This project investigates the moisture barrier properties of bio-based polymers and ways of improving them. The first section addresses the effect of crystallinity on the water permeability of poly(lactic acid) (PLA). The second section investigates PLA/talc composites and PLA/ montmorillonite nanocomposites. The third section is focused on a new polymer, polybutylene succinate (PBS), and its nanocomposites with montmorillonite. In the first section, the water vapour transmission rates (WVTR) through samples of polylactic acid of different crystallinities have been measured. Three different grades of commercial PLA were used with different ratios of L-lactide and D-lactide to give a range of crystallinities from 0 to 50%. Sheets of PLA were prepared by melt compounding followed by compression moulding and annealing at different temperatures and for different times to give the range of crystallinities required. Crystallinity was measured by differential scanning calorimetry (DSC) and the morphology of the samples was observed under crossed polars in a transmitted light microscope. Water vapour transmission rates through the films were measured at 38°C and at a relative humidity of 90%. It was found that the measured values of WVTR decreased linearly with increasing crystallinity of the PLA from 0 to 50%. The results are discussed in terms of the effect of crystallinity on solubility and shown to fit the tortuous path model. The model was also successfully used to explain published data on water permeability of polyethylene terephthalate. In the second section, a series of PLA/talc composites and PLA/ montmorillonite nanocomposites were prepared by melt compounding followed by compression moulding. The morphologies of the composites were investigated using transmission electron microscopy (TEM) and wide-angle X-ray diffraction (WAXD) and it was found that the fillers were well dispersed in the polymer matrix. The average aspect ratio of the compounded talc was found to be 8, and that of the nanoclay was found to be 50. Water vapour transmission rates (WVTR) through the films were measured at 38°C and at a relative humidity of 90%. It was found that the measured values of WVTR decreased with increasing filler content and the results gave good agreement with predictions from the Nielsen tortuous path model. In the third section, PBS/ montmorillonite nanocomposites were prepared by melt compounding followed by compression moulding. The melting and crystallisation behaviour of the pure PBS samples were investigated using differential scanning calorimetry (DSC) and cross polarised optical microscopy. A slight decrease of the degree of crystallinity was found in PBS containing 5% nanoclay. The morphology of the composites was investigated using transmission electron microscopy (TEM) and wide-angle X-ray diffraction (WAXD) and it was confirmed that that composite structures were intercalated. Water vapour transmission rates (WVTR) through the PBS sheets were measured using a MOCON Permatran-W®398. The measured values of WVTR decreased with increasing nanoclay content. However, the experimental values were all higher than the values predicted by the Nielsen tortuosity model. This result shows that in the case of PBS, which is a highly crystalline polymer, the nanoclay is not as well dispersed and is not as effective in reducing water vapour permeability as in the case of PLA.

During the production of paper in paper mills, detrimental wood resin is released into the water circuit of the mill during the pulping process of the wood into fibres. This wood resin, termed pitch, can detrimentally deposit on the paper and on the paper machine equipment. The deposits mark the paper or can lead to a tear of the paper web involving a loss of output and a reduction in paper quality. Furthermore, the wood resinous compounds in paper mill effluents need to be reduced in order to minimise their toxic effects on water organisms. Talc has been the benchmark for many years as a mineral additive in pitch control. Since the papermaking process has changed over the years, the concept of mineral addition needs to be redefined and adopted towards the new circumstances. By understanding the fundamentals behind the adsorption of wood resin compounds from aqueous systems on to talc new mineral additives can be developed. A model for the determination of the aspect ratio of platy and rod-like particles has been developed, based on commonly available characterisations such as particle size, specific surface area and shape. It was found that the adsorption capacity of a mineral is directly proportional to its specific surface area, but only within its mineral family. Including the effect of surface hydrophilicity and hydrophobicity allowed fine tuning of the adsorption capacity of newly developed calcium carbonate grades. Furthermore, size exclusion effects, in porous, high surface area modified calcium carbonate, were seen to hinder complete coverage of the surface area by wood resin. With increasing pH, the adsorption efficiency of talc for colloidal wood resin was found to decrease. Under these alkaline conditions, which are common in modern paper making processes, talc preferentially adsorbed dissolved species. The use of the newly developed surface treated and modified calcium carbonates allowed more efficient adsorption of the colloidal fraction and, therefore, represent an efficient alternative to talc in pitch control. An increase in temperature led to an increased adsorption capacity of talc. This observation indicates the type of interaction tat controls the adsorption of hydrophobic pitch particles onto talc, i.e. the entropically favoured release of water from the hydrophobic talc surface as well as the hydrophobic methylene backbone of the hemicellulose.

