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  • 101.
    Engström, Ann-Christine
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Graphite containing coatings aimed for supercapacitors2014Other (Other academic)
  • 102.
    Engström, Ann-Christine
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    UV-Vis spectrophotometry for analyzing the exfoliation of graphite in aqueous solutions2016Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Graphene has generated a great deal of interest all over the world in the last decade, mainly as a result of its unique properties such as high con-ductance and strength, which is of potential benefit for many electronic applications. One common strategy for producing increased quantities of few-layer graphene includes liquid-based methods, where graphite is peeled off or exfoliated. Ultraviolet-Visible (UV-Vis) spectrophotometry can be used for measuring the degree of exfoliation since the optical ab-sorbance at a given amount of graphite increases with the degree of exfo-liation. In this work, a UV-Vis method was tested where the exfoliated samples were stabilized with glycerol. This enabled measurements of both polydisperse samples directly after the exfoliation and also top-phase samples collected after gravitational sedimentation. Beer-Lam-bert’s law could be applied for quantifying the amount of exfoliated graphite in the samples. The samples were analyzed by focusing on the connection between absorbance, extinction and light scattering. It was found that the particle size and the contribution from light scattering de-creased at the presence of smaller particle sizes. It was also evident that the absorbance peak of graphite was shifted toward higher wavelengths as the exfoliation was progressed by repeated shearing. These are intri-guing results that warrant further studies as well as verification by alter-native spectroscopic analysis.In order to investigate the change in absorbance with different chemical and mechanical exfoliation conditions, studies were performed using a high-pressure capillary viscometer, ACAV A2. It was clear that an addi-tion of 2% polyacrylic acid (PAA) facilitated mixing and also increased the amount of dispersed graphite by more than six times. The mechanical treatment showed that both high-pressure shearing and sonication gave higher concentrations of nanographite compared to mechanical disper-sion by a rotary disperser. The overall conclusion of this study is that a combination of analysis is required for characterizing the particles. In or-der to quantify graphene, the analysis of chemical structure, inter-particle stability and flake cleanliness is very important.

  • 103.
    Eriksson, Anna-Maria
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Olsson, Jörgen
    Department of Ecology and Environmental Science, Umeå University, SE-901 87, Umeå, Sweden .
    Jonsson, Bengt Gunnar
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Toivanen, Sara
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Edman, Mattias
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Effects of restoration fire on deadwood heterogeneity and availability in three Pinus sylvestris forests in Sweden2013In: Silva Fennica, ISSN 0037-5330, E-ISSN 2242-4075, ISSN ISSN-L 0037-5330 | ISSN 2242-4075 (Online), Vol. 47, no 2, p. Art. no. 954-Article in journal (Refereed)
    Abstract [en]

    Restoration fires are increasingly used as a conservation tool in Sweden to recreate forests with characteristics of previous forests that were periodically disturbed by fires and promote firedependent species. Restoration fires can result in large inputs of fresh dead wood, but there are risks of losing some of the existing, pre-fire dead wood. To assess these counteracting effects we studied the heterogeneity and availability of dead wood before and after three restoration fires in boreal Scots pine forests. Specifically, we studied volumes of stumps, high stumps, snags and logs. The fires decreased the total volume of pre-fire dead wood (23-41%) and consumed logs in late decay stages (26-54%) to a higher extent than logs in earlier stages. The input of new fresh dead wood after the fires exceeded losses of pre-fire dead wood and resulted in a net increase of dead wood in all three sites. The added dead wood consisted of fresh snags killed by the fires. Fire also affected log characteristics: reducing their vegetation coverage (60-98%), decreasing their ground contact (4-50%) and increasing their surface area of charred wood (>50%). Such changes have important consequences for the micro environmental conditions inside logs, but have been rarely studied in relation to restoration fires. Our results show that restoration fire causes changes in dead wood availability and characteristics of logs. The results imply that ideally stands with low abundance of rare and heavily decayed wood substrates should be burned to optimize dead wood values. Alternatively, management practices should include protection of these substrates during restoration fires.

  • 104.
    Esseen, P. -A
    et al.
    Department of Ecology and Environmental Science, Umeå University, Umeå.
    Ekström, M.
    Department of Statistics, Umeå University, Umeå.
    Westerlund, B.
    Department of Forest Resource Management, Swedish University of Agricultural Sciences, Umeå.
    Palmqvist, K.
    Department of Ecology and Environmental Science, Umeå University, Umeå.
    Jonsson, Bengt Gunnar
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Grafström, A.
    Department of Forest Resource Management, Swedish University of Agricultural Sciences, Umeå.
    Ståhl, G.
    Department of Forest Resource Management, Swedish University of Agricultural Sciences, Umeå.
    Broad-scale distribution of epiphytic hair lichens correlates more with climate and nitrogen deposition than with forest structure2016In: Canadian Journal of Forest Research, ISSN 0045-5067, E-ISSN 1208-6037, Vol. 46, no 11, p. 1348-1358Article in journal (Refereed)
    Abstract [en]

    Hair lichens are strongly influenced by forest structure at local scales, but their broad-scale distributions are less understood. We compared the occurrence and length of Alectoria sarmentosa (Ach.) Ach., Bryoria spp., and Usnea spp. in the lower canopy of > 5000 Picea abies (L.) Karst. trees within the National Forest Inventory across all productive forest in Sweden. We used logistic regression to analyse how climate, nitrogen deposition, and forest variables influence lichen occurrence. Distributions overlapped, but the distribution of Bryoria was more northern and that of Usnea was more southern, with Alectoria's distribution being intermediate. Lichen length increased towards northern regions, indicating better conditions for biomass accumulation. Logistic regression models had the highest pseudo R2 value for Bryoria, followed by Alectoria. Temperature and nitrogen deposition had higher explanatory power than precipitation and forest variables. Multiple logistic regressions suggest that lichen genera respond differently to increases in several variables. Warmingdecreased the odds for Bryoria occurrence at all temperatures. Corresponding odds for Alectoria and Usnea decreased in warmer climates, but in colder climates, they increased. Nitrogen addition decreased the odds for Alectoria and Usnea occurrence under high deposition, but under low deposition, the odds increased. Our analyses suggest major shifts in the broad-scale distribution of hair lichens with changes in climate, nitrogen deposition, and forest management.

  • 105.
    Fagerlund-Edfeldt, Amelie
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Edman, Mattias
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Jonsson, Bengt Gunnar
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Effect of Debarking Water from Norway Spruce (Picea abies) on the Growth of Five Species of Wood-Decaying Fungi2014In: Zeitschrift für Naturforschung C - A Journal of Biosciences, ISSN 0939-5075, E-ISSN 1865-7125, Vol. 9-10, no 69c, p. 418-424Article in journal (Refereed)
    Abstract [en]

    Norway spruce (Picea abies) debarking water is an aqueous extract obtained as waste from the debarking of logs at paper mills. The debarking water contains a mixture of natural compounds that can exhibit diverse biological activities, potentially including fungicidal activity on some species of wood-decaying fungi. Thus, we investigated the growth rates of such fungi on agar plates to which debarking water extracts had been added. The experiment included five wood-decaying fungi, viz. Gloeophyllum sepiarium, Oligoporus lateritius, Ischnoderma benzoinum, Junghuhnia luteoalba, and Phlebia sp. Growth reduction was observed for all species at the highest tested concentrations of freeze-dried and ethanol-extracted debarking water, the ethyl acetate-soluble fraction and the diethyl ether-soluble fraction. However, the magnitude of the effect varied between different species and strains of individual species. The brown-rot fungi G. sepiarium and O. lateritius were generally the most sensitive species, with the growth of all tested strains being completely inhibited by the ethyl acetate-soluble fraction. These results indicate that development of antifungal wood-protecting agents from debarking water could potentially be a way to make use of a low-value industrial waste.

  • 106.
    Fors, Elin
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    En analys av lärarhandledningar inom biologi, årskurs F-32015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 107.
    Forsberg, Sven
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Andres, Britta
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Blomquist, Nicklas
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Dahlström, Christina
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Engström, Ann-Christine
    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.
    Paper-based supercapacitors2015Conference paper (Other academic)
  • 108.
    Forsberg, Sven
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Kumar, Vinay
    Åbo Akademi University.
    Engström, Ann-Christine
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Maristiina, Nurmi
    Åbo Akademi University.
    Dahlström, Christina
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Martti, Toivakka
    Åbo Akademi University.
    Effect of calendering and coating formulations on conductivity in paper-based electrodes2016Conference paper (Refereed)
  • 109.
    Forsberg, Viviane
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Liquid Exfoliation of Molybdenum Disulfide for Inkjet Printing2016Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Since the discovery of graphene, substantial effort has been put toward the synthesis and production of 2D materials. Developing scalable methods for the production of high-quality exfoliated nanosheets has proved a significant challenge. To date, the most promising scalable method for achieving these materials is through the liquid-based exfoliation (LBE) of nanosheetsin solvents. Thin films of nanosheets in dispersion can be modified with additives to produce 2D inks for printed electronics using inkjet printing. This is the most promising method for the deposition of such materials onto any substrate on an industrial production level. Although well-developed metallic and organic printed electronic inks exist on the market, there is still a need to improve or develop new inks based on semiconductor materials such as transition metal dichalcogenides (TMDs) that are stable, have good jetting conditions and deliver good printing quality.The inertness and mechanical properties of layered materials such as molybdenum disulfide (MoS2) make them ideally suited for printed electronics and solution processing. In addition,the high electron mobility of the layered semiconductors, make them a candidate to become a high-performance semiconductor material in printed electronics. Together, these features make MoS2 a simple and robust material with good semiconducting properties that is also suitable for solution coating and printing. It is also environmentally safe.The method described in this thesis could be easily employed to exfoliate many types of 2D materials in liquids. It consists of two exfoliation steps, one based on mechanical exfoliation of the bulk powder utilizing sand paper, and the other inthe liquid dispersion, using probe sonication to liquid-exfoliate the nanosheets. The dispersions, which were prepared in surfactant solution, were decanted, and the supernatant was collected and used for printing tests performed with a Dimatix inkjetprinter. The printing test shows that it is possible to use the MoS2 dispersion as a printed electronics inkjet ink and that optimization for specific printer and substrate combinations should be performed. There should also be advances in ink development, which would improve the drop formation and break-off at the inkjet printing nozzles, the ink jetting and, consequently, the printing quality.

