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  • 401.
    van Hees, P. A. W.
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Danielsson, R.
    Department of Analytical Chemistry, Uppsala University, P.O. Box 531, S-751 21 Uppsala.
    Nyberg, L.
    Department of Environmental Sciences, University of Karlstad, S-651 88 Karlstad.
    Controlling mechanisms of aluminium in soil solution: An evaluation of 180 of podzolic forest soils2001In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 45, no 6-7, p. 1091-1101Article in journal (Refereed)
    Abstract [en]

    To monitor the level of soil acidification in the county of Värmland in the middle west of Sweden 180 podzolic forest soils were investigated. Soil solutions from four horizons were obtained by centrifugation and the soil was sampled for a determination of the exchangeable pool by extraction. The concentrations of inorganic Al and its fraction of the total Al in solution were greater in the south of the county (up to 50%). The factors influencing the total Al and free inorganic Al3+ in the soil solutions were evaluated. Saturation indices (SI) for five different mineral phases were calculated but none implied equilibrium conditions. The relationships between pAl3+ and pH (in the pH range 4-6.2) gave slopes of about 1, which indicated that ion exchange/complexation reactions may be important for determining the Al3+ concentration in the B and C horizons. In the E horizon solutions complexation with soluble organic acids seemed to be the major factor which influenced the Al3+ activity. The influence of organic matter on Al solubility was supported by partial least square (PLS) regressions.

  • 402.
    van Hees, P. A. W.
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Giesler, R.
    Low molecular weight acids and their Al-complexes in soil solution- Composition, distribution and seasonal variation in three podzolized soils.2000In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 94, no 2-4, p. 173-200Article in journal (Refereed)
    Abstract [en]

    Low molecular weight organic acids have been determined qualitatively and quantitatively over a growing season in the soil solution of three podzolized soil profiles. Several low molecular weight (LMW) acids such as citric, shikimic, oxalic, fumaric, formic, acetic, malonic, malic, lactic and t-aconitic acids were identified in the range < 1-1100 μM. Citric acid was the acid generally present at the highest concentrations (15-250 μM) in the upper layers while shikimic and oxalic acids could be observed in all horizons at lower concentrations. The levels of LMW organic acids were always greatest in the organic (O) horizon, and declined in the deeper layers. The fraction of the dissolved organic carbon and total acidity made up by LMW acids was generally in the range 0.5-5% and 0.5-15%, respectively. No apparent seasonal variations were observed, and the differences between the sites were little. The fraction of Al in soil solution bound to LMW organic acids was evaluated using ultrafiltration (< 1000D) and size exclusion chromatography. Fe < 1000D was also determined. For the O1 horizon about 40% and 20% of the Al and Fe, respectively, were detected in the LMW fraction (< 1000D). The LMW fraction of the two elements decreased deeper down in the profile, but relative increases were sometimes observed in the B1 horizon. Labile and LMW (< 1000D) Si were determined by FIA and ultrafiltration, respectively. The results show that a major fraction (80-100%) of the Si is labile and of low molecular weight, most likely silicic acid. (C) 2000 Elsevier Science B.V.

  • 403.
    van Hees, P. A. W.
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Starr, M.
    Giesler, R.
    Factors influencing aluminium concentrations in soil solution of podzols2000In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 94, no 2-4, p. 289-310Article in journal (Refereed)
    Abstract [en]

    Mechanisms controlling the concentrations of free Al3+ and total Al in the soil solution from three podzolic soils were evaluated. Saturation indices (SI) were calculated for five mineral phases, but no single phase determined the Al3+ activity. E horizon samples were found to be undersaturated with respect to all phases. A more detailed equilibrium study indicated that formation of proto-imogolite sols was commonly possible in B horizon solutions with pH > 5. The poor relationship between pH and pAl3+ in the E and B1 horizons did not support control by exchange reactions with solid organic matter, although partial least square (PLS) regressions indicated importance of soil-exchangeable Al in the B and C horizons. It was concluded that in the E and most of the B1 horizon solutions, Al3+ activity is controlled by equilibrium with soluble organic acids which was supported by the PLS regressions. (C) 2000 Elsevier Science B.V.

  • 404.
    van Hees, P. A. W.
    et al.
    Örebro University.
    Rosling, A.
    Swedish University of Agricultural Sciences (SLU), Uppsala.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Finlay, R. D.
    Swedish University of Agricultural Sciences (SLU), Uppsala.
    The biogeochemical impact of ectomycorrhizal conifers on major soil elements (Al, Fe, K and Si)2006In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 136, no 1-2, p. 364-377Article in journal (Refereed)
    Abstract [en]

    Mobilisation of nutrients and dissolution of minerals are of key importance for plant growth and soil formation, as well as long term ecosystem sustainability. The effects of Pinus sylvestris seedlings, ectomycorrhizal colonisation and potassium supply on the mobilisation of Al, Fe, K and Si were studied in a soil column experiment. Budgets were constructed considering amounts in drainage water, accumulation in plants and changes in the pools of exchangeable ions (BaCl2 extractions). Drainage was the most important sink under the experimental conditions imposed, but the other two pools were also of quantitative significance. Plants had a significant positive effect on the total quantities of all elements mobilized. Mycorrhizal colonisation had limited quantitative impact on the mobilization, probably because the chosen mycorrhizal fungi did not cause any growth promotion in this experiment. Despite this, a multivariate analysis (PCA) showed a clear separate grouping of mycorrhizal, non-mycorrhizal and no-plant treatments, and in particular Si and K mobilization was related to soil biological variables which in turn were affected by the presence of mycorrhiza. When K was omitted from the watering solution, plants were able to mobilise significantly more K, which was reflected in plant uptake and a potential replenishment of the exchangeable pool. Up-scaling of total Al, K and Si mobilization to field conditions resulted in rates between equal to and up to 10 times higher than the average historical weathering rate.

  • 405.
    Van Hees, P
    et al.
    aMan–Technology–Environment Research Centre, Department of Natural Sciences, Örebro University.
    Jones, D.L.
    Finlay, R
    Godbold, D.L.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Information Technology and Media.
    The carbon we do not see: The impact of low molecular weight compounds on carbon dynamics and respiration in forest soils - A review2005In: Soil Biology and Biochemistry, ISSN 0038-0717, E-ISSN 1879-3428, Vol. 37, no 1, p. 1-13Article in journal (Refereed)
    Abstract [en]

    Dissolved organic matter (DOM), typically quantified as dissolved organic carbon (DOC), has been hypothesized to play many roles in pedogenesis and soil biogeochemical cycles, however, most research to date concerning forest soils has focussed on the high molecular weight (HMW) components of this DOM. This review aims to assess the role of low molecular weight (LMW) DOM compounds in the C dynamics of temperate and boreal forest soils focussing in particular on organic acids, amino acids and sugars. The current knowledge of concentrations, mineralization kinetics and production rates and sources in soil are summarised. We conclude that although these LMW compounds are typically maintained at very low concentrations in the soil solution (<50 muM), the flux through this pool is extremely rapid (mean residence time 1-10 h) due to continued microbial removal. Due to this rapid flux through the soil solution pool and mineralization to CO2, we calculate that the turnover of these LMW compounds may contribute substantially to the total CO2 efflux from the soil. Moreover, the production rates of these soluble transitory compounds could exceed HMW DOM production. The possible impact of climate change on the behaviour of LMW compounds in soil is also discussed.

