Water contamination through substances called per- and polyfluoroalkyl substances (PFAS) is a worldwide problem. Being able to measure the concentrations of PFAS in water is a first step towards beating this contamination. One alternative is to use a field test kit instead of extensive lab equipment to monitor the contaminated areas. This thesis has investigated the possibility of using amine-functionalized mesoporous carbon as adsorbent to develop a detection method based on adsorbing first PFAS and then dye in aqueous solutions. The non-adsorbed dye concentrations are depending on the amount of PFAS, and hence the colour intensity in the remaining solution is proportional to PFAS concentration. Mesoporous carbon with amine functional groups were chosen as specific adsorbents for PFAS because of its large surface area and high adsorption capacity. It has been shown that some colorants would react in a similar way as PFAS on sorbents and thus can be used as an indicator for the user. In the study, the two most common PFAS, PFOA and PFOS, were studied and Rose Bengal was the dye. The adsorbent’s morphology, pore structure and pore size was verified with scanning electron microscopy (SEM), transmission electron microscopy (TEM) and nitrogen sorption before being tested. Adsorption tests were performed using different PFAS concentrations and a dye solution range in order to find three things: the detection range, the ratio powder/solution in order to see a difference, and the adsorption or saturation time for both PFAS and dye. This thesis concluded that even though the adsorbent was not as efficient as predicted, this method could be used for detecting PFAS concentrations down to at least 0.1 pg/ml and could be a possible approach for quick field tests in the future.

The purpose of this thesis is to study how teachers teaches about controversial topics in the subject of social studies in relations to Albert Banduras theory of self-efficacy. Nine high school social studies teachers have been interviewed in order to fulfill this purpose. The teachers answers where then categorized into different categories of teaching strategies and influencing factors. The result shows that all of the teachers in the study applied teaching strategies that requires a high degree of self-efficacy. These strategies where pupil-centered to a high degree and correlates with ideals of deliberativ democracy as consensus weren’t necessarily the goal with the education. The source of the high degree of self-efficacy amongst the teachers seemed to be prior teaching experiences about controversial topics as all of the teachers claimed that their experiences where a major influencing factor for their classroom teachings. Other influencing factors such as the degree of heterogeneity in the classroom, type of high school program or the societal discourse surrounding the controversial topics where deemed as important but seemed to affect the choice of teaching strategies in a quite limited way. The fact that prior experiences where theprimary influencing factor supports the hypothesis that self-efficacy is an essential factor when teachers choose their teaching strategies as prior experiences of success (so-called mastery experiences) is the most important source for a strong sense of self-efficacy according to Bandura’s theory. / Denna uppsats har till syfte att granska samhällskunskapslärares undervisning om kontroversiella samhällsfrågor i ämnet samhällskunskap i relation till Banduras teori om upplevd självförmåga. För att uppfylla detta syfte har semistrukturerade intervjuer med 9 samhällskunskapslärare på gymnasienivå genomförts. Utifrån samhällskunskapslärarnas utsagor har en kategorisering kring lärarnas val av undervisningsstrategier samt de faktorer som påverkar detta val av undervisningsstrategier genomförts. Resultatet visade att samtliga lärare använde sig att undervisningsstrategier som i hög utsträckning förutsätter en stark upplevd självförmåga. Dessa strategier är elevcentrerade och bygger på samtalsdemokratiska ideal där konsensus inte nödvändigtvis är målet. Källan till denna starka upplevda självförmåga hos lärarna förefaller vara tidigare erfarenheter av undervisning om kontroversiella samhällsfrågor då samtliga lärare lyfte fram deras erfarenhetsgrad som en viktig påverkansfaktor för deras undervisning. Övriga påverkansfaktorer som graden av heterogenitet i klassrummet, typ av gymnasieprogram eller den samhällsdiskurs som omgärdar den kontroversiella samhällsfrågan uppgavs som viktiga men tycktes relativt sällan påverka valet av undervisningsstrategi i någon nämnvärd utsträckning. Att det är just erfarenheter som framförallt styr valet av undervisningsstrategi stödjer hypotesen att den upplevda självförmågan är central för valet av undervisningsstrategi då erfarenheter av framgång (s.k. mastery experiences) utgör den främsta källan till en stark känsla av upplevd självförmåga enligt Banduras teori.

