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  • 251.
    Razaz, Ghadir
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Carlberg, Torbjörn
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Segregation during metal sampling2014In: Materials science forum, Trans Tech Publications Inc., 2014, p. 83-88Conference paper (Refereed)
    Abstract [en]

    In order to obtain accurate chemical compositions in as-cast billets and ingots the sampling methods for the analysis have to give reproducible results with high precision. OES analysis made on samples at certain milling depths does not always show the desired nominal composition, and especially the macro segregation profiles within the samples can show significant variations. The present work examine the influence of main sampling parameters, such as the volume of the melt, the melt temperature, the mould design and the method of filling the mould, on the segregation. The results point out the importance of the convection in the mould during solidification, and thus the technique of pouring the melt into the sampling mould. © (2014) Trans Tech Publications, Switzerland.

  • 252.
    Razaz, Ghadir
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Carlberg, Torbjörn
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Solidification studies of 3003 alloys with different Mn and Ti contents2017In: Solidification processing 2017: proceedings of the 6th Decennial International Conference on Solidification Processing : 25-28 July 2017, Beaumont Estate, Old Windsor, UK / [ed] Fan, Zhongyun, bcast , 2017Conference paper (Refereed)
    Abstract [en]

    Aluminum alloys of AA3003 are widely used in heat exchangers. This type of alloy mainly contains manganese as alloying element, but in recent developments there have been additions of both titanium and copper. The limits of Mn solubility in aluminum are influenced by these additions, which can cause the formation of large particles of an unwanted AlMnTi phase.

    This project was initiated to investigate the effects of Mn contents in combination with Ti additions on the solidification and precipitation behavior using both Bridgman directional solidification and DTA equipment. The results show that coarse AlMnTi particles start forming when Mn contents are over 1.5 wt% in alloys with 0.14 wt% Ti and that the amount significantly increases with increasing Mn content from this level. Large particles were also found for Mn contents slightly below 1.4 wt%. If the Ti additions were on the level of 0.25 wt%. The DTA experiments show that AlMnTi phases grow in a limited temperature interval, and can reach a size of 150 microns. Such large sized particles are detrimental for the material in the ensuing rolling operation and must be avoided, and it is, therefore, important to accurately control the combinations of Mn and Ti contents.

  • 253.
    Razaz, Ghadir
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Carlberg, Torbjörn
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Study of manganese dissolution in aluminum melts2016In: TMS Light Metals, Minerals, Metals & Materials Society, 2016, p. 731-736Conference paper (Refereed)
    Abstract [en]

    Problems with the yield during Mn alloy additions and the occurrence of undissolved Mn rich phases in as cast material containing Ti is the background to the present study of the dissolution of Mn compacts in aluminum melts. The dissolution rate of Mn in liquid aluminum, have been studied in pure Al and in Al-0.12%Ti melts. It was found that Ti additions to the melt decreased the dissolution rate of Mn compacts. It was also shown that the intermediate phases formed at the interface between Mn and liquid aluminum was different after small Ti additions. Moreover, an undissolved Mn briquette, found after casting in a furnace, was examined and the conditions for this to happen have been discussed. The discussion was based on calculations of heat balances during the initial dissolution steps and studies of the transformations occurring within the briquette.

  • 254.
    Rimér Högberg, Karl
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Infästning till slipmaskin för skridskoskenor: Utvecklingsunderlag för en tilläggsmodul2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    ProSharp AB tillverkar och säljer automatiserade slipmaskiner för skridskoskenor. Slipmaskinerna är uppbyggda av ett antal komponenter, bland annat en infästningsanordning som studerats närmare i projektet. Infästningens uppgift är att låsa fast skridskoskenan i ett rätvinkligt läge för att möjliggöra en jämn och rak slipning. Denna infästning är anpassad för att låsa fast skenor som har en plan sidoyta men det börjar komma skenor som har mer komplexa sidoytor, exempelvis konkava. Problemet när dessa skenor skall fästas är att det skapas en fästpunkt istället för en fästyta mellan skenan och infästningen vilket medför att skenan går att vicka på i sidled. Syftet med arbetet är att undersöka möjligheten för att skapa en infästning som kan låsa fast dessa skenor utan att detta problem uppstår. Designprocessen är den metod som legat till grund för projektet och en slutgiltig CAD-konstruktion togs fram i 3D-modelleringsprogrammet Solidworks. Den kraft som behövdes för att räta upp skenan bestämdes samt om det med hjälp av enbart handstyrka går att vrida en knapp tills denna kraft uppstår mellan två klämblock. Det resultatet som erhölls var att det krävs minst 20 N för att räta upp skenan och att det utan svårigheter gick att uppnå denna kraft med enbart handstyrka. Utifrån dessa resultat kunde kraftsimuleringar i programmet Solidworks göras där resultaten visade hur stor utböjning klämblocket hade vid den framtagna lasten. Detta resultat kunde sedan analyseras för att utesluta självlåsning. En prototyp togs sedan fram och testades, resultatet visar att vidare utveckling krävs för att konstruera en väl fungerande infästning. Ett ändringsförslag för prototypen togs fram där de analyserade problemen har lösts genom konstruktionsändringar. Projektet har visat att det är möjligt att skapa en tilläggsmodul som löser problemet med glappande skena.

  • 255.
    Risberg, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Formgivning av monteringsbord: Förbättring av ett bords arbetsyta2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Permobil manufactures electrically powered wheelchairs and uses mobile assembly tables. The assembly tables have a carrying surface that is called "top plate" such is specially adapted for Permobil production. The top plate is made such that the assemblers can carry out their operations. At present, the load surface no longer fits all of Permobils models. Through a design process, a proposal for a new solution was proponed. The process began with an information phase where Permo-bils production was studied along with a literature study on ergonom-ics. A demand specification was produced from the information phase together with a questionnaire that the assemblers had to answer. Through a market research, other solutions that are expected to solve the issue were reviewed. In a creative phase, various proposals was drawn up and evaluated. The proposals were made digitally in the computer program SolidWorks. A prototype of the solution where created to perform actual tests. On the prototype, a risk analysis where done to review the possible risks with the design. By letting the fitters test the prototype in Permobils production the solution was tested against the daily requirements. The result presents a new solution that fits all models. The solution provides increased safety for the fitters and the ability to customize the top plate at the advent of new models. The test phase showed that the new solution will result in some unfavorable postures in the form of working with bent torso.

  • 256.
    Ruete, Alejandro
    et al.
    SLU, Uppsala.
    Snäll, Tord
    SLU, Uppsala.
    Jonsson, Bengt-Gunnar
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Jönsson, Mari
    SLU, Uppsala.
    Contrasting long-term effects of transient anthropogenic edges and forest fragment size on generalist and specialist deadwood-dwelling fungi2017In: Journal of Applied Ecology, ISSN 0021-8901, E-ISSN 1365-2664, Vol. 54, no 4, p. 1142-1151Article in journal (Refereed)
    Abstract [en]

    Forests are becoming increasingly fragmented world-wide, creating forest patches with reduced area and greater exposure to human land uses along fragment edges. In this study, we predict the future impacts of anthropogenic edges and fragment size on the future occupancy of deadwood-dwelling fungi in boreal old-growth forest fragments. We used Bayesian models fitted to empirical data to predict 40years of occupancy dynamics of logs by a group of old-growth forest indicator fungi and two common fungi under different scenarios of clear-cutting in adjacent forest (0%, 25%, 50% and 100%) and fragment sizes (1-20ha). Small fragment size (1-3<bold></bold>14ha) and intensified forestry with 50-100% clear-cutting of forest around old-growth forest fragments lead to lower predicted occupancy of old-growth indicator fungi while common generalist species like Fomitopsis pinicola increased. There was a trade-off between fragment size and management, where increasing fragment size buffered the negative long-term effects from increased adjacent clear-cutting. These changes in fungal occupancy at the edge should be accounted for when working towards conservation targets for protected areas, such as the Aichi target 11.Synthesis and applications. Preserve what is left - but buffer for change. Small forest fragments often represent the last vestiges of high habitat quality (i.e. species, structures) in managed forest landscapes. As effective area-based conservation measures for the long-term occupancy of old-growth fungi, small fragments need to be managed to protect species from degrading transient edge effects. Management should focus on increasing the size of conservation areas with permanent buffer zones. Alternatively, non-simultaneous adjacent clear-cutting in a way that reduces the edge effect over time (i.e. dynamic buffers) may increase the effective area and improve performance of set-asides in protecting species of special concern for conservation. Preserve what is left - but buffer for change. Small forest fragments often represent the last vestiges of high habitat quality (i.e. species, structures) in managed forest landscapes. As effective area-based conservation measures for the long-term occupancy of old-growth fungi, small fragments need to be managed to protect species from degrading transient edge effects. Management should focus on increasing the size of conservation areas with permanent buffer zones. Alternatively, non-simultaneous adjacent clear-cutting in a way that reduces the edge effect over time (i.e. dynamic buffers) may increase the effective area and improve performance of set-asides in protecting species of special concern for conservation.

