| 1. |
- Abedi, Hamidreza, 1979, et al.
(författare)
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Development of blade element momentum (BEM) method for hydropower
- 2022
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Ingår i: IOP Conference Series: Earth and Environmental Science. - : IOP Publishing. - 1755-1307 .- 1755-1315. ; 1079:1
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Konferensbidrag (refereegranskat)abstract
- The BEM method is extensively used for analyzing the aerodynamic performance of wind turbines and marine propellers. It is computationally fast and is easily implemented while it can give fairly accurate results. Application of the BEM method to predict the forces acting on rotor blades for a model scale axial shaft-driven Counter-Rotating Pump-Turbine (CRPT) is investigated. Some modifications have been proposed to adopt the classical BEM method for CRPT machine and the results are validated against results from Computational Fluid Dynamics (CFD). The results display that the proposed modifications can improve the loading predicted by BEM. However, the improvements are more pronounced in pump mode rather than turbine mode.
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| 2. |
- af Hällström, Anna, 1987, et al.
(författare)
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Collaborative governance models towards sustainable infrastructure projects: the case of resources
- 2020
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Ingår i: IOP Conference Series: Earth and Environmental Science. - : IOP Publishing. - 1755-1307 .- 1755-1315. ; 588:5
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Konferensbidrag (refereegranskat)abstract
- The construction and infrastructure industry contribute to almost a quarter of global greenhouse gas emissions and is one of the largest drivers of resource use. This sector of the global economy is thus a promising area to look at for reducing environmental impact and increase sustainability. The impact of collaboration and cooperation within the project organisation has begun to garner more attention as the scale and scope, as well as the levels of uncertainty and complexity in construction and infrastructure projects have grown. This has led to an increase in collaborative contracting models applied to complex construction projects. In order to investigate the impact of collaborative contracting and the possibilities to advance the goal of resource efficiency and decrease environmental impact, a case study of two Nordic projects, utilising a collaborative project management model, is conducted. The findings suggest that the potential of using collaborative project management models in order to increase the sustainability of construction solutions is high. However, the use and understanding of the models vary between project actors. We conclude that the new collaborative project management models are important features in reducing environmental impact from infrastructure construction, yet several organisational and practical issues remain to be solved.
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| 3. |
- Ahlström, F., et al.
(författare)
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Performance indicators of textile reverse logistics
- 2020
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Ingår i: IOP Conference Series: Earth and Environmental Science. - : IOP Publishing. - 1755-1307 .- 1755-1315.
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Konferensbidrag (refereegranskat)abstract
- © Published under licence by IOP Publishing Ltd. The reverse supply chain has gained increased attention across industries due to the high product return rates. Many strategic and economic benefits can be reaped by efficiently managing the reverse supply chain, such as; cost reduction and enhanced environmental performance. Despite the acknowledgement of the available advantages that can be reaped, there is an overall lack of academic research concerning performance metrics, in particular KPIs (Key Performance Indicators), that can help in managing reverse supply chains. Moreover, industry-specific KPIs have not been explored thoroughly. The apparel industry is currently plagued by high return rates, which suggests that it is even more important for clothing retailers to look over their reverse supply chains. The conceptual framework presented in this report seeks to diminish the gap in literature and provide clothing retailers with KPIs with a focus on environmental sustainability that can help in the decision-making process. The framework is expected to promote sustainability as a more central decision-making criterion within reverse supply chains, especially within the apparel industry.
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| 4. |
- Akperov, M., et al.
(författare)
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Trends of intense cyclone activity in the Arctic from reanalyses data and regional climate models (Arctic-CORDEX)
- 2019. - 1
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Ingår i: Turbulence, Atmosphere and Climate Dynamics. - : IOP Publishing. - 1755-1307. ; 231
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Konferensbidrag (refereegranskat)abstract
- The ability of state-of-the-art regional climate models (RCMs) to simulate the trends of intense cyclone activity in the Arctic is assessed based on an ensemble of 13 simulations from 11 models from the Arctic-CORDEX initiative. Some models employ large-scale spectral nudging techniques. Cyclone characteristics simulated by the ensemble in winter and summer are compared with the results from four reanalyses (ERA-Interim, NCEP-CFSR, NASA-MERRA2 and JMA-JRA55) in winter and summer for 1981-2010 period.
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| 5. |
- An, Siwen, et al.
(författare)
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Comparison of Elemental Analysis Techniques for Fly Ash from Municipal Solid Waste Incineration using X-rays and Electron Beams
- 2019
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Ingår i: IOP Conference Series. - : Institute of Physics (IOP).
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Konferensbidrag (refereegranskat)abstract
- With the rapid expansion of the waste incineration business both in Europe and globally, there is a growing need for the elemental analysis for fly ash from municipal solid waste incineration. In this work, samples of washed and unwashed ash from municipal solid waste incineration in Sundsvall are evaluated. Qualitative analysis and semi-quantitative analysis are used to compare two elemental analysis methods, scanning electron microscope with energy dispersive spectroscopy (SEM-EDS) and X-ray fluorescence (XRF) measurement. Both methods are used to retrieve the difference in elemental composition between washed and unwashed fly ash. SEM-EDS accurately detects light elements from well-prepared samples in a vacuum environment, while, for online measurements, XRF is a potential method that analyses hazardous metal content in the fly ash.
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| 6. |
- An, Siwen, et al.
(författare)
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Effects of Water Absorption on Mercury Contamination in Fiberbank Sediments using X-ray Fluorescence Spectrometer
- 2021
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Ingår i: IOP Conference Series: Earth and Environmental Science. - : Institute of Physics (IOP). - 1755-1307 .- 1755-1315.
