[pt] Não obstante os sofisticados avanços em tecnologias ópticas, ainda não existem fontes de luz artificial capazes de simular de forma adequada a luz do dia natural. Alcançar um padrão de iluminação como este representará uma redução nos custos de produção, em função de retrabalhos gerados por avaliações visuais pouco confiáveis, e nas divergências comerciais relacionadas a produtos que têm como característica de controle a cor, tais como artigos têxteis, gráficos, de merchandising etc. A presente pesquisa de mestrado em metrologia relaciona-se à avaliação metrológica das fontes luminosas e cabines de iluminação disponíveis no mercado e à sua adequação às normas que definem especificações técnicas, com o propósito de estimular introdução de inovação tecnológica em novos desenvolvimentos industriais capazes de melhorar o desempenho desses aparatos. A pesquisa contribui, também, com o desenvolvimento de um diagnóstico do acervo de normas técnicas disponíveis aplicáveis à padronização de sistemas de iluminação; investigação de lâmpadas fluorescentes usualmente utilizadas como simuladores de luz do dia e avaliação metrológica de cabines de iluminação disponíveis no mercado. Em particular, medições foram realizadas em um sistema espectroradiométrico de alta definição, que utiliza um monocromador duplo com capacidade de dispersão do feixe de 2 nm/mm. Ensaios e análises de repetitividade e reprodutibilidade conduzidas no sistema de medição espectroradiométrico permitiu quantificar a variabilidade associada a cada lote de fabricação dos simuladores de luz do dia, comercializados na forma de lâmpadas fluorescentes disponíveis no mercado nacional. Caracterizada a variação da distribuição espectral ao longo do eixo das fontes luminosas investigadas (lâmpadas) foi possível desenvolver uma análise do impacto induzido na uniformidade da iluminação obtida em cabines industrializadas, assim definindo um fator de diferenciação de interesse técnico e comercial. A pesquisa revelou que nenhum dos simuladores de luz do dia testados atingiu os requisitos mínimos estabelecidos para a comparação visual de cores, quando avaliados com base em normas e práticas internacionais. Foram ainda realizadas medições para se verificar a influência dos elementos construtivos das cabines na distribuição espectral de potência na área de avaliação. Fundamentado nas 1578 medições realizadas em condições laboratoriais que simulam ambientes industriais, a pesquisa comprova que alterações nas características construtivas das cabines possuem impacto no resultado da classificação das distribuições espectrais de potência, criando assim uma condição facilitadora para que as especificações normativas sejam atingidas, mesmo com a utilização de lâmpadas fluorescentes disponíveis no mercado e de preço reduzido. / [en] Notwithstanding the complex advances in optical technologies, there are still no artificial light sources capable of adequately simulating the natural daylight. Reaching such a lighting standard will represent a reduction of the production costs, in view of the rework caused by not so reliable visual evaluations, and of the commercial conflicts related to products that have colour as one of their control characteristics, such as textile, graphics and merchandising articles. The present Master degree metrology research is related to the metrological evaluation of the lighting sources and light booths available in the market (commercially available), and to their conformity to the technical specifications standards, aiming to stimulate the introduction of technological innovation to new industrial developments eligible to enhance the performance of these apparatus. The research has also contributed to the development of a diagnosis of the collection of the existing technical standards applied to the standardisation of lighting systems; to the investigation of fluorescent lamps generally used as daylight simulators, and to the metrological evaluation of light booths available in the market (commercially available). Particularly, analyses were done with a highly precise spectroradiometric system that uses a double monochromator with capacity for beam dispersion of 2 nm/mm. Tests and analyses on repeatability and reproducibility made with the spectroradiometric measurement system let to quantify the variety associated with each manufactured set of daylight simulators, commercialised as fluorescent lamps available at the local market. Having the spectral distribution determined throughout the axis of the studied lighting sources (lamps) it was possible to develop an analysis of the impact caused at the lighting uniformity obtained for industrial light booths, and so, specifying a distinctive factor technically and commercially interesting. The research revealed that, when evaluated considering the international practices and standards, none of the daylight simulators tested achieved the minimum requirement indicated for the visual comparison of colours. In addition, measurements were done to verify the influence of the light booths building pieces at the power spectral distribution within the evaluation area. Based on 1578 measurements done at laboratorial conditions simulating industrial environment, the research proves that changes in the building characteristics of the light booths produce an impact at the result of the power spectral distribution classification, creating, thus, a smooth condition for the attendance of the standards specifications, even when using low-cost fluorescents lamps available in the market.

Conserving the environment is an issue that is gaining popularity day by day. Phosphorus transfer from agricultural soils is an important environmental issue that is being closely observed as the transport of phosphorous to water bodies is adversely affecting water quality due to accelerated eutrophication. It is important to establish phosphorous models that accurately account for soil test phosphorous. Standard models like SWAT (Soil and Water Assessment Tool) and EPIC (Environmental Policy Integrated Climate) were designed for serving this purpose. They are now used as the basis for developing new models that can more accurately account for the phosphorus transport, depending on local soil conditions and external factors like climate, addition of biochar or other soil amendments. Our research involved development of new methods from published data that are applied to different soils from Kentucky that are incubated for various time periods, with and without the addition of biochar amendments. Changes in the soil labile phosphorus content after phosphorus addition to and depletion from these incubated soils was measured to discern the effect of biochar on the rates of phosphorus transport. The measured labile phosphorus was further analyzed using statistical analysis software drawing comparisons among treatments without biochar, with low temperature biochar and high temperature biochar for specific soil-biochar combinations. Loamy sand soils with both pine chips and switch grass biochar types have shown slightly increased leeching of phosphorus upon addition of biochar whereas clay loam soils have not shown any significant change upon addition of biochar.

