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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.
1541

Repartição da água da chuva sob o dossel e umidade do solo no gradiente fisionômico da vegetação do Cerrado / Rainfall partioning under the canopy and soil moisture in the physiognomy gradient of Cerrado vegetation

Eliane Akiko Honda 29 November 2013 (has links)
Apesar da grande área ocupada pelo Cerrado no território brasileiro e de sua importância ecológica e hidrológica, ainda é desconhecida a repartição da água das chuvas no gradiente fisionômico da vegetação nesse bioma. No presente estudo quantificamos a interceptação da água das chuvas e a umidade do solo, para estabelecer correlações entre as características estruturais da vegetação, representadas principalmente pela área basal, e os dados hidrológicos. Para tanto, quantificamos a transprecipitação e o escoamento pelo tronco das árvores, em 15 parcelas representativas do gradiente fisionômico entre o cerrado típico e o cerradão, localizados na Estação Ecológica de Assis (EEcA), SP, para obtenção da proporção da precipitação efetiva que atravessa o dossel e chega à superfície do solo, em comparação com a precipitação total, quantificada a céu aberto. Os indivíduos lenhosos em cada parcela com DAP 5 cm foram identificados e medidos. A quantidade de transprecipitação foi tanto maior quanto menos complexa a estrutura da vegetação, sendo também influenciada pelas características da chuva incidente. A proporção da transprecipitação também foi fortemente influenciada pela estrutura da vegetação, porém, não foi detectada influência das características das chuvas. Assim, foi possível concluir que, em ambiente de Cerrado, é a estrutura da vegetação que influencia de forma decisiva a proporção de água que alcançará o solo sob forma difusa. A facilidade em captar a água da chuva e escoá-la pelo tronco variou em função de atributos da árvore, sendo que árvores mais altas e com copa volumosa escoaram maior quantidade, enquanto árvores de crescimento monopodial, tronco ereto e reto e copa compacta têm maior eficiência de captação. O agrupamento das parcelas em diferentes fisionomias resultou em diferenças significativas nas taxas de precipitação efetiva e interceptação, indicando que elas devem ser caracterizadas hidrologicamente como ambientes distintos, onde há gradação na quantidade de água que chega ao solo em função do gradiente de biomassa. A transição da entrada de água ao solo no gradiente do Cerrrado é crescente e contínua, desde as comunidades menos densas (cerrado típico) até as comunidades mais densas (cerradão). A dinâmica e a disponibilidade de água do solo foram mais influenciadas pelas propriedades do solo do que pela cobertura vegetal, quando ambos os fatores são variáveis. Concluímos que, em regiões nas quais a água é um recurso escasso, o manejo visando controlar a biomassa da vegetação é um recurso válido, visto que os resultados apontam para a importância das fisionomias mais abertas do Cerrado para a produção hídrica. / Despite the large area occupied by the Cerrado in Brazil and its ecological and hydrological importance, the rainfall partioning in the physiognomy gradient of the vegetation in this biome is still to be ellucidated. In this study, we quantified rainfall interception and the of soil moisture to establish correlations between vegetation structure, represented by the basal area, and hydrological data. Therefore, we quantified the troughfall and stemflow of trees in 15 plots representing the physiognomic gradient between typical cerradão and cerradão, located at Assis Ecological Station (EEcA), SP, to obtain the net rainfall reaching the ground, compared to the total precipitation quantified at open adjacent area. The woody plants with DBH 5 cm were identified and measured in every plot. Troughfall was lower when the vegetation structure was more complex, and was not influenced by micrometeorological factors. We concluded that, in Cerrado, vegetation structure decisively influences the proportion of rainfall to reaching the soil. The stemflow amount was greater the larger the tree and the tree canopy, while trees with monopodial growing, erect and straight trunk and compact canopy had more capture efficiency. Grouping plots by Cerrado physiognomies resulted in significant differences in both net precipitation and interception, indicating that they must be categorizes as hydrologically distinct environments. There is increasing and continuous transition from the more open communities (cerrado típico) to the forest physiognomies (cerradão) in the proportion of rainfall retained by the canopies. The dynamics and the availability of soil water were more influenced by soil properties than the vegetation cover, when both factors varies. This study points out the importance of low biomassa Cerrado physiognomies for hydric production and we concluded that, when and where water is a scarce resource, controlling vegetation biomass can be recommended to aiming at water production.
1542

