NDLTD Innovative ETD Award 2005. The design of a multi-functional building entails the synthesis of multiple systems and networks. The needs of multiple clients must be effectively overlaid to create a build able, contextually suitable and aesthetically pleasing architectural solution. The proposed building is a public, urban building. City buildings consist of spaces that are essentially part of the city, simultaneously dependant on the whole and separated by building lines and security systems. The gradation of space from public to private exists everywhere. The focus of the design is on the creation of place in the Pretoria CBD. The scheme is integrated into its surroundings, and functions as a system in itself. The proposed multi-use building will be set on a currently built up site in the Pretoria CBD, on the c/o Paul Kruger and Schoeman Streets, one city block from Church Square. Building functions include retail, residential, a satellite gallery for the Tshwane Art Museum, and new offices and facilities for Talking Beads, a producer Arts and Crafts. / Dissertation (MArch (Prof))--University of Pretoria, 2006. / Architecture / unrestricted

La dynamique du déclenchement des avalanches dans un milieu granulaire lentement incliné passe par trois phases; (1) des petits réarrangements locaux et indépendants de grains (2) suivis de mouvements collectifs, successifs et quasi-périodiques, appelés 'précurseurs' (3) finissant par une avalanche. Cette dynamique peut dépendre de nombreux paramètres. Dans cette thèse, nous avons étudié, par des mesures optiques et acoustiques, la réponse du milieu granulaire soumis à une inclinaison lente de son container. Nous avons déterminé l'importance du choix de la puissance du signal acoustique sur nos mesures. Nous avons observé l'effet de l'état de surface des grains sur l'apparition des précurseurs et sur l'occurrence de l'avalanche. Nous avons réalisé des cycles d'inclinaison allant de -θ à +θ se terminant par une avalanche . Nous avons mis en évidence l'influence de l'angle du cycle θ sur les précurseurs et l'angle d'avalanche final. Nous avons aussi étudié des milieux granulaires soumis à des taux d'humidité comprises entre 40 et 96, par des mesures optiques surfaciques et latérales. Nous avons montré que les angles d'avalanche et l'apparition des premiers précurseurs dépendent de la taille des grains mais aussi de l'humidité. Cette dépendance est liée aux forces de cohésion qui sont relativement plus élevées à forte humidité et qui compensent la force de gravité pour des petits grains. Enfin, nous avons montré l'importance d'une diffusion homogène de l'humidité dans le milieu sur son comportement. L'impact de la mouillabilité des grains a été aussi abordé. / The dynamics of avalanche triggering in a slowly inclined granular medium passes through three phases; (1) small local and independent rearrangements of grains (2) followed by collective, successive and quasi-periodic movements, called 'precursors' (3) ending in an avalanche. This dynamic can depend on many parameters. In this thesis, we have studied, by optical and acoustic measurements, the response of the granular medium subjected to a slow inclination of its container. We determined the importance of choosing the power of the acoustic signal on our measurements. We observed the effect of the grain surface condition on the occurrence of precursors and the occurrence of the avalanche. We performed tilted cycles ranging from -θ to +θ ending in an avalanche. We have demonstrated the influence of the θ cycle angle on the precursors and the final avalanche angle. We have also studied granular media with moisture contents between 40 and 96%, by surface and lateral optical measurements. We have shown that the avalanche angles and the appearance of the first precursors depend on the grain size but also the humidity. This dependence is related to cohesive forces that are relatively higher at high humidity and that compensate for the force of gravity for small grains. Finally, we have shown the importance of a homogeneous diffusion of moisture in the environment on its behavior. The impact of grain wettability was also discussed.

New research has shed light on the origin of the Danish glass beads dating to the BronzeAge and the increase in long-distance exchange during this period. This has provided newknowledge about glass beads during the Bronze Age, which unlocked the question of whatit looks like in the rest of Scandinavia. To get a broader perspective I have chosen to studythe first evidence of early craft sites where glass beads were made in Scandinavia. Then acomparison is made between the Bronze and Iron Ages from a broader perspective, whichincludes both the use of glass beads and the glass productions sites. I have therefore chosento study glass beads from a long-term perspective, from the introduction of the first glassbeads in Scandinavia during the Early Bronze Age until the Vendel period when the firstglass beads were manufactured in Scandinavia. By studying glass beads from a long-termperspective, we can learn more about the significance of glass beads in society.

