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Desenvolvimento de método limpo para a determinação de uréia /Gigante, Andréa Cristina. January 2011 (has links)
Resumo: O presente trabalho propõe o desenvolvimento de um método limpo para determinação de ureia em amostras comerciais de fertilizantes utilizando a Espectroscopia de Reflectância Difusa combinada com spot test. O método desenvolvido é baseado na reação entre a ureia e o reagente cromogênico p-dimetilaminocinamaldeído (p-DAC) em meio de ácido clorídrico diluído, que resulta em um produto de coloração rósea cujo valor máximo de reflectância ocorre no comprimento de onda de 535 nm. Os parâmetros experimentais foram otimizados através dos planejamentos fatorial e composto central para a obtenção da superfície de resposta, os quais indicaram uma maior sensibilidade para o método quando se utiliza o reagente p-DAC na concentração de 0,196% (m/v) em meio de ácido clorídrico de concentração 0,0549 mol L-1, empregando etanol como solvente para as soluções. O suporte sólido para a reação é um papel de filtro qualitativo onde são colocados 20,0μL de solução de ureia seguidos de secagem com ar frio de um secador de cabelos e 20,0μL de solução de reagente p-DAC 0,196% (m/v) em meio de HCl 0,0549 mol L-1 e secagem ao ar livre, submetendo-se então o spot à leitura reflectométrica em máx. = 535 nm. Uma relação linear (R = 0,996) foi estabelecida na faixa de concentração de ureia compreendida entre 50,0 - 300 mg L-1. Os limites de detecção e de quantificação foram determinados em 5,13 mg L-1 e 17,10 mg L-1, respectivamente. O método limpo desenvolvido foi aplicado na determinação de ureia em amostras comerciais de fertilizantes onde demonstrou apresentar ótima precisão e exatidão, evidenciadas pela boa recuperação (94,2 - 107,4%), além de oferecer vantagens como simplicidade de execução e baixo consumo de reagentes, geração de mínima quantidade de resíduos, rapidez e segurança... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This work proposes the development of a clean method for determination of urea in commercial samples of fertilizers using the Diffuse Reflectance Spectroscopy combined with spot test. The method is based on the reaction between urea and the chromogenic reagent p-dimethylaminocinnamaldehyde (p-DAC) in diluted hydrochloric acid medium, which results in a pink colored product whose maximum value of reflectance occurs at a wavelength of 535 nm. The experimental parameters were optimized through a factorial and a central composite experimental design to obtain the response surface, which indicated a higher sensitivity for the method when using the reagent p-DAC in the concentration of 0.196% (w/v) in a hydrochloric acid 0.0549 mol L-1 medium, using ethanol as a solvent for the solutions. The solid support for the reaction is a qualitative filter paper where they are placed 20.0μL of urea solution followed by drying with cold air from a hair dryer and 20.0μL of reagent solution p-DAC 0.196% (w/v) in the HCl 0.0549 mol L-1 medium and drying in the air, then submitting the spot to the reflectometric reading at max = 535 nm. A linear relationship (R = 0.996) was established in the range of urea concentration between 50.0 to 300 mg L-1. The limits of detection and quantification were determined at 5.13 mg L-1 and 17.10 mg L-1, respectively. The method was applied to the clean determination of urea in commercial samples of fertilizers, which has shown to present great precision and accuracy as evidenced by the good recovery (94.2 to 107.4%) and also offers advantages such as simplicity of implementation and low consumption of reagents, generation of minimum quantity of wastes, rapidity and security, producing reliable results. As shown, the method is designed as environmentally friendly for determination of urea, as it is consistent with the Principles advocated by the Green Chemistry. / Orientador: Helena Redigolo Pezza / Coorientador: Leonardo Pezza / Banca: Maria Del Pilar Taboada Sotomayor / Banca: Adriana Vitorino Rossi / Mestre
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Magnetismo e cor na identificação de solos com diferentes potenciais de sorção de imazaquim / Magnetism and color in the identification of soils with different potentials of imazaquim sorptionPeluco, Rafael Gonçalves [UNESP] 24 November 2016 (has links)
