While the negative effects of the terrorist attack of September 11, 2001 are still permeating throughout the United States, a few novelists have taken on the extreme task of writing about this historic event. Richard Gray describes the failure of language after the attack took place, yet novelists wanted to write about this tragedy anyway. Reading trauma in 9/11 is inevitable as it is important. In looking at three novels that deal with the events during and the aftermath of 9/11, I hope to consider the way art is used in these texts. In doing so, my thesis will look at the possibility of art being able to heal the wounds of this traumatic event. My second chapter will focus on the novel Extremely Loud and Incredibly Close by Jonathan Safran Foer. This novel depicts the effect 9/11 had on the child protagonist, Oskar, and follows him as he works through the trauma of losing his father in the South Tower. The third chapter of my thesis will discuss Don DeLillo's Falling Man, which offers a depiction of the powerful effect trauma has on the main characters in the novel, particularly Lianne. The performance artist is discussed at length. My fourth chapter will discuss the novel The Submission by Amy Waldman. Just as Maya Lin's submission for her Vietnam memorial sparked controversy, Waldman takes the same approach by casting an American Muslim as the artist and memorial architect for 9/11. While the previous novels focus on the personal effects of trauma on the characters, my chapter on The Submission will elucidate how trauma is negotiated on a national scale. I hope to answer such questions as: What do we expect in a memorial? What should we expect? What are the various demands survivors place on memorials?

The two most visible representations of Afghanistan are arguably Steve McCurry’s ‘Afghan Girl’ on the cover of National Geographic (June 1985) and Khaled Hosseini’s award-wining novel 'The Kite Runner' (2004). These two products laid the basic premise that images and ideas about Afghanistan have been circulated and commodified worldwide, especially qualities of the exotic, oppressed, and weak. Since print photography and literary works belong to the culture industry, this research seeks to enquire if performing arts, more specifically theatre, projected Afghanistan in similar ways. More precisely, this research asks how Afghan cultures and identities have been represented in the post-9/11 period. Borrowing the circuit of culture model (1997) from Stuart Hall and Paul du Gay, this research then examines ten specific theatre performances within Afghanistan and outside Afghanistan in a spatio-temporal framework illustrating dynamic tensions from, and beyond, Kabul. Case studies from Kabul illustrate that Afghan cultures can be owned and regulated by competing stakeholders, including the Taliban, within its geopolitical boundaries. Case studies from/beyond Kabul show the export of Afghan cultures and performances outside Afghanistan, underscoring tropes of impoverishment and suffering while inviting or inciting international interventions and conciliations. Case studies beyond Kabul tend to imagine ‘Afghanistan’ by offering an ambivalent, and sometimes, contradictory response to the war on terror. This thesis argues that projective closure – the act of filling in absences and gaps to make sense of an Afghan narrative – often circulates and entrenches Afghans in victimhood tropes. Because there are constant fluctuations and contestations at what ‘Afghanistan’ was, is, and should be, Afghanistan as an imagined entity – or a global cultural commodity – becomes more evident. Derek Gregory was right to observe in 'The Colonial Present' (2004) that Afghanistan has been an object of international geopolitical manoeuvrings since the nineteenth century, and, as this thesis will show, even early twenty-first century. But the claw of the “colonial present” does not stem from hostilities enacted by imperial power, but a series of intimate engagements with non-government organisations, government agencies, embassies, foreign theatre directors, and even global audiences who uncritically celebrate narratives of Afghan heroism. This is further complicated by the readiness of local Afghan practitioners to consume and project themselves as victims of war who are in ‘need’ of foreign help. As such, the value that is being demanded and supplied in the global culture industry is still victimhood. Afghan cultures and identities are deeply embedded in contexts – situational, cultural, global – and unless these contexts are collocated and layered upon each other to add nuance to interrogate cultural practices, cultural workers and theatre practitioners continue to run the risks of reproducing conflicts, even if they are beyond the geographical space of Kabul – because the locations of the ‘local’ and ‘global’ are becoming increasingly intertwined.

