Co-located wave and offshore wind farms: A preliminary approach to the shadow effect

In recent years, with the consolidation of offshore wind technology and the progress carried out for wave energy technology, the option of combine both technologies has arisen. This combination rest mainly in two main reasons: in one hand, to increase the sustainability of both energies by means of a more rational harnessing of the natural resources; in the other hand, to reduce the costs of both technologies by sharing some of the most important costs of an offshore project. In addition to these two powerful reasons there are a number of technology synergies between wave and wind systems which makes their combination even more suitable. Co-located projects are one of the alternatives to combine wave-wind systems, and it is specially for these project were so-called shadow effect synergy becomes meaningful. In particular, this paper deals with the co-location of Wave Energy Conversion (WEC) technologies into a conventional offshore wind farm. More specifically, an overtopping type of WEC technology was considered in this work to study the effects of its co-location with a conventional offshore wind park. This study aims to give a preliminary approach to the shadow effect and its implications for both wave and offshore wind energies

CO-LOCATED WAVE AND OFFSHORE WIND FARMS: A PRELIMINARY CASE STUDY OF AN HYBRID ARRAY

In recent years, with the consolidation of offshore wind technology and the progress carried out for wave energy technology, the option of co-locate both technologies at the same marine area has arisen. Co-located projects are a combined solution to tackle the shared challenge of reducing technology costs or a more sustainable use of the natural resources. In particular, this paper deals with the co-location of Wave Energy Conversion (WEC) technologies into a conventional offshore wind farm. More specifically, an overtopping type of WEC technology was considered in this work to study the effects of its co-location with a conventional offshore wind park

Hybrid Wave and Offshore Wind Farms: a Comparative Case Study of Co-located Layouts

Marine energy is one of the most promising alternatives to fossil fuels due to the enormous energy resource available. However, it is often considered uneconomical and difficult. Co-located offshore wind turbines and wave energy converters have emerged as a solution to increase the competitiveness of marine energy. Among the benefits of colocated farms, this work focuses on the shadow effect, i.e. the reduction in wave height in the inner part of the farm, which can lead to significant savings in operation and maintenance (O&M) costs thanks to the augmented weather windows for accessing the wind turbines. The aim of this study is to quantify the wave height reduction achieved within a co-located wave-wind farm. Different locations and a large number of layouts are analysed in order to define the optimum disposition

A Review of Solar Thermochemical CO2 Splitting Using Ceria-Based Ceramics With Designed Morphologies and Microstructures

This review explores the advances in the synthesis of ceria materials with specific morphologies or porous macro- and microstructures for the solar-driven production of carbon monoxide (CO) from carbon dioxide (CO2). As the demand for renewable energy and fuels continues to grow, there is a great deal of interest in solar thermochemical fuel production (STFP), with the use of concentrated solar light to power the splitting of carbon dioxide. This can be achieved in a two-step cycle, involving the reduction of CeO2 at high temperatures, followed by oxidation at lower temperatures with CO2, splitting it to produce CO, driven by concentrated solar radiation obtained with concentrating solar technologies (CST) to provide the high reaction temperatures of typically up to 1,500°C. Since cerium oxide was first explored as a solar-driven redox material in 2006, and to specifically split CO2 in 2010, there has been an increasing interest in this material. The solar-to-fuel conversion 1097efficiency is influenced by the material composition itself, but also by the material morphology that mostly determines the available surface area for solid/gas reactions (the material oxidation mechanism is mainly governed by surface reaction). The diffusion length and specific surface area affect, respectively, the reduction and oxidation steps. They both depend on the reactive material morphology that also substantially affects the reaction kinetics and heat and mass transport in the material. Accordingly, the main relevant options for materials shaping are summarized. We explore the effects of microstructure and porosity, and the exploitation of designed structures such as fibers, 3-DOM (three-dimensionally ordered macroporous) materials, reticulated and replicated foams, and the new area of biomimetic/biomorphous porous ceria redox materials produced from natural and sustainable templates such as wood or cork, also known as ecoceramics

