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  • Journal article
    Hodgson DA, Bentley MJ, Smith JA, Klepacki J, Makinson K, Smith AM, Saw K, Scherer R, Powell R, Tulaczyk S, Rose M, Pearce D, Mowlem M, Keen P, Siegert MJet al., 2015,

    Technologies for retrieving sediment cores in Antarctic subglacial settings

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

    Accumulations of sediment beneath the Antarctic Ice Sheet contain a range of physical and chemical proxies with the potential to document changes in ice sheet history and to identify and characterize life in subglacial settings. Retrieving subglacial sediments and sediment cores presents several unique challenges to existing technologies. This paper briefly reviews the history of sediment sampling in subglacial environments. It then outlines some of the technological challenges and constraints in developing the corers being used in sub-ice shelf settings (e.g. George VI Ice Shelf and Larsen Ice Shelf), under ice streams (e.g. Rutford Ice Stream), at or close to the grounding line (e.g. Whillans Ice Stream) and in subglacial lakes deep under the ice sheet (e.g. Lake Ellsworth). The key features of the corers designed to operate in each of these subglacial settings are described and illustrated together with comments on their deployment procedures.
  • Journal article
    Reynolds C, Krevor S, 2015,

    Characterising flow behaviour for gas injection: relative permeability of CO sub 2 /sub -brine and N sub 2 /sub-water in heterogeneous rocks

    , Water Resources Research, Vol: 51, Pages: 9464-9489, ISSN: 0043-1397

    We provide a comprehensive experimental study of steady state, drainage relative permeability curves with CO2-brine and N2-deionized water, on a single Bentheimer sandstone core with a simple two-layer heterogeneity. We demonstrate that, if measured in the viscous limit, relative permeability is invariant with changing reservoir conditions, and is consistent with the continuum-scale multiphase flow theory for water wet systems. Furthermore, we show that under capillary limited conditions, the CO2-brine system is very sensitive to heterogeneity in capillary pressure, and by performing core floods under capillary limited conditions, we produce effective relative permeability curves that are flow rate and fluid parameter dependent. We suggest that the major uncertainty in past observations of CO2-brine relative permeability curves is due to the interaction of CO2 flow with pore space heterogeneity under capillary limited conditions and is not due to the effects of changing reservoir conditions. We show that the appropriate conditions for measuring intrinsic or effective relative permeability curves can be selected simply by scaling the driving force for flow by a quantification of capillary heterogeneity. Measuring one or two effective curves on a core with capillary heterogeneity that is representative of the reservoir will be sufficient for reservoir simulation.
  • Journal article
    Biastoch A, Durgadoo JV, Morrison AK, van Sebille E, Weijer W, Griffies SMet al., 2015,

    Atlantic multi-decadal oscillation covaries with Agulhas leakage.

    , Nature Communications, Vol: 6, ISSN: 2041-1723

    The interoceanic transfer of seawater between the Indian Ocean and the Atlantic, 'Agulhas leakage', forms a choke point for the overturning circulation in the global ocean. Here, by combining output from a series of high-resolution ocean and climate models with in situ and satellite observations, we construct a time series of Agulhas leakage for the period 1870-2014. The time series demonstrates the impact of Southern Hemisphere westerlies on decadal timescales. Agulhas leakage shows a correlation with the Atlantic Multi-decadal Oscillation on multi-decadal timescales; the former leading by 15 years. This is relevant for climate in the North Atlantic.
  • Journal article
    Bahadori L, Chakrabarti MH, Manan NSA, Hashim MA, Mjalli FS, AlNashef IM, Brandon Net al., 2015,

    The effect of temperature on kinetics and diffusion coefficients of metallocene derivatives in polyol-based deep eutectic solvents

    , PLOS One, Vol: 10, ISSN: 1932-6203

    The temperature dependence of the density, dynamic viscosity and ionic conductivity of several deep eutectic solvents (DESs) containing ammonium-based salts and hydrogen bond donvnors (polyol type) are investigated. The temperature-dependent electrolyte viscosity as a function of molar conductivity is correlated by means of Walden’s rule. The oxidation of ferrocene (Fc/Fc+) and reduction of cobaltocenium (Cc+/Cc) at different temperatures are studied by cyclic voltammetry and potential-step chronoamperometry in DESs. For most DESs, chronoamperometric transients are demonstrated to fit an Arrhenius-type relation to give activation energies for the diffusion of redox couples at different temperatures. The temperature dependence of the measured conductivities of DES1 and DES2 are better correlated with the Vogel-Tamman-Fulcher equation. The kinetics of the Fc/Fc+ and Cc+/Cc electrochemical systems have been investigated over a temperature range from 298 to 338 K. The heterogeneous electron transfer rate constant is then calculated at different temperatures by means of a logarithmic analysis. The glycerol-based DES (DES5) appears suitable for further testing in electrochemical energy storage devices.
  • Journal article
    Wright R, Abraham E, Parpas P, Stoianov Iet al., 2015,

