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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.
71

Aspectos geológicos, geotécnicos e problemas ambientais de áreas irrigadas: Bacia Ribeirão dos Cocais - Casa Branca/SP / Geological and geotechnical aspects and environmental problems of irrigated areas: basin Ribeirão dos Cocais - Casa Branca/SP

Kancelkis, Bianca Simoni 08 August 2016 (has links)
Este trabalho apresenta os resultados de um estudo realizado em uma região com presença de muitas áreas irrigadas na Bacia do Ribeirão dos Cocais - Casa Branca/SP, em termos de avaliação de problemas ambientais e aspectos geológicos e geotécnicos. Para sua realização, em uma primeira etapa, foram identificadas e delimitadas as áreas irrigadas por pivô central e os reservatórios, seguida de uma avaliação temporal e espacial. Em seguida, foram realizados trabalhos de campo, com o objetivo de coletar amostras de solo e água para posteriores análises em laboratório. De modo geral, o estudo permitiu concluir que as áreas irrigadas têm seu comportamento em função de características geológicas e geotécnicas dos materiais geológicos, assim como o cálculo da lamina de água para irrigação depende destas propriedades. A bacia objeto do estudo apresenta diversos problemas ambientais como presença de metais no solo, nas águas superficiais e subterrâneas decorrentes do uso de fertilizantes junto da prática de irrigação, assim como problemas na dinâmica das águas superficiais devido a construção dos reservatórios, erosão, assoreamento, eutrofização, turbidez e alterações dos canais de drenagem. / This paper presents the results from a study accomplished in a region with many irrigated areas in the Ribeirão dos Cocais - Casa Branca/SP, in terms of environmental problem, geological and geotechnical aspectassessment. For its accomplishment, in a first step, the central pivot - irrigated areas and reservoirs were identified and delimited, followed by a temporal and spatial analysis. In addition, field work for collectinggeological material and water samples for further laboratory tests. In general, the study allowed to conclude that behavior of the irrigated areas is controlled by geological and geotechnical characteristics of the geological materials, as well as the calculation of water layer for irrigation depends on these properties. The basin object of this study presents several environmental problems such as the presence of metals in the soil, surface and ground waters arising from the use of fertilizers by the practice of irrigation, as well as problems in the dynamics of surface water due to the construction of reservoirs, erosion, siltation, turbidity, eutrophication of the reservoirs and drainage channels and changes of drainage channel characteristics.
72

Static characteristics and rotordynamic coefficients of a four-pad tilting-pad journal bearing with ball-in-socket pivots in load-between-pad configuration

Harris, Joel Mark 15 May 2009 (has links)
Static characteristics and rotordynamic coefficients were experimentally determined for a four-pad tilting-pad journal bearing with ball-in-socket pivots in loadbetween- pad configuration. A frequency-independent [M]-[C]-[K] model fit the measurements reasonably well, except for the cross-coupled damping coefficients. Test conditions included speeds from 4,000 to 12,000 rpm and unit loads from 0 to 1896 kPa (0 to 275 psi). The test bearing was manufactured by Rotating Machinery Technology (RMT), Inc. Though it has a nominal diameter of 101.78 mm (4.0070 in.), measurements indicated significant bearing crush with radial bearing clearances of 99.6 μm (3.92 mils) and 54.6 μm (2.15 mils) in the axes 45º counterclockwise and 45º clockwise from the loaded axis, respectively. The pad length is 101.6 mm (4.00 in.), giving L/D = 1.00. The pad arc angle is 73º, and the pivot offset ratio is 65%. The preloads of the loaded and unloaded pads are 0.37 and 0.58, respectively. A bulk-flow Navier-Stokes model was used for predictions, using adiabatic conditions for the bearing fluid. Because the model assumes constant nominal clearances at all pads, the average of the measured clearances was used as an estimate. Eccentricities and attitude angles were markedly under predicted while power loss was under predicted at low speeds and very well predicted at high speeds. The maximum detected pad temperature was 71ºC (160ºF) and the rise from inlet to maximum bearing temperature was over predicted by 10-40%. Multiple-frequency force inputs were used to excite the bearing. Direct stiffness and damping coefficients were significantly over predicted, but addition of a simple stiffness-in-series model substantially improved the agreement between theory and experiment. Direct added masses were zero or negative at low speeds and increased with speed up to a maximum of about 50 kg; they were normally greater in the unloaded direction. Although significant cross-coupled stiffness terms were present, they always had the same sign. The bearing had zero whirl frequency ratio netting unconditional stability over all test conditions. Static stiffness in the y direction (obtained from steadystate loading) matched the rotordynamic stiffness Kyy (obtained from multiple-frequency excitation) reasonably at low loads but poorly at the maximum test load.
73

