[Truncated abstract] Pesticides are often transported to streams and/or groundwater as a result of the occurrence of rainfall events which trigger surface runoff or rapid preferential flow through the unsaturated zone. Much of the theory of solute transport has been derived assuming steady state or slowly varying upper boundary conditions and continuous, averaged process descriptions. However, a review of pesticide dynamics reveals that pesticides are episodically transported, predominantly through discrete flow pathways and this transport is often initiated as a near surface process, driven by naturally variable and intermittent rainfall intensities. The objective of the thesis is to better understand how the structure of natural variability of rainfall intensities impacts upon pesticide transport by these fast flow processes. We first conducted an analysis of a lysimeter leaching experiment that was aimed at identifying the rainfall controls on herbicide transport. Multivariate analyses revealed that average water balance behaviour at low temporal resolution controlled water and bromide transport while extreme rainfall events and rainfall event frequency controlled herbicide transport. A minimalist event based modelling approach was able to simulate the observed herbicide transport without or with only minor calibration. ... Finally we conduct a climate based regional risk assessment of pesticide leaching for the Wheatbelt region of the south-west of Western Australia. This is done for a suite of pesticides on a single soil to evaluate the impact of rainfall variability alone. Moderately sorbing, slowly degrading solutes have a greater regional potential for rapid leaching than both strongly and weakly sorbing solutes. High leaching potentials are found along the western and southern coast and in the far-east, with a band of low leaching potential through the central Wheatbelt. This is despite higher annual rainfall in the central areas compared to the east, and it is found that this occurs because of a change in the dominant fast flow triggers from frequent low intensity rainfall on the coasts to high intensity infrequent storms in the east. The coefficient of variation of annual leaching loads is similarly distributed. Spatial patterns of leaching potential depend upon chemical properties and application time. Peak loads of chemicals to fast flow pathways are found to converge to mid-winter, indicating periods of high loads of multiple pesticides may be an unavoidable consequence of the seasonality of storm properties.

Poor indoor air quality is a source of adverse health effects. TiO2 coatings deposited on well-illuminated surfaces, such as window panes, can be used to fully mineralize indoor air pollutants by photocatalysis. In such applications it is important to ensure stable photocatalytic activity for a wide range of operating conditions, such as relative humidity and temperature, and to avoid deactivation of the catalyst. In this thesis photocatalytic removal of the indoor-pollutant acetaldehyde (CH3CHO) on nanostructured TiO2 films is investigated, and in particular it is proposed how such films can be modified and operated for maximum performance. Catalyst deactivation can be reduced by purposefully changing the surface acidity of TiO2 by covalently attaching SO4 to the surface. Moreover, the overall photocatalytic activity on anatase TiO2 films can be improved by increasing the fraction of exposed reactive {001} surfaces, which otherwise are dominated by {101} surfaces. In the first part of the thesis mode-resolved in-situ FTIR is used to elucidate the reaction kinetics of CH3CHO adsorption and photo-oxidation on the TiO2 and SO4 – modified TiO2 surfaces. Surface concentrations of main products and corresponding reaction rates were determined. Formate is the major reaction product, whose further oxidation limits the complete oxidation to gaseous species, and is responsible for photocatalyst deactivation by site inhibition. The oxidation reaction is characterized by two reaction pathways, which are associated with two types of surface reaction sites. On the sulfate modified TiO2 catalyst fewer intermediates are accumulated, and this catalyst resists deactivation much better than pure TiO2. A hitherto unknown intermediate – surface-bound acetaldehyde dimer with an adsorption band at 1643 cm−1 was discovered, using interplay between FTIR spectroscopy and DFT calculations. The second part of the thesis treats the effect of increasing the relative abundance of exposed {001} facets on the photocatalytic