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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.
41

Modelagem da biomassa acima do solo (BAS), por meio de imagens de alta resolução espacial e índices de vegetação /

Macedo, Fabrício Lopes de. January 2014 (has links)
Orientador: Ricardo Antônio Ferreira Rodrigues / Co-orientador: Hélio Ricardo Silva / Banca: Marlene Cristina Alves / Banca: Artur Pantoja Marques / Banca: Adélia Maria de Oliveira Sousa / Banca: Edson Eyji Sano / Resumo: A estimativa de Biomassa Acima do Solo (BAS), com alta precisão, utilizando dados de sensoriamento remoto é um desafio presente. O objetivo deste estudo foi desenvolver uma função para estimar BAS em escala local e regional, através de imagens de alta resolução espacial, para Quercus rotundifolia e Eucalyptus, em uma área do Alentejo região do sul de Portugal e em Selvíria - MS, localizada na região Centro Oeste do Brasil, respectivamente. Para este fim, foram gerados alguns modelos empíricos, combinando os valores de biomassa estimada a partir de parcelas de inventário com alguns índices de vegetação baseados em imagem QuickBird e Pléiades. Analisando a área de estudo 1, o modelo que melhor se ajustou na estimativa da biomassa foi associado ao Índice de Vegetação por Diferença Normalizada (NDVI), apresentando um coeficiente de determinação (R 2 ) 75,6%. Na área de estudo 2, os modelos que melhor se ajustaram nas estimativas de biomassa fizeram uso do Índice de Vegetação Ajustado ao Solo (SAVI), apresentando um coeficientes de determinação (R 2 ) de 64,8%. Essas funções poderão ser utilizadas em outras regiões para as mesmas espécies, com clima semelhante e com as mesmas características locais. Esta abordagem pode ser usada como uma ferramenta de baixo custo para produzir estimativas de biomassa acima do solo preliminares em escala local e regional / Abstract: Estimating Above Ground Biomass (BAS), with high accuracy, using remote sensing data is a current challenge. The objective of this study was to develop a function to estimate BAS in local and regional level, through images of high spatial resolution, for Quercus rotundifolia and Eucalyptus, an area in the Alentejo region of southern Portugal and Selvíria - MS, located in the region central Brazil, respectively. To this end, some empirical models were generated by combining the values of biomass estimated from inventory plots with some vegetation indices based on QuickBird image and Pleiades. Analyzing the study area 1, the model that best fit the estimation of biomass was associated with the Index Normalized Difference Vegetation index (NDVI), with a coefficient of determination (R 2 ) 75.6%. In study area 2, the models that best fit the biomass estimates made using the Soil Adjusted Vegetation (SAVI) Index, with a coefficient of determination (R 2 ) of 64.8%. These functions can be used in other regions for the same species with similar climate and with the same local features. This approach can be used as an inexpensive tool to produce estimates of biomass above ground primary local and regional scale / Doutor
42

