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Journal articleTravers H, Winney K, Clements T, et al., 2015,
A tale of two villages: An investigation of conservation-driven land tenure reform in a Cambodian Protection Forest
, LAND USE POLICY, Vol: 43, Pages: 186-196, ISSN: 0264-8377- Author Web Link
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- Citations: 24
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Journal articleBal N, Rein G, 2015,
On the effect of inverse modelling and compensation effects in computational pyrolysis for fire scenarios
, FIRE SAFETY JOURNAL, Vol: 72, Pages: 68-76, ISSN: 0379-7112- Author Web Link
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- Citations: 26
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Journal articleBrindley H, Bantges R, Russell J, et al., 2015,
Spectral Signatures of Earth's Climate Variability over 5 Years from IASI
, JOURNAL OF CLIMATE, Vol: 28, Pages: 1649-1660, ISSN: 0894-8755- Author Web Link
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- Citations: 14
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Journal articleLiebel HT, Bidartondo MI, Gebauer G, 2015,
Are carbon and nitrogen exchange between fungi and the orchid <i>Goodyera repens</i> affected by irradiance?
, ANNALS OF BOTANY, Vol: 115, Pages: 251-261, ISSN: 0305-7364- Author Web Link
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- Citations: 26
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Journal articleWhittaker AC, Walker AS, 2015,
Geomorphic constraints on fault throw rates and linkage times: Examples from the Northern Gulf of Evia, Greece.
, Journal of Geophysical Research: Earth Surface, Vol: 120, Pages: 137-158, ISSN: 2169-9003 -
Journal articleFew S, Frost JM, Nelson J, 2015,
Models of charge pair generation in organic solar cells
, PHYSICAL CHEMISTRY CHEMICAL PHYSICS, Vol: 17, Pages: 2311-2325, ISSN: 1463-9076- Author Web Link
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- Citations: 139
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Conference paperSailer E, Taborda DMG, Keirstead J, 2015,
Assessment of Design Procedures for Vertical Borehole Heat Exchangers
, 40th Workshop on Geothermal Reservoir EngineeringThe use of ground source energy systems is a well-established method to provide low cost heating to buildings, diversify the energy mix and help meeting increasingly stricter sustainability targets. However, considerable uncertainties remain over their efficient design, with several standards, guidelines and manuals being proposed over the last few years. This paper aims at providing insight into the implications to the design of a vertical borehole heat exchanger of the adoption of different design procedures. The hypothetical case of a typical dwelling located in London, UK, is analysed in order to highlight the impact on the final design of the chosen methodology. Moreover, a parametric study using an analytical design procedure was performed to point out the influence of various factors, such as borehole characteristics and thermal properties of the ground. It is shown that there are considerable discrepancies between design methods and that uncertainties in some input parameters, such as the thermal properties of the ground, which for relatively small systems are often selected from tables rather than measured in situ, may have a substantial influence on the length of borehole required.
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Journal articleTidd AN, Vermard Y, Marchal P, et al., 2015,
Fishing for Space: Fine-Scale Multi-Sector Maritime Activities Influence Fisher Location Choice
, PLOS ONE, Vol: 10, ISSN: 1932-6203- Author Web Link
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- Citations: 16
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Journal articleCraske J, van Reeuwijk M, 2015,
Energy dispersion in turbulent jets. Part 2. A robust model for unsteady jets
, Journal of Fluid Mechanics, Vol: 763, Pages: 538-566, ISSN: 0022-1120In this paper we develop an integral model for an unsteady turbulent jet that incorporates longitudinal dispersion of two distinct types. The model accounts for the difference in the rate at which momentum and energy are advected (type I dispersion) and for the local deformation of velocity profiles that occurs in the vicinity of a sudden change in the momentum flux (type II dispersion). We adapt the description of dispersion in pipe flow by Taylor (Proc. R. Soc. Lond. A, vol. 219, 1953, pp. 186–203) to develop a dispersion closure for the longitudinal transportation of energy in unsteady jets. We compare our model’s predictions to results from direct numerical simulation and find a good agreement. The model described in this paper is robust and can be solved numerically using a simple central differencing scheme. Using the assumption that the longitudinal velocity profile in a jet has an approximately Gaussian form, we show that unsteady jets remain approximately straight-sided when their source area is fixed. Straight-sidedness provides an algebraic means of reducing the order of the governing equations and leads to a simple advection–dispersion relation. The physical process responsible for straight-sidedness is type I dispersion, which, in addition to determining the local response of the area of the jet, determines the growth rate of source perturbations. In this regard the Gaussian profile has the special feature of ensuring straight-sidedness and being insensitive to source perturbations. Profiles that are more peaked than the Gaussian profile attenuate perturbations and, following an increase (decrease) in the source momentum flux, lead to a local decrease (increase) in the area of the jet. Conversely, profiles that are flatter than the Gaussian amplify perturbations and lead to a local increase (decrease) in the area of the jet.