Numerical simulations of the micro flow field in the hinge region of bileaflet mechanical heart valves

Simon, Helene Anne 06 July 2009 (has links)
Native heart valves with limited functionality are commonly replaced by a bileaflet mechanical heart valve (BMHV). However, despite their widespread use, BMHVs still cause major complications, including hemolysis, platelet activation, and thromboembolic events. These complications are believed to be due to the non-physiologic hemodynamic stresses imposed on blood elements by the hinge flows. Three-dimensional characterization of the hinge flows is therefore crucial to ultimately design BMHVs with lower complication rates. This study aims at simulating the pulsatile 3D hinge flows of various BMHVs placed and estimating the thromboembolic potential associated with each hinge. The hinge and leaflet geometries of clinical BMHVs are reconstructed from micro-computed tomography scans. Simulations are conducted using a Cartesian sharp-interface immersed-boundary methodology combined with a second-order accurate fractional-step method. Physiologic flow boundary conditions and leaflet motion are extracted from the Fluid-Structure-Interaction simulations of the BMHV bulk flow. The accuracy of the solver is assessed by comparing the results with experimental data. The numerical results are analyzed using a particle tracking approach coupled with existing blood damage models to relate the flow structures to the risk for blood damage. Calculations reveal complex, unsteady, and highly 3D flow fields. Zones of flow stagnation and recirculation, favorable to thrombosis and regions of elevated shear stresses, which may induce platelet activation, are identified throughout the hinge and cardiac cycle. The hinge gap width and, more importantly, the shape of the hinge recess and leaflet are found to impact the flow distribution. Avoiding sharp corners or sudden shape transitions appear as key geometrical design parameters to minimize flow disturbances and thromboembolic potential. The computed flows underscore the need to perform full 3D pulsatile simulations throughout the cardiac cycle to fully capture the complexity and unsteadiness of the hinge flows. Though based only on three different designs, this study provides general guidelines to optimize the hinge design based on hemodynamic performance and thromboembolic potential. The developed framework enables rapid and cost-efficient pre-clinical evaluation of prototype BMHV designs prior to valve manufacturing. Application to a wide range of hinges with varying design parameters will eventually help in determining the optimal hinge design.
74

Las habilidades del pivote en la alta competición de balonmano

Daza Sobrino, Gabriel 03 February 2010 (has links)
En el presente estudio se identifican las habilidades de los pivotes considerados competentes de la liga ASOBAL a lo largo de la temporada 2006-07. Definimos pivote como el jugador que desarrolla sus habilidades en la fase de ataque y que, por su situación, es determinante para la intervención y el condicionamiento de las acciones de los compañeros (Román, 1993). La investigación analiza la figura del pivote desde la perspectiva del deportista competente, compilando las características aptitudinales y el análisis de las acciones de juego en la alta competición. Se presentan las habilidades del pivote desde la estructura funcional del desarrollo del juego. Bajo este enfoque, se clasifican y se definen las dimensiones para la observación de la actividad del jugador. En la competición de balonmano las situaciones no son idénticas a las entrenadas y por lo tanto, el deportista tiene que seleccionar la alternativa más próxima entre todas las que conoce. Pocas veces realiza una habilidad realmente nueva que no soporte, al menos parcialmente, en los aprendizajes anteriores (Riera, 1997). Para conocer estas habilidades se utilizan dos técnicas de recopilación de datos: la entrevista a entrenadores expertos y la observación de la competición de los pivotes. Del análisis de los partidos se destaca que los pivotes observados resuelven las situaciones de juego mediante un número reducido de encadenamiento de habilidades. La actividad del pivote se conforma a partir de la combinación de siete habilidades básicas: ganar la posición, bloquear, fintar, lanzar, desmarcarse, contener al adversario impar y mantenerse alejado de la acción de creación. Entre éstas, se destacan las habilidades que implican la utilización del cuerpo para la opción de alguna ventaja sobre el adversario. Asimismo, las habilidades del pivote se articulan mediante cuatro intenciones fundamentales: controlar el juego, pedir el balón, finalizar y ayudar. / The skills of the well-known competent pivots are identified within the present survey on the ASOBAL league during the 2006-07 seasons. A pivot is defined as the player whose skills are developed in the phase of attack, therefore, due to his position; he is decisive for the intervention and conditioning of his partners' actions (Román, 993). The research analyzes the figure of the pivot from the perspective of a competent sportsperson, gathering the characteristic abilities and the analysis of the playing actions in the high competition. The pivot’s skills are presented from the developmental functional structure of the game. From this approach, they are classified and the dimensions are defined for the observation of the player’s activity. In the handball competition, situations in the match are not identical to the ones in training and therefore, the sportsperson has to select the closest alternative among all those they know. Just a few times, they carry out real new skills they do not support, at least partially, from previous learning (Riera, 1997). To get to know these abilities, two data collection techniques are used: the interview to current skilled coaches and the observation of the pivots' competition. From the matches' analysis, it is emphasized that the pivots solve playing situations through a reduced number of concatenation of skills. The activity of the pivot is constituted from the combination of seven basic skills: earning the position, blocking, feinting, launching, disassociating, holding the odd in number opponent back and keeping up in distance from the action taking place. Among those mentioned before, skills which use the body and involve taking some advantage on the adversary stand out. Furthermore, skills of the pivot are articulated through four basic intentions: controlling the game, demanding the ball, finishing and to help.
75

