Prior to an underground excavation a site investigation is carried out. This includes reviewing and analysing existing data, field data collected through outcrop mapping, drill core logging and geophysical investigations. These data sources are combined and used to characterise, quantify and classify the rock mass for the tunnel design process and excavation method selection. Despite the best approaches used in a site investigation, it cannot reveal the required level of detail. Such gaps in information might become significant during the actual construction stage. This can lead to; for example, over-break due to unfavourable geological conditions. Even more so, an underestimation of the rock mass properties can lead to unplanned stoppages and tunnel rehabilitation. On-the-other-hand, the excavation method itself, in this case, drill and blast, can also cause severe damage to the rock mass. This can result in over-break and reduction of the strength and quality of the remaining rock mass. Both of these attributes pose risks for the tunnel during excavation and after project delivery. Blast damage encompasses over-break and the Excavation Damage Zone (EDZ). In the latter irreversible changes occur within the remaining rock mass inside this zone, which are physically manifested as blast fractures. In this thesis, a number of methods to determine blast damage have been investigated in two ramp tunnels of the Stockholm bypass. Herein, a comparison between the most common methods for blast damage investigation employed nowadays is performed. This comparison can be used to select the most suitable methods for blast damage investigation in tunnelling, based on the environment and the available resources. In this thesis Ground Penetrating Radar, core logging (for fractures) and P-wave velocity measurements were applied to determine the extent of the blast damage. Furthermore, the study of the two tunnels in the Stockholm bypass shows a significant overestimation of the actual rock mass quality during the site investigation. In order to gain a more accurate picture of the rock mass quality, Measurement While Drilling (MWD) technology was applied. The technology was investigated for rock mass quality prediction, quantifying the extent of blast damage, as well as to investigate the potential to forecast the required rock support. MWD data was collected from both grout and blast holes. These data sets were used to determine rock quality indices e.g. Fracture Indication and Hardness Indicator calculated by the MWD parameters. The Fracture Index was then compared with the installed rock support at the measurement location. Lastly, the extent of the damage is investigated by evaluating if the MWD parameters could forecast the extent of the EDZ. The study clearly shows the capability of MWD data to predict the rock mass characteristics, e.g. fractures and other zones of weakness. This study demonstrated that there is a correlation between the Fracture Index (MWD) and the Q-value, a parameter widely used to determine the required rock support. The study also shows a correlation between the extent of the blast damage zone, MWD data, design and excavation parameters (for example tunnel cross section and charge concentration).

New experimental strategies and algorithmic approaches were devised and tested to improve the analysis of pharmaceutically relevant materials. These new methods were developed to address key bottlenecks in the design of amorphous solid dispersions for the delivery of low-solubility active pharmaceutical ingredients in the final dosage forms exhibiting high bioavailability. <br>

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.

Le graphène, plan d'atomes de carbone agencés en nid d'abeille, possède des propriétés physico-chimiques remarquables, en particulier une excellente mobilité électronique, qui en font un matériau d'avenir pour de nombreuses applications. Si la synthèse par dépôt chimique en phase vapeur (CVD) est une méthode prometteuse en vue d'une production de graphène de qualité à grande échelle, il reste difficile de contrôler les caractéristiques du graphène formé. L'objectif de ce travail expérimental est à la fois de développer la croissance de graphène par CVD à pression atmosphérique et température modérée (600°C à 900°C) sur un substrat de cobalt et d'analyser le graphène formé par des techniques d'analyse complémentaires afin de déterminer ses caractéristiques physico-chimiques et structurales.Une étude de l'influence de plusieurs paramètres de synthèse sur les caractéristiques du graphène formé (nombre de couches, taux de recouvrement, défauts et taille des domaines cristallins) a été réalisée. En utilisant des feuilles de cobalt commerciales et en travaillant à 850°C avec une forte vitesse de refroidissement et un apport faible en carbone, un film continu de graphène de trois couches a été obtenu. De plus, en étudiant la distribution des atomes de carbone dans le cobalt après synthèse, nous avons mis en évidence une concentration de carbone extrêmement élevée, environ 100 fois supérieure à la solubilité du carbone dans le cobalt à 850°C.L'influence du cobalt sur les caractéristiques structurales a été étudiée par diffraction des rayons X sur source synchrotron. Pour cela, du graphène a été synthétisé par CVD à pression atmosphérique sur des films minces de cobalt. L'étude structurale