  • 257.
    Rönnander, Jonas
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Genetisk variation hos fjällkvanne, Angelica archangelica ssp. archangelica, med avseende på två enzymsystem samt grobarhet hos 19 populationer på Färöarna2014Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Rapporten beskriver två komplementära studier (Isozymstudie för två enzymsystem, pgm och gpi, samt en studie av grobarhet) av Fjällkvanne, Angelica archangelica ssp. archangelica, med frön insamlade på Färöarna under september 2000. Insamlingen utfördes från 19 populationer och från 2<N<27 individer. Isozymstudien, N=55, 15 pop., visade på två alleler för båda enzymsystemen. De båda enzymsystemen föreföll även vara kopplade då frekvenserna för pgm-2 och gpi-1 tydligt följdes åt. På Färöarnas västra sida kunde en hög andel av allel A1 observeras för båda enzymsystemen och i söder kunde en hög andel av allel A2 observeras. Ingen signifikans kunde ses för att Färöarna skulle vara ett genetiskt isolat och således måste frön migrera till öarna, troligtvis över Nordsjön. De insamlade fröna uppvisade även en diversitet med avseende på grobarhet, där grobarheten var signifikant lägre än tidigare studier. Grobarheten uppvisade en högre grobarhet (v0=0,19) för de västliga populationerna samt en låg grobarhet (v0=0,034) för de populationer som nås av frön från söder. Vi kan därför göra antagandet att Färöarnas population får genetiskt material från väster (eg. Island och Grönland) samt från söder (eg. Storbritannien). Studier av material från dessa länder skulle tydligare visa på möjliga spridningsvägar.    

  • 258.
    Rönnander, Jonas
    et al.
    Gävle högskola.
    Ljunggren, Joel
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Wright, Sandra Ann Ingela
    Gävle högskola.
    Biotransformation of vanillin into vanillyl alcohol by a novel strain of Cystobasidium laryngis isolated from decaying wood2018In: AMB Express, ISSN 2191-0855, E-ISSN 2191-0855, Vol. 8, no 1, article id 137Article in journal (Refereed)
    Abstract [en]

    Vanillin is an aromatic aldehyde found as a component of lignocellulosic material, and in the cured pods of orchidaceae plants. Like other phenolic substances, vanillin has antimicrobial activity and can be extracted from lignin either by a thermo-chemical process or through microbial degradation. Vanillin, can serve as a model monomer in biodegradation studies of lignin. In the present study, a yeast isolated from decaying wood on the Faroe Islands, was identified as Cystobasidium laryngis strain FMYD002, based on internal transcribed spacer sequence analysis. It demonstrated the ability to convert vanillin to vanillyl alcohol, as detected by ultra-high performance liquid chromatography-quadrupole-time-of-flight. Structural analysis of vanillyl alcohol was carried out by using gas chromatography-mass spectrometry and H-1 NMR spectroscopy, and further verified by synthesis. The reduction of vanillin to vanillyl alcohol has been documented for only a few species of fungi. However, to our knowledge, this biotransformation has not yet been reported for basidiomycetous yeast species, nor for any representative of the subphylum Pucciniomycotina. The biotransformation capability of the present strain might prove useful in the industrial utilisation of lignocellulosic residues.

  • 259.
    Rösth, John
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Comparison of the benthic fauna within the littoral in two affected lakes situated in central Sweden2016Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The benthic animals have important roles in benthic communities. Indicator organisms can tell things about a lakes status. Many of them are sensitive to acidification but there are also tolerant taxa. Some prefer eutrophic environments. The benthic fauna can therefore decide a lakes status since some species prefer different environments.

    The focus of this study was to compare benthic fauna within the littoral in the lakes Sidsjön and Vintertjärnen. They are situated a little south of Sundsvall, central Sweden and belong to the water system of Selångersån. The comparison was done at eight random locals in each lake at two occasions, during early and late summer to analyze if the benthic fauna differed between the two lakes and if it changed through the season. Five of the locals in each lake were protected and had soft bottoms and the remaining were exposed locals with hard bottom.

    Sidsjön is bigger than Vintertjärnen and has more variated bottom types so the biodiversity should be higher in Sidsjön. I also expect that the number of taxa should decrease during the later occasion due to hatchings.

    Three statistical analyses were done to see if these hypotheses were right or if they should be rejected. The two first analyses were ANOVA analyses, two-way with replication. The first ANOVA was for number of taxa and the second was for number of animals. The third analysis was a DCA analysis with the variables lakes, bottom types and emergent plants.

    ASPT index and Eq was also calculated and pH was measured during autumn for the lakes.

    The conclusion is that the there is no difference between the lakes but a significant effect when it comes to seasons according to the first ANOVA analysis. The second ANOVA analysis show that the lakes are not differing, that no factor is significant and there are no interactions. According to the DCA analysis there are differences between lakes and occasions when it comes to the variables. 

  • 260.
    Saleem, Jawad
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Majid, Abdul
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Bertilsson, Kent
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Carlberg, Torbjörn
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    3 Dimensional Finite Element Simulation of Seam Welding Process2013In: Elektronika Ir Elektrotechnika, ISSN 1392-1215, Vol. 19, no 8, p. 73-78Article in journal (Refereed)
    Abstract [en]

    The versatility, rich mathematical formulations and robustness of finite element methods make them attractive for simulations for a wide range of problems. Two dimensional models concerning the seam welding process do have some limitations. The longitudinal two dimensional models cannot be used to examine the effects of the electrode shape and thickness regarding heat generation during the seam welding process. The transversal two dimensional models are not helpful for examining the nugget growth during the seam welding process. The heat energy generated during the seam welding process mainly depends on the resistance between the electrodes, welding current, rotational speed and the geometry of the electrodes. The settings for appropriate parameters in relation to a seam welding machine, with regards to sheets of different thicknesses, depends on trial and error methods. These methods are expensive and time consuming. The three dimensional model developed in this paper is a step towards selecting the appropriate welding parameters so as to produce a good welding nugget. 

  • 261.
    Saleem, Jawad
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Majid, Abdul
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Bertilsson, Kent
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Carlberg, Torbjörn
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Spot welding Al 6082 Sheets with Preheating by Induction Heating ProcessManuscript (preprint) (Other academic)
  • 262.
    Saleem, Jawad
    et al.
    COMSATS Univ Informat Technol, Dept Elect Engn, Abbottabad, Pakistan.
    Majid, Abdul
    COMSATS Univ Informat Technol, Dept Elect Engn, Abbottabad, Pakistan.
    Malik, Abdul Waheed
    COMSATS Univ Informat Technol, Dept Elect Engn, Abbottabad, Pakistan.
    Bertilsson, Kent
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Carlberg, Torbjörn
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    An efficient method of spot welding Aluminium alloys with induction preheating2016In: Journal of Electrical Systems, ISSN 1112-5209, Vol. 12, no 4, p. 817-825Article in journal (Refereed)
    Abstract [en]

    Steel has been the material of choice for automobile manufacturers. In the recent years material such as aluminium and its alloys are taking over the market because of their light weight. The use of aluminium, in automobile manufacturing can result in overall fuel efficiency. Spot welding aluminium alloys require higher electric power and less welding time as compared to steel. Welding guns that can produce an electric current which is approximately 2 to 3 times higher, as compared to steel are required for spot welding aluminium. An efficient method of spot welding Aluminium alloys with the preheating process has been proposed in this paper. Preheating Aluminium sheet before spot welding reduces the thermal and electrical resistance which brings down the electric current requirement to spot weld Aluminium structures. Both spot welding and induction preheating process have been modelled in this paper. The test results of the preheating process have also been verified with practical heating trials. The preheating is performed on-the-fly in advance to spot welding process. The results show that spot welding Al 6082 after preheating up to 200 degrees C, the output current requirements to make the spot weld are reduced by 22%..