Theoretical part of the master thesis was aimed on giving an overview of basic characteristics of magnetic particles, their morphology, basic methods of their synthesis, interaction with DNA and recent applications in biotechnology and biomedicine. The experimental part of thesis was aimed on application of new designed magnetic particles for isolation of both lactobacilli DNA and calf thymus DNA. Two types of magnetic beads were used: hyperbranched poly(glycidyl methacrylate-co-[2-(methacryloyloxy) ethoxy]acetic acid-co-ethylene dimethylacrylate) microbeads covered with amino groups (P(GMA-MOEAA-EDMA)-NH2) and magnetic non-porous poly(2-hydroxyethyl methacrylate) microbeads covered with carboxyl groups (P(HEMA-co-GMA)-COOH). For both types of microbeads two different protocols for preparation of separation mixtures with two different concentrations od poly(ethyleneglycol) 6000 (PEG 6000) as condensation agent were tested. Differences among both types of magnetic microbeads and DNAs used were found. It was shown that both types of microbeads are suitable for DNA isolation in the presence of 8% PEG 6000.

The subject of the thesis is study of possible applications of isoform of glutamic acid polymer (-PGA). The theoretical part is focused on the properties of this biopolymer and potential applications in various areas. Producers and mechanisms of biosynthesis are also mentioned. In the experimental part, the polymer was firstly characterised by following methods: FT-IR spectroscopy, TGA, DSC and SEC-MALS. Its isoelectric point, antimicrobial activity and solubility in various solvents were also determined. The biopolymer was also precipitated by divalent cations and its interaction with oppositely charged CTAB surfactant was studied. The main experimental study was researching the effect of -PGA on viability of Saccharomyces cerevisiae and Lactobacillus rhamnosus under stress conditions by flow cytometry. The performed stresses included ethanol exposure, high temperature and freezing stress, in which its effects were compared to conventional cryoprotectants. The cells of the mentioned microorganisms were also stressed osmotically and exposed to model gastrointestinal juices - gastric, pancreatic and bile. The protective effects of -PGA on the cells were recorded in ethanol stress on Lactobacillus rhamnosus. Its excellent cryoprotection properties were confirmed and its protective effect of gastric juice exposure on Saccharomyces cerevisiae cells was also observed. At the end of the experimental part, -PGA/alginate beads suitable for encapsulation of probiotic bacteria and -PGA/chitosan nanoparticles for encapsulation of biologically active substances.

