Academic publications

Search or filter publications

Filter by type:

Filter by publication type

Filter by year:

to

Results

  • Showing results for:
  • Reset all filters

Search results

  • Journal article
    Buytaert W, Dewulf A, De Bievre B, Clark J, Hannah DMet al., 2016,

    Citizen Science for Water Resources Management: Toward Polycentric Monitoring and Governance?

    , Journal of Water Resources Planning and Management, Vol: 142, ISSN: 1943-5452
  • Journal article
    Marinescu M, Zhang T, Offer G, 2016,

    A zero dimensional model of lithium-sulfur batteries during charge and discharge

    , Physical Chemistry Chemical Physics, Vol: 18, Pages: 584-593, ISSN: 1463-9076

    Lithium-sulfur cells present an attractive alternative to Li-ion batteries due to their large energy density, safety, and possible low cost. Their successful commercialisation is dependent on improving their performance, but also on acquiring sufficient understanding of the underlying mechanisms to allow for the development of predictive models for operational cells. To address the latter, we present a zero dimensional model that predicts many observed features in the behaviour of a lithium-sulfur cell during charge and discharge. The model accounts for two electrochemical reactions via the Nernst formulation, power limitations through Butler-Volmer kinetics, and precipitation/dissolution of one species, including nucleation. It is shown that the precipitation/dissolution causes the flat shape of the low voltage plateau, typical of the lithium-sulfur cell discharge. During charge, it is predicted that the dissolution can act as a bottleneck, as for large enough currents smaller amounts dissolve. This results in reduced charge capacity and an earlier onset of the high plateau reaction, such that the two plateaus merge. By including these effects, the model improves on the existing zero dimensional models, while requiring considerably fewer input parameters and computational resources. The model also predicts that, due to precipitation, the customary way of experimentally measuring the open circuit voltage from a low rate discharge might not be suitable for lithium-sulfur. This model can provide the basis for mechanistic studies, identification of dominant effects in a real cell, predictions of operational behaviour under realistic loads, and control algorithms for applications.
  • Journal article
    Hills T, Leeson D, Florin N, Fennell Pet al., 2016,

    Carbon capture in the cement industry: technologies, progress, and retrofitting

    , Environmental Science & Technology, Vol: 50, Pages: 368-377, ISSN: 0013-936X

    Several different carbon-capture technologies have been proposed for use in the cement industry. This paper reviews their attributes, the progress that has been made toward their commercialization, and the major challenges facing their retrofitting to existing cement plants. A technology readiness level (TRL) scale for carbon capture in the cement industry is developed. For application at cement plants, partial oxy-fuel combustion, amine scrubbing, and calcium looping are the most developed (TRL 6 being the pilot system demonstrated in relevant environment), followed by direct capture (TRL 4–5 being the component and system validation at lab-scale in a relevant environment) and full oxy-fuel combustion (TRL 4 being the component and system validation at lab-scale in a lab environment). Our review suggests that advancing to TRL 7 (demonstration in plant environment) seems to be a challenge for the industry, representing a major step up from TRL 6. The important attributes that a cement plant must have to be “carbon-capture ready” for each capture technology selection is evaluated. Common requirements are space around the preheater and precalciner section, access to CO2 transport infrastructure, and a retrofittable preheater tower. Evidence from the electricity generation sector suggests that carbon capture readiness is not always cost-effective. The similar durations of cement-plant renovation and capture-plant construction suggests that synchronizing these two actions may save considerable time and money.
  • Journal article
    Sule MN, Templeton MR, Bond T, 2016,

    Rejection of organic micro-pollutants from water by a tubular, hydrophilic pervaporative membrane designed for irrigation applications

    , Environmental Technology, Vol: 37, Pages: 1382-1389, ISSN: 1479-487X

    The links between chemical properties, including those relating to molecular size, solubility,hydrophobicity and vapour pressure, and rejection of model aromatic micro-pollutants by atubular, hydrophilic polymer pervaporation membrane designed for irrigation applicationswas investigated. Open air experiments were conducted at room temperature for individualsolutions of fluorene, naphthalene, phenol, 1,2-dichlorobenzene, 1,2-diethylbenzene and 2-phenoxyethanol. Percentage rejection generally increased with increased molecular size forthe model micro-pollutants (47% - 86%). Molecular weight and logKow had the strongestpositive relationships with rejection, as demonstrated by respective correlation coefficients ofr = 0.898 and 0.824. Rejection was also strongly negatively correlated with aqueoussolubility and H-bond δ. However, properties which relate to vapour phase concentrations ofthe micro-pollutants were not well correlated with rejection. Thus, physicochemicalseparation processes, rather than vapour pressure, drives removal of aromatic contaminantsby the investigated pervaporation tube. This expanded knowledge could be utilised inconsidering practical applications of pervaporative irrigation systems for treating organiccontaminatedwaters such as oilfield produced waters.
  • Journal article
    Parker SJ, Butler AP, Jackson CR, 2016,

