| 1. |
- Gustafsson Coppel, Ludovic, 1975-, et al.
(author)
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Paper whiteness and its effect on perceived image quality
- 2010
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In: Final Program and Proceedings - IS and T/SID Color Imaging Conference. - : The Society for Imaging Science and Technology. - 9780892082940 - 9781629932156 ; , s. 62-67, s. 62-67, s. 62-67
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Conference paper (peer-reviewed)abstract
- 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.
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| 2. |
- Jonsson, Oskar, et al.
(author)
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CONSUMER PERCEPTIONS AND PREFERENCES ON SOLID WOOD, WOOD-BASED PANELS, AND COMPOSITES : A REPERTORY GRID STUDY
- 2008
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In: Wood and Fiber Science. - 0735-6161. ; 40:4, s. 663-678
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Journal article (peer-reviewed)abstract
- Knowledge about consumer perception and preferences on solid wood, wood-based panels, and wood-based composites is important for product development and marketing. The aim of this study was to identify attributes and associations that people use to describe different types of wood materials and to explore how they relate to preferences. The study involved nine samples that were evaluated with the Kelly's repertory grid technique and content analysis. Based on respondents' answers. 19 core categories reflecting sample attributes were extracted. General preferences for each sample were also recorded. Principal component analysis generated two factors describing 1) naturalness, wood-likeness, softness, unprocessed origin, living, pleasant, and high value; and 2) solid and homogeneous impression. A third, preliminary factor included categories describing irregular pattern,sleekness, and smoothness. The wood samples were most liked, whereas composites and panels were not appreciated. Preferred core categories were naturalness, wood-likeness, smoothness, living impression, and value. The least liked core categories were processed, hard, and high weigh. The implications of the results for product development and marketing are discussed.
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| 3. |
- Coppel, Ludovic, et al.
(author)
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Modelling the effect of simultaneous contrast on perceived whiteness
- 2008
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In: 4th European Conference on Colour in Graphics, Imaging, and Vision and 10th International Symposium on Multispectral Colour Science. - : The Society for Imaging Science and Technology. - 9781605607023 ; , s. 183-188
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Conference paper (peer-reviewed)abstract
- The perceived colour from a surface does not only depend on its optical properties and the illumination. Several studies have demonstrated the simultaneous contrast effect that makes the appearance of coloured patches depend on neighbouring colours. In this study the perceived whiteness of white patches surrounded by induction fields of different shades was evaluated by asking observers to give a magnitude estimate of perceived whiteness of the patches in comparison to a white reference. The perceived whiteness of patches with identical tristimulus values was highly dependent on the shade of the induction field and the patch size did not significantly affect the perceived whiteness. The recent CIECAM02-m2 colour appearance model was tested together with two whiteness equations. A combination of ClECAM02-m2 and a non-linear whiteness equation defined in the whole colour space predicted much of the observed simultaneous contrast effect. However, the model performed better for dark induction fields than for light induction fields. The model rated patches surrounded by light blue and light yellow equally, whereas the observers clearly rated the patches with light yellow induction field as whiter than the patches with light blue induction field. A deeper analysis of the CIECAM02-m2 model indicated that the simultaneous contrast model used cannot accurately predict the change in hue for high lightness induction fields. A potential improvement for predicting contrast simultaneous effect would be to base the calculations not only on the difference between the induction field and the background, but on the difference between the patch stimulus and the induction field.
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| 4. |
- Durmus, Dorukalp, et al.