  • 406.
    van Hees, Patrick
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Tipping, E.
    Institute of Freshwater Ecology, Ferry House, Ambleside, Cumbria LA22 0LP, United Kingdom.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Aluminium speciation in forest soil solution- modelling the contribution of low molecular weight organic acids2001In: Science Of The Total Environment, ISSN 0048-9697, Vol. 278, no 1-3, p. 215-229Article in journal (Refereed)
    Abstract [en]

    The concentrations of Al bound to identified low molecular weight organic acids (LMWOAs), phosphate and humic compounds in soil solutions (O1, O2, E, B1 and B2 horizons) from Fennoscandinavian coniferous forest soils were calculated. Two models were evaluated: WHAM (Winderemere Humic Aqueous Model) and a model treating the natural organic acids as monoprotic. The WHAM model was calibrated to find an average charge balance of unity, and then used for Al speciation. This was achieved considering approximately 80% of the natural fulvic acid to be 'active'. For the monoprotic model, constants obtained from previous fitting of soil solution data were used and the model was calibrated using acid/base titrations. The modelling confirms that the low molecular weight acids are important complex formers, binding on average 11-42% (O), 19-20% (E), and 0-30% (B) of the total Al in solution depending on the model used. The monoprotic model yielded higher concentrations than WHAM. Both models predicted that the major part of Al in solution was organically complexed to humic substances and LMWOAs, which was consistent with analytical values of 'quickly reacting' Al (monomenc inorganic forms; 12-14% of Altot on average in the E and B1 solutions). Both models could predict the magnitude of the analytical values (RMSD=4-5 μM). On average the WHAM model showed a better fit for the E horizon solutions and the monoprotic model for the upper B horizon. The pH dependence of the low molecular weight fraction of Al was modelled in the pH range 3-5.5 for a 'typical' O1 and E solution assuming no other changes in soil solution composition. The extrapolation showed that the models had a different pH dependence. The concentration of Al bound to LMWOAs in WHAM decreased with higher pH while the opposite was seen for the monoprotic model. Also the influence of the concentration of total Al in solution was modelled. The models showed similar trends but for the 'typical' O1 horizon sample the monoprotic model yielded higher concentrations of Al bound to LMWOAs than WHAM.

  • 407.
    van Hees, P.A.W.
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Mörth, C-M
    Dissolution of microcline and labradorite in a forest O horizon extract: the effect of naturally occurring organic acids.2002In: Chemical Geology, ISSN 0009-2541, Vol. 189, no 3-4, p. 199-211Article in journal (Refereed)
  • 408.
    van Hees, P.A.W.
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    van Hees, A.M.T.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Determination of aluminium complexes of low molecular weight organic acids in soil from forest soils using ultrafiltration2001In: Soil biology and biochemistry, ISSN 0038-0717, Vol. 33, no 7-8, p. 867-874Article in journal (Refereed)
    Abstract [en]

    Ultrafiltration (<1000 D) was evaluated as an analytical method for determination of Al bound to low molecular weight organic acids (LMWOA) in soil solutions from podzolised forest soils. The results were compared to those obtained by two chemical equilibrium models and a size exclusion chromatography method. The percentage of Al bound to LMWOAs was highest in the O horizon solutions (15-44%) and decreased in the deeper horizons. Citric acid was found to be the most important complex former. Generally the ultrafiltration method and modelling showed acceptable agreement. The method showed acceptable precision and good recovery of Al in the samples.

  • 409.
    Van Hess, Patrick A.W
    et al.
    Man-Technology-Environment Research Centre, Department of Natural Sciences, Örebro University, Örebro.
    Rosling, Anna
    Department of Forest Mycology and Pathology, Swedish University of Agricultural Sciences (SLU), Uppsala.
    Essén, Sofia
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Gobold, Douglas L
    School of Agricultural and Forest Sciences, University of Wales, Bangor, Gwynedd LL57 2UW, United Kingdom.
    Jones, David L
    School of Agricultural and Forest Sciences, University of Wales, Bangor, Gwynedd LL57 2UW, United Kingdom.
    Finlay, Roger D
    Department of Forest Mycology and Pathology, Swedish University of Agricultural Sciences (SLU), Uppsala.
    Oxalate and ferricrocin exudation by the extramatrical mycelium of an ectomycorrhizal fungus in symbiosis with Pinus sylvestris2006In: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 169, no 2, p. 367-378Article in journal (Refereed)
    Abstract [en]

    Accurate estimates of mycelial exudation in time and space are crucial for the assessment of ectomycorrhizal involvement in biogeochemical processes. Knowledge of exudation from mycelia of ectomycorrhizal fungi is still limited, especially for fungi in symbiosis with a host. Pinus sylvestris seedlings colonized by Hebeloma crustuliniforme were grown in aseptic multicompartment dishes. This novel system enabled identification of exudates originating only from extramatrical mycelium. At harvest, hyphal density and numbers were estimated using microscopic imaging. A fractal geometric approach was adopted for calculation of exudation rates. The main compounds identified were oxalate and ferricrocin. The exudation rate for oxalate was 19 +/- 3 fmol per hyphal tip h(-1) (mean +/- standard error of the mean) or 488 +/- 95 fmol hyphal mm(-2) h(-1). Ferricrocin rates were approx. 10 000 times lower. The fractal dimension (D) of the mycelia was 1.4 +/- 0.1, suggesting an explorative growth. Potassium nutrition was a significant regulatory factor for ferricrocin but not oxalate. The results suggest that hyphal exudation may alter the chemical conditions of soil microsites and affect mineral dissolution. Calculations also indicated that oxalate exudation may be a significant carbon sink.

  • 410. Van Hess, Patrick
    et al.
    Nyberg, Lars
    Holmström, Sara
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Pools and fluxes of cations, anions and DOC in limed and ash treated forest soils.2003In: Water, Air and Soil Pollution: Focus,, ISSN 1567-7230, Vol. 3, no 3, p. 145-165Article in journal (Refereed)
  • 411. Verheggen, F
    et al.
    Ryne, C
    Olsson, P. O. C.
    Arnaud, L
    Lognay, G
    Högberg, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Persson, D
    Haubruge, E
    Löfstedt, C
    Electrophysiological and Behavioral Activity of Secondary Metabolites in the Confused Flour Beetle, Tribolium confusum2007In: Journal of Chemical Ecology, ISSN 0098-0331, E-ISSN 1573-1561, Vol. 33, no 3, p. 525-539Article in journal (Refereed)
    Abstract [en]

    Several previous studies have addressed pheromone communication in various flour beetles (Coleoptera: Tenebrionidae), including the confused flour beetle, Tribolium confusum (du Val). Different stereoisomers of 4,8-dimethyldecanal (DMD) were reported as the only components of an aggregation pheromone, but the behavioral activity of DMD is low. In the present study, additional previously reported secondary metabolites (benzoquinones and hydrocarbons) were tested for electrophysiological activity (EAG) with both sexes of T. confusum. Two benzoquinones and three monoenic hydrocarbons elicited significant EAG activity from both male and female antennae. There was an elevated male EAG response (vs. the females) to two out of the three hydrocarbons and for both quinones. The EAG-active compounds were subsequently investigated for behavioral activity in a walking bioassay. Benzoquinones are considered toxic and have been assigned a function as alarm substances in flour beetles, but we found that methyl-1, 4-benzoquinone in intermediate concentrations was attractive to both male and female beetles and could therefore act as an aggregation pheromone component. Males were also attracted to ethyl-1,4-benzoquinone. The corresponding hydroquinones, presumed precursors of the benzoquinones, did not elicit any electrophysiological response and were not tested for behavioral activity. The unsaturated hydrocarbons (1-tetradecene, 1-pentadecene, and 1-hexadecene) elicited significant EAG responses from both male and female antennae and were also attractive in the behavioral assay. Our results show that several beetle-produced compounds, in addition to 4,8-dimethyldecanal, may be part of a complex pheromone system in flour beetles and play a role in mediating aggregation in T. confusum.

  • 412.
    Vestin, Jenny
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Growth and chemical characterisation of Norway spruce grown on alkaline and non-alkaline soilManuscript (Other academic)
  • 413.
    Vestin, Jenny L K
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla S
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    The impact of alkaline and non-alkaline parent material on soil solution composition and tree growth: Focus on soils, muntlig presentation 0509152005Conference paper (Other academic)
  • 414.
    Vestin, Jenny L. K.
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Norström, Sara H
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Lundström, Ulla S
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Soil solution and stream water chemistry in a forested catchment II: Influence of organic matter2008In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 144, no 2008, p. 271-278Article in journal (Refereed)
    Abstract [en]

    Differences between recharge and discharge areas in soil forming processes and nutrient conditions were observed in an earlier study of a catchment area in central Sweden (63°07′N, 16°70′E; Vestin, J.L.K., Norström, S.H., Bylund, D., Mellander, P-E., Lundström, U.S., submitted for publication to Geoderma. Soil solution and stream water chemistry in a forested catchment, I Dynamics.). To further examine the factors that determine the soil and stream water properties in the catchment area, the present study focused on the organic dynamics and the association of cations to different size fractions of organic matter. Six sampling plots were established in each of the recharge and discharge areas, respectively, with samples taken in June 2004. Dissolved organic carbon (DOC) and cation concentrations in the soil solution and stream water were determined. In the recharge area, low molecular mass (LMM) organics played an important role in transportation of several cations through the soil profile, inducing the podzolisation process by associating with Al and Fe. In the discharge area close to the stream, high molecular mass (HMM) organics appeared to play a crucial role in transportation of cations. Here the majority of recovered cations were associated with HMM organic matter, inhibiting the podzolisation process. The total concentration of C and DOC was higher than in the recharge area, and the concentration of cations increased with depth in the mineral soil. In the stream water, as in the discharge area soil solution, all carboxylic groups were associated to cations. Both Al and Fe were completely associated with the HMM DOC fraction, which indicated a rapid turnover of LMM DOC in stream water. Thus we conclude that DOC plays an important role in soil forming processes, and that its different size fractions have large effects on the transportation of elements in different soils and in stream water.