Teachers' Language of Inquiry : The Conflation Between Methods of Teaching and Scientific Inquiry in Science Education

Gyllenpalm, Jakob January 2010 (has links)
The objective of this thesis is to describe and analyse customs of science teaching in secondary schools and teacher education programmes in Sweden in relation to the notion of “inquiry” in science education. The main focus is on customs of language use and the educational goal of learning about scientific inquiry as distinct from the related goals of learning to do inquiry and learning canonical science content. There is also an exploration and description of different teaching approaches associated with “inquiry”. Previous research has noted that a key issue for reaching the goal of learning about scientific inquiry is the extent to which teachers are able to guide students to explicitly reflect upon this topic. A prerequisite is that teachers give students access to relevant categories of language for explicit reflection on the characteristics of scientific inquiry. Because of the situated nature of language use and learning, this also raises the need to address topics of context, culture and customs in science education. This thesis addresses the questions of how existing customs of teaching science are related to the goal of learning about scientific inquiry, how inquiry-related terminology is used in this context, and how relevant distinctions can be made to aid explicit reflection on these issues. Data has been collected in two studies and analysed and presented in four papers. Study 1 is based on interviews with twelve secondary school science teachers, and Study 2 is based on focus group interviews with 32 pre-service teacher students. The results include a description of the existing customs of inquiry-oriented instructional approaches in Swedish secondary schools. They show that these are often not connected with an explicit focus on teaching about the characteristics of scientific inquiry.  Inquiry-related terminology is analysed with a focus on the role and use of the terms “hypothesis” and “experiment”. Based on a theoretical framework of sociocultural and pragmatist views on language and learning, it is shown how the use of these terms, both in secondary schools and teacher education, tend to conflate the two categories methods of teaching and methods of scientific inquiry. Some problematic consequences for reaching the goal of learning about scientific inquiry are discussed, as well as possible origins of the problems and how the results from this thesis can be useful in overcoming these. / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Submitted. Paper 4: Submitted.
76

Otimização do uso da água e do zinco na cana-de-açúcar em tabuleiro costeiro paraibano. / Optimization of water and zinc in sugarcane in paraiban coastal land soil.

