The mechanisms and timescales associated with the triggering of caldera-forming eruptions remain ambiguous and poorly constrained. Do such eruptions start vigorously, then escalate, or can there be episodicity? Are they triggered through internal processes (e.g. recharge, buoyancy), or can external modulations play an important role? Key to answering these questions is the ability to reconstruct the state of the magma body immediately prior to eruption. My dissertation research seeks to answer these questions through detailed investigation of four voluminous caldera-forming eruptions: (1) 650 km3, 0.767 Ma Bishop Tuff, Long Valley, (2) 530 km3, 25.4 ka Oruanui eruption, Taupo, (3) 2,500 km3, 2.08 Ma Huckleberry Ridge Tuff, Yellowstone and (4) 250 km3, 26.91 Ma Cebolla Creek Tuff, Colorado. The main techniques I applied integrated glass geochemistry (major, trace and volatile), diffusion modeling, and detailed field sampling. In chapters two, three, and four these methods are applied to the initial fall deposits of three supereruptions (Bishop, Oruanui and Huckleberry Ridge) that preserve field-evidence for different opening behaviors. These behaviors range from continuous deposition of fall deposits and ignimbrite (Bishop), to repetitive start/stop behavior, with time breaks between eruptive episodes on the order of weeks to months (Oruanui, Huckleberry Ridge). To reconstruct the timescales of opening activity and relate this to conduit processes, I used two methods that exploit diffusion of volatiles through minerals and melt, providing estimates for the rate at which magmas ascended to the surface. This knowledge is then integrated with the pre-eruptive configuration of the magma body, based on melt inclusion chemistry, to interpret what triggered these systems into unrest. Finally, in chapter five I take a different approach by integrating geochemical data for melt inclusions and phenocryst minerals to test whether the mechanism of heat and volatile recharge often called upon to trigger crystal-rich dacitic magmas (the so-called monotonous intermediates), is applicable to the Cebolla Creek Tuff. This dissertation includes both previously published and unpublished co-authored material, and three online supplementary excel files.

In the mammalian retina, a small population of retinal ganglion cells are intrinsically photosensitive due to the expression of the photopigment melanopsin. These intrinsically photosensitive retinal ganglion cells (ipRGCs) integrate their own intrinsic light response with that of rod and cone photoreceptors to drive a variety of physiological and behavioural responses to light. Recently, however, a subset of these cells have been shown to project to the dorsal Lateral Geniculate Nucleus (dLGN) of the visual thalamus, where they directly contribute to visual perception. In the case of retinal degenerations (the most common being retinitis pigmentosa which affects up to 1:2000 people worldwide), the death of the rod and cone photoreceptors results in complete visual blindness with no available treatment. At least some ipRGCs survive retinal degeneration and can continue signalling light information to the dLGN, suggesting that these cells could support some form of visual perception. However, to-date little is known about this projection during retinal degeneration. Thus, characterising its anatomy and physiology is key to determining the quality of visual information that is conveyed to the dLGN during retinal degeneration and what prevents these cells supporting behaviourally relevant vision. A subset of ipRGCs target the dLGN and continue signalling light information even at advanced stages of retinal degeneration. However, it is unknown whether all ipRGC subtypes survive following the death of rod and cone photoreceptors, and whether they retain normal dendritic architecture following reorganisation of the remnant neural retina. We set out to answer these questions using the multi-colour labelling technique Brainbow. In doing so, we design and describe a unique methodology and toolset, based on Principal Component Analysis (PCA), to analyse 3-Dimensional (3D) multi-colour images. We then demonstrate its utility by identifying, isolating and reconstructing the 3D morphology of individual ipRGCs from a population of labelled cells in the degenerate retina and quantitatively characterise their dendritic architecture. The results indicate that all known ipRGC subtypes are resilient to the effects of outer photoreceptor degeneration. Melanopsin responses in the dLGN have been shown to support global brightness perception in mice with advanced retinal degeneration. However, to-date, it is unknown whether these cells can encode spatial information. Using in-vitro and in-vivo electrophysiological recordings from mice in advanced stages of retinal degeneration, we demonstrate for the first time that ipRGCs in the retina, and their target neurones in the dLGN, possess discrete spatial receptive fields. These receptive fields are large and lack a centre-surround organisation. The retinotopic organisation of these cells' projections would suggest they could support spatial vision. However the poor temporal resolution of the deafferented melanopsin response is the most significant limitation precluding melanopsin signalling from supporting behaviourally relevant vision under naturalistic viewing conditions. Considering these temporal limitations, we finally investigated if melanopsin could contribute to visual perception at earlier stages of degeneration which is more representative of clinical conditions in humans. Here, vision can rely on both the intrinsic melanopsin-driven light response and residual cone function. Using silent substitution in combination with in-vivo electrophysiological recordings from the dLGN of mice in early-stage degeneration, we identify a number of cone-driven responses which could support normal visual function. However, we were unable to detect a significant and robust contribution of melanopsin signalling to these residual light-responses using our silent substitution stimuli in both retinally degenerate and wildtype mice at these age. However, we did find a significant contribution to the Olivary Pretectal Nucleus (OPN) of visually intact mice at equivalent ages, and to the adult dLGN. Supported by anatomical data, this suggests that there is a specific temporal delay in the maturation of ipRGCs which project to the dLGN during development of the visual system.

