Paper A: In this paper, the development and implementation of a contact algorithm based on C2-continuous surface representations is discussed. In 3D contact simulations involving models with arbitrarily curved surfaces (as in the case of vessel walls), the discretization of the contact surfaces by means of facet-based techniques could lead to numerical instabilities and finally loss of quadratic convergence. These instabilities arise mainly due to the sliding of contractor (slave) nodes over the boundaries of target (master) contact facets, where jumps of the normal vector are experienced. The paper addresses successfully this problem, by discretization of the target surfaces by means of C2-continuous parameterization schemes. Initially, the uniform cubic B-spline surfaces are introduced. Next, in an attempt for more accurate representations of the geometric models of the contact surfaces, a new parameterization based on the expression of cubic B-splines is developed. The two approaches are implemented into a finite element framework and more specifically, into the multipurpose finite element analysis program FEAP. The special merits of the developed algorithms and the advantages of the smooth surfaces over facet-based approaches are exhibited through a classical contact mechanics problem, considering incompressibility, finite deformations and large slidings. Next, a simulation of balloon angioplasty with stenting is presented, where the contact between both medical devices (balloon and stent) with the arterial wall is modeled. The arterial wall is modeled in this first approach, as hyperelastic, homogeneous, isotropic, while a cylindrically orthotropic model is developed to capture the nonlinear, anisotropic behavior of the balloon catheter under pressure. Two stents with the same geometry but different strut thickness, are studied. Both are considered elasto-plastic. The performed simulations point out the outcome of the balloon angioplasty and stenting in terms of luminal gain and mechanical strains. Finally, a comparison between the two stent configurations is presented. Paper B: The second paper makes use of the contact tool developed in Paper A and focuses on the changes of the mechanical environment of the arterial wall due to stenting, as a function of a set of stent design parameters. In particular, Paper B presents a detailed geometric and material model of a postmortem human iliac artery, composed by distinct tissue components, each associated with specific mechanical properties. The constitutive formulation for the artery considers anisotropic, highly nonlinear mechanical characteristics under supraphysiological loadings. The material and structural parameters of the arterial model are obtained through uniaxial tensile tests on stripes extracted from the several arterial tissues that form the stenosis, axially and circumferentially oriented. Through cooperation with a well-established stent manufacturing company, an iliac stent was acquired. The dimensions of the stent are measured under a reflected-light microscope, while it is parameterized in such a way as to enable new designs to be simply generated through variations of its geometric parameters. The 3D balloon-stent-artery interaction is simulated by making use of the smooth contact surfaces with C2-continuity, as previously mentioned. Next, scalar quantities attempt to characterize the arterial wall changes after stenting, in form of contact forces induced by the stent struts, stresses within the individual components and luminal change. These numerically derived quantities allow the determination of the most appropriate stent configuration for an individual stenosis. Therefore, the proposed methodology has the potential to provide a scientific basis for optimizing treatment procedures, stent material and geometries on a patient-specific level. / <p>QC 20101118</p>

Banana peels account for about 61 million tons of waste each year globally. The aim of this project was to investigate the possibility of using banana peels as a substrate to cultivate edible filamentous fungi. The peels were subjected to physical and thermal pretreatments while variables such as changes in the medium pH, biomass concentration, fungal strain dependence, and protein content of the fungal biomass were analyzed. The experiments were carried out in three phases. The purpose of phase I was to identify which of the four fungal strains among Neurospora intermedia, Aspergillus oryzae, Rhizopus oryzae, and Rhizopus oligosporus could grow in a medium containing ball-milled banana peel powder (BPP) only. In phase II, the best performing strains from phase I in terms of biomass concentration, i.e., A. oryzae and R. oryzae, were cultivated using banana peel broth (BPB) obtained from thermal pretreatment of BPP. During this phase, the impact of medium supplementation with yeast extract was also assessed. The biomass yield for A. oryzae and R. oryzae 2.9 g/L and 1.6 g/L, respectively, yeast supplementation compared to 2.7 g/L and 0.7 g/L, respectively, without supplementation. In phase III, the experiments performed in phase II without yeast extract supplementation were scaled up, after which protein analysis was performed. A crude protein content of 8.82% was determined for A. oryzae, while in R. oryzae, a higher value of 21.1% was obtained. The protein content from both fungal strains was much higher than that present in the BPP, which was 4.8 g/L. The results showed the potential of using banana peel as a substrate to produce edible fungal biomass with higher protein content and thus has potential applications as animal feed or human food. Further studies are needed to optimize the process in order to raise the fungal biomass yield as well as increase the protein content of the biomass. In addition, comprehensive characterization of the fungal biomass would reveal other important components, such as the amino acid profile.