Tourist destinations have been under a significantly growing interest of academia from the second half of the 20th century. The underlying patterns that are shared by destinations’ past, and shapes their future constitute a good share for the context of this interest. This study applies Butler’s Tourist Area Life-Cycle model to an urban tourism destination, Umeå. The model puts the life of a tourism area (destination) on an s-curve and defines several stages on the curve with designated features. Application of the model to the case of Umeå is limited to accommodation branch of the hospitality industry to apply a comprehensive approach and it shows that the city is in the development stage for in this particular branch. However, there are some divergences in the case compared to the model. The capacity edge that causes pressure to the tourist destinations growth does not appear where the model expects, and some stage features appear to take place in a different sequence than the original model. Consequently, the study connects these divergences to the fact that Umeå is an urban destination and also offers a modified version of the model that might be a good alternative for applications on other urban tourist destinations.

Introdução: A pleurodese com talco é o método mais popular para controle sintomático do derrame pleural maligno recidivante. A administração intrapleural do talco pode ser por videotoracoscopia ou dreno de tórax e qual o melhor método é uma questão controversa. Ainda que a expansão pulmonar seja um dos principais critérios de sucesso do procedimento, suas características pós-pleurodese ainda são pouco estudadas. Objetivo: Avaliar a expansão pulmonar após dois diferentes métodos de pleurodese com talco (dreno de tórax ou videotoracoscopia) em pacientes com derrame pleural maligno recidivante, considerando a evolução radiológica, diferença entre os métodos e correlação com desfecho clínico. O objetivo secundário foi comparar ambos os métodos quanto a: efetividade clínica, segurança, qualidade de vida e sobrevivência. Método: Estudo prospectivo randomizado que incluiu 60 pacientes (45 Mulheres, 15 Homens, idade média: 55,2 anos) com derrame pleural maligno recidivante entre janeiro de 2005 e janeiro de 2008. Os pacientes foram alocados em dois grupos: videotoracoscopia com insuflação de talco (VT) ou instilação de talco por dreno de tórax (DT). A expansão pulmonar imediata e a evolução da expansão pulmonar foram avaliadas através de tomografias de tórax obtidas nos primeiros 7 dias, 1, 3 e 6 meses após a pleurodese, as quais foram analisadas por dois observadores independentes. Efetividade clínica (considerada como ausência de necessidade de novos procedimentos pleurais durante o seguimento), complicações, tempo de drenagem e de internação hospitalar e qualidade de vida (questionários gerais e específicos) foram também analisados. A análise estatística foi realizada através dos testes de Qui-quadrado e Fisher para as variáveis categóricas e Mann-Whitney para variáveis contínuas não paramétricas. A sobrevivência foi analisada através do método de Kaplan- Meier e o teste de log-Rank para foi usado para identificar fatores que interferissem na sobrevida. Os resultados dos questionários de qualidade de vida foram avaliados através de ANOVA de duplo-fator. Resultados: Não houve diferença significativa entre os grupos nas variáveis clínicas préoperatórias. A expansão imediata total (>90%) foi observada em 27 (45%) pacientes e foi mais freqüente no grupo VT (60 vs. 30%, p=0.027). Durante o seguimento, 71% dos pacientes estudados tiveram melhora ou ao menos mantiveram a expansão pulmonar observada na 1ª tomografia, fato que ocorreu de forma semelhante entre os grupos (p=0,58). Novos procedimentos pleurais foram necessários em 9(15%) pacientes (5 recidivas no grupo VT e 4 no grupo DT, p=0.999). Não foram encontradas diferenças entre os grupos quanto a: complicações, tempo e de internação. A análise dos questionários de qualidade de vida revelou resultados semelhantes para ambos os grupos. A expansão pulmonar imediata não se correlacionou com recidiva radiológica, recidiva clínica ou complicações (p= 0.60, 0.15 e 0.20, respectivamente). A sobrevida após ambos os procedimentos foi semelhante, porém a ocorrência de recidivas foi um fator relacionado a sobrevida mais curta (p=0,02). Conclusão: Expansão pulmonar imediata parcial foi freqüente, particularmente no grupo DT. Contudo, manutenção do quadro radiológico e até melhora radiológica ocorreram na maioria dos casos. Não foi encontrada correlação entre expansão pulmonar imediata