    Control of water distribution networks with dynamic DMA topology using strictly feasible sequential convex programming

    , Water Resources Research, Vol: 51, Pages: 9925-9941, ISSN: 0043-1397

    The operation of water distribution networks (WDN) with a dynamic topology is a recently pioneered approach for the advanced management of district metered areas (DMA) that integrates novel developments in hydraulic modelling, monitoring, optimization and control. A common practice for leakage management is the sectorization of WDNs into small zones, called DMAs, by permanently closing isolation valves. This facilitates water companies to identify bursts and estimate leakage levels by measuring the inlet flow for each DMA. However, by permanently closing valves, a number of problems have been created including reduced resilience to failure and suboptimal pressure management. By introducing a dynamic topology to these zones, these disadvantages can be eliminated whilst still retaining the DMA structure for leakage monitoring. In this paper, a novel optimization method based on sequential convex programming (SCP) is outlined for the control of a dynamic topology with the objective of reducing average zone pressure (AZP). A key attribute for control optimization is reliable convergence. To achieve this, the SCP method we propose guarantees that each optimization step is strictly feasible, resulting in improved convergence properties. By using a null space algorithm for hydraulic analyses, the computations required are also significantly reduced. The optimized control is actuated on a real WDN operated with a dynamic topology. This unique experimental programme incorporates a number of technologies set up with the objective of investigating pioneering developments in WDN management. Preliminary results indicate AZP reductions for a dynamic topology of up to 6.5% over optimally controlled fixed topology DMAs.
  • Journal article
    Woodward G, Bonada N, Feeley HB, Giller PSet al., 2015,

    Resilience of a stream community to extreme climatic events and long-term recovery from a catastrophic flood

    , FRESHWATER BIOLOGY, Vol: 60, Pages: 2497-2510, ISSN: 0046-5070
  • Journal article
    Cicciotti M, Xenos DP, Bouaswaig AEF, Thornhill NF, Martinez-Botas RFet al., 2015,

    Physical modelling of industrial multistage centrifugal compressors for monitoring and simulation

    , PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART C-JOURNAL OF MECHANICAL ENGINEERING SCIENCE, Vol: 229, Pages: 3433-3448, ISSN: 0954-4062
  • Journal article
    Tinetti G, Drossart P, Eccleston P, Hartogh P, Isaak K, Linder M, Lovis C, Micela G, Ollivier M, Puig L, Ribas I, Snellen I, Swinyard B, Allard F, Barstow J, Cho J, Coustenis A, Cockell C, Correia A, Decin L, de Kok R, Deroo P, Encrenaz T, Forget F, Glasse A, Griffith C, Guillot T, Koskinen T, Lammer H, Leconte J, Maxted P, Mueller-Wodarg I, Nelson R, North C, Palle E, Pagano I, Piccioni G, Pinfield D, Selsis F, Sozzetti A, Stixrude L, Tennyson J, Turrini D, Zapatero-Osorio M, Beaulieu J-P, Grodent D, Guedel M, Luz D, Norgaard-Nielsen HU, Ray T, Rickman H, Selig A, Swain M, Banaszkiewicz M, Barlow M, Bowles N, Branduardi-Raymont G, du Foresto VC, Gerard J-C, Gizon L, Hornstrup A, Jarchow C, Kerschbaum F, Kovacs G, Lagage P-O, Lim T, Lopez-Morales M, Malaguti G, Pace E, Pascale E, Vandenbussche B, Wright G, Ramos Zapata G, Adriani A, Azzollini R, Balado A, Bryson I, Burston R, Colome J, Crook M, Di Giorgio A, Griffin M, Hoogeveen R, Ottensamer R, Irshad R, Middleton K, Morgante G, Pinsard F, Rataj M, Reess J-M, Savini G, Schrader J-R, Stamper R, Winter B, Abe L, Abreu M, Achilleos N, Ade P, Adybekian V, Affer L, Agnor C, Agundez M, Alard C, Alcala J, Allende Prieto C, Alonso Floriano FJ, Altieri F, Alvarez Iglesias CA, Amado P, Andersen A, Aylward A, Baffa C, Bakos G, Ballerini P, Banaszkiewicz M, Barber RJ, Barrado D, Barton EJ, Batista V, Bellucci G, Belmonte Aviles JA, Berry D, Bezard B, Biondi D, Blecka M, Boisse I, Bonfond B, Borde P, Boerner P, Bouy H, Brown L, Buchhave L, Budaj J, Bulgarelli A, Burleigh M, Cabral A, Capria MT, Cassan A, Cavarroc C, Cecchi-Pestellini C, Cerulli R, Chadney J, Chamberlain S, Charnoz S, Jessen NC, Ciaravella A, Claret A, Claudi R, Coates A, Cole R, Collura A, Cordier D, Covino E, Danielski C, Damasso M, Deeg HJ, Delgado-Mena E, Del Vecchio C, Demangeon O, De Sio A, De Wit J, Dobrijevic M, Doel P, Dominic C, Dorfi E, Eales S, Eiroa C, Espinoza Contreras M, Esposito M, Eymet V, Fabrizio N, Fernandez M, Femena Castella B, Figueira Pet al., 2015,