activity of anatase TiO2 films prepared by DC magnetron sputtering. A positive effect was observed both for liquid-phase photo-oxidation of methylene blue, and for gas-phase photocatalytic removal of CH3CHO. In both cases it was found that the exposed {001} surfaces were an order of magnitude more reactive, compared to the {101} ones. Furthermore, it was found that the reactive films were more resilient towards deactivation, and exhibited almost unchanged activity under varying reaction conditions. Finally, a synergetic effect of SO4 – modification and high fraction of exposed {001} surfaces was found, yielding photocatalysts with sustained high activity. The results presented here for facet controlled and chemically modified TiO2 films are of interest for applications in the built environment for indoor air purification and as self-cleaning surfaces. / GRINDOOR

FERREIRA, Francicleber Martins. Expressividade e complexidade em lógicas preferenciais, híbridas e de grau limitado. 2012. 130 f. Tese (Doutorado em ciência da computação)- Universidade Federal do Ceará, Fortaleza-CE, 2012. / Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-07-20T11:58:10Z No. of bitstreams: 1 2012_tese_fmferreira.pdf: 772301 bytes, checksum: b1e1a404221e38ffb8e0712513749a4c (MD5) / Approved for entry into archive by Rocilda Sales (rocilda@ufc.br) on 2016-07-25T11:47:07Z (GMT) No. of bitstreams: 1 2012_tese_fmferreira.pdf: 772301 bytes, checksum: b1e1a404221e38ffb8e0712513749a4c (MD5) / Made available in DSpace on 2016-07-25T11:47:07Z (GMT). No. of bitstreams: 1 2012_tese_fmferreira.pdf: 772301 bytes, checksum: b1e1a404221e38ffb8e0712513749a4c (MD5) Previous issue date: 2012 / We investigate the model theory of Preferential Logics, Hybrid Logic and fragments of Second-Order Logic with respect to finite models. The semantics of these logics differ from the semantics of classical logics either by using relations between models or by restricting the cardinality of the models considered. This work has three main parts. In the first part of this work we study the model theory of preferential logics. Preferential logics arise in the context of nonmonotonic reasoning in Artificial Intelligence. The main characteristic of those logics is the existence of a relation between models. It allows the definition of a nonmonotonic consequence relation by considering the minimal models of a set of sentences. Using the approach of Abstract Model Theory we generalize some expressiveness results to classes of preferential logics. We show that whenever a class of minimal models of a finite set of sentences is axiomatizable, without considering the preference relation, then it is finitely axiomatizable. We also show that when such class of minimal models implicitly defines a symbol, then the finite axiomatization can be put in a very specic form, namely, the initial set of sentences plus a explicit definition for the symbol. In the second part of this work, we investigate the finite model theory of Hybrid Logic. Hybrid Logics are extensions of modal logics with hybrid terms which refer to single states in a Kripke model. We study the complexity of the model- and frame-checking problems for Hybrid Logic. We show that for each graph problem in the Polynomial Hierarchy and each natural number n there is a formula which expresses this problem for graphs of cardinality n. We also show that the size of such formulas is bounded by a polynomial in n. We show that one can disregard the global modalities if one consider only connected graphs with loops. We define fragments which correspond to each degree of the Polynomial Hierarchy. This leads to an alternative proof of the NP-hardness of the model-checking problem for an specic fragment of Full Hybrid Logic. In the last part of this work, we explore the descriptive complexity of the logic obtained by restricting second-order quantication to relations of bounded degree. Based on previous work from Schwentick et al. and Grandjean and Olive, we introduce the Bounded-Degree Second-Order Logic and show that it captures the class ALIN of classes of unary structures accepted by a alternating random access machine in linear time and bounded number of alternations. We also extend this logic with the transitive closure operator on high-order relations on bounded-degree relations. We show that the Bounded-Degree Second-Order Logic with Transitive Closure Operator captures linear number of registers in a nondeterministic random access machine provided that registers store values bounded by a linear function in the cardinality