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Journal articlePfeifer M, Kor L, Nilus R, et al., 2016,
Mapping the structure of Borneo's tropical forests across a degradation gradient
, Remote Sensing of Environment, Vol: 176, Pages: 84-97, ISSN: 0034-4257South East Asia has the highest rate of lowland forest loss of any tropical region, with logging and deforestation for conversion to plantation agriculture being flagged as the most urgent threats. Detecting and mapping logging impacts on forest structure is a primary conservation concern, as these impacts feed through to changes in biodiversity and ecosystem functions. Here, we test whether high-spatial resolution satellite remote sensing can be used to map the responses of aboveground live tree biomass (AGB), canopy leaf area index (LAI) and fractional vegetation cover (FCover) to selective logging and deforestation in Malaysian Borneo. We measured these attributes in permanent vegetation plots in rainforest and oil palm plantations across the degradation landscape of the Stability of Altered Forest Ecosystems project. We found significant mathematical relationships between field-measured structure and satellite-derived spectral and texture information, explaining up to 62% of variation in biophysical structure across forest and oil palm plots. These relationships held at different aggregation levels from plots to forest disturbance types and oil palms allowing us to map aboveground biomass and canopy structure across the degradation landscape. The maps reveal considerable spatial variation in the impacts of previous logging, a pattern that was less clear when considering field data alone. Up-scaled maps revealed a pronounced decline in aboveground live tree biomass with increasing disturbance, impacts which are also clearly visible in the field data even a decade after logging. Field data demonstrate a rapid recovery in forest canopy structure with the canopy recovering to pre-disturbance levels a decade after logging. Yet, up-scaled maps show that both LAI and FCover are still reduced in logged compared to primary forest stands and markedly lower in oil palm stands. While uncertainties remain, these maps can now be utilised to identify conservation win–win
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Journal articleGallego-Sala AV, Charman DJ, Harrison SP, et al., 2016,
Climate-driven expansion of blanket bogs in Britain during the Holocene
, Climate of the Past, Vol: 12, Pages: 129-136, ISSN: 1814-9332Blanket bog occupies approximately 6 % of the area of the UK today. The Holocene expansion of this hyperoceanic biome has previously been explained as a consequence of Neolithic forest clearance. However, the present distribution of blanket bog in Great Britain can be predicted accurately with a simple model (PeatStash) based on summer temperature and moisture index thresholds, and the same model correctly predicts the highly disjunct distribution of blanket bog worldwide. This finding suggests that climate, rather than land-use history, controls blanket-bog distribution in the UK and everywhere else. We set out to test this hypothesis for blanket bogs in the UK using bioclimate envelope modelling compared with a database of peat initiation age estimates. We used both pollen-based reconstructions and climate model simulations of climate changes between the mid-Holocene (6000 yr BP, 6 ka) and modern climate to drive PeatStash and predict areas of blanket bog. We compiled data on the timing of blanket-bog initiation, based on 228 age determinations at sites where peat directly overlies mineral soil. The model predicts that large areas of northern Britain would have had blanket bog by 6000 yr BP, and the area suitable for peat growth extended to the south after this time. A similar pattern is shown by the basal peat ages and new blanket bog appeared over a larger area during the late Holocene, the greatest expansion being in Ireland, Wales, and southwest England, as the model predicts. The expansion was driven by a summer cooling of about 2 °C, shown by both pollen-based reconstructions and climate models. The data show early Holocene (pre-Neolithic) blanket-bog initiation at over half of the sites in the core areas of Scotland and northern England. The temporal patterns and concurrence of the bioclimate model predictions and initiation data suggest that climate change provides a parsimonious explanation for the early Holocene distribution and later expansion of bl
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Journal articleZulkafli Z, Buytaert W, Manz B, et al., 2016,
Projected increases in the annual flood pulse of the western Amazon