Este trabalho descreve a adaptação de um equipamento CNC e ferramentas computacionais CAD/CAM (desenvolvidas originalmente para a área de usinagem) na conformação de chapas de alumínio comercialmente puro, através do processo de estampagem incremental. Através das simulações e dos testes reais foi possível obter resultados práticos, relativos às limitações geométricas e ao acabamento superficial. As peças conformadas têm o formato básico de um tronco de cone, onde foram alterados a profundidade e o ângulo do cone. A análise dimensional das peças, comparadas com seu respectivo modelo CAD revelou razoável conformidade geométrica. Por outro lado, ângulos de parede maiores que 65° causaram o rompimento da chapa. As estampagens foram realizadas em um centro de usinagem, e utilizaram-se como valores máximos a velocidade de avanço de 2.200 mm/min e o incremento vertical de 1mm, por questões de segurança e também pela constatação de problemas de acabamento superficial e de vibrações excessivas do equipamento. Como conclusão final, foi demonstrado que, para o tipo específico de peça (material, espessura e geometria), dispositivo prensa-chapas, ferramentas, equipamento CNC e softwares utilizados, o processo de estampagem incremental seria viável para lotes de até 600 peças. / This paper describes the adaptation of a CNC equipment and CAD/CAM computational tools (originally developed for the machining area) on the conformation of sheets of commercially pure aluminum, through the process of incremental forming. Through simulations and tests were unable to get practical results, for the geometric constraints and surface finishing. Forming parts have the basic format of a truncated cone, which have changed the depth and angle of the cone. A dimensional analysis of the parts, compared with their CAD model showed geometric reasonable compliance. Moreover, the wall angles greater than 65 ° caused the breaking of the plate. The sheets formings were performed in a machining center, with a maximum speed of advance of 2,200 mm/min and the vertical increase of 1mm, for reasons of safety and also for finding finishing surface problems and the excessive vibration equipment. As final conclusion, it was demonstrated that, for the specific type of piece (material, thickness and geometry), device-press plates, tools, CNC equipment and software used, the process of incremental sheet forming feasible for batches of up to 600 pieces.

