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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.
301

NUMERICAL AND EXPERIMENTAL STUDIES OF NATURAL CONVECTIVE HEAT TRANSFER FROM VERTICAL AND INCLINED NARROW FLAT PLATES AND SHORT CYLINDERS

KALENDAR, ABDULRAHIM 08 November 2011 (has links)
Natural convective heat transfer from flat plates and short cylinders inclined at an angle to the vertical in laminar and transition flow regions with isothermal or constant heat flux conditions have been numerically and experimentally studied. When the width of the plate is relatively small compared to its height, i.e., the plate is narrow, the heat transfer rate can be considerably greater than that predicted by these two-dimensional flow results. When the narrow plate is inclined to the vertical, pressure changes normal to the plate surface arise and these pressure changes can alter the nature and the magnitude of the edge effects. When two narrow inclined rectangular flat plates of the same size separated vertically or horizontally, the flow interaction between these heated plates can have a significant effect on the heat transfer. When relatively small square and circular cylinders with exposed top surfaces inclined to the vertical are used, the interaction of the flow over the surfaces that make up the cylinder and inclination angle have, in general, a considerable effect on the magnitude of the mean heat transfer rate and on the nature of the flow over the cylinder surfaces. In the present numerical studies it has been assumed that the fluid properties are constant except for the density change with temperature which gives rise to the buoyancy forces, this having been treated using the Boussinesq approach. The numerical solution was obtained by numerically solving the full three-dimensional form of the governing equations, these equations being written in dimensionless form. The solution was obtained using a commercial CFD code, FLUENT. Results were only obtained for a Prandtl number of 0.7; this being approximately the value of air. In the experimental studies, the average heat transfer rates from cylinders were determined by the transient method, which involves heating the model and then measuring its temperature-time variation while it cools. The average heat transfer rates from the flat plates were determined using a steady state method, which basically involved electrically heating the plate. The tests were carried out inside a large enclosure. / Thesis (Ph.D, Mechanical and Materials Engineering) -- Queen's University, 2011-06-27 19:27:45.724
302

