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The subject of study of this thesis is the Kerr-Newman-(anti-)de Sitter space- time, a rotating and charged exact black-hole solution of the Einstein-Maxwell equations with a non-zero cosmological constant. In the first part of the thesis we examine admissible extremal configurations, present the corresponding Penrose diagrams, and investigate the effects of frame-dragging. In the second part, we follow the motion of charged particles via the Lagrangian formalism, focusing on the equatorial plane and the axis where we arrived at some analytic results con- cerning the trajectories. Static particles, effective potentials and - in the case of the equatorial plane - stationary circular orbits are examined. We also perform numerical simulations of particle motion to be able to check our analytic results and also to foster our intuition regarding the behaviour of the test particles. The last part concerns quantum tunnelling of particles through the space-time's hori- zons, specifically the null geodesic method. The main goal of these computations is to obtain horizon temperatures, in which we succeed up to a constant multi- plicative factor. We discuss various pitfalls of the method and stake out a possible approach when applying it to the extreme horizons present in KN(a)dS. 1

As part of modernization of the Brno-Přerov railway line, is in the section between village Blažovice and town Vyškov desined tunnel composed of two monorail tubes about 640 meters length. Tubes are situated in neogenic clay with an overburden height of 11 meters. This master thesis deals with design suitable tunnel exavation, primary lining with static calculation and geotechnical monitoring.

This work deals with the theoretical foundations of electron emission into vacuum, various types of emissions, focused on the cold-emission and Schottky emission and the principle of quantum tunneling. The next part deals with the technical implementation of electron sources with a detailed study of the methodology of laboratory production of cathodes by electrochemical etching and construction of electron microscopes, using field-emission sources. This work also contains methods for measuring, processing and evaluation of electrical characteristics of emission sources.

The thesis focuses on the design of the underground garage in the centre of Brno under the Petrov hill. The main target of the thesis is to design spatial arrangement of the underground space and its feasibility study. In the following parts the design of the structural solution and its check calculation is carried out.

Ein Ansatz der Darstellung von neuartigen funktionalen Materialien basiert auf der Synthese von Foldameren mit charakteristischen Eigenschaften, die eine Kontrolle über Formgebung und Gestaltung der Makromoleküle und derer Aggregate zulassen. Bislang sind gerade größere Foldamerstrukturen definierter Größe und Form meist schwer darstellbar und eine strukturelle Modifizierbarkeit nicht ohne weiteres möglich. In dieser Arbeit konnte gezeigt werden, dass die hohe Effizienz der seit 2002 bekannten Kupfer(I)-katalysierten 1,3-dipolaren Azid-Alkin-Cycloaddition, kurz “Klick“-Reaktion genannt, verwendet werden kann, um neuartige heteroaromatische Gerüste für die Konstruktion von diversen (makromolekularen) Strukturen zu generieren. Hierbei wird der bei der Reaktion entstehende Triazol-Ring gezielt als funktionale und strukturgebende Einheit genutzt. Zunächst wurden auf einfache und hochmodulare Weise 2,6-Bis(1-aryl-1,2,3-triazol-4-yl)pyridine (BTPs) dargestellt, die in einer hufeisenförmigen, planaren Konformation vorliegen und sich daher als helikogene Einheiten für die Konstruktion von helikalen aromatischen Foldameren eignen. Zudem stellen die BTP-Strukturen eine neue Klasse von pyridinzentrierten, tridentaten