Cette thèse présente le développement de tests immunologiques innovants, rapides et sensibles combinant des nanoparticules superparamagnétiques (SPN) fonctionnalisées et des micro-aimants : nos immuno-essais magnétiques exploitent les forts gradients de champ magnétique de ces micro-aimants pour capturer les complexes immunologiques liés aux SPN. L’attraction magnétique est souvent utilisée en biotechnologies car elle peut générér des forces capables de capturer des molécules d’intérêt. Les immuno-essais sur billes utilisent habituellement des aimants centi- et millimétriques pour capturer des micro-particules. Réduire la taille des particules magnétiques est très intéressant pour réduire les cinétiques de réactions, tout en diminuant les phénomènes de sédimentation et d’agrégation. Cette réduction d’échelle des particules permet aussi d’augmenter la surface de réaction et ainsi d’augmenter la sensibilité des tests. Cependant les aimants millimétriques génèrent des gradients faibles qui capturent difficilement les SPN, trop mobiles. Les micro-aimants de l’Institut Néel génèrent des forts gradients locaux et ainsi des forces magnétiques importantes. Ces technologies innovantes sont utilisées dans cette thèse pour développer des immuno-essais rapides tirant profit de la réduction d’échelle des particules et des aimants, par rapport aux technologies commerciales.Dans un premier temps, nous avons développé un test immunologique magnétique (MagIA) colorimétrique, comme approche innovante du test ELISA. Nous avons réalisé une preuve de concept pour la détection d’anticorps dirigé contre l’ovalbumine et comparé les résultats avec ceux de tests ELISA. Le test MagIA optimisé présente une limite de détection et une zone dynamique similaires au test ELISA développé avec les mêmes réactifs biologiques. Les micro-aimants fabriqués selon la méthode de micro-magnetic imprinting sont intégrés à bas coût dans les micro-puits des plaques multi-puits ELISA, et permettent la capture efficace des complexes immunologiques couplés aux SPN. La méthode est générique est permet de réaliser des tests ELISA en 30 minutes avec le même équipement.Nous avons ensuite développé un test magnétique immunologique avec une détection fluorescente locale tirant profit des propriétés de capture locale des SPN sur les micro-aimants. Ce test permet la quantification de la molécule d’intérêt en à peine 15 minutes sans étape de lavage. Une preuve de concept réalisée sur la détection de l’anticorps anti-ovalbumine a été réalisée, avec des anticorps de détection fluorescents et des micro-aimants fabriqués selon la méthode de thermo-magnetic patterning. La mesure différentielle entre le signal fluorescent provenant des complexes immunologiques couplés aux SPN localisées sur les micro-aimants, et le signal non spécifique (à l’extérieur des micro-aimants) permet la quantification d’une molécule. Ce test MLFIA (magnetically localized FIA) possède des performances jusqu’à 100 fois meilleures que les tests ELISA standard, pour la détection d’anticorps anti-ovalbumine en PBS. Le test MLFIA a ensuite été transféré à la détection de paramètres cliniques tels que la protéine C réactive, l'ostéopontine, et les sérologies de la toxoplasmose (IgG et IgM). La comparaison des résultats avec des méthodes automatisées a montré d’excellentes corrélations. Le test MLFIA présente plusieurs avantages : il est versatile, compatible avec les milieux biologiques, utilise de faibles volumes et requiert peu d’énergie. Ces résultats ouvrent la voie à une nouvelle génération de tests immunologiques sensibles et nous développons désormais un lecteur miniature pour le diagnostic portable. / This thesis reports the development of innovative, sensitive and fast immunoassays combining functionalized superparamagnetic nanoparticles (SPN) and micro-magnets. Our magnetic immunoassays exploit high gradients generated by micro-magnets to capture immune-complexes captured on SPN. Magnetic attraction is widely used in biotechnology, because it provides long-range forces able to capture molecules of interest. Bead-based immunoassays use common centimetre-scale magnets to attract micro-particles. Those magnets generate low magnetic gradients and struggle to capture superparamagnetic nano-particles, which are too small and mobile to be efficiently trapped. Down-scaling the size of magnetic particles is very interesting since it allows diffusion-based transport to perform faster reactions, while avoiding particle sedimentation and aggregation. Furthermore, it increases the reaction surface, which improves the sensitivity of immunoassays. Thanks to the scaling law effects micro-magnets from Institut Néel generate high local gradients and therefore large magnetic volume forces: we use this innovative technology to develop fast immuno-assays that take advantage of a radical size reduction, compared to commercial technology.We first developed a colorimetric magnetic immunoassay (MagIA) as a new approach to standard ELISA. A proof-of-concept based on colorimetric quantification of anti-ovalbumin antibody in buffer was performed and compared with conventional ELISAs. After optimization, MagIA exhibits a limit of detection and dynamic range similar to ELISAs developed using the same biochemical tools. Micromagnets made by the micro-magnetic imprinting method can be fully integrated in multi-well plates at low cost, allowing the efficient capture of immuno-complexes carried by SPNs. The method is generic and performs magnetic ELISA in 30 min.We then developed a magnetically localized fluorescent immunoassay (MLFIA) exploiting the local capture of SPN on micro-magnets. The differential measurement of fluorescence localized on and besides micro-magnet arrays allows the detection and quantification of a molecule in only 15 minutes without fluid handling. We present a proof of concept based on the detection of monoclonal antibody anti-ovalbumin. Functionalized nanoparticles are incubated with fluorescent detection antibody and the sample containing the molecule to be detected. After a single incubation step, the nanoparticles are captured on micro-magnets made by thermo-magnetic patterning. Fluorescence is then read under a microscope. Differential measurement between the signal from the immunological complex localised on the micro-magnets and the non-specific signal localised besides micro-magnets allows the quantification of mAb anti-OVA. The performance of MLFIA was compared with conventional ELISA and exhibits a limit of detection up to 100 times better for anti-OVA mAb in PBS. For further validation, MLFIA was used to measure clinical parameters: we developed a sandwich assay to detect C-reactive protein, and a serology for Toxoplasma gondii immunoglobulin G and M or osteopontin in human samples. Comparisons with data obtained with routine clinical automatized methods show excellent correlation. Our MLFIA technology presents several key advantages: it is compatible with biological media (serum, plasma), uses small volumes and requires little energy. It also is versatile and thus can be used to detect any antigen or antibody in complex media. We are currently developing a portable prototype for point-of-care diagnostics. The results will open the way to a new generation of sensitive immunological lab-on-chip.

