Bioprinting is one of the most promising technologies for future healthcare as it may benefit the repairing of wounds and injuries, disease modeling and development, transplantation of organs and reduce animal testing. This thesis aim to investigate this industry further, as there is no excessive literature on how to handle the innovation in regards to entrepreneurial and biotechnological knowledge. Hence, a research gap can be spotted and the purpose of the conducted research questions should contribute to this gap. In order to fully understand the bioprinting industry, an outline of the technology is made as part of the research. In addition to this, secondary data for patents, market valuation and annual growth rates are collected to support arguments from previous literature. Also, interviews are conducted to gather specific knowledge. As a result, bioprinting may be presented as a disruptive innovation in an uncertain market, which places certain demands on companies to act more in line with the complexity of the technology. Such companies must think more strategically and design more complex and long-term strategies. The patent data shows that there has been a decline in the technological development as patent applications have decreased significantly. Even though the technology (regarding the patents) has started to slowly decline, there is still hope for some technological improvements to come. It can be concluded that developments in bioink, scaffolds, expansion of cells and diffusion is expected, and that the use of bioprinting is increasing and will most likely continue to do so.

Mycelium-based composite (MBC) is being developed and researched in multiple commercial markets as an alternative sustainable material. MBC utilizes the mycelium ability to create a web-like structure in lignocellulosic structures. However, producing the material in a natural environment and subjecting it to various tests; the study aims to examine the distress of the southern Swedish climate on MBC grown in different substrates. The selection of substrates are based on their compatibility to fungal growth, the substrates are also locally sourced and grown. This is to explore MBC material production with a focus on circular economy as biodegradable material in architecture could help develop a reuse and recycle system. Various tests were done on the different substrate MBC to determine its characteristics, limitations and opportunities. The tests were developed with a focus on architectural construction and the southern Swedish climate; meaning experiments including MBC reaction to fire, water and temperatures. The results are based on the different MBC materials reaction, this ends with a description on how the materials could be used and developed in the future.

Microalgae are considered as a potential feedstock for many promising applications. Some active substances in microalgae have plant biostimulation effects potentially useful in agriculture. However, to produce such a microalgal biomass, specific microalgae cultivation and post-treatment processes must be designed to preserve active substances. A particular focus is provided on cultivation (tubular photobioreactor) and different plausible post-treatment scenarios for microalgae separation (flocculation and centrifugation) and preservation (sterilization and drying). For each step, yield and energy consumption are modeled using data taken from literature or lab and pilot scale experiments. Industrial equipment for scale-up process is also studied by comparing existing systems. These models enable to make an economic evaluation of the whole process and to study its profitability for each scenario. The breakeven price is calculated as a function of the production rate. Several parameters are suggested to improve system efficiency and profitability at the end of this study. However, a better microalgae characterization and more experiments on potential post-treatment systems are required to improve the accuracy of the model.

