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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Near infrared reflectance in Anura

Blount, Christopher January 2018 (has links)
Increased near infrared (NIR) reflection, closely resembling the red edge found in leaves, has been known in frogs for many years. Whereas previously thought of as an isolated rarity, we have shown that it is likely far more prevalent than previously believed, occurring in multiple distinct family groups and world regions. To date, there are now 26 anuran species known to demonstrate increased NIR reflectance, from 12 different genera, 4 families, and 3 ecozones. The visible/NIR reflection spectra of each individual measured was found to be characteristic of its species; whether it was wild or captive bred; and its sex. A machine learning based classification system was demonstrated as a viable method of identifying these properties from a frog's reflection spectra alone. How this reflection spectra developed from a pre-metamorphosis froglet through to adult frog was tracked, with the gradual changes to the reflection spectra of both NIR reflective and other frogs identified as being most likely dominated by the reduction in epidermal melanophores, and the increasing number of dermal iridophores. A modified consumer camera was shown to be a viable method for rapid identification of increased NIR reflection in anurans, and was used to identify that salamanders also show variation in NIR reflection between ground dwelling and leaf sitting species. The overnight colour change in Hylomantis lemur was observed, and found to occur pre-emptively of the frog's future location; with the frogs regularly transitioning from pale green ‘daytime' colouration, to the dark brown ‘night time' colouration, while still on the green leaf surface before becoming active, and undertaking the reverse transition while still active, but shortly before returning to the leaf. It seems likely that this change is for protection from silhouetting whilst active. Optical coherence tomography images were taken of several species of frog, and found to be a viable method for non-invasive investigation of anuran skin structure, with structural differences observed between the two colourations of H. lemur. It was found that the most likely cause of the increased NIR reflection in frogs is a reduction in melanin, either by absence or substitution with pterorhodin. Although the true benefit to the frog is difficult to determine, it seems likely that cryptic thermoregulation plays a key role: the maintenance of body temperature for the purpose of camouflage from animals capable of far-infrared vision. This thesis demonstrates the legitimacy of several techniques and approaches for non-invasive study of anurans, but the ultimate scope of the project is fundamentally limited by the range of frogs available. Further insight is likely to arise from increasing this scope, applying these techniques to more frogs, from more species, in more regions, and the author wishes all future researchers the greatest success in this endeavour.
2

A influência dos detergentes em pó comercial na solidez da cor à lavagem doméstica dos substratos têxteis / The influence of detergents on commercial powder on color fastness to domestic washing of textile substrates

Salvi, Paulo Sergio 29 November 2017 (has links)
A presente pesquisa consiste em analisar a solidez da cor dos substratos têxteis à lavagem, perante a utilização de detergentes em pó comerciais, e comparar com a utilização do detergente pó padrão previsto na norma ABNT NBR ISO 105-C06: Têxteis Ensaios de solidez da cor parte C06: Solidez da cor à lavagem doméstica e comercial. Para que as variáveis do substrato têxtil: a) composição; b) preparação para o tingimento; c) processo de tingimento; d) intensidade da cor; e) classe de corante. E as do processo de lavagem: temperaturas não comprometessem a conclusão da pesquisa, contemplou-se o controle de todas elas, de forma que, a única variável foi o tipo de detergente em pó utilizado, para tanto, levou-se em consideração: a) utilizado substratos 100% algodão, 100% poliéster, 100% poliamida e 100% acrílico; b) preparação para garantir a homogeneidade das amostras; c) substratos tintos em cores claras, médias e escuras; d) utilizadas classes de corantes que possuem boa solidez à lavagem; e) lavagem a 40ºC e a 60ºC. Foi utilizado um ambiente integrado contemplando equipamentos de laboratório para preparação, tingimento das amostras e para os ensaios de solidez da cor à lavagem, segundo a norma técnica específica. Os corpos de prova, após o processo de lavagem, foram submetidos à avaliação da alteração da cor, de acordo com a norma ABNT NBR ISO 105-A05: Têxteis Ensaios de solidez da cor parte A05: Avaliação instrumental da alteração da cor para classificação na escala cinza. Os resultados dos ensaios apontaram que somente os substratos 100% algodão e 100% poliamida, cor clara, lavados com detergentes comerciais apresentam resultados divergentes dos lavados com detergente padrão. Já os demais substratos não apresentaram alterações significativas quando comparados aos resultados obtidos na lavagem com o detergente padrão, o que aponta que o tipo de detergente utilizado no ensaio não influencia no resultado / The present research consists in analyzing the fastness of colors in textile substrates to washing, in relation to the use of commercial powder detergents, and compare it with the use of the standard detergent powder according to ABNT NBR ISO 105-C06: Textiles - color fastness of C06: Color fastness to domestic and commercial washing. So that the variables of the textile substrate: a) composition; b) preparation for dyeing; c) dyeing process; d) color intensity; e) dye class. And the of washing process: temperature, did not compromise the conclusion of the research, it was contemplated the control of them all, so that the only variable was the type of detergent powder used, for that, it was taken into consideration: a) used 100% cotton, 100% polyester, 100% polyamide and 100% acrylic substrates, because they are the most consumed fibers in Brazil; b) preparation to guarantee the homogeneity of the samples; c) red substrates in light, medium and dark colors; d) classes of dyes, which have good wash fastness, were used; e) washing at 40 ° C and at 60 ° C. An integrated environment was used, contemplating laboratory equipment for preparation, dyeing of the samples and the tests of color fastness to the wash, according to the specific technical standard. After the washing process, the specimens were submitted to the color change evaluation according to ABNT NBR ISO 105-A05: Textiles - Color fastness tests part A05: Instrumental evaluation of the color changing for Classification on the gray scale. The results of the tests indicated that only the 100% cotton and 100% polyamide substrates light colored washed with commercial detergents showed divergent results from the standard detergent washings. However, on the other substrates, did not present significant alterations when compared to the substrates obtained in washing with standard detergent, which indicates that the type of Detergent used in the test does not influence the result
3