Verotoxin-producing Escherichia coli (VTEC) of serotype O157:H7 is a pathogen causing illness in humans worldwide. The path and nature of transmission from and among cattle is important knowledge when it comes to preventing cases of disease in humans. Two concepts potentially playing an important role in transmission of VTEC O157:H7 are super-shedding and super-spreading. Super-shedders are individuals (here calves) shedding a high amount of bacteria. Super-spreaders are individuals (here calves) spreading the disease in a higher extent compared to the rest of the population investigated. Little is known about these phenomenons’ effect on transmission as well as the relation between them. Therefore, it is important to investigate this further. The purpose of this master thesis was to get a better understanding of how super-spreaders can be identified. One way to identify super-spreaders and explore the transmission of a pathogen is to investigate molecular data using computational methods. Here, a literature study with a systematic approach was conducted in order to scan the literature for such methods. In this first phase of the master thesis three methods, all constructing transmission trees, were identified as relevant methods for the second phase. These methods are called outbreaker2, phybreak and TransPhylo. In the second phase of the master thesis, 32 whole genome sequences of VTEC O157:H7 collected from four different cattle farms were investigated using the methods outbreaker2 and phybreak. Both methods were able to identify samples infecting more secondary cases compared to the rest of the investigated population. Some of these samples came from the environment, possibly shedding light on the importance of the pathogen's ability to survive outside of the host, and therefore playing an important role in transmission of the disease. The rest of the samples infecting more secondary cases were from calves, and a minority of these were super-shedders. From this the importance of the relation between super-shedders and super-spreaders can neither be confirmed nor denied. Outbreaker2 suggested that the spread of the pathogen is frequently occurring between the four neighbouring farms, while phybreak instead suggested that the spread mostly occurs within the farms. From this, a scenario explaining that the transmission possibly occurs within farms is presented.

Water is an essential and indispensable component is the pulp- and paper production industry.The increase in energy costs, stricter environmental regulations and water resource shortageshave caused a reduction of the water footprint in the industry as well as an increase in waterrecycling and water circuit closure. Reducing water usage requires an understanding of wherecontaminants originate, as well as which streams are critical to the process and how they impactmill operation. The recirculation of water can cause contaminant accumulation; therefore millsemploy technologies for water treatment in the internal water cycles, the so-called ‘kidneys’.Application of membrane technology is one such option which can improve the recycled waterquality and reduce contaminant buildup.The present study was carried out on a lab-scale for the treatment of a tissue mill effluent usingmembrane separation. A combination of pretreatment methods and various membranes werecompared with regards to separation, flux and fouling. The AlfaLaval M20 device was to treatwastewater samples sent from the mill, where the permeate was recirculated to the feed tank.COD and TOC levels are compared with regards to determining the separation efficiency. Thepermeate flux was measured over the two-hour filtration period, as well as flux recovery todetermine fouling levels. Additionally, some economic aspects of the process are discussed.This study suggests the potential application of a combination of flocculation or centrifugationpretreatment, with reverse osmosis membranes for recycling water to replace freshwater intake.The results also indicate the possibility of using ultrafiltration as kidneys to decreasecontamination buildup for further water loop closure.