  • 110.
    Forsberg, Viviane
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Andersson, Henrik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Engholm, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Thungström, Göran
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Zhang, Renyun
    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.
    Norgren, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Photodetector of multilayer exfoliated MoS2 deposited on polyimide films2018Conference paper (Other academic)
    Abstract [en]

    We fabricated a photodetector based on multilayer molybdenum disulfide (MoS2) by micromechanical cleavage of a molybdenite crystal using a polyimide film. We deposited 40 nm of gold by vacuum sputtering and copper tape was used for the contacts.  Without any surface treatment, we achieved high responsivity at different incident optical power. The calculated responsivity was 23 mA/W of incident optical power in the range between 400 and 800 nm. For the responsivity measurement it was estimated that MoS2 have a bandgap of 1.6 eV, which lies between monolayer and multilayer films. The thickness of the MoS2 thin film was determined by Raman spectroscopy evaluating the difference between the in plane  and out of plane  Raman modes. The measurement of IV curves indicated Ohmic contacts in respect to the Au regardless of the incident optical power. Our device fabrication was much simpler than previous reported devices and can be used to test the light absorption and luminescence capabilities of exfoliated MoS2.

  • 111.
    Forsberg, Viviane
    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.
    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.
    Cellulose stabilizers for 2D materials inkjet inks2017Conference paper (Refereed)
    Abstract [en]

    To date, the most promising scalable method for achieving 2D materials dispersions is through liquidbasedexfoliation of nanosheets in solvents. We study the use of high throughput shear exfoliation insteadof sonication to exfoliate water dispersions of MoS2 using environmental friendly stabilizers based oncellulose. The resulted dispersion was then concentrated and inkjet printed on a flexible substrate. We usedethyl cellulose, cellulose nanofibers (CNF) and ultra-fine cellulose nanofibers (UF-CNF). The stability wasevaluated by measuring the differences in concentration over time. The particle size distribution (PSD) ofthe dispersed particles was evaluated using statistical methods applied to SEM images of the dispersions(See Fig 1 and 2). The zeta potential and the mechanisms of stabilization involved was evaluated (See Fig4). All three stabilizers appear to work very well for MoS2 nanosheets even though the mechanisms ofstabilization were different i.e. steric stabilization for MoS2-EC and electrostatic stabilization for MoS2-CNF and MoS2-UF-CNF dispersions. For the MoS2-EC dispersions we achieved a broader PSD (Fig. 1)and higher stability. Thin nanosheets was observed from the SEM image of MoS2-EC dispersions depositedonto cellulose filters by vacuum filtration (Fig. 5) which demonstrated that the exfoliation technique usedwas successful. The estimated concentration of the MoS2-EC dispersion after 8 days of sample preparationwas 0.24 mg/mL, 77% of the initial concentration (see Fig. 6) and it was relatively steady after 40 days ofsample preparation (0.22 mg/mL). To adjust the concentration and the viscosity of the MoS2-EC dispersion,we concentrated it using a rotary evaporator solvent exchange technique. For this we used terpineol andadjusted the viscosity using ethanol. This paper presents the results of an inkjet 2D material ink usingenvironmental friendly components different than previous 2D materials inks that used organic solvents orwater based dispersions containing surfactants.

  • 112.
    Forsberg, Viviane
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Maslik, Jan
    Tomas Bata University.
    Andersson, Henrik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Dahlström, Christina
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Toivakka, Martti
    Åbo Akademi University.
    Koppolu, Rajesh
    Åbo Akademi University.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Norgren, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Printability of functional inkjet inks onto commercial inkjet substrates and a taylor made pigmented coated paper2018Conference paper (Other academic)
    Abstract [en]

    Printed electronics are of increasing interest. The substrates used have primarily been plastics although the interest for cellulose-based substrates is increasing due to the environmental aspect as well as cost. The requirements of substrates for electronically active inks differs from graphical inks and therefore we have investigated a custom-made pigment based coated paper and compared it to commercial photo-papers and a coated PE film.

    Our goal with the study of different substrates was to select the most suitable substrate to print water based 2D materials inkjet inks for flexible electronics.

    The discovery of graphene, a layered material achieved from the exfoliation of graphite, has resulted in the study of other materials with similar properties to cover areas where graphene could not be used due to the absence of a bandgap in the material. For example in thin film transistors (TFT) a semiconductor layer is essential to enable turn on and off the device. This semiconductor layer can be achieved using various materials but particular interest have been dedicated to abundant and cheap 2D materials such as the transition metal dichalcogenide (TMD) molybdenum disulfide (MoS2). To date, most of the dispersions based on TMDs use organic solvents or water solutions of surfactants. Previously we focus on the study of environmental friendly inks produced by liquid phase exfoliation (LPE) of MoS2 in water using cellulose stabilizers such as ethyl cellulose (EC), cellulose nanofibrils (CNF) and nanofibrilcellulose (NFC). We have study various aspects of the ink fabrication includi  ng pH range, the source of MoS2, nanosheets thickness, particle size distribution,  ink stabilizers, ink concentration, viscosity and surface tension. These inks have very low concentration requiring a number of printing passes to cover the substrate. Therefore the substrate selection is crucial as a large amount of solvent is to be absorb by the substrate. Our goal was to use such an ink to print electrodes of MoS2 into a paper substrate after substrate selection.

    Commercial photo papers, a commercial coated PE film and a tailor made multilayer pigment coated paper substrate were used for the substrate selection analysis.  We print the substrates using a DIMATIX inkjet printer with a 10 pL printing head using the distillated water waveform supplied by the printer manufacturer. The voltage used was 23V and 4 nozzles were used for the print outs. The inkjet ink used was the organic PEDOT:PSS. We printed lines ranging from 1 pixel to 20 pixels with 1, 2 and 3 printing passes. The printing quality was evaluated through measurements of the waviness of the printed lines measured after imaging the printed samples with a SEM microscope. The line width measurement was done using the software from the SEM.

    We also evaluated the structure of the coatings using SEM and topography measurements. The ink penetration through the substrates was evaluated using Raman Spectroscopy. For the pigmented coated sample we measured 4% of ink penetration through the substrate for the 1pxl printed line printed once onto the paper.  Cross-section SEM images of the printed lines were made to visualize the ink penetration into the substrate.

    Regarding the electrical conductivity of the printed samples, the differences in resistivity varying the width of the printed lines and the number of printed passes were evaluated. The resistivity of the printed electrodes was evaluated using the 2-points probe method. Before the resistivity measurements, the printed substrates were heated at 50°C and 100°C for 30 minutes in an oven.

    We choose the PEDOT:PSS ink because it is a low price ink compared to metal nanoparticles inks for printed electronics. The print outs had low resistivity at a few printing passes with no need for sintering at high temperatures. The MoS2 ink has a very high resistance at a few printing passes due to lower coverage of the substrate therefore for this ink these measurements were not possible to be made. The main pigment composition of the paper coatings of the substrates was evaluated using FT-IR and EDX, these data plus the coating structure evaluated by SEM was related to the print quality.

    The best in test papers were used to print MoS2 electrodes. After the printing tests, another step for the optimization of the MoS2 ink properties shall be carried out in future studies for better print quality. We also evaluated the surface energy of the substrates through contact angle measurements to match the surface tension of the PEDOT:PSS ink and later the MoS2 ink. Although the pigmented coated printing substrate did not show better results than the commercial photo papers and PE foil in terms of line quality, it shows the lowest resistivity and sufficient results for low cost recyclable electronics, which do not require high conductivity. Nevertheless, the substrate was very thin and it could even be used in magazines as traditional lightweight coated papers (LWC) are used but with the additional of a printed electronic feature.

  • 113.
    Forsberg, Viviane
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Norgren, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Green materials for inkjet printing of 2D materials and transparent electronics2018Conference paper (Other (popular science, discussion, etc.))
  • 114.
    Forsberg, Viviane
    et al.
    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.
    Andersson, Henrik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Bäckström, Joakim
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Dahlström, Christina
    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.
    Andres, Britta
    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.
    Liquid Exfoliation of Layered Materials in Water for Inkjet Printing2016In: Printing for Fabrication 2016: Materials, Applications, and Processes, USA: Curran Associates, Inc., 2016Conference paper (Refereed)
    Abstract [en]

    MoS2 is a layered material which is abundant and non-toxic and has been increasingly studied during the last few years as a semiconducting alternative to graphene. While most studies have been performed on single MoS2 nanosheets, for example to demonstrate high-performance electronic transistors, more work is needed to explore the use of MoS2 in printed electronics. The importance of using MoS2 as a printed electronic material could be understood by considering the several orders higher electron mobility in MoS2, even in several nanometer thick layers, compared to the organic and other materials used today. In the few studies performed so far on printing MoS2, the developed dispersions used mainly organic solvents that might be detrimental for the environment. Here, we show an environmentally friendly liquid-based exfoliation method in water where the solution was stabilized by sodium dodecyl sulfate (SDS) surfactant. The dispersions consisted of very thin MoS2 nanosheets with average lateral size of about 150 nm, surface tension of 28 mN m-1 and a shelf life of a year. Although both the concentration and viscosity was less than optimal, we were able to inkjet print the MoS2 solution on paper and on PET films, using multiple printing passes. By tuning the concentration/viscosity, this approach might lead to an environmentally friendly MoS2 ink suitable for printed electronics.