Caracterização da cinza de bagaço de cana-de-açúcar e aplicação no solo /

Oliveira, Darlene Lopes do Amaral. January 2015 (has links)
Orientador: José Eduardo Corá / Banca: Edson Luiz Mendes Coutinho / Banca: Carolina Fernandes / Banca: Adolfo Valente Marcelo / Banca: Anice Garcia / Resumo: O aumento do uso do bagaço de cana-de-açúcar para geração de energia elétrica no Estado de São Paulo tem resultado em grandes quantidades de cinzas que necessitam de manuseio e disposição adequada. O destino corrente deste resíduo em grande escala tem sido a utilização no solo de áreas plantadas com cana-de-açúcar, porém esse método não é autorizado pelas agências ambientais do país ou pelo Ministério da Agricultura e são escassas as avaliações sobre vantagens ou desvantagens de sua aplicação. Esta pesquisa foi proposta visando avaliar os efeitos da aplicação de cinza de bagaço de cana-de-açúcar (CBCA) em diferentes doses nos atributos químicos do solo. Para isso foram propostos três estudos: a) ensaio de incubação visando avaliar a biodegradação da fração orgânica da CBCA; b) ensaios em colunas de solo em casa de vegetação com estrutura preservada com o objetivo de detectar possíveis alterações em água percolada, e sua possível implicação ecológica, em solos representativos da região de Jaboticabal- SP (Latossolo) e c) ensaio de campo em duas áreas sob Argissolo com cultivo de citros com diferentes manejos da CBCA (incorporado e sem incorporação na superfície). A CBCA foi caracterizada por meio de diferentes métodos físicos químicos. Foram avaliadas nos estudos o efeito de diferentes doses de CBCA (0, 5, 10, 20, 40 e 80 Mg ha-1) quanto ao comportamento dos metais: tóxicos (Cr ) e fitotóxicos (Zn, Cu, Mn e Ni); do semimetal (Si) e dos ânions (SO42- e PO42-). Os resultados evidenciaram que a CBCA é rica em SiO2 (82,2%) com predomínio de quartzo cristalino e em menor concentração silicato de potássio. A fração de mineralização de C em C-CO2 foi menor do que 1,6 % em 182 dias de incubação. A taxa de mineralização do carbono adicionado pela cinza de bagaço de cana-de-açúcar foi alterada em função da textura do solo sendo que a inibição da respiração da microflora ... / Abstract: The increased use of sugarcane bagasse for electric energy production in the State of São Paulo has resulted in large amounts of ashes that requires its proper handling and disposal. The current target of this large-scale residue has been its use in sugarcane soil areas, though this method is not authorized by the country's environmental agencies or by the Ministry of Agriculture and the assessments about advantages or disadvantages of its application are scarce. This research was proposed to evaluate the effects of sugar bagasse ashes (SBA) application in different doses on chemical soil attributes. Three studies were proposed for this: a)The incubation test to evaluate the biodegradation of the organic fraction of the SBA; b)Tests in soil columns with preserved structure using completely randomized design with 3 replications in order to detect possible changes in water percolated, and its possible implication in vegetation ecological conditions on soils, representing the region of Jaboticabal-SP (Oxisol); and c)Field trial in two areas under Ultisol with citrus cultivation with different SBA managements (incorporated and surface application) through the randomized block designs with 5 repetitions. The SBA was characterized through different physical chemical methods, to identify their organic and inorganic fraction. Were evaluated in the studies the effect of different doses of SBA (0, 5, 10, 20, 40 and 80 Mg ha-1) as regards the behavior of metals: toxic (Cr) and phytotoxic (Zn, Cu, Mn and Ni); the semimetal (Si) and anions (SO42- and PO42-). The results showed that the SBA is rich in SiO2 (82.2%) with predominance of crystalline quartz and potassium silicate in lower concentration. The mineralization fraction of C in C-CO2 was less than 1.6% in 182 days of incubation and this indicated that the SBA contributes to increase the stocks of soil organic matter. The carbon mineralization rate added by sugarcane bagasse ashes has ... / Doutor
43

Funkce horských luk při různých způsobech jejich obhospodařování / Functioning of Mountain Meadows under Different Management Impacts

MAŠKOVÁ, Zuzana January 2008 (has links)
Influence of different management practices on the mountain meadows communities and possibilities of their maintenance in the National Park, Protected Landscape Area and Biosphere Reserve of Šumava are discussed. The aim of the study was to compare the effect of mulching of grassland vegetation with those of traditional mowing or leaving a grassland fallow. The results of a ten-year field experiment are presented - the changes of plant biomass, plant community structure and physical properties of the soil A horizon. Acceptable possibilities of mulching as an alternative technique for the maintenance of secondary grassland in the Bohemian Forest are proposed on the basis of data obtained during the experiment.
44

Estudo da pirólise de cana-de-açúcar integral / Study of the pyrolysis of sugar cane integral

