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Detailed radiation modeling of two flames relevant to fire simulation using Photon Monte Carlo — Line by Line radiation model
No full textPublisher Copyright: © 2024 Elsevier LtdThis work reports benchmark data sets for radiative heat transfer in two distinct fire configurations obtained from the Measurement and Computation of Fire Phenomena (MaCFP) working group database. The cases include a 19.2 kW non-sooting turbulent methanol pool fire and a 15 kW sooting ethylene flame (referred to as the FM burner). The base configurations were simulated with large eddy simulation (LES) approaches using two different codes, namely FireFOAM and Fire Dynamics Simulator, respectively. Multiple frozen snapshots from these LES runs were radiatively evaluated using a photon Monte Carlo radiation solver and a line-by-line spectral model. The results were presented at three levels: Firstly, the radiative fields, including radiative emission, reabsorption, and heat flux contours, were shown. Secondly, the global radiative contributions from molecular gas species, soot, and wall boundaries were compared. Thirdly, a detailed spectral analysis of radiative fields for different components within five distinct spectral bands was presented. In the case of the non-sooting methanol pool fire, the radiative emission from CO2 predominates. However, for the radiation reaching the boundaries, both CO2 and H2O contribute almost equally. Conversely, for the sooty FM burner configuration, radiative emission from soot, CO2, and H2O all contribute similarly. In terms of radiation reaching the boundary, soot is the primary contributor in FM Burner. In the methanol pool fire, the pool surface receives a comparable contribution from CO2, H2O, and burner rim radiation, whereas, for the FM burner, the burner inlet surface primarily receives radiation from soot.Peer reviewe
Climate risk disclosures and auditor expertise
No full textPublisher Copyright: © 2024Many jurisdictions are establishing requirements for corporations to disclose climate-related risks, and for those disclosures to be audited. One of the first jurisdictions to do so is Australia, where the Australian Accounting Standards Board (AASB) and Auditing and Assurance Standards Board (AUASB) issued a Joint Bulletin in 2018 stating that both preparers and auditors should consider the impact of climate risks on the company's financials. Utilising the Australian setting, this paper introduces a new measure of audit partner expertise, namely expertise in climate-related issues, and examines whether it is associated with the client company's climate risk reporting. We define audit partner expertise in climate-related issues based on their client portfolio composition in terms of greenhouse gas emissions. We find that the likelihood and quality of climate risk disclosures is higher when the audit partner has climate risk expertise, and this finding is driven by clients in industries with material climate risks.Peer reviewe
QoE-Driven Resource Management Framework for Next-Generation Mobile Networks
No full textPublisher Copyright: © The Author(s), under exclusive licence to Springer Nature Singapore Pte Ltd. 2025.Due to the massive growth in global data traffic, next-generation wireless communication technologies must meet the demands of emerging applications and services by providing enhanced Quality-of-Service (QoS) levels to end-users, by enabling a ubiquitous cellular coverage, characterized by ultra-high reliability and minimal latency. Notably, most cellular network traffic comes from densely populated urban areas, where dense infrastructure and high user demands lead to interference-limited conditions and competition for radio resources, resulting in degraded QoS levels for mobile User Equipment (UE). This work proposed a Quality-of-Experience (QoE)-driven framework for defining UE types according to defined QoS requirements, with application-specific diverse value-oriented services. The proposed framework primarily focuses on assessing cellular network performance with a user-centric approach via subjective metrics like end-user satisfaction, rather than solely on traditional communication-centric metrics. The proposed scheduling framework integrates a theoretical approach to guarantee QoS for various mobile UE types by dynamically allocating the necessary bandwidth resources. This also ensures guaranteed optimal performance for UEs, along with the minimal impact on the operational efficiency of UEs without specific service requirements.Peer reviewe
A comprehensive evaluation of crumb rubber modified asphalt-aggregate interfacial behavior and the effect of water : Molecular dynamics simulation and experimental investigation
