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Fuel cell electrode degradation followed by identical location transmission electron microscopy
Get PDFIdentical location transmission electron microscopy (IL-TEM) is a powerful technique that has previously been used to study degradation of catalyst materials for proton exchange membrane fuel cells (PEMFCs) in half-cell environments. Here, we demonstrate that IL-TEM can be used to follow degradation at the top of the catalytic Pt/C layer in a real PEMFC on the atomic scale under operation. We find that during an accelerated stress test (AST), mimicking normal operation, Pt nanoparticles grow mainly by Ostwald ripening, while the carbon support is stable. Under AST mimicking start-up/shutdown conditions, the carbon support degrades mainly by loss of volume and collapse, which forces the Pt nanoparticles closer, promoting additional particle growth. The observed degradation correlates with the measured decrease in electrochemical performance for the respective AST. The results show the feasibility of performing IL-TEM imaging in PEMFCs under real-operating conditions, opening up the possibility for similar studies in other fully operational systems
Collaborative electric vehicle routing with meet points
No full textIn this paper, we develop a profit-sharing-based optimal routing mechanism to incentivize horizontal collaboration among urban goods distributors. This paper investigates a collaborative routing problem for urban logistics, in which the exchange of goods at meet points is optimally planned en route. We show that collaboration does not only reduce the total cost but also increases the profit of each company by sharing some customers and the related profit. Hence, we focus on solving a collaborative electric vehicle routing problem under constraints such as customer-specific time windows, opportunity charging, vehicle capacity, and meet-point synchronization. The proposed Collaborative Electric Vehicle Routing Problem with Meet Point (CoEVRPMP) is modeled as a mixed-integer nonlinear programming problem. We first present an exact method for optimal benchmarks via decomposition. To handle real-world problems, we suggest using a metaheuristic method: adaptive large neighborhood search with linear programming. The viability and scalability of the collaborative method are demonstrated via numerical case studies: (i) a real-world case of two grocery stores in the city of Gothenburg, Sweden, and (ii) a large-scale experiment with 500 customers. The results underline the importance of horizontal collaboration among delivery companies. Collaboration helps to reduce the environmental footprint (total energy consumed) and to increase the individual company\u27s profit at the same time
Electromyography-Based Control of Lower Limb Prostheses: A Systematic Review
Get PDFMost amputations occur in lower limbs and despite improvements in prosthetic technology, no commercially available prosthetic leg uses electromyography (EMG) information as an input for control. Efforts to integrate EMG signals as part of the control strategy have increased in the last decade. In this systematic review, we summarize the research in the field of lower limb prosthetic control using EMG. Four different online databases were searched until June 2022: Web of Science, Scopus, PubMed, and Science Direct. We included articles that reported systems for controlling a prosthetic leg (with an ankle and/or knee actuator) by decoding gait intent using EMG signals alone or in combination with other sensors. A total of 1,331 papers were initially assessed and 121 were finally included in this systematic review. The literature showed that despite the burgeoning interest in research, controlling a leg prosthesis using EMG signals remains challenging. Specifically, regarding EMG signal quality and stability, electrode placement, prosthetic hardware, and control algorithms, all of which need to be more robust for everyday use. In the studies that were investigated, large variations were found between the control methodologies, type of research participant, recording protocols, assessments, and prosthetic hardware
Evidence of a causal and modifiable relationship between kidney function and circulating trimethylamine N-oxide
Get PDFThe host-microbiota co-metabolite trimethylamine N-oxide (TMAO) is linked to increased cardiovascular risk but how its circulating levels are regulated remains unclear. We applied "explainable" machine learning, univariate, multivariate and mediation analyses of fasting plasma TMAO concentration and a multitude of phenotypes in 1,741 adult Europeans of the MetaCardis study. Here we show that next to age, kidney function is the primary variable predicting circulating TMAO, with microbiota composition and diet playing minor, albeit significant, roles. Mediation analysis suggests a causal relationship between TMAO and kidney function that we corroborate in preclinical models where TMAO exposure increases kidney scarring. Consistent with our findings, patients receiving glucose-lowering drugs with reno-protective properties have significantly lower circulating TMAO when compared to propensity-score matched control individuals. Our analyses uncover a bidirectional relationship between kidney function and TMAO that can potentially be modified by reno-protective anti-diabetic drugs and suggest a clinically actionable intervention for decreasing TMAO-associated excess cardiovascular risk
Synthetic biology tools for environmental protection
