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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.
11

Biblioteca espectral de solos e sua aplicação na quantificação de atributos e classificação / Soil Spectral Library and its application in the attributes quantification and classification

Bellinaso, Henrique 08 June 2009 (has links)
O Brasil é um dos maiores produtores mundiais na área agrícola tendo o solo como base dos seus sistemas de produção. O planejamento adequado dos sistemas de produção exige a obtenção de dados geoespaciais básicos como o mapa de solos e fertilidade. Entretanto, os levantamentos pedológicos ainda consomem muito tempo, são onerosos e necessitam de grande número de análises laboratoriais. O desenvolvimento de técnicas de sensoriamento remoto laboratorial tem se apresentado como alternativa para o avanço de levantamentos pedológicos mais rápidos e menos onerosos. As técnicas de espectroscopia (VIS-NIR) também tem demonstrado boa eficiência na predição de atributos de solos de maneira rápida e menos poluente. Estas técnicas se baseiam em informações espectrais de solos e na montagem de um banco de dados espectral (Biblioteca Espectral). Portanto, tanto para a caracterização de classes de solo, quanto para a estimativa de atributos é necessário o desenvolvimento de Bibliotecas Espectrais (BE) que contenham dados representativos da variabilidade dos solos. Neste sentido, o presente trabalho teve por objetivo a montagem de uma BE de solos de diferentes regiões agrícolas do Brasil e a partir destas informações desenvolver técnicas de classificação de perfis e quantificação de atributos de solo. Para isso foram coletadas 7185 amostras de terra provenientes de perfis e de tradagens. Foi montado um banco de dados com o comportamento espectral de cada horizonte de 233. Também foram geradas bibliotecas espectrais de diferentes abragências geográficas, com finalidade de desenvolver modelos de predição de atributos. Baseado nos dados da BE gerada foi possível caracterizar distintas classes de solos e utilizar essas informações para classificar perfis de classe desconhecida a partir de dados espectrais. Também foram obtidos bons modelos de predições de atributos como areia, argila e Fe2O3 Foi demonstrado que BE que contenham dados de regiões com alta variabilidade de solos apresentam piores predições de atributos químicos. Um importante fator a ser considerado na montagem de BE é a alta amplitude de teor do atributo a ser predito. A montagem da BE contribuiu para avanços nas técnicas qualitativas e quantitavivas de avaliação espectral dos solos. / The Brazil is one of the major world agriculture producers having the soil like base of his production systems. The right planning of production systems needs the basic geospatial data obtaining such as soil and fertility maps. However, pedological surveys consume a lot of time, are expensive and need many laboratorial analyses. The development of laboratorial remote sensing techniques is an alternative for advanced of quicker and cheaper pedological surveys. The VIS-NIR spectroscopy techniques have been demonstrated a good efficiency in the fast and not pollutant soil attributes predictions. These techniques are based on soil spectral information and on development of the spectral data base (Spectral Library). Therefore, as much soil class characterization as attribute estimate its necessary spectral library (SL) development that have representative data of soil variability. In this sense, this work aim to build a soil SL from Brazils different agricultural regions and from this information on to develop profile classification techniques and soil attributes quantification. 7185 soil samples were collected from profiles and polls. A data base was built with spectral behavior of the 233 profiles and their horizons. SLs with different geographical coverage are purpose-built of development of attributes predictions models. Based on SL data created, it was possible distinguish different soil classes and use these information to classify profiles of unknown classes from spectral data. Good attributes prediction models were obtained to sand, clay and Fe2O3. It was demonstrated that SL containing regional data with high variability of soil have shown worse chemical attribute predictions. An important factor needs being considered in the SL building is the high amplitude of predicted attribute content. The SL building has brought advances to qualitative and quantitative soil spectral evaluation techniques.
12

Metagenômica comparativa e perfil metabólico in silico de solos no município de Cubatão, SP. / Comparative metagenomics and metabolic soil profiling in Cubatão County, SP.