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Journal articleMagee C, Duffy OB, Purnell K, et al., 2015,
Fault-controlled fluid flow inferred from hydrothermal vents imaged in 3D seismic reflection data, offshore NW Australia
, Basin Research, Vol: 28, Pages: 299-318, ISSN: 1365-2117Fluid migration pathways in the subsurface are heavily influenced by pre-existing faults. Although studies of active fluid-escape structures can provide insights into the relationships between faults and fluid flow, they cannot fully constrain the geometry of and controls on the contemporaneous subsurface fluid flow pathways. We use 3D seismic reflection data from offshore NW Australia to map 121 ancient hydrothermal vents, likely related to magmatic activity, and a normal fault array considered to form fluid pathways. The buried vents consist of craters up to 264 m deep, which host a mound of disaggregated sedimentary material up to 518 m thick. There is a correlation between vent alignment and underlying fault traces. Seismic-stratigraphic observations and fault kinematic analyses reveal that the vents were emplaced on an intra-Tithonian seabed in response to the explosive release of fluids hosted within the fault array. We speculate that during the Late Jurassic the convex-upwards morphology of the upper tip-lines of individual faults acted to channelize ascending fluids and control where fluid expulsion and vent formation occurred. This contribution highlights the usefulness of 3D seismic reflection data to constraining normal fault-controlled subsurface fluid flow.
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Journal articleDattani R, Gibson KF, Few S, et al., 2015,
Fullerene oxidation and clustering in solution induced by light
, Journal of Colloid and Interface Science, Vol: 446, Pages: 24-30, ISSN: 1095-7103We investigate the environmental stability of fullerene solutions by static and dynamic light scattering, FTIR, NMR and mass spectroscopies, and quantum chemical calculations. We find that visible light exposure of fullerene solutions in toluene, a good solvent, under ambient laboratory conditions results in C60 oxidation to form fullerene epoxides, and subsequently causes fullerene clustering in solution. The clusters grow with time, even in absence of further illumination, and can reach dimensions from ≈100 nm to the μm scale over ≈1 day. Static light scattering suggests that resulting aggregates are fractal, with a characteristic power law (df) that increases from approximately 1.3 to 2.0 during light exposure. The clusters are bound by weak Coulombic interactions and are found to be reversible, disintegrating by mechanical agitation and thermal stress, and reforming over time. Our findings are relevant to the solution processing of composites and organic photovoltaics, whose reproducibility and performance requires control of fullerene solution stability under storage conditions.
