| 11. |
- André, Hampus, et al.
(författare)
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Are second-hand shell jackets better than users think? A comparison of perceived, assessed and measured functionality throughout lifespans
- 2024
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Ingår i: Resources, Conservation and Recycling. - : Elsevier B.V.. - 0921-3449 .- 1879-0658. ; 204, s. 107470-
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Tidskriftsartikel (refereegranskat)abstract
- Using the case of outdoor shell jackets, this research studies obsolescence and potential lifespan extension by re-examining how product functionality, objectively and subjectively, develops over the course of product lifespans. In particular, the study focuses on second-hand stores for outdoor products. Functionality is indicated by user perceptions, visual assessments, laboratory measurements and price data, collected at first use, second-hand resale and end-of-life. Perceived functionality and price decline more rapidly (5–6 % per year) than assessed and measured functionality (around 3 % per year). This could be explained by properties related to appearance, which are not assessed nor measured but influence user perceptions and price. Discontentment regarding such properties appears more relevant for obsolescence than inadequate performance, suggesting the potential for design for attachment and timeless design. The relative stability of measured functionality over time suggests that a barrier for second-hand sales, concern about performance, could be ameliorated by a potential functionality-label.
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| 12. |
- André, Hampus, et al.
(författare)
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Secondhand shell jackets are better than users think : A comparison of perceived, assessed and measured functionality throughout lifespans
- 2023
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Ingår i: Product lifetimes and the environment (PLATE). - Espoo, Finland : Aalto University.
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Konferensbidrag (refereegranskat)abstract
- Knowledge about obsolescence and its possible causes is instrumental to extend product lifespans. Product obsolescence may be caused by both subjective perceptions as well as objective and measurable deterioration of functionality. In order to extend lifetimes by avoiding and reversing obsolescence, this study addresses the current knowledge gap on how functionality of products develops over time, using a case study on shell jackets for outdoor recreational activities. Functionality over time is compared in terms of user perceptions, ocular assessments, laboratory measurements and, in addition, price. Data were collected at beginning of use, secondhand resale and end-of-life. In addition to ocular assessments and laboratory measurements, a survey was used to collect data from users on e.g. perceived functionality, price and duration of use span. Linear representations of perceived functionality and price decline more rapidly (5-6% per year) than assessed and measured functionality (both around 3% per year). This could be explained by properties such as appearance, which are included and seemingly important to user perceptions and price, but which are not assessed nor measured. The perception of such properties as low seems to be a more relevant cause of obsolescence than inadequate performance. This points to, for instance, timeless design to avoid obsolescence. The finding that measured functionality remains relatively high over time is important since concern about performance is a key barrier to secondhand sales. Information policy, such as performance-labelling, could thus contribute to reversing obsolescence. Future research could test the robustness of these findings as well as their generalizability to other products.
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| 13. |
- Andreasson, B., et al.
(författare)
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Determination of fibre pore structure : influence of salt, pH and conventional wet strength resins
- 2005
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Ingår i: Cellulose. - : Springer Science and Business Media LLC. - 0969-0239 .- 1572-882X. ; 12:3, s. 253-265
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Tidskriftsartikel (refereegranskat)abstract
- It has been shown, in the present investigation, that the two methods used to investigate the pore size distribution of unbleached chemical pulps, i.e. inverse size exclusion chromatography (ISEC) and nuclear magnetic resonance (NMR), give different average pore radius for the pores inside the fibre wall. This is due to the way in which these experiments are performed and the sensitivity of the methods to different types of pores in the cell wall. It was also shown that the two methods gave different results when changing the pH and the ionic strength of the pulp suspension. The pore radius, as detected with ISEC, decreased with both increasing ionic strength and decreasing pH, indicating a loose structure of the exterior of the fibrillar network. However, the pore radius as detected with NMR, was virtually unaffected when increasing the ionic strength, indicating a very rigid structure of the interior of the fibre wall. Decreasing pH though, lead to a decrease in pore radius indicating that upon protonation of the carboxylic groups in the fibre wall, the electrostatic repulsion is diminished and the average pore radius decreases. The NMR technique was also used to study wet strength aid penetration into the fibre wall. It was shown that wet strength aids with a small molecular weight, penetrated the fibre wall, as detected by a decrease in pore radius. It was also shown that addition of different wet strength aids increased the tensile index of the sheet and decreased the fibre strength, measured as zero span-strength of the sheets.
