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Träfflista för sökning "WFRF:(Lundqvist Per Professor) srt2:(2015-2019)"

Sökning: WFRF:(Lundqvist Per Professor) > (2015-2019)

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1.
  • Bixby, H., et al. (författare)
  • Rising rural body-mass index is the main driver of the global obesity epidemic in adults
  • 2019
  • Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 569:7755, s. 260-4
  • Tidskriftsartikel (refereegranskat)abstract
    • Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities(.)(1,2) This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity(3-6). Here we use 2,009 population-based studies, with measurements of height and weight in more than 112 million adults, to report national, regional and global trends in mean BMI segregated by place of residence (a rural or urban area) from 1985 to 2017. We show that, contrary to the dominant paradigm, more than 55% of the global rise in mean BMI from 1985 to 2017-and more than 80% in some low- and middle-income regions-was due to increases in BMI in rural areas. This large contribution stems from the fact that, with the exception of women in sub-Saharan Africa, BMI is increasing at the same rate or faster in rural areas than in cities in low- and middle-income regions. These trends have in turn resulted in a closing-and in some countries reversal-of the gap in BMI between urban and rural areas in low- and middle-income countries, especially for women. In high-income and industrialized countries, we noted a persistently higher rural BMI, especially for women. There is an urgent need for an integrated approach to rural nutrition that enhances financial and physical access to healthy foods, to avoid replacing the rural undernutrition disadvantage in poor countries with a more general malnutrition disadvantage that entails excessive consumption of low-quality calories.
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2.
  • Mölleryd, Bengt A, 1947- (författare)
  • Governance of innovation - deploying an architectural framework for innovation of technological systems for energy, security and defence
  • 2018
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • Governance of innovation – deploying an architectural framework for innovation of technological systems for energy, security and defence Innovation has a great deal of attraction but is associated with serious uncertainties and downsides. It is potentially beneficial for growth, sector and industrial development and competitiveness. Innovation brings hope of solving societal challenges, such as climate change and environment protection, and could help secure a supply of energy. Furthermore, it improves resilience and strengthens security and defence.The downside of innovations of some magnitude concern severe transitions and disruptions. Digitisation, with associated net technologies, is an illustrative example of an innovation that creates new services, competitiveness and other benefits which is enormously positive and attractive, while simultaneously dismantles and destroys existing systems, firms and branches, and whole sectors and practices.The thesis deals with promoting innovations at large but specifically systemic, defined as a value-adding (to customers and users) set or convergence of new products/services from technological systems in processes which emerge by evolutionary association and integration of systems transforming businesses, industries and sectors (with disruptions as consequence). Innovations are distinguished by certain structural properties namely systemicitiness. The systemicitiness of innovations suggests a distinct architectural framework that determines the structure of innovations. The purpose of the proposal for an architectural framework for innovation is guidance to governance of innovation. Platform based ecosystems exemplifies an emulation of systemic innovation that aligns with the proposed framework. The framework is distilled from cases, events, patterns, landscapes and models of innovation in the literature, connected with examination of systemicitiness and governance approaches to innovation and innovation processes. The architectural framework is conjected as compatible and complementary to common policies and instruments for innovation and innovation processes as holistic systems engineering, standards and protocols (e.g. ISO/IEC 15288:2015, ISO/IEC 42010:2011, NISP).
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3.