  • 263.
    Samyn, Pieter
    et al.
    Hasselt University, Diepenbeek, Belgium.
    Barhoum, Ahmed
    Vrije Universiteit Brussel (VUB), Brussels, Belgium; Helwan University, Cairo, Egypt.
    Öhlund, Thomas
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Dufresne, Alain
    Université Grenoble Alpes, Grenoble, France.
    Review: Nanoparticles and Nanostructured Materials in Papermaking2018In: Journal of Materials Science, ISSN 0022-2461, E-ISSN 1573-4803, Vol. 53, no 1, p. 146-184Article in journal (Refereed)
    Abstract [en]

    The introduction of nanoparticles (NPs) and nanostructured materials (NSMs) in papermaking originally emerged from the perspective of improving processing operations and reducing material consumption. However, a very broad range of nanomaterials (NMs) can be incorporated into the paper structure and allows creating paper products with novel properties. This review is of interdisciplinary nature, addressing the emerging area of nanotechnology in papermaking focusing on resources, chemical synthesis and processing, colloidal properties, and deposition methods. An overview of different NMs used in papermaking together with their intrinsic properties and a link to possible applications is presented from a chemical point of view. After a brief introduction on NMs classification and papermaking, their role as additives or pigments in the paper structure is described. The different compositions and morphologies of NMs and NSMs are included, based on wood components, inorganic, organic, carbon-based, and composite NPs. In a first approach, nanopaper substrates are made from fibrillary NPs, including cellulose-based or carbon-based NMs. In a second approach, the NPs can be added to a regular wood pulp as nanofillers or used in coating compositions as nanopigments. The most important processing steps for NMs in papermaking are illustrated including the internal filling of fiber lumen, LbL deposition or fiber wall modification, with important advances in the field on the in situ deposition of NPs on the paper fibers. Usually, the manufacture of products with advanced functionality is associated with complex processes and hazardous materials. A key to success is in understanding how the NMs, cellulose matrix, functional additives, and processes all interact to provide the intended paper functionality while reducing materials waste and keeping the processes simple and energy efficient.

  • 264.
    Sandin, Staffan
    et al.
    KTH.
    Cheritat, Alicia
    KTH.
    Bäckström, Joakim
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Cornell, Ann
    KTH.
    Deposition efficiency in the preparation of ozone-producing nickel and antimony doped tin oxide anodes2017In: Journal of Electrochemical Science and Engineering, ISSN 1847-9286, Vol. 7, no 1, p. 51-64Article in journal (Refereed)
    Abstract [en]

    The influence of precursor salts in the synthesis of nickel and antimony doped tin oxide (NATO) electrodes using thermal decomposition from dissolved chloride salts was investigated. The salts investigated were SnCl45H2O, SnCl22H2O, SbCl3and NiCl26H2O. It was shown that the use of SnCl45H20 in the preparation process leads to a tin loss of more than 85 %. The loss of Sb can be as high as 90 % while no indications of Ni loss was observed. As a consequence, theconcentration of Ni in the NATOcoating will be much higher than in the precursor solution. This high and uncontrolled loss of precursors during the preparation process will lead to an unpredictable composition in the NATOcoating and will have negative economic and environmental effects. It was found that using SnCl22H20 instead of SnCl45H2Ocan reduce the tin loss to less than 50 %. This tin loss occurs at higher temperatures than when using SnCl45H2Owhere the tin loss occurs from 56–147°C causingthe composition to change both during the drying (80–110°C) and calcination (460 -550 °C) steps of the preparation process. Electrodes coated with NATObased on the two different tin salts were investigated for morphology, composition, structure, and ozone electrocatalytic properties.

  • 265.
    Sandström, Evelina
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Wiberg, Alexandra
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Framtagning av joystick för barn 0-3 år2018Independent thesis Basic level (degree of Bachelor)Student thesis
  • 266.
    Sandström, Jennie
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Old-Growth Forests in the High Coast Region in Sweden and Active Management in Forest Set-Asides2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In today´s intensively managed landscape, very few forests with old-growth characteristics and little human impact exist. One of the rare exceptions is pine forests on rocky soils, a forest type which has probably escaped extensive human use because of its low productivity. Our objective was to investigate the structure, dynamics, and history as well as the abundance and richness of wood-inhabiting fungi in these types of forest. We chose rocky pine forests situated in the High Coast Region to exemplify this forest type since the regional County Administration had already made surveys of the conservation value in 26 rocky pine forest stands in this region. We investigated the forests by recording tree species and measuring tree size and age in eight of the stands that were ranked with the highest conservation value. We also sampled dead wood to examine time since death and we sampled living and dead trees with fire scars to date fires. In addition, we made an inventory of wood-inhabiting fruiting bodies and took woodchip samples from logs to learn (by DNA analysis) whether five rare wood inhabiting fungi species were present as mycelia in logs.

    We found that rocky pine forests in the High Coast Region have a multi-sizedand multi-aged structure and old pine trees (approximately 13 ha-1 older than 300 years) are present. Fire has been common (an average of 42 years betweenfires) but they were likely to have been low-intense and small. Although the amount of dead wood is relatively low (4.4 m3 ha-1 on average) compared to many other boreal forests with old-growth characteristics, the share of deadwood of the total tree basal area (18%) was in line with other pine forests with low levels of human impact. The low dead wood volume is therefore likely to be an effect of the low productivity rather than dead wood extraction by humans. We also discovered that dead wood can be present for a really longtime without totally decomposing; we found logs and snags that had been dead for 500 years. This continuity of dead wood might be important for organisms dependent on dead wood as a substrate and even though we found that the species richness of wood-inhabiting fungi was somewhat low, we did find some rare species. Cinereomyces lenis and Hyphodontia halonata were present as fruiting bodies and we also found Antrodia albobrunnea, Antrodiainfirma, Crustoderma corneum and Anomoporia kamtschatica present as myceliain logs.

    The second part of this thesis reports two systematic reviews studying the effects of active management on the biodiversity in boreal and temperate forests. A systematic review follows certain guidelines and aims to compile the evidence base in well-defined topics, so that managers, researchers and policymakers can gain access to a high-quality compilation of current research. In our systematic map, we found almost 800 relevant papers but the set of papers turned out to be too heterogenic (many intervention types, e.g. thinning, burning, grazing and many types of outcomes) to allow any quantitative analysis. However, this map identified knowledge gaps and several detailed research questions that had sufficient data to provide aquantitative statistical analysis.

    One of these questions was: What is the impact of dead wood creation or addition on dead wood-dependent species? We focused on three types of interventions: creation of dead wood, addition of dead wood from elsewhere and prescribed burning. The selected outcomes were: saproxylic insects (rareand pest species), saproxylic fungi (rare species), ground-living insects and cavity-nesting birds. There was no significant negative effect on any of the investigated species groups but a positive effect on the abundance and richness of saproxylic insects and fungi. We also found that, although the amount of dead wood created was much less (50%) with prescribed burning, the abundance and richness of saproxylic insects showed similar positive effects to those of other intervention methods. A likely explanation for this is that burning results in a diversity of dead wood of various levels of quality (e.g. dense and/or charred wood), which creates a heterogeneity of dead woodtypes having a positive effect on the diversity of species dependent on deadwood. In summary, active management generally has a positive effect on biodiversity but the choice of management type should always be made carefully, and in consideration of the effect you want to achieve. In addition, there is a need for more long-term primary studies and more species groups in more geographical areas need to be incorporated so that the systematic reviews in this field will be even more informative in the future.

