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  • 1.
    Aurusell, Louise
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för byggnadskvalitet.
    Ytbehandling baserad på hampolja2008Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The varieties of paint are today very big, but many of the more popular paints are less than environmental friendly. The uses of fossilized fuel in paints are common because these paints dry fast and are color true. It would be beneficial for the environment if more renewable source were used to produce paint. Linseed oil is an old base for oil paints. It is renewable and easily procured. But linseed oils have some aspects that give it a bad reputation. There are problems with the slow drying and the color turning yellow when exposed to darkness for long periods of time. Researchers at KTH have connected the yellowing to linolenic acid, one of the common fatty acids in linseed oil (Svensson, M. Johansson, M, Stenberg, C. Samuelsson, J. 2003). Hempseed oil is also a drying oil like linseed, but hempseed oil contains a larger amount of the fatty acid linoleic acid and a smaller amount of linolenic acid (http://en.wikipedia.org/wiki/Hempseed_oil). This might mean that oil paint based on hempseed-oil instead of linseed-oil might have fewer problems with yellowing.Experiments with the two oils have been executed side by side in order to compare results. Two oil paints have also been produced and tested. Test pieces painted with the two different oil paints were exposed to moisture, daylight and complete darkness and then compared.

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  • 2.
    Blom, Jonas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Industrial economics.
    Optimizing spare-parts management2018Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Abstract

    Purpose:

    The purpose of the study is to develop a model that will facilitate the choice of maintenance strategy within the Swedish pulp and paper industry. Without compromising system availability, the model aims to reduce inventory holding costs.

    Methodology:

    At first, a literary research was conducted to create a holistic view over the chosen topic, in time it developed into a literature framework. Secondly, a case study was conducted in order to obtain empirical data. The data were obtained through interviews and archival records. The literature framework and the empirical data were then cross-analyzed with each other.

    Findings:

    In this thesis, a model has been developed based on previously applied and accepted methods. The methods have been identified and described in order to provide a strategy in which the inventory levels- and value could be lowered. The findings indicate that the organization must seek to assign ABC-classified and VED-analyzed components different maintenance actions in order to reduce the total cost.

    Theoretical contribution:

    This thesis contributes to a methodology development regarding spare parts management. It aims to add knowledge to the existing gap regarding spare parts order point and batch size. The thesis provides a procedure in which systems including critical and expensive components are evaluated in order to assign them the appropriate maintenance.

    Practical relevance:

    The model has only been exemplified by using a system position from Stora Enso Skutskär, the numerical values are examples. The model must be tested with real values and the risk analysis must be carried out with a group of employees with great insight regarding the selected component and system position.

    Limitations:

    This thesis is delimited to spare parts management and inventory management. The study only involves one Swedish organization, whereas the organization and its spare parts management illustrates the complexity concerning spares. The model will not be verified as the focus is to highlight the research gap and to develop the model.

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  • 3. Carlsson, Thomas
    Fukttransport i autoklaverad lättbetong: inverkan av mikrostruktur1999Report (Other academic)
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  • 4.
    Coppel, L. G.
    et al.
    RISE., Innventia.
    Norberg, O.
    RISE., Innventia.
    Lindberg, Siv M
    RISE., Innventia.
    Paper whiteness and its effect on perceived image quality2010In: 18th Color and Imaging Conference: Color Science and Engineering Systems, Technologies, and Applications, Technical Papers and Proceedings: CIC18, 2010, p. 62-67Conference paper (Refereed)
    Abstract [en]

    Whiteness is a commercially important characteristic of paper and board, although its perception depends on many factors that often are neglected by instrumental measurements. High whiteness improves the contrast of printed areas and increases the number of reproducible colours, but few quantitative studies have been published. In this paper, we report just-noticeable image quality difference (JND) from pair wise comparisons of images printed on paper substrate of different shades and whiteness. The JND was estimated to approximately 15 CIE whiteness, for the images and whiteness levels in this study, implying that a large substrate whiteness difference is required to get a significant visual impact on image quality. Unlike previous studies limited to colour rendering issues, the influence of the substrate’s shade as a surrounding frame to the images was also investigated here. It was found that the surrounding frame did not have a significant impact on image quality, when the images had an inherent dim background around the objects in the image. However, floating images in which the image objects are adjacent to the unprinted substrate would need further attention, since their perceived image quality seemed to depend both on the colour reproduction related to whiteness and shade, and on the contrast between the image and the substrate.

  • 5.
    Coppel, L. G.
    et al.
    Innventia AB; Mid-Sweden University.
    Norberg, O.
    Mid-Sweden University.
    Lindberg, Siv M
    Innventia AB.
    Paper whiteness and its effect on perceived image quality2010In: Final Program and Proceedings - IS and T/SID Color Imaging Conference, 2010, p. 62-67Conference paper (Refereed)
    Abstract [en]

    Whiteness is a commercially important characteristic of paper and board, although its perception depends on many factors that often are neglected by instrumental measurements. High whiteness improves the contrast of printed areas and increases the number of reproducible colours, but few quantitative studies have been published. In this paper, we report just-noticeable image quality difference (JND) from pair wise comparisons of images printed on paper substrate of different shades and whiteness. The JND was estimated to approximately 15 CIE whiteness, for the images and whiteness levels in this study, implying that a large substrate whiteness difference is required to get a significant visual impact on image quality. Unlike previous studies limited to colour rendering issues, the influence of the substrate’s shade as a surrounding frame to the images was also investigated here. It was found that the surrounding frame did not have a significant impact on image quality, when the images had an inherent dim background around the objects in the image. However, floating images in which the image objects are adjacent to the unprinted substrate would need further attention, since their perceived image quality seemed to depend both on the colour reproduction related to whiteness and shade, and on the contrast between the image and the substrate.

  • 6.
    Coppel, Ludovic Gustafsson
    et al.
    Gjøvik University College, Norway.
    Andersson, Mattias
    Mid Sweden University, Sweden.
    Norberg, Ole
    Mid Sweden University, Sweden.
    Lindberg, Siv M
    RISE.
    Impact of illumination spectral power distribution on radiance factor of fluorescing materials2013In: 2013 Colour and Visual Computing Symposium (CVCS), 2013Conference paper (Refereed)
    Abstract [en]

    The spectral radiance factor and thereby the appearance of fluorescing material is known to depend strongly on the spectral power distribution (SPD) of the illumination in the fluorophore's excitation wavelength band. The present work demonstrates the impact of the SPD in the fluorescence emission band on the total radiance factor. The total radiance factor of a fluorescing paper is measured in three different illuminations. The presence of peaks in the SPD of fluorescent light tubes dramatically decreases the luminescent radiance factor. This effect will impact the appearance of fluorescing media under illuminations with large variation in SPD, which includes recent LED illuminations.

  • 7.
    Dominic, Chris
    Sustainability and Foresight, Innventia, Stockholm, Sweden.
    Packaging logistics performance and how to evaluate the packaging performance by applying the tool Packaperforma2010In: 17th IAPRI World Conference on Packaging 2010, 2010, p. 245-250Conference paper (Other academic)
    Abstract [en]

    Packaperforma is a tool developed in order to increase the efficiency, effectiveness and differentiation in the future design of packaging systems. The tool is based on the theory Packaging Logistics Performance. Packaperforma is a further development of Packaging Scorecard and it could be utilized by packaging designers and supply chain managers to see the functions of the packaging system in the logistics processes. This means that the gap between packaging decisions and logistics decisions can be mitigated, as it can share the downstream information with the upstream and the designers. Packaperforma is used to conduct comparative studies in multiple Supply-Demand Chains. A study as such increases the quantity of data in the Packaperforma database that could be used to indicate the performances of the packaging, the agent and the Supply Demand Chains. The paper presents a study on Packaging Logistics Performance, how to evaluate packaging performance; how to collect feedback information from different agents and efficiently solve packaging related problem. Further the paper describes a web system based tool, packaging performance indicators and packaging performance database.