  • Poppi, Stefano, 1982- (författare)
  • Solar heat pump systems for heating applications : Analysis of system performance and possible solutions for improving system performance
  • 2017
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • Solar heat pump systems (SHPs) are systems that combine solar energy and heat pumps. SHPs have been investigated for several decades and have been proven to increase the share of renewable energy and reduce electric energy demand in residential heating applications. Many solar thermal heat pump systems have become market-available in recent years; however these systems are still not widely employed in the residential sector. This is due mainly to the high initial costs (investment and installation costs) of solar thermal heat pump systems, which limits their cost-effectiveness. Enhancing cost-effectiveness of solar thermal heat pump systems is necessary for a more effective and broader market penetration.In this thesis, solar thermal and photovoltaic systems combined with heat pumps for heating applications are treated. The overall aims of the thesis are to: 1) investigate techno-economics of SHPs and 2) investigate possible solutions for improving system performance of a reference solar thermal and heat pump system for residential heating applications.In the first part of the thesis, the influence of climatic boundary conditions on economic performance of SHPs has been investigated by means of: a) an economic comparison of SHPs found in the relevant literature and b) system simulations of the reference solar thermal heat pump system.In the second part of the thesis, potential solutions for improving system performance of the reference solar thermal heat pump system with limited change in system’ costs are investigated. A systematic approach was used for investigating cost-effectiveness of the system improvements in the reference system.Based on results of the cost-effectiveness analysis, some of the investigated system improvements were chosen for being included in the design of a novel solar thermal and air source heat pump system concept. The novel system was designed for a house standard with relatively high operating temperatures (55°C/45°C) in the space heating distribution system and for high space heating demand (123 kWh/m2·year). Finally, the thesis ends with a cost-effectiveness analysis of the novel system.
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4.
  • Öhman, Henrik, 1964- (författare)
  • Low temperature difference power systems and implications of multi-phase screw expanders in Organic Rankine Cycles
  • 2016
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • New and old data on screw expanders operating with 2-phase mixtures in the admission line has been combined to enable the first public correlation of adiabatic expansion efficiency as a function of entry vapour fraction. Although not yet perfected, these findings have enabled an entirely new approach to the design and optimisation of Organic Rankine Cycles, ORCs. By allowing a continuous variation of vapour fraction at expander entry optima for thermal efficiency, second law efficiency and cost efficiency can be found. Consequently one can also find maxima for power output in the same dimension.This research describes a means of adapting cycle characteristics to various heat sources by varying expander inlet conditions from pure liquid expansion, through mixed fluid and saturated gas expansion, to superheated gas. Thermodynamic analysis and comparison of the above optimisations were a challenge. As most terms of merit for power cycles have been developed for high temperature applications they are often simplified by assuming infinite heat sinks. In many cases they also require specific assumptions on e.g. pinch temperatures, saturation conditions, critical temperatures etc, making accurate systematic comparison between cycles difficult. As low temperature power cycles are more sensitive to the ‘finiteness’ of source and sink than those operating with high temperatures, a substantial need arises for an investigation on which term of merit to use.Along with an investigation on terms of merit, the definition of high level reversible reference also needed revision. Second law efficiency, in the form of exergy efficiency, turned out to be impractical and of little use. A numerical approach, based on a combination of first and second law, was developed. A theory and method for the above is described. Eventually low temperature power cycle test data was compiled systematically. Despite differences in fluid, cycle, temperature levels and power levels the data correlated well enough to allow for a generalised, rough correlation on which thermal efficiency to expect as a function of utilization of source and sink availability. The correlation on thermal efficiency was used to create a graphical method to pre-estimate key economic factors for low temperature site potential in a very simple manner. A major consequence from the findings of this thesis is the reduced dependency on unique choices of process fluid to match heat source characteristics. This development significantly simplifies industrial standardisation, and thereby potentially improves cost efficiency of commercial ORC power generators.
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5.
  • Ahl, Amanda, et al. (författare)
  • Balancing formal and informal success factors perceived by supply chain stakeholders : A study of woody biomass energy systems in Japan
  • 2018
  • Ingår i: Journal of Cleaner Production. - : Elsevier. - 0959-6526 .- 1879-1786. ; 175, s. 50-59
  • Tidskriftsartikel (refereegranskat)abstract
    • Small-scale woody biomass energy systems have an inherent ability to aid in emissions reduction while stimulating local economies and, as collective energy systems, are strongly connected to supply chain design based on local conditions and stakeholder integration. Despite an abundance of forest area alongside the promotion of biomass in energy policies, however, woody biomass utilization still remains low in Japan. The woody biomass supply chain, considered as a socio-technical system, involves a complex, cross-sectoral stakeholder network in which inter-organizational dynamics necessitates well-organized management based on an understanding of formal factors such as technology, as well as informal factors such as social relations and culture. In this paper, success factor perceptions from across the woody biomass supply chain are investigated based on semi-structured interviews with four stakeholders in the Kyushu region of Japan. Identified success factors here are: 1) respect of values & traditions, 2) transportation infrastructure, 3) business model integration, 4) relationship & trust, 5) local vitalization and 6) biomass quality control. A convergence as well as divergence of perceptions are observed, involving both formal and informal dimensions. Aiming to balance perceptions and to enable long-term success of woody biomass in Japan, a series of policy implications are drawn, including cross-ministerial integration, knowledge building on wood logistics, forest certification, local coordinators, biomass quality control standards and a feed-in-tariff for heat. This paper suggests a new arena of policy-making based on the importance of considering both informal and formal dimensions in energy policy.