Liganden dar. Sie koordinieren an eine Vielzahl von Übergangsmetallionen unter Ausbildung von Metallkomplexen, die über interessante magnetische und lumineszierende Eigenschaften verfügen. Durch die Koordination, aber auch bei Protonierung, lassen sich die BTP-Gerüste von der gebeugten anti-anti-Konformation in eine gestreckte syn-syn-Konformation schalten. Dies wurde in Lösung, im kristallinen Festkörper und an der Flüssig-Fest-Grenzfläche zu Graphit untersucht. Über Selbstorganisation großflächig ausgebildete hochgeordnete BTP-Monoschichten an der Graphitoberfläche lassen sich mit Hilfe der Rastertunnel-Mikroskopie visualisieren und durch oben genannte externe Stimuli umstrukturieren. Eine neue Klasse von (BTP-basierten) responsiven heteroaromatischen oligomeren und polymeren Foldameren wurde mit Hilfe der „Klick“-Reaktion generiert. Die Oligomeren, sogenannte ”Klickamere“, mit einer Länge von 17 aromatischen Ringen zeigen in polaren Lösungsmitteln ein ausgeprägtes helikales Faltungsverhalten. Ein aus 17 aromatischen Ringen bestehender Foldamerstrang ist gegenüber Chloridionen responsiv, wobei es durch die Wechselwirkung mit diesem achiralen Stimulus bemerkenswerter Weise zu einer Helixinversion kommt. Die entsprechenden responsiven Polymere falten in eine stabile helikale Konformation, die bei Zugabe von Metallionen aufbricht und zu der Bildung von koordinativ kreuzverlinkten, stark viskosen Gelen führt. / One approach to develop novel functional materials is based on the synthesis of macromolecules with characteristic properties, in particular foldamers. However, preparation and structural variation of macromolecules of controllable size and specific shape are often cumbersome and versatile synthetic routes are still needed. In this dissertation, the high efficiency of the so called “click”-reaction, i.e. the Cu(I)-catalyzed Huisgen-type 1,3-dipolar cycloaddition, has been used to design a novel class of heteroaromatic (macromolecular) scaffolds. In these structures the formed triazole moieties constitute an essential integral part rather than a mere connecting unit. In a first step, structurally varying 2,6-Bis(1-aryl-1,2,3-triazolyl-4-yl)pyridines (BTPs) have been generated in an easy and modular way. The BTP scaffold adopts a kinked conformation and therefore functions as helicogenic building block for the construction of helical foldamers. Additionally, the BTP framework is responsive towards protonation and transition metal ion complexation, thereby undergoing a significant structural change from the kinked anti-anti into the extended syn-syn conformation. The conformational switching has been investigated in solution and in the solid state but can also be visualized at the liquid-solid interface on graphite by STM imaging. The BTPs represent a novel class of pyridine-centered, tridentate ligands, which form complexes with interesting magnetic and luminescent properties by the coordination to numerous transition metal ions. Varying heteroaromatic oligomeric and polymeric foldamers with remarkable properties have been generated using the “click”-reaction as synthesis tool. The BTP building blocks, which have (partly) been integrated into the backbones, support the stability of the helical conformation and provide responsiveness towards external stimuli. Three oligomer series of different length have been synthesized and analyzed. Oligomers consisting of 17 aromatic rings, termed clickamers, fold into a helical conformation in polar solvents. One of the three clickamers shows an unexpected phenomenon of helix inversion upon interaction with chloride ions as an achiral stimulus. The corresponding polymeric strands fold into an even more stable helical conformation, which breaks up upon exposure to transition metal ions leading to coordinatively crosslinked, highly viscous gels.

