In this thesis technical nonionic surfactants are studied using multivariate techniques. The surfactants studied were alkyl ethoxylates (AEOs) and alkyl polyglucosides (APGs). The aquatic toxicity of the surfactants towards two organisms, a shrimp and a rotifer, was examined. The specified effect was lethality, LC50, as indicated by immobilisation. In a comparative study, the LC50 values obtained were used to develop two different types of model. In the log P model the toxicity was correlated to log P alone, while in the multivariate model several physicochemical variables, including log P, were correlated to the toxicity. The multivariate model gave smaller prediction errors than the log P model. Further, the change in reactivity when a surfactant mixture was added to dissolving pulp under alkaline conditions was studied, using the amount of residual cellulose as a measure of the reactivity. Ten AEO/APG mixtures were tested, and the mixture with greatest potential was studied in more detail. An optimum in the amount of added surfactant was found that seems to coincide, according to surface tension measurements, with the CMC.

The broad objective of the study was to determine feeding behaviour and gut health of pigs fed different fibres at varying inclusion levels. Maize cob, maize stover, sunflower hulls, veld grass, sawdust, lucerne and dried citrus pulp were used in growing and finishing pig diets to provide a wide range of physicochemical properties. Time spent eating, drinking, lying down, sitting/standing and other activities was observed using video cameras. Blood samples were collected at the end of the trial for both growing and finishing pigs for analysis of glycated haemoglobin, albumin, globulin, total protein, creatine kinase, urea and uric acid. Intestinal segments were collected at the end of trial for growing pigs to determine mucosal architecture of the intestines. Digestible energy (DE), bulk density (BD), acid detergent fibre (ADF) and water holding capacity (WHC) were the most important variables predicting time spent on different behavioural activities in growing pigs (P < 0.001). Water holding capacity, neutral detergent fibre (NDF) and ADF were the most important variables involved in predicting time spent on different behavioural activities in finishing pigs (P < 0.001). Physicochemical properties influenced time spent on different behavioural activities and they provided relationships with time spent on different behavioural activities in both growing and finishing pigs. Glycated haemoglobin, albumin, globulin, total protein and uric acid were factors that influenced time spent eating in growing pigs (P < 0.05). In finishing pigs, only serum total protein was selected as the best predictor variable influencing time spent eating (P < 0.05). The blood metabolites were correlated with time spent eating and drinking. They provided threshold values with time spent eating and drinking by pig. Hence, they can also be used as potential biomarkers that modulate neuronal pathways which reduce time spent eating and drinking. In this study, bulk density (BD) and NDF were the best predictor variables influencing villi height (VH) and apparent villi surface area (AVSA) in pigs (P < 0.05). Grouped pigs fed fibrous diet spent more time eating, lying down, standing, walking and fighting (P < 0.05). Skin lesions appeared the most on neck and shoulder region followed by chest, stomach and hind leg region, and finally head region (P < 0.05). Fibrous diet did not reduce aggressive behaviours, rather aggressive behaviours emanated out of frustration when queuing at the feeder. It was concluded that physicochemical properties of fibrous diets and nutritionally-related blood metabolites influence feeding behaviour. Mucosal architecture was also influenced by physicochemical properties of the fibrous diets. / Ph.D. University of KwaZulu-Natal, Pietermaritzburg 2013.