Thesis (PhD (Chemical Engineering))--Cape Peninsula University of Technology, 2019 / The South African wine industry is constantly facing several challenges which affect the quality of wine, the local/global demand and consequently the revenue generated. These challenges include the ongoing drought, bush fires, climate change and several liquor amendment bills aimed at reducing alcohol consumption and alcohol outlets in South Africa. It is therefore critical for the wine industry to expand and find alternative ways in which sub-standard or surplus wine grapes can be used to prevent income losses and increase employment opportunities. Traditional Balsamic Vinegar (TBV) is a geographically and legislative protected product produced only in a small region in Italy. However, the methodology can be used to produce similar vinegars in other regions. Balsamic-styled vinegar (BSV), as defined in this thesis, is a vinegar produced by partially following the methods of TBV while applying process augmentation techniques. Balsamic-styled vinegar is proposed to be a suitable product of sub-standard quality or surplus wine grapes in South Africa. However, the production of BSV necessitates the use of cooked (high sugar) grape must which is a less favourable environment to the microorganisms used during fermentation. Factors that negatively affect the survival of the microorganisms include low water activity due to the cooking, high osmotic pressure and high acidity. To counteract these effects, methods to improve the survival of the non-Saccharomyces yeasts and acetic acid bacteria used are essential. The primary aim of this study was to investigate several BSV process augmentation techniques such as, aeration, agitation, cell immobilization, immobilized cell reusability and oxygen mass transfer kinetics in order to improve the performance of the microbial consortium used during BSV production. The work for this study was divided into four (4) phases. For all the phases a microbial consortium consisting of non-Saccharomyces yeasts (n=5) and acetic acid bacteria (n=5) was used. Inoculation of the yeast and bacteria occurred simultaneously. The 1st phase of the study entailed evaluating the effect of cells immobilized by gel entrapment in Ca-alginate beads alongside with free-floating cells (FFC) during the production of BSV. Two Ca-alginate bead sizes were tested i.e. small (4.5 mm) and large (8.5 mm) beads to evaluate the effects of surface area or bead size on the overall acetification rates. Ca-alginate beads and FFC fermentations were also evaluated under static and agitated (135 rpm) conditions. The 2nd phase of the study involved studying the cell adsorption technique for cell immobilization which was carried-out using corncobs (CC) and oak wood chips (OWC), while comparing to FFC fermentations. At this phase of the study, other vinegar bioreactor parameters such as agitation and aeration were studied in contrast to static fermentations. One agitation setting (135 rpm) and two aeration settings were tested i.e. high (0.3 vvm min−1) and low (0.15 vvm min−1) aeration conditions. Furthermore, to assess the variations in cell adsorption capabilities among individual yeast and AAB cells, the quantification of cells adsorbed on CC and OWC prior- and post-fermentation was conducted using the dry cell weight method. The 3rd phase of the study entailed evaluating the reusability abilities of all the matrices (small Ca-alginate beads, CC and OWC) for successive fermentations. The immobilized cells were evaluated for reusability on two cycles of fermentation under static conditions. Furthermore, the matrices used for cell immobilization were further analysed for structure integrity by scanning electron microscopy (SEM) before and after the 1st cycle of fermentations. The 3rd phase of the study also involved the sensorial (aroma and taste) evaluations of the BSV’s obtained from the 1st cycle of fermentation in order to understand the sensorial effects of the Ca-alginate beads, CC and OWC on the final BSV. The 4th phase of the study investigated oxygen mass transfer kinetics during non-aerated and aerated BSV fermentation. The dynamic method was used to generate several dissolved oxygen profiles at different stages of the fermentation. Consequently, the data obtained from the dynamic method was used to compute several oxygen mass transfer parameters, these include oxygen uptake rate ( 𝑟𝑟𝑂𝑂2 ), the stoichiometric coefficient of oxygen consumption vs acid yield (𝑌𝑌𝑂𝑂/𝐴𝐴), the oxygen transfer rate (𝑁𝑁𝑂𝑂2 ), and the volumetric mass transfer coefficients (𝐾𝐾𝐿𝐿𝑎𝑎). During all the phases of the study samples