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Previous issue date: 2016-11-24 / O conhecimento da variabilidade dos atributos do solo é importante para recomendação racional de herbicidas, contribuindo para prática da agricultura de maneira mais sustentável. Objetivou-se com este estudo avaliar a utilização da suscetibilidade magnética e da cor do solo, obtida por espectroscopia de reflectância difusa, para identificação de solos com diferentes potenciais de sorção de herbicida. Para medição da espectroscopia de reflectância difusa, foram coletadas 86 amostras de solo a cada 30 m, em uma transeção de 2600 m, seguindo o espigão da paisagem ao longo da área, e mais 155 pontos em uma malha de densidade amostral de 1 ponto a cada 2,5 ha, na profundidade de 0,00 - 0,25 m totalizando 241 amostras de solo em uma área experimental de 380 ha. A partir dos componentes de cor do solo (matiz, valor e croma) foi calculado um índice de avermelhamento. Foram selecionados 12 pontos da transeção para realização das análises mineralógicas do solo. Para medição da suscetibilidade magnética e determinação dos teores de ferro ditionito (Ferro livre, pedogenético) e oxalato (Ferro amorfo, de baixa cristalinidade), foram coletadas 374 amostras de solo na profundidade de 0,00 - 0,25 m, numa malha com densidade amostral de 1 ponto a cada 2,4 ha, em outra área experimental, desta vez com dimensão de 908 ha. Em todos os pontos amostrais, de ambas as áreas, foram determinados o pH, os teores de matéria orgânica e os teores de argila do solo. O coeficiente de Freundlich para sorção do herbicida imazaquim foi determinado indiretamente a partir do teor de argila, por meio da metodologia da meta-análise. Foram construídos modelos de regressão da suscetibilidade magnética e dos componentes de cor com os demais atributos estudados. Os dados foram submetidos à análise estatística descritiva, e também foram calculadas as médias de cada atributo conforme as classes de solo e compartimentos geológicos e foi aplicado o teste de Tukey a 5%. A análise da dependência espacial dos dados foi feita por meio da geoestatística, utilizando-se o variograma. Também foram construídos mapas de padrão espacial. Os resultados indicam que o uso da suscetibilidade magnética possibilita a quantificação indireta da sorção do herbicida imazaquim. Solos com maior expressão magnética apresentam características de maior sorção do herbicida imazaquim. A assinatura magnética dos solos pode auxiliar no mapeamento e na identificação de áreas com diferentes potenciais de aplicação de herbicidas. Dentre os componentes da cor, obtidos por espectroscopia de reflectância difusa, o mais eficiente na estimativa do coeficiente de sorção do herbicida imazaquim foi o croma (98% de precisão), seguido pelo matiz (85%) e valor (54%). A cor obtida pela espectroscopia de reflectância difusa foi eficaz na identificação de áreas com diferentes potenciais de sorção do herbicida imazaquim. Estes resultados podem balizar futuros estudos para planejamento estratégico de manejo de herbicidas pré-emergentes em grandes áreas. / The knowledge of the soil attributes variability is important for the herbicides rational recommendation, contributing to the practice of a more sustainable agriculture.The aim of this study was to evaluate the use of magnetic susceptibility and soil color, obtained by diffuse reflectance spectroscopy, to identify areas with different herbicide sorption potential. For measuring the diffuse reflectance spectroscopy, 86 soil samples were collected every 30m on a transect of 2600m, following the crest of landscape along the area, and more 155 points were collected into a grid of sample density of 1 point per 2.5ha, in the depth 0.00 to 0.25m, totaling 241 soil samples on an experimental area of 380ha. From the soil color components (hue, value and chroma) it was calculated a redness index. We selected 12 points from the transect for carrying out soil mineralogical analysis. For measuring the magnetic susceptibility and the determination of dithionite (Free iron, pedogenic) and oxalate (Amorphous iron, of low crystallinity) iron content, 374 soil samples were collected in the depth 0.00 to 0.25m, into a grid of sample density of 1 point per 2.4ha in another experimental area, which dimension is 908ha. The pH, soil organic matter and soil clay content were determined in all soil sampling points. The Freundlich coefficient for imazaquim herbicide sorption was determined indirectly from the clay content, using the methodology of meta-analysis. Regression models of the magnetic susceptibility and color components with the other soil studied attributes