No full textPublisher Copyright: © 2024 Elsevier LtdThe incorporation of crumb rubber (CR) makes the asphalt-aggregate interfacial properties highly complex and uncertain, while water is a key environmental factor causing interfacial failure. This paper aims to evaluate the characteristics of crumb rubber modified asphalt (CRMA)-aggregate interaction and the interfacial failure mechanism under the influence of different material properties and water at ambient temperature. Firstly, the CRMA-aggregate interfacial behavior before and after water intrusion is investigated using molecular dynamics simulations at the molecular scale. Next, the failure process and characteristics of the CRMA-aggregate interface were analyzed using the disk-shaped compact tension (DCT) test at the macro scale. Finally, the effect of water intrusion on the interface failure mode was analyzed through image processing. The results show that CR enhances binder cohesion and significantly affects its adhesion to aggregates with high CaO and MgO contents regardless of the presence of water. The asphalt concentration distribution on the CaO and MgO surfaces is more concentrated with higher peak concentration, leading to superior interfacial adhesion and water damage resistance with binder, while Al2O3 and SiO2 were inferior. The use of asphalt with higher creep stiffness, high-strength alkaline aggregates, and smaller CR particle size is beneficial for enhancing the CRMA binder-aggregate interfacial fracture performance. Water intrusion severely affected the interfacial adhesion, resulting in a significant increase in the proportion of adhesion failure, which is the main cause of the deterioration of the interface properties. The findings of this study provide insights into the factors affecting the CRMA-aggregate interfacial behavior, which facilitate the accurate design and application of high-strength durable CRMA mixtures.Peer reviewe
Sources of Uncertainty in 3D Scene Reconstruction
No full textThe process of 3D scene reconstruction can be affected by numerous uncertainty sources in real-world scenes. While Neural Radiance Fields (NeRFs) and 3D Gaussian Splatting (GS) achieve high-fidelity rendering, they lack built-in mechanisms to directly address or quantify uncertainties arising from the presence of noise, occlusions, confounding outliers, and imprecise camera pose inputs. In this paper, we introduce a taxonomy that categorizes different sources of uncertainty inherent in these methods. Moreover, we extend NeRF- and GS-based methods with uncertainty estimation techniques, including learning uncertainty outputs and ensembles, and perform an empirical study to assess their ability to capture the sensitivity of the reconstruction. Our study highlights the need for addressing various uncertainty aspects when designing NeRF/GS-based methods for uncertainty-aware 3D reconstruction.Peer reviewe
A Dynamic Bayesian Network model to evaluate the availability of machinery systems in Maritime Autonomous Surface Ships
No full textFunding Information: The research was supported by the Hubei Provincial Natural Science Foundation of China (2019CFA039), the National Natural Science Foundation of China (51920105014; 52071247), and the Innovation and entrepreneurship team import project of Shaoguan city (201212176230928). Publisher Copyright: © 2023 Elsevier LtdWith their complex structure, multiple failure modes and lack of maintenance crew, the safety problem of Maritime Autonomous Surface Ships’ (MASS) machinery systems are becoming an important research topic. The present study presents an availability model for ship machinery systems incorporating a maintenance strategy based on Dynamic Bayesian Networks (DBN). First, the availability of conventional ship machinery systems is evaluated and used as a benchmark based on the configuration and planned maintenance strategy. Secondly, the availability of MASS machinery systems is compared to the benchmark, before the introduction of any changes to the ship's configuration and planned maintenance strategy. Finally, the availability improvement strategies, including redundant designs and planned maintenance strategies at port, are proposed based on sensitivity analysis and planned maintenance cost minimization. To exemplify the model's application, a case study of a cooling water system is explored. Based on a sensitivity analysis using the model, it is possible to decide which components need to be redundant. Different redundancy designs and corresponding planned maintenance strategies can be adopted to meet the availability demand. It is also shown that redundancy and enhanced detection capabilities reduce much of the planned maintenance cost. This framework can be used in the early design stages to determine whether the MASS machinery systems’ availability is at least equivalent to that of conventional ships, and has certain reference significance for redundant configuration designs and MASS planned maintenance strategy schedule.Peer reviewe
How Can We Design with a Multi-Species Mindset Towards Regenerative Practices?
