Neste trabalho foi avaliada a influência das condições de processamento (pouring temperature and de vazamento e condições de isolamento térmico dos moldes cerâmicos) na formação de trincas nas palhetas de turbinas policristalinas, a base da superliga B1914, produzidas por microfusão. E devido à falta de informações sobre a superliga B1914 foram levantadas informações sobre o equilíbrio de fases (THERMOCALC) e foi realizada a caracterização microestrutural e mecânica deste material desta liga no estado bruto e tratada termicamente. Todas as palhetas vazadas a 1570, 1520 e 1470 °C em moldes sem isolamento e com isolamento parcial apresentaram trincas e outros defeitos de solidificação. Já as palhetas vazadas em moldes totalmente isolados estavam livres das trincas. No entanto foram identificados aglomerados de microporos na raíz de todas as palhetas. Os resultados de simulação de fração de fases mostraram que o equilíbrio de fases da superliga B1914 é constituído majoritariamente pelas fases γ e γ\' e pelas fases minoritárias MB2, M3B2 e sigma. A caracterização microestrutural da superliga B1914 confirmou os resultados de simulação e foram identificadas as fases gama (&#947) - dendritas e os precipitados da fase gama linha (&#947\') - no interior das dendritas e na região interdendrítica. As fases M3B2 e eram os microconstituintes do eutético. Os resultados de DTA e Scheil mostraram que o processo de solidificação, da superliga B1914, ocorreu fora de equilíbrio. Nos resultados obtidos a partir dos tratamentos térmicos, ficaram evidentes as dificuldades encontradas para solubilização das placas da fase &#947\'. A integridade estrutural dos corpos-de-prova foi comprometida pela presença de defeitos de solidificação (vazios). Tanto que os valores de LR e r obtidos nos ensaios estão muito abaixo dos valores encontrados na literatura. / This study was evaluated the influence of processing conditions (temperatures of casting conditions and thermal insulation of ceramic shells) in crack formation of equiaxed B1914 turbine blades produced by investment casting. Due to lack of information about B1914 alloy was performed microstructural and mechanical characterization of this alloy material in the raw state and treated. In shells uninsulated and partly insulated, after pouring was observed casting solidification defects. However the shells in a fully insulated were not observed casting crack formation. However were identified clusters of micropores in the root of all blades. The results of simulation phase fraction showed that the balance of phases in B1914 alloy is made mostly by γ and γ\' phases and the minority phases: MB2, M3B2 and sigma. The microstructural characterization of B1914 alloy confirmed the results of simulation and were identified: gamma (γ) - dendrites and gamma prime (γ\') - inside the dendrites and interdendritic regions. The M3B2 was found in eutectic. The results of DTA and Scheil showed that the process of solidification occurred in non-equilibrium. The results obtained from the thermal treatments showed difficulties to solubilize γ\' phase. The structural integrity of samples was compromised by the presence of solidification defects (pores). Both values of LR and εr obtained in the tests are much below the values found in literature.

The late Neolithic of North Mesopotamia has long been held up as the first example of a ‘global’ culture with aspects of shared material culture, most notably pottery styles and subsistence strategies, spread across North Mesopotamia, the Northern Levant, and parts of south-east Anatolia. Increasing research in the past twenty years has illustrated that the material similarities visible in the late Neolithic do not represent a closed cultural community, but instead reflect a network of loosely connected groups who were members of imagined communities that linked people within shared cosmologies. Since their discovery in the early decades of the twentieth century stamp seals have been treated as a type artefact of the late Neolithic (particularly one of its constituent parts the Halaf) where they have been used to argue for the presence of sealing systems based around administrative storage of personal or communal property and possibly trade relations. However, except for a thesis published in 1990, late Neolithic stamp seals have never been comprehensively studied or interpreted primarily within their own context. Instead previous studies of stamp seals have tied stamp seals into a modernist narrative of progression that implicitly culminates in modern, Western, Nation States. This research challenges and deconstructs this narrative to demonstrate there is little evidence that seals in the late Neolithic were used for administrative purposes. To this end it gathered and re-classified the available data on provenanced stamp seals using a classificatory ontology called prototype theory that allows for more reflexive classification then the existing Aristotelian classifications. The thesis argues that stamp seals were indexical symbols with their symbolism being used to link members of imagined communities within real communities across the late Neolithic ‘world’. These people were members of a perceived descent group originating in shifting relationships to place during the change from sedentary farming communities in the eighth millennium BC to more mobile communities in the seventh millennium BC. At the same time as negotiating these supra-community identities seals were also used indexically in a variety of sub-community ways being used for a variety of magical (primarily apotropaic and talismanic) uses. As part of this I argue sealing practices in the late Neolithic relate to specific events of efficacious sealing using the power in the seal’s design.

