20505 research outputs found
Sort by
Numerical simulation of subfields in a multi-tower concentrated solar field
Get PDFThe research introduces an innovative approach to enhancing the efficiency of Multi-tower Concentrated Solar Power (CSP) through a configuration termed Auxiliary Tower with Subfield (ATS). ATS introduces an auxiliary tower and creates a subfield by adding heliostats near its position, aiming to optimize the solar field's optical efficiency and offer modular decentralized power output. ATS configuration employs existing field configurations to pinpoint inefficiencies where an additional tower can be installed, and heliostats are systematically added to the subfields through numerical optimization using various design variables. Although the inclusion of a subfield in the ATS configuration enhances energy output, it does not always offset the additional costs of the auxiliary tower, receiver, and extra heliostats, in small fields. However, when applied to larger fields, starting from 200MWth, ATS begins to provide a lower Levelized Cost of Heat (LCOH) compared to optimized conventional thermal fields, demonstrating its potential applicability and efficiency in larger-scale CSP setups. Applying ATS to a 120 MWth Gemasolar-like plant further confirms its advantages, with 160 MWth emerging as the optimal enhancement point that boosted efficiency while lowering LCOH. ATS shows promise as an efficient, modular approach to scaling up power tower system.SolarPACES 202
Navigating circular economy and digitalisation: a comparative study of manufacturing strategies in the UK and Saudi Arabia
Get PDFThis study presents an integrated framework for evaluating manufacturing maturity in embracing circular economy principles and digital technologies, with a focus on comparing best practices between the UK and Saudi Arabia. The framework incorporates circular economy principles, such as waste elimination, material circulation, and nature regeneration, across product, process, and business model innovations. It also encompasses key Industry 4.0 technologies that facilitate smart and connected manufacturing. Utilising secondary data sources, the research maps the capabilities of selected manufacturers in both countries across categories including operations and technology. The findings indicate that the UK leads in most areas due to its sustained emphasis on sustainability and digitalisation over the past decade. In contrast, Saudi Arabia exhibits a lack of concrete policies and investments in these domains but demonstrates the potential for adapting UK practices to its unique context. The study proposes a staged roadmap to guide Saudi Arabia in a systematic transition towards circular and digital manufacturing, emphasising coordinated efforts in policy, infrastructure development, skills enhancement, and industry collaboration. This comparative assessment offers valuable insights into manufacturing best practices and opportunities for improvement.The authors would like to acknowledge the British Council for their support and funding this research work.57th CIRP Conference on Manufacturing Systems 2024 (CMS 2024)Procedia CIR
Low level coupling techniques for the HIRF clearance of air systems
Get PDFCurrent methods for the assessment of military and civil systems for their response to High Intensity Radiated Fields (HIRF) are numerous and varied in their approach. The two principal methods employ either low level techniques for the calculation of transfer functions for extrapolation to high power environments or the use of high power sources specific to the environment to be considered. Low Level Swept (LLS) techniques are commonly used in the certification of both military and civil aircraft to HIRF. This paper examines the Low Level Swept Current (LLSC) technique and demonstrates the effect that the receive antenna height may have on the reference field calibrations. The results of this study show significant variation of up to 10dB which may be directly attributed to the electromagnetic test configuration. Moreover, recommendations are made to reduce measurement uncertainty.This work was supported by UK MoD CRP SEW fundingEMC Europe 2004, International Symposium on Electromagnetic Compatibilit
Techno-Economic analysis of ceramic matrix composites integration in remaining useful Life Aircraft Engine Hot Section Components
Get PDFCeramic Matrix Composites (CMCs), specifically SiC/SiC composites, represent a significant innovation in aerospace material technology, offering superior performance over traditional nickel-based superalloys in high-temperature turbine blade applications. This study presents a novel techno-economic assessment, filling a critical gap in the literature by directly comparing the economic and technical viability of CMCs versus superalloys. Unlike previous studies, which primarily focus on technical performance or cost analysis independently, this work integrates both aspects, providing a holistic comparison across key economic metrics, including acquisition, machining, maintenance, and recycling costs. The results demonstrate that SiC/SiC blades offer a 15–20% higher Net Present Value (NPV) and a 17% greater Internal Rate of Return (IRR) over a 20-year lifecycle than superalloys. Despite higher initial costs, CMCs achieve