Thesis (M.App.Sc.) - Carleton University, 2007. / Includes bibliographical references (p. 66-71). Also available in electronic format on the Internet.

A membrana amniótica é a camada interna das membranas fetais (placenta), amplamente utilizada em transplantes por ser um tecido que combina propriedades anti-inflamatórias, antimicrobianas e antifibróticas, além da limitada capacidade de provocar reações imunológicas. O uso da membrana fresca tem algumas limitações, como a necessidade de rápida utilização e a impossibilidade de obter total segurança diante de certas infecções. Qualquer tecido biológico utilizado para transplante deve ser estéril. A radioesterilização é uma alternativa para garantir a qualidade e segurança dos tecidos usados em transplantes e outras aplicações clínicas, a fim de minimizar os riscos de contaminação do receptor do tecido, porém a mesma pode causar alterações indesejáveis no tecido. No presente trabalho, foram testadas doses de 10, 15, 25 e 35 kGy, utilizando duas fontes de radiação ionizante: raios gama proveniente de fonte de Cobalto-60 e feixe de elétrons. Na análise qualitativa visual e táctil foi observado que, nas doses mais elevadas (a partir de 25 kGy) para ambas as fontes de radiação, as membranas irradiadas sofreram maior alteração de cor, tornando-se mais amareladas e com diminuição da elasticidade, deixando-as mais rígidas. A colorimetria sólida possibilitou minimizar a subjetividade da análise visual e a microscopia óptica foi essencial para avaliar as alterações histológicas comprovando, respectivamente, que a alteração de cor da membrana e o grau de degradação das camadas subjacentes do tecido tem relação direta com a dose de radiação empregada. Desse modo, as doses de 10-35 kGy podem ser aplicadas nas membranas amnióticas para sua utilização como bandagem biológica, porém, para as doses a partir de 25 kGy deve-se levar em consideração a alteração de coloração e condensação das camadas da membrana se estas forem destinadas para o uso oftálmico ou como substrato transportador para transplante de tecido cultivado in vitro. Com as técnicas de OCT, TG e ensaio de tração não foi possível avaliar as alterações biomecânicas encontradas na análise qualitativa, nas condições experimentais realizadas devido aos desvios-padrão obtidos para as cinco membranas testadas. / The amniotic membrane is the inner layer of the fetal membranes (placenta), widely used in transplantation as it is a tissue that combines properties anti-inflammatory and antifibrotic antimicrobial, and limited ability to induce immune reactions. The use of fresh membrane has some limitations such as the need for rapid deployment and not being completely safe against of certain infections. Any biological tissue used for transplantation should be sterile. The radiosterilization is an alternative to ensure the quality and safety of tissues used in transplants, and other clinical applications to minimize the risk of contamination of the tissue´s receptor, but it can cause undesirable changes in the tissue. In this study, we tested doses of 10, 15, 25 and 35 kGy, using two sources of ionizing radiation: gamma rays from cobalt-60 source and electron beam. In qualitative, visual and tactile analysis it has been observed that higher doses (25 kGy and up, to both sources of radiation) irradiated membranes had a greater color change, becoming yellowed and decreased elasticity, becoming more rigid. The solid colorimetry minimized the subjectivity of visual analysis and optical microscopy was essential to evaluate the histological changes showing, respectively, the color change of the membrane and the degree of degradation of the underlying layers of tissue is directly related to the dose of radiation employed. Thus, doses of 10-35 kGy can be applied in the amniotic membranes for application as a biological bandage, however doses from 25 kGy and up should take into account the changes in color and condensation of the layers of the membrane for ophthalmic use or as a carrier substrate for transplantation of cultured tissue in vitro. With the techniques of OCT, TG and tensile testing was not possible to evaluate the biomechanical findings in the qualitative analysis, the experimental conditions due to the standard-deviations obtained for the five membranes tested.