Im ersten Teil der Arbeit werden Graphen sowie von Monolagen von auf Nanometer großen Graphenen basierenden Hexa-peri(Dodekyl)-Hexabenzocoronen-Molekülen (HBC-C12), adsorbiert auf Graphen, mit Rastertunnelmikroskopie und –spektroskopie an der Fest-Flüssig-Grenzfläche untersucht. Nanographen-Moleküle selbstaggregieren epitaktisch zu hochgeordneten Monolagen. Die Einheitszellen der Moleküllagen auf Monolage Graphen, Bilage Graphen und auf Graphit sind ununterscheidbar. Die Strukturen der Moleküllagen auf gewellten und flachen Teilen des Graphens stimmen überein. Strom-Spannungs-Kennlinien an Nanographen auf Graphen und auf Graphit weisen auf sehr ähnliche elektronische Eigenschaften hin. Zusammengefasst sind strukturelle sowie elektronische Eigenschaften der Nanographenlage homogen, stabil und definiert. Graphen erweist sich als bestens als Substrat und gleichzeitig als Elektrode für hochgeordnete Lagen von Nanographen-Molekülen geeignet. Im zweiten Teil der Arbeit wird Graphen mit der Sonde eines Rasterkraftmikroskops im Kontaktmodus mechanisch manipuliert. Es wird gezeigt, dass Graphen in nur einem Manipulationsschritt zu Streifen und Spalt geschnitten werden kann. Dieses Verhalten wird mit einem klassischen Modell des Biegens theoretisch erklärt. Das Schnittverhalten liegt in der 2-Dimensionalität des Graphens sowie in dessen Faltbarkeit auf Grund hinreichender Elastizität begründet. Durch mechanische Manipulation mit der Sonde des Rasterkraftmikroskops im Kontaktmodus unter atmosphärischen Bedingungen wird eine Flüssigkeitsschicht zwischen Graphen und dem Siliziumdioxidsubstrat nachgewiesen, welche eine mögliche Erklärung des stark kraftabhängigen Materialkontrasts zwischen Graphen und Siliziumdioxid im Amplitudenmodulationsmodus des Rasterkraftmikroskops darstellt. Weiter wird gezeigt, dass das Falten des Graphens durch mechanische Manipulation eine geeignete Methode zur Herstellung nicht epitaktisch aufeinander gestapelter Graphene darstellt. / In the first part of the thesis graphene as well as monolayers of hexa-peri(dodecyl)-hexabenzocoronene molecules (HBC-C12) based on nanometer sized graphenes adsorbed on graphene is investigated by scanning tunnelling microscopy and tunneling spectroscopy at the solid-liquid interface. The nanographene molecules self-assemble on graphene epitaxially to form highly ordered monolayers. The unit cells of the molecular layers on monolayer graphene, bilayer graphene and on graphite appear identical. The structures of the molecular layers occur equal on corrugated and on flat parts of graphene. Current-voltage-characteristics show that the electronic properties of nanographene on graphene and on graphite are very similar. Summarized, structural as well as electronic properties of the nanographene layer are homogeneous, stable and defined. Graphene proves to be excellently qualified for simultaneously being substrate as well as electrode for highly ordered layers of nanographene based molecules. In the second part of the thesis graphene is mechanically manipulated in air in contact mode of a scanning force microscope. It is shown that a single manipulation process can lead to a stripe cut out of graphene. This behaviour is theoretically explained by a classical bending model. The cutting behavior originates from the 2-dimensionality of graphene and its folding ability because of sufficient elasticity. A liquid layer between graphene and the silicon dioxide substrate is verified by mechanical manipulation in contact mode of a scanning force microscope. Hence a possible explanation could be found for the strongly force dependent material contrast between graphene and silicon dioxide in amplitude modulation mode of the scanning force microscope. Further, it is demonstrated that folding graphene by mechanical manipulation is a proper method for the production of graphene stacked on each other non-epitaxially.