  • 415.
    Vestin, Jenny L. K.
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Norström, Sara H
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Mellander, Per-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Lundström, Ulla S
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Soil solution and stream water chemistry in a forested catchment I: Dynamics2008In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 144, no 1/2, p. 256-270Article in journal (Refereed)
    Abstract [en]

    Soil solution and stream water chemistry were studied during two years in a catchment in Bispgården in central Sweden (63°07′N, 16°70′E). Soil samples and soil solution were collected in a slope at two distances (10 and 80 m) from a stream. The aims were to examine interactions between recharge (podzol) and discharge (arenosol) areas and to investigate the relations between soil solution and stream water chemistry. The parent material was similar within the catchment, but the content of C and N were higher in the discharge area most likely due to the difference in hydrological conditions compared to the recharge area. Exchangeable cations and base saturation were higher in the discharge area than in the recharge area, which may be due to the higher content of C. The concentrations in soil solution of H, DOC, NO3, SO4, Al, Si, Ca and K charge area compared to the recharge area which was probably caused by transportation of elements in soil and retention due to the increased content of C. During snow melt, the concentrations in soil solution of DOC, SO4, Al, Si, Ca and K were low due to dilution and low biological activity. The concentrations were then increasing during the seasons as an effect of biological activity and mineral weathering. NO3 concentration in soil solution was found in higher concentrations during snow melting and was then diminishing during summer likely as a result of biological uptake. After a dry period followed by an intensive rain in August 2003, the stream water chemistry was markedly altered for a few days. The concentrations of H, DOC SO4, Al and Ca were increased and the concentration of Si was decreased in the stream water. It therefore appeared that the stream water mirrored the upper soil horizons in the discharge area during high flows, while reflecting the lower soil horizons and ground water during low flows.

  • 416.
    Vestin, Jenny L. K.
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Söderberg, Ulf
    Department of Forest Resource Management, Swedish University of Agricultural Sciences, 901 83 Umeå, Sweden .
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Nambu, Kei
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    van Hees, Patrick A. W.
    Eurofins Environm AB, S-53117 Lidköping, Sweden.
    Haslinger, Edith
    AIT Austrian Inst Technol GmbH, Hlth & Environm Dept, A-3430 Tulln, Austria.
    Ottner, Franz
    Univ Nat Resources & Appl Life Sci, Inst Appl Geol, A-1190 Vienna, Austria.
    Lundstrom, Ulla S.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    The influence of alkaline and non-alkaline parent material on Norway spruce tree chemical composition and growth rate2013In: Plant and Soil, ISSN 0032-079X, E-ISSN 1573-5036, Vol. 370, no 1-2, p. 103-113Article in journal (Refereed)
    Abstract [en]

    This study investigated the influence of contrasting parent materials on tree chemical composition and growth rate under field conditions. On the island of Alno, Sweden, alkaline intrusions are interspersed into non-alkaline gneiss bedrock, which provides a unique opportunity to conduct this study with a minimum of confounding effects. Three plots with alkaline and three plots with non-alkaline parent material were established in a homogenous Norway spruce stand. The chemical composition of soil and soil solution was determined throughout the soil profiles. The chemical composition of bark, wood and needles was determined for each plot, and the latest 5 year basal area growth increment calculated. Concentrations of Ca in needles were correlated with the soil exchangeable Ca levels. Tree growth rate was significantly higher on the alkaline plots and positively correlated with soil concentrations of Ca, Mg, P, and Zn. The tree growth rate also tended to correlate with soil N concentrations, but levelled out for the highest soil N concentrations. Tree growth was enhanced on the alkaline plots and was correlated with several elements. However, none of these elements could be confirmed as the limiting one for tree growth at the current site.

  • 417.
    Vestin, Jenny
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Nambu, Kei
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Holmström, Sara J.M.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    van Hees, P.A.W.
    Jones, D.L.
    Söderberg, U.
    Lundström, Ulla S.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    The impact of soil parent material on soil chemical conditions, needle composition and tree growth2003Conference paper (Other academic)
  • 418.
    Vestin, Jenny
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Nambu, Kei
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    van Hees, P. A. W.
    Örebro University.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    The influence of alkaline and non-alkaline parent material on soil chemistry2006In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 135, p. 97-106Article in journal (Refereed)
    Abstract [en]

    The gneiss bedrock at Alnö Island, (62o24N, 17o30E) in the middle of Sweden, has alkaline intrusions interspersed in narrow dikes. This gives an opportunity to study the impact of different parent material on soil solution in a homogeneous spruce stand. In this study, the alkaline parent materials gave rise to a soil solution with significantly (p 0.05) higher concentrations of DOC, SO4, NO3, Ca and Mg compared to the non-alkaline sites. For the deepest mineral horizons, 25-30cm, F and pH were also higher in the alkaline soil solutions. There were almost no differences between the organic horizons at alkaline and non-alkaline sites, probably explained by the influence of litter and recirculation of nutrients. The multivariate analyses emphasized the correlation between the parent material and the soil solution concentrations of Ca, Mg, PO4 and Al. The data were statistically evaluated by t-tests, ANOVA (Analysis of variances), PCA (Principal Component Analysis) and PLS (Partial Least Squares regression).

  • 419.
    Volpati, Diogo
    et al.
    University of São Paulo, Brazil.
    Aoki, Pedro H. B.
    UNESP, Brazil.
    Alessio, Priscila
    UNESP, Brazil.
    Pavinatto, Felippe J.
    University of São Paulo, Brazil.
    Miranda, Paulo B.
    University of São Paulo, Brazil.
    Constantino, Carlos J. L.
    UNESP, Brazil.
    Oliveira, Osvaldo N., Jr.
    University of São Paulo, Brazil.
    Vibrational spectroscopy for probing molecular-level interactions in organic films mimicking biointerfaces2014In: Advances in Colloid and Interface Science, ISSN 0001-8686, E-ISSN 1873-3727, Vol. 207, no Special Issue: Helmuth Möhwald Honorary Issue, p. 199-215Article in journal (Refereed)
    Abstract [en]

    Investigation into nanostructured organic films has served many purposes, including the design of functionalized surfaces that may be applied in biomedical devices and tissue engineering and for studying physiological processes depending on the interaction with cell membranes. Of particular relevance are Langmuir monolayers, Langmuir-Blodgett (LB) and layer-by-layer (LbL) films used to simulate biological interfaces. In this review, we shall focus on the use of vibrational spectroscopy methods to probe molecular-level interactions at biomimetic interfaces, with special emphasis on three surface-specific techniques, namely sum frequency generation (SFG), polarization-modulated infrared reflection absorption spectroscopy (PM-IRRAS) and surface-enhanced Raman scattering (SERS). The two types of systems selected for exemplifying the potential of the methods are the cell membrane models and the functionalized surfaces with biomolecules. Examples will be given on how SFG and PM-IRRAS can be combined to determine the effects from biomolecules on cell membrane models, which include determination of the orientation and preservation of secondary structure. Crucial information for the action of biomolecules on model membranes has also been obtained with PM-IRRAS, as is the case of chitosan removing proteins from the membrane. SERS will be shown as promising for enabling detection limits down to the single-molecule level. The strengths and limitations of these methods will also be discussed, in addition to the prospects for the near future.