[pt] Para substituir parcialmente a demanda em óleo diesel de origem fóssil, reduzir os elevados custos de importação e respeitar as normas ambientais, políticas sustentáveis já levaram a substituir parcialmente óleo diesel por biodiesel. Entretanto, outras tecnologias, como as misturas diesel-biodiesel-etanol, estão sendo investigadas. O principal desafio dessas misturas consiste em melhorar a miscibilidade e a estabilidade do álcool no óleo diesel. No presente trabalho, formulou-se um aditivo original, a partir de compostos renováveis, que permitiu melhorar a faixa de concentração de etanol anidro dentro de óleo diesel com 15 por cento em volume de biodiesel e de temperatura onde observa-se misturas estáveis. Diversas propriedades físico-químicas das misturas aditivadas foram medidas em uma larga faixa de concentração de etanol para avaliar os aspetos de consumo, qualidade da combustão, comportamento a baixa temperatura, interação entre fluido e superfície, e segurança. Os resultados obtidos mostraram que misturas com, pelo menos, 1,0 por cento em volume de aditivo e até 20 por cento em volume de etanol anidro são estáveis para temperaturas superiores a 10 graus Celsius e respeitam a maioria das especificações brasileiras atuais para óleo diesel. Ensaios experimentais em um motor de ignição por compressão MWM 4.10 TCA (Euro III) foram realizados com estas misturas. Os resultados obtidos mostraram que a substituição do óleo diesel altera as características da combustão: o crescente teor de etanol leva ao aumento do atraso de ignição, à liberação de calor mais rápida e à diminuição da pressão máxima. Mesmo nessas condições não otimizadas de injeção e de combustão, os resultados mostraram uma melhor conversão da energia química no etanol para produzir potência efetiva, comparado com os valores encontrados nos motores flex fuel de ciclo Otto, além de um pequeno aumento no rendimento térmico do motor. / [en] In order to partially replace the demand of fossil diesel fuels, to reduce high import costs and to comply with environmental standards, sustainable policies have led to partially replace diesel fuel by biodiesel. However, other technologies, such as diesel-biodiesel-ethanol mixtures, are being investigated. The major challenge of these mixtures is to improve the miscibility and the stability of alcohol in diesel fuel. In this study, an original additive, from renewable compounds, improved the miscibility of anhydrous ethanol in diesel fuel with 15 per cent by volume of biodiesel and temperature in which stable mixtures were observed. Several physicochemical properties of the additivated mixtures were measured in a large range of ethanol concentration to evaluate aspects of consumption, combustion quality, behavior at low temperature, interaction between the fluid and the surface, and safety. The results showed that blends with, at least 1.0 per cent, by volume of additive and 20 per cent by volume of anhydrous ethanol are stable at temperatures above 10 degrees Celsius and respected most of the current Brazilian specifications for diesel fuel. Experimental tests on a compression ignition engine MWM 4.10 TCA (Euro III) were performed with these mixtures. The results showed that the diesel fuel substitution alters the characteristics of combustion: the increased ethanol content implied an increase of the ignition delay, a faster heat release and a decrease of maximum pressure. Despite these non-optimized conditions for injection and combustion, results showed a better conversion of ethanol chemical energy into brake power, in comparison to the values found in flex fuel spark ignition engine, in addition to a small increase in the indicated efficiency of the engine.

Os métodos computacionais da química quântica foram empregados para estudar as estruturas moleculares e as energias de interação de cátions e ânions que são componentes de alguns líquidos iônicos funcionalizados, derivados do imidazólio. O estudo teve como objetivo comparar e relacionar os efeitos da presença de funcionalização nos substituintes das posições 1 e 3 do cátion imidazólio, nas propriedades desses líquidos iônicos. Essa funcionalização pode ocorrer pela presença de insaturações, grupos aromáticos, éteres, álcoois, tióis, aminas, nitrilas entre outros grupos nas cadeias dos substituintes. Nesta tese são reportados os estudos dos complexos formados por ânions tetrafluorborato e cátions imidazólio substituídos por grupos metila, etila, propila, butila, isobutila, vinila, propargila, alila, crotila e metalila, observando assim o efeito da presença de substituintes contendo cadeias insaturadas em comparação com os de cadeias saturadas nas estruturas, distribuições de carga, energias de interação e propriedades físico-químicas desses sistemas. Nesses sistemas foram observados intensos efeitos de polarização e transferência de carga ânion-cátion. Foram encontradas diversas relações entre volumes iônicos, energias de interação dos íons e as propriedades de transporte dos respectivos líquidos iônicos. / The methods of computational quantum chemistry have been used to study the molecular structures and the interaction energies of cations and anions which are components of some functionalized ionic liquids derived from imidazolium. The objective of this study is comparing and relating the effects of the presence of functionalization of the side chains of the imidazolium with the properties of these ionic liquids. This functionalization can occur by the presence of unsaturated side chains, aromatic groups, ether, alcohols, thiols, amines, nitriles among other groups in the side chains. In this thesis are reported the studies of the complexes formed of tetrafluorborate anions and imidazolium cations with side chains methyl, ethyl, propyl, butyl, isobutyl, vinyl, propargyl, allyl, crotyl and methallyl, thus observing the effects of the presence of unsaturated side chains compared to saturated ones on the structures, charge distributions, interaction energies and physicochemical properties of these systems. It was observed in these systems strong effects of polarization and anion-cation charge transfer. It was found several relations between ionic volumes, interation energies of the ions and the transport properties of the respective ionic liquids.