were built. Data were analyzed using descriptive statistics, and the attributes average values were also calculated for each soil class and geological compartments and the Tukey test at 5 % was applied. The spatial dependence analysis of data was performed using geostatistics by the variograms. Spatial pattern maps were also constructed. The results indicate that use of magnetic susceptibility enables the indirect quantification of imazaquim herbicide sorption. Soils with higher magnetic expression have characteristics of increased imazaquim herbicide sorption. The soil magnetic signature can assist in mapping and identifying areas with different potential of herbicides application. Among the components of the color obtained by diffuse reflectance spectroscopy, the more efficient estimate of the herbicide imazaquim sorption coefficient, was chroma (98% accuracy), followed by hue (85%) and by value (54%). The color obtained by diffuse reflectance spectroscopy was effective in identifying areas with different imazaquim herbicide sorption potential. These results can beacon future studies for strategic planning management of pre-emergent herbicides over large areas.
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Gênese, mineralogia e dinâmica do fósforo nos solos do Planalto Ocidental Paulista / Clay mineralogy of phosphorus related in the geological and geomorphological compartments of the Western Paulista PlateauGomes, Romário Pimenta [UNESP] 27 July 2017 (has links)
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Previous issue date: 2017-07-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Nos solos tropicais, o fenômeno de adsorção de fósforo é regido pela mineralogia da fração argila, que, por sua vez, é afetada pelo material de origem e intensidade de dissecação da paisagem. Desse modo, objetivou-se relacionar o fósforo total e adsorvido com principais minerais da fração argila dos solos do Planalto Ocidental Paulista, São Paulo, associando com a geologia e o grau de dissecação da paisagem. Foram selecionadas cinquenta e cinco amostras de solo representativas da variabilidade fisiográfica do Planalto Ocidental Paulista, na profundidade de 0,0 – 0,2 m, para a caracterização das formas de fósforo, mineralogia da argila por difração de raios-x (DRX) e espectroscopia de reflectância difusa (ERD); utilizou-se também calibração quimiométrica através da regressão de mínimos quadrados parciais (PLSR). Verificou-se que o P total e o P adsorvido são influenciados pela geologia e grau de dissecação da paisagem, e são covariativos dos óxidos de Fe e Al, sendo esses óxidos importantes indicadores de ambientes com maiores e menores potenciais de adsorção e com baixos e altos teores de P. A caracterização das curvas espectrais permite diferenciar o conteúdo de P total com base na mineralogia da fração argila. A análise por regressão de mínimos quadrados parciais (PLSR) dos dados espectrais evidencia a influência dos óxidos de ferro no conteúdo de P total e adsorvido, sendo a Hm ao P total e a Gt ao P adsorvido. / In tropical soils, the phenomenon of phosphorus adsorption is governed by the mineralogy of the clay fraction, which in turn is affected by the material of origin and intensity of dissection of the landscape. the objective was to relate the total phosphorus and adsorbed with the main minerals of the clay fraction of the soils of the Planalto Ocidental Paulista, associating with the geology and the degree of dissection of the landscape. Were selected fifty - five soil samples representative of the physiographic variability of the Planalto Ocidental Paulista, in the depth of 0.0 - 0.2 m, for the characterization of phosphorus forms, clay mineralogy by X - ray diffraction (XRD) and diffuse reflectance spectroscopy (DRS); it was also used chemometric calibration Through the partial least squares regression (PLSR). It was verified that the total P and adsorbed P are influenced by the geology and degree of dissection of the landscape, and are covariate of the Fe and Al oxides, and these oxides are important indicators of environments with higher and lower adsorption potentials and with low and high levels of P. The characterization of the spectral curves allows to differentiate the total P content based on the mineralogy of the clay fraction. Partial least squares regression analysis (PLSR) of the spectral data shows the influence of iron oxides on the total and adsorbed P content, with Hm at the total P and Gt at the adsorbed P.
