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Etude de la dynamique spatio-temporelle de l'humidité du sol : Applications du satellite SMOS au suivi de rendement agricole en Afrique de l'Ouest et à la correction des produits satellitaires de pluies / Study of spatio-temporal dynamics of soil moisture : SMOS satellite application to study the crop yield variations in West Africa and to correct uncertaintiees in satellite-based precipitation produtcGibon, François 18 May 2018 (has links)
L’humidité du sol à été déclarée Essential Climate Variable (ECV) en 2010 par l’European Space Agency (ESA) en support du travail du Groupe d'experts Intergouvernemental sur l'Évolution du Climat (GIEC). Dans des zones vulnérables comme l’Afrique de l’Ouest (agriculture faiblement irriguée et de subsistance, températures extrêmes et forte variabilité des précipitations), la valeur ajoutée d’informations concernant l’humidité du sol est importante, surtout dans un contexte de changement climatique. La première partie de ces travaux de thèse concerne la représentation de l'humidité en profondeur à grande échelle en utilisant le triptyque mesures in-situ/télédétection/modélisation. Ces 3 méthodes présentent chacune des limites: (i) la faible densité des réseaux in-situ (3 sites de mesures sur toute l'Afrique de l'Ouest), (ii) les estimations de SMOS uniquement en surface (0-5 cm) et (iii) les incertitudes des forçages de précipitation temps-réel utilisés dans les modèles de surface. Afin de réduire ces limitations, une méthode d'assimilation (filtre particulaire) des données SMOS à été implémentée dans un modèle de surface empirique (API) et comparées aux mesures in-situ AMMA-CATCH. Les résultats montrent une amélioration des humidités modélisée après assimilation. La seconde partie concerne l'impact des variations d'humidité du sol sur les rendements de mil. Une relation statistique a tout d'abord été déterminée à partir de données de rendements mesurés sur 10 villages autour de Niamey. Les résultats montrent que les anomalies d'humidité du sol sur 20 jours début Juillet et fin Août - mi Septembre (période reproductive et période de remplissage du grain), à une profondeur d'environ 30 cm, expliquent les variations de rendement mesuré à R2=0.77 sur l'ensemble de 9 villages. Cette relation à ensuite été appliquée à l'échelle du Niger à partir de données de rendement issues de la FAO et de cartes d'humidité en profondeur développées dans la première partie de la thèse. Les résultats montrent une corrélation à R2=0.62 sur les années 1998-2014. Puis la méthode a été appliquée à 3 autres pays du Sahel, montrant une corrélation de 0.77. La dernière partie de ces travaux concerne l'exploitation des résidus du schéma d'assimilation afin de réduire les incertitudes sur les précipitations. Les produits de précipitations satellites CMORPH, TRMM et PERSIANN, dans leur version temps-réel ont été comparées à des pluviomètres avant et après assimilation. Le résultat de cette étude montre une nette amélioration des intensités estimées. La méthode a ensuite été appliquée à un produit de précipitation utilisé au centre régional AGRHYMET pour le suivi agricole, le produit TAMSAT.Ces travaux de thèse ont permis d'approfondir les recherches concernant le potentiel des données d'humidité par satellite pour des applications agronomiques. Les perspectives de ces travaux portent principalement sur : (i) l'utilisation d'autres capteurs (SMAP, ASCAT, AMSR) pour augmenter la fréquence des observations d'humidité dans l'assimilation, (ii) sur des méthodes de désagrégation des coefficients pour la correction des précipitations à plus haute résolution spatiale et (iii) sur l'utilisation de données multispectrales (indices de végétation, température du sol, ...) pour un meilleur suivi des rendements. / Soil moisture was declared Essential Climate Variable (ECV) in 2010 by the European Space Agency (ESA) in support of the work of the Intergovernmental Panel on Climate Change (IPCC). In vulnerable areas such as West Africa (poorly irrigated and subsistence agriculture, extreme temperatures and high variability of rainfall), the added value of informations on soil moisture is important, especially in a changing climate. The first part of this thesis concerns the representation of root-zone soil moisture on a large scale using the triptych in-situ measurements / remote sensing / modeling. These 3 methods each have limitations: (i) the low density of in-situ networks (3 measurement sites throughout West Africa), (ii) SMOS estimates only at the surface (0-5 cm) and (iii) the uncertainties of the real-time precipitation forcing used in surface models. In order to reduce these limitations, an assimilation method (particle filter) of SMOS data has been implemented in an empirical surface model (API) and compared to AMMA-CATCH in-situ measurements. The results show an improvement of the humidities modeled after assimilation. The second part