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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

Studium transportu huminových látek skrz rostlinné kutikuly / Study on the transport of humic acids through the plant cuticles

Smilková, Marcela January 2014 (has links)
This diploma thesis is focused on foliar fertilization. It is nowadays one of the most widespread types of application of commercial fertilizers. Concern of this thesis is the study of plant cuticles as a thin layer on the leaves. These thin membranes are responsible for regulation of water transport and nutrients. Further function of plant cuticles is the mechanical protection of the outer part of the plant. Plant cuticles were characterized by fluorescence spectroscopy, classical optical microscopy and profilometry. The main aim of this thesis is the optimization and verification of experimental methodology aimed to the transport of commercial humic product through plant cuticles by simple diffusion techniques. The results obtained by presented diffusion techniques of humic product through plant cuticles were correlated with the same diffusion experiments through synthetic membranes with defined pore size and density. The study on transport of commercial humic product was realized in hydrogel medium by two different diffusion methods – non-stationary diffusion technique and diffusion couple. The important part of this diploma thesis is the characterization of supported hydrogel matrix by rheology tests, mercury intrusion porosimetry and scanned electron microscopy. Conclusions of this diploma thesis could be used for improving of efficiency of foliar fertilization.
2

NCF/Wax nano composites inspired by plant cuticles / Nanokompositer inspirerade av barriärskikt i växter

Qi, Chuan January 2012 (has links)
Plant cuticles are extracellular membranes covering aerial organs of plants, whose main functions rely on the protection against water loss, mechanical injury from the environment, attack of microorganism, and also regulation of gas exchange. Among the several constituents of plant cuticles, waxes are those that play an important role in their barrier properties. In order to enhance the mechanical properties of wax, NFC was applied in. In the project, mainly two kinds of methods were used to prepare wax-NFC composites. One way was wax and NFC were dissolved in toluene and casted to be a film, another way was to prepare NFC aerogel firstly, and then, impregnated the aerogel into wax liquid. After pressing it the structure was more compact. In order to characterize the properties of samples, SEM, XRD, TGA, DSC, Contact angle testing, tensile test and oxygen permeability methods were applied in.
3

Variação das frequências estomáticas em folhas de glossopteris no permiano da Bacia do Paraná (Formação Rio Bonito) e sua relação com níveis paleoatmosféricos de CO2