1 The crime of habitual drunkenness under s. 360 of the Criminal C. Abstract The aim of this diploma thesis is to analyze complexly the problems associated with the legal regulation of the crime of drunkenness. The crime of habitual drunkenness or otherwise called the "Rauschdelikt" is an illustrative option of how to deal with the issue of an insane people, which act unlawfully and how to punish them. The person which commits an unlawful act in a state of insanity, committed an act of otherwise criminal, quasi-delict. Where the perpetrator has caused a state of insanity by consuming or applying an addictive substance. The above-mentioned concept of "Rauschdelikt" appears to be the best option, for the sake of consistency with the fundamental principles and principles of criminal law, the nullum crimen sine culpa principle. The thesis is organized in individual chapters, which are gradually dealing with the historical development, and this crime does not present in modern criminal law no novelty; on the contrary, the institute of drunkenness has deep historical roots. The following chapters analyzes some individual basic terms that are necessary for the definition of a crime of habitual drunkenness and include and clarify the legal institutes that are close to and closely related to this crime, such as the...

Este trabalho descreve a adaptação de um equipamento CNC e ferramentas computacionais CAD/CAM (desenvolvidas originalmente para a área de usinagem) na conformação de chapas de alumínio comercialmente puro, através do processo de estampagem incremental. Através das simulações e dos testes reais foi possível obter resultados práticos, relativos às limitações geométricas e ao acabamento superficial. As peças conformadas têm o formato básico de um tronco de cone, onde foram alterados a profundidade e o ângulo do cone. A análise dimensional das peças, comparadas com seu respectivo modelo CAD revelou razoável conformidade geométrica. Por outro lado, ângulos de parede maiores que 65° causaram o rompimento da chapa. As estampagens foram realizadas em um centro de usinagem, e utilizaram-se como valores máximos a velocidade de avanço de 2.200 mm/min e o incremento vertical de 1mm, por questões de segurança e também pela constatação de problemas de acabamento superficial e de vibrações excessivas do equipamento. Como conclusão final, foi demonstrado que, para o tipo específico de peça (material, espessura e geometria), dispositivo prensa-chapas, ferramentas, equipamento CNC e softwares utilizados, o processo de estampagem incremental seria viável para lotes de até 600 peças. / This paper describes the adaptation of a CNC equipment and CAD/CAM computational tools (originally developed for the machining area) on the conformation of sheets of commercially pure aluminum, through the process of incremental forming. Through simulations and tests were unable to get practical results, for the geometric constraints and surface finishing. Forming parts have the basic format of a truncated cone, which have changed the depth and angle of the cone. A dimensional analysis of the parts, compared with their CAD model showed geometric reasonable compliance. Moreover, the wall angles greater than 65 ° caused the breaking of the plate. The sheets formings were performed in a machining center, with a maximum speed of advance of 2,200 mm/min and the vertical increase of 1mm, for reasons of safety and also for finding finishing surface problems and the excessive vibration equipment. As final conclusion, it was demonstrated that, for the specific type of piece (material, thickness and geometry), device-press plates, tools, CNC equipment and software used, the process of incremental sheet forming feasible for batches of up to 600 pieces.

O propósito deste trabalho é a modelagem experimental e estudo do controle do processo de hidroconformação de tubos. Assim, o trabalho visa o projeto e a construção de um dispositivo servo-controlado de hidroconformação de tubos com um sistema de controle digital. O trabalho compreende o projeto e a construção de um dispositivo a ser acoplado em uma prensa hidráulica, a instrumentação dos equipamentos usados e a implantação do sistema de controle automático do processo através de um computador PC e de placas de interface A/D e D/A. Os aplicativos de controle foram desenvolvidos em linguagem de alto nível no sistema operacional Windows. No projeto do aplicativo, inicialmente foram realizadas rotinas para testes do sistema em malha aberta. As demais rotinas são aquelas associadas às funções matemáticas do modelo fenomenológico do sistema de hidroconformação, aquelas destinadas ao controlador de malha fechada. O tipo de estratégia de controle a ser utilizada foi definida no decorrer do projeto e foi baseada em um modelo de processo não linear, linearizado em torno de cada ponto de operação. Para fins de obtenção do modelo nominal para o controlador, os atuadores e sensores tiveram suas dinâmicas desprezadas face a dinâmica do processo e suas curvas de processo foram levantadas experimentalmente. / This works aims is the experimental modeling of a tube hydroforming (THF) “T” branch, and de THF process automatic control study. Thus, the design and the construction of a servo-controlled hydraulic device for THF, with a automatic digital control system, is embedded in our objectives. Design and construction of device to append on a hydraulic press, implantation of the measurement equipment and implementation of the control system algorithms through a PC with I/O interface boards is necessary. Control algorithms were developed in Hi-level language for windows operating system. The application design was based on experimental initial tests performed with no feed-backing controlling mode. Routes related to phenomenological mathematical model of the THF process were validate against the literature database, and were devoted to the feed-backing controller mode. Control strategy to employ in final application was defined during the process calibration, based on the non-linear characteristics of the “T” branch THF. To obtain the final load path model sensors and cylinders had their dynamics neglected because the THF dynamic is very much higher, and had their behavior curves experimentally raised.