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| 14. |
- Andreasson, B., et al.
(författare)
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The porous structure of pulp fibres with different yields and its influence on paper strength
- 2003
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Ingår i: Cellulose. - 0969-0239 .- 1572-882X. ; 10:2, s. 111-123
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Tidskriftsartikel (refereegranskat)abstract
- The porous structure of the interior of papermaking fibres is a well-known important property of the fibres. Changes of this structure will influence tensile and burst strength of paper formed from the fibres and a change in pore size of the pores within the fibre wall is also important for the ability of molecules to diffuse in and out of the fibre wall. Relevant examples of this latter effect are the removal of lignin during cooking and the addition of performance chemicals during papermaking. In this paper, pore sizes and the pore size distribution of unbleached softwood fibres have been studied. A well-characterised fibre material consisting of laboratory cooked spruce and pine pulp of various lignin contents was used. Pore size and pore size distribution were measured by studies of the relaxation behaviour of H-2 in fibres saturated with (H2O)-H-2. Beside this the total and surface charge of the fibres were also measured together with strength properties of papers from unbeaten fibres. For both pulps, there is a maximum in pore radius at a yield around 46%. Calculations of fibre wall volume from water retention values and yield levels show that there is a discontinuity in pore radius as a function of the fibre wall volume around a yield of 51%. It is suggested that this discontinuity is caused by the breakdown of the hemicellulose/ lignin matrix within the fibre wall at this yield level. The strength of the papers formed from the fibres shows a correlation with the surface charge of the fibres. Based on the change in surface charge with yield and the change in total charge with yield, this correlation is suggested to be due to an opening up of the external part of the fibre wall. This stresses the importance of the chemical composition and physical structure of the outer layer of the fibre wall.
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| 15. |
- Arman, Rebecka, et al.
(författare)
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Work activities and stress among managers in health care
- 2012. - 1
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Ingår i: The Work of Managers. - Oxford : Oxford University Press. - 9780199639724
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- This chapter reports on the work activities, time-use patterns, and stress patterns of ten health care managers in Sweden. The qualitative and quantitative evidence reveals the fragmentation in their nine-hour working days where each activity, on average, lasts only ten minutes. The time-use patterns vary individually though some patterns are related to position and unit type. Activities deal with the coexisting and competing logics of employeeship, administration, and strategy and risk handling. None of the managers’ approaches for handling the multiple legitimation processes and delimiting their workload boundaries really challenges the complexity of the coexistence of the multiple logics or the boundlessness of their working hours. Using biophysical measures, the research finds that stress reported by the managers is caused by (a) interruptions during challenging tasks and (b) personal situations such as private dilemmas and conflict-loaded or ineffective meetings. It is important to acknowledge managers’ fragmented working situation and to recognize that management should be seen as collective process, or as part of an administrative system.
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| 16. |
- Asem, H., et al.
(författare)
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Functional Nanocarriers for Drug Delivery by Surface Engineering of Polymeric Nanoparticle Post-Polymerization-Induced Self-Assembly
- 2021
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Ingår i: ACS Applied Bio Materials. - : American Chemical Society. - 2576-6422. ; 4:1, s. 1045-1056
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Tidskriftsartikel (refereegranskat)abstract
- Engineered polymeric nanoparticles (NPs) have been comprehensively explored as potential platforms for diagnosis and targeted therapy for several diseases including cancer. Herein, we designed functional poly(acrylic acid)-b-poly(butyl acrylate) (PAA-b-PBA) NPs using reversible addition-fragmentation chain-transfer (RAFT)-mediated emulsion polymerization via polymerization-induced self-assembly (PISA). The hydrophilic PAA-macroRAFT, forming a stabilizing shell (i.e., corona), was chain-extended using the hydrophobic monomer n-butyl acrylate (n-BA), resulting in stable, monodisperse, and reproducible PAA-b-PBA NPs, typically having a diameter of 130 nm. The surface engineering of the PAA-b-PBA NP post-PISA were explored using a two-step approach. The hydrophilic NP-shell corona was modified with allyl groups under mild conditions, using allylamine in water, which resulted in stable allyl-functional NPs (allyl-NPs) suitable for further bioconjugation. The allyl-NPs were subsequently conjugated with a thiol-functional fluorescent dye (BODIPY-SH) to the allyl groups using "thiol-ene"-click chemistry, to mimic the attachment of a thiol-functional target ligand. The successful attachment of BODIPY-SH to the allyl-NPs was corroborated by UV-vis spectroscopy, showing the characteristic absorbance of the BODIPY-fluorophore at 500 nm. Despite modification of NPs with allyl groups and attachment of BODIPY-SH, the NPs retained their colloidal stability and monodispersity as indicated by DLS. This demonstrates that post-PISA functionalization is a robust method for synthesizing functional NPs. Neither the NPs nor allyl-NPs showed significant cytotoxicity toward RAW264.7 or MCF-7 cell lines, which indicates their desirable safety profile. The cellular uptake of the NPs using J774A cells in vitro was found to be time and concentration dependent. The anti-cancer drug doxorubicin was efficiently (90%) encapsulated into the PAA-b-PBA NPs during NP formation. After a small initial burst release during the first 2 h, a controlled release pattern over 7 days was observed. The present investigation demonstrates a potential method for functionalizing polymeric NP post-PISA to produce carriers designed for targeted drug delivery.