Marin Mesa, Liena del Rosario 19 August 2018 (has links)
Orientadores: Caio Glauco Sánchez, Elisabete Maria Saraiva Sanchez / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-19T23:59:46Z (GMT). No. of bitstreams: 1 MarinMesa_LienadelRosario_M.pdf: 3046850 bytes, checksum: d16d04046b66c91b2aa858a286e8566f (MD5) Previous issue date: 2011 / Resumo: Neste trabalho foi feita a caracterização físico-química de três variedades de cana-de-açúcar: a cana tradicional e dois novos tipos de cana para energia, visando avaliar o potencial energético. Ensaios de pirólise foram realizados numa balança termogravimétrica e uma planta de pirólise de capacidade de 20 kg/h de alimentação. Foi realizado um balanço de massa do processo, e foram obtidos modelos matemáticos que caracterizaram o comportamento do processo de pirólise nas diferentes condições. Esses resultados permitiram avaliar tecnicamente o processo de pirólise de cana integral, comparar os rendimentos obtidos em instalações de diferentes escalas e coletar informações para posteriores estudos desta tecnologia. A comparação entre as características físico-químicas dos três tipos de cana apresentou diferenças na umidade e no teor de cinzas para as diferentes partes da cana (colmo, ponteiro e folhas). Os ensaios em balança termogravimétrica mostraram que a taxa de aquecimento tem influência significativa no rendimento dos produtos líquidos, e nos ensaios de pirólise em planta piloto de 20 kg/h de alimentação, não apresentaram diferenças significativas nos rendimentos nem nas características dos produtos. Através do balanço de massa e energia, comparou-se a eficiência energética dos três tipos de cana, quando transformada através do processo de pirólise rápida. Observou-se que a diferença entre as três variedades está na produtividade destas por unidade de área cultivada, sendo a cana para energia Tipo 2, a que apresentou maior quantidade de energia útil por hectare (3110 MJ/hec), seguido da cana Tipo 1 (2400 MJ/hec) e com menor eficiência energética a cana tradicional (Tipo 3), com 1500 MJ/hec / Abstract: This work was carried out physico-chemical characterization of three varieties of cane sugar: cane traditional and new types of sugar for energy, to evaluate the potential energy. Pyrolysis tests were performed in a thermogravimetric balance and a pyrolysis plant capacity of 20 kg / h of power. We conducted a mass balance of the process, and mathematical models were obtained that characterized the behavior of the pyrolysis process in different conditions. These results allowed us to evaluate technically the pyrolysis of cane integral, compare the yields obtained in facilities of different scales and collect information for further study of this technology. Comparison of the physicochemical characteristics of three types of cane showed differences in moisture and ash content for different parts of the cane (stem, leaves and pointer). The thermogravimetric balance tests showed that the rate of warming has significant influence on the yield of liquid products, and pyrolysis tests in a pilot plant of 20 kg / h of feeding, no significant differences in income or the characteristics of the products. Through the balance of mass and energy, compared the energy efficiency of three types of cane, when transformed through the process of fast pyrolysis. It was observed that the difference between the three varieties of these is the productivity per unit area cultivated with sugarcane for energy type 2, had the greatest amount of useful energy per hectare (3110 MJ / ha), followed by a cane type 1 (2400 MJ / ha) and less energy efficient sugarcane traditional (Type 3), 1500 MJ / ha / Mestrado / Termica e Fluidos / Mestre em Engenharia Mecânica
45

Queima do canavial: aspectos sobre a biomassa vegetal, fertilidade do solo e emissão de CO2 para atmosfera / Burning of the sugarcane crop: biomass aspects, soil, fertility and CO2 emission in atmosphere