  • 115.
    Forsberg, Viviane
    et al.
    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.
    Andersson, Henrik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Bäckström, Joakim
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Dahlström, Christina
    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.
    Andres, Britta
    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.
    Liquid Exfoliation of Layered Materials in Water for Inkjet Printing2016In: Journal of Imaging Science and Technology, ISSN 1062-3701, E-ISSN 1943-3522, Vol. 60, no 4, p. 1-7, article id 040405Article in journal (Refereed)
    Abstract [en]

    MoS2 is a layered material which is abundant and non-toxic and has been increasingly studied during the last few years as a semiconducting alternative to graphene. While most studies have been performed on single MoS2 nanosheets, for example to demonstrate high-performance electronic transistors, more work is needed to explore the use of MoS2 in printed electronics. The importance of using MoS2 as a printed electronic material could be understood by considering the several orders higher electron mobility in MoS2, even in several nanometer thick layers, compared to the organic and other materials used today. In the few studies performed so far on printing MoS2, the developed dispersions used mainly organic solvents that might be detrimental for the environment. Here, we show an environmentally friendly liquid-based exfoliation method in water where the solution was stabilized by sodium dodecyl sulfate (SDS) surfactant. The dispersions consisted of very thin MoS2 nanosheets with average lateral size of about 150 nm, surface tension of 28 mN m(-1), and a shelf life of a year. Although both the concentration and viscosity was less than optimal, we were able to inkjet print the MoS2 solution on paper and on PET films, using multiple printing passes. By tuning the concentration/viscosity, this approach might lead to an environmentally friendly MoS2 ink suitable for printed electronics.

  • 116.
    Forsberg, Viviane
    et al.
    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.
    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.
    The Influence of pH on the Stability of Inks of Two-Dimensional Materials for Digital Fabrication2017Conference paper (Refereed)
    Abstract [en]

    We aim to achieve stable printable 2D inks with environmental friendly solvents using a surfactant as a stabilizer. This study focuses on the influence of the pH on the stability of the MoS2 dispersionsin acetic acid at concentrations ranging from pH 1 to 5.The effectiveness of liquid-based exfoliation using shear exfoliation was also evaluated though SEM images and resulted in very thin nanosheets. We observed that at pH concentrations higher than 2, the dispersions were more stable.

  • 117.
    Forsberg, Viviane
    et al.
    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.
    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.
    Towards flexible and cheap printed electronics using inks of exfoliated 2D materials stabilized by cellulose2017Conference paper (Other academic)
    Abstract [en]

    Flexible and cheap electronics are needed for simple applications such as sensors and solar cells. To achieve this, thin functional materials should be deposited efficiently to flexible substrates such as paper. A promising method for the deposition of such materials is through inkjet printing that said a stable and printable dispersion is necessary. We achieved this through liquid-based exfoliation of 2D materials in water using shear exfoliation and cellulose stabilizers. The resulted dispersion was then concentrated and inkjet printed on a flexible substrate. We used ethyl cellulose, cellulose nanofibers (CNF) and ultra-fine cellulose nanofibers (UF-CNF). All three stabilizers appear to work very well for MoS2 nanosheets even though the mechanisms of stabilization were different among them. For the MoS2-EC dispersions we achieved a broader PSD and higher dispersion stability. Thin nanosheets were observed from the SEM image of MoS2-EC dispersions deposited onto cellulose filters. The estimated concentration of the MoS2-EC dispersion after 20 days of sample preparation was 0.20 mg/mL. This dispersion was further processed to adjust the concentration and viscosity.  Good coverage of the substrate was achieved after 50 printing passes. If the same technique is applied to other 2D materials such as graphene (conductor) and boro nitride (insulator), a transistor can be fabricated.

  • 118.
    Forsberg, Viviane
    et al.
    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.
    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.
    Towards stable 2D materials inkjet inks: a study of stabilizers and MoS2 grades2017Conference paper (Refereed)
  • 119.
    Forsberg, Viviane
    et al.
    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.
    Joakim, Bäckström
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Dahlström, Christina
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Andres, Britta
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Norgren, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Andersson, Mattias
    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.
    Exfoliated MoS2 in Water without Additives2016In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 11, no 4, article id 0154522Article in journal (Refereed)
    Abstract [en]

    Many solution processing methods of exfoliation of layered materials have been studied during the last few years; most of them are based on organic solvents or rely on surfactants andother funtionalization agents. Pure water should be an ideal solvent, however, it is generallybelieved, based on solubility theories that stable dispersions of water could not be achievedand systematic studies are lacking. Here we describe the use of water as a solvent and thestabilization process involved therein. We introduce an exfoliation method of molybdenumdisulfide (MoS2) in pure water at high concentration (i.e., 0.14±0.01 g L−1). This was achieved by thinning the bulk MoS2by mechanical exfoliation between sand papers and dis-persing it by liquid exfoliation through probe sonication in water. We observed thin MoS2nanosheets in water characterized by TEM, AFM and SEM images. The dimensions of thenanosheets were around 200 nm, the same range obtained in organic solvents. Electropho-retic mobility measurements indicated that electrical charges may be responsible for the sta-bilization of the dispersions. A probability decay equation was proposed to compare thestability of these dispersions with the ones reported in the literature. Water can be used as asolvent to disperse nanosheets and although the stability of the dispersions may not be ashigh as in organic solvents, the present method could be employed for a number of applications where the dispersions can be produced on site and organic solvents are not desirable.

  • 120.
    Fransson, Petra
    et al.
    Swedish Univ Agr Sci, Uppsala BioCtr, Dept Forest Mycol & Plant Pathol, Uppsala, Sweden.
    Andersson, Alexandra
    Swedish Univ Agr Sci, Uppsala BioCtr, Dept Forest Mycol & Plant Pathol, Uppsala, Sweden.
    Norström, Sara
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences. Umeå Univ, Dept Chem, SE-90187 Umeå, Sweden.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Bent, Elizabeth
    Univ Guelph, Sch Environm Sci, Guelph, ON N1G 2W1, Canada.
    Ectomycorrhizal exudates and pre-exposure to elevated CO2 affects soil bacterial growth and community structure2016In: Fungal ecology, ISSN 1754-5048, E-ISSN 1878-0083, Vol. 20, p. 211-224Article in journal (Refereed)
    Abstract [en]

    Ectomycorrhizal fungi produce low molecular weight organic compounds, supporting diverse microbial communities. To link mycorrhizal root exudation directly to bacterial responses, we used Scots pine exudates with (Suillus variegatus and Piloderma fallax) and without mycorrhiza as substrata for forest soil bacteria. Bacterial growth and vitality was monitored, and community composition determined using TRFLP, cloning and sequencing. We investigated if the amount of organic acids in exudates explained bacterial growth, and whether bacterial communities were influenced by pre-exposure to elevated atmospheric CO2. We demonstrated functional differences in bacterial growth rates related to CO2. There was a shift in the bacterial community (e.g. Burkholderia sp. and gamma-proteobacteria) toward organisms better able to rapidly utilize exudates when pine microcosms were pre-exposed to elevated CO2. Soil bacteria from all treatments tended to grow more abundantly and rapidly in exudates from Pilo derma -colonized seedlings, suggesting that the organic acids and/or unidentified compounds present supported greater growth.

  • 121.
    Fraver, Shawn
    et al.
    Department of Forest Resources, University of Minnesota, St. Paul, MN, 55108, United States .
    D'Amato, Anthony W.
    Department of Forest Resources, University of Minnesota, St. Paul, MN, 55108, United States .
    Bradford, John B.
    US Geological Survey, Southwest Biological Science Center, Flagstaff, AZ, 86001, United States .
    Jonsson, Bengt Gunnar
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Jönsson, Mari
    The Swedish Species Information Centre, Swedish University of Agricultural Sciences, Uppsala, 750 07, Sweden .
    Esseen, Per-Anders
    Department of Ecology and Environmental Science, Umeå University, Umeå, 901 87, Sweden .
    Tree growth and competition in an old-growth Picea abies forest of boreal Sweden: influence of tree spatial patterning2014In: Journal of Vegetation Science, ISSN 1100-9233, E-ISSN 1654-1103, Vol. 25, no 2, p. 374-385Article in journal (Refereed)
    Abstract [en]

    Question What factors best characterize tree competitive environments in this structurally diverse old-growth forest, and do these factors vary spatially within and among stands? Location Old-growth Picea abies forest of boreal Sweden. Methods Using long-term, mapped permanent plot data augmented with dendrochronological analyses, we evaluated the effect of neighbourhood competition on focal tree growth by means of standard competition indices, each modified to include various metrics of trees size, neighbour mortality weighting (for neighbours that died during the inventory period), and within-neighbourhood tree clustering. Candidate models were evaluated using mixed-model linear regression analyses, with mean basal area increment as the response variable. We then analysed stand-level spatial patterns of competition indices and growth rates (via kriging) to determine if the relationship between these patterns could further elucidate factors influencing tree growth. Results Inter-tree competition clearly affected growth rates, with crown volume being the size metric most strongly influencing the neighbourhood competitive environment. Including neighbour tree mortality weightings in models only slightly improved descriptions of competitive interactions. Although the within-neighbourhood clustering index did not improve model predictions, competition intensity was influenced by the underlying stand-level tree spatial arrangement: stand-level clustering locally intensified competition and reduced tree growth, whereas in the absence of such clustering, inter-tree competition played a lesser role in constraining tree growth. Conclusions Our findings demonstrate that competition continues to influence forest processes and structures in an old-growth system that has not experienced major disturbances for at least two centuries. The finding that the underlying tree spatial pattern influenced the competitive environment suggests caution in interpreting traditional tree competition studies, in which tree spatial patterning is typically not taken into account. Our findings highlight the importance of forest structure - particularly the spatial arrangement of trees - in regulating inter-tree competition and growth in structurally diverse forests, and they provide insight into the causes and consequences of heterogeneity in this old-growth system.

