Academic publications

This paper analyzes the interaction between credit constraints and trading behavior, decomposing trade in extensive and intensive margins. I construct a unique dataset containing firm-level trade transaction data, balance sheets and credit scores from an independent credit insurance company for Belgian manufacturing firms between 1999 and 2007. Firms are more likely to be exporting or importing if they enjoy lower credit constraints. Also, firms that have better credit rating export and import more. Importing and exporting behaviors differ in how both the level and growth of the various margins of trade are related to credit constraints in one important dimension. In the case of exports, it is the intensive and extensive margins of exports in terms of both product and destinations that are significantly associated with credit constraints whereas for imports it is the extensive margin in terms of products only.

Journal article

Mazur C, Contestabile M, Offer GJ, Brandon NPet al., 2015,

Assessing and comparing German and UK transition policies for electric mobility

, ENVIRONMENTAL INNOVATION AND SOCIETAL TRANSITIONS, Vol: 14, Pages: 84-100, ISSN: 2210-4224

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Citations: 46

Journal article

Newton P, Martinez-Botas R, Seiler M, 2015,

A Three-Dimensional Computational Study of Pulsating Flow Inside a Double Entry Turbine

, JOURNAL OF TURBOMACHINERY-TRANSACTIONS OF THE ASME, Vol: 137, ISSN: 0889-504X

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Citations: 19

Journal article

Malloy AC, Martinez-Botas RF, Lamperth M, 2015,

Measurement of Magnet Losses in a Surface Mounted Permanent Magnet Synchronous Machine

, IEEE TRANSACTIONS ON ENERGY CONVERSION, Vol: 30, Pages: 323-330, ISSN: 0885-8969

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Citations: 21

Journal article

Desiro A, Faccio A, Kaech A, Bidartondo MI, Bonfante Pet al., 2015,

<i>Endogone</i>, one of the oldest plant-associated fungi, host unique Mollicutes-related endobacteria

, NEW PHYTOLOGIST, Vol: 205, Pages: 1464-1472, ISSN: 0028-646X

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Citations: 53

Journal article

Rimington WR, Pressel S, Duckett JG, Bidartondo MIet al., 2015,

Fungal associations of basal vascular plants: reopening a closed book?

, NEW PHYTOLOGIST, Vol: 205, Pages: 1394-1398, ISSN: 0028-646X

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Citations: 63

Journal article

AghaKouchak A, Norouzi H, Madani K, Mirchi A, Azarderakhsh M, Nazemi A, Nasrollahi N, Farahmand A, Mehran A, Hasanzadeh Eet al., 2015,

Aral Sea syndrome desiccates Lake Urmia: Call for action

, JOURNAL OF GREAT LAKES RESEARCH, Vol: 41, Pages: 307-311, ISSN: 0380-1330

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Citations: 222

Journal article

Templeton MR, Hammoud AS, Butler AP, Braun L, Foucher JA, Grossmann J, Boukari M, Faye S, Jourda JPet al., 2015,

Nitrate pollution of groundwater by pit latrines in developing countries

, AIMS Environmental Science, Vol: 2, Pages: 302-313

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Journal article

Togashi HF, Prentice IC, Evans BJ, Forrester DI, Drake P, Feikema P, Brooksbank K, Eamus D, Taylor Det al., 2015,

Morphological and moisture availability controls of the leaf area-to-sapwood area ratio: analysis of measurements on Australian trees

, ECOLOGY AND EVOLUTION, Vol: 5, Pages: 1263-1270, ISSN: 2045-7758

The leaf area-to-sapwood area ratio (LA:SA) is a key plant trait that links photosynthesis to transpiration. The pipe model theory states that the sapwood cross-sectional area of a stem or branch at any point should scale isometrically with the area of leaves distal to that point. Optimization theory further suggests that LA:SA should decrease toward drier climates. Although acclimation of LA:SA to climate has been reported within species, much less is known about the scaling of this trait with climate among species. We compiled LA:SA measurements from 184 species of Australian evergreen angiosperm trees. The pipe model was broadly confirmed, based on measurements on branches and trunks of trees from one to 27 years old. Despite considerable scatter in LA:SA among species, quantile regression showed strong (0.2 < R1 < 0.65) positive relationships between two climatic moisture indices and the lowermost (5%) and uppermost (5–15%) quantiles of log LA:SA, suggesting that moisture availability constrains the envelope of minimum and maximum values of LA:SA typical for any given climate. Interspecific differences in plant hydraulic conductivity are probably responsible for the large scatter of values in the mid-quantile range and may be an important determinant of tree morphology.

