| 1. |
- Barros, Gustavo Gil, 1976-
(författare)
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Influence of Substrate Topography on Ink Distribution in Flexography
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The printability of paper in flexography is largely dependent on the topographical characteristics of the substrate. Topography imaging instruments make it possible to obtain three-dimensional scans of paper surfaces that can be further used to calculate valuable quality parameters. The primary aim of the work described in this thesis has been to identify and isolate structural properties of the paper surface which significantly influence the ink distribution during printing and limit the subsequently attainable print quality.OptiTopo is an optical imaging technique which provides precise and fast topographic scans of both printed and unprinted paper surfaces. The potential and limitations of the technique have been evaluated. The optical requirements on the substrate for an accurate and precise topographic scan were determined. Detail-rendering was substantially improved using a custom-designed restoring filter, and a new enhanced spatial resolution range was established. A combination of further algorithm improvements made it possible also to obtain reflectance-factor-calibrated intensity images of scanned printed surfaces.Serious deficiencies affecting the quality of flexographic prints may appear in the form of local unprinted areas (UCA) in a full-tone print, generally caused by incomplete ink transfer. An algorithm detecting and quantifying local uncovered area was developed, tested and successfully integrated with the OptiTopo instrument. A UCA occurrence frequency distribution, indicating the percentage of the uncovered area at a certain topographical elevation, was calculated for different prints. The topographic characteristics of the uncovered areas clearly indicate that surface depressions are the primary cause of uncovered areas in flexographic printing.Four different predictive models based on topography thresholding were proposed and tested using two independent quality judgement criteria. These quality indices took into account both the amount and location of the predictions. A deeper understanding of the topographical features governing UCA occurrence was established with a proposed ink bridging effect. The total risk of non-ink-covered areas in flexography printing due to topographical features was estimated.The overall influence of paper topography on the flexography printability of full-tone areas was studied and its importance for the ink distribution assessed. The impacts of printing plate hardness, printing pressure, anilox cylinder volume and substrate roughness were quantified. Two typical flexography patterns were identified and their origin discussed: sub-millimetre elongated structures and millimetre-scale blotches.
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| 2. |
- Johnson, Johanna, 1970-
(författare)
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Aspects of Flexographic Print Quality and Relationship to some Printing Parameters
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Flexographic printing is a common printing method in the packaging field. The printing method is characterized primarily by the flexible printing plate and the low viscosity inks which make it suitable for use on almost any substrate. The object of this study was to obtain further knowledge of the some important mechanisms of flexographic printing and how they influence the print quality. The thesis deals with printing primarily on board and liner but also on newsprint with water-borne ink using a full-scale flexographic central impression (CI) printing press. Several printing trials have been performed with a focus on the chemical interaction between the ink and substrate and the physical contact between the ink-covered printing plate and the substrate. Multicolour printing exposes the substrate to water from the water-containing ink. The emphasis was to investigate the relation between print quality and water-uptake of the paper surface with heat and water. Printing trials was carried out on substrates possessing a hydrophobic, and also a rather hydrophilic surface using a regular commercial water-borne ink. The favorable effect which water or surfactant solution had on the hydrophobic substrate with regard to print mottle could depend on its surface compressibility in combination with the hydrophobic nature of its surface that could affect the wetting properties. Conventional printing involves physical contact between plate and ink and between ink and substrate. A method for measuring the dynamic nip pressure using thin load cells is presented. Print quality was influenced by the plate material. A correction procedure taking into account the size of the sensor was developed in order to estimate the maximum dynamic pressure in the printing nip. An attempt was made to identify essential mechanical and chemical parameters, and also geometrical properties of the plate that affected print quality. Laboratory printing trials were carried out and a multivariate analysis was applied for evaluation of print quality data. The impact of the plate properties on print quality was evident. The essential properties of the plate that influence print quality were the small-scale roughness and long-scale roughness.
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| 3. |
- Jonhed, Anna, 1975-
(författare)
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Properties of modified starches and their use in the surface treatment of paper
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The papermaking industry uses a large amount of starch each year, both as a wet-end additive and as a rheological modifier in surface sizing and coating colors. It is important to be able to reduce the amount of chemicals used in the papermaking and surface treatment process, to reduce costs and to make the process even more efficient. Interest in new high-performance starches is great. By using these new types of starches, improved recycling of barrier products may be obtained as well as a reduction in the use of synthetic sizing agents. The objectives of this work were to understand the behavior of temperature-responsive hydrophobically modified starches, where the solubility in water simply can be adjusted by temperature or by polymer charge, to improve the barrier properties, like the water vapor permeability, mechanical properties and water resistance (Cobb and contact angle) of papers surface sized by starch-containing solutions, and to investigate the potential for industrial use of these temperature-responsive starches. It was demonstrated that the temperature-responsive starches phase separate upon cooling and, depending on the charge density of the starch, a particulate precipitation or a gel-like structure was obtained. The starch with zero net charge showed a larger increase in turbidity than the starch with a cationic net charge, indicating that particulate precipitation is favored by a zero net charge and that the formation of a gel network is favored by charged starch molecules. Further, the starches formed inclusion complexes with surfactants, giving stabilization to the starches in the presence of surfactants. The net charge density of the starch and the charge of the surfactant determined whether or not an inclusion complex would form between them. Important mechanisms for the stability of the starch seemed to be formation of mixed micellar-like structures between the hydrophobic chain of the starch and the surfactant along the starch backbone in addition to formation of inclusion complexes between the starch and the surfactant. The hydrophobically modified starches showed higher hydrophobic surface character when applied to the paper surface above the critical phase separation temperature than with application at room temperature. Free films of the temperature-responsive starches showed good barrier against oxygen, but no barrier against water vapor. The mechanical properties decreased with addition of glycerol to the films.