    Seasonal and interannual behaviour of groundwater catchment boundaries in a Chalk aquifer

    , Hydrological Processes, Vol: 30, Pages: 3-11, ISSN: 1099-1085

    Groundwater catchment boundaries and their associated groundwater catchment areas are typically assumed to be fixed on a seasonal basis. We investigated whether this was true for a highly permeable carbonate aquifer in England, the Berkshire and Marlborough Downs Chalk aquifer, using both borehole hydrograph data and a physics-based distributed regional groundwater model. Borehole hydrograph data time series were used to construct a monthly interpolated water table surface, from which was then derived a monthly groundwater catchment boundary. Results from field data showed that the mean annual variation in groundwater catchment area was about 20% of the mean groundwater catchment area, but interannual variation can be very large, with the largest estimated catchment size being approximately 80% greater than the smallest. The flow in the river was also dependent on the groundwater catchment area. Model results corroborated those based on field data. These findings have significant implications for issues such as definition of source protection zones, recharge estimates based on water balance calculations and integrated conceptual modelling of surface water and groundwater systems.
  • Book
    Voulvoulis N, Barcelo D, Verlicchi P, 2016,

    Pharmaceutical Residues in Sewage Treatment Works and their Fate in the Receiving Environment

    , Publisher: ROYAL SOC CHEMISTRY, ISBN: 978-1-78262-189-8
  • Journal article
    Durance I, Bruford MW, Chalmers R, Chappell NA, Christie M, Cosby BJ, Noble D, Ormerod SJ, Prosser H, Weightman A, Woodward Get al., 2016,

    The Challenges of Linking Ecosystem Services to Biodiversity: Lessons from a Large-Scale Freshwater Study

    , Advances in Ecological Research, Vol: 54, Pages: 87-134, ISSN: 0065-2504

    There is a growing consensus that inappropriate valuation of the world's ecosystem services has historically led to widespread errors in environmental management, with associated negative social consequences. Freshwater ecosystems are prime examples: when managed appropriately, they provide major services, such as fish production, water supply, nutrient transport, health benefits and recreational value. However, these services are often compromised because they are seldom recognised explicitly in catchment use and planning. Moreover, pressures on river ecosystem services will grow as land use intensifies, water demands increase, and climate change accelerates over the coming decades.Maintaining and protecting river ecosystem services will depend increasingly on understanding the processes that underpin and degrade them, and especially in terms of characterising the roles played by the biota. While the integrity and stability of ecosystem processes tend to increase with biodiversity, how services and biodiversity are related is largely unknown, due to a range of unresolved practical and philosophical issues.We explore some of the key challenges and opportunities that lie in assessing the role of freshwater biodiversity in sustaining ecosystem services, using the recent large interdisciplinary NERC-DURESS project (www.nerc-DURESS.org) as an exemplar case study of wider issues. The conceptual and methodological challenges raised are identified, explored and a range of methods are proposed to quantify how freshwater ecoservices, such as fish production or water quality regulation, depend on river organisms, and how we might identify biodiversity thresholds under which a service is likely to be compromised. We conclude that interdisciplinary, large scale, in situ approaches like these are needed to (i) fully understand how river biodiversity sustains ecosystem services; (ii) help evaluate if, where, and how the ecosystem approach can benefit long-term resource management
  • Conference paper
    Al-Menhali A, Krevor S, 2016,

    The impact of crude oil induced wettability alteration on remaining saturations of CO<inf>2</inf> in carbonates reservoirs: A core flood method

    Oil is an essential commodity in modern economies but the magnitude of carbon emissions associated with its consumption is significantly increasing the challenges of climate change mitigations. Carbon storage is well recognized as an important technology for CO2 emissions reduction on industrial scales. Observations and modeling have shown that residual trapping of CO2 through capillary forces within the pore space of saline aquifers, characterized as water-wet, is one of the most significant mechanisms for storage security and is also a factor determining the ultimate extent of CO2 migration within the reservoir. In contrast, most of the major CO2 storage projects in operation and under construction are in depleting oil reservoirs utilizing CO2 for enhanced oil recovery (EOR). Carbon utilization and storage has a significant energy and economic benefits and is considered as an important component in achieving the widespread commercial deployment of carbon storage technology. However, there are no observations characterizing the extent of capillary trapping of CO2 in mixed-wet carbonate systems, a characteristic of most conventional oil reservoirs in the world. In this work, residual trapping of supercritical CO2 is measured in water-wet and mixed-wet carbonate systems on the same rock sample before and after wetting alteration with crude oil. In particular, CO2 trapping was characterized before and after wetting alteration so that the impact of the wetting state of the rock is observed directly. A reservoir condition core-flooding laboratory was used to make the measurements. The setup included high precision pumps, temperature control, stir reactor, the ability to recirculate fluids for weeks at a time and an X-ray computed tomography (CT) scanner. The wetted parts of the flow-loop were made of anti-corrosive material that can handle co-circulation of CO2 and brine at reservoir conditions. The measurements were made while maintaining chemical equilibrium between t
  • Conference paper
    Djabbarov S, Jones ADW, Krevor S, Muggeridge AHet al., 2016,

