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  • Conference paper
    Mumford J, DeVos Y, Liu Y, Mestagh S, Waigmann Eet al., 2016,

    EFSA guidelines on environmental risk assessment of GM animals, including insects

    , GMOs in Integrated Plant Production, Publisher: IOBC, Pages: 39-46, ISSN: 0253-1100

    Future applications for the marketing of genetically modified organisms (GMOs) in the EU may include food/feed products derived from genetically modified (GM) animals, and the release of GM animals, including insects, into the environment. Efforts towards the development of GM insects to control insect vectors of human diseases and manage agricultural pests have progressed substantially with various GM insect × trait combinations in the development pipeline. As a proactive measure, the scientific GMO Panel of the European Food Safety Authority (EFSA) has developed guidelines on: (1) the risk assessment of food/feed derived from GM animals including animal health and welfare aspects; and (2) the environmental risk assessment (ERA) of living GM animals, including insects, released into the environment for commercial purposes. The latter assists applicants in the preparation and presentation of their applications by describing the elements and data requirements for a structured ERA of GM insects consistent with the current Directive 2001/18/EC. A dedicated Working Group (WG) was involved in the elaboration of the ERA guidelines on GM insects, which underwent a public consultation before their finalisation. Relevant comments received were considered by the WG. The WG also took into account the external scientific report on GM insects commissioned by EFSA (Benedict et al., 2010). This report provided background information by mapping relevant fields of expertise and identified essential elements to be considered when performing an ERA of GM insects. Content and stakeholder involvement for the EFSA guidelines are presented.
  • Journal article
    Huang X, Restuccia F, Gramola M, Rein Get al., 2016,

    Experimental study of the formation and collapse of an overhang in the lateral spread of smouldering peat fires

    , Combustion and Flame, Vol: 168, Pages: 393-402, ISSN: 1556-2921

    Smouldering combustion is the driving phenomenon of wildfires in peatlands, and is responsible for large amounts of carbon emissions and haze episodes world wide. Compared to flaming fires, smouldering is slow, low-temperature, flameless, and most persistent, yet it is poorly understood. Peat, as a typical organic soil, is a porous and charring natural fuel, thus prone to smouldering. The spread of smouldering peat fire is a multidimensional phenomenon, including two main components: in-depth vertical and surface lateral spread. In this study, we investigate the lateral spread of peat fire under various moisture and wind conditions. Visual and infrared cameras as well as a thermocouple array are used to measure the temperature profile and the spread rate. For the first time the overhang, where smouldering spreads fastest beneath the free surface, is observed in the laboratory, which helps understand the interaction between oxygen supply and heat losses. The periodic formation and collapse of overhangs is observed. The overhang thickness is found to increase with moisture and wind speed, while the spread rate decreases with moisture and increases with wind speed. A simple theoretical analysis is proposed and shows that the formation of overhang is caused by the spread rate difference between the top and lower peat layers as well as the competition between oxygen supply and heat losses.
  • Journal article
    Sarwar W, Engstrom T, Marinescu M, Green N, Taylor N, Offer GJet al., 2016,

    Experimental analysis of Hybridised Energy Storage Systems for automotive applications

    , Journal of Power Sources, Vol: 234, Pages: 388-401, ISSN: 0378-7753

    The requirements of the Energy Storage System (ESS) for an electrified vehicle portfolio consisting ofa range of vehicles from micro Hybrid Electric Vehicle (mHEV) to a Battery Electric Vehicle (BEV) varyconsiderably. To reduce development cost of an electrified powertrain portfolio, a modular systemwould ideally be scaled across each vehicle; however, the conflicting requirements of a mHEV andBEV prevent this. This study investigates whether it is possible to combine supercapacitors suitablefor an mHEV with high-energy batteries suitable for use in a BEV to create a Hybridised EnergyStorage System (HESS) suitable for use in a HEV. A passive HESS is found to be capable of meetingthe electrical demands of a HEV drive cycle; the operating principles of HESSs are discussed andfactors limiting system performance are explored. The performance of the HESS is found to besignificantly less temperature dependent than battery-only systems, however the heat generatedsuggests a requirement for thermal management. As the HESS degrades (at a similar rate to aspecialised high-power-battery), battery resistance rises faster than supercapacitor resistance; as aresult, the supercapacitor provides a greater current contribution, therefore the energy throughput,temperature rise and degradation of the batteries is reduced.
  • Journal article
    Chen Z, Wang X, Atkinson A, Brandon Net al., 2016,

    Spherical indentation of porous ceramics: cracking and toughness

    , Journal of the European Ceramic Society, Vol: 36, Pages: 3473-3480, ISSN: 0955-2219

