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Item Unknown Agricultural decision-making under uncertainty: a loss function on the kriging variance from soil properties predicted by infrared and X-ray fluorescence spectroscopy(EGU: European Geophysical Union, 2021-04-30) Breure, Timo Samuel; Haefele, Stephan M.; Webster, Richard; Hannam, Jacqueline A.; Corstanje, Ronald; Milne, Alice E.Item Open Access An anti-fraud double auction model in vehicle-to-vehicle energy trading with the k-factor approach(IEEE, 2024-05-01) Xu, Yiming; Zhang, Lu; Ozkan, Nazmiye; Long, ChaoThe rise in electric vehicle adoption has reduced greenhouse gas emissions in transportation but overloads the power grid due to charging demands. This paper introduces a Double Auction (DA) model in Vehicle-to-Vehicle (V2V) energy trading with the K-factor approach. The novel approach defines unique market clearing prices for each successfully matched V2V transaction pairs, robustly counteracts potential economic fraud. It overcomes shortcoming of some other models of sacrificing participants who could have conducted V2V transactions in order to prevent economic fraud. Meanwhile, the model ensures transactional economic benefits, transparency and fairness. This work facilitates EV adoption across the UK and globally, by increasing confidence and convenience in energy trading mechanisms.Item Open Access Approaches to modelling fireside corrosion of superheater / reheater tubes in coal and biomass fired combustion power plants(ASM International, 2019-10-24) Simms, Nigel J.; Ekpe, Blessing; Riccio, Chiara; Mori, Stefano; Sumner, Joy; Oakey, John E.The combustion of coal and biomass fuels in power plants generates deposits on the surfaces of superheater / reheater tubes that can lead onto fireside corrosion. This type of materials degradation can limit the lives of such tubes in the long term, and better methods are needed to produce predictive models for such damage. This paper reports on four different approaches that are being investigated to tackle the challenge of modelling fireside corrosion damage on superheaters / reheaters: (a) CFD models to predict deposition onto tube surfaces; (b) generation of a database of available fireside corrosion data; (c) development of mechanistic and statistically based models of fireside corrosion from laboratory exposures and dimensional metrology; (d) statistical analysis of plant derived fireside corrosion datasets using multi-variable statistical techniques, such as Partial Least Squares Regression (PLSR). An improved understanding of the factors that influence fireside corrosion is resulting from the use of a combination of these different approaches to develop a suite of models for fireside corrosion damage.Item Unknown Assessing the opportunities of landfill mining as a source of critical raw materials in Europe(Eurowaste, 2017-10-16) Särkkä, H.; Kaartinen, T.; Hannus, E.; Hirvonen, S.; Valjus, Tuire; Lerssi, J.; Dino, G. A.; Piergiorgio, R.; Griffiths, Zoe; Wagland, Stuart; Coulon, FredericMany of the metals in landfill constitute valuable and scarce natural resources. It has already been recognised that the recovery of these elements is critical for the sustainability of a number of industries. Arsenic (which is an essential part of the production of transistors and LEDs) is predicted to run out sometime in the next five to 50 years if consumption continues at the present rate. Nickel used for anything involving stainless steel and platinum group metals (PGMs) used in catalytic converters, fertilisers and others are also identified as critical materials (CM) to the EU economy at risk of depletion However, despite the increasing demand, none of this supply is supported by recycling. This is due to the high cost of recovery from low concentrations when compared to conventional mining. As demonstrated by the two pilot case studies of this study, mining landfill sites only for their metals content is not expected to be financially viable. However, other opportunities such as Waste-derived fuels from excavated materials exist which if combined , form the concept of ‘enhanced landfill mining’. have the potential to be highly energetic. The energy potential is comparable to the levels of energy of Refuse-Derived Fuels (RDF) produced from non-landfilled wastes.Item Unknown Assessing the source and delivery of organic carbon at a catchment scale using a combined sediment fingerprinting and carbon loss modelling approach(EGU: European Geophysical Union, 