de ce système a révélé un empilement des feuillets de graphène de type graphite turbostratique et des domaines cristallins présentant deux orientations différentes par rapport au cobalt.L'étude du système graphène/cobalt est complétée par une analyse multi-techniques et localisée du graphène permettant d'analyser la même zone de graphène lorsqu'elle est sur cobalt puis sur SiO2, après transfert. La caractérisation est réalisée par microcopie et par spectroscopie Raman. L'influence du substrat de cobalt sur le graphène formé, notamment des contraintes mécaniques et du dopage électronique, est mise en évidence.Une étude de l'influence de plusieurs paramètres expérimentaux sur les caractéristiques du graphène formé (nombre de couches, taux de recouvrement, défauts et taille des domaines cristallins) a été réalisée. En utilisant des feuilles de cobalt commerciales et en travaillant à 850°C avec une forte vitesse de refroidissement et un apport faible en carbone, un film continu de graphène de trois couches a été obtenu. De plus, en étudiant la distribution des atomes de carbone dans le cobalt après synthèse, nous avons mis en évidence une concentration de carbone extrêmement élevée, environ 100 fois supérieure à la solubilité du carbone dans le cobalt à 850°C.L'influence du cobalt sur la croissance du graphène a été étudiée par diffraction des rayons X sur source synchrotron. Pour cela, du graphène a été synthétisé par CVD à pression atmosphérique sur des films minces de cobalt. L'étude structurale de ce système a révélé un empilement des feuillets de graphène de type graphite turbostratique. De plus, il a été montré que 95 % des domaines cristallins du graphène sont orientés à 20° ± 7° par rapport au cobalt tandis que 5 % des domaines est très bien orientée à 30° ± 0,6°.L'étude du système graphène/cobalt est complétée par une analyse multi-techniques et localisée du graphène permettant d'analyser la même zone de graphène lorsqu'elle est sur cobalt puis sur SiO2, après transfert. L'influence, notamment mécanique, du substrat de croissance sur le graphène formé est mise en évidence. / Graphene, a two-dimensional material composed of carbon atoms arranged in hexagonal lattice, has outstanding physical and chemical properties, i.e. its exceptional electronic mobility. This material is thus promising for many applications in the future. However, if chemical vapour deposition (CVD) is a very promising method for large-scale graphene growth , it is still very challenging to control graphene characteristics. The objective of this experimental work is both to develop graphene growth by CVD at atmospheric pressure and moderate temperature (600°C / 850°C) on cobalt and to analyse grown graphene with complementary techniques to determine its physical, chemical and structural characteristics.A study of the influence of different synthesis parameters on graphene characteristics (number of layer, coverage, defect and crystallite size) has been achieved. By combining the use of commercial cobalt foils with growth temperature of 850°C, a high cooling rate (100°C/min) and a low carbon supply, a continuous graphene film of three layers has been synthesized. Moreover, by measuring carbon distribution in the cobalt substrate after graphene growth, we have highlighted a carbon concentration about 100 times higher than carbon solubility in cobalt at 850 °C.The influence of cobalt on graphene structure was studied by X-ray diffraction using a synchrotron beamline. Prior to experiments, graphene was grown by CVD at atmospheric pressure on cobalt thin film. The structural study of this system has revealed a turbostratic stacking of graphene and two different orientations for graphene domains with respect to cobalt.The study of the graphene/cobalt system is completed by a multi-technique and localised characterisation of graphene which enables to analyse a same area of graphene when it is on cobalt and then after transfer on SiO2 substrate. Sample characterisation is based on microscopy and Raman spectroscopy. The influence of cobalt substrate on grown graphene, especially on mechanical strain and electronic doping, is highlighted.

Dans le cadre de ses actions de R&D sur la caractérisation non destructive, le CEA dispose d’un système d'imagerie photonique de haute énergie. Ce dispositif, unique en France, permet de réaliser des radiographies et des tomographies sur des objets de grands volumes, tels que des colis de déchets radioactifs. Le Laboratoire de Mesures Nucléaires, qui mène les projets de recherche sur cette installation, a engagé une évolution majeure du système en lançant l'approvisionnement d'une nouvelle source X d'énergie augmentée et d'un banc mécanique de positionnement d'une capacité de 5 tonnes afin de pouvoir caractériser des objets de grande épaisseur : jusqu'à 140 cm de béton. Les travaux qui ont fait l'objet de cette thèse s'inscrivent dans ce contexte de caractérisation et de mise en service du nouveau tomographe, qui permet la mise en place de nouvelles modalités d'examen telles que la tomographie bi-énergie.La première partie de la thèse consiste en une étude approfondie des performances du nouveau tomographe en termes de capacité de pénétration et de résolution spatiale. Elle concerne à la fois la source X et le système de détection. La source X est un accélérateur linéaire Saturne reconditionné pour atteindre des