This Thesis explores the deposition techniques of magnetron sputtering and high velocity oxy-fuel (HVOF) spraying for Ti2AlC as a promising high-temperature material. Magnetron sputtering aims at producing thin (≤1 μm) Ti2AlC films of high crystal quality for use as a model system in understanding the material’s basic properties. HVOF is a new method for deposition of thick (≥200 μm) coatings by spraying Ti2AlC powder, with the aim of transferring the good bulk properties to coatings. The oxidation behavior of Ti2AlC coatings has been investigated for temperatures up to 1200 °C in air. As-deposited Ti2AlC(0001) thin films decompose into TiC during vacuum annealing at 700 °C by out-diffusion of Al as shown by x-ray diffraction analysis. The release of Al starts already at 500 °C in ambient air as driven by aluminum oxide formation on the film surface where the oxide initially forms clusters as observed by electron microscopy. While sputtering from a Ti2AlC target is simpler than by using different elemental targets, the resulting film composition differs from the target stoichiometry. This is due to differences in energy and angular distribution of the sputtered species and evaporation of Al at substrate temperatures above 700 °C. The composition can be compensated for by adding Ti to bind the Al and obtain phase-pure Ti2AlC coatings. For HVOF, I demonstrate how the total gas flow of a H2/O2 mixture (441-953 liter/min) and the powder grain size (30-56 μm) determine the thickness, density, and microstructure of the coatings. High gas flow and small grain size yield thick coatings of 210 μm with a low porosity of 2-8 % and a tensile stress of ≥80 MPa. A fraction of the Ti2AlC powder decomposes during spraying into TiC, Ti3AlC2, and Ti-Al alloys. The coatings also contain as much as 25 at.% O since the powder partly oxidizes during the spraying process. Increasing the powder size and decreasing the total gas flow yield a higher amount of Ti2AlC, but produces thinner coatings with lower cohesion. Post-annealing of the coatings at 900 °C in vacuum increases the Ti2AlC content due to a reversible phase transformation of the as-sprayed material. The high oxygen content, however, hinders the coating to completely transform into Ti2AlC and deteriorates its oxidation resistance. The work thus offers insights to the key parameters for optimizing Ti2AlC coating processing.

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Hard coatings are often used for protection of tool surfaces due to coating properties like low friction and high wear resistance. Even though many of the hard coatings have been tested for wear, it is important to try new wear test setups to fully understand tribological mechanisms and the potential of hard coatings. Few experiments have been performed with dual-coated systems where the sliding contact surfaces are coated with the same, or different, hard coating. The dual-coated system could be the solution to many new technical devices and perhaps a further improvement of conventional coated systems. In this thesis, the wear tests of dual-coated systems were performed in dry reciprocating sliding mode at room temperature. This, quite off the ordinary, wear test setup was performed to study selected hard coatings and set focus on wear mechanisms in forthcoming future surface coating application areas like MEMS and orthopedic implants. Wear tests of four different PVD hard coatings, CrN, TiAlN, WC/C and diamond-like coating (DLC) were performed in a slider-on-flat-surface (SOFS) tribo-tester with reciprocation sliding mode at room temperature and dry sliding with TiAlN coated counter body. Wear mechanisms and the amount of wear were estimated, by investigation of the wear scars produced in SOFS, by means of scanning electron microscopy (SEM), atomic force microscopy (AFM) and optical profilometer (OP). Typical wear mechanisms found for coated surfaces in reciprocation sliding contact were crack formation, surface flattening for shorter sliding distance, elongation of surface defects, debris and thin film formation. Two types of film formation were found: tribo-oxidation film and formation of a self-lubrication film. The tribo-oxidation was the most evident for CrN and the formation of a self-lubrication film was revealed for DLC, where smearing of asperities were the initiation of the process. The DLC coatings showed lowest friction coefficient and worn volume of all the selected hard coatings. Adhesion measurements were performed for all coatings by AFM. Both the unworn and worn surface of each coating were investigated and two coatings, DLC and TiAlN, showed low adhesion forces, which indicated promising properties for small scale devices like MEMS and NEMS with coated, non-sticking, surfaces. / <p>Grundutbildningsprogram: Civilingenjör Bred Ingång Inriktning: Civilingenjör Maskinteknik och Materialteknik</p>