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L’objectif de ce travail de thèse est de mettre en évidence et de comprendre le mécanisme de synergie observé au niveau des propriétés retard au feu de polyuréthanes (PUs) intumescents par l’ajout de nanoparticules (NPs). En effet, l’addition de polyphospha te d’ammonium (APP) dans une matrice PU conduit à une amélioration de ses propriétés retard au feu. La substitution d’une petite quantité d’APP par des NPs (MgO, SiO2, octamethyl polyhedral oligomeric silsesquioxanes (OMPOSS) et or) conduit de plus à un phénomène de synergie. Il a été montré que la nature et la quantité de NPs jouent un rôle important sur les propriétés retard au feu et sur le mécanisme de protection. L’étude de la stabilité thermique des différents systèmes a premièrement mis en évidence une stabilisation entre l’APP et les NPs à l’exception de l’OMPOSS. Il a donc été proposé que la synergie intervienne en phase condensée où diverses réactions chimiques, caractérisées par RMN du solide, ont lieu lors de la dégradation des matériaux entrainant la formation d’une barrière protectrice intumescente. Les propriétés de cette barrière, telles que sa conductivité thermique, son expansion et sa morphologie, ont été étudiés dans un second temps à l’aide de techniques spécifiques développées dans le cadre de cette étude (en particulier la tomographie). Ces propriétés ont été reliées à la meilleure protection observée pour le système contenant l’APP et les NPs. La résistance mécanique de barrières intumescentes développées dans différentes conditions a finalement été étudiée mais n’intervient pas dans le mécanisme de synergie. / The purpose of this Ph.D work is to present and to understand the synergy observed in the fire performances of intumescent polyurethane (PU) formulations by the addition of nanoparticles (NP). Indeed, it was shown that the addition of ammonium polyphosphate (APP) in PU leads to interesting fire properties that can be enhanced substituting a small amount of APP by NPs (MgO, SiO2, octamethyl polyhedral oligomeric silsesquioxanes (OMPOSS) and gold). The nature and content of the NPs play an important role on the fire retardant properties and mechanisms. First, a thermal stabilization was observed between APP and the different NPs except OMPOSS. The synergy mechanism was thus attributed to a condensed phase action where a range of chemical species, characterized by solid state NMR, are created upon heating the material in different conditions. The char properties, such as thermal conductivity, expansion and morphology, were then characterized using novel techniques (in particular tomography). It was shown that they are linked with the thermal barrier effect of the residual material explaining the good fire properties obtained when combining APP and NPs. The mechanical strength of chars developed in different conditions was also investigated but do not play a significant role on the synergy mechanism.

The leach solution obtained by leaching of zinc containing ores typically has to be highly purified before it can be used as electrolyte for the electrowinning of zinc. Cobalt is a troublesome impurity in the sense that not only has it even at relatively low concentrations a very significant negative impact on the zinc electrowinning process, but that is also difficult to remove by the zinc cementation process typically used for this purpose. The aim with the present work was to better understand the arsenic activated cementation of cobalt using zinc powder to enable the optimization of an industrial purification plant. Thermodynamic based calculations confirmed that the role of arsenic in the process is to allow for the precipitation of the cobalt at more positive potentials as cobalt arsenide and that it should be possible to remove the cobalt to very low concentrations with zinc cementation. The kinetics of cobalt cementation was studied using batch cementation experiments using different sizes and quantities of zinc dust and by varying the temperature. The nature of the cementation products was characterized using scanning electron microscopy and energy dispersive spectroscopy. It was found that the cobalt cementation could be described by a first order rate equation but with a faster initial stage with an activation energy of 43 kJ/mol followed by a much slower temperature insensitive second stage. Activating species such as copper, cadmium and arsenic cemented faster than the cobalt on the zinc. The rate of cobalt cementation was increased by using the same mass of finer zinc, increasing the temperature and recirculation of some of the cemented cobalt. It was shown that the zinc dust consumption and/or the minimum temperature required to achieve the required cobalt removal could be reduced by recirculation of the cobalt cement from the early stages of a train of backmix reactors or by using zinc dust with a finer size distribution. / Dissertation (MSc)--University of Pretoria, 2014. / Materials Science and Metallurgical Engineering / unrestricted