of the input structure. / Nós investigamos a teoria dos modelos de Lógicas Preferenciais, Lógica Híbrida e fragmentos da Lógica de Segunda-Ordem com relação a modelos finitos. A semânticas dessas lógicas diferem da abordagem clássica pelo uso de relações entre modelos ou por restringir a cardinalidade dos modelos a cardinais finitos. Este trabalho tem três partes. Na primeira parte deste trabalho nós estudamos a teoria dos modelos de lógicas preferenciais. Lógicas preferenciais surgem no contexto do raciocínio não-monotônico em Inteligência Artificial. A principal característica dessas lógicas é a existência de uma relação entre modelos. Isso permite a definição de uma relação de consequência não monotônica considerando-se os modelos minimais de um conjunto de sentenças. Usando a abordagem da Teoria dos Modelos Abstrata, nós generalizamos alguns resultados de expressividade para classes de lógicas preferenciais. Nós mostramos que sempre que uma classe de modelos minimais de um conjunto finito de sentenças é axiomatizável, então tal classe é finitamente axiomatizável. Nós mostramos que se tal classe define implicitamente um símbolo do vocabulário, existe uma axiomatização finita de uma forma particular, a saber, o conjunto finito de sentenças inicial mais uma definição explícita para o símbolo definido. Na segunda parte desse trabalho, nós investigamos a teoria dos modelos finitos da Lógica Híbrida. Lógicas Híbridas são extensões da lógica modal através de termos híbridos que se referem a estados individuais em um modelo de Kripke. Nós estudamos a complexidade computacional dos problemas de model- e frame- checking para a Lógica Híbrida. Nós mostramos que para cada problema de grafos na Hierarquia Polinomial e cada número n, existe uma fórmula que exprime esse problema para grafos de cardinalidade n. Nós mostramos que o tamanho das fórmulas é limitado por um polinômio em n. Nós mostramos que podemos abrir mão das modalidades globais se nos limitarmos a grafos conexos com loops. Nós definimos fragmentos da Lógica Híbrida que correspondem a cada nível da Hierarquia Polinomial. Isso nos leva a uma prova alternativa da NP-dificuldade do problema de model-checking para um fragmento específico de da Lógica Híbrida. Na última parte desse trabalho, nós exploramos a complexidade descritiva da lógica obtida ao restringirmos a quantificação de segunda-ordem a relações de grau limitado. Baseados em trabalhos anteriores de Schwentick et al. e de Grandjean e Olive, nós introduzimos a Lógica de Segunda-Ordem de Grau Limitado e mostramos que ela captura a classe ALIN de classes de estruturas unárias aceitas por uma máquina de acesso randômico em tempo linear e um número fixo de alternâncias dependente apenas do problema. Nós estendemos essa lógica com o operador de fecho transitivo sobre relações de ordem superior sobre relações de grau limitado. Nós mostramos que a Lógica de Segunda- Ordem de Grau Limitado com Fecho Transitivo captura quantidade linear de registradores em uma máquina de acesso randômico não-determinística onde os valores armazenados em cada registrador durante a computação são limitados por uma função linear na cardinalidade da estrutura de entrada.

The ecological value and the value of ecosystem services of the former military area in Čtyři Dvory in České Budějovice was evaluated in this thesis. The expert method of BVM (?Biotope Valuation Method?) and the Replacement Cost method (cost of technological alternative to ecosystem function) according to Seják et al. (2003, 2010) were applied. Four ecosystem services were evaluated: climatic service (evapotranspiration), little water cycle, oxygen production, and the support of biodiversity. For comparison, the sale price of the area and the ?recreation? value calculated by the contingent valuation (CV) method were also evaluated. The estimated sale price was 837 million CZK, which was by twelve-times higher than the ecological value estimated by the BVM method. Most of the area (57 %) was formed by the biotop XK4 ? pioneer shrub vegetation of atropogenic noncultivated areas with 13 points per m2. The most valuable biotop was V2.2 ? periodic waters with 44 points per m2, which formed 1.5 % of the examined area. The estimated value of ecosystem services was 1 372 millions CZK per year. The realization of all the planned construction projects on the examined area would lead to the depression of the ecological value according to the BVM method by 19.5 millions CZK and the depression of the value of the formerly mentioned four ecosystem services by 459 millions CZK.