In today’s paper and board production, quality control is made on a single cross direction (CD)sample from each tambour. As several different properties are analysed, only a limited number of measurement results are obtained for one property. Therefore, the measurement results might not be representative for the properties of the entire width of the tambour. The first objective of the project was to investigate variations of thickness, surface roughness and mechanical properties with a much higher resolution and number of measurements. The results of the measurement were compared with the routine quality control of the mill. The second objective of the project was to evaluate the influence of the wire shake unit in the centreply on the properties of the produced board. The measurements were performed on Iggesundpaperboard samples.The high-resolution measurements were performed using the STFI structural thicknessmeasurement device, an OptiTopo topography measurement device and a modified Autolinedevice at RISE Bioeconomy. The statistical evaluation of the results was performed in Matlab.Standard deviation, local variance and a frequency analysis were calculated for the thicknessmeasurements. Only standard deviation was considered for the topography data. For the mechanical properties, the distribution was evaluated using the Weibull distribution, since theresults had a single-sided distribution. In addition, the properties were analysed as a function of their location, for example to identify deterministic deviations in cross direction.The results of the first part of the project showed that the everyday control conducted in Iggesund is sufficient for most of the properties. Greatest difference was found at the edges ofthe samples, where Iggesund standard quality control does not detect a major variation inproperties, as no measurements are performed that close to the edge of the web. For example,at one edge, the high frequent measurements showed a significant drop in thickness which were not detected with the everyday quality control.In the second part of the project, the effect of a shake unit on the paper properties was evaluated. Here it was seen that the thickness variation were reduced, which also can be interpreted as an improvement of formation in the centre ply of the paperboard. As for thesurface roughness a slight improvement was found. Also for the mechanical properties, the shake unit appeared to improve the uniformity of the product / I dagens pappers-och kartongproduktion görs kvalitetskontroll på en enda tvärremsa (CD) från varje tambour. Eftersom flera olika egenskaper analyseras, erhålls endast ett begränsat antal mätresultat för en egenskap. Därför är informationen begränsad och kanske inte representativ för hela bredden av tambours egenskaper. Projektets första mål var att undersöka variationer i tjocklek, ytjämnhet och mekaniska egenskaper med mycket högre upplösning och antal mätningar. Resultaten av mätningen jämfördes med brukets rutinmässiga kvalitetskontroll.Det andra syftet med projektet var att utvärdera effekten av viraskaken på egenskaperna hos den producerade kartongen. Samtliga mätningar utfördes på kartongprover från IggesundsBruk.Mätningarna med hög upplösning utfördes med hjälp av en STFI-mätare för strukturtjocklek,en OptiTopo-enhet och en modifierad L&W Autoline-enhet. Den statistiska utvärderingen avresultaten utfördes i Matlab. Standardavvikelse, lokal variation och en frekvensanalys beräknades för tjockleksmätningarna. Endast standardavvikelse utvärderades för ytråhetsdata.För de mekaniska egenskaperna utvärderades fördelningen med hjälp av Weibullfördelningen,eftersom resultaten visade ett ensidigt beteende. Dessutom analyserades egenskaperna som en funktion av deras placering, till exempel för att identifiera deterministiska avvikelser i tvärriktningen.Resultaten av projektets första del visade att den dagliga kontrollen i Iggesund är tillräcklig för de flesta egenskaperna. Den största skillnaden hittades vid provets kanter, där Iggesundsstandardkvalitetskontroll Missar stora variationer för vissa egenskaper, eftersom inga mätningar utförs i det området på produkten. Vid ena sidan av nätverket visade de högfrekventa mätningarna en betydande minskning av tjockleken.I den andra delen av projektet utvärderades effekten av en skakningsenhet på pappersegenskaperna. Här såg man att variansen i tjockleksmätningarna indikerar en förbättring av formationen i kartongens mittskikt. När det gäller ytråheten konstaterades en liten förbättring. För de mekaniska egenskaperna föreföll viraskaken förbättra produktenslikformighet.

In order to extend the applications of aluminium, organic coatings may be applied on sheet materials, for instance for corrosion protection or aesthetic surface finish purposes in the automotive and construction industries, or on foil materials in the flexible packaging industry. The most common mechanisms for deterioration and structural failure of organically coated aluminium structures are triggered by exposures to the surrounding environment. Despite the great importance to elucidate the influence of exposure parameters on a buried aluminium/polymer interface, there is still a lack of knowledge regarding the mechanisms that destabilise the structure. It is generally believed that a detailed in situ analysis of the transport of corroding species to the buried interface, or of surface processes occurring therein, is most difficult to perform at relevant climatic and real-time conditions. In this work, Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR) in the Kretschmann-ATR configuration was successfully applied to in situ studies of the transport of water and ionic species through polymer films to the aluminium/polymer interface upon exposure to ultra pure deionised water and to a 1 M sodium thiocyanate (NaSCN) model electrolyte. Other main processes distinguished were the formation of corrosion products on the aluminium surface and swelling of the surface-near polymer network. Hence, in situ ATR-FTIR was capable to separate deterioration-related processes from each other. To perform more unambiguous interpretations, a spectro-electrochemical method was also developed for in situ studies of the buried aluminium/polymer interface by integrating the ATR-FTIR technique with a complementary acting technique, Electrical Impedance Spectroscopy (EIS). While transport of water and electrolyte through the polymer film to the aluminium/polymer interface and subsequent oxidation/corrosion of aluminium could be followed by ATR-FTIR, the protective properties of the polymer as well as of processes at the aluminium surface were simultaneously studied by EIS. The integrated set-up provided complementary information of the aluminium/polymer sample investigated, with ATR-FTIR being sensitive to the surface-near region and EIS being sensitive to the whole system. While oxidation/corrosion and delamination are difficult to distinguish by EIS, oxide formation could be confirmed by ATR-FTIR. Additionally, while delamination and polymer swelling may be difficult to separate with ATR-FTIR, EIS distinguished swelling of the polymer network and also identified ultimate failure as a result of delamination. The capability of the integrated ATR-FTIR / EIS in situ technique was explored by studying aluminium/polymer systems of varying characteristics. Differences in water and electrolyte ingress could be monitored, as well as metal corrosion, polymer swelling and delamination. / QC 20101124