  • 8.
    Dominic, Chris
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Industrial economics. University of Gävle, Center for Logistics and Innovative Production.
    Johansson, Jennie
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Industrial economics. University of Gävle, Center for Logistics and Innovative Production.
    Building network integration solutions for locally produced foods: new requirements on supply chain, logistics and packaging2017In: International Agriculture Innovation and Cross-border EC Conference (IAICEC), Chiang Mai, Thailand, 18-19th October 2017 / [ed] Dr. Tzong-Ru Lee, Chiang Mai, 2017Conference paper (Refereed)
    Abstract [en]

    One important ongoing development in the grocery foods industry is the increase growth of Locally Produced Foods. This emerging market that based on the pillars of sustainability, demands new logistics challenges that requires innovative supply chain models . These chains are designed through the application of digitalized media. The paper presents an on-going study in establishing Network Integration for Locally Produced foods in Mid-Sweden Region. The objective of this study is to present an approach to explore locally produced foods. A case study based on logistics activities, supply chain management, packaging is presented. The data used in the study are from micro-producers of food, customers from local restaurants , consumers and the public sector from Mid-Sweden Region. The results indicates that th e main aspects of Network Integration actively contributes to better performance for this industry in almost all items considered in the study. This approach is considered particularly innovative, hence there are scarcity of literature that deals jointly with packaging, logistics and Network Integration from an empirical standpoint.

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  • 9.
    Edqvist, Helena
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering.
    Hide and seek: Ett utforskande av nya materialupplevelser i ull2019Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The information that wool is burned in quantities while we are importing wool speaks its clearlanguage, something needs to be done. Wool, which is a durable and 100% renewablematerial with both historical connections as well as fantastic properties, is a huge waste ofresources to burn as if it were rubbish.

    From a sustainability perspective as well as a personal interest, based on my years as astylist, I have investigated the sensual properties of the wool to find new materialexperiences in one of the world's oldest textile materials. The climate issue that is mostup-to-date, which we all have to relate to in one way or another, and that I want to make myresearch available to everyone, means that my work is relevant from a sustainabilityperspective.

    I have worked from a material-driven design, where the meaning of the material has beenimportant in order to weave the emotional connection to a material. With an artisticapproach, I wanted to take on my work in exploring, evaluating and questioning myself andmy work in a material-driven process, in which I turn materials and user tests to contributewith new material experiences of wool. I hope that my work contributes to seeing Swedishwool with new eyes. With new associations and perspectives. To see opportunities insteadof impossibilities.

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  • 10.
    Edvardsson, Linnea
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Industrial Management.
    Spåls, Klara
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Industrial Management.
    Hantera slöseri i omrullningsprocesser: En fallstudie på ett pappersföretag2023Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The following study aims to map the planning process and identify deficiencies within it, as well as provide improvement measures for the rewinding process in a case company. By developing a general conceptual model to enhance rerolling planning processes. Over the years, post-processing operations have been overseen, including the planning process associated with them. In paper production, like in many industries, defective products are generated during manufacturing. These defective products can often be salvaged and sold through post-processing, with one such process being rewinding. Examining and understanding processes within companies is crucial for making improvements. This study aims to map the planning process of rewinding and develop a conceptual model to enhance post-processing planning.

     

    The study presents improvement suggestions based on the deficiencies identified in the planning process. The suggestions include creating a more efficient IT system, establishing clear communication channels, and increasing management involvement. These efforts can enhance efficiency, reduce waste, better meet customer needs, thereby increasing competitiveness and profitability within the paper industry. The company can implement these improvement efforts by collectively analyzing and breaking down the target vision into smaller short-term goals that can be achieved. Based on the collected data, the study presents a conceptual model for analyzing and improving the rerolling planning process. Suggestions for further studies have been provided, where the same process can be examined in multiple companies to determine if similar issues exist. Additionally, further research can be conducted in more companies using the developed model to analyze and improve post-processing planning processes, aiming to increase generalizability.

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  • 11.
    Elgammal, Karim
    et al.
    Department of Applied Physics, School of Engineering Sciences, KTH Royal Institute of Technology, Kista, Sweden; SeRC (Swedish e-Science Research Center), KTH Royal Institute of Technology, Stockholm, Sweden.
    Hugosson, Håkan Wilhelm
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Physics.
    Smith, Anderson D.
    Department of Integrated Devices and Circuits, School of Information and Communication Technology, KTH Royal Institute of Technology, Kista, Sweden; Department of Microtechnology and Nanoscience, Electronics Materials Systems Laboratory, Chalmers Institute of Technology, Gothenburg, Sweden.
    Råsander, Mikael
    Department of Materials, Imperial College London, London, United Kingdom.
    Bergqvist, Lars
    Department of Applied Physics, School of Engineering Sciences, KTH Royal Institute of Technology, Kista, Sweden; SeRC (Swedish e-Science Research Center), KTH Royal Institute of Technology, Stockholm, Sweden.
    Delin, Anna
    Department of Applied Physics, School of Engineering Sciences, KTH Royal Institute of Technology, Kista, Sweden; SeRC (Swedish e-Science Research Center), KTH Royal Institute of Technology, Stockholm, Sweden; Department of Physics and Astronomy, Materials Theory Division, Uppsala University, Uppsala, Sweden.
    Density functional calculations of graphene-based humidity and carbon dioxide sensors: effect of silica and sapphire substrates2017In: Surface Science, ISSN 0039-6028, E-ISSN 1879-2758, Vol. 663, p. 23-30Article in journal (Refereed)
    Abstract [en]

    We present dispersion-corrected density functional calculations of water and carbon dioxide molecules adsorption on graphene residing on silica and sapphire substrates. The equilibrium positions and bonding distances for the molecules are determined. Water is found to prefer the hollow site in the center of the graphene hexagon, whereas carbon dioxide prefers sites bridging carbon-carbon bonds as well as sites directly on top of carbon atoms. The energy differences between different sites are however minute – typically just a few tenths of a millielectronvolt. Overall, the molecule-graphene bonding distances are found to be in the range 3.1–3.3 Å. The carbon dioxide binding energy to graphene is found to be almost twice that of the water binding energy (around 0.17 eV compared to around 0.09 eV). The present results compare well with previous calculations, where available. Using charge density differences, we also qualitatively illustrate the effect of the different substrates and molecules on the electronic structure of the graphene sheet.

  • 12.
    Eriksson Skytt, Linda
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Brink, Christian
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Tvärkraftsförstärkning av limträ: En undersökning av metoder med förstärkningselement av träribbor2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this thesis is to examine the shear capacity of glulam beams through various designs of reinforcement with wooden bars. A literature study is conducted to identify previous research on the subject. There are a number of tested reinforcement methods of glulam available, however, only a few of them are about shear capacity.

    This work is an extension of a previous study of Ahlskog and Ross (2015). Their study is based on a method where glulam beams were reinforced for shear breakage by strengthening wooden bars glued to the beam with PVAc.

    Five different test series have been examined for shear capacity. To obtain a statistical basis each series contained eight specimens. One series was unreinforced, two series were reinforced with glued wooden bars and two series were reinforced with milled in wooden bars. The reinforcement bars were put at an angle to take tensile or compressive force in the different methods.

    The capacity of the reinforcement bars is tested with a tensile and compressive testing machine which recorded deformation and compression force. The measured values were treated by a statistical analysis and normal distribution curves were drawn for the entire number of specimens based on the assumption that the test results were normally distributed. The four series were compared with both the unreinforced series and the other reinforced methods.

    The work resulted in an increase of shear capacity by 16% for the average of the sample series with milled in wooden bars subjected to compressive force. It has also been found that the characteristic value of shear capacity increased by 14% in the test series with the glued wooden bars exposed to traction.