    Experimental and numerical studies of first contact miscible injection in a quarter five spot pattern

    Copyright 2016, Society of Petroleum Engineers. We quantify the impact of mobility, simple heterogeneities and grid orientation error on the performance of first contact miscible gas flooding in a quarter five spot configuration by comparing the outputs from experimental and numerical models. The aim is to quantify the errors that may arise during simulation and to identify a workflow for minimizing these when conducting field scale fingering studies. A commercial reservoir simulator was validated by comparing its predictions with the results obtained from physical experiments. An uncorrelated, random permeability distribution was used to trigger fingering in the simulations. The physical experiments were carried out using a Hele-Shaw cell (40x40cm) designed and constructed for this study. The impact of a square low permeability inclusion (20x20cm) on flow was investigated by varying its permeability, location and orientation. For lower mobility ratios (M=2 to M=10) the commercial numerical simulator was able to reproduce the experimental observations within the uncertainty range of the permeability distribution used to trigger the fingers, provided a nine-point scheme was used for the pressure solution. At higher mobility ratios (M=20 to M=100) the grid orientation effect meant that the simulator overestimated the areal sweep even when a nine-point scheme was used. The introduction of a square, low permeability inclusion near the injection well reduced the discrepancy between experimental and numerical results, bringing it back within uncertainty limits in some of the cases. This was mainly because the real flow was then forced to move parallel to the edges of the Hele-Shaw cell and thus parallel to the simulation grid. Breakthrough times were well predicted by the numerical simulator at all mobility ratios.
  • Book chapter
    Haigh JD, 2016,

    Blue Sky; Mirages, haloes and sundogs; Rainbows; Space Weather; Sunshine; Sunspots and Climate

    , 30-Second Meteorology: The 50 Most Significant Events and Phenomena, Each Explained in Half a Minute, Editors: Scaife, ISBN: 978-1-7824-0310-4
  • Journal article
    Guxens M, Ghassabian A, Gong T, Garcia-Esteban R, Porta D, Giorgis-Allemand L, Almqvist C, Aranbarri A, Beelen R, Badaloni C, Cesaroni G, de Nazelle A, Estarlich M, Forastiere F, Forns J, Gehring U, Ibarluzea J, Jaddoe VW, Korek M, Lichtenstein P, Nieuwenhuijsen MJ, Rebagliato M, Slama R, Tiemeier H, Verhulst FC, Volk HE, Pershagen G, Brunekreef B, Sunyer Jet al., 2016,

    Air Pollution Exposure during Pregnancy and Childhood Autistic Traits in Four European Population-Based Cohort Studies: The ESCAPE Project.

    , Environmental Health Perspectives, Vol: 124, Pages: 133-140, ISSN: 1552-9924

    BACKGROUND: Prenatal exposure to air pollutants has been suggested as a possible etiologic factor for the occurrence of autism spectrum disorder. OBJECTIVES: We aimed to assess whether prenatal air pollution exposure is associated with childhood autistic traits in the general population. METHODS: Ours was a collaborative study of four European population-based birth/child cohorts-CATSS (Sweden), Generation R (the Netherlands), GASPII (Italy), and INMA (Spain). Nitrogen oxides (NO2, NOx) and particulate matter (PM) with diameters of ≤ 2.5 μm (PM2.5), ≤ 10 μm (PM10), and between 2.5 and 10 μm (PMcoarse), and PM2.5 absorbance were estimated for birth addresses by land-use regression models based on monitoring campaigns performed between 2008 and 2011. Levels were extrapolated back in time to exact pregnancy periods. We quantitatively assessed autistic traits when the child was between 4 and 10 years of age. Children were classified with autistic traits within the borderline/clinical range and within the clinical range using validated cut-offs. Adjusted cohort-specific effect estimates were combined using random-effects meta-analysis. RESULTS: A total of 8,079 children were included. Prenatal air pollution exposure was not associated with autistic traits within the borderline/clinical range (odds ratio = 0.94; 95% CI: 0.81, 1.10 per each 10-μg/m3 increase in NO2 pregnancy levels). Similar results were observed in the different cohorts, for the other pollutants, and in assessments of children with autistic traits within the clinical range or children with autistic traits as a quantitative score. CONCLUSIONS: Prenatal exposure to NO2 and PM was not associated with autistic traits in children from 4 to 10 years of age in four European population-based birth/child cohort studies. CITATION: Guxens M, Ghassabian A, Gong T, Garcia-Esteban R, Porta D, Giorgis-Allemand L, Almqvist C, Aranbarri A, Beelen R, Badaloni C, Cesaroni G, de Nazelle A, Estarlich M, Fora
  • Journal article
    Alhajaj A, Mac Dowell N, Shah N, 2016,

