AuthorsKhan, M. Anwar H.; orcid: 0000-0001-7836-3344; email: firstname.lastname@example.org
Bonifacio, Sophia; email: email@example.com
Clowes, Joanna; email: firstname.lastname@example.org
Foulds, Amy; email: email@example.com
Holland, Rayne; orcid: 0000-0002-1975-0587; email: firstname.lastname@example.org
Matthews, James C.; orcid: 0000-0002-5908-0610; email: J.C.Matthews@bristol.ac.uk
Percival, Carl J.; email: email@example.com
Shallcross, Dudley E.; email: firstname.lastname@example.org
MetadataShow full item record
AbstractAn accelerating global energy demand, paired with the harmful environmental effects of fossil fuels, has triggered the search for alternative, renewable energy sources. Biofuels are arguably a potential renewable energy source in the transportation industry as they can be used within current infrastructures and require less technological advances than other renewable alternatives, such as electric vehicles and nuclear power. The literature suggests biofuels can negatively impact food security and production; however, this is dependent on the type of feedstock used in biofuel production. Advanced biofuels, derived from inedible biomass, are heavily favoured but require further research and development to reach their full commercial potential. Replacing fossil fuels by biofuels can substantially reduce particulate matter (PM), carbon monoxide (CO) emissions, but simultaneously increase emissions of nitrogen oxides (NOx), acetaldehyde (CH3CHO) and peroxyacetyl nitrate (PAN), resulting in debates concerning the way biofuels should be implemented. The potential biofuel blends (FT-SPK, HEFA-SPK, ATJ-SPK and HFS-SIP) and their use as an alternative to kerosene-type fuels in the aviation industry have also been assessed. Although these fuels are currently more costly than conventional aviation fuels, possible reduction in production costs has been reported as a potential solution. A preliminary study shows that i-butanol emissions (1.8 Tg/year) as a biofuel can increase ozone levels by up to 6% in the upper troposphere, highlighting a potential climate impact. However, a larger number of studies will be needed to assess the practicalities and associated cost of using the biofuel in existing vehicles, particularly in terms of identifying any modifications to existing engine infrastructure, the impact of biofuel emissions, and their chemistry on the climate and human health, to fully determine their suitability as a potential renewable energy source.
CitationAtmosphere, volume 12, issue 10, page e1289
DescriptionFrom MDPI via Jisc Publications Router
History: accepted 2021-09-30, pub-electronic 2021-10-03
Publication status: Published
Funder: Natural Environment Research Council; Grant(s): NE/K004905/1
Showing items related by title, author, creator and subject.
Abundance of NO 3 Derived Organo-Nitrates and Their Importance in the AtmosphereFoulds, Amy; email: email@example.com; Khan, M. Anwar H.; orcid: 0000-0001-7836-3344; email: firstname.lastname@example.org; Bannan, Thomas J.; orcid: 0000-0002-1760-6522; email: Thomas.email@example.com; Percival, Carl J.; email: firstname.lastname@example.org; Lowenberg, Mark H.; orcid: 0000-0002-1373-8237; email: email@example.com; Shallcross, Dudley E.; email: firstname.lastname@example.org (MDPI, 2021-10-22)The chemistry of the nitrate radical and its contribution to organo-nitrate formation in the troposphere has been investigated using a mesoscale 3-D chemistry and transport model, WRF-Chem-CRI. The model-measurement comparisons of NO2, ozone and night-time N2O5 mixing ratios show good agreement supporting the model’s ability to represent nitrate (NO3) chemistry reasonably. Thirty-nine organo-nitrates in the model are formed exclusively either from the reaction of RO2 with NO or by the reaction of NO3 with alkenes. Temporal analysis highlighted a significant contribution of NO3-derived organo-nitrates, even during daylight hours. Night-time NO3-derived organo-nitrates were found to be 3-fold higher than that in the daytime. The reactivity of daytime NO3 could be more competitive than previously thought, with losses due to reaction with VOCs (and subsequent organo-nitrate formation) likely to be just as important as photolysis. This has highlighted the significance of NO3 in daytime organo-nitrate formation, with potential implications for air quality, climate and human health. Estimated atmospheric lifetimes of organo-nitrates showed that the organo-nitrates act as NOx reservoirs, with particularly short-lived species impacting on air quality as contributors to downwind ozone formation.