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| 4. |
- Kjellgren, Henrik, 1970-
(författare)
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Influence of paper properties and polymer coatings on barrier properties of greaseproof paper
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Greaseproof paper has a dense structure and therefore provides a natural barrier against materials like fat and oils. The barrier is obtained by extensive refining of the pulp. This refining is however a costly operation, not only in terms of direct costs for the refining but also in terms of indirect costs because the energy consumption for the drying of the paper is affected by the refining. A full-scale trial was performed to investigate the role of the pulp with respect to the energy demand and the barrier properties of the final papers. Paper made of 100% sulphite pulp with a low degree of refining exhibited the lowest energy consumption at a given level of air permeance. In addition, the effect of refining on the air permeance was compared with that of calendering. The calendering affected the air permeance less than the refining. The papers produced in the full-scale trial were later used as substrates for coatings and for detailed studies of the paper structure. Coating with chitosan was examined on a bench-scale and on a pilot scale. The studies showed that greaseproof paper can be upgraded with an oxygen barrier, but also that suitable coating techniques are lacking for the application of the coating in a sufficient amount. The influence of the base paper on the barrier properties of chitosan-coated paper was investigated in another study, in which it was found that greaseproof paper possesses a unique coating hold-out which cannot be met by other types of paper with a more open structure. It was also found that the coated paper had a lower oxygen permeability than the chitosan coating itself, and this indicates that the dense surface layer of greaseproof paper contributed to the oxygen permeability of the coated paper. The pore volume fraction of the greaseproof paper was found to be approximately 40% and it is therefore surprising that its air permeance is so low. To bring understanding to this question, the structure of greaseproof paper was studied using several methods. It was found that the structure was dominated by very small pores with a median diameter of <0.3 µm. The fraction of closed pores was also substantial. A porosity gradient was also found, indicating that the papers used in the study had a closed surface. The hypothesis that the surface layer of the paper contributed to the oxygen barrier was tested in an experiment in which greaseproof paper was extrusion-coated with polyethylene. The oxygen permeability was measured at 0%, 50% and 90% relative humidity, and the permeability was found to increase with increasing moisture content. Because only the cellulose layer in the paper and not the polyethylene layer in the coating is affected by moisture, this result supports the hypothesis that the surface layer of the paper contributed to the oxygen barrier properties of the coated paper.
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| 5. |
- Kvarnlöf, Niklas, 1971-
(författare)
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Activation of dissolving pulps prior to viscose preparation
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The conventional viscose manufacturing process is a mature process that needs to be improved with respect to its environmental impact and its production cost structure. Therefore a research study has been done with the aim to improve the reactivity of the dissolving pulp used, in order to reduce the chemical demand in the viscose process and thus reduce the cost and indirectly the environmental impact.The work described in this thesis has shown that it is possible to enhance the pulp reactivity and to use less carbon disulphide in the production of viscose, while maintaining a good quality viscose dope, by two entirely different pretreatment methods, one chemical and one enzymatic.The chemical method used pressurized oxygen after the mercerisation step, which increased the reactivity of the alkali cellulose. The viscose dopes produced from the pressurized oxygen treated alkali cellulose had lower filter clogging values, Kw, compared to conventionally produced viscoses. The temperature and the oxygen treatment time of the alkali cellulose were however crucial for the viscose quality.The best performing enzyme of several tested was a cellulase of the mono component endoglucanase preparation Carezyme®. This enzymatic treatment was optimized with respect to viscose dope preparation. The study showed that the enzyme treatment could be carried out under industrially interesting conditions with respect to temperature, enzyme dose and reaction time. A re-circulation study of the enzyme showed that it was possible to re-use the spent press water from the enzymatic treatment step several times, and thus lower the production cost. Some of the viscose process stages were modified to properly fit the enzymatically treated dissolving pulp and a comparison between viscose made from enzyme-treated pulp and viscose made from conventional pulp, showed that the enzyme-treated samples had a lower filter clogging value, Kw. This indirectly indicates that the enzyme pretreatment could reduce the carbon disulphide charge in the viscose manufacturing process. An initial study of how the Carezyme® influenced different cellulosic sources was also performed.