    A techno-economic analysis of post-combustion CO2 capture and compression applied to a combined cycle gas turbine: Part I. A parametric study of the key technical performance indicators

    , International Journal of Greenhouse Gas Control, Vol: 44, Pages: 26-41, ISSN: 1750-5836

    In order to mitigate significant capital expenditure and parasitic energy demands associated with post combustion capture plant, many studies focused on improving its performance and efficiency through improvement in the design, integration of utilities and selection of key operating parameters (KOPs) using various key performance indicators (KPIs). In this study, an equilibrium monoethanolamine-based CO2 capture plant and compression train model was developed, validated and then used to assess the effects of KOPs on the performance of the CO2 capture and compression process applied to a 400 MWe combined cycle gas turbine (CCGT) power plant in hot countries using selected non-monetized key economic and environmental performance indicators. These were selected so as to allow performance comparisons without resorting to economic assumptions (e.g., discount rates, costs of energy), which make such comparisons difficult. The results illustrate higher compression power and dramatic increase of cooling water requirements in coolers and washing water systems in hot countries. This work elucidates the complex compromise between minimizing capital and operating expenditure indicators, and environmental impacts. It highlights the importance of considering the whole process, as opposed to simply focusing on the energy penalty associated with solvent regeneration.
  • Journal article
    Gerike R, de Nazelle A, Nieuwenhuijsen M, Panis LI, Anaya E, Avila-Palencia I, Boschetti F, Brand C, Cole-Hunter T, Dons E, Eriksson U, Gaupp-Berghausen M, Kahlmeier S, Laeremans M, Mueller N, Orjuela JP, Racioppi F, Raser E, Rojas-Rueda D, Schweizer C, Standaert A, Uhlmann T, Wegener S, Goetschi Tet al., 2016,

    Physical Activity through Sustainable Transport Approaches (PASTA): a study protocol for a multicentre project

    , BMJ Open, Vol: 6, ISSN: 2044-6055
  • Journal article
    Sherman P, van Sebille E, 2016,

    Modeling marine surface microplastic transport to assess optimal removal locations

    , Environmental Research Letters, Vol: 11, ISSN: 1748-9326

    Marine plastic pollution is an ever-increasing problem that demands immediate mitigation and reduction plans. Here, a model based on satellite-tracked buoy observations and scaled to a large data set of observations on microplastic from surface trawls was used to simulate the transport of plastics floating on the ocean surface from 2015 to 2025, with the goal to assess the optimal marine microplastic removal locations for two scenarios: removing the most surface microplastic and reducing the impact on ecosystems, using plankton growth as a proxy. The simulations show that the optimal removal locations are primarily located off the coast of China and in the Indonesian Archipelago for both scenarios. Our estimates show that 31% of the modeled microplastic mass can be removed by 2025 using 29 plastic collectors operating at a 45% capture efficiency from these locations, compared to only 17% when the 29 plastic collectors are moored in the North Pacific garbage patch, between Hawaii and California. The overlap of ocean surface microplastics and phytoplankton growth can be reduced by 46% at our proposed locations, while sinks in the North Pacific can only reduce the overlap by 14%. These results are an indication that oceanic plastic removal might be more effective in removing a greater microplastic mass and in reducing potential harm to marine life when closer to shore than inside the plastic accumulation zones in the centers of the gyres.
  • Journal article
    Hoque MA, Butler AP, 2016,

    Medical Hydrogeology of Asian Deltas: Status of Groundwater Toxicants and Nutrients, and Implications for Human Health

    , International Journal of Environmental Research and Public Health, Vol: 13, ISSN: 1660-4601

    Drinking water, a fluid primarily for human hydration, is also a source of mineral nutrients. Groundwater, a drinking water source for more than 70% of inhabitants living in Asian deltas, has received much attention because of its naturally occurring arsenic, but the linkage of arsenic toxicity with other water constituents has not been studied. In addition, although nutrients are generally provided by food, in under developed rural settings, where people subsist on low nutrient diets, drinking-water-nutrients may supply quantities critical to human health thereby preventing diseases. Here, we show, using augmented datasets from three Asian deltas (Bengal, Mekong, and Red River), that the chemical content of groundwater is so substantial that in some areas individuals obtain up to 50% or more of the recommended daily intake (RDI) of some nutrients (e.g. calcium, magnesium, iron) from just 2 litres of drinking water. We also show some indications of a spatial association of groundwater nutrients and health outcome using demographic health data from Bangladesh. We therefore suggest that an understanding of the association of non-communicable disease and poor nutrition cannot be developed, particularly in areas with high levels of dissolved solids in water sources, without considering the contribution of drinking water to nutrient and mineral supply.
  • Journal article
    Ypma SL, van Sebille E, Kiss AE, Spence Pet al., 2016,

    The separation of the East Australian Current: A Lagrangian approach to potential vorticity and upstream control