Schmidt, Isabela Degani January 2010 (has links)
Está demonstrado em plantas atuais que níveis atmosféricos de CO2 e frequência estomática estão inversamente correlacionados. A utilização de dados estomáticos na calibração das curvas de CO2 paleoatmosférico do Fanerozoico tem sido eficiente não apenas para o Cenozoico, mas também apresenta excelente correspondência desde o Eodevoniano. Cutículas de glossopterídeas provenientes das jazidas de carvão de Faxinal (RS) e Figueira (PR), incluídas em níveis estratigráficos distintos da Formação Rio Bonito (Sakmariano e Artinskiano respectivamente), viabilizaram análises para floras desenvolvidas sob a vigência de megaciclo icehouse. Cabe ressaltar que o uso de glossopterídeas, classificadas dentro do grupo extinto das Pteridospermophyta, esbarra na impossibilidade de se estabelecer um equivalente ecológico atual, dada a ausência de relações taxonômicas, estruturais e ecológicas com grupos viventes. Portanto, optou-se por uma abordagem proposta por outros autores como alternativa para diferentes grupos de pteridospermas, que consistiu em comparar entre si resultados de análises estomáticas na morfo-espécie Glossopteris communis Feistmantel procedente de distintos níveis associados a carvões na Bacia do Paraná. O objetivo geral do presente estudo foi estabelecer possíveis relações entre os padrões estomáticos calculados e flutuações nos teores de CO2 paleoatmosférico. A metodologia consistiu em resgatar mecanica e quimicamente as cutículas da rocha matriz, clareá-las em solução de Schulze e montá-las em lâminas de gelatina glicerinada para observação em microscopia de luz transmitida. A observação deu-se com auxílio de filtro de contraste por interferência diferencial e as contagens foram feitas com o auxílio de programa para análise de imagens. As técnicas de estudo compreenderam cálculos de densidade estomática (DE- número de estômatos por unidade de área da folha) e índice estomático (IE- percentual de estômatos sobre o total de células epidérmicas). Os resultados obtidos foram de DE média= 234,73 e IE médio= 15,7 para a jazida de Faxinal (Sakmariano) e de DE média= 284,14 e IE= 18,9 para a jazida de Figueira (Artinskiano). Esses valores enquadram-se dentro da curva global de CO2 atmosférico para o Fanerozoico (modelo GEOCARB). As frequências estomáticas mais baixas das folhas do Faxinal com relação àquelas de Figueira foram relacionadas a processo de reversão temporária da tendência global de baixos teores de CO2 atmosférico para a base do Permiano. Essa reversão é atribuída à provável influência de fatores paleoecológicos locais relativos à grande extensão das turfeiras na parte sul da bacia, responsável pela emissão em larga escala de gases-estufa. Além disso, a flora de Faxinal está preservada em uma camada de tonstein, registro de atividade vulcânica que poderia ter afetado os níveis de CO2. Por outro lado, as turfeiras de registro muito esparso ocorrentes no nordeste da bacia, em intervalo mais jovem, por sua pequena extensão e ausência de indícios de vulcanismo, não alteraram o padrão paleoatmosférico. Estudos focados no final do Paleozoico têm especial relevância porque, nesse intervalo vigoravam, nas diferentes paleolatitudes, condições ambientais análogas àquelas ocorrentes na atualidade, como a existência de calotas de gelo nos pólos e períodos de aquecimento global. / In extant plants stomatal frequency and the concentration of the atmospheric CO2 have been shown to correlate inversely. The use of stomatal data to calibrate phanerozoic paleoatmospheric CO2 curves has been considered a reliable technique not only for the Cenozoic estimates but also for results obtained since the Early Devonian. Glossopterid cuticles from Faxinal and Figueira coalfields (respectively in Rio Grande do Sul and Paraná States) from distinct stratigraphic levels in the Rio Bonito Formation allowed stomatal counting for floras developed under icehouse megacycle. However, it is important to highlight that the efficiency of Glossopteris, classified in the extinct group of Pteridospermophyta, is restricted as paleo-CO2 proxy for the Paleozoic due to the difficulty of establishing a nearest living equivalent for it, given the lack of taxonomic, structural and ecological relationships with extant groups. Thus it was here adopted an alternative approach proposed by different authors analyzing other groups of pteridosperms, which consists in comparing results obtained from the morphospecies Glossopteris communis Feistmantel between two different coal levels in the Paraná Basin. The general aim of this study was to establish possible relations between the calculated stomatal patterns and the fluctuation in the paleoatmospheric CO2 levels. The methodology consisted in mechanically and chemically isolating the cuticles from the matrix rock, bleaching them with Schulze solution and then mounting glycerin jelly slides for observation in transmitted light microscopy. The microscopic observation was made using a differential interference contrast filter and the counting was carried out with the help of software for image analysis. The study techniques included the calculation of stomatal densities (SD- number of stomata per foliar area unit) and of stomatal indices (SI- a ratio of the number of the stomata to the total number of epidermal cells). The results were mean SD= 234.73 and mean SI= 15.7 in Faxinal coalfield (Sakmarian) and mean SD= 284.14 and SI= 18.9 in Figueira coalfield (Artinskian). These values agree with the curve of global atmospheric CO2 for the Phanerozoic (GEOCARB model). The lower stomatal frequencies detected at the climax of the coal interval (Faxinal coalfield, Sakmarian) when compared to the higher ones obtained in leaves from a younger interval (Figueira coalfield, Artinskian) could be attributed to temporarily high levels of atmospheric CO2. Therefore, the occurrence of an extensive peat generating event at the southern part of the basin and the consequent greenhouse gases emissions from this environment may have been enough to reverse regionally and temporarily the reduction trend in atmospheric CO2. Additionally, the Faxinal flora is preserved in a tonstein layer, which is a record of a volcanic activity that could also imply a rise in atmospheric CO2. During the Artinskian, the scarce generation of peat mires, as revealed by the occurrence of thin and discontinuous coal layers, and the lack of volcanism evidences would be insufficient to affect the general low CO2 trend. Studies focused in the Late Paleozoic are especially relevant because of the presently shared icehouse climate with glacial-interglacial cyclicity which includes times of global warming.
4