Made available in DSpace on 2014-06-11T19:23:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-02-18Bitstream added on 2014-06-13T19:29:27Z : No. of bitstreams: 1 leite_td_me_sjrp.pdf: 1234484 bytes, checksum: a978ecd0d075bc681b8906a7611095d9 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Amidos e gomas são hidrocolóides usados freqüentemente em alimentos para conferir textura apropriada, controlar a umidade e a mobilidade da água. Estudos têm relatado que a interação de gomas e amidos em sistemas alimentícios pode alterar o inchamento dos grânulos, as propriedades de gelatinização e reológicas dos amidos. Em bebidas lácteas fermentadas, a maioria dos polissacarídeos de interesse comercial é incompatível com as proteínas do leite em solução, e desta forma, os hidrocolóides tipicamente utilizados são amido e carragena. Neste trabalho foi avaliado o efeito da adição das gomas xantana, carboximetilcelulose sódica e carragena (nas concentrações de 0,15, 0,25, 0,35 e 0,45% - p/v) nas propriedades de pasta, térmicas, de poder de inchamento (PI), reológicas e na microscopia do amido de mandioca, bem como o efeito de misturas de amido de mandioca e as referidas gomas nas propriedades reológicas de bebidas lácteas fermentadas. Os resultados obtidos sugerem que a goma carragena (CAR) praticamente não modifica as propriedades do amido em função da inexistência de interações entre a referida goma e o amido de mandioca; já a goma xantana (GX) envolve praticamente por completo os grânulos de amido, possivelmente através da formação de pontes de hidrogênio, promovendo desta forma aumentos nas viscosidades de pasta, poder de inchamento, nos módulos G’ e G” e diminuição na tendência a retrogadação; a carboximetilcelusose sódica (CMC), por sua vez, aumenta drasticamente as viscosidades e o poder de inchamento do amido devido a sua grande capacidade de retenção de água e não a sua interação com o amido de mandioca. Nas bebidas lácteas fermentadas, as misturas quando empregadas praticamente não modificaram seu comportamento reológico, exceto para as bebidas elaboradas a partir das misturas amido - goma xantana, onde observou-se... / Starches and gums are hydrocolloids frequently used in food systems to provide proper texture, moisture and water mobility. Studies have reported that the gum and starch interaction in food systems can modify the granule swelling, the gelatinization and rheological properties of starches. In fermented dairy beverages, the majority of commercial interest polysaccharides is not compatible with milk proteins in solution, consequently, starch and carrageenan are the hydrocolloids typically used. In this work, the effect of gum addition such as xanthan, sodium carboxymethyl cellulose and carrageenan was evaluated (in the concentrations of 0,15, 0,25, 0,35 and 0.45% - w/v) in paste, thermal, swelling power (SP), rheological and microscopy properties of cassava starch, as well as the effect of mixtures of cassava starch and the referred gums in rheological properties of fermented dairy beverages. The results suggest that carrageenan gum (CAR) practically does not modify the starch properties since there is no interaction between this gum and cassava starch. Xanthan gum (GX) seems to involve the starch granules completely, possibly through the formation of hydrogen bonds, which increases paste viscosities, swelling power, increased the modulus G' and G” and decreased retrogradation behavior. Sodium carboxymethyl cellulose (CMC), in turn, drastically increases viscosities and the starch swelling power due to its great capacity of water retention and not to the interaction with the cassava starch. In fermented dairy beverages, the gum - starch mixtures practically didn´t modify its rheological behavior, except for beverages with mixtures xanthan gum - starch, where an initial reduction in the shear stress as deformation rate was increased, followed by a gradual increase, suggesting a possible incompatibility between cassava starch, xanthan gum and milk proteins. Keywords: Cassava starch... (Complete abstract click electronic access below)