    , Journal of Geophysical Research: Oceans, Vol: 121, Pages: 758-774, ISSN: 2169-9291

    The East Australian Current (EAC) is the western boundary current flowing along the east coast of Australia separating from the coast at approximately 34°S. After the separation two main pathways can be distinguished, the eastward flowing Tasman Front and the extension of the EAC flowing southward. The area south of the separation latitude is eddy-rich and the separation latitude of the EAC is variable. Little is known of the properties of the water masses that separate at the bifurcation of the EAC. This paper presents new insights from the Lagrangian perspective, where the water masses that veer east and those that continue south are tracked in an eddy-permitting numerical model. The transport along the two pathways is computed, and a 1:3 ratio between transport in the EAC extension and transport in the Tasman Front is found. The results show that the “fate” of the particles is to first order already determined by the particle distribution within the EAC current upstream of the separation latitude, where 85% of the particles following the EAC extension originate from below 460 m and 90% of the particles following the Tasman Front originate from the top 460 m depth at 28°S. The separation and pathways are controlled by the structure of the isopycnals in this region. Analysis of anomalies in potential vorticity show that in the region where the two water masses overlap, the fate of the water depends on the presence of anticyclonic eddies that push isopycnals down and therefore enable particles to travel further south.
  • Journal article
    Aitken ARA, Betts PG, Young DA, Blankenship DD, Roberts JL, Siegert MJet al., 2016,

    The Australo-Antarctic Columbia to Gondwana transition

    , Gondwana Research, Vol: 29, Pages: 136-152, ISSN: 1342-937X

    From the Mesoproterozoic to Cambrian, Australo-Antarctica was characterised by tectonic reconfiguration as part of the supercontinents Columbia, Rodinia and Gondwana. New tectonic knowledge of the Wilkes Land region of Antarctica allows Australo-Antarctic tectonic linkages to be resolved through reconstruction into ca. 160 Ma Gondwana. We also resolve 330 ± 30 km of sinistral strike-slip offset on the > 3000 km long Mundrabilla-Frost Shear Zone and 260 ± 20 km of dextral offset on the > 1000 km long Aurora Fault to reconstruct the ca. 1150 Ma geometry of Australo-Antarctica. Using this revised geometry, we derive the first model of the Columbia to Gondwana reconfiguration process that is geometrically constrained to ~ 100 km scale. In this model, early Mesoproterozoic tectonics is driven by two opposing subduction systems. A dominantly west-dipping subduction zone existed at the eastern margin of Australo-Antarctica until ca. 1.55–1.50 Ga. A predominantly east-dipping subduction zone operated at the western margin of the Mawson Craton from ca. 1.70 Ga to ca. 1.42 Ga. The latter caused gradual westwards motion and clockwise rotation of the Mawson Craton relative to the West and North Australian Craton and the accretion of a series of continental ribbons now preserved in the Musgrave Province and its southern extensions. A mid-Mesoproterozoic switch to predominantly west-dipping subduction beneath the West Australian Craton brought about the final closure of the Mawson Craton with the North and West Australian Craton along the Rodona-Totten Shear Zone. Convergence was achieved prior to 1.31 Ga, but final collision may not have occurred until ca. 1.29 Ga. Post-1.29 Ga intraplate activity involved prolonged high-temperature orogenesis from 1.22 to 1.12 Ga, and significant movement on the Mundrabilla-Frost Shear Zone between 1.13 and 1.09 Ga, perhaps in response to the assembly of Rodinia at ca. 1.1 Ga. The Australo-Antarctic Craton was amalgama
  • Journal article
    Vanniere B, Czaja A, Dacre H, Woollings T, Parfitt Ret al., 2016,

    A Potential Vorticity Signature for the Cold Sector of Winter Extratropical Cyclones

    , Quarterly Journal of the Royal Meteorological Society, Vol: 142, Pages: 432-442, ISSN: 1477-870X

    The cold sector of mid-latitude storms is characterised by distinctive features such as strong surface heat fluxes, shallow convection, convective precipitation and synoptic subsidence. In order to evaluate the contribution of processes occurring in the cold sector to the mean climate, an appropriate indicator is needed. This study describes the systematic presence of negative PV behind the cold front of extratropical storms in winter. The origin of this negative PV is analysed using ERA-Interim data, potential vorticity tendencies averaged over the depth of the boundary layer are evaluated. It is found that negative PV is generated by diabatic processes in the cold sector and by Ekman pumping at the low centre, whereas positive PV is generated by Ekman advection of potential temperature in the warm sector. We suggest here that the negative PV at low-levels can be used to identify the cold sector. A PV-based indicator is applied to estimate the respective contributions of the cold sector and the remainder of the storm to upward motion, and large scale and convective precipitation. We compare the PV-based indicator with other distinctive features that could be used as markers of the cold sector, and find that potential vorticity is the best criterion when taken alone, and the best when combined with any other.
  • Journal article
    Halonen JI, Blangiardo M, Toledano MB, Fecht D, Gulliver J, Anderson HR, Beevers SD, Dajnak D, Kelly F, Tonne Cet al., 2016,