Este trabalho descreve a adaptação de um equipamento CNC e ferramentas computacionais CAD/CAM (desenvolvidas originalmente para a área de usinagem) na conformação de chapas de alumínio comercialmente puro, através do processo de estampagem incremental. Através das simulações e dos testes reais foi possível obter resultados práticos, relativos às limitações geométricas e ao acabamento superficial. As peças conformadas têm o formato básico de um tronco de cone, onde foram alterados a profundidade e o ângulo do cone. A análise dimensional das peças, comparadas com seu respectivo modelo CAD revelou razoável conformidade geométrica. Por outro lado, ângulos de parede maiores que 65° causaram o rompimento da chapa. As estampagens foram realizadas em um centro de usinagem, e utilizaram-se como valores máximos a velocidade de avanço de 2.200 mm/min e o incremento vertical de 1mm, por questões de segurança e também pela constatação de problemas de acabamento superficial e de vibrações excessivas do equipamento. Como conclusão final, foi demonstrado que, para o tipo específico de peça (material, espessura e geometria), dispositivo prensa-chapas, ferramentas, equipamento CNC e softwares utilizados, o processo de estampagem incremental seria viável para lotes de até 600 peças. / This paper describes the adaptation of a CNC equipment and CAD/CAM computational tools (originally developed for the machining area) on the conformation of sheets of commercially pure aluminum, through the process of incremental forming. Through simulations and tests were unable to get practical results, for the geometric constraints and surface finishing. Forming parts have the basic format of a truncated cone, which have changed the depth and angle of the cone. A dimensional analysis of the parts, compared with their CAD model showed geometric reasonable compliance. Moreover, the wall angles greater than 65 ° caused the breaking of the plate. The sheets formings were performed in a machining center, with a maximum speed of advance of 2,200 mm/min and the vertical increase of 1mm, for reasons of safety and also for finding finishing surface problems and the excessive vibration equipment. As final conclusion, it was demonstrated that, for the specific type of piece (material, thickness and geometry), device-press plates, tools, CNC equipment and software used, the process of incremental sheet forming feasible for batches of up to 600 pieces.

This study explored the narratives people living with sickle cell disorder construct to explain how the experience of employment influences their identity and subsequently their quality of life. Nine individuals with sickle cell disorder were interviewed and gave detailed autobiographical narratives which were transcribed and processed using narratives analysis. Participants were 4 men and 5 women aged between 22 and 60 years. Participants' passion for their job roles was illustrated by their positive work identities. Earlier experiences were felt to be influential on drive and resilience to work challenges. In the narratives, poor understanding of sickle cell disorder by organisations and reduced ability to manage their condition impacted physical health; psychological and emotional wellbeing; social and cultural experiences. This study has implications for the clinical practice and future research of adults living with sickle cell disorder, contributing to the broadening general understanding of sickle cell disorder.