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Journal articleMacLachlan AJ, Rath T, Cappel UB, et al., 2015,
Polymer/Nanocrystal Hybrid Solar Cells: Influence of Molecular Precursor Design on Film Nanomorphology, Charge Generation and Device Performance
, ADVANCED FUNCTIONAL MATERIALS, Vol: 25, Pages: 409-420, ISSN: 1616-301X- Author Web Link
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- Citations: 42
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Journal articleHolliday S, Ashraf RS, Nielsen CB, et al., 2015,
A rhodanine flanked nonfullerene acceptor for solution-processed organic photovoltaics
, Journal of the American Chemical Society, Vol: 137, Pages: 898-904, ISSN: 0002-7863A novel small molecule, FBR, bearing 3-ethylrhodanine flanking groups was synthesized as a nonfullerene electron acceptor for solution-processed bulk heterojunction organic photovoltaics (OPV). A straightforward synthesis route was employed, offering the potential for large scale preparation of this material. Inverted OPV devices employing poly(3-hexylthiophene) (P3HT) as the donor polymer and FBR as the acceptor gave power conversion efficiencies (PCE) up to 4.1%. Transient and steady state optical spectroscopies indicated efficient, ultrafast charge generation and efficient photocurrent generation from both donor and acceptor. Ultrafast transient absorption spectroscopy was used to investigate polaron generation efficiency as well as recombination dynamics. It was determined that the P3HT:FBR blend is highly intermixed, leading to increased charge generation relative to comparative devices with P3HT:PC60BM, but also faster recombination due to a nonideal morphology in which, in contrast to P3HT:PC60BM devices, the acceptor does not aggregate enough to create appropriate percolation pathways that prevent fast nongeminate recombination. Despite this nonoptimal morphology the P3HT:FBR devices exhibit better performance than P3HT:PC60BM devices, used as control, demonstrating that this acceptor shows great promise for further optimization.
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Journal articleRuiz-Trejo E, Atkinson A, Brandon NP, 2015,
Metallizing porous scaffolds as an alternative fabrication method for solid oxide fuel cell anodes
, Journal of Power Sources, Vol: 280, Pages: 81-89, ISSN: 1873-2755A combination of electroless and electrolytic techniques is used to incorporate nickel into a porous Ce0.9Gd0.1O1.90 scaffold. First a porous backbone was screen printed into a YSZ electrolyte using an ink that contains sacrificial pore formers. Once sintered, the scaffold was coated with silver using Tollens' reaction followed by electrodeposition of nickel in a Watts bath. At high temperatures the silver forms droplets enabling direct contact between the gadolinia-doped ceria and nickel. Using impedance spectroscopy analysis in a symmetrical cell a total area specific resistance of 1 Ωcm2 at 700 °C in 97% H2 with 3% H2O was found, indicating the potential of this fabrication method for scaling up.
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Journal articleWong HS, Barakat R, Alhilali A, et al., 2015,
Hydrophobic concrete using waste paper sludge ash
, Cement and Concrete Research, Vol: 70, Pages: 9-20, ISSN: 1873-3948The feasibility of using a low-cost super hydrophobic powder as water-resisting admixture or water-repellent surface coating for concrete has been investigated. The powder was produced from paper sludge ash (PSA), a by-product from the manufacture of recycled paper. The effect of hydrophobic PSA on workability, strength and transport properties, including sorptivity, water absorption, diffusivity, permeability and electrical conductivity is reported. Samples were prepared at water/cement ratio of 0.38, cured up to 28 days and conditioned at 50 °C to constant mass prior to testing. It was found that replacing Portland cement with 12% hydrophobic PSA reduced water absorption, sorptivity and conductivity by 84%, 86% and 85% respectively, with no major detrimental effects on hydration, strength and density. When used as a surface coating, the hydrophobic PSA reduced both absorption and sorptivity by 85–99% depending on the adhesive used. Samples surface coated with hydrophobic PSA showed excellent water repelling and self-cleaning characteristics.