Journal article

Goldberg SJ, Ball GI, Allen BC, Schladow SG, Simpson AJ, Masoom H, Soong R, Graven HD, Aluwihare LIet al., 2015,

Refractory dissolved organic nitrogen accumulation in high-elevation lakes

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

The role of dissolved organic matter (DOM) as either a sink for inorganic nutrients or anadditional nutrient source is an often-neglected component of nutrient budgets in aquaticenvironments. Here, we examined the role of DOM in reactive nitrogen (N) storage in SierraNevada (California, USA) lakes where atmospheric deposition of N has shifted the lakestoward seasonal phosphorus (P)-limitation. Nuclear magnetic resonance (NMR) spectroscopyand isotope analyses performed on DOM isolated from Lake Tahoe reveal the accumulationof refractory proteinaceous material with a 100–200-year residence time. Incontrast, smaller lakes in the same watershed contain DOM with typical terrestrial characteristics,indicating that proteins in Lake Tahoe are autochthonously produced. These datasupport the role of DOM as a possible sink for reactive N in these lake ecosystems andidentify a potential role for DOM in affecting the inorganic nutrient stoichiometry of theseenvironments.

Journal article

Bakewell C, White AJP, Long NJ, Williams CKet al., 2015,

Scandium and Yttrium Phosphasalen Complexes as Initiators for Ring-Opening Polymerization of Cyclic Esters

, Inorganic Chemistry, Vol: 54, Pages: 2204-2212, ISSN: 1520-510X

Journal article

Paul S, Zhu Y, Romain C, Brooks R, Saini PK, Williams CKet al., 2015,

Ring-opening copolymerization (ROCOP): synthesis and properties of polyesters and polycarbonates

, Chemical Communications, Vol: 51, Pages: 6459-6479, ISSN: 1364-548X

Controlled routes to prepare polyesters and polycarbonates are of interest due to the widespread application of these materials and the opportunities provided to prepare new copolymers. Furthermore, ring-opening copolymerization may enable new poly(ester–carbonate) materials to be prepared which are inaccessible using alternative polymerizations. This review highlights recent advances in the ring-opening copolymerization catalysis, using epoxides coupled with anhydrides or CO2, to produce polyesters and polycarbonates. In particular, the structures and performances of various homogeneous catalysts are presented for the epoxide–anhydride copolymerization. The properties of the resultant polyesters and polycarbonates are presented and future opportunities highlighted for developments of both the materials and catalysts.

Journal article

Tauxe L, Sugisaki S, Jimenez-Espejo F, Escutia C, Cook CP, van de Flierdt T, Iwai Met al., 2015,

Geology of the Wilkes land sub-basin and stability of the East Antarctic Ice Sheet: Insights from rock magnetism at IODP Site U1361

, EARTH AND PLANETARY SCIENCE LETTERS, Vol: 412, Pages: 61-69, ISSN: 0012-821X

Journal article

Hardwick SR, Toumi R, Pfeifer M, Turner EC, Nilus R, Ewers RMet al., 2015,

The relationship between leaf area index and microclimate in tropical forest and oil palm plantation: Forest disturbance drives changes in microclimate

, Agricultural and Forest Meteorology, Vol: 201, Pages: 187-195, ISSN: 0168-1923

Land use change is a major threat to biodiversity. One mechanism by which land use change influences biodiversity and ecological processes is through changes in the local climate. Here, the relationships between leaf area index and five climate variables – air temperature, relative humidity, vapour pressure deficit, specific humidity and soil temperature – are investigated across a range of land use types in Borneo, including primary tropical forest, logged forest and oil palm plantation. Strong correlations with the leaf area index are found for the mean daily maximum air and soil temperatures, the mean daily maximum vapour pressure deficit and the mean daily minimum relative humidity. Air beneath canopies with high leaf area index is cooler and has higher relative humidity during the day. Forest microclimate is also found to be less variable for sites with higher leaf area indices. Primary forest is found to be up to 2.5 °C cooler than logged forest and up to 6.5 °C cooler than oil palm plantations. Our results indicate that leaf area index is a useful parameter for predicting the effects of vegetation upon microclimate, which could be used to make small scale climate predictions based on remotely sensed data.