Filtration and separation technologies remain as one of the biggest challenges humanity currently faces. The separation of different elements such as bacteria, viruses, heavy metals, particles, and chemical agents require the development of multifunctional membranes. In membrane technology, one of the most promising fabrication techniques is electrospinning, which can produce highly tailored non-woven fibrous multifunctional membranes with a high surface area. On the other hand, cellulose derivatives, like cellulose acetate, have many beneficial properties for filtering technology such as high availability and easy functionalization. Likewise, cellulose nanocrystals are used to improve mechanical properties and functionalize membranes. In this project, a cellulose nanocrystal (CNCs) functionalized cellulose acetate electrospun multifunctional membrane is developed for adsorption and separation of nanosized particles. In this work, cellulose acetate (CA) fibers with an average fiber diameter of approximately 900 nm were electrospun and tested as membranes for size and affinity based filtration. First, the electrospinning process was optimized regarding solution and process parameters. As a result, solution parameters were found to be 12 wt% solid content CA dissolved in a 1:1 acetone:acetic acid solution. Regarding process parameters, the suitable electrospinning parameters were found to be 18 kV applied voltage, a feeding rate of 5 mL/h, and a tip-to-collector distance of 20 cm.   The electrospun CA membrane was coated with cationic (+) and anionic (-) cellulose nanocrystals up to a 25 wt% concentration. The incorporation of CNCs, of either anionic or cationic surface charge, affected membrane wettability. The neat CA membrane had a hydrophobic behavior with a contact angle of 110°. The addition of CNCs decrease contact angle, to 31.5° for CA-CNCs(-) and 50° for CA-CNCs(+), which resulted in functionalized membranes with a hydrophilic behavior. Both functionalized membranes managed to maintain high flux values. CA-CNCs(-) maintained a flux of 9500 Lm−2h−1, while CA-CNCs(+) maintained a flux of 6700 Lm−2h−1. The addition of cellulose nanocrystals improved the mechanical properties of the CA membranes. The tensile strength increases from 410 kPa to 4990 kPa for CA-CNCs(-) membranes and 3010 MPa for CA-CNCs(+) membranes, and is accompanied by an increase in Young’s modulus as well. To evaluate the adsorption efficiency and size-exclusion filtration, an anionic dye (Congo red), a cationic dye (Victoria blue), and 500 nm model particles were used. CA-CNC(-) membranes achieved a removal efficiency of 96% of 500 nm particles with an affinity-based dye removal of 63% of Victoria blue dye. On the other hand, CA-CNC(+) membranes achieved a removal efficiency of 43% of 500 nm particles with a dye removal of 27% of Congo red dye. In this regard, CA-CNC(-) membranes were the best candidate for size-exclusion filtration, while also maintaining a good level of adsorption. Cellulose based composite membranes were successfully produced as multifunctional filters that could act in both size-exclusion regime and affinity-based regime. A cellulose acetate fibrous membrane was produced by electrospinning, tuning for fiber size and porosity, while the incorporation of cellulose nanocrystals functionalizes the membranes and enhance mechanical properties, and wettability.

Since the beginning of the 20th century plastic has been a widely used material, which has resulted in large quantities of plastic being produced in the last century. The plastics of today are mainly produced from fossil raw materials, which gives it a high climate impact. Plastic also has a long service life, which creates problems with handling after the new period when new plastic is produced at a faster rate than plastic debris can be recycled or incinerated. One possible approach is to switch from plastic from fossil sources to bioplastics, which is produced by renewable sources. This means a reduction in the environmental impact as the amount of fossil CO2 emissions from combustion of plastics would decrease. Polyhydroxyalkanoates (PHAs) are created by short volatile fatty acids (VFAs) added to bio sludge from a wastewater treatment plant at a pulp and paper mill where there is a lot of bacteria and microorganisms. Some of the bacteria in the sludge have the ability to accumulate PHA when VFA is added in excess and then be able to use it as an energy and carbon source in cases of starvation. This means that PHA produced in this way can be degraded by bacteria making it biodegradable while having similar properties as oil-based plastics. Production of PHA is currently expensive as it is often necessary to purchase VFA for production. To make it economically sustainable to replace oil-based plastics with PHA, the cost of PHA production must therefore be reduced. This can be done by using mixed bacterial cultures from, for example, industrial wastewater treatment plants and by creating their own composition of VFA through fermentation. At the paper mill at BillerudKorsnäs Gruvön there are several process streams that today are led to the water treatment plant, one of which is from PM6 (Paper Machine 6). By fermenting that stream, VFA can be formed with a composition of acetic acid, propionic acid, and butyric acid. The current may thus be suitable to use as a substrate in PHA production. Another way to produce VFA is to ferment the residual flow from hydrothermal carbonation (HTC) of bio sludge. According to (Samorì et al., 2019), acetic acid, butyric acid and valeric acid are formed, which means that even this stream may be suitable as a substrate for PHA production. The purpose of this thesis is to investigate the effects of the composition of VFA on the production of PHA from forest industrial bio sludge. The study covers two different cases, Case PM6 and Case HTC, where two different types of composition of VFA are added to paper sludge from the paper mill. The experiments were performed in cylindrical tanks on three occasions where the first two experiments had a volume of 30 liters and the last experiment a volume of 10 liters. On the first occasion, the maximum accumulation rate in the growth phase was studied. In the second instance, a high accumulation rate was sought, but also survival after the growth phase. The first two trials were batch trials where the sludge was dosed until saturation was achieved. On the third occasion, the possibility of carrying out PHA production with a continuous sludge exchange was studied. The experiments were analyzed by FTIR which provided information on the absorbance of the sludge which shows how the PHA concentration increased during the course of the experiments. Extractions were then performed to obtain the concentration of PHA that eventually accumulated in the sludge. The results show that biomass from BillerudKorsnäs Gruvön's mills accumulated PHA faster with VFA composition from fermented PM6 effluent compared to VFA composition from fermented HTC condensate. Calculations made with input from the experiments indicate that it is possible to produce a larger amount of PHA per year with Case PM6. The conclusion is therefore that Case PM6 is preferable if as large a PHA production as possible wants to be achieved. Case HTC is instead preferred if reduced PHA production can be tolerated in favor of biocarbon production.