Variação das frequências estomáticas em folhas de glossopteris no permiano da Bacia do Paraná (Formação Rio Bonito) e sua relação com níveis paleoatmosféricos de CO2

Schmidt, Isabela Degani January 2010 (has links)
Está demonstrado em plantas atuais que níveis atmosféricos de CO2 e frequência estomática estão inversamente correlacionados. A utilização de dados estomáticos na calibração das curvas de CO2 paleoatmosférico do Fanerozoico tem sido eficiente não apenas para o Cenozoico, mas também apresenta excelente correspondência desde o Eodevoniano. Cutículas de glossopterídeas provenientes das jazidas de carvão de Faxinal (RS) e Figueira (PR), incluídas em níveis estratigráficos distintos da Formação Rio Bonito (Sakmariano e Artinskiano respectivamente), viabilizaram análises para floras desenvolvidas sob a vigência de megaciclo icehouse. Cabe ressaltar que o uso de glossopterídeas, classificadas dentro do grupo extinto das Pteridospermophyta, esbarra na impossibilidade de se estabelecer um equivalente ecológico atual, dada a ausência de relações taxonômicas, estruturais e ecológicas com grupos viventes. Portanto, optou-se por uma abordagem proposta por outros autores como alternativa para diferentes grupos de pteridospermas, que consistiu em comparar entre si resultados de análises estomáticas na morfo-espécie Glossopteris communis Feistmantel procedente de distintos níveis associados a carvões na Bacia do Paraná. O objetivo geral do presente estudo foi estabelecer possíveis relações entre os padrões estomáticos calculados e flutuações nos teores de CO2 paleoatmosférico. A metodologia consistiu em resgatar mecanica e quimicamente as cutículas da rocha matriz, clareá-las em solução de Schulze e montá-las em lâminas de gelatina glicerinada para observação em microscopia de luz transmitida. A observação deu-se com auxílio de filtro de contraste por interferência diferencial e as contagens foram feitas com o auxílio de programa para análise de imagens. As técnicas de estudo compreenderam cálculos de densidade estomática (DE- número de estômatos por unidade de área da folha) e índice estomático (IE- percentual de estômatos sobre o total de células epidérmicas). Os resultados obtidos foram de DE média= 234,73 e IE médio= 15,7 para a jazida de Faxinal (Sakmariano) e de DE média= 284,14 e IE= 18,9 para a jazida de Figueira (Artinskiano). Esses valores enquadram-se dentro da curva global de CO2 atmosférico para o Fanerozoico (modelo GEOCARB). As frequências estomáticas mais baixas das folhas do Faxinal com relação àquelas de Figueira foram relacionadas a processo de reversão temporária da tendência global de baixos teores de CO2 atmosférico para a base do Permiano. Essa reversão é atribuída à provável influência de fatores paleoecológicos locais relativos à grande extensão das turfeiras na parte sul da bacia, responsável pela emissão em larga escala de gases-estufa. Além disso, a flora de Faxinal está preservada em uma camada de tonstein, registro de atividade vulcânica que poderia ter afetado os níveis de CO2. Por outro lado, as turfeiras de registro muito esparso ocorrentes no nordeste da bacia, em intervalo mais jovem, por sua pequena extensão e ausência de indícios de vulcanismo, não alteraram o padrão paleoatmosférico. Estudos focados no final do Paleozoico têm especial relevância porque, nesse intervalo vigoravam, nas diferentes paleolatitudes, condições ambientais análogas àquelas ocorrentes na atualidade, como a existência de calotas de gelo nos pólos e períodos de aquecimento global. / In extant plants stomatal frequency and the concentration of the atmospheric CO2 have been shown to correlate inversely. The use of stomatal data to calibrate phanerozoic paleoatmospheric CO2 curves has been considered a reliable technique not only for the Cenozoic estimates but also for results obtained since the Early Devonian. Glossopterid cuticles from Faxinal and Figueira coalfields (respectively in Rio Grande do Sul and Paraná States) from distinct stratigraphic levels in the Rio Bonito Formation allowed stomatal counting for floras developed under icehouse megacycle. However, it is important to highlight that the efficiency of Glossopteris, classified in the extinct group of Pteridospermophyta, is restricted as paleo-CO2 proxy for the Paleozoic due to the difficulty of establishing a nearest living equivalent for it, given the lack of taxonomic, structural and ecological relationships with extant groups. Thus it was here adopted an alternative approach proposed by different authors analyzing other groups of pteridosperms, which consists in comparing results obtained from the morphospecies Glossopteris communis Feistmantel between two different coal levels in the Paraná Basin. The general aim of this study was to establish possible relations between the calculated stomatal patterns and the fluctuation in the paleoatmospheric CO2 levels. The methodology consisted in mechanically and chemically isolating the cuticles from the matrix rock, bleaching them with Schulze solution and then mounting glycerin jelly slides for observation in transmitted light microscopy. The microscopic observation was made using a differential interference contrast filter and the counting was carried out with the help of software for image analysis. The study techniques included the calculation of stomatal densities (SD- number of stomata per foliar area unit) and of stomatal indices (SI- a ratio of the number of the stomata to the total number of epidermal cells). The results were mean SD= 234.73 and mean SI= 15.7 in Faxinal coalfield (Sakmarian) and mean SD= 284.14 and SI= 18.9 in Figueira coalfield (Artinskian). These values agree with the curve of global atmospheric CO2 for the Phanerozoic (GEOCARB model). The lower stomatal frequencies detected at the climax of the coal interval (Faxinal coalfield, Sakmarian) when compared to the higher ones obtained in leaves from a younger interval (Figueira coalfield, Artinskian) could be attributed to temporarily high levels of atmospheric CO2. Therefore, the occurrence of an extensive peat generating event at the southern part of the basin and the consequent greenhouse gases emissions from this environment may have been enough to reverse regionally and temporarily the reduction trend in atmospheric CO2. Additionally, the Faxinal flora is preserved in a tonstein layer, which is a record of a volcanic activity that could also imply a rise in atmospheric CO2. During the Artinskian, the scarce generation of peat mires, as revealed by the occurrence of thin and discontinuous coal layers, and the lack of volcanism evidences would be insufficient to affect the general low CO2 trend. Studies focused in the Late Paleozoic are especially relevant because of the presently shared icehouse climate with glacial-interglacial cyclicity which includes times of global warming.
5