Journal article

Gambhir A, Tse LKC, Tong D, Martinez-Botas Ret al., 2015,

Reducing China’s road transport sector CO2 emissions to 2050: Technologies, costs and decomposition analysis

, Applied Energy, Vol: 157, Pages: 905-917, ISSN: 1872-9118

The growth of China’s road transport sector has driven huge increases in China’s oil demand and CO2 emissions over the last two decades, and these trends are likely to continue in the absence of specific measures to reduce the average carbon intensity of road vehicles. This paper describes a model, provided in full online, to undertake scenario analysis on the cost and CO2 emissions impact of substituting current vehicle drivetrain types with alternatives during the period 2010–2050. A detailed decomposition of the additional costs and CO2 emissions savings of each low-carbon vehicle type into their component parts is undertaken to calculate the marginal abatement cost of each vehicle and drivetrain type in 2050. The results indicate that passenger cars and heavy-duty trucks constitute the majority of future CO2 emissions savings potential, but that, using the central cost assumptions, alternative vehicle drivetrains are significantly more cost-effective for trucks than passenger cars. The low-carbon scenario sees demand for oil products (gasoline and diesel) more than 40% below the business-as-usual scenario in 2050. The total mitigation cost in 2050 is (US2010)$64 billion per year, or 1.3% of the total annual expenditure on road transport in China in 2050, using a discount rate of 5% to annualise vehicle purchase costs, although this cost increases with higher discount rates. A sensitivity analysis demonstrates that measures in addition to those assumed in the low-carbon scenario could achieve further emissions reductions, in some cases at negative costs. The availability and transparency of the model allows testing and development of a range of further scenarios and sensitivities, to aid in planning an optimal decarbonisation strategy for this highly carbon-intensive sector.

Journal article

Lynd LR, Sow M, Chimphango AFA, Cortez LAB, Brito Cruz CH, Elmissiry M, Laser M, Mayaki IA, Moraes MAFD, Nogueira LAH, Wolfaardt GM, Woods J, van Zyl WHet al., 2015,

Bioenergy and African transformation

, Biotechnology for Biofuels, Vol: 8, ISSN: 1754-6834

Journal article

Dodds PE, Staffell L, Hawkes AD, Li F, Grunewald P, McDowall W, Ekins Pet al., 2015,

Hydrogen and fuel cell technologies for heating: A review

, International Journal of Hydrogen Energy, Vol: 40, Pages: 2065-2083, ISSN: 1879-3487

Report

Green RJ, Staffell I, 2015,

Evidence on Wind Farm Performance Decline in the UK

, Evidence on Wind Farm Performance Decline in the UK

Onshore wind farms in the UK have aged at about the same rate as other kinds ofpower station. The average wind farm has an annual load factor of about 28% whenfirst commissioned, which declines by about 0.4 percentage points per year. After 15years, the load factor would have fallen to 23%. This ageing does not appear to havemade developers replace their farms early. Forty out of the first forty-five windfarms commissioned in the UK were still operating at this age; four had beenrepowered. Taking this deterioration into account raises the levelised cost ofelectricity by around 9% over a 24-year lifespan, discounting at 10 per cent a year.This is a summary of the peer-reviewed paper “How does wind farm performancedecline with age?” published in Renewable Energy, vol. 65, pp 775-786, which isavailable to download from http://tinyurl.com/wind-decline.

Journal article

Emmott CJM, Roehr JA, Campoy-Quiles M, Kirchartz T, Urbina A, Ekins-Daukes NJ, Nelson Jet al., 2015,

Organic photovoltaic greenhouses: a unique application for semi-transparent PV?