, Environmental Research Letters, Vol: 11, ISSN: 1748-9326The impact of a changing climate on the Amazon basin is a subjectof intensive research because of its rich biodiversity and the significant role ofrainforests in carbon cycling. Climate change has also a direct hydrological impact,and increasing efforts have focused on understanding the hydrological dynamics atcontinental and subregional scales, such as the western Amazon. New projectionsfrom the Coupled Model Inter-comparison Project Phase 5 (CMIP5) ensemble indicateconsistent climatic warming and increasing seasonality of precipitation in the PeruvianAmazon basin. Here we use a distributed land surface model to quantify the potentialimpact of this change in the climate on the hydrological regime of the upper Amazonriver. Using extreme value analysis, historical and future projections of the annualminimum, mean, and maximum river flows are produced for a range of return periodsbetween 1 and 100 years. We show that the RCP 4.5 and 8.5 scenarios of climatechange project an increased severity of the wet season flood pulse (7.5% and 12%increases respectively for the 100-year return floods). These findings agree withpreviously projected increases in high extremes under the Special Report on EmissionsScenarios climate projections, and are important to highlight due to the potentialconsequences on reproductive processes of in-stream species, swamp forest ecology,and socio-economy in the floodplain, amidst a growing literature that more stronglyemphasises future droughts and their impact on the viability of the rainforest systemover greater Amazonia
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Journal articleMaimoun M, Madani K, Reinhart D, 2016,
Multi-level multi-criteria analysis of alternative fuels for waste collection vehicles in the United States
, Science of the Total Environment, Vol: 550, Pages: 349-361, ISSN: 0048-9697Historically, the U.S. waste collection fleet was dominated by diesel-fueled waste collection vehicles (WCVs); the growing need for sustainable waste collection has urged decision makers to incorporate economically efficient alternative fuels, while mitigating environmental impacts. The pros and cons of alternative fuels complicate the decisions making process, calling for a comprehensive study that assesses the multiple factors involved. Multi-criteria decision analysis (MCDA) methods allow decision makers to select the best alternatives with respect to selection criteria. In this study, two MCDA methods, Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) and Simple Additive Weighting (SAW), were used to rank fuel alternatives for the U.S. waste collection industry with respect to a multi-level environmental and financial decision matrix. The environmental criteria consisted of life-cycle emissions, tail-pipe emissions, water footprint (WFP), and power density, while the financial criteria comprised of vehicle cost, fuel price, fuel price stability, and fueling station availability. The overall analysis showed that conventional diesel is still the best option, followed by hydraulic-hybrid WCVs, landfill gas (LFG) sourced natural gas, fossil natural gas, and biodiesel. The elimination of the WFP and power density criteria from the environmental criteria ranked biodiesel 100 (BD100) as an environmentally better alternative compared to other fossil fuels (diesel and natural gas). This result showed that considering the WFP and power density as environmental criteria can make a difference in the decision process. The elimination of the fueling station and fuel price stability criteria from the decision matrix ranked fossil natural gas second after LFG-sourced natural gas. This scenario was found to represent the status quo of the waste collection industry. A sensitivity analysis for the status quo scenario showed the overall ranking of diesel and f
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Journal articleAng CP, Toper B, Gambhir A, 2016,
Financial impacts of UK's energy and climate change policies on commercial and industrial businesses
, Energy Policy, Vol: 91, Pages: 273-286, ISSN: 1873-6777 -
Journal articleHoogakker BAA, Smith RS, Singarayer JS, et al., 2016,
Terrestrial biosphere changes over the last 120 kyr
, Climate of the Past, Vol: 12, Pages: 51-73, ISSN: 1814-9332A new global synthesis and biomization of long (> 40 kyr) pollen-data records is presented and used with simulations from the HadCM3 and FAMOUS climate models and the BIOME4 vegetation model to analyse the dynamics of the global terrestrial biosphere and carbon storage over the last glacial–interglacial cycle. Simulated biome distributions using BIOME4 driven by HadCM3 and FAMOUS at the global scale over time generally agree well with those inferred from pollen data. Global average areas of grassland and dry shrubland, desert, and tundra biomes show large-scale increases during the Last Glacial Maximum, between ca. 64 and 74 ka BP and cool substages of Marine Isotope Stage 5, at the expense of the tropical forest, warm-temperate forest, and temperate forest biomes. These changes are reflected in BIOME4 simulations of global net primary productivity, showing good agreement between the two models. Such changes are likely to affect terrestrial carbon storage, which in turn influences the stable carbon isotopic composition of seawater as terrestrial carbon is depleted in 13C.