    The EChO science case

    , Experimental Astronomy, Vol: 40, Pages: 329-391, ISSN: 1572-9508

    The discovery of almost two thousand exoplanets has revealed an unexpectedlydiverse planet population. We see gas giants in few-day orbits, whole multi-planet systemswithin the orbit of Mercury, and new populations of planets with masses between that of theEarth and Neptune—all unknown in the Solar System. Observations to date have shown thatour Solar System is certainly not representative of the general population of planets in ourMilky Way. The key science questions that urgently need addressing are therefore: What areexoplanets made of? Why are planets as they are? How do planetary systems work and whatcauses the exceptional diversity observed as compared to the Solar System? The EChO(Exoplanet Characterisation Observatory) space mission was conceived to take up thechallenge to explain this diversity in terms of formation, evolution, internal structure andplanet and atmospheric composition. This requires in-depth spectroscopic knowledge of theatmospheres of a large and well-defined planet sample for which precise physical, chemicaland dynamical information can be obtained. In order to fulfil this ambitious scientificprogram, EChO was designed as a dedicated survey mission for transit and eclipsespectroscopy capable of observing a large, diverse and well-defined planet sample withinits 4-year mission lifetime. The transit and eclipse spectroscopy method, whereby the signalfrom the star and planet are differentiated using knowledge of the planetary ephemerides,allows us to measure atmospheric signals from the planet at levels of at least 10−4 relative tothe star. This can only be achieved in conjunction with a carefully designed stable payloadand satellite platform. It is also necessary to provide broad instantaneous wavelengthcoverage to detect as many molecular species as possible, to probe the thermal structureof the planetary atmospheres and to correct for the contaminating effects of the stellarphotosphere. This requires wavelength coverage of at l
  • Journal article
    Holland RA, Scott KA, Florke M, Brown G, Ewers RM, Famer E, Kapos V, Muggeridge AH, Scharlemann JPW, Taylor G, Barrett J, Eigenbrod Fet al., 2015,

    Global impacts of energy demand on the freshwater resources of nations

    , Proceedings of the National Academy of Sciences of the United States of America, Vol: 112, Pages: E6707-E6716, ISSN: 0027-8424

    The growing geographic disconnect between consumption of goods, the extraction and processing of resources, and the environmental impacts associated with production activities makes it crucial to factor global trade into sustainability assessments. Using an empirically validated environmentally extended global trade model we examine the relationship between two key resources underpinning economies and human well-being - energy and freshwater. A comparison of three energy sectors (petroleum, gas, electricity) reveals that freshwater consumption associated with gas and electricity production is largely confined within the territorial boundaries where demand originates. This contrasts with petroleum, which exhibits a varying ratio of territorial to international freshwater consumption depending on the origin of demand. For example, while the USA and China have similar demand associated with the petroleum sector, international freshwater consumption is three times higher for the former than the latter. Based on mapping patterns of freshwater consumption associated with energy sectors at subnational scales, our analysis also reveals concordance between pressure on freshwater resources associated with energy production and freshwater scarcity in a number of river basins globally. These energy-driven pressures on freshwater resources in areas distant from the origin of energy demand complicate the design of policy to ensure security of fresh water and energy supply. While much of the debate around energy is focussed on greenhouse gas emissions, our findings highlight the need to consider the full range of consequences of energy production when designing policy.
  • Journal article
    Watson J, Gross R, Ketsopoulou I, Winskel Met al., 2015,

