Mid Sweden University

Celulose nanofibers are lightweight, recycable, biodegradable, and renewable. Hence, there is a great interest of using them instead of fossil-based components in new materials and biocomposites. In this study, we disclose an environmentally benign (green) one-step reaction approach to fabricate lactic acid ester functionalized cellulose nanofibrils from wood-derived pulp fibers in high yields. This was accomplished by converting wood-derived pulp fibers to nanofibrillated “cellulose lactate” under mild conditions using lactic acid as both the reaction media and catalyst. Thus, in parallel to the cellulose nanofibril production, concurrent lactic acid-catalyzed esterification of lactic acid to the cellulose nanofibers surface occured. The direct lactic acid esterification, which is a surface selective functionalization and reversible (de-attaching the ester groups by cleavage of the ester bonds), of the cellulose nanofibrils was confirmed by low numbers of degree of substitution, and FT-IR analyses. Thus, autocatalytic esterification and cellulose hydrolysis occurred without the need of metal based or a harsh mineral acid catalysts, which has disadvantages such as acid corrosiveness and high recovery cost of acid. Moreover, adding a mineral acid as a co-catalyst significantly decreased the yield of the nanocellulose. The lactic acid media is successfully recycled in multiple reaction cycles producing the corresponding nanocellulose fibers in high yields. The disclosed green cellulose nanofibril production route is industrial relevant and gives direct access to nanocellulose for use in variety of applications such as sustainable filaments, composites, packaging and strengthening of recycled fibers. 

There is a growing demand for the utilization of sustainable materials, such as cellulose-based alternatives, over fossil-based materials. However, the inherent drawbacks of cellulosic materials, such as extremely low wet strength and resistance to moisture, need significant improvements. Moreover, several of the commercially available wet-strength chemicals and hydrophobic agents for cellulosic material treatment are toxic or fossil-based (e.g., epichlorohydrin and fluorocarbons). Herein, we present an eco-friendly, high-yield, industrially relevant, and scalable method inspired by birch bark for fabricating hydrophobic and strong cellulosic materials. This was accomplished by combining simple surface modification of cellulosic fibers in water using colloidal particles of betulin, an abundant triterpene extracted from birch bark, with sustainable chemical engineering (e.g., lignin modification and hot-pressing). This led to a transformative process that not only altered the morphology of the cellulosic materials into a more dense and compact structure but also made them hydrophobic (contact angles of up to >130°) with the betulin particles undergoing polymorphic transformations from prismatic crystals (betulin III) to orthorhombic whiskers (betulin I). Significant synergistic effects are observed, resulting in a remarkable increase in wet strength (>1400%) of the produced hydrophobic cellulosic materials.

Studien behandlar ämnet intresseskapande faktorer i klassrummet och har i huvudsak sin målgrupp i årskurs F-3 där både personal och elever agerat respondenter. Studien baseras framför allt på två intervjuer med grundlärare från två olika skolor och 10 intervjuer med elever som tillhör klasserna där de två lärarna undervisar. Enligt studier som både TIMSS och PISA har elever i grundskolan ett lågt intresse för de naturvetenskapliga ämnena. Studiens syfte är därför att öka kunskapsbasen om vad som skapar intresse hos eleverna i undervisningen. Resultatet visar att elever påverkas av de arbetssätt som används i klassrummet, detta både i hur stoffet presenteras och bedöms men till största del av hur de tillåts arbeta med det stoff som ska behandlas. Eleverna uttrycker bland annat ett ökat intresse för det stoff som presenteras genom experiment eller genom arbete i grupp där de tillåts diskutera och själva upptäcka. Slutsatser som kan dras är bland annat att ett undersökande arbetssättet där pedagogerna diskuterar tillsammans med eleverna utifrån deras egna intressen, tankar och teorier verkar skapa nyfikna elever som inte är främmande för att dra egna slutsatser. Eleverna verkar uppskatta arbetssätt där de själva utforskar och i synnerhet utomhus samt när de tillåts arbete i grupp. Gjord studie är kvalitativ och till viss del komparativ.

Trangia is a brand that has been developing camping stoves since year 1925. In today's portfolio, they have no options for lightweight hikers, however, they are developing a new concept that they believe will suit this target group. The purpose of this report is to find out how a new windshield can look like for Trangias new product and develop a final concept. This has been done by examining the existing products: Trangia 27–1 UL, Optimus Elektra FE and a stand-alone aluminium foil windshield. Prototypes have been developed whose effectiveness have been tested in a wind tunnel, both without and with wind (5–6 m/s).A wind tunnel was constructed for the project in order to carry out these tests. To preserve Trangia's current design, semi-structured interviews have also been performed towards Trangia's staff. The final concept was developed by following a traditional product development.The result shows that the Trangia 27–1 UL was the most efficient kitchen of those tested. In the wind tunnel test, the cooking time of this camping stove had increased by 9.83% with wind, compared to without. The semi-structured interview showed that the design of Trangia's products was soft, robust, and simple.In conclusion, the report shows that a cylindrical wind shield with a sufficiently large ventilation is most efficient during wind load. The product should be able to be packed down and be simple to assemble. On the other hand, further studies are needed to be able to make thorough analyses of the wind shelter. 

Hydrogen sulfide (H2S) is a highly toxic and corrosive gas commonly found in industrial emissions and natural gas processing, posing serious risks to human health and environmental safety even at low concentrations. The early detection of H2S is therefore critical for preventing accidents and ensuring compliance with safety regulations. This study presents the development of porous ZnO/SnO2-nanocomposite gas sensors tailored for the ultrasensitive detection of H2S at sub-ppb levels. Utilizing a screen-printing method, we fabricated five different sensor compositions—ranging from pure SnO2 to pure ZnO—and characterized their structural and morphological properties through X-ray diffraction (XRD) and scanning electron microscopy (SEM). Among these, the SnO2/ZnO sensor with a composition-weight ratio of 3:4 demonstrated the highest response at 325 °C, achieving a low detection limit of 0.14 ppb. The sensor was evaluated for detecting H2S concentrations ranging from 5 ppb to 500 ppb under dry, humid air and N2 conditions. The relative concentration error was carefully calculated based on analytical sensitivity, confirming the sensor’s precision in measuring gas concentrations. Our findings underscore the significant advantages of mixture nanocomposites in enhancing gas sensitivity, offering promising applications in environmental monitoring and industrial safety. This research paves the way for the advancement of highly effective gas sensors capable of operating under diverse conditions with high accuracy. 

