Circular Business Models for Remanufacturing in the Electric Bicycle Industry

The rising popularity and strong increase in the number of electric bicycles make it necessary to consider the built-in resources as well as possible treatments after the use phase. The time lag between the purchase and the occurrence of relevant defects suggests significant increases in defective components. Especially the great dynamics of the market due to regular innovations, product renewals, and the lack of spare parts availability for older models make the long-term use by customers much more difficult than for conventional bicycles. Therefore, it is necessary to analyze circular business models for the electric bicycle market. In this way, the required structures for a sustainable electric bicycle industry can be created so that valuable materials do not go into disposal but undergo a new use phase. Based on the results of “AddRE-Mo–Value Preservation Scenarios for Urban Electromobility of Persons and Loads through Additive Manufacturing and Remanufacturing,” a research project funded by the German Federal Ministry of Education and Research, this paper addresses four circular business models, two sales models, and two service models. The guiding research interest of this paper is the combination of remanufacturing and additive manufacturing from a business model perspective, analyzing the extent to which additive remanufacturing can be considered a solution for electric bicycles' circularity. After describing the approach and methods used to develop these four circular business models the business models are described and analyzed using the Business Model Canvas. Based on this analysis, it is shown that the combination of remanufacturing and additive manufacturing can be applied to the electric bicycle market and be integrated into both sales and service models. The description of these business models will help managers design viable business models in the context of sustainable electric bicycles. It also shows that the individual partners within the value chain must collaborate more closely. In the electric bicycle industry, a single company will probably not be able to close the product cycle completely. Further research is needed to develop concepts of the business models and examine their practical feasibility in technical and organizational operations to achieve a circular economy.

Development of a Cost Model for Vertical Milling Machines to Assess Impact of Lightweighting

Lightweighting is a design strategy to reduce energy consumption through the reduction of mass of a product. Lightweighting can be applied to machine tools to reduce the amount of energy consumed during the use phase. Thus, the energy cost of machine operation will be reduced. One might also hypothesize that since a lighter-weight machine tool requires less material to build, the cost to produce such a machine will be less. However, it may also be the case that lightweighting a machine tool increases its complexity, which will likely drive up the cost to manufacture the machine. To explore the cost drivers associated with building a machine tool, data on the features associated with a wide variety of vertical milling machine tools are collected. Then, empirical cost models are fit to this data. The results from the cost models show that the machine tool mass is a significant cost driver; other key drivers are the number of axes and spindle power. The models are used to predict the cost benefits of lightweighting in terms of mass, which are compared to potential increased manufacturing costs associated with complexities introduced due to lightweighting.

Modelling the coupling of the M-clock and C-clock in lymphatic muscle cells

Lymphoedema develops due to chronic dysfunction of the lymphatic vascular system which results in fluid accumulation between cells. The condition is commonly acquired secondary to diseases such as cancer or the therapies associated with it. The primary driving force for fluid return through the lymphatic vasculature is provided by contractions of the muscularized lymphatic collecting vessels, driven by electrical oscillations. However, there is an incomplete understanding of the molecular and bioelectric mechanisms involved in lymphatic muscle cell excitation, hampering the development and use of pharmacological therapies. Modelling in silico has contributed greatly to understanding the contributions of specific ion channels to the cardiac action potential, but modelling of these processes in lymphatic muscle remains limited. Here, we propose a model of oscillations in the membrane voltage (M-clock) and intracellular calcium concentrations (C-clock) of lymphatic muscle cells. We modify a model by Imtiaz and colleagues to enable the M-clock to drive the C-clock oscillations. This approach differs from typical models of calcium oscillators in lymphatic and related cell types, but is required to fit recent experimental data. We include an additional voltage dependence in the gating variable control for the L type calcium channel, enabling the M-clock to oscillate independently of the C-clock. We use phase-plane analysis to show that these M-clock oscillations are qualitatively similar to those of a generalised FitzHugh-Nagumo model. We also provide phase plane analysis to understand the interaction of the M-clock and C-clock oscillations. The model and methods have the potential to help determine mechanisms and find targets for pharmacological treatment of lymphoedema.

Evaluation of Water Resources Sustainable Utilization in Wuhan Based on the Model of SUDE

SUDE model is a systematic sustainable use model based on the view of the whole life cycle of water resources. The analysis of the model water resources has been divided into four stages according to the state of motion water resourcesat different times in its life cycle, namely the water supply stage (“S”),water use phase (“U”),water collection,treatment anddrainage stage (“D”) and water return to natural ecological (ecology) environment for dilution, degradation stage (“E”).on the analysis above,SUDE theoretical model of water system has been built and corresponding evaluation index systemhas therefore been established. Then, we use entropy weight TOPSIS method to evaluate thesustainability of water resource during 2013∼2017 yearsin Wuhan, and finally the corresponding conclusions and suggestion have been drawn according to the result of evaluation in the paper.