Submitted by Deyse Queiroz (deysequeirozz@hotmail.com) on 2018-05-21T13:15:49Z No. of bitstreams: 1 LUANA MUNIZ DE OLIVEIRA - DISSERTAÇÃO PPGHT 2018.pdf: 1302911 bytes, checksum: c41df1699816a23a47dfcc1b9ca0abfa (MD5) / Made available in DSpace on 2018-05-21T13:15:49Z (GMT). No. of bitstreams: 1 LUANA MUNIZ DE OLIVEIRA - DISSERTAÇÃO PPGHT 2018.pdf: 1302911 bytes, checksum: c41df1699816a23a47dfcc1b9ca0abfa (MD5) Previous issue date: 2018-03-06 / O uso de tecnologias de forma ecológica é de grande importância para a conservação da romã, especialmente, quando se necessita atingir mercados a longas distancias, sendo indispensável associar técnicas de armazenamento para o aumento na durabilidade do fruto in natura. O objetivo deste trabalho foi avaliar o efeito de recobrimentos à base de Spirulina platensis na conservação pós-colheita de romã ‘Comum’ em duas condições de armazenamento. A pesquisa foi realizada no laboratório de tecnologia de alimentos da UFCG-CCTA, Pombal, PB, e os frutos foram provenientes de Petrolina-PE, colhidos manualmente no estádio de maturação comercial. Instalou-se dois experimentos em delineamento inteiramente ao acaso, com 3 repetições e 2 frutos por parcela. Um experimento foi realizado para avaliar a qualidade dos frutos mantidos armazenados sob refrigeração, sendo analisados aos 24 dias de armazenamento sob refrigeração (10 ± 2ºC e 85 ± 5% UR) e em seguida, 2 dias em condição ambiente 25ºC e 60% UR. No outro experimento, os frutos foram mantidos sob temperatura ambiente a 24°C e 60% UR, e avaliados aos 15 dias. Os tratamentos (T) foram representados por diferentes concentrações de Spirulina platensis, (0%, 1%, 2%, 3%, e 4%) acrescidos de 0,5 mL L-1 de óleo mineral. Foram realizadas analises de perda de massa, aparência externa e aparência interna, cor da casca, sólidos solúveis, acidez titulável, pH, vitamina C, flavonoides, antocianinas, compostos fenólicos, açucares totais e açucares redutores. Inicialmente foi utilizado uma amostragem de 12 frutos para caracterização das romãs por ocasião da colheita. O uso do recobrimento com Spirulina platensis em romã não prejudica a aparência dos frutos para a comercialização, para ambas condições de armazenamento.O recobrimento a 1% de Spirulina platensis promove menor conteúdo de compostos fenólicos, fato que pode contribuir para a redução da adstringência do suco, quando destinado ao consumo in natura, para ambas condições de armazenamento.O uso de Spirulina platensis não promove a conservação do suco do arilo da romã ‘Comum’ no que se refere aos compostos bioativos como vitamina C, flavonoides, antocianinas, sob armazenamento por 26 dias, sendo 24 dias a 10ºC e 85%UR e, em seguida, dois dias a 25ºC e 60%UR. Sob armazenamento em condições ambiente, 15 dias a 25ºC e 42%UR, os frutos tratados com 1% de Spirulina platensis tiveram maiores conteúdos de compostos bioativo, tais como vitamina C, flavonoides e antocianinas. / The use of technologies in an ecological way is of great importance for the conservation of the pomegranate, especially, when one need to reach markets the long ones distance, being indispensable to associate storage techniques for the increase in the durability of the fruit in nature. The objective of this work was to evaluate the effect of coatings based on Spirulina platensis in the conservation pomegranate powder-crop 'Common' in two storage conditions. The research was accomplished at the laboratory of technology of foods of UFCG-CCTA, Pombal, PB, and the fruits were coming of Petrolina-PE, picked manually at the stadium of commercial maturation. Two experiments were set up in a completely randomized design, with 3 repetitions and 2 fruits for portion. An experiment was accomplished to evaluate the quality of the maintained fruits stored under cooling, being analyzed to the 24 days of storage under cooling (10 ± 2ºC and 85 ± 5% UR) and soon afterwards, 2 days in condition it adapts 25ºC and 60% UR. In the other experiment, the fruits were maintained under room temperature to 24°C and 60% UR, and appraised to the 15 days. The treatments (T) they were represented by different concentrations of Spirulina platensis, (0%, 1%, 2%, 3%, and 4%) added of 0,5 mL L1 of mineral oil. They were accomplished analyze of mass loss, appearance expresses and appearance interns, color of the peel, soluble solids, titratable acidity, pH, vitamin C, flavonoids, anthocyanins, phenolic compounds, sugar total and sugar reducers. Initially a sampling of 12 fruits was used for characterization of the pomegranates by occasion of the crop. The use of the coating with Spirulina platensis in pomegranate doesn't harm the appearance of the fruits for the commercialization, for both storage conditions. The coating at 1% of Spirulina platensis promotes smaller content of phenolic compounds, fact that can contribute to the reduction of the astringency of the juice, when destined to the consumption in nature, for both Storage conditions. The use of Spirulina platensis it doesn't promote the conservation of the juice of the arilo of the pomegranate 'Common' in what it refers to the bioactive compounds as vitamin C, flavonoids, anthocyanins, under storage for 26 days, being 24 days to 10ºC and 85%UR and, soon afterwards, two days to 25ºC and 60%UR. Under storage in conditions atmosphere, 15 days to 25ºC and 42%UR, the fruits treated with 1% of Spirulina platensis had larger contents of bioactive compounds, such as vitamin C, flavonoids and anthocyanins.

