257,742 research outputs found

    Hydrological response to ~30 years of agricultural surface water management

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    Amongst human practices, agricultural surface-water management systems represent some of the largest integrated engineering works that shaped floodplains during history, directly or indirectly affecting the landscape. As a result of changes in agricultural practices and land use, many drainage networks have changed producing a greater exposure to flooding with a broad range of impacts on society, also because of climate inputs coupling with the human drivers. This research focuses on three main questions: which kind of land use changes related to the agricultural practices have been observed in the most recent years (~30 years)? How does the influence on the watershed response to land use and land cover changes depend on the rainfall event characteristics and soil conditions, and what is their related significance? The investigation presented in this work includes modelling the water infiltration due to the soil properties and analysing the distributed water storage offered by the agricultural drainage system in a study area in Veneto (north-eastern Italy). The results show that economic changes control the development of agro-industrial landscapes, with effects on the hydrological response. Key elements that can enhance or reduce differences are the antecedent soil conditions and the climate characteristics. Criticalities should be expected for intense and irregular rainfall events, and for events that recurrently happen. Agricultural areas might be perceived to be of low priority when it comes to public funding of flood protection, compared to the priority given to urban ones. These outcomes highlight the importance of understanding how agricultural practices can be the driver of or can be used to avoid, or at least mitigate, flooding. The proposed methods can be valuable tools in evaluating the costs and benefits of the management of water in agriculture to inform better policy decision-making

    Decision Support Tools for Cloud Migration in the Enterprise

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    This paper describes two tools that aim to support decision making during the migration of IT systems to the cloud. The first is a modeling tool that produces cost estimates of using public IaaS clouds. The tool enables IT architects to model their applications, data and infrastructure requirements in addition to their computational resource usage patterns. The tool can be used to compare the cost of different cloud providers, deployment options and usage scenarios. The second tool is a spreadsheet that outlines the benefits and risks of using IaaS clouds from an enterprise perspective; this tool provides a starting point for risk assessment. Two case studies were used to evaluate the tools. The tools were useful as they informed decision makers about the costs, benefits and risks of using the cloud.Comment: To appear in IEEE CLOUD 201

    Evaluating urban freight transport policies within complex urban environments

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    Urban Freight Transport (UFT) entails significant advantages for the economic growth of cities, but can also hamper population quality of life, obstructing vehicles and people movements while exacerbating environmental problems. Many initiatives have been engaged by many city administrators in order to efficiently manage UFT, evaluating different policies at a global scale. From the perspective of operators, most works analyze a limited set of policies or only focus on the benefits of companies. In this work, a decisionmaking process is used to evaluate a large set of UFT policies, through different attributes representing the advantages and limitations of each policy over promoter companies and the society. To do so, an ex-ante procedure in five steps is proposed to classify the policies: (1) attributes definition, (2) attributes weighting, (3) policy-attribute assessment, (4) policy ranking, and (5) feasibility threshold satisfaction. The whole process is supported on consultations to 26 experts regarding shop supply and restocking activities within complex urban environments. Results show a classification of the analyzed policies, according to their suitability for implementation ; which could be extended (directly or with small adjustments) to other contexts, given the flexibility of the decision-making procedure developed.Peer ReviewedPostprint (author's final draft

    The economic and environmental performance of distribution networks: A case study from the petrochemical industry

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    Designing a company's distribution network is a challenging task that requires the consideration of different aspects. In this respect, especially trade-offs between, for example, operational costs and customer service are the focus of the companies' attention. However, growing concerns of governments and customers about environmental protection have raised awareness towards the environmental impact of operations. Activities associated with the distribution of products, i.e. transportation and warehousing, are not yet subject to strict environmental regulations, but this situation is expected to change soon. Companies must, therefore, start to concentrate not only on economic but also on environmental aspects in the design of their supply chain. Based on a case study from the petrochemical industry, this paper presents a way to combine both, economic as well as environmental criteria, when evaluating (strategic) distribution network design decisions. The results show a trade-off between total (distribution) costs and transport carbon emissions. (author's abstract