FARIAS, Carlos Henrique de Azevedo. 21 September 2018 (has links)
Submitted by Maria Medeiros (maria.dilva1@ufcg.edu.br) on 2018-09-21T11:41:40Z No. of bitstreams: 1 CARLOS HENRIQUE DE AZEVEDO FARIAS - TESE (PPGRN) 2006.pdf: 1797165 bytes, checksum: c1306ada6c17a8b1211eb71a42f5e313 (MD5) / Made available in DSpace on 2018-09-21T11:41:40Z (GMT). No. of bitstreams: 1 CARLOS HENRIQUE DE AZEVEDO FARIAS - TESE (PPGRN) 2006.pdf: 1797165 bytes, checksum: c1306ada6c17a8b1211eb71a42f5e313 (MD5) Previous issue date: 2006-12-19 / A pesquisa foi instalada em uma área experimental (latitude 6º54’59,88”S, longitude 35º09’17,86”O e altitude de 121,00 m) da Fazenda Capim II, localizada no Município de Capim/PB, com objetivo de se avaliar a cultura da cana-de-açúcar (Saccharum spp), variedade SP 79 1011, submetida a dois fatores: lâminas de água de irrigação e níveis de adubação com zinco. O delineamento experimental consistiu em blocos casualizados (DBC), com três repetições em esquema fatorial 5 x 5 analisados conjuntamente. As lâminas de irrigação foram: sequeiro, 25% da ETc (256,64 mm), 50% da ETc (513,29 mm), 75% da ETc (769,93 mm) e 100% da ETc (1026,57 mm) com as respectivas precipitações efetivas 780,06, 713,31, 487,54, 243,71 e 194,51 mm. Os níveis de zinco foram 0, 1, 2, 3 e 4 kg ha-1. O equipamento de irrigação utilizado na pesquisa foi do tipo pivô central fixo. O turno de irrigação, definido em função da análise físico-hídrica do solo, foi de nove dias utilizando 100% da água do solo. A ETo foi definida através do tanque “classe A” e a ETc foi determinada em função da idade da planta e de seu respectivo Kc. Abateu-se, do cálculo da lâmina de irrigação, a precipitação efetiva dentro do turno de irrigação. Foram determinadas as funções de resposta, em termos de crescimento e desenvolvimento fisiológico, bem como em termos econômicos, definindo-se, para tanto, os níveis dos dois fatores que proporcionam os melhores resultados econômicos. Até os sete meses de idade, a queda média de 50% no perfilhamento ocorreu independentemente dos fatores estudados ocorrendo diferenças significativas ao final do ano de cultivo. A resposta fisiológica aos fatores estudados foi significativa em altura, índice de área foliar, fitomassa total, fitomassa das folhas e fitomassa dos colmos. Do ponto de vista da qualidade da matéria-prima, o rendimento mínimo em açúcares totais recuperáveis foi de 96,57 kg t-1 e o máximo foi de 153,55 kg t-1. A cultura respondeu a lâmina de água de irrigação, em termos de produtividade, de forma significativamente diferente, sendo a mínima de 28,33 t ha-1 e a máxima de 106,47 t ha-1. Em termos de eficiência no uso da água pela cultura, o valor mínimo foi de 3,63 kg m3 e o máximo de 8,71 kg m3. Do ponto de vista econômico, foi calculado um modelo de função de resposta P(L,Zn) = a +b*L+c*L²+d*Zn+e*Zn²+f*LZn para estimar, diante do efeito conjunto dos dois fatores, qual combinação (L, Zn) resultaria em maiores produtividades (Lm, Znm) e maiores lucros brutos (L*,Zn*). De acordo com a tendência do modelo, a combinação que maximizou a produtividade em 181,26 t ha-1 foi (1.947,82 mm de lâmina total com 3,94 kg ha-1 de zinco) propiciando um lucro bruto de R$ 16,57 t-1. Ainda segundo o modelo, a combinação que maximiza o lucro bruto em R$ 21,06 t-1 é 1.628,06 mm com 1,80 kg ha-1 para uma produtividade de 168,59 t ha-1. Entretanto, a adoção da lâmina que maximiza o lucro bruto implica um volume de água maior que aquele aplicado à cultura, quando irrigada com 100% da ETc (1.221,08 mm). A cana de sequeiro conferiu ao produtor um prejuízo de R$ -1,43 t-1, independentemente da combinação. Quando foram aplicados 25% da ETc, o prejuízo foi maior, da ordem de R$ -9,64 t-1 em detrimento da combinação estudada. A combinação L50, Zn3 