A quantificação colorimétrica da pele do rosto humano apresenta uma grande dispersão de valores. Esta dispersão varia de acordo com o espaço de cor (HSV ou YCbCr) adotado para a análise e quanto menor a dispersão mais adequado é o espaço ao reconhecimento facial. O objetivo deste trabalho é analisar a distribuição estatística da colorimetria de imagens de rostos digitalizadas. A análise poderá dizer se as coordenadas de cor, tais como saturação, matiz e valor podem auxiliar em técnicas de reconhecimento de faces. Como resultado da análise, espera-se concluir qual dos sistemas de coordenadas de cor (HSV ou YCbCr) é o mais adequado à aplicações em reconhecimento facial. Os resultados obtidos serão apresentados com fundamentação no design da informação. O grande número de amostras fotográficas disponíveis para análise (530) e o correto equilíbrio de iluminação, contraste e temperatura de cor constituem o principal diferencial desse trabalho. / The colorimetric quantification of the human face skin presents a large dispersion of values. This dispersion varies according to the color space (YCbCr or HSV) adopted for the analysis. The smaller the dispersion the more appropriate is a certain color space for face recognition methods. The objective of this paper is to analyze the colorimetric statistical distribution of digital face images. The analysis will show how color coordinates (such as hue, saturation and brightness), can help with facial recognition techniques. The result of this analysis will tell which color space (HSV or YCbCr) is more adequate to be used in face recognition systems. The results obtained will be presented in accordance with the fundamentals of information design. The large number of photographic samples available for analysis (530) and the right balance of lighting, contrast and color temperature are the main differential of this work.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2018-05-07T12:26:10Z No. of bitstreams: 2 Dissertação - Brunno Conrado Bertolucci Tomé - 2018.pdf: 3728339 bytes, checksum: 8c1f81e78aecf70adcf906824026f800 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-05-07T13:02:22Z (GMT) No. of bitstreams: 2 Dissertação - Brunno Conrado Bertolucci Tomé - 2018.pdf: 3728339 bytes, checksum: 8c1f81e78aecf70adcf906824026f800 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-05-07T13:02:22Z (GMT). No. of bitstreams: 2 Dissertação - Brunno Conrado Bertolucci Tomé - 2018.pdf: 3728339 bytes, checksum: 8c1f81e78aecf70adcf906824026f800 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-03-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This report describes the fabrication of devices in poly(dimethyl)siloxane (PDMS) for colorimetric determination of ethanol in whisky. The devices were fabricated via 3D printing and used to perform colorimetric assays with image detection using a scanner. The PDMS devices were evaluated comparing the results obtained from the water aliquot scans by extracting the pixel intensities in the RGB channel, where there was no statistical difference for a confidence level of 0.05. The iron complexation reaction with 1,10-phenanthroline was also evaluated by comparing the results of two different devices. Ferrous ammonium sulphate solutions were used at concentrations of 0,1 to 10 mg.L -1 , where correlation curves were obtained from the pixels intensities extracted in the yellow channel. The obtained equations were used to estimate the concentration of a known iron solution of 8 mg.L -1 , obtaining a difference of 0.74% between the results of both devices. The oxidation reaction of ethanol with potassium dichromate was used to determine ethanol in samples of seized whiskeys by Federal Police. It was possible to determine ethanol in the range of 0% to 60% (v/v), using a gray color channel for the concentration range of 0% to 20% (v/v) with R 2 = 0.993, with a detection limit of 0,86% and quantification limit of 1.44% and the yellow color channel for the concentration range of 20% to 60% (v/v) with R 2 = 0.998. It was possible to determine the ethanol content in 66 samples of seized whiskeys. Where 53 samples were discriminated as falsified and 13 samples were not discriminated from original samples based on the ethanol content. / O presente trabalho descreve a fabricação de dispositivos em poli(dimetil)siloxano (PDMS) para determinação colorimétrica de etanol em uísques. Os dispositivos foram fabricados via impressão 3D e utilizados para a realização de ensaios colorimétricos com detecção por imagem a partir de um scanner de mesa. Os dispositivos de PDMS foram avaliados comparando os resultados obtidos de digitalizações de alíquotas de água extraindo as intensidades de pixel no canal RGB,onde não houve diferença estatística para um nível de confiança de 0,05. Foi avaliado também a reação de complexação do ferro com a 1,10 fenantrolina comparando os resultados de dois dispositivos diferentes. Foram utilizadas soluções sulfato ferroso amoniacal nas concentrações de 0,1 até 10 mg.L -1 , onde foram obtidas curvas de correlação para as intensidades de pixels extraídas no canal amarelo. As equações obtidas foram utilizadas para estimar a concentração de uma solução conhecida de ferro de 8 mg.L -1 , obtendo-se uma diferença de 0,74% entre os resultados dos dois dispositivos. A reação de oxidação de etanol com dicromato de potássio foi utilizada para determinar etanol em amostras de uísques apreendidos pela Polícia Federal. Foi possível determinar etanol na faixa de 0% a 60%(v/v) utilizando canal de cor cinza para a faixa de concentração de 0% a 20%(v/v) com R 2 =0,993, com um limite de detecção 0,86% de e limite de quantificação de 1,44% e o canal de cor amarelo para a faixa de concentração de 20% a 60%(v/v) com R 2 =0,998. Foi possível determinar o teor de etanol em 66 amostras de uísques apreendidos. Onde 53 amostras foram discriminadas como falsificadas, com 13 sendo classificadas como autênticas com base no teor de etanol.