Abstract Peroxisomes are small oxidative organelles found in all eukaryotes. They contain a matrix which is surrounded by a single membrane and consists mainly of soluble proteins. Peroxisomal enzymes are involved in a broad spectrum of metabolic pathways including conversion of lipids, amino- and hydroxyacids, purines and reactive oxygen species. The carbon fluxes through peroxisomal pathways require a continuous metabolite crossing of the peroxisomal membrane. A long-standing and still unresolved problem of the physiology of mammalian peroxisomes is the role of the membrane of these organelles as a permeability barrier to solute molecules. In this study, we have shown that the peroxisomal membrane represents a type of biomembrane where channel-forming proteins coexist with solute transporters. Disruption of the mouse Pxmp2 gene, encoding the peroxisomal integral membrane protein Pxmp2 also known as PMP22, leads to partial restriction of peroxisomal membrane permeability to solutes in vitro and in vivo. Multiple-channel recording of liver peroxisomal preparations revealed that the channel-forming components with a conductance of 1.3 nS in 1.0 M KCl were lost in Pxmp2-/- mice. The channel-forming properties of Pxmp2 were confirmed with recombinant protein expressed in insect cells and with native Pxmp2 purified from mouse liver. The Pxmp2 channel, with an estimated diameter of 1.4 nm, shows weak cation selectivity and no voltage dependence. The long-lasting open states of the channel indicate its functional role as a protein forming a general diffusion pore in the membrane. Hence, Pxmp2 is the first peroxisomal pore-forming protein identified, and its existence suggests that the mammalian peroxisomal membrane is permeable to small solutes, while transfer of bulky metabolites, e.g., cofactors (NAD/H, NADP/H, and CoA) and ATP, requires specific transporters. In addition, the phenotypic characterisation of Pxmp2-/- mice has revealed a role for Pxmp2 during the development of the epithelia in the mammary glands of female mice. The disruption of Pxmp2 leads to the impairment of ductal outgrowth of mammary glands at puberty, which is followed by the inability of Pxmp2-/- mice to nurse their offspring.

Some metals, such as Ti-6Al-4V, have a high elongation to failure when strained at certain rates and temperatures. Superplastic forming is the utilisation of this property, and it can be used to form thin, geometrically complex components. Superplastic forming is a slow process, and this is one of the reasons why it is an expensive manufacturing process. Localised thinning occurs if the specimen is strained too quickly, and components with locally thin wall thickness fail prematurely. The goal of this study is to find a technique that can be used to minimise the forming time while limiting the minimum final thickness. The superplastic forming process is investigated with the finite element method. The finite element method requires a material model which describes the superplastic behaviour of the metal. Several material models are investigated in order to select a material model that can show localised thinning at higher strain rates. The material models are calibrated with stress-strain data, grain size-time data and strain rate sensitivity-strain data. The digitised data from literature is for Ti-6Al-4V with three different initial grain sizes strained at different strain rates at 927 C. The optimisation of the forming time is done with an approximate optimisation algorithm. This algorithm involves fitting a metamodel to simulated data, and using the metamodels to find the optimum instead of using the finite element model directly. One metamodel is fitted to the final forming time results, and another metamodel is fitted to the final minimum thickness results. A regressive radial basis function method is used to construct the metamodels. The interpolating radial basis function method proved to be unreliable at the design space boundaries due to non-smooth finite element results. The non-smooth results are due to the problem being path dependent. The final forming time of the superplastic forming of a rectangular box was successfully minimised while limiting the final minimum thickness. The metamodels predicted that allowing a 4% decrease in the minimum allowable thickness (1.0 mm to 0.96 mm) and a 1 mm gap between the sheet and the die corner the forming time is decreased by 28.84%. The finite element verification indicates that the final minimum thickness reduced by 3.8% and that the gap between the sheet and the die corner is less than 1 mm, resulting in the forming time being reduced by 28.81%. / Dissertation (MEng)--University of Pretoria, 2017. / Mechanical and Aeronautical Engineering / MEng / Unrestricted