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| 17. |
- Ashraf, Shakeel, 1984-, et al.
(författare)
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Thermoelectric Properties of n-Type Molybdenum Disulfide (MoS2) Thin Film by Using a Simple Measurement Method
- 2019
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Ingår i: Materials. - : MDPI. - 1996-1944 .- 1996-1944. ; 12:21
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, a micrometre thin film of molybdenum disulfide (MoS2) is characterized for thermoelectric properties. The sample was prepared through mechanical exfoliation of a molybdenite crystal. The Seebeck coefficient measurement was performed by generating a temperature gradient across the sample and recording the induced electrical voltage, and for this purpose a simple measurement setup was developed. In the measurement, platinum was utilized as reference material in the electrodes. The Seebeck value of MoS2 was estimated to be approximately -600 mu V/K at a temperature difference of 40 degrees C. The negative sign indicates that the polarity of the material is n-type. For measurement of the thermal conductivity, the sample was sandwiched between the heat source and the heat sink, and a steady-state power of 1.42 W was provided while monitoring the temperature difference across the sample. Based on Fourier's law of conduction, the thermal conductivity of the sample was estimated to be approximately 0.26 Wm(-1) K-. The electrical resistivity was estimated to be 29 Omega cm. The figure of merit of MoS2 was estimated to be 1.99 x 10(-4).
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| 18. |
- Atari Jabarzadeh, Sevil, et al.
(författare)
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Image Analysis Determination of the Influence of Surface Structure of Silicone Rubbers on Biofouling
- 2015
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Ingår i: International Journal of Polymer Science. - : Hindawi Limited. - 1687-9422 .- 1687-9430.
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Tidskriftsartikel (refereegranskat)abstract
- This study focuses on how the texture of the silicone rubber material affects the distribution of microbial growth on the surface of materials used for high voltage insulation. The analysis of surface wetting properties showed that the textured surfaces provide higher receding contact angles and therefore lower contact angle hysteresis. The textured surfaces decrease the risk for dry band formation and thus preserve the electrical properties of the material due to a more homogeneous distribution of water on the surface, which, however, promotes the formation of more extensive biofilms. The samples were inoculated with fungal suspension and incubated in a microenvironment chamber simulating authentic conditions in the field. The extent and distribution of microbial growth on the textured and plane surface samples representing the different parts of the insulator housing that is shank and shed were determined by visual inspection and image analysis methods. The results showed that the microbial growth was evenly distributed on the surface of the textured samples but restricted to limited areas on the plane samples. More intensive microbial growth was determined on the textured samples representing sheds. It would therefore be preferable to use the textured surface silicone rubber for the shank of the insulator.
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| 19. |
- Axelsson, Karolin, et al.