Semiconductor quantum dots (QDs) are fascinating systems for potential applications in quantum information processing and communication, since they can emit single photons and polarisation entangled photons pairs on demand. The asymmetry and inhomogeneity of real QDs has driven the development of a universal and fine post-growth tuning technique. In parallel, new growth methods are desired to create QDs with high emission efficiency and to control combinations of closely-spaced QDs, so-called "QD molecules" (QDMs). These systems are crucial for the realisation of a scalable information processing device after a tuning of their interaction energies. In this work, GaAs/AlGaAs QDs with low surface densities, high optical quality and widely tuneable emission wavelength are demonstrated, by infilling nanoholes fabricated by droplet etching epitaxy with different GaAs amounts. A tuning over a spectral range exceeding 10 meV is obtained by inducing strain in the dot layer. These results allow a fine tuning of the QD emission to the rubidium absorption lines, increasing the yield of single photons that can be used as hybrid semiconductor-atomic-interface. By embedding InGaAs/GaAs QDs into diode-like nanomembranes integrated onto piezoelectric actuators, the first device allowing the QD emission properties to be engineered by large electroelastic fields is presented. The two external fields reshape the QD electronic properties and allow the universal recovery of the QD symmetry and the generation of entangled photons, featuring the highest degree of entanglement reported to date for QD-based photon sources. A method for controlling the lateral QDM formation over randomly distributed nanoholes, created by droplet etching epitaxy, is demonstrated by depositing a thin GaAs buffer over the nanoholes. The effect on the nanohole occupancy of the growth parameters, such as InAs amount, substrate temperature and arsenic overpressure, is investigated as well. The QD pairs show good optical quality and selective etching post-growth is used for a better characterisation of the system. For the first time, the active tuning of the hole tunnelling rates in vertically aligned InGaAs/GaAs QDM is demonstrated, by the simultaneous application of electric and strain fields, optimising the device concept developed for the single QDs. This result is relevant for the creation and control of entangled states in optically active QDs. The modification of the electronic properties of QDMs, obtained by the combination of the two external fields, may enable controlled quantum operations.

The involvement of dynamical fluctuations in driving enzymatic processes is widely accepted. With respect to NQM tunnelling enzymes, the role of promoting motions in facilitating hydrogenic transfers is well studied. Few studies have however, specifically attributed, dedicated dynamical fluctuations characterised by their timescales and magnitudes, as a function of a reaction coordinate, to specific groups in a protein system. An effectively full suite of backbone resonance assignments were obtained for PETNR and on relevant ligand complexes. This provided an essential platform on which residue specific, backbone amide fluctuations were assessed. This thesis documents the application of pressure up to 1500 bar, in tandem with high resolution TROSY based NMR analysis, as a means of studying residue specific, conformer exchange perturbations. Residue specific amide compression profiles of the PETNR:FMN free enzyme system, and complexes with progesterone and tetrahydropyridine dinucleotides have been obtained. The binding of progesterone appears to induce conformational tightening of residues within the active site vicinity. The complexation of PETNR:FMN with tetrahydropyridine dinucleotides, appears to stimulate conformational shifts towards intermediate, and in some cases, slow exchange regimes in multiple residues about the active site vicinity. This is evidenced by extensive intensity attenuation of 1H-15N TROSY resonances, on the binding of tetrahydropyridine dinucleotides at 1 bar pressure, and on going from 1 bar to 1500 bar pressure. Multiple regions of sequence, spatially clustering about the active site vicinity within a 10 Å sphere of the FMN binding pocket, display appreciable sensitivity to ligand binding. Differential responses of residues to the application of high pressure between complexes was noted within segments of these regions. A region of sequence, named the β-hairpin flap displays significant differential compression profiles between the PETNR:FMN free enzyme system, and associated progesterone and tetrahydropyridine dinucleotide complexes. A role in mediating ligand engagement is proposed for R130 and R142 in the β-hairpin flap. A central hydrogen bonding network, perhaps constituting a putative proton wire in the active site of the PETNR:FMN:Progesterone complex, has been identified that could enable the shuttling of protons following catalytic protonation of oxidative substrate. The resonance response behaviour of G185 acts as a sensitive reporter on the formation of these interactions, revealed by an interrogation of the differences in chemical shift changes on progesterone binding, and in response to high pressure. The recruitment of high resolution crystallographic data sets readily supported a structural and dynamical interpretation of the observed chemical shift responses to ligand binding at 1 bar pressure, and on the application high pressure. A definitive atomistic identification of fast motion contribution to activation barrier compression was not obtained. Nevertheless, detailed, residue specific amide compression profiles, and shifts in backbone amide conformational exchange regimes in response to ground state ligand binding, and at high pressure, have been catalogued in the PETNR:FMN free enzyme system. These dynamical profiles in the free enzyme are contrasted against comparative, residue specific observations in analogue complexes of the oxidative and reductive half reactions of PETNR.