proporcionou um LB de R$ 5,86 t-1; para L75, Zn3 o LB foi de R$ 7,17 t-1. A combinação que conferiu o maior LB (R$ 19,60 t-1), com uma produtividade de 101,05 t ha-1, foi 1.221,08 mm de lâmina total e 3,0 kg de Zn ha-1 (L100, Zn3). / The research was conducted in an experimental area (coordinates 6º54’59,88”S; 35º09’17,86”W and 121,00m of altitude) of the Capim II Farm in the municipality of Capim/PB with the objective to evaluate the response of sugarcane crop (Saccharum spp.) variety SP 79 1011, submitted to different depths of irrigation water and fertilization levels with zinc to obtain their response functions for the growth and physiologic development, as well in economical terms. . The experimental design consisted of randomizered blocks, with three repetitions in 5 x 5 factorial scheme analyzed jointly. The irrigation depths were cultivation without irrigation, 25% of ETc (256,64 mm), 50% of ETc (513,29 mm), 75% of ETc (769,93 mm) e 100% of ETc (1.026,57 mm) with the respective effective precipitations of 780,06, 713,31, 487,54, 243,71 and 194,51 mm and the levels of zinc were 0, 1, 2, 3 and 4 kg ha-1. The irrigation equipment used in this research was a fixed central pivot . The irrigation frequency was defined in function of physical properties of soil and frequency of irrigation was of nine days using 100% of soil moisture. ETo was defined through the tank Class “A” and ETc was calculated in function of the plant age and respective Kc. The effective precipitation during the interval of irrigation was substracted from the calculation of depth of irrigation to be applied.. Until the seven months of age the mean reduction of 50% in number of plants occurred independently of the factors studied presenting significant differences at the end after one year of cultivation. The physiologic response to the studied factors, at the end of the year was significant, in plant height, leaf area index, total dry mass, dry mass of leaves and dry mass of stems. The point of view quality of the raw material. the minimum yield in recoverable total sugars (RTS) was of 96,57 kg t-1 and the maximum was of 153,55 kg t-1. The crop responded in terms of production significantly where the minimum was of 28,33 t ha-1 and the maximum was of 101,05 t ha-1. In terms of EUW (efficiency use water) for the crop, the minimum value was of 3,63 kg m-3 and the maximum was of 8,71 kg m-3. From the economical point of view, a model response function was calculations (P(L,Zn) = a+b*L+c*L²+d*Zn+e*Zn²+f*LZn) to estimate the combined effect of two factors, with combination (L, Zn) it would result in larger productivities (Lm, Znm) and larger gross profit (L*,Zn*). It was Verified that in agreement with the tendency of the model, the combination that had maximized the productivity of 181,26 t ha-1 , was 1.947,82 mm with 3,94 kg ha-1 of zinc, resulting in a gross profit (GP) of R$ 16,57 t-1. However, the same model estimated that the combination which maximizes the GP of R$ 21,06 t-1, consisted of 1.628,06 mm water with 1,80 kg ha-1 of zinc, for a productivity of 168,59 t ha-1. However, the adoption of irrigation depth that maximizes GP implicates in a larger volume of water compared to that applied to the crop when irrigated with 100% of the ETc (1.221,08 mm). the sugar cane without irrigation (control) resulted in a loss of R$ -1,43t-1 to producer, independently of the combination. When irrigation was applied equivalent to 25% of the ETc the loss was more, of the order of R$ 9,64 t-1 independently of studied combination. The combination (L50, Zn3) provided a GP of R$ 5,86 t-1. For L75, Zn3 GP was of R$ 7,17 t-1. The combination that provided highest GP (R$ 19,60 t-1) with a productivity of 101,05 t ha-1 was 1.221,08 mm with 3,0 kg ha-1 (L100, Zn3).
77