Sasso, Carlos Guilherme 20 September 2007 (has links)
Made available in DSpace on 2016-01-26T18:56:33Z (GMT). No. of bitstreams: 1 CARLOS GUILHERME_DISSERTACAO_TEXTO.pdf: 280186 bytes, checksum: d4cf929cf3647cdde2332128553f159b (MD5) Previous issue date: 2007-09-20 / The objective of the work was to evaluate the changes that occur in the ground, the plant and the atmosphere immediately after the practical one of the burning of the canavial. For in such a way, it compared the effect of the burning of the sugarcane plantation in the ground and the proper sugar cane, thus, samples of these items in two situations had been collected show before (treatments) and after burning. The standardized areas had been referencing as pulley and had been repeated five times, for each pulley five samples had been carried through. All the data had been submitted to the analysis of variance (ANOVA, p<0,05) and to the test of comparison of Scott-Knott averages (p<0,05) and for the analysis multivaried for main components (PCA). In the multivaried analysis it had a clear division it enters the data of the daily pay and after-burns. The data show that before the burning only the variable leaves they had presented variations in the standardized pulley and that subsequent to burns these differences for leaves had disappeared. With regard to comparison of the one before and of after-it burns, the variable, Leaves, Hands, Stalk, Total and % Leaves had presented statistical differences. The variable % ponter and corrected Brix had not presented differences when comparative before and subsequent to it burns. The result of I calculate it of the amount of CO2 emitted for the burning of leaves was of 3,89 Mg ha-1 and had the burning of the hands 0,92 Mg ha-1 of CO2 they had been more launched by hectares, totalizing therefore 4.81 Mg ha-1 of CO2. In the data of Mo, Mn, Cu e B they had presented statistical text differences when compared before and after-it burns. / O objetivo do trabalho foi avaliar as mudanças que ocorrem no solo, na planta e na atmosfera imediatamente após a prática da queima do canavial. Para tanto, foram coletadas amostras de solo e da planta em duas situações (tratamentos) pré e pós-queima. As áreas foram padronizadas e referenciadas como talhões, cinco foram os talhões usados para cada tratamento (repetições). Para cada talhão foram realizadas cinco amostras. Estimou-se a emissão de CO2 utilizando as reduções de folhas, ponteiros e colmos proporcionadas pela queima, nos tratamentos. Todos os dados foram submetidos à análise de variância (ANOVA, p<0,05) com o teste de comparação de médias Scott-Knott (p<0,05) e estudados por análise multivariada por componentes principais (PCA). Com relação à comparação da pré e da pós-queima, as variáveis de biomassa (folhas, ponteiros, colmos) apresentaram diferenças estatísticas. Entretanto, as variáveis % de MS do ponteiro (%ponteiro) e brix corrigido não apresentaram diferenças quando comparadas a pré e a pós-queima. O resultado do cálculo da quantidade de CO2 emitida pela queima das folhas foi de 3,89 Mg ha-1 (toneladas por hectare) e devido à queima dos ponteiros mais 0,92 Mg ha-1 de CO2 foram lançadas na atmosfera, totalizando 4,81 Mg ha-1 de CO2 totais. Os dados referentes ao Mn, Cu e B apresentaram diferenças estatísticas de teores quando comparados antes e após a queima. Na análise multivariada houve uma divisão clara entre os dados da pré e pós-queima, influenciados pela biomassa vegetal. O trabalho concluiu que a queima da cana promove redução de folhas, ponteiros e colmos em 92,48%, 33,52% e 30,70% respectivamente. No solo ocorreu redução de manganês em 21,04%, de cobre em 19,32% e de boro em 30,56%. Na atmosfera ocorre emissão de 4,8 Mg ha-1 de CO2, provenientes da queima de 10,41 Mg de biomassa vegetal.
46

Queima do canavial: aspectos sobre a biomassa vegetal, fertilidade do solo e emissão de CO2 para atmosfera / Burning of the sugarcane crop: biomass aspects, soil, fertility and CO2 emission in atmosphere