    A combined experimental-numerical approach is used to characterise the fracture of a porous bulk ceramic material (La0.6Sr0.4Co0.2Fe0.8O3) with porosities of 5-45%, undergoing spherical indentation. The Gurson model was used in FEM to describe the densification of the porous material. Indentation-induced radial cracks were observed, when the applied nominal contact pressure exceeded threshold values, with no Hertzian ring-cone cracks found. FEM analysis indicated that the cracks propagated mainly during unloading, driven by the tensile hoop stress generated near the contact circle. The stress intensity at the crack tip was estimated using an approximate analysis of the FEM stress field to derive toughness values that were consistent with values determined by conventional methods, provided that the crack length is sufficiently large compared with the contact radius and can be measured accurately. The absence of ring-cone cracks in the elastic field during loading is due to the material’s high modulus-to-hardness ratio and the small indenter radius as predicted by established theory.
  • Journal article
    Blaker JJ, Anthony DB, Tang G, Shamsuddin SR, Kalinka G, Weinrich M, Abdolvand A, Shaffer MSP, Bismarck Aet al., 2016,

    Property and shape modulation of carbon fibers using lasers

    , ACS Applied Materials & Interfaces, Vol: 8, Pages: 16351-16358, ISSN: 1944-8244

    An exciting challenge is to create unduloid-reinforcing fibers with tailored dimensions to produce synthetic composites with improved toughness and increased ductility. Continuous carbon fibers, the state-of-the-art reinforcement for structural composites, were modified via controlled laser irradiation to result in expanded outwardly tapered regions, as well as fibers with Q-tip (cotton-bud) end shapes. A pulsed laser treatment was used to introduce damage at the single carbon fiber level, creating expanded regions at predetermined points along the lengths of continuous carbon fibers, whilst maintaining much of their stiffness. The range of produced shapes was quantified and correlated to single fiber tensile properties. Mapped Raman spectroscopy was used to elucidate the local compositional and structural changes. Irradiation conditions were adjusted to create a swollen weakened region, such that fiber failure occurred in the laser treated region producing two fiber ends with outwardly tapered ends. Upon loading the tapered fibers allow for viscoelastic energy dissipation during fiber pull-out by enhanced friction as the fibers plough through a matrix. In these tapered fibers, diameters were locally increased up to 53%, forming outward taper angles of up to 1.8°. The tensile strength and strain to failure of the modified fibers were significantly reduced, by 75% and 55%, respectively, ensuring localization of the break in the expanded region; however, the fiber stiffness was only reduced by 17%. Using harsher irradiation conditions, carbon fibers were completely cut, resulting in cotton-bud fiber end shapes. Single fiber pull-out tests performed using these fibers revealed a 6.75 fold increase in work of pull-out compared to pristine carbon fibers. Controlled laser irradiation is a route to modify the shape of continuous carbon fibers along their lengths, as well as to cut them into controlled lengths leaving tapered or cotton-bud shapes.
  • Journal article
    Wu B, Ibrahim KA, Brandon NP, 2016,

    Electrical conductivity and porosity in stainless steel 316L scaffolds for electrochemical devices fabricated using selective laser sintering

    , Materials and Design, Vol: 109, Pages: 51-59, ISSN: 1873-4197

    Battery electrode microstructures must be porous, to provide a large active surface area to facilitate fast charge transfer kinetics. In this work, we describe how a novel porous electrode scaffold, made from stainless steel 316L powder can be fabricated using selective laser sintering by proper selection of process parameters. Porosity, electrical conductivity and optical microscopy measurements were used to investigate the properties of fabricated samples. Our results show that a laser energy density between 1.50–2.00 J/mm2 leads to a partial laser sintering mechanism where the powder particles are partially fused together, resulting in the fabrication of electrode scaffolds with 10% or higher porosity. The sample fabricated using 2.00 J/mm2 energy density (60 W–1200 mm/s) exhibited a good electrical conductivity of 1.80 × 106 S/m with 15.61% of porosity. Moreover, we have observed the porosity changes across height for the sample fabricated at 60 W and 600 mm/s, 5.70% from base and increasing to 7.12% and 9.89% for each 2.5 mm height towards the top surface offering graded properties ideal for electrochemical devices, due to the changing thermal boundary conditions. These highly porous electrode scaffolds can be used as an electrode in electrochemical devices, potentially improving energy density and life cycle.
  • Journal article
    Sukhodolov T, Rozanov E, Ball WT, Bais A, Tourpali K, Shapiro AI, Telford P, Smyshlyaev S, Fomin B, Sander R, Bossay S, Bekki S, Marchand M, Chipperfield MP, Dhomse S, Haigh JD, Peter T, Schmutz Wet al., 2016,

    Evaluation of simulated photolysis rates and their response to solar irradiance variability

    , JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, Vol: 121, Pages: 6066-6084, ISSN: 2169-897X

