1,900 research outputs found

    Reconfiguring an Irrigation Landscape to Improve Provision of Ecosystem Services

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    Over-allocation of fresh water resources to consumptive uses, coupled with recurring drought and the prospect of climate change, is compromising the stocks of natural capital in the world’s basins and reducing their ability to provide ecosystem services. To combat this, governments world wide are making significant investment in efforts to improve sharing of water between consumptive uses and the environment, with many investments centred on modernisation of inefficient irrigation delivery systems, and the purchase of water by government for environmental flows. In this study, spatial targeting was applied within a cost-benefit framework to reconfigure agricultural land use in an irrigation district to achieve a 20% reduction in agricultural water use to increase environmental flows and improve the provision of other ecosystem services. We demonstrate using spatial planning and optimisation models that a targeted land use reconfiguration policy approach could potentially increase the net present value of ecosystem services by up to AUS463.7m.Thisprovidesathresholdlevelofinvestmentthatwouldbejustifiedonthebasisofbenefitsthattheinvestmentproduces.Theincreaseinecosystemservicesincluderecovering61GLofwaterforenvironmentalflows,thesequestrationof10.6mtonnesofCO2e/yr,a13EC(?S/cm)reductioninriversalinity,andanoverall24463.7m. This provides a threshold level of investment that would be justified on the basis of benefits that the investment produces. The increase in ecosystem services include recovering 61 GL of water for environmental flows, the sequestration of 10.6m tonnes of CO2-e/yr, a 13 EC (?S/cm) reduction in river salinity, and an overall 24% increase in the value of agriculture. Without a targeted approach to planning, a 20% reduction in water for irrigation could result in the loss of AUS68.7m in economic returns to agriculture which may be only marginally offset by the increased value of ecosystem services resulting from the return of 61 GL of water to the environment.landscape planning, geographic information systems, cost-benefit analysis, irrigation, climate change, water management, spatial targeting, environmental valuation

    Research and development of low cost processes for integrated solar arrays

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    Si reduction, purification and sheet generation work has been concentrated on gaining information about a reduction process combined with purification (higher purity arc furnace with gas blowing and gradient freezing), transport process with purification and polycrystal sheet growth potential (SiF2), plastic deformation for sheet generation, and float zone sheet recrystallization

    A MATLAB-Based Upper Division Systems Analysis Course for Engineering Technology

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    The Department of Engineering Technology at Old Dominion University offers TAC of ABET accredited baccalaureate programs in Civil Engineering Technology, Electrical Engineering Technology, and Mechanical Engineering Technology. All students are required to take traditional courses in algebra and trigonometry, as well as differential and integral calculus, at the freshman and sophomore levels. While these courses provided the necessary basic mathematical skills, it was difficult to justify the traditional upper-division mathematics courses such as differential equations, vector analysis, etc., as appropriate for the special needs of engineering technology students. To address this issue, the Department has undertaken the development of a new systems analysis course that will cover the necessary upper-division engineering technology mathematical needs for ET students and it will be taught around a MATLAB based paradigm. While there are a number of fine computational software packages, MATLAB appears to be gaining broad acceptance in the engineering work place as one of the primary tools for advanced analysis. The course will consist of selected topics in linear algebra and matrices, differential equations, Laplace transforms, curve fitting, statistics, and optimization. Preliminary versions of the course have been offered several times to Electrical Engineering Technology Students and have received an excellent response. Beginning in the Spring of 2003, it will be offered to all Engineering Technology majors. Modifications to achieve that goal are currently underway. All topics will be first introduced in their basic mathematical forms, but once the concepts are mastered with simple numbers and forms, students will begin utilizing MATLAB extensively to solve more practical and challenging problems. The paper presents a detailed breakdown of the topics selected for coverage in this new course along with examples of complex problems that are easily solved by students with MATLAB. A discussion of problems observed during the integration of students from all the discipline areas into the course will be made and proposed changes to improve the course will be discussed

    Fragment screening reveals salicylic hydroxamic acid as an inhibitor of <em>Trypanosoma brucei</em> GPI GlcNAc-PI de-N-acetylase

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    The zinc-metalloenzyme GlcNAc-PI de-N-acetylase is essential for the biosynthesis of mature GPI anchors and has been genetically validated in the bloodstream form of Trypanosoma brucei, which causes African sleeping sickness. We screened a focused library of zinc-binding fragments and identified salicylic hydroxamic acid as a GlcNAc-PI de-N-acetylase inhibitor with high ligand efficiency. This is the first small molecule inhibitor reported for the trypanosome GPI pathway. Investigating the structure activity relationship revealed that hydroxamic acid and 2-OH are essential for potency, and that substitution is tolerated at the 4- and 5-positions