e desfecho clínico neste estudo. / Introduction: Talc pleurodesis is the most popular method to control recurrent malignant pleural effusion symptoms. Two methods may be used to deliver talc into the pleural space: videothoracoscopy or talc slurry through a chest tube ; which is the best method is still controversial. Although lung expansion is the most accepted pleurodesis outcome variable, its features are poorly studied. Objective: To analyze and compare radiological lung expansion after talc pleurodesis performed either by videothoracoscopy or chest tube and correlate it with clinical outcome. Secondary endpoints evaluated were: clinical efficacy, safety, quality of life and survival. Methods: Prospective randomized study that included 60 patients (45 Female, 15 Male, mean age: 55,2 years) with recurrent malignant pleural effusion, between January, 2005 and January, 2008. They were enrolled into two groups: videothoracoscopic talc poudrage (VT) and talc slurry through a chest tube (TS). Lung expansion was evaluated through chest CT scans obtained in the first 7 days and 1, 3 and 6 months after pleurodesis. All examinations were revised by two independent observers. Clinical efficacy (considered as lack of new procedures during follow up), complications, drainage duration, hospital stay and quality of life (general and specific questionnaires) were also analyzed. Categorical variables were compared with the Chi-Square test or Fisher´s exact test for small samples. Mann-Whitney test was used to compare continuous non parametric variables. Survival curves were calculated according to the Kaplan-Meier method and Log-rank test was used to identify factors that could interfere with survival. Double factor ANOVA was used to compare quality of life questionnaires results. Results: No significant difference in pre-procedure clinical variables was observed between groups. Postoperative lung expansion was total (>90%) in 27 (45%) patients and was more frequent in VT group (60% vs. 30%, p=0.027). During follow-up 71% of the patients showed unaltered or improved lung expansion and lung expansion evolution was similar in both groups (p=0.58). Nine (15%) patients needed new pleural procedures (5 recurrences in VT group and 4 in DT group, p=0.999). No statistical difference was found between groups regarding complications, drainage time and hospital stay. Quality of life questionnaires were evaluated but no difference between study arms was observed. There was no correlation between initial lung expansion and clinical recurrence, radiological recurrence or complications (p = 0.60, 0.15 and 0.20, respectively). No difference in survival between study arms was observed, but a shorter survival was observed in patients that developed clinical recurrence (p=0.02). Conclusion: Immediate partial lung expansion was a frequent finding and was more frequent in TS group. However, maintenance of the radiological image and even radiological improvement occurred in most cases. No correlation between immediate lung expansion and clinical outcome was found in this study

Neste trabalho foi realizado o estudo térmico, cinético e dielétrico durante a cura de um compósito constituído de uma matriz de resina epóxi-anidrido e de talco como carga modificadora das características dielétricas e mecânicas da matriz polimérica. Foram analisadas também as propriedades dinâmicas mecânicas e morfológicas dos compósitos completamente curados. O interesse na investigação das características térmicas, cinéticas e dielétricas visou encontrar correlação entre essas características e as propriedades dinâmicas mecânicas finais dos compósitos. Foram estudados os compósitos com diferentes concentrações de carga, variando de 0 a 10% m/m, utilizando as técnicas de calorimetria exploratória diferencial (DSC), de análise dielétrica (DEA), análise termomecânica dinâmica (DMTA) e análise por microscopia eletrônica de varredura (MEV). Os resultados da análise DSC foram analisados por método isotérmico (modelo de Sourour-Kamal modificado) e por método dinâmico (modelo isoconversional). Os resultados da análise da cura dos compósitos mostraram que a concentração da carga retarda o processo de cura, conforme observado pela análise dielétrica; a temperatura de transição vítrea do compósito curado apresentou valores mínimos nas concentrações de 7 e 10%, enquanto que a análise térmica dinâmica previu que a energia de ativação aumenta com o grau de conversão. Os resultados da análise termomecânica dinâmica mostraram o aumento no módulo de armazenamento a 25ºC de 2,1 GPa (0% talco) a 3,3 GPa (10% talco), indicando haver o efeito reforçador do talco sobre a matriz polimérica. As micrografias dos compósitos foram um excelente recurso para estudar suas morfologias e se correlacionam com os resultados cinéticos e mecânicos. / In this work we performed the thermal, kinetics, dielectrical and morphological studies on the curing of a hybrid composite material composed of epoxy-anhydride matrix and talc as modifier agent of the dielectrical and mechanical properties of the polymer matrix. It also was studied the dynamic mechanical properties of the full-cured composite materials. This investigation aimed to correlate the thermal, kinetics, and dielectrical characteristics of the curing material with their final mechanical properties. Composite materials with different talc concentrations were studied in the range from 0% up to 10% w/w, employing the Differential Scanning Calorimetry (DSC), the Dielectric Analysis (DEA), Dynamic Mechanical Thermal Analysis (DMTA) and Microscopy Electron Scanning (SEM) techniques. The DSC experimental results were analyzed through the isothermal method (Modified Sourour-Kamal model) and the dynamic method (Isoconversional model). The cure analysis results of the composite specimens showed the talc acting as a cure retardant as observed from DEA results; the glass transition temperature of the full-cured composite materials showed minimum values at talc concentrations of 7 and 10%, while the dynamic thermal analysis predicted the activation energy is increasing with the conversion degree. The DMTA results exhibited the storage modulus at 25ºC increases from 2.1 GPa for the matrix without talc up to 3.3 GPa at 10% talc concentration composite, thus indicating the reinforcement role of the talc on the polymer matrix. The composites micrographs were an excellent resource for study their morphologies and for correlation of kinetics and mechanical results.

Os silicones requerem várias caraterísticas e requisitos para seu uso na confecção de próteses faciais, principalmente, referente a textura da pele; para alcançar essa meta devem ser adicionados outros materiais. O objetivo deste trabalho foi avaliar as propriedades mecânicas de um silicone nacional RTV. de cura acética, disponível no mercado, adicionando silicato de magnésio (talco). O material foi estudado em seu estado original e com acréscimo de 10% e 20% de silicato de magnésio. Foi submetido a testes de alongamento de ruptura, resistência à tração ou tensão de ruptura e de resistência ao rasgamento. Após a avaliação individual dos corpos de prova, obteve-se uma média total de cada grupo e submeteu-se a estudo comparativo frente aos resultados obtidos por meio de análise de variância (ANOVA) e teste de Tukey. O silicone em estado original mostrou-se mais resistente ao alongamento. O silicone com adição de 10 % de silicato de magnésio modificou suas propriedades mecânicas e obteve maior resistencia à tração. O silicone com adição de 20 % de silicato magnésio obteve maior resistência ao rasgamento. O silicone em que foi adicionado 10 % de silicato de magnésio de maneira geral obteve os valores mais significativos nas três propriedades testadas, o que indica que adicionando mais de 10 % diminui as propriedades mecânicas gradualmente, tornando-se inversamente proporcionais. / The silicones request many characteristics and requirements for the use in the making of facial prostheses. To reach that objective other materials should be added. The aim of this work was to evaluate the mechanical properties of a national acetic cure silicone RTV, available in the market, adding silicate of magnesium (talc). The material was studied in your natural state and with increment of 10% and 20% of silicate of magnesium. It was submitted to tests of elongation and break, tensile strength and tear strength. After the individual evaluation of the specimens, it was obtained measured total of the each group and submitted to study comparative front to the results obtained through variance analysis (ANOVA) and Tukey test. The silicone in been original it showed to be more resistant to the elongation. The silicone with addition of 10% of silicate of magnesium modified your mechanical properties and obtained larger tear resistance. The silicone with addition of 20% of silicate magnesium obtained larger resistance to the tear strength. The silicone in witch it added 10% of silicate of magnesium in general obtained the more significant values in the three tested properties; that means that the increment of more than 10% lesses the properties gradually, becoming inversely proportional.