, Energy & Environmental Science, Vol: 8, Pages: 1317-1328, ISSN: 1754-5706

Organic photovoltaics are an emerging solar power technology which embody properties such astransparency, flexibility, and rapid, roll to roll manufacture, opening the potential for unique nicheapplications. We report a detailed techno-economic analysis of one such application, namely thephotovoltaic greenhouse, and discuss whether the unique properties of the technology can provideadvantages over conventional photovoltaics. The potential for spectral selectivity through the choice ofOPV materials is evaluated for the case of a photovoltaic greenhouse. The action spectrum of typicalgreenhouse crops is used to determine the impact on crop growth of blocking different spectral rangesfrom the crops. Transfer matrix optical modelling is used to assess the efficiency and spectrally resolvedtransparency of a variety of commercially available semi-conducting polymer materials, in addition to anon-commercial low-band-gap material with absorption outside that required for crop growth. Economicanalysis suggests there could be a huge potential for OPV greenhouses if aggressive cost targets can bemet. Technical analysis shows that semi-transparent OPV devices may struggle to perform better thanopaque crystalline silicon with partial coverage, however, OPV devices using the low-band-gap materialPMDPP3T, as well as a high efficiency mid-band-gap polymer PCDTBT, can demonstrate improvedperformance in comparison to opaque, flexible thin-film modules such as CIGS. These results stress theimportance of developing new, highly transparent electrode and interlayer materials, along with highefficiency active layers, if the full potential of this application is going to be realised.

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Journal article

Rein G, Jervis FX, 2015,

Experimental study on the burning behaviour of Pinus halepensis needles using small-scale fire calorimetry of live, aged and dead samples

, Fire and Materials, Vol: 40, Pages: 385-395, ISSN: 1099-1018

Limited research has been conducted on the burning characteristics of live fuels, which are commonly assumed to behave like moist dead fuels. We use small-scale laboratory calorimetric experiments to investigate the differences in fire dynamics between live and dead Pinus halepensis needles. The study includes laboratory-aged samples and different moisture conditions (fresh or oven dry). A series of ten fire behaviour parameters are extracted from the measurements to identify and quantify differences. The main parameters are the following: time to ignition; flaming time; mass loss pre-ignition, during flaming, and during smouldering; peak power; effective heat of combustion; mean and peak CO/CO2; and radiative fraction. Using these parameters, we show that the most flammable samples are fresh dead and aged needles, followed by dry dead and dry live needles. The least flammable is fresh live needles. Live needles ignite about four times slower, and burn with ~60% lower power and ~50% lower heat of combustion than dead needles. Aged needles resemble most closely the behaviour of dead needles, but many fire behaviour parameters were significantly different. The results confirm the importance of moisture content in the burning behaviour of pine needles, but the differences between live and dead samples cannot be explained solely in terms of moisture but require consideration of plant chemistry and sample drying.

Journal article

Ruiz-Trejo E, Boldrin P, Medley-Hallam JL, Darr J, Atkinson A, Brandon NPet al., 2015,

Partial oxidation of methane using silver/gadolinia-doped ceria composite membranes

, Chemical Engineering Science, Vol: 127, Pages: 269-275, ISSN: 1873-4405

Methane was partially oxidised to CO using oxygen permeated through a 1 mm thick silver/Ce0.9Gd0.1O2−x (Ag/CGO) composite membrane operating at 500–700 °C with air at 1 bar pressure. The membranes were fabricated by sintering ultrafine nanoparticles of gadolinia-doped ceria (<5 nm) coated with silver using Tollens׳ reaction. This unique combination led to dense composites with low content of silver (7 vol%), no reaction between the components and predominant metallic conductivity. When feeding 4% methane at 700 °C to a 1-mm thick Ag/CGO using Ni as reforming catalyst, the conversion reached 21% and the CO selectivity 92% with an estimated oxygen flux of 0.18 mL min−1 cm−2 (NTP). The samples were stable in carbon-containing atmospheres and under a large pO2 transmembrane pressure difference at temperatures below 700 °C for 48 h.