Anaerob jäsning antas vara en bra och effektiv metod för behandling av organiskt avfall. Avloppsvatten från denna process är mer utmanande beroende främst på dess höga innehåll av bland annat flyktiga fettsyror (VFA). Mikroalger har en stor potential för hållbart avlägsnande av näringsämnen från vatten samtidigt som algbiomassa kan användas för produktion av bio-gödsel, biobränsle och bioplaster. Därför var syftet med denna studie att undersöka möjligheten att odla två svenska stammar av mikroalger, anpassade till det nordiska klimatet, på olika syntetiska kulturer. Kulturerna innehöll två bestämda totalkoncentrationer av ättiksyra, propionsyra och smörsyra med tre olika förhållande till varandra. Stammarna som studeras i detta experiment var Chlorella vulgaris (13–1) och Chlorococcum sp. (MC-1). Stammarna visade olika förmågor att tolerera VFA som kolkälla. Chlorococcum sp. kunde ge betydligt högre biomassakoncentrationer i närvaro av VFA än C. vulgaris. Vid totalkoncentrationen 2 g/L VFA och den största halten av ättiksyra erhölls den högsta biomassakoncentrationen. C. vulgaris i kulturerna med VFA visade samma beteende som i referensodlingen utan VFA. De slutliga biomassakoncentrationerna i närvaro av VFA liknade den biomassakoncentrationen från referensodlingen. Att Chlorococcum sp. kan växa på VFA kan minska miljöpåverkan av industriella utflöden från anaerob jäsning i Sverige och andra nordiska länder. / Anaerobic fermentation is believed to be a good and effective method for treating organic waste. Wastewater from this process is more challenging mainly due to its high content of for instance volatile fatty acids (VFA). Microalgae have shown great potential for the sustainable removal of nutrients from water sources. At the same time, algal biomass can be used to produce bio-fertilizer, biofuel, and bioplastics. Therefore, the purpose of this study was to investigate the possibility of growing two Swedish microalgae strains, adapted to the Nordic climate, on different synthetic cultures. The cultures contain two determined total concentrations of acetic acid, propionic acid, and butyric acid with three different ratios to each other. The strains studied in this experiment were Chlorella vulgaris (13–1) and Chlorococcum sp. (MC-1). The strains showed different abilities to tolerate VFA as a carbon source under the same biotic and abiotic conditions. Chlorococcum sp. was able to produce significantly higher biomass concentrations in the presence of VFA than in the reference culture without VFA. The culture with the total concentration of 2 g/L of VFA and the ratio that had the greatest content of acetic acid gave the highest biomass concentration. C. vulgaris was not affected by VFA and the algal cells in the cultures with VFA show the same behaviour as in the reference culture. Moreover, the final biomass concentrations in the presence of VFA were similar to the biomass concentration from the optimal culture. Since Chlorococcum sp. could grow on VFA it can reduce the environmental impact of industrial effluents from anaerobic fermentation in Sweden and other Nordic countries.

The circular economy is about rethinking the definition of waste into resource. Tempeh boiling water is cheap and would otherwise be washed into the river and pollute the water which would affect the environment badly. Tempeh boiling water is going to be used as substrate to produce mycoprotein with the fungi Rhizopus oligosporus. This study is about making a mycoprotein nugget and evaluate it with a sensory evaluation and to evaluate the protein content in the nugget and chemical oxygen demand of the boiling water. The sensory evaluation will have 65 panellists to assess the liking of the nugget with two control samples. The purpose of this project was to evaluate the potential of tempeh boiling water for the circular economy as substrate. To produce high mycoprotein nugget that will be accepted by the community. Assess the protein content in the mycoprotein nugget and assess the carbon used by the fungi with chemical oxygen demand analyse. The target group for evaluating the fungal nugget was students studying at Gadjah Mada University, Yogyakarta, Indonesia. The project was done in multiple following stages: Finding best formula of mycoprotein, mycoprotein production, sensory evaluation, and protein analyse with Kjeldahl method and COD analyse of the boiling water.The result of this study is that the mycoprotein nugget were not liked nor disliked with the average score of 3,9 out of 7. The overall characteristics (appearance, colour, texture, and taste) were 4,0 out of 7. The COD before and after fermentation were 6,6 g/L. The most COD were removed by pre-treatment of the boiling water from 172 to 121 g/L.The protein content of the mycoprotein nugget were 23,8%. The social aspect to produce healthy foods to a low cost at the same time improve water quality by removing foods for toxic microorganisms.