  • 267.
    Sandström, Jennie
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Phytoplankton response to a changing climate in lakes in northern Sweden2013Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    In a climate change perspective, increased air temperatures are already a reality and are expected to increase even more in the future, especially in areas at high latitudes. The present thesis therefore addresses the influence of climate change on the physical properties and the phytoplankton communities of typical small and oligotrophic lakes in northern Sweden (62-64˚N). In the first part of the study, we found a significant trend (10 lakes from 1916 to 2010) of ice break-ups occurring increasingly earlier. The timing of ice break-up was strongly influenced by the April air temperature indicating that expected increases in air temperature in the future will also result in an earlier ice break-up. We also used concentrations of chlorophyll a (chl a) as estimations of phytoplankton biomass and discovered a positive relationship between surface water temperature and concentrations of chl a in Lake Remmaren (from 1991 to 2008). The second part of the thesis focuses on climatic conditions and cyanobacteria abundance in three small, oligotrophic lakes in northern Sweden; Lake Remmaren, Lake S. Bergsjön and Lake Gransjön. The concentration and relative abundance of cyanobacteria differ between 2011 and 2012, with different climatic conditions. The "warm" year of 2011 had higher concentrations and relative abundance of cyanobacteria than the "cold" year of 2012. Trends in increasing surface water temperatures as well as increasing abundance of cyanobacteria in August were found in Lake Remmaren (from 1988 to 2011). The direct or indirect effects of warming had a positive effect on the cyanobacteria abundance, since nutrients (Tot N and Tot P) did not display an increasing trend in Lake Remmaren. An analysis on the composition of phytoplankton species in Lake Remmaren, Lake S. Bergsjön and Lake Gransjön revealed that the cyanobacteria Merismopedia sp. was more common in 2011 than 2012. If different cyanobacteria become more common in oligotrophic lakes in the future, the functioning of lake ecosystems may be impacted. Small zooplankton eats small phytoplankton and if smaller phytoplankton species, e.g. cyanobacteria, increase at the expense of other phytoplankton groups, an extra step in the food chain might be added. Less energy might be transferred to the upper levels because many cyanobacteria contain toxic compounds and are less edible than other phytoplankton groups. An increase of toxic containing cyanobacteria in lakes can also make lakes less attractive for recreational purposes in the future.

  • 268.
    Sandström, Jennie
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Carlsson, Fredrik
    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.
    Wei, Yu-Lian
    Jonsson, Bengt-Gunnar
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Wood-inhabiting fungi in rocky pine forests in the High Coast Region in SwedenManuscript (preprint) (Other academic)
  • 269.
    Sandström, Jennie
    et al.
    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.
    Jonsson, Bengt-Gunnar
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Rocky pine forests in the High Coast Region in Sweden: structure, dynamics and historyManuscript (preprint) (Other academic)
  • 270.
    Sandström, Jennie
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Ekelund, Nils
    Malmö University.
    Climate warming influences the timing of ice break-up and phytoplankton chlorophyll a in northern Sweden.Manuscript (preprint) (Other academic)
  • 271.
    Sandström, Jennie
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Ekelund, Nils
    Malmö University.
    Climatic impact on the abundance of cyanobacteria in oligotrophic lakes in northern SwedenManuscript (preprint) (Other academic)
  • 272.
    Sani, Negar
    et al.
    RISE Acreo AB, Norrköping.
    Linderhed, Ulrika
    RISE Acreo AB, Norrköping.
    Sandberg, Mats
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences. RISE Acreo AB, Norrköping.
    Monolithically integrated electrochemical energy storage modules2018In: Journal of Energy Storage, ISSN 2352-152X, Vol. 16, p. 139-144Article in journal (Refereed)
    Abstract [en]

    The concept of monolithic integration of electrochemical energy storage modules was tested on serially connected supercapacitor cells balanced by passive resistive dissipation. Five electrode pairs with collectors, interconnects, corrosion protection layers, electrode material and shunt resistors were printed on a single substrate. The printed patterns, lamination film, and a hot-sealing tool were designed so that upon folding, lamination, and electrolyte filling and sealing, five serial cells were formed with each having a shunt resistance. In an open circuit idling period following charge and discharge, the standard deviation of the individual cell voltages decreased, demonstrating the balancing function of this so called “modulit”, a short term proposed for a monolithically integrated electrochemical energy storage module. 

  • 273.
    Santoro, S.
    et al.
    Stockholm Univ, Arrhenius Lab, Dept Organ Chem, SE-10691 Stockholm, Sweden.
    Deiana, L.
    Stockholm Univ, Arrhenius Lab, Dept Organ Chem, SE-10691 Stockholm, Sweden.
    Zhao, G. -L
    Stockholm Univ, Arrhenius Lab, Dept Organ Chem, SE-10691 Stockholm, Sweden.
    Lin, S.
    Stockholm Univ, Arrhenius Lab, Dept Organ Chem, SE-10691 Stockholm, Sweden.
    Himo, F.
    Stockholm Univ, Arrhenius Lab, Dept Organ Chem, SE-10691 Stockholm, Sweden.
    Córdova, Armando
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences. Stockholm Univ, Arrhenius Lab, Dept Organ Chem, SE-10691 Stockholm, Sweden.
    Mechanism of palladium/amine cocatalyzed carbocyclization of aldehydes with alkynes and its merging with "Pd oxidase catalysis"2014In: ACS Catalysis, ISSN 2155-5435, E-ISSN 2155-5435, Vol. 4, no 12, p. 4474-4484Article in journal (Refereed)
    Abstract [en]

    The reaction mechanism for the palladium and amine cocatalyzed carbocyclization of aldehydes with alkynes has been investigated by means of density functional theory calculations and experiments. The Pd/amine cocatalyzed transformation is a carbocyclization of in situ generated enaminynes where the C-C bond-forming step is most likely promoted by a Pd(II) species. Notably, the latent Pd(0)/Pd(II) catalytic redox cycle of this metal/organo cooperative catalytic reaction can be merged with catalytic direct aerobic alcohol oxidation (Pd oxidase catalysis). (Chemical Equation Presented).

  • 274.
    Sjölander, Joel
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Spin-coated antimony- and nickel-doped tin dioxide electrodes foranodic ozone evolution2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This work have served as a preliminary work for a more extensiveresearch on antimony- and nickel-doped tin dioxide electrodes used forozone generation in electrolytic reactions. The target has been to test themanufacturing process of Sb/Ni-doped SnO2 with spin-coating techniqueand succeed to make electrodes for anodic ozone evolution and tocharacterize them. Electrode manufacturing was made using sol-gelfrom chloride salts of tin, antimony and nickel, which were applied to atitanium substrate through spin-coating. The substrates were spun todifferent thickness followed by drying and baking of the substrate. A setof electrodes with three layers were made just with spin-coating, additionallya set of electrodes with twenty layers were made with bothspin-coating and dip-coating. To characterize physical properties of theelectrodes, x-ray diffraction, scanning electron microscopy and transmissionelectron microscopy were conducted. Electrochemical measurementswere made in open beakers with a platinum cathode andsulphuric acid electrolyte using a galvanostatic measurement with afixed current. To measure the ozone evolution the optical absorbancedifference from the electrolyte compared to a clean electrolyte wasmeasured, this however only measures the amount of aqueous ozonepresent. Assembling of SnO2 electrodes for ozone evolution was successful.For the three-layered electrodes the absorbance readings wereinconclusive but with the twenty-layered electrodes there was a smell ofozone present within the electrolyte and absorbance reading of the dipcoatedelectrode presented a clear peak for ozone.