The Hydrodynamic Effects of Long-line Mussel Farms

Plew, David Russell January 2005 (has links)
The hydrodynamic effects of long-line mussel farms are studied through a two-pronged approach. Large-scale hydrodynamic effects are investigated through the use of field measurements, primarily at a large mussel farm in Golden Bay, New Zealand (230 long-lines, covering an area of 2.45 km by 0.65 km). The research focuses on three areas: the effect of the farm on currents, mixing and stratification, and the dissipation of wave energy. Measurements are also made of the forces on long-line anchor ropes, and a limited investigation is made of phytoplankton depletion. The second approach is the use of laboratory drag measurements and Particle Tracking Velocimetry (PTV) to study the effect of mussel dropper (vertical lengths of mussel-encrusted crop rope) roughness and spacing on flow at small scales. These experiments provide data on very rough cylinders, and on cylinder arrays. The field measurements show that the local effects of mussel farms on currents are significant, but that magnitudes of the effects depend on dropper density, mussel sizes, orientation of the long-lines to the flow, and other parameters that are necessary to characterise the complex interactions between a farm and the flow. The drag on the submerged structures reduces water velocities within the Golden Bay farm by between 47% and 67%. Mussel farms present a porous obstacle to the flow, and flow that does not pass through the farm must be directed around or beneath it. The field measurements indicate that at the study site, most of the flow is diverted around the farm despite its large horizontal dimensions. The droppers at the study site extend over most of the water column (average dropper length ~ 8 m, average water depth ~ 11 m), providing a restriction to the flow beneath the farm. The strength of the density stratification may also favour a horizontal diversion. The flow around the farm is essentially two-dimensional. This suggests that two-dimensional numerical models should be sufficient to obtain reasonable predictions of the velocity drop within, and the diversion around, mussel farms. A simple two-dimensional pipe-network model gives reasonable estimates of the velocity within the farm, demonstrating that the drag of the farm may be adequately parameterised through local increases of bed friction. A wake in the form of reduced velocities extends downstream of the farm, and a mixing layer analogy suggests that this wake spreads slowly. The downstream extent of the wake cannot be determined, although it is likely to be limited by the tidal excursion. The degree of vertical mixing caused by the flow through a mussel farm cannot be quantified, although there are clear interactions between the stratification and the farm. Two mixing mechanisms are considered. A shear layer is generated beneath the farm due to the difference in velocities between the retarded flow within the farm and the flow beneath. Shear layers beneath mussel farms are likely to be weak unless the ambient currents are strong. It will be necessary for stratification to be weak or non-existent for this mechanism to generate significant mixing. The second mechanism is smaller-scale turbulence generated by the mussel droppers. Although the efficiency of this form of mixing is likely to be low, the large number of mussel droppers suggests that there will be some enhancement of vertical mixing. Frequency-dependent wave attenuation is recorded, and is predicted with some success by an analytical model. Both the model and the field data show that wave dissipation increases as the wave period decreases. Wave energy dissipation at the study site averages approximately 10%, although the measurements are made during a period of low wave heights (Hs < 0.25 m). Measurements of long-line anchor rope tension at two study sites indicate that the loadings are induced by the tide, currents, and waves. Dynamic wave loadings may be significant, and higher wave forces are measured at the offshore end of a long-line. The issue of seston or phytoplankton depletion is considered briefly through the examination of fluorescence, turbidity, and acoustic backscatter data. Although the results are consistent with a reduction of seston within the farm, differences between the inside and outside of the farm are not statistically significant. Mussel droppers resemble extremely rough circular cylinders, with the mussel shells forming the surface roughness elements. Drag measurements and PTV flow visualisation are used to investigate the importance of the large surface roughness, and the influence of dropper spacing and long-line orientation on flow. Drag measurements conducted with smooth and rough cylinders show that high surface roughness (ks/D ~ 0.092) has little effect on the drag coefficient of single cylinders in the range 4,000 < Re < 13,000, yet increases the drag coefficient of a row of cylinders normal to the flow. High surface roughness on single cylinders has the effect of shortening the near-wake region, increasing the peak turbulent kinetic energy (TKE) behind the cylinder, and decreasing the Strouhal number (St = 0.21, 0.19, 0.17 for ks/D = 0, 0.048, and 0.094 respectively). Arrays of rough cylinders (ks/D = 0.094) demonstrate similar flow characteristics to those of smooth cylinders. At cylinder spacings of S/D < 2.2, the surface roughness acts to favour the formation of a particular metastable wake pattern, whereas different metastable wake patterns are formed each run behind the smooth cylinders. The experiments show that the drag on single row arrays of cylinders are related to the cylinder spacing (increasing drag with decreasing spacing), and the drag also varies with the sine of the angle to the flow, except where the array is at low angles to the flow. The PTV measurements provide new data regarding the two-dimensional distributions of velocity, TKE, and turbulence statistics behind the cylinder arrays.
303

Cracked Semi-infinite Cylinder And Finite Cylinder Problems

Kaman, Mete Onur 01 May 2006 (has links) (PDF)
This work considers a cracked semi-infinite cylinder and a finite cylinder. Material of the cylinder is linearly elastic and isotropic. One end of the cylinder is bonded to a fixed support while the other end is subject to axial tension. Solution for this problem can be obtained from the solution for an infinite cylinder having a penny-shaped rigid inclusion at z = 0 and two penny-shaped cracks at z = &plusmn / L. General expressions for this problem are obtained by solving Navier equations using Fourier and Hankel transforms. When the radius of the inclusion approaches the radius of the cylinder, the end at z = 0 becomes fixed and when the radius of the cracks approaches the radius of the cylinder, the ends at z = &plusmn / L become cut and subject to uniformly distributed tensile load. Formulation of the problem is reduced to a system of three singular integral equations. By using Gauss-Lobatto and Gauss-Jacobi integration formulas, these three singular integral equations are converted to a system of linear algebraic equations which is solved numerically.
304

Transferência de calor em reator cilíndrico elíptico de leito fixo: aspectos termofluidodinâmicos e geométricos.

