1,569 research outputs found

    Recovering resources from abandoned metal mine waters : an assessment of the potential options at passive treatment systems

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    PhD Thesis Appendices can be consulted at the Philip Robinson Library.Remediation of metal-rich discharges from abandoned mines entails capture of metals within a treatment system and, typically, disposal of the waste. A preferable option would be to recover the metals for reuse. For many long-abandoned mines metal loads are often relatively small, albeit they often cause significant environmental pollution. Low-cost passive treatment systems, in which metals are retained in some form of treatment substrate, such as compost, are often preferred. This thesis investigates the amenability of such treatment systems to resource recovery. Two down-flow compost bioreactors, treating zinc-rich discharges, were the focus of the research: a pilot-scale unit at Nenthead, and a full-scale system at Force Crag, both in Cumbria, England. Laboratory investigations of the Nenthead substrate identified 7,900mg/kg zinc in the upper horizons of the substrate, and 2,400mg/kg in the lower horizons, after two years of operation. Acid leaching tests effectively de-contaminated the substrate with respect to zinc and cadmium. Complete recovery of zinc was observed after ≤30 hours across a range of acid leach tests, although 23-37 days were required before equivalent recovery was achieved by biological leaching. The Force Crag system removed >95% zinc over the first year of operation and, removal rates suggest that after 10 years of operation >20,000mg/kg zinc will have accumulated in the substrate. Substrate de-contamination could offer substantial life-cycle cost savings at passive treatment sites, especially by limiting volumes of material for disposal to landfill. Furthermore, recovery of metals has important implications for resource sustainability and circular economics. Other resource recovery options may exist at abandoned mine sites. At Force Crag 1.6kW of kinetic energy exists in flowing mine water, in addition to thermal energy which could be recovered for space heating applications. Recovering this energy would convert this site into a net-generator of power. Because of their often remote locations, renewable energy may be of particular value to off-grid facilities at some mine sites.partially funded by The Coal Authorit

    Community-Government Partnership and Sustainability of Rural Water Programmes in Anambra State, Nigeria

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    In a Multi-Indicator survey published in 2013 by the National Bureau of statistics, has shown that over 70 million Nigerians have no access to safe water and thereby projecting Nigeria as the third globally ranked number of people without access to safe water. However, the Nigerian constitution as contained in the second Draft of the National water Resources Bill of April 2007 accords jurisdiction over rural water supply to states in conjunction with the benefitting communities. The  unbalanced community-government partnership in relinquishing responsibilities in terms of ownership, control, improved service delivery and as well as provision of the required technical know-how, has become a principal factor constraining sustainable rural water projects in Anambra State for so long. It is evident from a deductive rational survey with what is obtainable in Nigerian rural water projects as against 2007 constitutional provision that disclosed dormant rural water policy propagation across the states and its docile forms of practice. Rural water projects are dynamic in nature, the choice and use of good management approach or combination of approaches is always circumspect. Community-government partnership is a worthwhile management approach that acquaint with the strength and weaknesses inherent in other management methods, and is able to use these effectively and circumspectly. This paper takes detailed explanations at factors weighing-down the success of a sustainable water provision in the rural communities in the State. We proffered a prolific approach to contain the plaguing constraints in the essential elements of planning, participation, project implementation and water policies of the State. The idea in community-government partnership is to strike a balance where the objectives of having sustainable rural water projects are achieved through proactive co-operation. Keywords: Community-government partnership, Rural water supply, Sustainability

    High available and fault tolerant mobile communications infrastructure

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    Early pathogenesis of foot-and-mouth disease in cattle after aerosol inoculation, The

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    Department Head: Edward Arthur Hoover.2010 Summer.Includes bibliographical references.The goal of the efforts described in this dissertation was to characterize the early pathogenesis of foot-and-mouth disease (FMD) in cattle after simulated natural infection. More specifically, emphasis was placed upon two critical knowledge gaps: identification of the primary site(s) of infection of FMD virus (FMDV) and the mechanism of establishment of viremia. In order to investigate these processes, novel systems were developed for (1) consistent experimental aerosol infection of steers, (2) molecular and virological detection of FMDV in bovine tissues, and (3) microscopic localization of FMDV antigens in bovine tissues. These novel tools were then applied to a thorough, prospective, time-course analysis of bovine FMD. Screening of antemortem samples indicated that establishment of primary infection in the respiratory tract was detectable between 4 - 6 hours post aerosol inoculation (hpa); establishment of viremia was detectable between 24 - 48 hpa. Examination of tissue samples collected postmortem demonstrated that in previremic steers, FMDV was most consistently localized to nasopharyngeal tissues by all detection methods indicating this region as the most important site of primary viral replication. The earliest site of microscopic localization of FMDV antigens was the lymphoid follicle-associated epithelium of the pharyngeal mucosa - associated lymphoid tissue (PALT) of the nasopharynx. At early time points after aerosol inoculation, viral antigens colocalized with cytokeratin-positive pharyngeal epithelial cells; intraepithelial, FMDV-negative, MHCII/CD11c-double positive dendritic cells were present in close proximity to FMDV-positive cells. Onset of viremia coincided with marked increase of viral loads in pulmonary tissues and substantial decrease of viral detection in nasopharyngeal tissues. These data indicate that subsequent to aerogenous exposure to FMDV, the temporally defined critical pathogenesis events are (1) primary replication in epithelial cells of the PALT crypts, (2) subsequent widespread replication in pneumocytes in the lungs which coincides with (3) the establishment of sustained viremia. This body of work is unique for its breadth and depth of investigation of FMD in cattle; the importance of the conclusions described herein may be separated into three tiers. The detailed characterization of the early virus-host interactions provides a greater level of understanding of the pathogenesis of this important disease and thus directly contributes to basic science knowledge. Additionally, the novel techniques described herein may be applied to a wide range of subsequent pathogenesis studies which will further elucidate FMDV-host interactions in various species and stages of infection. However, the translational implications of the findings are likely to, ultimately, have greatest significance by contributing to the development of rationally designed FMDV vaccines and biotherapeutics. Specifically, the data described in the chapters which follow strongly suggest that improved mucosal immunity (particularly in the nasopharynx) should be a high-priority goal of "next generation" FMDV prophylaxis