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  • 13.
    Gebeyaw, Getiye Wodaje
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Romanov, Pavel
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Jahedi, Mohammad
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Calmunger, Mattias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Moshfegh, Bahram
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Effect of spatial-temporal behavior of a newly developed cooling system on carbon and stainless steel bar properties2023Report (Other academic)
    Abstract [en]

    This report summaries the work within the project ”Effect of spatial-temporal behavior of a newly developed cooling system on carbon and stainless-steel bar properties”. The project was conducted from 2020-01-01 to 2022-12-31 and was co-produced by SSAB, Outokumpu and University of Gävle (UoG). The Knowledge Foundation, SSAB, Outokumpu and UoG financed the project.

    For the Swedish steel companies SSAB and Outokumpu producing special steels, it is very important to be able to control the cooling process in order to produce steel bars with excellent properties. Both steel companies also want to be able to control the cooling process so that the excellent steel properties become even over the bars’ spatial configuration.

    The aim of the present project is to reveal the spatial-temporal behavior of a newly developed cooling technology in order to produce steel bars with excellent properties and to control the phase transformation to achieve optimal performance of the steel bars.

    By using the special test rig at the UoG, detail temperature measurement mapping, invers solution and direct numerical simulation, the present project has identified and quantified several important aspects related to the quenching process, operating conditions, and temperature field development within the investigated products. The result from the proposed cooling process provides an outstanding cooling rate that is very crucial to obtain the required steel phase and thus the correct properties of the bar with different sizes. Results from this study have also shown that the cost per kg product can be reduced by tunning the process parameters such as soaking time and bar temperature before starting the cooling process.

    In addition, both experimental and numerical results of the material investigation show that the cooling technology has resulted in the desired phase transformation and subsequently the desired steel phases and material properties. The results show that the cooling technology and the control of the cooling parameters can be used to optimize the material properties of the bar materials.

    These good results and conclusions have been obtained via the deep collaboration between the SSAB, Outokumpu and UoG. The co-production, starting in the steering group planning the work along with the combination of research conducted at UoG and at the companies, have led to a successful project with great knowledge transfer in all direction during the duration of the project.

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  • 14.
    Granberg, Hjalmar
    et al.
    RISE.
    Béland, Marie-Claude
    RISE.
    Lindberg, Siv M
    RISE.
    Berthold, Fredrik
    RISE.
    Vomhoff, Hannes
    RISE.
    Wickholm, Kristina
    RISE.
    Lindström, Mikael
    RISE.
    It’s a bird! It’s a plane! It’s a super multimaterial!2015In: Paper Conference and Trade Show (PaperCon 2015), TAPPI Press , 2015, Vol. 1, p. 492-504Conference paper (Refereed)
    Abstract [en]

    Matching market demands and technological solutions is not always straightforward. In this article, we report on one material, a cellulose-PLA multimaterial, which was made on a full-scale pilot paper machine and adapted to five different market applications having specialized and often conflicting demands. The material can be injection molded, 3D-printed, hot pressed, treated as a textile, used in a laminate, or converted as a paper board, giving it a wide range of possible properties depending on how it is processed.The five application areas presented here were identified as gaps in the marketplace where seemingly conflicting needs were desired: opacity and transparency; compact for transport but having an expanded size during use; stiffness and flexibility; strength and light-weight; and durability and degradability. These properties are exemplified in a number of material and product demonstrators, illustrating how tailored solutions can give products with distinctly different personalities. The material can be made flexible and given movement as graceful as the wing of a bird or be processed to be strong and light-weight enough to be used in vehicles like airplanes. By having one material that is produced on a large scale, but then processed according to specific market demands and expectations, the gap between needing scale and needing scope is bridged.

  • 15.
    Gudmundsson, Kjartan
    et al.
    School of Civil and Architectural Engineering, KTH.
    Sjöström, Christer
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Buildning science - material science.
    Norberg, Peter
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Buildning science - material science.
    Trinius, Wolfram
    Twumasi, Ebenezer
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Buildning science - material science.
    Durable and robust vacuum insulation technology for buildings2011In: XII DBMC: 12th International Conference on Durability of Building Materials and Components (Vol. 4) / [ed] Michael A. Lacasse, Vasco Peixoto de Freitas, Helena Corvacho, Porto: FEUP Edições , 2011, , p. 8Conference paper (Refereed)
    Abstract [en]

    Vacuum insulation panels (VIPs) provide unprecedented opportunities for obtaining excellent thermal insulation with light and slender constructions. This article discusses the performance over time of VIPs, and the possibilities to overcome the current problems related to fragility and limited durability. Aerogels are together with fumed silica among the most competitive core materials for VIP's. The use of classical aerogels, as produced in autoclaves is, however, limited due to the high production costs. The fumed silica on the other hand requires vacuum levels that are difficult to maintain with the currently available vacuum envelopes. A material with comparatively smaller pores will on the other hand allow obtaining low thermal conductivity at higher pressure (less vacuum) and will therefore reduce the pressure difference over the envelope. There is therefore much to be gained by reducing the pore size. New cost and performance efficient silica aerogels offers opportunities to enhance the properties of the panels by customizing the pore structure and pore size distribution. Building technologies and how the panels are applied in a manner that improves the structural, thermal and hygroscopic performances of vacuum insulated constructions have been studied and are discussed.

  • 16.
    Hallberg, Daniel
    et al.
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för byggnadskvalitet.
    Stojanovic, Bojan
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för byggnadskvalitet.
    Analytical and numerical thermal modelling & analysis of an building integrated unglazed solar collector: PhD course paper2007In: Mathematics for PhD-students in building science, Stockholm: Architecture and the Built Environment, Royal Institute of Technology , 2007Chapter in book (Other (popular science, discussion, etc.))
    Abstract [en]

    The objective of this report is to derive an analytical and numerical USC model for thermal analysis. These models are meant to calculate USC temperature variation across the USC duct as well as the fluid temperature along the USC. The main purpose of the analytical model is to attain a detailed steady state tool for USC (as in this report) design and dimensioning. The numerical model is meant to calculate the time dependant USC thermal performance as well as being a benchmark for the analytical model.

  • 17.
    Hallberg, Daniel
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Buildning science - material science.
    Stojanovic, Bojan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Buildning science - material science.
    Akander, Jan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Building engineering.
    Status, needs and possibilities for service life prediction and estimation of district heating distribution networks2012In: Structure and Infrastructure Engineering, ISSN 1573-2479, E-ISSN 1744-8980, Vol. 8, no 1, p. 41-54Article, review/survey (Refereed)
    Abstract [en]

    An optimised and proactive maintenance strategy aims to maximise the economical profit, minimise environmental impacts and keep the risk of failure to a low level. Implementation of such strategy in the context of district heating requires efforts and abilities for predicting future performances and estimating service life of district heating components. A literature review on failures (damages and performance reductions) occurring on district heating pipes, reveals that failures in district heating pipes are mainly leaks due to corrosion or mechanical impacts and reduced thermal insulation performance: leaks being the more serious damage type. A feasible service life estimation method for this type of damage is the Factor Method. Since the application of this method within the context of DH pipes has not been found in other publications, this paper focuses on describing the method and discusses the possibilities on how to apply it in two specific cases with respect to leakage: service life estimation of repaired district heating pipe sections (i.e. maintenance of district heating network) and of district heating pipes in new or extended district heating networks. A particular attention is paid on which modifying factors to consider and how to quantify them.

  • 18.
    Hedén, Caroline
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Wellpapp: Början på en ny våg2006Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
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  • 19.
    Jarl, Magnus
    et al.
    Örebro Universitet.
    Enghag, Per
    Lundberg, Sven-Erik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Mechanical Engineering.
    Chapter 6: Manufacture of Steel Wire and Steel Wire Products2017In: The Making, Shaping and Treating of Steel: Long Products Volume / [ed] Lundberg, S.-E., Warrendale, PA: Association for Iron & Steel Technology (AIST) , 2017, p. 571-656Chapter in book (Other academic)
  • 20.
    Jeppsson, Ola
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Nya material - Nya möjligheter: En applikation av ett cellulosabaserat material2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The interest in replacing oil based materials with the equivalent from cellulose increases in the same rate as we consume the resources of our community. The cellulose based materials and their attributes are researched and the presented new materials are more or less ready for production. There are a large number of different materials available to choose from when developing and manufacturing a new product. The traditional and well established materials are thoroughly researched and their attributes are also well known and well documented. This is not always the case when new materials emerge from science research and  development. An opinion is that it can be difficult for a new material to evolve from being a new interesting material to find its way into production or to be implemented in a product.