Submitted by (edna.saturno@ufrpe.br) on 2016-06-15T15:55:46Z No. of bitstreams: 1 Andreza Santos da Costa.pdf: 640841 bytes, checksum: 86ed764bfeb547a2eeeadd160bc62aca (MD5) / Made available in DSpace on 2016-06-15T15:55:47Z (GMT). No. of bitstreams: 1 Andreza Santos da Costa.pdf: 640841 bytes, checksum: 86ed764bfeb547a2eeeadd160bc62aca (MD5) Previous issue date: 2009-02-13 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Postharvest conservation of heliconia cut flowers is an important factor for the success on its commercialization, mainly for export. Inadequate temperatures during shipping and commercialization of tropical cut flowers may accelerate senescence processes and cause chilling injuries, generating symptoms that are not yet identified and described. The objective of this study was to evaluate the physioiogical responses and symptoms of senescence and chilling injury of cut inflorescences of Heliconia bihai cv. Lobster Claw (LC) and cv. Halloween (11W) and to study the effect of five different storage times on flowering stems of Heliconia bihai cv. Lobster Claw (LC) at two temperatures (12 and 19°C). In the first experiment, the variables measured were fresh weight (FW), color of bracts (L*, a* e b*), percentage of absolute integrity of ceil membrane (PAI) and leakage of potassium ion (LPI). The cut inflorescences were evaluatcd at five different intervais after harvested (zero, two, four, six and eight days), stored in refrigerated chamber (RC), at mean temperature (Tm) of 6,5°C and mean relative humidity (RHm) of 85%, and without refrigeration, in conditions of laboratory (CL), at 24°C and RHm of 66%. The low temperature of 6,5°C was used in order to promote chiiiing injury symptoms to the inflorescences. In the second experiment, it was evaluated the maximum storage time of flowering stems of Heliconia bihai cv. Lobster Claw under two different temperatures (12°C and 19°C), compared to laboratory conditions (25°C), for the variables: visual quality (VQ), fresh weight (FW), bract color (BC) and activity of peroxidase enzyme (POD). The visual quality of inflorescences and the fresh weight of ali treatments decreased with time. In both cultivars the senescence symptoms were characterized as dryness of bract tissue and chilling injury symptoms, as dark stains that evolved to a burnt aspect and to necrosed area of tissue. The visual quality of inflorescences decreased with time in both cuitivars. The severity of chilling injury increased with time for both cultivars. There was significant effect of RC and CL treatments for FW in both cultivars. Bract color changed in both cultivars only for the refrigerated treatment. Without refrigeration the bract color changed only for the HW cultivar. Storing the inflorescences at 6,5°C during six and eigth days decreased the values of PAI. For both cultivars the non-refrigerated inflorescences did not present any increase in LPI, however, for refrigerated treatment the LPI increased after the sixth day of storage. Symptoms of chilling injury were observed on the inflorescences stored at 12°C during six and eight days. Color of bracts was affected by the temperature, storage period. For the inflorescences kept in laboratory conditions, the peroxidase activity increased initially and subsequently decreased. Results indicate that for both cultivars storage period and temperature promoted alterations in the physiological responses, which were demonstrated by chilling injury and senescence. The temperature of 12°C is recommended for storage time longer than four days for inflorescences of H. bihai cv. Lobster Claw. Temperature of 19°C is recommended for storage time up to eight days. Peroxidase activity in the refrigerated Heliconia cut flowers did not foliow any standard trend as a function of temperature and storage time. The elevated activity of peroxidase enzyme during the two first days for ali treatments may suggest a reaction to the stress caused by cutting the inflorescences. / As flores tropicais de corte, após a colheita, podem estar sujeitas a temperaturas inadequadas,principalmente durante a comercialização, o que pode acelerar o processo de senescência e causar injúria por frio, cujos sintomas ainda não foram descritos. A conservação pós-colheita adequada das hastes florais de helicônia é importante para o sucesso da comercialização desse produto, sobretudo no tocante à exportação. Este trabalho objetivou avaliar sintomas e respostas fisiológicas da senescência e da injúria por frio em hastes de heliconia bihai cv. Lobster Claw (LC) e cv. Halloween (HW), bem como o efeito do tempo máximo de armazenamento de hastes florais de Heliconia bihai cv. Lobster Claw em duas temperaturas (12 e 19°C) e cinco períodos de armazenamento.No primeiro experimento, foram avaliados a massa fresca (MF), coloração das brácteas, percentagem de integridade absoluta da membrana celular (PIA) e teor de potássio extravasado (TPE) do tecido das brácteas. As avaliações foram realizadas em cinco períodos (zero, dois,quatro,seis