Solar thermochemical CO2 splitting using cork-templated ceria ecoceramics

This work addresses the solar-driven thermochemical production of CO and O2 from two-step CO2-splitting cycles, using both ceria granules prepared from cork templates (CG) and ceria foams from polyurethane templates (CF). These materials were cycled in a high-temperature indirectly-irradiated solar tubular reactor using a temperature-swing process. Samples were typically reduced at 1400 °C using concentrated solar power as a heating source and subsequently oxidised with CO2 between 1000-1200 °C. On average, CO production yields for CG were two times higher than for CF, indicating that the morphology of this three-dimensionally ordered macroporous (3-DOM) CeO2 improves the reaction kinetics. Their performance stability was demonstrated by conducting 11 cycles under solar irradiation conditions. Slightly increasing the reduction temperature strongly enhanced the reduction extent, and thus the CO production yield (reaching about 0.2 mmol g-1 after reduction at 1450 °C in inert gas), while decreasing the oxidation temperature mainly improved the CO production rate (up to 1.43 μmol s-1 g-1 at 1000 °C). Characterisation of the 3-DOM structure, by means of XRD and SEM, provided insights into the reactivity behaviour of the developed materials. The pre-sintered ceria granules retained their structure after cycling. The fact that the mean cell size of CG is smaller (at least one order of magnitude) than that of CF suggests that its exposed surfaces enhanced reaction rates by a factor of two. Moreover, the maximum fuel production rate of CG was roughly three times greater than that reported previously for a ceria reticulated porous foam with dual-scale porosity

A review of solar thermochemical CO2 splitting using ceria-based ceramics with designed morphologies and microstructures

ABSTRACT: This review explores the advances in the synthesis of ceria materials with specific morphologies or porous macro- and microstructures for the solar-driven production of carbon monoxide (CO) from carbon dioxide (CO2). As the demand for renewable energy and fuels continues to grow, there is a great deal of interest in solar thermochemical fuel production (STFP), with the use of concentrated solar light to power the splitting of carbon dioxide. This can be achieved in a two-step cycle, involving the reduction of CeO2 at high temperatures, followed by oxidation at lower temperatures with CO2, splitting it to produce CO, driven by concentrated solar radiation obtained with concentrating solar technologies (CST) to provide the high reaction temperatures of typically up to 1,500 degrees C. Since cerium oxide was first explored as a solar-driven redox material in 2006, and to specifically split CO2 in 2010, there has been an increasing interest in this material. The solar-to-fuel conversion efficiency is influenced by the material composition itself, but also by the material morphology that mostly determines the available surface area for solid/gas reactions (the material oxidation mechanism is mainly governed by surface reaction). The diffusion length and specific surface area affect, respectively, the reduction and oxidation steps. They both depend on the reactive material morphology that also substantially affects the reaction kinetics and heat and mass transport in the material. Accordingly, the main relevant options for materials shaping are summarized. We explore the effects of microstructure and porosity, and the exploitation of designed structures such as fibers, 3-DOM (three-dimensionally ordered macroporous) materials, reticulated and replicated foams, and the new area of biomimetic/biomorphous porous ceria redox materials produced from natural and sustainable templates such as wood or cork, also known as ecoceramics.info:eu-repo/semantics/publishedVersio

3DOM ceria ecoceramics from sustainable cork templates for solar thermochemical CO2 splitting

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Managing Achilles Pain (the MAP study) – A process evaluation of data collection methods