No full textIn this chapter Julia Lohmann introduces key insights she gained through her practice and practice-led research in multi-species design over the past twenty years, illustrated by auto-ethnographic case studies. They range from context sensitivity, process led immersion, reflection and enabling discourses to rethinking our bodies as eco-systems. Lohmann encourages thinking further at the fringes of disciplines and beyond anthropocentric comfort zones, introduces how materials may enable time-based reflections, the importance of bodily engagements, transdisciplinary ruminations and co-speculation, her view of materials as muses and methods, and her framework on fostering knowing, caring and acting. Each of these aspects, she hopes, can nudge us to reflect more, connect further, instil care in ourselves and others and help us embrace a multispecies mindset and a widened understanding of our multispecies selves.Peer reviewe
Enhancing thermal comfort of older adults during extreme weather : Combined personal comfort system and ventilated vest
No full textPublisher Copyright: © 2024 Elsevier B.V.This study proposes using a personal comfort system (PCS) with a ventilated vest to improve the thermal comfort of older people in hot conditions with low energy requirements. A chair-based PCS that establishes a cool microclimate around body parts influential for thermal comfort is used with a ventilated vest that draws cool air from the established microclimate. The vest acts as an additional heat removal measure to provide adequate elderly thermal sensation (TS) with the chair PCS. The research methodology incorporates a ventilated vest model integrated with an elderly bioheat and TS models, as well as computational fluid dynamics for predicting the flow and thermal fields of microclimate and space. Models are validated by i) conducting experiments on a chair-based PCS with a vest on thermal manikin in a climatic chamber and ii) comparing predictions with published data on elderly TS. The validated models are used to evaluate the effect of combining the vest and the chair PCS on improving elderly TS. The combined system reduced the elderly TS from 0.8 to 0.5 (between neutral and slightly warm) at 33 °C microclimate with a chair PCS supply flow rate of 21 l/s and a vest suction fan flow rate of 11 l/s. In contrast, achieving a TS of 0.5 using the chair PCS alone necessitate a supply flow rate of 34 l/s, which results in 19 % higher energy consumption compared to the combined mode. Using the vest with the chair PCS is a viable solution for elderly individuals in hot conditions.Peer reviewe
Coordinated operation of source–station–road–network system considering traffic flow uncertainty
No full textPromoting large-scale transportation electrification and developing new solar energy harvesting and converting technologies are effective ways to achieve ’dual carbon goals’. In this paper, a new road energy harvesting technology, solar road (SR) power generation technology, is introduced. A SR power generation model considering the variation of solar radiation intensity, traffic flow and dynamic shadows of vehicles is constructed. Secondly, considering the uncertainty of traffic network (TN) caused by users’ stochastic routing behavior, a model of TN under stochastic user equilibrium (SUE) is constructed. Then the influence of traffic flow on the electric load of charging and battery swapping stations (CBSSs) is analyzed, and the local consumption strategy of SR is established. Meanwhile, information gap decision theory (IGDT) is introduced to reduce the impact of uncertainty on the system. Finally, the coupling system of IEEE-33 node of distribution network (DN) and Nguyen–Dupuis of TN is used to verify the effectiveness of the proposed model and optimal management method, which improves the utilization rate of solar energy, promotes carbon emission reduction, reduces the congestion degree of DN, and ensures the safe and stable operation of the system.Peer reviewe
Facile, scalable and Substrate-Independent omniphobic surface
No full textPublisher Copyright: © 2024 Elsevier B.V.Omniphobic surfaces have a very wide range of applications. However, limited by substrate material and/or fabrication processes, scalable synthesis of robust omniphobic surfaces with universality and versatility remains challenging for both academia and industry. Here, we present a facile and scalable slippery omniphobic surface (FSSOS) based on the straightforward blending and dip/spray-coating of polysilazane (PSZ) and minute low surface energy silane under room temperature. Water shows a contact angle hysteresis (CAH) of 18°, and the overall trend across all tested solvents suggests a relatively low CAH (＜10°), further enhancing its surface omniphobicity. The one-step synthesis protocol is cost-effective, substrate-independent, and does not require curing aids such as UV irradiation or heat. The FSSOS achieves multi-liquid omni-repellency with chemical and mechanical durability under various harsh exposure conditions. The CAH remains stable even after exposure to 4 m/s water jet impact for 8 h, 130 W ultrasonic vibration for 250 min, 10 kPa pressure tape-peel test for 250 cycles, heating at 250 °C for 10 min, and 205 mW/cm2 UV irradiation for 28 days. This approach highlights a functional design of liquid-repellent surfaces for numerous real-world applications.Peer reviewe