e oito dias), com refrigeração(CR) em câmara fria à temperatura média (Tm) de6,5°C e umidade relativa média (URm) de 85%, e sem refrigeração (SR) em ambiente de laboratório com Tm de 24°C e URm de 66%.O uso da temperatura de 6,5°C objetivou provocar sintomas de injúrias por frio nas hastes florais. No segundo experimento foi avaliado o efeito do tempo máximo de armazenamento de hastes florais de Heliconia bihai cv. Lobster Claw em duas temperaturas (12°C e 19°C) e comparadas com a condição de ambiente de laboratório (25°C), por meio da qualidade visual,massa fresca, coloração das inflorescências e atividade da enzima peroxidase.Nas duas cultivares do primeiro experimento, o sintoma de senescência foir caracterizado como ressecamento do tecido das brácteas e o sintoma de injúria por frio como manchas escuras que adquiriram aspecto de queima e posterior necrose. A redução da qualidade visual das inflorescências e da massa fresca das hastes foi progressiva ao longo dos dias em todos os tratamentos.O grau de injúria por frio foi agravado com o aumento do período de armazenamento das inflorescências das duas cultivares. Houve diferença na MF das hastes florais das cultivares LC e HW de ambos os tratamentos SR e CR. Houve alteração da cor das brácteas das inflorescências das duas cultivares mantidas com refrigeração e das inflorescências da cv. HW sem refrigeração. O armazenamento das hastes florais em câmara fria causou uma redução da PIA a partir do sexto dia, que coincidiu com um aumento do TPE. Nas hastes florais mantidas sem refrigeração a PIA só aumentou no oitavo dia e não houve alteração nos valores de TPE. A redução da qualidade visual e da massa fresca has hastes florais da cv. Lobster Claw foi progressiva ao longo do período de avaliação em todos os tratamentos. Foram observados sintomas de injúria por frio nas inflorescências armazenadas em câmara fria a 12°C por seis e oito dias. A cor das brácteas se alterou em função da temperatura, do período de armazenamento. Nas hastes florais mantidas nas condições do ambiente do laboratório, observou-se, inicialmente, uma elevação na atividade da peroxidase e posterior decréscimo.Os resultados permitem afirmar que o período de armazenamento e a temperatura promoveram alterações nas respostas fisiológicas evidenciadas por sintomas de injúria por frio e senescência.A temperatura de 12°C não é indicada para armazenamento de hastes florais de H.bihai cv. Lobster Claw, por mais de quatro dias.A temperatura de 19°C é indicada para o armazenamento d ehastes florais de H.bihai cv. LC por oito dias. Não foi observada uma tendência padrão para a atividade da peroxidase nas hastes florais submetidas à refrigeração, independente da temperatura e do tempo de armazenamento .A elevada atividade da peroxidase, nos dois primeiros dias, nas hastes florais de todos os tratamentos,sugere uma reação ao estresse induzido pelo corte.

Orientadores: Adriana Vitorino Rossi, Matthieu Tubino / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-11T04:54:42Z (GMT). No. of bitstreams: 1 Martins_LucianaFoltram_M.pdf: 1935744 bytes, checksum: f05f16f5c0380e513d0ae7b7af183efe (MD5) Previous issue date: 2008 / Resumo: O método ASTM D 1209-00 descreve o procedimento para a medida visual da coloração de líquidos levemente coloridos, que envolve a comparação visual entre a coloração de amostras com a coloração de padrões Pt-Co com concentração variando de 1 a 500 na escala do ASTM D 1209-00 (soluções obtidas pela mistura de cloroplatinato de potássio, com concentração na faixa de 1,5x10 a 3,6x10 mol L e cloreto de cobalto hexahidratado nas concentrações de 1,7x10 a 4,2x10 mol L). Sabe-se e foi constatado em teste com voluntários, que há grandes dificuldades de aplicação para as soluções mais diluídas (soluções de concentração 1 a 25 unidades de Pt-Co), que são extremamente claras, de difícil distinção em observações visuais e, em muitos casos, representam as amostras de maior interesse em alguns setores de aplicação. Na tentativa de superar essas dificuldades, desenvolveu-se um equipamento robusto e de baixo custo para análises rápidas. Foi utilizado um diodo emissor de luz (LED) azul como fonte de radiação e um fotodiodo com CI S7183 (Hamamatsu) como detector num conjunto de celas de PVC preto com diferentes opções de caminho óptico e com a opção de uso de tubo de vidro interno para conter as soluções. Foram obtidas curvas analíticas com ajuste de segundo grau com as celas de 340 e 170 mm. Com cela de 85 mm foi obtida curva analítica linear com coeficiente de correlação = 0,9978 entre 25 e 500 unidades de Pt-Co. Com o uso de um tubo de vidro obtiveram-se curvas com ajuste polinomial de segunda ordem com as celas de 170 e 85 mm. Para testar o desempenho do dispositivo desenvolvido, foram utilizadas amostras de bisfenol epóxi, hidroperóxido de cumeno, ácido salicílico em etanol e em solução aquosa de carbonato de sódio 10 % m/v e ciclohexanol. Os resultados apresentaram desvios da ordem de ±1 unidade de Pt-Co, mais precisos do que o método ASTM que apresenta desvios de até ±4 unidades de Pt-Co; com relação à exatidão, houve diferença estatística ao nível de 95 %, o que pode remeter a problemas com o método de referência / Abstract: The ASTM D1209-00 method describes the procedure for the visual measurement of the color of essentially light colored liquids, which involves the visual comparation between the color of the samples with the color of Pt-Co standards solutions, with concentration from 1 to 500 unities