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Journal articleLe Vine N, Butler A, McIntyre N, et al., 2016,
Diagnosing hydrological limitations of a land surface model: application of JULES to a deep-groundwater chalk basin
, Hydrology and Earth System Sciences, Vol: 20, Pages: 143-159, ISSN: 1027-5606Land surface models (LSMs) are prospective starting points to develop a global hyper-resolution model of the terrestrial water, energy, and biogeochemical cycles. However, there are some fundamental limitations of LSMs related to how meaningfully hydrological fluxes and stores are represented. A diagnostic approach to model evaluation and improvement is taken here that exploits hydrological expert knowledge to detect LSM inadequacies through consideration of the major behavioural functions of a hydrological system: overall water balance, vertical water redistribution in the unsaturated zone, temporal water redistribution, and spatial water redistribution over the catchment's groundwater and surface-water systems. Three types of information are utilized to improve the model's hydrology: (a) observations, (b) information about expected response from regionalized data, and (c) information from an independent physics-based model. The study considers the JULES (Joint UK Land Environmental Simulator) LSM applied to a deep-groundwater chalk catchment in the UK. The diagnosed hydrological limitations and the proposed ways to address them are indicative of the challenges faced while transitioning to a global high resolution model of the water cycle.
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Journal articleVire A, Spinneken J, Piggott MD, et al., 2016,
Application of the immersed-body method to simulatewave–structure interactions
, European Journal of Mechanics B: Fluids, Vol: 55, Pages: 330-339, ISSN: 1873-7390This study aims at demonstrating the capability of the immersed-body method to simulate wave–structure interactions using a non-linear finite-element model. In this approach, the Navier–Stokes equations are solved on an extended mesh covering the whole computational domain (i.e. fluids and structure). The structure is identified on the extended mesh through a nonzero solid-concentration field, which is obtained by conservatively mapping the mesh discretising the structure onto the extended mesh. A penalty term relaxes the fluid and structural velocities to one another in the regions covered by the structure. The paper is novel in that it combines the immersed-body method with wave modelling and mesh adaptivity. The focus of the paper is therefore on demonstrating the capability of this new methodology in reproducing well-established test cases, rather than investigating new physical phenomena in wave–structure interactions. Two cases are considered for a bottom-mounted pile. First, the pile is placed in a numerical wave tank, where propagating waves are modelled through a free-surface boundary condition. For regular and irregular waves, it is shown that the wave dynamics are accurately modelled by the computational fluid dynamics model and only small discrepancies are observed in the close vicinity of the structure. Second, the structure is subjected to a dam-break wave impact obtained by removing a barrier between air and water. In that case, an additional advection equation is solved for a fluid-concentration field that tracks the evolution of the air–water interface. It is shown that the load associated with the wave impact on the structure compares well with existing numerical and experimental data.
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Journal articleMetz A, Darch G, Workman M, 2016,
Realising a climate-resilient UK electricity and gas system
, Proceedings of the Institution of Civil Engineers - Energy, Vol: 169, Pages: 30-43, ISSN: 1751-4223The risks presented by climate change mean that there is a need to future-proof the UK's energy (electricity and natural gas) infrastructure. The scale of investment required is estimated at more than £200 billion by 2030. Although there are a variety of funding sources available, increasing proportions of infrastructure investment are now being funded by the private sector. Therefore, it will be necessary to find ways to incentivise private investors to accommodate for adaptation requirements in their decision-making processes. Research was undertaken to explore the UK energy infrastructure under the following three main lenses. (a) What technical aspects of energy infrastructure need to consider the effects of climate change? (b) What investment is required in the near future to adapt to climate change? (c) What types of policy could create reliable signals for investment in climate change adaptation? This paper presents key findings and considerations for policy covering the three questions above: (a) there are data gaps, interdependencies not effectively assessed and techniques available but not yet adopted; (b) the investment community suffers from a lack of climate change expertise and a short-term mindset; and (c) there is a need for a clearer policy vision and greater collaboration.