    An Economic, Energy, and Environmental Analysis of PV/Micro-CHP Hybrid Systems: A Case Study of a Tertiary Building

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    Our present standard of living depends strongly on energy sources, with buildings being a primary focus when it comes to reducing energy consumption due to their large contribution, especially in tertiary buildings. The goal of the present study is to evaluate the performance of two different designs of hybrid systems, composed of natural gas engines and photovoltaic panels. This will be done through simulations in TRNSYS, considering a representative office building with various schedules of operation (8, 12, and 24 h), as well as different climates in Spain. The main contributions of this paper are the evaluations of primary energy-consumption, emissions, and economic analyses for each scenario. In addition, a sensitivity analysis is carried out to observe the influence of energy prices, as well as that of the costs of the micro-CHP engines and PV modules. The results show that the scenario with the conventional system and PV modules is the most profitable one currently. However, if electricity prices are increased in the future or natural gas prices are reduced, the scenario with micro-CHP engines and PV modules will become the most profitable option. Energy service engineers, regulators, and manufacturers are the most interested in these results

    Online Modified Greedy Algorithm for Storage Control under Uncertainty

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    This paper studies the general problem of operating energy storage under uncertainty. Two fundamental sources of uncertainty are considered, namely the uncertainty in the unexpected fluctuation of the net demand process and the uncertainty in the locational marginal prices. We propose a very simple algorithm termed Online Modified Greedy (OMG) algorithm for this problem. A stylized analysis for the algorithm is performed, which shows that comparing to the optimal cost of the corresponding stochastic control problem, the sub-optimality of OMG is bounded and approaches zero in various scenarios. This suggests that, albeit simple, OMG is guaranteed to have good performance in some cases; and in other cases, OMG together with the sub-optimality bound can be used to provide a lower bound for the optimal cost. Such a lower bound can be valuable in evaluating other heuristic algorithms. For the latter cases, a semidefinite program is derived to minimize the sub-optimality bound of OMG. Numerical experiments are conducted to verify our theoretical analysis and to demonstrate the use of the algorithm.Comment: 14 page version of a paper submitted to IEEE trans on Power System

    MS4 Resource: BMP Cost Estimates

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    BMP Cost estimate approach outlined in a recent EPA Region 1 mem

    The impact of postharvest research

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    While research on the improvement of agricultural production has received considerable attention and funding, until recently postharvest activities have not attracted much attention from international research organizations. However, there is an emerging consensus on the critical role that postharvest systems can play in meeting the overall goals of food security, poverty alleviation and sustainable agriculture particularly in developing countries. This study provides preliminary evidence on the impact of postharvest research on these goals; furthermore the study argues that postharvest research at international agricultural research organizations is justified by its international public good nature.postharvest technology ,food security ,Poverty alleviation ,Research institutes ,postharvest technology ,

    Evaluation of power generation operations in response to changes in surface water reservoir storage

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    We used a customized, river basin-based model of surface water rights to evaluate the response of power plants to drought via simulated changes in reservoir storage. Our methodology models surface water rights in 11 river basins in Texas using five cases: (1) storage decrease of existing capacity of 10%, (2) storage decrease of 50%, (3) complete elimination of storage, (4) storage increase of 10% (all at existing locations), and (5) construction of new reservoirs (at new locations) with a total increase in baseline reservoir capacity for power plant cooling of 9%. Using the Brazos River basin as a sample, we evaluated power generation operations in terms of reliability, resiliency, and vulnerability. As simulated water storage decreases, reliability generally decreases and resiliency and vulnerability remain relatively constant. All three metrics remain relatively constant with increasing reservoir storage, with the exception of one power plant. As reservoir storage changes at power plants, other water users in the basin are also affected. In general, decreasing water storage is beneficial to other water users in the basin, and increasing storage is detrimental for many other users. Our analysis reveals basin-wide and individual power plant-level impacts of changing reservoir storage, demonstrating a methodology for evaluation of the sustainability and feasibility of constructing new reservoir storage as a water and energy management approach.Mechanical Engineerin
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