Background Physical activity has many benefits, including the prevention of multiple different diseases. One way to perform physical activity is through resistance training, where some sort of resistance is used to increase the load on the muscles during contraction. For training the upper-body, the bench press exercise is a good option. However, not everyone has the equipment to perform this exercise. The push-up exercise has a similar movement pattern and uses the same muscles as well as no requirement for equipment. Therefore, it would be interesting to see which exercise activates the pectoralis major and triceps brachii, respectably, more. Aim The aim of this study was to compare the muscle activation of the pectoralis major and triceps brachii during push-up and bench press with push-up replicated resistance through EMG-testing. Method 21 male subjects participated in this study. EMG measurement was used on the pectoralis major and triceps brachii to record muscle activity. Following a MVIC test for both muscles, to get a reference value, five repetitions of the bench press exercise at 64% of the subject’s body weight, at rate of 40 beats per minute. Following a three-minute rest, the subjects performed five repetitions of the push-up exercise at the same rate. Three of the five repetitions were selected for further analysis. All data collected was converted to percent of MVIC (%MVIC) before any analysis. Results The results of this study showed a significantly higher activation of the pectoralis major during the bench press exercise compared to the push-up exercise (p=0.014). The results did not show a significant difference in the activation of the triceps brachii during the two exercises. Conclusion This study shows that for training the pectoralis major, the bench press exercise is preferable to the push-up exercise at the same load. For training the triceps brachii, the bench press and pushup exercises seem interchangeable at the same load.

Bakgrund: Inom golfbranschen finns behovet av att alltid förbättra sitt golfspel då konkurrensen är enormt stor inom världseliten. En viktig faktor inom golfen är golfswingen och ju högre klubbhastigheten i själva golfswingen ju länge blir utslaget så länge precisionen är densamma. Klubbhastighet kan förbättras med ökad styrka, och ett sätt som en styrkeökning kan ske kortvarigt är med hjälp av postaktiveringspotentiering (PAP) och därmed påverka ökning av klubbhastigheten.  Syfte: Studiens syfte var att undersöka om genomförandet av en tyngre rotationsövning direkt följt av en golfswing ger en postaktiveringspotentieringseffekt på klubbhastigheten jämfört med bara vila. Metod: En cross-over studie med 2 protokoll, samt 19 testpersoner som jämförde skillnaden i klubbhastighet mellan protokoll 2; en tyngre pre- övning i form av 5 tunga rotationer i Quantum innan 5 golfswingar och protokoll 1; 5 golfswingar med enbart vila som aktiveringsövning. Resultat: Ingen signifikant skillnad i klubbhastighet fanns varken i protokoll 1 med vila som intervention (p=0,65) eller i och protokoll 2 med PAP som intervention (p=0,94). Slutsats: I avsaknad av tidigare studier samt nuvarande studies negativa resultat är det fortfarande okänt huruvida postaktiveringspotentiering existerar i en golfswing och om det kan påverka klubbhastigheten. / Background: Within the golf industry, there is constantly a need to improve the golf game, as competition is high in the world elite. An important factor in golf is the golf swing, the higher club speed, the longer shot if precision is maintained. The club speed can be improved with increased strength, and one way to increase the strength is by adding post activation potentiation (PAP) and thus affecting the club speed. Purpose: The purpose of the study was to investigate whether the implementation of a heavy rotational exercise directly followed by a golf swing gives a post-activation potentiation effect on club speed compared to just resting. Method: A cross- over study with 2 protocols. 19 participants completed protocol number 2; with the content of a heavier pre- exercise rotation in Quantum, performed 5 times followed by 5 golf swings and also protocol 1, with the content of 5 golf swings with exclusively rest as a pre- activation exercise. Results: No significant difference was found in the club speed between protocol 1 with only rest as the intervention (p=0,65) and protocol 2 with PAP as intervention (p=0,94). Conclusion: In the absence of previous studies and with the negative results in the current study, it is still unknown whether post-activation potentiation exists in a golf swing and if it can affect club speed.

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De senaste decennierna har TIMMS undersökningar visat att svenska elevers resultat försämrats inom de naturvetenskapliga ämnena. Forskningen menar att möjliga faktorer till dessa resultat kan bero på elevernas inställning till ämnet samt hur undervisningen är utformad. Denna studie syftar till att undersöka litteratur kring elevers föreställningar kring naturvetenskapliga begrepp, med fokus på matspjälkning och näringsupptag, samt hur lärare undervisar om mat och hälsa i naturvetenskap. I studien har internationella och nationella litteraturer behandlats, dessutom har valda lärandeteorier analyserats med fokus på konstruktivismen och det sociokulturella perspektivet. I Studien har vi även behandlat olika undervisningsmetoder verksamma lärare använder sig av för att främja elevernas kunskapsinhämtning. Då studiens metod är en litteraturstudie har vetenskapliga artiklar från olika databaser analyserats och valts ut efter studiens valda syfte. Resultatet av vår litteraturstudie visar på att elever har svårigheter att förstå och förklara naturvetenskapliga begrepp. Elever använder sig av vardagsbegrepp när de ska förklara vad som sker i magsäck och tarm. Resultatet visar att elever tillämpar sina tidigare erfarenheter för att förklara matspjälkning och näringsupptag. Resultatet innefattar också två lärandeteorier som presenterar deras synsätt och förhållningssätt i de naturvetenskapliga ämnena. Resultatet visar även att lärarens kvalité på undervisningen har en stor betydelse för elevernas kunskapsinhämtning. Enligt forskningen är det lärarens egna attityder och kunskaper till ämnet som speglar undervisningen, där det är viktigt att lärare har en korrekt förståelse för det aktuella begreppet. Detta betyder att lärare med hög ämneskunskap och god pedagogisk skicklighet gynnar elevers begreppsförändring.