Introduction : L'Accident Vasculaire Cérébral (AVC) est la 1ère cause de handicap acquis chez l'adulte, dans les pays industrialisés. 20% des patients décèdent dans le mois qui suit, 75% des survivants gardent des séquelles définitives, 33% deviennent dépendant à vie. Il n'existe pour l'heure aucune thérapie de récupération quand les déficits fonctionnels sont en place hormis la rééducation. Chez l'homme, 80% des AVC thrombotiques touchent l'artère cérébrale moyenne, qui irrigue le cortex moteur primaire (M1). M1 projette des axones jusque dans la moelle épinière et forme le Faisceau Cortico Spinal (FCS). Après une atteinte de M1, ce faisceau dégénère et cela induit des déficits fonctionnels de force et de dextérité. M1 est indispensable pour les mouvements volontaires dextres garants de l'indépendance du patient. Objectif : Mise au point d'un modèle de lésion cérébrale, chez un primate non humain, le marmouset, qui permette d'évaluer la récupération fonctionnelle motrice afin d'étudier l'effet de neuro-implants. Méthode : 14 marmousets ont servi à caractériser le nouveau modèle lésionnel induit par une injection stéréotaxique d'une toxine inhibant le métabolisme cellulaire. Des tests comportementaux, évaluant le score neurologique, la dextérité et la force de traction du membre supérieur, ont permis d'évaluer la récupération fonctionnelle en phase aiguë, subaiguë et chronique jusqu'à 6 mois après la lésion. Le suivi longitudinal structural et fonctionnel de la lésion et de la récupération a été réalisé par IRM (T1, T2, DTI). Le suivi de l'intégrité du FCS a été étudié, pour la première fois chez le marmouset, grâce à une technique (ME-MRI, manganese-enhanced-MRI) utilisant un agent de contraste injecté directement dans le cortex M1, capté par les neurones et traçant les voies neuronales. Une étude pilote sur 3 marmousets a testé l'effet de neuro-implants microstructurés dans la lésion cérébrale associés à l'injection de chondroïtinase ABC (enzyme de dégradation de la matrice extracellulaire). / Introduction: Stroke is the first leading cause of acquired handicap and disability in adults in industrialized countries. 20% of patients die in the following month, 75% of survivors remain with definitive sequelae, 33% become dependent for life. No therapy in the recovery phase exists today when functional deficits are installed except rehabilitation. In human, 80% of thrombotic stroke affect middle cerebral artery, which supplies the primary motor cortex (M1). M1 projects axons to the spinal cord and forms the CorticoSpinal Tract (CST). After an M1 insult, this tract degenerates and functional deficits of force and dexterity are induced. M1 is essential for voluntary dexterous movements that make patients independent. Objective: Setting up of a cerebral lesion model in a non-human primate, the marmoset, where the functional motor recovery can be assessed in order to study thereafter the effect of neuro-implant. Methods: 14 marmosets served to characterize the new lesion model induced by stereotaxic injection of a toxin inhibiting the cellular metabolism. Behavioral tests assessing the neurological score, dexterity and pulling strength of the upper limb, could assess the functional recovery in the acute, sub-acute and chronic phases until 6 months after the lesion. The longitudinal structural and functional follow-up after the lesion and during the recovery was done with MRI (T1, T2, EPI, DTI). The follow-up of the integrity of the CST was studied for the first time in the marmoset with a technic (ME-MRI, manganese-enhanced-MRI) using a contrast agent injected directly in the cortex M1, taken up by neurons and that traced neuronal tracts. A pilot study on 3 marmosets tested the effect of micro-patterned neuro-implants in the cerebral lesion associated with the injection of chondroïtinase ABC (enzyme of extracellular matrix degradation).