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In Vivo Characterization of Myocardial Tissue Post Myocardial Infarction Using Combined Fluorescence and Diffuse Reflectance SpectroscopyTi, Yalin 10 July 2009 (has links)
Accurately assessing the extent of myocardial tissue injury induced by Myocardial infarction (MI) is critical to the planning and optimization of MI patient management. With this in mind, this study investigated the feasibility of using combined fluorescence and diffuse reflectance spectroscopy to characterize a myocardial infarct at the different stages of its development. An animal study was conducted using twenty male Sprague-Dawley rats with MI. In vivo fluorescence spectra at 337 nm excitation and diffuse reflectance between 400 nm and 900 nm were measured from the heart using a portable fiber-optic spectroscopic system. Spectral acquisition was performed on - (1) the normal heart region; (2) the region immediately surrounding the infarct; and (3) the infarcted region - one, two, three and four weeks into MI development. The spectral data were divided into six subgroups according to the histopathological features associated with various degrees / severities of myocardial tissue injury as well as various stages of myocardial tissue remodeling, post infarction. Various data processing and analysis techniques were employed to recognize the representative spectral features corresponding to various histopathological features associated with myocardial infarction. The identified spectral features were utilized in discriminant analysis to further evaluate their effectiveness in classifying tissue injuries induced by MI. In this study, it was observed that MI induced significant alterations (p < 0.05) in the diffuse reflectance spectra, especially between 450 nm and 600 nm, from myocardial tissue within the infarcted and surrounding regions. In addition, MI induced a significant elevation in fluorescence intensities at 400 and 460 nm from the myocardial tissue from the same regions. The extent of these spectral alterations was related to the duration of the infarction. Using the spectral features identified, an effective tissue injury classification algorithm was developed which produced a satisfactory overall classification result (87.8%). The findings of this research support the concept that optical spectroscopy represents a useful tool to non-invasively determine the in vivo pathophysiological features of a myocardial infarct and its surrounding tissue, thereby providing valuable real-time feedback to surgeons during various surgical interventions for MI.
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Model-based analysis of fiber-optic extended-wavelength diffuse reflectance spectroscopy for nerve detectionSun, Yu, 0000-0003-0048-8352 January 2022 (has links)
Optical spectroscopy is a real-time technique that holds promise as a potential surgical guidance tool. Fiber-optic diffuse reflectance spectroscopy (DRS) is a technique capable of intraoperative tissue differentiation. The common DRS focuses on estimating chromophore concentrations in the visible (VIS) wavelength range (400-1000 nm), where spectroscopic features of the blood, pigments, and tissue densities are present between 400 and 700 nm. Recently, extended-wavelength DRS (EWDRS), which extends the spectral window from the VIS through the short wave-infrared region (SWIR) up to 1800 nm, has emerged as a promising approach for identifying nerves and nerve bundles due to the SWIR including robust tissue absorption features associated with nerve-tissue related chromophores, including lipids, water and collagen proteins. One potential application of EWDRS is guiding minimally invasive surgical techniques, such as laparoscopy, where inadvertent injury to pelvic autonomic nerves (PANs) is a primary complication that can result in over 70% of patients suffering long-term side effects, including urinary incontinence and sexual dysfunction. There is a need for objective laparoscopic surgical guidance to precisely identify PANs from other tissues, and an improved basis for EWDRS development could assist clinical translation. Prior development of Fiber-optic DRS for tissue classification in the VIS greatly benefited from the application of modeling techniques for simulation of optical measurements, analysis, and fiber-probe design. Model-based analysis can inform fundamental understanding of measured signals in different measurement scenarios, such as the varying tissue morphologies possible in laparoscopic procedures, and guide application-specific fiber-probe design through comparison of unique illumination/collection geometries; however, the demonstration of these approaches in EWDRS is not widely reported. This dissertation focuses on the advancement of platforms for model-driven analysis of EWDRS for nerve identification. In order to advance the current state of EWDRS, a model-based characterization platform for analysis of a custom-developed fiber-optic EWDRS system was developed in Aim 1, which