421 research outputs found

    Appropriate Methodologies to Better Measure Consumer Preferences for Postal Services

    Get PDF
    This report summarises work undertaken testing the use of stated preference discrete choice experiments to measure consumer preferences for postal services. It discusses the importance of understanding and quantifying consumer priorities in the postal sector and presents different methods used for valuing non-market goods. We recommend the use of stated preference discrete choice experiments, and test the use of this approach in three member states. We provide the findings for these member states, as well as a “tool kit” for applying this methodology in other member states in future.Consumer preferences, postal services, discrete choice, two-sided market

    Studies of Fission Fragment Rocket Engine Propelled Spacecraft

    Get PDF
    The NASA Office of Chief Technologist has funded from FY11 through FY14 successive studies of the physics, design, and spacecraft integration of a Fission Fragment Rocket Engine (FFRE) that directly converts the momentum of fission fragments continuously into spacecraft momentum at a theoretical specific impulse above one million seconds. While others have promised future propulsion advances if only you have the patience, the FFRE requires no waiting, no advances in physics and no advances in manufacturing processes. Such an engine unequivocally can create a new era of space exploration that can change spacecraft operation. The NIAC (NASA Institute for Advanced Concepts) Program Phase 1 study of FY11 first investigated how the revolutionary FFRE technology could be integrated into an advanced spacecraft. The FFRE combines existent technologies of low density fissioning dust trapped electrostatically and high field strength superconducting magnets for beam management. By organizing the nuclear core material to permit sufficient mean free path for escape of the fission fragments and by collimating the beam, this study showed the FFRE could convert nuclear power to thrust directly and efficiently at a delivered specific impulse of 527,000 seconds. The FY13 study showed that, without increasing the reactor power, adding a neutral gas to the fission fragment beam significantly increased the FFRE thrust through in a manner analogous to a jet engine afterburner. This frictional interaction of gas and beam resulted in an engine that continuously produced 1000 pound force of thrust at a delivered impulse of 32,000 seconds, thereby reducing the currently studied DRM 5 round trip mission to Mars from 3 years to 260 days. By decreasing the gas addition, this same engine can be tailored for much lower thrust at much higher impulse to match missions to more distant destinations. These studies created host spacecraft concepts configured for manned round trip journeys. While the vehicles are very large, they are primarily made up of a habitat payload on one end, the engine on the opposite end and a connecting spine containing radiator acreage needed to reject the heat of this powerful, but inefficient engine. These studies concluded that the engine and spacecraft are within today's technology, could be built, tested, launched on several SLS launchers, integrated, checked out, maintained at an in-space LEO base, and operated for decades just as Caribbean cruise ships operate today. The nuclear issues were found to be far less daunting that [than for] current nuclear engines. The FFRE produces very small amounts of radioactive efflux compared to their impulse, easily contained in an evacuated "bore-hole" test site. The engine poses no launch risk since it is simply a structure containing no fissionable material. The nuclear fuel is carried to orbit in containers highly crash-proofed for launch accidents from which it, in a liquid medium, is injected into the FFRE. The radioactive exhaust, with a velocity above 300 kilometers per second rapidly leaves the solar system

    A role for liming as a conservation intervention? Earthworm abundance is associated with higher soil pH and foraging activity of a threatened shorebird in upland grasslands

    Get PDF
    The relationship between farmland bird populations and agricultural intensification has been well studied. However, the impact of variation in soil conditions and soil management is an exception, especially in upland (sub-alpine) farming systems. In this study, we examined the relationships between liming history, soil pH and patterns of foraging by Northern Lapwing,Vanellus vanellus, chicks in order to test the potential utility of soil amendment as a conservation intervention for shorebirds nesting in agricultural grasslands. Limed fields had higher soil pH than unlimed fields, and soil pH declined with the number of years since a field was last limed. The most important predictor of total earthworm abundance was soil organic matter with very few earthworms in peats of very high organic matter content. However, there was a marked additive effect of soil pH with earthworms more than twice as abundant at high (pH 6.0) as at the low (pH 3.5) extremes of soil pH recorded in the study. Specifically, at Lapwing chick foraging locations, the density ofAllolobophora chlorotica, an acid-intolerant species of earthworm found just below the surface of the soil, was significantly higher than at randomly selected locations. These results suggest that liming helped to maintain breeding habitat quality for Lapwings and other species dependent on earthworms. This is of conservation significance in upland agricultural grasslands in the UK, where there has been a long-term reduction in agricultural lime use since the mid-20th century. Field-scale trials of liming would be valuable to test whether targetted amendment of soil pH in agriculturally improved grasslands could retain an important role in conservation management for shorebirds in upland landscapes where geology, high rainfall, and leaching tend to acidify soils over time

    Interview with Linda Turner and Rob Snow, 1 July 2010

    Get PDF
    Linda Turner and Rob Snow are history teachers working at King James School in Knaresborough, North Yorkshire. They both reflect on the deficiencies of their teacher training. Linda recalls her early career in a secondary modern in Buckinghamshire in the mid-1970s. Here she worked with an 'inspirational' head of department who engaged the students through local history. Rob by contrast recalls the challenge of moving to a multi-cultural school in Bradford where each teacher had to sort out their own curriculum. Rob and Linda talk about the changes in the teaching of history over their careers - the impact of GCSE, the National Curriculum, of technology and of the lack of time to do 'fun' things, such as the 'trip around Rome' in the school quad, with chariot races on hobby horses and mock gladiator fights, or the Arkwright song competition, which involved the singing of the songs as well as the writing of them! Interviewed by Nicola Sheldon