Karolski, Bruno 19 June 2013 (has links)
Cubatão, o maior pólo industrial da américa latina também já foi uma das cidades mais poluídas do mundo. Os 30 anos de intensa atividade industrial vêm pressionando o meio ambiente com substâncias tóxicas e afetando gravemente a saúde da população. Dentre as substâncias contaminantes mais importantes da região estão os derivados de petróleo como o benzeno, tolueno, etilbenzeno e xilenos. Conhecidos como BTEX, eles são produzidos e utilizados em larga escala e a contaminação ocorre frequentemente através de vazamentos. Nos solos, devido à sua solubilidade em água, essas substâncias podem se espalhar por longas distâncias a partir do ponto afetado contaminando locais distantes. Já foi comprovada a capacidade de micro-organismos de sobreviver e até utilizar BTEX como fonte de carbono. Os micro-organismos adaptados catabolizam os contaminantes transformando-os em substâncias menos tóxicas e até mesmo eliminando-os do ambiente, capacidade de grande interesse econômico e ambiental. Nessa linha, nossa proposta visa o estudo das comunidades microbianas de solos afetados e não afetados por BTEX. Para isso foi utilizada a metagenômica como abordagem de estudo identificando-se diferenças qualitativas e quantitativas nas estruturas microbianas de três diferentes locais do município de Cubatão, sendo um deles afetado diretamente por BTEX. Pelo método utilizado e aqui desenvolvido, foi possível identificar um panorama metabólico geral identificando-se genes relevantes e o potencial de degradação de hidrocarbonetos aromáticos de micro-organismos conhecidos e desconhecidos, revelando melhor o potencial metabólico dos solos identificados. Os resultados apresentados podem contribuir para um melhor entendimento da dinâmica in situ de uma comunidade microbiana afetada por BTEX assim como melhorar o conhecimento sobre a comunidade microbiana de um local altamente impactado como Cubatão. / Cubatão is the largest industrial site in Latin America and was in the past one of the most polluted cities in the world. 30 years of intense industrial activity has pushed environmental limits with toxic substances and has severely affected the inhabitants\' health. Among the contaminants found in the region, the petroleum derivatives benzene, toluene, ethylbenzene and xylenes are the most important. Known collectively as BTEX, they are produced and used at a large scale and contamination frequently occurs. Because it is highly soluble in water, when in soil BTEX can spread long distances from the original contamination site, thus affecting large areas. Some microorganisms are known to live in contaminated environments and use contaminants such as BTEX as a unique carbon source for energy production. They catabolize contaminants into less dangerous products or even eliminate them from environment, a feature which has great commercial and environmental interest. We therefore compared the microbial communities in soils which were affected and un-affected by BTEX contamination. To this end, we used a metagenomics approach and developed a comparison method to identify microorganisms and degradation potential of soils studied. We found qualitative and quantitative differences in microbial structures from three different sites in Cubatão County, one of which is contaminated with BTEX. We constructed a metabolic overview identifying important genes, degradation potential and microorganisms related to BTEX degradation. The results presented here could contribute to understanding the in situ dynamics of a BTEX affected microbial community as well as improving our knowledge of the microbial community of Cubatão, a highly environmentally impacted place.
13

Sistema integrado de diagnose e recomendação (DRIS) para a cultura da soja (Glycine max L. Merril) na região de Rio Verde-GO / Diagnosis and recommendation integrated system (DRIS) for soybean (Glycine max L. Merril) in the Rio Verde region, GO