concerns the impact of soil moisture variations on millet yields. A statistical relationship was first determined from yield data measured in 10 villages around Niamey. The results show that the 20-day soil moisture anomalies at the beginning of July and the end of August - mid September (reproductive period and grain filling period), at a depth of about 30 cm, explain the variations in yield measured at R2=0.77. This relationship was then applied to the Nigerien scale from FAO yield data and in-depth moisture maps developed in the first part of the thesis. The results show a correlation at R2=0.62 over the years 1998-2015. Then, the method was apply to 3 other sahelian countries, showing a agreement of 0.77. The last part of this work concerns the exploitation of the residuals of the assimilation scheme in order to reduce the uncertainties on the precipitations. The satellite precipitation products CMORPH, TRMM and PERSIANN, in their real-time version, were compared to rain gauges before and after assimilation. The result of this study shows a marked improvement in the estimated precipitations intensities. The method was then applied to a precipitation product used at the AGRHYMET regional center for agricultural monitoring, the TAMSAT product.This thesis work has led to further research into the potential of satellite moisture data for agronomic applications. The perspectives of this work mainly concern: (i) the use of other sensors (SMAP, ASCAT, AMSR) to increase the frequency of the observations of humidity in the assimilation, (ii) on methods of disaggregation of the coefficients for the correction of precipitation at higher spatial resolution and (iii) the use of multispectral data (vegetation indices, soil temperature, ...) for a better monitoring of yields.
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Le mottage du lactose : Compréhension des mécanismes et prévention / Lactose caking : understanding the mechanisms as a route to preventionCarpin, Mélanie 08 March 2018 (has links)
L’augmentation de la demande en lait infantile génère une forte croissance de la production mondiale de lactose. En raison d’exigences accrues sur la qualité du produit, le mottage, ou prise en masse spontanée de la poudre, est une non-conformité pouvant s’avérer très coûteuse. En utilisant une approche procédé – produit, ce projet vise à identifier les paramètres critiques et comprendre les mécanismes de mottage du lactose, pour donner les moyens aux industriels de prévenir le mottage. Les résultats obtenus sur des poudres produites à l’échelle pilote montrent le rôle déterminant des impuretés (i.e. composés autres que le lactose) et de la granulométrie. En effet, les impuretés renforcent l’hygroscopicité et le mottage. De plus, en augmentant la teneur en impuretés, la surface spécifique et le nombre de points de contact, une diminution de la taille des particules et une hétérogénéité de tailles accrue intensifient le mottage. L’analyse des poudres commerciales a confirmé ces résultatUn autre résultat marquant de ce travail est le développement d’un test de mottage accéléré, qui permet de classer des poudres de lactose en fonction de leur tendance au mottage en moins d’une journée, après un stockage à 50°C et 60% d’HR. Un test similaire implémenté sur chaque site de production permettrait l’identification rapide des lots à risque avant expédition. Grâce à la meilleure compréhension des mécanismes de mottage fourni par ce travail, les industriels peuvent cibler les étapes critiques du procédé à optimiser pour prévenir le mottage du lactose. / Driven by the growth in the infant formula market, lactose production is increasing worldwide, and the requirements for the product quality are becoming stricter. Caking, or the unwanted agglomeration of lactose powder particles, is synonym of poor quality for the customers and should therefore be prevented to avoid large economic loss. Focusing on the process–product relationship, this PhD project aimed at finding the critical parameters and understanding the caking mechanisms in lactose powder in order to establish means to limit caking. In samples from pilot production, impurities (i.e. non-lactose components) were shown to increase moisture sorption and caking. The particle size distribution of the powder also exhibited a large effect on caking. Indeed, smaller particles and a broader distribution were characterized by enhanced moisture sorption and stronger caking, which were explained by a larger impurity content and surface area and more contact points.Analyses on the commercial powder confirmed these results and revealed the instability of the water activity during storage of the powder after drying, which was linked to caking in the bags. This PhD project also addressed an essential need in the dairy industry, i.e. the development of an accelerated caking test. Samples from different production sites were discriminated in terms of caking in less than a day, using appropriate test conditions (50°C and 60% RH). A similar test implemented at all sites would highlight batches with a high caking tendency before shipment to the customers. The better understanding of th