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Journal articleLuporini F, Varbanescu AL, Rathgeber F, et al., 2015,
Cross-Loop Optimization of Arithmetic Intensity for Finite Element Local Assembly
, ACM Transactions on Architecture and Code Optimization, Vol: 11, Pages: 1-25, ISSN: 1544-3566<jats:p>We study and systematically evaluate a class of composable code transformations that improve arithmetic intensity in local assembly operations, which represent a significant fraction of the execution time in finite element methods. Their performance optimization is indeed a challenging issue. Even though affine loop nests are generally present, the short trip counts and the complexity of mathematical expressions, which vary among different problems, make it hard to determine an optimal sequence of successful transformations. Our investigation has resulted in the implementation of a compiler (called COFFEE) for local assembly kernels, fully integrated with a framework for developing finite element methods. The compiler manipulates abstract syntax trees generated from a domain-specific language by introducing domain-aware optimizations for instruction-level parallelism and register locality. Eventually, it produces C code including vector SIMD intrinsics. Experiments using a range of real-world finite element problems of increasing complexity show that significant performance improvement is achieved. The generality of the approach and the applicability of the proposed code transformations to other domains is also discussed.</jats:p>
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Conference paperAhmad F, Murphy W, Lawrence JA, et al., 2015,
Strength Mobilisation of Rock Masses in Relation to Deep Seated Landslide
, Geophysical Research Abstracts 17, EGU2015, 8151 -
Conference paperZhou Z, Krevor S, Reynolds C, 2015,
A simulation investigation into the influence of thermophysical fluid properties on CO<inf>2</inf> brine core flooding experiments
, Pages: 1141-1157We used conventional numerical simulation of immiscible multiphase flow to reproduce laboratory observations of the CO2/Brine system. A model of homogeneous rock properties was QC'ed on Buckley-Leverett, gravity effect and capillary end effect. The natural rock heterogeneity in the core was modelled by capillary heterogeneity, and calibrated by fluid distribution observed during the experiment. The calibrated model was then used to produce synthetic relative permeability observables by changing thermophysical fluid properties, knowing what the intrinsic relative permeabilities are. It was discovered that a change in reservoir conditions and particularly CO2 viscosity can lead to changing the impact that a natural rock heterogeneity in the core has on the fluid distribution. We showed that viscous-pressuredrive determines the extent to which rock heterogeneity matters in a core flooding experiment and demonstrated that heterogeneity can lead to a deviation in observed relative permeability from its intrinsic value. Given CO2 viscosity changes much more dramatically with reservoir conditions than other fluids, the impact of reservoir conditions on relative permeability tests is apparently observed because the changing conditions increases or decreases the role of heterogeneity in the core. We therefore concluded that appropriate relative permeability observations require a homogeneous fluid distribution and thus flow rates should be used where possible to minimize the impact of heterogeneity.
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Journal articleJacobs CT, Goldin TJ, Collins GS, et al., 2015,
An improved quantitative measure of the tendency for volcanic ash plumes to form in water: implications for the deposition of marine ash beds
, JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH, Vol: 290, Pages: 114-124, ISSN: 0377-0273- Author Web Link
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- Citations: 9
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Journal articleYu W, Graham NJD, 2015,
Application of Fe(II)/K<inf>2</inf>MnO<inf>4</inf> as a pre-treatment for controlling UF membrane fouling in drinking water treatment
, Journal of Membrane Science, Vol: 473, Pages: 283-291, ISSN: 0376-7388This paper describes some results of mini-pilot-scale tests concerning the performance of potassium manganate (K2MnO4) as a pre-treatment chemical prior to ultrafiltration. Manganate is an intermediate in the commercial preparation of permanganate and in aqueous reactions MnO42- can act as both an oxidant and a coagulant/adsorbent arising from the formation of insoluble MnO2. In addition, the combination of ferrous sulfate and manganate (Fe/Mn), offers a potentially cheaper and effective combination of pre-oxidant and coagulant compared to the chemicals used currently in water treatment (e.g. ozone, chlorine, ferric sulfate). In comparative tests with conventional ferric sulfate and using simulated raw water, the results showed that Fe/Mn pre-treatment substantially reduced membrane fouling in terms of the rate of trans-membrane pressure development (arising from both external and internal fouling). Fe/Mn pre-treatment was effective in reducing bacterial activity, changing the characteristics of organic matter and decreasing the production of extracellular polymeric substances (EPS) by bacteria. The external fouling in this process was determined by the EPS concentration, and the internal fouling mainly determined by the adsorption of lower MW organic matter to the membrane pores. Fe/Mn pre-treatment reduced the amounts of both types of fouling material within the cake layer and membrane pores in comparison to conventional pre-treatment with ferrous sulfate, most likely through the formation of solid-phase Fe(III) and MnO2 and by MnO42- oxidation, thereby leading to a substantial increase in membrane run time.