    The impact of uncertainties on the UK's medium-term climate change targets

    , ENERGY POLICY, Vol: 87, Pages: 685-695, ISSN: 0301-4215
  • Journal article
    Morel CRG, van Reeuwijk M, Graf T, 2015,

    Systematic investigation of non-Boussinesq effects in variable-density groundwater flow simulations

    , JOURNAL OF CONTAMINANT HYDROLOGY, Vol: 183, Pages: 82-98, ISSN: 0169-7722
  • Journal article
    Blyth W, McCarthy R, Gross R, 2015,

    Financing the UK power sector: Is the money available?

    , ENERGY POLICY, Vol: 87, Pages: 607-622, ISSN: 0301-4215
  • Journal article
    Dewage HH, Yufit V, Brandon NP, 2015,

    Study of Loss Mechanisms Using Half-Cell Measurements in a Regenerative Hydrogen Vanadium Fuel Cell

    , Journal of the Electrochemical Society, Vol: 163, Pages: A5236-A5243, ISSN: 0013-4651

    The positioning of reference electrodes in redox flow batteries without disturbing the cell operation represents a great challenge. However decoupling anode and cathode processes is crucial in order to fully understand the losses in the system so it can be further optimized. The feasibility of a regenerative fuel cell based on an V(IV)/V(V) electrolyte and hydrogen gas has previously been demonstrated. In this investigation, using electrochemical impedance spectroscopy, the various losses of the cathode, anode and whole cell were established using an alternative reference electrode set-up. The findings showed that the largest irreversible losses under the conditions tested arose from diffusion limitations in the cathode and the effect of vanadium crossover and therefore adsorption onto the platinum layer of the hydrogen electrode leading to higher losses on the anode. These results highlight the potential for further improvement and optimization of cell design and materials for both electrodes in the Regenerative Hydrogen Vanadium Fuel Cell.
  • Journal article
    Makinson K, Pearce D, Hodgson DA, Bentley MJ, Smith AM, Tranter M, Rose M, Ross N, Mowlem M, Parnell J, Siegert MJet al., 2015,

    Clean subglacial access: prospects for future deep hot-water drilling

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

    Accessing and sampling subglacial environments deep beneath the Antarctic Ice Sheet presents several challenges to existing drilling technologies. With over half of the ice sheet believed to be resting on a wet bed, drilling down to this environment must conform to international agreements on environmental stewardship and protection, making clean hot-water drilling the most viable option. Such a drill, and its water recovery system, must be capable of accessing significantly greater ice depths than previous hot-water drills, and remain fully operational after connecting with the basal hydrological system. The Subglacial Lake Ellsworth (SLE) project developed a comprehensive plan for deep (greater than 3000 m) subglacial lake research, involving the design and development of a clean deep-ice hot-water drill. However, during fieldwork in December 2012 drilling was halted after a succession of equipment issues culminated in a failure to link with a subsurface cavity and abandonment of the access holes. The lessons learned from this experience are presented here. Combining knowledge gained from these lessons with experience from other hot-water drilling programmes, and recent field testing, we describe the most viable technical options and operational procedures for future clean entry into SLE and other deep subglacial access targets.
  • Journal article
    Watson J, Gross R, Ketsopoulou I, 2015,

    Energy policy special issue: UK Energy Research Centre uncertainties project

    , ENERGY POLICY, Vol: 87, Pages: 604-606, ISSN: 0301-4215
  • Journal article
    Donaire-Gonzalez D, de Nazelle A, Cole-Hunter T, Curto A, Rodriguez DA, Mendez MA, Garcia-Aymerich J, Basagana X, Ambros A, Jerrett M, Nieuwenhuijsen MJet al., 2015,

    The Added Benefit of Bicycle Commuting on the Regular Amount of Physical Activity Performed

    , American Journal of Preventive Medicine, Vol: 49, Pages: 842-849, ISSN: 0749-3797