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The wood over time passes through a process natural what that gradually losing their (mechanical, physical or chemical) properties in a gradual state of decay. This fact is compounded by the action of wood-destroying organisms that under favorable weather conditions such as rain, wind, damage with the quality of the wood. The present study aimed to evaluate the natural durability of wood Tetrorchidium rubrivenium Poeppig & Endlicher (Canemaçu) under the action of deteriorative organisms in field tests and laboratory analyzing two regions of wood, peripheral region and central region. The wood used for this work were obtained from five trees Canemaçu. We analyzed the apparent specific gravity for the two regions studied wood. For the laboratory test was followed to ASTM D 2017 (ASTM , 2005) with modification in the specimens to 2.0 x 2.0 x 0.9 cm , which were sawn parts of the peripheral region and the central region of same samples prepared for testing field with dimensions of 2.0 x 2.0 x 30 . Were analyzed for laboratory testing and field: mass loss and colorimetry and the field test: index behavior, static bending (MOR and MOE) and solubility in sodium hydroxide. For mass density at 12% moisture was obtained for peripheral region 0.483 g / cm ³ and central 0.424 g / cm ³ , which statistically significantly. The loss of mass in the laboratory test for brown rot was similar in the two regions with an average of 33 %, while for white rot results are different, with the peripheral region 23.35% and 36.57 % central region. The colorimetric parameters L *, a * and b * were significantly different depending on the fungal attack of brown rot and white rot in laboratory test values. In field trial samples installed in the open field showed a trend towards higher mass losses for samples of the forest. The deterioration index was reduced with the passage of time of exposure to the environment. The MOE and MOR were being reduced over time, but with periods of oscillation. The values obtained in solubility in 1% sodium hydroxide solution been declining with increasing time of exposure in the field. All wood samples exposed to natural weathering demonstrated a reduction in the b * parameter, causing the browning of the samples. Comparing the results obtained in laboratory tests and field for both regions analyzed the wood, it is concluded that both conditions do not have to be exposed in contact with the ground. / A madeira passa ao longo do tempo por um processo em que acontece aos poucos a perda de suas propriedades (mecânicas, físicas ou químicas) em um gradativo estado de apodrecimento. Este fato é potencializado pela ação de organismos xilófagos que em condições favoráveis de intempéries, como chuvas, ventos, entre outros corrompem com a qualidade da madeira. A presente pesquisa teve por objetivo avaliar a durabilidade natural da madeira de Tetrorchidium rubrivenium Poeppig & Endlicher (Canemaçu) sob a ação de organismos biodeterioradores, em ensaios de campo e de laboratório, analisando duas regiões da madeira, região próxima a casca e região próxima a medula. A madeira utilizada para a realização deste trabalho foi obtida de cinco árvores de Canemaçu. Foi analisada a massa especifica aparente para as duas regiões da madeira estudadas. Para o ensaio em laboratório foi seguido à norma ASTM D 2017 (ASTM, 2005) com modificação nos corpos de prova para 2,0 x 2,0 x 0,9 cm, onde foram serrados de peças da região próxima a casca e da região próximo a medula das mesmas amostras confeccionadas para ensaio de campo com dimensões de 2,0 x 2,0 x 30 cm. Foram analisados para ensaios de laboratório e campo: perda de massa e colorimetria, e para o ensaio de campo: indicie de comportamento, flexão estática (MOE e MOR) e solubilidade em hidróxido de sódio. Para a massa específica aparente a 12% de umidade obteve-se para região próxima a casca 0,483g/cm³ e região próxima a medula 0,424g/cm³, onde apresentou diferença estatística. A perda de massa sofrida em ensaio de laboratório para a podridão parda foi parecida nas duas regiões com uma média de 33%, já para podridão branca os resultados foram distintos, com na região próxima a casca 23,35 % e região próximo a medula 36,57%. Os parâmetros colorimétricos L*, a* e b* apresentaram valores significativamente distintos em função do ataque dos fungos de podridão parda e podridão branca em ensaio de laboratório. Em ensaio de campo as amostras instaladas no campo aberto apresentaram a tendência de maiores perdas de massa em relação às amostras da floresta. O Índice de deterioração foi reduzindo-se com o decorrer do tempo de exposição ao ambiente. O MOE e o MOR foram sendo reduzidos com o passar do tempo, porém com períodos de oscilação. Para os valores obtidos na solubilidade em hidróxido de sódio 1% observou-se que foram decaindo conforme aumenta o tempo em exposição a campo de apodrecimento. Todas as amostras de madeira expostas ao desgaste natural demostraram uma redução do parâmetro b*, ocasionando o escurecimento das amostras. Comparando-se os resultados obtidos nos testes de laboratório e de campo para ambas as regiões da madeira analisadas, conclui-se que ambas não apresentam condições de serem expostas em contato com o solo.