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Journal articleYu W, Gregory J, Campos LC, et al., 2015,
Dependence of floc properties on coagulant type, dosing mode and nature of particles
, WATER RESEARCH, Vol: 68, Pages: 119-126, ISSN: 0043-1354- Author Web Link
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- Citations: 54
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Journal articleManap N, Voulvoulis N, 2015,
Environmental management for dredging sediments - The requirement of developing nations
, Journal of Environmental Management, Vol: 147, Pages: 338-348, ISSN: 0301-4797Scientific research has characterized the effects of dredging, an underwater excavation process for navigational purposes or material extraction, and has shown its association with a number of chemical, physical and biological impacts. Due to this, much environmental management has been applied in the dredging industry in order to manage its detrimental effects. However, developing nations may have different approaches towards their dredging environmental management to compare to their companions with higher economic strength. Moreover, scientific evidence to make an informed decision is often lacking, hence affecting the number of research executed at these nations, limiting their efforts to preserve the environment. This paper reviews the dredging environmental impacts and its two important factors, dredging technology and sediment characteristic, that determine the magnitude of impacts through literature review, and discusses the need for a more integrated dredging environmental management to be developed for developing nations.
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Conference paperMehleri ED, Bhave A, Shah N, et al., 2015,
Techno-economic assessment and environmental impacts of Mineral Carbonation of industrial wastes and other uses of carbon dioxide
, Pages: 576-585In this contribution, we present the results of an in-depth techno-economic analysis of some leading CO2 capture and utilisation (CCU) and conversion (CCC) options. Specifically, we consider CO2 conversion to methanol, formic acid and urea (CCC) in addition to mineral carbonation of industrial wastes (CCU). We compare the CCC and CCU options using a range of key performance indicators (KPIs), including 2nd law efficiency, CO2 avoided and tonneCo2/tonneproduct. The results indicate that CCU and CCC technologies are unlikely to provide a significant contribution to mitigating anthropogenic climate change. The primary bottleneck to industrial scale deployment of CCC technologies is likely to be the cost effective availability of low carbon-hydrogen in the case that the conversion option requires hydrogen. Further, we find that mineral carbonation may have niche applications in the context of industrial waste remediation but the large scale deployment of this technology as a substitute for the geological sequestration of CO2 is unlikely to be either cost effective or scalable. Moreover, although formic acid offers attractive economic profiles, we note that this process is at a lower TRL (TRL 4-5). Thus, we conclude that CCC and CCU technologies are only likely to be viable at scale in the event that substantial subsidies are available to offset the high costs associated with producing renewable hydrogen and the thermodynamic cost associated with processing such a stable molecule.
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Journal articleHuang X, Rein G, Chen H, 2015,
Computational smoldering combustion: Predicting the roles of moisture and inert contents in peat wildfires
, Proceedings of the Combustion Institute, Vol: 35, Pages: 2673-2681, ISSN: 0082-0784Abstract Smoldering combustion is the slow, low-temperature, flameless burning of porous fuels and the most persistent type of combustion. It is the driving phenomenon of wildfires in peatlands, like those causing haze episodes in Southeast Asia and Northeast Europe, but is poorly understood. In this work, we develop a comprehensive 1-D model of a reactive porous media, using the open-source code Gpyro, to investigate smoldering combustion of natural fuels with an emphasis on the roles of the moisture and inert contents. The model solves the species, momentum, and energy conservation equations and includes heterogeneous chemical reactions. A previously developed 5-step reaction scheme for peat, including evaporation of water, is adopted to describe the drying, thermal and oxidative degradation during the smoldering combustion. The model predicts the transient temperature, species, and reaction profiles during ignition, spread, and extinction. The predicted smoldering thresholds related to the critical moisture and inorganic contents for ignition show a good agreement with the experimental results in the literature for a wide range of peat types and organic soils. The influences of the kinetic parameters, physical properties, and ignition protocol are investigated. This is the first time that a physics-based model of smoldering peat fires is developed, thus helping to understand this important natural and widespread phenomenon.