Conference paper

Green RJ, Staffell I, 2015,

Storage in the electricity market

, International Ruhr Energy Conference 2015

Journal article

Young DA, Lindzey LE, Blankenship DD, Greenbaum JS, Garcia De Gorordo A, Kempf SD, Roberts JL, Warner RC, Van Ommen T, Siegert MJ, Le Meur Eet al., 2015,

Land-ice elevation changes from photon-counting swath altimetry: first applications over the Antarctic ice sheet

, Journal of Glaciology, Vol: 61, Pages: 17-28, ISSN: 1727-5652

Satellite altimetric time series allow high-precision monitoring of ice-sheet mass balance.Understanding elevation changes in these regions is important because outlet glaciers along ice-sheetmargins are critical in controlling flow of inland ice. Here we discuss a new airborne altimetry datasetcollected as part of the ICECAP (International Collaborative Exploration of the Cryosphere by AirborneProfiling) project over East Antarctica. Using the ALAMO (Airborne Laser Altimeter with MappingOptics) system of a scanning photon-counting lidar combined with a laser altimeter, we extend the2003–09 surface elevation record of NASA’s ICESat satellite, by determining cross-track slope and thusindependently correcting for ICESat’s cross-track pointing errors. In areas of high slope, cross-trackerrors result in measured elevation change that combines surface slope and the actual z=t signal.Slope corrections are particularly important in coastal ice streams, which often exhibit both rapidlychanging elevations and high surface slopes. As a test case (assuming that surface slopes do not changesignificantly) we observe a lack of ice dynamic change at Cook Ice Shelf, while significant thinningoccurred at Totten and Denman Glaciers during 2003–09.

Journal article

Kennicutt MC, Chown SL, Cassano JJ, Liggett D, Peck LS, Massom R, Rintoul SR, Storey J, Vaughan DG, Wilson TJ, Allison I, Ayton J, Badhe R, Baeseman J, Barrett PJ, Bell RE, Bertler N, Bo S, Brandt A, Bromwich D, Cary SC, Clark MS, Convey P, Costa ES, Cowan D, Deconto R, Dunbar R, Elfring C, Escutia C, Francis J, Fricker HA, Fukuchi M, Gilbert N, Gutt J, Havermans C, Hik D, Hosie G, Jones C, Kim YD, Le Maho Y, Lee SH, Leppe M, Leitchenkov G, Li X, Lipenkov V, Lochte K, López-Martínez J, Lüdecke C, Lyons W, Marenssi S, Miller H, Morozova P, Naish T, Nayak S, Ravindra R, Retamales J, Ricci CA, Rogan-Finnemore M, Ropert-Coudert Y, Samah AA, Sanson L, Scambos T, Schloss IR, Shiraishi K, Siegert MJ, Simões JC, Storey B, Sparrow MD, Wall DH, Walsh JC, Wilson G, Winther JG, Xavier JC, Yang H, Sutherland WJet al., 2015,

A roadmap for Antarctic and Southern Ocean science for the next two decades and beyond

, Antarctic Science, Vol: 27, Pages: 3-18, ISSN: 1365-2079

Antarctic and Southern Ocean science is vital to understanding natural variability, the processesthat govern global change and the role of humans in the Earth and climate system. The potential for newknowledge to be gained from future Antarctic science is substantial. Therefore, the international Antarcticcommunity came together to ‘scan the horizon’ to identify the highest priority scientific questions thatresearchers should aspire to answer in the next two decades and beyond. Wide consultation was afundamental principle for the development of a collective, international view of the most important futuredirections in Antarctic science. From the many possibilities, the horizon scan identified 80 key scientificquestions through structured debate, discussion, revision and voting. Questions were clustered into seventopics: i) Antarctic atmosphere and global connections, ii) Southern Ocean and sea ice in a warming world,iii) ice sheet and sea level, iv) the dynamic Earth, v) life on the precipice, vi) near-Earth space and beyond,and vii) human presence in Antarctica. Answering the questions identified by the horizon scan will requireinnovative experimental designs, novel applications of technology, invention of next-generation field andlaboratory approaches, and expanded observing systems and networks. Unbiased, non-contaminatingprocedures will be required to retrieve the requisite air, biota, sediment, rock, ice and water samples.Sustained year-round access to Antarctica and the Southern Ocean will be essential to increase winter-timemeasurements. Improved models are needed that represent Antarctica and the Southern Ocean in theEarth System, and provide predictions at spatial and temporal resolutions useful for decision making.A co-ordinated portfolio of cross-disciplinary science, based on new models of international collaboration,will be essential as no scientist, programme or nation can realize these aspirations alone.