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EMERGENCE PATTERNS OF COMMON WATERHEMP AND PALMER AMARANTH IN SOUTHERN ILLINOISFranca, Lucas Xavier 01 August 2015 (has links)
The continued spread of glyphosate-resistant common waterhemp [Amaranthus tuberculatus (Moq.) Sauer (syn. rudis)] and Palmer amaranth [Amaranthus palmeri (S. Wats.)] have complicated weed control efforts in soybean and corn production in Illinois. A thorough understanding of the weed biology of these species is fundamental in developing effective weed management strategies. The determination of emergence patterns as well as the influence of tillage practices on soil microclimate and soil seed bank will allow control strategies to be implemented at the most effective timing. Field experiments were conducted in southern Illinois throughout the growing season of 2013 and 2014 on two separate sites with populations of common waterhemp and Palmer amaranth. Three tillage treatments were evaluated: no-tillage; early tillage, preferably performed around a recommended soybean planting date of May 1st; and late tillage, preferably performed on June 1st to simulate a late soybean planting. Amaranthus seedlings were identified and enumerated in the center 1 m2 quadrat of each plot within a 7-day interval from April through November or first frost. All weed seedlings were removed from the plot area after each enumeration. Soil temperature and soil moisture were recorded hourly throughout the experiment using data loggers established in the plot area. First emergence of common waterhemp occurred earlier in the season than did Palmer amaranth. In 2013, initial emergence of common waterhemp and Palmer amaranth was observed at the first and second week of May, respectively. In 2014, initial common waterhemp emergence was observed in late April, while Palmer amaranth initial emergence was similar to previous year. Palmer amaranth emerged over a longer period compared to waterhemp. By the end of June, 90% of common waterhemp had emerged regardless of tillage or year. By the same measure, Palmer amaranth emergence was extended to the third week of July and second week of August in 2013 and 2014, respectively. Soil temperature did not differ across tillage treatments in both years. On the other hand, differences in soil moisture were observed, mostly over two weeks following each tillage operation. The single best predictor for common waterhemp emergence was soil temperature (weekly highs and lows) followed by soil moisture. For Palmer amaranth emergence the single best predictor was spikes in soil moisture (high for the week). In 2013, common waterhemp emergence was initially positively and later in the growing season negatively interacted with maximum temperature 13 days prior to counts, with temperatures above 30 C observed with decreased emergence (R2 = 0.35). In the same year spikes in soil moisture interacted with Palmer amaranth emergence were those observed 11 days before each seedling enumeration date (R2 = 0.30). In 2014, with first common waterhemp emergence in April, a positive interaction to high soil temperature was initially observed followed by a positive interaction to minimum temperatures later in the season (R2 = 0.55). Spikes in soil moisture observed 2 weeks prior to emergence and weekly high temperatures 8 days prior to emergence were the best predictors of Palmer amaranth emergence in 2014 (R2 =0.37). Soil seed bank depletion was also estimated by comparing field emergence with greenhouse experiment results of soil seed bank estimation. Greater emergence of common waterhemp from the soil seed bank was observed in early tillage in 2013 and no-tillage in 2014 than late tillage, respectively; for Palmer amaranth, the greatest emergence from the soil seed bank was observed in no-tillage and late tillage in 2013, and no-tillage, in 2014. The emergence patterns observed in this research suggest that although common waterhemp and Palmer amaranth exhibit discontinuous emergence throughout the growing season, greater attention should be placed on managing peaks of emergence from late April to late July, which is critical to provide a foundation for early-season weed management. Furthermore, knowledge regarding the emergence patterns of common waterhemp and Palmer amaranth combined with monitoring environmental factors such as soil moisture and soil temperature may assist efforts for scouting fields to determine the likely presence of these weed species. The timing of viable postemergence herbicide options for control of glyphosate-resistant waterhemp and Palmer amaranth is critical and monitoring weather patterns to direct scouting efforts may improve the timeliness of these postemergence applications.