Efeito do teor de fibra e do processamento de milho na qualidade e perfil de ácidos graxos da carne de bovinos Nelore / Effect of roughage level and corn processing on meat quality and fatty acid profile of Nellore bulls

Pâmela Marcos Rizzo 27 February 2013 (has links)
Foi avaliado o efeito do método de processamento do milho (PRC) e do teor de fibra insolúvel em detergente neutro proveniente de forragem (FDNf) na qualidade físico- químicas, analise sensorial e no perfil de ácidos graxos da carne in natura e após cocção de bovinos Nelore em confinamento. Foram utilizados 56 bovinos não castrados da raça Nelore, com peso inicial de 382 kg. Os animais foram distribuídos em baias individuais sendo separados de acordo com o peso vivo inicial, formando assim o delineamento em blocos completos casualizados, em esquema fatorial 2x4. Do total de 112 animais foram selecionados aleatoriamente 56 bovinos perfazendo sete animais de cada tratamento. Foram confinados durante 81 dias, sendo 21 dias de adaptação e 60 dias de tratamento. As dietas de tratamento continham teores de 3, 8, 13 e 18% de fibra insolúvel em detergente neutro proveniente de forragem (FDNf) e dois métodos de processamentos dos grãos de milho, sendo grão úmido ensilado - GU e grão seco moído fino - MM. Os dados foram analisados pelo procedimento MIXED e as medias foram determinadas pelo LSMEANS. As medias foram determinadas pelo LSMEANS. Testes para os efeitos fixos com valores de probabilidade inferiores ou iguais a 0,05 foram considerados significativos. Não foi observado efeito de interação entre FDNf e PRC para as características de qualidade da carne como umidade, força de cisalhamento, pH, cor e características sensoriais. Ao avaliar o teor de EE do músculo Longissimus dorsi houve diferença (P=0,05) entre os métodos de PRC utilizados. Os valores de EE obtidos no músculo L. dorsi dos animais alimentados foram de 1,80 vs. 1,48 para GU e MM, respectivamente. A relação ?6:?3 apresentou decréscimo linear com o aumento no teor de FDNf, mostrando uma relação de 4,24 na dieta com 3% e 3,31 para as dietas contendo 18% de FDNf (P<0,05). A concentração de CLA encontrada na carne de animais alimentados com GU está dentro da faixa recomendada para carne bovina que é de 0,2 a 1,0% do total de ácidos graxos. Houve um aumento no teor de lipídios na carne dos animais que receberam dietas com milho grão úmido ensilado. O aumento no teor de FDNf na dieta resultou em menor relação ?6:?3 na carne, algo desejável sob o ponto de vista da saúde do consumidor. O cozimento da carne não alterou o perfil de ácidos graxos da carne, pode-se então estimar o perfil de ácidos graxos por meio da análise em carnes cruas. / Was evaluated the effect of corn processing method (PRC) and the content of neutral detergent fiber from roughage (NDF) in physicochemical quality and sensory analysis in the fatty acid profile of fresh beef and after cooking of Nelore cattle feedlot. We used 56 Nellore bulls with an initial weight of 382 kg. The animals were divided into individual stalls being separated according to initial body weight, thus forming the randomized complete block design in a 2x4 factorial design. Of the total of 112 animals were randomly selected 56 bulls totaling seven animals of each treatment. Were confined for 81 days, being 21 days of adaptation and 60 days of treatment. The treatment diets contained levels of 3, 8, 13 and 18% neutral detergent fiber from roughage (NDFr) and two methods of processing corn grains, being high moisture corn - GU and finely ground dry corn - MM. The data were analyzed using the MIXED procedure and the media were determined by LSMEANS. Tests for fixed effects with probability values less than or equal to 0.05 were considered significant.] There was no interaction effect between NDFr and PRC for meat quality characteristics such as moisture, shear force, pH, color and sensory characteristics. When evaluating the EE content of the Longissimus dorsis there was difference (P=0.05) between the PRC methods used. The EE values obtained in the animals L. dorsi muscle were 1.80 vs. 1.48 for GU and MM, respectively. The concentration of CLA found in animals meat fed with GU is within the recommended range for beef which is 0.2 to 1.0% of total fatty acids. The relationship ?6:?3 displayed a linear decrease with the increase of NDFr level, showing a ratio of 4.24 in the diet with 3% NDFr and 3.31 in diets containing 18% NDFr (P<0.05). The concentration of CLA found in animals meat fed with GU is within the recommended range for beef which is 0.2 to 1.0% of total fatty acids. There was an increase in fat content in the meat of animals fed diets with high moisture corn silage. The increase in the content of FNDr in the diet, resulted in a lower ratio of ?6: ?3 in the flesh, desirable from the point of view of consumer health. The cooking of the meat did not alter the fatty acid profile of meat, can then estimate the fatty acid profile by analyzing in raw meats.
1543