This master’s thesis studies the effect of weathering on thermally modified Norway spruce (Picea abies) and Scots pine (Pinus sylvestris) with different surface treatments. Most importantly colour changes were analysed, especially, the greying. However, other aspects of appearance changes, like cracks, mould and chemical changes on the surface were included. Special emphasis was on analysing the influence of tree species, type of thermal modification and surface treatment on these properties. Furthermore, it was tested if near infra-red (NIR) spectroscopy allows to estimate the colour, in addition, to measuring chemical changes. The whole study was set up as a decking of a gangway in Northern Sweden and evaluated after the first year of exposure. With the help of colorimetry, changes in colour based on the CIE L*C*hab colour space were measured. Test results showed that within one year all surfaces turned greyer significantly due to changes in content of lignin and cellulose measured with NIR spectroscopy. Differences could neither be observed between the uses of the two tree species nor between the uses of the thermal modifications, pressurised saturated steam at a temperature of 180 °C and superheated steam at a temperature of 212 °C. However, the surface treatment affects the colour change. Timber treated with a silicon based treatment had from the beginning a greyer colour and turned greyest after one year, while oil and pigmented oil stain slowed down the greying compared to untreated and iron vitriol treated timber. After one year of exposure for none of the treatments the colour had stabilised. Qualitative analysis of cracks and mould growth on the surface indicated some dependence on thermal modification and surface treatment. The PLS model for the prediction was not good, so no universally valid conclusions could be drawn of them. Timber with silicon based treatment showed a tendency for mould growth and timber thermally modified with pressurised saturated steam at a temperature of 180 °C tends to have cracks more often. It was possible to estimate the colour from NIR spectroscopy. Best estimations were achieved for the Chroma, followed by lightness and hue. Even better prediction of the Chroma could be achieved by fitting different models based on the surface treatments.  Hence, NIR spectroscopy allows a good estimation of the greying without needing a further measurement instrument, like a colorimeter.

abstract: Human breath is a concoction of thousands of compounds having in it a breath-print of physiological processes in the body. Though breath provides a non-invasive and easy to handle biological fluid, its analysis for clinical diagnosis is not very common. Partly the reason for this absence is unavailability of cost effective and convenient tools for such analysis. Scientific literature is full of novel sensor ideas but it is challenging to develop a working device, which are few. These challenges include trace level detection, presence of hundreds of interfering compounds, excessive humidity, different sampling regulations and personal variability. To meet these challenges as well as deliver a low cost solution, optical sensors based on specific colorimetric chemical reactions on mesoporous membranes have been developed. Sensor hardware utilizing cost effective and ubiquitously available light source (LED) and detector (webcam/photo diodes) has been developed and optimized for sensitive detection. Sample conditioning mouthpiece suitable for portable sensors is developed and integrated. The sensors are capable of communication with mobile phones realizing the idea of m-health for easy personal health monitoring in free living conditions. Nitric oxide and Acetone are chosen as analytes of interest. Nitric oxide levels in the breath correlate with lung inflammation which makes it useful for asthma management. Acetone levels increase during ketosis resulting from fat metabolism in the body. Monitoring breath acetone thus provides useful information to people with type1 diabetes, epileptic children on ketogenic diets and people following fitness plans for weight loss. / Dissertation/Thesis / Ph.D. Chemistry 2013

Os enxertos hepáticos com esteatose apresentam risco aumentado para a disfunção e o não funcionamento primário. Entretanto, considerando o permanente desequilíbrio entre a oferta e a demanda de enxertos, justifica-se o uso de fígados esteatóticos com um risco aceitável. O padrão ouro para o diagnóstico do grau da esteatose hepática, na prática clínica, é o exame histológico. Entretanto, no cenário dos transplantes, a estimativa do grau de esteatose do enxerto hepático depende do exame macroscópico. Nesse procedimento a leitura da cor é realizada de forma subjetiva e a força da associação cor-esteatose não é conhecida. Considerando esses aspectos, a presente pesquisa teve como objetivo verificar a associação entre a cor do fígado e a intensidade da esteatose hepática, aferindo a cor do fígado, de forma precisa com