Leandro, Wilson Mozena 28 August 1998 (has links)
Submitted by Erika Demachki (erikademachki@gmail.com) on 2015-02-26T14:19:45Z No. of bitstreams: 2 Tese - Wilson Mozena Leandro - 1998.pdf: 1039643 bytes, checksum: d32b2d66c06a5a99eadf33e6697c512a (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Erika Demachki (erikademachki@gmail.com) on 2015-02-26T14:22:44Z (GMT) No. of bitstreams: 2 Tese - Wilson Mozena Leandro - 1998.pdf: 1039643 bytes, checksum: d32b2d66c06a5a99eadf33e6697c512a (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-02-26T14:22:44Z (GMT). No. of bitstreams: 2 Tese - Wilson Mozena Leandro - 1998.pdf: 1039643 bytes, checksum: d32b2d66c06a5a99eadf33e6697c512a (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 1998-08-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In order to diagnose the most limiting nutrients for soybean crop, in Rio Verde region, GO, farms were divided in distinct and homogeneous plots. Soil and leaf sampling were performed at the 50% soybean flowering stage. The third leaf from the top of 30 plants were sampled per plot. Yield was estimated from plants in 1m rows in 10 points per plot. Soil and tissue analysis were interpreted by critical levels and DRIS methods. The diagnosis precision was tested by different DRIS indices (expressions, ratios) calculation procedures. Plant nutrient condition diagnosis methods showed different interpretations. The original Beaufils method was the most precise. As related to DRIS use for soils, the resin-extracted P method was more precise than the Mehlich I extractor. Phosphorus was the most limiting nutrient for soybean crop. Potassium applied in excess caused exchangeable bases unbalance and induced a magnesium defficiency. The DRIS method showed higher sensitivity to diagnose nutrition problems, especially for micronutrients. / Com o objetivo de diagnosticar quais os nutrientes mais limitantes a produção da soja, áreas de fazendas da região de Rio Verde, GO, foram divididas em glebas, conforme as características locais de topografia, tipo de solo etc., procurando-se manter uniformidade dentro das glebas e diferenças entres elas. As amostras de terra e de folhas de soja foram coletadas na fase R2 (quando mais de 50% das plantas estavam no florescimento). Coletou-se a 3a. folha, a partir do ápice, 30 folhas por gleba. A produção foi obtida, retirando-se um metro linear de plantas de soja em 10 pontos, aleatoriamente. As análises foliares e de terra foram interpretadas pelo métodos dos níveis críticos e o DRIS. Testou-se a precisão de diagnóstico por diferentes procedimentos de cálculo dos índices DRIS. Os métodos de diagnose do estado nutricional apresentaram interpretações diferentes. O procedimento de Beaufils original foi mais preciso que os demais procedimentos. O P foi o nutriente mais limitante a cultura da soja. O excesso de adubação potássica provocou desequilíbrio entre as bases trocáveis com indução deficiência de Mg. Na aplicação do método DRIS no solo, as normas com o extrator resina apresentaram maior precisão de diagnóstico que as normas para o extrator Mehlich I. O método DRIS apresentou maior sensibilidade para diagnosticar problemas nutricionais, especialmente, para micronutrientes.
14

Biblioteca espectral de solos e sua aplicação na quantificação de atributos e classificação / Soil Spectral Library and its application in the attributes quantification and classification

Henrique Bellinaso 08 June 2009 (has links)
O Brasil é um dos maiores produtores mundiais na área agrícola tendo o solo como base dos seus sistemas de produção. O planejamento adequado dos sistemas de produção exige a obtenção de dados geoespaciais básicos como o mapa de solos e fertilidade. Entretanto, os levantamentos pedológicos ainda consomem muito tempo, são onerosos e necessitam de grande número de análises laboratoriais. O desenvolvimento de técnicas de sensoriamento remoto laboratorial tem se apresentado como alternativa para o avanço de levantamentos pedológicos mais rápidos e menos onerosos. As técnicas de espectroscopia (VIS-NIR) também tem demonstrado boa eficiência na predição de atributos de solos de maneira rápida e menos poluente. Estas técnicas se baseiam em informações espectrais de solos e na montagem de um banco de dados espectral (Biblioteca Espectral). Portanto, tanto para a caracterização de classes de solo, quanto para a estimativa de atributos é necessário o desenvolvimento de Bibliotecas Espectrais (BE) que contenham dados representativos da variabilidade dos solos. Neste sentido, o presente trabalho teve por objetivo a montagem de uma BE de solos de diferentes regiões agrícolas do Brasil e a partir destas informações desenvolver técnicas de classificação de perfis e quantificação de atributos de solo. Para isso foram coletadas 7185 amostras de terra provenientes de perfis e de tradagens. Foi montado um banco de dados com o comportamento espectral de cada horizonte de 233. Também foram geradas bibliotecas espectrais de diferentes abragências geográficas, com finalidade de desenvolver modelos de predição de atributos. Baseado nos dados da BE gerada foi possível caracterizar distintas classes de solos e utilizar essas informações para classificar perfis de classe desconhecida a partir de dados espectrais. Também foram obtidos bons modelos de predições de atributos como areia, argila e Fe2O3 Foi demonstrado que BE que contenham dados de regiões com alta variabilidade de solos apresentam piores predições de atributos químicos. Um importante fator a ser considerado na montagem de BE é a alta amplitude de teor do atributo a ser predito. A montagem da BE contribuiu para avanços nas técnicas qualitativas e quantitavivas de avaliação espectral dos solos. / The Brazil is one of the major world agriculture producers having the soil like base of his production systems. The right planning of production systems needs the basic geospatial data obtaining such as soil and fertility maps. However, pedological surveys consume a lot of time, are expensive and need many laboratorial analyses. The development of laboratorial remote sensing techniques is an alternative for advanced of quicker and cheaper pedological surveys. The VIS-NIR spectroscopy techniques have been demonstrated a good efficiency in the fast and not pollutant soil attributes predictions. These techniques are based on soil spectral information and on development of the spectral data base (Spectral Library). Therefore, as much soil class characterization as attribute estimate its necessary spectral library (SL) development that have representative data of soil variability. In this sense, this work aim to build a soil SL from Brazils different agricultural regions and from this information on to develop profile classification techniques and soil attributes quantification. 7185 soil samples were collected from profiles and polls. A data base was built with spectral behavior of the 233 profiles and their horizons. SLs with different geographical coverage are purpose-built of development of attributes predictions models. Based on SL data created, it was possible distinguish different soil classes and use these information to classify profiles of unknown classes from spectral data. Good attributes prediction models were obtained to sand, clay and Fe2O3. It was demonstrated that SL containing regional data with high variability of soil have shown worse chemical attribute predictions. An important factor needs being considered in the SL building is the high amplitude of predicted attribute content. The SL building has brought advances to qualitative and quantitative soil spectral evaluation techniques.
15