of Pt-Co, the ASTM D 1209-00 scale (solutions obtained by mixing potassium chloroplatinate, from 1,5x10 to 3,6x10 mol L and cobalt chloride in the concentrations of 1,7x10 to 4,2x10 mol L). It is kown and was confirmed in tests with volunteers that there and serious difficulties with this method for very diluted solutions (concentration from 1 to 25 unities of Pt-Co), that are extremely clear, hardly distinguished by visual observation, whose in many cases represent the samples of most interest in some application sectors. In an attempt to overcome these difficulties, a robust and low cost device was developed for a rapid analysis. A blue light emitting diode (LED) was used as a radiation source and a Photo IC Diode S7183 (Hamamatsu) as the detector, in a set of black PVC cells with different options of optical path and with the option of using or not an internal glass tube to load the solutions. Analytical curves were obtained with second degree fitting for 340 and 170 mm cells. An 85 mm cell gives linear analytical curve with correlation coefficient = 0.9978, from 25 to 500 units of Pt-Co. With the use of the glass tube, curves with second order polynomial fitting were obtained for 170 and 85 mm cells. The performance of the device developed were tested with samples of epoxy bisfenol, cumene hidroperoxide, salicilic acid in ethanol and in aqueous solution of sodium carbonate 10 % w/v and cyclohexanol. The results presented deviations of the order of ± 1 units of Pt-Co, more precises than the ASTM method, which presents deviations up to ± 4 units of Pt-Co; with respect to the accuracy, there was statistic difference at the level of 95 %, which can be related to problems with the reference method / Mestrado / Quimica Analitica / Mestre em Química

This diploma thesis deals with characterization of sea buckthorn oil. The sea buckthorn oil is frequently used as a food supplement and in dermatology. The first part summarizes the literature on sea buckthorn oil and its biological effects. In the experimental part, the thesis deals with the comparison of three commercially available preparates of sea buckthorn oils. We employed the basic characteristics of these oils, including the determination of peroxide value, iodine value, saponification value and acid value using titration methods. Spectroscopic measurements were used to further characterize the oils. The comparised sea buckthorn oil samples differed strongly in the peroxide value and in the stability during storage. In this respect, the oil from Relikt - Art Engel company had significantly lower value (2,95 mekv/kg) compared to other two oil samples studied from Elith Phito and Virde companies with peroxide values 12,68 and 8,97 mekv/kg. This value was also much less prone to increase during storage. A similar difference was also found in spectral and colorimetric characteristics of the oil samples, where this oil displayed much less optical density then the other two samples. This might be a result of different technology used for production of oils, or it may reflect some adulteration,...

INTRODUCTION: Les gouttières thermoplastiques orthodontiques doivent souvent être retirées par les patients avant de consommer des aliments ou des liquides autres que l’eau. Cette précaution évite notamment des changements de couleur au niveau du matériau les constituant. Des études antérieures ont concentré leurs recherches sur des changements de coloration chez des marques limitées d’aligneurs thermoplastiques en excluant certaines marques américaines populaires. OBJECTIFS: L’objectif principal de cette étude vise à évaluer la résistance au changement de teinte du polymère formant trois différentes marques d’aligneurs américaines. Un but secondaire est de comparer le pouvoir de retrait de taches de deux produits nettoyants conçus pour ces appareils amovibles. Un but tertiaire est d’évaluer le type de polymère qui constitue les surfaces interne et externe de chaque marque étudiée de gouttières. MATÉRIELS ET MÉTHODES : Les gouttières ont été exposées à l’un des divers liquides colorants de l’alimentation courante (thé, café, vin rouge et cola) ou à une solution de contrôle formée d’un gel de remplacement salivaire Biotène® Oral Balance. Les trois marques évaluées étaient Invisalign®, ClearCorrect® et Minor Tooth Movement®. Après leur immersion de douze heures ou de sept jours, les mêmes gouttières étaient nettoyées pendant quinze minutes avec soit les cristaux Invisalign®, soit le bain Cordless Sonic Cleaner combiné avec un comprimé Retainer Brite®. Les données de colorimétrie étaient obtenues à l’aide d’un numériseur calibré et du logiciel Adobe Photoshop® en utilisant l’espace chromatique CIELAB pour comparer les changements de coloration (E) entre les divers moments à l’étude. Les paramètres L*, a*, b* étaient mesurés au temps initial (T0), après douze heures d’immersion (T1), après sept heures d’exposition (T2) et après nettoyage (T3). Les deltas E étaient ensuite convertis en unités du National Bureau of Standards (NBS) pour faciliter l’interprétation clinique des données. Selon la section, les analyses statistiques employées (test de Levene, ANOVA, méthode de Brunner-Langer, test de Tukey ou test-t) permettaient d’évaluer les interactions entre les trois marques entre elles ou entre les marques et les nettoyeurs. Une valeur de p < 0,05 était considérée statistiquement significative. RÉSULTATS ET DISCUSSION: Les résultats suggèrent qu’une exposition de douze heures au café pour