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| 6. |
- Pérez Prieto, Héctor
(författare)
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HISTORIEN OM RÄVEN OCH ANDRA BERÄTTELSER : Om klasskamrater och skolan på en liten ort – ur ett skol- och livsberättelse perspektiv
- 2006
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Pérez Prieto, Héctor 1999: Historien om räven och andra berättelser. Om klasskamrater och skolan på en liten ort – ur ett skol- och livsberättelseperspektiv. Pedagogisk Forskning i Uppsala, nr 37, januari 2000.Berättelser om mötet med klasskamraterna och vad det innebar att växa upp och gå i skola i Åby, en liten jord- och skogsbrukspräglad ort står i fokus för rapporten. Berättelserna skapades med hjälp av livshistorie-intervjuer med fyra ungdomar, som har gått i samma klass under hela skoltiden, tio år efter att de hade avslutat skolan. De f.d. elevernas berättelser organiseras och presenteras med hjälp av både en individuell livsberättelse och en mosaik formad av samtliga ungdomars kollektiva och personliga minnen. Identitetskonstruktionen är central i berättelserna: De lyfter fram hur dessa ungdomar i interaktion med varandra hanterade de omständigheter under vilka de levde och i och med det agerandet formade sig själva och bidrog till konstruktionen av dessa omständigheter, men också om hur de i efterhand, ’med facit i handen’ väljer att framställa sig själva och den kontext i vilken de levde.Den bild av skolan som berättelserna ger grundas på elevernas agerande och erfarenheter och den lyfter fram hur klasskamraternas agerande konstruerade klassens stökighet, dess väl sammansvetsade grupperingar och dess ointresse för studierna, dvs. hur de med sitt agerande konstituerade de konkreta förutsättningar för kunskapsinhämtande, vidare studier, gemenskap och identitetsskapande.
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| 7. |
- Svanholm, Erik, 1975-
(författare)
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Printability and Ink-Coating Interactions in Inkjet Printing
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Inkjet is a digital printing process where the ink is ejected directly onto a substrate from a jet device driven by an electronic signal. Most inkjet inks have a low viscosity and a low surface tension, which put high demands on the coating layer’s porosity and absorbency characteristics.The aim of this study has been to gain an increased knowledge of the mechanisms that control the sorption and fixation of inkjet inks on coated papers. The focus has been on printability aspects of high print quality (although not photographic quality) laboratory-coated inkjet papers for printers using aqueous-based inks.Papers coated solely with polyvinyl alcohol (PVOH) and starch presented excellent gamut values and good print sharpness over the uncoated substrate, due to good film-forming characteristics observed by light microscopy and ESCA. ESEM analyses showed the complexity and variation of PVOH surface structures, which has probably explained the wide scatter in the colour-to-colour bleed results. Pure PVOH coatings also gave a surface with high gloss variations (2-8 times greater than that of commercial inkjet papers), prolonged ink drying time, and cracked prints when using pigmented inks. When an amorphous silica gel pigment (with broad pore size distribution) was used in combination with binder, a new structure was formed with large pores in and between the pigments and a macro-roughness generated by the large particles. The inkjet ink droplets could quickly penetrate into the large pores and the time for surface wicking was reduced, which was beneficial for the blurriness. However, the macro-roughness promoted bulk spreading in the coarse surface structure, and this tended to increase the line width. Finally, when the ink ends up within the coating, the colorant is partly shielded by the particles, and this reduced the gamut area to some extent. The binder demand of the silica pigments was strongly related to their pore size distributions. Silica gel required two to three times the amount of binder compared to novel surfactant-templated mesoporous silica pigments (with small pores and narrow pore size distribution). This finding was attributed to the significant penetration of PVOH binder into the pores in the silica gel, thereby, increasing its binder demand. Furthermore, this binder penetration reduced the effective internal pore volume available for rapid drainage of the ink vehicle. Consequently, the surfactant-templated pigments required significantly lower amounts of binder, and gave improvements in print quality relative to the commercial pigment.
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| 8. |
- Alfredsson, Stefan, 1976-
(författare)
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TCP in Wireless Networks: Challenges, Optimizations and Evaluations
- 2005
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis presents research on transport layer behavior in wireless networks. As the Internet is expanding its reach to include mobile devices, it has become apparent that some of the original design assumptions for the dominant transport protocol, TCP, are approaching their limits. A key feature of TCP is the congestion control algorithm, constructed with the assumption that packet loss is normally very low, and that packet loss therefore is a sign of network congestion. This holds true for wired networks, but for mobile wireless networks non-congestion related packet loss may appear. The varying signal power inherent with mobility and handover between base-stations are two example causes of such packet loss. This thesis provides an overview of the challenges for TCP in wireless networks together with a compilation of a number of suggested TCP optimizations for these environments. A TCP modification called TCP-L is proposed. It allows an application to increase its performance, in environments where residual bit errors normally give a degraded throughput, by making a reliability tradeoff. The performance of TCP-L is experimentally evaluated with an implementation in the Linux kernel. The transport layer performance in a 4G scenario is also experimentally investigated, focusing on the impact of the link layer design and its parameterization. Further, for emulation-based protocol evaluations, controlled packet loss and bit error generation is shown to be an important aspect.
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| 9. |
- Algervik, Robert, 1981-
(författare)
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Embedding Theorems for Mixed Norm Spaces and Applications
- 2008
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis is devoted to the study of mixed norm spaces that arise in connection with embeddings of Sobolev and Besov type spaces. The work in this direction originates in a paper due to Gagliardo (1958), and was continued by Fournier (1988) and by Kolyada (2005). We consider fully anisotropic mixed norm spaces. Our main theorem states an embedding of these spaces into Lorentz spaces. Applying this result, we obtain sharp embedding theorems for anisotropic fractional Sobolev spaces and anisotropic Sobolev-Besov spaces. The methods used are based on non-increasing rearrangements and on estimates of sections of functions and sections of sets. We also study limiting relations between embeddings of spaces of different type. More exactly, mixed norm estimates enable us to get embedding constants with sharp asymptotic behaviour. This gives an extension of the results obtained for isotropic Besov spaces $B_p^\alpha$ by Bourgain, Brezis, and Mironescu, and for Besov spaces $B^{\alpha_1,\dots,\alpha_n}_p$ by Kolyada. We study also some basic properties (in particular the approximation properties) of special weak type spaces that play an important role in the construction of mixed norm spaces and in the description of Sobolev type embeddings.