2022-05-27) Wiltshire, Catherine; Waine, Toby; Grabowski, Robert C.; Glendell, Miriam; Thornton, Barry; Addy, Steve; Meersmans, JeroenQuantifying land use sources and understanding the dynamics of organic carbon (OC) in river catchments is essential to reduce both on-site and off-site impacts of soil OC erosion. The lake area of Loch Davan, located in Aberdeenshire, Scotland, has been significantly reduced over the last century due to sediment inputs and, in this study, we aimed to identify the primary source(s) and delivery of OC to the loch’s main feeder stream, Logie Burn and its major tributaries.Item Open Access Avocado firmness monitoring with values obtained by means of laser doppler vibrometry(International Society for Horticultural Science, 2012-04-01) Terry, Leon A.; Landahl, SandraAvocado (Persea americana Mill.) ripeness is usually evaluated by destructive firmness assessment, yet quality is notorious for being heterogeneous within a consignment. This problem, which is especially true for imported avocado fruit, lends itself to searching for non-destructive methods for firmness evaluation. Firmness of objects can be analysed by impulse-response. This technique utilizes recording of a vibration signature and interpretation of the resonant frequency. In this study a laser Doppler vibrometer (LDV) was used for non-contact recording. The aim of this study was to show the feasibility of using a LDV to monitor avocado firmness. In order to create avocado batches of different homogeneity, three groups were treated with and without ethylene, inside or outside a box. After day 0 a third of the fruit were transferred into boxes (325 L) to be treated with ethylene for 24 h. A third was kept in boxes untreated and another third was kept on open trays. Avocado fruit cultivar ‘Hass’ were ripened at 18°C and measured on days 0, 2, 3, 4 and 6. Individual fruit were impacted once and two LDV measurements were taken simultaneously at the stem-end and seed-end. This was repeated twice around the fruit. Force-deformation measurements in compression mode were performed by means of uniaxial testing (Instron model 5542) on two opposite sides (day 0 n=8, then n=24 i.e., 8 per treatment/d). Significant differences were found between firmness of avocados over time and across treatments. Firmness decreased exponentially as expected (304.1 to 2.1 N) over six days. The LDV results showed significant differences between days, treatments and laser-location. The resonant frequency of the fruit decreased linearly until day 4 and then decreased more slowly (1671 to 476 Hz). On average, the frequency found at the seed-end of the fruit was higher than the resonant frequency at the stem-end. This is thought to be due to the seed itself, which could influence the vibration pattern. Resonant frequencies showed good correlation to the logarithm of firmness (r=0.87) and therefore were shown capable of monitoring avocado firmness.Item Open Access CFD modeling of a high enthalpy geothermal context(2018-02-28) Renaud, Théo; Stebel, Michal; Verdin, Patrick G.; Falcone, GioiaThe promising development of highly energetic geothermal resources could considerably enhance geothermal power production worldwide. The first attempt at tapping supercritical/heated fluids was made by the Iceland Deep Drilling project (IDDP), but unfortunately a magma layer at a depth of 2,100m was encountered, and the drilling was abandoned. Yet, this drilling operation failure generated new opportunities for assessing the potential power generation close to shallow magmatic intrusions. Detailed numerical methods are required to assess the heat transfer and fluid thermodynamics at wellbore and reservoir scale at near supercritical conditions to provide production scenarios and forecasts as accurate as possible. A primary steady-state study of reservoir and wellbore heat extraction from a geothermal well near a magmatic chamber has been performed with Computational Fluid Dynamics (CFD) techniques. Using simplified geological assumptions based on the IDDP-1 well description, a 2D axisymmetric single phase flow model was developed and its results were compared to those obtained with a full 3D CFD model. The simulated output power simulations reached 25 MW at 350°C and a wellhead pressure of 140 bars. Methodology and results from this study show that CFD techniques can be successfully used to assess geothermal energy outputs for unconventional geothermal wells and can provide details of a vapor superheated flow structure at wellbore-reservoir scale.Item Open Access The challenges, uncertainties