um colorímetro e quantificando a esteatose com dois exames considerados de referência. Método: Ratos wistar, machos, foram divididos em quatro grupos de quinze animais. Os animais do grupo controle receberam dieta padrão. Os outros três grupos receberam dieta esteatogênica durante, respectivamente, dois, quatro e seis dias. Os ratos foram submetidos à laparotomia, biópsia hepática (pré e pós-perfusão do fígado) para realizar o exame histológico, colorimetria no padrão RGB (pré e pós-perfusão do fígado), conversão da cor, do padrão RGB, para o padrão CINZA, coleta de sangue para realizar exames laboratoriais e hepatectomia (para determinar o peso relativo do fígado e a extração da gordura). A análise estatística foi realizada com o pacote de software estatístico IBM SPSS Statistics 18, e o valor p < 0.05 foi considerado com significado estatístico. Resultados: Foi observada correlação positiva entre os percentuais de gordura e a intensidade das cores pré perfusão (coeficiente de correlação da cor vermelha 0,874, cor verde 0,747 e cor azul 0,763) e pós-perfusão (coeficiente de correlação da cor vermelha 0,900, cor verde 0,886 e cor azul 0,856). As medias dos valores da colorimetria, pré e pós perfusão, apresentaram diferença estatisticamente significativa (p < 0,001). A acurácia da colorimetria pós perfusão, determinada pela curva ROC, foi de100% na determinação da presença de esteatose, 96,2% para o grau moderado ou intenso e 80,4% para o grau intenso da esteatose. Foi verificada diferença significativa dos valores da colorimetria (p < 0,001) entre as medias dos diversos grupos com exceção entre os grupos concentração de gordura moderada X gordura intensa e entre os grupos graus histológicos da esteatose leve X moderada X intensa. Conclusões: a) A cor do fígado, pré e pós perfusão, apresentou correlação forte com a esteatose, de forma positiva e linear; b) A colorimetria, pré e pós perfusão, apresenta a mesma acurácia na identificação da esteatose c) A colorimetria apresentou acurácia perfeita na identificação da presença da esteatose e tendência para classificar, em um mesmo grupo, a esteatose moderada e intensa. / Hepatic grafts with steatosis are at increased risk for dysfunction and primary non-functioning. However, considering the permanent imbalance between supply and demand of grafts, the use of specially selected livers with steatosis is justified. The gold standard for the diagnosis of hepatic steatosis in clinical practice is histological examination. However, in the transplant scenario, the estimation of the grade of hepatic graft steatosis depends on macroscopic examination. In this procedure the color reading is carried out subjectively and the strength of the association of color-steatosis is not known. Considering these aspects, the present study aimed to verify the association between liver color and liver steatosis intensity, accurately assessing the color of the liver with a colorimeter and quantifying steatosis with two exams considered as reference. Method: Male wistar rats were divided into four groups of fifteen animals. The animals in the control group received a standard diet. The other three groups received a steatogenic diet during, respectively, two, four and six days. Rats were submitted to laparotomy, liver biopsy (pre and post-perfusion of the liver) for conventional histological examination, colorimetry in the RGB pattern (pre and post-perfusion of the liver), color conversion from the RGB standard to the GRAY standard, Blood collection for laboratory tests and hepatectomy (to determine relative liver weight and fat extraction). Statistical analysis was performed with the statistical software package SPSS Statistics 18, and p value <0.05 was considered statistically significant. Results: A positive correlation was observed between fat percentages and preperfusion color intensity (red color correlation coefficient 0.874, green color 0.747 and blue color 0.763) and postperfusion (correlation coefficient of red color 0.900, green color 0.866 and blue color 0.856). The mean values of the colorimetry, pre- and post-perfusion, presented a statistically significant difference (p <0.001). The accuracy of the post-perfusion colorimetry, determined by the ROC curve, was 100% in the determination of the presence of steatosis, 96.2% for the moderate or intense degree and 80.4% for the intense degree of steatosis. There was a significant difference (p <0.001) between the means of the different groups except for the groups of moderate fat X intense fat concentration and between the histological grades groups of mild X intense moderate X steatosis. Conclusions: a) The color of the liver, pre and post perfusion, showed a strong correlation with steatosis, in a positive and linear way; B) Colorimetry, pre- and post-perfusion, shows the same accuracy in the identification of steatosis. C) Colorimetry showed perfect accuracy in the presence of steatosis and a tendency to classify moderate and severe steatosis in the same group.