    IntroductionPhysical inactivity is a leading cause of death and disability globally. Active transportation such as bicycling may increase physical activity levels. It is currently uncertain whether a shift from motorized transport modes to bicycle commuting leads to increased physical activity overall or substitutes other forms of physical activity. The study aims to disentangle whether bicycle commuting adds to or replaces other physical activities by comparing the physical activity performed by bicycle and motorized commuters.MethodsPhysical activity, travel behavior, health status, sociodemographic, and built environment characteristics were assessed for 752 adults, between June 2011 and May 2012, in Barcelona, Spain. Statistical analyses, performed in 2013–2014, included linear, non-linear, and mixture models to estimate disparities and the dose–response relationship between physical activity duration and commute mode.ResultsRegular bicycle commuters traveled by bicycle an average of 3.1 (SD=2.5) hours in the previous week. Bicycle commuting contributed positively to physical activity duration across participants (p<0.05). It amounted to 2.1 (95% CI=0.84, 3.55) hours/week extra of physical activity for bicycle commuters versus motorized commuters. Among bicycle travelers, there was a positive dose–response relationship between bicycle commuting and physical activity duration, with an average extra physical activity duration of 0.5 (95% CI=0.4, 0.6) hours/week for every additional 1 hour/week of bicycle commuting.ConclusionsBicycle commuting likely adds to overall physical activity. The extra physical activity performed by bicycle commuters is undertaken as moderate physical activity and follows a sigmoidal dose–response relationship with bicycle duration.
  • Journal article
    Cetina-Heredia P, Roughan M, van Sebille E, Feng M, Coleman MAet al., 2015,

    Strengthened currents override the effect of warming on lobster larval dispersal and survival

    , GLOBAL CHANGE BIOLOGY, Vol: 21, Pages: 4377-4386, ISSN: 1354-1013
  • Journal article
    Hynson NA, Bidartondo MI, Read DJ, 2015,

    Are there geographic mosaics of mycorrhizal specificity and partial mycoheterotrophy? A case study in Moneses uniflora (Ericaceae).

    , New Phytol, Vol: 208, Pages: 1003-1007
  • Journal article
    Chu W, Yao D, Gao N, Bond T, Templeton MRet al., 2015,

    The enhanced removal of carbonaceous and nitrogenous disinfection by-product precursors using integrated permanganate oxidation and powdered activated carbon adsorption pretreatment

    , Chemosphere, Vol: 141, Pages: 1-6, ISSN: 0045-6535
  • Report
    Hanna R, Gross R, Speirs J, Heptonstall PJ, Gambhir Aet al., 2015,

    Innovation timelines from invention to maturity: A rapid review of the evidence on the time taken for new technologies to reach widespread commercialisation
  • Journal article
    Collier JS, Oggioni F, Gupta S, Garcia-Moreno D, Trentesaux A, De Batist Met al., 2015,

    Streamlined islands and the English Channel megaflood hypothesis

    , Global and Planetary Change, Vol: 135, Pages: 190-206, ISSN: 0921-8181

    Recognising ice-age catastrophic megafloods is important because they had significant impact on large-scale drainage evolution and patterns of water and sediment movement to the oceans, and likely induced very rapid, short-term effects on climate. It has been previously proposed that a drainage system on the floor of the English Channel was initiated by catastrophic flooding in the Pleistocene but this suggestion has remained controversial. Here we examine this hypothesis through an analysis of key landform features. We use a new compilation of multi- and single-beam bathymetry together with sub-bottom profiler data to establish the internal structure, planform geometry and hence origin of a set of 36 mid-channel islands. Whilst there is evidence of modern-day surficial sediment processes, the majority of the islands can be clearly demonstrated to be formed of bedrock, and are hence erosional remnants rather than depositional features. The islands display classic lemniscate or tear-drop outlines, with elongated tips pointing downstream, typical of streamlined islands formed during high-magnitude water flow. The length-to-width ratio for the entire island population is 3.4 ± 1.3 and the degree-of-elongation or k-value is 3.7 ± 1.4. These values are comparable to streamlined islands in other proven Pleistocene catastrophic flood terrains and are distinctly different to values found in modern-day rivers. The island geometries show a correlation with bedrock type: with those carved from Upper Cretaceous chalk having larger length-to-width ratios (3.2 ± 1.3) than those carved into more mixed Paleogene terrigenous sandstones, siltstones and mudstones (3.0 ± 1.5). We attribute these differences to the former rock unit having a lower skin friction which allowed longer island growth to achieve minimum drag. The Paleogene islands, although less numerous than the Chalk islands, also assume more perfect lemniscate shapes. These lithologies therefore
  • Journal article
    Samsatli S, Staffell I, Samsatli NJ, 2015,