The goal of this thesis is to evaluate the current state of Bedřichov from the perspective of tourism and draw the attention to the threats and opportunities stemming from its potential further development. This thesis employs the Tourism Area Life Cycle (TALC) model, firstly applied to Bedřichov itself and later compared to Špindlerův Mlýn. This method allows for the analysis of the current position of Bedřichov in its life cycle as well as its expected development. The outcome of this thesis should be beneficial in the evaluation of further development in Bedřichov with respect to the ecological sustainability in the region.

Neste trabalho foi realizado o estudo térmico, cinético e dielétrico durante a cura de um compósito constituído de uma matriz de resina epóxi-anidrido e de talco como carga modificadora das características dielétricas e mecânicas da matriz polimérica. Foram analisadas também as propriedades dinâmicas mecânicas e morfológicas dos compósitos completamente curados. O interesse na investigação das características térmicas, cinéticas e dielétricas visou encontrar correlação entre essas características e as propriedades dinâmicas mecânicas finais dos compósitos. Foram estudados os compósitos com diferentes concentrações de carga, variando de 0 a 10% m/m, utilizando as técnicas de calorimetria exploratória diferencial (DSC), de análise dielétrica (DEA), análise termomecânica dinâmica (DMTA) e análise por microscopia eletrônica de varredura (MEV). Os resultados da análise DSC foram analisados por método isotérmico (modelo de Sourour-Kamal modificado) e por método dinâmico (modelo isoconversional). Os resultados da análise da cura dos compósitos mostraram que a concentração da carga retarda o processo de cura, conforme observado pela análise dielétrica; a temperatura de transição vítrea do compósito curado apresentou valores mínimos nas concentrações de 7 e 10%, enquanto que a análise térmica dinâmica previu que a energia de ativação aumenta com o grau de conversão. Os resultados da análise termomecânica dinâmica mostraram o aumento no módulo de armazenamento a 25ºC de 2,1 GPa (0% talco) a 3,3 GPa (10% talco), indicando haver o efeito reforçador do talco sobre a matriz polimérica. As micrografias dos compósitos foram um excelente recurso para estudar suas morfologias e se correlacionam com os resultados cinéticos e mecânicos. / In this work we performed the thermal, kinetics, dielectrical and morphological studies on the curing of a hybrid composite material composed of epoxy-anhydride matrix and talc as modifier agent of the dielectrical and mechanical properties of the polymer matrix. It also was studied the dynamic mechanical properties of the full-cured composite materials. This investigation aimed to correlate the thermal, kinetics, and dielectrical characteristics of the curing material with their final mechanical properties. Composite materials with different talc concentrations were studied in the range from 0% up to 10% w/w, employing the Differential Scanning Calorimetry (DSC), the Dielectric Analysis (DEA), Dynamic Mechanical Thermal Analysis (DMTA) and Microscopy Electron Scanning (SEM) techniques. The DSC experimental results were analyzed through the isothermal method (Modified Sourour-Kamal model) and the dynamic method (Isoconversional model). The cure analysis results of the composite specimens showed the talc acting as a cure retardant as observed from DEA results; the glass transition temperature of the full-cured composite materials showed minimum values at talc concentrations of 7 and 10%, while the dynamic thermal analysis predicted the activation energy is increasing with the conversion degree. The DMTA results exhibited the storage modulus at 25ºC increases from 2.1 GPa for the matrix without talc up to 3.3 GPa at 10% talc concentration composite, thus indicating the reinforcement role of the talc on the polymer matrix. The composites micrographs were an excellent resource for study their morphologies and for correlation of kinetics and mechanical results.