Ce travail de thèse porte sur l’étude de divers mécanismes de fragilisation d’un acier inoxydable supermartensitique 16Cr-4Ni à basse teneur en carbone (Virgo™38) utilisé pour la fabrication des compresseurs centrifuges produits par GE Oil&Gas.Il a été montré que la microstructure fine, polyphasée et morphologiquement très complexe de cet alliage était sensible aux conditions de traitement thermique. Notamment, la proportion et la répartition de l’austénite de réversion, la présence de carbure de chrome et la ségrégation intergranulaire d’éléments fragilisant tel que le phosphore ont été mis en évidence suite à plusieurs traitements thermiques. La ségrégation du phosphore aux joints de grain (SPJG) est l’un des mécanismes entrainant la fragilisation du Virgo™38 sous certaines conditions de traitement thermique.La présence d’austénite de réversion n’entraine pas seulement une amélioration de la ténacité de l’alliage mais également le piégeage de l’hydrogène dans cette phase. Etant donnée la grande instabilité mécanique de l’austénite, sa transformation sous contrainte provoque la libération de cet hydrogène piégé et ainsi une surconcentration locale en hydrogène. La fragilisation par hydrogène est le deuxième mécanisme entrainant la fragilisation du Virgo™38 étudié dans cette thèse.Les mécanismes mis en jeu lors de la formation de l’austénite de réversion conduisent à la répartition hétérogène des éléments d’alliage. L’une des conséquences de cette répartition hétérogène est la corrosion sélective de l’une ou l’autre des phases de l’alliage en fonction du pH de l’environnement et de la charge appliquée. La dissolution préférentielle est le dernier mécanisme abordé. / This PhD thesis is focused on the study of embrittlement mechanisms in a 16Cr-4Ni low carbon supermartensitic stainless steel (Virgo™38) used for the construction of rotating parts of centrifugal compressors produced by GE Oil&Gas.It is shown that the morphologically complex multiphase microstructure of this alloy is very sensitive to the heat treatment conditions. In particular, the fraction and repartition of retained austenite, the presence of chromium carbides and the phosphorous grain boundary segregation (PGBS) are evidenced consecutive to several heat treatments. PGBS is one of the mechanisms leading to brittle failure of Virgo™38 after specific heat treatments.The presence of retained austenite is not only beneficial for toughness but also leads to hydrogen trapping in this phase. Due to the mechanical instability of retained austenite, its transformation under applied stress leads to the release of trapped hydrogen into newly formed martensite and thus to a local overconcentration of hydrogen. Hydrogen embrittlement is the second mechanism studied in this report.Mechanisms involved during the formation of retained austenite lead to the heterogeneous repartition of alloying elements (partitioning). One of the consequences being the selective dissolution of one or the other phase of the alloy as a function of the pH of the environment and of the load applied. Preferential dissolution is the third mechanism studied.

Cette étude a pour but la mise au point d'un procédé de dépôt en vue de réaliser des fibres piézoélectriques. Ces fibres pourront être utilisées soit comme jauge de déformation (extensomètre) soit comme système de récupération d'énergie liée au mouvement d'un utilisateur (tissu) pour alimenter un dispositif d'électronique embarqué. Une fibre piézoélectrique constituée d'un dépôt cylindrique d'oxyde de zinc sur un fil d'acier inoxydable a été réalisée par pulvérisation magnétron à impulsion de haute puissance (HiPIMS) à l'aide d'un prototype de traitement au défilé conçu, réalisé et décrit lors de cette étude. Une caractérisation précise des échantillons réalisés dans différentes conditions expérimentales a permis de décrire et comprendre en partie les mécanismes de croissance des dépôts, ceci de manière, en particulier, à déterminer les conditions de fonctionnement optimum pour l'élaboration de dépôts possédant une orientation cristalline préférentielle hors plan. Pour envisager le traitement de fibres ne supportant pas les hautes températures nous avons montré qu'il était possible de contrôler cette température en ajustant certains paramètres du procédé, tel que la pression et la puissance moyenne. Un mécanisme de germination préférentielle suivi d'une croissance par auto-épitaxie a été proposé afin d'expliquer la très forte orientation préférentielle des films réalisés à faible température. Pour des fortes valeurs de courant crête, le phénomène de germination préférentielle associé à la croissance évolutionnaire pourrait favoriser l'orientation (101)*. Pour les plus fortes valeurs de courant, aucune orientation préférentielle n'est observée et les fortes contraintes mesurées ont été attribuées à l'excès d'oxygène détecté dans les couches / A piezoelectric fiber constituted of ZnO cylindrical coating on a stainless steel wire has been achieved by High Power Impulse Magnetron Sputtering (HiPIMS) by using a prototype designed and assembled during this PhD work. The piezoelectric fiber can be used as a strain probe or as a vibration harvesting generator for embedded electronics. The analyses of deposited layer allow to understand ZnO growth mechanism in order to optimize to deposition process. A special emphasis has been placed on the selection of preferential orientation during the growth. The low volume of steel wire, allow to control his temperature by adjusting some process parameters, like the pressure and the average power. Temperature sensitive wires (e.g. polymer) can be treated in the mildest conditions. Preferential nucleation followed by self-epitaxy have been proposed to explain the very strong preferential orientation identified in coatings deposited at low temperature. At high peak current, preferential nucleation and evolutionary growth can promote the (101)* orientation. At highest peak currents no preferential orientation was identified and the high residual stress has been attributed to the excess of oxygen in the coating