    The purpose of this project is for it to be a help to people involved in the developing of a new material in understanding what interested parties need to know about a new material. The primary questions this project proposes to answer are:• Who is an interested party in a new material?• What does an interested party initially need to know about a new material?• How can the attributes of a new material be presented to a specific target group the best way possible.A series of interviews were committed at the beginning of the project where the need for information about a new material from especially the industrial designer’s point of view. The survey shows that there are more important aspects in choosing materials than only the technical attributes of the material. It also shows that it’s hard to determine what kind of information is needed when not having a specific case to relate to. Three different strategies were formed to show how a new material can evolve from being a new interesting material to find its way into a production. The three strategies were:• Develop a product of your own • Replace a detail in an existing product• Replace a material

    In an attempt to exemplify one of these strategies a working case was formed. The material for the case was decided to be DuraPulp from Södra, the production method was pressure forming, the industry was the furniture industry and the product was the conference chair Yin from Kinnarps. There were a series of practical tests performed on material and production method to determine the suitability of the material concept. A tool for testing the material concept was also produced. The project resulted in a cellulose based material concept targeted for the furniture industry. The concept can be applied to the existing production line with advantages in efficiency for the production. The concept also contains environmental and sustainable aspects. The material concept shows good potential in replacing plastic in some cases and manages complicated shapes in the pressure forming process.

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  • 21. Johansson, Gun-Britt
    et al.
    Rohlin, Lennart
    Svarvning och borrningi metallmatriskompositer (MMC)1993Report (Other academic)
    Abstract [sv]

    Fyra gjutna metallmatriskompositer (MMC) har bearbetats vid svarvning och borrning. De fyra MMC-materialen bestod av aluminiummatriser förstärkta med partiklar av kiselkarbid (Sirp) i volymshalter mellan 10 och 20 %.

    Målet med arbetet har varit dels att utreda arbetsmaterialets inverkan på bearbetningen, dels att klarlägga prestanda för PCD och andra verktygsmaterial.

    Svarvning har utförts med verktyg av polykristallin diamant (PCD), diamantbelagda skär av hårdmetall och kiselnitrid, belagd och obelagd hårdmetall samt keramisict skär. Vid borrförsöken användes borr med skruvade skär av hårdmetall (U-borr från Sandvik Coromant) och lödd spiralborr (Deltaborr från Sandvik Coromant), med variation av hårdmetallsort och slipning av borrgeometrierna.

    Vi har inte sett någon större skillnad mellan de olika matrismaterialen. Högre volymshalt SiC-partiklar ger som förväntat högre förslitning.

    Vid både svarvning och borrning i aluminiumbaserade MMC år PCD ett oslagbart verktygsmaterial. PCD ger en utslitningstid på 10 minuter vid en skärhastighet på 437 m/minut. Bra resultat visar också de diamantbelagda verktygen, så länge diamantskiktet är intakt. Bästa resultat bland övriga testade verktyg uppvisar whiskersförstärkt keramik (CC670), beroende på dess kombination av hårdhet i grundmaterialet och seghet genom whiskersförstärkningen.

    Vid borrning med U-borr, var skåren utslitna redan efter 10 mm borrad längd. Beläggning gav ingen förbittring i det extremt abrasiva materialet, ej heller slipad egg. Vid testerna med Deltaborr (vars geometri är gynnsammare för borrning i MMC) höll borrarna längre, ca 200 mm. Här erhölls lägre förslitning med specialslipad egg jämfört med standardegg. Vid borrning med spiralborr av PCD borrades 2500 mm utan att borrarna var utslitna.

    Skärkraftsmätning i olika arbetsmaterial visade ingen signifikant skillnad. Skärkrafterna stiger snabbare för de keramiska skären i jämförelse med PCD, vilket tyder på att de keramiska skären förslits under skärkraftsmätningen medan diamantens eggskärpa år intakt.

  • 22.
    Jonsson, Chatrine
    University of Gävle, Faculty of Engineering and Sustainable Development.
    A GreenHanger: En galge i DuraPulp2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Today the clothing industry is just growing and growing, in average every swede consumes 15kg clothing a year and every year 8kg clothes is thrown. In Sweden clothes is purchased for around 71 billion swedish kronor a year. The shopping and the constant demand subjects great strain on both the environment and the humans on the earth. With every garments a hanger is included which is made of either plastic, metal or wood. The idea of the project was to come up with a proposition of a hanger made of the material DuraPulp. Also to take a stand wether it is possible to replace such a commercial product like the plastic hanger with a hanger made of DuraPulp and what that would mean.

    DuraPulp is a relatively new material from lab research and it has the same characteristics as plastic. What sepa- retes the materials is that DuraPulp is made from paper pulp with the unique binding agent PLA compared to plastic which is a product from oil. With heat and pres- sure the binding agent is activated and encloses the fibers so the material is percieved and acts just like plastic.

    The project has been executed in cooperation with the clothing company H&M which has provided information and knowledge in their work with hangers. The company Södra has also contributed with knowledge and experi- ence around DuraPulp.

    Costumers and clerks in shops around Gävle center has been interviewed on their experience and also wishes around hangers. The project resulted in a hanger in DuraPulp and alu- minium with the appropriate sale concept. The project has focused on making a clear environmental profile of the hanger based on the interviews and also to strengthen the company brand. The sale concept has been formed according to required demands and abilities.

    The DuraPulp hanger has through a simpler life cycle analysis, with the projects interpretation of the real- ity, been compared with a plastic hanger. This has been done to visualize every step from cradle to grave and to illustrate the difference though an environmental point of view.

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  • 23.
    Kihlstedt, Annika
    et al.
    RISE.
    Lindberg, Siv M
    RISE.
    Lindström, Annika
    RISE.
    Pousette, Sandra
    RISE.
    Material identity in a packaging context2014Conference paper (Refereed)
    Abstract [en]

    Package design includes a number of considerations ranging from protecting the content to conveying the brand image. The aim of this study was to gain a deeper understanding on how Swedish consumes perceive product packaging attributes, with a special emphasis on in which way packaging material (carton, paper plastic), and structural design (folding carton, paper bag, standing pouch and plastic bag), have an emotional impact on consumers' evaluation of the product and packaging. Assessing the appearance and effectiveness of a packaging system is often confounded by branding, why it is important to separate the brand influence from the attributes of the packaging system. Thus, in the experimental part, packaging prototypes of different structural design and materials were manufactured in order to present commercial cereal brands in different types of packaging. The research involved a combination of qualitative and quantitative methods, comprising (i) focus groups on cereal (muesli) packaging; (ii) a mock-up study of four muesli packaging types: transparent plastic bag, carton box, paper bag, and a resalable stand-up plastic pouch; and (iii) a questionnaire on environmental attitudes to packaging materials. Fourteen respondents participated in the focus groups and 20 in the mock-up study. Result show that the paper bag and the carton box were perceived to be the most environmentally friendly packaging material. Heavy ink usage on paper bags and carton boxes can however raise concern regarding the environmental impact. Introducing functionality and good print quality can cause preferences to divert to an alternative packaging material. In the mock-up study the standing pouch was the most liked package type regardless of brands. Functional reasons (protect, re-closable etc.) and appearance reasons (nice print, nice colours) was claimed for giving this package high ratings.

