91 resultados para Economic resource use


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Traditional resource management has had as its main objective the optimisation of throughput, based on pa- rameters such as CPU, memory, and network bandwidth. With the appearance of Grid Markets, new variables that determine economic expenditure, benefit and opportunity must be taken into account. The SORMA project aims to allow resource owners and consumers to exploit market mechanisms to sell and buy resources across the Grid. SORMA’s motivation is to achieve efficient resource utilisation by maximising revenue for resource providers, and minimising the cost of resource consumption within a market environment. An overriding factor in Grid markets is the need to ensure that desired Quality of Service levels meet the expectations of market participants. This paper explains the proposed use of an Economically Enhanced Resource Manager (EERM) for resource provisioning based on economic models. In particular, this paper describes techniques used by the EERM to support revenue maximisation across multiple Service Level Agreements.

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The techno-economic performance of a small wind turbine is very sensitive to the available wind resource. However, due to financial and practical constraints installers rely on low resolution wind speed databases to assess a potential site. This study investigates whether the two site assessment tools currently used in the UK, NOABL or the Energy Saving Trust wind speed estimator, are accurate enough to estimate the techno-economic performance of a small wind turbine. Both the tools tend to overestimate the wind speed, with a mean error of 23% and 18% for the NOABL and Energy Saving Trust tool respectively. A techno-economic assessment of 33 small wind turbines at each site has shown that these errors can have a significant impact on the estimated load factor of an installation. Consequently, site/turbine combinations which are not economically viable can be predicted to be viable. Furthermore, both models tend to underestimate the wind resource at relatively high wind speed sites, this can lead to missed opportunities as economically viable turbine/site combinations are predicted to be non-viable. These results show that a better understanding of the local wind resource is a required to make small wind turbines a viable technology in the UK.

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Experimental results from the open literature have been employed for the design and techno-economic evaluation of four process flowsheets for the production of microbial oil or biodiesel. The fermentation of glucose-based media using the yeast strain Rhodosporidium toruloides has been considered. Biodiesel production was based on the exploitation of either direct transesterification (without extraction of lipids from microbial biomass) or indirect transesterifaction of extracted microbial oil. When glucose-based renewable resources are used as carbon source for an annual production capacity of 10,000 t microbial oil and zero cost of glucose (assuming development of integrated biorefineries in existing industries utilising waste or by-product streams) the estimated unitary cost of purified microbial oil is $3.4/kg. Biodiesel production via indirect transesterification of extracted microbial oil proved more cost-competitive process compared to the direct conversion of dried yeast cells. For a price of glucose of $400/t oil production cost and biodiesel production cost are estimated to be $5.5/kg oil and $5.9/kg biodiesel, correspondingly. Industrial implementation of microbial oil production from oleaginous yeast is strongly dependent on the feedstock used and on the fermentation stage where significantly higher productivities and final microbial oil concentrations should be achieved.

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Medical universities and teaching hospitals in Iraq are facing a lack of professional staff due to the ongoing violence that forces them to flee the country. The professionals are now distributed outside the country which reduces the chances for the staff and students to be physically in one place to continue the teaching and limits the efficiency of the consultations in hospitals. A survey was done among students and professional staff in Iraq to find the problems in the learning and clinical systems and how Information and Communication Technology could improve it. The survey has shown that 86% of the participants use the Internet as a learning resource and 25% for clinical purposes while less than 11% of them uses it for collaboration between different institutions. A web-based collaborative tool is proposed to improve the teaching and clinical system. The tool helps the users to collaborate remotely to increase the quality of the learning system as well as it can be used for remote medical consultation in hospitals.

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In analysing the release of agricultural land to urban development, the urban fringe literature has not focused on whether farmers are able to relocate from the urban fringe to remoter rural areas. Through interviews with representatives from the poultry industry in two Australian states, this paper identifies that poultry farm relocation strategies are constrained by off-farm economic relations, the land-use planning system and financial considerations. Closely aligned to these constraints on relocation is the on-going process of poultry farm intensification, which is seen as presenting rising problems for land-use management around expanding metropolitan centres in Australia. Of particular concern is the potential for amenity complaints and associated land-use conflicts, which have not been comprehensively investigated. Recognising that existing environmental and land-use planning controls are ineffective in producing amicable solutions when conflict involving poultry farming is at its most intense, the paper calls for improvements to the regulatory system, including greater consideration for how the process of relocation can be encouraged. (c) 2005 Elsevier Ltd. All rights reserved.

