398 research outputs found

    Leveraging Circular Economy through a Methodology for Smart Service Systems Engineering

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    Product Service Systems (PSS) and Smart Services are powerful means for deploying Circular Economy (CE) goals in industrial practices, through dematerialization, extension of product lifetime and efficiency increase by digitization. Within this article, approaches from PSS design, Smart Service design and Model-based Systems Engineering (MBSE) are combined to form a Methodology for Smart Service Architecture Definition (MESSIAH). First, analyses of present system modelling procedures and systems modelling notations in terms of their suitability for Smart Service development are presented. The results indicate that current notations and tools do not entirely fit the requirements of Smart Service development, but that they can be adapted in order to do so. The developed methodology includes a modelling language system, the MESSIAH Blueprinting framework, a systematic procedure and MESSIAH CE, which is specifically designed for addressing CE strategies and practices. The methodology was validated on the example of a Smart Sustainable Street Light System for Cycling Security (SHEILA). MESSIAH proved useful to help Smart Service design teams develop service-driven and robust Smart Services. By applying MESSIAH CE, a sustainable Smart Service, which addresses CE goals, has been developed

    Utilization of Product Lifecycle Data from PLM Systems in Platforms for Industrial Symbiosis

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    Industrial Symbiosis represents a promising approach to foster the transformation towards a circular economy. To involve businesses in Industrial Symbiosis, online platforms and input-output matching tools for facilitating the exchange of by-products have been provided by industry organizations and facilitators. Regarding the discrete parts and product manufacturing industry (DPPM), little success is being reported for such platforms and tools. Within the scope of this research, a list of Input-Output matching tools was analysed regarding data sources which are currently used for input-output Matching. Specifications of by-products in the DPPM industry were reviewed in order to identify a list of requirements for data sources. Shortcomings of the currently existing input-output matching tools were identified and suggestions for additional data sources used for input-output matching in IS in DPPM were given. Results show that datasets currently used do not include organisational data sources such as Product Data Management (PDM) systems, Enterprise Resource Planning (ERP) systems, Supply Chain Management (SCM) systems, and or Manufacturing Execution Systems (MES)

    Periodic solutions and refractory periods in the soliton theory for nerves and the locust femoral nerve

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    Close to melting transitions it is possible to propagate solitary electromechanical pulses which reflect many of the experimental features of the nerve pulse including mechanical dislocations and reversible heat production. Here we show that one also obtains the possibility of periodic pulse generation when the boundary condition for the nerve is the conservation of the overall length of the nerve. This condition generates an undershoot beneath the baseline (`hyperpolarization') and a `refractory period', i.e., a minimum distance between pulses. In this paper, we outline the theory for periodic solutions to the wave equation and compare these results to action potentials from the femoral nerve of the locust (locusta migratoria). In particular, we describe the frequently occurring minimum-distance doublet pulses seen in these neurons and compare them to the periodic pulse solutions.Comment: 10 pages, 6 Figure

    Synthesizing, Purifying, and Characterizing Molten Chloride Salts

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    Molten chloride salts have vast potential as heat transfer fluids with both nuclear and concentrated solar power applications. For application in energy systems, the characteristics that govern these systems must be well understood. This work focuses on inorganic molten chloride salts with a special emphasis on the experimental aspect of chemical research. Chapter 2 covers the synthetic approaches for the formation of molten chloride mixtures. Many salts can be purchased from industrial suppliers, but most must be purified therefore, Chapter 3 evaluates various methodology developed for removal of impurities in salt mixtures. Once the salt of proper content and purity is obtained it can be characterized. Chapter 4 reviews the characterization of various salts utilizing many analytical approaches. The remaining chapters focus on fluid property optimization needed for the industrial use of molten chlorides as heat transfer fluid. A novel mechanochemical synthetic route for the formation of MgCl2:KCl carnallite was instituted and is reviewed in Chapter 5. Chapter 6 reviews a novel apparatus designed to supercool chloride salts while still in the amorphous state. Magnetic nanoparticles are utilized in Chapter 7 to demonstrate the efficacy and first-time formation of an ultra-high temperature ferrofluid

    The influence of anesthetics, neurotransmitters and antibiotics on the relaxation processes in lipid membranes

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    In the proximity of melting transitions of artificial and biological membranes fluctuations in enthalpy, area, volume and concentration are enhanced. This results in domain formation, changes of the elastic constants, changes in permeability and slowing down of relaxation processes. In this study we used pressure perturbation calorimetry to investigate the relaxation time scale after a jump into the melting transition regime of artificial lipid membranes. This time corresponds to the characteristic rate of domain growth. The studies were performed on single-component large unilamellar and multilamellar vesicle systems with and without the addition of small molecules such as general anesthetics, neurotransmitters and antibiotics. These drugs interact with membranes and affect melting points and profiles. In all systems we found that heat capacity and relaxation times are related to each other in a simple manner. The maximum relaxation time depends on the cooperativity of the heat capacity profile and decreases with a broadening of the transition. For this reason the influence of a drug on the time scale of domain formation processes can be understood on the basis of their influence on the heat capacity profile. This allows estimations of the time scale of domain formation processes in biological membranes.Comment: 12 pages, 6 figure

    Landesentwicklungspolitik von den 70er in die 90er Jahre

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    dCache @ gridKa

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