Mobile devices have excelled in the 21st century due to the increasing popularity and continuous improvement of mobile technology. Today mobile devices have become all-in-one portable devices, providing inter-connectivity, device-to-device communication and the capability to compete with personal computers. The improved capabilities and popularity of mobile devices have, however, caught the attention of botnet developers, allowing the threat of botnets to move into the mobile environment. A mobile botnet is de fined as a collection of compromised mobile devices, controlled by a botmaster through a command and control (C&C) network to serve a malicious purpose. Previous studies of mobile botnet designs focused mostly on the C&C structure, investigating other mechanisms as potential C&C channels. None of these studies dealt with the use of a hybrid C&C structure within a mobile botnet design. This research consequently examines the problem of designing a new mobile botnet that uses a hybrid C&C structure. A model of this new hybrid design is proposed, describing the propagation vectors, C&C channels, and the topology. This hybrid design, called the Hybrid Mobile Botnet, explores the efficiency of multiple C&C channels against the following characteristics: no single point of failure must exist in the topology, low cost for command dissemination, limited network activities and low battery consumption per bot. The objectives were measured by using a prototype built according to the Hybrid Mobile Botnet model. The prototype was deployed on a small collection of mobile devices running the Android operating system. In addition, the prototype allowed for the design of a physical Bluetooth C&C channel, showing that such a channel is feasible, able to bypass security and capable of establishing a stealthy C&C channel. The successful execution of the prototype shows that a hybrid C&C structure is possible, allowing for a stealthy and cost-eff ective design. It also revels that current mobile technology is capable of supporting the development and execution of hybrid mobile botnets. Finally, this dissertation concludes with an exploration of the future of mobile botnets and the identifi cation of security steps users of mobile devices can follow to protect against their attacks. / Dissertation (MSc)--University of Pretoria, Pretoria 2014 / Computer Science / unrestricted

Objetivo: El objetivo de este estudio fue determinar la asociación entre hipertensión arterial (HTA) y síntomas depresivos, así como estimar la prevalencia de HTA y de síntomas depresivos en la población peruana. Métodos: Estudio transversal, analítico de base poblacional. Se incluyó a individuos de 18 años a más, residentes habituales de las áreas seleccionadas. La presencia de síntomas depresivos fue medida con la escala PHQ-9, mientras que la HTA se midió utilizando el promedio de dos mediciones realizadas durante la entrevista o el auto-reporte de diagnóstico previo. Se usaron modelos de regresión de Poisson con errores estándar robustos para estimar las razones de prevalencia (RP) y los intervalos de confianza al 95% (IC95%) de la asociación de interés. Resultados: Los datos de 25699 individuos fueron analizados, media de edad 44,1 (DE: 17,7) años, 54,0% de mujeres. La prevalencia de síntomas depresivos e HTA fue de 2,7% (IC95%: 2,5%-3,0%) y 21,9% (IC95%: 21,1%-22,9%), respectivamente. En el análisis multivariable, HTA no estuvo asociado a la presencia de síntomas depresivos (PR=1.16; IC95%: 0,90-1,50) después de controlar por potenciales confusores y el diseño del estudio. Conclusión: Este estudio no encontró asociación entre la presencia de HTA y de síntomas depresivos. / Objective: This study aimed to determine the association between hypertension and depressive symptoms, as well as to estimate the prevalence of both hypertension and depressive symptoms in the Peruvian population. Methods: Data from a population-based study was utilized. People aged ≥18 years and current residents of selected areas were included. The presence of depressive symptoms was measured using the PHQ-9 scale while hypertension was estimated using the mean of two measurements made during the interview. Poisson regression with robust standard errors was used to estimate prevalence ratios (PR) and confidence intervals at 95% (95% CI) for the association of interest. Results: Data from 25699 individuals were analyzed, mean age was 44.1 (DE: 17.7) years, 54.0% were females. The prevalence of depressive symptoms and HTA were 2.7% ((IC95%: 2.5%-3.0%) and 21.9% (IC95%: 21.1%-22.9%), respectively. In the multivariable analysis, HTA was not associated with the presence of depressive symptoms (PR=1.16; IC95% 0.90-1.50) after adjusting for confounders and the study design. Conclusion: This study found no association between hypertension and the presence of depressive symptoms.

Arsenic (As) exposure is associated with cancer, lung and cardiovascular disease, yet the mechanisms involved are not clearly understood. Elevated matrix metalloproteinase-9 (MMP-9) levels are also associated with these diseases, as well as with exposure to water As. Our objective was to evaluate the effects of dietary components of inorganic As (iAs) intake on serum MMP-9 concentration at differing levels of tap water As. In a cross-sectional study of 214 adults, dietary iAs intake was estimated from 24-h dietary recall interviews using published iAs residue data; drinking and cooking water As intake from water samples and consumption data. Aggregate iAs intake (food plus water) was associated with elevated serum MMP-9 in mixed model regression, with and without adjustment for covariates. In models stratified by tap water As, aggregate intake was a significant positive predictor of serum MMP-9 in subjects exposed to water As≤10 μg/l. Inorganic As from food alone was associated with serum MMP-9 in subjects exposed to tap water As≤3 μg/l. Exposure to iAs from food and water combined, in areas where tap water As concentration is ≤10 μg/l, may contribute to As-induced changes in a biomarker associated with toxicity.

Una mirada a las NIIF 15, y sus efectos financieros bajo en contexto del Covid 19.