demonstrated agreement between data collected from optical phantoms, ex vivo microsurgical model, and Monte Carlo (MC) computational simulations of EWDRS measurements. In Aim 2, the model-based platform was used to perform a detailed analysis of two similar EWDRS fiber-optic probes, which indicated subtle differences in the depth-dependent measurement performance. Finally, in Aim 3, the custom EWDRS was prepared for adapting laparoscopic use to demonstrate laparoscopic measurement feasibility, including evaluation of placement variance and customized EWDRS package for short-distance transportation. The successful completion of this dissertation will enable improved analyses of EWDRS devices for a variety of future intraoperative applications. / Bioengineering
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Evaluation of Diffuse Reflectance Spectroscopy and Fluorescence Spectroscopy for Detection of Glioma Brain TumorsLe, Vinh Nguyen Du January 2017 (has links)
Imaging instruments are required for accurate tumor resection during neurosurgery, especially in the case of glioblastoma multiforme (GBM) - the most common and aggressive malignant glioma. However, current intraoperative imaging techniques for detection of glioma either suffer low sensitivity and low specificity or require a significant capital cost. Advances in diffuse reflectance spectroscopy and fluorescence spectroscopy have offered high sensitivity and high specificity in differentiating tumors from normal tissues with much lower capital cost. Whereas diffuse reflectance spectroscopy alone and fluorescence spectroscopy alone has been used in limited studies to differentiate normal brain tissues from brain tumors with moderate sensitivity and specificity, low specificity and sensitivity were usually observed when studying high grade glioma (HGG) such as GBM. Furthermore, optical properties and diffuse reflectance signal of HGG and low grade glioma (LGG) have not been observed separately, and thus a relation between optical properties and glioma progression has not been established. Intraoperative differentiation of GBM and LGG can be helpful in making treatment plan at the first surgery.
This thesis focuses on characterizing a previous integrated system of diffuse reflectance spectroscopy and fluorescence spectroscopy to extract optical properties and fluorescence properties of LGG and GBM. First, tissue-simulating phantom models were developed to calibrate the integrated system. The direct method and Mie theory were used to calculate optical scattering of the phantoms while Beer-Lambert’s law was used to calculate optical absorption. Second, an experimental method was introduced to recover intrinsic fluorescence because the measured fluorescence signal is likely distorted by the presence of scatterers and absorbers in tissue (i.e. hemoglobin). Third, an experimental method was developed to recover optical properties of both GBM and LGG. In addition, the sensitivity and specificity of the integrated system was optimized. / Thesis / Doctor of Philosophy (PhD)
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Intracerebral quantitative chromophore estimation from reflectance spectra captured during deep brain stimulation implantationJohansson, Johannes, Wårdell, Karin January 2013 (has links)
Quantification of blood fraction (fblood), blood oxygenation (S<img src="http://onlinelibrary.wiley.com/store/10.1002/jbio.201200055/asset/equation/tex2gif-inf-2.gif?v=1&t=h70man4a&s=4a6d004ec608a2a6ec8e8597f73bdb6be30286e8" />), melanin, lipofuscin and oxidised and reduced Cytochrome aa 3 and c was done from diffuse reflectance spectra captured in cortex, white matter, globus pallidus internus (GPi) and subthalamus during stereotactic implantations of 29 deep brain stimulation (DBS) electrodes with the aim of investigating whether the chromophores can give physiological information about the targets for DBS. Double-sided Mann-Whitney U -tests showed more lipofuscin in GPi compared to white matter and subthalamus (p < 0.05). Compared to the other structures, fbloodwas significantly higher in cortex (p < 0.05) and S<img src="http://onlinelibrary.wiley.com/store/10.1002/jbio.201200055/asset/equation/tex2gif-inf-4.gif?v=1&t=h70man4c&s=855c70105e88a292de25618487573dfc7d30e08a" /> lower in GPi (p < 0.05). Median values and range for fblood were 1.0 [0.2–6.0]% in the cortex, 0.3 [0.1–8.2]% in white matter, 0.2 [0.1–0.8]% in the GPi and 0.2 [0.1–11.7]% in the subthalamus. Corresponding values for S<img src="http://onlinelibrary.wiley.com/store/10.1002/jbio.201200055/asset/equation/tex2gif-inf-6.gif?v=1&t=h70man4e&s=151ec25bee7270bcfc2292e70d6f4aea18348dbc" /> was 20 [0–81]% in the cortex, 29 [0–78]% in white matter, 0 [0–0]% in the GPi and 0 [0–92]% in the subthalamus. In conclusion, the measurements indicate very low oxygenation and blood volume for DBS patients, especially in the GPi. It would be of great interest to investigate whether this is due to the disease, the normal situation or an artefact of doing invasive measurements.