    Optimal design and operation of integrated wind-hydrogen-electricity networks for decarbonising the domestic transport sector in Great Britain

    , International Journal of Hydrogen Energy, Vol: 41, Pages: 447-475, ISSN: 1879-3487

    This paper presents the optimal design and operation of integrated wind-hydrogen-electricity networks using the general mixed integer linear programming energy network model, STeMES (Samsatli and Samsatli, 2015). The network comprises: wind turbines; electrolysers, fuel cells, compressors and expanders; pressurised vessels and underground storage for hydrogen storage; hydrogen pipelines and electricity overhead/underground transmission lines; and fuelling stations and distribution pipelines.The spatial distribution and temporal variability of energy demands and wind availability were considered in detail in the model. The suitable sites for wind turbines were identified using GIS, by applying a total of 10 technical and environmental constraints (buffer distances from urban areas, rivers, roads, airports, woodland and so on), and used to determine the maximum number of new wind turbines that can be installed in each zone.The objective is the minimisation of the total cost of the network, subject to satisfying all of the demands of the domestic transport sector in Great Britain. The model simultaneously determines the optimal number, size and location of each technology, whether to transmit the energy as electricity or hydrogen, the structure of the transmission network, the hourly operation of each technology and so on. The cost of distribution was estimated from the number of fuelling stations and length of the distribution pipelines, which were determined from the demand density at the 1 km level.Results indicate that all of Britain's domestic transport demand can be met by on-shore wind through appropriately designed and operated hydrogen-electricity networks. Within the set of technologies considered, the optimal solution is: to build a hydrogen pipeline network in the south of England and Wales; to supply the Midlands and Greater London with hydrogen from the pipeline network alone; to use Humbly Grove underground storage for seasonal storage and pressurised ve
  • Journal article
    Yang M, Martinez-Botas R, Rajoo S, Yokoyama T, Ibaraki Set al., 2015,

    An investigation of volute cross-sectional shape on turbocharger turbine under pulsating conditions in internal combustion engine

    , Energy Conversion and Management, Vol: 105, Pages: 167-177, ISSN: 0196-8904

    Engine downsizing is a proven method for CO2 reduction in Internal Combustion Engine (ICE). A turbocharger, which reclaims the energy from the exhaust gas to boost the intake air, can effectively improve the power density of the engine thus is one of the key enablers to achieve the engine downsizing. Acknowledging its importance, many research efforts have gone into improving a turbocharger performance, which includes turbine volute. The cross-section design of a turbine volute in a turbocharger is usually a compromise between the engine level packaging and desired performance. Thus, it is beneficial to evaluate the effects of cross-sectional shape on a turbine performance. This paper presents experimental and computational investigation of the influence of volute cross-sectional shape on the performance of a radial turbocharger turbine under pulsating conditions. The cross-sectional shape of the baseline volute (denoted as Volute B) was optimized (Volute A) while the annulus distribution of area-to-radius ratio (A/R) for the two volute configurations are kept the same. Experimental results show that the turbine with the optimized volute A has better cycle averaged efficiency under pulsating flow conditions, for different loadings and frequencies. The advantage of performance is influenced by the operational conditions. After the experiment, a validated unsteady computational fluid dynamics (CFD) modeling was employed to investigate the mechanism by which performance differs between the baseline volute and the optimized version. Computational results show a stronger flow distortion in spanwise direction at the rotor inlet with the baseline volute. Furthermore, compared with the optimized volute, the flow distortion is more sensitive to the pulsating flow conditions in the baseline volute. This is due to the different secondary flow pattern in the cross-sections, hence demonstrating a direction for desired volute cross-sectional shape to be used in a turbocharger rad
  • Journal article
    Bond T, Templeton MR, Mokhtar Kamal NH, Graham NJD, Kanda Ret al., 2015,

    Nitrogenous disinfection byproducts in English drinking water supply systems: occurrence, bromine substitution and correlation analysis