    The state of the stratospheric ozone layer and the temperature structure of the atmosphere are largely controlled by the solar spectral irradiance (SSI) through its influence on heating and photolysis rates. This study focuses on the uncertainties in the photolysis rate response to solar irradiance variability related to the choice of SSI data set and to the performance of the photolysis codes used in global chemistry-climate models. To estimate the impact of SSI uncertainties, we compared several photolysis rates calculated with the radiative transfer model libRadtran, using SSI calculated with two models and observed during the Solar Radiation and Climate Experiment (SORCE) satellite mission. The importance of the calculated differences in the photolysis rate response for ozone and temperature changes has been estimated using 1-D a radiative-convective-photochemical model. We demonstrate that the main photolysis reactions, responsible for the solar signal in the stratosphere, are highly sensitive to the spectral distribution of SSI variations. Accordingly, the ozone changes and related ozone-temperature feedback are shown to depend substantially on the SSI data set being used, which highlights the necessity of obtaining accurate SSI variations. To evaluate the performance of photolysis codes, we compared the results of eight, widely used, photolysis codes against two reference schemes. We show that, in most cases, absolute values of the photolysis rates and their response to applied SSI changes agree within 30%. However, larger errors may appear in specific atmospheric regions because of differences, for instance, in the treatment of Rayleigh scattering, quantum yields, or absorption cross sections.
  • Journal article
    Aitken ARA, Roberts JL, van Ommen TD, Young DA, Golledge NR, Greenbaum JS, Blankenship DD, Siegert MJet al., 2016,

    Repeated large-scale retreat and advance of Totten Glacier indicated by inland bed erosion

    , Nature, Vol: 533, Pages: 385-389, ISSN: 0028-0836
  • Journal article
    Liberti E, Menzel R, Shaffer MS, McComb DWet al., 2016,

    Probing the size dependence on the optical modes of anatase nanoplatelets using STEM-EELS

    , Nanoscale, Vol: 8, Pages: 9727-9735, ISSN: 2040-3372

    Anatase titania nanoplatelets with predominantly exposed {001} facets have been reported to have enhanced catalytic properties in comparison with bulk anatase. To understand their unusual behaviour, it is essential to fully characterize their electronic and optical properties at the nanometer scale. One way of assessing these fundamental properties is to study the dielectric function. Valence electron energy-loss spectroscopy (EELS) performed using a scanning transmission electron microscope (STEM) is the only analytical method that can probe the complex dielectric function with both high energy (<100 meV) and high spatial (<1 nm) resolution. By correlating experimental STEM-EELS data with simulations based on semi-classical dielectric theory, the dielectric response of thin (<5 nm) anatase nanoplatelets was found to be largely dominated by characteristic (optical) surface modes, which are linked to surface plasmon modes of anatase. For platelets less than 10 nm thick, the frequency of these optical modes varies according to their thickness. This unique optical behaviour prompts the enhancement of light absorption in the ultraviolet regime. Finally, the effect of finite size on the dielectric signal is gradually lost by stacking consistently two or more platelets in a specific crystal orientation, and eventually suppressed for large stacks of platelets.
  • Journal article
    Siegert MJ, Ross N, Li J, Schroeder DM, Rippin D, Ashmore D, Bingham R, Gogineni Pet al., 2016,

    Subglacial controls on the flow of Institute Ice Stream, West Antarctica

    , Annals of Glaciology, Vol: 57, Pages: 19-24, ISSN: 1727-5644

    The Institute Ice Stream (IIS) rests on a reverse-sloping bed, extending >150 km upstream into the ~1.8 km deep Robin Subglacial Basin, placing it at the threshold of marine ice-sheet instability. Understanding IIS vulnerability has focused on the effect of grounding-line melting, which is forecast to increase significantly this century. Changes to ice-flow dynamics are also important to IIS stability, yet little is known about them. Here we reveal the trunk of the IIS occurs downstream of the intersection of three discrete subglacial features; a large ‘active’ subglacial lake, a newly-discovered sharp transition to a zone of weak basal sediments, and a major tectonic rift. The border of IIS trunk flow is confined by the sediment on one side, and by a transition between basal melting and freezing at the border with the Bungenstock Ice Rise. By showing how basal sediment and water dictate present-day flow of IIS, we reveal that ice-sheet stability here is dependent on this unusual arrangement.
  • Journal article
    O'Keeffe J, Buytaert W, Mijic A, Brozovic N, Sinha Ret al., 2016,

    The use of semi-structured interviews for the characterisation of farmer irrigation practices

    , Hydrology and Earth System Sciences, Vol: 20, Pages: 1911-1924, ISSN: 1607-7938