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Dados espectrais dos solos do Centro-Oeste Paulista por meio de sensores próximos / Spectral data of midwest paulista soils by means of near sensorsCarmo, Danilo Almeida Baldo do [UNESP] 05 April 2018 (has links)
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Previous issue date: 2018-04-05 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A agricultura moderna no contexto internacional propõe inovações para o agronegócio, em especial para as práticas agrícolas. No entanto, este avanço deverá auxiliar o empresário rural a aumentar a eficiência, utilizando de forma sustentável os recursos naturais: água, terra e energia. Desse modo, objetivou-se, neste estudo, verificar o potencial dos sensores para obter os dados espectrais de um argissolo com cultivo de café. Utilizou-se de um conjunto de dados de um grid com 51 amostras de solo, em 39 hectares, com cultivo de café (Catuaí Amarelo, linhagem IAC 62). A obtenção das variáveis da cor: matiz, valor, croma, red, green e blue foi determinada por espectroscopia de reflectância difusa (ERD) e sensor próximo móbile (SPM). Os resultados mostraram relação com os atributos do solo nos seguintes casos: redSPM e argila: (R2 = 0,70, p < 0,01), greenSPM e CTC (R2 = 0,73, p < 0,01), redSPM e P (R2 = 0,64, p < 0,05), blueSPM e EC (R2 = 0,96, p < 0,01) e, greenSPM e Fe (R2 = 0,75, p < 0,01). Para os atributos da planta, foram: greenSPM e P17 (R2 = 0,70, p < 0,01), defeitos com regressões variando de 0,71 - 0,84 e, redSPM e produtividade (R2 = 0,95, p < 0,01). Os resultados mostraram que o uso da cor determinada pelo red, green e blue permitiu identificar atributos do solo e áreas com potenciais produtivos e qualitativos do café. Para o estudo no Planalto Ocidental Paulista, realizou-se um grid em área de 13 milhões de hectares, totalizando 600 amostras na profundidade de 0,00-0,20 metros. Nestas amostras, foram determinadas as variáveis da cor. Observou-se semelhança no uso dos métodos ERD e SPM. Os semivariogramas da ERD tiveram alcance para as variáveis matiz, valor, croma, red, green e blue de 112 km, 216 km, 19 km, 207 km, 183 km e 158 km, respectivamente. Com o uso do SPM, os alcances foram de: 19 km, 226 km, 30 km, 160 km, 218 km e 75 km, respectivamente. Os semivariogramas cruzados estimaram os atributos físico-químicos (Argila, capacidade de troca catiônica - CTC, fósforo - P e hematita - Hm). Os semivariogramas cruzados explicaram a distância máxima de correlação observada entre as variáveis. Os resultados do SPM mostraram que a cor nos sistemas red, green e blue pode ser utilizada na predição do teor de argila (77%), CTC (99%), P (90%) e Hm (70%). Com o uso da ERD, os sistemas red, green e blue predizem o teor de argila (79%), CTC (94%), P (86%) e Hm (67%). Estes resultados mostram que a cor é um indicativo seguro dos atributos do solo. Como alternativa de baixo custo, o SPM mostrou ser uma ferramenta eficiente que possibilita a avaliação destes atributos. / Modern agriculture in the international context proposes innovations for agribusiness, especially for agricultural practices. However, this progress must help the rural entrepreneur to increase efficiency, using sustainable natural resources: water, land and energy. Thus, the objective of this study was, to verify the potential of the sensors to obtain the spectral data of an argisol with coffee cultivation. We used a set of data with a grid 51 soil samples on 39 hectares, with coffee cultivation (Yellow Catuaí, lineage IAC 62). Obtaining the color variables: hue, value, chroma, red, green and blue was determined by diffuse reflectance spectroscopy (DRS) and mobile near sensor (MNS). The results were related to soil attributes in the following cases: redMNS and clay: (R2 = 0.70, p <0.01), greenMNS and CTC (R2 = 0.73, p <0.01), redMNS and P (R2 = 0.64, p <0.05), blueMNS and EC (R2 = 0.96, p <0.01) and, greenMNS and Fe (R2 = 0.75, p <0.01). For the