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| 10. |
- Alriksson, Björn
(författare)
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Ethanol from lignocellulose : Management of by-products of hydrolysis
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Fuel ethanol can be produced from lignocellulosic materials, such as residues from agriculture and forestry. The polysaccharides of lignocellulose are converted to sugars by hydrolysis and the sugars can then be fermented to ethanol using microorganisms. However, during hydrolysis a wide range of by-products are also generated. By-product formation can affect ethanol yield and productivity. Management of by-products of hydrolysis is therefore important in the development of commercially viable production of cellulosic ethanol. Detoxification of inhibitory dilute-acid lignocellulose hydrolysates by treatment with Ca(OH)2 (overliming) efficiently improves the fermentability, but is associated with drawbacks like sugar degradation and CaSO4 precipitation. In factorial designed experiments, in which pH and temperature were varied, dilute-acid spruce hydrolysates were treated with Ca(OH)2, NH4OH or NaOH. The concentrations of sugars and inhibitory compounds were measured before and after the treatments. The fermentability was examined using the yeast Saccharomyces cerevisiae and compared with reference fermentations of synthetic medium without inhibitors. The treatment conditions were evaluated by comparing the balanced ethanol yield, which takes both the degradation of sugars and the ethanol production into account. Treatment conditions resulting in excellent fermentability and minimal sugar degradation were possible to find regardless of whether Ca(OH)2, NH4OH or NaOH was used. Balanced ethanol yields higher than those of the reference fermentations were achieved for hydrolysates treated with all three types of alkali. As expected, treatment with Ca(OH)2 gave rise to precipitated CaSO4. The NH4OH treatments gave rise to a brownish precipitate but the amounts of precipitate formed were relatively small. No precipitate was observed in treatments with NaOH. The findings presented can be used to improve the effectiveness of alkali detoxification of lignocellulose hydrolysates and to minimize problems with sugar degradation and formation of precipitates. Overexpression of different S. cerevisiae genes was investigated with the aim to engineer a biocatalyst with increased inhibitor tolerance. Overexpression of YAP1, a gene encoding a transcription factor, conveyed increased resistance to lignocellulose-derived inhibitors as well as to a dilute-acid hydrolysate of spruce. Recombinant Aspergillus niger expressing the Hypocrea jecorina endoglucanase Cel7B was cultivated on spent lignocellulose hydrolysate (stillage). The fungus simultaneously removed inhibitors present in the stillage and produced higher amounts of endoglucanase than when it was grown in a standard medium with comparable monosaccharide content. The concept can be applied for on-site production of enzymes in a cellulose-to-ethanol process and facilitate recycling of the stillage stream.
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| 11. |
- Alriksson, Björn, 1979-
(författare)
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Ethanol from lignocellulose : Alkali detoxification of dilute-acid spruce hydrolysates
- 2006
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Detoxification of dilute-acid lignocellulose hydrolysates by treatment with Ca(OH)2 (overliming) efficiently improves the production of fuel ethanol, but is associated with drawbacks like sugar degradation and CaSO4 precipitation. In factorial designed experiments, in which pH and temperature were varied, dilute-acid spruce hydrolysates were treated with Ca(OH)2, NH4OH or NaOH. The concentrations of sugars and inhibitory compounds were measured before and after the treatments. The fermentability was examined using the yeast Saccharomyces cerevisiae and compared with reference fermentations of synthetic medium without inhibitors. The treatment conditions were evaluated by comparing the balanced ethanol yield, which takes both the degradation of sugars and the ethanol production into account. Treatment conditions resulting in excellent fermentability and minimal sugar degradation were possible to find regardless of whether Ca(OH)2, NH4OH or NaOH was used. Balanced ethanol yields higher than those of the reference fermentations were achieved for hydrolysates treated with all three types of alkali. As expected, treatment with Ca(OH)2 gave rise to precipitated CaSO4. The NH4OH treatments gave rise to a brownish precipitate but the amounts of precipitate formed were relatively small. No precipitate was observed in treatments with NaOH. The possibility that the ammonium ions from the NH4OH treatments gave a positive effect as an extra source of nitrogen during the fermentations was excluded after experiments in which NH4Cl was added to the medium. The findings presented can be used to improve the effectiveness of alkali detoxification of lignocellulose hydrolysates and to minimize problems with sugar degradation and formation of precipitates.