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An examination of vegetation modeling-related issues and the variation and climate sensitivity of vegetation and hydrology in ChinaTang, Guoping 09 1900 (has links)
xvi, 156 p. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / This dissertation examined a number of general vegetation-modeling issues, and the sensitivity of terrestrial net primary productivity (NPP), soil moisture and actual evapotranspiration (ET) to climatic variations in China. The specific issues addressed included: (1) the sensitivity of the performance of an equilibrium vegetation model to the choice of monthly-mean climatologies, observed validation data sets, and three map-comparison approaches; and (2) the limitations of existing map-comparison approaches in vegetation modeling; and the variation and climate sensitivity of (3) terrestrial NPP and (4) soil moisture and actual ET in China.
To address the first issue, BIOME4 (Kaplan et al., 2002), a typical example of an equilibrium vegetation model, was used along with a set of 19 different monthly-mean climatologies, three validation data sets, and several map-comparison methods. To address the second issue, the "opposite and identity" (01) index (Tang, 2008) was developed for evaluating the correspondence of two simulation results. To examine the third issue, a set of historical NPP dynamics were derived from normalized-difference vegetation index data by modifying the CASA (Potter et al., 1999) approach and then were linked to the variation of temperature and precipitation to analyze the climatic effects on terrestrial NPP in China. To examine the fourth issue, a stand-alone water balance model, LH (LPJ-hydrology), was developed by modifying the LPJ dynamic global vegetation model (Sitch et al., 2003), and applying it to a China case study.
The results of these analyses indicate that (1) the 30-year mean-climatology preceding the observed data produces the most accurate vegetation simulations; (2) the OI index is a useful tool to compare two simulation results or to evaluate simulation results against observed spatiotemporal data; (3) climate and land-use change jointly controlled NPP dynamics in the eastern monsoon zone of China. In contrast, NPP dynamics in the north-west and zone and in the Tibet Plateau frigid zone depended more on climatic variation; and (4) the spatial patterns of soil moisture and ET in China were correlated with the variation of temperature and precipitation. However, the strength of such relationship varies spatially.
This dissertation includes my published and coauthored materials. / Adviser: Patrick J. Bartlein
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Análise termodinâmica da incorporação de hidrogênio pelo aço líquido através da escória de refino secundárioZorzato, Marília Girardi January 2013 (has links)
Durante a fabricação do aço, a etapa de refino secundário tem como um de seus objetivos a redução do teor de hidrogênio. Porém, as previsões finais do teor de hidrogênio no produto devem presumir a existência de um fator de captura deste elemento pelo aço líquido, proveniente de diferentes fontes. Este trabalho tem como objetivo quantificar, através de estudo termodinâmico, a influência de um dos principais contribuintes com o aumento dos teores finais de hidrogênio: a umidade do ar capturada pela escória de refino secundário e repassada ao aço líquido. Para tanto, foi utilizado o programa de simulação termodinâmica FactSage. Primeiramente, foi realizado um estudo para a escolha das bases de dados do FactSage mais adequadas à pesquisa em questão. Posteriormente, foi realizada a simulação da exposição de escórias líquidas dos sistemas ternário CaO-MgO-SiO2 e quaternário CaO-MgO-SiO2-Al2O3 a duas diferentes pressões parciais de água na atmosfera, a fim de quantificar a solubilidade da água nestas escórias. Após, as escórias umidificadas foram simuladas em contato com o ferro líquido e a quantidade de hidrogênio transferido ao ferro foi analisada. Por fim, foi realizado um estudo termodinâmico de solubilidade de água em escórias do sistema quaternário CaO-MgO-SiO2-Al2O3, com basicidade binária igual a 2 e temperatura de 1600 °C; a exposição dessas escórias a duas pressões parciais de água na atmosfera foi simulada, sob duas abordagens: uma considerando escórias líquidas e outra considerando escórias com possíveis frações sólidas. A relação entre o teor de água destas escórias úmidas e o teor de hidrogênio no ferro também foi analisada. Desta forma, a influência das diferentes escórias na captura e transferência de hidrogênio ao ferro líquido foi