  • 24.
    Kumar, Ajith
    et al.
    Department of Mechanical Engineering, Amrita Vishwa Vidyapeetham 1 , Amritapuri, Kollam 690525, India.
    Murali, Damu
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Petha Sethuraman, Vignesh Ram
    Department of Aerospace System Engineering, Sejong University 3 , Seoul 05006, South Korea.
    Flow control using hot splitter plates in the wake of a circular cylinder: A hybrid strategy2024In: Physics of fluids, ISSN 1070-6631, E-ISSN 1089-7666, Vol. 36, no 1, article id 013624Article in journal (Refereed)
    Abstract [en]

    A novel and effective hybrid technique, which involves active surface heating strategies in conjunction with the use of passive splitter plates in the wake of the cylinder, is proposed. In this report, we present the results of a numerical investigation on the two-dimensional, laminar mixed convection flow over a circular cylinder with a hot rigid splitter plate attached to it on the wake side. A projection algorithm-based finite volume method is employed to obtain the solution of the coupled, nonlinear governing partial differential equations subjected to Courant–Friedrichs–Lewy conditions. The isothermal heating of the splitter plate under the influence of the gravity field generates an upward buoyancy force in the wake of the cylinder. For different length-to-diameter (L/D) ratios, the effect of heating on aerodynamic, wake, and heat transfer characteristics has been studied for a wide range of parameters; 75  ≤ Re ≤ 150, 0  ≤ Ri ≤ 1, and 0.5  ≤ L/D ≤ 1 at Pr = 0.7. It is observed that the hot splitter plate would bring about conspicuous changes such as asymmetry in the vortex shedding behind the cylinder at low Reynolds numbers. The outcomes demonstrate a notable improvement in convective heat transfer and drag, with gains of up to 7% and 15%, respectively. It is found that the rate of heat transfer and vortex shedding frequency decrease with an increase in L/D ratio. Correlations for the estimation of Strouhal number and Nusselt number have also been proposed which helps provide a more thorough understanding of thermal and aerodynamic features of the hybrid approach.

  • 25.
    Kus, Hulya
    et al.
    Institutionen för teknik och byggd miljö.
    Marteinsson, Björn
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för byggnadskvalitet.
    Norberg, Peter
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för byggnadskvalitet.
    Temperature and moisture conditions in materials: effects on risk for degradation of rendered autoclaved aerated concrete2005In: Paper TT1-107, 2005, p. 60-67Conference paper (Other academic)
    Abstract [en]

    Temperature and moisture conditions are, in general, the two major factors influencing the long-term performance of external walls made of porous mineral building materials. Degradation of wall components is accelerated by temperature and moisture induced stresses which lead to cracks and in turn a surface more vulnerable to other degradation agents. The degradation rate depends on both the environmental conditions and the material-inherent and component design properties. Extreme and rapid temperature fluctuations as well as moderate diurnal and seasonal temperature cycles cause thermal stresses and strains in the material, resulting in expansion or contraction and eventual deformation such as cracking or fracture. Material properties such as thermal expansion, elasticity and tensile strength determine if cracking occurs either immeadiately when the surface temperature drops below the initial temperature after rapid cooling or after a period of time if alternating or repeated stresses result in creep and fatigue.

    In this paper an attempt is made to evaluate the temperature effects on the risk for degradation of external walls made of rendered autoclaved aerated concrete (AAC) based on temperature measurement data and the material properties. The measurement results are obtained from the continuous microenvironment monitoring carried out on a test cabin built on the roof of the Centre for Built Environment building in Gävle, Sweden. A finite element model (FEM) is used to simply calculate the temperature induced stresses in two different cases; with and without creep and relaxation in the material. According to the microenvironment measurement results the test panels attain maximum surface temperatures up to about 60 °C during summer and experience surface temperature fluctuations between day and night up to about 55 °C during winter. Rapid changes in surface temperatures frequently occur particularly throughout late spring and early summer. The preliminary calculated results indicate that the tensile forces built up during cold spells may be sufficient to crack the surface of AAC panels but the risk for fatigue damages due to combined moisture and temperature cycles induced by radiation from the sun seems to be small. Further studies are needed for better knowledge and reliable information on the degradation mechanisms related to temperature by complementary measurements of stress-strain, stress relaxation, creep and fatigue behaviour of AAC panels under different and cyclic temperature loading.

  • 26. Kus, Hulya
    et al.
    Norberg, Peter
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för byggnadskvalitet.
    Monitoring of moisture in rendered autoclaved aerated concrete wall by nail electrodes2001In: The international conference on building envelope systems and technologies (ICBEST) 2001, Vol 1, 2001, p. 237-242Conference paper (Other academic)
  • 27.
    Kus, Hulya
    et al.
    University of Gävle, Department of Technology and Built Environment.
    Nygren, Kjell
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för byggnadskvalitet.
    Norberg, Peter
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för byggnadskvalitet.
    In-use performance of rendered autoclaved aerated concrete walls by long-term moisture monitoring2004In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 39, no 6, p. 677-687Article in journal (Refereed)
    Abstract [en]

    The importance of long-term performance and durability of building materials and components has received increasing consideration with regard to a sustainable built environment. Degradation due to exposure to environment conditions, particularly driving rain, play a significant role in the service life of porous materials used in external wall components. Microenvironment monitoring data are presented in this paper to show how different surface coatings can contribute to moisture performance of external walls made of autoclaved aerated concrete (AAC). Renderings modifed with hydrophobic products on AAC substrate prove to have less wetting and better drying properties than unmodified renderings according to the performance assessment based on the amount and duration of moisture measured in the material.

  • 28.
    Kus, Hülya
    et al.
    stanbul Technical University , Faculty of Architecture, Turkey.
    Norberg, Peter
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental engineering.
    Sjöström, Christer
    Building Science, KTH, Stockholm.
    Durability assessment of external renderings on AAC based on 10-year long-term monitoring data2013In: Third International Conference  on  Sustainable construction Materials and Technologies: Conference proceedings / [ed] Peter Claisse, 2013Conference paper (Refereed)
    Abstract [en]

    Long-term performance and durability of external walls made of rendered autoclaved aerated concrete was investigated within a research project, based on continuous monitoring of temperature and moisture in the materials employed in the weathering test conducted in Gavle, Sweden. The details of natural exposure test set-up and preliminary measurement and experiment results were published elsewhere. Among the external rendering systems applied on AAC wall panels, a variety of coatings including inorganic and organic coatings with and without hydrophobic agents were tested. Together with the surface and bulk temperatures and moisture contents of the tested materials, microclimate parameters were also continuously measured. In this paper, monitoring data collected during 10 years of natural exposure are examined, and some results, particularly on moisture performance of external rendering systems, are presented and briefly discussed. 

  • 29.
    Lambrix, Patrick
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Armiento, Rickard
    Linköping University.
    Li, Huanyu
    Linköping University.
    Hartig, Olaf
    Linköping University.
    Pour, Mina
    Linköping University.
    Li, Ying
    Linköping University.
    The Materials Design Ontology2023In: Semantic Web, ISSN 1570-0844, E-ISSN 2210-4968Article in journal (Refereed)
    Abstract [en]

    In the materials design domain, much of the data from materials calculations is stored in different heterogeneous databases with different data and access models. Therefore, accessing and integrating data from different sources is challenging. As ontology-based access and integration alleviates these issues, in this paper we address data access and interoperability for computational materials databases by developing the Materials Design Ontology. This ontology is inspired by and guided by the OPTIMADE effort that aims to make materials databases interoperable and includes many of the data providers in computational materials science. In this paper, first, we describe the development and the content of the Materials Design Ontology. Then, we use a topic model-based approach to propose additional candidate concepts for the ontology. Finally, we show the use of the Materials Design Ontology by a proof-of-concept implementation of a data access and integration system for materials databases based on the ontology.