The National Institute for Occupational Safety and Health (NIOSH) has established exposure limits for sulfur-based volatile components, particularly hydrogen sulfide (H2S), at 20 ppm for an 8-hour exposure and 50 ppm for durations under 10 minutes. Detecting such toxic gases at low levels necessitates innovative sensor fabrication. This study introduces a unique sensor design, involving the direct thermophoretic deposition of SnO2 aerosol streams on one side and densely compacted SnO2 thick films via ultrasonic spray pyrolysis (UPS) on the other side, acting as a heater. Analyzing flame-made SnO2 particles using BET, XRD, and TEM techniques revealed highly crystalline particles approximately 8 nm in size. Methyl mercaptan (CH3SH) and H2S were employed as analyte gases, ranging from 20 ppb to 25 ppm and 20 ppb to 50 ppm, respectively. The results indicate that the flame-made SnO2 exhibits significant potential for developing gas sensors that are highly sensitive to CH3SH and H2S gases across a broad concentration range. The sensor demonstrates a linear increase in response at lower concentrations, saturating at concentrations exceeding 20 ppm. Consequently, highly sensitive gas sensors capable of detecting very low levels can be manufactured, suitable for machine learning applications in environmental monitoring, healthcare, and industrial safety. 

Science education is crucial for students to comprehend the role of science in modern society and make informed decisions about their future careers. To gain insight into students' attitudes towards science education, the students in the study write argumentative texts, providing justifications using facts, opinions, and experiences. The project examines students' perceptions of how gender affects students' ability to learn science, their interest in science subjects, and whether they see science education as a way to develop the world and solve real-world problems.

The primary objective of this project is to identify factors that impact students' interest in science education. The analysis of the argumentative texts provides educators with insights into students' opinions and attitudes toward science education. This research can help develop effective strategies to improve science education, identify strengths and weaknesses in learning, and address issues that may hinder students' interest in science.

As the researcher of a related study, my findings suggest that utilizing complex social issues in science education can effectively foster student interest and engagement, while also enhancing critical thinking and decision-making skills. Furthermore, my research highlights the significance use of negative heuristics in their argumentation and given that individual differences in core values and intellectual backgrounds may impact how information is weighed.

All the students participating in this study had access to the same information but weighed it differently. These differences may reflect differences in their core values and intellectual baggage. To improve science education, educators need to consider students' attitudes, opinions, and experiences and develop strategies to promote interest and engagement among students.

This study focuses on how students can argue and make decisions about socio-scientific issues that are relevant to their culture or region. The goal of this study is to present these dilemmas at the conference and propose incorporating decision-making about socio-scientific issues into the science education curriculum. The study explores students' skills in SSI argumentation and aims to clarify the relationship between values, knowledge and experiences in their SSI decision-making. Although all the students had access to the same information and agreed on the factual aspects of the issue, they came to different decisions, the difference depending on their background knowledge, values, and experiences. The result of the study found that students weighed the same information differently based on their core values and experiences. The results showed that the use of SSI in science classrooms can promote students' decision-making skills, critical thinking and awareness of different factors that influence SSI issues.

Cellulose nanocrystals, which have unique properties of high aspect ratio, high surface area, high mechanical strength, and a liquid crystalline nature, constitute a renewable nanomaterial with great potential for several uses (e.g., composites, films and barriers). However, their intrinsic hydrophilicity results in materials that are moisture sensitive and exhibit poor water stability. This limits their use and competitiveness as a sustainable alternative against fossil-based materials/plastics in packaging, food storage, construction and materials application, which cause contamination in our oceans and environment. To make cellulose nanocrystal films superhydrophobic, toxic chemicals such as fluorocarbons are typically attached to their surfaces. Hence, there is a pressing need for environmentally friendly alternatives for their modification and acquiring this important surface property. Herein, we describe the novel creation of superhydrophobic, fluorocarbon-free and transparent cellulose nanocrystal films with functional groups by a bioinspired combination of self-assembly and organocatalytic surface modification at the nanoscale using food approved organic acid catalysts. The resulting film-surface is superhydrophobic (water contact angle > 150°) and has self-cleaning properties (the lotus effect). In addition, the superhydrophobic cellulose nanocrystal films have excellent water stability and significantly decreased oxygen permeability at high relative humidity with oxygen transmission rates better than those of commonly used plastics. 

 To quickly identify maritime sites polluted by heavy metal contaminants, reductions in the size of instrumentation have made it possible to bring an X-ray fluorescence (XRF) analyzer into the field and in direct contact with various samples. The choice of source-sample-detector geometry plays an important role in minimizing the Compton scattering noise and achieving a better signal-to-noise ratio (SNR) in XRF measurement conditions, especially for analysis of wet sediments. This paper presents the influence of geometrical factors on a prototype, designed for in situ XRF analysis of mercury (Hg) in wet sediments using a ⁵⁷Co excitation source and an X-ray spectrometer. The unique XRF penetrometer prototype has been constructed and tested for maritime wet sediment. The influence on detection efficiency and SNR of various geometrical arrangements have been investigated using the combination of Monte Carlo simulations and laboratory experiments. Instrument calibration was performed for Hg analysis by means of prepared wet sediments with the XRF prototype. The presented results show that it is possible to detect Hg by K-shell emission, thus enabling XRF analysis for underwater sediments. Consequently, the XRF prototype has the potential to be applied as an environmental screening tool for analysis of polluted sediments with relatively high concentrations (e.g., >2880 ppm for Hg), which would benefit in situ monitoring of maritime pollution caused by heavy metals.

This work focuses on bending sheet metal using printed tools (punch). These tools aim to bend a number of 4 mm sheets without deforming and give a similar result as a steel tool would have done. The goal is to reduce the amount of material used in a bending tool. It would reduce weight and cost and improve the working environment for those working on changing tools. One wants to find advantages and disadvantages that may arise from using additive manufacturing in this environment.

These are produced using data analyzes of materials and with a simulated load case. They are printed using a 3d printer and are tested by being pressed together in a machine called INSTRON that provides metrics to analyze. Several smaller prototypes are tested and a final prototype is printed in full-scale. These are presented and tested at the company Jonsson and Paulsson until a satisfactory tool is ready. The project succeeded in this and the tool met its goals and purposes.

Concept2 is a leading supplier of fitness equipment, including rowing machines, ski machines and exercise bikes. Their products enable fitness training regardless of weather conditions. SkiErg is a ski ergometer used for cardio and strength training for arms, core, and legs. Users include cross-country skiers, general fitness enthusiasts, and CrossFit practitioners. SkiErg comes with a strapless handle that can be replaced with a ski handle. The main challenge is handle-replacement as the current assembly is classed as semi-permanent.

The purpose of the project was to create an improved user experience of the Concept2 SkiErg handle and promote social sustainability by focusing on individual needs. The goal was to present a finished concept with one or more physical prototypes consisting of an adaptable handle with technical solutions for different types of users.

The work follows a product development process that includes several steps, including market analysis to explore competitors and user needs, concept development, prototype development and user testing.

The project resulted in two feasible concepts: SkiErg Grip Adapter and SkiErg ErgoGrip. The concepts were presented through physical prototypes and renderings.

The project achieved its purpose by creating an enhanced user experience validated through user testing. The project provides valuable insights into the product development process and the challenges that may arise.