and opportunities of bioaerosol dispersion modelling from open composting facilities(WIT Press, 2017-08-06) Williams, Ben; Hayes, Enda; Nasir, Zaheer A.; Rolph, Catherine A.; Jackson, Simon; Khera, Shagun; Bennett, Alan; Gladding, Toni; Drew, Gillian H.; Tyrrel, Sean F.Bioaerosols are ubiquitous organic particles that comprise viruses, bacteria and coarser fractions of organic matter. Known to adversely affect human health, the impact of bioaerosols on a population often manifests as outbreaks of illnesses such as Legionnaires Disease and Q fever, although the concentrations and environmental conditions in which these impacts occur are not well understood. Bioaerosol concentrations vary from source to source, but specific human activities such as water treatment, intensive agriculture and composting facilitate the generation of bioaerosol concentrations many times higher than natural background levels. Bioaerosols are not considered ‘traditional’ pollutants in the same way as PM10, PM2.5, and gases such as NO2, and consequently dispersion models do not include a bespoke method for their assessment. As identified in previous studies, priority areas for improving the robustness of these dispersion models include: 1) the development of bespoke monitoring studies designed to generate accurate modelling input data; 2) the publication of a robust emissions inventory; 3) a code of practice to provide guidelines for consistent bioaerosol modelling practices; and 4) a greater understanding of background bioaerosol emissions. The aim of this research project, funded by the Natural Environmental Research Council (NERC), is to address these key areas through a better understanding of the generation, concentration and potential dispersion of bioaerosols from intensive agricultural and biowaste facilities, using case studies developed at specific locations within the UK. The objective is to further refine existing bioaerosol monitoring and modelling guidelines to provide a more robust framework for regulating authorities and site operators. This contribution outlines the gaps that hinder robust dispersion modelling, and describes the on-site bioaerosol data collection methods used in the study, explaining how they might be used to close these gaps. Examples of bioaerosol dispersion modelled using ADMS 5 are presented and discussed.Item Open Access Characterisation of excavated plastics for thermochemical upcycling to platform chemicals and liquid fuels(2018-2-28) Canopoli, Luisa; Fidalgo Fernandez, Beatriz; Wagland, Stuart T.In Europe there are ~500,000 landfills; plastics represent a consistent and significant proportion of waste in landfill (typically 5-25% w/w). This fraction remains in the landfill, along with other non-biodegradable materials, long after the readily biodegradable organics have degraded. During storage in landfill the plastics physicochemical structure is likely to change because of the occurrence of chemical and biochemical reactions, which can lead to their degradation. For instance, H2S and organic acids produced during the acetogenesis phase of landfill are known to degrade plastics, therefore it can be hypothesised that plastics excavated from landfill are not suitable for conventional recycling. The fate of plastics in landfill has not been largely investigated and limited data exists addressing the changes in chemical and physical properties. The aim of this work is to investigate the degradation of plastics in landfill by characterising chemical and physical properties of samples excavated from different landfill depths. Waste samples were extracted from landfills across the UK at depths of 5-40 m. These were sorted in order to determine the total plastic content and the percentage of each type of plastic present (i.e. PET, HDPE etc). The types of plastics were identified using near infrared [NIR] spectroscopy. The surface properties of the excavated plastics were characterised using SEM/EDS to analyse and evaluate their degradation and contamination levels. Chemical characterisation of each plastic fraction has been carried out by proximate and ultimate analyses. Finally, the surface contamination (metal content) of the plastics was determined by ICP. Fresh, non-landfilled, plastic samples matching the plastic types of those found in landfill were characterised for comparison. The data highlighted plastic type variation across the samples, largely dependent on the age of the excavated material. The extent of degradation, was found to depend on the type of plastic