Physical Modelling of Offshore Wind Turbine Foundations for TRL (Technology Readiness Level) StudiesBhattacharya, Subhamoy; orcid: 0000-0002-8290-194X; email: S.Bhattacharya@surrey.ac.uk; Lombardi, Domenico; email: email@example.com; Amani, Sadra; orcid: 0000-0002-4072-4703; email: firstname.lastname@example.org; Aleem, Muhammad; email: email@example.com; Prakhya, Ganga; email: firstname.lastname@example.org; Adhikari, Sondipon; email: email@example.com; Aliyu, Abdullahi; email: firstname.lastname@example.org; Alexander, Nicholas; orcid: 0000-0002-6837-5330; email: Nick.Alexander@bristol.ac.uk; Wang, Ying; orcid: 0000-0003-1572-6333; email: email@example.com; Cui, Liang; orcid: 0000-0002-5546-5097; email: firstname.lastname@example.org; et al. (MDPI, 2021-05-29)Offshore wind turbines are a complex, dynamically sensitive structure due to their irregular mass and stiffness distribution, and complexity of the loading conditions they need to withstand. There are other challenges in particular locations such as typhoons, hurricanes, earthquakes, sea-bed currents, and tsunami. Because offshore wind turbines have stringent Serviceability Limit State (SLS) requirements and need to be installed in variable and often complex ground conditions, their foundation design is challenging. Foundation design must be robust due to the enormous cost of retrofitting in a challenging environment should any problem occur during the design lifetime. Traditionally, engineers use conventional types of foundation systems, such as shallow gravity-based foundations (GBF), suction caissons, or slender piles or monopiles, based on prior experience with designing such foundations for the oil and gas industry. For offshore wind turbines, however, new types of foundations are being considered for which neither prior experience nor guidelines exist. One of the major challenges is to develop a method to de-risk the life cycle of offshore wind turbines in diverse metocean and geological conditions. The paper, therefore, has the following aims: (a) provide an overview of the complexities and the common SLS performance requirements for offshore wind turbine; (b) discuss the use of physical modelling for verification and validation of innovative design concepts, taking into account all possible angles to de-risk the project; and (c) provide examples of applications in scaled model tests.
Optimization of a Patient-Specific External Fixation Device for Lower Limb InjuriesAlqahtani, Mohammed S.; orcid: 0000-0002-9178-8168; email: email@example.com; Al-Tamimi, Abdulsalam Abdulaziz; email: aaaltamimi@KSU.EDU.SA; Hassan, Mohamed H.; orcid: 0000-0002-0832-8559; email: Mohamed.firstname.lastname@example.org; Liu, Fengyuan; email: email@example.com; Bartolo, Paulo; orcid: 0000-0003-3683-726X; email: firstname.lastname@example.org (MDPI, 2021-08-10)The use of external fixation devices is considered a valuable approach for the treatment of bone fractures, providing proper alignment to fractured fragments and maintaining fracture stability during the healing process. The need for external fixation devices has increased due to an aging population and increased trauma incidents. The design and fabrication of external fixations are major challenges since the shape and size of the defect vary, as well as the geometry of the human limb. This requires fully personalized external fixators to improve its fit and functionality. This paper presents a methodology to design personalized lightweight external fixator devices for additive manufacturing. This methodology comprises data acquisition, Computer tomography (CT) imaging analysis and processing, Computer Aided Design (CAD) modelling and two methods (imposed predefined patterns and topology optimization) to reduce the weight of the device. Finite element analysis with full factorial design of experiments were used to determine the optimal combination of designs (topology optimization and predefined patterns), materials (polylactic acid, acrylonitrile butadiene styrene, and polyamide) and thickness (3, 4, 5 and 6 mm) to maximize the strength and stiffness of the fixator, while minimizing its weight. The optimal parameters were found to correspond to an external fixator device optimized by topology optimization, made in polylactic acid with 4 mm thickness.