(författare)
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Chemical defence responses of Norway spruce to two fungal pathogens
- 2020
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Ingår i: Forest Pathology. - : Blackwell Verlag. - 1437-4781 .- 1439-0329. ; 50:6
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Tidskriftsartikel (refereegranskat)abstract
- Constitutive and inducible terpene production is involved in conifer resistance against insects and fungal infestations. To gain knowledge about local defence responses of Norway spruce bark against pathogens and to find potential chemical markers for resistance breeding, we inoculated the stem of 8-year-old Norway spruce (Picea abies) clonal trees with bothEndoconidiophora polonica(Ep, a common fungal pathogen associated with the spruce bark beetleIps typographus) andHeterobasidion parviporum(Hp, a severe pathogen causing root and stem rot disease). Three weeks after inoculation, the fungal-inoculated and intact bark from each tree was sampled. The terpenes in tree bark were extracted with hexane and characterized by gas chromatography-mass spectrometry (GC-MS). The two fungi induced varied terpene responses in the four spruce clones used. Three of the clones showed a 2.3-fold to 5.7-fold stronger terpene response to Hp relative to Ep inoculation, while one clone responded similarly to inoculation with the two fungal pathogens. The amount of the diterpenes thunbergol and geranyllinalool varied between the clones. The level of thunbergol was higher in both intact and fungal-inoculated bark from the less susceptible clones compared with the more susceptible clones. Geranyllinalool was present in higher amounts in the susceptible clones and is thus a possible marker for susceptibility. Our observations show that Norway spruce employs a similar chemical mechanism against the two fungal pathogens. Based on the present and earlier published data, we suggest that certain Norway spruce genotypes have a strong defence reaction against these two pathogens. The diterpenes thunbergol and geranyllinalool might be useful markers of susceptibility in tree-breeding programmes and should be the focus of further detailed investigations.
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| 20. |
- Baalsrud Hauge, Jannicke, 1969-, et al.
(författare)
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Educational Location-based Interaction
- 2022
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Ingår i: IxD&A. - : ASLERD. - 1826-9745 .- 2283-2998. ; :52, s. 141-143
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Tidskriftsartikel (refereegranskat)abstract
- Focus section on 'Educational Location-based Interaction' PrefaceJannicke Baalsrud Hauge, Esteban Clua, Jimmy Jaldemark, Heinrich Söbke(https://doi.org/10.55612/s-5002-052-001pfs)1. Thematic introduction Mobile devices have become more common in recent years. A key feature is their location awareness. The absolute location as well as the relative location awareness related to an object can be exploited for location-based applications on mobile devices allowing location-based interactions. A common example are digital scavenger hunt apps that guide users to different locations. Social inclusion [1] and social interaction [2] are a common goal of location-based experiences. Location-based apps are also used for learning purposes, as they support a variety of learning concepts. In their literature review on mobile apps in general [3], the authors found situated learning, inquiry-based learning, sociocultural theory, scaffolding, communities of practice, and seamless learning, which can be taken as an indication of the manifold didactic options of location-based apps. Moreover, developments opening up new possibilities have been observed for more than a decade [4] are related to Internet of Things (IoT), ensuring that interaction possibilities of mobile devices with many other technical objects are provided. In addition, the Smart Cities paradigm provides more sensors and location-based data both offering options for location-based interactions potentially fostering learning. This is being enhanced through the 5G networks being implemented over the world, with more and more connected devices.Another group of location-based interactions is given by commercial location-based entertainment games. Games such as Ingress, Pokémon GO and Minecraft Earth attract a large player base on the one hand and are increasingly credited for learning effects on the other [5,6]. However, it has also been observed that convergence between the real world and superimposed virtual layers does not necessarily exist [7]. The relevance to learning remains to be investigated.Based on these trends, this special issue intends to foster a more general discourse on the specific contexts in which location-based interactions, e.g. enabled by location-based apps, might be at the core of learning tools, based on the debate of mobile and context-based learning. Some of the contributions in this focus section provide some guidelines on the balance between technical content and educational purpose, while the main contribution of others is more in the area of user experience and immersiveness. Among the topics of interest were design frameworks for (educational) location-based interactions and Augmented Reality (AR) technology enabling location-based interactions. 