  • 420.
    Volpati, Diogo
    et al.
    University of São Paulo, Brazil.
    Chachaj-Brekiesz, Anna
    Jagiellonian University, Poland.
    Souza, Adriano L.
    University of São Paulo, Brazil.
    Rimoli, Caio Vaz
    University of São Paulo, Brazil.
    Miranda, Paulo B.
    University of São Paulo, Brazil.
    Oliveira, Osvaldo N., Jr.
    University of São Paulo, Brazil.
    Dynarowicz-Latka, Patrycja
    Jagiellonian University, Poland.
    Semifluorinated thiols in Langmuir monolayers: A study by nonlinear and linear vibrational spectroscopies2015In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 460, p. 290-302Article in journal (Refereed)
    Abstract [en]

    A series of semifluorinated thiols of the general formula CmF2m+1CnH2nSH (abbr. FmHnSH) have been synthesized and characterized in Langmuir monolayers with surface pressure-area isotherms, complemented with polarization-modulated reflection absorption spectroscopy (PM-IRRAS) and sum-frequency generation (SFG) techniques. A comparative analysis was performed for compounds having the same length of fluorinated segment (F-10) and variable length of the hydrogenated part (H-6, H-10, H-12), and having identical hydrogenated segment (H-12) connected to a fluorinated moiety of different lengths (F-6, F-8, F10). For the sake of comparison, an alkanethiol (H18SH) was also examined, and F10H10COOH and F10H10OH molecules were used for helping the assignment of SFG spectra of CH stretches. SFG was applied to investigate the hydrocarbon chain and the terminal CF3 group, while PM-IRRAS was used to probe CF2 groups. The number of gauche defects in the hydrocarbon chain increased with the increasing length of the molecule, either by elongation of the hydrogenated or perflu-orinated part. SFG measurements recorded at three polarization combinations (ppp, ssp, sps) enabled us to estimate the tilt angle of the terminal CF3 group in semifluorinated thiol molecules as ranging from 35 to 45, which is consistent with nearly vertical fluorinated segments. Upon increasing the surface pressure, the fluorinated segment gets slightly more upright, but the hydrocarbon chain tilt increases while keeping the same average number of gauche defects. The extent of disorder in the hydrogenated segment may be controlled by varying the size of the fluorinated segment, and this could be exploited for designing functionalized surfaces with insertion of other molecules in the defect region.

  • 421.
    Vörde, Carin
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Högberg, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Resolution of 2-Methylalkanoic esters: Enantioselective Aminolysis by (R)-1-Phenylethyl-amine of Ethyl 2-Methyloctanoate Catalysed by Lipase B from Candida antarctica1996In: Tetrahedron: Asymmetry, ISSN 0957-4166, Vol. 7, no 5, p. 1507-1513Article in journal (Refereed)
  • 422.
    Wahlberg [Schröder], Jessica
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Persson, P. V.
    Olsson, Torbjörn
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Information Technology and Media.
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Iversen, T
    Structural Characterization of a Lipase-Catalyzed Copolymerization of epsilon-Caprolactone and D,L-Lactide2003In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 4, no 4, p. 1068-1071Article in journal (Refereed)
    Abstract [en]

    The copolymerization of epsilon-caprolactone (epsilon-CL) and D,L-lactide catalyzed by Candida antarctica lipase B was studied. Copolymerizations with different epsilon-CL-to-lactide ratios were carried out, and the product was monitored and characterized by MALDI-TOF MS, GPC, and H-1 NMR. The polymerization of epsilon-CL, which is normally promoted by C. antarctica lipase B, is initially slowed by the presence of lactide. During this stage, lactide is consumed more rapidly than epsilon-CL, and the incorporation occurs dimer-wise with regard to the lactic acid (LA) units. As the reaction proceeds, the relative amount of CL units in the copolymer increases. The nonrandom copolymer structure disappears with time, probably due to a lipase-catalyzed transesterification reaction. In the copolymerizations with a low content of lactide, macrocycles of poly(epsilon-caprolactone) and copolymers having up to two LA units in the ring were detected.

  • 423.
    Wakeham, D.
    et al.
    Centre for Organic Electronics, University of Newcastle, Callaghan, NSW 2308, Australia.
    Niga, Petru
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Information Technology and Media. KTH Royal Inst Technol, Dept Chem Surface & Corros Sci, SE-10044 Stockholm, Sweden.
    Ridings, C
    Centre for Nano Scale Science and Technology, Flinders University, SA 5001, Australia.
    Andersson, G
    Centre for Nano Scale Science and Technology, Flinders University, SA 5001, Australia.
    Nelson, A
    Bragg Institute, Australian Nuclear Science and Technology Organisation, PMB 1, Menai, NSW 2234, Australia.
    Warr, G
    School of Chemistry, University of Sydney, NSW 2006, Australia.
    Baldelli, S
    Department of Chemistry, University of Houston, Houston, TX 77204-5003, United States.
    Rutland, M
    Department of Chemistry, Surface and Corrosion Science, KTH Royal Institute of Technology, Drottning Kristinas Väg 51, SE-100 44 Stockholm, Sweden.
    Atkin, R
    Centre for Organic Electronics, University of Newcastle, Callaghan, NSW 2308, Australia.
    Surface structure of a "non-amphiphilic" protic ionic liquid2012In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 14, no 5, p. 5106-5114Article in journal (Refereed)
    Abstract [en]

    The nanostructure of the ethanolammonium nitrate (EtAN)-air surface has been investigated using X-ray reflectometry (XRR), vibrational sum frequency spectroscopy (VSFS) and neutral impact collision ion scattering spectroscopy (NICISS). The XRR data decays more rapidly than expected for a perfectly sharp interface, indicating a diffuse electron (scattering length) density profile. Modelling of the XRR data using three different fitting routines produced consistent interfacial profiles that suggest the formation of interfacial EtAN clusters. Consistent with this, VSFS reveals that the EtAN surface is predominantly covered by -CH 2- moieties, with the -NH 3 + and -OH groups of the cation buried slightly deeper in the interface. The elemental profiles determined using NICISS also show enrichment of carbon relative to nitrogen and oxygen in the outermost surface layer, which is consistent with the surface cation orientation deduced from VSFS, and with the presence of EtAN aggregates at the liquid surface. © 2012 the Owner Societies.

  • 424. Walker, P W
    et al.
    Allen, G R
    Davies, N W
    Smith, J A
    Molesworth, P P
    Nilsson, Anna
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Andersson, Fredrik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Identification, Synthesis and Field Testing of (3Z,6Z,9Z)-3,6,9-Henicosatriene, a Second Bioactive Component of the Sex Pheromone of the Autumn Gum Moth, Mnesampela privata2009In: Journal of Chemical Ecology, ISSN 0098-0331, E-ISSN 1573-1561, Vol. 35, no 12, p. 1411-1422Article in journal (Refereed)
    Abstract [en]

    Abstract - The sex pheromone of Mnesampela privata, an endemic pest of Eucalyptus plantations in Australia, was previously identified as containing a single bioactive compound, (3Z,6Z,9Z)-3,6,9-nonadecatriene (C19 triene). Initial field testing of lures containing 1, 5 or 10 mg of C19 triene (>98% purity) caught no or very few male M. privata. (3Z,6Z,9Z)-3,6,9-Henicosatriene (C21 triene) was identified as an additional minor pheromone component in abdominal tip extracts of M. privata females from Tasmania. Levels of C19 and C21 trienes extracted from individual females varied greatly, but the ratio was relatively constant at 33:1. Electroantennograms (EAG) of synthetic C21 triene with male M. privata gave positive but consistently lower responses than elicited by the C19 triene. Field tests showed that the addition of 1-6% C21 triene to 1mg C19 triene significantly increased trap catch and the detection of M. privata in plantations. Traps baited with a 16:1 ratio caught significantly more moths than those baited with a ratio approximating that of females.

  • 425.
    Wallin, Erika
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    The Scents of Nature: Identification and Synthesis of Bioactive Compounds Used in Insect Communication2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Pest insects cause great financial losses in the forest and food industry every year. To fight these pests industries have used insecticides, which are sometimes harmful to nature and humans. One potential way of avoiding insecticides is the use of integrated pest management based on insect communication, which would offer species-specific methods for protecting forest and food resources. Insects use chemicals known as semiochemicals for both intra- and interspecies communication. By learning how insects use these semio-chemicals to talk to each other we can eavesdrop and mimic their communication for our benefit. One research area dealing with these questions is chemical ecology, which is an interdisciplinary area as knowledge in chemistry and biology is required. Collaborations between groups within and outside of Sweden are essential in order to make progress in this field of research.