  • 122.
    Gradin, Per
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Berg, Jan-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Nyström, Staffan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Measuring Tangential Forces in a Pulp Refiner: A Novel Approach2016In: Experimental techniques (Westport, Conn.), ISSN 0732-8818, E-ISSN 1747-1567, Vol. 40, no 2, p. 789-793Article in journal (Refereed)
    Abstract [en]

    To get some insight into the processes that are active during the refining of wood, the tangential force distribution in the plate gap is of interest. Over the years several designs of force sensors have been developed for this purpose. One drawback with these designs is that each sensormeasures forces over quite a small area such that in order to cover the whole disc with a reasonably good resolution, many sensors have to be used. Also, there are problems to protect the active parts of the sensors from the harsh environment in the plate gap. In this paper a different concept is presented, in that the sensor is continuous and consists of a hollow radial bar equipped with strain gages on the inside. The force sensor was calibrated before mounting by loading it with a known load in the tangential direction and in different positions while measuring the strains in the points where the gages are located. This makes it possible to determine the so-called influence (or Green) functions. Knowing these it is possible to determine the tangential force distribution from strain values measured during operation of the refiner. Guidelines for doing this are presented together with a detailed description of the load sensor and some experimental results.

  • 123.
    Graça, Juliana Santos
    et al.
    Federal University of São Carlos, Center for Sciences and Technology for Sustainability, Sorocaba, SP, Brazil.
    Miyazaki, Celina Massumi
    Federal University of São Carlos, Center for Sciences and Technology for Sustainability, Sorocaba, SP, Brazil.
    Shimizu, Flavio M.
    University of São Paulo, São Carlos, SP, Brazil.
    Volpati, Diogo
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Mejía-Salazar, J. R.
    University of São Paulo, São Carlos, SP, Brazil.
    Oliveira Jr, Osvaldo N.
    University of São Paulo, São Carlos, SP, Brazil.
    Ferreira, Marystela
    Federal University of São Carlos, Center for Sciences and Technology for Sustainability, Sorocaba, SP, Brazil.
    On the importance of controlling film architecture in detecting prostate specific antigen2018In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 434, p. 1175-1182Article in journal (Refereed)
    Abstract [en]

    Immunosensors made with nanostructured films are promising for detecting cancer biomarkers, even at early stages of the disease, but this requires control of film architecture to preserve the biological activity of immobilized antibodies. In this study, we used electrochemical impedance spectroscopy (EIS) to detect Prostate Specific Antigen (PSA) with immunosensors produced with layer-by-layer (LbL) films containing anti-PSA antibodies in two distinct film architectures. The antibodies were either adsorbed from solutions in which they were free, or from solutions where they were incorporated into liposomes of dipalmitoyl phosphatidyl glycerol (DPPG). Incorporation into DPPG liposomes was confirmed with surface plasmon resonance experiments, while the importance of electrostatic interactions on the electrical response was highlighted using the Finite Difference Time-Domain Method (FDTD). The sensitivity of both architectures was sufficient to detect the threshold value to diagnose prostate cancer (ca. 4 ng mL−1). In contrast to expectation, the sensor with the antibodies incorporated into DPPG liposomes had lower sensitivity, though the range of concentrations amenable to detection increased, according to the fitting of the EIS data using the Langmuir-Freundlich adsorption model. The performance of the two film architectures was compared qualitatively by plotting the data with a multidimensional projection technique, which constitutes a generic approach for optimizing immunosensors and other types of sensors. 

  • 124.
    Gudrunsson, Mikael
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Forest fire drives long-term community changes of wood-decaying fungi in a boreal forest archipelago2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Conservation of wood-decaying fungi requires improved knowledge about the long-term effects of forest management; regarding habitat loss, fragmentation and fire suppression. To better understand such effects, I examined the influence of area, isolation, fire history and forest stand characteristics on communities of wood-decaying fungi. Species richness and composition were studied along a gradient of 22 forested islands varying in size (0.16 to 17.58 ha) and fire history (spanning 5000 years) in a boreal forest archipelago in northern Sweden. A total of 490 records of 41 polypore species were found in 33 circular plots, each 0.1 ha in size. Species richness and the number of red-listed species were analyzed using generalized linear models (GLMs), while species composition was examined using non-metric multidimensional scaling (NMDS) ordination. The species composition was clearly different between recent-fire (< 300 years since last fire) and old-fire (≥ 300 years since last fire) islands, mirroring the shift in tree species composition as pine-associated fungal species were replaced by spruce-associated fungal species. The volume of logs was the only variable influencing the species richness, although the diversity of logs showed a clear trend of also influencing species richness positively. The results demonstrate the importance of having both recent-fire and old-fire forests as landscape-level habitats and species pools, where fire naturally would constitute a key role for maintaining forest biodiversity in the boreal forest landscape. The results also stress the importance of dead wood for species richness at the individual forest stands.

  • 125.
    Gustafsson Coppel, Ludovic
    et al.
    Norwegian Colour and Visual Computing Laboratory, Gjøvik University College, Gjøvik, Norway.
    Andersson, Mattias
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Norberg, Ole
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lindberg, S.
    Innventia AB, Stockholm, Sweden.
    Impact of illumination spectral power distribution on radiance factor of fluorescing materials2013In: 2013 Colour and Visual Computing Symposium, CVCS 2013, 2013, p. Art. no. 6626275-Conference paper (Refereed)
    Abstract [en]

    The spectral radiance factor and thereby the appearance of fluorescing material is known to depend strongly on the spectral power distribution (SPD) of the illumination in the fluorophore's excitation wavelength band. The present work demonstrates the impact of the SPD in the fluorescence emission band on the total radiance factor. The total radiance factor of a fluorescing paper is measured in three different illuminations. The presence of peaks in the SPD of fluorescent light tubes dramatically decreases the luminescent radiance factor. This effect will impact the appearance of fluorescing media under illuminations with large variation in SPD, which includes recent LED illuminations. © 2013 IEEE.

  • 126.
    Gustafsson Coppel, Ludovic
    et al.
    Gjovik Univ Coll, Fac Comp Sci & Media Technol, N-2815 Gjovik, Norway.
    Johansson, Niklas
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Neuman, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Angular dependence of fluorescence from turbid media2015In: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 23, no 15, p. 19552-19564Article in journal (Refereed)
    Abstract [en]

    We perform Monte Carlo light scattering simulations to study the angular distribution of the fluorescence emission from turbid media and compare the results to measured angular distributions from fluorescing white paper samples. The angular distribution of fluorescence emission is significantly depending on the concentration of fluorophores. The simulations show also a dependence on the angle of incidence that is however not as evident in the measurements. A detailed analysis of the factors affecting this angular distribution indicates that it is strongly correlated to the mean depth of the fluorescence process. The findings can find applications in fluorescence spectroscopy and are of particular interest when optimizing the impact of fluorescence on e.g.the appearance of paper as the measured values are angle dependent.

  • 127.
    Gylle, A. Maria
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Nygård, Charlotta A.
    Cty Adm, Dept Environm, S-87186 Harnosand, Sweden .
    Svan, Carina I.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Pocock, Tessa
    Heliospectra AB, S-50630 Boras, Sweden.
    Ekelund, Nils G. A.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Photosynthesis in relation to D1, PsaA and Rubisco in marine and brackish water ecotypes of Fucus vesiculosus and Fucus radicans (Phaeophyceae)2013In: Hydrobiologia, ISSN 0018-8158, E-ISSN 1573-5117, Vol. 700, no 1, p. 109-119Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to investigate photosynthetic differences between the marine, Norwegian Sea ecotype and the brackish, Bothnian Sea ecotype of F. vesiculosus and F. radicans and to see whether photosynthetic differences could be connected with the relative amounts of D1 protein (PSII), PsaA (PSI) protein and/or Rubisco. For this purpose, we tested if a higher photosynthetic maximum (P (max)) in the Atlantic Ocean ecotype of F. vesiculosus relative to the Baltic Sea ecotype, and an increase of the P (max) in Baltic Sea ecotype of F. vesiculosus at higher salinity, could be due to an increase in the relative amounts of Rubisco. The proteins have been evaluated on a relative basis. Immunoblot signals showed that the amount of Rubisco was higher in both ecotypes of F. vesiculosus than in F. radicans, but no differences could be detected between the two ecotypes of F. vesiculosus. The results suggest an uneven photosystem protein stoichiometry in Fucus, with more of the PSI protein PsaA relative to the PSII protein D1. The difference in P (max) between the two ecotypes of F. vesiculosus might be related to the difficulties for the algae to adapt to the environment in Bothnian Sea.