    , Water Research, Vol: 85, Pages: 85-94, ISSN: 0043-1354

    Despite the recent focus on nitrogenous disinfection byproducts in drinking water, there is limited occurrence data available for many species. This paper analyses the occurrence of seven haloacetonitriles, three haloacetamides, eight halonitromethanes and cyanogen chloride in 20 English drinking water supply systems. It is the first survey of its type to compare bromine substitution factors (BSFs) between the haloacetamides and haloacetonitriles. Concentrations of the dihalogenated haloacetonitriles and haloacetamides were well correlated. Although median concentrations of these two groups were lower in chloraminated than chlorinated surface waters, median BSFs for both in chloraminated samples were approximately double those in chlorinated samples, which is significant because of the higher reported toxicity of the brominated species. Furthermore, median BSFs were moderately higher for the dihalogenated haloacetamides than for the haloacetonitriles. This indicates that, while the dihalogenated haloacetamides were primarily generated from hydrolysis of the corresponding haloacetonitriles, secondary formation pathways also contributed. Median halonitromethane concentrations were remarkably unchanging for the different types of disinfectants and source waters: 0.1 μg·mgTOC−1 in all cases. Cyanogen chloride only occurred in a limited number of samples, yet when present its concentrations were higher than the other N-DBPs. Concentrations of cyanogen chloride and the sum of the halonitromethanes were not correlated with any other DBPs.
  • Journal article
    Dons E, Goetschi T, Nieuwenhuijsen M, de Nazelle A, Anaya E, Avila-Palencia I, Brand C, Cole-Hunter T, Gaupp-Berghausen M, Kahlmeier S, Laeremans M, Mueller N, Orjuela JP, Raser E, Rojas-Rueda D, Standaert A, Stigell E, Uhlmann T, Gerike R, Panis LIet al., 2015,

    Physical activity through sustainable transport approaches (PASTA): protocol for a multi-centre, longitudinal study

    , BMC Public Health, Vol: 15, ISSN: 1471-2458

    BackgroundPhysical inactivity is one of the leading risk factors for non-communicable diseases, yet many are not sufficiently active. The Physical Activity through Sustainable Transport Approaches (PASTA) study aims to better understand active mobility (walking and cycling for transport solely or in combination with public transport) as an innovative approach to integrate physical activity into individuals’ everyday lives. The PASTA study will collect data of multiple cities in a longitudinal cohort design to study correlates of active mobility, its effect on overall physical activity, crash risk and exposure to traffic-related air pollution.Methods/DesignA set of online questionnaires incorporating gold standard approaches from the physical activity and transport fields have been developed, piloted and are now being deployed in a longitudinal study in seven European cities (Antwerp, Barcelona, London, Oerebro, Rome, Vienna, Zurich). In total, 14000 adults are being recruited (2000 in each city). A first questionnaire collects baseline information; follow-up questionnaires sent every 13 days collect prospective data on travel behaviour, levels of physical activity and traffic safety incidents. Self-reported data will be validated with objective data in subsamples using conventional and novel methods. Accelerometers, GPS and tracking apps record routes and activity. Air pollution and physical activity are measured to study their combined effects on health biomarkers. Exposure-adjusted crash risks will be calculated for active modes, and crash location audits are performed to study the role of the built environment. Ethics committees in all seven cities have given independent approval for the study.DiscussionThe PASTA study collects a wealth of subjective and objective data on active mobility and physical activity. This will allow the investigation of numerous correlates of active mobility and physical activity using a data set that advances previous efforts in
  • Journal article
    Brown S, Mahgerefteh H, Martynov S, Sundara V, Mac Dowell Net al., 2015,

    A multi-source flow model for CCS pipeline transportation networks

    , International Journal of Greenhouse Gas Control, Vol: 43, Pages: 108-114, ISSN: 1750-5836

    As part of the operation of the carbon capture and storage process, there are clear practical and economic incentives in employing an integrated pipeline network system involving the capture of CO2 from multiple emission sources such as power plants or steel works followed by injection into a single storage site. This paper presents the development and testing of multi-source flow model for predicting the entire flow conditions such as pressure, temperature, fluid phase and CO2 composition throughout the pipeline network and the delivery to the storage site. The model also accounts for pipeline elevation and periodic variations in feed source flow rate, for example as a result of the ramping up or ramping down of power production from coal fired power stations connected to the pipeline network. The ability to produce the above information is of vital importance given the large impact of the stream impurities on the CO2 phase behaviour and their physiochemical interactions with the pipeline material of construction, compressor power requirements and the storage reservoir performance.
  • Journal article
    Kowal J, Pressel S, Duckett JG, Bidartondo MIet al., 2015,