    Generating information on the behaviours, characteristics and drivers of users, as well on the resource itself, is vital in developing sustainable and realistic water security options. In this paper we present a methodology for collecting qualitative and quantitative data on water use practices through semi-structured interviews. This approach facilitates the collection of detailed information on actors' decisions in a convenient and cost-effective manner. The interview is organised around a topic guide, which helps lead the conversation in a standardised way while allowing sufficient opportunity to identify relevant issues previously unknown to the researcher. In addition, semi-structured interviews can be used to obtain certain types of quantitative data. While not as accurate as direct measurements, it can provide useful information on local practices and farmers' insights. We present an application of the methodology on two districts in the State of Uttar Pradesh in North India. By means of 100 farmer interviews, information was collected on various aspects of irrigation practices, including irrigation water volumes, irrigation cost, water source and their spatial variability. A statistical analysis of the information, along with some data visualisation is also presented, which highlights a significant variation in irrigation practices both within and between the districts. Our application shows that semi-structured interviews are an effective and efficient method of collecting both qualitative and quantitative information for the assessment of drivers, behaviours and their outcomes in a data scarce region. The collection of this type of data could significantly improve insight on water resources, leading to more realistic management options and increased water security in the future.
  • Journal article
    Bradley AV, Duarte Rosa IM, Pontius Jr RG, Ahmed SE, Araujo MB, Brandão Jr A, Câmara G, Carnerio TGS, Hartley A, Smith MJ, Ewers RMet al., 2016,

    SimiVal, a Multi-Criteria Map Comparison Tool for Land-Change Model Projections

    , Environmental Modelling and Software, Vol: 82, Pages: 229-240, ISSN: 1873-6726

    The multiple uses of land-cover models have led to validation with choice metrics or an adhoc choice of the validation metrics available. To address this, we have identified the majordimensions of land-cover maps that ought to be evaluated and devised a SimilarityValidation (SimiVal) tool. SimiVal uses a linear regression to test a modelled projectionagainst benchmark cases of, perfect, observed and systematic-bias, calculated by rescalingthe metrics from a random case relative to the observed, perfect case. The most informativeregression coefficients, p-value and slope, are plot on a ternary graph of ‘similarity space’whose extremes are the three benchmark cases. This plot provides a rigorous similarityassessment against these extremes and other projections. SimiVal is tested on projectionsof two deliberately contrasting land-cover models to show the similarity between intra- andinter-model parameterisations. Predictive and exploratory models can benefit from the tool.
  • Journal article
    Lu X, Gray C, Brown LE, Ledger ME, Milner AM, Mondragón RJ, Woodward G, Ma Aet al., 2016,

    Drought rewires the cores of food webs

    , Nature Climate Change, Vol: 6, Pages: 875-878, ISSN: 1758-678X

    Droughts are intensifying across the globe with potentially devastating implications for freshwater ecosystems. We used new network science approaches to investigate drought impacts on stream food webs and explored potential consequences for web robustness to future perturbations. The substructure of the webs was characterized by a core of richly connected species surrounded by poorly connected peripheral species. Although drought caused the partial collapse of the food webs, the loss of the most extinction-prone peripheral species triggered a substantial rewiring of interactions within the networks’ cores. These shifts in species interactions in the core conserved the underlying core/periphery substructure and stability of the drought-impacted webs. When we subsequently perturbed the webs by simulating species loss in silico, the rewired drought webs were as robust as the larger, undisturbed webs. Our research unearths previously unknown compensatory dynamics arising from within the core that could underpin food web stability in the face of environmental perturbations.
  • Journal article
    Stocker BD, Prentice IC, Cornell SE, Davies-Barnard T, Finzi AC, Franklin O, Janssens I, Larmola T, Manzoni S, Näsholm T, Raven JA, Rebel KT, Reed S, Vicca S, Wiltshire A, Zaehle Set al., 2016,

    Terrestrial nitrogen cycling in Earth system models revisited.

    , New Phytologist, Vol: 210, Pages: 1165-1168, ISSN: 1469-8137
  • Journal article
    Tainio M, de Nazelle AJ, Götschi T, Kahlmeier S, Rojas-Rueda D, Nieuwenhuijsen MJ, de Sá TH, Kelly P, Woodcock Jet al., 2016,

    Can air pollution negate the health benefits of cycling and walking?

    , Preventive Medicine, Vol: 87, Pages: 233-236, ISSN: 1096-0260

    Active travel (cycling, walking) is beneficial for the health due to increased physical activity (PA). However, active travel may increase the intake of air pollution, leading to negative health consequences. We examined the risk–benefit balance between active travel related PA and exposure to air pollution across a range of air pollution and PA scenarios.The health effects of active travel and air pollution were estimated through changes in all-cause mortality for different levels of active travel and air pollution. Air pollution exposure was estimated through changes in background concentrations of fine particulate matter (PM2.5), ranging from 5 to 200 μg/m3. For active travel exposure, we estimated cycling and walking from 0 up to 16 h per day, respectively. These refer to long-term average levels of active travel and PM2.5 exposure.For the global average urban background PM2.5 concentration (22 μg/m3) benefits of PA by far outweigh risks from air pollution even under the most extreme levels of active travel. In areas with PM2.5 concentrations of 100 μg/m3, harms would exceed benefits after 1 h 30 min of cycling per day or more than 10 h of walking per day. If the counterfactual was driving, rather than staying at home, the benefits of PA would exceed harms from air pollution up to 3 h 30 min of cycling per day. The results were sensitive to dose–response function (DRF) assumptions for PM2.5 and PA.PA benefits of active travel outweighed the harm caused by air pollution in all but the most extreme air pollution concentrations.
  • Journal article
    Sunyer MA, Luchner J, Onof C, Madsen H, Arnbjerg-Nielsen Ket al., 2016,

