Research was initiated to examine the feasibility of removing the majority of 4-PCH from the XSBR latex employed in carpet manufacturing. The reduction of 4-PCH from such latices would lend insight into the control of certain carpet related illnesses.

Miniaturized stretchable electronic devices that can be bent and strained elastically without breaking, have drawn considerable research interest in recent years for wearable computers and integrated bio-sensor applications. Portable electrical power harvesting remains a critical challenge in flexible electronics materials. One proposed solution has been to convert waste heat from the human body into electricity using thermoelectric materials. Traditionally, however, these materials are brittle ceramic semiconductors with limited fracture resistance under deformation. The primary objective of this thesis is to address this challenge by fabricating and studying the mechanical, thermal and electrical performance of stretchable composites combining natural latex polymer with either metallic (Ni) or thermoelectric (InSb) powders. Ni-based and InSb-based latex specimens were synthesized with different powder concentrations up to 36 vol.%. The effects of the powder concentration on tensile elongation, electrical conductivity, and thermal conductivity of the composites were measured at ambient temperature. Strong dependences of mechanical and electrical properties on powder concentration were found. By contrast, thermal conductivity was observed to remain low at all concentrations, suggesting that the predominant heat transport process is through the low-conductivity latex matrix rather than the conductive particles. This thesis was conducted with the support of a Vermont Space Grant Consortium graduate research assistantship.

Package exams provides a framework for automatic generation of standardized statistical exams which is especially useful for large-scale exams. To employ the tools, users just need to supply a pool of exercises and a master file controlling the layout of the final PDF document. The exercises are specified in separate Sweave files (containing R code for data generation and LaTeX code for problem and solution description) and the master file is a LaTeX document with some additional control commands. This paper gives an overview of the main design aims and principles as well as strategies for adaptation and extension. Hands-on illustrations - based on example exercises and control files provided in the package - are presented to get new users started easily.

[pt] O aumento da poluição nos grandes centros urbanos tem forçado a demanda por novos equipamentos capaz de fazer a amostragem correta das partículas em suspensão no ar. Estas partículas são de especial atenção, pois causam danos à nossa saúde. As partículas menores que 10um são consideradas inaláveis, sendo que as de tamanho menores que 3um são consideradas respiráveis, atingindo a região alveolar dos pulmões. Na busca para a diminuição dos efeitos da poluição, faz-se necessário monitorar as características físicas dos aerossóis (concentração e tamanho). No entanto, os procedimentos necessários para a calibração de medidores de aerossol são mal definidos, sem instruções formais e documentação. A fim de prover um ambiente com escoamento uniforme e controlado, foi construída uma câmara de calibração de aerossol, com pressão atmosférica em torno de 1atm e velocidade do ar variando entre 1,1cm/s a 3,1cm/s, para avaliação de amostradores de aerossol. Essa câmara é grande o bastante para acomodar vários instrumentos simultaneamente, tendo uma área de seção de teste relativamente ampla (aproximadamente 1,0m2) com uma concentração de aerossol controlável. Esta pesquisa propõe uma metodologia de calibração de amostradores atmosféricos em geral e em particular de impactadores em cascata. Adota metodologia de cálculo de incerteza de medição segundo o Guia para a expressão da Incerteza de Medição e utiliza terminologia respaldada no Vocabulário internacional de Termos Fundamentais e Gerais de Metrologia. Utilizando a Metrologia como ciência, para solucionar problemas oriundos da Medição de Aerossol. / [en] Increasing pollution in large urban centers has forced the demand for new equipment capable of making a correct sampling of the particles suspended in the air. These particles are of particular attention because they cause damage to our health. Particles smaller than 10um are considered respirable, and the size smaller than 3um are considered respirable, reaching the alveolar region of the lungs. In seeking to reduce the effects of pollution, it is necessary to monitor the physical characteristics of aerosols (size and concentration). However, the procedures for calibration of aerosol are poorly defined, without formal instruction and documentation. In order to provide an environment with controlled and uniform flow, we constructed a calibration chamber aerosol, with atmospheric pressure around 1atm and air velocity ranging between 1.1cm/s to 3.1 cm/s for evaluation of samplers aerosol. This chamber is large enough to accommodate multiple instruments simultaneously, having a test section area relatively wide (approximately 1.0m2) at a concentration of aerosol controllable. This research proposes a methodology for calibration of atmospheric samplers in general and in particular of cascade impactors. It adopts the methodology of calculation of measurement uncertainty according to the Guide to the Expression of Uncertainty in Measurement and uses terminology backed Vocabulary international General Terms and Fundamental Metrology. Using Metrology as a science, to solve problems arising from the Aerosol Measurement.