    COLLABORATIVE RESEARCH: CONTINUOUS DYNAMIC GRID ADAPTATION IN A GLOBAL ATMOSPHERIC MODEL: APPLICATION AND REFINEMENT

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    Functional Annotation Analytics of Rhodopseudomonas palustris Genomes

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    Rhodopseudomonas palustris, a nonsulphur purple photosynthetic bacteria, has been extensively investigated for its metabolic versatility including ability to produce hydrogen gas from sunlight and biomass. The availability of the finished genome sequences of six R. palustris strains (BisA53, BisB18, BisB5, CGA009, HaA2 and TIE-1) combined with online bioinformatics software for integrated analysis presents new opportunities to determine the genomic basis of metabolic versatility and ecological lifestyles of the bacteria species. The purpose of this investigation was to compare the functional annotations available for multiple R. palustris genomes to identify annotations that can be further investigated for strain-specific or uniquely shared phenotypic characteristics. A total of 2,355 protein family Pfam domain annotations were clustered based on presence or absence in the six genomes. The clustering process identified groups of functional annotations including those that could be verified as strain-specific or uniquely shared phenotypes. For example, genes encoding water/glycerol transport were present in the genome sequences of strains CGA009 and BisB5, but absent in strains BisA53, BisB18, HaA2 and TIE-1. Protein structural homology modeling predicted that the two orthologous 240 aa R. palustris aquaporins have water-specific transport function. Based on observations in other microbes, the presence of aquaporin in R. palustris strains may improve freeze tolerance in natural conditions of rapid freezing such as nitrogen fixation at low temperatures where access to liquid water is a limiting factor for nitrogenase activation. In the case of adaptive loss of aquaporin genes, strains may be better adapted to survive in conditions of high-sugar content such as fermentation of biomass for biohydrogen production. Finally, web-based resources were developed to allow for interactive, user-defined selection of the relationship between protein family annotations and the R. palustris genomes

    World Report on Disability, Chapter 8: Work and Employment

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    Across the world, people with disabilities are entrepreneurs and selfemployed workers, farmers and factory workers, doctors and teachers, shop assistants and bus drivers, artists, and computer technicians (1). Almost all jobs can be performed by someone with a disability, and given the right environment, most people with disabilities can be productive. But as documented by several studies, both in developed and developing countries, working age persons with disabilities experience significantly lower employment rates and much higher unemployment rates than persons without disabilities (2–9). Lower rates of labour market participation are one of the important pathways through which disability may lead to poverty (10–15). In Article 27 the United Nations Convention on the Rights of Persons with Disabilities (CRPD) “recognizes the right of persons with disabilities to work, on an equal basis with others; this includes the opportunity to gain a living by work freely chosen or accepted in a labour market and work environment that is open, inclusive and accessible to persons with disabilities” (16). Furthermore, the CRPD prohibits all forms of employment discrimination, promotes access to vocational training, promotes opportunities for self-employment, and calls for reasonable accommodation in the workplace, among other provisions. A number of factors impact labour market outcomes for persons with disabilities including; productivity differentials; labour market imperfections related to discrimination and prejudice, and disincentives created by disability benefit systems (2, 17–19). To address labour market imperfections and encourage the employment of people with disabilities, many countries have laws prohibiting discrimination on the basis of disability. Enforcing antidiscrimination laws is expected to improve access to the formal economy and have wider social benefits. Many countries also have specific measures, for example quotas, aiming to increase employment opportunities for people with disabilities (20). Vocational rehabilitation and employment services – job training, counselling, job search assistance, and placement – can develop or restore the capabilities of people with disabilities to compete in the labour market and facilitate their inclusion in the labour market. At the heart of all this is changing attitudes in the workplace
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