an estimated 2 to 3 years reduction in payback period, mainly due to their superior thermal and creep resistance, leading to fewer maintenance interventions and longer operational lifetimes. Although machining costs for CMCs are higher, these are more than offset by the long-term savings achieved through improved fuel efficiency and lower maintenance costs. A comprehensive sensitivity analysis, incorporating fluctuations in discount rates and material costs, further validates the economic robustness of CMCs in various operational scenarios. This study is the first to compare CMCs and superalloys, offering new insights into the financial implications of material selection in aerospace manufacturing. The findings present critical engineering recommendations that empower aerospace manufacturers and decision-makers to optimise material selection for improved efficiency and cost-effectiveness in high-performance turbine applications.This work was supported by Clean Sky 2 Joint Undertaking (JU) (Grant number No 886840).The International Journal of Advanced Manufacturing Technolog
Impact of political and legal environments on international trade
Get PDFInternational trade has become increasingly important in the functioning of the global economy as a result of financial globalization and differences in resource endowments, prompting extensive economic research and increased demand for regional and global integration among nations and continents. International trade is one of the most salient changes in the world economy since 1980. However, many nations and other regional economic blocs have over the years instituted trade restrictions, tariffs, trade policies such as subsidies, and tax waivers among others to harness the potentials of economic comparative advantages in and within their jurisdictions. Political ideologies, instability, and insurgencies and risks are important factors that affect international trade across the globe. Legal regimes are equally important factors that determine the flow of free trade among nations. Civil and common law countries which have different focus of trade regulations and dividend policies are critical matters that affect trade decisions among MNCs and countries. This chapter examines the political and legal environments of international trade. In this chapter, we provide an overview of the emerging political and legal environments in Africa. We then discuss how the political as well as the legal environments and policy trends impact international trade of African countries.The Palgrave Handbook of International Trade and Development in Afric
Hexanal-containing dip treatment enhances kiwifruit resistance to Botrytis cinerea
Get PDFThis study evaluated the effectiveness of a hexanal-based enhanced freshness formulation (EFF), containing antioxidants such as geraniol, α-tocopherol and ascorbic acid, to inhibit the fungal decay caused by Botrytis cinerea in ‘Y368’ kiwifruit. In vitro and in vivo experiments using three treatments: control (untreated), 0.03 and 0.06 % (v/v) EFF were set up. In the in vitro experiment, mycelial growth and spore germination of Botrytis cinerea exposed to EFF were examined. In the in vivo experiment, disease incidence, lesion diameter, activity of defense-related enzymes (Phenylalanine Ammonia Lyase, Guaiacol Peroxidase, β-1,3-glucanase and Chitinase), total phenolics and flavonoids were evaluated. The results demonstrated that 0.03 and 0.06 % EFF treatments reduced mycelial growth of Botrytis cinerea by 41 and 89 %, respectively. The lesion diameter of the 0.03 and 0.06 % EFF-treated fruit was 28 and 76 % smaller than the control. Furthermore, EFF-treated fruit exhibited significantly higher activities of defense-related enzymes compared to the control, with total phenolic content increasing by 1.2 and 1.3-fold for the 0.03 and 0.06 % treatments, respectively. These findings provide compelling evidence regarding the efficacy of EFF in suppressing Botrytis cinerea and highlight the role of defense-related enzymes in enhancing the fruit's resistance to decay. Overall, the study underscores the potential of EFF as a valuable and practical method for controlling fungal decay in kiwifruit during postharvest storage.This work was supported by the National Research Foundation of South Africa (Grant number: SFH220123657394).Physiological and Molecular Plant Patholog
A bespoke carbon footprint framework to set the path towards Net Zero in foundries
Get PDFA bespoke carbon footprint framework for the metal casting industry is presented to enable swifter carbon accounting of foundries and identify energy and carbon footprint hotspots to support the drive towards Net Zero goals. Many manufacturing enterprises in the United Kingdom and Europe are already struggling to maintain financial competitiveness as well as drive towards a sustainable shift, particularly SMEs. This framework is to help alleviate the pressure on the industry by providing an outside tool to direct companies to sustainable solutions. This paper validates such framework breaking down the environmental footprint of ferrous products through energy and material profiles of sand casting processes in two real UK foundries identified as “A” and “B”. During environmental visits, it was established that Foundry A emitted an average of 41700 tons of CO2 annually and Foundry B 1400 tons. The framework developed to estimate the melting process energy (to be, then, converted into carbon footprint) predicted with about 15% accuracy the actual data. Furthermore, the framework can be expanded and improved on for its accuracy and into other processes within the casting process including melting, core and mould making, pouring sand reclamation, ancillaries and fettling.The authors gratefully acknowledge the two foundries for providing access to their facilities and data, Foseco International for funding this work and Auwal Muhammad for some of the foundational work carried out during his MSc thesis.57th CIRP Conference on Manufacturing Systems 2024 (CMS 2024)Procedia CIR