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This paper discusses the dangers inherent in allempting to simplify something as complex as development. It does this by exploring the Lynn and Vanhanen theory of deterministic development which asserts that varying levels of economic development seen between countries can be explained by differences in 'national intelligence' (national IQ). Assuming that intelligence is genetically determined, and as different races have been shown to have different IQ, then they argue that economic development (measured as GDP/capita) is largely a function of race and interventions to address imbalances can only have a limited impact. The paper presents the Lynne and Vanhanen case and critically discusses the data and analyses (linear regression) upon which it is based. It also extends the cause-effect basis of Lynne and Vanhanen's theory for economic development into human development by using the Human Development Index (HDI). It is argued that while there is nothing mathematically incorrect with their calculations, there are concerns over the data they employ. Even more fundamentally it is argued that statistically significant correlations between the various components of the HDI and national IQ can occur via a host of cause-effect pathways, and hence the genetic determinism theory is far from proven. The paper ends by discussing the dangers involved in the use of over-simplistic measures of development as a means of exploring cause-effect relationships. While the creators of development indices such as the HDI have good intentions, simplistic indices can encourage simplistic explanations of under-development. (c) 2005 Elsevier B.V. All rights reserved.

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Soil forms the outer skin of the earth's land surface. Often less than a metre in depth, it is essential to sustain natural terrestrial ecosystems and human life. Soils result from the interactions over time between climate, parent material, topography, vegetation, and biota. They vary from place to place. Mineral soils are composed of mineral matter, organic matter, and gas- or liquid-filled pores in varying proportions. Soils perform a wide range of functions and provide many ecosystem or environmental services; with the climate problem, the soil is increasingly being recognised as a potential sink for carbon from the atmosphere. In part because of humankind's (over)use of soils and in part because of natural and human-induced environmental change, there is a widespread decline in soil quality and an increasing number of threats to soil, which jeopardise both the soil's natural functions and its use by humans. As a limited resource, soils must be used sustainably. Soil protection strategies have been indirectly embodied in a number of United Nations conventions, and there are now national and supranational developments towards specific regulations and legislation to protect soils and their functions.

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The LINK Integrated Farming Systems (LINK-IFS) Project (1992-1997) was setup to compare conventional and integrated arable farming systems (IAFS), concentrating on practical feasibility and economic viability, but also taking into account the level of inputs used and environmental impact. As part of this, an examination into energy use within the two systems was also undertaken. This paper presents the results from that analysis. The data used is from the six sites within the LINK-IFS Project, spread through the arable production areas of England and from the one site in Scotland, covering the 5 years of the project. The comparison of the energy used is based on the equipment and inputs used to produce I kg of each crop within the conventional and integrated rotations, and thereby the overall energy used for each system. The results suggest that, in terms of total energy used, the integrated system appears to be the most efficient. However, in terms of energy efficiency, energy use per kilogram of output, the results are less conclusive. (C) 2003 Elsevier Science B.V. All rights reserved.

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A dynamic, deterministic, economic simulation model was developed to estimate the costs and benefits of controlling Mycobacterium avium subsp. paratuberculosis (Johne's disease) in a suckler beef herd. The model is intended as a demonstration tool for veterinarians to use with farmers. The model design process involved user consultation and participation and the model is freely accessible on a dedicated website. The 'user-friendly' model interface allows the input of key assumptions and farm specific parameters enabling model simulations to be tailored to individual farm circumstances. The model simulates the effect of Johne's disease and various measures for its control in terms of herd prevalence and the shedding states of animals within the herd, the financial costs of the disease and of any control measures and the likely benefits of control of Johne's disease for the beef suckler herd over a 10-year period. The model thus helps to make more transparent the 'hidden costs' of Johne's in a herd and the likely benefits to be gained from controlling the disease. The control strategies considered within the model are 'no control', 'testing and culling of diagnosed animals', 'improving management measures' or a dual strategy of 'testing and culling in association with improving management measures'. An example 'run' of the model shows that the strategy 'improving management measures', which reduces infection routes during the early stages, results in a marked fall in herd prevalence and total costs. Testing and culling does little to reduce prevalence and does not reduce total costs over the 10-year period.