South Africa has the largest economy in Africa, with significant mining and metallurgical activities. A large fraction of the mineral assets is concentrated in the Bushveld Igneous Complex (BIC), with the western limb being the most exploited. Although the western BIC is considered to be an air pollution hotspot, inadequate air quality data currently exists for this area. To partially address this knowledge gap, a comprehensive air quality monitoring station was operated for more than two years at Marikana in the western BIC. Basic meteorological parameters, precipitation, Photosynthetic Photon Flux Density (PPFD), trace gas concentrations (SO2, NO, NOx, O3, and CO), physical aerosol parameters (particle number and air ion size distributions, as well as aerosol light absorption) and total PM10 mass concentration were measured. Compared with South African and European ambient air quality standards, SO2, NO2 and CO concentrations were generally below the air quality standards, with average concentrations for the sampling period of 3.8ppb (9.9μg/m³), 8.5ppb (15.9μg/m³) and 230ppb (270μg/m³), respectively. The major source of SO2 was identified as high-stack industry emissions, while household combustion was identified as the predominant source of NO2 and CO. In contrast, O3 exceeded the eight-hour moving average standard (61ppb / 120μg/m³) 322 times per year. The main contributing factor was identified to be the influx of regional air masses, with high O3 precursor concentrations. PM10 exceeded the current South African 24-hour standard (120μg/m³) on average 6.6 times per year, the future 2015 standard (75μg/m³) 42.3 times per year and the European standard (50μg/m³) 120.2 times per year. The PM10 average concentration for the sampling period was 44μg/m³, which exceeded the current European and future (2015) South African annual average standard (40μg/m³), emphasising the PM pollution problem in the western BIC. The main source of PM10 was identified as household combustion. / Thesis (M.Sc. (Chemistry))--North-West University, Potchefstroom Campus, 2012

Wastewater disposal often has deleterious impacts on the receiving environment. Low levels of dissolved oxygen are of particular concern. Here I investigate the impacts on dissolved oxygen and carbon chemistry of screened municipal wastewater in the marine waters off Victoria, B.C., Canada. I analyzed data from a series of undersea moorings, ship-based monitoring, and underwater remotely-operated vehicle video. I used these observations to construct a two-layer box model of the nearfield receiving environment. Despite the lack of more advanced treatment, dissolved oxygen levels near the outfalls are well above the commonly used 63 umol kg-1 hypoxic threshold and that the outfalls’ impact on water column oxygen is likely less than a few umol kg-1. Likewise, dissolved inorganic carbon is not elevated and pH not depressed compared to the surrounding region. Strong tidal currents and the cold, well-oxygenated waters of Victoria’s marine environment give these waters a high assimilative capacity for organic waste. / Graduate / 0595 / 0403 / 0543 / jeremykrogh@gmail.com