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| 12. |
- Altun, Zeki, 1978-
(författare)
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New Techniques for Sample Preparation in Analytical Chemistry : Microextraction in Packed Syringe (MEPS) and Methacrylate Based Monolithic Pipette Tips
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Sample preparation is often a bottleneck in systems for chemical analysis. The aim of this work was to investigate and develop new techniques to address some of the shortcomings of current sample preparation methods. The goal has been to provide full automation, on-line coupling to detection systems, short sample preparation times and high-throughput. In this work a new technique for sample preparation that can be connected on-line to liquid chromatography (LC) and gas chromatography (GC) has been developed. Microextraction in packed syringe (MEPS) is a new solid-phase extraction (SPE) technique that is miniaturized and can be fully automated. In MEPS approximately 1 mg of sorbent material is inserted into a gas tight syringe (100-250 μL) as a plug. Sample preparation takes place on the packed bed. Evaluation of the technique was done by the determination of local anaesthetics in human plasma samples using MEPS on-line with LC and tandem mass spectrometry (MS-MS). MEPS connected to an autosampler was fully automated and clean-up of the samples took about one minute. In addition, in the case of plasma samples the same plug of sorbent could be used for about 100 extractions before it was discarded. A further aim of this work was to increase sample preparation throughput. To do that disposable pipette tips were packed with a plug of porous polymer monoliths as sample adsorbent and were then used in connection with 96-well plates and LC-MS-MS. The evaluation of the methods was done by the analysis of local anaesthetics lidocaine and ropivacaine, and anti-cancer drug roscovitine in plasma samples. When roscovitine and lidocaine in human plasma and water samples were used as model substances, a 96-plate was handled in about two minutes. Further, disposable pipette tips may be produced at low cost and because they are used only once, carry-over is eliminated.
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| 13. |
- Altun, Zeki
(författare)
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New Techniques for Sample Preparation in Analytical Chemistry
- 2005
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Sample preparation is often a bottleneck in systems for chemical analysis. The aim of this work was to investigate and develop new techniques to address some of the shortcomings of current sample preparation methods. The goal has been to provide full automation, on-line coupling to detection systems, short sample preparation times and high-throughput. A new technique for sample preparation that can be connected on-line to liquid chromatography (LC) and gas chromatography (GC) has been developed. Microextraction in packed syringe (MEPS) is a new solid-phase extraction (SPE) technique that is miniaturized and can be fully automated. In MEPS approximately 1 mg of sorbent material is inserted into a gas tight syringe (100-250 μL) as a plug. Sample preparation takes place on the packed bed. Evaluation of the technique was done by the determination of local anaesthetics in human plasma samples using MEPS on-line with LC and tandem mass spectrometry (MS-MS). MEPS connected to an autosampler was fully automated and clean-up of the samples took one minute. In addition, in the case of plasma samples the same plug of sorbent could be used for about 100 extractions before it was discarded. A further aim of this work was to increase sample preparation throughput. To do that disposable pipette tips were packed with a plug of porous polymer monoliths as sample adsorbent and were then used in connection with 96-well plates and LC-MS-MS. When roscovitine in human plasma and water samples was used as model substance, a 96-plate was handled in two minutes.
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| 14. |
- Anderberg, Patrice, 1967-
(författare)
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Bevarad värdighet vid vård av äldre personer på äldreboende
- 2009
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Andelen äldre personer kommer i framtiden att öka och behovet av en god och värdig vård blir en utmaning inom den kommunala äldreomsorgen. I samband med att vård utvärderas relateras det ofta till bevarad eller kränkt värdighet. Begreppet värdighet är ett grundbegrepp inom omvårdnad som är något fundamentalt och självklart hos alla människor. Upplevelsen av bevarad värdighet är beroende av i vilken utsträckning viktiga värden kan uppnås. Media skriver om att kränkningar förekommer i vården av äldre som bor och lever på äldreboende. I vilken mån upplevelsen av värdighet kan återfås efter en kränkning är beroende av om en försoning med situationen kan ske. Avsikten med studien var att utifrån litteratur beskriva innebörden av begreppet bevarad värdighet och vidga förståelsen för den äldre personens erfarenheter av vård och hjälp samt hur livet förändras på äldreboende. I de två delstudierna framkommer nya dimensioner av begreppet bevarad värdighet och när vårdaren är inkännande och lyssnar till den äldres berättelse framträder bevarad värdighet. I beskrivningen av hur äldre personer erfar att vara i behov av vård och hjälp de sista levnadsåren synliggörs att de strävar efter att behålla en inre känsla av stolthet. Vården bör vara planerad och utformad så att den äldre kan komma tillrätta när kroppen och livssituation förändras och de blir i behov av vård och omsorg.
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| 15. |
- Andersson, Björn, 1978-, et al.
(författare)
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Skolbränder och skolbrandsprevention : Underlag för planerade insatser enligt ”Karlstadsmodellen”
- 2009
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Kan man förebygga anlagda bränder och annan skadegörelse i skolor med miljöinriktade åtgärder? Den bedömningen gör man i Karlstads kommun med stöd i kriminologisk teori och erfarenheter från andra sektorer. Den traditionella ansatsen är annars är att kombinera brandtekniska åtgärder med ett mer individorienterat perspektiv riktat mot gärningspersoner. Syftet med föreliggande rapport är att ge en djupare belysning av den teoretiska grundvalen för en bredare miljöinriktad strategi, samt att peka på möjligheter att följa och utvärdera effekter av en lokal tillämpning. I bilaga redovisas även en forskningsöversikt kring den vetenskapliga evidens som idag föreligger beträffande miljöinriktad brottsprevention.