On-chip impedance tuning is used to overcome IC perturbations caused by packaging stress. Tuning is more important for matching networks of radio frequency (RF) systems. Possible package resonance and fabrication process variations may cause instability, which is a major problem in RF systems. Thus, precautions need to be taken in order to maintain the overall stability of components and the final system itself. Electrically erasable programmable read-only memory switches (EEPROMs) occupy less die area compared to e-fuses and microelectromechanical system (MEMS) switches, thus EEPROMs are proposed to be used as tuning switches in millimetre-wave (mm-wave) applications. It is anticipated that EEPROM switches will also enable multi-time programming because of the smaller area and the fact that more switches can be used for fine-tuning. The problem addressed in this research is how suitable EEPROMs are for switching applications in the mm-wave region. The main focus of this dissertation is to characterise the suitability of EEPROM switches qualitatively for tuning with systems operating in the mm-wave spectrum. 130 nm SiGe BiCMOS IBM 8HP process technology was used for simulation and the fabricated prototypes. The Dickson charge pump (CP), two voltage doubler CPs and four floating gate (FG) devices were investigated. Literature and theoretical verification was done using computer aided design (CAD) Cadence software through circuit analysis and the layouts were also designed for integrated circuit (IC) prototype fabrication. The qualitative evaluation of the hypothesis was based on investigating reliability issues, switching characteristics, CP output drive capability and mm-wave characterisation. The maximum measured drain current for FGs was 1.4 mA, 2.7 mA and 3 mA for devices 2, 3 and 4, respectively. The ratio between ON state switching current (after tunnelling) and OFF state switching current (after injection) was 1.5, 1.35 and 6 for devices 2, 3 and 4, respectively. The ratios correlated with the expected results in terms of FG transistor area: a high area results in a higher ratio. Despite the correlation, devices 2 and 3 may be unsuitable because the ratio is less than 2: a smaller ratio between the ON and OFF states could also result in higher losses. The Dickson CP achieved an output voltage of 2.96 V from an input of 1.2 V compared to 3.08 V as computed from the theoretical analysis and 4.5 V from the simulation results. The prototypes of the voltage doubler CP did not perform as expected: a maximum of 1 V was achieved compared to 4.1 – 5 V as in the simulation results. The suitability of FG devices for switching applications depends on the ratio of the ON and OFF states (associated to insertion and isolation losses): the larger the FG transistor area, the higher the ratio. The reliability issues are dominated by the oxide thickness of the transistor, which contributes to charge leakages and charge trapping: smaller transistor length causes more uncertainties. Charge trapping in the oxide increases the probability of leakages and substrate conduction, thus introduces more losses. Based on the findings of this research work, the FG devices promise to be suitable for mm-wave switching applications and there is a need for further research investigation to characterise the devices in the mm-wave region fully. AFRIKAANS : Impedansie-instelling op skyf word gebruik om steurings in geïntegreerde stroombane wat deur verpakkingstres veroorsaak word, te oorkom. Instelling is meer belangrik om netwerke van radiofrekwensiesisteme te paar. Moontlike verpakkingresonansie en variasies in die vervaardigingsproses