Sorocarpy is the aggregation of unicellular organisms to form multicellular fruiting bodies (sorocarps). This thesis is about the two best-known groups of sorocarpic amoebae, Dictyostelids and Acrasids. Paper I describes assembly and analysis of a multigene dataset to identify the root of the dictyostelid tree. Phylogenetic analyses of 213 genes (conserved in all sequenced dictyostelid genomes and an outgroup) place the root between Groups 1+2 and 3+4 (now: Cavenderiaceae + Acytosteliaceae and Raperosteliaceae + Dictyosteliaceae). Resolution of the dictyostelid root made it possible to proceed with a major taxonomic revision of the group. Paper II focuses on the taxonomic revision of Dictyostelia based on molecular phylogeny and SSU ribosomal RNA sequence signatures. The two major divisions were treated at the rank of order as Acytosteliales ord. nov. and Dictyosteliales. The two major clades within each of these orders were given the rank of family. Twelve genera were recognized. This is the first revision of a major protist taxon using molecular signatures and offers guidelines for taxonomic revision of protist groups where morphology is insufficient. Paper III presents the mitochondrial genome (mtDNA) of Acrasis kona. Over a quarter of the genome consists of novel open reading frames, while 16 genes present in the mtDNA of its relative, Naegleria gruberi, are missing. We identified many of these genes in the A. kona nuclear DNA, and used phylogenetic analyses to show that most of these genes arose by transfer from mtDNA. Paper IV presents the nuclear genome of A. kona, the second genome sequence of a free-living excavate. The 44 Mb genome has 15,868 open reading frames of which 4,987 are novel. A surprising number of genes are most similar to homologs in distant relatives, suggesting acquisition by horizontal gene transfer (HGT). Most HGT candidates are expressed and many constitute multi-gene families and/or have acquired introns and membrane targeting sequences. Strong HGT candidates include some genes essential to development and signaling in Dictyostelia. Flagellar motility and meiosis genes are also present and conserved, suggesting cryptic flagellar and sexual stages.

I denna rapport har elever på högstadiet genom en enkätundersökning fått berätta vad de tycker att de lärsig genom att laborera. En majoritet av de tillfrågade eleverna svarar att det är roligt att laborera, de anser även att de lär sig mer om ämnet, skriva rapporter och att samarbeta. Det visar sig att det inte finns några större skillnader mellan vad pojkar och flickor tycker, inte heller syns någon tydlig trend när de olika årskurserna jämförs.

Conjugated polymers have been found useful in a wide range of applications such as sensors, electrochemical transistors, solar cells, and printed electronics due to their mechanical, optical and electronic properties. An amazing research field has grown during the last three decades since the discovery of conducting polymers in 1976. Since the materials can be made from solutions, different processing methods such as spin coating and vapor phase polymerization can be used to coat a huge variety of substrates. The choice of method depends mainly on monomer solubility and kind of substrate to be coated. During the synthesis the polymers can be chemically modified to tailor their functionalities. Due to this variability in materials and the processability, electronics can be achieved on unconventional substrates such as flexible plastic foils and cell culturing dishes. As a contrast to inorganic, usually metallic materials, conducting polymers are built up from organic compounds in a molecular structure with soft mechanical properties that have shown to be a benefit in combination with biology, ranging from interactions with cells to interactions with advanced biological species such as tissues. This combination of research fields and the possible applications are merged within the field of organic bioelectronics. The primary purpose of this thesis is to give a background to organic electronics in general and how electrochemical devices can be processed and developed for biological applications in particular. An organic electronic surface switch is introduced to control cell adhesion and proliferation as well as an electrochemical transistor to spatially tune the cell adhesion along an electrochemical gradient. To mimic a more natural cell environment a three dimensional fiber substrate was used to design an electronically active matrix to promote nerve cell adhesion and communication. By combining standard microfabrication techniques and conjugated polymers desired patterns of electroactive polymer were created to enable active regulation of cell populations and their extracellular environment at high spatial resolution. Finally, a brief look into future challenges will also be presented.