    This thesis presents the identification and synthesis of semiochemicals from several insect species, most of which are considered to be pests. Synthesised compounds have been sent to collaboration partners around Sweden and Europe for biological evaluations.

    Studies of the African butterfly, Bicyclus anynana, have unravelled particular biological phenomena that may aid in the understanding of the Bicyclus genus, though recognizing individual species variation is crucial. In 2008 the putative male sex pheromone of B. anynana was determined to consist of three compounds: hexadecanal, (Z)-9-tetradecenol and 6,10,14-trimethylpentadecan-2-ol, and the specific stereoisomer for 6,10,14-trimethylpentadecan-2-ol has been determined in this thesis. The ratio of 6,10,14-trimethylpentadecan-2-ol and the corresponding ketone were investigated for seventeen Bicyclus species (including B. anynana) that live in overlapping regions in Africa. The stereochemistry was determined for most of the species and may provide a way to chemically distinguish them.

    The orchid bees, Euglossa spp, are important pollinators of many orchids in Central America. Insight about pollination and conservation of endangered orchid species may be possible by gathering more information about the Euglossa genus. Males of the Euglossa genus have pouch-like structures on their hind legs where they store compounds collected from their surroundings. 6,10,14-Trimethyl-pentadecan-2-one is a common component of leg extracts from Euglossa imperialis, E. crassipunctata and E. allosticta, the specific stereochemistry of which has been determined in this thesis. Another, different compound was found in high amounts in E. viridissima and its structure has been elucidated; several synthetic pathways are under investigation to obtain the target compound.

    Bed bugs (Cimex lectularius and C. hemipterus) are an ectoparasite that feed on human blood, and the number of reported infestations of these parasites has increased considerably during the last decade. Two 5th instar nymph-specific compounds, 4-oxo-hexenal and 4-oxo-octenal, were identified and synthesised.

    Utilizing domestic dogs (Canis lupus familiaris) in the identification of bed bug infestations has become popular during recent years. Their training is usually conducted using live bed bugs, however this thesis describes an alternative method of teaching dogs to find infestations. This alternative method is based on synthetic compounds and dogs trained in this manner have achieved a high positive indication rate.

    Two species of the tiny, Acacia leaf-eating insect pests in Australia known as thrips, Kladothrips nicolsoni and K. rugosus, have been investigated by means of larval extracts and have been shown to contain large amount of (Z)-3-dodecenoic acid which was synthesised and tested in bioassays.

    Fruit flies are common pests on fruit in almost every private household. Even though fruit flies has been investigated extensively, their chemical communication has not been completely elucidated. (Z)-4-undecenal was identified as a compound emitted by females, it was synthesised in high stereoisomeric purity and evaluated in biological assays.

  • 426.
    Wallin, Erika
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Andersson, Annica
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Chemical tools for training domestic dogs (Canis lupus familiaris) to detect bed bugsManuscript (preprint) (Other academic)
  • 427.
    Wallin, Erika
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    De Facci, Monica
    Department of Biology, Lund University, Sölvegatan 37, SE-223 62 Lund, Sweden .
    Anderbrant, Olle
    Department of Biology, Lund University, Sölvegatan 37, SE-223 62 Lund, Sweden .
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    (Z)-3-Dodecenoic Acid Is the Main Component of Full-Body n-Hexane Extracts from Two Acacia Gall-Inducing Thrips (Thysanoptera) and May Function as an Alarm Pheromone2014In: Zeitschrift für Naturforschung C - A Journal of Biosciences, ISSN 0939-5075, E-ISSN 1865-7125, Vol. 69C, no 7-8, p. 335-345Article in journal (Refereed)
    Abstract [en]

    A major interest in the gall-inducing thrips of Australia began with the discovery that some species have eusocial colonies. The origin of social castes remains one of the outstanding questions in evolutionary biology. The inference of the ancestral stage from study of solitary species is important to understanding the evolutionary history of semiochemicals in the social species. Here we investigated two solitary species, Kladothrips nicolsoni and K. rugosus. Whole body extracts revealed that (Z)-3-dodecenoic acid, here reported for the first time in a thrips species, is the main component. (Z)-3-Dodecenoic acid and (E)-3-dodecenoic acid were synthesized in high stereoisomeric purity (> 99.8 %) and exposed to K. nicolsoni 2nd-instar larvae in a contact chemoreception bioassay to test for potential bioactivity. Both isomers decreased the average time spent in the treated area per entry suggesting repellence at the tested dose. (Z)-3-Dodecenoic acid may function as alarm pheromone. (E)-3-Dodecenoic acid increased also the absolute change in direction of larvae compared to an n-hexane control and could potentially function as a repellent.

  • 428. Wassgren, A.-B.
    et al.
    Anderbrant, O.
    Löfqvist, J.
    Hansson, B. S.
    Bergström, G.
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Högberg, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Pheromone Related Compounds in Pupal and Adult Female Pine Sawflies, Neodiprion sertifer, of different Age and in different Parts of the Body1992In: Journal of Insect Physiology, ISSN 0022-1910, Vol. 38, no 11, p. 885-893Article in journal (Refereed)
  • 429. Wassgren, A.-B.
    et al.
    Bergström, G.
    Sierpinski, A.
    Anderbrant, O.
    Högberg, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Sex Pheromone of the Pine Sawfly Macrodiprion nemoralis (Hymenoptera : Diprionidae): Identification of (2S,3R,7R,9S)-3,7,9-Trimethyl-2-tridecanol as the Precursor for the Active Pheromone Acetate2000In: Die Naturwissenschaften, ISSN 0028-1042, E-ISSN 1432-1904, Vol. 87, no 1, p. 24-29Article in journal (Refereed)
    Abstract [en]

    The main component of the sex pheromone precursor in females of Macrodiprion nemoralis was identified as a threo-3,7,9-trimethyl-2-tridecanol isomer, approximately 800 pg per female, by gas chromatography-mass spectrometry. Comparison of mass spectrometric ion chromatograms showed that the natural compound in the female extract has the same retention time and mass spectrum as one of the two synthetic threo peaks. The acetate of the synthetic 16-isomer mixture caught a large number of males in the field, confirming the structure of the active pheromone. Comparison of gas chromatograms of the natural female extract with the eight synthetic threo stereoisomers showed that the pheromone is the (2S,3R,7R,9S)-stereoisomer of 3,7,9-trimethyl-2-tridecyl acetate.

  • 430. Wågberg, Lars
    et al.
    Decher, Gero
    Norgren, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Lindström, Tom
    Ankerfors, Mikael
    Axnäs, Karl
    The build-up of polyelectrolyte multilayers of microfibrillated cellulose and cationic polyelectrolytes2008In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 24, no 3, p. 784-795Article in journal (Refereed)
    Abstract [en]

    A new type of nanocellulosic material has been prepared by high-pressure homogenization of carboxymethylated cellulose fibers followed by ultrasonication and centrifugation. This material had a cylindrical cross-section as shown by transmission electron microscopy with a diameter of 5-15 nm and a length of up to 1 mu m. Calculations, using the Poisson-Boltzmann equation, showed that the surface potential was between 200 and 250 mV, depending on the pH, the salt concentration, and the size of the fibrils. They also showed that the carboxyl groups on the surface of the nanofibrils are not fully dissociated until the pH has reached pH = similar to 10 in deionized water. Calculations of the interaction between the fibrils using the Derjaguin-Landau-Verwey-Overbeek theory and assuming a cylindrical geometry indicated that there is a large electrostatic repulsion between these fibrils, provided the carboxyl groups are dissociated. If the pH is too low and/or the salt concentration is too high, there will be a large attraction between the fibrils, leading to a rapid aggregation of the fibrils. It is also possible to form polyelectrolyte multilayers (PEMs) by combining different types of polyelectrolytes and microfibrillated cellulose (MFC). In this study, silicon oxide surfaces were first treated with cationic polyelectrolytes before the surfaces were exposed to MFC. The build-up of the layers was monitored with ellipsometry, and they show that it is possible to form very well-defined layers by combinations of MFC and different types of polyelectrolytes and different ionic strengths of the solutions during the adsorption of the polyelectrolyte. A polyelectrolyte with a three-dimensional structure leads to the build-up of thick layers of MFC, whereas the use of a highly charged linear polyelectrolyte leads to the formation of thinner layers of MFC. An increase in the salt concentration during the adsorption of the polyelectrolyte results in the formation of thicker layers of MFC, indicating that the structure of the adsorbed polyelectrolyte has a large influence on the formation of the MFC layer. The films of polyelectrolytes and MFC were so smooth and well-defined that they showed clearly different interference colors, depending on the film thickness. A comparison between the thickness of the films, as measured with ellipsometry, and the thickness estimated from their colors showed good agreement, assuming that the films consisted mainly of solid cellulose with a refractive index of 1.53. Carboxymethylated MFC is thus a new type of nanomaterial that can be combined with oppositely charged polyelectrolytes to form well-defined layers that may be used to form, for example, new types of sensor materials.