    Long-term exposure to traffic pollution and hospital admissions in London

    , Environmental pollution, Vol: 208, Pages: 48-57, ISSN: 1873-6424
  • Journal article
    De Kauwe MG, Lin Y-S, Wright IJ, Medlyn BE, Crous KY, Ellsworth DS, Maire V, Prentice IC, Atkin OK, Rogers A, Niinemets U, Serbin SP, Meir P, Uddling J, Togashi HF, Tarvainen L, Weerasinghe LK, Evans BJ, Ishida FY, Domingues TFet al., 2015,

    A test of the 'one-point method' for estimating maximum carboxylation capacity from field-measured, light-saturated photosynthesis

    , New Phytologist, Vol: 210, Pages: 1130-1144, ISSN: 1469-8137
  • Journal article
    Diaz S, Kattge J, Cornelissen JHC, Wright IJ, Lavorel S, Dray S, Reu B, Kleyer M, Wirth C, Prentice IC, Garnier E, Boenisch G, Westoby M, Poorter H, Reich PB, Moles AT, Dickie J, Gillison AN, Zanne AE, Chave J, Wright SJ, Sheremet'ev SN, Jactel H, Baraloto C, Cerabolini B, Pierce S, Shipley B, Kirkup D, Casanoves F, Joswig JS, Guenther A, Falczuk V, Rueger N, Mahecha MD, Gorne LDet al., 2015,

    The global spectrum of plant form and function

    , Nature, Vol: 529, Pages: 167-U73, ISSN: 0028-0836

    Earth is home to a remarkable diversity of plant forms and life histories, yet comparatively few essential trait combinations have proved evolutionarily viable in today’s terrestrial biosphere. By analysing worldwide variation in six major traits critical to growth, survival and reproduction within the largest sample of vascular plant species ever compiled, we found that occupancy of six-dimensional trait space is strongly concentrated, indicating coordination and trade-offs. Three-quarters of trait variation is captured in a two-dimensional global spectrum of plant form and function. One major dimension within this plane reflects the size of whole plants and their parts; the other represents the leaf economics spectrum, which balances leaf construction costs against growth potential. The global plant trait spectrum provides a backdrop for elucidating constraints on evolution, for functionally qualifying species and ecosystems, and for improving models that predict future vegetation based on continuous variation in plant form and function.
  • Journal article
    Jamieson SSR, Ross N, Greenbaum JS, Young DA, Aitken ARA, Roberts JL, Blankenship DD, Bo S, Siegert MJet al., 2015,

    An extensive subglacial lake and canyon system in Princess Elizabeth Land, East Antarctica

    , Geology, Vol: 44, Pages: 87-90, ISSN: 1943-2682

    The subglacial landscape of Princess Elizabeth Land (PEL) in East Antarctica is poorly known due to a paucity of ice thickness measurements. This is problematic given its importance for understanding ice sheet dynamics and landscape and climate evolution. To address this issue, we describe the topography beneath the ice sheet by assuming that ice surface expressions in satellite imagery relate to large-scale subglacial features. We find evidence that a large, previously undiscovered subglacial drainage network is hidden beneath the ice sheet in PEL. We interpret a discrete feature that is 140 × 20 km in plan form, and multiple narrow sinuous features that extend over a distance of ∼1100 km. We hypothesize that these are tectonically controlled and relate to a large subglacial basin containing a deep-water lake in the interior of PEL linked to a series of long, deep canyons. The presence of 1-km-deep canyons is confirmed at a few localities by radio-echo sounding data, and drainage analysis suggests that these canyons will direct subglacial meltwater to the coast between the Vestfold Hills and the West Ice Shelf.
  • Journal article
    Oostrom M, White MD, Porse SL, Krevor SCM, Mathias SAet al., 2015,

    Comparison of relative permeability-saturation-capillary pressure models for simulation of reservoir CO2 injection

    , International Journal of Greenhouse Gas Control, Vol: 45, Pages: 70-85, ISSN: 1750-5836