Orientador: Claudio Airoldi / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-11T15:31:53Z (GMT). No. of bitstreams: 1 SilvaFilho_EdsonCavalcanti_D.pdf: 2613904 bytes, checksum: d11afdfd88c2cca6c7defe5b058e97bd (MD5) Previous issue date: 2008 / Resumo: Dentre agentes usados para clorar a celulose, o cloreto de tionila apresentou melhor resultado com grau de substituição 1,00 na hidroxila primária. Esse intermediário reagiu para incorporar as moléculas 1,2-etilenodiamina, 1,4-butilenodiamina, acetilacetona e 2- aminometilpiridina. Na reação com etilenodiamina foram otimizadas as condições de síntese variando a quantidade e os solventes água ou N-N¿-dimetilformamida, demonstrando que quanto menor o volume de solvente 10,0 cm, maior a incorporação. Na ausência de solvente a quantidade incorporada foi maior, com 3,03±0,01 mmol de grupos pendentes por grama de celulose. Com 1,4-butilenodiamina não houve sucesso na ausência de solvente, porém, com a quantidade mínima de solvente foi 0,66±0,04 mmol g. A acetilacetona não reagiu com a celulose clorada, mas apenas após ser modificada com etilenodiamina e 5,70±0,22 mmol de nitrogênio ficou pendente por grama de celulose, após a formação da base de Schiff em ligações cruzadas. A molécula 2-aminometilpiridina foi incorporada na ausência de solvente, conseguindo 0,10±0,01 mmol g. Esses materiais foram caracterizados e aplicados na remoção de metais divalentes em meio aquoso, com as capacidades de adsorção: a) etilenodiamina 1,32±0,07; 1,91±0,07; 1,08±0,04 e 1,31±0,02, b) etilenodiamina/acetilacetona 2,32±0,06; 1,85±0,02; 1,70±0,04 e 1,65±0,02, c) butilenodiamina 0,32±0,03; 0,29±0,01; 0,26±0,03 e 0,25±0,02 e d) 2-aminometilpiridina 0,100±0,012, 0,093±0,021, 0,074±0,011 e 0,071±0,004 mmol g, para cobre cobalto, níquel e zinco, respectivamente. Foram determinadas as interações cátion-centro básico através de titulação calorimétrica em meio heterogêneo com valores exotérmicos de entalpia. A espontaneidade das reações é expressa pelos valores negativos da energia livre de Gibbs. Com exceção do cobre na celulose modificada com etilenodiamina, do cobalto, níquel e zinco com a celulose modificada com a 2-aminometilpiridina, todos os outros valores de entropia foram positivos, havendo assim um favorecimento entrópico / Abstract: Among the agents used to chlorinate cellulose, thionyl chloride gave better results with a degree of substitution 1.00 on primary hydroxyl group. This intermediate reacted to incorporate the molecules 1,2-ethylenediamine, 1,4-butylenediamine, acetylacetone and 2- aminomethylpyridine. For the reaction with 1,2-ethylenediamine the synthetic conditions was optimized, by varying the amounts and the solvents water or N,N¿-dimethylformamide, demonstrating that the lower the volume of solvent 10 cm, the higher is the incorporation. The absence of solvent yielded the highest amount incorporated, 3.03±0.01 mmol of pendant groups per gram of cellulose. For 1,4-butylenediamine the reaction in absence of solvent failed, however, with a minimum amount of solvent, it gave 0.66±0.04 mmol g. Acetylacetone did not react directly with the chlorinated cellulose, but when the precursor was chemically modified with 1,2-ethylenediamine to give 5.70±0.22 mmol of pendant nitrogen atom per gram of cellulose, Schiff base formation with crosslinking bonds was observed. Aminemethylpyridine was incorporated in the absence of solvent to give 0.10±0.01 mmol g. These materials were characterized and applied for divalent cations removal in aqueous solution. The adsorption capacities gave for: a) 1,2-ethylenediamine 1.32±0.07; 1.91±0.07; 1.08±0.04 and 1.31±0.02, b) 1,2-ethylenediamine/acethylacetone 2.32±0.06; 1.85±0.02; 1.70±0.04 and 1.65±0.02, c) butylenediamine 0.32±0.03; 0.29±0.01; 0.26±0.03 and 0.25±0.02 and d) 2-aminemethylpyridine 0.100±0.012, 0.093±0.021, 0.074±0.011 and 0.071±0.004 mmol g, for copper, cobalt, nickel and zinc, respectively. The cation-basic center interactions determined through calorimetric titration in heterogeneous conditions gave exothermic values, with spontaneity of reactions through all negative free Gibbs energies. With the exception of copper with cellulose chemically modified with 1,2-ethylenediamine, cobalt, nickel and zinc with cellulose modified with 2- aminemethylpyridine, all entropy values were endothermic, to give a favorable entropic conditions / Doutorado / Quimica Inorganica / Doutor em Quimica