    A global threats overview for Numeniini populations: synthesising expert knowledge for a group of declining migratory birds

    Get PDF
    The Numeniini is a tribe of thirteen wader species (Scolopacidae, Charadriiformes) of which seven are near-threatened or globally threatened, including two critically endangered. To help inform conservation management and policy responses, we present the results of an expert assessment of the threats that members of this taxonomic group face across migratory flyways. Most threats are increasing in intensity, particularly in non-breeding areas, where habitat loss resulting from residential and commercial development, aquaculture, mining, transport, disturbance, problematic invasive species, pollution and climate change were regarded as having the greatest detrimental impact. Fewer threats (mining, disturbance, problematic native species and climate change) were identified as widely affecting breeding areas. Numeniini populations face the greatest number of non-breeding threats in the East Asian-Australasian Flyway, especially those associated with coastal reclamation; related threats were also identified across the Central and Atlantic Americas, and East Atlantic flyways. Threats on the breeding grounds were greatest in Central and Atlantic Americas, East Atlantic and West Asian flyways. Three priority actions were associated with monitoring and research: to monitor breeding population trends (which for species breeding in remote areas may best be achieved through surveys at key non-breeding sites), to deploy tracking technologies to identify migratory connectivity, and to monitor land-cover change across breeding and non-breeding areas. Two priority actions were focused on conservation and policy responses: to identify and effectively protect key non-breeding sites across all flyways (particularly in the East Asian - Australasian Flyway), and to implement successful conservation interventions at a sufficient scale across human-dominated landscapes for species’ recovery to be achieved. If implemented urgently, these measures in combination have the potential to alter the current population declines of many Numeniini species and provide a template for the conservation of other groups of threatened species

    Higher harmonic anisotropic flow measurements of charged particles at 2.76 TeV with the ALICE detector

    Full text link
    We report the measurements of elliptic flow v2v_{2}, as well as higher harmonics triangular flow v3v_{3} and quadrangular flow v4v_{4}, in sNN=\sqrt{s_{_{NN}}} = 2.76 TeV Pb--Pb collisions, measured with the ALICE detector. We show that the measured elliptic and triangular flow can be understood from the initial spatial anisotropy and its event--by--event fluctuations. The resulting fluctuations of v2v_{2} and v3v_{3} are also discussed.Comment: 6 pages, 4 figures, proceeding of Strangeness in Quark Matter 2011, Cracow, Polan

    Severe early onset preeclampsia: short and long term clinical, psychosocial and biochemical aspects

    Get PDF
    Preeclampsia is a pregnancy specific disorder commonly defined as de novo hypertension and proteinuria after 20 weeks gestational age. It occurs in approximately 3-5% of pregnancies and it is still a major cause of both foetal and maternal morbidity and mortality worldwide1. As extensive research has not yet elucidated the aetiology of preeclampsia, there are no rational preventive or therapeutic interventions available. The only rational treatment is delivery, which benefits the mother but is not in the interest of the foetus, if remote from term. Early onset preeclampsia (<32 weeks’ gestational age) occurs in less than 1% of pregnancies. It is, however often associated with maternal morbidity as the risk of progression to severe maternal disease is inversely related with gestational age at onset2. Resulting prematurity is therefore the main cause of neonatal mortality and morbidity in patients with severe preeclampsia3. Although the discussion is ongoing, perinatal survival is suggested to be increased in patients with preterm preeclampsia by expectant, non-interventional management. This temporising treatment option to lengthen pregnancy includes the use of antihypertensive medication to control hypertension, magnesium sulphate to prevent eclampsia and corticosteroids to enhance foetal lung maturity4. With optimal maternal haemodynamic status and reassuring foetal condition this results on average in an extension of 2 weeks. Prolongation of these pregnancies is a great challenge for clinicians to balance between potential maternal risks on one the eve hand and possible foetal benefits on the other. Clinical controversies regarding prolongation of preterm preeclamptic pregnancies still exist – also taking into account that preeclampsia is the leading cause of maternal mortality in the Netherlands5 - a debate which is even more pronounced in very preterm pregnancies with questionable foetal viability6-9. Do maternal risks of prolongation of these very early pregnancies outweigh the chances of neonatal survival? Counselling of women with very early onset preeclampsia not only comprises of knowledge of the outcome of those particular pregnancies, but also knowledge of outcomes of future pregnancies of these women is of major clinical importance. This thesis opens with a review of the literature on identifiable risk factors of preeclampsia

    Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

    Full text link
    This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good

    The politicisation of science in the Murray-Darling Basin, Australia:discussion of ‘Scientific integrity, public policy and water governance’

    Get PDF
    Many water scientists aim for their work to inform water policy and management, and in pursuit of this objective, they often work alongside government water agencies to ensure their research is relevant, timely and communicated effectively. A paper in this issue, examining 'Science integrity, public policy and water governance in the Murray-Darling Basin, Australia’, suggests that a large group of scientists, who work on water management in the Murray-Darling Basin (MDB) including the Basin Plan, have been subject to possible ‘administrative capture'. Specifically, it is suggested that they have advocated for policies favoured by government agencies with the objective of gaining personal benefit, such as increased research funding. We examine evidence for this claim and conclude that it is not justified. The efforts of scientists working alongside government water agencies appear to have been misinterpreted as possible administrative capture. Although unsubstantiated, this claim does indicate that the science used in basin water planning is increasingly caught up in the politics of water management. We suggest actions to improve science-policy engagement in basin planning, to promote constructive debate over contested views and avoid the over-politicisation of basin science
    corecore