  • 431.
    Xu, Chao
    et al.
    Stockholm Univ, Berzelii Ctr EXSELENT Porous Mat, SE-10691 Stockholm, Sweden.
    Deiana, Luca
    Stockholm Univ, Berzelii Ctr EXSELENT Porous Mat, SE-10691 Stockholm, Sweden.
    Afewerki, Samson
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Incerti-Pradillos, Celia
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Cordova, Oscar
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Guo, Peng
    Stockholm Univ, Berzelii Ctr EXSELENT Porous Mat, SE-10691 Stockholm, Sweden.
    Cordova, Armando
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences. Stockholm Univ, Berzelii Ctr EXSELENT Porous Mat, SE-10691 Stockholm, Sweden.
    Hedin, Niklas
    Stockholm Univ, Berzelii Ctr EXSELENT Porous Mat, SE-10691 Stockholm, Sweden.
    The Use of Porous Palladium(II)-polyimine in Cooperatively-catalyzed Highly Enantioselective Cascade Transformations2015In: Advanced Synthesis and Catalysis, ISSN 1615-4150, E-ISSN 1615-4169, Vol. 357, no 9, p. 2150-2156Article in journal (Refereed)
    Abstract [en]

    Porous organic polymers have prospects as functional substrates for catalysis, with quite different molecular properties from inorganic substrates. Here we disclose for the first time that porous palladium(II)-polyimines are excellent catalysts for cooperatively catalyzed and enantioselective cascade reactions. In synergy with a chiral amine co-catalyst, polysubstituted cyclopentenes and spirocyclic oxindoles, including the all-carbon quaternary stereocenter, were synthesized in high yields. High diastereo- and enantioselectivities were achieved for these dynamic kinetic asymmetric transformations (DYKAT) of enals with propargylic nucleophiles.

  • 432.
    Yang, Jiayi
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Medronho, Bruno
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Lindman, Björn
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Norgren, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Simple one pot preparation of chemical hydrogels from cellulose dissolved in cold LiOH/Urea2020In: Polymers, ISSN 2073-4360, E-ISSN 2073-4360, Vol. 12, no 2, article id 373Article in journal (Refereed)
    Abstract [en]

    In this work, non-derivatized cellulose pulp was dissolved in a cold alkali solution (LiOH/urea) and chemically cross-linked with methylenebisacrylamide (MBA) to form a robust hydrogel with superior water absorption properties. Different cellulose concentrations (i.e., 2, 3 and 4 wt%) and MBA/glucose molar ratios (i.e., 0.26, 0.53 and 1.05) were tested. The cellulose hydrogel cured at 60 °C for 30 min, with a MBA/glucose molar ratio of 1.05, exhibited the highest water swelling capacity absorbing ca. 220 g H2O/g dry hydrogel. Moreover, the data suggest that the cross-linking occurs via a basic Michael addition mechanism. This innovative procedure based on the direct dissolution of unmodified cellulose in LiOH/urea followed by MBA cross-linking provides a simple and fast approach to prepare chemically cross-linked non-derivatized high-molecular-weight cellulose hydrogels with superior water uptake capacity. 

  • 433.
    Zasadowski, Darius
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Strand, Anders
    Laboratory of Wood and Paper Chemistry, Åbo Academy University, Porthansgatan 3, 20500 Turku, Finland .
    Sundberg, Anna
    Laboratory of Wood and Paper Chemistry, Åbo Academy University, Porthansgatan 3, 20500 Turku, Finland .
    Edlund, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Norgren, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Selective purification of bleached spruce TMP process water by induced air flotation (IAF)2014In: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, Vol. 68, no 2, p. 157-165Article in journal (Refereed)
    Abstract [en]

    The environmentally benign closure of water systems in paper mills leads to the problem of accumulation of dissolved and colloidal wood substances (DCS) in process water. Notably, pitch affects the pulp and paper production negatively and increases the demand for additional treatment of the process water. In the present article, the purification of thermomechanical pulping process water from the alkaline peroxide bleaching stage has been investigated, with the induced air flotation (IAF) in focus. The following parameters were considered concerning the IAF efficiency to remove detrimental substances: concentration of cationic foaming agent, pH value, calcium concentration, and temperature. The amounts and characteristics of residual DCS were determined by gas chromatography and turbidity measurements. Residual concentrations of the foaming agent dodecyltrimetylammonium chloride were determined by electrospray ionization mass spectrometry. Up to 90% of pitch was removed, whereas hemicelluloses, which are important in preventing pitch problems, remained in the waters. Up to 70% of the pectic acids accounted for the high cationic demand of the process waters were removed by optimization of the IAF parameters. The presented separation process gives new opportunities to a selective purification of the process waters.

  • 434.
    Zasadowski, Dariusz
    Mid Sweden University, Faculty of Science, Technology and Media, Department of applied science and design.
    REMOVAL OF LIPOPHILIC EXTRACTIVES AND MANGANESE IONS FROM SPRUCE TMP WATER BY FLOTATION2012Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Dissolved and Colloidal substances (DisCo) and metals are released from wood during thermomechanical pulp (TMP) production. The mechanical treatment causes that these components have a tendency to accumulate in process waters, as the water circulation systems in integrated paper mills are being closed. Disturbances such as pitch depositions on the paper machine (pitch problems), specks in the paper, decreased wet and dry strength, interference with cationic process chemicals, and impaired sheet brightness and friction properties appear in the presence of DisCo substances. The presence of transition metal ions such as manganese results in higher consumption of bleaching chemicals (hydrogen peroxide) and lowers the optical quality of the final product, and addition of complexing agents, such as EDTA or DTPA, to prevent this is needed. The never ending trends to decrease water consumption and increase process efficiency in pulp and paper production stress that it is very important both to know the effects of wood substances on pulping and papermaking and to be able to remove them in an efficient way.

    Carried out investigations presented in this thesis show that the lipophilic extractives can be removed from TMP press water to high extent. A 90% decrease in turbidity and a 91% removal of lipophilic extractives from TMP press water can be obtained by addition of a cationic surfactant as foaming agent during flotation. Additionally, fibres located in TMP press water are not removed with the foam fraction but purified. A retained concentration of hydrophilic extractives in the process water indicates that the flotation is selective. Moreover, by introduction of a new recoverable surface active complexing agent, a chelating surfactant, manganese ions in the form of chelates can be successfully removed from the pulp fibres and separated from the process water in the same flotation process.

    iii

    The findings presented above indicate new possibilities for internal water cleaning and decreased emissions to water if flotation technology is applied in an integrated mechanical pulp mill.