À l'heure actuelle, la voiture n'est plus un objet qui permet seulement de transporter une personne d'un endroit à un autre et il suffit de regarder les publicités automobiles pour en avoir la certitude. En effet, le champ lexical utilisé dans ces dernières se rapproche plus des sens, voire du rêve, que de la mobilité. La voiture n'est donc plus reléguée au simple rang de transporteur, mais à celui de véritable habitat dans lequel nous sommes amenés à découvrir de nouvelles sensations. Dans ce cadre, la réalité virtuelle est l'un des outils qui est utilisé dans l'industrie automobile afin de vérifier, en amont, l'ergonomie d'un prototype. En effet, en immergeant partiellement un usager dans cette autre réalité, il est possible d'avoir des retours pertinents quant à une maquette numérique, une interface, etc. Cela permet ainsi de tester différentes pièces avant même leur production ce qui est un gain notable en temps et en argent. Cependant, l'utilisation de cette technologie pose des questions quant au photo-réalisme de la reproduction virtuelle, et ce, tout particulièrement lorsque des pièces tels que les blocs optiques de la voiture sont analysés. Sur cette thématique, des études antérieures ont montré que le système reproduisait correctement les intensités lumineuses, mais pas la couleur des phares. Ainsi, dans le contexte du rendu de phare photoréaliste, nous avons tout d'abord proposé deux échelles colorimétriques afin d'analyser à quel point nous pouvions nous éloigner de la réalité sans que la différence de couleur ne gêne l'utilisateur final. À la suite de cela, nous avons proposé un système qui suit, au jour le jour, le vieillissement du simulateur dans le but de corriger ladite différence colorimétrique. Enfin, dans une étude exploratoire, nous avons souhaité regarder comment le comportement des conducteurs pouvait être influencé par la couleur des phares de voiture. Nous supposions que ce facteur pouvait avoir un impact sur la perception des distances et donc sur la distance intervéhiculaire à laquelle le conducteur se positionnait. / Nowadays, a car is not limited to the transportation of one or many people. Indeed, if we take a look at some automobile advertisement, it's more the idea of desir or even dream that is conveyed. Therefore, a car is no longer related to the simple rank of carrier but is a real new habitat in which we will discover new sensations. In this context, the car company that offers the best experience at the better price should be the one that dominates the market. For that purpose, virtual reality is one of the tools that is used by the automotive industry. Indeed, by partially immerging a user in this "other" reality, it is possible to get a relevent feedback for a digital model, Human-Machine Interface, etc. This allows to test different pieces before their production which is a significant gain in time and money. However, the use of this technology raises questions about the fidelity of the reproduction. Do the virtual reproduction of an object is close enough to the original ? If there is a difference, how could it impact the judgment of a person ? Those questions are even more important when it comes to the virtual evaluation of car headlight because they must respect international standard in term of color and light intensity. For these points, previous studies have shown that the system correctly reproduced the light intensities but not the headlights color. Thus, in the context of rendering photorealistic headlights, we first investigate on how a color difference can affect, discomfort the headlight specialist. To this end, we lead psychometric experiments and proposed two color difference scales (one for a naïve population and the other for an expert one). With this first result, we have proposed a system that follows, day by day, the aging simulator in order to correct the said color difference. Finally, in an exploratory study, we wanted to look at how the driver behavior could be influenced by the color of the car headlights. We assumed that this factor could affect depth perception and therefore the distance intercar in which the driver was positioning.