  • 275.
    Skytt, Torbjörn
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Ecotechnology and Sustainable Building Engineering.
    Nielsen, Soeren Nors
    Aalborg University, Centre for Bioscience and Techno-anthropology.
    Jonsson, Bengt-Gunnar
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Carbon dioxide and methane fluxes as indicators of regional sustainability – A case study of Jämtland, SwedenManuscript (preprint) (Other academic)
    Abstract [en]

    This study presents a regional model showing carbon dioxide and methane fluxes in Jämtland applying a 20-year time horizon to meet the Paris agreement horizon and regional policy goals. This short time horizon compared to the long horizon of 100 years typically applied, shows clearly the necessity to take both anthropogenic and non-anthropogenic emissions into consideration in analyses to be able to make proper priorities in future action strategies. The total annual GWP impact from Jämtland calculated as CO2eq is an uptake of 2.4 Mton/year (19 ton/capita) as shown in Figure 1. Jämtland shows large annual uptakes in forests (8 Mton carbon dioxide), but also large emissions of methane (80 kton), mainly from lakes, mires and ruminants. The (theoretical) sustainability (ref to global warming) of Jämtland is highly dependent of the choice of a GWP CO2 equivalent factor for methane, defined from the time horizon applied. Since methane respond quickly to emission pulse changes due to the short atmospheric life length of 11-13 years, it is necessary to evaluate regional activities contributing to changes of methane emissions to optimise regional CO2eq balance. But not only methane emissions need to be evaluated during a short-term time horizon. Also the use of woody biomass can have completely different outcomes from a CO2eq balance perspective if a 20-year time horizon is applied compared to a 100-year time horizon (or even longer). An increased regional awareness about the effects of the time horizon applied is needed when regional policy goals are to be set. This is not to say that a 20-year horizon is to be applied just because policy goals use this time horizon, but if the differences in short-term and long-term effects are not considered, ‘sustainability activites’ might be counterproductive from either a short-term or long-term time horizon. Especially an increased understanding about radiative forcing effects from the complex interplays in forest and mire/wetland ecosystem emissions and uptakes is necessary to be able to tell how the region actually influence climate change. The anthropogenic contribution in Jämtland, about 15% of total emissions, is easier to understand, but not necessarily easier to decrease.

  • 276.
    Ståhl, Göran
    et al.
    Swedish University of Agricultural Sciences, Umeå.
    Ekström, Magnus
    Umeå University, Umeå.
    Dahlgren, Jonas
    Swedish University of Agricultural Sciences, Umeå.
    Esseen, Per-Anders
    Umeå University, Umeå.
    Grafström, Anton
    Swedish University of Agricultural Sciences, Umeå.
    Jonsson, Bengt-Gunnar
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Informative plot sizes in presence-absence sampling of forest floor vegetation2017In: Methods in Ecology and Evolution, ISSN 2041-210X, E-ISSN 2041-210X, Vol. 8, no 10, p. 1284-1291Article in journal (Refereed)
    Abstract [en]

    Plant communities are attracting increased interest in connection with forest and landscape inventories due to society's interest in ecosystem services. However, the acquisition of accurate information about plant communities poses several methodological challenges. Here, we investigate the use of presence-absence sampling with the aim to monitor state and change in plant density. We study what plot sizes are informative, i.e. the estimators should have as high precision as possible. Plant occurrences were modelled through different Poisson processes and tests were developed for assessing the plausibility of the model assumptions. Optimum plot sizes were determined by minimizing the variance of the estimators. While state estimators of similar kind as ours have been proposed in previous studies, our tests and change estimation procedures are new. We found that the most informative plot size for state estimation is 1·6 divided by the plant density, i.e. if the true density is 1 plant per square metre the optimum plot size is 1·6 square metres. This is in accordance with previous findings. More importantly, the most informative plot size for change estimation was smaller and depended on the change patterns. We provide theoretical results as well as some empirical results based on data from the Swedish National Forest Inventory. Use of too small or too large plots resulted in poor precision of the density (and density change) estimators. As a consequence, a range of different plot sizes would be required for jointly monitoring both common and rare plants using presence-absence sampling in monitoring programmes. 

  • 277.
    Sundström, Edvin
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Nordvall, Robbin
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Dimensionering och simulering av ny stomkonstruktion2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Uppdragsgivaren har sedan tidigare jobbat inom bygg- och snickarbranschen, vil-ket fick honom att inse hur onödigt lång tid det tar att bygga en villa. Detta gav honom idén för hur tidsåtgången till att bygga en husstomme möjligtvis kan minskas. Det arbete som uppdragsgivaren nu vill utföra är att testa detta koncept genom att bygga en carport. Arbetet som genomförts i detta examensarbete har byggt på att beräkna om denna stomkonstruktion kan fungera. Detta har utförts genom att räkna fram hur mycket snö- och vindlast påverkar konstruktionen. Där-efter har dessa laster använts i dimensionsberäkningar och i finita elementmeto-den, för att simulera hur höga påfrestningar och förflyttningar som uppstår. I detta arbete har även ett försök på att förbättra smidesdetaljen genomförts, eftersom smidesdetaljerna är nyckeln till denna lösning. Detta har utförts genom att för-söka minska materialåtgången som används, vilket leder till att vikten minskar och troligtvis hållfastheten. Resultaten visar att den nuvarande dimensioneringen på stommen inte klarar av belastningarna. Simuleringarna har även visat att de-taljerna med mindre material är starkare än originalet. Detta kan vara dock bero på att det uppstått något litet fel under simuleringen. Men om tjockleken på stom-mens beståndsdelar ökas är denna lösning fullt möjlig att genomföras.

  • 278.
    Svanedal, Ida
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Boija, Susanne
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Almesåker, Ann
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Persson, Gerd
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Andersson, Fredrik
    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.
    Bylund, Dan
    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.
    Edlund, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Metal Ion Coordination, Conditional Stability Constants and Solution Behavior of Chelating Surfactant Metal Complexes2014In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 30, no 16, p. 4605-4612Article in journal (Refereed)
    Abstract [en]

    Coordination complexes of some divalent metal ions with the DTPA (diethylenetriaminepentaacetic acid)-based chelating surfactant 2-dodecyldiethylenetriaminepentaacetic acid (4-C12-DTPA) have been examined in terms of chelation and solution behavior. The headgroup of 4-C 12-DTPA contains eight donor atoms that can participate in the coordination of a metal ion. Conditional stability constants for five transition metal complexes with 4-C12-DTPA were determined by competition measurements between 4-C12-DTPA and DTPA, using electrospray ionization mass spectrometry (ESI-MS). Small differences in the relative strength between the coordination complexes of DTPA and 4-C12-DTPA indicated that the hydrocarbon tail only affected the chelating ability of the headgroup to a limited extent. The coordination of Cu2+ ions was investigated in particular, using UV-visible spectroscopy. By constructing Job's plots, it was found that 4-C12-DTPA could coordinate up to two Cu2+ ions. Surface tension measurements and NMR diffusometry showed that the coordination of metal ions affected the solution behavior of 4-C 12-DTPA, but there were no specific trends between the studied divalent metal complexes. Generally, the effects of the metal ion coordination could be linked to the neutralization of the headgroup charge of 4-C 12-DTPA, and the resulting reduced electrostatic repulsions between adjacent surfactants in micelles and monolayers. The pH vs concentration plots, on the other hand, showed a distinct difference between 4-C12-DTPA complexes of the alkaline earth metals and the transition metals. This was explained by the difference in coordination between the two groups of metal ions, as predicted by the hard and soft acid and base (HSAB) theory.

  • 279.
    Tejbo, Per-Olof
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Torkningens inverkan på dragstyrka och töjning hos papper och fibrer2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 280.
    Thapa, Anshu
    et al.
    Univ Sao Paulo, Sao Carlos, SP, Brazil; Univ Bath, England.
    Soares, Andrey Coatrini
    Univ Sao Paulo, Sao Carlos, SP, Brazil.
    Soares, Juliana Coatrini
    Univ Sao Paulo, Sao Carlos, SP, Brazil.
    Awan, Iram Taj
    Univ Sao Paulo, Sao Carlos, SP, Brazil.
    Volpati, Diogo
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Melendez, Matias Eliseo
    Barretos Canc Hosp, Barretos, Brazil.
    Guerreiro Fregnani, Jose Humberto Tavares
    Barretos Canc Hosp, Barretos, Brazil.
    Carvalho, Andre Lopes
    Barretos Canc Hosp, Barretos, Brazil.
    Oliveira, Osvaldo N., Jr.
    Univ Sao Paulo, Sao Carlos, SP, Brazil.
    Carbon Nanotube Matrix for Highly Sensitive Biosensors To Detect Pancreatic Cancer Biomarker CA19-92017In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 9, no 31, p. 25878-25886Article in journal (Refereed)
    Abstract [en]

    Biosensors fabricated with nanomaterials promise faster, cheaper, and more efficient alternatives to traditional, often bulky devices for early cancer diagnosis. In this study, we fabricated a thin film sensing unit on interdigitated gold electrodes combining polyethyleneimine and carbon nanotubes in a layer by layer fashion, onto which antibodies anti-CA19-9 were adsorbed with a supporting layer of N-hydroxysuccini-mide and 1-ethyl-3 (3-dimethylaminopropyl) carbodiimide solution. By use of impedance spectroscopy, the pancreatic cancer biomarker CA19-9 was detected in a buffer with limit of detection of 0.35 U/mL. This high sensitivity allowed for distinction between samples of blood serum from patients with distinct probabilities to develop pancreatic cancer. The selectivity of the biosensor was confirmed in subsidiary experiments with HT-29 and SW-620 cell lines and possible interferents, e.g., p53 protein, ascorbic acid, and glucose, where significant changes in capacitance could only be measured with HT-29 that contained the CA19-9 biomarker. Chemisorption of CA19-9 molecules onto the layer of anti-CA19-9 antibodies was the mechanism responsible for sensing while electrostatic interactions drove the adsorption of carbon nanotubes, according to polarization modulated infrared reflection absorption spectroscopy (PM-IRRAS). The adsorption behavior was successfully described by the Langmuir-Freundlich isotherm.