Irrigação e tipos de poda no cultivo de pinhão-manso em Piracicaba, SP / Irrigation and types of pruning in jatropha cultivation in Piracicaba, SP

Otávio Neto Almeida Santos 15 January 2016 (has links)
O pinhão-manso (Jatropha curcas L) é uma espécie da família da Euforbiácea que tem se destacado por ser uma planta perene, rústica e com elevada produção de óleo. A avaliação dos efeitos da poda e da irrigação no crescimento e produção do pinhão-manso é relevante para o manejo de um cultivo com essa espécie. Este estudo teve como objetivo principal avaliar os efeitos de diferentes tipos de poda e manejos hídricos no cultivo do pinhão-manso em Piracicaba, SP. O experimento foi conduzido na área experimental do Departamento de Engenharia de Biossistemas (ESALQ/USP), com plantas de quatro anos de idade dispostas em espaçamento 3 x 4 m, totalizando 833 plantas ha-1. Os tratamentos foram arranjados de forma aleatória em blocos compostos de quatro repetições, sendo que os fatores foram constituídos de dois manejos hídricos (irrigado e sem irrigação) e três tipos de poda, sendo P1 (sem poda), P2 (1,5 m de altura x 1,5 m de diâmetro de copa) e P3 (poda a 2 m de altura e 1,5 m de diâmetro da copa). A irrigação teve influência no diâmetro da copa, nas taxas de crescimento absoluto em altura e diâmetro, na taxa de crescimento relativo em diâmetro e nas variáveis produtivas. O fator poda apresentou diferenças em todas as variáveis de crescimento, sendo a poda drástica (P2) a que exibiu as maiores taxas médias de crescimento. As plantas irrigadas apresentaram os maiores rendimentos por planta e por hectare. A análise de ressonância magnética nuclear de hidrogênio (RMN de 1H) revelou que a irrigação e a poda não influenciaram o teor de óleo nas sementes de pinhão-manso. Em relação ao perfil graxo, a irrigação teve influência em plantas submetidas a poda drástica (P2), de modo que a ausência de irrigação favoreceu o maior acúmulo de ácido oleico no óleo. Pela análise energética, observou-se que os fertilizantes foram os insumos com maior participação na demanda energética (42,57 GJ ha-1) para os dois sistemas estudados, seguido dos combustíveis (32,96 GJ ha-1). A área irrigada consumiu 100,4 GJ ha-1, sendo 16% devido ao acionamento do pivô central. A energia bruta dos frutos de pinhão-manso foi de 69,82 e 45,31 GJ ha-1 para o sistema irrigado e o sem irrigação, respectivamente. O balanço energético (BE) para as duas áreas foi negativo e a lucratividade energética (EROI) foi de 0,63 para a área irrigada e 0,49 para a área sem irrigação, evidenciando a ineficiência e a não sustentabilidade do cultivo de pinhão-manso nas condições deste estudo para geração de energia. / Jatropha (Jatropha curcas L) is a species from Euforbiácea family that has been widely studied because of some particular characteristics such as being a perennial plant, its rusticity and the high oil production. The evaluation of pruning and irrigation on growth development and yield of jatropha is very important for the culture management. The objective of this study was to evaluate the effects on jatropha under different types of pruning and water management in Piracicaba, SP. The experiment was conducted in the experimental area of the Department of Biosystems Engineering (ESALQ/USP) during the fourth year crop growing and with 3 x 4 m planting spacing, totalizing 833 plants ha-1. The treatments were randomly arranged in blocks with two water management (irrigation and rainfed) and three pruning types (P1, no pruning; P2, with 1.5 m height x 1.5 m canopy diameter and; P3, with 2.0 height x 1.5 m canopy diameter). In each block, there were three pruning types with 4 blocks in each water management. Irrigation have influenced the canopy diameter values, absolute growth rates for height and canopy diameter, relative growth rate for canopy diameter and yield parameters., pruning management have influenced in all growth parameters, with drastic pruning (P2) representing the highest average growth rates. The irrigation have showed the highest yield per plant and per hectare. The analysis of Nuclear Magnetic Resonance of hydrogen (1H NMR) have shown that the irrigation and pruning have not influenced the oil content on jatropha seeds. Regarding the fatty profile, the irrigation management have influenced only the P2, since that no irrigation have influenced to largest accumulation of oleic acid in the oil. In energy analysis, it was noted that fertilizers were the inputs with the largest participation in energy input (42.57 GJ ha-1) for both water management, followed by fuels (32.96 GJ ha-1). The irrigated area consumed 100.4 GJ ha-1 energy, representing 16% due to the central pivot usage. The gross energy of jatropha fruits was 69.82 and 45.31 GJ ha-1 for irrigated and rainfed system, respectively. The energy balance for the two areas was negative and the energy return over investment, with 0.63 and 0.49 for irrigated and rainfed, respectively, have showed the inefficiency and unsustainability of jatropha cultivation to generate energy.
78

Viabilidade econômica da irrigação de pastagem de capim tanzânia em diferentes regiões do Brasil. / Pasture irrigation economic viability for tanzania grass in different Brazilian regions.