and depth of the sample. This work contributes to address the potential utilisation of excavated plastics, such as for upcycling to platform chemicals and/or liquid fuels through thermochemical conversion.Item Open Access Citric acid aerospace stainless steel passivation: a green approach(Unknown, 2015-09) Bragaglia, Mario; Cherubini, Valeria; Cacciotti, Ilaria; Rinaldi, Marianna; Mori, Stefano; Soltani, P.; Nanni, F.; Kaciulis, S.; Montesperelli, G.Passivation is a common treatment to maximize the corrosion resistance of stainless steel. Nitric acid is generally used and involves several ecological problems, citric acid could be a promising and environmentally friendly alternative to nitric acid. In this work citric acid has been extracted from lemon waste using and eco- friendly procedure. The stainless steel samples have been treated in both nitric and citric acid (commercial and extracted) and corrosion test have been performed. The results show how citric acid can be used as substitute of nitric acid in passivation treatment.Item Open Access A cluster analysis of investment strategies in the offshore wind energy market(Institute of Electrical and Electronics Engineers, 2017-08-18) Ioannou, Anastasia; Vaienti, Claudio; Angus, Andrew; Brennan, Feargal P.This paper maps different investor strategies in the offshore wind energy market based on data from existing wind farms in the UK. This is realized through the employment of cluster analysis, which classifies offshore wind energy investors - who have purchased equity stakes-in terms of the entry timing, exit timing, purchase timing and stake purchased. We, then, perform a SWOT analysis to identify the major strengths, weaknesses, opportunities and threats encountered by each cluster of stakeholders. Cluster analysis revealed the existence of three distinct investment strategy profiles: i) Late entry investors, ii) Pre-commissioning investors, and iii) Own-build-transfer investors. Corporate and institutional investors tend to be late entry investors, whose strategy is based on buying assets while they are fully operational avoiding construction risks, retaining a risk aversion profile. The exit timing of OEMs and EPCI contractors usually takes place before or right after the commissioning of the wind farm. Finally, major Utilities tend to keep the operating assets on their balance sheet and divest only part of them (mostly minority stakes) during the operating stage; Independent energy companies are found in both 2nd and 3rd cluster; however, exceptions may be observed.Item Open Access CNTs-added PMNT/PDMS flexible piezoelectric nanocomposite for energy harvesting application(Taylor and Francis, 2018-04-05) Promsawat, Napatporn; Promsawat, Methee; Janphuang, Phatthanapong; Beeby, Steve; Rojviriya, Catleya; Pakawanit, Phakkhananan; Pojprapai, Soodkhet; Luo, ZhenhuaThe flexible piezoelectric nanocomposites based on lead magnesium niobate titanate [Pb(Mg1/3Nb2/3)0.65Ti0.35O3; PMNT] particles in polydimethylsiloxane (PDMS) matrix were fabricated and characterized. PMNT powders are synthesized using the columbite precursor method. PMNT/PDMS flexible nanocomposites are then prepared by spin casting technique, where a small amount of carbon nanotubes (CNTs) is added into the PMNT/PDMS composite to enhance cross-links between PMNT particles and PDMS matrix. The phase and microstructure of the nanocomposite are investigated by using X-ray diffraction and scanning electron microscope (SEM). The electromechanical behavior is evaluated by using an autonomous pneumatic actuator. The flexible composite, occupying approximately 300 mm2, is capable of generating an open-circuit voltage (Voc) of 2.83 ± 0.24 V and a short-circuit current (Isc) signal of 0.33 ± 0.01 µA across 10 Ω resistor under mechanical load of 300 N. The generated electrical charges are 29026 pC. The relative dielectric constant is measured at 10 kHz and found to be 6.76 ± 1.15. The piezoelectric PMNT/PDMS composite can potentially be used in a variety of applications such as wearable sensors, actuators, and energy harvesting for converting kinetic energy into useful electrical energy.Item Open Access A comparison on the dynamics of a floating vertical axis wind turbine on three different floating support structures(Elsevier, 2014) Collu, Maurizio; Borg, MichaelTo increase the competitiveness of offshore wind energy in the global energy market, it is necessary to identify optimal offshore wind turbine configurations to deliver the lowest cost of energy. For deep waters where floating