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Journal articleGill RJ, Baldock KCR, Brown MJF, et al., 2016,
Protecting an Ecosystem Service: Approaches to Understanding and Mitigating Threats to Wild Insect Pollinators
, Advances in Ecological Research, Vol: 54, Pages: 135-206, ISSN: 0065-2504Insect pollination constitutes an ecosystem service of global importance, providing significant economic and aesthetic benefits as well as cultural value to human society, alongside vital ecological processes in terrestrial ecosystems. It is therefore important to understand how insect pollinator populations and communities respond to rapidly changing environments if we are to maintain healthy and effective pollinator services. This chapter considers the importance of conserving pollinator diversity to maintain a suite of functional traits and provide a diverse set of pollinator services. We explore how we can better understand and mitigate the factors that threaten insect pollinator richness, placing our discussion within the context of populations in predominantly agricultural landscapes in addition to urban environments. We highlight a selection of important evidence gaps, with a number of complementary research steps that can be taken to better understand: (i) the stability of pollinator communities in different landscapes in order to provide diverse pollinator services; (ii) how we can study the drivers of population change to mitigate the effects and support stable sources of pollinator services and (iii) how we can manage habitats in complex landscapes to support insect pollinators and provide sustainable pollinator services for the future. We advocate a collaborative effort to gain higher quality abundance data to understand the stability of pollinator populations and predict future trends. In addition, for effective mitigation strategies to be adopted, researchers need to conduct rigorous field testing of outcomes under different landscape settings, acknowledge the needs of end-users when developing research proposals and consider effective methods of knowledge transfer to ensure effective uptake of actions.
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Journal articleChen Z, Wang X, Atkinson A, et al., 2016,
Spherical Indentation of Porous Ceramics: Elasticity and Hardness
, Journal of the European Ceramic Society, Vol: 36, Pages: 1435-1445, ISSN: 1873-619XA combined experimental and numerical approach is used to characterise the elastic and plastic deformation of a porous bulk ceramic material (La0.6Sr0.4Co0.2Fe0.8O3, LSCF) with porosities in the range 5–45 vol%, undergoing spherical indentation. The Gurson model was used in FEM simulations to describe the densification of the porous material in the plastic zone under the indenter. The simulated indentation response curves, extracted elastic modulus, hardness and densification in the plastic zone all showed good agreement with corresponding experimental observations. The results show that the hardness increases with maximum indentation depth over a representative depth that depends on porosity. In this particular ceramic the hardness, at sufficiently large penetration depth, is approximately 1.7 times the uniaxial yield stress of the porous material.
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Journal articleHui R, Lund JR, Madani K, 2016,
Game theory and risk-based leveed river system planning with noncooperation
, Water Resources Research, Vol: 52, Pages: 119-134, ISSN: 1944-7973Optimal risk-based levee designs are usually developed for economic efficiency. However, in river systems with multiple levees, the planning and maintenance of different levees are controlled by different agencies or groups. For example, along many rivers, levees on opposite riverbanks constitute a simple leveed river system with each levee designed and controlled separately. Collaborative planning of the two levees can be economically optimal for the whole system. Independent and self-interested landholders on opposite riversides often are willing to separately determine their individual optimal levee plans, resulting in a less efficient leveed river system from an overall society-wide perspective (the tragedy of commons). We apply game theory to simple leveed river system planning where landholders on each riverside independently determine their optimal risk-based levee plans. Outcomes from noncooperative games are analyzed and compared with the overall economically optimal outcome, which minimizes net flood cost system-wide. The system-wide economically optimal solution generally transfers residual flood risk to the lower-valued side of the river, but is often impractical without compensating for flood risk transfer to improve outcomes for all individuals involved. Such compensation can be determined and implemented with landholders' agreements on collaboration to develop an economically optimal plan. By examining iterative multiple-shot noncooperative games with reversible and irreversible decisions, the costs of myopia for the future in making levee planning decisions show the significance of considering the externalities and evolution path of dynamic water resource problems to improve decision-making.