The slow self-arresting nature of low-frequency earthquakes

Low-frequency earthquakes are a series of recurring small earthquakes that are thought to compose tectonic tremors. Compared with regular earthquakes of the same magnitude, low-frequency earthquakes have longer source durations and smaller stress drops and slip rates. The mechanism that drives their unusual type of stress accumulation and release processes is unknown. Here, we use phase diagrams of rupture dynamics to explore the connection between low-frequency earthquakes and regular earthquakes. By comparing the source parameters of low-frequency earthquakes from 2001 to 2016 in Parkfield, on the San Andreas Fault, with those from numerical simulations, we conclude that low-frequency earthquakes are earthquakes that self-arrest within the rupture patch without any introduced interference. We also explain the scaling property of low-frequency earthquakes. Our findings suggest a framework for fault deformation in which nucleation asperities can release stress through slow self-arrest processes.

The role of concrete in life cycle greenhouse gas emissions of US buildings and pavements

Concrete is a critical component of deep decarbonization efforts because of both the scale of the industry and because of how its use impacts the building, transportation, and industrial sectors. We use a bottom-up model of current and future building and pavement stocks and construction in the United States to contextualize the role of concrete in greenhouse gas (GHG) reductions strategies under projected and ambitious scenarios, including embodied and use phases of the structures’ life cycle. We show that projected improvements in the building sector result in a reduction of 49% of GHG emissions in 2050 relative to 2016 levels, whereas ambitious improvements result in a 57% reduction in 2050, which is 22.5 Gt cumulative saving. The pavements sector shows a larger difference between the two scenarios with a 14% reduction of GHG emissions for projected improvements and a 65% reduction under the ambitious scenario, which is ∼1.35 Gt. This reduction occurs despite the fact that concrete usage in 2050 in the ambitious scenario is over three times that of the projected scenario because of the ways in which concrete lowers use phase emissions. Over 70% of future emissions from new construction are from the use phase.

Requirements for a Product Lifecycle Management System Using Internet of Things and Big Data Analytics for Product-as-a-Service

Product-as-a-service (PaaS) offerings have advantages and potential for transforming societies to a circular economy and for improving environmental performance. Original equipment manufacturers providing PaaS offerings take higher responsibility for product performances in the use phase than those selling products. This responsibility can be supported by digital technologies such as the Internet of Things (IoT) and big data analytics (BDA). However, insights on how data of product designs and in-use services are managed for PaaS offerings in product lifecycle management (PLM) software are scarce. This mini-review first gives an account of extant major research works that successfully applied BDA, a specific technique of artificial intelligence (AI), to cases in industry through a systematic literature review. Then, these works are analyzed to capture requirements for a PLM system that will exploit the IoT and BDA for PaaS offerings. The captured requirements are summarized as (1) facilitate product and service integration, (2) address multiple lifecycles, (3) adopt an ontology approach encompassing several product standards, and (4) include reading data to process in an interoperation layer.

Life Cycle Assessment of a Plant-Based, Regionally Marketed Shampoo and Analysis of Refill Options

The environmental impact of a plant-based shampoo produced and marketed in Zurich, Switzerland, was analyzed using the life cycle assessment method. Beside the identification of environmental hotspots and mitigation possibilities, the focus of the study was on the analysis and comparison of different refill offers. The results of the study show that one hair wash using the investigated shampoo is related to greenhouse gas emissions of 161 gCO2eq. For all investigated impact categories, the use phase represents the dominant life stage, except for land use, which is dominated by the production of the purely plant-based shampoo ingredients. The environmental impact related to the use phase is highly sensitive on the consumers’ showering habits, such as water consumption and water temperature, due to predominantly fossil-based heating in Zurich. On the producer’s side, a switch to renewable energy sources both for heating and electricity is identified as most effective measure to reduce the environmental impact of the manufacturing phase. As to the product end-of-life, the results suggest that emissions of the shampoo ingredients after wastewater treatment have a negligible impact on freshwater ecotoxicity. In this context, a need for further research is identified with respect to characterization factors and specific removal rates in wastewater treatment plants. From a life cycle perspective, packaging production and disposal have rather low contributions. Offering refill possibilities can reduce the packaging related contributions by several percentage points, however, higher mitigation potentials are found for use phase and manufacturing.

DESIGNING FOR CALIBRATED TRUST: EXPLORING THE CHALLENGES IN CALIBRATING TRUST BETWEEN USERS AND AUTONOMOUS VEHICLES

Trust is an important factor in building acceptance of autonomous vehicles within our society, but the complex nature of trust makes it challenging to design for an appropriate level of trust. This can lead to instances of mistrust and/or distrust between users and AV’s. Designing for calibrated trust is a possible option to address this challenge. Existing research on designing for calibrated trust focuses on the human machine interaction (HMI), while from literature we infer that trust creation beings much before the first interaction between a user and an AV. The goal of our research is to broaden the scope of calibrated trust, by exploring the pre-use phase and understand the challenges faced in calibration of trust. Within our study 16 mobility experts were interviewed and a thematic analysis of the interviews was conducted. The analysis revealed the lack of clear communication between stakeholders, a solutionism approach towards designing and lack of transparency in design as the prominent challenges. Building on the research insights, we briefly introduce the Calibrated Trust Toolkit as our design solution, and conclude by proposing a sweet spot for achieving calibration of trust between users and autonomous vehicles.