Variação das frequências estomáticas em folhas de glossopteris no permiano da Bacia do Paraná (Formação Rio Bonito) e sua relação com níveis paleoatmosféricos de CO2

Schmidt, Isabela Degani January 2010 (has links)
Está demonstrado em plantas atuais que níveis atmosféricos de CO2 e frequência estomática estão inversamente correlacionados. A utilização de dados estomáticos na calibração das curvas de CO2 paleoatmosférico do Fanerozoico tem sido eficiente não apenas para o Cenozoico, mas também apresenta excelente correspondência desde o Eodevoniano. Cutículas de glossopterídeas provenientes das jazidas de carvão de Faxinal (RS) e Figueira (PR), incluídas em níveis estratigráficos distintos da Formação Rio Bonito (Sakmariano e Artinskiano respectivamente), viabilizaram análises para floras desenvolvidas sob a vigência de megaciclo icehouse. Cabe ressaltar que o uso de glossopterídeas, classificadas dentro do grupo extinto das Pteridospermophyta, esbarra na impossibilidade de se estabelecer um equivalente ecológico atual, dada a ausência de relações taxonômicas, estruturais e ecológicas com grupos viventes. Portanto, optou-se por uma abordagem proposta por outros autores como alternativa para diferentes grupos de pteridospermas, que consistiu em comparar entre si resultados de análises estomáticas na morfo-espécie Glossopteris communis Feistmantel procedente de distintos níveis associados a carvões na Bacia do Paraná. O objetivo geral do presente estudo foi estabelecer possíveis relações entre os padrões estomáticos calculados e flutuações nos teores de CO2 paleoatmosférico. A metodologia consistiu em resgatar mecanica e quimicamente as cutículas da rocha matriz, clareá-las em solução de Schulze e montá-las em lâminas de gelatina glicerinada para observação em microscopia de luz transmitida. A observação deu-se com auxílio de filtro de contraste por interferência diferencial e as contagens foram feitas com o auxílio de programa para análise de imagens. As técnicas de estudo compreenderam cálculos de densidade estomática (DE- número de estômatos por unidade de área da folha) e índice estomático (IE- percentual de estômatos sobre o total de células epidérmicas). Os resultados obtidos foram de DE média= 234,73 e IE médio= 15,7 para a jazida de Faxinal (Sakmariano) e de DE média= 284,14 e IE= 18,9 para a jazida de Figueira (Artinskiano). Esses valores enquadram-se dentro da curva global de CO2 atmosférico para o Fanerozoico (modelo GEOCARB). As frequências estomáticas mais baixas das folhas do Faxinal com relação àquelas de Figueira foram relacionadas a processo de reversão temporária da tendência global de baixos teores de CO2 atmosférico para a base do Permiano. Essa reversão é atribuída à provável influência de fatores paleoecológicos locais relativos à grande extensão das turfeiras na parte sul da bacia, responsável pela emissão em larga escala de gases-estufa. Além disso, a flora de Faxinal está preservada em uma camada de tonstein, registro de atividade vulcânica que poderia ter afetado os níveis de CO2. Por outro lado, as turfeiras de registro muito esparso ocorrentes no nordeste da bacia, em intervalo mais jovem, por sua pequena extensão e ausência de indícios de vulcanismo, não alteraram o padrão paleoatmosférico. Estudos focados no final do Paleozoico têm especial relevância porque, nesse intervalo vigoravam, nas diferentes paleolatitudes, condições ambientais análogas àquelas