Get PDFSynthetic biology transforms the way we perceive biological systems. Emerging technologies in this field affect many disciplines of science and engineering. Traditionally, synthetic biology approaches were commonly aimed at developing cost-effective microbial cell factories to produce chemicals from renewable sources. Based on this, the immediate beneficial impact of synthetic biology on the environment came from reducing our oil dependency. However, synthetic biology is starting to play a more direct role in environmental protection. Toxic chemicals released by industries and agriculture endanger the environment, disrupting ecosystem balance and biodiversity loss. This review highlights synthetic biology approaches that can help environmental protection by providing remediation systems capable of sensing and responding to specific pollutants. Remediation strategies based on genetically engineered microbes and plants are discussed. Further, an overview of computational approaches that facilitate the design and application of synthetic biology tools in environmental protection is presented
Voices from the field: Working for a just climate in India
No full textIn this chapter, Seema Arora-Jonsson discusses the question of just transitions with a cross section of people working for a better climate in India: a former civil servant and climate negotiator who has long worked with climate issues, a practitioner/activist working on just transitions in an NGO, an activist with a long history in the women’s grassroots movements, a gender activist who has worked extensively with climate change at the international level as well as a networker who maintains a platform for corporations for climate finance. We discuss the context in which transitions are taking place, go on to current policy approaches and its gendered aspects and the structural challenges and barriers of policy approaches to a just transition. In the overarching gloom, we also discuss the rays of hope, and we end with what we believe is needed to take the world into a sustainable and climate-resilient place
Role of a dry port stakeholder network in intermodal transportation
No full textThe concept of a dry port, which emerged from intermodal transportation research approximately 20 years ago, has gained popularity due to its financial benefits and positive environmental impact. The core idea behind the dry port concept is the establishment of high-capacity intermodal transportation in the seaport’s hinterland. This means that dry ports contribute to modal shift, which is recognized as a crucial factor in achieving global goals for reducing carbon emissions, as specified in the Paris Agreement. However, despite their advantages, established dry ports face various challenges related to their location, cargo volume, capacity, service quality, cost and collaboration and communication, which hinder the facilitation of modal shift. Elaborating on the multi-stakeholder nature of the phenomenon, the aim is to investigate how the network can mitigate the challenges that impact stakeholders, the network and the broader domain of intermodal transportation. Throughout the thesis, the objectives, characteristics and activities are identified, described, and analysed in relation to the network value. Therefore, the purpose of the thesis is to advance knowledge about stakeholders’ objectives, characteristics and activities in order to contribute to the dry port stakeholder network value.The thesis is built upon a systematic literature review and four case studies that are informed by empirical data collected through interviews and additional information from relevant documents, site visits and secondary data from previously published research papers. Understanding the objectives of stakeholders and the interplay between them, may assist stakeholders in reconciling competing interests and seeking win-win solutions. For example, knowledge of stakeholders’ objectives facilitates the establishment of effective contracts and steers effective governance arrangements. In turn, the characteristics of the stakeholder groups, in this thesis – dry port terminals – are interconnected with the stakeholders’ ability to achieve their own objectives. Finally, coopetitive activities, aligned with the stakeholders’ objectives within the investigated network, have the potential to contribute to mitigating the challenges of the network and, through it, contribute to facilitating intermodal transportation. Dry port terminals, for example, jointly participate in professional fairs to promote intermodal transportation. Coopetition between shippers and rail operators aims to improve container utilization and fill rates of rail shuttles in the dry port stakeholder network. To further steer the stakeholders’ ability to improve the network’s functioning, the establishment of an independent and neutral entity to facilitate stakeholder relationships in the dry port stakeholder network is seen as beneficial
Development of Production and Environmental Platforms for the European Aggregates and Minerals Industries
No full textBoth quantification and communication of environmental impacts can create the foundation for improved sustainable production and decision-making. Without widespread information about site-specific environmental impacts, stakeholders cannot make a well-informed decision based on the local system boundaries. With organization-wide digital platforms, different aspects of production and management can be integrated and customized based on the organization\u27s needs. This paper aims to give an overview of the development of three different process and environmental platforms, their purposes, system structure, system constraints and the applied framework. These respective platforms are being developed separately for the Swedish aggregates industry, the European aggregates industry and the European critical raw materials sector. The initial demonstrator can integrate site-specific information with a simulation-based allocation of resources and generate Life-Cycle Assessment and Environmental Product Declaration reports harmonized with the EN 15804 standard and the associated Product Category Rules