No description available.

I ett samhälle som stävar alltmer mot hållbarhet och minskade utsläpp så är det viktigt att arbeta med nya material som bidrar till detta. Denna studie undersöker om den träfiberbaserade termoplasten Prime från Woodcomposites kan vara ett potentiellt ersättningsmaterial till toppkåpan på Husqvarnas Automower. Prime är en termoplast som innehåller 20% träfiber. Komponenten är idag tillverkad i ASA, vilket är en petroleumbaserad termoplast och nära släkting till ABS. På grund av den ökade tillgängligheten till materialdata för ABS jämfört med ASA och plasternas synnerligen liknande egenskaper så kommer samtliga tester i rapporten att utföras med ABS. Rapporten kommer att ta reda på om det går att minska koldioxidutsläppen vid tillverkning av kåpan, samt om Prime klarar av Husqvarnas hållfasthetskrav och att användas i utomhusmiljö. Förutom att de mekaniska egenskaperna är viktiga så spelar även ett materials utseende stor roll i hur attraktiv en produkt blir. Därför presenterar rapporten två designkoncept som syftar till att ge förslag på hur man kan integrera materialet i Husqvarnas design. Resultaten visar att det går att göra en minskning i CO2-utsläpp vid tillverkning på 34,7% om man byter ut ABS mot Prime. Dessutom, i kontrast till hypotesen så absorberar Prime endast marginellt mer fukt. Det handlar om tiondels procentenheter. Utöver detta så är det mer styvt än ABS och har ett liknande inköpspris vilket tyder på goda möjligheter att kunna använda Prime som alternativ till ASA i denna applikation. / In a society where sustainability and reduced carbon emissions is an increasingly important topic, it’s important to work with materials that contributes to this. This study is investigating if the wood-fibre based thermoplastic Prime from Woodcomposites has the potential to replace the material of the top cover for Husqvarna’s Automower. Prime is a thermoplastic containing 20% wood-fibres. Today the component is made from ASA, which is a petroleum-based thermoplastic that is closely related to ABS. Due to the increased availability of material data for ABS compared to ASA and the fact that they have very similar physical properties, all of the tests in this report will be performed with ABS. The study will find out if it’s possible to reduce the carbon emissions from manufacturing of the cover, but also if Prime is up to the material standards of Husqvarna and is fit to be used in an outdoor environment. Besides the importance of the mechanical properties, the look of the material also plays a big role in determining if it’s applicable to the product. It has to match the current design language and brand image of the company. Therefore, there are two design concepts presented in the report to give an idea of how the material can be implemented in Husqvarna’s design. The results show that it’s possible to reduce the carbon emissions from manufacturing by 34,7% if you change the material from ASA to Prime. Furthermore, in contrast to the hypothesis the absorption of moisture in Prime is only a fraction of a percent larger than ABS. Prime is also stiffer and has a similar price which speaks for the possibility to use it as an alternative to ASA in this application.