Simulation of soil water movement model (SWaMM) using the Spider Distributed System

Wang, Li 01 January 2003 (has links)
This project implements a real application on the Spider II, which is a simulation of Soil Water Movement Model. The main objectives of this project were to develop a parallel and distributed algorithm for the Soil Water Model; implement the Soil Water Movement Simulation model on the Spider II distributed system and to evaluate the performance of simulating the Soil Water Movement Model on Spider II.
1544

Topografi och markfuktighet för granbarkborreskadad skog / Topography and soil moisture for spruce bark beetle damaged forest

Magnebäck, Anders, Fälth, Peter January 2020 (has links)
En stor skadegörare på de svenska granskogarna är den åttatandade granbarkborren Ips typographus (L.). Torkstress, vattentillgång och landskapets topografi är faktorer som påverkar granens vitalitet. Om granen har en låg vitalitet riskerar den i högre utsträckning att bli angripen av granbarkborren. Syftet med studien var att analysera topografi och markfuktighet för granbarkborreskadad skog. Områden med skadade träd och oskadade träd jämfördes i GIS-programmet QGIS för att se om det fanns en skillnad med avseende på markfuktighet, lutning, lutningsriktning och höjd över havet. Resultatet visade att granbarkborren angriper främst gran i syd till sydvästlig och östlig riktning. Även områden på torrare marker har en ökad risk för angrepp samt områden där terrängen inte sluttar. Troligtvis löper områden där ovan nämnda variabler sammanfaller större risk att bli angripna av granbarkborren.
1545

Fuktförändring hos korslimmade träelement vid förvaring / Moisture content in cross laminated timber during storage

Hedström, Vilhelm, Haidari, Shukrullah January 2021 (has links)
The risk of moistening wood material should be considered and avoided as varying moisture content in the air causes the wood to swell and shrink. Moisture content in the material has influence on its mechanical properties, which may lead to damage due to reduced strength of the material. Wood material should be stored in places where the external climate does not contribute to an increase in the moisture content of the element. An optimal storage location is where the moisture content of wood material decreases. The purpose of this study is to increase knowledge about how the moisture content in cross-laminated timber (CLT) changes under different storage conditions. To achieve the purpose and get a broad picture of how moisture varies within CLT element, a measurement method that could handle measurements at different depths in the element was chosen. Furthermore, the CLT elements were placed in several storage places that simulated storage conditions at the workplace, where the amount of moisture in the environment varied based on the diurnal variation. The study has shown that, over the entire measurement period, the CLT elements that were placed indoors had a reduction of moisture content by 4.5%. The elements that were placed in a tent hall showed a decreasing of moisture content by about 1.5%. The elements that were placed outdoors with weather protection had an increasing moisture ratio of about 3%. The elements that were placed outdoors without weather protection had been affected greatly by the external climate and during precipitation the moisture content increased even greater. According to the study, CLT should be stored indoors or in a tent hall where the external climate does not contribute to an increase in the element's moisture content compared with outdoor storage. Furthermore, the study showed that cracks in the CLT elements led to higher moisture contents in the material. For the elements that were placed outdoors without weather protection that the cracked element reached its saturation point during precipitation, while the element without cracks showed increase of moisture content by a certain percentage and this increase is much slower.
1546