    Assessing the importance of spatio-temporal RCM resolution when estimating sub-daily extreme precipitation under current and future climate conditions

    , International Journal of Climatology, Vol: 37, Pages: 688-705, ISSN: 1097-0088

    The increase in extreme precipitation is likely to be one of the most significant impacts of climate change in cities due to increased pluvial flood risk. Hence, reliable information on changes in sub-daily extreme precipitation is needed for robust adaptation strategies. This study explores extreme precipitation over Denmark generated by the regional climate model (RCM) HIRHAM-ECEARTH at different spatial resolutions (8, 12, 25 and 50 km), three RCM from the RiskChange project at 8 km resolution and three RCMs from ENSEMBLES at 25 km resolution at temporal aggregations from 1 to 48 h. The performance of the RCM simulations in current climate as well as projected changes for 2081–2100 is evaluated for non-central moments of order 1–3 and for the 2- and 10-year events. The comparison of the RCM simulations and observations shows that the higher spatial resolution simulations (8 and 12 km) are more consistent across all temporal aggregations in the representation of high-order moments and extreme precipitation. The biases in the spatial pattern of extreme precipitation change across temporal and spatial resolution. The hourly extreme value distributions of the HIRHAM-ECEARTH simulations are more skewed than the observational dataset, which leads to an overestimation by the higher spatial resolution simulations. Nevertheless, in general, under current conditions RCM simulations at high spatial resolution represent extreme events and high-order moments better. The changes projected by the RCM simulations depend on the global climate model (GCM)–RCM combination, spatial resolution and temporal aggregation. The simulations disagree on the magnitude and spatial pattern of the changes. However, there is an agreement on higher changes for lower temporal aggregation and higher spatial resolution. Overall, the results from this study show the influence of the spatial resolution on the precipitation outputs from RCMs. The bia
  • Journal article
    Sandwell P, Chan NLA, Foster S, Nagpal D, Emmott CJM, Candelise C, Buckle SJ, Ekins-Daukes N, Gambhir A, Nelson Jet al., 2016,

    Off-grid solar photovoltaic systems for rural electrification and emissions mitigation in India

    , Solar Energy Materials and Solar Cells, Vol: 156, Pages: 147-156, ISSN: 0927-0248

    Over one billion people lack access to electricity and many of them in rural areas far from existing infrastructure. Off-grid systems can provide an alternative to extending the grid network and using renewable energy, for example solar photovoltaics (PV) and battery storage, can mitigate greenhouse gas emissions from electricity that would otherwise come from fossil fuel sources. This paper presents a model capable of comparing several mature and emerging PV technologies for rural electrification with diesel generation and grid extension for locations in India in terms of both the levelised cost and lifecycle emissions intensity of electricity. The levelised cost of used electricity, ranging from $0.46–1.20/kWh, and greenhouse gas emissions are highly dependent on the PV technology chosen, with battery storage contributing significantly to both metrics. The conditions under which PV and storage becomes more favourable than grid extension are calculated and hybrid systems of PV, storage and diesel generation are evaluated. Analysis of expected price evolutions suggest that the most cost-effective hybrid systems will be dominated by PV generation around 2018.
  • Journal article
    Blanga R, Berman M, Biton M, Tariq F, Yufit V, Gladkich A, Greenbaum SG, Brandon N, Golodnitsky Det al., 2016,

    Peculiarities of ion transport in confined-in-ceramics concentrated polymer electrolytes

    , Electrochimica Acta, Vol: 208, Pages: 71-79, ISSN: 1873-3859

    Polyethylene-oxide/lithium-aluminate films were deposited by electrophoretic deposition. Films impregnated with lithium iodide formed highly concentrated polymer-in-ceramic solid electrolytes. Solid-state NMR, FIB-SEM tomography with modelling, and EIS studies showed that only a few percent of the interfacial lithium in the sample is capable of inducing a fast ion-migration path in the system. We suggest that despite suppressed crystallinity of PEO confined in ceramics the ion transport in the polymer medium impedes the total conductivity of the composite electrolyte at near-ambient temperatures. After melting of the polymer and its complexes, the interfacial conduction through perpendicular LiAlO2/LiI grain boundaries becomes feasible. This, together with ion transport via molten, confined polymer electrolyte is followed by the increase of the overall conductivity of the composite system.
  • Journal article
    Hey J, Malloy AC, Martinez-Botas R, Lamperth Met al., 2016,