les aligneurs Invisalign® engendre un changement de couleur statistiquement significatif par rapport aux deux autres marques. Il en est de même pour une durée identique d’immersion dans le vin rouge ; les coquilles Invisalign® présentent un changement de teinte statistiquement significatif par rapport à ses compétiteurs. Après sept jours d’exposition au café ou au vin rouge, les coquilles de la marque Invisalign® ont aussi des changements de coloration statistiquement significatifs par rapport aux deux autres marques, mais plus prononcés qu’après douze heures. Le thé noir engendre des changements de couleur importants au niveau clinique chez les trois marques après sept jours d’exposition sous forme de taches extrinsèques. Les deux méthodes de nettoyage étudiées présentent un potentiel clinique de retrait de taches accru pour celles extrinsèques du thé noir par rapport aux taches intrinsèques des autres solutions étudiées. Les résultats par spectrophotométrie à lumière infrarouge démontrent des spectres similaires pour les surfaces interne et externe de chaque marque. Or, ce n’est pas le même polymère qui est employé par chaque compagnie. Des spectres ATR-FTIR d’un matériau à base de polyuréthane sont observés pour les marques Invisalign® et ClearCorrect®. Des spectres ATR-FTIR de matériau à base de polyéthylène téréphtalate glycolisé sont plutôt représentatifs de la marque Minor Tooth Movement®. CONCLUSION: Les aligneurs de la compagnie Invisalign® sont plus susceptibles de souffrir de pigmentation par le café et le vin rouge que les deux autres marques qui ont présenté une stabilité accrue de leur coloration au contact de ces solutions. Le thé a engendré des changements de couleur extrinsèques importants chez les trois marques étudiées. / INTRODUCTION: Manufacturers of orthodontic aligners suggest that users take off removable appliances every time they consume solid foods or any drink (except water). This is to avoid a color change within the clear thermoplastic material of which they are made. Prior studies have focused on a limited set of aligners, excluding some popular American brands on the market. OBJECTIVES: The main objective of this study is to evaluate the stain resistance of the polymer forming three different American aligner brands. A secondary aim is to evaluate the stain-removal potential of two cleaning techniques for these devices. A tertiary goal is to determine the type of polymer forming the internal and external surfaces of the studied brands of aligners. MATERIALS AND METHODS: The removable appliances were exposed to different staining agents common in a regular diet (coffee, red wine, black tea and cola) or to a control solution made of a Biotene® Oral Balance saliva replacement gel. The three brands evaluated were Invisalign®, ClearCorrect® and Minor Tooth Movement®. Following exposure, the same aligners were cleaned during fifteen minutes with either the Invisalign® cleaning crystals or the Cordless Sonic Cleaner combined with a Retainer Brite® tablet. Colorimetry data was acquired via a calibrated scanner and the Adobe Photoshop® software, using a CIELAB color space approach to compare color changes (E) in aligners exposed to various media. The CIE color parameters (L*, a*, b*) of each specimen were measured before immersion (T0), after a twelve-hour exposure (T1), after a seven-day exposure (T2) and after cleaning (T3). Those color differences were then converted into National Bureau of Standards (NBS) units to facilitate the clinical interpretation. Statistics methods (Levene’s test, ANOVA, Brunner-Langer model, Tukey’s range test and t-test) were used to identify interactions between the brands themselves or between the brands and the cleaning methods. A p value < 0.05 was considered statistically significant. RESULTS AND DISCUSSION: This study suggests that an exposure of twelve hours to instant coffee affects significantly the color of the Invisalign® aligners compared to the two other brands. A twelve-hour immersion into red wine also causes a statistically significant color change for the Invisalign® devices compared to their competitors. After seven days of exposure, a more conspicuous intrinsic color change is observed in the Invisalign® aligners exposed to instant coffee and red wine. In both media, the results are statistically significant for the Invisalign® appliances compared to the ClearCorrect® and the Minor Tooth Movement® aligners. The black tea creates an important extrinsic color change in the three brands after seven days. While normal exposure conditions would not typically consist of 12 h to 7 days of continuous exposure, these data indicate that repeated, cumulative exposure may be problematic. The two cleaning methods tend to show a better efficacy in removing extrinsic stains from black tea compared to intrinsic stains of other substrates. The infrared spectrophotometry confirms that the internal and external surfaces of each studied brand of aligners were made of the same polymer. ATR FTIR spectra of polyurethane-based material are observed for the Invisalign® and the ClearCorrect® devices. However, for the Minor Tooth Movement® aligners, the ATR FTIR analysis shows that the appliances are a polyethylene glycol terephthalate polyester. CONCLUSION: The Invisalign® aligners were more prone to pigmentation from coffee and red wine than the ClearCorrect® or the Minor Tooth Movement® devices. Black tea caused important extrinsic stains on the surface of the three tested brands.