  • 281.
    Uesaka, Tetsu
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Complex matters: Things that matter2015Conference paper (Refereed)
  • 282.
    Vandekerkhove, Kris
    et al.
    INBO, Brussels, Belgium.
    Thomaes, Arno T
    INBO, Brussels, Belgium.
    Jonsson, Bengt Gunnar
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Connectivity and fragmentation: Island biogeography and metapopulationapplied to old-growth elements2013In: Integrative approachesas an opportunity forthe conservationof forest biodiversity / [ed] Daniel Kraus and Frank Krumm, Freiburg, Germany: European Forest Institute , 2013, p. 104-115Chapter in book (Other academic)
  • 283.
    Venugopal, Parvathy
    et al.
    University of Eastern Finland.
    Junninen, Kajsa
    University of Eastern Finland.
    Edman, Mattias
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Kouki, Jari
    University of Eastern Finland.
    Assemblage composition of fungal wood-decay species has major influence on how climate and wood quality modify decomposition2017In: FEMS Microbiology Ecology, ISSN 0168-6496, E-ISSN 1574-6941, Vol. 93, no 3, article id fix002Article in journal (Refereed)
    Abstract [en]

    The interactions among saprotrophic fungal species, as well as their interactions with environmental factors, may have a major influence on wood decay and carbon release in ecosystems. We studied the effects that decomposer diversity (species richness and assemblage composition) have on wood decomposition when the climatic variables and substrate quality vary simultaneously. We used two temperature (16 and 21°C) and two humidity (70% and 90%) levels at two wood qualities (wood from managed and old-growth forests) of Pinus sylvestris. In a nine-month experiment, the effects of fungal diversity were tested using four wood-decaying fungi (Antrodia xanthaDichomitus squalensFomitopsis pinicola and Gloeophyllum protractum) at assemblage levels one, two and four species. Wood quality and assemblage composition affected the influence of climatic factors on decomposition rates. Fungal assemblage composition was found to be more important than fungal species richness, indicating that species-specific fungal traits are of paramount importance in driving decomposition. We conclude that models containing fungal wood-decay species (and wood-based carbon) need to take into account species - and assemblage composition - specific properties to improve predictive capacity in regard to decomposition related carbon dynamics.

  • 284.
    Venugopal, Parvathy
    et al.
    School of Forest Sciences, University of Eastern Finland, Joensuu, Finland.
    Junninen, Kajsa
    Metsähallitus Parks & Wildlife Finland, Joensuu, Finland.
    Linnakoski, Riikka
    Department of Forest Sciences, University of Helsinki, Finland.
    Edman, Mattias
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Kouki, Jari
    School of Forest Sciences, University of Eastern Finland, Joensuu, Finland.
    Climate and wood quality have decayer-specific effects on fungal wood decomposition2016In: Forest Ecology and Management, ISSN 0378-1127, E-ISSN 1872-7042, Vol. 360, p. 341-351Article in journal (Refereed)
    Abstract [en]

    Any process that affects wood decomposition and decomposers in boreal forests may also affect the role that dead wood has on global carbon storages. We investigated under controlled laboratory conditions the impact of three major variables – temperature, humidity and wood quality – on Scots pine wood decomposition by four different fungal species. To reveal these effects, we conducted a nine-month factorial experiment. Wood quality was found to have a much more pronounced effect on fungal wood decay than climate variables. Furthermore, the fast-grown pine wood from managed forests decayed much faster than centuries old ‘kelo’ pine trees from natural forests as well as the slow-grown wood from managed forests. We found an overall increase in decomposition with temperature and humidity in Gloeophyllum protractum, except that the decay rate of the fast-grown wood declined with increasing temperature at higher humidity levels. The overall decomposition rates varied greatly with decayer species and wood type, and several interactions between temperature, humidity and wood quality effects were documented. In particular, we found that the fast decayers, Dichomitus squalens and Fomitopsis pinicola did not show any response to climate variables, but responded to wood quality only. The slow decayers Antrodia xantha and G. protractum responded to wood quality and interaction effects of climate and wood quality. Our results demonstrated species-specific effects of climate and wood quality when tested simultaneously, and show that it is critical to understand the different and complex mechanisms that affect wood decomposition and, consequently, carbon storages in forests, in order to increase the reliability of the climate-carbon prediction models.

  • 285.
    Vesterlund, Caroline
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Daily movement patterns of common crane (Grus grus) during the staging period in lake Kvismaren2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 286.
    Vesterlund, Niklas
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hjälparm för timmerstockshantering: Mekanik för att låsa fast och hantera grova trästockar inför kapningsarbete2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of the assignment was to design a new component within a product of the forest industry. A new sawmill of larger proportions required a new method of holding and handling lumber with profile dimensions reaching 0.6 by 0.45 meters. Some requirements of the solution included a certain operating range, a specific amount of re-quired force against the lumber and a solution of limited size for advan-tageous implementation. Multiple studies were conducted to find a suitable solution and following some qualified evaluations, a potential expedient involving trapezoidal thread forms was found. The solution revolved around two levels of trapezoidal threads with nuts that moved independently, each nut containing an axle of which upholds a metal rod. The rod will be in contact with the wood and have the ability to lean and follow the independent nuts due to a slot in the rod around the upper axle, giving the rod an operating range surpassing the require-ments. Further calculations determined the dimensions of the entire packet including internal components and expected forces on key parts within the solution, which concluded that the given design could handle all specified demands. The design and its different iterations was then drawn within the software IronCAD and implemented on the existing sawmill. Concluding the assignment, the solution was deemed practical and viable to live up to the given demands and even surpass the most essential requirements.

  • 287.
    Vestin, Jenny L. K.
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Söderberg, Ulf
    Department of Forest Resource Management, Swedish University of Agricultural Sciences, 901 83 Umeå, Sweden .
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Nambu, Kei
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    van Hees, Patrick A. W.
    Eurofins Environm AB, S-53117 Lidköping, Sweden.
    Haslinger, Edith
    AIT Austrian Inst Technol GmbH, Hlth & Environm Dept, A-3430 Tulln, Austria.
    Ottner, Franz
    Univ Nat Resources & Appl Life Sci, Inst Appl Geol, A-1190 Vienna, Austria.
    Lundstrom, Ulla S.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    The influence of alkaline and non-alkaline parent material on Norway spruce tree chemical composition and growth rate2013In: Plant and Soil, ISSN 0032-079X, E-ISSN 1573-5036, Vol. 370, no 1-2, p. 103-113Article in journal (Refereed)
    Abstract [en]

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

  • 288.
    Vilches, Ana Paola
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Effects of Bio-Ash Amendments on the Metabolism of Ectomycorrhizal Fungi: A Method Development and Metabolomic Study2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Forest ecosystems have played a fundamental role in the development of our society. Since the beginning of the civilization, forest have provided us with wood as a product for construction, tools, furniture and domestic heating. The well-being of the forest is therefore fundamental to our existence. Today, our growing societies have increased energy needs; the resulting depletion of fossil reserves and the effects of their use has again shown how the forest is among the most important alternatives for sustainability of our ecosystem. In order to responsibly make this resource a key part of our energy and material supply, we need to understand how forestry practices influence the different processes taking place in the forest ecosystems.