    Online Monitoring of Electromagnetic Losses in an Electric Motor Indirectly Through Temperature Measurement

    , IEEE TRANSACTIONS ON ENERGY CONVERSION, Vol: 31, Pages: 1347-1355, ISSN: 0885-8969
  • Journal article
    Doblin MA, van Sebille E, 2016,

    Drift in ocean currents impacts intergenerational microbial exposure to temperature

    , Proceedings of the National Academy of Sciences of the United States of America, Vol: 113, Pages: 5700-5705, ISSN: 1091-6490
  • Journal article
    Jamil Z, Ruiz-Trejo E, Boldrin P, Brandon NP, Jamil Z, Ruiz-Trejo E, Boldrin P, Brandon Net al., 2016,

    Anode fabrication for solid oxide fuel cells: Electroless and electrodeposition of nickel and silver into doped ceria scaffolds

    , International Journal of Hydrogen Energy, Vol: 41, Pages: 9627-9637, ISSN: 1879-3487

    A novel fabrication method using electroless and electrodeposited Ni/Ag/GDC for SOFC anodes is presented. First a porous Ce0.9Gd0.1O2−x (GDC) scaffold was deposited on a YSZ electrolyte by screen printing and sintering. The scaffold was then metallized with silver using Tollens' reaction, followed by electrodeposition of nickel from a Watt's bath. The electrodes (Ni/Ag/GDC) were tested in both symmetrical and fuel cell configurations. The microstructures of the Ni/Ag/GDC anodes were analyzed using scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDX). Nano-particles of Ni formed in the porous GDC scaffold provided triple phase boundaries (TPB). The electronic conductivity of the Ni/Ag/GDC (3.5/24.7/71.8 vol%) electrode was good even at relatively low Ni volume fractions. The electrochemical performance was examined in different concentrations of humidified hydrogen (3% H2O) and over a range of temperatures (600–750 °C). The total area specific resistance (ASR) of the anode at 750 °C in humidified 97 vol% H2 was 1.12 Ω cm2, with low-frequency polarization (R_l) as the largest contributor. The electrodes were successfully integrated into a fuel cell and operated in both H2 and syngas.
  • Report
    Parrish B, Heptonstall PJ, Gross R, 2016,

    The potential for UK residential demand side participation

    , Publisher: HubNet
  • Report
    Parrish B, Heptonstall PJ, Gross R, 2016,

    The potential for UK residential demand side participation

    , Publisher: HubNet
  • Journal article
    Siegert MJ, Frederick BC, Young DA, Blankenship DD, Richter TG, Kempf SD, Ferraccioli Fet al., 2016,

    Distribution of subglacial sediments across the Wilkes Subglacial Basin, East Antarctica

    , Journal of Geophysical Research. Earth Surface, Vol: 121, Pages: 790-813, ISSN: 2169-9003

    Topography, sediment distribution, and heat flux are all key boundary conditions governing the dynamics of the East Antarctic Ice Sheet (EAIS). EAIS stability is most at risk in Wilkes Land across vast expanses of marine-based catchments including the 1400 km × 600 km expanse of the Wilkes Subglacial Basin (WSB) region. Data from a recent regional aerogeophysical survey (Investigating the Cryospheric Evolution of the Central Antarctic Plate (ICECAP)/IceBridge) are combined with two historical surveys (Wilkes basin/Transantarctic Mountains System Exploration-Ice-house Earth: Stability or DYNamism? (WISE-ISODYN) and Wilkes Land Transect (WLK)) to improve our understanding of the vast subglacial sedimentary basins impacting WSB ice flow and geomorphology across geologic time. Analyzing a combination of gravity, magnetic and ice-penetrating radar data, we present the first detailed subglacial sedimentary basin model for the WSB that defines distinct northern and southern subbasin isopachs with average sedimentary basin thicknesses of 1144 m ± 179 m and 1623 m ± 254 m, respectively. Notably, more substantial southern subbasin sedimentary deposition in the WSB interior supports a regional Wilkes Land hypothesis that basin-scale ice flow and associated glacial erosion is dictated by tectonic basement structure and the inherited geomorphology of preglacial fluvial networks. Orbital, temperate/polythermal glacial cycles emanating from adjacent alpine highlands during the early Miocene to late Oligocene likely preserved critical paleoclimatic data in subglacial sedimentary strata. Substantially thinner northern WSB subglacial sedimentary deposits are generally restricted to fault-controlled, channelized basins leading to prominent outlet glacier catchments suggesting a more dynamic EAIS during the Pliocene.
  • Journal article
    Ferrandiz-Mas V, Bond T, Zhang Z, Melchiorri J, Cheeseman Cet al., 2016,

    Optimising the bioreceptivity of porous glass tiles based on colonization by the alga Chlorella vulgaris