OLIVEIRA, Laercio Gomes de. 14 September 2018 (has links)
Submitted by Maria Medeiros (maria.dilva1@ufcg.edu.br) on 2018-09-14T12:44:26Z No. of bitstreams: 1 LAERCIO GOMES DE OLIVEIRA - TESE (PPGEP) 2004.pdf: 4405529 bytes, checksum: 8b65ffb3723d9c3b423cde424d99a1ef (MD5) / Made available in DSpace on 2018-09-14T12:44:26Z (GMT). No. of bitstreams: 1 LAERCIO GOMES DE OLIVEIRA - TESE (PPGEP) 2004.pdf: 4405529 bytes, checksum: 8b65ffb3723d9c3b423cde424d99a1ef (MD5) Previous issue date: 2004-10-08 / Neste trabalho, foram desenvolvidos e apresentados vários modelos matemáticos tridimensionais analíticos e numéricos para estudar a transferência de calor no interior de um reator de leito fixo, usando condição na fronteira do sistema: de equilíbrio ou convectiva, condutividade térmica do reator constante ou variável e sistema com ou sem reação química. A modelagem matemática apresentada tem a flexibilidade de adaptar-se a leitos com forma geométrica variando desde um canal retangular até o cilindro elíptico, incluindo o cilindro circular. A metodologia numérica utilizada para resolver as equações diferenciais que representam o fenômeno físico baseia-se no método dos volumes finitos. Para discretizar a equação geral da conservação da energia foi utilizado o esquema WUDS (Weigthed Upstream Diference Scheme) como função de interpolação para os termos convectivos e difusivos e uma formulação totalmente implícita. O sistema de equações algébricas lineares resultantes da discretização da equação da energia em todos os pontos do domínio computacional é resolvido iterativamente pelo método Gauss-Seidel. Resultados da distribuição de temperatura no interior do reator em função das posições radial e angular, em várias posições ao longo do equipamento são mostradas e analisadas. Várias condições de processo foram estudadas, variando-se o coeficiente convectivo de transferência de calor, a razão de aspecto geométrica do reator, a concentração do reagente, a temperatura do fluido na entrada do sistema e a velocidade superficial do fluido. Como uma aplicação deste trabalho, os modelos matemáticos desenvolvidos foram utilizados para ajustar os dados experimentais de temperatura coletados numa célula de medidas térmicas (reator de leito fixo) de seção transversal cilíndrica circular, visando obter estimativas da condutividade térmica e coeficiente de transferência de calor do leito de partículas sob várias condições experimentais, usando-se a técnica do erro quadrático mínimo. / In this work, various analytic and numeric three-dimensional mathematical models were developed and presented to study heat transfer inside a fixed bed reactor, using a equilibrium or convective boundary condition, constant or variable thermal conductivity of the reactor and system with or without chemical reaction. The mathematical modeling presented has been the flexibility of adapting to beds with geometric shape varying from a rectangular channel to the elliptic cylinder, including the cylinder circular. The numeric methodology used to solve the differential equations that represent the physical phenomenon is based in the finite volume method. For discretize the general conservation energy equation the WUDS (Weighted Upstream Differentiates Scheme) scheme was used as interpolation function for convective and diffusive terms and a totally implicit formulation. The linear algebraic equations system resultant of the discretization of the energy equation in all points of the computational domain is iteratively solved by Gauss-Seidel method. Results of the temperature distribution inside the reactor in function of the radial and angular positions, in different positions along the equipment are shown and analyzed. Several process conditions were studied, varying the heat transfer convective coefficient, the reactor geometric aspect ration, the reagent concentration, the temperature and superficial velocity of the fluid in entrance of the system. As an application of this work, the mathematical models developed were used to adjust the temperature experimental data collected in a thermal measures cell (fixed bed reactor) of cylindrical traverse section, seeking estimate thermal conductivity and heat transfer coefficient of the particles bed under several experimental conditions, using the minimum quadratic error technique.
305

Comportamento geotécnico de um solo coluvionar de São Vendelino (RS) / Geotechnical behavior of a colluvium soil from São Vendelino (RS, Brazil)