    Constitutive relations between relative permeability (kr), fluid saturation (S), and capillary pressure (Pc) determine to a large extent the distribution of brine and supercritical CO2 (scCO2) during subsurface injection operations. Published numerical multiphase simulations for brine-scCO2 systems so far have primarily used four kr-S-Pc models. For the S-Pc relations, either the Brooks-Corey (BC) or Van Genuchten (VG) equations are used. The kr-S relations are based on Mualem, Burdine, or Corey equations without the consideration of experimental data. Recently, two additional models have been proposed where the kr-S relations are obtained by fitting to experimental data using either an endpoint power law or a modified Corey approach. The six models were tested using data from four well-characterized sandstones (Berea, Paaratte, Tuscaloosa, Mt. Simon) for two radial injection test cases. The results show a large variation in plume extent and saturation distribution for each of the sandstones, depending on the used model. The VG-Mualem model predicts plumes that are considerably larger than for the other models due to the overestimation of the gas relative permeability. The predicted plume sizes are the smallest for the VG-Corey model due to the underestimation of the aqueous phase relative permeability. Of the four models that do not use fits to experimental relative permeability data, the hybrid model with Mualem aqueous phase and Corey gas phase relative permeabilities provide the best fits to the experimental data and produce results close to the model with fits to the capillary pressure and relative permeability data. The model with the endpoint power law resulted in very low, uniform gas saturations outside the dry-out zone for the Tuscaloosa sandstone, as the result of a rapidly declining aqueous phase relative permeability. This observed behavior illustrates the need to obtain reliable relative permeability relations for a potential reservoir, beyond permeabi
  • Journal article
    Parkes MA, Chen T, Wu B, Yufit V, Offer GJet al., 2015,

    “can” you really make a battery out of that?

    , Journal of Chemical Education, Vol: 93, Pages: 681-686, ISSN: 1938-1328

    This classroom activity introduces students to battery electrochemistry through the construction of a simple battery made from household products. Students will use a set of simple design rules to improve the performance of the battery, and power a light emitting diode. The electrochemical performance of the batteries is characterized using potentiostatic cyclic voltammetry and chronoampometry, and suggestions for implementing this activity into a high school teaching environment are presented. Designed for United Kingdom secondary schools and exam boards, the supplementary teaching package contains problem sheets and activities appropriate for students age 14 and up.
  • Journal article
    De Kauwe MG, Zhou S-X, Medlyn BE, Pitman AJ, Wang Y-P, Duursma RA, Prentice ICet al., 2015,

    Do land surface models need to include differential plant species responses to drought? Examining model predictions across a mesic-xeric gradient in Europe

    , Biogeosciences, Vol: 12, Pages: 7503-7518, ISSN: 1726-4189

    Future climate change has the potential to increase drought in many regions of the globe, making it essential that land surface models (LSMs) used in coupled climate models realistically capture the drought responses of vegetation. Recent data syntheses show that drought sensitivity varies considerably among plants from different climate zones, but state-of-the-art LSMs currently assume the same drought sensitivity for all vegetation. We tested whether variable drought sensitivities are needed to explain the observed large-scale patterns of drought impact on the carbon, water and energy fluxes. We implemented data-driven drought sensitivities in the Community Atmosphere Biosphere Land Exchange (CABLE) LSM and evaluated alternative sensitivities across a latitudinal gradient in Europe during the 2003 heatwave. The model predicted an overly abrupt onset of drought unless average soil water potential was calculated with dynamic weighting across soil layers. We found that high drought sensitivity at the most mesic sites, and low drought sensitivity at the most xeric sites, was necessary to accurately model responses during drought. Our results indicate that LSMs will over-estimate drought impacts in drier climates unless different sensitivity of vegetation to drought is taken into account.
  • Conference paper
    Jacobs CT, Avdis A, Mouradian SL, Piggott MDet al., 2015,

    Integrating Research Data Management into Geographical Information Systems

    , http://ceur-ws.org/Vol-1529/, 5th International Workshop on Semantic Digital Archives (SDA 2015), Pages: 7-17

    Ocean modelling requires the production of high-fidelity computational 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 associated 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 research 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 assigned unique identifiers to enable proper citation of the meshes in journal articles.
  • Journal article
    Barraclough TG, Lawrence D, Bell T, 2015,

    The effect of immigration on the adaptation of microbial communities to warming

    , American Naturalist, Vol: 187, ISSN: 1537-5323

    Theory predicts that immigration can either enhance or impair the rate at which species and whole communities adapt to environmental change, depending on the traits of genotypes and species in the source pool relative to local conditions. These responses in turn will determine how well whole communities function in changing environments. We tested the effects of immigration and experimental warming on microbial communities during an 81 day field experiment. The effects of immigration depended on the warming treatment. In warmed communities immigration was detrimental to community growth whereas in ambient communities it was beneficial. This result is explained if colonists came from a local species pool pre-adapted to ambient conditions. Loss of metabolic diversity, however, was buffered by immigration in both environments. Communities showed increasing local adaptation to temperature conditions during the experiment and this was independent of whether or not they received immigration. Genotypes that comprised the communities were not locally adapted, however, indicating that community local adaptation can be independent of adaptation of component genotypes. Our results are consistent with a greater role for species interactions rather than adaptation of constituent species in determining local adaptation of whole communities, and confirm that immigration can either enhance or impair community responses to environmental change depending on the environmental context.
  • Journal article
    Siegert MJ, Priscu JC, Alekhina IA, Wadham JL, Lyons WBet al., 2015,

    Antarctic subglacial lake exploration: first results and future plans

    , Journal: Philosophical Transactions A: Mathematical, Physical and Engineering Sciences, Vol: 374, ISSN: 1471-2962