Neste trabalho é investigado o comportamento de partículas coloidais em cristais líquidos liotrópicos nas diferentes fases nemáticas. Nessas fases, existe uma ordem orientacional de longo alcance das micelas no volume. O regime de ancoramento das micelas na superfície das partículas, que pode ser forte ou fraco, depende diretamente da energia de ancoramento W, do raio R das partículas coloidais, e da constante elástica K do crista/líquido [8]. Em casos de ancoramento fraco, a simetria da ordem orientacional das micelas próxima às superfícies das partículas, bem como no volume, é a mesma nas fases nemáticas calamítica (\'N IND. c\') e discótica (\'N IND. d\'). Utilizando-se partículas de sílica nanométricas, observa-se por técnicas de microscopia óptica, que, para amostras mais concentradas (fração volumétrica \'fi\'\'DA ORDEM DE\'\'10 POT. -3\'), ocorre uma separação de fases, enquanto que, em sistemas mais diluídos (\'fi\'\'DA ORDEM DE\'\'10 POT. -5\'), existe uma organização das partículas no meio líquido cristalino em temperaturas próximas à \'N IND. d\'. Quando partículas de látex de diâmetro 90nm são dispersadas no cristal líquido liotrópico na fase \'N IND. c\'. c, agregados anisométricos tridimensionais são observados. Apesar de esse tipo de agregado não ter sido anteriormente observado, esse comportamento era previsto teoricamente dentro de certas condições que são satisfeitas pelo sistema nemático liotrópico liotrópico + látex. No entanto, esses agregados desaparecem na fase \'N IND. d\'. Os diferentes comportamentos em \'N IND. c\' e \'N IND. d\' estão ligados à organização do meio liquido-cristalino, assim como às interações entre as partículas e entre as partículas e o meio. F oram feitas também medidas diretas de força por meio de um SFA (surface Force Apparatus) em um cristal líquido liotrópico puro confinado entre duas superfícies. Tais medidas mostram que o perfil da força em função da distância entre as superfícies é diferente em \'N IND. d\' e \'N IND. c\'. / In this work, the behavior of colloidal particles dispersed into a nematic lyotropic liquid crystal matrix is investigated. In such systems, there is a long range orientational order of the micelles in the volume. The micelles anchoring on the particles surfaces can be strong or weak, depending of the anchoring strength W, the particles radius R and the liquid crystal elastic constant K. For weak anchoring, the symmetry of the orientational order in the surroundings of the particles surfaces, and also in the volume, remains the same for both calamitic (\'N IND. c\') and discotic (\'N IND. d\') nematic phases. It was observed that high concentrated solution of nanometric silica particles in a lyotropic medium leads to phase segregation. In more diluted systems, the silica particles tend to organize themselves in the nematic medium for temperatures close to \'N IND. d\'. For 90nm latex particles in the lyotropic matrix, 3D anisotropic aggregates was observed in \'N IND. c\' phases. Although it was never observed before, this behavior was theoretically previewed. On the other hand, there are no aggregates in \'N IND. d\' phase. The different behaviors observed on \'N IND. c\' and \'N IND. d\' phases are related to the liquid crystalline medium organization, as well as to the interparticles and medium with particles interactions. It is also shown in this work, by direct measurements in a pure lyotropic liquid crystal confined between two surfaces, that the force profiles in function of the distance between surfaces are different for \'N IND. c\' and \'N IND. d\' phases.