wind turbines are the feasible support structure option, the vertical axis wind turbine concept might prove to be one of these optimal configurations. This paper carries out a preliminary investigation into the dynamics of a vertical axis wind turbine coupled with three generic floating support structures originally intended for horizontal axis wind turbines. The modifications to the original characteristics of the support structures were kept to a minimum to illustrate the use of floating horizontal axis wind turbine platforms for floating vertical axis wind turbines Issues regarding the adequacy of the mooring systems are outlined and an overview of platform responses in a number of varying met-ocean conditions is presented and discussed.Item Open Access Control strategy for a modified cascade multilevel inverter with dual DC source for enhanced drivetrain operation(IEEE, 2017-02-16) Bendyk, Maciej; Luk, Patrick Chi-KwongThis paper presents a new control strategy for a modified cascade multilevel inverter used in drivetrain operations. The proposed inverter is a three-phase bridge with its dc link fed by a dc source (battery), and each phase series-connected respectively to an H-bridge fed with a floating dc source (ultracapacitor). To exploit the potentials of the inverter for enhanced drivetrain performance, a sophisticated yet efficient modulation method is proposed to optimise energy transfer between the dc sources and with the load (induction motor) during typical operations, and to minimise switching losses and harmonics distortion. Detailed analysis of the proposed control method is presented, which is supported by experimental verifications.Item Open Access Creating agroforestry innovation and best practice leaflets(European Agroforestry Federation and the University of Santiago de Compostela, 2018-05-30) Burgess, Paul; Moreno, Gerardo; Pantera, Anastasia; Kanzler, Michael; Hermansen, John; van Lerberghe, Philippe; Balaguer, Fabien; Girardin, Nicolas; Rosati, Adolfo; Graves, Anil; Watté, Jeroen; Mosquera-Losada, Rosa; Waldie, Kevin; Pagella, Tim; Liagre, FabienA key output of the EU FP7 project AGFORWARD was a series of 46 agroforestry innovation and 10 agroforestry best practice leaflets for European farmers and other stakeholders. This paper describes the process of over 80 people working together to create the leaflets and the overall result.Item Open Access Design challenge of high-speed high-power density motor for advanced electrical submersible pump(IEEE, 2023-09-06) Luk, Patrick Chi-KwongElectrical Submersible Pumps (ESP) have been widely used in oil and gas extraction as a reliable and efficient method of artificial lift to enhance flow rate of oil and gas from a well. However, as the world shifts towards a less fossil-fuel based future, the role of ESP will need to evolve in order to continue to play an important role in the transitional period. One key challenge facing ESP technology is the increasing depth of exploitable oil reserves, with many new ones located at depths of 3km-4km. This implies the need for more advanced ESP technology that operates at high-speed and high-power density to generate additional artificial lift while keeping a compact and robust structure. These competing features demand a disciplined design methodology. This paper presents the electromagnetic design considerations of a 150kW permanent magnet (PM) motor driving an advanced centrifugal pump at 10,000rpm through a 90mm tubing. Three motor designs are undertaken, and their performances are compared. The results show all three designs meet the target specifications. However, the most optimal option will be dependent on its adaptability in integrating thermal management on the cable length and the operating voltage.Item Open Access Design of a multi-layer interior ferrite permanent magnet synchronous machine for traction applications(IET, 2014-04-10) Xia, Bing; Fei, Wei-Zhong; Luk, Patrick Chi-Kwong; Wu, DA novel design of interior ferrite permanent magnet synchronous machine with multi-layer configuration is proposed for traction applications. Although the ferrite magnet can be disadvantaged by its low residual flux density and energy product, it is proposed that flux-focusing and multi-layer configurations can be utilized to harness both permanent magnet (PM) torque and reluctance torque to recoup the loss of the PM torque due to its intrinsic property. The machines with up to three-layer magnets are presented and evaluated comprehensively. The results suggest that the two-layer machine