ocorrentes na atualidade, como a existência de calotas de gelo nos pólos e períodos de aquecimento global. / In extant plants stomatal frequency and the concentration of the atmospheric CO2 have been shown to correlate inversely. The use of stomatal data to calibrate phanerozoic paleoatmospheric CO2 curves has been considered a reliable technique not only for the Cenozoic estimates but also for results obtained since the Early Devonian. Glossopterid cuticles from Faxinal and Figueira coalfields (respectively in Rio Grande do Sul and Paraná States) from distinct stratigraphic levels in the Rio Bonito Formation allowed stomatal counting for floras developed under icehouse megacycle. However, it is important to highlight that the efficiency of Glossopteris, classified in the extinct group of Pteridospermophyta, is restricted as paleo-CO2 proxy for the Paleozoic due to the difficulty of establishing a nearest living equivalent for it, given the lack of taxonomic, structural and ecological relationships with extant groups. Thus it was here adopted an alternative approach proposed by different authors analyzing other groups of pteridosperms, which consists in comparing results obtained from the morphospecies Glossopteris communis Feistmantel between two different coal levels in the Paraná Basin. The general aim of this study was to establish possible relations between the calculated stomatal patterns and the fluctuation in the paleoatmospheric CO2 levels. The methodology consisted in mechanically and chemically isolating the cuticles from the matrix rock, bleaching them with Schulze solution and then mounting glycerin jelly slides for observation in transmitted light microscopy. The microscopic observation was made using a differential interference contrast filter and the counting was carried out with the help of software for image analysis. The study techniques included the calculation of stomatal densities (SD- number of stomata per foliar area unit) and of stomatal indices (SI- a ratio of the number of the stomata to the total number of epidermal cells). The results were mean SD= 234.73 and mean SI= 15.7 in Faxinal coalfield (Sakmarian) and mean SD= 284.14 and SI= 18.9 in Figueira coalfield (Artinskian). These values agree with the curve of global atmospheric CO2 for the Phanerozoic (GEOCARB model). The lower stomatal frequencies detected at the climax of the coal interval (Faxinal coalfield, Sakmarian) when compared to the higher ones obtained in leaves from a younger interval (Figueira coalfield, Artinskian) could be attributed to temporarily high levels of atmospheric CO2. Therefore, the occurrence of an extensive peat generating event at the southern part of the basin and the consequent greenhouse gases emissions from this environment may have been enough to reverse regionally and temporarily the reduction trend in atmospheric CO2. Additionally, the Faxinal flora is preserved in a tonstein layer, which is a record of a volcanic activity that could also imply a rise in atmospheric CO2. During the Artinskian, the scarce generation of peat mires, as revealed by the occurrence of thin and discontinuous coal layers, and the lack of volcanism evidences would be insufficient to affect the general low CO2 trend. Studies focused in the Late Paleozoic are especially relevant because of the presently shared icehouse climate with glacial-interglacial cyclicity which includes times of global warming.
6