Sasso, Carlos Guilherme 20 September 2007 (has links)
Made available in DSpace on 2016-07-18T17:51:14Z (GMT). No. of bitstreams: 1 CARLOS GUILHERME_DISSERTACAO_TEXTO.pdf: 280186 bytes, checksum: d4cf929cf3647cdde2332128553f159b (MD5) Previous issue date: 2007-09-20 / The objective of the work was to evaluate the changes that occur in the ground, the plant and the atmosphere immediately after the practical one of the burning of the canavial. For in such a way, it compared the effect of the burning of the sugarcane plantation in the ground and the proper sugar cane, thus, samples of these items in two situations had been collected show before (treatments) and after burning. The standardized areas had been referencing as pulley and had been repeated five times, for each pulley five samples had been carried through. All the data had been submitted to the analysis of variance (ANOVA, p<0,05) and to the test of comparison of Scott-Knott averages (p<0,05) and for the analysis multivaried for main components (PCA). In the multivaried analysis it had a clear division it enters the data of the daily pay and after-burns. The data show that before the burning only the variable leaves they had presented variations in the standardized pulley and that subsequent to burns these differences for leaves had disappeared. With regard to comparison of the one before and of after-it burns, the variable, Leaves, Hands, Stalk, Total and % Leaves had presented statistical differences. The variable % ponter and corrected Brix had not presented differences when comparative before and subsequent to it burns. The result of I calculate it of the amount of CO2 emitted for the burning of leaves was of 3,89 Mg ha-1 and had the burning of the hands 0,92 Mg ha-1 of CO2 they had been more launched by hectares, totalizing therefore 4.81 Mg ha-1 of CO2. In the data of Mo, Mn, Cu e B they had presented statistical text differences when compared before and after-it burns. / O objetivo do trabalho foi avaliar as mudanças que ocorrem no solo, na planta e na atmosfera imediatamente após a prática da queima do canavial. Para tanto, foram coletadas amostras de solo e da planta em duas situações (tratamentos) pré e pós-queima. As áreas foram padronizadas e referenciadas como talhões, cinco foram os talhões usados para cada tratamento (repetições). Para cada talhão foram realizadas cinco amostras. Estimou-se a emissão de CO2 utilizando as reduções de folhas, ponteiros e colmos proporcionadas pela queima, nos tratamentos. Todos os dados foram submetidos à análise de variância (ANOVA, p<0,05) com o teste de comparação de médias Scott-Knott (p<0,05) e estudados por análise multivariada por componentes principais (PCA). Com relação à comparação da pré e da pós-queima, as variáveis de biomassa (folhas, ponteiros, colmos) apresentaram diferenças estatísticas. Entretanto, as variáveis % de MS do ponteiro (%ponteiro) e brix corrigido não apresentaram diferenças quando comparadas a pré e a pós-queima. O resultado do cálculo da quantidade de CO2 emitida pela queima das folhas foi de 3,89 Mg ha-1 (toneladas por hectare) e devido à queima dos ponteiros mais 0,92 Mg ha-1 de CO2 foram lançadas na atmosfera, totalizando 4,81 Mg ha-1 de CO2 totais. Os dados referentes ao Mn, Cu e B apresentaram diferenças estatísticas de teores quando comparados antes e após a queima. Na análise multivariada houve uma divisão clara entre os dados da pré e pós-queima, influenciados pela biomassa vegetal. O trabalho concluiu que a queima da cana promove redução de folhas, ponteiros e colmos em 92,48%, 33,52% e 30,70% respectivamente. No solo ocorreu redução de manganês em 21,04%, de cobre em 19,32% e de boro em 30,56%. Na atmosfera ocorre emissão de 4,8 Mg ha-1 de CO2, provenientes da queima de 10,41 Mg de biomassa vegetal.
47

Influence of a Human Lipodystrophy Gene Homologue on Neutral Lipid Accumulation in Arabidopsis Leaves

James, Christopher Neal 08 1900 (has links)
CGI-58 is the defective gene in the human neutral lipid storage disease called Chanarin-Dorfman syndrome. This disorder causes intracellular lipid droplets to accumulate in nonadipose tissues, such as skin and blood cells. Here, disruption of the homologous CGI-58 gene in Arabidopsis thaliana resulted in the accumulation of neutral lipid droplets in mature leaves. Mass spectroscopy of isolated lipid droplets from cgi-58 loss-of-function mutants showed they contain triacylglycerols with common leaf specific fatty acids. Leaves of mature cgi-58 plants exhibited a marked increase in absolute triacylglycerol levels, more than 10-fold higher than in wild-type plants. Lipid levels in the oil-storing seeds of cgi-58 loss-of-function plants were unchanged, and unlike mutations in beta-oxidation, the cgi-58 seeds germinated and grew normally, requiring no rescue with sucrose. We conclude that the participation of CGI-58 in neutral lipid homeostasis of nonfat-storing tissues is similar, although not identical, between plant and animal species. This unique insight may have implications for designing a new generation of technologies that enhance the neutral lipid content and composition of corp plants.
48