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Konferensbidrag (refereegranskat)abstract
- A large amount of contaminated cellulose and wood fibers were emitted directly onto the seabed by the pulp and paper industry before the year of 1970. This fiber-rich sediment contains concentrations of hazardous substances that cause environmental problems. Mercury (Hg) in the fiber sediment is a worldwide threat because it can bioaccumulate in the aquatic ecosystem and eventually affect human health. X-ray fluorescence (XRF) analysis is anelemental analysis method for earth materials, which is rapid and requires minimal sample preparation. However, for in-situ XRF analyses, constraints in the measurement conditions will strongly affect the measurement sensitivity and accuracy, such as the scattered background and the water content surrounding the sample. In this work, we showed that applying an X-ray beam filter foil, optimized by using the material absorption edge, can improve the sensitivity of the XRF spectrometer system for Hg determination. Furthermore, the influence of water content in XRF measurement for Hg contamination analysis was investigated. The attenuation coefficient in water was determined by simulation of water layer with varying thickness using a Monte Carlo simulation code. The measured intensity for Hg was decreased exponentially asthe water thickness increase, as expected. We propose a method to correct the attenuation in water with XRF analysis and we expect that these findings can contribute to an accurate in-situ Hg detection experiment.
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| 7. |
- Andersson, Rickard, 1988
(författare)
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Public policies as obstacle to sustainable CDWM practices
- 2020
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Ingår i: IOP Conference Series: Earth and Environmental Science. - : IOP Publishing. - 1755-1307 .- 1755-1315. ; 588:2
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Konferensbidrag (refereegranskat)abstract
- The sustainable management of construction and demolition waste (CDW) should play a significant role to achieve the SDG11 for sustainable cities and communities as well as the SDG12 on responsible consumption and production. However, the construction sector is still a major contributor to the waste generated within the European union and contributes with around 25-30 percent of the total amount. The EU followed by the Swedish agencies and the professional associations have defined successive policies to increase the recycling ratio of CDW and mitigate its negative effect. The role of these public policies is to define and to encourage the implementation of sustainable solutions. In the case of management of CDW and in particular the renovation and demolition waste, those policies are not delivering the expected result. Building on multiple regulatory levels with the intent to govern professional's behavior, they so far fail to support change in practice. The aim of this study is therefore to study and analyze how the policy framework and professional guidelines are defining the conditions for adopting more sustainable waste management practices in the industry. The study is based on a document analysis of grey literature in terms of governmental reports, official guidelines, regulatory publications and other publicly published documents concerning CDW management. The analysis highlight ambiguity and contradictions within the material as to how the challenges concerning CDW should be addressed. There is a misalignment between the different actors view on definitions, responsibility and the design of roadmaps toward a more sustainable agenda. This ambiguity and complexity could explain the maintaining of the current practices, hampering practitioners to act. We therefore emphasize the need for a more coherent framework to create the necessary conditions for the industry to move towards a more sustainable agenda.
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| 8. |
- Angelaki, Stavroula, et al.
(författare)
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A review of lighting research in educational spaces
- 2022
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Ingår i: IOP Conference Series. - : IOP Publishing.
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Konferensbidrag (refereegranskat)abstract
- The present paper summarises tendencies related to research in lighting for school environments from 1980 to 2020. Methods and tools used to evaluate and analyse both daylight and electric lighting are presented. The studies in this literature review were grouped in four decades and are presented chronologically. The review suggests a shift from on-site evaluations in the early decades, both when using qualitative and quantitative research methods, to software-based research and analysis in more recent studies. during the past decade, there appears to be a general increase in both software and user-based techniques for evaluation and design of educational spaces. However, it is interesting that the lighting layout in classrooms does not show significant changes during the four decades since it follows the same grid pattern regardless of the changes in architectural, design and teaching tendencies.
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| 9. |
- Arabnejad Khanouki, Mohammad Hossein, 1988, et al.
(författare)
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Scale-resolving simulations of the flow in the Francis-99 turbine at part-load condition
- 2022
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Ingår i: IOP Conference Series: Earth and Environmental Science. - : IOP Publishing. - 1755-1307 .- 1755-1315. ; 1079:1
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Konferensbidrag (refereegranskat)abstract
- In this paper, we investigate the formation of the Rotating Vortex Rope (RVR) using scale-resolving methods, SAS and Wall-Modeled LES (WMLES). We compare the results from these simulation methods with the experimental data of the Francis-99 workshop. This comparison shows that the general features of the RVR can be captured with both methods. However, using WMLES methods would lead to a better quantitative agreement between the velocity profiles in the draft tube in the simulation and the experiment. The reasons for this better agreement are discussed in detail. A comparison of the pressure fluctuations in the draft tube captured in the simulations and the experiment is also presented. This comparison shows that all simulations under-predict the Root Mean Square (RMS) of these pressure fluctuations, although the RMS values predicted by the WMLES simulation are closer to the experimental values.
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| 10. |
- Arfvidsson, J., et al.
(författare)
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A method for status determination and risk assessment of energy measures in historic buildings
- 2021. - 1
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Ingår i: IOP Conference Series : Earth and Environmental Science - Earth and Environmental Science. - : IOP Publishing. - 1755-1307 .- 1755-1315. ; 863
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Konferensbidrag (refereegranskat)abstract
- Implementing energy efficiency measures in historic buildings is a challenging task and require knowledge in a number of different disciplines. The measures to reduce energy use must create a good indoor environment without jeopardizing the loss of important cultural historical values or entailing damages to building materials or load-bearing structures. Building antiquarian-, building biological- and building physical aspects are central, and must be taken into account in the entire process, from planning to implementation of energy update measures in historic buildings. This paper presents a methodology for status determination and risk assessment of energy measures in historic buildings. The method (KuReRA) has been developed in collaboration between curators, building biologists and building physicists.
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