Made available in DSpace on 2014-12-17T15:01:44Z (GMT). No. of bitstreams: 1 JosiniraAA.pdf: 2069893 bytes, checksum: f72b269f6b8b693ef45bd7120dd46ee5 (MD5) Previous issue date: 2007-11-26 / The composition of petroleum may change from well to well and its resulting characteristics influence significantly the refine products. Therefore, it is important to characterize the oil in order to know its properties and send it adequately for processing. Since petroleum is a multicomponent mixture, the use of synthetic mixtures that are representative of oil fractions provides a better understand of the real mixture behavior. One way for characterization is usually obtained through correlation of physico-chemical properties of easy measurement, such as density, specific gravity, viscosity, and refractive index. In this work new measurements were obtained for density, specific gravity, viscosity, and refractive index of the following binary mixtures: n-heptane + hexadecane, cyclohexane + hexadecane, and benzene + hexadecane. These measurements were accomplished at low pressure and temperatures in the range 288.15 K to 310.95 K. These data were applied in the development of a new method of oil characterization. Furthermore, a series of measurements of density at high pressure and temperature of the binary mixture cyclohexane + n-hexadecane were performed. The ranges of pressure and temperature were 6.895 to 62.053 MPa and 318.15 to 413.15 K, respectively. Based on these experimental data of compressed liquid mixtures, a thermodynamic modeling was proposed using the Peng-Robinson equation of state (EOS). The EOS was modified with scaling of volume and a relatively reduced number of parameters were employed. The results were satisfactory demonstrating accuracy not only for density data, but also for isobaric thermal expansion and isothermal compressibility coefficients. This thesis aims to contribute in a scientific manner to the technological problem of refining heavy fractions of oil. This problem was treated in two steps, i.e., characterization and search of the processes that can produce streams with economical interest, such as solvent extraction at high pressure and temperature. In order to determine phase equilibrium data in these conditions, conceptual projects of two new experimental apparatus were developed. These devices consist of cells of variable volume together with a analytical static device. Therefore, this thesis contributed with the subject of characterization of hydrocarbons mixtures and with development of equilibrium cells operating at high pressure and temperature. These contributions are focused on the technological problem of refining heavy oil fractions / A composi??o do petr?leo pode variar de po?o para po?o e as suas caracter?sticas influenciam significativamente os produtos obtidos no processo de refino. Sendo assim, ? de suma import?ncia caracterizar o petr?leo para que se possam conhecer suas caracter?sticas e assim destin?-lo de maneira adequada para o seu processamento. Como o petr?leo ? uma mistura multicomponente, utilizar misturas sint?ticas representativas das fra??es proporciona um melhor entendimento do comportamento da mistura. Um caminho para a caracteriza??o de fra??es ? geralmente atrav?s de correla??o entre propriedades f?sicoqu?micas de f?cil medi??o em que algumas dessas propriedades como massa espec?fica, densidade, viscosidade e ?ndice de refra??o s?o freq?entemente utilizadas. Visando a caracteriza??o de fra??es de petr?leo, neste trabalho foram obtidos dados de massa espec?fica, viscosidade e ?ndice de refra??o de misturas bin?rias n-heptano + hexadecano, ciclohexano + hexadecano e benzeno + hexadecano em baixa press?o e temperaturas de 288,15 K a 310,95 K e esses dados foram utilizados no desenvolvimento de uma proposta de caracteriza??o de fra??es de fra??es de petr?leo atrav?s da rela??o de propriedades f?sico-qu?micas com a composi??o. Os resultados obtidos mostraram uma ferramenta promissora e flex?vel na caracteriza??o termof?sica de