Valter Dantas Pinheiro 13 March 2002 (has links)
A estacionalidade da produção de forragens é um fator de grande importância, porque se relaciona com os baixos índices de lucratividade na pecuária de corte nacional. Nos últimos 5 anos, alguns pecuaristas capitalizados dos Estados de Goiás e Mato Grosso do Sul, implantaram aproximadamente, 120 equipamentos de irrigação (pivô central), totalizando cerca de 10.000 ha de pastagens irrigadas com gado de corte no Brasil Central. Os resultados econômicos obtidos até o presente momento, apresentam-se variáveis e imprevisíveis, sendo que alguns pecuaristas já apresentaram insucessos na condução desses projetos, enquanto outros, demonstram lucros surpreendentes para esse setor agropecuário. O objetivo dessa pesquisa é apresentar uma metodologia de análise econômica da viabilidade de irrigação de pastagens em diferentes regiões do Brasil, estimando-se a produtividade do capim tanzânia irrigado, através de um modelo matemático, calibrado em um experimento de campo, conduzido no município de Piracicaba - SP, com base na disponibilidade mensal local de unidades fototérmicas (temperatura e fotoperíodo) para diferentes níveis de adubações nitrogenadas. No estudo realizado, foram ajustados os parâmetros da função de Gompertz para as diferentes doses de adubação nitrogenada analisadas, sendo os melhores ajustes observados para as maiores dosagens de nitrogênio: 275, 756 e 2079 kg N ha-1 ano-1 com r2 = 0,9650; 0,8938 e 0,9784 respectivamente; já as menores dosagens estudadas, 0 e 100 kg N ha-1 ano-1, a equação ajustada apresentou precisão moderada para estimativa da produção, r2 = 0,7047 e 0,7112 respectivamente. As simulações efetuadas da viabilidade econômica da irrigação (pivô central elétrico) em pastagens de capim tanzânia em território nacional apresentaram retornos econômicos interessantes (R$ 400,00 a 600,00 ha-1 ano-1) em diversas regiões analisadas (Cuiabá – MT, Aragarças – GO, Petrolina – PE, Porto Nacional - TO). Em outros casos, os retornos econômicos foram pouco atraentes aos investidores (R$ -100,00 a 300,00 ha-1 ano-1), (Campo grande - MS, Uberaba – MG, Rio Verde – GO, Piracicaba - SP), o que justifica a utilização da metodologia desenvolvida no processo de tomada de decisão do pecuarista, visando minimizar os riscos de insucesso nesse tipo de empreendimento. / The seasonality in forage production is one of the most important factors related to low profit indexes concerning the national beef cattle raising activities. In the last 5 years, some cattle breeders captalized in Goiás and Mato Grosso do Sul states, have set up nearly 120 irrigation machines (center pivot), totalizing around 10.000 ha of irrigated pastures for beef cattle in Central Brazil. The economic results achieved so far, have shown to be variable and unpredictable, as while some cattle breeders have already failed to carry on these projects, others have obtained surprising profitability for this activity. The purpose of this study is to present a methodology for the economic analysis of pasture irrigation viability in different Brazilian regions, estimating the productivity of irrigated Tanzania grass through a mathematical model adjusted by means of a field experiment carried out in Piracicaba – SP, based on the local monthly availability of photo-thermal units (temperature and photoperiod) for different nitrogen fertilization levels. In the present study, the parameters of the Gompertz function were adjusted for the different nitrogen doses analyzed, being the best adjustments observed for the highest nitrogen doses: 275, 756 and 2079 kg N ha-1 year-1, with r2 = 0,9650; 0,8938 and 0,9784 respectively. Yet, for the lowest nitrogen doses studied, 0 and 100 kg N ha-1 year-1, the adjusted equation presented moderate precision for the production estimative, r2 = 0,7047 and 0,7112, respectively. The simulations carried out for the center pivot irrigation of tanzania grass pastures in the Brazilian territory, presented interesting economic responses (R$ 400,00 to 600,00 ha year-1) in several regions analyzed (Cuiabá – MT, Aragarças – GO, Petrolina – PE, Porto Nacional - TO). In other cases, the profit was little attractive to investors (R$ -100,00 to 300,00 ha year-1), (Campo Grande - MS, Uberaba – MG and Rio Verde – GO, Piracicaba - SP), justifying the use of the developed methodology in the cattle raiser’s decision making process, aiming to minimizing the risks of failure in this business.
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Contribution to 3D modelling of the human thorax in breathing movement: In vivo analysis of thorax joint kinematics: Contribution à la modélisation 3D du thorax humain durant le mouvement respiratoire: Analyse in vivo de la cinématique des articulations du thorax