    , Science of the Total Environment, Vol: 563-564, Pages: 71-80, ISSN: 0048-9697

    Green façades on buildings can mitigate greenhouse gas emissions. An option to obtain green facades is through the natural colonisation of construction materials. This can be achieved by engineering bioreceptive materials. Bioreceptivity is the susceptibility of a material to be colonized by living organisms. The aim of this research was to develop tiles made by sintering granular waste glass that were optimised for bioreceptivity of organisms capable of photosynthesis. Tiles were produced by pressing recycled soda-lime glass with a controlled particle size distribution and sintering compacted samples at temperatures between 680 and 740 °C. The primary bioreceptivity of the tiles was evaluated by quantifying colonisation by the algae Chlorella vulgaris (C. vulgaris), which was selected as a model photosynthetic micro-organism. Concentrations of C. vulgaris were measured using chlorophyll-a extraction. Relationships between bioreceptivity and the properties of the porous glass tile, including porosity, sorptivity, translucency and pH are reported. Capillary porosity and water sorptivity were the key factors influencing the bioreceptivity of porous glass. Maximum C. vulgaris growth and colonization was obtained for tiles sintered at 700 °C, with 2 of tile. Bioreceptivity was positively 1 correlated with sorptivity and porosity and negatively correlated with light transmittance. The research demonstrates that the microstructure of porous glass, determined by the processing conditions, significantly influences bioreceptivity. Porous glass tiles with high bioreceptivity that are colonised by photosynthetic algae have the potential to form carbon-negative façades for buildings and green infrastructure.
  • Journal article
    Herceg TM, Abidin MSZ, Greenhalgh ES, Shaffer MSP, Bismarck Aet al., 2016,

    Thermosetting hierarchical composites with high carbon nanotube loadings: En route to high performance

    , Composites Science and Technology, Vol: 127, Pages: 134-141, ISSN: 0266-3538

    A wet powder impregnation route to manufacture carbon fibre reinforced thermoplastic composites was adapted to accommodate thermosetting matrices reinforced with high fractions (20 wt%/13.6 vol%) of multiwalled carbon nanotubes (CNTs). The produced carbon fibre prepregs were consolidated into laminates with fibre volume fractions of 50–58% and up to 6.1 vol% CNTs. Microscopic imaging confirmed successful consolidation at intermediate CNT loadings, but some voidage at the highest CNT loading due to the highly viscoelastic uncured matrix. Nonetheless, through-thickness electrical conductivity and Mode I interlaminar fracture toughness were enhanced by as much as 152% and 24% to unprecedented values of σ = 53 S m−1 and GIC = 840 J m−2, respectively. Fractographic characterisation indicated that crack deflection was the mechanism responsible for the improved fracture toughness. The material properties were shown to be strongly dependent on the microstructure of the matrix.
  • Journal article
    Sweeney S, Leo BF, Chen S, Abraham-Thomas N, Thorley AJ, Gow A, Schwander S, Zhang JJ, Shaffer MS, Chung KF, Ryan MP, Porter AE, Tetley TDet al., 2016,

    Pulmonary surfactant mitigates silver nanoparticle toxicity in human alveolar type-I-like epithelial cells.

    , Colloids and Surfaces B - Biointerfaces, Vol: 145, Pages: 167-175, ISSN: 1873-4367

    Accompanying increased commercial applications and production of silver nanomaterials is an increased probability of human exposure, with inhalation a key route. Nanomaterials that deposit in the pulmonary alveolar region following inhalation will interact firstly with pulmonary surfactant before they interact with the alveolar epithelium. It is therefore critical to understand the effects of human pulmonary surfactant when evaluating the inhalation toxicity of silver nanoparticles. In this study, we evaluated the toxicity of AgNPs on human alveolar type-I-like epithelial (TT1) cells in the absence and presence of Curosurf(®) (a natural pulmonary surfactant substitute), hypothesising that the pulmonary surfactant would act to modify toxicity. We demonstrated that 20nm citrate-capped AgNPs induce toxicity in human alveolar type I-like epithelial cells and, in agreement with our hypothesis, that pulmonary surfactant acts to mitigate this toxicity, possibly through reducing AgNP dissolution into cytotoxic Ag(+) ions. For example, IL-6 and IL-8 release by TT1 cells significantly increased 10.7- and 35-fold, respectively (P<0.01), 24h after treatment with 25μg/ml AgNPs. In contrast, following pre-incubation of AgNPs with Curosurf(®), this effect was almost completely abolished. We further determined that the mechanism of this toxicity is likely associated with Ag(+) ion release and lysosomal disruption, but not with increased reactive oxygen species generation. This study provides a critical understanding of the toxicity of AgNPs in target human alveolar type-I-like epithelial cells and the role of pulmonary surfactant in mitigating this toxicity. The observations reported have important implications for the manufacture and application of AgNPs, in particular for applications involving use of aerosolised AgNPs.
  • Journal article
    Rodriguez-Lloveras X, Buytaert W, Benito G, 2016,