misturas de hidrocarbonetos. Adicionalmente, foi realizada a medi??o de massa espec?fica em alta press?o e temperatura da mistura bin?ria ciclohexano + n-hexadecano numa faixa de 6,895 a 62,053 MPa e 318,15 a 413,15 K e a partir desses dados, uma proposta de modelagem de densidade de l?quidos comprimidos utilizando o modelo de Peng-Robinson e escalonamento de volume foi desenvolvida, utilizando um n?mero menor de par?metros que outros modelos da literatura. Os resultados foram satisfat?rios mostrando a acur?cia do modelo n?o apenas para massa espec?fica, mas tamb?m para coeficiente de expans?o t?rmica e compressibilidade isot?rmica. Esta tese visou contribuir de maneira cientifica com o problema tecnol?gico de refino de ?leos pesados, que pode ser configurado como um problema de caracteriza??o e de busca de processos que possibilitem a obten??o de correntes fracionadas com interesse comercial, como por exemplo a extra??o com solventes em alta temperatura e press?o. Visando obter dados de equil?brio de fases nessas condi??es, foram desenvolvidos projetos conceituais de dois dispositivos experimentais, que consiste de uma c?lula de volume vari?vel como componente de um aparato de equil?brio est?tico anal?tico. Sendo assim, essa tese contribuiu com propostas de caracteriza??o de misturas de hidrocarbonetos e com projetos de montagem de uma c?lula de equil?brio operando em alta temperatura e alta press?o, o que pode contribuir para o problema tecnol?gico de refino de ?leos pesados

Os métodos computacionais da química quântica foram empregados para estudar as estruturas moleculares e as energias de interação de cátions e ânions que são componentes de alguns líquidos iônicos funcionalizados, derivados do imidazólio. O estudo teve como objetivo comparar e relacionar os efeitos da presença de funcionalização nos substituintes das posições 1 e 3 do cátion imidazólio, nas propriedades desses líquidos iônicos. Essa funcionalização pode ocorrer pela presença de insaturações, grupos aromáticos, éteres, álcoois, tióis, aminas, nitrilas entre outros grupos nas cadeias dos substituintes. Nesta tese são reportados os estudos dos complexos formados por ânions tetrafluorborato e cátions imidazólio substituídos por grupos metila, etila, propila, butila, isobutila, vinila, propargila, alila, crotila e metalila, observando assim o efeito da presença de substituintes contendo cadeias insaturadas em comparação com os de cadeias saturadas nas estruturas, distribuições de carga, energias de interação e propriedades físico-químicas desses sistemas. Nesses sistemas foram observados intensos efeitos de polarização e transferência de carga ânion-cátion. Foram encontradas diversas relações entre volumes iônicos, energias de interação dos íons e as propriedades de transporte dos respectivos líquidos iônicos. / The methods of computational quantum chemistry have been used to study the molecular structures and the interaction energies of cations and anions which are components of some functionalized ionic liquids derived from imidazolium. The objective of this study is comparing and relating the effects of the presence of functionalization of the side chains of the imidazolium with the properties of these ionic liquids. This functionalization can occur by the presence of unsaturated side chains, aromatic groups, ether, alcohols, thiols, amines, nitriles among other groups in the side chains. In this thesis are reported the studies of the complexes formed of tetrafluorborate anions and imidazolium cations with side chains methyl, ethyl, propyl, butyl, isobutyl, vinyl, propargyl, allyl, crotyl and methallyl, thus observing the effects of the presence of unsaturated side chains compared to saturated ones on the structures, charge distributions, interaction energies and physicochemical properties of these systems. It was observed in these systems strong effects of polarization and anion-cation charge transfer. It was found several relations between ionic volumes, interation energies of the ions and the transport properties of the respective ionic liquids.