Background Process evaluations explore the way in which a study was conducted. The Managing Achilles Pain study (MAP study) had the primary aim of assessing the feasibility of the protocol for a future large longitudinal cohort study that would investigate the association and predictive relationship of self-efficacy, working alliance and expectations with outcome in the management of Achilles tendinopathy. Objectives This study aimed to evaluate the processes conducted in the MAP study by exploring the acceptability of the study procedures from the participants' and physiotherapists' perspectives. Design A qualitative evaluation using semi-structured telephone interviews. Method All physiotherapists and participants who participated in the MAP study were invited. Data from physiotherapists (n = 6) and participants (n = 7) were transcribed and analysed using the Framework Approach. Findings From the physiotherapists' perspective 4 themes were identified relating to obstacles; (1) access to participants; (2) recall; (3) visibility; (4) time, and 4 themes were identified relating to facilitating success; (1) training; (2) motivation; (3) incentives; (4) simplicity. From the participants' perspective 2 themes were identified relating to obstacles; (1) information from the physiotherapist; (2) follow up, 3 themes were identified relating to facilitating success; (1) motivation; (2) website; (3) questionnaire, and 1 theme relating to unintended consequences of participating in the study; positive experience. Conclusions Although clinicians are enthused to be involved in research, organisational factors impact levels of engagement. Key influences to optimising the potential success of a study include the publicising of the study; optimising verbal recruitment strategies; and clarity in communication

Tuning the Endocytosis Mechanism of Zr-Based Metal–Organic Frameworks through Linker Functionalization

A critical bottleneck for the use of metal-organic frameworks (MOFs) as drug delivery systems has been allowing them to reach their intracellular targets without being degraded in the acidic environment of the lysosomes. Cells take up particles by endocytosis through multiple biochemical pathways, and the fate of these particles depends on these routes of entry. Here, we show the effect of functional group incorporation into a series of Zr-based MOFs on their endocytosis mechanisms, allowing us to design an effi-cient drug delivery system. In particular, naphthalene-2,6-dicarboxylic acid and 4,4'-biphenyldicarboxylic acid ligands promote entry through the caveolin-pathway, allowing the particles to avoid lysosomal degradation and be delivered into the cytosol, en-hancing their therapeutic activity when loaded with drugs.C.A.O. thanks Becas Chile and the Cambridge Trust for funding. S.H. thanks the Cambridge Trust for funding. R.S.F. and D.F.-J. thank the Royal Society for the receipt of University Research Fellowships. D.F.-J. thanks financial support from ERC-2016-COG 726380. R.S.F., R.J.M., and I.A.L. thank the University of Glasgow and the EPSRC (EP/L004461/1) for funding. G.B., I.I., and D.M. acknowledge the financial support from 2014-SGR-80, MAT2015-65354-C2-1-R and EU FP7 ERC-Co 615954. ICN2 received support from the Spanish MINECO through the Severo Ochoa Centers of Excellence Program, under Grant No. SEV-2013-0295

Solar Redox Cycling of Ceria Structures Based on Fiber Boards, Foams, and Biomimetic Cork-Derived Ecoceramics for Two-Step Thermochemical H2O and CO2Splitting

Solar thermochemical conversion of H2O and captured CO2 is considered for the production of high-value solar fuels and CO2 valorization, using nonstoichiometric oxygen-exchange redox materials. This work aims to compare the thermochemical cycle performance of different ceria structures, including biomimetic cork-templated ceria (CTCe), ceria foams (CeF), and ceria bulk fiber boards (CeFB), to study the effect of the morphology on fuel production from two-step H2O and CO2 splitting via solar redox cycling. The considered materials underwent thermochemical cycles in a directly irradiated solar reactor under various operating conditions. Typically, a thermal reduction at 1400 °C under Ar at atmospheric pressure, using concentrated solar energy, was carried out followed by an oxidation step with H2O or CO2 between 800 and 1050 °C. The comparison of the fuel production rate and yield from the reactive materials highlighted the importance of the material thermal stability during cycling. CTCe and CeF showed good O2 and fuel production stability over repeated cycles, while CeFB exhibited a decrease of the production because of sintering and thermal gradient due to its low thermal conductivity. Biomimetic CTCe showed a higher fuel production rate compared to the other investigated materials, explained by the favorable microstructure of the cork-based ceramic. The morphology obtained from the cork structure led to the improvement of the redox activity, demonstrating the relevance of studying this material for thermochemical H2O and CO2 splitting cycles. In addition, the impact of the operating conditions was investigated. A decrease of the starting oxidation temperature, an increase of the CO2 molar fraction (lower CO/CO2 ratio), or a high total gas flow rate favoring gas product dilution had a beneficial impact on the CO (or H2) production rate