PISA-rapporten 2012 identifierade försämrade matematiska kunskaper hos svenska elever i förhållande till tidigare rapporter. En av regeringens åtgärder på de dåliga resultaten var att implementera nationella bedömningsstöd i matematik. Trots implementeringen av bedömningsstöden visar PISA-rapporten 2022 att matematikkunskaperna fortsätter dala bland svenska elever. Syftet med bedömningsstöden är att ge läraren summativa underlag om elevernas sammantagna matematiska kunskaper som läraren sedan ska arbeta formativt med i undervisningen. Tidigare forskning eller rapportsammanställningar har inte klargjort vilken effekt bedömningsstöden i matematik har på undervisningen. Studien syftar därför till att utöka kunskaperna om användningen av de nationella bedömningsstöden i matematikundervisningen. Med en enkätundersökning undersöktes lärarnas åsikter om hur bedömningsstöden påverkar undervisningen om det matematiska innehållet och de matematiska förmågorna, som sammantaget ger elevernas matematiska kunskaper. Resultaten visar att bedömningsstöden i huvudsak används i avsett syfte, dock kan avvikelser urskiljas som tyder på att andra verktyg och stödmaterial hellre används för att kartlägga elevernas matematiska kunskaper. Slutsatsen av studiens resultat är att lärare i stor utsträckning arbetar med elevresultaten på bedömningsstöden i taluppfattning i ett kombinerat syfte med fokus på de sammantagna matematiska kunskaperna. Studien visar att den komplexa aktiviteten, att kartlägga och bedöma elevernas matematiska kunskaper är ett område i behov av mer forskning.

This report presents a product development project aimed at creating an insulated hydration reservoir for Coxa Carry's hydration system. The purpose of the project was to develop a prototype capable of effectively resisting cold, thereby improving performance compared to existing market solutions.

The development method included several steps: concept generation based on identified user needs, prototype development, and manufacturing using Mylar® film for its insulating properties, followed by testing the prototype in a controlled environment to evaluate its thermal performance. Feedback from a stakeholder group consisting of elite skiers was also integrated to fine-tune the design.

The results from the tests showed that the insulated hydration bladder performed well compared to an uninsulated reference system. The prototype maintained a warmer liquid temperature under extreme cold, confirming its ability to preserve heat in the hydration system. 

The conclusion of the report is that the project successfully achieved its goal of developing a functional and effective insulated hydration bladder. The report recommends further field testing and exploration of alternative materials for future improvements.

This report presents a project carried out for Sunds Fibertech, where the goal was to create a digital concept for a modular test facility of cyclones. The purpose was to give the company the opportunity to build a physical plant at a further stage to experiment with the cyclone's designs and optimize it. To get a clear idea of the plant's requirements, an initial literature study was made, and interviews were conducted with the client. Then a systematic development methodology was applied, in which individual solutions for various problems were created using brainstorming and evaluated using Pugh's matrix. By combining these solutions, a 3D model was eventually created to visualize how the cyclone can be designed to allow easy change of its configuration. A proposal on which sensors and other components would be needed for the cyclone body to design a positive-fed system was also developed. The goals andrequirements set for the digital model were met mostly. Further work is required to construct a complete physical facility.

Using the case of outdoor shell jackets, this research studies obsolescence and potential lifespan extension by re-examining how product functionality, objectively and subjectively, develops over the course of product lifespans. In particular, the study focuses on second-hand stores for outdoor products. Functionality is indicated by user perceptions, visual assessments, laboratory measurements and price data, collected at first use, second-hand resale and end-of-life. Perceived functionality and price decline more rapidly (5–6 % per year) than assessed and measured functionality (around 3 % per year). This could be explained by properties related to appearance, which are not assessed nor measured but influence user perceptions and price. Discontentment regarding such properties appears more relevant for obsolescence than inadequate performance, suggesting the potential for design for attachment and timeless design. The relative stability of measured functionality over time suggests that a barrier for second-hand sales, concern about performance, could be ameliorated by a potential functionality-label.

Knowledge about obsolescence and its possible causes is instrumental to extend product lifespans. Product obsolescence may be caused by both subjective perceptions as well as objective and measurable deterioration of functionality. In order to extend lifetimes by avoiding and reversing obsolescence, this study addresses the current knowledge gap on how functionality of products develops over time, using a case study on shell jackets for outdoor recreational activities. Functionality over time is compared in terms of user perceptions, ocular assessments, laboratory measurements and, in addition, price. Data were collected at beginning of use, secondhand resale and end-of-life. In addition to ocular assessments and laboratory measurements, a survey was used to collect data from users on e.g. perceived functionality, price and duration of use span. Linear representations of perceived functionality and price decline more rapidly (5-6% per year) than assessed and measured functionality (both around 3% per year). This could be explained by properties such as appearance, which are included and seemingly important to user perceptions and price, but which are not assessed nor measured. The perception of such properties as low seems to be a more relevant cause of obsolescence than inadequate performance. This points to, for instance, timeless design to avoid obsolescence. The finding that measured functionality remains relatively high over time is important since concern about performance is a key barrier to secondhand sales. Information policy, such as performance-labelling, could thus contribute to reversing obsolescence. Future research could test the robustness of these findings as well as their generalizability to other products.

Matematisk ekvivalens och likhetstecknet är två viktiga områden att behärska inom matematikens samtliga områden. Dock är det många elever i grundskolan som har svårt att förstå likhetstecknets innebörd och hur de ska använda det. Forskare tror att detta beror på att majoriteten av de uppgifter eleverna får möta i grundskolans tidigare år är dynamiskt operationellt utformade. Detta leder därför till att eleverna ofta har en felaktig uppfattning om vad området faktiskt innebär. Tidigare forskning visar att elever besitter en operationell förståelse för likhetstecknet vilket innebär att eleverna ser på likhetstecknet som en operation som ska lösas och där de ska producera ett svar. Syftet med studien är att se vilken förståelse elever i årskurs 1 har för likhetstecknet, om de besitter en operationell eller relationell förståelse. Detta gjordes genom två kvalitativa undersökningar där sex stycken första årselever fick arbeta med ett arbetsblad innehållande 14 additions uppgifter. En del av uppgifterna var dynamiskt utformade och andra var statisk utformade. Under undersökningen utfördes observationer och intervjuer. Utifrån resultatet visar undersökningen att eleverna har en operationell förståelse.

Additive Innovation and Manufacturing AB (Aim) is a company working in the field of industrial additive manufacturing. With specialized expertise in electron beam melting (E-PBF). Through this expertise, Aim has created a tooling concept for molded fiber-production. The tooling concept goes by the brand of FreeFlow® and the main product being a perforated titanium mesh. A titanium mesh manufactured by E-PBF. Aim has received criticism from their customers regarding an undesirably high moisture content in the molded fiber-products, formed with their tools. The hypothesis is that this issue is due to the current design of the perforated mesh, which is believed to be mitigated by changing the pin density and pin length as well as adding paint to the surface. This report aimed to investigate the possibility and benefit of implementing these design changes. The results shows that the hypothesis was confirmed and painted meshes completely without pins formed the driest pulp. This report has provided insight into how Aim can improve the design of their tools and thereby create a more competitive product for their customers.