Os métodos computacionais da química quântica foram empregados para estudar as estruturas moleculares e as energias de interação de cátions e ânions que são componentes de alguns líquidos iônicos funcionalizados, derivados do imidazólio. O estudo teve como objetivo comparar e relacionar os efeitos da presença de funcionalização nos substituintes das posições 1 e 3 do cátion imidazólio, nas propriedades desses líquidos iônicos. Essa funcionalização pode ocorrer pela presença de insaturações, grupos aromáticos, éteres, álcoois, tióis, aminas, nitrilas entre outros grupos nas cadeias dos substituintes. Nesta tese são reportados os estudos dos complexos formados por ânions tetrafluorborato e cátions imidazólio substituídos por grupos metila, etila, propila, butila, isobutila, vinila, propargila, alila, crotila e metalila, observando assim o efeito da presença de substituintes contendo cadeias insaturadas em comparação com os de cadeias saturadas nas estruturas, distribuições de carga, energias de interação e propriedades físico-químicas desses sistemas. Nesses sistemas foram observados intensos efeitos de polarização e transferência de carga ânion-cátion. Foram encontradas diversas relações entre volumes iônicos, energias de interação dos íons e as propriedades de transporte dos respectivos líquidos iônicos. / The methods of computational quantum chemistry have been used to study the molecular structures and the interaction energies of cations and anions which are components of some functionalized ionic liquids derived from imidazolium. The objective of this study is comparing and relating the effects of the presence of functionalization of the side chains of the imidazolium with the properties of these ionic liquids. This functionalization can occur by the presence of unsaturated side chains, aromatic groups, ether, alcohols, thiols, amines, nitriles among other groups in the side chains. In this thesis are reported the studies of the complexes formed of tetrafluorborate anions and imidazolium cations with side chains methyl, ethyl, propyl, butyl, isobutyl, vinyl, propargyl, allyl, crotyl and methallyl, thus observing the effects of the presence of unsaturated side chains compared to saturated ones on the structures, charge distributions, interaction energies and physicochemical properties of these systems. It was observed in these systems strong effects of polarization and anion-cation charge transfer. It was found several relations between ionic volumes, interation energies of the ions and the transport properties of the respective ionic liquids.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2014-11-25T10:17:54Z No. of bitstreams: 2 Tese - Omar Zina - 2013.pdf: 1884367 bytes, checksum: ac70615bb4bc9a680a17fead9dac004b (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2014-11-25T12:28:09Z (GMT) No. of bitstreams: 2 Tese - Omar Zina - 2013.pdf: 1884367 bytes, checksum: ac70615bb4bc9a680a17fead9dac004b (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-11-25T12:28:09Z (GMT). No. of bitstreams: 2 Tese - Omar Zina - 2013.pdf: 1884367 bytes, checksum: ac70615bb4bc9a680a17fead9dac004b (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2013-09-13 / The aim of this study was to determine the solution-powder ration and to evaluate the setting time, solubility, dimensional change, pH and radiopacity of White structural and non-structural Portland cement, ProRoot MTA® and MTA BIO® associated to 2% glycolic solution of Aloe vera. Five samples of each material were used for each test according to American National Standards Institute/American Dental Association specification 57. Statistical analyses were carried out using ANOVA and Tukey’s test at 5% level of significance. When sample distribution was non-normal, nonparametric analysis of variance were performed with Kruskal-Wallis test (α=0.05). The results revealed no statistical difference in the water-powder ratio among the tested materials. ProRoot MTA® had the longest setting time (116.50 ± 4.08) (P<0.05). White structural and nonstructural Portland cements did not have means values on the radiopacity test (109.76 ± 10.40 and 118.75 ± 15.44, respectively) in accordance with ANSI/ADA, being significantly different from the MTA-based cements (P<0.05), and demonstrated higher mean solubility values (2.30 ± 0.36 and 2.81 ± 0.40, respectively) (P<0.05). The values for dimensional change of all tested materials were considered acceptable by ANSI/ADA. There were no significant differences between the mean pH values recorded for the materials (p>0.05). It was alkaline from the beginning to the end of the tests. MTA BIO presented lower setting time and lower solubility. The cements did not showed a higher solubility than 3%. All the assessed cements showed acceptable values of dimensional variation and high pH during the test time. MTA BIO and ProRoot MTA had adequate radiopacity values. / Esse estudo teve como objetivo determinar propriedades físico-químicas dos cimentos Portland branco estrutural e não estrutural, ProRoot MTA® e MTA BIO® associados à solução glicólica de Aloe vera a 2%. Após o estabelecimento da proporção pó/líquido para cada cimento, foram analisadas as propriedaes físicoquímicas: tempo de endurecimento, alteração dimensional, pH