relacionada com as composições de escória e com a pressão parcial de água na atmosfera. Foi observado que o teor de hidrogênio no ferro possui dependência linear com o teor de água na escória. No entanto, é possível variar a composição da escória e diminuir a quantidade de água que ela absorve da atmosfera e, desta forma, diminuir a quantidade de hidrogênio repassada ao metal. / During steelmaking, one of the main processes is the reduction of hydrogen levels. However, the degassing process and the final predictions of hydrogen levels in steel must presume the existence of a hydrogen pick-up factor in liquid steel, originated from different sources. This work aims to quantify, thermodynamically, the influence of one of the main contributors to the high final levels of hydrogen in steel: air humidity captured by the slag and transferred to the liquid steel. To achieve this, the thermodynamics software FactSage was used. First, the databases from FactSage were studied and the most adequate were chosen for the purpose of this work. After, the exposition of liquid ternary CaO-MgO-SiO2 and quaternary CaO-MgO-SiO2-Al2O3 slag systems to two different water pressures was simulated, to quantify the water solubility in these slags. Then, the moist slags were simulated with liquid steel and the hydrogen content transferred to the metal was analyzed. Finally, the solubility of water in slags of the system CaO-MgO-SiO2-Al2O3, with binary basicity equal to 2 and temperature of 1600 °C, was studied; the exposition of these slags to two different water pressures was simulated, under two views: considering liquid slags and slags with solid fractions. The relationship between water content in these slags and hydrogen content in steel was analyzed. Hence the influence of slags on water capture from atmosphere and transfer of hydrogen to liquid iron was related to the slag chemical compositions and to water vapor partial pressures. It was observed that hydrogen content in iron is linearly dependent on the water solubility of slags. However, according to the variation of the slag composition, it is possible to lower the quantity of water captured by the slag and therefore the steel hydrogen pick-up.
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Aquametria por micro-ondasSevero, Sergio Luiz Schubert January 2016 (has links)
A medida do teor de umidade de materiais resulta em ganhos econômicos e ambientais ao possibilitar o controle preciso da secagem de produtos agrícolas, de processos de cura e armazenagem, e reduzir perdas de material e consumo de energia. Tal medida pode ser feita através da interação de ondas eletromagnéticas nas frequências de micro-ondas. Apresenta-se o desenvolvimento histórico e o estado da arte dessa área da metrologia que é conhecida por aquametria por micro-ondas. Detalha-se o comportamento das ondas eletromagnéticas em dielétricos, o modelo de espalhamento nas interfaces das amostras, a relação entre a permissividade complexa e a umidade, métodos para a determinação da permissividade, instrumentos, sistemas e aspectos metrológicos da cadeia de medição para espectroscopia dielétrica. Dois novos métodos, com equações explícitas originais para a determinação da permissividade são obtidos. As novas equações resultam em incerteza menor que os métodos clássicos. Uma nova metodologia, através do método de Monte Carlo, é empregada para a avaliação das mesmas. Conclui-se que o desenvolvimento da aquametria passa, necessariamente, pelo aperfeiçoamento dos instrumentos e métodos para determinação da permissividade dos materiais. / The measurement of moisture content of materials results in economic and environmental gains. Monitoring drying and curing of materials prevents loss of products and waste of energy. This can be done through the interaction of electromagnetic waves at microwave frequencies. This dissertation presents the historical development and the state-of-the-art in aquametry, the behavior of electromagnetic waves in dielectrics, sample interface scattering model, the relationship between the complex permittivity and moisture, methods for determining permittivity, instruments and metrological aspects of the measurement chain, and some instruments for dielectric spectroscopy. Two new methods, capable of providing explicit equation for the permittivity, are obtained and the Monte Carlo method is applied to determine their uncertainty. The new equations have lower uncertainty than the classic methods. The general conclusion is that the development of instrumentation and techniques in aquametry must be based in improvements in permittivity measurement.