    After more than a decade of planning, three attempts were made in 2012–2013 to access, measure in situ properties and directly sample subglacial Antarctic lake environments. First, Russian scientists drilled into the top of Lake Vostok, allowing lake water to infiltrate, and freeze within, the lower part of the ice-core borehole, from which further coring would recover a frozen sample of surface lake water. Second, UK engineers tried unsuccessfully to deploy a clean-access hot-water drill, to sample the water column and sediments of subglacial Lake Ellsworth. Third, a US mission successfully drilled cleanly into subglacial Lake Whillans, a shallow hydraulically active lake at the coastal margin of West Antarctica, obtaining samples that would later be used to prove the existence of microbial life and active biogeochemical cycling beneath the ice sheet. This article summarizes the results of these programmes in terms of the scientific results obtained, the operational knowledge gained and the engineering challenges revealed, to collate what is known about Antarctic subglacial environments and how to explore them in future. While results from Lake Whillans testify to subglacial lakes as being viable biological habitats, the engineering challenges to explore deeper more isolated lakes where unique microorganisms and climate records may be found, as exemplified in the Lake Ellsworth and Vostok missions, are considerable. Through international cooperation, and by using equipment and knowledge of the existing subglacial lake exploration programmes, it is possible that such environments could be explored thoroughly, and at numerous sites, in the near future.
  • Journal article
    Pearce DA, Magiopoulos I, Mowlem M, Tranter M, Holt G, Woodward J, Siegert MJet al., 2015,

    Microbiology: lessons from a first attempt at Lake Ellsworth

    , Philosophical Transactions A: Mathematical, Physical and Engineering Sciences, Vol: 374, ISSN: 1364-503X

    During the attempt to directly access, measure and sample Subglacial Lake Ellsworth in 2012–2013, we conducted microbiological analyses of the drilling equipment, scientific instrumentation, field camp and natural surroundings. From these studies, a number of lessons can be learned about the cleanliness of deep Antarctic subglacial lake access leading to, in particular, knowledge of the limitations of some of the most basic relevant microbiological principles. Here, we focus on five of the core challenges faced and describe how cleanliness and sterilization were implemented in the field. In the light of our field experiences, we consider how effective these actions were, and what can be learnt for future subglacial exploration missions. The five areas covered are: (i) field camp environment and activities, (ii) the engineering processes surrounding the hot water drilling, (iii) sample handling, including recovery, stability and preservation, (iv) clean access methodologies and removal of sample material, and (v) the biodiversity and distribution of bacteria around the Antarctic. Comparisons are made between the microbiology of the Lake Ellsworth field site and other Antarctic systems, including the lakes on Signy Island, and on the Antarctic Peninsula at Lake Hodgson. Ongoing research to better define and characterize the behaviour of natural and introduced microbial populations in response to deep-ice drilling is also discussed. We recommend that future access programmes: (i) assess each specific local environment in enhanced detail due to the potential for local contamination, (ii) consider the sterility of the access in more detail, specifically focusing on single cell colonization and the introduction of new species through contamination of pre-existing microbial communities, (iii) consider experimental bias in methodological approaches, (iv) undertake in situ biodiversity detection to mitigate risk of non-sample return and post-sample contamination, and (
  • Journal article
    Ross N, Le Brocq AM, Siegert MJ, 2015,

    Recent advances in understanding Antarctic subglacial lakes and hydrology

    , Journal: Philosophical Transactions A: Mathematical, Physical and Engineering Sciences, Vol: 374, ISSN: 1471-2962

    It is now well documented that over 400 subglacial lakes exist across the bed of the Antarctic Ice Sheet. They comprise a variety of sizes and volumes (from the approx. 250 km long Lake Vostok to bodies of water less than 1 km in length), relate to a number of discrete topographic settings (from those contained within valleys to lakes that reside in broad flat terrain) and exhibit a range of dynamic behaviours (from ‘active’ lakes that periodically outburst some or all of their water to those isolated hydrologically for millions of years). Here we critique recent advances in our understanding of subglacial lakes, in particular since the last inventory in 2012. We show that within 3 years our knowledge of the hydrological processes at the ice-sheet base has advanced considerably. We describe evidence for further ‘active’ subglacial lakes, based on satellite observation of ice-surface changes, and discuss why detection of many ‘active’ lakes is not resolved in traditional radio-echo sounding methods. We go on to review evidence for large-scale subglacial water flow in Antarctica, including the discovery of ancient channels developed by former hydrological processes. We end by predicting areas where future discoveries may be possible, including the detection, measurement and significance of groundwater (i.e. water held beneath the ice-bed interface).

This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.

Request URL: http://wwwtest.imperial.ac.uk:80/respub/WEB-INF/jsp/search-t4-html.jsp Request URI: /respub/WEB-INF/jsp/search-t4-html.jsp Query String: id=278&limit=30&page=12&respub-action=search.html Current Millis: 1759613445521 Current Time: Sat Oct 04 22:30:45 BST 2025