As relações entre a União Europeia (UE) e os seus parceiros comerciais incluem Acordos Preferenciais de Comércio (APCs) com países em desenvolvimento para produtos agrícolas e industriais, destacando-se países da África, Caraíbas e Pacífico. A política de caráter cooperativo no setor agrícola da APC-UE, possui por objetivo a preservação do ambiente, segurança alimentar, crescimento econômico e desenvolvimento sustentável. Excetuando-se esses Acordos Preferenciais, a União Europeia possui no setor agrícola um dos segmentos de maior proteção comercial. Trata-se do principal mercado para os produtos agrícolas brasileiros. No entanto, esse setor, no Brasil, poderia obter melhor desempenho caso a UE não praticasse tarifas de importação elevadas aos seus produtos. Assim sendo, aplica-se no presente trabalho o modelo gravitacional para mensurar o efeito de criação ou desvio de comércio, resultado da aplicação de tarifas pela União Europeia com relação aos seus 48 parceiros comerciais selecionados, incluindo-se o Brasil, e também o impacto de um possível Acordo Preferencial de Comércio entre Brasil e União Europeia. A análise enfoca os efeitos para um grupo selecionado de produtos agrícolas, que recebem a incidência de picos tarifários, incluindo-se carne bovina congelada, carne bovina fresca, carne de frango, carne suína, açúcar bruto e suco de fruta. O período considerado para a análise compreende os anos de 1996 a 2013, ou seja, desde o alargamento da União Europeia no ano de 1995. O modelo gravitacional é estimado por meio do modelo de efeitos fixos e os resultados mostram a existência de desvio de comércio com relação às importações europeias de carne bovina fresca (SH 0202) e carne suína (SH 0203) e impacto positivo da concretização de um Acordo Preferencial de Comércio para carne bovina fresca (SH 0201), carne bovina congelada (SH 0202) e carne de frango (SH 0207). Tais resultados confirmam as hipóteses levantadas na literatura com relação à consolidação do referido acordo. Ou seja, os resultados indicam que o Brasil pode aumentar suas exportações de produtos agrícolas para a União Europeia caso ocorra um acordo preferencial que elimine as barreiras tarifárias impostas pelo bloco da UE. / Trade relations between the European Union (EU) and its trading partners have feature for the granting of tariff reduction or exemption for developing countries, through preferential agreements. With regard to preferential trade agreements (PTA) put in place by the European Union, stands out those performed with the group of African, Caribbean and Pacific (ACP) countries for agricultural and industrial products. The cooperative nature of politics in the ACP-EU agricultural sector has the objective of preserving the environment, food security, economic growth and sustainable development. Except for some preferred sealed agreements with some countries, the European Union has in the agricultural sector, one of the segments most subject to trade protection. With regard to Brazil, the European Union is the main market for its agricultural products. Even so, the Brazilian agricultural sector could have a better performance if the EU did not ascribe excessively high import tariffs to their products. Therefore, a gravity model is used in this analysis to measure the effect of trade creation or trade diversion as a result of the tariff applied by the European Union in relation for 48 selected trading partners, including Brazil and also the impact of a possible Preferential Trade Agreement between Brazil and the European Union. The analysis focuses on the effects for a selected group of agricultural products receiving the incidence of tariff peaks, including frozen beef, fresh beef, chicken, pork, raw sugar and fruit juice The period considered for the analysis covers the years from 1996 to 2013, which incorporates the enlargement of the European Union starting at 1995. The gravity model is estimated using the fixed effects model and the results show the existence of trade diversion with respect to European imports of fresh beef (HS 0202) and pork (HS 0203) and positive impact of the implementation of a Preferential Trade Agreement for fresh beef (HS 0201), frozen beef (HS 0202) and chicken (HS 0207). These results confirm the hypotheses rose in the literature with regard to the consolidation of the Agreement. That is, the results indicate that Brazil could increase its exports of agricultural products to the EU in the event of a preferential agreement eliminating tariff barriers imposed by the EU bloc.