    The use of raw material from forest as energy source produces huge amounts of ash. The ash contains the base cations that have once been translocated from soil to the upper parts of the trees. Ash recycling has therefore been suggested as a measure to counteract soil acidification due to extensive harvest. Since spreading of ash can have great effects on the forest, it is important to understand which these effects are and how big they might be.

    This thesis focuses on the effects that such an ash recycling may have on the metabolism of ectomycorrhizal fungi; that is, fungi that are able to colonize root of trees, and contribute to the acquisition of nutrients and water from soil. The work presented here utilized an in vitro metabolomic approach on eight species of ectomycorrhizal fungi normally found in boreal forests. A targeted metabolomic study addressed the effects of ash amendments on growth, external pH and the exudation of low molecular mass organic acids, amino acids and hydroxamate siderophores. This was complemented by an untargeted metabolomic study to address the effects of ash amendment on the general metabolism of the fungal species.

    Analyses were performed with well-established chemical methods, and some that had to be developed specifically for this thesis work. A method for the analysis of amino acids without derivatization and yet compatible with mass spectrometry had to be developed and validated. The result was a robust method that works well with external calibration, shows good long-term stability, relatively low detections limits and high sample throughput. A screening protocol for the determination of siderophores from mass spectrometry data was also established.

    The metabolomic studies showed that bio-ash amendment increased the exudation of low molecular mass organic compounds from all the studied species. This means that the species tended to exude more of the same compounds compared to the controls without ash. In some cases, the bio-ash also triggered the exudation of new compounds. There was some exceptions, though; bio-ash amendment had negative effects on the exudation of certain metabolites, but these negative effects were of lower magnitude compared to the positive effects.

    Both metabolomics studies showed a differentiation between the ascomycetes and the basidiomycetes species. The targeted metabolomic study, indicated a trade-off in the utilization of carbon for accumulation of biomass or for the exudation of low molecular mass organic compounds, in which the ascomycetes accumulated more carbon as biomass compared to the basidiomycetes. According to the untargeted metabolomic study, the ascomycetes species presented the greatest number of metabolites that were influenced significantly by ash treatment, either as increase or decrease.

    Adding extracted ash to the culturing medium at the beginning of the experiment increased the pH, but this was counteracted by species metabolism as exudation of organic acids correlated with a drop in external pH. Ash treatment triggered the total exudation of low molecular mass organic acids in five of the eight studied species and especially in Cortinarius glaucopus. Ash treatment also triggered the exudation of amino acids from Tomentellopsis submollis and ferricrocin from Hymenoscyphus ericae.

    Of note was that no metabolite significantly influenced by ash was found to be common to all species, indicating that the ash amendments mainly affected the secondary metabolism under the culturing conditions used. Additionally, the ascomycetes Hymenoscyphus ericae exuded the greatest number of metabolites affected by ash that were exuded only by a single species. Conversely, Piloderma olivaceum exuded the largest number of unique metabolites not influenced by ash.

  • 289.
    Vilches, Ana Paola
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Gallampois, Christine
    Olofsson, Madelen A.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Norström, Sara H.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Fransson, Petra
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Effects of bio-ash on the exudation pattern of eight ectomycorrhizal fungi - an untargeted metabolomic studyManuscript (preprint) (Other academic)
  • 290.
    Vilches, Ana Paola
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Norström, Sara H
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Direct analysis of free amino acids by mixed-mode chromatography with tandem mass spectrometry2017In: Journal of Separation Science, ISSN 1615-9306, E-ISSN 1615-9314, Vol. 40, no 7, p. 1482-1492Article in journal (Refereed)
    Abstract [en]

    We developed a straightforward, robust, and relatively fast method for the analysis of amino acids by mixed-mode high-performance liquid chromatography coupled to electrospray ionization tandem mass spectrometry. The method does not involve derivatization and allows the detection of 21 amino acids, representing a wide range of isoelectric points, in less than 40 min. Chromatographic separation was governed by a silica-based mixed-mode column providing simultaneous hydrophobic and ion exchange separation mechanisms. The use of tandem mass spectrometry increased selectivity, reducing potential problems associated with poor selectivity in the chromatographic system. For an injection volume of 1 μL, we obtained detection limits <3 μM for the majority of analytes. For all analytes, a linearity of r > 0.99 was obtained, recovery in matrix was >86%, and the retention times were highly reproducible. The method was successfully applied to soil solution and fungal culture samples, demonstrating the advantages in successfully avoiding issues associated with high amounts of substances that may interfere with derivatization-based methods. This method represents an alternative to derivatization-based methods and can be applied in areas where sample matrices are highly complex.

  • 291.
    Vilches, Ana Paola
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Norström, Sara
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Olofsson, Madelen
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Fransson, Petra
    Swedish University of Agricultural Sciences, Uppsala.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Biofuel ash addition increases ectomycorrhizal fungal exudation in pure culture2018In: Environmental Chemistry, ISSN 1448-2517, E-ISSN 1449-8979, Vol. 15, no 8, p. 481-492Article in journal (Refereed)
    Abstract [en]

    Environmental context. Spreading recycled wood ash in forests may counteract acidification and nutrient losses, but the process may also affect symbiotic fungi in these eco-systems. We show how fungal species react when exposed to ash solutions; for example, by an increased release of organic acids and other compounds. These effects can influence pH and metal availability in forest soils treated with ash.. Recycling of wood ash may counteract acidification and losses of base cations resulting from whole-tree harvesting in boreal forest ecosystems. The effects of ash treatment on growth and exudation of eight ectomycorrhizal fungal species were investigated in this study. Six basidiomycetes and two ascomycetes were grown in liquid pure culture with different levels of ash amendments. Biomass production, pH and the exudation of 17 low-molecular-mass organic acids (LMMOAs), 23 amino acids (AAs) and 9 hydroxamate siderophores (HSs) were recorded after 1, 2 and 4 weeks of incubation. Ash did not affect fungal growth, but resulted in higher exudation of the investigated compounds, in particular LMMOAs. Ash also influenced the composition of the exudates. We measured exudation of LMMOAs and AAs up to millimolar and micromolar concentrations respectively. For example, Rhizopogon roseolus mainly produced oxalic acid, whereas Lactarius rufus and Tomentellopsis submollis produced the highest concentrations of AAs. Ferricrocin, the only HS detected, was exuded at the nanomolar level. Exudation responses were also highly species-dependent, e.g. the ascomycetous isolates that produced the largest biomass released low amounts of exudates compared with the basidiomycetes, and were the only ones producing siderophores. This growth–exudation response to ash is likely a trade-off in carbon allocation whereby the mycorrhizal fungal species invest carbon in either higher biomass production or higher exudation.

  • 292.
    Vilches, Ana Paola
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Olofsson, Madelen A.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    A siderophore candidate screening protocol based on gallium exchange and electrospray mass spectrometryManuscript (preprint) (Other academic)
  • 293.
    Volpati, Diogo
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences. Sol Voltaics AB, Lund, Sweden.
    Mårtensson, Niklas
    Sol Voltaics AB, Lund, Sweden.
    Anttu, Nicklas
    Sol Voltaics AB, Lund, Sweden.
    Viklund, Per
    Sol Voltaics AB, Lund, Sweden.
    Sundvall, Christian
    Sol Voltaics AB, Lund, Sweden.
    Åberg, Ingvar
    Sol Voltaics AB, Lund, Sweden.
    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.
    Björk, Mikael
    Sol Voltaics AB, Lund, Sweden.
    Castillo-Leon, Jaime
    Sol Voltaics AB, Lund, Sweden.
    Spectroscopic investigations of arrays containing vertically and horizontally aligned silicon nanowires2016In: Materials Research Express, ISSN 2053-1591, Vol. 3, no 12, article id 125021Article in journal (Refereed)
    Abstract [en]

    The properties of nanowire arrays have been investigated mainly in comparison with isolated nanowires or thin films, owing to the difficulty in controlling the nanowire alignment. In this study, we report on arrays containing vertically or horizontally aligned silicon nanowires, whose alignment and structure were determined using x-ray diffraction and scanning electron microscopy. The Raman spectra of the nanowire arrays differ from those of isolated nanowires because of distinct heat dissipation rates of the absorbed energy from the laser, in agreement with recent theoretical calculations. The tailored alignment of the nanowires on solid substrates up to 1 inch of diameter also enabled the observation of resonance modes associated with light trapped into the nanowires. This was proven by comparing the light absorbed and scattered by the arrays, and may be exploited to enhance light harvesting in tandem solar cells. Significantly, the control of the assembly of nanowire arrays may have a direct impact on bottom-up technologies of high anisotropy nanomaterials.