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| 16. |
- Andersson, Christer, 1975-
(författare)
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Design and Evaluation of Anonymity Solutions for Mobile Networks
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Internet and mobile communications have had a profound effect on today's society. New services are constantly being deployed, in which personal data are being processed in return for personally tailored services. While mobile networks lay the groundwork for new innovative services, at the same time they pose numerous privacy challenges. There is the risk that honest citizens participating in mobile communications will have their privacy invaded for "the greater good". We argue that it is highly important that individuals are empowered to retain control over their personal spheres. Thus, the goal of this thesis is to design and evaluate anonymous overlay networks} adapted for mobile networks that allow users to control which information leaves their personal spheres in a mobile communication. Technically, by using an anonymous overlay network, users can communicate with their communication partners without disclosing their network identities. In this thesis, we propose three different anonymous overlay networks tailored for mobile networks. First, two approaches are proposed for anonymous browsing on the mobile Internet, namely mCrowds and a Tor-based approach. By applying theoretical analysis and\,/\,or practical experiments, we show that these approaches offer an appropriate trade-off between the offered degree of anonymity and performance loss. Second, an anonymous overlay network for use in mobile ad hoc networks - Chameleon - is suggested. Besides the actual design of these anonymous overlay networks, this thesis provides novel contributions in other essential areas of privacy protection and anonymous communication. First, also non-technical aspects of privacy protection are thoroughly discussed, including legal, social, and user interface aspects. Second, we survey existing metrics for quantifying anonymity and also propose new ideas regarding anonymity metrics. Third, we review and classify existing mechanisms for anonymous communication in mobile ad hoc networks. Lastly, we also propose a cryptographic technique for building up the user base of an anonymous overlay network in a secure and privacy-friendly manner.
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| 17. |
- Andersson, Christer, 1975-
(författare)
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Enhancing Privacy for Mobile Networks : Examples of Anonymity Solutions and Their Analysis
- 2005
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Internet and mobile communications have had a profound effect on today’s society. New services are constantly being deployed, in which an increasing amount of personal data is being processed in return for personally tailored services. Further, the use of electronic surveillance is increasing. There is the risk that honest citizens will have their privacy invaded for “the greater good”. We argue that it is of uttermost importance to retain the individuals’ control over their personal spheres. One approach for enhancing the users’ privacy is to deploy technical measures for safeguarding privacy, so-called Privacy-Enhancing Technologies (PETs). This thesis examines a set of PETs for enabling anonymous communication, so-called anonymous overlay networks,which eliminate the processing of personal data altogether by allowing the users act anonymously when communicating in a networked environment. This thesis focuses mainly on mobile networks. These are of great interest because on the one hand they lay the groundwork for new innovative applications, but on the other hand they pose numerous novel challenges to privacy. This thesis describes the implementation and performance evaluation of mCrowds – an anonymous overlay network for mobile Internet that enables anonymous browsing. It also describes the ongoing investigation on how to design anonymous overlay networks in order to make them suitable for mobile ad hoc networks, a required building block for ambient intelligence.
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| 18. |
- Andersson, Jan-Olov, 1966-
(författare)
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A GIS-based landscape analysis of dissolved organic carbon in boreal headwater streams
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In boreal catchments, stream water chemistry is influenced and controlled by several landscape factors. The influence of spatially distributed variables is in turn dependent on the hydrological scale. Headwater streams have larger variability of water chemistry, and thus together represent a large biodiversity, and therefore need to be monitored in official environmental assessments. One objective of this study was, using Geographical Information Systems (GIS), to analyse co-variation between landscape variables and water chemistry and to determine which of the landscape variables have a major influence on the concentration of dissolved organic carbon (DOC) in headwater streams. Another objective was to find a simple method for predicting sources of DOC, using official map data and publically available GIS applications. Totally 85 headwater catchments (0.1-4 km2) in the county of Värmland, western south Sweden, were used in the study. Water chemistry was analysed for water sampled at low, medium and high flows, and landscape variables were extracted from official map data sources: topographic maps, a digital elevation model (DEM, 50 m grid), and vegetation data. Statistical analyses showed that topography (mean slope and mean topographic wetness index (TWI)) and wetland cover often correlated well with DOC in headwater catchments. Official map data could satisfactorily extract landscape variables (mean slope, mean TWI) that were useful in predicting stream water chemistry (DOC). A high-resolution elevation model, which was generated by interpolation of photogrammetric data, was used to calculate and evaluate two different wetness indices and their ability to predict the occurrence of wetlands in six catchments of different sizes and topography. The SAGA (System for Automated Geoscientific Analyses) wetness index (SWI) gave substantially better results than the TWI. The effects of resolution of DEMs on calculations of the SWI were investigated using 5, 10, 25 and 50 m grids. The results showed that SWI values increased with increasing cell size. The near linear increment of mean values for resolutions 10-50 m suggests a independence of terrain type and catchment size, which supported previous findings that indicated that mean slope and mean wetness index calculated from coarse elevation models may be used for prediction of DOC in headwater streams.
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| 19. |
- Andersson, Roger, 1969-
(författare)
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Teaching and learning geometrical optics with computer assisted instruction : changing conceptions about vision, image and ray
- 2007
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The information and communication technology, ICT, is opening new possibilities for the educational arena. Previous research shows that achieving positive educational outcomes requires more than simply providing access to computer hardware and software. How does this new technology affect the teaching and learning of physics? This thesis focuses on the field of geometrical optics. It reports two studies, both in Swedish upper secondary school. Important for the use of the ICT in physics education is the teaching strategy for using the new technology. The first study investigates with a questionnaire, how 37 teachers in a region of Sweden use computers in physics education and what intentions they follow while doing so. The results of this study show that teachers’ intentions for using ICT in their physics teaching were to increase students' interest for physics, to increase their motivation, to achieve variation in teaching, and to improve visualization and explanation of the phenomena of physics. The second study investigates students’ conceptual change in geometrical optics during a teaching sequence with computer-assisted instruction. For this purpose we choose the computer software "Constructing Physics Understanding (CPU)", which was developed with a base in research on students conceptions in optics. The thesis presents the teaching sequence developed together with the teacher. The study is based on a constructivist view of learning. The concepts analysed in this study were vision, image, ray and image formation. A first result of this study is a category system for conceptions around these concepts, found among the students. With these categories we found that students even at this level, of upper secondary school, have constructed well-known alternative conceptions before teaching, e.g. about a holistic conception of image. The results show also some learning progress: some alternative conceptions vanish, in some cases the physics conceptions are more often constructed after teaching. The students and the teacher also report that the CPU program gave new and useful opportunities to model multiple rays and to model vision.