Orientador: Rondinelli Donizetti Herculano / Coorientador: Eduardo Maffud Cilli / Coorientador: Ricardo José de Mendonça / Banca: Reinaldo Marchetto / Banca: Renê de Oliveira Beleboni / Resumo: O látex extraído da seringueira Hevea brasiliensis têm mostrado promissores resultados em aplicações biomédicas, onde m embranas produzidas dest e material têm sido utilizadas como próteses e enxertos médicos devido às suas características de biocompatibilidade e estímulo natural à angiogênese. O objetivo desse trabalho consiste na incorporação de peptídeos em membranas de látex natural e no estudo de suas liberações. Esperamos com os resultados, viabilizar o uso do látex natural como sistema de liberação sustentada de peptídeos e/ou proteínas. A taxa de liberação dos peptídeos foi monitorada e quantificada por Cromatografia Líquida de Alta Eficiênc ia (CLAE) em modo analítico. A incorporação do peptídeo às membranas de látex acompanhou diferentes caracterizações, dentre elas: Espectroscopia de Infravermelho por Transformada de Fourier (FTIR) que identificou a estabilidade dos peptídeos após incorpora ção ao látex natural pela preservação de bandas características para os peptídeos, dentre elas, as bandas 1643 - 1638 cm - 1 deformação NH de aminas e C=O de amidas; 1524 - 1514 cm - 1 deformação C=C de aromáticos; e 542 - 498 cm - 1 deformação S - S, Capacidade d e absorção de fluídos, Perda de massa em soluções aquosas, CLAE e Microscopia Eletrônica de Varredura (MEV). Durante os ensaios de liberação dos peptídeos pelas membra nas de látex natural, observou - se a instabi lidade dos peptídeos em solução, com degradaçã o total em períodos que variaram de 48 a 120 horas nos valores de pH 7,4; 12,0 ; e água destilada (pH 5,6 - 6,4) . Entretanto, para a solução de tampão acetato pH 4,0 não houve instabilidade dos peptídeos em solução. Desta forma, estes resultados sugerem a p ossível interferência causada por proteases alcal inas presentes no látex natural . Adicionalmente, com o propósito de eliminar das membranas o agente c... / Abstract: The latex extracted from Hevea brasiliensis rubber tree have shown promising results in biomedical applications, where membranes produced from this material have been used as medical implants and grafts, due to its biocompatibility and natural stimulation of angiogenesis. Th e aim of this work was t o incorporate peptides in to natural latex membranes and the study of its release. We look forward to the results, enabling the use of natural latex as Controlled Release System of peptides and/or proteins. The rate of peptide releas e were monitored and quantified by High Performance Liquid Chromatography (HPLC) in an analytical way. The peptides incorporation into latex membranes followed different characterizations, such as: Fourier Transform Infrared Spectroscopy (FTIR) which ident ified the stability of peptides after incorporation into the natural latex by the preservation of characteristic bands for peptides, among them, 1643 - 1638 cm - 1 NH strain of amines and amides C=O; 1524 - 1514 cm - 1 strain C=C aromatic; and 542 - 498 cm - 1 s train S - S, fluid absorption capacity, the loss in weight in aqueous solutions, HPLC and Scanning Electron Microscopy (SEM). During the release tests of peptides by the natural latex membranes, it was observed instability of the peptides in solution, with t otal extinction in periods that ranged between 48 and 120 hours in pH 7.4; 12.0; and distilled water (pH 5.6 - 6.4). However, for acetate buffer solution (pH 4.0) was not observed instability of peptides. Therefore, these results suggest that there are pos sible interferences caused by alkaline proteases present in the natural latex. Additionally, in order to remove the causative agent of degradation, were prepared new membranes subjected to washing treatment, and the peptides posteriorly adsorbed on the mem branes. During the release tests, i t was possible to observe the release and stability of peptides wi... / Mestre