  • 128.
    Haddaway, Neal R.
    et al.
    Stockholm Environm Inst, Mistra Council Evidence Based Environm Management, Stockholm.
    Bernes, Claes
    Stockholm Environm Inst, Mistra Council Evidence Based Environm Management, Stockholm.
    Jonsson, Bengt Gunnar
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hedlund, Katarina
    Lund Univ, Dept Biol, Lund.
    The benefits of systematic mapping to evidence-based environmental management2016In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 45, no 5, p. 613-620Article in journal (Refereed)
    Abstract [en]

    Reviews of evidence are a vital means of summarising growing bodies of research. Systematic reviews (SRs) aim to reduce bias and increase reliability when summarising high priority and controversial topics. Similar to SRs, systematic maps (SMs) were developed in social sciences to reliably catalogue evidence on a specific subject. Rather than providing answers to specific questions of impacts, SMs aim to produce searchable databases of studies, along with detailed descriptive information. These maps (consisting of a report, a database, and sometimes a geographical information system) can prove highly useful for research, policy and practice communities, by providing assessments of knowledge gaps (subjects requiring additional research), knowledge gluts (subjects where full SR is possible), and patterns across the research literature that promote best practice and direct research resources towards the highest quality research. Here, we introduce SMs in detail using three recent case studies that demonstrate their utility for research and decision-making.

  • 129.
    Hafrén, Jonas
    et al.
    Swedish University of Agricultural Sciences, Uppsala.
    Córdova, Armando
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences. Stockholm University.
    Organoclick: Applied Eco-Friendly and Metal-Free Catalysis for Wood and Fiber Modifications2016In: Industrial Biorenewables: A Practical Viewpoint, John Wiley & Sons, 2016, p. 437-450Chapter in book (Other academic)
    Abstract [en]

    This chapter provides a brief background to the research area of organocatalysis with respect to wood and fiber modification. It focuses on some of the examples of industrially produced materials from the chemical company OrganoClick AB, which employ organocatalytic reactions for modification, and to add new or improved functionalities to wood and natural fiber materials. The biomimetic activation of organic compounds via fundamental activation mechanisms is key in our efforts to create new functionally modified wood or fiber materials. There has been extensive research on the cross-linking of polysaccharides. The most common methods apply inorganic acids as catalysts for the cross-linking of the polysaccharide chains with low-molecular cross-linking agents, which are actually not eco-friendly. The novel materials could be of interest for the printing- or cellulose-based packaging industries. The OrganoWood process is based on mimicking the natural fossilization process in which wood is slowly transformed into mineral.

  • 130.
    Halme, P.
    et al.
    Department of Biological and Environmental Science, University of Jyväskylä, Finland.
    Allen, K. A.
    School of Environmental Sciences, University of Liverpool, United Kingdom .
    Auniņš, A.
    Faculty of Biology, University of Latvia, Riga, Latvia .
    Bradshaw, R. H. W.
    School of Environmental Sciences, University of Liverpool, United Kingdom .
    Brumelis, G.
    Faculty of Biology, University of Latvia, Riga, Latvia .
    Čada, V.
    Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Czech Republic .
    Clear, J. L.
    School of Environmental Sciences, University of Liverpool, United Kingdom .
    Eriksson, Anna-Maria
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hannon, G.
    School of Environmental Sciences, University of Liverpool, United Kingdom .
    Hyvärinen, E.
    Metsähallitus, Natural Heritage Services, Finland.
    Ikauniece, S.
    Faculty of Natural Sciences and Mathematics, Daugavpils University, Daugavpils, Latvia .
    Iršenaite, R.
    Institute of Botany of Nature Research Centre, Vilnius, Lithuania.
    Jonsson, Bengt Gunnar
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Junninen, K.
    Metsähallitus, Natural Heritage Services, Finland.
    Kareksela, S.
    Department of Biological and Environmental Science, University of Jyväskylä, Finland.
    Komonen, A.
    Department of Biological and Environmental Science, University of Jyväskylä, Finland.
    Kotiaho, J. S.
    Department of Biological and Environmental Science, University of Jyväskylä, Finland.
    Kouki, J.
    School of Forest Sciences, University of Eastern Finland, Joensuu, Finland.
    Kuuluvainen, T.
    Department of Forest Sciences, University of Helsinki, Finland .
    Mazziotta, A.
    Department of Biological and Environmental Science, University of Jyväskylä, Finland.
    Mönkkönen, M.
    Department of Biological and Environmental Science, University of Jyväskylä, Finland.
    Nyholm, K.
    Department of Biological and Environmental Science, University of Jyväskylä, Finland.
    Oldén, A.
    Department of Biological and Environmental Science, University of Jyväskylä, Finland.
    Shorohova, E.
    Finnish Forest Research Institute Metla, Vantaa, Finland .
    Strange, N.
    Forest and Landscape, Centre for Macroecology, Evolution and Climate, University of Copenhagen, Denmark.
    Toivanen, T.
    Department of Biological and Environmental Science, University of Jyväskylä, Finland.
    Vanha-Majamaa, I.
    Finnish Forest Research Institute Metla, Vantaa, Finland .
    Wallenius, T.
    Department of Forest Sciences, University of Helsinki, Finland .
    Ylisirniö, A. -L
    Arctic Centre, University of Lapland, Finland .
    Zin, E.
    Forest Research Institute (IBL), European Centre for Natural Forests, Białowieza, Poland.
    Challenges of ecological restoration: Lessons from forests in northern Europe2013In: Biological Conservation, ISSN 0006-3207, E-ISSN 1873-2917, Vol. 167, p. 248-256Article, review/survey (Refereed)
    Abstract [en]

    The alarming rate of ecosystem degradation has raised the need for ecological restoration throughout different biomes and continents. North European forests may appear as one of the least vulnerable ecosystems from a global perspective, since forest cover is not rapidly decreasing and many ecosystem services remain at high level. However, extensive areas of northern forests are heavily exploited and have lost a major part of their biodiversity value. There is a strong requirement to restore these areas towards a more natural condition in order to meet the targets of the Convention on Biological Diversity. Several northern countries are now taking up this challenge by restoring forest biodiversity with increasing intensity. The ecology and biodiversity of boreal forests are relatively well understood making them a good model for restoration activities in many other forest ecosystems. Here we introduce northern forests as an ecosystem, discuss the historical and recent human impact and provide a brief status report on the ecological restoration projects and research already conducted there. Based on this discussion, we argue that before any restoration actions commence, the ecology of the target ecosystem should be established with the need for restoration carefully assessed and the outcome properly monitored. Finally, we identify the most important challenges that need to be solved in order to carry out efficient restoration with powerful and long-term positive impacts on biodiversity: coping with unpredictability, maintaining connectivity in time and space, assessment of functionality, management of conflicting interests and social restrictions and ensuring adequate funding. © 2013 Elsevier Ltd.

  • 131.
    Hamburg, Henrik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Sprickor i knivhållare: En haveriutredning2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 132.
    Hammarling, Krister
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Hilborn, J.
    Uppsala University, Ångströmlaboratoriet, Lägerhyddsvägen 1, Uppsala, Sweden .
    Nilsson, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Manuilskiy, Anatoliy
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Blood pH optrode based on evanescent waves and refractive index change2014In: Progress in Biomedical Optics and Imaging - Proceedings of SPIE, 2014, p. Art. no. 89381F-Conference paper (Refereed)
    Abstract [en]

    Sensing pH in blood with an silica multimode optical fiber. This sensor is based on evanescent wave absorption and measures the change of the refractive index and absorption in a cladding made of a biocompatible Polymer. In contrast to many existing fiber optical sensors which are based upon different dyes or florescent material to sense the pH, here presents a solution where a part of the cladding is replaced with a Poly (β-amino ester) made of 1.4-Butanediol diacrylate, Piperazine, and Trimethylolpropane Triacrylate. Piperazine has the feature of changing its volume by swelling or shrinking in response to the pH level. This paper utilizes this dimension effect and measure the refractive index and the absorption of the cladding in respect to different pH-levels. The alteration of refractive index also causes a change in the absorption and therefore the output power changes as a function of the pH level. The sensor is sensitive to pH in a wide spectral range and light absorbency can be observed for wavelengths ranging from UV to far IR. © 2014 SPIE.

  • 133.
    Hansson, T.
    et al.
    Department of Applied Environmental Science (ITM), Stockholm University, 10691 Stockholm, Sweden .
    Hansen, Wenche
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences. Environmental Protection Unit, Länsstyrelsen Västernorrland, 87127 Härnösand, Sweden .
    Tjärnlund, U.
    Department of Applied Environmental Science (ITM), Stockholm University, 10691 Stockholm, Sweden .
    Balk, L.
    Department of Applied Environmental Science (ITM), Stockholm University, 10691 Stockholm, Sweden .
    Bengtsson, B. -E
    Department of Applied Environmental Science (ITM), Stockholm University, 10691 Stockholm, Sweden .
    Biomarker investigations in adult female perch (Perca fluviatilis) from industrialised areas in northern Sweden in 20032014In: Archives of Environmental Contamination and Toxicology, ISSN 0090-4341, E-ISSN 1432-0703, Vol. 66, no 2, p. 237-247Article in journal (Refereed)
    Abstract [en]

    Since the new millennium, a notion has developed in certain parts of society that environmental pollutants and their associated effects are under control. The primary objective of this investigation, performed in 2003, was to test whether this was actually the case in an industrialised region in the County of Västernorrland in northern Sweden with well-documented environmental pollution from past and present activities. This was performed by measuring a moderate battery of simple biomarkers in adult female perch at several stations. The point sources included sewage-treatment plants, pulp and paper mills, as well as other industries. The biomarkers included growth, somatic indices, gonad maturation status, gonad pigmentation, fin erosion, skin ulcers, and ethoxyresorufin-O-deethylase (EROD) activity in the liver. The results showed that the environmental pollutants and their associated effects were not under control. In fact, the health of the perch was impaired at all of the polluted stations. Many responses were unspecific with respect to underlying cause, whereas some effects on EROD activity and gonad maturation status were attributed to historical creosote pollution and current kraft pulp mill effluents, respectively. The data presented may also be used as reference values for future investigations of health effects in perch. © Springer Science+Business Media 2013.