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| 20. |
- Arvidson, Markus
(författare)
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Den fabricerande människan : Om bedrägeri som vardaglig interaktionsform
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The present dissertation takes the multi-faceted phenomenon of deception as its point of departure. The aim is to make a case for deception as a social phenomenon, and to frame theoretically and define the skills and abilities that make deception possible.A theoretical model based on a number of ideal types is constructed. The purpose of the model is to differentiate particular aspects of deception, and the model is illustrated with examples of actions of more or less well-known impostors. The examples were collected from a variety of sources, such as autobiographies and television programs.As a first step, the legal definition of deception, i.e. fraud, and statistics on crimes of deception in Sweden are presented. Different theoretical approaches are also discussed; deception as a personality trait, and deception as communication and interaction.In order to illuminate the social dimensions, it is emphasized that deception constitutes a particular type of relationship between deceiver and deceivee. This particular form of interaction exploits elementary forms, and it is also asymmetrical in terms of the intentions of the parties involved.The concept of social competence is used to describe the skills and abilities required for successful acts of deception. It is argued that the social competence of deceivers consists of three types: strategic, normative, and dramaturgic competencies. The strategic competency involves being goal-rational and strategic, for example, the ability to predict the actions of the potential addressee. In the normative competency, norms and reference to norms are used strategically. The dramaturgic competency represents an operationalization and enactment of the two other competencies, and resembles the preparation and performance of an actor.The different contexts in which deception can occur are also discussed. A preliminary typology is presented, with the aim of demonstrating the difficulties in drawing clear lines between various types of deception. The extended approach to deception also means that it can be viewed as a part of everyday social interaction.Finally, some thoughts on deception in the light of societal changes are presented. It is argued that the increasing demands on people to promote themselves in various ways in today’s society can be perceived as an invitation to deception and fabrication. These demands can generate feelings of inferiority and a fear of eventually being unmasked as an impostor, or a phony.
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| 21. |
- Arvidsson, Björn, 1952-, et al.
(författare)
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Flodpärlmussla - vad behöver vi göra för att rädda arten? : En workshop på Karlstads universitet
- 2006
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Flodpärlmusslans situation i Sverige är bekymmersam, och i en stor del av de återstående populationerna sker ingen nyrekrytering av små musslor. För att belysa kunskapsläget om flodpärlmusslans situation och för att diskutera olika åtgärdsmöjligheter genomfördes i november 2005 en work shop vid Karlstads universitet med deltagande av naturvårdare från olika myndigheter och forskare. Vid mötet presenterades aktuell forskning i Skandinavien och olika uppföljningar som sker i olika myndigheters regi. Mötet bekostades av länsstyrelsen i Västernorrland, som fått ett nationellt ansvar att ta fram ett åtgärdsprogram för arten. I denna sammanställning redovisas en del av de föredrag och diskussioner som förekom vid mötet.
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| 22. |
- Arvidsson, Björn, 1952-, et al.
(författare)
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Förändringar och kontinuitet i vardagslivets Värmland
- 2008
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Den här studien ingår i Karlstads universitets och fakultetens för samhälls- och livsvetenskaper satsning på mångvetenskaplig forskning om "uthålliga livsmiljöer och komplexa nätverk". Målet med fakultetens satsning är att stimulera forskning och samverkan mellan offentliga och privata aktörer så att Karlstads universitet effektivt kan bidra till och bli en motor i det långsiktigt hållbara utvecklingsarbetet i regionen. Studien tar sin utgångspunkt i intervjuer med några värmländska familjer om hur vardagen gestaltar sig idag, hur det såg ut historiskt och hur det kan tänkas se ut i framtiden. Intervjuerna kommenteras av forskare från olika ämnesområden. I mötet mellan forskare från olika ämnen och forskningstraditioner uppstår nya sätt att problematisera det komplicerade växelspelet mellan olika sektorer av vår tillvaro. Problemen kan omformuleras, nya möten och kontakter vänder invanda tankegångar mot nya och innovativa riktningar och beredskapen att möta framtida utmaningar såväl för forskare som för regionala aktörer stärks och uppgraderas. Förhoppningen är att studien ska fungera som en plattform för den viktiga diskussionen kring uthållig regional utveckling för kvinnor, män, barn och gamla och stimulera innovationer och forskning som garanterar en framtid där utveckling och tillväxt balanseras mot uthållig miljö för människor och natur.