(author)
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Investigating the methods and health outcomes of research studies on light pollution and human physiology and behaviour : a systematic review
- 2022
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In: 2022 Joint Conference - 11th International Conference on Energy Efficiency in Domestic Appliances and Lighting and 17th International Symposium on the Science and Technology of Lighting, EEDAL/LS:17 2022. - : Institute of Electrical and Electronics Engineers Inc.. - 9782492754005 - 9781665431439
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Conference paper (peer-reviewed)abstract
- Light at night (LAN) enables humans to extend their lifestyle and exploration, cultivates economic growth, and increases the perception of safety. On the other hand, LAN has been connected to adverse health outcomes, such as circadian disruption, mood effects, and increased breast cancer incidence risk in humans. Studies investigating health outcomes of LAN utilize a variety of methods sometimes resulting in conflicting outcomes. We conducted a systematic review focusing on the experimental methods and health outcomes of LAN studies. While most studies found a negative impact of LAN on human health, lighting conditions were not adequately reported or controlled in many cases. Recommendations are provided for future research studies investigating LAN effects on human health outcomes.
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| 5. |
- Eckersten, Henrik, et al.
(author)
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Nitrogen leaching and soil organic carbon sequestration of a Barley crop with improved N use efficiency : A regional case study
- 2017
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In: Acta Agriculturae Scandinavica - Section B. - : Taylor and Francis Ltd.. - 0906-4710 .- 1651-1913. ; 67:7, s. 615-627
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Journal article (peer-reviewed)abstract
- The potential of modified spring barley crops with improved nitrogen (N) use efficiency to reduce nitrogen (N) leaching and to increase soil organic carbon (SOC) storage was assessed at the regional scale. This was done using simulation model applications designed for reporting according to the Helcom (Helsinki Commission) and Kyoto protocols. Using model simulations based on modified crops N dynamics and SOC were assessed for three agro-ecological regions (latitudes ranging 55°20′–60°40′ N) in Sweden over a 20-year period. The modified N use properties of spring barley were implemented in the SOILNDB model (simulating soil C, N, water and heat, and plant N dynamics) by changing the parameters for root N uptake efficiency and plant N demand within a range given by previous model applications to different crops. A doubling of the daily N uptake efficiency and increased N demand (by ca 30%) reduced N leaching by 24%–31%, increased plant N content by 9%–12%, depending on region. The effects of the modified crop on SOC was simulated with the ICBM model, resulting in an increased SOC content (0–25 cm depth) by 57–79 kg C ha−1 y−1. The results suggest that a modified crop might reduce N leaching from spring barley area, in a range similar to the targets of relevant environmental protection directives, a result which held more in the northern than southern regions. The simulated SOC increase on a hectare basis was highest for the central region and least for the most northern region. For the total agricultural area the share of spring barley area was small and more crops would need to be modified to reach the emission reduction targets.
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| 6. |
- Eriksson, Ola, et al.
(author)
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Life cycle assessment of horse manure treatment
- 2016
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In: Energies. - : MDPI AG. - 1996-1073. ; 9:12
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Journal article (peer-reviewed)abstract
- Horse manure consists of feces, urine, and varying amounts of various bedding materials. The management of horse manure causes environmental problems when emissions occur during the decomposition of organic material, in addition to nutrients not being recycled. The interest in horse manure undergoing anaerobic digestion and thereby producing biogas has increased with an increasing interest in biogas as a renewable fuel. This study aims to highlight the environmental impact of different treatment options for horse manure from a system perspective. The treatment methods investigated are: (1) unmanaged composting; (2) managed composting; (3) large-scale incineration in a waste-fired combined heat and power (CHP) plant; (4) drying and small-scale combustion; and (5) liquid anaerobic digestion with thermal pre-treatment. Following significant data uncertainty in the survey, the results are only indicative. No clear conclusions can be drawn regarding any preference in treatment methods, with the exception of their climate impact, for which anaerobic digestion is preferred. The overall conclusion is that more research is needed to ensure the quality of future surveys, thus an overall research effort from horse management to waste management.
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| 7. |
- Eriksson, Ola, et al.