Recently, much research has investigated nanocomposites and their properties for the development of energy storage systems. Supercapacitor performance is usually enhanced by the use of porous electrode structures, which produce a larger surface area for reaction. In this work, a biocompatible polymer of starch medium was used to create the porous nanostructure. Two powders, i.e., Nickel molybdate/reduced graphene oxide (NiMoO4-rGO) and Nickel molybdate/nitrogen-doped reduced graphene oxide (NiMoO4-NrGO), were synthesized using the deposition method in a medium containing starch, nickel nitrate salts, sodium molybdate, and graphene oxide powder. In terms of electrochemical performance, the NiMoO4-NrGO electrode displayed a higher specific capacitance, i.e., 932 Fg−1 (466 Cg−1), than the NiMoO4-rGO electrode, i.e., 884 Fg−1 (442 Cg−1), at a current density of 1 Ag−1. In fact, graphene oxide sheets could lose more oxygen groups in the presence of ammonia, resulting in increased electrical conductivity. For the asymmetric supercapacitor of NiMoO4-NrGO//AC, the specific capacitance at 1 Ag−1, energy density, and power density were 101.2 Fg−1 (111.32 Cg−1), 17 Wh kg−1, and 174.4 kW kg−1, respectively. In addition, this supercapacitor material displayed a good cycling stability of over 82%.

Lärares behov av att utvärdera digitala verktygs användning i undervisningen har föranlett ramverket för teknik som ersättande, förstärkande och transformerande (Ramverket EFT). Ersättande innebär att digitala verktyg erbjuder ett alternativt lärande. Förstärkande medför att digitala verktyg förstärker undervisningen. Transformerande betecknar att digitala verktyg medför ökade möjligheter för lärande av ett reformerat innehåll: undervisningen omstruktureras beroende på elevernas upptäckter. Syftet med studien var att öka medvetenheten kring hur legitimerade grundlärare i årskurs F-3 använder sig av digitala verktyg i ämnet matematik utifrån kategorierna ersättande, förstärkande och transformerande. En kvantitativ metod genomfördes i form av en webbaserad enkätundersökning och urvalet bestod av 35 respondenter. Enkätfrågorna formulerades utifrån ramverket EFT, samt utifrån dimensioner som kan användas vid analys av digitala verktygs användning i undervisningen. För att kunna analysera och utläsa kategorierna utifrån ramverket EFT, skapades en tabell utifrån dessa. Resultatet visar att de digitala verktygen används mestadels som ersättande och förstärkande, och endast till viss del som transformerande. Författarna kopplar transformerad användning av digitala verktyg till Skolverkets formulering om vikten av att elevernas kreativitet och upptäckarlust vitaliseras (Skolverket, 2022b). Författarnas slutsats är att: för att en fördjupad förståelse för matematiska begrepp ska kunna utvecklas hos eleverna, behöver digitala verktyg i matematikundervisningen användas mer transformerande. 

Vårt arbete fokuserar på undervisningsmaterial och identifikation av de faktorer som påverkar valen av dessa, särskilt för årskurserna 4 - 6. Vi har analyserat användningen av undervisningsmaterial inom naturvetenskap ute på skolor för elever i årskurs 4–6. Genom detta har vi kartlagt vilka material som för närvarande används och identifierat viktiga faktorer som påverkar valet av dessa i undervisningen. En betydande del av studien fokuserade på att samla data om de specifika läromedel som lärare och skolor har gjort. Genom intervjuer fick vi en bild av vilka resurser som används för att undervisa i naturvetenskap i dessa årskurser. Detta innefattade läroböcker, digitala plattformar, experimentmaterial, utflykter och andra undervisningsresurser. Resultaten från undersökningen visar på att det är vissa läromedel som tycks vara vanligt förekommande och att dessa anpassas utifrån skolmiljön och olika pedagogiska behov. Digitala resurser tycks bli alltmer betydelsefulla och flera skolor har övergått till att integrera teknologi för att förbättra inlärningsupplevelsen. När det gäller faktorer som påverkar valen av materialet framkom det att lärarnas kompetens och pedagogiska metoder spelar en avgörande roll. Lärarnas bedömning av materialets lämplighet för elevernas nivå, engagemang och intresse var centrala överväganden. Dessutom påverkades valen av läromedel utifrån faktorer som tillgänglighet, kostnad och överensstämmelse med läroplanen.

Ethylene brassylate is a renewable macrolactone from castor oil that can be polymerized via ring-opening polymerization (ROP) to obtain a fully biosourced biodegradable polyester. ROP mediated by organometallic catalysts leads to high molar mass poly(ethylene brassylate) (PEB). However, the use of metal-free organocatalysis has several advantages, such as the reduction of toxic and expensive metals. In this work, a novel cellulose nanofibril (CNF)/PEB nanocomposite fabrication process by organocatalysis and reactive extrusion (REx) is disclosed. Here, ROP was carried out via solvent-free REx in the presence of CNFs using organic 1,5,7-triazabicyclo[4.4.0]dec-5-ene as a catalyst. Neat or lactate-esterified CNFs (LACNF) were used as initiators to investigate the effect of surface topochemistry on the in situ polymerization and the properties of the nanocomposites. A molar mass of 9 kDa was achieved in the presence of both unmodified and LACNFs with high monomer conversion (>98%) after 30 min reaction in a microcompounder at 130 °C. Tensile analysis showed that both nanofibril types reinforce the matrix and increase its elasticity due to the efficient dispersion obtained through the grafting from polymerization achieved during the REx. Mechanical recycling of the neat polymer and the nanocomposites was proven as a circular solution for the materials’ end-of-life and showed that lactate moieties induced some degradation. 

The scientific community is deeply concerned about the social impacts stemming from the consequences of Traumatic Brain Injuries (TBIs). Therefore, Anti-Rotational Technologies (ART) were designed to mitigate TBI severity. Advanced helmet testing, involving standard rigid headforms and numerical models of the human head, faces challenges regarding biofidelity and validation against rare cadaver data. The present study uses an innovative Instrumented Human Head Replica (IHHR), including cerebrospinal fluid (CSF), meninges, and brain simulants, to tackle biofidelity concerns. The IHHR assesses severity of impacts using embedded brain and skull pressure sensors, accelerometers, and gyros. Protected drop tests were conducted from three heights, incorporating ART and balaclava, onto an inclined anvil with a motorcycle helmet. A significant height-dependent reduction in Brain Injury Criterion (BrIC) with ART was shown (p-value≤0.001), while balaclava effects were not significant. The observed relative skull-brain motion was affected by ART (p-value≤0.001) and drop height (p-value=0.003). CSF pressures were significantly affected by ART and balaclava (p-values≤0.01), showing an increase in the coup duration and a decrease in pressure peaks with ART. These findings highlight the potential of the IHHR as a valuable tool for estimating the effect of ART on the severity of TBIs, allowing the calculation of injury criteria. 