A influência dos detergentes em pó comercial na solidez da cor à lavagem doméstica dos substratos têxteis / The influence of detergents on commercial powder on color fastness to domestic washing of textile substrates

Paulo Sergio Salvi 29 November 2017 (has links)
A presente pesquisa consiste em analisar a solidez da cor dos substratos têxteis à lavagem, perante a utilização de detergentes em pó comerciais, e comparar com a utilização do detergente pó padrão previsto na norma ABNT NBR ISO 105-C06: Têxteis Ensaios de solidez da cor parte C06: Solidez da cor à lavagem doméstica e comercial. Para que as variáveis do substrato têxtil: a) composição; b) preparação para o tingimento; c) processo de tingimento; d) intensidade da cor; e) classe de corante. E as do processo de lavagem: temperaturas não comprometessem a conclusão da pesquisa, contemplou-se o controle de todas elas, de forma que, a única variável foi o tipo de detergente em pó utilizado, para tanto, levou-se em consideração: a) utilizado substratos 100% algodão, 100% poliéster, 100% poliamida e 100% acrílico; b) preparação para garantir a homogeneidade das amostras; c) substratos tintos em cores claras, médias e escuras; d) utilizadas classes de corantes que possuem boa solidez à lavagem; e) lavagem a 40ºC e a 60ºC. Foi utilizado um ambiente integrado contemplando equipamentos de laboratório para preparação, tingimento das amostras e para os ensaios de solidez da cor à lavagem, segundo a norma técnica específica. Os corpos de prova, após o processo de lavagem, foram submetidos à avaliação da alteração da cor, de acordo com a norma ABNT NBR ISO 105-A05: Têxteis Ensaios de solidez da cor parte A05: Avaliação instrumental da alteração da cor para classificação na escala cinza. Os resultados dos ensaios apontaram que somente os substratos 100% algodão e 100% poliamida, cor clara, lavados com detergentes comerciais apresentam resultados divergentes dos lavados com detergente padrão. Já os demais substratos não apresentaram alterações significativas quando comparados aos resultados obtidos na lavagem com o detergente padrão, o que aponta que o tipo de detergente utilizado no ensaio não influencia no resultado / The present research consists in analyzing the fastness of colors in textile substrates to washing, in relation to the use of commercial powder detergents, and compare it with the use of the standard detergent powder according to ABNT NBR ISO 105-C06: Textiles - color fastness of C06: Color fastness to domestic and commercial washing. So that the variables of the textile substrate: a) composition; b) preparation for dyeing; c) dyeing process; d) color intensity; e) dye class. And the of washing process: temperature, did not compromise the conclusion of the research, it was contemplated the control of them all, so that the only variable was the type of detergent powder used, for that, it was taken into consideration: a) used 100% cotton, 100% polyester, 100% polyamide and 100% acrylic substrates, because they are the most consumed fibers in Brazil; b) preparation to guarantee the homogeneity of the samples; c) red substrates in light, medium and dark colors; d) classes of dyes, which have good wash fastness, were used; e) washing at 40 ° C and at 60 ° C. An integrated environment was used, contemplating laboratory equipment for preparation, dyeing of the samples and the tests of color fastness to the wash, according to the specific technical standard. After the washing process, the specimens were submitted to the color change evaluation according to ABNT NBR ISO 105-A05: Textiles - Color fastness tests part A05: Instrumental evaluation of the color changing for Classification on the gray scale. The results of the tests indicated that only the 100% cotton and 100% polyamide substrates light colored washed with commercial detergents showed divergent results from the standard detergent washings. However, on the other substrates, did not present significant alterations when compared to the substrates obtained in washing with standard detergent, which indicates that the type of Detergent used in the test does not influence the result
4

Tetrazine functionalized zirconium MOF as an optical sensor for oxidizing gases

Nickerl, Georg, Senkoska, Irena, Kaskel, Stefan 19 December 2019 (has links)
Dihydro-1,2,4,5-tetrazine-3,6-dicarboxylate was introduced into the chemically stable UiO-66 structure by a postsynthetic linker exchange reaction to create an optical sensor material for the detection of oxidative agents such as nitrous gases. The incorporated tetrazine unit can be reversibly oxidized and reduced, which is accompanied by a drastic colour change from yellow to pink and vice versa. The high stability of the framework during redox reaction was proven by powder X-ray diffraction and nitrogen physisorption measurements.

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