    Wave equations for the perturbations of a charged black hole

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    A pair of simple wave equations is presented for the symmetric gravitational and electromagnetic perturbations of a charged black hole. One of the equations is uncoupled, and the other has a source term given by the solution of the first equation. The derivation is presented in full detail for either axially symmetric or stationary perturbations, and is quite straightforward. This result is expected to have important applications in astrophysical models.Comment: 4 page

    Using ecosystem services to represent the environment in hydro-economic models

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    [EN] Demand for water is expected to grow in line with global human population growth, but opportunities to augment supply are limited in many places due to resource limits and expected impacts of climate change. Hydro-economic models are often used to evaluate water resources management options, commonly with a goal of understanding how to maximise water use value and reduce conflicts among competing uses. The environment is now an important factor in decision making, which has resulted in its inclusion in hydro-economic models. We reviewed 95 studies applying hydro-economic models, and documented how the environment is represented in them and the methods they use to value environmental costs and benefits. We also sought out key gaps and inconsistencies in the treatment of the environment in hydro-economic models. We found that representation of environmental values of water is patchy in most applications, and there should be systematic consideration of the scope of environmental values to include and how they should be valued. We argue that the ecosystem services framework offers a systematic approach to identify the full range of environmental costs and benefits. The main challenges to more holistic representation of the environment in hydro-economic models are the current limits to understanding of ecological functions which relate physical, ecological and economic values and critical environmental thresholds; and the treatment of uncertainty. (C) 2016 Elsevier B.V. All rights reserved.The authors acknowledge the backing of Universitat Politecnica de Valencia through its Support Programme for Research and Development. Support by the CSIRO for an internship visit by the lead author is also acknowledged. We also wish to thank the European Commission for financing the Seventh Framework Program project ENHANCE (FP7-ENV-2012, 308438) and the H2020 project IMPREX (H2020-WATER-2014-2015, 641811), and the Spanish Ministry of Economy and Competitiveness for granting the project NUTEGES (VI Plan Nacional de I+D+i 2008-2011, CGL2012-34978).Momblanch Benavent, A.; Connor, JD.; Crossman, ND.; Paredes Arquiola, J.; Andreu Álvarez, J. (2016). Using ecosystem services to represent the environment in hydro-economic models. Journal of Hydrology. 538:293-303. https://doi.org/10.1016/j.jhydrol.2016.04.019S29330353

    Using mental-modelling to explore how irrigators in the Murray-Darling Basin make water-use decisions

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    Study region: Water stress and over-allocation are at the forefront of water management and policy challenges in Australia, especially in the Murray–Darling Basin (MDB). Because irrigated agriculture is a major social and economic component of the MDB, farmer decision-making plays a major role in water sustainability in the region. Study focus: This study used a fuzzy cognitive mapping methodology, ‘mental modeling’, to understand the perceived constraints of irrigator water-use decisions in the MDB, for two different types of irrigation: permanent and annual crops. The approach elicits and documents irrigator insights into the complex and networked nature of irrigation water use decisions in relation to farm-based dynamics. New hydrological insights for the region: Results suggest support for greater local and irrigator involvement in water management decisions. Many, if not most, of the irrigators understood the need for, or at least the inevitability of, governmental policies and regulations. However, a lack of accountability, predictability, and transparency has added to the uncertainty in farm-based water decision-making. Irrigators supported the concept of environmental sustainability, although they might not always agree with how the concept is implemented. The mental modelling approach facilitated knowledge sharing among stakeholders and can be used to identify common goals. Future research utilizing the mental modelling approach may encourage co-management and knowledge partnerships between irrigators, water managers and government officials.Ellen M. Douglas, Sarah Ann Wheeler, David J. Smith, Ian C. Overton, Steven A. Gray, Tanya M. Doody, Neville D. Crossma

    Drought forecasting isn\u27t just about water- to get smart we need health and financial data too

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    The Millennium Drought taught Australians many lessons about living under extremely dry conditions – not just about how to conserve water, but also about human suffering. In a drought, farmers find it more difficult to make an income, leading to mental health problems and raising the rate of male suicides. In the city, the impact is felt through water restrictions and more expensive infrastructure. With very dry conditions returning to Tasmania, central Queensland and western Victoria, are we better prepared for the next big drought? This is an issue not just for Australia, but across the world, from California, to England, to the Levant region in the eastern Mediterranean, which from 1998-2012 experienced its worst drought in 900 years

    Charged black holes: Wave equations for gravitational and electromagnetic perturbations

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    A pair of wave equations for the electromagnetic and gravitational perturbations of the charged Kerr black hole are derived. The perturbed Einstein-Maxwell equations in a new gauge are employed in the derivation. The wave equations refer to the perturbed Maxwell spinor Φ0\Phi_0 and to the shear σ\sigma of a principal null direction of the Weyl curvature. The whole construction rests on the tripod of three distinct derivatives of the first curvature κ\kappa of a principal null direction.Comment: 12 pages, to appear in Ap.
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