  • 294.
    Wedin, J. O.
    et al.
    Sundsvall Cty Hosp, Dept Clin Chem, SE-85186 Sundsvall, Sweden.
    Henriksson, Anders E.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences. Sundsvall Cty Hosp, Dept Clin Chem, SE-85186 Sundsvall, Sweden.
    Postgame elevation of cardiac markers among elite floorball players2015In: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, E-ISSN 1600-0838, Vol. 25, no 4, p. 495-500Article in journal (Refereed)
    Abstract [en]

    Cardiac biomarker release after exercise is well documented in endurance sports, but neither the impact of intermittent high-intensity exercise nor the reproducibility has yet been established. Floorball, a popular sport in Scandinavia, involves intermittent periods of high-intensity exercise. This study aimed to determine the prevalence and reproducibility of elevated cardiac marker levels among elite floorball players after two games. Twenty-three healthy male elite floorball players of median age 19 years (range 16-34 years) participated in two standard games. Blood was drawn at three time points: pregame, immediately after, and 2h after the game. Creatine kinase MB (CK-MB), myoglobin, and high-sensitivity cardiac troponin T (hs-cTnT) were measured. The results showed significantly elevated median postgame values in all markers. In both games, hs-cTnT exceeded the cutoff for myocardial damage (14ng/L) 2h postgame in the same six players. The major findings were that postgame cardiac hs-cTnT values among elite floorball players were significantly elevated and reproducible. The findings imply that extended investigations should incorporate evaluation of myocardial function and myocardial perfusion during exercise to seek the clinical significance and underlying mechanisms of elevated cardiac troponin after high-intensity exercise.

  • 295.
    Wennhall, Thomas
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Provmiljö för mekaniskt hjärta: Konstruktion av mätutrustning2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Företaget Real Heart i Västerås håller på att utveckla ett mekaniskt hjärta.Företaget har som slutmål att det skall kunna vara ett alternativ tillhjärttransplantation. När en sådan produkt utvecklas finns det en

    forskningsprocess som är viktig att följa. Real heart har under 10 år skapat nio prototyper och det är nu dags att verifiera att den nionde prototypen är redo för prekliniska tester. För att göra detta behöver det mekaniska hjärtat utsättas för

    liknande förhållanden som i en människokropp och relevanta parametrar som det tryck och flöde som det mekaniska hjärtat kommer ge upphov till i aortan i kroppen skall mätas. I denna studie har en sådan provmiljö utvecklats. För att

    åstadkomma detta har en designprocess använts vilken resulterade i en provmiljö där tryck kan mätas med hjälp av två olika metoder och flöde kan mätas med en metod. Provmiljön ger i ett och samma system värden från dessa

    metoder. När provmiljön var färdig utvärderades den genom att göra ett test med det mekaniska hjärtat, detta test följde en experimentell metod.

    Testet resulterade i värden som var lovande, mätvärdena hade dock lite för stor spridning och förbättringsförslag på detta och annat formulerades.

  • 296.
    Willén, Zimon
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Impact of forest fertilization on the abundance of reindeer lichen (Cladina sp.)2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 297.
    Xiong, Ye
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Malaria infection in relation to reproductive success and secondary sexual traits in collared flycatcher: In new and old breeding areas2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Life-history theory is based on the idea that every individual face a limitation of energy, nutrients and time in its lifespan. This optimization problem is resulting in trade-offs between resource demanding tasks and traits. It has been shown that parasite resistance and specific immune response is reduced by increased reproductive effort in birds. Reproduction success and malaria infection state were tested on 434 individuals in two old and one new breeding area on Gotland. With a high accuracy and fast PCR method, three genera of protozoan haemosporidians, which are also known as avian malaria parasites, were analyzed in this study to detect host-parasite interactions. The reproduction success, indicated as lay-date and fledge, in Rums and OLD areas, Gotland, Sweden, did not show any significant relation to infection state. Instead, age (Young < 2yrs vs Old ≥ 2yrs) was found to be the most influential factor affecting reproduction success. A trade-off between infection state and patch size (secondary sexual traits) has not been shown in this study. However, there are still pieces missing in understanding how avian malaria parasites affect their host's fitness, such as the host bird immunity response to the blood parasite species and intensity levels, which need to be examined in future studies.

  • 298.
    Xu, Chao
    et al.
    Stockholm Univ, Stockholm.
    Afewerki, Samson
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences. Stockholm Univ, Stockholm.
    Tai, Cheuk-Wai
    Stockholm Univ, Stockholm.
    Cordova, Armando
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences. Stockholm Univ, Stockholm.
    Hedin, Niklas
    Stockholm Univ, Stockholm.
    Cyclopalladated Azo-linked Porous Polymers in C-C Bond Forming Reactions2016In: CHEMISTRYSELECT, ISSN 2365-6549, Vol. 1, no 18, p. 5801-5804Article in journal (Refereed)
    Abstract [en]

    We designed a new cyclopalladated porous polymer (cyclo-Pd (II)/PP-2) with up to 20.7 wt% of Pd and investigated it as a heterogeneous catalyst for C-C bond-forming transformations. It was also shown to be an effective scavenger for Pd2+ in solution. The palladacycles formed along the backbone of the azo-linked porous polymer (PP-2) with (Pd-N) and (Pd-C) bonds as were confirmed by a combination of spectroscopies. The cyclo-Pd(II)/PP-2 decomposed when used for Suzuki and Heck cross-coupling reactions, and acyclic-Pd/PP-2 formed with Pd nanoparticles (NPs) bound to the PP-2. The Suzuki couplings were highly efficient in water and exhibited excellent recyclability. The cyclo-Pd(II)/PP-2 was also an effective heterogeneous Lewis-acid catalyst for stereoselective carbocyclization reactions.

  • 299.
    Xu, Chao
    et al.
    Stockholm Univ, Berzelii Ctr EXSELENT Porous Mat, SE-10691 Stockholm, Sweden.
    Deiana, Luca
    Stockholm Univ, Berzelii Ctr EXSELENT Porous Mat, SE-10691 Stockholm, Sweden.
    Afewerki, Samson
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Incerti-Pradillos, Celia
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Cordova, Oscar
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Guo, Peng
    Stockholm Univ, Berzelii Ctr EXSELENT Porous Mat, SE-10691 Stockholm, Sweden.
    Cordova, Armando
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences. Stockholm Univ, Berzelii Ctr EXSELENT Porous Mat, SE-10691 Stockholm, Sweden.
    Hedin, Niklas
    Stockholm Univ, Berzelii Ctr EXSELENT Porous Mat, SE-10691 Stockholm, Sweden.
    The Use of Porous Palladium(II)-polyimine in Cooperatively-catalyzed Highly Enantioselective Cascade Transformations2015In: Advanced Synthesis and Catalysis, ISSN 1615-4150, E-ISSN 1615-4169, Vol. 357, no 9, p. 2150-2156Article in journal (Refereed)
    Abstract [en]

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

  • 300.
    Zhang, Di
    et al.
    College of Chemistry, Jilin University, Changchun, China.
    Liu, Jianguo
    Cordova, Armando
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences. Stockholm University.
    Liao, Wei-Wei
    College of Chemistry, Jilin University, Changchun, China.
    Recent developments in palladium-catalyzed oxidative cascade carbocyclization2017In: ACS Catalysis, ISSN 2155-5435, E-ISSN 2155-5435, Vol. 7, no 10, p. 7051-7063Article in journal (Refereed)
    Abstract [en]

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

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