(author)
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ORWARE : a simulation tool for waste management
- 2002
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In: Resources, Conservation and Recycling. - 0921-3449 .- 1879-0658. ; 36:4, s. 287-307
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Journal article (peer-reviewed)abstract
- A simulation model, ORWARE (ORganic WAste REsearch) is described. The model is mainly used as a tool for researchers in environmental systems analysis of waste management. It is a computer-based model for calculation of substance flows, environmental impacts, and costs of waste management. The model covers, despite the name, both organic and inorganic fractions in municipal waste. The model consists of a number of separate submodels, which describes a process in a real waste management system. The submodels may be combined to design a complete waste management system. Based on principles from life cycle assessment the model also comprises compensatory processes for conventional production of e.g. electricity, district heating and fertiliser. The compensatory system is included in order to fulfil the functional units, i.e. benefits from the waste management that are kept constant in the evaluation of different scenarios. ORWARE generates data on emissions, which are aggregated into different environmental impact categories, e.g. the greenhouse effect, acidification and eutrophication. Throughout the model all physical flows are described by the same variable vector, consisting of up to 50 substances. The extensive vector facilitates a thorough analysis of the results, but involves some difficulties in acquiring relevant data. Scientists have used ORWARE for 8 years in different case studies for model testing and practical application in the society. The aims have e.g. been to evaluate waste management plans and to optimise energy recovery from waste.
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| 8. |
- Fröjdh, Christer, 1952-, et al.
(author)
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Precision scan-imaging for paperboard quality inspection utilizing X-ray fluorescence
- 2018
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In: Journal of Instrumentation. - : Institute of Physics Publishing. - 1748-0221 .- 1748-0221. ; 13:1
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Journal article (peer-reviewed)abstract
- Paperboard is typically made up of a core of cellulose fibers [C6H10O5] and a coating layer of [CaCO3]. The uniformity of these layers is a critical parameter for the printing quality. Current quality control methods include chemistry based visual inspection methods as well as X-ray based methods to measure the coating thickness. In this work we combine the X-ray fluorescence signals from the Ca atoms (3.7 keV) in the coating and from a Cu target (8.0 keV) placed behind the paper to simultaneously measure both the coating and the fibers. Cu was selected as the target material since its fluorescence signal is well separated from the Ca signal while its fluorescence's still are absorbed sufficiently in the paper. A laboratory scale setup is built using stepper motors, a silicon drift detector based spectrometer and a collimated X-ray beam. The spectroscopic image is retrieved by scanning the paperboard surface and registering the fluorescence signals from Ca and Cu. The exposure time for this type of setups can be significantly improved by implementing spectroscopic imaging sensors. The material contents in the layers can then be retrieved from the absolute and relative intensities of these two signals.
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| 9. |
- Gustafsson Coppel, Ludovic, et al.
(author)
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Impact of illumination spectral power distribution on radiance factor of fluorescing materials
- 2013
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In: 2013 Colour and Visual Computing Symposium, CVCS 2013. - 9781479906093 ; , s. Art. no. 6626275-
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Conference paper (peer-reviewed)abstract
- 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. © 2013 IEEE.
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| 10. |
- Hartzén, Ann-Sofie, et al.
(author)
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The material expression of new pulp-fibre reinforced composites in relation to other material categories
- 2016
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In: Proceedings - D and E 2016. - Amsterdam : Universidad de los Andes. - 9789461867254 ; , s. 191-200
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Conference paper (peer-reviewed)abstract
- To help bridge the gap between the science lab and commercial production there is a need for a better understanding of how new bio-based materials are perceived by users. The aim of the studies in this paper was to identify the material expression, sensorial properties and semantic dimensions of a group of pulp-fibre reinforced composites that are still in the research phase and how these relate to other, better-known materials already on the market. The studies involved 21 different materials, divided into different material groups such as metals, solid woods, wood fibre materials, plastic and fibre-reinforced composites in which the pulp-fibre reinforced composites were included. The materials were evaluated for meaning in a product semantic study and for sensory perception in a sensorial study. The results of the semantic study gave two underlining dimensions explaining most of the variations between the materials, Quality and Naturalness. These dimensions also had strong correlations to some of the sensorial properties. The results indicate that the pulp-fibre reinforced composites were not perceived as having high quality or expressing naturalness. They were hard to distinguish from the plastics in the study. The implications for further research and material development are discussed.
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