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Journal articleGill RJ, Woodward G, 2016,
Networking our way to better ecosystem service provision
, Trends in Ecology & Evolution, Vol: 31, Pages: 105-115, ISSN: 0169-5347The ecosystem services (EcoS) concept is being used increasingly to attach values to natural systems and the multiple benefits they provide to human societies. Ecosystem processes or functions only become EcoS if they are shown to have social and/or economic value. This should assure an explicit connection between the natural and social sciences, but EcoS approaches have been criticized for retaining little natural science. Preserving the natural, ecological science context within EcoS research is challenging because the multiple disciplines involved have very different traditions and vocabularies (common-language challenge) and span many organizational levels and temporal and spatial scales (scale challenge) that define the relevant interacting entities (interaction challenge). We propose a network-based approach to transcend these discipline challenges and place the natural science context at the heart of EcoS research.
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Journal articleStruve T, van de Flierdt T, Robinson LF, et al., 2016,
Neodymium isotope analyses after combined extraction of actinide and lanthanide elements from seawater and deep-sea coral aragonite
, Geochemistry Geophysics Geosystems, Vol: 17, Pages: 232-240, ISSN: 1525-2027Isotopes of the actinide elements protactinium (Pa), thorium (Th) and uranium (U), and the lanthanide element neodymium (Nd) are often used as complementary tracers of modern and past oceanic processes. The extraction of such elements from low abundance matrices, such as seawater and carbonate, is however labor-intensive and requires significant amounts of sample material. We here present a combined method for the extraction of Pa, Th and Nd from 5 to 10 L seawater samples, and of U, Th and Nd from <1 g carbonate samples. Neodymium is collected in the respective wash fractions of Pa-Th and U-Th anion exchange chromatographies. Regardless of the original sample matrix, Nd is extracted during a two-stage ion chromatography, followed by thermal ionization mass spectrometry (TIMS) analysis as NdO+. Using this combined procedure, we obtained results for Nd isotopic compositions on two GEOTRACES consensus samples from Bermuda Atlantic Time Series (BATS), which are within error identical to results for separately sampled and processed dedicated Nd samples (εNd = -9.20 ± 0.21 and -13.11 ± 0.21 for 15 and 2000 m water depths, respectively; intercalibration results from 14 laboratories: εNd = -9.19 ± 0.57 and -13.14 ± 0.57). Furthermore, Nd isotope results for an in-house coral reference material are identical within analytical uncertainty for dedicated Nd chemistry and after collection of Nd from U-Th anion exchange chromatography. Our procedure does not require major adaptations to independently used ion exchange chromatographies for U-Pa-Th and Nd, and can hence be readily implemented for a wide range of applications.
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Journal articleCurto A, de Nazelle A, Donaire-Gonzalez D, et al., 2016,
Private and public modes of bicycle commuting: a perspective on attitude and perception.