For as long as light and matter have partnered, impurities have played a role in optical system performance. This remains generally true for photonic heat engines and especially the case for optical refrigeration. Building on the history of light and glass, including the materials development of low loss telecom fibers, this paper briefly discusses the sources of heat generation in materials and all-material means for their reduction. Particularly attention will be paid to active optical fibers and connect thermal management to parasitic optical nonlinearities, both critical to high and low power amplifier and laser systems. 

The focus of this study was the development of a second generation of fiber lasers internally cooled by anti-Stokes fluorescence. The laser consisted of a length of a single-mode fiber spliced to fiber Bragg gratings to form the optical resonator. The fiber was single-moded at the pump (1040 nm) and signal (1064 nm) wavelengths. Its core was heavily doped with Yb, in the initial form of CaF2 nanoparticles, and co-doped with Al to reduce quenching and improve the cooling efficiency. After optimizing the fiber length (4.1 m) and output-coupler reflectivity (3.3%), the fiber laser exhibited a threshold of 160 mW, an optical efficiency of 56.8%, and a radiation-balanced output power (no net heat generation) of 192 mW. On all three metrics, this performance is significantly better than the only previously reported radiation-balanced fiber laser, which is even more meaningful given that the small size of the single-mode fiber core (7.8-µm diameter). At the maximum output power (∼2 W), the average fiber temperature was still barely above room temperature (428 mK). This work demonstrates that with anti-Stokes pumping, it is possible to induce significant gain and energy storage in a small-core Yb-doped fiber while keeping the fiber cool. 

For applications such as laser cooling of doped fibers, where it is critical to measure accurately the temperature of a cooled fiber that is very close to room temperature, it is paramount to develop a reliable, very short (mm) fiber temperature sensor with millikelvin resolution and very little drift. We report a second generation of a unique slow-light fiber Bragg grating (FBG) temperature sensor that meets these stringent requirements. Experiments and modeling establish that its temperature response depends only on well-known material constants of the silica FBG and the response of the probe laser's wavelength controller. The response is independent of the linewidth of the slow-light resonance, hence different FBGs and/or resonances have the exact same response. Examples of measured cooling in optically pumped Yb-doped fibers show that more reliable thermal contact with the cooled fiber is obtained by wrapping the FBG and the cooled fiber. 

This work assesses the effectiveness of dilute inorganic alumino-silicate polymer suspensions in enhancing wood's durability, fire resistance, and mechanical properties. Alumino-silicate polymer-treated wood exposed to Coniophora puteana lost less than 3% mass on average, compared to 20% for controls. The moduli of elasticity and rupture of treated specimens were nearly twice as high as those of the controls. Coating with the inorganic polymer was also effective as a fire retardant. Results indicate that inorganic alumino-silicate polymers are a very promising wood treatment.

This study aimed to investigate the potential of converting bio-based residues from industrial production of mushrooms and tomatoes into more valuable chemicals with antifungal properties using hydrothermal liquefaction (HTL). Liquid fractions were obtained from HTL of spent substrate of Agaricus bisporus (Lange) Imbach and Pleurotus ostreatus (jacq.) P. kumm., recomposted Agaricus bisporus spent substrate, and tomato residues. The quantitative 1H NMR spectroscopy analysis revealed that the HTL liquids of all residues contained antifungal constituents like phenols and organic acids. The HTL liquids at dilutions of 10 % were able to inhibit the fungi by over 80 %. Interestingly, the fungus P. ostreatus showed tolerance to these constituents as its growth was promoted at the lowest concentration of all the HTL liquids. The HTL liquids had lower ecotoxicity than the commercial wood preservative. These results suggest that the tested residues could be a promising source of preservative chemical constituents for the wood industry. 

In order to achieve a desirable result during extrusion, even flow at the die exit is required. To achieve this, the die entrance is adjusted by hand according to information gathered by iterative physical testing. This testing process is time demanding and uses a lot of material that then needs further processing if to be used to produce finished products. This study aims to explore the possibilities to use fluid simulations to aid in the die adjusting process and achieve uniform flow. To examine this, the study looks at several different simulation software and their ability to run simulations through a given extrusion die. The study takes abilities like handling non-Newtonian flow according to a rheological model and temperature change into consideration. The study then compares the different simulation results with experimentally measured die exit temperatures and visually compares the simulations with adjustments made on existing dies. The results show that all the studied programs provide the ability to carry out simulations, but that they each show different strengths and weaknesses. The conclusion of the study is that by using today’s available tools, it is possible to perform simulations that represent the flow to such a degree that they can be useful when adjusting extrusion dies, given that additional information is gathered. It was noted that the programs were sensitive to utilized data and to transition into using simulation, a more detailed description of the setup and the used materials will be required. However, all examined software displayed similar flow behavior in areas like endpoints and intersections. 

Collaborative arrangements between schools and universities explored through a lens of organizing

Malin Benerdal1, Anna-Karin Westman2

1Umeå university, Sweden; 2Mid university, Sweden

Knowledge production in collaboration between academia and society has been put forward in governmental policies on research and development to an increasing extent over the last two decades (Jonsson et al., 2022; Skoglund, 2022) in the Nordics and beyond. This article focuses on one such effort, abbreviated ULF in Swedish, aiming at testing different models of collaboration between universities and school organizers in Sweden. It was initiated as a state-funded trial during the years 2017-2021. Drawing on an evaluation of the work at six participating universities, the aim of the paper is to analyze the organizing of the collaborative project focusing on university representative’s experienced efforts and challenges in relation to organizing the collaboration. The framework for analysis builds on literature of partial organization (Ahrne & Brunsson, 2011) and the analysis was conducted in two steps. First, we analyzed the material to determine which organizational elements were present and visible in the setup of the collaboration at the different universities. In the second step we focused on expressions and statements tied to the different elements focusing expressed efforts, solutions and difficulties in relation to the different elements of organization. The material consisted of transcripts from group interviews with 22 representatives from six universities and written responses from a survey.

The results indicate a partial organization where the elements of membership, hierarchy and rules being present. Different solutions were sought in relation to the universities and school organizers different contextual conditions, and different solutions to overcome hindrances was evident. The execution of the elements of organization were partly similar, but variation in prerequisites seems to have influenced the design. Thus, illustrating the importance of the contextual circumstances of both universities and schools. As the trial with ULF being prolonged and the previous government declared the intent of permanenting the initiative, the national organization is under reconstruction. It is therefore important to continue following the organizing and the consequences of collaborative initiatives such as ULF. As collaboration and partnerships between universities and school organizers is in demand, not at least from the political level in the Nordic countries, we need to further scrutinize how they are constructed and experienced not least from the outset of power dynamics in play and their consequences.