Beyer, Benoît 20 December 2016 (has links)
Breathing is a vital phenomenon that implies synergy of various anatomical structures that constitute the thorax. Joint physiology remains a relatively poorly-known component of the overall thorax physiology. Quantitative literature related to in vivo thorax kinematics during breathing is scarce. The present work focuses specifically on developing and applying a methodology to reach this goal. The developed method combined processing of CT data obtained at different lung volumes and infographic techniques. Detailed ranges of motion (ROMs) and axes of movement (mean helical axes, MHAs) were obtained at costovertebral joints in 12 asymptomatic subjects; rib ROMs gradually decrease with increasing rib number; lung volume and rib level have a significant influence on rib ROM; MHAs did not differ between rib levels. In addition, the method was applied on a sample of 10 patients with cystic fibrosis. The pathological condition significantly influenced CVJ ROMs while the orientation of the MHAs did not differ. Finally, the sternal displacement, sternal angle variations and sternocostal joints (SCJ at rib1 to 7) kinematics during breathing motion were analyzed. Rib ranges of motion relative to sternum decreased with increasing rib number similarly to CVJ. Orientation of the MHAs did not differ between SCJ levels. A significant linear correlation was demonstrated between sternum vertical displacement and rib ranges of motion at both CVJ and SCJ. The present work substantially contributes to 3D modelling of human thorax in breathing at a joint level both qualitatively and quantitatively. / Doctorat en Sciences biomédicales et pharmaceutiques (Médecine) / info:eu-repo/semantics/nonPublished
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Recherches sur les relatives à pivot interne en japonais : description syntaxique et questions d'interprétation / On Head-Internal Relatives in Japanese : syntactic description and problems of interpretation

Yamamoto, Shiho 14 May 2010 (has links)
Cette thèse a pour objet l'étude de la syntaxe et de l'interprétation des constructions dites relatives à pivot interne [RPI] en japonais. Le japonais est souvent décrit comme disposant de deux systèmes de relativisation, la relative régulière, prénominale, et la RPI. Reprenant les premiers travaux sur ces constructions, dus à S.-Y. Kuroda, nous montrons que la RPI n'est pas un cas de modification nominale comparable à celui de la relative régulière, mais plutôt un cas de coordination de deux propositions internes à la phrase compète. Nous proposons, sur le plan syntaxique, une analyse de -no comme réalisation phonologique d'un déterminant, D, suivant partiellement les hypothèses générales de Kayne [1994]. Pour l'interprétation de la RPI, nous défendons l'hypothèse selon laquelle elle se comporte comme un topique scénique qui précède les topiques ordinaires, itérables, de Rizzi [1997]. Nous proposons dans un premier temps, la montée en FL de la proposition enchâssée, et dans un second temps, une analyse de la suite de [trace + -no] qui reste in situ comme équivalent du pronom démonstratif sore. / This dissertation is a study of the syntax and semantics of the so-called Head-Internal Relative [HIR] clauses in Japanese. This language is generally describe as possessing two distinct relativisation strategies, the unmarked, prenominal, relatives clauses on the one hand, and the HIRs on the other. Returning to the first descriptions of the latter [cf. S-Y. Kuroda 1974, 1975-76], I demonstrate that, semantically, IHR clauses are not a case of adnominal modification; thus, what appears to be a case of [syntactic] embedding is in fact an unexpected case of coordination of two propositions, corresponding to the IHR clause and the main clause. The syntactic analysis of the HIR relies on the idea that -no is a D, borrowing in part from Kayne's [1994] well-known analysis of relative clauses. However, at the semantic interpretation level, we propose that the contents of the HRI is a proposition which functions like a scenic topic which precedes Rizzi's [1997] iterable topic phrases. We are thus led to suggest that the IHR[or its contents] raises to the left periphery, and that the sequence [trace + -no] left behind functions like the demonstrative pronoun sore when it is used anaphorically rather than deictically.

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