A submersible power station: Part A helium power conversion unit
Get PDFNuclear power continues to hold great promise in the green revolution, however public opinion regarding its deployment is mixed. A submersible nuclear power station concept is presented here that is expected to allay many concerns that are holding back the growth of nuclear power. This submersible can move under its own power during emergencies and routine maintenance. Being stationed at sea it is earthquake proof. In the case of a tsunami it could decouple from the coast and sail to a location several miles to deeper waters in less than 30 min. Furthermore, it could be built, commissioned, maintained, refueled and scrapped in a country like the UK. This makes it proliferation-proof, a key concern with the wider deployment of nuclear power. In the present evaluation the philosophy and the electric power generation capability of the submersible power station are investigated. This includes a pre-feasibility visualization of the design. An evaluation is carried out into fitting it in a submersible of a size similar to the largest existing nuclear submarines. These designs may enable it to deliver 0.6 to 1 GW of electrical power.Journal of Marine Science and Engineerin
Selecting sustainable packaging materials and strategies: a holistic approach considering whole life cycle and customer preferences
Get PDFWith the increasing public awareness of packaging and the environmental impact caused by it, companies are driving their businesses to introduce and promote practices that help ease the negative impact of packaging on the environment. Studies done on consumer behaviour show that decisions nowadays are influenced by sustainability. Yet, companies struggle with changing practices and justifying adopting environmentally friendly packaging materials. The current paper presents a holistic approach, addressing the need for identifying, assessing, and selecting sustainable materials for packaging applications. The Kano model prioritises features that are then used with Ashby plots for identifying alternative materials. Life cycle assessment, as well as life cycle costing, are used for assessing the environmental and financial impact of the use of such materials. Automatically weighted Multi-Criteria Decision-Making Analysis (MCDA) is used to select the most appropriate packaging material. This methodology provides a combinatorial ranking for each criterion set by four pre-defined weight distributions for Technique for Order Preference by Similarity to the Ideal Solution (TOPSIS). The proposed methodology allows for a systematic and holistic design process when deciding on packaging materials for any product. The methodology is validated for the case of packaging weather-sensitive cast stone products and carbonated drinks. In cast stone, three packaging materials are ranked for pallets based on their attributes. Similarly, for carbonated drinks, three packaging materials are recommended at the end of the study.Journal of Cleaner Productio
Felid scavenging in forensic taphonomic research: an experimental approach
Get PDFAnimal scavenging on human remains presents a major challenge at a forensic scene. These lasting changes can influence the interpretation of a post-mortem interval, the overall state of the remains and any associated evidence, impacting the integrity of the scene. Therefore, identifying taphonomic related changes due to animal scavenging is important to understand the post-deposition sequence of events. However, knowing where to look is challenging and animal scavenging studies are difficult to create. Therefore, this study worked in collaboration with zoological institutes in the UK to capture the scavenging changes to horse bone, focussing on the locations of scavenging on bone and the characteristics left. This study focused on large felid (cheetah, lion, tiger, leopard) scavenging, which is less documented in comparison to canine scavenging. This research demonstrated the distribution patterns of tooth activity associated with large felid scavenging is consistent with those reported in the taphonomic literature on lions. Specifically, pits, punctures, scalloping and furrowing were found and characteristics were frequently noted at the borders and flat regions of bones. This study adds to the forensic discussion of scavenging. While focussing on large cats, the work demonstrates anatomical regions that may be affected by scavenging and the visual cues that may help identify animal interaction over human.Forensic Science Internationa