The thesis reports on fabricating alternative solid phase extraction (SPE) sorbents and colorimetric probes based on electrospun nanofibers for alkylphenols (APs). Hydroxyl methylated styrene [poly(co-styrene-CH₃OH)] and 3-oxobutanoate styrene [poly(co-styrene-OCOCH₃COCH₃)] copolymers were synthesized and fabricated into sorbent materials by electro-spinning/spraying. The fabricated morphologies consisting of bead free fibers, beaded fibers and particles were evaluated as SPE sorbents using batch experiments. Electropun fibers proved to be better sorbents as they exhibited extraction efficiency that exceeded 95% compared to 60% for beaded fibers and 40% for particles. In view to reduce sample and solvent volumes, smooth fibers were packed into pipette tips as SPE devices that yielded quantitative recoveries of APs from spiked wastewater samples. Recoveries ranged from 70% to 125% with LOD of 0.008, 0.01 and 0.1 μg mL⁻¹ for 4-tert octylphenol (4-t-OP), 4-octylphenol (4-OP) and 4-nonylphenol (4-NP) respectively, when using high performance liquid chromatography-fluorescence detector (HPLC-FLD). Furthermore, amino functionalised polydiacetylene polymers (PDAs), citrate capped gold (AuNPs) and silver nanoparticles (AgNPs) were evaluated as colorimetric probes for visual detection of APs. In colloidal studies, AuNPs probe showed a colour change from wine red to green upon introduction of analyte. UV-vis spectroscopy revealed the shifting of the surface plasmon resonance (SPR) peak from 525 nm to 729 nm induced by aggregation of AuNPs. For AgNPs probe, a colour change was observed from yellowish green to brown. Transmission electron microscopy (TEM) studies showed growth of AgNPs. A presumed oxidation of the analyte, forming an absorbing compound at 279 nm in both AgNPs and PDAs probes was also observed. For PDAs probe the colour change was from purple to pink. Concentrations as low as 30 μg mL⁻¹ were detectable in all colloidal based probes. Further colorimetric investigations were conducted with electrospun AuNPs-nylon 6 fiber mat. A colour change from purplish red to navy blue at concentrations of 1000 μg mL⁻¹ was observed. Electrospun AgNPs –nylon 6 fiber mat did not show a distinct colour change. High resolution scanning electron microscopy (HRSEM) revealed the analyte inducing the assembly of AuNPs and AgNPs as they covered the surface of the nanofiber mat. Electrospun nanofibers are a platform for analysis and thus tuning their chemistry will lead to sensitive and selective methods

[pt] O controle das cores, seja visual ou instrumental, necessita de padrões de comparação. No caso visual esse padrão tem que ser uma amostra real, mas no caso instrumental existe a possibilidade de definir padrões virtuais em forma de valores de refletância espectral. Os padrões reais não são permanentes. A cor muda com o tempo dependendo do substrato, dos corantes ou pigmentos e dependendo da forma de armazenamento essa mudança se torna perceptível após algumas semanas, meses ou anos. Outra limitação dos padrões reais é a dificuldade de reproduzi-los em número suficiente com reprodutibilidade aceitável. Nas indústrias é muito comum usar coleções de cores padrões (por exemplo, Pantone, NCS, RAL, ColorCurve), mas mesmo assim sempre há uma diferença entre amostras até da mesma edição, e muito mais entre edições diferentes. Os padrões virtuais não têm essas desvantagens, mas para poder utilizá-los, tem-se que determinar o efeito da estrutura da amostra (não mostrada pelos valores de refletância) na cor percebida, e os limites de tolerância permissíveis na iluminação primária (luz do dia) e em outras iluminações (incandescente, fluorescente). Apresentam-se no texto conceitos relevantes e básicos sobre colorimetria limitados ao escopo abordado no trabalho. O objetivo do trabalho é verificar quantitativamente a diferença instrumental de cor de tecidos com diferentes estruturas, a eficiência de diferentes métodos de cálculo computadorizado de correção de receitas de tingimento e a influência do fenômeno da metameria na tolerância colorimétrica. As amostras têxteis com diferentes estruturas serão tingidas em diversas cores e medidas para a determinação da relação da estrutura com a tolerância instrumental, para vários padrões virtuais e vários iluminantes. Demandou-se a preparação de amostras padrão e medições espectrofotométricas, com elevado controle metrológico, realizadas nas dependências do SENAI-CETIQT, mais especificamente nas UOEQ (Unidade Operacional de Ensaios Químicos) e UOC (Unidade Operacional de Colorimetria). Para a análise dos resultados utilizou-se de métodos estatísticos e matemáticos, auxiliada por planilhas eletrônicas. Complementando a formação acadêmica, o desenvolvimento da pesquisa realizou-se nas instalações do SENAI/CETIQT, que possui comprovada competência técnica