  • 30.
    Lindberg, Siv M
    et al.
    RISE.
    Béland, Marie-Claude
    RISE.
    Edström, Karin
    RISE.
    Granberg, Hjalmar
    RISE.
    Berthold, Fredrik
    RISE.
    Towards a cellulose-based society: Demonstrating the feasibility of new bio-based material concepts and products2016In: Proceedings - D and E 2016: 10th International Conference on Design and Emotion - Celebration and Contemplation, 2016, p. 411-419Conference paper (Refereed)
    Abstract [en]

    In moving towards a cellulose-based society, interdisciplinary effort is required as it is at this interface that new ideas are found and can grow. New bio-based materials will play a key role but getting them into the marketplace is not always straightforward. Many options are available both for sourcing and for producing composite materials from wood-based cellulose and poly-lactic acid (PLA). Depending on how the material is processed, a multitude of properties can be generated. The main goal with this work was to attempt to reduce the research-To-market gap. This was done by testing a new way of working together where we bundled innovation-oriented projects and research-oriented projects around the theme of material experience. We then systematically worked with material demonstrators. In this article, we exemplify the results by focusing on one research-oriented project that did not at the outset have a market context and on one innovation-oriented project with clear market requirements. In addition to introducing a new concept in bundling research-oriented and innovation-oriented projects, this paper contributes several practical examples of what material demonstrators can do. We also present an application and analysis of Moultrie’s extended Science-Technology-Application-Market (STAM) model to analyze the material demonstrators and design phases of the bundled projects. We modified the proposed classification with different types of material demonstrators according to how close they are to an actual product segment. Designers and scientists worked together but with different emphasis in each phase.

  • 31.
    Lindberg, Siv M
    et al.
    STFI, Swedish Pulp and Paper Research Institute.
    Fahlcrantz, Carl-Magnus
    STFI, Swedish Pulp and Paper Research Institute.
    Perceptual assessment of simulated print noise with random and periodic structure2005In: Journal of Visual Communication and Image Representation, ISSN 1047-3203, E-ISSN 1095-9076, Vol. 16, no 3, p. 271-287Article in journal (Refereed)
    Abstract [en]

    Lightness variation in a supposedly uniform printed surface is referred to as "print mottle." This phenomenon is one of the most detrimental to overall print quality. A fundamental problem in the evaluation of human sensitivity to a print quality variable such as mottle is the difficulty in controlling external variables, such as variations in color or in average print density, that arise in the printing process. These variables can influence the rating of quality. To analyze the impact of a systematic mottle pattern compared to that of the common case of a random pattern, a digital simulation technique was used to create gray test samples with various amounts of stochastic and systematic noise of different characters. The samples were printed using a high quality inkjet printer and evaluated by a panel of judges. Two different evaluation methods were used. Observers rated dissimilarity and preference in a pairwise comparison task, and also by positioning samples in the horizontal and vertical directions of a digitizing tablet. The results show that individuals rate the samples in a very consistent way and that systematic noise is perceived to be more annoying than random noise of a similar physical magnitude. Furthermore, the consistency between the two different evaluation methods is very good, which suggests that two-dimensional scaling on a digitizing tablet is a viable method for grouping samples in a plane. The results also show that digital simulation of print artifacts is a powerful tool for creating samples with controlled disturbances. © 2004 Elsevier Inc. All rights reserved.

  • 32.
    Lindberg, Siv M
    et al.
    RISE.
    Fahlcrantz, Carl-Magnus
    RISE.
    Forsgren, Gunnar
    Iggesund Paper Board.
    Making subjective assessments objective: A mottle ruler for calibration of panel assessments of perceived print mottle2008In: TAPPI Press - Paper Conference and Trade Show, PaperCon '08, 2008, Vol. 4, p. 2086-2124Conference paper (Other academic)
    Abstract [en]

    The objective was to establish principles and procedures for: a) digital simulation and output of reference samples for perceived print mottle assessment, b) calibration of subjective assessments to a common unit of measurement. We decided to calibrate our scales using the just-noticeable difference (jnd) as the unit of subjective measurement and adapt a ruler system for the assessment of perceived print mottle as suggested by Keelan [1]. Jnd used in this context means the smallest difference in mottle required for 50 % of a test panel to genuinely detect a difference. Reference samples were designed in Matlab by adding a stochastic noise to a homogeneous gray (33 % reflectance) and a cyan image, that, when printed would have the resemblance of print mottle typically seen in offset printing. Digital images were converted to CMYK images, rasterized using a Best Color Rip, and printed on Epson Archival Matte paper on an Epson Stylus Photo 2100 ink-jet printer. The resulting prints were evaluated for the magnitudes of perceived visual mottle as well as for the just-noticeable differences, jnds, using panels of assessors. The prints were also evaluated for instrumental mottle using STFI-Packforsk’s image analysis based STFI-mottle software. Two mottle rulers were assembled. A mottle ruler is a set of 5 cm ח5 cm reference samples, varying widely in magnitudes of reflectance variation resembling real print mottle. Rulers were constructed for simulated K40 % (gray) and cyan 100 % (cyan) samples. The rulers are arranged with approximate twelve reference samples separated by intervals of three jnds each. A Round Robin evaluation of visually perceived print mottle was performed. Two rulers, cyan and gray, together with test samples to be evaluated against the rulers, were sent out to four participating companies. The test sets consisted of eight commercially produced samples (printed paper and board) and twelve simulated samples varying not only in the magnitude of mottle but also in character (e.g. coarseness and the orientation of the simulated noise). The purpose of using test samples with appearances that differed from the reference samples was to test the performance of the approach. The mottle rulers were also applied at Iggesund Paperboard during a test period of eight months in which more than 300 printed samples were assessed against the rulers. Round robin results showed good agreement between participating paper companies. The average standard deviations of the ratings against the rulers were ˜2.5 jnd units for the gray samples and ˜3.5 jnd units for the cyan samples. Some difficulties with the assessment technique were observed for the simulated samples, due to some samples having a very different visual character in terms of uncovered areas or noise that had a distinct orientation e.g. banding. Results from the testing period at Iggesund show less variability; average standard deviation for cyan 1.61 jnd and for gray 2.3 jnd. Overall, the calibration approach developed works very well, with the results showing a low variability of the ratings and a very good agreement between the different test panels, as well as a reasonably good correspondence between ratings of commercially produced samples and mottle measurements.

  • 33.
    Lindberg, Siv M
    et al.
    RISE., Innventia.
    Hansen, Peeter
    RISE., Innventia.
    Drotz, Mattias
    RISE., Innventia.
    Kihlstedt, Annika
    RISE., Innventia.
    Rosén, Fredrik
    RISE., Innventia.
    Tactile and instrumental characterization of tissue products2015Conference paper (Other academic)
    Abstract [en]

    The feeling of softness and smoothness of paper tissue products is an important performance factor in the market place. In a series of panel tests, the relationship between instrumental measurements and perceived softness and smoothness was investigated. Samples of tissue base paper – napkin and toilet paper – were evaluated for surface roughness. The samples were placed on a hard, smooth glass substrate and the respondents used one finger to stroke along the sample surface. Instrumental measurement and characterization were performed using differentinstruments: Emtec TSA and Lena Softness Tester. The results divide the base paper material into product groups, but general mathematical relationships could be found between the test panel and the measurements when normalized in different ways. Measurements using the Lena produced the best correlation with the panel ratings because its principle resembled the method of the test panel most closely. However, a general relationship usingmaterial properties was shown to produce as good an estimator for the surface roughness as the results obtained with the Lena. This relationship consisted of the ratio between the plasticity and the elasticity of the tissue paper (in-plane properties), normalized for thickness. This suggests that those three material properties are fundamental to the perception of surface roughness as evaluated in this study. Using a trained haptic panel to evaluate test samples of similar grammage with variations in furnish and machine operation settings generated a good correlation to the TSA measurement (r=0.9). The panel was more susceptible to variation in furnish than variation in peak pressure, and this was particularly evident for samples evaluated on the Yankee side.