A América do Sul, na história recente, foi palco de diversas ações de integração regional relacionadas ao comércio, influenciando os posicionamentos dos países em matéria de políticas de comércio interncional bem como formando um emaranhado de relações que se sobrepõe muitas vezes de formas antagônicas. Neste contexto, a presente dissertação aborda o histórico das principais blocos regionais que envolvem a América do Sul como base para mostrar a atual fragmentação deste subcontinente em três visões principais de política de comércio internacional, sendo uma visão intermediária caracterizada pelo Brasil e acompanhada pelos membros do MERCOSUL em uma vertente regional-multilateralista. Em um extremo estão Venezuela, Equador e Bolívia, representantes da ALBA, com seus governos de posicionamento extremo-nacionalista. E em posição antagônica a estes estão Chile, Peru e Colômbia, que conformam o eixo liberal-bilateralista. Objetivando comprovar que há uma tendência de fortalecimento da visão liberal-bilateralista na região será feito um estudo com base nas suas principais formas de atuação, ou seja, por meio da análise de Acordos Preferenciais de Comércio, mais especificamente FTAs bilaterais celebrados com países de distintas regiões com foco especial ao período imediatamente após a eclosão da crise de 2008, de 2009-2014. Finalmente, se a hipótese se confirmar, restando evidenciada a retomada do posicionamento bilateralista, após período de predominância da visão multilateralista na América do Sul, é importante apontar os desafios para o Brasil neste cenário. / South America, in recent history, has had several regional integration actions related to trade, influencing the countries positions in terms of international trade policies as well as forming a tangle of relationships that often overlaps with contrary views. In this context, this thesis addresses the history of the main regional blocs involving South America as a basis to show the current fragmentation of this subcontinent in three main views of international trade policy, with an intermediate vision characterized by Brazil and followed also by members of the MERCOSUR in a regional-multilateralist position. At one extreme, the countries Venezuela, Ecuador and Bolivia, ALBA representatives, present their extreme-nationalist position. And in an antagonistic position, Chile, Peru and Colombia constitute the liberal-bilateralist axis. In order to prove that there is a trend towards the strengthening of the liberal-bilateralist vision in the region, a research based on analysis of Preferential Trade Agreements will be held, focusing bilateral FTAs concluded with different countries regions with special attention to the period immediately after the outbreak of the 2008 crisis, from 2009 to 2014. Finally, if the hypothesis is confirmed, demonstrating the resumption of the bilateralist position after a period in which the multilateralist vision was predominant in South America, it is important to point the challenges of this scenario for Brazil.