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Journal articleWu B, Yufit V, Merla Y, et al., 2015,
Differential thermal voltammetry for tracking of degradation in lithium-ion batteries
, Journal of Power Sources, Vol: 273, Pages: 495-501, ISSN: 0378-7753Monitoring of lithium-ion batteries is of critical importance in electric vehicle applications in order to manage the operational condition of the cells. Measurements on a vehicle often involve current, voltage and temperature which enable in-situ diagnostic techniques. This paper presents a novel diagnostic technique, termed differential thermal voltammetry, which is capable of monitoring the state of the battery using voltage and temperature measurements in galvanostatic operating modes. This tracks battery degradation through phase transitions, and the resulting entropic heat, occurring in the electrodes. Experiments to monitor battery degradation using the new technique are compared with a pseudo-2D cell model. Results show that the differential thermal voltammetry technique provides information comparable to that of slow rate cyclic voltammetry at shorter timescale and with load conditions easier to replicate in a vehicle.
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Journal articleNazzal D, Zabinski J, Hugar A, et al., 2015,
Introduction of sustainability concepts into industrial engineering education: A modular approach
, Advances in Engineering Education, Vol: 4Sustainability in operations, production, and consumption continues to gain relevance for engineers. This trend will accelerate as demand for goods and services grows, straining resources and requiring ingenuity to replace boundless supply in meeting the needs of a more crowded, more prosperous world. Industrial engineers are uniquely positioned to incorporate sustainability concepts into this work; their focus is on systems, and in observing these systems at a high level, they can most effectively choose which parts of the systems to modify to produce desired results. In this paper, we explore using the vehicle of education to introduce sustainability concepts into industrial engineers' training. We first survey the current state of sustainability education in industrial engineering programs. We then discuss a curricular modification program in which sustainability was introduced into several courses through use of content-focused modules. We conclude with our recommendations on how such a structure can be used to expand sustainability education in industrial engineering programs at all levels.
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Journal articleJacobs CT, Avdis A, Mouradian SL, et al., 2015,
Integrating research data management into geographical information systems
, CEUR Workshop Proceedings, Vol: 1529, Pages: 7-17, ISSN: 1613-0073Ocean modelling requires the production of high-fidelity com-putational meshes upon which to solve the equations of motion. The production of such meshes by hand is often infeasible, considering the complexity of the bathymetry and coastlines. The use of Geographical Information Systems (GIS) is therefore a key component to discretising the region of interest and producing a mesh appropriate to resolve the dynamics. However, all data abociated with the production of a mesh must be provided in order to contribute to the overall recomputability of the subsequent simulation. This work presents the integration of re-search data management in QMesh, a tool for generating meshes using GIS. The tool uses the PyRDM library to provide a quick and easy way for scientists to publish meshes, and all data required to regenerate them, to persistent online repositories. These repositories are abigned unique identifiers to enable proper citation of the meshes in journal articles.
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Book chapterBarndorff-Nielsen OE, Benth FE, Veraart AED, 2015,
Cross-commodity modelling by multivariate ambit fields
, Commodities, Energy and Environmental Finance, Editors: Aid, Ludkovski, Sircar, Publisher: Springer, Pages: 109-148 -
Book chapterVoulvoulis N, Georges K, 2015,
Industrial and agricultural sources and pathways of aquatic pollution
, Impact of Water Pollution on Human Health and Environmental Sustainability, Pages: 29-54This chapter provides an introduction to the topic of aquatic pollution and looks at the major sources and pathways of pollutants to the environment from agriculture and industry. The section on agricultural pollution focuses on the use of fertilizers and pesticides. Industrial pollution covers a large topic and so three groups of pollutants are examined to provide an overview of the key issues faced within this sector.
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Journal articleHoskins B, 2015,
Potential Vorticity and the PV Perspective
, ADVANCES IN ATMOSPHERIC SCIENCES, Vol: 32, Pages: 2-9, ISSN: 0256-1530- Author Web Link
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- Citations: 26
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