plant atributes, were: greenMNS and P17 (R2 = 0.70, p <0.01), defects with regressions ranging from 0.71 - 0.84 and, redMNS and productivity (R2 = 0.95, p <0.01). The results showed that the use of the color determined by red, green and blue allowed to identify soil attributes and areas with productive and qualitative potentials of coffee. For the study in the Midwest Paulista Plateau, a grid was realized in an area of 13 million hectares, totaling 600 samples in the depth of 0.00-0.20 meters. In these samples, the color variables were determined. Similarity was observed in the use of DRS and MNS methods. The DRS semivariograms were range for the hue, value, chroma, red, green and blue variables of 112 km, 216 km, 19 km, 207 km, 183 km and 158 km, respectively. With the use of MNS, the ranges were: 19 km, 226 km, 30 km, 160 km, 218 km and 75 km, respectively. The crossed semivariograms estimated the physical-chemical attributes (clay, cation exchange capacity - CTC, phosphorus - P and hematite-Hm). Crossed semivariograms explained the maximum correlation distance observed between the variables. The results of the MNS showed that the color in the red, green and blue systems can be used to predict the content of clay (77%), CTC (99%), P (90%) and Hm (70%). With the use of DRS, red, green and blue systems predict the content of clay (79%), CTC (94%), P (86%) and Hm (67%). These results show that color is a safe indication of soil attributes. As an alternative of low cost, the MNS has shown to be an efficient tool that allows the evaluation of these attributes.
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Efeito de tensoativos e radiação ultravioleta na solidez da cor de cabelos tingidos / Color fading of dyed hair caused by surfactants and ultraviolet radiationAlves, Scheila Daiana Fausto, 1988- 25 August 2018 (has links)
Orientador: Inés Joekes / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-25T11:57:45Z (GMT). No. of bitstreams: 1
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Previous issue date: 2013 / Resumo: Os cabelos tingidos, como é de conhecimento comum, desbotam com o passar do tempo. Estudos mostram que tanto cabelos naturais quanto tingidos apresentam desbotamento quando expostos à radiação ultravioleta, e este mesmo fenômeno também é observado em outras fibras naturais. Além disso, o processo de lavagem tem grande influência nesta perda de cor. No entanto, há poucos estudos que combinem os efeitos da radiação ao de tensoativos, utilizados no processo de lavagem. Neste trabalho, estudamos a permanência da cor em cabelos Caucasianos tingidos frente à exposição à radiação UV-Vis e a três diferentes tensoativos, coco glucosídeo, cocoil sarcosinato de sódio e coco sulfato de sódio, de mesma cadeia apolar e diferente grupo polar. Cabelos castanhos foram oxidados antes do tingimento. Cabelos loiros foram tingidos sem oxidação prévia. Cabelos castanhos e loiros sem tingir foram usados como controles. Foram simulados danos diários por meio de irradiação em lâmpada de vapor de mercúrio e lavagens, em 30 ciclos sequenciais de 8 h de irradiação e uma lavagem. As diferenças de cor foram medidas por espectrofotometria de reflectância difusa.. Foram obtidos espectros no UV-Vis das soluções de lavagem com os diferentes tensoativos. Como esperado, todas as mechas, naturais e tingidas, apresentaram diferença de cor. No caso das mechas sem tingir, os espectros das soluções de lavagem correspondem aos das melaninas. No caso das mechas tingidas, as soluções de lavagem têm o mesmo perfil de absorbância que as soluções de tintura. As mechas oxidadas e tingidas desbotaram mais que as que foram apenas tingidas. Observou-se diferença entre o efeito dos tensoativos apenas nas mechas que foram tingidas. Tanto para o cabelo castanho oxidado e tingido quanto para o cabelo loiro tingido, a ordem de extração do pigmento é: coco sulfato de sódio > cocoil sarcosinato de sódio > coco glucosídeo, concordando