  • 435.
    Zasadowski, Dariusz
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering. Mittuniversitetet.
    Selective Separation Of Wood Components In Internal Process Waters Originating From Mechanical Pulping2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Dissolved and Colloidal substances (DSC) and metals are released from woodduring thermomechanical pulp (TMP) production. These components have atendency to accumulate in process waters, as the water circulation systems inintegrated paper mills are closed. Disturbances such as pitch depositions in thepaper machine (pitch problems), specks in the paper, decreased wet and drystrength, interference with cationic process chemicals, and impaired sheetbrightness and friction properties appear when DSC are present. Transition metalions such as manganese results in higher consumption of bleaching chemicals(hydrogen peroxide) and lowers the optical quality of the final product, andaddition of complexing agents, such as EDTA or DTPA, to prevent this is needed.The never ending trends to decrease water consumption and increase processefficiency in pulp and paper production emphasizes that it is very important bothto know the effects of wood substances on pulping and papermaking and to beable to remove them in an efficient way. From a biorefinery point of view, DSCcomponents can be promising renewable raw materials for biofuels, bio‐basedchemicals and materials.In this thesis, a new approach using induced air flotation (IAF) without a cationicpolyelectrolyte addition for the removal of pitch and metal ions from mechanicalpulp mill process waters is presented. The induced air flotation of different processwaters is facilitated by the addition of a chelating surfactant and different foamingagents. The influence of the pH value, temperature and foaming agentconcentration on the flotation efficiency has been investigated. The investigations

    presented show that the disturbing components can be removed from TMP presswater to a high extent. A 90% decrease in turbidity and a 91% removal of lipophilicextractives (i.e. resin and fatty acids, triglycerides, sterols and steryl esters) fromunbleached and bleached TMP process water can be obtained by addition of acationic surfactant as foaming agent during flotation. Lower amount of foamingagent is needed to purify efficiently bleached TMP process water, than unbleached.Additionally, fibres located in TMP press water are not removed with the foamfraction but purified. A retained concentration of hydrophilic extractives (i.e.hemicelluloses and lignans) in the process water indicates that the flotation isselective. Moreover, by introduction of a new recoverable surface activecomplexing agent, a chelating surfactant, manganese ions in the form of chelatescan be successfully removed from the pulp fibres and separated from the processwater in the same flotation process. Furthermore, from the purified unbleachedTMP process water a 90% recovery of dissolved hemicelluloses by anti‐solventprecipitation was obtained.The findings presented above indicate new possibilities for the internal watercleaning stage to decrease DSC emissions to recipient and for recovery of valuableraw materials from purified process water if flotation technology is applied in anintegrated mechanical pulp mill.

  • 436.
    Zhang, Di
    et al.
    College of Chemistry, Jilin University, Changchun, China.
    Liu, Jianguo
    Cordova, Armando
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences. Stockholm University.
    Liao, Wei-Wei
    College of Chemistry, Jilin University, Changchun, China.
    Recent developments in palladium-catalyzed oxidative cascade carbocyclization2017In: ACS Catalysis, ISSN 2155-5435, E-ISSN 2155-5435, Vol. 7, no 10, p. 7051-7063Article in journal (Refereed)
    Abstract [en]

    In this Perspective, we describe recent advances on Pd-catalyzed oxidative cascade carbocyclizations. These cascade processes enable efficient construction of the molecular complexity and structural diversity of carbocyclic compounds via introducing diverse functionalities concomitant with multiple C-C bond-formations in one-pot operations. In many cases, these processes are facilitated by Pd-catalysts alone, while cocatalysis by combination of Pd catalyst and other catalysts are also discussed, since they represent a new entry to address the preparation of functionalized cyclic compounds with high efficiency and selectivity. 

  • 437. Zhang, Zhen
    et al.
    Wang, Hongbin
    Chen, Guofa
    Anderbrant, Olle
    Zhang, Yun
    Zhou, Shuzhi
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Högberg, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Sex pheromone for monitoring flight periods and population densities of the pine sawfly, Diprion jingyuanensis2005In: Journal of Applied Entomology, ISSN 0931-2048, Vol. 129, no 7, p. 368-374Article in journal (Refereed)
    Abstract [en]

    Sex pheromone for monitoring flight periods and population densities of the pine sawfly, Diprion jingyuanensis

  • 438. Zhao, Gui-Ling
    et al.
    Córdova, Armando
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    ECAs of Organolithium reagents, Grignard reagents and Examples of Cu-Catalyzed ECAs2010In: Catalytic Asymmetric Conjugate Reactions, Wiley-VCH Verlagsgesellschaft, 2010Chapter in book (Refereed)
  • 439. Zhao, Gui-Ling
    et al.
    Hafrén, Jonas
    Deiana, Luca
    Córdova, Armando
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Heterogeneous “Organoclick” Derivatization of Polysaccharides: Photochemical Thiol-Ene Click Modification of Solid Cellulose2010In: Macromolecular rapid communications, ISSN 1022-1336, E-ISSN 1521-3927, Vol. 31, no 8, p. 740-744Article in journal (Refereed)
  • 440. Zhao, Gui-Ling
    et al.
    Lin, Shuangzheng
    Korotvicka, Ales
    Deiana, Luca
    Kullberg, Martin
    Cordova, Armando
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Asymmetric Synthesis of Maraviroc (UK-427,857)2010In: Advanced Synthesis and Catalysis, ISSN 1615-4150, E-ISSN 1615-4169, Vol. 352, no 13, p. 2291-2298Article in journal (Refereed)
    Abstract [en]

    The asymmetric synthesis of Maraviroc (UK-427,857), a chemochine receptor 5 (CCR-5) receptor antagonist, based on an expeditious organocatalytic enantioselective assembly of the chiral beta-amino aldehyde key fragment is presented. The reactions were performed on a gram-scale and allow for the rapid construction of new Maraviroc analogues.

  • 441. Zhao, Gui-Ling
    et al.
    Ullah, Farman
    Deiana, Luca
    Lin, Shuangzheng
    Zhang, Qiong
    Sun, Junliang
    Ibrahem, Ismail
    Department of Organic Chemistry, The Arrhenius Laboratory, Stockholm University,.
    Dziedzic, Pawel
    Córdova, Armando
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Dynamic kinetic asymmetric transformation (DYKAT) by combined amine and transition metal catalyzed enantioselective cycloisomerization2010In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765Article in journal (Refereed)
  • 442.
    Zhu, Can
    et al.
    Stockholms Universitet.
    Liu, Jie
    Stockholms Universitet.
    Mai, Binh Khanh
    Stockholms Universitet.
    Himo, Fahmi
    Stockholms Universitet.
    Bäckvall, Jan-Erling
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences. Stockholms Universitet.
    Efficient Stereoselective Carbocyclization to cis-1,4-Disubstituted Heterocycles Enabled by Dual Pd/Electron Transfer Mediator (ETM) Catalysis2020In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 142, p. 5751-5759Article in journal (Refereed)
    Abstract [en]

    An efficient Pd/ETM (ETM = electron transfer mediator)-cocatalyzed stereoselective oxidative carbocyclization of dienallenes under aerobic oxidation conditions has been developed to afford six-membered heterocycles. The use of a bifunctional cobalt complex [Co(salophen)-HQ] as hybrid ETM gave a faster aerobic oxidation than the use of separated ETMs, indicating that intramolecular electron transfer between the hydroquinone unit and the oxidized metal macrocycle occurs. In this way, a class of important cis-1,4-disubstituted six-membered heterocycles, including dihydropyran and tetrahydropyridine derivatives were obtained in high diastereoselectivity with good functional group compatibility. The experimental and computational (DFT) studies reveal that the pendent olefin does not only act as an indispensable element for the initial allene attack involving allenic C(sp3)-H bond cleavage, but it also induces a face-selective reaction of the olefin of the allylic group, leading to a highly diastereoselective formation of the product. Finally, the deuterium kinetic isotope effects measured suggest that the initial allenic C(sp3)-H bond cleavage is the rate-limiting step, which was supported by DFT calculations. 

  • 443. Zhu, Mingzhao
    et al.
    Shuangzheng, Lin
    Zhao, Gui-Ling
    Sun, Junliang
    Córdova, Armando
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Organocatalytic diasteroselective dibromination of alkenes2010In: Tetrahedron Letters, ISSN 0040-4039, E-ISSN 1359-8562, Vol. 51, p. 2708-2712Article in journal (Refereed)
    Abstract [en]

    A highly diastereoselective pyrrolidine-promoted dibromination of alkenes by combination of NBS and succinimide is presented. The pyrrolidine-mediated dibromination of alkenes is higly anti-selective and gives the corresponding products in moderate to high yields and up to >25:1 dr.