Polymeric composites reinforced with bio-materials have advantages over composites with synthetic reinforcements. Bio-based composites use low-cost and renewable reinforcements, have nonabrasive properties for machining, have improved damping characteristics, and have potential for energy recycling. However, the limited use of bio-based composites is because their mechanical properties are typically much lower than those of synthetic composites. The objective of this study was to combine state-of-the-art imaging tools with emerging numerical modeling methods for an integrated, multi-level characterization of bio-based reinforcements and their composites. Digital photography (2D) will allow collection of full-field digital images of the surface of sample composites, which will be used for characterization of the morphological structure of fillers (copper wire or wood particle) and of model composites. Mechanical experiments (tension load) on isolated fillers and on model composites will allow imaging of the deformed material. By correlating relative positions of thousands of surface features between consecutive images, digital image correlation (DIC) algorithms can be used to map surface deformation fields and calculate surface strain fields. Digital imaging methods can only record deformations and strains. The interpretation of those strains in terms of material properties, such as position-dependent modulus of a heterogeneous composite material, requires simultaneous modeling. The modeling must use morphology-based methods that can handle anisotropy, heterogeneity, and the complex structure of bio-based composites such as wood plastic composites. This research used the material point method (MPM) as a modeling tool. MPM is a particle-based, meshless method for solving problems in computational mechanics. The crucial advantage of MPM over other methods is the relative ease of translating pixels from digital images into material points in the analysis. Thus digital images (2D) used in our experiments were used as direct input to the MPM software, so that the actual morphologies, rather than idealized geometries, were modeled. This procedure removes typical uncertainties connected with idealization of the internal features of modeled materials. It also removes variability of specimen to specimen due to morphology variations. Full-field imaging techniques and computer modeling methods for analysis of complex materials have developed independently. This research Coupled imaging and modeling and used inverse problem methodology for studying bio-particulate composites. The potential of coupling experiments with morphology-based modeling is a relatively new area. This work studied the morphology and mechanical properties of copper wire (for validation experiments) and wood particles used for reinforcement in polymer composites. The goal was to determine the in situ mechanical and interfacial properties of copper wire and then wood particles. By comparison of DIC results to MPM, the conclusion is MPM simulation works well by simulating 3D composite structure and using Matlab software to do qualitative and quantitative comparisons. Copper validation tests showed that copper wire is too stiff compared to polymer such that the inclusion modulus had low effect on the surface strains (DIC experimental results). Wood particle worked better because modulus of wood is much lower than copper. By qualitative comparison of the wood particle specimens, we could deduce that the in situ properties of wood particles are lower than bulk wood. Quantitative analysis concentrated on small area and got more exact results. In a 90 degree particle quantitative study, MPM simulations were shown to be capable of tracking the structure of wood particle plastic, which involved failure. The entire approach, however, is not very robust. We can get some results for mechanical properties, but it does not seem possible to extract all anisotropic properties from a few DIC tests, as some researcher have suggested. / Graduation date: 2012

Use of arsenic-rich groundwater for crop irrigation can increase the arsenic (As) content in food crops and act as a carcinogen, compromising human health. Using aquatic plant based phytofiltration is a potential eco-technique for removing arsenic from water. The aquatic moss species Warnstorfia fluitans grows naturally in mining areas in northern Sweden, where high concentrations of arsenic occur in lakes and rivers. This species was selected as a model for field, climate chamber and greenhouse studies on factors governing arsenic removal and arsenic phytofiltration of irrigation water. The arsenic and silicon (Si) concentrations in soil, water and plant samples were measured by AAS (atomic absorption spectrophotometry), while arsenite and arsenate species were determined using AAS combined with high pressure liquid chromatography (HPLC) with an anion exchange column. The arsenic content in grains of hybrid and local aromatic rice (Oryza sativa) cultivars with differing arsenic accumulation factor (AF) values was investigated in an arsenic hotspot in Bangladesh. The results showed that arsenic AF was important in identifying arsenic-safer rice cultivars for growing in an arsenic hotspot. The study based on silicon effect on arsenic uptake in lettuce showed that arsenic accumulation in lettuce (Lactuca sativa) could be reduced by silicon addition. The aquatic moss had good phytofiltration capacity, with fast arsenic removal of up to 82% from a medium with low arsenic concentration (1 µM). Extraction analysis showed that inorganic arsenic species were firmly bound inside moss tissue. Absorption of arsenic was relatively higher than adsorption in the moss. Regarding effects of different abiotic factors, plants were stressed at low pH (pH 2.5) and arsenic removal rate was lower from the medium, while arsenic efflux occurred in arsenate-treated medium at low (12°C) and high (30°C) temperature regimes. Besides these factors, low oxygenation increased the efficiency of arsenic removal from the medium. Finally, combining W. fluitans as a phytofilter with a lettuce crop on a constructed wetland significantly reduced the arsenic content in edible parts (leaves) of lettuce. Thus W. fluitans has great potential for use as an arsenic phytofilter in temperate regions. / <p>QC 20170323</p>