kan onstabiliteit veroorsaak, wat ‟n groot probleem is in radiofrekwensiesisteme. Voorsorg moet dus getref word om die oorhoofse stabiliteit van komponente en die finale sisteem self te handhaaf. Elektries uitveebare programmeerbare slegs-lees-geheueskakelaars (EEPROMs) neem minder matrysarea op as e-sekerings en die sekerings van mikro-elektromeganiese sisteme en word dus voorgestel vir gebruik as instellingskakelaars in millimetergolfaanwendings. Daar word verwag dat EEPROM-skakelaars ook multi-tydprogrammering sal moontlik maak as gevolg van die kleiner area en die feit dat meer skakelaars gebruik kan word vir fyn instellings. Die probleem wat in hierdie navorsing aandag geniet, is die geskiktheid van EEPROMS vir skakelaanwendings in die millimetergolfstreek. The hooffokus van die verhandeling is om die geskiktheid van EEPROM-skakelaars kwalitatief te karakteriseer vir instelling met sisteme wat in die millimetergolfspektrum funksioneer. Department of Electrical, Electronic and Computer Engineering v University of Pretoria 130 nm SiGe BiCMOS IBM 8HP-prosestegnologie is gebruik vir simulasie en die vervaardigde prototipes. Die Dickson-laaipomp is gebruik vir simulasie en die vervaardigde prototipes. Die Dickson-laaipomp, twee spanningverdubbelinglaaipompe en vier swewendehektoestelle is ondersoek. Literatuur- en teoretiese verifikasie is gedoen met behulp van rekenaarondersteunde-ontwerp (CAD) Cadence-sagteware deur stroombaananalise en die uitleg is ook ontwerp vir die vervaardiging van geïntegreerdestroombaanprototipes. Die kwalitatiewe evaluasie van die hipotese is gebaseer op die ondersoek van betroubaarheidkwessies, skakelingeienskappe, laaipompuitsetdryfvermoë en millimetergolfkarakterisering. Die maksimum gemete dreineerstroom vir swewende hekke was 1.4 mA, 2.7 mA en 3 mA vir onderskeidelik toestelle 2, 3 en 4. Die verhouding tussen die AAN-toestand van die skakelstroom (na tonnelling) en die AF-toestand van die skakelstroom (na inspuiting) was 1.5, 1.35 en 6 vir toestelle 2, 3 en 4, onderskeidelik. Die verhoudings het ooreengestem met die verwagte resultate rakende die swewendehek-transistorareas: ‟n groot area het ‟n hoër verhouding tot gevolg. Nieteenstaande die ooreenstemming, mag toestelle 2 en 3 moontlik nie geskik wees nie, omdat die verhouding kleiner as 2 is: ‟n kleiner verhouding tussen die AAN- en AF-toestande mag ook hoër verliese tot gevolg hê. Die Dickson-laaipomp het ‟n uitsetspanning van 2.96 V vanaf ‟n inset van 1.2 V vergeleke met 3.08 V soos bereken volgens die teoretiese analise en 4.5 V volgens die simulasieresultate. Die prototipes van die spanningverdubbelinglaaipomp het nie gefunksioneer soos verwag is nie: ‟n maksimum van 1 V is bereik vergeleke met 4.1 – 5 V soos in die simulasieresultate. Die geskiktheid van swewendehektoestelle vir skakelingtoepassings hang af van die verhouding van die AAN- en AF-toestande (wat met invoer-en isolasieverlies geassosieer word): hoe groter die swewendehektransistorarea, hoe hoër die verhouding. Die betroubaarheidkwessies word oorheers deur die oksieddikte van die transistor, wat bydra tot ladinglekkasies en ladingvasvangs: korter transistorlengte veroorsaak meer onsekerheid. Ladingvasvangs in die oksied verhoog die moontlikheid van lekkasies en substraatgeleiding en veroorsaak dus groter verlies. Die bevindings van hierdie navorsing toon dat swewendehektoestelle waarskynlik geskik is vir millimetergolfaanwendings en verdere navorsing is nodig om die toestelle volledig in die millimetergolfstreek te karakteriseer. Copyright / Dissertation (MEng)--University of Pretoria, 2013. / Electrical, Electronic and Computer Engineering / unrestricted