were extracted on weekly intervals to evaluate pH, sugar, salinity, alcohol and total acidity using several analytical instruments. The 4th phase of the study involved additional analytical tools, i.e. an oxygen µsensor to evaluate dissolved oxygen and the ‘Speedy breedy’ to measure the respiratory activity of the microbial consortium used during fermentation. The data obtained from the 1st phase of the study demonstrated that smaller Ca-alginate beads resulted in higher (4.0 g L-1 day−1) acetification rates compared to larger (3.0 g L-1 day−1) beads, while freely suspended cells resulted in the lowest (0.6 g L-1 day−1) acetification rates. The results showed that the surface area of the beads had a substantial impact on the acetification rates when gel entrapped cells were used for BSV fermentation. The 2nd phase results showed high acetification rates (2.7 g L-1 day−1) for cells immobilized on CC in contrast to cells immobilized on OWC and FFC, which resulted in similar and lower acetification rates. Agitated fermentations were unsuccessful for all the treatments (CC, OWC and FFC) studied. Agitation was therefore assumed to have promoted cell shear stress causing insufficient acetification during fermentations. Low aerated fermentations resulted in better acetification rates between 1.45–1.56 g L-1 day−1 for CC, OWC and FFC. At a higher aeration setting, only free-floating cells were able to complete fermentations with an acetification rate of 1.2 g L-1 day−1. Furthermore, the adsorption competence data showed successful adsorption on CC and OWC for both yeasts and AAB with variations in adsorption efficiencies, whereby OWC displayed a lower cell adsorption capability compared to CC. On the other hand, OWC were less efficient adsorbents due to their smooth surface, while the rough surface and porosity of CC led to improved adsorption and, therefore, enhanced acetification rates. The 3rd phase results showed a substantial decline in acetification rates on the 2nd cycle of fermentations when cells immobilized on CC and OWC were reused. While cells entrapped in Ca-alginate beads were able to complete the 2nd cycle of fermentations at reduced acetification rates compared to the 1st cycle of fermentations. The sensory results showed positive ratings for BSV’s produced using cells immobilized in Ca-alginate beads and CC. However, BSV’s produced using OWC treatments were neither ‘liked nor disliked’ by the judges. The SEM imaging results further showed a substantial loss of structural integrity for Ca-alginate beads after the 1st cycle fermentations, with minor changes in structural integrity of CC being observed after the 1st cycle fermentations. OWC displayed the same morphological structure before and after the 1st cycle fermentations which was attributed to their robustness. Although Ca-alginate beads showed a loss in structural integrity, it was still assumed that Ca-alginate beads provided better protection against the harsh environmental conditions in contrast to CC and OWC adsorbents due to the acetification rates obtained on both cycles. The 4th phase data obtained from the computations showed that non-aerated fermentations had a higher 𝑌𝑌𝑂𝑂/𝐴𝐴, 𝑟𝑟𝑂𝑂2 , 𝑁𝑁𝑂𝑂2 and a higher 𝐾𝐾𝐿𝐿𝑎𝑎 . It was clear that aerated fermentations had a lower aeration capacity due to an inappropriate aeration system design and an inappropriate fermentor. Consequently, aeration led to several detrimental biochemical changes in the fermentation medium thus affecting 𝐾𝐾𝐿𝐿𝑎𝑎 and several oxygen mass transfer parameters which serve as a driving force. Overall, it was concluded that the best method for BSV production is the use of cells entrapped in small alginate beads or cells adsorbed on CC under static and non-aerated fermentations. This conclusion was based on several factors such as cell affinity/cell protection, acetification rates, fermentation period and sensorial contributions. However, cells entrapped in Ca-alginate beads had the highest acetification rates. The oxygen mass transfer computations demonstrated a high 𝐾𝐾𝐿𝐿𝑎𝑎 when Ca-alginate beads were used under static-non-aerated conditions compared to fermentations treated with CC. Therefore, a fermentor with a high aeration capacity needs to be designed to best suit the two BSV production systems (Ca-alginate beads and CC). It is also crucial to develop methods which can increase the robustness of Ca-alginate beads in order to improve cell retention and reduce the loss of structural integrity for subsequent cycles of fermentation. Studies to define parameters used for upscaling the BSV production process for large scale productions are also crucial.