Manipulations of Sucrose/Proton Symporters and Proton-pumping Pyrophosphatase Lead to Enhanced Phloem Transport But Have Contrasting Effects on Plant Biomass

Khadilkar, Aswad S 05 1900 (has links)
Delivery of photoassimilate, mainly sucrose (Suc) from photoautotrophic source leaves provides the substrate for the growth and maintenance of sink tissues such as roots, storage tissues, flowers and fruits, juvenile organs, and seeds. Phloem loading is the energized process of accumulating solute in the sieve element/companion cell complex of source leaf phloem to generate the hydrostatic pressure that drives long-distance transport. In many plants this is catalyzed by Suc/Proton (H+) symporters (SUTs) which are energized by the proton motive force (PMF). Overexpression of SUTs was tested as means to enhance phloem transport and plant productivity. Phloem specific overexpression of AtSUC2 in wild type (WT) tobacco resulted in enhanced Suc loading and transport, but against the hypothesis, plants were stunted and accumulated carbohydrates in the leaves, possibly due to lack of sufficient energy to support enhanced phloem transport. The energy for SUT mediated phloem loading is provided from the PMF, which is ultimately supplied by the oxidation of a small proportion of the loaded photoassimilates. It was previously shown that inorganic pyrophosphate (PPi) is necessary for this oxidation and overexpressing a proton-pumping pyrophosphatase (AVP1) enhanced both shoot and root growth, and augmented several energized processes like nutrient acquisition and stress responses. We propose that AVP1 localizes to the PM of phloem cells and uses PMF to synthesize PPi rather than hydrolyze it, and in doing so, maintains PPi levels for efficient Suc oxidation and ATP production. Enhanced ATP production in turn strengthens the PMF via plasma membrane (PM) ATPase, increasing phloem energization and phloem transport. Phloem-specific and constitutive AVP1 overexpressing lines showed increased growth and more efficiently moved carbohydrates to sink organs compared to WT. This suggested changes in metabolic flux but diagnostic metabolites of central metabolism did not show changes in steady state levels. This research focuses on fundamental aspects of carbon utilization and transport, and has a strong applied component, since increased H+-PPase activity enhances plant biomass, nutrient up-take capacities, and stress tolerance for as yet not fully characterized reasons.
49

Covariation in plant abundance and diversity estimators in an old field herbaceous plant community

LaJeunesse, Katherine J. 27 April 2007 (has links)
No description available.
50

Thermocycle-regulated WALL REGULATOR INTERACTING bHLH Encodes a Protein That Interacts with Secondary-Cell-Wall-Associated Transcription Factors

Whitney, Ian P 18 March 2015 (has links) (PDF)
Lignocellulosic biomass is one of the most abundant raw materials on earth that can be utilized to created carbon-neutral biofuels as a replacement for conventional fossil fuels. In order to create ideal energy crops, the regulation and deposition of cell wall polysaccharides must first be fully understood. Improved understanding of cell wall regulation will enable selection of traits that can optimize biofuel feedstocks. Herein, I utilize the grass model system Brachypodium distachyon in order to understand the transcriptional regulation of secondary cell wall deposition. Gene expression profiling was used to elucidate transcription factors that regulate secondary cell wall biosynthesis. Through this method, WALL REGULATOR INTERACTING bHLH (WRIB) was identified and its role as a secondary cell wall regulator was tested. Yeast-one- and yeast-two-hybrid assays showed that WRIB is capable of binding to promoters of secondary cell wall biosynthesis genes, as well as interacting with known secondary cell wall transcription factor proteins and also Phytochrome B. These results suggest that WRIB plays an important role in the secondary cell wall regulatory network and could perhaps be modulated by Phytochrome B. Discovery of this novel and interesting gene furthers the overall understanding of secondary cell wall development with the goal of improving our ability to engineer biofuel feedstocks.

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