A RMN em baixo campo (RMN-BC) é uma importante ferramenta analítica que vem sendo usada para substituir os métodos clássicos de análise. As principais características da RMN-BC sobre esses métodos são: rapidez da análise, pouca ou nenhuma preparação da amostra, análise não-invasiva e não-destrutiva e não tem descarte de produtos químicos. O presente trabalho avaliou o uso da RMN-BC com sensor (ímã e sonda) unilateral (RMNU). Neste equipamento de baixo custo, a região de análise é projetada para frente do imã, o que permite analisar amostras com grande volume, diferente dos espectrômetros convencionais onde o tamanho da amostra é limitado pelo gap ou bore do ímã. Como o sensor RMNU possui um intenso gradiente de campo magnético é possível investigar o comportamento da amostra em diferentes alturas. Essa propriedade foi explorada para medir a temperatura e a difusividade térmica de sementes de macadâmia em três profundidades. Para isso fez-se uma curva de calibração com o tempo de relaxação transversal (T2) do óleo da semente versus a temperatura. Os resultados obtidos com a RMNU foram coerentes com encontrados na literatura usando sensores invasivos como termopares. Também foram realizadas análises de viscosidade de óleos lubrificantes automotivos dentro das embalagens utilizando a sequência de CPMG. Com o método foi possível discriminar se o óleo base é mineral ou sintético. O sensor RMNU não foi sensível para identificar amostras de diesel com diferentes composição e origem. Para isso usou-se espectrômetro de RMN convencional onde analisou 118 blendas de diesel/biodiesel/óleo vegetal, em que se variou a refinaria, teor de enxofre do diesel (S500 e S10), a origem do biodiesel e do óleo. Os modelos de classificação de análise multivariada apresentaram alta capacidade de distinguir as respectivas blendas. Investigou-se também o uso do acoplamento indutivo para ampliar a região de detecção do sensor a partir da sua superfície. O acoplamento permitiu aumentar da região sensível de 2 mm para 20 mm. Esse sistema foi usado para monitorar a cura de uma amostra de gesso utilizando a sequência de CPMG. / The Low-Field NMR (LF-NMR) is an important analytical tool that has been used to replace the classical methods of analysis. The main features of LF-NMR about these methods are: speed of analysis, little or no sample preparation, non-invasive and non-destructive analysis and no disposal of chemicals. This study evaluated the use of LF-NMR with sensor (magnet and probe) unilateral (UNMR). In this low cost equipment, the region of analysis is projected forward of the magnet, which allows analyzing samples in large volumes, unlike conventional spectrometers where the sample size is limited by the gap or bore of the magnet. As UNMR sensor has an intense magnetic field gradient is possible to investigate the behavior of the sample at different heights. This property has been exploited to measure the temperature and the thermal diffusivity Macadamia seed at three depths. For this became a calibration curve with the transverse relaxation time (T2) of the seed\'s oil versus temperature. The results obtained with the UNMR were consistent with the one found in literature, using invasive sensors such as thermocouples. They were also held viscosity analysis of automotive lubricants in the packaging using the CPMG sequence. With the method it was possible to discriminate whether the base oil is mineral or synthetic. The UNMR sensor was not sensitive enough to diesel samples with different composition and origin. To it was used conventional LF-NMR spectrometer, where 118 blends diesel / biodiesel / vegetable oil, as it the refinery varied, sulfur diesel (S500 and S10), the source of biodiesel and oil were analyzed. The multivariate classification models showed high ability to distinguish their blends. It was also investigated using inductive coupling to expand the sensor detection region from its surface. Coupling allowed to increase the sensitive region of 2 mm to 20 mm. This system was used to monitor the cure of plaster sample using the CPMG sequence.

Este trabalho propõe a tradução do discurso Panegírico, de autoria do ateniense Isócrates. A versão vem acompanhada de notas, que visam a fornecer um breve comentário das passagens mais importantes do texto. Um estudo introdutório, cujo primeiro capítulo pretende discutir algumas questões propostas pelo texto, tratando de sua composição, do tratamento dos fatos históricos e um breve relato das principais interpretações modernas do Panegírico. O capítulo seguinte aborda o problema dos bárbaros no Panegírico e como o retrato de Isócrates dos povos não gregos visa a reforçar as propostas feitas pelo autor em seu texto. Na parte final do estudo, examina-se a relação desse texto com obras precedentes tratando das mesmas questões que o Panegírico. / This work proposes to translate the Panegyricus, a speech by the Athenian Isocrates. Endnotes have been added, in order to comment the most important passages in the text. In addition, an introductory study is included to clarify the some points of the text, such as the problems posed by the composition of the text, its treatment of the historical facts and a brief review of the main modern interpretations of the Panegyricus. The next chapter discusses the role which the barbarians play in the Panegyricus and how Isocrates portrait of the non-Greek peoples serves the propositions advanced by the author in his text. The final part of the study examines the relation of the Panegyricus with texts treating the same questions.

No description available.