2. Summaries Overall the work with this special issue embraced the involvement of 30 scholars in the role of authors, editors and reviewers. This project was a true global enterprise by scholars from four continents and ten countries, including Australia, Austria, Brazil, Colombia, Cyprus, Finland, Germany, Italy, Romania, Spain, Sweden, and the US. The article by Nekoui and Roig “Children and the Mediated City. Place Attachment Development Using Augmented Reality in Urban Spaces” focused on augmented spaces as main elements of mediated cities. The authors discuss the application of Augmented Reality to facilitate communication and interaction between digital and physical spaces. The paper explored three case studies that exhibit how children use AR technology to develop various skills. The goal was to promote AR as a contemporary tool that helps children better perceive and experience the feeling of place attachment in their city.The article “A framework for designing applications to support knowledge construction on learning ecosystems” written by Silveira, Cury and de Menezes discussed the increased digital immersion of education and the role learning ecosystems have to support informal and personal aspects of learning. The article develops a framework for location-based applications that may support the modeling of Smart Learning Environments. Cases are included to demonstrate the framework and show its practical implications.The article 'Attention, stimulus and augmented reality for urban daily life education on a social peripheral setting: the 'Altamira - story-telling streets'' by Ricca, Lupo, Diniz, Veras, and Mazzilli addresses designers of location-based experiences. The authors consider location-based experiences in the urban environment as cognitive and attentional stimuli and develop a stimulus level framework in which they distinguish between linear, circular and spiraled stimuli. The framework, which is validated in the article, aims at reflecting on contextual educational experiences.Raber, Ferdig, Gandolfi and Clements explore foundations of AR in teaching related to psychology of learning in their article 'An analysis of motivation and situational interest in a location-based augmented reality application'. Interestingly, they find a decrease in motivation alongside an increase in situational interest as well as a gain in knowledge. What needs to be noted is that the subject of the AR experience, namely tragic shootings at the authors' institution just over 50 years ago may likely not be conducive to motivation. Thus, one lesson may be that assertions regarding psychology of learning must also be contextualized in terms of the knowledge being imparted.Special thanks go to the editor, Carlo Giovanella, who gave the inspiration for this focus section and who patiently and constructively guided the editing process, and to the reviewers, without whom this focus section would not have been possible. 3. Conclusion The multifaceted topics of the articles in this focus section highlight that location-based interactions have found their way into various learning scenarios for different age groups and teaching topics. It also illustrates the wide range of factors and the multi-disciplinarity that characterize a good location-based digital app. As digitalisation continues to spread, the technical foundations are broadening, suggesting that the possibilities and importance of location-based interaction will continue to grow in the future. We believe that the articles provide valuable insights into the current state of location-based interactions and the prospects for the future, and we are intrigued about potential further developments. May the articles be a good inspiration for the readers' own approaches to the use of location-based interactions and researches! References: 1. Bengs, A., Hägglund, S., Wiklund-Engblom, A., & Staffans, S. (2015). Designing for suburban social inclusion: A case of geo-located storytelling. Interaction Design and Architecture(S), 25(1), 85–99.2. Fonseca, X., Lukosch, S., & Brazier, F. (2022). Design Framework for Social Interaction with Location-based Games. International Journal of Serious Games, 9(1), 59–81. https://doi.org/10.17083/ijsg.v9i1.4813. Zydney, J. M., & Warner, Z. (2016). Mobile apps for science learning: Review of research. Computers and Education, 94, 1–17. https://doi.org/10.1016/j.compedu.2015.11.0014. Sintoris, C., Yiannoutsou, N., Demetriou, S., & Avouris, N. (2013). Discovering the invisible city: Location-based games for learning in smart cities. Interaction Design and Architecture(S), 16(1), 47–64.5. Mozelius, P., Eriksson Bergström, S., & Jaldemark, J. (2017). Learning by Walking-Pokémon Go and Mobile Technology in Formal Education. In 10th International Conference of Education, Research and Innovation, Seville, Spain, NOV 16-18, 2017 (Vol. 10, pp. 1172-1179). The International Academy of Technology, Education and Development.6. Söbke, H., Baalsrud Hauge, J., & Stefan, I. A. (2017). Prime Example Ingress: Reframing the Pervasive Game Design Framework (PGDF). International Journal of Serious Games, 4(2), 39–58. https://doi.org/10.17083/ijsg.v4i2.1827. Laato, S., Inaba, N., & Hamari, J. (2021). Convergence between the real and the augmented: Experiences and perceptions in location-based games. Telematics and Informatics, 65, 101716. https://doi.org/https://doi.org/10.1016/j.tele.2021.101716
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