com o respectivo índice HLB / Abstract: It is well known that dyed hair fades with time. There are studies showing that dyed and natural hair, besides other natural fibers, have their color lightened when exposed to ultraviolet radiation. Futhermore, shamppoing has a big effect on this color lightening. However, there are few studies combining the effects of radiation and surfactants. In this work, we studied the color durability in dyed Caucasian hair when exposed to radiation and three surfactants, coco glucoside, sodium cocoyl sarcosinate and sodium coco sulfate, with same carbonic chain and different polar groups. Brown hair was chemically bleached before dyeing and blond hair was dyed without previous oxidation. Brown and blond hair with no dyeing was used as control. Simulation of diary damages was done by a mercury vapor lamp and washing cycles, in 30 sequential cycles of 8 h of irradiation and one shampooing. Color changes were measured by diffuse reflectance spectroscopy (DRS), using CIELab system. UV-Vis spectra were obtained from washing solutions with the different surfactants. All tresses, natural and dyed, showed color changes. UV-Vis spectra of the washing solutions of the hair without dyeing are consistent with melanin spectra. Dyed hair washing solutions spectra have the same profile of the dye solutions. The chemically bleached and dyed tresses faded more than the only dyed ones. Differences among the surfactants were observed only in the dyed tresses The pigment removal order for both, oxidized and dyed and only dyed tresses is: sodium coco sulfate > sodium cocoyl sarcosinate > coco glucoside, agreeing with their HLB index / Mestrado / Físico-Química / Mestra em Química
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In Vivo Tissue Diagnosis for Myocardial Infarction Using Optical Spectroscopy with Novel Spectral Interpretation AlgorithmsChen, Po-Ching 31 March 2011 (has links)
In recent decades, the rapid development of optical spectroscopy for tissue diagnosis has been indicative of its high clinical value. The goal of this research is to prove the feasibility of using diffuse reflectance spectroscopy and fluorescence spectroscopy to assess myocardial infarction (MI) in vivo. The proposed optical technique was designed to be an intra-operative guidance tool that can provide useful information about the condition of an infarct for surgeons and researchers.
In order to gain insight into the pathophysiological characteristics of an infarct, two novel spectral analysis algorithms were developed to interpret diffuse reflectance spectra. The algorithms were developed based on the unique absorption properties of hemoglobin for the purpose of retrieving regional hemoglobin oxygenation saturation and concentration data in tissue from diffuse reflectance spectra. The algorithms were evaluated and validated using simulated data and actual experimental data.
Finally, the hypothesis of the study was validated using a rabbit model of MI. The mechanism by which the MI was induced was the ligation of a major coronary artery of the left ventricle. Three to four weeks after the MI was induced, the extent of myocardial tissue injury and the evolution of the wound healing process were investigated using the proposed spectroscopic methodology as well as histology. The correlations between spectral alterations and histopathological features of the MI were analyzed statistically.
The results of this PhD study demonstrate the applicability of the proposed optical methodology for assessing myocardial tissue damage induced by MI in vivo. The results of the spectral analysis suggest that connective tissue proliferation induced by MI significantly alter the characteristics of diffuse reflectance and fluorescence spectra. The magnitudes of the alterations could be quantitatively related to the severity and extensiveness of connective tissue proliferation.
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