Cette étude porte sur la cristallochimie du manganèse dans les silicates ferromagnésiens, clino-amphiboles et phyllosilicates 2:1, abordée par voie expérimentale en milieu hydrothermal, sous différentes conditions de température, de pression, et de fugacité d'oxygène qui conditionnent ses états de valence. La caractérisation des phases et assemblages obtenus a été réalisée par diffraction des rayons X, microsonde électronique, microscopie électronique à balayage, absorption optique, analyses thermogravimétriques, spectrométries infrarouge et Raman, et spectrométrie d'absorption X (EXAFS).<br /><br />Le manganèse, qui possède plusieurs états de valence, se traduisant par des valeurs de rayon ionique variées, est susceptible d'occuper différents sites dans les silicates ferromagnésiens, comme dans les oxydes et bien d'autres composés.<br /><br /> Dans les clino-amphiboles, de type trémolite, et de type richtérite prise comme modèle des clino-amphiboles sodi-calciques, comme dans les phyllosilicates 2:1, talc, phlogopite et clintonite, l'importance des contraintes stériques sur la capacité d'incorporation du manganèse et sa possible distribution dans les différents sites des structures concernées a été démontrée. La multiplicité des sites aptes à accueillir le manganèse permet sa distribution sur l'ensemble des sites octaédriques M1,2,3 et antiprisme pseudo-cubique M4 des clino-amphiboles, comme des phyllosilicates 2:1 en sites M1 et M2 et potentiellement en position interfoliaire. <br /><br /> Cette étude montre que le manganèse divalent peut effectivement se distribuer sur l'ensemble des sites M dans la manganocummingtonite, équivalent manganifère de la trémolite. Dans les clino-amphiboles de type richtérite, synthétisées en conditions oxydantes, la présence du manganèse en sites octaédriques M1,2,3 provoque un changement d'état de valence 2+ ® 3+, qui entraîne une non-protonation locale voire totale de l'amphibole, comme dans la ungarettiite, NaNa2( )Si8O22O2, décrite dans le milieu naturel, et dont les conditions de stabilité ont été déterminées au cours de ce travail.<br /><br />De même, dans les phyllosilicates, on montre la possibilité d'occupation de différents sites par Mn2+, les sites M, mais aussi le site interfoliaire dans la clintonite. Dans le talc, le remplacement de Mg2+ par Mn2+ est restreint à moins de 20%, pour des raisons d'adaptation dimensionnelle entre couches tétra- et octaédriques. Par contre, la souplesse structurale des micas permet une incorporation plus élevée de Mn2+. L'association du manganèse divalent avec des éléments de plus faible taille, tels que l'aluminium, le magnésium ou le zinc, dans les micas de type phlogopite, permet, pour des raisons stériques, de stabiliser leur structure. En conditions oxydantes, Mn3+, de plus faible rayon ionique que Mn2+, contribue aussi à cette adaptation, comme dans la norrishite, K( Li)Si4O12, ce qui entraîne, comme dans les amphiboles, une non-protonation.

BACKGROUND: Malignant and paramalignant pleural effusions are important complications of many malignancies. The two main management options debated in the literature are: 1) insertion of an indwelling pleural catheter (IPC) to achieve chronic drainage of the effusion, or 2) hospitalization with tube thoracostomy and subsequent chemical pleurodesis (CP) with talc or doxycycline to prevent fluid reaccumulation. We aimed to describe a large series of patients with malignant pleural effusions managed with an IPC, identify and validate factors identified in the literature as predictors of spontaneous pleurodesis in the IPC group and compare the group managed with IPC to patients managed with CP. METHODS: We designed a retrospective cohort study comparing patients with malignant and paramalignant pleural effusions managed either with CP between March 1, 2003 and February 28, 2006 or IPC insertion between May 1, 2006 and April 1, 2009. The CP group was identified through the prescription of talc or doxycycline and the IPC group from the IPC clinic database. Data were collected from paper and electronic records and from the Government of Ontario. RESULTS: We identified 193 consecutive patients with an ECOG performance status of less than 4 (ECOG less than 4 means that the patient is not completely disabled and confined to bed or chair) having undergone IPC insertion and 168 who were managed with CP. None of the variables we tested were significant predictors of spontaneous pleurodesis in the IPC group. Pleural effusion control rates at 6 months were higher in the IPC group than in the CP group (52.7% vs 34.0%, p<0.01) but the rate of freedom from pleural effusion at 180 days and catheter removal at 90 days was not significantly different (25.8% in the IPC group and 34.0% in the CP group p=0.14). Patients in the IPC group had a significantly longer median survival (148 days measured from the date of catheter insertion vs 133 days in the CP group, log-rank p<0.05). CONCLUSION: We found an intriguing possible survival benefit favouring management of malignant or paramalignant effusions with an IPC. Given possible biases due to the design of this study and uncertain explanatory mechanism, this needs to be confirmed in a randomized controlled trial. Quality of life, an important measure of success for these palliative procedures, should also be measured.