  • 34.
    Lindberg, Siv M
    et al.
    RISE.
    Hartzen, Ann-Sofie
    Wodke, Thomas
    Lindström, Mikael
    RISE.
    Hierarchic design and material identity2013Conference paper (Other academic)
  • 35.
    Lindberg, Siv M
    et al.
    RISE.
    Lindström, Annika
    RISE.
    Cederström, Caroline
    RISE.
    From, Anders
    Westerlind, Christine
    RISE.
    Shoppers' attention to packaging and in-store media2013Conference paper (Other academic)
  • 36.
    Lindberg, Siv M
    et al.
    Innventia.
    Roos, Anders
    SLU.
    Kihlstedt, Annika
    Innventia.
    Lindström, Mikael
    Innventia.
    A product semantic study of the influence of the sense of touch on the evaluation of wood-based materials2013In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 52, p. 300-307Article in journal (Refereed)
    Abstract [en]

    Based on product semantics, this study investigated how the tactile attributes of wood and wood-based composites are perceived and interpreted semantically. The wood-based samples included ash, birch, elm, oak, pine, OSB (oriented strand board), two wood pulp-reinforced polylactide composites, Comp A and B and one wood-fiber reinforced polypropene composite, Comp C. The subjects rated the samples by the descriptive words natural, exclusive, eco-. friendly, rough, inexpensive, reliable, warm, modern, snug and solid. The most significant differences between the samples were found for roughness and for the descriptors, reliable, natural and solid. A principal component analysis yielded three attributes based on the tactile perceptions: reliable, old-. fashioned and smooth. The solid wood pieces were perceived as natural and oak was perceived as being exclusive. The composite materials presented a greater variation in terms of perceived attributes than the wood specimens.

  • 37.
    Lundberg, Sven-Erik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Mechanical Engineering.
    Chapter 3: Roll Pass Design2017In: The Making, Shaping and Treating of Steel: Long Products Volume / [ed] Lundberg, S.-E., Warrendale, PA: Association for Iron & Steel Technology (AIST) , 2017, p. 337-412Chapter in book (Other academic)
  • 38.
    Lundberg, Sven-Erik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    The Making, Shaping and Treating of Steel: Long Products Volume2017Collection (editor) (Other academic)
    Abstract [en]

    This book provides a detailed description of what long products are, how they are classified, how they are produced, as well as the types of equipment that produce long products. The volume provides a comprehensive overview of long product production from describing the roll pass design, to the different shapes and sections, to the manufacturing of wire and wire products, to tubular products, and finally to high-alloy steel semi-finished products by casting and ingots.

  • 39.
    Lundberg, Sven-Erik
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Mechanical Engineering.
    Allgood, Lee E.
    Lamb, Charles W.
    Ragger, Katharina Sophie
    Materials Center Leoben Forschung GmbH, Leoben, Austria.
    Paal, Jürgen
    Schoeller Bleckmann Edelstahlrohr GmbH (SBER), Ternitz, Austria.
    Buchmayr, Bruno
    Materials Center Leoben Forschung GmbH, Leoben, Austria.
    Chapter 7: Manufacture of Steel Tubular Products2017In: The Making, Shaping and Treating of Steel: Long Products Volume / [ed] Lundberg, S.-E., Warrendale, PA: Association for Iron & Steel Technology (AIST) , 2017, p. 657-729Chapter in book (Other academic)
  • 40.
    Lundberg, Sven-Erik
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Mechanical Engineering.
    Toschi, Francesco
    Primetals Technology, Castellanza, Italy.
    Head, Mel
    Chapter 4: Production of Bar and Light Sections2017In: The Making, Shaping and Treating of Steel: Long Products Volume / [ed] Lundberg, S.-E., Warrendale, PA: Association for Iron & Steel Technology (AIST) , 2017, p. 413-507Chapter in book (Other academic)
  • 41.
    Lundström, Hans
    University of Gävle, Faculty of Engineering and Sustainable Development, BMG laboratory.
    Improving long-term stability of hot-wire anemometer sensors by means of annealing2015In: Review of Scientific Instruments, ISSN 0034-6748, E-ISSN 1089-7623, Vol. 86, no 8, article id 086104Article in journal (Refereed)
    Abstract [en]

    Annealing procedures for hot-wire sensors of platinum and platinum-plated tungsten have been investigated experimentally. It was discovered that the two investigated sensor metals behave quite differently during the annealing process, but for both types annealing may improve long-term stability considerably. Measured drift of sensors both without and with prior annealing is presented. Suggestions for suitable annealing temperatures and times are given. 

  • 42.
    Martinez, Pablo
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Quenching a steel plate by water - impinging jets and different simultaneous flow rates2019Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Regarding the great importance of fast cooling in steel industry for the production processes, a deep understanding of heat transfer and fluid dynamics must be held. A steel plate is heated up until a maximum temperature of 700 ⁰ C to be the n cooled down seconds later by a configuration of multi ple impinging water jets. Different flow rates are used simultaneously by different adjacent jets to perform quenching over the sample, so different hardness is obtained in the material over a small area . Temperature drop in time i s measured and monitored by embedded thermocouples and LabVIEW program. To achieve greater understanding of the quenching performance with different flow rates , several parameters are selected to be varied in order to achieve the best working conditions. Jet diameter takes values between 4 and 10 mm, initial temperature of quenching varies from 400 to 700 ⁰ C , subcooling temperature is tested for 65 and 75 K, and jet velocity varies between 1.9 and 3.9 m/s. The result of total number of 9 expe riments shown that v ariation of jet diam eter does not influence substantially on the cooling rate if flow rate is kept constant. High initial quenching temperature (600 - 700 ⁰ C ) led to slightly higher cooling rate in the stagnation region of water jets. The peak value of heat transfer rate in the upwash flow zone was more highlighted for initial quenching temperature 600 ⁰ C and below it. High er values of subcooling and jet velocity produce better cooling rates. The result shown higher jet velocity at one column of water jets changes position of upw ash flow slightly toward the adjacent column of jets with lower jet velocity. In general, the result shown that all the studied parameters did not have negative effect on obtaining various cooling rates over the steel plate.

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    Master Thesis
  • 43.
    Matero, Markus
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Quartzene i gips: Densitet och hållfasthet2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
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    Quartzene i gips
  • 44.
    Nakkeeran, G.
    et al.
    Département of Civil Engineering, SRM Institute of Science and Technology, Kattankulathur, Chengalpattu, Tamil Nadu, India 603203.
    Krishnaraj, L.
    Département of Civil Engineering, SRM Institute of Science and Technology, Kattankulathur, Chengalpattu, Tamil Nadu, India 603203.
    Bahrami, Alireza
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Almujibah, Hamad
    Department of Civil Engineering, College of Engineering, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia.
    Panchal, Hitesh
    Mechanical Engineering Département, Government Engineering College Patan, Patan, Gujarat, India.
    Zahra, Musaddak Maher Abdul
    Computer Techniques Engineering Department, Al-Mustaqbal University College, Hillah 51001, Iraq; Electrical Engineering Department, College of Engineering, University of Babylon, Hilla, Babil, Iraq .
    Machine learning application to predict the mechanical properties of glass fiber mortar2023In: Advances in Engineering Software, ISSN 0965-9978, E-ISSN 1873-5339, Vol. 180, article id 103454Article in journal (Refereed)
    Abstract [en]

    In this study, the mechanical properties of concrete mortars have been predicted using machine learning tools, Response Surface Methodology (RSM), and Artificial Neural Network (ANN) approach. This study focused on mortar, in which cement has been partially replaced by 20% fly ash (FA) and 20% hydrated lime. In the experiment, the compressive strength (CS) of mortar has determined after curing the mix for 7 and 28 days, respectively. Glass fiber was added in the proportions of 0%, 0.2%, 0.4%, 0.6%, 0.8%, and 1% by weight of concrete to the mortar accordingly. The compressive strength of mortar incorporated with glassfiber increases according to an increase in the proportion of the glass fiber. Results indicates that the optimal fiber proportion of the glass fiber in the mortar had been observed to be 0.6%. The predicted compressive strength at day 28 has been modeled using RSM and ANN. The RSM model has been used to predict mechanical properties (R2 ≥ 0.7534) accurately. Furthermore, the appropriate R threshold (R > 0.999) for training, testing, and validation demonstrates that the ANN model has successfully captured the variability in the data. The results show that with the high correlation between the experimental and prediction results in data, more accuracy has been observed in the ANN model than in the RSM model.

