5,687 research outputs found

    Emission tester for high-power vacuum tubes

    Get PDF
    A simple emission-testing circuit for high power vacuum tubes to check their output stability is described. With modification it may be useful in testing mercury-arc rectifiers

    Probes for measuring noise current in an electronic cable

    Get PDF
    Electromagnetic interference in deep-space network receiver is often caused by stray coupling from power lines. These stray signals create potential differences between ground terminals, which leads to excessive noise in receiver circuits. Pair of probes detect and measure noise currents in conductors

    Means for mapping radiated fields and for measuring differential movement of antenna elements

    Get PDF
    Null seeking system uses two transponders located at selected points on dish to detect phase-front of received signal. One signal line has continuously variable phase shifter driven by reversible stepmotor. Each of two transponders on dish is a dipole with mixer crystal between elements. Crystal is driven, in turn, by 181.6MHz signal carried by miniature coaxial cable

    Integrating sciences to sustain urban ecosystem services

    Get PDF
    Effective water management within urban settings requires robust multidisciplinary understanding and an appreciation of the value added to urban spaces by providing multifunctional green-blue spaces. Multifunctional landscapes where ecosystem service provisions are ‘designed-in’ can help ‘transition’ cities to more sustainable environments which are more resilient to changing future conditions. With benefits ranging from the supply of water, habitat and energy to pollutant removal, amenity and opportunities for recreation, urban water bodies can provide a focal point for reconnecting humans and nature in otherwise densely built-up areas. Managing water within urban spaces is an essential infrastructure requirement but has historically been undertaken in isolation from other urban functions and spatial requirements. Increasingly, because of the limits of space and need to respond to new drivers (e.g. mitigation of diffuse pollution), more sustainable approaches to urban water management are being applied which can have multiple functions and benefits. This paper presents a review of ecosystem services associated with water, particularly those in urban environments, and uses the emerging language of ecosystem services to provide a framework for discussion. The range of supporting, provisioning, regulating and cultural ecosystem services associated with differing types of urban water bodies are identified. A matrix is then used to evaluate the results of a series of social, ecological and physical science studies co-located on a single stretch of a restored urban river. Findings identify the benefits of, but also barriers to, the implementation of a transdisciplinary research approach. For many, transdisciplinary research still appears to be on the edge of scientific respectability. In order to approach this challenge, it is imperative that we bring together discipline specific expertise to address fundamental and applied problems in a holistic way. The ecosystem services approach offers an exciting mechanism to support researchers in tackling research questions that require thinking beyond traditional scientific boundaries. The opportunity to fully exploit this approach to collaborative working should not be lost

    A Lesson Plan for Partnerships: Insights from Leading STEM Nonprofits

    Get PDF
    In 2013, the U.S. Chamber of Commerce Foundation conducted research to better understand partnerships between corporations and nonprofits. The research, which was conducted through its Corporate Citizenship Center (CCC), looked at a specific set of nonprofit organizations. Each organization works to improve education in Science, Technology, Engineering, and Mathematics (STEM), and all received grants from the Department of Education's Investing in Innovation Fund.The goal of the research was to discover two things: (1) how leading nonprofits effectively partner with corporations, and (2) how nonprofits measure their success and share it with corporate donors. While STEM nonprofits were chosen for this study, the findings in this paper may apply to other types of nonprofit relationships

    Cost Sharing for Health Care: France, Germany, and Switzerland

    Get PDF
    Provides an overview of the French, German, and Swiss healthcare systems and compares the exemptions and limits on cost-sharing for the chronically and acutely ill. Considers what lessons U.S. policy makers might draw in considering reform options

    Review of transitions to adult services for young people with learning disabilities