Xyloglucans are polysaccharides found as storage polymers in seeds and tubers, and as cross-linking glycans in the cell wall of plants. Their structure is complex with intricate branching patterns, which contribute to the physical properties of the polysaccharide including its binding to and interaction with other glycans such as cellulose. Xyloglucan is widely used in bulk quantities in the food, textile and paper making industries. With an increasing interest in technically more advanced applications of xyloglucan, such as novel biocomposites, there is a need to understand and control the properties and interactions of xyloglucan with other compounds, to decipher the relationship between xyloglucan structure and function, and in particular the effect of different branching patterns. However, due to the structural heterogeneity of the polysaccharide as obtained from natural sources, relevant studies have not been possible to perform in practise. This fact has stimulated an interest in synthetic methods to obtain xyloglucan mimics and analogs with well-defined structure and decoration patterns. Glycosynthases are hydrolytically inactive mutant glycosidases that catalyse the formation of glycosidic linkages between glycosyl fluoride donors and glycoside acceptors. Since its first conception in 1998, the technology is emerging as a useful tool in the synthesis of large, complex polysaccharides. This thesis presents the generation and characterisation of glycosynthases based on xyloglucanase scaffolds for the synthesis of well-defined homogenous xyloglucan oligo- and polysaccharides with regular substitution patterns.

Major studies conducted in Europe and North America has concluded that the current processes in wastewater treatment plants insufficiently degrade micropollutants e.g. pharmaceutical residues. Several sorption and oxidation methods has therefore been investigated with the purpose of removing or degrading micropollutants in wastewater. The main purpose of this project was, firstly, to validate the results from a pilot study conducted by Tekniska verken i Linköping AB (2014) which investigated the use of ozone to degrade pharmaceutical residues. Secondly, to investigate and design a suitable process control strategy for the ozonation process. Four different tests were conducted during the project, a dose-response test, step-response tests, a trace test, and a performance test. A poorer average reduction of pharmaceutical residues was observed in this project compared to the pilot study. An average reduction of approximately 80% was observed at the highest tested dose, 0.67 mg O3/mg DOC, N corr. Whilst an average reduction of 90% was observed at approximately 0.46 mg O3/mg DOC, N corr, in the pilot study. However, the quality of the wastewater was worse during this project compared to the pilot study. ΔUVA254 and offgas concentration of ozone were found to be suitable control parameters for process control. A control strategy based on a combination of these parameters was designed, where ΔUVA254 was used as the main control parameter and the off-gas concentration of ozone was used as a limiting controller to ensure a sufficient mass transfer in the system. In conclusion, a suitable flow proportional base ozone dose valid for current water conditions has been identified, 10 mg/L. Differences in wastewater quality which heavily influence the ozonation process have been identified. Lastly, a control strategy for process control of the ozonation have been identified, designed and is ready for implementation.