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Hodnocení sklízecích mlátiček JOHN DEERE 9880 a NEW HOLLAND CR 9080 při sklizni obilovin a ozimé řepky. / Rating combine harvesters John Deere 9880 and New Holland CR 9080 at harvest of cereals and oilseed rape.WEBER, Michal January 2012 (has links)
The aim of this thesis was to compare the activity and quality of work of the combine harvester New Holland CR 9080 and John Deere 9880 STS at harvest of cereals and oilseed rape and their simple economic evaluation. The thesis was focused on comparing losses and influence of moisture of harvested crops on the size of the losses, on the quality of crushing and the spreading of plant residues. Then the inf luence of moisture of harvested crops on the quality of crushing and the spreading of plant residues, analysis of performance and consumption of diesel were compared.
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Thermal modification of wood :process and properties /Čermák, Petr January 2013 (has links)
No description available.
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Variabilidade espaço-temporal da emissão de CO2 do solo em curto período sob influência de eventos de precipitação / Short-term spatiotemporal variability of soil CO2 emission under the influence of rainfall eventsSilva, Elienai Ferreira da [UNESP] 26 February 2016 (has links)
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Previous issue date: 2016-02-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A emissão de CO2 do solo (FCO2) em áreas agrícolas é um processo resultante da interação de diferentes fatores, tais como as condições de clima e solo. Nesse sentido, objetivou-se, com este estudo, investigar a variabilidade espaço-temporal da FCO2, temperatura (Tsolo), umidade (Usolo) e porosidade livre de água (PLA) do solo e suas interações, em área de reforma do canavial. O estudo foi conduzido em área de cana-de-açúcar sob reforma, na qual foi instalada malha amostral de 90 × 90 m2 contendo 100 pontos espaçados entre si em 10 m. Nestes pontos foram avaliadas a FCO2, Tsolo e Usolo em 10 avaliações ao longo de um período de 28 dias. Para as avaliações da FCO2, foi utilizado o sistema portátil LI-8100A. Concomitantemente à avaliação de FCO2, foram determinadas a Tsolo (termômetro integrante do sistema LI-8100A) e a Usolo (aparelho TDR). A emissão de CO2 e a Usolo foi maior no dia 276, com maior valor médio de 4,67 µmol m-2 s-1 e 31,75% em função das precipitações na área de estudo. Contrariamente os menores valor médios foram observados para PLA 19,17% e para a Tsolo 20,90 ºC. Os modelos de regressão linear utilizando somente a Usolo e a PLA explicaram 85% e 80%, respectivamente, da variabilidade temporal da FCO2, indicando que ao longo do tempo, a emissão de CO2 foi controlada pela variação do conteúdo de água e aeração do solo. Por outro lado, não foram encontrados modelos lineares ou quadráticos significativos (p>0,05) entre a FCO2 e a Tsolo. Os modelos ajustados para descrever a variabilidade espacial da FCO2, Tsolo, Usolo e PLA foram esféricos e exponenciais, sendo o modelo esférico predominante. Com exceção de alguns dias específicos, a partir dos mapas não foi possível a visualização de regiões características da área que indicassem um padrão de variabilidade espacial. Possivelmente o fato da amostragem ter sido conduzida em uma escala reduzida pode ter colaborado para um comportamento aleatório das variáveis no tempo. A variabilidade espaço-temporal da emissão de CO2, temperatura, umidade e a aeração do solo é afetada pelas precipitações na área de estudo, e pode ser dividida em três períodos: antes, durante e após as precipitações. Valores mais elevados da emissão de CO2 do solo são observados durante as precipitações e menores valores antes e pós-precipitações. / Soil CO2 emission (FCO2) in agricultural areas is a process that
results of the interaction of different factors such as climate and soil conditions. In this
sense, the aim of this study was to investigate the spatial and temporal variability of
FCO2, soil temperature (Tsoil), soil moisture (Msoil) and air-filled pore space (AFPS) and
their interactions in a sugarcane field reform. This study was conducted in a 90 × 90-
m sampling grid with 100 points spaced at distances of 10 m; at these points, 10
measurements were performed over a period of 28 days. In order to measure the
FCO2, it was used a LI-8100A. Along with the measurements of FCO2, Tsoil and Msoil
were also measured. It was observed an increase of 78% in FCO2 due to the rainfall
in the study area. The linear regression models using only Msoil and AFPS explained
85% and 80%, respectively, of the variability of FCO2, indicating that over the time, the
emission of CO2 was controlled by varying the content of water and soil aeration. The
adjusted models to describe the spatial variability of FCO2, Tsoil, Msoil and AFPS were
spherical and exponential. However, the spherical model was more predominant. We
did not identify spatial variability using the maps for some days. Probably this
happened because we used the small scale. It can have collaborated for random
behavior. The spatiotemporal variability of CO2 emission, temperature, moisture and
air-filled pore space was affected by rainfall in the study area. We can divide this
variability in three periods: before, during and after rainfall. The higher values of CO2
emissions was observed during rainfall and lower values before and after rainfall.