Desenvolvimento de metodologias para determinação de resíduos de atrazina em solos e águas naturais empregando técnicas eletroanalíticas. / Development of methodologies for determination of residues of atrazine in soil and natural waters employing electroanalytical techniques.

Santos, Luciana Bagdeve de Oliveira dos 28 April 2006 (has links)
Esta tese descreve o desenvolvimento de metodologias eletroanalíticas, em especial a voltametria de onda quadrada com o eletrodo de gota pendente de Hg, para determinação de atrazina em águas de rios do Estados de São Paulo e em amostras de solo. A exatidão das metodologias foi avaliada por comparação com HPLC e estudos de recuperação. Inicialmente desenvolveu-se o método em modo estático, no qual a maior sensibilidade foi obtida em pH 2 e freqüência de 400 Hz, com limites de detecção e determinação de 2 e 10 microgramas L-1, respectivamente. O estudo do comportamento eletroquímico revelou que a atrazina comporta-se reversivelmente em altas freqüências de onda quadrada. Dentre os metabólitos da atrazina, a desetilatrazina e desiosopropilatrazina, também são eletroativas nas condições estudadas, sendo possíveis interferentes, ao contrário da hidroxiatrazina e didealquilatrazina. Sistemas em fluxo contínuo e de injeção seqüencial foram desenvolvidos para determinação de atrazina em extrato de solo e águas naturais, bem como em estudos de adsorção. Em águas, os limites de detecção e determinação obtidos por injeção seqüencial foram de 4,5 e 15 microgramas L-1. Estudos de adsorção revelaram que atrazina liga-se mais fortemente a solos em meios ácidos. As metodologias em fluxo permitiram um significativo aumento da velocidade analítica e economia de reagentes, automatizando as determinações. / This thesis describes the development of electroanalytical methodologies, especially the square wave voltammetry with the hanging mercury drop electrode, for determination of the herbicide atrazine in river waters of the São Paulo state and soil samples. The accuracy of the methodologies was evaluated by comparison with HPLC and recovery studies. Initially, a stationary method was developed, in which the highest sensitivity was attained at pH 2 and at frequency of 400 Hz, with detection and quantification limits of 2 and 10 micrograms L-1, respectively. The electrochemical behavior of atrazine was reversible at the higher square wave frequencies. Among the atrazine metabolites, deethylatrazine and deisopropylatrazine are also electroactive under the studied conditions, being possible interferences, contrary to hydroxyatrazine and didealkylatrazine. Continuous flow and sequential injection systems were developed for determination of atrazine in soil extracts and natural waters, as well as in adsorption studies. In waters, the detection and quantification limits attained by sequential injection were 4.5 and 15 micrograms L-1. Adsorption studies showed that atrazine binds more strongly to soil in acidic media. The flow analysis methodologies lead to significant increase in the sampling throughput and reagent saving, automating the determinations.
16