provides the best performance among the three configurations. Furthermore, compared against a commercial rare-earth equivalent, the proposed ferrite machine is shown to have nearly the same torque with 32% less electromagnetic losses. The findings underpin interior ferrite permanent magnet synchronous machine as an attractive alternative for traction applicationsItem Open Access Design of a novel CSP/MED desalination system(American Institute of Physics (AIP), 2022-05-12) Sansom, Christopher L.; Patchigolla, Kumar; Jonnalagadda, Kranthi; King, PeterWe describe the design of a large-scale thermal desalination demonstrator unit for use in arid locations with a medium-to-high DNI. Most of thermal energy is provided by a conventional parabolic trough field, in the case of the demonstrator this being 4MWt. The desalination sub-system comprises a 3-effect MED, the first stage of which is a large 20 m diameter glass and steel-structured geodesic and transparent dome. The thermal energy is supplemented by direct sunlight transmitted through the dome and by an arc of small heliostats which focus yet more sunlight onto the dome itself. The prototype is under construction at Neom in KSA.Item Open Access Developing scenarios for product longevity and sufficiency(IOS Press, 2017-11-10) Dewberry, E. L.; Sheldrick, Leila; Sinclair, M.; Moreno, Mariale; Makatsoris, CharalamposThis paper explores the narrative of peoples' relationships with products as a window on understanding the types of innovation that may inform a culture of sufficiency. The work forms part of the ‘Business as Unusual: Designing Products with Consumers in the Loop’ [BaU] project, funded as part of the UK EPSRC-ESRC RECODE network (RECODE, 2016) that aims to explore the potential of re-distributed manufacturing (RdM) in a context of sustainability. This element of the project employed interviews, mapping and workshops as methods to investigate the relationship between people and products across the product lifecycle. A focus on product longevity and specifically the people-product interactions is captured in conversations around product maintenance and repair. In exploring ideas of ‘broken’ we found different characteristics of, and motivations for, repair. Mapping these and other product-people interactions across the product lifecycle indicated where current activity is, who owns such activity (i.e. organisation or individual) where gaps in interactions occur. These issues were explored further in a workshop which grouped participants to look at products from the perspective of one of four scenarios; each scenario represented either short or long product lifespans and different types of people engagement in the design process. The findings help give shape to new scenarios for designing sufficiency-based social models of material flows.Item Open Access Difficulties in using spectral properties to map irrigated areas in a temperate climate: A case study of potatoes in England(2008) Shamal, S.; Weatherhead, E. K.; Knox, Jerry W.Irrigation in England is supplemental to rainfall and only used on a small proportion of the cultivated land, notably on high value vegetable and potato crops. However, it is a significant water user as most of the irrigated area is located in the driest part of England. The existing data on irrigated areas are based on government and industry surveys. Recently these datasets have been used with Geographic Information Systems (GIS) to produce irrigated maps, but these can only be published at catchment level due to confidentiality constraints on the datasets. To assess the possibility of using remote sensing data for mapping the irrigated area, one Landsat image for the summer 2003 was used to compare the spectral signature between irrigated and non-irrigated potato fields in the East of England. ISODATA algorithm was used to perform unsupervised classification, and 50 spectral classes were created. A ground truth dataset was then used to identify the most representative spectral class for irrigated and nonirrigated fields. The result showed that categories both fall into the same spectral class, suggesting there are no significant differences between their spectral properties. Therefore, using satellite imagery may not yet be an appropriate method or need more research for mapping irrigated area in temperate climates such as England. The summer rainfall reduces the water stress differences between irrigated and non-irrigated potato fields such that these satellite sensors cannot yet differentiate the crops.