Submitted by LUCILENE DOS REIS BARROS null (lureisbarros@ibest.com.br) on 2017-03-24T11:46:17Z No. of bitstreams: 1 Dissertação mestrado Lucilene Ferreira.pdf: 2177054 bytes, checksum: 8673fd6a85a2ca423d1533a6021c69f1 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-03-24T16:36:32Z (GMT) No. of bitstreams: 1 ferreira_lrb_me_ilha.pdf: 2177054 bytes, checksum: 8673fd6a85a2ca423d1533a6021c69f1 (MD5) / Made available in DSpace on 2017-03-24T16:36:32Z (GMT). No. of bitstreams: 1 ferreira_lrb_me_ilha.pdf: 2177054 bytes, checksum: 8673fd6a85a2ca423d1533a6021c69f1 (MD5) Previous issue date: 2017-01-31 / Esta dissertação trata-se de uma pesquisa, com acréscimo de látex natural e látex sintético SBR (estireno butadieno) na massa do concreto para aplicação em pavimento e análise de seu comportamento, tanto no estado fresco quanto endurecido. A proposta visa analisar o comportamento do látex sintético SBR e do látex coletado diretamente do seringal, apenas com adição de amônia. Sendo que o látex sintético já é usado para ser acrescido na argamassa. Os ensaios realizados foram de: Resistência à compressão axial, Resistência à tração na flexão e Módulo de Elasticidade para as idades de 7, 28 e 50 dias. Em uma segunda etapa, foram realizados novos ensaios, mas com o látex sem a amônia, apenas com o látex puro, apenas para analisar a influência da amônia. Nessa nova etapa foi realizado, somente ensaio de resistência à compressão. Os resultados mostraram que o látex com a amônia diminuíram as resistências à compressão e à tração na flexão para as idades de 7 e 28 dias e para 50 dias essa tendência desaparece. O módulo de elasticidade também apresentou queda, para o concreto com látex com amônia, entretanto isto é positivo para o concreto aplicado em pavimento, pois indica um aumento na capacidade de deformação para a mesma carga, ou seja, o material apresentou maior capacidade de deformação elástica. O módulo de elasticidade para o concreto com látex sintético foi maior que o de referência, para todas as idades. O Látex sem a amônia apresentou queda para o ensaio de resistência à compressão, confirmando que o aditivo aplicado para não deixar o látex coagular, não influência nas propriedades do concreto. / This dissertation is about a research, with addition of natural latex and synthetic latex SBR (styrene butadiene) in the concrete mass for application in pavement and analysis of its behavior, in both the fresh and hardened state. The purpose is analyze the behavior of synthetic latex SBR (styrene butadiene) and latex collected directly from the rubber tree, being that the synthetic latex is already used to be added in concrete. The tests were: axial compression strength, flexural tensile strength and modulus of elasticity for the ages of 7, 28 and 50 days. In a second step, new tests were performed, but with latex without ammonia, only with pure latex to analyze the influence of ammonia. In this new step, only the compressive strength test was performed. The results showed that latex with ammonia decreased the compressive and flexural tensile strengths at the ages of 7 and 28 days and for 50 days this tendency disappears. The modulus of elasticity also showed a drop, for latex concrete with ammonia, however this is positive for the concrete applied in pavement, since it indicates an increase in the capacity of deformation for the same load, that is, it indicates that the material is more ductile. The modulus of elasticity for concrete with synthetic latex was higher than the reference, for all ages. Latex without ammonia showed a drop for the compressive strength test, confirming that the additive applied not to allow the latex to stiffen does not influence the properties of the concrete.