    Get PDF

    Professional ethics in occupational health & safety practice

    Get PDF
    This thesis provides a critical evaluation of a real world project involving the researcher as leader of a review and subsequent development of a new Code of Conduct for the world’s largest health and safety body, the Institution of Occupational Safety Health (IOSH, 2011). The health and safety profession in the UK has seen many changes over the last 10-years, in particular a stronger focus on degree education, continual professional development (CPD) and Chartered Practitioner status. In addition to these progressive changes the profession has also seen a rise in the negative media coverage regarding reported risk aversion in decision-making processes. In response to the negative media and at the request of the conservative party, then in opposition, Lord Young led a complete review of health and safety in Great Britain(Young, 2010). More recently, the Government requested a further independent review into health and safety legislation (Löfstedt, 2011). Since the publication of these reports there have been calls for more rigorous competence standards for consultants and a move towards more industry led self-regulation. This has seen IOSH placed in a strong influencing position, albeit with added scrutiny of its own regulation of members. The researcher led a critical review of the existing Code as part of an IOSH standing Committee, the Profession Committee (PC) that has the responsibility among other things for examining allegations of misconduct. The project was conducted as action research and was divided into 4 cycles or stages. Stage 1 involved the critical review and benchmarking of the existing Code against other Codes using an adaptation of the PARN criteria. Stage 2 involved the consultation process for the development of a new Code. This included the researcher’s role as leader of the project and an evaluation of misconduct cases reviewed by the PC. Stage 3 involved semi-structured interviews of practitioners to explore experiential accounts of ethical issues from practice to inform the guidance on the Code. Finally, Stage 4 involved the concluding consultation and consolidation of all the stages for presentation of the revised Code to IOSH Council for approval. The project reinforced the benefits of applying a systematic approach for the development of professional body documentation. It also revealed the value of applying a flexible iterative methodology in the real world environment to prevent the project from diverging from its real world objectives. The outcome of the project has been positively received by IOSH. A new Code was produced with guidance and a revised disciplinary procedure that is fit for purpose and adaptable to change through the use of robust development and broad consultation processes. It is anticipated that these changes will make a significant contribution to the wider profession and practice. An ethical decision making model was developed from the findings and includes a dissemination strategy for the profession

    The use of constructed wetlands for the treatment of urban runoff

    Get PDF
    In 1995, the Environment Agency for England and Wales developed urban runoff treatment wetlands at two selected locations in Outer London. The systems have been monitored for a wide range of parameters including heavy metals, suspended solids and BOD over a period of two years. Seven storm events were also monitored. The ability of micro-organisms, isolated from the rhizosphere of wetland plants collected at both systems, to tolerate and accumulate heavy metals has also been investigated. This study has demonstrated that constructed wetland treatment systems are capable of reducing the pollutant loadings associated with urban runoff, and that such systems can be successfully established within urban areas. During dry weather, pollutant concentrations and loadings were typically low and associated removal efficiencies highly variable. However, during storm events, pollutant loadings increased and removal efficiencies improved, with mean removal efficiencies of 71% for Pb and 81% for Cr at the Dagenham wetland. An exception to this was for suspended solids which showed an overall increase of 99% during storm events. Several design and operational issues have been identified and addressed during the course of the monitoring programme, and recommendations for the improved design and operation of urban runoff treatment wetland systems have been made. A range of micro-organisms, isolated from both wetland systems, were able to tolerate elevated Zn and Pb concentrations. Two strains (Beauveria bassiana and Rhodotorula mucilaginosa) were selected for further work. Both strains could accumulate Zn and Pb, with B. bassiana showing a high capacity to bind Pb (maximum concentration of 136mgPb/g cells dry weight). Comparison of the growth of B. bassiana at 4°C and 30°C suggested that processes of microbial metal accumulation may occur throughout the year in treatment wetlands. The presence of Pb inside hyphae of B. bassiana, associated with hyphae walls and in the surrounding medium was confirmed. This study has found that micro-organisms isolated from urban runoff treatment wetlands can tolerate and accumulate Zn and Pb, and the application of these results to wetland treatment processes is discussed
    corecore