e científica na área colorimétrica e uma adequada infra-estrutura laboratorial em metrologia da cor que deu suporte ao trabalho. A presente pesquisa de mestrado voltada ao equacionamento de problemas de interesse industrial desenvolveu-se no contexto de um convênio celebrado entre o Programa de Pós-Graduação em Metrologia da PUC-Rio e o SENAI/CETIQT, que somam esforços para consolidar no País uma nova área de pesquisa em metrologia da cor. Por essa razão, o trabalho foi incluído dentre os 10 projetos-piloto que participaram do Convênio FINEP/MCT no. 22.01.0692.00, Referência 1974/01, que aportou recursos do Fundo Setorial Verde Amarelo para direcionar o esforço de pesquisa em metrologia para a solução de problemas de interesse industrial. Foi com esse propósito que padrões virtuais e tolerâncias colorimétricas no controle instrumental das cores foi selecionado como tema central da pesquisa, cujo desenvolvimento beneficiou-se do ambiente acadêmico e de pesquisa da universidade e da excelente infra-estrutura laboratorial em colorimetria do SENAI/CETIQT. A cooperação inter-institucional estabelecida evidencia o potencial da parceria na solução de complexos problemas de interesse industrial. / [en] The control of colors, either visual or instrumental, needs comparison standards. In the visual case this standard has to be a real, physical sample, but in the instrumental case, it is possible to define virtual standards in the form of spectral reflectance values. The real standards are not permanent. Their color changes over time depending on the substrate, the dyes or pigments, and - depending on the storage form - this change becomes perceptible after some weeks, months or years. Another limitation of the real standards is the difficulty to reproduce them in sufficient number with acceptable reproducibility. In industry it is very common to use collections of colors standards (for example, Pantone, NCS, RAL, Color-Curve), but even then there is always a difference between samples even of the same edition, and much more between different editions. Virtual standards do not have these disadvantages, but to be able to use them, the effect of the structure of the sample on the perceived color (not shown by the values of spectral reflectance), as well as the acceptable limits of tolerance under the primary illumination (daylight) and under other illuminations (incandescent, fluorescent) have to be determined. Relevant and basic concepts of colorimetry are presented in the text, limited to the scope of the work. The objective of the work is to quantitatively verify the instrumental color difference between fabrics with different structures, the efficiency of different methods of computerized dye recipe correction calculation and the influence of the phenomenon of metamerism on colorimetric tolerances. Textile samples with different structures will be dyed in diverse colors and the effect of the structure on the instrumental tolerance for some virtual standards and some illuminants will be determined by instrumental measurements. Sample preparation and spectrophotometric measurements were performed under careful metrological control, carried out in the installations of SENAI-CETIQT, more specifically in the UOEQ (Chemical Testing Laboratory) and UOC (Applied Colorimetry Laboratory). Statistical and mathematical methods, assisted by electronic spread sheets, were used for the analysis of the results. Complementing the academic development, the experimental research took place at SENAI/CETIQT, an institution with proven scientific and technical capabilities in the field of colorimetry and outstanding laboratorial infrastructure in color metrology, that gave support to the work. The present M.Sc. Dissertation aiming at the solution of problems of industrial interest was developed in connection with an agreement celebrated between the Post-graduate Programme in Metrology of PUC-Rio and SENAI/CETIQT which cooperate to implement in the country a new area of research in metrology applied to colorimetry. For this reason, the research work was included among the 10 pilot-projects which benefited from the financial support received from the FINEP/MCT Agreement no. 22.01.0692.00, Reference 1974/01 (Green-Yellow governmental Fund) driving the research effort in metrology to the solution of industrial problems. This is why virtual standards and colorimetric tolerances in the instrumental control of the colors was selected as the central topic of this research, which successful development strongly benefited from the academic and scientific environment provided by the university and also by the outstanding laboratory infrastructure in colorimetry offered by SENAI/CETIQT. The agreement established proved to speed up the solution of complex problems requiring advanced knowledge of metrology.