, European Journal of Public Health, Vol: 26, Pages: 717-723, ISSN: 1464-360XBACKGROUND: Public bicycle-sharing initiatives can act as health enhancement strategies among urban populations. The aim of the study was to determine which attitudes and perceptions of behavioural control toward cycling and a bicycle-sharing system distinguish commuters with a different adherence to bicycle commuting. METHODS: The recruitment process was conducted in 40 random points in Barcelona from 2011 to 2012. Subjects completed a telephone-based questionnaire including 27 attitude and perception statements. Based on their most common one-way commute trip and willingness to commute by bicycle, subjects were classified into Private Bicycle (PB), public bicycle or Bicing Bicycle (BB), Willing Non-bicycle (WN) and Non-willing Non-bicycle (NN) commuters. After reducing the survey statements through principal component analysis, a multinomial logistic regression model was obtained to evaluate associations between attitudinal and commuter sub-groups. RESULTS: We included 814 adults in the analysis [51.6% female, mean (SD): age 36.6 (10.3) years]. BB commuters were 2.0 times [95% confidence interval (CI) = 1.1-3.7] less likely to perceive bicycle as a quick, flexible and enjoyable mode compared to PB. BB, WN and NN were 2.5 (95% CI = 1.46-4.24), 2.6 (95% CI = 1.53-4.41) and 2.3 times (95% CI = 1.30-4.10) more likely to perceive benefits of using public bicycles (bicycle maintenance and parking avoidance, low cost and no worries about theft and vandalism) than did PB. CONCLUSION: Willing non-bicycle and public-bicycle commuters had more favourable perception toward public-shared bicycles compared to private cyclists. Hence, public bicycles may be the impetus for those willing to start bicycle commuting, thereby increasing physical activity levels.
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Journal articleWu B, Merla Y, Yufit V, et al., 2016,
Novel application of differential thermal voltammetry as an in-depth state-of-health diagnosis method for lithium-ion batteries
, Journal of Power Sources, Vol: 307, Pages: 308-319, ISSN: 1873-2755Understanding and tracking battery degradation mechanisms and adapting its operation have become a necessity in order to enhance battery durability. A novel use of differential thermal voltammetry (DTV) is presented as an in-situ state-of-health (SOH) estimator for lithium-ion batteries.Accelerated ageing experiments were carried on 5Ah commercial lithium-ion polymer cells operated and stored at different temperature and loading conditions. The cells were analysed regularly with various existing in-situ diagnosis methods and the novel DTV technique to determine their SOH. The diagnosis results were used collectively to elaborate the degradation mechanisms inside the cells. The DTV spectra were decoupled into individual peaks, which each represent particular phases in the negative and positive electrode combined. The peak parameters were used to quantitatively analyse the battery SOH.A different cell of the same chemistry with unknown degradation history was then analysed to explore how the cell degraded. The DTV technique was able to diagnose the cell degradation without relying on supporting results from other methods nor previous cycling data.
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Journal articleBuytaert W, Dewulf A, De Bievre B, et 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 articleMarinescu 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: 1463-9076Lithium-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.
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Journal articleHills T, Leeson D, Florin N, et al., 2016,
Carbon capture in the cement industry: technologies, progress, and retrofitting
, Environmental Science & Technology, Vol: 50, Pages: 368-377, ISSN: 0013-936XSeveral 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.
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Journal articleSule 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: 1479-487XThe 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.
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Journal articleGuxens M, Ghassabian A, Gong T, et 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: 1552-9924BACKGROUND: 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
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Book chapterHaigh 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 -
Conference paperDjabbarov S, Jones ADW, Krevor S, et 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.
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Conference paperAl-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
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Journal articleParker 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: 1099-1085Groundwater 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.
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Journal articleDurance I, Bruford MW, Chalmers R, et 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: 0065-2504There 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
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Journal articleAlhajaj 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: 1750-5836In 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.
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Journal articleGerike R, de Nazelle A, Nieuwenhuijsen M, et al., 2016,
Physical Activity through Sustainable Transport Approaches (PASTA): a study protocol for a multicentre project
, BMJ Open, Vol: 6, ISSN: 2044-6055 -
Journal articleAitken ARA, Betts PG, Young DA, et al., 2016,
The Australo-Antarctic Columbia to Gondwana transition
, Gondwana Research, Vol: 29, Pages: 136-152, ISSN: 1342-937XFrom 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
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Journal articleHoque 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: 1660-4601Drinking 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.
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