énergies comprises entre 15 et 20 MeV pour des débits de dose supérieurs à 100 Gy/min. Les caractéristiques attendues de cette source sont évaluées par simulation : spectres, taches focales et débits de dose. En parallèle, la recherche d'un système de détection adapté conduit à mettre en compétition trois détecteurs : une série de semi-conducteurs CdTe non jointifs, une caméra linéaire à scintillateur CdWO4 segmenté et des écrans horizontaux de CsI filmés par des caméras bas bruit. Tous trois font l'objet d'une analyse par comptage de quanta (Quantum Accounting Diagram) permettant de mettre en lumière les qualités et limites de chacun à travers l'évaluation et la comparaison d'indicateurs complémentaires de leurs performances : efficacité quantique de détection, rapport signal sur bruit, résolution spatiale et gamme dynamique. Cette étude théorique est complétée, corrigée et validée par des campagnes de mesures expérimentales et permet finalement de prévoir les performances attendues avec l'accélérateur Saturne, et ainsi définir le meilleur détecteur pour l'imagerie des objets ciblés.La seconde partie de la thèse concerne le développement d'une nouvelle méthode de caractérisation des matériaux par tomographie bi-énergie afin d’identifier au mieux le numéro atomique effectif du matériau et sa densité. L'état de l'art sur les techniques actuelles fait ressortir une méthode potentiellement intéressante pour les besoins de la caractérisation de colis de déchets nucléaires : la décomposition en double effet. Initialement développée pour l'imagerie de plus basse énergie, elle a été adaptée à la gamme d’énergie du tomographe en modifiant les interactions photon-matière prises en compte dans le procédé. La méthode a été testée et validée sur des simulations d'examens tomographiques obtenues avec le code de simulation MODHERATO.Il ressort de ces travaux de thèse que le nouveau système d'imagerie du CEA Cadarache devrait être en mesure à la fois d'accueillir et caractériser des objets massifs avec une qualité d'image satisfaisante et une résolution spatiale submillimétrique, mais également de mettre en œuvre des examens de tomographie bi-énergie permettant d'évaluer le numéro atomique et la densité des matériaux composant les objets examinés. / As part of its research and development activities on non-destructive characterisation, CEA utilizes a high-energy photonic imaging system. This instrument, unique in France, allows radiographic and tomographic analyses on large objects (e.g., nuclear waste drums). The "Laboratoire de Mesures Nucléaires", responsible for running research projects in the facility, has launched a major upgrade of the system by providing a new higher energy X-ray source and a new mechanical bench possessing a 5 t load, which allows the characterisation of thick objects (up to 140 cm concrete thickness). This PhD thesis concerns the characterisation and commissioning of the new computed tomography (CT) system and introduces new examination modalities, such as dual-energy CT.The first part of the thesis is a comprehensive study of the performance of the upgraded CT system, specifically regarding penetration capacity and spatial resolution and concerning both the X-ray source and the detection system. The X-ray source is a linear accelerator called Saturne, which has been repackaged to reach energies between 15 and 20 MeV with dose rates greater than 100 Gy/min. Simulation is used to assess the expected features of this source: spectra, focal spots and dose rates. Parallel comparison among three detectors -a series of non-abutting CdTe semiconductor sensors, a linear camera with segmented CdWO4 scintillators and horizontal screens of CsI filmed by low noise cameras - assessed the most suitable detection system. All three detection systems are studied using a quantum accounting analysis that highlights potentials and limitations of each system and enables measurement of complementary indicators of their performance: detector quantum efficiency, signal to noise ratio, spatial resolution and dynamic range. This theoretical study is completed, corrected and validated by experimental measurement campaigns. This extensive study predicts the expected performance when combined with the Saturne accelerator, allowing selection of the most appropriate detector for the imaging of large objects.The second part of the thesis concerns the development of a new method for the characterisation of materials by dual-energy CT, allowing a better assessment of the effective atomic number and the density of the material. The state of the art of current techniques highlights the potential interesting method for the characterising nuclear waste: the double effect decomposition. Initially developed for lower energy X-ray imaging, it has been adapted to match the energy range of the CT system by adapting the photon/matter interactions taken into account in the process. The method has been tested and validated on tomographic simulations obtained with the simulation code MODHERATO.This PhD work has shown that the new CT system of the CEA Cadarache has the potential to characterise massive objects with a satisfactory image quality and milli-scale spatial resolution. It also opens opportunities for the execution of dual-energy CT evaluations allowing the assessment of the atomic number and density of materials composing the examined objects.