A RMN em baixo campo (RMN-BC) é uma importante ferramenta analítica que vem sendo usada para substituir os métodos clássicos de análise. As principais características da RMN-BC sobre esses métodos são: rapidez da análise, pouca ou nenhuma preparação da amostra, análise não-invasiva e não-destrutiva e não tem descarte de produtos químicos. O presente trabalho avaliou o uso da RMN-BC com sensor (ímã e sonda) unilateral (RMNU). Neste equipamento de baixo custo, a região de análise é projetada para frente do imã, o que permite analisar amostras com grande volume, diferente dos espectrômetros convencionais onde o tamanho da amostra é limitado pelo gap ou bore do ímã. Como o sensor RMNU possui um intenso gradiente de campo magnético é possível investigar o comportamento da amostra em diferentes alturas. Essa propriedade foi explorada para medir a temperatura e a difusividade térmica de sementes de macadâmia em três profundidades. Para isso fez-se uma curva de calibração com o tempo de relaxação transversal (T2) do óleo da semente versus a temperatura. Os resultados obtidos com a RMNU foram coerentes com encontrados na literatura usando sensores invasivos como termopares. Também foram realizadas análises de viscosidade de óleos lubrificantes automotivos dentro das embalagens utilizando a sequência de CPMG. Com o método foi possível discriminar se o óleo base é mineral ou sintético. O sensor RMNU não foi sensível para identificar amostras de diesel com diferentes composição e origem. Para isso usou-se espectrômetro de RMN convencional onde analisou 118 blendas de diesel/biodiesel/óleo vegetal, em que se variou a refinaria, teor de enxofre do diesel (S500 e S10), a origem do biodiesel e do óleo. Os modelos de classificação de análise multivariada apresentaram alta capacidade de distinguir as respectivas blendas. Investigou-se também o uso do acoplamento indutivo para ampliar a região de detecção do sensor a partir da sua superfície. O acoplamento permitiu aumentar da região sensível de 2 mm para 20 mm. Esse sistema foi usado para monitorar a cura de uma amostra de gesso utilizando a sequência de CPMG. / The Low-Field NMR (LF-NMR) is an important analytical tool that has been used to replace the classical methods of analysis. The main features of LF-NMR about these methods are: speed of analysis, little or no sample preparation, non-invasive and non-destructive analysis and no disposal of chemicals. This study evaluated the use of LF-NMR with sensor (magnet and probe) unilateral (UNMR). In this low cost equipment, the region of analysis is projected forward of the magnet, which allows analyzing samples in large volumes, unlike conventional spectrometers where the sample size is limited by the gap or bore of the magnet. As UNMR sensor has an intense magnetic field gradient is possible to investigate the behavior of the sample at different heights. This property has been exploited to measure the temperature and the thermal diffusivity Macadamia seed at three depths. For this became a calibration curve with the transverse relaxation time (T2) of the seed\'s oil versus temperature. The results obtained with the UNMR were consistent with the one found in literature, using invasive sensors such as thermocouples. They were also held viscosity analysis of automotive lubricants in the packaging using the CPMG sequence. With the method it was possible to discriminate whether the base oil is mineral or synthetic. The UNMR sensor was not sensitive enough to diesel samples with different composition and origin. To it was used conventional LF-NMR spectrometer, where 118 blends diesel / biodiesel / vegetable oil, as it the refinery varied, sulfur diesel (S500 and S10), the source of biodiesel and oil were analyzed. The multivariate classification models showed high ability to distinguish their blends. It was also investigated using inductive coupling to expand the sensor detection region from its surface. Coupling allowed to increase the sensitive region of 2 mm to 20 mm. This system was used to monitor the cure of plaster sample using the CPMG sequence.

In this thesis, I analyze the classical tripartite definition of knowledge. According to this definition there are three conditions for a knowledge claim to arise, namely, belief, truth and justification conditions. The main problem with this definition is even if these three conditions are satisfied one may not know a proposition p because of the fact that the justification of the proposition p may not be relevant in showing that p is true. Therefore, my primary purpose is to establish a strong conceptual connection between justification and truth conditions. To realize this, first, I defend a three-way interrelation between these three conditions. Second, I inquire as to which kind of justification should lead us to which kind of truth. To answer to this question, I postulate three kinds of realities, namely, Subjective Reality, Inter-Subjective Reality, and Allegedly Pure Reality. Furthermore, I re-define the justification condition in such way that there is a kind of whole justification and it requires both internal and external justification. According to this conception of reality and re-definition of justification there already exists a strong conceptual connection between internal justification and Subjective Reality which is completely subject-relative. And I defend the existence of such a connection also between the whole justification and Inter-Subjective Reality. Finally, I argue that no conception of justification can lead us to an Allegedly Pure Reality that the hardest version of skepticism claims to exist.

The dissertation aims to set out a methodological framework conducive to further research into the demarcation problem of logical constants through a critical examination of the principal proposals for the problem. Logical constants should be characterised so as the essential values of logic, i.e., necessity, normativity and formality, are secured. Formality is central to the proposed framework in consideration of its relation to validity / necessity and normativity are established with reference to formality. Logical constanthood is analysed into logicality and constanthood to explore the conditions and constraints on logical form. On the purpose of their determination, a Wittgensteinian stance is endorsed, focusing on the view of language as a reflexive autonomous realm. The autonomy of language unfolds a specific viewpoint that indicates that logical form is existentially grounded in the possibilities presented by the autonomy. v Gentzen&rsquo / s natural deduction and sequent calculi are adopted as the proper perspectives to discuss the relations of logicality and constanthood to formalisation. Logical constants are required to be fixed so that the resultant logical form is sterile of content and semantically inert with respect to argument content. In addition to the conditions of harmony in logical form, mutual disharmony is introduced. Analytic and grammatical truths are specified as constraints to logical form. In particular, the conservativeness condition is found to be irrelevant to logical form. The framework incorporates methodological pluralism as a probe into the understanding of logicality. The dissertation suggests a bidimensional programme of research related to formal conditions and the Wittgensteinian grammatical constraints.