Journal article

Vandeginste V, John CM, Beckert J, 2015,

Diagenetic Geobodies: Fracture-Controlled Burial Dolomite in Outcrops From Northern Oman

, SPE RESERVOIR EVALUATION & ENGINEERING, Vol: 18, Pages: 84-93, ISSN: 1094-6470

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Citations: 9

Journal article

Jorquera CO, Oates CJ, Plant JA, Kyser K, Ihlenfeld C, Voulvoulis Net al., 2015,

Regional hydrogeochemical mapping in Central Chile: natural and anthropogenic sources of elements and compounds

, GEOCHEMISTRY-EXPLORATION ENVIRONMENT ANALYSIS, Vol: 15, Pages: 72-96, ISSN: 1467-7873

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Citations: 11

Journal article

Agostini L, Touber E, Leschziner MA, 2015,

The turbulence vorticity as a window to the physics of friction-drag reduction by oscillatory wall motion

, INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW, Vol: 51, Pages: 3-15, ISSN: 0142-727X

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Citations: 22

Heavy-duty engine electric turbocompounding

On the Dynamics of Flows Induced by Topographic Ridges

Properties and Origins of the Anisotropic Eddy-Induced Transport in the North Atlantic

Exporters, importers and credit constraints

Assessing and comparing German and UK transition policies for electric mobility

A Three-Dimensional Computational Study of Pulsating Flow Inside a Double Entry Turbine

Measurement of Magnet Losses in a Surface Mounted Permanent Magnet Synchronous Machine

<i>Endogone</i>, one of the oldest plant-associated fungi, host unique Mollicutes-related endobacteria

Fungal associations of basal vascular plants: reopening a closed book?

Aral Sea syndrome desiccates Lake Urmia: Call for action

Nitrate pollution of groundwater by pit latrines in developing countries

Morphological and moisture availability controls of the leaf area-to-sapwood area ratio: analysis of measurements on Australian trees

Refractory dissolved organic nitrogen accumulation in high-elevation lakes

Scandium and Yttrium Phosphasalen Complexes as Initiators for Ring-Opening Polymerization of Cyclic Esters

Ring-opening copolymerization (ROCOP): synthesis and properties of polyesters and polycarbonates

Geology of the Wilkes land sub-basin and stability of the East Antarctic Ice Sheet: Insights from rock magnetism at IODP Site U1361

The relationship between leaf area index and microclimate in tropical forest and oil palm plantation: Forest disturbance drives changes in microclimate

Reducing China’s road transport sector CO2 emissions to 2050: Technologies, costs and decomposition analysis

Bioenergy and African transformation

Hydrogen and fuel cell technologies for heating: A review

Evidence on Wind Farm Performance Decline in the UK

Organic photovoltaic greenhouses: a unique application for semi-transparent PV?

Experimental study on the burning behaviour of Pinus halepensis needles using small-scale fire calorimetry of live, aged and dead samples

Partial oxidation of methane using silver/gadolinia-doped ceria composite membranes

Storage in the electricity market

Land-ice elevation changes from photon-counting swath altimetry: first applications over the Antarctic ice sheet

A roadmap for Antarctic and Southern Ocean science for the next two decades and beyond

Diagenetic Geobodies: Fracture-Controlled Burial Dolomite in Outcrops From Northern Oman

Regional hydrogeochemical mapping in Central Chile: natural and anthropogenic sources of elements and compounds

The turbulence vorticity as a window to the physics of friction-drag reduction by oscillatory wall motion

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