Desoxyribonukleinsäure (DNS) ermöglicht die Selbstorganisation von nanoskopischen Elementen zu dreidimensionalen Einheiten mit vorgegebener Form, Zusammensetzung und Größe wie sie in der Nanoelektronik, Nanophotonik und Metamaterialien Verwendung finden. In dieser Arbeit werden DNS Origami Strukturen, in der Gestaltvon Nanoformen, Nanoblätchen und Nanoröhren, als Gerüste für den Aufbau von Nanodrähten und Metall/Halbleiter/Metall Heterostrukturen aus Goldnanoteilchen, Halbleiterquantenpunkten und Halbleiterstäbchen verwendet. Die so hergestellten Einheiten wurden mittels Elektronenstrahllithographie kontaktiert um ihre elektrische Leitwerte zwischen 4:2K und Raumtemperatur zu charakterisieren. Ein neues Konzept für die lösungsbasierte Herstellung von leitenden Goldnanodrähten mittels DNS-Templates wurde eingeführt: hierbei wurden DNS-Nanoformen eingesetzt in denen positionsspezifisch angedockte Goldkeime durch auÿenstromlose Goldabscheidung wachsen. Durch konfigurierbare Verbindungsstellen können sich die einzelnen Formen zu mikrometerlangen Strukturen verbinden. Während der folgendenden Abscheidung von Gold schränken die Wände der Gussformen über das Wachstum so ein, dass sehr homogene Nanodrähte gewonnen werden können. Goldnanodrähte wurden auch C-förmig hergestellt indem Goldnanoteilchen in der gewünschten Form auf DNS Origami-Nanoblättchen angeordnet und wiederum durch außenstromlose Goldabscheidung zu durchgängigen Drähten vergröbert wurden. Einige Abschnitte der DNS-Nanoform-geprägten Drähte zeigen metallische Leitfähigkeit, während andere durch Lücken zwischen den Goldkörnern deutlich höhere Widerstände aufweisen. Alle hergestellten C-förmigen Nanodrähte stellten sich als nicht-metallisch heraus, sie zeigten Eigenschaften von Hopping-, thermionischem und Tunneltransport in Abhängigkeit von der Temperatur. Die Anwesenheit dieser verschiedenen Transportmechanismen deutet darauf hin, dass die C-förmigen Nanodrähte aus metallischen Abschnitten bestehen welche aber nur schwach miteinander verbunden sind. Zwei verschiedene Metall/Halbleiter/Metall-Heterostrukturen wurden hergestellt: Metall/Halbleiternanstäbchen/Metall-Strukturen mittels DNS-Nanoformen und Metall/Quantenpunkt/Metall-Strukturen mittels DNS-Nanoröhren-Vorlagen Goldnanoteilchen konnten durch die DNA templates mit hoher Ausbeute neben den Halbleiterelementen platziert werden. Nach der erfolgter Anordnung wurden die Goldnanoteilchen gewachsen um durchgängige Heterostrukturen zu erhalten. Die Einflüsse des Inkubationsmediums und der -zeit, des Buffers, sowie der Quantenpunkt- und Goldnanopartikelkonzentrationen auf die Abscheidungseffzienz von Goldnanotailchen auf DNS Nanoröhren wurden systematisch untersucht. Zusätzlich zur Bestimmung der Morphologie der durch Selbstorganisation hergestellten Heterostrukturen, wurden auch ihre elektrischen Eigenschaften im Hinblick auf ihre Anwendung in nanelektronischen Bauelementen, wie Einzelelektronentransitoren untersucht.:1. Introduction 2. Overview on DNA Nanotechnology 2.1. Basic Concepts of DNA 2.1.1. Nanoscale Dimensions 2.2. Self-Assembled Architectures from DNA 2.3. DNA Origami: Nanomolds, Nanosheets and Nanotubes 2.3.1. DNA Origami Method 2.3.2. Nanomolds 2.3.3. Nanosheets 2.3.4. Nanotubes 2.4. DNA/DNA Origami-Templated Metallic Nanowire Fabrication 2.4.1. DNA/DNA Origami Templates 2.4.2. Metal Nanoparticle Attachment Yield 2.4.3. Metal Growth 2.5. Electron Transport Mechanisms of DNA-Templated Metallic Nanowires 2.5.1. Lithographically Defined Contacts and I-V Measurements of the DNA-Templated Metal Wires 2.5.2. Lithographically Defined Contacts and I-V Measurements of the DNA Origami-Templated Metal Nanowires 2.6. Applications 2.6.1. Introduction to Metamaterials: DNA-Templated Metamaterial Fabrication 2.6.2. Introduction to Single Electron Tunneling: A DNA-Templated Self-Assembly Concept 3. Experimental Details 3.1. Preparation of Substrates 3.2. DNA Origami Preparation and Deposition 3.2.1. DNA Nanomolds and Formation of linear mold superstructures 3.2.2. DNA Nanotubes 3.2.3. DNA Nanosheets 3.3. Metallization of DNA Origami Structures 3.3.1. DNA Nanomolds 3.3.2. DNA Nanotubes 3.3.3. DNA Nanosheets 3.3.4. Gold Growth on the DNA Origami Nanotube and Nanosheet 3.4. Semiconductor Nanoparticle Preparation and Assembly 3.4.1. CdS Semiconductor Quantum Rods for DNA Nanomold. 