<p>The semantic web is a vision of the Internets future, there machines and humans can understand the same information. To make this possible, documents have to be provided with metadata in a general language. W3C has created Web Ontology Language (owl) for this purpose.</p><p>This report present the creation of a LaTeX package, which makes it possible to include metadata in pdf files. It also presents how you can create annotations, which are bound to the metadata that's been generated. With the help of this package it's easy to create pdf documents with automatically generated metadata and annotations.</p>

<p>The objective of this master thesis was to investigate the possibility to measure the gain in stiffness of the dry coating due to film formation of latex with a Dynamic Mechanic Thermal Analyzer (DMTA). This could tell when and to which extent the latex forms a film after the drying process.</p><p>Two latices with different Tg was used for the experiments, one with a Tg of 36°C, denoted hard, and the one with a Tg of 8°C, denoted soft. The hard latex was used to make coating samples that would not form a film when dried at room temperature and the soft latex was used as a reference to the coating with hard latex since it would form a film at room temperature.</p><p>It was shown that a gain in stiffness due to film formation of latex in coating can be measured with a DMTA. It was also shown that that the film forming of latex in coatings depend on time, temperature and the history of the sample. Further investigations were carried out to try to determine the time for film formation to be completed at a certain temperature.. These investigations showed that this type of trials cannot be carried out in a DMTA directly since the stiffness seemed to increase monotonically during a very ling time. This might be due to the rearrangements in the pigment structure that might affect the gain in stiffness. Therefore, a method involving oven curing was developed. Only one series of test were performed with this method due to lack of time but the method showed promising results.</p> / <p>Syftet med detta examensarbete var att undersöka möjligheten att använda en Dynamic Mechanic Thermal Analyzer (DMTA) för att mäta ökningen av styvhet som följd av filmbildning av latex i en torr bestrykning.</p><p>Två olika latexer användes för experimenten, en med Tg = 36°C (hård) och en med Tg = 8°C (mjuk). Den hårda latexen användes för att kunna göra tester på prover som ännu inte filmbildat när de torkat vid rumstemperatur och den mjuka latexen användes för att göra referens prover mot bestrykningen med hård latex.</p><p>Resultaten visade att det går att mäta styvhetsökning i bestrykningen som en följd av filmformation med DMTA och filmformation av latex i bestrykningen troligtvis beror på både tid, temperatur och provets historia. Ett försök att mäta vilken uppehålls tid vid en specifik temperatur som krävs för att filmbildningen skall fulländas genomfördes. Dessa försök visade att DMTA:n inte var en lämplig metod för att mäta denna tid då styvheten verkade öka under en längre tid. Detta kan bero på att pigment partiklarna packade sig tätare och på så sätt orsakade en ökning av styvheten. Därför gjordes ett annat försök som involverar ugns härdning, men på grund av tidsbrist blev det bara en mätserie utförd. Den sist nämnda metoden visade dock goda resultat och måste därför bedömas ha en potential.</p>

Gemeinsamer Workshop von Universitaetsrechenzentrum und Professur "Rechnernetze und verteilte Systeme" der Fakultaet fuer Informatik der TU Chemnitz. Workshop-Thema: Mobilitaet Eine Vielzahl von Browsern und anderen Werkzeugen analysiert, verarbeitet, manipuliert oder erzeugt mehr oder weniger erfolgreich HTML-Dateien. Doch browserspezifische Erweiterungen machen den Nutzern das Leben schwer. Die Übertragung wird dank Firewalls, Filterfunktionen und browserspezifischen Erweiterungen instabil. Lokal gespeicherte Dateien vermeiden dies, erfüllen jedoch andere Wünsche des modernen, mobilen Lerners nicht. Der Einsatz von HTML als Zielformat in der Lehre mit neuen Medien muß gelegentlich überdacht werden. Ein weiterer denkbarer Kandidat ist das PDF-Format, das durch die Einbindung von Hyperlinks, Inhaltsverzeichnissen, Stichwortregistern und sogar Formularen viele Anforderungen an multimediale Lehrmaterialien erfüllt.