  • 134.
    Harper, Karen A.
    et al.
    School for Resource and Environmental Studies, Dalhousie University, Halifax, NS, Canada .
    Macdonald, S. Ellen
    Univ Alberta, Dept Renewable Resources, Edmonton, AB T6G 2H1, Canada.
    Mayerhofer, Michael S.
    Mt St Vincent Univ, Dept Biol, Halifax, NS B3M 2J6, Canada.
    Biswas, Shekhar R.
    Lakehead Univ, Dept Biol, Thunder Bay, ON P7B 5E1, Canada.
    Esseen, Per-Anders
    Umea Univ, Dept Ecol & Environm Sci, SE-90187 Umea, Sweden.
    Hylander, Kristoffer
    Stockholm Univ, Dept Ecol Environm & Plant Sci, SE-10691 Stockholm, Sweden.
    Stewart, Katherine J.
    Yukon Coll, Yukon Res Ctr, Whitehorse, YT Y1A 5K4, Canada.
    Mallik, Azim U.
    Lakehead Univ, Dept Biol, Thunder Bay, ON P7B 5E1, Canada.
    Drapeau, Pierre
    Univ Quebec, Dept Sci Biol, Chaire Ind CRSNG UQAT UQAM Amenagement Forestier, Ctr Etud Foret, Montreal, PQ H3C 2P8, Canada.
    Jonsson, Bengt-Gunnar
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lesieur, Daniel
    Univ Quebec, Dept Sci Biol, Chaire Ind CRSNG UQAT UQAM Amenagement Forestier, Ctr Etud Foret, Montreal, PQ H3C 2P8, Canada.
    Kouki, Jari
    Univ Eastern Finland, Sch Forest Sci, FI-80101 Joensuu, Finland.
    Bergeron, Yves
    Univ Quebec Abitibi Temiscamingue, Inst Rech Forets, Rouyn Noranda, PQ J9X 5E4, Canada.
    Edge influence on vegetation at natural and anthropogenic edges of boreal forests in Canada and Fennoscandia2015In: Journal of Ecology, ISSN 0022-0477, E-ISSN 1365-2745, Vol. 103, no 3, p. 550-562Article in journal (Refereed)
    Abstract [en]

    Although anthropogenic edges are an important consequence of timber harvesting, edges due to natural disturbances or landscape heterogeneity are also common. Forest edges have been well studied in temperate and tropical forests, but less so in less productive, disturbance-adapted boreal forests. We synthesized data on forest vegetation at edges of boreal forests and compared edge influence among edge types (fire, cut, lake/wetland; old vs. young), forest types (broadleaf vs. coniferous) and geographic regions. Our objectives were to quantify vegetation responses at edges of all types and to compare the strength and extent of edge influence among different types of edges and forests. Research was conducted using the same general sampling design in Alberta, Ontario and Quebec in Canada, and in Sweden and Finland. We conducted a meta-analysis for a variety of response variables including forest structure, deadwood abundance, regeneration, understorey abundance and diversity, and non-vascular plant cover. We also determined the magnitude and distance of edge influence (DEI) using randomization tests. Some edge responses (lower tree basal area, tree canopy and bryophyte cover; more logs; higher regeneration) were significant overall across studies. Edge influence on ground vegetation in boreal forests was generally weak, not very extensive (DEI usually <20m) and decreased with time. We found more extensive edge influence at natural edges, at younger edges and in broadleaf forests. The comparison among regions revealed weaker edge influence in Fennoscandian forests.Synthesis. Edges created by forest harvesting do not appear to have as strong, extensive or persistent influence on vegetation in boreal as in tropical or temperate forested ecosystems. We attribute this apparent resistance to shorter canopy heights, inherent heterogeneity in boreal forests and their adaptation to frequent natural disturbance. Nevertheless, notable differences between forest structure responses to natural (fire) and anthropogenic (cut) edges raise concerns about biodiversity implications of extensive creation of anthropogenic edges. By highlighting universal responses to edge influence in boreal forests that are significant irrespective of edge or forest type, and those which vary by edge type, we provide a context for the conservation of boreal forests.

  • 135.
    Hedenstedt, Kristoffer
    et al.
    Göteborgs Universitet; AkzoNobel.
    Bäckström, Joakim
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences. Göteborgs Universitet.
    Ahlberg, Elisabet
    Göteborgs Universitet.
    In-Situ Raman Spectroscopy of α- and γ-FeOOH during Cathodic Load2017In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 164, no 9, p. H621-H627Article in journal (Refereed)
    Abstract [en]

    Water reduction on corroded iron surfaces is technologically and fundamentally important. Here, the technological interest originatesfrom the chlorate process where water reduction is the main cathodic process. Fundamentally, water reduction on oxide surfaces raisesquestions on the stability of the oxide and the nature of electrocatalytic surface sites. Two iron oxyhydroxides,α-andγ-FeOOH,were electrodeposited on titanium substrate and their reduction processes were followed in detail with in-situ Raman spectroscopy,using low incident laser power to avoid sample damaging. Polarization to negative potentials show two reduction peaks forγ-FeOOHand one peak forα-FeOOH prior to hydrogen evolution. The characteristic Raman peaks gradually disappear as the potential ismade more negative but no new peaks can be observed.δ-FeOOH was detected as an intermediate phase upon oxidation of thereduced surface layer. This indicates that Fe(OH)2is formed during cathodic polarization and initially re-oxidized to the isostructuralδ-FeOOH. Characteristic Raman signals of the original phases appear upon further oxidation in air.

  • 136.
    Hedenström, Erik
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Fagerlund-Edfeldt, Amelie
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Edman, Mattias
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Jonsson, Bengt-Gunnar
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Resveratrol, piceatannol, and isorhapontigenin from Norway spruce (Picea abies) debarking wastewater as inhibitors on the growth of nine species of wood-decaying fungi2016In: Wood Science and Technology, ISSN 0043-7719, E-ISSN 1432-5225, Vol. 50, no 3, p. 617-629Article in journal (Refereed)
    Abstract [en]

    The diethyl ether extract obtained from solvent-solvent extraction of Norway spruce (Picea abies) debarking water, a byproduct from debarking of logs in the pulp and paper industry, was tested for inhibition of growth on agar plates of nine species of wood-decaying fungi: Antrodia sinuosa, Antrodia xantha, Coniophora puteana, Fomitopsis pinicola, Gloeophyllum sepiarium, Heterobasidion parviporum, Phlebiopsis gigantea, Serpula himantioides, and Serpula lacrymans. One fraction of the extract showed excellent antifungal activity for a majority of the species, with complete inhibition of growth for A. sinuosa, A. xantha, and G. sepiarium. The major constituents of the most active fraction were identified as the hydroxystilbenes resveratrol, isorhapontigenin (synonymous with methyl piceatannol), and piceatannol (synonymous with astringenin). The active compounds were isolated or synthesized and used individually for dose-response studies. It was found that isorhapontigenin and piceatannol inhibited all growth of A. sinuosa, A. xantha, and G. sepiarium in 0.35 % weight concentration. The hydroxystilbenes were the three most abundant substances in the debarking water and can be obtained as a mixture or in enriched forms. From some extraction steps of the raw debarking water, it would be possible to obtain the hydroxystilbenes in quantities that might be of commercial interest as efficient natural fungicides.

  • 137.
    Hedenström, Erik
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Wallin, Erika
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Andersson, J
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Bång, Joakim
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Wang, H-L
    Department of Biology, Lund University, Sölvegatan 37, Lund, Sweden .
    Löfstedt, C
    Department of Biology, Lund University, Sölvegatan 37, Lund, Sweden .
    Brattström, O
    Department of Zoology, Cambridge University, Cambridge, United Kingdom.
    Baquet, P
    Evolutionary Ecology and Genetics group, Biodiversity Research Centre, Earth and Life Institute, Académie Louvain, Croix du Sud 4, Louvain-la-Neuve, Belgium.
    Stereoisomeric Analysis of 6,10,14-Trimethylpentadecan-2-ol and the Corresponding Ketone in Wing Extracts from African Bicyclus Butterfly Species2015In: Journal of Chemical Ecology, ISSN 0098-0331, E-ISSN 1573-1561, Vol. 41, no 1, p. 44-51Article in journal (Refereed)
    Abstract [en]

    Gas chromatography (GC) and mass spectrometry (MS) were used to determine the stereoisomeric compositions of 6,10,14-trimethylpentadecan-2-ol and 6,10,14-trimethylpentadecan-2-one in wing extracts from 17 Bicyclus butterfly species from different regions of Africa. All samples were purified using solid phase extraction (SPE). Since some species contained both alcohol and ketone, these were separated and the ketone was reduced to the alcohol before analysis as either (R)-trans-chrysanthemoyl or (S)-2-acetoxypropionyl esters. A novel asymmetric synthesis was developed for a reference mixture of (2R/S,6S,10R)-6,10,14-trimethylpentadecan-2-ol with known composition of the eight stereoisomers. The mixture then was used as the (R)-trans-chrysanthemoyl esters to correlate each of the eight gas chromatographic peaks to a specific stereoisomer of the extracted wing compounds. Seven butterfly species showed (2R,6R,10R)-configuration of the alcohol, four species contained minute amounts of alcohol too small to determine the stereochemistry, nine species showed (6R,10R)-configuration of the ketone, and one species contained minute amounts of ketone too small to determine the stereochemistry. No other stereoisomers of alcohol or ketone could be detected in the extracts, and the quantities of the compounds in the wing extracts varied from 5 to 900 ng per sample for each species.