3.4.2. CdSe/ZnS Core-shell quantum Dots for DNA Nanotube 3.5. Deposition of DNA origami structures on SiO2 /Si surface 3.5.1. Deposition of DNA Nanomolds 3.5.2. Deposition of DNA Nanosheets and Nanotubes 3.6. Structural Characterization 3.6.1. Atomic Force Microscopy 3.6.2. Scanning Electron Microscopy 3.7. Electrical Characterization 4. Results and Discussion 4.1. DNA Nanomold-Templated Assembly of Conductive Gold Nanowires 4.1.1. Introduction 4.1.2. Results and Discussion 4.1.3. Conclusion 4.2. Conductance measurements on Gold/Semiconductor/Gold heterojunctions templated by DNA Nanomolds 4.2.1. Introduction 4.2.2. Results and Discussion 4.2.3. Conclusion 4.3. C-shaped Gold Nanowires Templated by DNA Nanosheet 4.3.1. Introduction 4.3.2. Results and Discussion 4.3.3. Conclusion 4.4. Self-Assembled Gold/Semiconductor/Gold heterojunctions templated by DNA Nanotube 4.4.1. Introduction 4.4.2. Results and Discussion 4.4.3. Conclusion 5. Conclusion and Future Work A. Supplement for DNA Nanomold-Templated Assembly of Conductive Gold Nanowires B. Conductance measurements on Gold/Semiconductor/Gold heterojunctions templated by DNA Nanomolds C. Supplement for C-shaped Gold Nanowires Templated by DNA Nanosheet D. Supplement for heterojunctions templated by DNA Nanotube / DNA allows self-assembly of nanoscale units into three dimensional nanostructures with definite shape and size in fields such as nanoelectronics, metamaterials and nanophotonics. Different DNA origami templates, such as: nanomold, nanosheet and nanotube templates have been used to assemble gold nanoparticles, quantum dots and semiconductor rods into nanowires and metal/semiconductor/metal heterostructures. Structures have been contacted using electron-beam lithography for electrical conductance characterization at temperatures between 4:2K and room temperature has been performed. A new concept has been introduced for the solution-based fabrication of gold nanowires. To this end, DNA nanomolds have been employed, inside which electroless gold deposition is initiated by site-specifically attached seeds. Using configurable interfaces, individual mold elements self-assemble into micrometer-long mold structures. During subsequent internal gold deposition, the mold walls constrain the metal growth, such that highly homogeneous nanowires are obtained. Gold nanowires have also been manufactured in a C-shape using gold nanoparticles arranged in the desired shape on a DNA origami nanosheet and enhanced to form a continuous wire through electroless gold deposition. Some sections of the DNA nanomold-templated wires show metallic conductance, while other sections of the wires have a much higher resistance which is caused by boundaries between gold grains. All C-shaped wires have been found to be resistive showing hopping, thermionic and tunneling transport characteristics at different temperatures. The different transport mechanisms indicate that the C-shaped nanowires consist of metallic segments which are weakly coupled along the wire. Two types of metal/semiconductor/metal heterostructures have been fabricated: Metal/semiconductor-rod/metal using DNA nanomolds and metal/quantum-dot/metal structures using DNA nanotube. AuNPs were assembled with high yield adjacent to the semiconductor material using origami templates. After the assembly, the gold nanoparticles were grown to produce continuous heterostructures. The influence of the incubation medium, time, buffer, quantum dot and gold nanoparticle concentration on nanoparticle attachment yield was systematically investigated for the nanotube templates. In addition to the determination of the self-assembled heterostructures' morphology, electrical properties were investigated to evaluate their applicability nanoelectronic devices such as single electron transistors.:1. Introduction 2. Overview on DNA Nanotechnology 2.1. Basic Concepts of DNA 2.1.1. Nanoscale Dimensions 2.2. Self-Assembled Architectures from DNA 2.3. DNA Origami: Nanomolds, Nanosheets and Nanotubes 2.3.1. DNA Origami Method 2.3.2. Nanomolds 2.3.3. Nanosheets 2.3.4. Nanotubes 2.4. DNA/DNA Origami-Templated Metallic Nanowire Fabrication 2.4.1. DNA/DNA Origami Templates 2.4.2. Metal Nanoparticle Attachment Yield 2.4.3. Metal Growth 2.5. Electron Transport Mechanisms of DNA-Templated Metallic Nanowires 2.5.1. Lithographically Defined Contacts and I-V Measurements of the DNA-Templated Metal Wires 2.5.2. Lithographically Defined Contacts and I-V Measurements of the DNA Origami-Templated Metal Nanowires 2.6. Applications 2.6.1. Introduction to Metamaterials: DNA-Templated Metamaterial Fabrication 2.6.2. Introduction to Single Electron Tunneling: A DNA-Templated Self-Assembly Concept 3. Experimental Details 3.1. Preparation of Substrates 3.2. DNA Origami Preparation and Deposition 3.2.1. DNA Nanomolds and Formation of linear mold superstructures 3.2.2. DNA Nanotubes 3.2.3. DNA Nanosheets 3.3. Metallization of DNA Origami Structures 3.3.1. DNA Nanomolds 3.3.2. DNA Nanotubes 3.3.3. DNA Nanosheets 3.3.4. Gold Growth on the DNA Origami Nanotube and Nanosheet 3.4. Semiconductor Nanoparticle Preparation and Assembly 3.4.1. CdS Semiconductor Quantum Rods for DNA Nanomold. 