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Biosecurity is a great challenge to policy-makers globally. Biosecurity policies aim to either prevent invasions before they occur or to eradicate and/or effectively manage the invasive species and diseases once an invasion has occurred. Such policies have traditionally been directed towards professional producers in natural resource based sectors, including agriculture. Given the wide scope of issues threatened by invasive species and diseases, it is important to account for several types of stakeholders that are involved. We investigate the problem of an invasive insect pest feeding on an agricultural crop with heterogeneous producers: profit-oriented professional farmers and utility-oriented hobby farmers. We start from an ecological-economic model conceptually similar to the one developed by Eiswerth and Johnson [Eiswerth, M.E. and Johnson, W.S., 2002. Managing nonindigenous invasive species: insights from dynamic analysis. Environmental and Resource Economics 23, 319-342.] and extend it in three ways. First, we make explicit the relationship between the invaded state carrying capacity and farmers' planting decisions. Second, we add another producer type into the framework and hence account for the existence of both professional and hobby fanners. Third, we provide a theoretical contribution by discussing two alternative types of equilibria. We also apply the model to an empirical case to extract a number of stylised facts and in particular to assess: a) under which circumstances the invasion is likely to be not controllable; and b) how extending control policies to hobby farmers could affect both types of producers. (C) 2008 Elsevier B.V. All rights reserved.

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Answering many of the critical questions in conservation, development and environmental management requires integrating the social and natural sciences. However, understanding the array of available quantitative methods and their associated terminology presents a major barrier to successful collaboration. We provide an overview of quantitative socio-economic methods that distils their complexity into a simple taxonomy. We outline how each has been used in conjunction with ecological models to address questions relating to the management of socio-ecological systems. We review the application of social and ecological quantitative concepts to agro-ecology and classify the approaches used to integrate the two disciplines. Our review included all published integrated models from 2003 to 2008 in 27 journals that publish agricultural modelling research. Although our focus is on agro-ecology, many of the results are broadly applicable to other fields involving an interaction between human activities and ecology. We found 36 papers that integrated social and ecological concepts in a quantitative model. Four different approaches to integration were used, depending on the scale at which human welfare was quantified. Most models viewed humans as pure profit maximizers, both when calculating welfare and predicting behaviour. Synthesis and applications. We reached two main conclusions based on our taxonomy and review. The first is that quantitative methods that extend predictions of behaviour and measurements of welfare beyond a simple market value basis are underutilized by integrated models. The second is that the accuracy of prediction for integrated models remains largely unquantified. Addressing both problems requires researchers to reach a common understanding of modelling goals and data requirements during the early stages of a project.

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The United States and the European Union have set targets for biofuel production to decrease reliance on fossil fuels and to reduce fossil carbon emissions. Attainment of biofuel targets d6pends upon policy and infrastructure development but also on production of suitable raw materials. Production of relevant crops relies on the decisions that farmers make in their economic and political environment. We need to identify any farmer-related barriers to biofuel production and to determine whether novel policy and technology are required to meet targets. These aspects of the emerging biofuel industry are relevant across international barriers and have notyet been addressed quantitatively. We describe a case study from the UK of farmers' intentions toward producing two biofuel crops for which refining capacity either exists or is under construction. Given farmers' intentions, current land use, and conversion efficiency, we estimate potential biofuel production. These estimates indicate that EU targets are not achievable using domestically grown raw materials without policy intervention, use of alternative feedstocks, and either significant improvements in processing efficiency or largescale changes in land use.

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In many river floodplains in the UK, there has been a long history of flood defence, land reclamation and water regime management for farming. In recent years, however, changing European and national policies with respect to farming, environment and flood management are encouraging a re-appraisal of land use in rural areas. In particular, there is scope to develop, through the use of appropriate promotional mechanisms, washland areas, which will simultaneously accommodate winter inundation, support extensive farming methods, deliver environmental benefits, and do this in a way which can underpin the rural economy. This paper explores the likely economic impacts of the development of flood storage and washland creation. In doing so, consideration is given to feasibility of this type of development, the environmental implications for a variety of habitats and species, and the financial and institutional mechanisms required to achieve implementation. (C) 2007 Elsevier Ltd. All rights reserved.

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In the 'rice-wheat' and the 'cotton-wheat' farming systems of Pakistan's Punjab, late planting of wheat is a perennial problem due to often delayed harvesting of the previously planted and late maturing rice and cotton crops. This leaves very limited time for land preparation for 'on-time' planting of wheat. 'No-tillage' technologies that reduce the turn-round time for wheat cultivation after rice and cotton have been developed, but their uptake has not been as expected.-This paper attempts to determine the farm and farmer characteristics and other socio-economic factors that influence the adoption of 'no-tillage' technologies'. Logit models were developed for the analysis undertaken. In the 'cotton-wheat' system personal characteristics like education, tenancy status, attitude towards risk implied in the use of new technologies and contact with extension agents are the main factors that affect adoption. As regards the 'rice-wheat' system, resource endowments such as farm size, access to a 'no-tillage' drill, clayey soils and the area sown to the rice-wheat sequence along with tenancy and contact with extension agents were dominant in explaining adoption. (C) 2002 Elsevier Science Ltd. All rights reserved.