This thesis is about thwo papers related to extra dimensions. Paper A discusses extrinsic curvature effects, and paper B treats symmetries of supersymmetric membranes. In the part of this thesis related to paper A, we extend the theory of non-relativistic quantum particles confined to submanifolds to relativistic boson fields. We show that a Klein-Gordon field constrained to a submanifold of a Lorentzian manifold experiences an induced potential similar to the one for the Schr{\"o}dinger equation. We embedd the Schwarzschild solution and the Robertson-Walker space-time and derive the induced potentials. Possible physical consequences of these induced potentials are also discussed. The second part is related to paper B, we study the dynamics of supersymmetric membranes, which are higher dimensional generalizations of supersymmetric strings. We derive a supersymmetric analogue of a dynamical symmetry for bosonic membranes. / QC 20110427

The mutualism between the fig tree and the fig wasp pollinator is an important keystone interaction for tropical forests. However, many antagonistic and parasitic species take advantage of the fig/fig wasp mutualism. One such parasite is the gall midge that develops inside fig syconia. Gall midges in fig syconia have sporadically been seen around the world, but until now they have never been observed in Panama. In this study a new Panamanian gall midge in fig syconia is described, together with a supposed parasitoid of the gall midge. The study furthermore investigates the gall midge effect on reproductive success for the fig/fig wasp mutualism. The gall midge is thought to be a new species belonging to the Ficiomyia family. The parasitoid share morphological similarities with the Physothorax family. However, both species need further investigation for proper identification. The gall midge had a significant negative effect on the fig/fig wasp mutualism’s reproductive success. Figs with gall midges inside had less flowers and a lower number of fig wasp offspring. Although, the effect on the reproductive success is small with low gall midge infestation rates.