3.4.2. CdSe/ZnS Core-shell quantum Dots for DNA Nanotube 3.5. Deposition of DNA origami structures on SiO2 /Si surface 3.5.1. Deposition of DNA Nanomolds 3.5.2. Deposition of DNA Nanosheets and Nanotubes 3.6. Structural Characterization 3.6.1. Atomic Force Microscopy 3.6.2. Scanning Electron Microscopy 3.7. Electrical Characterization 4. Results and Discussion 4.1. DNA Nanomold-Templated Assembly of Conductive Gold Nanowires 4.1.1. Introduction 4.1.2. Results and Discussion 4.1.3. Conclusion 4.2. Conductance measurements on Gold/Semiconductor/Gold heterojunctions templated by DNA Nanomolds 4.2.1. Introduction 4.2.2. Results and Discussion 4.2.3. Conclusion 4.3. C-shaped Gold Nanowires Templated by DNA Nanosheet 4.3.1. Introduction 4.3.2. Results and Discussion 4.3.3. Conclusion 4.4. Self-Assembled Gold/Semiconductor/Gold heterojunctions templated by DNA Nanotube 4.4.1. Introduction 4.4.2. Results and Discussion 4.4.3. Conclusion 5. Conclusion and Future Work A. Supplement for DNA Nanomold-Templated Assembly of Conductive Gold Nanowires B. Conductance measurements on Gold/Semiconductor/Gold heterojunctions templated by DNA Nanomolds C. Supplement for C-shaped Gold Nanowires Templated by DNA Nanosheet D. Supplement for heterojunctions templated by DNA Nanotube

Testing equipment based on the propagation of elastic waves are commonly used for measuring specific material properties. As a prerequisite for accurate measurements a reliable acoustic coupling of probe and specimen is highly important. Therefore, high-resolution testing equipment is using fluids as couplant. In certain conditions, only non-contacting methods can be considered. This is the case for example, if particular high or low temperatures are present, if topographic features impede the use of ultrasonic probes, diffusion or solubility processes exist, measurements at vacuum are addressed and if high purity requirements need to be fulfilled. Hence, subject of this work is a method which offers to handle these constraints. With the emergence of modern laser systems the scientific basics for a non-contacting, laser-acoustic excitation of ultrasound were discovered. The tremendous development of commercially available laser systems during the last decade was taken as reason to investigate, to which extent former scientifically designed laboratory setups can now be merged into one single application oriented measuring system. All considerations are based on the thermoelastic excitation of ultrasound in combination with a likewise laser-based detection. By this, a self-contained measuring chain is built which combines the attributes non-destructive, non-contacting and application oriented within one ultrasonic measurement system for the first time. Thermal calculations lead to more precise equations which predict a laser-induced, local temperature rise of about 100 K. The examination of sound field simulations, as a prerequisite for the design of ultrasonic systems, identified an additional complex of problems. Although existing calculation approaches presuppose laser intensity profiles what can be described in analytical terms, real-world laser sources exhibit a complex shaped spatial distribution of laser energy. Based on a preceding CEFIT simulation, the developed CPSS method enables the calculation of the time resolved, 3D wave propagation of arbitrary shaped sources. A comparison to measured data successfully validated the results of simulation. By presenting selected scenario of measurements, the practical suitability of this non-contacting method is demonstrated. Using a transmission setup enables the characterization of open-pore ceramic coatings as well as the deduction of longitudinal and transversal speeds of sound. Equally, the imaging and estimation of the depth position of artificial defects with 0.7 mm in diameter is shown. Measurements based on a reflection setup provided evidence of a resolution limit of at least FBH = 1 mm in 4.5 mm depth. Additional examples demonstrate the ability to detect close-surface defects, the analysis of the challenging lamb waves zero-group-velocity S1 mode as well as the utilization of buried laser-acoustic sources. / Prüfsysteme, welche die