    Liverworts to the rescue: an investigation of their efficacy as mycorrhizal inoculum for vascular plants

    , Functional Ecology, Vol: 30, Pages: 1014-1023, ISSN: 1365-2435

    1. Pezoloma ericae (D.J. Read) Baral, a widespread mycorrhizal fungus of plants in the Ericales,is known to form intracellular associations with several families of leafy liverworts(Schistochilaceae, Lepidoziaceae, Cephaloziaceae, Cephaloziellaceae) in vitro. The ecologicalsignificance of this link between vascular and non-vascular plants is unknown.2. Fungal symbionts were isolated from rhizoids of the leafy liverworts Cephalozia connivens(Dicks.) Lindb. and C. bicuspidata (L.) Dum. (Cephaloziaceae), as well as from the hair rootsof two dominant ericoid mycorrhiza-forming species of European heathlands, Erica tetralix(L.) and Calluna vulgaris (L.).3. Using pure cultures of P. ericae, we resynthesized liverwort–fungus associations to use colonizedliverworts as inoculum which was applied to substrates supporting the growth of heatherseedlings and cuttings. Effects were quantified using germination, rooting, plant colonization,plant survival under waterlogging stress and growth in height in experimental systems withand without liverworts and/or fungi.4. Fungal symbionts growing from liverwort rhizoids readily colonized the hair roots of ericaceousplants to form typical ericoid mycorrhizas.5. The presence of inoculum-bearing liverworts led to significant increases in plant growth.Erica tetralix was more responsive to inoculation than C. vulgaris.6. Ericaceous cuttings rooted and survived more successfully when they were coplanted withpreviously colonized liverwort stems.7. We demonstrate, under realistic ecological circumstances, that liverworts can deliver mycorrhizalinoculum and improve the establishment of vascular plants. We propose that by providingsources of mycorrhizal inoculum, symbiotic non-vascular plants can contribute to therestoration of plant communities dominated by Ericales plants. This research leads to broaderknowledge about the function of ericoid mycorrhizas in ecosystems.
  • Journal article
    Costall AW, Gonzalez Hernandez A, Newton PJ, Martinez-Botas RFet al., 2015,

    Design methodology for radial turbo expanders in mobile organic Rankine cycle applications

    , Applied Energy, Vol: 157, Pages: 729-743, ISSN: 0306-2619

    Future vehicles for clean transport will require new powertrain technologies to further reduce CO2 emissions. Mobile organic Rankine cycle systems target the recovery of waste heat in internal combustion engines, with the exhaust system identified as a prime source. This article presents a design methodology and working fluid selection for radial turbo expanders in a heavy-duty off-road diesel engine application. Siloxanes and Toluene are explored as the candidate working fluids, with the latter identified as the preferred option, before describing three radial turbine designs in detail. A small 15.5. kW turbine design leads to impractical blade geometry, but a medium 34.1. kW turbine, designed for minimum power, is predicted to achieve an isentropic efficiency of 51.5% at a rotational speed of 91.7. k. min-1. A similar 45.6. kW turbine designed for maximum efficiency yields 56.1% at 71.5. k. min-1. This emphasizes the main design trade-off - efficiency decreases and rotational speed increases as the power requirement falls - but shows reasonable radial turbine efficiencies and thus practical turbo expanders for mobile organic Rankine cycle applications are realizable, even considering the compromised flow geometry and high speeds imposed at such small scales.
  • Journal article
    Haghtalab S, Xanthopoulos P, Madani K, 2015,

    A robust unsupervised consensus control chart pattern recognition framework

    , EXPERT SYSTEMS WITH APPLICATIONS, Vol: 42, Pages: 6767-6776, ISSN: 0957-4174
  • Journal article
    Arku RE, Dionisio KL, Hughes AF, Vallarino J, Spengler JD, Castro MC, Agyei-Mensah S, Ezzati Met al., 2015,

    Personal particulate matter exposures and locations of students in four neighborhoods in Accra, Ghana

    , JOURNAL OF EXPOSURE SCIENCE AND ENVIRONMENTAL EPIDEMIOLOGY, Vol: 25, Pages: 557-566, ISSN: 1559-0631

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