  • 45.
    Norberg, Peter
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för inomhusmiljö.
    Hampberedning med tornadoteknik: En förstudie2009Report (Other academic)
    Abstract [sv]

    Möjligheterna att bereda hampa med tornadoteknik har studerats. Företaget Airgrinder AB i Skelleftehamn har en pilotanläggning som utnyttjats för att testköra hampa som skördats vid olika tillfällen under året. Tekniken innebär att hampan både sönderdelas och torkar under inverkan av den kraftiga luftström som pressas genom en speciellt utformad cyklon. Hampans fibrer passerar relativt opåverkade medan resten av stjälken samt eventuella blad och jordrester pulveriseras. Fibrerna kan därefter sållas fram och tillvaratas separat medan resten kan användas som t ex bränsle.

    För tornadotekniken spelar det ingen roll när på året hampan skördas. Separeringstekniken fungerar lika bra för fuktig höstskördad hampa som för torr vårskördad hampa. Fiberkvaliteten beror av skördetillfället och den återfinns givetvis även i slutprodukten. Kapaciteten för processen är däremot starkt beroende av det ingående materialets fukthalt. Detta innebär att hampa med hög fukthalt kräver en längre uppehållstid i tornadon än vad ett torrare material gör.

    Fibermaterialets egenskaper gör det lämpligt att användas som värmeisolering och provningar visar att egenskaperna blir lika bra som för andra cellulosabaserade isoleringsmaterial. Fibrerna kan även med fördel användas som armering i olika typer av kompositmaterial. För gips åstadkoms en förbättring av böjdraghållfastheten med 33% tack vare en tillsats av mindre än 0.5 vikt-% av tornadohampan. Liknande förbättringar är att räkna med även för andra kompositer med matriser av betong, plast och trä.

    En investeringskalkyl utvärderad enligt nettonuvärdesmetoden har genomförts för en anläggning som kan betjäna en odling på ungefär 250 ha. Investeringskostnaden för en anläggning bestående av tornsilos med volymen 2000 m3 samt en tornado från Airgrinder AB uppskattats till 7 MSEK. Lönsamheten bestäms av en mängd olika faktorer där skördens storlek per hektar är särskilt betydelsefull. Även andelen fibrer i förhållande till andelen skävor samt fukthalten i det ingående materialet är viktiga parametrar i kalkylen. I slutänden spelar priset på fibrer och även skävor en avgörande roll. Mindre genomslag på investeringens lönsamhet har allt som förknippas med odling och skörd, löner, energipriser och underhållskostnader. Utnyttjande av spillvärme samt andra samkörningsmöjligheter med intilliggande industrier förbättrar kapaciteten hos anläggningen markant och därmed även lönsamheten.

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    FULLTEXT01
  • 46.
    Norberg, Peter
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för inomhusmiljö.
    Lösullsisolering med hampa2009In: Bygg och Teknik, ISSN 0281-658X, E-ISSN 2002-8350, no 5, p. 28-32Article in journal (Other (popular science, discussion, etc.))
    Abstract [sv]

    Lösullsisolering gjord av hampfiber varken tillverkas eller säljs som en kommersiell produkt i Sverige idag. Möjligheterna är emellertid goda att på olika sätt få igång en inhemsk lokal produktion. Beredning av fibrerna med tornadoteknik kan vara ett sätt att åstadkomma ett utgångsmaterial lämpligt för bl a lösull. Försök visar att lösullsprodukter av hampfiber går att åstadkomma med egenskaper som är likvärdiga de hos träbaserad cellulosaisolering.

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    FULLTEXT01
  • 47.
    Norberg, Peter
    et al.
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för byggnadskvalitet.
    Krigsvoll, Guri
    Gumucio, Juan Carlos
    Maintaining the traditional churches of Chiloé2004In: Interaction between science, technology and architecture in timber construction: Proceedings of Culture 2000 project: Greek, Norwegian and Italian actions, Paris: Elsevier SAS , 2004, p. 405-421Chapter in book (Other academic)
    Abstract [en]

    The 16 churches of Chiloé in southern Chile, recently inscribed on UNESCO’s World Heritage List, represent the only example in Latin America of a rare form of ecclesiastical wooden architecture. They were built on the initiative of the Jesuit Peripatetic Mission in the 17th and 18th centuries and bear testimony to a successful fusion of indigenous and European culture and technical expertise. Most of these churches are in immediate need of restoration and maintenance. The present paper summarises experience and impressions acquired by the authors during a trip made to Chile in June 2002. The purpose of the trip was to establish contacts with people and organisations that are linked to the care and maintenance of the traditional wooden churches of Chiloé. In this context it has been of mutual interest to find out in what possible ways Scandinavian resources and know-how could be utilised and implemented in the process of restoring and maintaining these churches. The recently developed Maintenance Management System (MMS), capable of structuring condition surveys and assessments, as well as being an aid to plan and follow up conservation and maintenance work, might prove a suitable and elaborate alternative to traditional systems of building management and documentation. In addition, a brief description is presented of various tasks identified that could tentatively be the basis for mutual exchange of know-how, culture and traditions as well as of researchers, students and other resources, between the partners in Chile and in Sweden and Norway. These tasks address issues linked to aspects of both the physical maintenance of these churches and of their socio-cultural significance today and in the future.

  • 48.
    Norberg, Peter
    et al.
    University of Gävle, Department of Technology and Built Environment.
    Lindahl, Lars G
    Abrahamsson, Jörgen
    University of Gävle, Department of Technology and Built Environment.
    En metod för framställning av agglomerat av utfällt silikamaterial, ett mikroporöst material innefattande sådan agglomerat och användning därav2007Patent (Other (popular science, discussion, etc.))
    Abstract [sv]

    Föreliggande uppfinning avser en metod att producera ett material som innefattar agglomererade partiklar av utfälld kiseldioxid, innefattande framställning av en lösning av åtminstone ett metallsalt (M), där metalljonen/-jonerna är tvåvärd(a) eller flervärd(a). En lösning av alkalimetall (M) silikat med ett molförhållande SiO2/M2O om 0.5 - 100 framställs. Lösningarna blandas och blandningen omrörs, och ett koagel tillåts bildas. Koaglet uppsamlas och behandlas för att tillhandahålla ett material som har en torrsubstans om >15, företrädesvis >97%. Ett material som kan erhållas med processen tillhandahålles också.

  • 49.
    Osto, Emanuele
    et al.
    Primetals Technology, Castellanza, Italy.
    Giacomini, Luigi
    Primetals Technology, Castellanza, Italy.
    Lundberg, Sven-Erik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Mechanical Engineering.
    Lagergren, Jonas
    Åkers AB, Åkers Styckebruk, Sweden.
    Oppitz, Mattias
    Ellis, Glyn
    Kocks Pittsburgh Co., Pittsburgh, PA, USA.
    Fabro, Mario
    SMS group.
    Thorstenson, Eric
    Russula, A Coruña, Spain.
    Fernández, Silvia
    Russula, A Coruña, Spain.
    Sánchez, Daniel
    Russula, A Coruña, Spain.
    Chapter 2: Design and Construction of Rolling Mills for Long Products2017In: The Making, Shaping and Treating of Steel: Long Products Volume / [ed] Lundberg, S.-E., Warrendale, PA: Association for Iron & Steel Technology (AIST) , 2017, p. 101-336Chapter in book (Other academic)
  • 50.
    Rajapakshe, Chinthana
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering. Royal Institute of Technology.
    HEAT STORAGE APPLICATION IN ELECTRIC MOTOR COOLING SYSTEM: SMOKE VENTILATION MOTORS2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
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    fulltext
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