Ausbreitungseigenschaften elastischer Wellen zur Ableitung spezifischer Messgrößen nutzen, sind etablierte Messverfahren. Voraussetzung für zuverlässige Ergebnisse ist stets die sichere akustische Kopplung zwischen Sensor und Material. Daher arbeiten hochauflösende Prüfsysteme mit Fluiden als Koppelmedium. Unter bestimmten Bedingungen scheiden kontaktierende Ultraschallsysteme allerdings ersatzlos aus. Dies ist beispielsweise der Fall, wenn die Probe eine besonders niedrige oder hohe Temperatur besitzt, topografische Eigenschaften ein sicheres Ankoppeln der Kontaktprüfköpfe erschweren, Diffusionsvorgänge oder Löslichkeiten zu beachten sind, in Vakuum zu arbeiten ist oder erhöhte Reinheitsanforderungen vorliegen. Gegenstand der vorliegenden Arbeit ist eine Technik welche hilft, diese Einschränkungen zu umgehen. Mit dem Aufkommen der ersten Laserquellen entstanden die wissenschaftlichen Grundlagen zur kontaktlosen Anregung und Detektion von Ultraschall. Die rasante Entwicklung kommerziell verfügbarer Lasersysteme der vergangenen Dekade wurde zum Anlass genommen zu untersuchen, in wie weit sich die einst wissenschaftlich orientierte Laboraufbauten zu einem anwendungsnahen Messsystem zusammenführen lassen. Basis der Arbeiten ist die thermoelastische Anregung von Ultraschall in Kombination mit einer ebenfalls kontaktlosen Detektion. Damit entsteht eine geschlossene Messkette welche erstmals die Eigenschaften zerstörungsfrei, kontaktlos und anwendungsorientiert in einem Ultraschallmesssystem vereint. Ausgangspunkt stellt die thermische Simulation der Anregung dar. Mit Hilfe präzisierter Gleichungen wird eine lokale Erwärmung von lediglich 100 K vorausgesagt. Für die zur Auslegung eines akustischen Messsystems notwendige Schallfeldsimulation wurde eine weitere Problematik identifiziert. Während bekannte Rechenansätze stets analytisch beschreibbare Strahlprofile des Lasers voraussetzen, zeigen reale Laserquellen kompliziert gestaltete räumliche Intensitätsverteilungen. Auf Basis einer vorangestellten CEFIT-Simulation ist mit der entwickelten CPSS-Methode eine zeitdiskrete Berechnung der 3D-Wellenausbreitung beliebiger Quellgeometrien möglich. Vergleiche mit realen Messdaten bestätigen die Simulationsrechnungen. Anhand ausgewählter Messszenarien wird die Praxistauglichkeit der kontaktlosen Arbeitsweise demonstriert. Neben der Charakterisierung einer offenporigen keramischen Beschichtung erlauben Transmissionsmessungen die Berechnung der longitudinalen und transversalen Schallgeschwindigkeiten. Ebenso ist die Abbildung wie auch die Beurteilung der Tiefenlage von Referenzfehlern mit lediglich 0,7 mm Durchmesser möglich. In Reflexionsmessungen wurde eine Auflösungsgrenze von mindestens KSR = 1 mm in 4,5 mm Tiefe nachgewiesen. Weitere Beispiele zeigen die Sensitivität hinsichtlich oberflächennaher Fehler, die Auswertung der anspruchsvollen „Zero Group Velocity“ S1-Mode der Lambwelle wie auch die Nutzung eingebetteter Quellen.

Es wurden die Zusammenhänge zwischen den Herstellungsbedingungen und dem nanostrukturellen Aufbau von Multischichten, mit Rücksicht auf das mechanische Verhalten aufgeklärt. Dazu wurden durch plasmaunterstützte Gasphasenabscheidung (PACVD) Hartmetallsubstrate mit Viellagen beschichtet und vorrangig mittels analytischer Transmissionselektronenmikroskopie (TEM) charakterisiert. Als Schichkomponenten wurden hauptsächlich TiN und Al2O3 untersucht, daneben aber auch Schichtsysteme der Komponenten AlON, (TiAl)N, und (Ti,Al)ON. Darüber hinaus wurden noch TiC-aC (TiC mit amorphem Kohlenstoffanteil)-Schichten einbezogen. Ziel waren gleichmäßige Multischichten mit Korngrößen von einigen Nanometern, geringer Testur und geringer Mikrorissdichte, die hart sind und gut haften. Die TEM-Untersuchungen dienten insbesondere der Aufklärung der Nanostruktur in den Interface-Bereichen der Schichtsysteme, wobei an Hand der Elektronenenergie-Verlustspektroskopie (EELS) sowohl element- als auch phasenspezifische Signale ausgewertet wurden. Zur verbesserten Bewertung der anfallenden Datenmengen wurden z. T. faktoranalytische Methoden eingesetzt. Je nach Prozessführung der Schichtherstellung kommt es in den Interface-Bereichen zur Durchmischung der Komponenten. Insbesondere führt diffundierender Sauerstoff zur Bildung von TiO2, was sich nachteilig auf die Qualität der Schichten auswirkt. Die Tiefe der &amp;quot;gestörten&amp;quot; Zonen begrenzt die wünschenswerte Verringerung der Einzelschichtdicken. Als wirkungsvolle Gegenmaßnahme hat sich der Einbau von Kohlenstoff erwiesen, wodurch sich dünnere Einzelschichten verwirklichen lassen.