    Land use can offset climate change induced increases in erosion in Mediterranean watersheds

    , CATENA, Vol: 143, Pages: 244-255, ISSN: 0341-8162

    The aim of this paper is to assess the impacts of projected climate change on a Mediterranean catchment, and to analyze the effects of a suite of representative land use practices as an adaptation tool to reduce climate change-driven erosion and hydrologic extremes. Relevant climatic variables from the ERA-Interim global atmospheric reanalysis of the European Centre for Medium-Range Weather Forecasts (ECMWF) were downscaled for the study area, and perturbed with the anomalies of 23 global circulation models for three emission scenarios (B1, A1B and A2). Both a projected daily rainfall time series for the period 2010–2100, and a single precipitation event with a one-hundred year return period were used to assess the impact of climate change. The downscaled data were fed into a distributed hydro-sedimentary model (TETIS) with five land use configurations representative of future demographic tendencies, geographical characteristics and land management policies (e.g. European Union CAP). The projected changes showed a general decrease in runoff and sediment production by the end of the century regardless of land use configuration. Sediment production showed a positive relationship with an increase in agricultural land and a decrease in natural land under present day agricultural management. According to our simulations, some conservation practices in agriculture can effectively reduce net erosion while maintaining agricultural production. As such, they can play a critical role as an adaptation tool to reduce climate change impacts in the 21st century.
  • Journal article
    Kempf A, Mumford J, Levontin P, Leach A, Hoff A, Hamon KG, Bartelings H, Vinther M, Staebler M, Poos JJ, Smout S, Frost H, van den Burg S, Ulrich C, Rindorf Aet al., 2016,

    The MSY concept in a multi-objective fisheries environment - Lessons from the North Sea

    , Marine Policy, Vol: 69, Pages: 146-158, ISSN: 1872-9460

    One of the most important goals in current fisheries management is to maintain or restore stocks above levels that can produce the maximum sustainable yield (MSY). However, it may not be feasible to achieve MSY simultaneously for multiple species because of trade-offs that result from interactions between species, mixed fisheries and the multiple objectives of stakeholders. The premise in this study is that MSY is a concept that needs adaptation, not wholesale replacement. The approach chosen to identify trade-offs and stakeholder preferences involved a process of consulting and discussing options with stakeholders as well as scenario modelling with bio-economic and multi-species models. It is difficult to intuitively anticipate the consequences of complex trade-offs and it is also complicated to address them from a political point of view. However, scenario modelling showed that the current approach of treating each stock separately and ignoring trade-offs may result in unacceptable ecosystem, economic or social effects in North Sea fisheries. Setting FMSY as a management target without any flexibility for compromises may lead to disappointment for some of the stakeholders. To treat FMSY no longer as a point estimate but rather as a “Pretty Good Yield” within sustainable ranges was seen as a promising way forward to avoid unacceptable outcomes when trying to fish all stocks simultaneously at FMSY. This study gives insights on how inclusive governance can help to reach consensus in difficult political processes, and how science can be used to make informed decisions inside a multi-dimensional trade-off space.
  • Journal article
    Zhu Z, Piao S, Myneni RB, Huang M, Zeng Z, Canadell JG, Ciais P, Sitch S, Friedlingstein P, Arneth A, Cao C, Cheng L, Kato E, Koven C, Li Y, Lian X, Liu Y, Liu R, Mao J, Pan Y, Peng S, Peñuelas J, Poulter B, Pugh TAM, Stocker BD, Viovy N, Wang X, Wang Y, Xiao Z, Yang H, Zaehle S, Zeng Net al., 2016,

    Greening of the Earth and its drivers

    , Nature Climate Change, Vol: 6, Pages: 791-795, ISSN: 1758-678X

    Global environmental change is rapidly altering the dynamics of terrestrial vegetation, with consequences for the functioning of the Earth system and provision of ecosystem services1, 2. Yet how global vegetation is responding to the changing environment is not well established. Here we use three long-term satellite leaf area index (LAI) records and ten global ecosystem models to investigate four key drivers of LAI trends during 1982–2009. We show a persistent and widespread increase of growing season integrated LAI (greening) over 25% to 50% of the global vegetated area, whereas less than 4% of the globe shows decreasing LAI (browning). Factorial simulations with multiple global ecosystem models suggest that CO2 fertilization effects explain 70% of the observed greening trend, followed by nitrogen deposition (9%), climate change (8%) and land cover change (LCC) (4%). CO2 fertilization effects explain most of the greening trends in the tropics, whereas climate change resulted in greening of the high latitudes and the Tibetan Plateau. LCC contributed most to the regional greening observed in southeast China and the eastern United States. The regional effects of unexplained factors suggest that the next generation of ecosystem models will need to explore the impacts of forest demography, differences in regional management intensities for cropland and pastures, and other emerging productivity constraints such as phosphorus availability.

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