References

Ahrne, G., & Brunsson, N. (2011). Organization outside organizations: The significance of partial organization. Organization, 18(1), 83–104. https://doi.org/10.1177/1350508410376256

Jonsson, A., Grafström, M., & Klintman, M. (2022). Unboxing knowledge in collaboration between academia and society: A story about conceptions and epistemic uncertainty. Science and Public Policy, scac010. https://doi.org/10.1093/scipol/scac010

Skoglund, K. N. (2022). Social interaction of leaders in partnerships between schools and universities: Tensions as support and counterbalance. International Journal of Leadership in Education, 25(5), 747–766. https://doi.org/10.1080/13603124.2020.1797178

Collaboration between universities and schools has been emphasised byboth governments and within educational development research in the Nordic countries. However, educational research has tended to focus onthe practitioners’ perspectives and experiences, i.e., researchers andteachers. Our intention is to contribute to the field with research from another perspective; that of organising for collaboration. This is done by focusing on the experiences of university representatives responsible for the organisation of collaboration within a Swedish nation-wide initiative,the ULF project. Our theoretical framework draws on the literature of partial organisation. The results indicate that the different approaches and solutions used by universities could not only potentially strengthen schools’ opportunities to participate in educational collaboration with universities but also lead to different opportunities, reinforcing previously existing differences between school organisers. The results are discussed in relation to governmental intentions and guidelines.

Dalum is a relatively new company in the market with a focus on outdoor life. They have identified a gap in the market for griddles, which has led them to now sell compact, portable griddles in a lighter weight class. Based on customer feedback and their own experiences, the company wanted to expand their market with a product that facilitates the use of griddle pans in winter. From this, the aim of the work was to design a compact, portable product that facilitates cooking in nature during winter while being usable year-round. The goal of the product was divided into four steps, with the primary goal of creating 1–4 detailed CAD designs with an accompanying description of features and usage. Time permitting, a prototype, field test, and production would be carried out.

The method was based on the product development process, including pre-study, concept generation, evaluation/concept selection, and detailed design. To ensure that the work met its goal and purpose, a qualitative collection of opinions via a survey was conducted as a form of validation. The reference group used for validation was tailored to the background and purpose of the work. The results of the validation would also be used to compare the final concepts.

The results were presented based on the same product development process described by the method, where the various processes eventually resulted in two concepts containing detailed CAD designs. Due to time constraints, only the primary objective was achieved. The results were presented to the client, Dalum, and through assurance against the requirements and goals in the specification, the primary endpoint was deemed to have been theoretically achieved.

Since the validation was based on a detailed CAD design, opinions were collected on requirements that were possible for the reference group to assess. Therefore, it was not possible to say that the purpose of enabling cooking in nature during winter conditions was achieved. Since the work resulted in two final concepts, the concepts were compared using a Wilcoxon sign-ranked test. The comparison showed that one of the concepts was better on one of the three points compared. The three points included in the test were assembly, design, and overall rating, where the assembly for one of the concepts was found to be more convenient. 

The conclusion is that the project achieved its goal. To ensure that the product contributes to the purpose, further steps are required, including prototype development and field testing. 

There is much research on the role of theory in mathematics education research, at least from more overarching or theoretical perspectives. Micro analyses of the role of theory in particular research studies are rarer. We contribute by analysing one empirical study to allow for in-depth analyses and discussions around the role of theory in a specific case, concerning relationships between mathematics and reading. Our results show that studies that do not use an explicit theoretical model can still be strongly influenced by implicit theoretical assumptions. We conclude that it is important to identify existing theoretical assumptions in an empirical research study and try to convey them as clearly as possible, and we discuss specific issues concerning research on relationships between mathematics and reading. 

I vår presentation kommer vi att rapportera från ett forskningsprojekt som syftar till att öka kunskapen om hur undervisningen i naturvetenskap och teknik (NT) kan utvecklas genom studiebesök. Ett övergripande mål med utvecklingen av undervisningen är att öka elevernas intresse för dessa ämnen. Forskning visar att en viktig pusselbit för att få fler studenter att intressera sig för naturvetenskap och teknik är att förstärka känslan av att se sig själv som någon som sysslar med och är intresserad av dessa ämnen. Intresse för naturvetenskap och teknik är med andra ord också en fråga om identitet. Begreppet “vetenskapligt kapital i naturvetenskap och teknik” har i projektet använts för att identifiera aspekter av elevers NT-identiteter. Genom att uppmärksamma vilket vetenskapligt kapital elever har, skulle undervisningen kunna ge fler elever känslan av att NT är något för dem. I projektet har vi undersökt om och i så fall hur dessa aspekter påverkas när eleverna deltagit i ett studiebesök. Datainsamlingen har gjorts genom elevenkäter och observationer. Analyserna fokuserar på vilkenbetydelse design och genomförande har för elevers upplevelser av besöken. Resultaten visar att aktiviteter och goda förebilder under studiebesöket är viktiga komponenter för att ge eleverna en positiv upplevelse och stärka den naturvetenskapliga identiteten. Resultaten visade också att eleverna upplevde en begränsad vardagsanknytning under besöket. För att utveckla denna aspekt identifierades förberedelserna inför besöket som en avgörande faktor. Slutsatsen är att studiebesök kan påverka flera aspekter av elevernas vetenskapliga kapital om dessa uppmärksammas vid design och genomförande.

During the construction of outdoor substation, loads need to be calculated to design the foundations, frames, and anchor bolts. These calculations are time-consuming and require a good understanding of standards for substations. The development of an Excel document that calculates the forces acting on the foundations, frames, and anchor bolts, along with a substation template and associated steel drawings, facilitates and speeds up the work.

Depending on the voltage for which the substation is designed, the safety clearance between the equipment and the ground changes. Therefore, different templates are needed for different voltages. The equipment used becomes heavier and larger at higher voltages, so the steel must be dimensioned accordingly. These templates are created in Solidworks and consist of an assembly of all frames and equipment, as well as a foundation plan where all parts are paired to easily modify the design of the substation.

Standards for the mechanical design of substation structures have been followed to create an Excel document that calculates the design loads on the substation frames and foundations. By entering some measurements from the substation drawings and some technical information from the client into the Excel document, the bending stress and shear stress in the frames, normal and shear stress in the bolts, and edge pressure on the base plate are calculated.

The Excel document is expected to save approximately 12 hours when calculating stresses in the frames and foundations. For the substation template, the hope is to save around 80 hours.

Due to time constraints, only one out of the planned nine templates was completed. The Excel document could be further developed to calculate wind loads on the frames and short-circuit forces, but with minimal time savings.

This article focuses on a multiscale modelling approach to describe the delignification of softwood during the kraft pulping process. A framework for modelling the lignocellulosic feedstock on a fibre scale which considered the fundamental chemical components of wood as a distributed variable is re-assessed and extended to include chip-level phenomena such as diffusion limitations and initial component distributions within a softwood chip mixture. A new description of the wood chip is presented using a finite volume discretisation along one spatial dimension by simultaneously considering the anisotropic structural differences of the wood. Additionally, based on literature data, a distinction between the softwood chips' early- and latewood regions with their differences in densities and chemical composition is suggested. The presented model framework uses published sub-models for kinetics, diffusion etc. The validation and estimation of the remaining parameters are conducted from experimental data that quantifies the kappa number distribution of individual softwood fibres after kraft pulping. The investigation hypothesises a Gaussian distribution for the initial chemical component distribution within wood chips from a well-defined region. In contrast, a Log-normal distribution is used to describe the initial chemical distribution within a softwood chip mixture. The established sub-models for the kraft pulping process's kinetics and mass transfer phenomena could not predict the experimental data satisfactorily. However, modifying the sub-models by including a change in lignin reactivity and a temperature dependency of the lignin reactivity decline during the delignification progress could predict the essence of the observed experimental kappa number distribution. 