  • 138.
    Hedlund, Jens
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Gripskopa för flis: Ett konstruktionsarbete2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Engbergs Transportsystem is a company responsible for all internal logis-tics at the pulp mill of SCA Östrand in Sundsvall. This includes a work process where wooden chips is being unloaded off of ships with a mate-rial handler equipped with a clamshell bucket. The clamshell bucket cur-rently used is cracking in its structure at every event of use and therefore requires constant repair work. This project aims to eliminate the need for repairs by delivering a solution proposal for a brand new clamshell bucket, which is thought to avoid the shortcomings of the existing one. All this without impair the other specifications of the existing bucket. The entire project is a design process in which, at first, a feasibility study has been performed and analyzed to obtain a solid image of the situation and the problem in its whole. With this in mind a specification of require-ments was produced in a collaboration with Engbergs. The specification sheet has then acted as a guideline for the construction process through-out the project. Solutions have been generated, evaluated and screened in two iterations with increasing level of detail. Evaluations of the solutions has been done with Pughs decision-matrix method where values for as-sessment has been produced with different methods, like stress analysis of digital models. The last remaining solution proposal was then opti-mized and verified towards the specification of requirements. The project has resulted in a solution proposal for a brand new clamshell that meets 15 of 18 the specified requirements. Although the solution does not meet all the goals of the project, the results makes a solid foundation for further development.

  • 139.
    Hellström, Lisbeth M.
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Biller, Sven-Olov
    Andritz Iggesund Tools AB, Iggesund, Sweden.
    Edvardsson, Sverker
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Gradin, Per A.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    A theoretical and experimental study of the circular sawing process2014In: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, Vol. 68, no 3, p. 307-312Article in journal (Refereed)
    Abstract [en]

    To gain further insight into the energy dissipation during the wood sawing process, a theoretical model has been developed. The model is based on the assumption that there are two basic causes for energy dissipation during sawing: the creation of a new surface and the compression of material below a saw tooth. It is assumed that both contributions can be dependent on the cutting angle (the angle between the fiber direction and the tangent to the path followed by a saw tooth) because a saw tooth changes its angle of attack during its way through a log. To determine this dependence of the dissipation on the cutting angle, a series of experiments with pine plank sawing were performed by means of different feeding rates and cutting angles while the electrical power supplied to the saw was measured. The parameters in the theoretical model were derived from the experimental findings. Finally, two tests were carried out under different conditions with respect to thickness and cutting angles and the validity of the model was confirmed concerning the prediction of the electrical power consumption.

  • 140.
    Henriksson, Anders E.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences. Sundsvall Cty Hosp, Dept Lab Med, SE-85186 Sundsvall, Sweden.
    S100B and the influence of seasonal variation2016In: Scandinavian Journal of Clinical and Laboratory Investigation, ISSN 0036-5513, E-ISSN 1502-7686, Vol. 76, no 4, p. 338-340Article in journal (Refereed)
    Abstract [en]

    Background A blood test for S100B can be used to rule out intracranial complications after minor head injury and thereby reduce the need for computed tomography (CT) examinations. The aim of this study was to investigate the clinical importance of a possible influence of seasonal variation on S100B. Methods The individual seasonal variation of S100B in 69 healthy volunteers living at latitudes with extremely variable seasonal exposure to sunlight was investigated. Results The mean serum concentration of S100B was 13% higher in August than in February, but however, not statistically significant (p = 0.068). A good agreement between summer and winter S100B values was confirmed by Bland-Altman analysis and a significant correlation (r = 0.317, p = 0.008) was shown between summer and winter S100B values. Conclusion This study did not show any clinical importance of seasonal variation of S100B that may influence the decision of CT scanning patients with head injuries.

  • 141.
    Henriksson, Anders E.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    The impact of blood component transfusion practices on patient survival after abdominal aortic aneurysm surgery2013In: Vascular and Endovascular Surgery, ISSN 1538-5744, Vol. 47, no 1, p. 38-41Article in journal (Refereed)
    Abstract [en]

    Background: The aim of the present study was to investigate the blood transfusion practice in patients operated for abdominal aortic aneurysm (AAA) with special emphasis on massive transfusion in cases with rupture. Material and methods: From a database, 504 patients operated for AAA were stratified into 2 groups; an early transfusion period (1992-1999) and a late transfusion period (2000-2008) to evaluate the changes in transfusion practices over the course of time. Results: Patients operated for nonruptured AAA (n = 330) showed a decreased mortality rate from 4% (early transfusion period) to 1% (late transfusion period) without significant changes in the transfusion practices. In patients operated for ruptured AAA (n = 174) an unexpected low mortality rate was found compared to the 30-day mortality reported in earlier studies. The transfusion practices in ruptured AAA surgery showed a significant increase in platelet use and change of fresh frozen plasma: red blood cell ratio from 0.8 to 0.9 between the early and the late transfusion period. Conclusion: The present database study shows that the operating mortality for AAA surgery has declined during the past decades. The cause of the decline in mortality in patients with ruptured AAA was interpreted as partly due to a modern blood component therapy. © The Author(s) 2012.

  • 142.
    Henriksson, Anders E.
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences. Sundsvall County Hospital, Sundsvall.
    Lindqvist, Markus
    Sundsvall County Hospital, Sundsvall.
    Sihlbom, Carina
    University of Gothenburg, Gothenburg.
    Bergström, J.
    University of Gothenburg, Gothenburg.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Identification of potential plasma biomarkers for abdominal aortic aneurysm using tandem mass tag quantitative proteomics2018In: Proteomes, ISSN 2227-7382, Vol. 6, no 4, article id 43Article in journal (Refereed)
    Abstract [en]

    Plasma biomarkers that identify abdominal aortic aneurysm (AAA) rupture risk would greatly assist in stratifying patients with small aneurysms. Identification of such biomarkers has hitherto been unsuccessful over a range of studies using different methods. The present study used an alternative proteomic approach to find new, potential plasma AAA biomarker candidates. Pre-fractionated plasma samples from twelve patients with AAA and eight matched controls without aneurysm were analyzed by mass spectrometry applying a tandem mass tag (TMT) technique. Eight proteins were differentially regulated in patients compared to controls, including decreased levels of the enzyme bleomycin hydrolase. The down-regulation of this enzyme was confirmed in an extended validation study using an enzyme-linked immunosorbent assay (ELISA). The TMT-based proteomic approach thus identified novel potential plasma biomarkers for AAA. 

  • 143.
    Henschel, Till
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Fuel flexibility for gasification: Analysis and evaluation of different biomass2015Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The objective of this degree project has been to apply different methods of analysis to evaluate a variety of feedstock. The application of different feedstock can increase the fuel flexibility of gasification reactors and therefore increase their profitability. The syngas produced through gasification is important for the production of electricity, different chemicals and biomass to liquid fuels. It has further been the aim to analyse potential correlations between the gas composition and tar yields of gasification and pyrolysis processes. The study is based on the experimental analysis of the properties of hemicellulose, cellulose, lignin, spirolina, scenedesmus quadricauda, pine bark, peat, forest residues, straw, hemp, black liquor, sawdust and wood. These biomass feedstocks have been analysed by pyrolysis, proximate, thermogravi-metric, gas, partially ultimate and gasification analysis. The results of the fuel analysis of wood, sawdust, forest residue and pine bark indicate a good pyrolysis and gasification potential. Microalgae, may be more suitable for other chemical processes but could as well as peat be used as an additive for gasification. Black liquor is unsuitable for unpressur-ised gasification. The thermogravimetric analysis of varying fuel frac-tions of peat and forest residues indicates a predictability of the result-ing mass loss curves. The measured gas and tar yields of the gasification and pyrolysis experiments reveal that correlations between the two different processes partially exist. A possible correlation between me-thane and tar yields could be observed as well. It is recommended to conduct further experiments including ash analysis and construction of a drop tube reactor.

  • 144.
    Henshaw Osong, Sinke
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Dahlström, Christina
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Forsberg, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Andres, Britta
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Engstrand, Per
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Norgren, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Engström, Ann-Christine
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Development of CTMP-based nanofibrillated Cellulose /nanographite composites for paper applications2015Conference paper (Other academic)
  • 145.
    Hepworth, Jo
    et al.
    Norwich Research Park, Norwich, UK.
    Antoniou-Kourounioti, Rea L.
    Norwich Research Park, Norwich, UK.
    Bloomer, Rebecca H.
    Norwich Research Park, Norwich, UK.
    Selga, Catja
    Lund University.
    Berggren, Kristina
    Mid Sweden University, Faculty of Science, Technology and Media.
    Cox, Deborah
    Norwich Research Park, Norwich, UK.
    Collier Harris, Barley R.
    Norwich Research Park, Norwich, UK.
    Irwin, Judith A.
    Norwich Research Park, Norwich, UK.
    Holm, Svante
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Säll, Torbjörn
    Lund University.
    Howard, Martin
    Norwich Research Park, Norwich, UK.
    Dean, Caroline
    Norwich Research Park, Norwich, UK.
    Absence of warmth permits epigenetic memory of winter in Arabidopsis2018In: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 9, no 1, article id 639Article in journal (Refereed)
    Abstract [en]

    Plants integrate widely fluctuating temperatures to monitor seasonal progression. Here, we investigate the temperature signals in field conditions that result in vernalisation, the mechanism by which flowering is aligned with spring. We find that multiple, distinct aspects of the temperature profile contribute to vernalisation. In autumn, transient cold temperatures promote transcriptional shutdown of Arabidopsis FLOWERING LOCUS C (FLC), independently of factors conferring epigenetic memory. As winter continues, expression of VERNALIZATION INSENSITIVE3 (VIN3), a factor needed for epigenetic silencing, is upregulated by at least two independent thermosensory processes. One integrates long-term cold temperatures, while the other requires the absence of daily temperatures above 15 °C. The lack of spikes of high temperature, not just prolonged cold, is thus the major driver for vernalisation. Monitoring of peak daily temperature is an effective mechanism to judge seasonal progression, but is likely to have deleterious consequences for vernalisation as the climate becomes more variable. 