e radiopacidade. Cinco amostras de cada cimento foram usadas para cada teste, seguindo a especificação n. 57 da American National Standards Institute/American Dental Association (ANSI/ADA). A análise estatística foi realizada usando ANOVA e o teste de Tukey em nível de significância de 5%. Quando a distribuição das amostras foi não normal, a análise de variância não paramétrica foi realizada com o teste de Kruskal-Wallis (α=0,05). Os resultados não mostraram diferenças estatisticamente significantes (p>0,05) entre os cimentos em relação à proporção pó/líquido, que variou de 3,14 a 3,52 gramas. O ProRoot MTA® apresentou o tempo de endurecimento mais longo (116,50 min) e o MTA BIO® o menor (66,75 min) (p<0,05). Os cimentos Portland brancos estrutural e não estrutural apresentaram valores médios de solubilidade mais elevados (2,30 e 2,81%, respectivamente) (p<0,05). Todos os cimentos testados apresentaram valores de alteração dimensional semelhantes entre si (1,00%). O pH dos cimentos manteve-se elevado do início ao final do experimento, não havendo diferenças significantes entre os valores médios obtidos (cimento Portland branco estrutural, 11,96; cimento Portland branco não estrutural, 11,80; MTA BIO® 12,07; ProRoot MTA® 11,77) (p>0,05). Os cimentos Portland branco estrutural e não estrutural não apresentaram valores médios em conformidade com ANSI/ADA no teste de radiopacidade (109,76 e 118,75 mmAl, respectivamente), significantemente diferentes dos cimentos MTA BIO® (156,83 mmAl) e ProRoot MTA® (157,95 mmAl) (p<0,05), que apresentaram valores de densidade radiográfica acima do degrau 3 do penetrômetro de alumínio. O MTA BIO® evidenciou menor tempo de endurecimento e menor percentual de solubilidade. Nenhum cimento apresentou solubilidade maior que 3%. Todos os xiv cimentos analisados mostraram valores aceitáveis de alteração dimensional e pH elevado durante todo o período de teste. O MTA BIO® e o ProRoot MTA® apresentaram valores de radiopacidade adequados..

L’émollience est un terme définissant la capacité d’une matière première à adoucir, amollir, ou lubrifier la peau. Dans le domaine de la cosmétique, les émollients sont utilisés pour modifier la consistance, la viscosité ou la polarité d’une formulation. Il existe un nombre non négligeable d’émollients pouvant être utilisés en cosmétique. Cependant, les données aussi bien physico-chimiques que sensorielles disponibles dans la littérature sont encore très rares, rendant le choix des émollients complexe. De plus, les analyses sensorielles habituellement réalisées par les fournisseurs constituent une méthode de caractérisation particulièrement chronophage et coûteuse.Parmi les différents types d’émollients, les dérivés siliconés se démarquent par des propriétés bien spécifiques. Il s’agit notamment d’un très bon étalement, un toucher doux, non huileux et non collant, ou encore d’un effet sec sans effet de fraicheur. Cependant, malgré ces propriétés sensorielles exceptionnelles, de récentes études soulèvent la question de la toxicité d’un dérivé cyclique particulièrement utilisé dans les produits cosmétiques : le décaméthylcyclopentasiloxane (D5). Ainsi, deux problématiques font le sujet de ces travaux : une portant sur la recherche d’un substituant biosourcé au D5 et pour laquelle des molécules commerciales et synthétisées ont été caractérisés et comparés par des mesures physico-chimiques et sensorielles. La seconde problématique repose sur la recherche de corrélations entre les données physico-chimiques et sensorielles dans le but de faciliter le travail des formulateurs lors du screening des émollients par la prédiction de certaines de leurs propriétés sensorielles. / Emolliency is a word used to define the ability of a compound to soften or lubricate the skin. ln the cosmetic field, emollients are used to modify the consistency, the viscosity or the polarity of a formulation. Many emollients can be used in cosmetic products. However, in the literature both physicochemical and sensory data ar still lacking, making it difficult to choose an emollient. Furthermore, the sensory analysis usually performed to characterize emollients are particularly time-consuming and thus, expensive. Among the different chemical families of emollients, silicone derivatives stand out thanks to their specific properties. Indeed, they are characterized by an excellent spreading on skin and hair, a smooth skin feel, non-greasy and non-sticky, or by a dry skin feel without a fresh effect. However, even though these sensory properties are exceptional, recent studies wonder about the toxicity of a cyclic silicone particularly used in cosmetic products: the decamethylcyclopentasiloxane (D5). Thus, this work deals With two main objectives. The first one consists in the research of a bio-based alternative to the D5 For this purpose, a number of commercial and synthesized molecules were characterized and compared With physicochemical measurements and sensory analysis, allowing the observations of trends between structures and properties. The second objective relies on the study of correlations between physico-chemical and sensory data in order to predict the emollient properties of cosmetic ingredients. This would ease the work of formulators during the screening of ingredients.