Hyaluronic acid (HA) is an unbranched polysaccharide consisting of the repeating disaccharide unit β(1→4)-GlcA-β(1→3)-GlcNAc and is a naturally occurring biopolymer in bacteria and vertebras. HA is predominantly found in the extracellular matrix (ECM) and the in vivo function of HA can vary depending on molecular weight (Mw) for instance high Mw HA is reported to be anti-angiogenic while low Mw HA induces angiogenesis. HA is a popular component for hydrogels such as dermal fillers. HA is commonly used in dermal fillers. However, other materials, such as other polymers, can be used as well. The project goal was to investigate different degradation processes for production of target Mw HA. Alkaline and acidic degradation processes in combination with increased temperatures seemed as the most promising methods. Degradation tests performed both in aqueous solution as well as heterogeneously in ethanol were evaluated. The acidic degradation in aqueous solution was proven to have the largest degradation constant. Both a robustness test as well as a Design of Experiments (DoE) was performed to investigate the influence different factors had on the degradation speed. The investigated factors were HA concentration, HCl concentration and temperature. Temperature and HCl concentrations proved to be the most influencing factors and a model was developed in the DoE software MODDE to describe how the factors influenced the degradation constant. The model was established as a good significant model with a Q2 value of 0.998 and relative standard deviation (RSD) value of 0.022 after a logarithmic transformation was performed as well as a simplification of the model by excluding some of the factor interactions. The acidic degradation method also proved to be a highly robust method which easily could be used to produce target Mw HA.

Affibody® molecules are small therapeutic proteins which mimics antibody functionality. This is a report of several methods for increasing productivity and yield in recombinant production of Affibody® molecules. This literature study shows several steps in the production line which can be optimised, several novel methods for cultivating and harvesting cells and purication of proteins. There is also a section about validation of therapeutic protein production according to The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) are presented.

Free analyte is measured to be able to understand the pharmacological effects of a drug in the body, the binding to its ligand, and the effective drug level among other things. Thereby, it is important with correct measurements of free analyte, although it is not that easy to achieve since overestimations can occur. In this project, several immunoassays were developed for the bioanalytical methods Gyrolab and ELISA to measure free analyte, where the biotherapeutics Avastin® and Lucentis®, and the ligand VEGF were used as analytes. One difference between the methods is the short contact time of just a few seconds for Gyrolab compared to the sample incubation time of a couple of hours for ELISA. One difference between the antibodies is that Lucentis is an affinity-matured Fab region, and therefore, has a stronger affinity to VEGF compared to Avastin. When free Avastin was measured, the difference was significant, with ELISA estimating higher concentrations compared to Gyrolab. However, this was not the case for all assays. In some cases, this was probably due to differences between the methods that could not be seen. Otherwise, the results with no difference between the methods, when measuring free analyte with Lucentis as the drug, were expected due to the stronger affinity and longer halftime of dissociation. However, the difference with the longer sample incubation time for ELISA compared to the short contact time for Gyrolab seems to influence the measurement of free analyte, depending on the affinity of the components being measured.

Waste Stabilisation Ponds (WSPs) are characterised by low phosphorus (P) removal capacity. Heterotrophic bacteria are principal microbial agents in WSPs in addition to algae. As treatment proceeds in WSPs, algal growth increases and pH rises, this has lead to believe that P removal is mainly through sedimentation as organic P algal biomass and precipitation as inorganic P. In activated sludge treatment plants (AS), microbial P removal has been improved and is termed as enhanced biological phosphorus removal. There was a need to establish whether it was possible to enhance P removal in WSPs. A performance assessment of pond system at the University of Dare s Salaam (UDSM), Tanzania, has shown that 90% of the P removed was in the primary pond (facultative) and the rest in the maturation pond (aerobic). In these studies, a pure strain A. hydrophyla was isolated from an activated sludge wastewater treatment plant in Sweden. This plant has a train that functions with enhanced biological phosphorus removal. The strain was tested for P uptake in minimal media supplemented with glucose, succinate or acetate, grown aerobically and anaerobically/aerobically. This strain was able to take up P without having been subjected to the anaerobic phase. It was observed that P uptake was enhanced after the anaerobic phase with media supplemented with glucose, but not with succinate or acetate. Phosphorus uptake repeatedly followed the bacterial growth pattern with correlation coefficients of more than 95%. Therefore P removal has a direct correlation with bacterial growth. Two isolates Acinetobacter sp. (isolated from the primary facultative pond) and E .coli (isolated from the maturation pond) were obtained from a tropical WSP treatment system at the UDSM. They were subjected to aerobic P uptake experiment similar to those of A.hydrophyla. The uptake per unit absorbance of bacterial growth was found to be comparable to that of A.hydrophyla, isolated from AS. These results showed that heterotrophic activity is important in WSPs. It is possible to enhance P removal in these systems by designing the primary ponds for maximum heterotrophic activity and probably enrichment. / QC 20101119