Studium transportu kapalných lignohumátů přes listy rostlin a rostlinné kutikuly / Study on transport of liquid lignohumates through plant leaves and plant cuticles

Rampáčková, Eliška January 2019 (has links)
This thesis deals with the study of transport commercial solution of pottasium lignohumate through the plant cuticles, as the main barriers in transport of active ingredience to plant tissues. The problematics has been studied to obtain the informations about ability of transport liquid active ingredience during foliar fertilization, which became popular in theme of efective utilization fertilizers and reduction their negative impact to enviroment. The aim of this thesis was to optimize technics of diffusion for demanded purposes in the Stokes diffusion cells. As the transport barriers have been used the plant cuticles, that have been isolated by various methods. The ultraviolet and visible spectrometry (UV-VIS) was the analytical method for determination of transported volume of lignohumate and to the mentioned experiments the cuticles of Prunus laurocerasus and cuticles of tomato fruit have been used. The isolated cuticles have been analyzed by optical microscopy, scanning electron microscopy and profilometry. The characterisation of the used solution of lignohumate was also important part of this thesis. It has been used the basic physico-chemical methods and also the advanced methods as tensiometry, size exclusion chromatography with UV detector and differential refractive index detector (SEC-UV-dRI) and thermogravimetry (TGA).
7

Studium autekologie vybraných taxonů křídových rostlin pomocí izotopů uhlíku / Autecological study of selected Cretaceous plants using stable Carbon isotopes

Zahajská, Petra January 2016 (has links)
1 Abstract This thesis presents an analysis of fossil plants from the Cenomanian Peruc-Korycany Formation of the Bohemian Cretaceous Basin and from the Bückeberg Formation of the Lower Saxony Basin in Germany. Based on earlier studies, both areas provide sediments that are considered to have developed in tidally influenced fluvial systems. Studied fossil plants are represented by ginkgoalean plant leaves (Ertemophyllum, Tritaenia), branches of conifers (Frenelopsis) and lauroid angiosperms (Eucalyptolaurus). Frenelopsis, Eretmophyllum and Tritaenia are considered to be halophytic plants, while Lauroid angiosperms were considered to grow in fresh water conditions. The fossil plants were studied using cuticle analysis and two methods of stable carbon isotope analysis: Bulk carbon isotope analysis and Compound Specific Isotope analysis. For cuticle analysis samples were observed and documented macroscopically and microscopically. To specify the environmental conditions, recent samples from three salt marshes in Great Britain were studied and analysed using the same methods as the fossil samples. The data from all observations and measurements were processed and their interpretation supported the modelled environment based on the sedimentological data. Frenelopsis were growing in a haline environment with low...

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