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6.
  • Bagge, Ebba, et al. (författare)
  • Pattern of endocrine treatment for epithelial ovarian cancer in the Southeast medical region of Sweden: a population-based study
  • 2019
  • Ingår i: Acta Oncologica. - : TAYLOR & FRANCIS LTD. - 0284-186X .- 1651-226X. ; 58:3, s. 320-325
  • Tidskriftsartikel (refereegranskat)abstract
    • Aim of the study: Endocrine treatment (ET) is an alternative as salvage therapy in epithelial ovarian cancer (EOC) but the usage in routine care is unknown. We evaluated the treatment patterns and outcome of patients receiving ET for EOC in the Southeast medical region in Sweden.Method: Patients were identified through the population-based Southeast Quality Registry for gynaecological cancer. Inclusion criteria were: age 18 years, histologically verified EOC diagnosed 2000-2013, ET for 4 weeks. Coverage compared with the Swedish National Cancer Registry was 100%. Data extracted from medical records was collected by means of a study-specific Case Report Form. Last date of follow-up was February 1st, 2018. All statistics were descriptive.Results: Altogether 248 (18%) of 1414 patients were treated with ET. Most (49%) had received only one, and 34% two previous lines of chemotherapy. Time from last chemotherapy to ET was 4 months, range 0-55months. The reason for initiating ET was tumor progression (66%), chemotherapy related toxicity (29%) and maintenance (4%). Tamoxifen was prescribed in 94% of cases. Best response was partial (amp;lt; 5%) and stable disease (50%). No patient had a complete response. 194 (78%) patients received subsequent chemotherapy, of these 27% had 3-7 lines of chemotherapy. Duration of ET was a median 4 months (range 1-80 months). Median time from ET to subsequent chemotherapy was 5 months (range 0-79). The median overall survival was 45 months (range 9-173).Conclusion: In the Southeast region of Sweden, endocrine treatment for EOC was prescribed inconsistently and in various settings, usually initiated by a rising CA-125 level. Poorer documentation and irregular tumor response assessment were observed for endocrine treatment compared to chemotherapy.
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7.
  • Bengtsson, Peder, 1968- (författare)
  • Apply heat pump systems in commercial household products to reduce environmental impact : How to halve the electricity consumption for a household dishwasher
  • 2017
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • In the household appliance industry, heat pump systems have been used for a long time in refrigerators and freezers to cool food, and the industry has driven the development of small, high-quality, low-price heat pump components. In the last few decades, heat pump systems have been introduced in other household appliances, with the express purpose of reducing electricity consumption. Heat pump tumble dryers have been on the market since 2000 and dominate the market today. A heat pump dishwasher was introduced on the market in 2014 and a heat pump washing machine in 2016. The purpose of adding a heat pump system in these three products was to decrease electricity consumption.Papers I and II used a methodology where transient simulation models were developed and used to increase knowledge about how to decrease electricity consumption for a tumble dryer and a dishwasher by adding a heat pump system. Papers II to V showed that a lower electricity consumption and lower global warming potential together with an energy-efficient drying method, where no humid air evacuates to the kitchen, give a heat pump dishwasher competitive advantages compared to any conventional dishwasher currently on the market. Using simulations, this dissertation concludes that a future commercial heat pump dishwasher, using R600a as a refrigerant, will reduce electricity consumption and total equivalent warming impact (TEWI) by 50% compared to the conventional dishwasher.The willingness from the customer chain to pay extra for this heat pump dishwasher is because of the decreases electricity consumption and the fact that no humid air evacuates to the kitchen. This willingness makes the heat pump dishwasher to a variant which have possibility to succeed on the future market.The challenge for the manufacturer is to develop and produce a high-quality heat pump dishwasher with low electricity consumption, predict future willingness to pay for it, and launch it on the market at the right moment with the right promotion in order to succeed.