Silveira, Rodrigo Moraes da January 2008 (has links)
Nesta tese foram executados diversos ensaios geotécnicos em um solo coluvionar de uma encosta em que ocorreu uma ruptura translacional, seguida de liquefação e corrida de detritos, em São Vendelino (RS). Na mesma área ocorreram dezenas de rupturas de taludes em dezembro de 2000, durante um evento pluviométrico com chuvas de 148 mm medidas em 2 h. Os taludes da região apresentam declividades em torno de 27-36° com uma camada superficial de solo coluvionar (aproximadamente 2 m). Os solos amostrados foram retirados junto da cicatriz de um destes movimentos, o qual uma testemunha ocular descreveu como uma ruptura de grande mobilidade e fluidez. No trabalho é apresentada (a) uma caracterização geral das propriedades geotécnicas dos solos coluvionares da área de estudo, a partir de um conjunto de ensaios realizados em amostras deformadas e indeformadas coletadas em campo; (b) resultados do monitoramento de poro-pressões por piezômetros elétricos e um pluviômetro, instalados na encosta; (c) ensaios de condutividade hidráulica de laboratório e de campo (permeâmetro de Guelph, piezômetros de Casagrande e cilindros concêntricos); (d) um conjunto de resultados de ensaios de cisalhamento direto, ensaios de compressão triaxial CID, CIU, CID-U e CSD (constant shear drained) e (e) um conjunto de ensaios hollow cylinder. Os ensaios de condutividade hidráulica realizados em laboratório com amostras indeformadas forneceram valores entre 2,5x10-4 e 5,4x10-3 cm/s. Os resultados dos ensaios de cisalhamento resultaram em valores c =4-10 kPa e f = 26º (remoldados ou indeformados) e c =0-10 kPa e f =25,8-36,9º (triaxiais em solo remoldado). Os ensaios hollow cylinder realizados mostraram que há uma grande influência da rotação das tensões principais nos parâmetros de resistência ao cisalhamento e no comportamento do solo pré e pós-ruptura. Os resultados também sugerem que análises de estabilidade de taludes baseadas nos parâmetros de resistência ao cisalhamento obtidos a partir de ensaios de compressão triaxial não são conservativas. Análises de fluxo de água e de estabilidade da encosta sugerem que somente chuvas com intensidade de magnitude semelhante à de dezembro de 2000 podem provocar rupturas na encosta estudada. / In this thesis several geotechnical tests were performed in a colluvium soil from a slope in which a translational slide occurred, followed by liquefaction and debris flow, in São Vendelino, RS, Brazil. In the same area several other slope failures occurred in December 2000 during a rain event with precipitation of 148mm in 2 hours. The inclination of the slopes in the region are in the range of 27-36o with a surficial layer of colluvium soil (approximately 2 m). The soil samples soil were collected close to a scar generated by one of those movements, which an eye-witness described as a failure with great mobility. This thesis presents (a) a basic characterization of colluvium soils from the studied area, using disturbed and undisturbed samples; (b) monitored values of in-situ pore-pressure using electric piezometers and results of a pluviometer installed in the studied area; (c) results of hydraulic conductivity from laboratory and field tests (Guelph permeameter, Casagrande piezometers and concentric cylinders); (d) results from direct shear and triaxial tests (CID, CIU, CID-U and CSD) and (e) a set of hollow cylinder tests. The laboratory conductivity hydraulic tests carried out on undisturbed samples showed values variyng from 2.5x10-4 to 5.4x10-3 cm/s. The direct shear results resulted in c =4-10 kPa e f =26º (undisturbed or reconstituted samples) and triaxial tests resulted in c =0-10 kPa and f =25.8-36.9º (reconstituted samples). The hollow cylinder tests showed that there is a strong influence of principal stress rotation in the shear strength and in the soil behavior pre and post failure. The results also suggest that slope stability analyses based on shear strength parameters obtained from triaxial tests are not conservative. Seepage and slope stability analyses suggest that only rains of great intensity, similar to the event of December 2000, may generate failures in the studied slope.
306

Développement de méthodes de pénalisation pour la simulation de l’écoulement turbulent autour d’obstacles / Development of penalty methods for the simulation of turbulent flow around obstacles