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| 23. |
- Augustsson, Christian, 1966-
(författare)
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Unga idrottares upplevelser av föräldrapress
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Over the last decades intense debates have taken place, in the mass media, regarding the child-parent relation within sport. Questions have been raised if parent’s involvement can be a source of pressure for children and youth. In Sweden relatively little research have been undertaken to study this problem.Therefore the aim of this thesis is:- to describe and analyse children’s and youth’s experiences of parental involvement within the sport milieu, focusing on parental pressure.The purpose has also led to the following formulated problems:- How do children and youth experience parent’s presence, actions and open reactions toward young athletes in the sport milieu?- What does it mean for young athletes to experience parental pressure?Parents can unintentionally impose pressure on children just by trying too hard to be a good sport parent. Earlier research has proposed that young athletes experience pressure from parents when there is an imbalance between the experienced intensity in the parental involvement and what they desire. Given this background parental pressure was defined as: young athlete’s experiences of feelings of insufficiency in sport, which is emanated from parent’s, both hidden and outspoken, demands and expectations to achieve within the sport milieu”. For this thesis a critical factor in the theoretical framework is young athlete’s subjective experiences of parents, and especially parental pressure, in the public sport milieu.The data collection consisted of both questionnaires and interviews. The respondents (n=601, age 8 to 16) were selected from twelve of the most popular sports for children and youth (football, handball, swimming, equestrian sport, tennis, floor hockey, athletics, golf, ice hockey, gymnastics, figure skating and table tennis. The data from the interviews was collected from a sample of twelve young athletes (age 10 to14).The results showed support for how children in general are happy and satisfied with their parent’s involvement (81%). However it was also found that there was a minority group of 19% that indicated experiences of high parental pressure. In the results there were also tendencies that showed how certain sports (tennis, swimming, golf and equestrian sport) scored higher on the parental pressure scale than others. The respondents who scored low (under the mean) on the self-perception scale showed tendencies to score high on the parental pressure scale (Rho= -.38, p<.01). The factors connected to parental pressure, highlighted in the interviews, were also emphasized in an open-ended question.Stronger guiding principles, reinforced motivation and designed education dealing with these subjects in organised sport are inevitable. Otherwise organised youth sport will never succeed in oppressing the primary sources of children’s experiences of parental pressure.
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| 24. |
- Axelsson, Jonas, 1974-
(författare)
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Dominanser : En utveckling av den realistiska livsformsteorin
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The present dissertation develops a specific theory about everyday life called realist life mode theory. This theory is based on critical realism and consists of "work", "love" and "life mode" as central concepts. The background of the theory is the Danish life mode analysis developed by Thomas Højrup in the 1980:s. The aim of the study is to develop the central clusters of concepts in the realist life mode theory - i. e. "work", "love", "life mode" in a theoretical way. These concepts are seen as clusters since other related concepts are developed in connection to the concepts mentioned above. In connection to work I also discuss the concepts of "labour power", "labour receptor", and "work form"; in relation to love, "love power", "love receptor" and "love form" are discussed. And "life mode" is connected with the concept of "everyday life" in a more exact way than before. The argument of this study is that realist life mode theory is about two fundamental types of dominance - personal dominance and structural dominance. "Personal dominance" is used synonymously with "ownership". "Structural dominance" is dominance between non-personal, non-conscious entities. Life mode theory is a theory about ownership surrounded by structural dominances both beneath the owning person (sub-personally), and above (socially). Personal dominance - ownership - is produced via two human and societal processes - work and love. Work is defined as doing and occuring in the sphere of necessity. In work there especially are possibilities for ownership of the material surroundings. Love is defined as doing and occuring in the sphere of freedom. In love humans produce each other as self-owned persons through transaction of love power. Both work and love has great emancipatory potentials, and this theme is discussed in the present study. But, unfortunately, really existing work and love practices are to a great extent exploitative. Labour power is exploited in capitalism, and love power in patriarchy. When it comes to structural dominance, this study focuses on the following dominances: The dominance of labour receptor over labour power in men´s working life; the dominance of love power over love receptor in women´s love life. The dominance of work over love in men´s everyday life; the dominance of love over work in women´s everyday life. And on a more social level we find the following dominances: in the male life modes the work form dominates the love form. In female life modes the love form dominates the work form. And finally, in society as a whole male life modes have dominance over female life modes. When the dominance between social structures is analyzed, a distinction is made between "dominance form" and "the substance of dominance".
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| 25. |
- Bellström, Peter
(författare)
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View Integration in Conceptual Database Design : Problems, Approaches and Solutions
- 2006
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- View integration is a complex and time-consuming task because there are several problems that need to be addressed. Two such problems are conflict identification and conflict resolution. Conflicts occur because end users may define concepts on different levels of abstraction and because end users may name concepts differently. Therefore there is a need for methods that can cope with these problems when applying the chosen conceptual modeling language. The aim of this thesis is to develop a method for view integration in conceptual database design in which the dependencies of the Enterprise Modeling approach are applied. For this purpose four research studies have been conducted and each study is presented in one paper. In the first study the problem of semantic loss during view integration is addressed; in the second, the problems of identification and resolution of the homonym conflicts are addressed; in the third, the problem of how to define both databases and software components using Enterprise Modeling as a generic and integrated approach are addressed; and finally, in the fourth study, the problems of applying inference rules for conflict simplification or resolution and for interschema property simplification or resolution are addressed. These research studies together with the five introductory chapters contribute to answering the overall research question: In what way is view integration supported by applying the semantic dependencies of the Enterprise Modeling approach? In this thesis it is argued that using the dependencies of the Enterprise Modeling approach simplifies the view integration process and using the proposed resolution techniques for name conflicts reduces the possibility of semantic loss occurring.
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