13,702 research outputs found
Applications study of advanced power generation systems utilizing coal-derived fuels. Volume 1: Executive summary
The technology status of phosphoric acid and molten carbon fuel cells, combined gas and steam turbine cycles, and magnetohydrodynamic energy conversion systems was assessed and the power performance of these systems when operating with medium-Btu fuel gas whether delivered by pipeline to the power plant or in an integrated mode in which the coal gasification process and power system are closely coupled as an overall power plant was evaluated. Commercially available combined-cycle gas turbine systems can reach projected required performance levels for advanced systems using currently available technology. The phosphoric acid fuel cell appears to be the next most likely candidate for commercialization. On pipeline delivery, the systems efficiency ranges from 40.9% for the phosphoric acid fuel cell to 63% for the molten carbonate fuel cell system. The efficiencies of the integrated power plants vary from approximately 39-40% for the combined cycle to 46-47% for the molden carbonate fuel cell systems. Conventional coal-fired steam stations with flue-gas desulfurization have only 33-35% efficiency
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Socio-economic causes of food insecurity in Malawi
The food crisis that Malawi experienced in 2002 led to hundreds â maybe thousands â of hunger-related deaths, which is more than any famine in living memory. During this famine, maize production fell by over 30% and maize prices rose by over 300% (Devereux, 2002). At the peak of the crisis, nearly a third of the population were dependent on food aid (USAID/Malawi, 2004)
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Income-generating activities for young people in southern Africa: Exploring AIDS and other constraints
Copyright @ 2010 The Authors. The Geographical Journal © 2010 Royal Geographical Society (with the Institute of British Geographers). The published version of the article can be accessed via the link below.This paper reports on a study with rural young people (aged 10â24 years) in Malawi and Lesotho, focusing on their opportunities to learn skills and access capital and assets to engage in incomegenerating activities (IGAs). Participatory group exercises and individual interviews provide many examples of how young people learn skills and start small businesses, as well as an insight into their strategic thinking about engaging in these livelihood options. Various factors, including the effects of AIDS, are shown to affect young peopleâs prospects of succeeding in their ventures.Young people are very keen on starting IGAs, and are supported by adult members of their communities in asking for interventions to help them. We argue that expanded vocational and business training, focusing on locally appropriate types and scale of businesses, coupled with help to raise start-up capital has the potential to improve the chances of young people who are poor and/or AIDS-affected securing sustainable rural livelihoods in their futures. Since AIDS is intertwined with many other issues affecting young peopleâs livelihoods, it is problematic to single out and target only AIDS-affected young people with interventions on skills building and IGAs. Policymakersâ attitudes to vocational skills training and support for IGAs in Malawi and Lesotho are also explored, and policy recommendations made to support vulnerable rural young people in their attempts to build sustainable livelihoods.ESRC/DFI
The spatial construction of young people's livelihoods in rural southern Africa
Young people in southern Africa, in common with young people around the world, are social agents, constructing their own lives, albeit within significant structural constraints. Unlike young people in some regions, for most the need to generate a livelihood is a key consideration. Livelihood construction is a profoundly spatial activity, yet while there have been a number of studies of the spatial construction of young people's livelihoods in African cities, the spatiality of rural livelihoods has received less attention. Rural environments pose particular challenges for livelihood construction, and require particular spatial strategies. Four are discussed here: accessing education and training; migration for work; developing extensive social networks; and producing for markets. There are, however, aspects of the spatial structuring of rural southern African societies that seriously constrain the pursuit of productive livelihoods by young people. Two are considered: migration (for reasons unconnected with young people's livelihoods) and marriage practices
Rural young people's opportunities for employment and entrepreneurship in globalised southern Africa: The limitations of targeting policies
This paper is based on a study with rural young people in Malawi and Lesotho, focusing on their possibilities for accessing (self)employment in the face of the various constraints imposed by their poor rural situations. Participatory group exercises, combined with individual interviews in two rural villages, provided personal stories about jobs and businesses that the young people were engaged in, as well as previous experiences and future plans. Constraints, as well as enabling factors, working at both individual and structural levels were analysed. Policies intended to address the needs of young people tend to seek to target the most vulnerable, often on the basis of individual-and household-level characteristics (e.g. women, orphans and AIDS-affected households). We argue that this: (1) neglects the structural factors operating at national and global levels; and (2) fails to recognise that factors interact to produce vulnerability, rather than this being rooted in separate characteristics. We demonstrate that an intersectional approach, drawn from feminist studies, is a useful theoretical lens, which, in combination with a livelihoods perspective, helps illuminate the needs of rural young people. In situations characterised by high levels of poverty and multiple vulnerabilities, we argue that it can be costly and ineffective to try to decide 'who is most vulnerable'; rather, resources can be more effectively spent in trying to improve conditions that will benefit all rural young people
The Consequences Of Low Birthweight
An extensive literature investigating the consequences of low birthweight for childhood development has focused on group differences and the prediction of global cognitive outcomes. The purpose of this thesis was to identify factors that predict specific childhood outcomes and to consider explanatory models of the role of early medical risk for childhood language, motor and attention outcomes. Ninety low birthweight children participating in a prospective longitudinal study were assessed at {dollar}5{lcub}1\over2{rcub}{dollar} years of age. Although there were no consistent differences between within-sample medical risk subgroups on the childhood outcome measures, regression analyses demonstrated that both early medical risk and environmental factors must be considered in prediction, as the predictive utility of these factors varied for different childhood outcomes. Medical risk predicted motor outcome, whereas infant environmental factors predicted language and attention outcomes. Path analyses of models of language, motor and attention outcomes suggested that both early medical risk and infant environmental factors had an indirect effect on childhood outcomes, and that the effects of these factors, infant developmental status, and the quality of the childhood environment vary for different outcomes. The relations between these models and underlying developmental processes were discussed, as were implications for future research
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Structural barriers provide obstacles to change in special education
Observations of cold dust in nearby elliptical galaxies
Spectral energy distribution (SED) analyses that include new millimeter to far-infrared (FIR) observations obtained with continuum instruments on the Nobeyama and James Clerk Maxwell Telescopes and the Infrared Space Observatory are presented for seven nearby (<45 Mpc) FIR-bright elliptical galaxies. These are analyzed together with archival FIR and shortwave radio data obtained from the NASA/IPAC Extragalactic Database (NED). The radio to infrared SEDs are best-fitted by power law plus graybody models of dust residing in the central galactic regions within a 2.4 kpc diameter and with temperatures between ~21 and 28 K, emissivity index simeq2, and masses from ~1.6 to 19 Ă 105 Mâ. The emissivity index is consistent with dust constituting amorphous silicate and carbonaceous grains previously modeled for stellar-heated dust observed in the Galaxy and other nearby extragalactic sources. Using updated dust absorption coefficients for this type of dust, dust masses are estimated that are similar to those determined from earlier FIR data alone, even though the latter results implied hotter dust temperatures. Fluxes and masses that are consistent with the new FIR and submillimeter data are estimated for dust cooler than 20 K within the central galactic regions. Tighter physical constraints for such cold, diffuse dust (if it exists) with low surface brightness will need sensitive FIR to submillimeter observations with the Spitzer Space Telescope, SCUBA2, or ALMA
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