Rekonstrukce Knurrova paláce, Fulnek / Reconstruction of the Knurr palace, Fulnek

Kvapilová, Vendula January 2018 (has links)
This diploma thesis deals with the reconstruction and rehabilitation of a real cultural monument in Fulnek. It is a four-winged object with almost rectangular atrium. The main subject of the diploma thesis is the change in the use of the building and the proposals for remediation of damp walls. Knurr's palace has three above-ground floors and is non-decked, covered by a classic shell with fiber cement. The use of the object is mainly designed as a civic amenities, now the building is not used. The building is located in close proximity to the slope and the building is adjacent to the building. The project is solved at the level of the documentation for construction.
1547

Analýza transportu vzdušné vlhkosti v obalových konstrukcích budov / Analysis of humid air transport in the building envelope

Tománek, Jan January 2018 (has links)
The diploma thesis deals with the analysis of temperature and humidity in the construction of flat roofs with influence even without influence of solar radiation. It was necessary to study and verify the properties of building materials, the physical nature of the influence of solar radiation on building structures and the transport mechanisms of moisture. The theoretical part describes the basic physical theory on solved problems, the essence and division of solar radiation, the description of thermal moisture properties of building materials and the calculation method of determination of moisture in structures according to valid standards. Practical part deals with description of work in software DEKSOFT - Thermal technology 1D and WUFI 2D software, description of individual models and analysis of achieved results. At the end of the practical part the achieved theoretical knowledge is validated by analyzing the obtained data from the practical model.
1548

Vliv injektáže na postup vlhkosti a termofyzikální vlastnosti malt / Impact of injection on mechanical and physical characteristics of mortar

Fridrich, Pavel Unknown Date (has links)
The increased moisture of the building materials causes the change of its mechanical and physical characteristic. In particular the high amount of loose water in construction shorten the lifetime of the building, is harmful to human beings due to biotic factors and increase the economic expenses of usage of the building. Apart from the costs of rehabilitation the loose water deteriorates the thermal insulative ability (thermal conductivity coefficient ) of perimeter masonry as well. The moisture gets into masonry not only through its deffects but also due to many different reasons. In order to improve the utility value of the buildings we have to deal with the rehabilitation of damp masonry with view to all possible causes. Only the properly working damp proofing ensures the protection against the water leaking from the subfoundation of the building. One of the direct techniques which have undergone rapid progress in last few years is the injection procedure. With use of experimental methods in my dissertation I deal with evaluation of two injection compounds used in Czech Republic and with its impact on the characteristics of the mortar. With the modern hollow bricks (system THERM) it is possible to create horizontal infusion into the lateral mortar grooves in future.
1549

Vývoj tepelně izolačních a akusticko izolačních materiálů na bázi druhotných surovin z textilního průmyslu / Development of thermal a acoustic insulations based on secondary raw sources from textil industry

Kosturová, Andrea January 2019 (has links)
The objective of the presented diploma thesis is to evaluate the influence of modification on surface layer of products with their base structure from organical fibers and on the ability to resist increased humidity. Emphasis is puted on the description of humidity propagation in fiber materials ant he approximation of secondary waste from the textile industry as a potencional material for thermal insulation. The end of the theoretical part focuses on the types of possible surface treatment to prevent the ingress water into the structure of the material. The practical part verifies the selected type of modification of the surface layer of three materials choosen as test ensemble. After applying surface treatment, the effect of treatment on humidity sensitivity and water absorption was assessed. The determination of the thermal conductivity coefficient, the short-term absorption at partial immersion and the determination of the sorption humidity were made.
1550

Studium vlhkostně-transportních vlastností polymer-cementových stěrek pro vnější kontaktní zateplovací systémy budov / Study of the moisture-transport properties of polymer cementious screed for external thermal insulation composite systems

Janíček, Vít January 2019 (has links)
This diploma thesis deals with study of the moisture-transport properties of polymer cementious ETICS mortars at different doses of redispersible polymer powder. The effect of aerate on these screeds is also investigated. The thesis also evaluates the effect of use various external surface treatments due to risk of cumulate moisture in the perimeter structure.

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