Biofilms represent universal strategy for bacterial survival. Living in form of biofilms, bacteria acquire wide range of advantages over planktonically growing cultures. It can be assumed that nearly 99% of world bacterial population is living in form of biofilms. There are benefits and drawbacks associated with bacterial biofilms for mankind. Life in biofilms makes pathogens more effective and persistent through higher antibiotic resistance and helps them to hide before immune system of the host. Mycobacteria, which are capable of forming biofilms on variety of surfaces, differ from most of other bacteria by unique composition of their cell wall. It provides them with high resistance against physical or chemical damage. This is one of the reasons for considering Mycobacterium tuberculosis as a highly potent pathogen. The studies of mycobacterial biofilms are motivated by effort to improve or find new therapeutic methods. This work is aimed at morphological and proteomic comparative analyses of biofilms obtained from Mycobacterium smegmatis grown on surface of glass and silica/zirconium beads, on liquid medium surface or grown submerged in shaken planktonic culture. We have developed technique for preparation of "floating" biofilm sample to be observed in SEM. We have shown that the growth of...

Produktionen av rekombinanta biofarmaceutiska läkemedel, exempelvis monoklonala antikroppar, är en oumbärlig men ansträngande process. Under 2019 var sju av de tio mest sålda läkemedlen globalt baserade på rekombinant producerade monoklonala antikroppar. En betydande flaskhals i utvecklingen av stabila cellinjer är screening och selektion av högproducerande singelcellkloner. Tekniker som utspädningskloning (limiting dilution) och fluorescensaktiverad cellsortering (FACS) når idag medelmåttiga resultat som bäst, men saknar förmåga att både isolera produktiva singelcellkloner och hålla cellviabilitet på en acceptabel nivå. Samtidigt kan CellCelectorn™, ett helt automatiserat instrument utformat för att detektera, selektera och isolera singelcellkloner, screena celler för att kartlägga deras produktivitet. CellCelectorn™ är utrustad både med brightfield- och fluorescerande kameror och kan ranka samtliga cellkloner i en provplatta efter produktivitet för att sedan överföra de mest lovande klonerna till en destinationsplatta för vidare analyser och singelklonexpansion. Med avstamp i detta instrument var syftet med projektet att utveckla ett automatiserat arbetsflöde för screening och selektion av högproducerande singelcellkloner med hög genomströmning vid generering av stabila cellinjer. Inledande tester med redan utvecklade och produktiva cellinjer genomfördes för att undersöka CellCelectorns™ prestanda och för att upprätta och optimera sekundära parametrar relevanta för instrumentets kapacitet. Då dessa inledande tester var framgångsrika utfördes en polyklonal selektion i syfte att utveckla tre stabila cellinjer producerandes olika antikroppar. Dessa cellinjer skulle sedan användas för att undersöka CellCelectorns™ förmåga att isolera och överföra de mest lovande singelklonerna till en destinationsplatta. Dessa test kunde tyvärr inte genomföras, då kontaminering i de polyklonala poolerna hade uppstått, men de övergripande resultaten av detta projekt indikerar att CellCelectorn™ är kapabel till att screena för och ranka singelkloner efter deras produktivitet samt att selektera högproducerande klonkandidater under en enda arbetsvecka. Framtida tester är dock nödvändiga för att säkerställa CellCelectorns™ förmåga att isolera singelcellkloner med hög genomsnittlig cellviabilitet för att kunna genomföra singelklonexpansion. / The production of recombinant biopharmaceuticals, such as monoclonal antibodies (mAbs), from stable mammalian cell lines is an indispensable yet strenuous process. In 2019, seven of the top ten most sold drugs globally were based on monoclonal antibodies produced recombinantly. A prominent bottleneck in stable cell line development is the screening and selection of high target protein producing single clone candidates. Today, techniques such as limiting dilution and Fluorescence Activated Cell Sorting (FACS) receive moderate success at best at isolating single clones while keeping cell viability high. Simultaneously, the CellCelector™ is a fully automated instrument designed for the detection, selection, and isolation of single cell clones. Containing both a brightfield and fluorescence-detecting camera, the CellCelector™ can screen cells to measure their productivity and rank them accordingly, meaning high target protein producing clones can be selected and transferred to a destination plate for single clone expansion. Thus, this project aimed at developing an automated high-throughput workflow using the CellCelector™ to streamline the screening and selection steps of stable mammalian cell line generation. Several tests with stable proof-of-concept cells were performed to evaluate the performance of the CellCelector™ and to establish favorable secondary parameter settings. As initial proof-of-concept tests showed promise, a polyclonal selection to obtain three stable Human Embryonic Kidney (HEK) cultures expressing different antibodies was carried out in order to test the CellCelector™ proficiency in clone selection and picking. Unfortunately, no clone picking or single clone expansion could be executed due to bacterial contamination in the cell cultures. Nevertheless, the overall results of this project indicate high potential of the CellCelector™ to detect and identify promising stable clone candidates for single clone expansion over the course of a single work week. Future tests are however required to solidify CellCelector™ ability to isolate monoclonal clones while preserving cell viability for single clone expansion.

Glaspärlor är en viktig del av vikingatidens dräkt. Syftet med denna studie är att få en inblick i hur befolkningen i Fröjel såg på och använde pärlor. Aktörskap som teori används i studien. Undersökningsmaterialet är 100 glaspärlor som kan dateras mellan 900–1000 e.v.t och har hittats i Fröjel, genom Fröjel Discovery Programme. Pärltyperna sorterades med Callmers typologi och har tillsammans med pärlornas fyndplats analyserats och diskuterats. Undersökningsmaterialet har diskuterats utifrån tidigare forskning kring vikingatiden, handelssystem och glaspärlor, som ett material och föremål. Callmers typologi bidrog till att urskilja pärlornas ursprung vilka stämmer med Fröjels handelsvägar. Studien visar, med hjälp av Callmers typologi och rumslig spridning, att pärlorna är av värde och ett resultat av social struktur, handel och val gjorda av både individen och grupper vilket ökar relevansen av aktörskap vad gäller individers val och kläddetaljer. / Glass beads have long been a part of the viking age costume. The purpose of this study is to get an insight to how the population of Fröjel viewed and used the beads. Agency as a theory was used in the study. The research material is 100 glass beads that can be dated between 900-1000 CE, have been found in Fröjel, through Fröjel Discovery Programme. The bead types have been sorted with Callmers typology and along with the location of the finds have been analyzed and discussed. The research material has been discussed based on previous research surrounding the viking age, trade systems and glass beads as a material and item. The origins of the beads which could be distinguished through Callmers typology matches with Fröjels trade networks. The study shows, with the help of Callmer’s typology and the spatial spread of the beads, that the beads are an accessory of value and a result of social structure, such as trade, and choices made by both the individual and groups which heightens the relevance of agency regarding individuals and clothing details.

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