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Relação das condições de armazenamento com a qualidade fisiológica de sementes e composição do óleo extraído de cultivares de soja / Relation of storage conditions with quality physiology of seeds and compositon oil extracted of soybean cultivatesBordignon, Bruno Cesar Silva 27 March 2009 (has links)
The aim of this work was measure influence of parameters as environment conditions upon the seeds quality physiology and on aspects of oil quality extracted of soybean grains upon different storage conditions. For this the work had two experiments. The experiment one measured the quality physiology of soybean s seeds in levels the germination and vigor (accelerate aging and electric condutividy) with valuation initial, six and twelve months. The experiment had twelve treatment, with diferents combinations of temperature that varied of 25, 20, 10⁰C fix and regime of intermittence and air relative moisture high and low too in regime of intermittence, simulating the changes of weather conditions, during twelve months of storage. The experiment two had five treatments with temperature combinations of 20 and 10⁰C with air relative moisture, applied the fix form during the period the twelve months, utilized too two treatments with controlled atmosphere (CA), used the partial pressure of gases O2 1kPa and 0 kPa of CO2 and CO2 15kPa and 21 kPa of O2 maintain during the storage. The results for measures in experiment one was seeds exposed to high air moisture to shorts time period maintain the physiology potential of seeds, germination and vigor, the same of the initial, the better condition found in this work to storage of seeds was the 10⁰C with 74,1% air moisture, maintain the same initial quality in the 6 and 12 months, absent to cv. Miréia . The experiment two the measures of acidity index and peroxide showed that the combination of low temperature and air moisture were effectives in the grain conservation, to obtain oil. / O objetivo deste trabalho foi medir a influência dos parâmetros de condições ambientais sobre a qualidade fisiológica de sementes, e sobre aspectos de qualidade do óleo extraídos de grãos de soja sob diferentes condições de armazenamento. Para isso o trabalho consta de dois experimentos. O experimento um avaliou a condição de qualidade fisiológica das sementes de soja em nível de teste de geminação e vigor (envelhecimento acelerado e condutividade elétrica), com avaliações iniciais aos seis e doze meses. O experimento perfazia um total de doze tratamentos, com combinações diferentes de temperatura que variavam de 25, 20, 10⁰C fixas e em regime de intermitência e umidade relativa do ar, alta e baixa também em regime de intermitência, simulando as mudanças das condições de tempo, durante doze meses de armazenamento. O experimento dois constava de cinco tratamentos com combinações de temperatura 20 e 10⁰C e umidade relativa do ar, aplicadas de forma fixa durante o período de doze meses, utilizou-se dois tratamento com atmosfera controlada (AC), com as pressões parciais da composição de gases O2 1kPa e 0 kPa de CO2 e CO2 15kPa e 21 kPa de O2 mantidas durante o armazenamento. Os resultados para as avaliações do experimento um constataram que sementes expostas a alta umidade relativa do ar por curtos períodos de tempo mantem seu potencial fisiológico, germinação e vigor, iguais aos iniciais, a melhor condição encontrada neste trabalho para armazenamento de sementes foi a 10°C com 74,1% de UR do ar, mantendo a mesma qualidade inicial tanto aos 6 como aos 12 meses, exceto para a cv. Miréia. Para o experimento dois as avaliações do índice de acidez e peróxido mostraram que combinação de baixa temperatura e umidade relativa do ar foram efetivas na conservação dos grãos, para obtenção de óleo.
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