219 research outputs found

    Decarbonization of construction supply chains - Achieving net-zero carbon emissions in the supply chains linked to the construction of buildings and transport infrastructure

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    Sweden has committed to reducing greenhouse gas (GHG) emissions to a net-zero level by Year 2045. In Sweden, about 20% of its annual CO2 emissions are from the manufacture, transport and processing of materials for both the construction and refurbishment of buildings and transport infrastructure. Cement and steel, together with diesel use in construction processes and material transport account for the majority of the CO2 emissions associated with building and infrastructure construction.This thesis assesses the challenges associated with reducing CO2 emissions from the supply chains for buildings and transport infrastructure construction. The main aim is to determine the extent to which abatement technologies across the supply chain can reduce the GHG emissions associated with construction if combined to exploit their full potential, while identifying key barriers towards their implementation.The work takes its starting point from material, energy and emissions flow analyses conducted across the construction supply chain, followed by the development of stylized models, which are subsequently used for scenario analysis. This quantitative analysis work is integrated with a participatory process that involves relevant stakeholders in the assessment process. The participatory process serves to identify the main abatement options, as well as to adjust decisions and assumptions regarding abatement portfolios and timelines, so as to make these as realistic and feasible as possible. Supported by a comprehensive literature review, a detailed inventory of abatement options in the supply chain of building and transport infrastructure construction is developed. This includes technologies and practices that are currently available and that are deemed available on a timescale up to Year 2045.The results show that on a national level, it is possible to reduce GHG emissions associated with the construction of buildings and transport infrastructure by 50% up to Year 2030, through applying already available measures. Moreover, it will be feasible to reach close-to-zero emissions by Year 2045, with this requiring comprehensive measures across-the-board, including breakthrough technologies for heavy vehicles, cement and steel production. Attaining the full abatement potential of measures that are already available would rely on sufficient availability of sustainably produced second-generation biofuels, requiring accelerated implementation of alternative abatement measures, involving optimization of material use, mass handling and transport systems, as well as the use of alternative materials and designs, with focus on circularity and material efficiency measures. To realize the potential linked to applying measures across the supply chain, there is a need for extensive collaboration along the whole value chain. Policy measures and procurement strategies should be aligned to support these measures with a clear supply chain focus, so as to enable balanced risk sharing and the involvement of contractors early in the planning and design process.The results also illustrate the importance of intensifying efforts to identify and manage both soft and hard barriers to implementation and the importance of acting promptly to implement available measures (e.g., material efficiency, recycling and material/fuel substitution measures) while actively planning for long-term measures (electrification of heavy vehicles and low-CO2 steel or cement). There are immediate and clear needs to prepare for deeper abatement and associated transformative shifts and to consider carefully the pathway towards these goals while avoiding pitfalls along the way, such as an over-reliance on biofuels or cost optimizations that cannot be scaled up to the levels required to reach deep emissions reductions.Therefore, strategic planning must be initiated as early as possible, as lead times related to planning, securing permits and construction of the support infrastructure (renewable electricity supply, electricity grid expansion, hydrogen storage, CCS infrastructure) and piloting and upscaling to commercial scale of the actual production units will all influence the speed of change

    CPM LCA Database – Life Cycle Inventory Datasets

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    This report contains all 748 complete LCI datasets in the CPM LCA Database as published in 2020-11-20. Contents:Table 1 (pp 3-23) lists all LCI process names in alphabetical order.Table 2 (pp 24-2543) lists all complete LCI datasets in alphabetical order.For information about the database please refer to the Swedish Life Cycle Center, lifecyclecenter.se

    Time Localization of Abrupt Changes in Cutting Process using Hilbert Huang Transform

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    Cutting process is extremely dynamical process influenced by different phenomena such as chip formation, dynamical responses and condition of machining system elements. Different phenomena in cutting zone have signatures in different frequency bands in signal acquired during process monitoring. The time localization of signal’s frequency content is very important. An emerging technique for simultaneous analysis of the signal in time and frequency domain that can be used for time localization of frequency is Hilbert Huang Transform (HHT). It is based on empirical mode decomposition (EMD) of the signal into intrinsic mode functions (IMFs) as simple oscillatory modes. IMFs obtained using EMD can be processed using Hilbert Transform and instantaneous frequency of the signal can be computed. This paper gives a methodology for time localization of cutting process stop during intermittent turning. Cutting process stop leads to abrupt changes in acquired signal correlated to certain frequency band. The frequency band related to abrupt changes is localized in time using HHT. The potentials and limitations of HHT application in machining process monitoring are shown

    Economic growth, energy consumption and CO2 emissions in Sweden 1800-2000.