Graphene oxide (GO) was used in this study as a template to successfully synthesize silicon oxide (SiOx) based 2D-nanomaterials, adapting the same morphological features as the GO sheets. By performing a controlled condensation reaction using low concentrations of GO (<0.5 wt%), the study shows how to obtain 2D-nanoflakes, consisting of GO-flakes coated with a silica precursor that were ca. 500 nm in lateral diameter and ca. 1.5 nm in thickness. XPS revealed that the silanes had linked covalently with the GO sheets at the expense of the oxygen groups present on the GO surface. The GO template was shown to be fully removable through thermal treatment without affecting the nanoflake morphology of the pure SiOx-material, providing a methodology for large-scale preparation of SiOx-based 2D nanosheets with nearly identical dimensions as the GO template. The formation of SiOx sheets using a GO template was investigated for two different silane precursors, (3-aminopropyl) triethoxysilane (APTES) and tetraethyl orthosilicate (TEOS), showing that both precursors were capable of accurately templating the graphene oxide template. Molecular modeling revealed that the choice of silane affected the number of layers coated on the GO sheets. Furthermore, rheological measurements showed that the relative viscosity was significantly affected by the specific surface area of the synthesized particles. The protocol used showed the ability to synthesize these types of nanoparticles using a common aqueous alcohol solvent, and yield larger amounts (& SIM;1 g) of SiOx-sheets than what has been previously reported.

Forskning visar att det är viktigt att elever erbjuds olika huvudräkningsstrategier för subtraktion i matematikundervisningen. Eftersom läroboken till stor del styr matematikundervisningen är det angeläget att undersöka vilka subtraktionsstrategier som presenteras i läroböckerna. Syftet med analysen är att undersöka vilka subtraktionsstrategier som presenteras i läromedel för årskurs 1–3. Metoden är en innehållsanalys av tre läromedel för årskurs 1–3: Favorit matematik, Mattekojan och Rik matematik. Metoden är deduktiv och analysen kretsar kring fem olika subtraktionsstrategier. Resultatet visar att samtliga fem strategier förekommer i alla tre läromedel men i varierande omfattning. Tre av strategierna förekommer mer frekvent i samtliga läromedel. Dessa är ta bort, jämföra och omvandla subtraktion till addition. Strategin ta bort förekommer löpande i årskurs 1–3 i Favorit matematik samt i Mattekojan. I Rik matematik förekommer strategin enbart i årskurs 1. Vi har också sett stora variationer i hur synliga de olika strategierna är i läromedlen, huruvida man benämner strategierna och gör eleverna medvetna om vilka olika strategier som används. I Rik matematik och Mattekojan är strategierna tydligt uttalade i både lärarhandledning och lärobok, med egna begrepp för dessa strategier. I Favorit matematik benämns inte strategierna med samma tydlighet och vi kan enbart hitta ett exempel på när läromedlet benämner en strategi med egna ord.

This review focuses on the use of polyolefins in high-voltage direct-current (HVDC) cables and capacitors. A short description of the latest evolution and current use of HVDC cables and capacitors is first provided, followed by the basics of electric insulation and capacitor functions. Methods to determine dielectric properties are described, including charge transport, space charges, resistivity, dielectric loss, and breakdown strength. The semicrystalline structure of polyethylene and isotactic polypropylene is described, and the way it relates to the dielectric properties is discussed. A significant part of the review is devoted to describing the state of art of the modeling and prediction of electric or dielectric properties of polyolefins with consideration of both atomistic and continuum approaches. Furthermore, the effects of the purity of the materials and the presence of nanoparticles are presented, and the review ends with the sustainability aspects of these materials. In summary, the effective use of modeling in combination with experimental work is described as an important route toward understanding and designing the next generations of materials for electrical insulation in high-voltage transmission. 

Lithium-ion batteries are widely used today due to their high energy density, long life cycles, and low self-discharge rates. It commonly uses graphite as an anode material with a high theoretical capacity of 372mAh/g. At the same time, several research groups explore ways to further increase the energy storage capacity of lithium-ion batteries by, for example, adding silicon to the graphite anode material. Silicon is naturally abundant and inexpensive, with low environmental impact and a significantly higher theoretical specific capacity of ~4200mAh/g. A drawback is that graphite-silicon composite anode materials tend to degrade during the charge/discharge cycles, leading to decreased storage capacity over time. This degradation is associated with the size of the silicon particles, where large, micrometer-sized silicon particles are more susceptible to instability than smaller, nanometre-sized particles. To address this issue, we present an investigation using laser-assisted processing of nano-graphite-silicon composites. This process uses low-cost micrometer-sized silicon particles mixed with nano-graphite powder and a 1064 nm continuous wave laser to process the nano-graphite-silicon-coated anode material under various conditions and atmospheres (ambient and nitrogen). The performance of the lithium-ion battery is affected by different processing conditions. Specifically, the intensity of the 0.25V and 0.5V anodic peaks, which indicate the delithiation of silicon, is particularly affected, with the inclusion of an additional broader shoulder peak at around 0.3-0.35V. Our investigation suggests that laser-assisted processing of nano-graphite-silicon-composite materials is a scalable concept with the potential to improve the performance of nano-graphite-silicon anodes for lithium-ion batteries. 

Lithium-ion batteries are pivotal in modern energy storage, commonly utilizing graphite anodes for their high theoretical capacity and long cycle life. However, graphite anodes face inherent limitations, such as restricted lithium-ion storage capacity and slow diffusion rates. Enhancing the porosity of graphite and increasing d-spacing in expanded graphite anodes have been explored to improve lithium-ion diffusion and intercalation. Recent advancements suggest that nanoscale modifications, such as utilizing nano-graphite and graphene, can further enhance performance. Laser processing has emerged as a promising technique for synthesizing and modifying graphite and graphene-related materials, offering control over surface defects and microstructure. Here, we demonstrate an industrially compatible one-step laser processing method to transform a nano-graphite and graphene mixture into a nanoporous matrix, significantly improving lithium-ion battery performance. The laser-processed anodes demonstrated significantly enhanced specific capacities at all charge rates, with improved relative performance at higher charge rates. Additionally, long-term cycling at 1 C showed that laser-processed cells outperformed their non-processed counterparts, with specific capacities of 323 and 241 mAh/g, respectively.