Esta tese aborda o desenvolvimento da regulação internacional sobre o comércio de serviços educacionais, em especial nos acordos preferenciais de comércio de Austrália, Chile, China, Cingapura, Estados Unidos, Índia e União Europeia. O seu objetivo foi avaliar o atual nível de liberalização comercial da educação superior no plano global, de modo que sua compatibilidade com o direito à educação pudesse ser criticamente analisada, assim como os seus possíveis impactos sobre a regulação da educação superior no Brasil. Para tanto, a pesquisa começa pela realização de entrevistas com atores que acompanham o processo de comercialização da educação superior no Brasil. Os passos seguintes envolvem a compreensão do funcionamento das disciplinas internacionais sobre o comércio de serviços, da formulação das posições no processo negociador e, finalmente, dos compromissos em serviços de educação superior em acordos preferenciais de comércio. Uma primeira hipótese é de que, mesmo sem acordos de comércio, o mercado brasileiro já se encontra significativamente liberalizado no que diz respeito aos investimentos estrangeiros em educação superior, sem qualquer restrição ao ingresso de capital internacional. Ainda assim, a regulação internacional do comércio de serviços aprofundaria esse processo a partir da ideia de consolidação do marco regulatório liberal doméstico e de mecanismos que conduzem à aceleração do processo de liberalização comercial. / This thesis analyses the development of international regulation on trade in educational services, especially in preferential trade agreements signed by Australia, Chile, China, Singapore, United States, India and the European Union. The goal was to determine a parameter of the current global level of trade liberalization on higher education, so that the compatibility between trade agreements and the right to education could be critically examined, as well as their possible impacts on the regulation of higher education in Brazil. Therefore, the research began by conducting interviews with professionals that accompany the commercialization process in the Brazilian higher education sector. The following steps involved understanding the operation of international disciplines on trade in services, the formulation of positions in the negotiating process, and finally, the commitments on higher education services in preferential trade agreements. A first hypothesis is that, even without trade agreements, the Brazilian market is already significantly liberalized regarding foreign investment on higher education, without any restriction on the inflow of international capital. Even so, international regulation on trade in services would deepen this process from an idea of consolidation of a liberal domestic regulatory framework and mechanisms leading to accelerate trade liberalization process.

Doctor of Philosophy / Department of Chemistry / Mark D. Hollingsworth / The ferroelastic urea inclusion compound (UIC) of 2,10-undecanedione/urea exhibits a striking pseudoelastic memory effect. Although pseudoelasticity is possible for UICs containing only 2,10-undecanedione, introduction of a structurally similar guest impurity (2-undecanone) gives rise to rubber-like behavior, a form of pseudoelasticity. This phenomenon depends on both the crystal strain and the concentration of monoketone: above 13-14% 2-undecanone, pseudoelastic behavior is observed reliably, even at strains as high as 2.4%. The dramatic change in ferroelastic behavior over a small range of impurity content indicates that this is a critical threshold phenomenon. Because the impurity concentration has such a dramatic effect on domain switching, it was important to determine the sector-dependent patterns of incorporation of this relaxive impurity. Preliminary HPLC analyses of guest populations suggest that preferential incorporation of monoketone guests occurs between nonequivalent growth sectors, and that these patterns can be rationalized using a symmetry specific growth model. Birefringence mapping and HPLC studies of optically anomalous UICs containing mixtures of 2,9-decanedione and 2-decanone (which possess trigonal metric symmetry) suggest analogous patterns in guest incorporation and/or ordering that can also be rationalized. Although crystals of 2,9-decanedione/urea exhibit no ferroelastic strain at ambient temperature, they exhibit a proper ferroelastic phase transition near -170[degrees]C. It is proposed that differential perfection of domains gives rise to pseudoelasticity in UICs, and that relaxive impurities play an important role in the energetics of this process. Because ultrafast video studies of domain reversion kinetics demonstrate no clear correlation of observed rates with impurity content, it is proposed that the relaxive impurities facilitate spontaneous domain reversion by annealing stressed defect sites that would otherwise lead to irreversible or plastic domain switching. Following earlier work using synchrotron white beam X-ray topography, the driving force for domain reversion is thought to involve the presence of nanoscopic twins whose strain is epitaxially mismatched with neighboring daughter domains. The behavior of these nanoscopic twins was monitored with in-situ X-ray diffraction studies of stressed crystals, and this has led to a more thorough understanding of the role of these nanoscopic twins in the ferroelastic domain switching and rubber-like behavior in this class of materials.