in situ on optical surfaces in real time during deposition of molecular contaminants. The measurements are taken using non-coherent VUV sources with the predominant wavelengths being the Krypton resonance lines at 1236 and 1600 A. Detection of the scattered light is accomplished using a set of three solar blind VUV photomultipliers. An in-plane VUV BRDF (Bidirectional Reflectance Distribution Functions) experiment is described and details of the ongoing program to characterize optical materials exposed to the space environment is reported
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The Management of Corporate Social Responsibility in the UK Rail Sector
There is increasing interest from the public and private sector in not only how companies do business in financial and commercial terms, but also in the way they take into account the impacts they have on the communities, stakeholders, and environments in which they operate. There is increasing evidence from these sectors that companies that actively manage social, environmental, health and safety issues, demonstrating Corporate Social Responsibility (CSR), will do better financially and in share price valuation. Companies that take this CSR initiative are also rated in surveys as companies where people want to work and do business.
To date there has been little previous research carried out on CSR in the UK rail sector. This thesis therefore examines the evolution of the relationship between CSR and the UK rail sector, assesses the significance of the relationship between CSR and the corporate success of UK rail sector organisations and appraises the efficacy of the implementation and use of CSR management in UK rail organisations. Using results and findings taken from a questionnaire-based survey, supported by personal interviews, of the experience of a sample of UK rail sector managers with responsibility for CSR, and an analysis of documentation from a literature review, a case is presented for the proposal that effective CSR management can improve stakeholder perception.
Specifically, the research reported in this thesis addresses the proposition that the management of CSR is essential in successful UK rail organisations and that the implementation of CSR could help reduce the impact from catastrophic incidents such as rail fatalities at pedestrian level crossings and derailments
Comment on : 'multi-element signatures of stream sediments and sources under moderate to low flow conditions' by M.I. Stutter, S.J. Langan, D.G. Lumsdon, L.M. Clark
In a recent paper on ‘Multi-element signatures of stream sediments and sources under moderate to low flow conditions’, Stutter et al., 2009 M.I. Stutter, S.J. Langan, D.G. Lumsdon and L.M. Clark, Multi-element signatures of stream sediments and sources under moderate to low flow conditions, Appl. Geochem. 24 (2009), pp. 800–809. Article | PDF (392 K) | View Record in Scopus | Cited By in Scopus (2)Stutter et al. (2009) presented results of a simple sediment source tracing method based on major and trace elements for a small agricultural catchment in NE Scotland. The authors reported statistically significant, larger concentrations of four trace elements (Ce, Nd, Th and Y) in bank subsoils (n = 5) and stream bed sediments (n = 3) compared to topsoils from both pasture (n = 5) and arable (n = 5) land. They used these differences to aid discrimination between topsoil and subsoil (stream bank erosion) contributions to bed sediment. These elements may be more depleted in topsoil compared to subsoil because the former have been subject to more intense weathering over a longer period. If these naturally occurring trace elements could be used to understand the relative proportions of topsoil and subsoil contributions to headwater bed sediments this approach might be applied more widely to elucidate transport pathways for the transfer of agricultural contaminants such as particulate phosphorus to streams (Walling et al., 2008). This approach warrants further investigation across a range of catchments at different scales with contrasting land use and bedrock types. This can be undertaken using data from regional-scale geochemical surveys (Johnson et al., 2005) which include analyses of both stream bed sediments and subsoil samples. Previous studies have shown that much of lowland central England is at risk of topsoil transfer to watercourses via land drains (Chapman et al., 2003). A geochemical survey across part of central England covering 15 400 km2 was recently undertaken and these data are well-suited to testing whether three of the four trace elements identified by Stutter et al. (2009) might be used to discriminate between topsoil and subsoil in sediments more widely. Specifically, if the concentrations of these elements are significantly smaller in stream bed sediments than in the subsoil, this may be due to mixing with topsoils which have lower concentrations of these elements. Below the regional-scale survey, the methods the author used to compare the geochemical data in subsoil and bed sediments described, and the findings and their implications discussed
Wastewater Treatment Comes To Detroit: Law, Politics, Technology And Funding
Detroit was one of the cities identified by the International Joint Commission as polluting the Great Lakes in contravention of the Boundary Waters Treaty of 1909. The United States Public Health Service also reported on the pollution that entered the Detroit River from Detroit\u27s sewers. Pollution by sewage threatened lives with a dramatic increase in cases of Typhoid Fever and other gastro intestinal sicknesses. Chlorination of water supplies reduced these incidents to an acceptable level minimizing the arguments of sanitarians proposing wastewater treatment. Expansion of the city to encompass a rapidly rising population channeled the city\u27s financial resources into infrastructure. Wastewater treatment was not deemed necessary to accommodate this growth. Adjacent communities, affected by the pollution attempted to create a metropolitan approach to wastewater treatment; this effort failed through a lack of political will and clearly defined objectives. Efforts by Detroit to build a plant were stymied by inter city and statewide politics, and insufficient city finances. New Deal programs and innovative legislation at the city and state level eventually provided the capital required to construct and operate a wastewater plant and provide for repayment of the loans to the federal government. Detroit with this wastewater treatment plant and its water treatment plant is unique in that it is the only central city acting as a service provider for a metropolitan area unlike most metropolises where metropolitan districts extend beyond political boundaries to provide utilities. Federal involvement in this and other large scale civil engineering projects during this period was the only way it was possible for them to be completed
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