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8.
  • Lundqvist, Per, Professor, et al. (författare)
  • Global Efficiency of Heat Engines and Heat Pumps with Non-Linear Boundary Conditions
  • 2017
  • Ingår i: Entropy. - : MDPI. - 1099-4300. ; 19:8
  • Tidskriftsartikel (refereegranskat)abstract
    • Analysis of global energy efficiency of thermal systems is of practical importance for a number of reasons. Cycles and processes used in thermal systems exist in very different configurations, making comparison difficult if specific models are required to analyze specific thermal systems. Thermal systems with small temperature differences between a hot side and a cold side also suffer from difficulties due to heat transfer pinch point effects. Such pinch points are consequences of thermal systems design and must therefore be integrated in the global evaluation. In optimizing thermal systems, detailed entropy generation analysis is suitable to identify performance losses caused by cycle components. In plant analysis, a similar logic applies with the difference that the thermal system is then only a component, often industrially standardized. This article presents how a thermodynamic "black box" method for defining and comparing thermal efficiency of different size and types of heat engines can be extended to also compare heat pumps of different apparent magnitude and type. Impact of a non-linear boundary condition on reversible thermal efficiency is exemplified and a correlation of average real heat engine efficiencies is discussed in the light of linear and non-linear boundary conditions.
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9.
  • Malakhatka, Elena, et al. (författare)
  • End-user activities context information management framework for sustainable building operation
  • 2019
  • Ingår i: CISBAT 2019 | Climate Resilient Cities – Energy Efficiency & Renewables in the Digital Era4–6 September 2019, EPFL Lausanne, Switzerland. - : Institute of Physics Publishing (IOPP).
  • Konferensbidrag (refereegranskat)abstract
    • The concept of sustainable buildings includes not only technological aspects related to energy efficiency and resources usage optimization, but also aspects related to end-users' comfort, wellbeing, and everyday needs support. To understand the end-users' life activities in general and their preferences in particular, is necessary to enrich standard Building Management Systems (BMS) with human-generated and personal data. In this conceptual paper, we present an end-user context information management framework, which includes a reasoning layer, an acquisition layer, and a dissemination layer. The proposed framework is currently implemented in the KTH Live-in-Lab - a fully equipped testbed for research and innovation in the build environment.
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10.
  • Shahrooz, Mina, et al. (författare)
  • Natural refrigerants for low temperature power cycles
  • 2018
  • Ingår i: Refrigeration Science and Technology. - : International Institute of Refrigeration. - 9782362150265 ; , s. 1373-1380
  • Konferensbidrag (refereegranskat)abstract
    • Working fluid selection determines various characteristics of low temperature Rankine cycles. Among other factors, the selected working fluid affects thermal performance, apparatus size and economic feasibility of the cycle. Beyond only affecting characteristics of the system, unrealistic preconditions for the working fluid of the system may force the designers in using environmentally harmful mixtures and force the outcome beyond boundaries of environmental regulations. There has been numerous research and scrutiny on various working fluids, but due to the unstructured and unorganized orientation of previous studies, there is no comprehensive insight on relationship of different characteristics of the working fluid and overall performance of the system. This work intends to develop a numerical evaluation approach, using a modified stochastic optimization algorithm as a search engine. The paper further explores and questions the existing criteria for optimization of working fluids in Rankine cycle. Rather than just finding the optimum fluids for different cases, this study aims to investigate the behavior of different fluids around optimum points and see the bigger picture to find trends in different fluid behaviors. Analysis of results show two main behaviors among the fluids in subcritical cycles. In the first type behavior, the optimum points for output work, thermal efficiency and exergy efficiency lie very close to each other, while in second type, these optimum points are not close. There is a transition from first type behavior to second type for a ratio of critical temperature around 0.9 of heat source inlet temperature. These results also show the importance of key performance parameter determination.
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