  • 146.
    Hjelm, Celie
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Nordberg, Felicia
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Möbel som skapar sittmöjligheter: En innovativ lösning för små boenden2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Detta examensarbete är ett samarbete med IKEA Sundsvall och har utförts i syfte att hitta en lösning som erbjuder extra sittplatser för boenden mindre än 60 kvadratmeter. Projektet utgår från designproces-sen och inleds med en marknadsundersökning och en fältstudie. Detta för att skapa förståelse för användarnas behov och för att därefter kunna genomföra en idégenerering. Skisserna på alternativa lösningar utvärderades en första gång av en expertgrupp från IKEA och därefter ännu en gång enligt Pughs relativa beslutsmatris. Efter utvärderingen vidareutvecklades ett av koncepten och en funktionsmodell byggdes. Därefter utfördes ett användartest för att se vilka ytterligare områden som kunde vidareutvecklas. Materialval och försäljningspris bestämdes i samråd med handledarna från IKEA. Bordskivan och sittmodulerna ska tillverkas av Medium Density Fibreboard, så kallad MDF, och bordsbenen av lockläckt. Soffbordet ska kosta 399 kronor och sitt- modulerna ska kosta 149 kronor styck. De förbättringsområden som framkom vid användartestet justerades och en slutgiltig digital tredimensionell modell skapades. En prisuppskattning utfördes för att säkerhetsställa att materialkostnaderna inte överstiger försäljningspriset. Priset för möbelns materialåtgång uppskattades till 464 kronor och var då beräknad för soffbordet samt fyra sittmoduler. Utifrån den digitala modellen byggdes därefter en prototyp för att möjliggöra för fler utvärderingar och förbättringar. Slutligen utfördes en beräkning av soff-bordets tipprisk. Detta resulterade i att tippning inträffar då bordet belastas med sin egenvikt på ett av dess hörn. Det slutgiltiga konceptet är ett soffbord som kombinerar extra sittplatser med förvaring. Bordet har dimensionerna 73,2 x 73,2 x 49 centimeter och sittmodulerna har dimensionerna 32 x 32 x 45 centimeter. De säljs separat för att ge kunden valfrihet att välja önskat antal sittmoduler och de båda ska inneha namnet Stöde.

  • 147.
    Holmin, Susanne
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences. Permascand AB, Ljungaverk, Sweden .
    Näslund, Lars-Ake
    Department of Physics, Chemistry, and Biology (IFM), Thin Film Physics Division, Linköping University, Linköping, Sweden.
    Ingason, Arni S.
    Department of Physics, Chemistry, and Biology (IFM), Thin Film Physics Division, Linköping University, Linköping, Sweden.
    Rosen, Johanna
    Department of Physics, Chemistry, and Biology (IFM), Thin Film Physics Division, Linköping University, Linköping, Sweden.
    Zimmerman, Erik
    Permascand AB, Ljungaverk, Sweden .
    Corrosion of ruthenium dioxide based cathodes in alkaline medium caused by reverse currents2014In: Electrochimica Acta, ISSN 0013-4686, E-ISSN 1873-3859, Vol. 146, no 10, p. 30-36Article in journal (Refereed)
    Abstract [en]

    A reverse current obtained during power shutdowns in industrial processes, such as chlor-alkali production or alkaline water electrolysis, is deleterious for hydrogen evolving ruthenium dioxide (Ru02) based cathodes. It has been observed that RuO2 coatings after a power shutdown, necessary for e.g. maintenance, are severely damaged unless polarization rectifiers are employed. In this work we show why these types of cathodes are sensitive to reverse currents, i.e. anodic currents, after hydrogen evolution. RuO2 coatings deposited on nickel substrates were subjected to different electrochemical treatments such as hydrogen evolution, oxygen evolution, or reverse currents in 8 M NaOH at 90 degrees C. Polarity inversion was introduced after hydrogen evolution to simulate the effect of reverse currents. Because of chemical interaction with hydrogen, a significant amount of the RuO2 coating was transformed into hydroxylated species during cathodic polarization. Our study shows that these hydroxylated phases are highly sensitive to electrochemical corrosion during anodic polarization after extended hydrogen evolution. (C) 2014 Elsevier Ltd. All rights reserved.

  • 148.
    Hummelgård, Christine
    et al.
    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.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Karlsson, Rasmus
    Applied Electrochemistry, School of Chemical Science and Engineering, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden .
    Cornell, Ann
    Applied Electrochemistry, School of Chemical Science and Engineering, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden .
    Habibur Rahman, S.M.
    Department of Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 gothenburg, Sweden .
    Eriksson, Sten
    Department of Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 gothenburg, Sweden .
    Physical and electrochemical properties of cobalt doped (ti,ru)O2 electrode coatings2013In: Materials Science & Engineering: B. Solid-state Materials for Advanced Technology, ISSN 0921-5107, E-ISSN 1873-4944, Vol. 178, no 20, p. 1515-1522Article in journal (Refereed)
    Abstract [en]

    The physical and electrochemical properties of ternary oxides Ti 0.7Ru0.3-xCoxO2 (x = 0.093 and x = 0) have been investigated and compared. Samples of three different thicknesses were prepared by spin-coating onto polished titanium to achieve uniform and well-defined coatings. The resulting electrodes were characterized with a variety of methods, including both physical and electrochemical methods. Doping with cobalt led to a larger number of micrometer-sized cracks in the coating, and coating grains half the size compared to the undoped samples (10 instead of 20 nm across). This is in agreement with a voltammetric charge twice as high, as estimated from cyclic voltammetry. There is no evidence of a Co 3O4 spinel phase, suggesting that the cobalt is mainly incorporated in the overall rutile structure of the (Ti,Ru)O2. The doped electrodes exhibited a higher activity for cathodic hydrogen evolution compared to the undoped electrodes, despite the fact that one third of the active ruthenium was substituted with cobalt. For anodic chlorine evolution, the activity was similar for both electrode types.

  • 149.
    Hummelgård, Christine
    et al.
    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.
    Gustafsson, John
    Applied Electrochemistry, School of Chemical Science and Engineering, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden .
    Cornell, Ann
    Applied Electrochemistry, School of Chemical Science and Engineering, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden .
    Bäckström, Joakim
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Spin coated titanium-ruthenium oxide thin films2013In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 536, p. 74-80Article in journal (Other academic)
    Abstract [en]

    Substrates of different roughness spin coated with Ti0.7Ru 0.3O2 films have been evaluated as model system for fundamental studies of the industrially and scientifically interesting (Ti,Ru)O2 based electrodes. The approach allowed for much more accurate control over the material synthesis than the traditionally used brush-, dip-, or spray-coating, on titanium-metal substrates. It moreover yielded well-defined samples suitable for basic studies of the surface properties that are of fundamental importance for understanding the electrochemical functionality of the electrode. We have compared the films on silicon substrates to films prepared by spin coating the same material on titanium-metal substrates. Samples have been characterized using atomic force microscopy (AFM), X-ray diffraction, scanning electron microscopy (SEM), and cyclic voltammetry. The samples displayed a uniformity of the films appropriate for AFM characterization. The smoother the substrate the less cracks in the coating. Using easily broken silicon wafers as substrate, a straightforward sample preparation technique was demonstrated for cross-section SEM. In addition, using high spinning velocities we have deposited the oxide films directly on silicon-nitride grids, thin enough to allow for studies with transmission electron microscopy without further sample preparation.

  • 150.
    Hägglund, Håkan
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Norberg, Ole
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Edström, Per
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Non-destructive high resolution measurements of spatial filler content distribution in paper2013In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 28, no 1, p. 131-136Article in journal (Refereed)
    Abstract [en]

    In this work, a non-destructive method is presented that enables the measurement of filler content in paper with high spatial resolution. The method uses an X-ray fluorescence setup that enables high resolution measurements of calcium content in the paper, together with a beta radiography measurement method, to assess the local filler content in the paper. An image registration method is used to combine the two measurement maps, and a calibration polynomial is applied to the point-wise values in order to calculate the local filler content. The measurement methods show good accuracy. The grammage and the calcium content can be measured at a spatial resolution of 0.1 mm × 0.1 mm but the resolution for the filler content map was in this work chosen to 1 mm × 1 mm in order to minimize image registration errors. The method is illustrated using two paper samples, a laboratory paper and a commercial 80 g/m2 copy paper. From the methods used in this work, a difference is shown between the two paper samples in how the filler content distribution is related to the paper formation. With the help of image registration, point-wise measurements of filler content from both sides of the samples can be compared. The method can be used together with other high resolution measurements in order to analyze the simultaneous interrelation between different paper properties. The high resolution measurements of filler content will be particularly valuable for the analysis of the underlying causes to optical variations in paper and print.

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