  • 444. Zou, Xuejun
    et al.
    Gurnagul, Norayr
    Uesaka, Tetsu
    Bouchard, Jean
    ACCELERATED AGING OF PAPERS OF PURE CELLULOSE - MECHANISM OF CELLULOSE DEGRADATION AND PAPER EMBRITTLEMENT1994In: Polymer degradation and stability, ISSN 0141-3910, E-ISSN 1873-2321, Vol. 43, no 3, p. 393-402Article in journal (Refereed)
  • 445. Zou, Xuejun
    et al.
    Uesaka, Tetsu
    Gurnagul, Norayr
    Prediction of paper permanence by accelerated aging .2. Comparison of the predictions with natural aging results1996In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 3, no 4, p. 269-279Article in journal (Refereed)
  • 446.
    Öhlund, Thomas
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Metal Films for Printed Electronics: Ink-substrate Interactions and Sintering2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    A new manufacturing paradigm may lower the cost and environmental impact of existing products, as well as enable completely new products. Large scale, roll-to-roll manufacturing of flexible electronics and other functionality has great potential. However, a commercial breakthrough depends on a lower consumption of materials and energy compared with competing alternatives, and that sufficiently high performance and reliability of the products can be maintained. The substrate constitutes a large part of the product, and therefore its cost and environmental sustainability are important. Electrically conducting thin films are required in many functional devices and applications. In demanding applications, metal films offer the highest conductivity.

     

    In this thesis, paper substrates of various type and construction were characterized, and the characteristics were related to the performance of inkjet-printed metal patterns. Fast absorption of the ink carrier was beneficial for well-defined pattern geometry, as well as high conductivity. Surface roughness with topography variations of sufficiently large amplitude and frequency, was detrimental to the pattern definition and conductivity. Porosity was another important factor, where the characteristic pore size was much more important than the total pore volume. Apparent surface energy was important for non-absorbing substrates, but of limited importance for coatings with a high absorption rate. Applying thin polymer–based coatings on flexible non-porous films to provide a mechanism for ink solvent removal, improved the pattern definition significantly. Inkjet-printing of a ZnO-dispersion on uncoated paper provided a thin spot-coating, allowing conductivity of silver nanoparticle films. Conductive nanoparticle films could not form directly on the uncoated paper.

     

    The resulting performance of printed metal patterns was highly dependent on a well adapted sintering methodology. Several sintering methods were examined in this thesis, including conventional oven sintering, electrical sintering, microwave sintering, chemical sintering and intense pulsed light sintering. Specially designed coated papers with modified chemical and physical properties, were utilized for chemical low-temperature sintering of silver nanoparticle inks. For intense pulsed light sintering and material conversion of patterns, custom equipment was designed and built. Using the equipment, inkjet-printed copper oxide patterns were processed into highly conducting copper patterns. Custom-designed papers with mesoporous coatings and porous precoatings improved the reliablility and performance of the reduction and sintering process.

     

     

     

     

    The thesis aims to clarify how ink-substrate interactions and sintering methodology affect the performance and reliability of inkjet-printed nanoparticle patterns on flexible substrates. This improves the selection, adaptation, design and manufacturing of suitable substrates for inkjet-printed high conductivity patterns, such as circuit boards or RFID antennas.  

  • 447.
    Öhlund, Thomas
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Sintering Inhibition of Silver Nanoparticle Films via AgCl Nanocrystal Formation2017In: Nanomaterials, ISSN 2079-4991, Vol. 7, no 8, article id 224Article in journal (Refereed)
    Abstract [en]

    Electrically conductive films are key components in most printed and flexible electronics applications. For the solution processing of conductive films, inks containing silver nanoparticles (AgNPs) remain important because of their relatively easy processing and generally low resistivity after a sintering procedure. Because the commonly used, moderate sintering temperatures of 150-300 °C are still too high for most low-cost flexible substrates, expanding the knowledge of surface-ink interactions that affect the sintering temperature is desirable. It is known that chloride ions can assist the sintering of AgNP films by displacing capping agents on the surfaces of AgNPs. However, very little is known about other possible Cl-AgNP interactions that affect the resistivity and no interaction having the opposite effect (sintering inhibition) has been identified before. Here we identify such a Cl-AgNP interaction giving sintering inhibition and find that the mechanism involves the formation of AgCl nanocrystals within the AgNP film. The AgCl formation was observed after inkjet-printing of AgNP inks with polyvinylpyrrolidone (PVP) as the capping agent onto papers with quick-absorbing coatings containing 0.3 wt % KCl. Our findings show that chloride can have opposite roles during sintering, either assisting or inhibiting the sintering depending on the prevalence of AgCl formation. The prevalence of AgCl formation depends on the absorption properties and the capping agent.

  • 448.
    Öhlund, Thomas
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Schuppert, Anna
    Schoeller Technocell GmbH & Co KG, D-49086 Osnabruck, Germany.
    Andres, Britta
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Andersson, Henrik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Forsberg, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Schmidt, Wolfgang
    Schoeller Technocell GmbH & Co KG, D-49086 Osnabruck, Germany.
    Nilsson, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Andersson, Mattias
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Zhang, Renyun
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Assisted sintering of silver nanoparticle inkjet inks on paper with active coatings2015In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 5, p. 64841-64849Article in journal (Refereed)
    Abstract [en]

    Inkjet-printed metal films are important within the emerging field of printed electronics. For large-scale manufacturing, low-cost flexible substrates and low temperature sintering is desired. Tailored coated substrates are interesting for roll-to-roll fabrication of printed electronics, since a suitable tailoring of the ink-substrate system may reduce, or remove, the need for explicit sintering. Here we utilize specially designed coated papers, containing chloride as an active sintering agent. The built-in sintering agent greatly assists low-temperature sintering of inkjet-printed AgNP films. Further, we examine the effect of variations in coating pore size and precoating type. Interestingly, we find that the sintering is substantially affected by these parameters.

  • 449.
    Öhlund, Thomas
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Schuppert, Anna
    Institut Charles Gerhardt de Montpellier, France.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Bäckström, Joakim
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Nilsson, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Inkjet Fabrication of Copper Patterns for Flexible Electronics: Using Paper with Active Precoatings2015In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 7, no 33, p. 18273-18282Article in journal (Refereed)
    Abstract [en]

    Low-cost solution-processing of highly conductive films is important for the expanding market of printed electronics. For roll-to-roll manufacturing, suitable flexible substrates and compatible postprocessing are essential. Here, custom-developed coated papers are demonstrated to facilitate the inkjet fabrication of high performance copper patterns. The patterns are fabricated in ambient conditions using water-based CuO dispersion and intense pulsed light (IPL) processing. Papers using a porous CaCO3 precoating, combined with an acidic mesoporous absorption coating, improve the effectiveness and reliability of the IPL process. The processing is realizable within 5 ms, using a single pulse of light. A resistivity of 3.1 ± 0.12 μΩ·cm is achieved with 400 μm wide conductors, corresponding to more than 50% of the conductivity of bulk copper. This is higher than previously reported results for IPL-processed copper.

  • 450. Örtegren, Jonas
    et al.
    Wantke, Klaus-Dieter
    Motschmann, Hubert
    An oscillating bubble device for direct measurement of molecular exchange processes at the air-liquid interface in the medium frequency range2003In: Review of Scientific Instruments, ISSN 0034-6748, E-ISSN 1089-7623, Vol. 74, no 12, p. 5167-5172Article in journal (Refereed)
    Abstract [en]

    An experiment for the investigation of the exchange dynamics of adsorbed and dissolved surfactantsat the air–water interface is described. The experiment combines two established techniques: themethod of the oscillating bubble generates in a well-defined fashion a nonequilibrium state by aperiodic compression and expansion of the surface layer. The state of the adsorption layer is theninvestigated by surface second harmonic generation ~SHG!. SHG is a second order nonlinear opticaltechnique, which probes only the adsorbed molecules. Contribution of the bulk is widely suppressedand information on the orientational order of the surfactant and the corresponding number densityof the adsorbed species are gained. These data are of utmost importance to assess the establishedmodels of Gibbs adsorption layer. The combination of the nonlinear optical technique with a rapidlyoscillating bubble imposes severe experimental hurdles such as the synchronization of the laserpulses with the state of the bubble or problems arising from a bad signal to noise ratio. Theexperimental setup discussed in this article overcomes these problems and outlines all relevantdesign parameters.

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