Special relativity is a subject that attracts interest among students, but there are many things that make students experience it as difficult. As a physics teacher, it is important to both have a solid base of knowledge in physics as well as educational knowledge within the subject. You need to know what students usually struggle with, which parts to focus on to give the students a good understanding of physics, et cetera. This project is a literature study that examines special relativity in four parts. The first part of the project is a historical description of special relativity, summarizing how researchers have concluded the theory of special relativity. It consists of a series of experiments and hypotheses before Einstein tied everything together with his theory of special relativity. Then the central ideas of special relativity are described, with a focus on exercises that describe relativistic phenomena. The ideas covered in this second part are the relativity of simultaneity, time dilation, length contraction and mass and energy equivalence. The third part consists of a summary of current educational research to explore different ways to teach special relativity, according to the educational research. Many students make up their own explanations when presented with a relativistic phenomenon, that matches their Newtonian view in mechanics. It is a challenge to get students to think in a new relativistic way. A common difficulty is to move between different reference systems, which is necessary since relativistic phenomena in movement is only visible when looking at the same movement from different reference system. For the last part of the project, the Swedish curriculum and Swedish textbooks are examined. The section on relativity often begins with what students struggle most with, moving between frames of reference. Before introducing special relativity, it is useful to practice switching between different reference systems in classical mechanics, using Galilean transformations and relative motion. Another idea might be to introduce special relativity with, for example, the equivalence in mass and energy, where students do not encounter the problem with reference systems. / Speciell relativitetsteori är något som väcker nyfikenhet hos elever, men det finns mycket som gör att eleverna upplever det som svårt. Som lärare är det viktigt att ha en gedigen ämneskunskap och mycket didaktisk kunskap. Man måste ha koll på vad eleverna brukar ha svårt för, vilka delar man bör fokusera på för att eleverna ska få en bra grund, med mera. Det här projektet är en litteraturstudie som undersöker speciell relativitetsteori i gymnasieskolan i fyra delar. Första delen i projektet är en historisk beskrivning av speciell relativitetsteori, hur forskare har kommit fram till den speciella relativitetsteorin. Historiebeskrivningen består av en serie experiment och hypoteser innan Einstein knöt ihop säcken med den speciella relativitetsteorin. Sedan beskrivs de centrala idéerna inom relativitetsteori, med fokus på många exempel som beskriver relativistiska fenomen. De delar som behandlas i det här projektet är relativiteten i simultanitet, tidsdilatation, längdkontraktion samt massa- och energiekvivalens. Den tredje delen består av en sammanfattning av modern fysikdidaktisk forskning, för att ta reda på hur man kan undervisa forskningsbaserat inom speciell relativitet. Elever skapar ofta egna förklaringar till relativistiska fenomen, som stämmer bättre överens med en Newtonsk uppfattning. Att få eleverna till ett nytt relativistiskt tankesätt är en utmaning. Det som elever främst har svårt med är att gå mellan olika referenssystem, vilket är nödvändigt för att uppfatta relativistiska fenomen inom rörelse. Till sist undersöks den svenska läroplanen och svenska läroböcker. Ofta börjar avsnittet om relativitetsteori med det elever har som svårast för, att gå mellan olika referenssystem. Innan speciell relativitetsteori introduceras är det bra att öva att gå mellan olika referenssystem inom klassisk mekanik, arbeta med relativ rörelse och Galileitransformationer. En annan idé kan vara att introducera speciell relativitetsteori med till exempel ekvivalensen i massa- och energi, där eleverna inte stöter på det problemet.

The purpose of the study is to contribute knowledge about children's understanding of the physical phenomenon of friction by conducting a planned learning activity together with the children. In the activity, the children had the opportunity to investigate high and low friction with varied materials in a slide. A total of seven five-year-old children participated on two separate occasions. The observations were carried out at the respective preschool's slide, where the children had to ride with the different materials and investigate the friction that arose. The observations were recorded with audio and video recording, which were then analysed using a content analysis and based on the theory of variation. The results of the study indicate that most children had a certain understanding of the phenomenon of friction even before the activity, but not of the scientific concepts or knowledge enough to explain their thoughts about the phenomenon. The results also showed that the design of the learning activity contributed to an increased understanding of the phenomenon of friction. They developed their thoughts and explanations about the phenomenon in relation to the different materials that were investigated and several of the children also adopted the concept of friction towards the end of the activity. Key words: friction, research method, variation theory, preschool / Studiens syfte är att bidra med kunskap kring barns förståelse för det fysika-liska fenomenet friktion genom att genomföra en planerad lärandeaktivitet till-sammans med barnen. I aktiviteten fick barnen möjlighet att undersöka hög och låg friktion med olika material i en rutschkana. Det deltog totalt sju femå-riga barn vid två olika tillfällen. Observationerna genomfördes vid respektive förskolas rutschkana där barnen fick åka med de olika materialen och under-söka friktionen som uppstod. Observationerna spelades in med ljud och vide-oinspelning som sedan analyserades med hjälp av en innehållsanalys och uti-från variationsteorin. Resultatet av studien tyder på att de flesta barn hade en viss förståelse för fenomenet friktion redan innan aktiviteten, men dock inte för de vetenskapliga begreppen eller kunskaper tillräckligt för att förklara sina tankar kring fenomenet. I resultatet framkom även att utformningen av läran-deaktiviteten bidrog till en ökad förståelse för fenomenet friktion. De utveck-lade sina tankar och förklaringar om fenomenet i relation till de olika materi-alen som undersöktes och flera av barnen anammade även begreppet friktion mot slutet av aktiviteten.