Ancient Maya Agricultural Resources in the Rio Amarillo Valley near Copán, Honduras

Brown, Bryce Matthew 01 December 2016 (has links)
The purpose of this study was to use soil physical and chemical analyses to better understand the ancient agricultural landscape around the ancient Maya cities of Rio Amarillo and Piedras Negras, two tributary sites to Copan, Honduras. Our primary objective was to determine whether a mass erosion event around 800 A.D. occurred which could have caused crop failure and famine or if stable soil conditions persisted during the collapse of these city-states. Stable carbon isotope analysis of the humin fraction of the soils showed that much of this valley was used anciently for agriculture, including hillslopes and hilltops; however, there is no evidence of mass erosion in the soil profiles. Soil horizon development and texture is consistent with stable soil conditions in this area. The demise of these city-states was likely caused by a variety of factors including warfare and political unrest, and not solely by environmental degradation as postulated in previous studies of the valley.
17

Capillary electrophoresis as a fast and universal tool in soil analysis

Howald, Markus, Elsenbeer, Helmut, Laczko, Endre, Schlunegger, Urs Peter January 1995 (has links)
Fast analysis of different species of molecules in soils is investigated by capillary electrophoresis (CE). Several CE techniques for the analysis of inorganic ions and carbohydrates have been tested. With regard to the intents of pedologists and the usually large number of soil analyses a bundle of CE systems is proposed, capable of effecting time-saving soil analyses. Adapted electrolyte systems recently published and new separation systems are described. Examples of the application of these methods to two different soil samples are presented.
18

The Dirt on Prehispanic Water Management at Palmarejo, Honduras

Darley, Zaida 01 January 2011 (has links)
Water is an essential resource for human life. Even in the tropical environment of the Maya Lowlands, water scarcity is a concern, because the region cycles between abundant rainfall and seasonal droughts. To understand how societies flourished during periods of water scarcity, archaeologists have studied prehispanic water management in the Maya Lowlands. Yet, water management research has tended to focus predominantly on large urban Maya populations, excluding smaller-scale societies that face the same challenges associated with water scarcity. This study investigates the neighboring non-Maya society of Late Classic (A.D.650-900) Palmarejo in northwestern Honduras to explore how water management was organized in a rural setting. Utilizing GIS, soil science, and archaeological investigations, this study explores how Palmarejo's residents may have collected and stored water for certain sectors of the population. This investigation suggests that the elite may have legitimized their rights over water using monumental architecture and site planning.
19

The transformation of Tarahumara agriculture in Chihuahua, Mexico

Rudow, Joshua Martin 08 July 2011 (has links)
The Tarahumara are one of the most isolated and intact indigenous groups in Mexico. Their agriculture has traditionally been practiced within the steep canyons and uplands of the Sierra Madre Occidental in southwestern Chihuahua. Adapting to these rugged conditions, the Tarahumara developed a variety of agricultural techniques that allowed them to be self-sufficient in food production and independent of external inputs. As varied and ingenious as their techniques are, they share one main objective -- to overcome the lack of organic matter in the stony mountain soils. Since the arrival of the Spaniards, the addition of organic matter has involved large amounts of animal manure to increase organic matter in the soil and maintain fertility. The focus of this study is to investigate new agricultural techniques that the Tarahumara are adopting due to the pressures of globalization and alleged climate change. These new technologies may still include many traditional agricultural methods, but they are increasingly using commercially available fertilizers and other modern agricultural additions, thereby losing self-sufficiency. This study includes in depth interviews with 28 Tarahumara farmers to better understand the modern agricultural techniques, their motivations, and overall sustainability. Soil samples determined the viability of Tarahumara agricultural techniques on soil fertility by examining the visual description, organic matter content, soil texture, and a chemical analysis. The analyses showed that traditional Tarahumara agricultural practices are efficient and sustainable, while modern additions are often ill-suited for their environment and are disruptive to Tarahumara culture. / text
20

Nitrogen isotope analysis of ammonium and glycine : method development for aqueous solutions and soil extracts /

Norlin, Elin, January 2005 (has links) (PDF)
Diss. (sammanfattning) Umeå : Sveriges lantbruksuniversitet, 2005. / Härtill 4 uppsatser.

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