Die term speurverhaal impliseer ’n spesifieke soort verhaal of genre, tradisioneel triviaalliteratuur of ontspanningslektuur, met spesifieke kodes en konvensies. Enige konvensies is egter aanpasbaar en die grense tussen hoë kuns en populêre kultuur is vloeibaar, sodat dit moontlik is dat daar wel ʼn vertakking of subgenre wat die literêre speurverhaal genoem kan word, kon ontwikkel het. Die doel van hierdie verhandeling is om die volgende navorsingsvrae te beantwoord: Is daar wel speurverhale wat as literêre speurverhale gekategoriseer kan word? Indien nie, waarom word die kodes van die speurverhaal as narratiewe strategie gekies vir sekere romans? Wat is die verskille en ooreenkomste tussen die tradisionele speurverhaal en die sogenaamde literêre speurverhaal? Die verskynsel word ondersoek word deur twee romans wat moontlik as literêre speurverhale geklassifiseer kan word, nl. Een vir Azazel (Leroux, 1984) en Die boek van toeval en toeverlaat (Winterbach, 2006), te vergelyk met twee tradisionele speurverhale, nl. Reuk van die dood (Mouton, 2008) en Plaasmoord (Brynard, 2009), aan die hand van sekere struktuurelemente, nl. spanningslyn, plot, intrige, karakterisering, verteller, vertellersperspektief, tyd, en ruimte. ENGLISH : The term detective story indicates a specific kind of story or genre, traditionally recreational and light reading, with specific codes and conventions. However, any set of conventions are pliable and the boundaries between recreational and high art are fluid and constantly shifting. It is therefore possible that a subgenre of the detective story that can be called the literary detective story could have developed. The goal of this dissertation is to answer the following research questions: Are there detective stories that can be categorised as literary detective stories? If not, why is the detective element chosen as a narrative strategy for some novels? What are the differences and similarities between the traditional detective story and the so called literary detective novel? / Dissertation (MA)--University of Pretoria, 2010. / Afrikaans / unrestricted

<p>Zein is a major storage protein of corn, with unique amphiphilic film forming properties. It is insoluble in water, but soluble in 70% ethanol and acetic acid, and has been declared ‘generally recognized as safe’ (GRAS) by the FDA. Due to new advances in food nanotechnology, zein is being investigated for various applications such as biodegradable packaging, oral delivery of proteins and peptides, scaffold for tissue engineering, as well as biodegradable sensor platforms. The time consuming and highly complicated methods for toxin and allergen analysis in the food industry necessitates the need for a rapid, selective, compact and easy-to-use method of detection for analytes. In the scope of this dissertation, we investigated the feasibility of functional zein nanocomposite films and formation of a zein nanocomposite sensor assembly for rapid and highly selective electrochemical measurements of food toxins and allergens. Fabrication of a zein based electrochemical amperometric sensor assembly was studied, first through the comparison of various zein film characteristics changes with the application of Laponite®, graphene oxide and carbon nanotube nanoparticles, followed by a proof-of-concept study by detecting the gluten allergen protein gliadin. </p> <p>To mechanistically study the functional zein nanocomposite films, Laponite®, a silica nanoparticle, was added in the presence of 70% ethanol solvent and oleic acid plasticizer. The films were studied using various characterization techniques like transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), water contact angle measurements etc. Through Si-N bond formation between Laponite® and zein, fabricated zein nanocomposite films showed increase in surface hydrophobicity, water vapor barrier properties, tensile strength and Young’s modulus. Graphene oxide (GO), a carbon nanoparticle, was also incorporated into zein through the solvent casting process. Uniform dispersion of GO nanoparticles within zein matrix were confirmed up to 1% GO loading, and covalent and hydrogen bonding mechanisms were proposed. Similar to zein-Laponite® (Z-LAP) nanocomposites, zein-GO (Z-GO) showed increase in hydrophobic tendencies, rougher surface and a 300% improvement in Young’s modulus and 180% improvement in tensile strength at only 3% GO loading. Both nanoparticles increased tensile strength, thermal stability and water vapor barrier property of the films, indicating a potential for food packaging as an alternative application for the nanocomposite films.</p> Finally, the research focused on the fabrication of an electrochemical amperometric sensor, capable of detecting the protein gliadin, which is responsible for the allergic reaction with people having celiac disease. Novel biodegradable coatings made from zein nanocomposites: zein-graphene oxide, zein-Laponite® and zein-multiwalled carbon nanotubes (Z-CNT) using drop casting technique were tested for fabricating the electrochemical sensors using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and square wave voltammetry (SWV) techniques. As Z-CNT produced the strongest signals compared to other nanomaterials, the active tip of the electrochemical sensor was functionalized through a sequence of layer by layer deposition of Z-CNT nanocomposite, antibody and target analyte. Here, Z-CNT acts as a natural linker molecule with large number of functional groups, that causes immobilization of capture antibody and target, to ensure high sensor performance. Both CV curves and SWV curves indicated successful sequential immobilization of gliadin antibody onto the Z-CNT coated electrode. The Z-CNT biosensor was successfully able to give CV signals for gliadin toxins for as low as 0.5 ppm and was highly specific for gliadin in the presence of other interfering molecules, and remained stable over a 30-day period. The low-cost, thin, conductive zein films offered a promising alternative for protein immobilization platforms used in sensors and can be extended to other matrices in biosensors as well as other functional film applications