Additive manufacturing is rapidly growing, where selective laser sintering technology dominates for industrial use. In the case of polymer selective laser sintering, polyamide is the standard material. However, polyamide is an electrical insulator, and for specific applications, it would be desirable to be able to manufacture polymer-based electrically conductive parts. Electromagnetic Compatibility is one of the most significant targeted applications, where the introduction of electric vehicles raises new electromagnetic compatibility demands. The goal is, therefore, to develop an electrically conductive composite material for selective laser sintering using graphene as the additive. Composites are prepared by mixing polyamide, graphene, and additives with varying graphene/polyamide ratios. The aim of this investigation is the laser-assisted processing of the resulting graphene/polyamide composites with various parameters to sinter the material, forming a solid conductive structure. The structure is characterized using SEM and resistance measurements. Results show sheet resistance values of about 700Ω/sq after laser-assisted processing with good powder flowability. 

There is a growing demand for nanopowders and nanoparticles in fields like medicine, healthcare, optics, sensors, and environmental monitoring. To produce these particles, pulsed laser ablation in liquid is an emerging technology offering numerous benefits over more commonly used methods like chemical synthesis, despite its relatively low production rate. For photonics applications, the production of NPs via pulsed laser ablation in liquid of rare-earth doped crystals like YAG and YVO4 is of significant interest due to their high absorption and emission cross-section, as well as high thermal conductivity. There is an increasing interest in developing laser-active hybrid materials, such as nanoparticle-doped silica optical fibers, potentially offering new and unique optical properties in, e.g., fiber lasers. In this work, we present an investigation of using pulsed laser ablation in liquid to synthesize Yb:YVO4 nanoparticles using a 1030 nm femtosecond pulsed laser under various conditions. The size and structure of Yb:YVO4 nanoparticles were affected by the pulse repetition rate (frequency) and solvent parameters, producing ovoid-like and spherical structures in deionized water and ammonia solution, respectively, with increased colloidal stability utilizing ammonia. The produced NPs are in the 10 - 150 nm range, with smaller NPs formed using the ammonia solution. The NPs are characterized by dynamic light scattering, Raman spectroscopy, scanning electron microscopy and energy dispersive x-ray spectroscopy. 

In this study, the structural integrity of mullite (3Al2O3·2SiO2) films, deposited on silicon carbide (SiC) substrates using chemical vapor deposition (CVD), was investigated via increasing load nanoscratch tests. The films were configured by mullite columns of stoichiometric composition growing from a silica-rich layer in contact with the SiC substrate. Controlled damage was induced in the 3Al2O3·2SiO2 films at relatively low scratch loads. Radial and lateral cracking were applied until final delamination and repeated chipping were achieved as the load increased. The intrinsic integrity of the 3Al2O3∙2SiO2 film and the performance of the coated 3Al2O3·2SiO2/SiC system, regarded as a structural unit, were analyzed. With the aid of advanced characterization techniques at the surface and subsurface levels, the configuration and morphology of the damage induced in the coated system by the nanoscratch tests were characterized, and the scratch damage micromechanisms were identified. Finally, the adhesion of the film, in terms of energy of adhesion and interfacial fracture toughness, was determined using different models proposed in the literature. The results from this investigation contribute to the understanding of the mechanical performance and structural integrity of EBC/SiC-based systems, which over the past few years have increasingly been implemented in novel applications for gas turbines and aircraft engines. 

Electron-Beam Powder Bed Fusion (EB-PBF) is one of the most important metal additive manufacturing (AM) technologies. In EB-PBF, a focused electron beam is used to melt metal powders in a layer by layer approach. In this investigation two pre-alloyed steel-based powders, stainless steel 316L and V4E, a tool steel developed by Uddeholm, were used to manufacture functionally graded materials. In the proposed approach two powders are loaded into the feeding container, V4E powder on top of 316L one, preventing their mixing. Such type of feeding yields components with two distinct materials separated by a zone with gradual transition from 316L to V4E. Microstructure and local mechanical properties were evaluated in the manufactured samples. Optical Microscopy, Scanning Electron Microscopy and EDX on the polished cross-sections show a gradual microstructural and compositional transition from characteristic 316L at the bottom of the specimens to the tool steel towards the top. Nanoindentation experiments confirmed a consequent gradient in hardness and elastic modulus, which gradually increase towards the top surface of the samples. The achieved results provide great possibilities to tailor the composition, microstructure, mechanical properties, and wear resistance by combining different powders in the powder bed AM technology. Potential applications include the tooling industry, where hard and wear-resistant materials are demanded on the surface with tougher and more ductile materials in the core of the tool.

Most Powder Bed Fusion (PBF) methods for the Additive Manufacturing (AM) of metals are based on the melting of powder of one specific metallic material; either of pure-elemental or pre-alloyed composition. Although the potential to build components from different materials in AM has recently gained a lot of attention, it is still not feasible in the current metal PBF systems. In the specific case of Electron beam- based PBF (PBF-EB), it is possible to precisely control the beam parameters in each site of the build area, which opens great possibilities for adaptive processes that allows melting powders of different nature in the same build. In this investigation, different steel-based and Ti6Al4V alloy powders are used to create metal-metal assemblies. By steering the fetching of two powders loaded in different hoppers it was possible to build different metal-metal assemblies. The microstructure and mechanical properties of the final materials were evaluated. 

In the pulp industry, pulp is being pressed into bales which are later shipped to factories to be used for production of cardboard and paper products. The bales produced requires packaging to be protected from damage during shipping. A machine is used to automatically package the bales. The material used to package the bales is refilled manually by an operator and could be considered time consuming and unsafe if not handled correctly. The purpose of this thesis was to develop a new concept of feeding packaging material to the machine. The new concept will be safer for operators and allow for faster refills of packaging material. The thesis has followed the design process in three phases: Analytical phase, creative phase, and an evaluating phase. The current construction wasanalyzed, and new concepts were developed using Morphology and evaluated using Pugh’s matrix.The result was evaluated and showed a concept considered to allow faster and safer refills of material than the current design. The resulting concept is however physically untested and exists only as a digital model.

This study is a thesis during the last semester of three years at the SportsTechnology program at the Mid Sweden University in Östersund. Theaim of the study is to give the swedish clothing brand Didriksons ananswer to the question of which padding used in their production thathas the best thermal insulation properties and which factors that mayhave an impact on it. The goal for this study is to present a satisfactoryresult for Didriksons from all the executed tests combined which laterhopefully will help them within their product development. To answerthat question, nine equal jackets with different isolation materials andways of construction have been tested in various laboratories such as thecold chamber at National Wintersport Centre and the wind tunnel atSports Tech Research Centre all within the Mid Sweden University. Thetests have not been according to any ISO-standards or such, but hasbeen produced by the student together with Didriksons and researcherswith expertise within the subject at the university. Studies showed thatthe jacket with the best thermal isolation property was the onefabricated with synthetic down. The study also showed that so calledcold spots, stiches, zippers and so on, may affect the padding whichresults in a big negative impact to the thermal isolation, especially whenthe garment is exposed to wind. Jackets with the same type of paddingbut different amounts of cold spots have delivered the best and theworst results during the tests. The different paddings have also beeninvestigated in laboratories to see how they withstand wind and toanalyze their micro structure. All this to get a better understanding ofthe materials and its various properties.