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    Large transformations of technologies have occurred in the Swedish economy during the last two centuries, resulting in higher income, better quality of products and changing composition of GDP. An agrarian society has given way to an industrial society and lately to a post-industrial phase. The energy supply systems have changed, from traditional energy carriers, such as firewood and muscle energy to modern carriers like coal, oil and electricity, with effects on CO2 emissions. Not only the energy supply has gone through fundamental changes, but also forest management, which affects the net emissions of CO2. The interrelations of growth, energy and CO2 are analyzed in this thesis, which uses standard calculations, relative price analyses and energy quality factors, to determine the relative effects of structural and technical changes, including changes in energy carrier composition to explain the long term delinking of energy consumption, CO2 emissions and economic growth that takes place. Technical change is the main reason of energy intensity decline. Total factor productivity gains, including improvements in technical energy efficiency, saves energy in relation to output. The most spectacular energy savings took place in the sectors transportation & communications and industry. Structural changes at the sector level tended to increase energy intensity between 1870 and 1970. No correlation was found between increasing energy quality and decreasing energy intensity, but energy quality may have had an impact on economic growth rates. The consumers’ surplus was exceptionally high during the interwar period and the three decades after the Second World War, and the total energy quality was outstanding during the latter period. The most rapid relative decline in energy intensity took place between 1970 and 2000. In this period structural changes at the sector level no longer worked to increase energy intensity and the new growth direction of the third industrial revolution saved energy in relation to output. The decrease in energy intensity after 1970 was not caused by changed patterns of foreign trade for Sweden, but by changed patterns of demand in Sweden as well as abroad. CO2 intensity, when only emissions from fossil fuels are counted, shows a pattern of either one long Environmental Kuznets’ Curve, interrupted by the Wars, or of three separate EKCs. The main determinants of this CO2 intensity are energy intensity and energy carrier composition, where the latter turned out to be most influential. The three costs involved in energy consumption, purchasing cost, handling costs and environmental costs are intended to play different roles at different income levels, with effects on energy carrier composition. The estimate of CO2 emissions and sequestration by Swedish forests showed a magnitude well in parity with emissions from fossil fuels. The aggregate CO2 emissions over the period 1800-2000 were not much altered, but the pattern of CO2 intensity was profoundly altered when forest emissions were included. Furthermore the analysis of forest management questioned the idea that firewood caused net CO2 emissions in a dynamic perspective, because the demand for thin timber dimensions stimulated a rational forestry

    Transportation Systems:Managing Performance through Advanced Maintenance Engineering

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    ECOS 2012

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    The 8-volume set contains the Proceedings of the 25th ECOS 2012 International Conference, Perugia, Italy, June 26th to June 29th, 2012. ECOS is an acronym for Efficiency, Cost, Optimization and Simulation (of energy conversion systems and processes), summarizing the topics covered in ECOS: Thermodynamics, Heat and Mass Transfer, Exergy and Second Law Analysis, Process Integration and Heat Exchanger Networks, Fluid Dynamics and Power Plant Components, Fuel Cells, Simulation of Energy Conversion Systems, Renewable Energies, Thermo-Economic Analysis and Optimisation, Combustion, Chemical Reactors, Carbon Capture and Sequestration, Building/Urban/Complex Energy Systems, Water Desalination and Use of Water Resources, Energy Systems- Environmental and Sustainability Issues, System Operation/ Control/Diagnosis and Prognosis, Industrial Ecology

    Development of biomedical devices for the extracorporeal real-time monitoring and perfusion of transplant organs

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    The goal of this Thesis is to develop a range of technologies that could enable a paradigm shift in organ preservation for renal transplantation, transitioning from static cold storage to warm normothermic blood perfusion. This transition could enable the development of novel pre-implantation therapies, and even serve as the foundation for a global donor pool. A low-hæmolysis pump was developed, based on a design first proposed by Nikola Tesla in 1913. Simulations demonstrated the theoretical superiority of this design over existing centrifugal pumps for blood recirculation, and provided insights for future avenues of research into this technology. A miniature, battery-powered, multimodal sensor suite for the in-line monitoring of a blood perfusion circuit was designed and implemented. This was named the ‘SmartPipe’, and proved capable of simultaneously monitoring temperature, pressure and blood oxygen saturations over the biologically-relevant ranges of each modality. Finally, the Thesis details the successful implementation and optimisation of a combined microfluidic and microdialysis system for the real-time quantitation of creatinine in blood or urine through amperometric sensing, to act as a live renal function monitor. The range of detection was 4.3μM – 500μM, with the possibility of extending this in both directions. This work also details and explores a novel methodology for functional monitoring in closed-loop systems which avoids the need for sensor calibration, and potentially overcomes the problems of sensor drift and desensitisation.Open Acces
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