Bizid, Wided 30 June 2017 (has links)
En vue d’applications aux turbines éoliennes, cette thèse vise à étendre l’utilisation des méthodes de type domaines fictifs et en particulier la méthode de pénalisation pour la simulation de l’écoulement turbulent instationnaire autour d’obstacles de géométrie complexe.La modélisation de la turbulence instationnaire à nombres de Reynolds élevés a été abordée par des approches hybrides RANS/LES telles que la (DES) et la (DDES). Afin d’améliorer la prédiction, un modèle de paroi de type TBLE a été introduit.Après une brève présentation des méthodes et des outils mis en oeuvre, des simulations2D/3D sur la configuration de cylindre et du canal sont ensuite présentées, analysées et comparées aux résultats numériques et expérimentaux.Les résultats de simulation montrent la faisabilité et l’efficacité des modèles et de la méthode de couplage (DDES/TBLE). La dernière étude se concentre sur la simulation de l’écoulement d’air autour d’un profil de pale. Les réussites et les échecs des simulations numériques sont soulignés et étudiés.En conclusion, l’étude établit les fondements pour une future application dans le cas de l’écoulement autour d’un rotor éolien en mouvement. / In the perspective of application to wind turbine design, this thesis aims to extend theuse of fictitious domain methods and in particular the method of penalization for the simulation of unsteady turbulent flows around obstacles of complex geometry. The unsteady turbulence modeling at high Reynolds numbers was studied by hybrid approaches(RANS / LES) such as (DES) and (DDES). In order to improve the prediction, a wall model based on simplified Thin Boundary Layer Equations (TBLE) was introduced.After a brief presentation of the tools and methods implemented, full 2D / 3D computations on cylinder and channel configuration are then presented, analyzed and compared to numerical and experimental results.The simulation results show the feasibility and effectiveness of the proposed models and the coupling method (DDES / TBLE).The latest investigation focuses on the simulation of the flow around the airfoil of a wind turbine. The success and fails of the computations are highlighted and explained.
307

Étude de faisabilité d'un revêtement élastique pour la furtivité acoustique / Feasibility study of an acoustic cloak using a multi-layered elastic coating

Dutrion, Cécile 26 February 2014 (has links)
Dans le cadre de certaines applications militaires ou méthodologiques, on peut chercher à rendre un objet « invisible » vis-à-vis des ondes acoustiques. Différentes méthodes passives ont été proposées ces dernières années pour éviter ou atténuer la diffraction d'ondes acoustiques sur des obstacles rigides. Ces techniques reposent sur des phénomènes purement acoustiques, avec par exemple la présence de multiples résonateurs ou d'objets diffractants. L'étude présentée ici s'intéresse pour sa part aux effets que l'on pourrait obtenir au moyen d'un revêtement multicouche élastique fixé à un cylindre que l'on souhaite rendre indétectable. Le comportement vibro-acoustique d'un tel revêtement est d'abord modélisé. Par optimisation, on détermine les caractéristiques mécaniques et dimensionnelles des couches permettant une atténuation omnidirectionnelle de la diffraction. Des configurations réalistes de revêtements composés d'une couche orthotrope et d'une couche isotrope sont dégagées dans le cas d'un milieu extérieur constitué d'air. On montre que de tels dispositifs permettent d'atténuer la diffraction à une fréquence donnée ou sur une bande de fréquence. Le problème de la caractérisation expérimentale de ces revêtements est également abordé. Dans un second temps, le cas d'un milieu extérieur constitué d'eau est étudié. On met alors en évidence une réduction de la diffraction avec des revêtements composés de deux couches isotropes. L'influence des différents paramètres de la couche intérieure est analysée. Enfin, des exemples montrent que la bande de fréquence sur laquelle a lieu l'atténuation de la diffraction peut être élargie en augmentant le nombre de couches. / Making an object invisible to acoustic waves could prove useful for military applications or measurements in confined space. Different passive methods have been proposed in recent years to avoid acoustic scattering from rigid obstacles.These techniques are exclusively based on acoustic phenomena, and use for instance multiple resonators or scatterers. This thesis deals with a different method and studies the effects in terms of scattering reduction of an elastic multi-layered coating fixed to the object to conceal. Vibrations of the coating subject to acoustic waves are first modelled to compute the scattered pressure in the external fluid. Mechanical and dimensional properties of the layers leading to omnidirectional scattering reduction are optimised. Considering an external fluid consisting of air, realistic configurations of coatings emerge, composed of a thick internal orthotopic layer and a thin external isotropic layer. These coatings are shown to enable scattering reduction at a precise frequency or on a larger frequency band. The problem of experimental characterisation is also addressed.The study then focuses on a cylinder immersed in water. Bi-layer isotropic coatings can be used in such configuration. A parametric study is led on the characteristics of the internal layer. Finally, significant scattering reduction is achieved for alarger frequency range by increasing the number of layers. Examples of four-layer isotropic coatings are presented to highlight this result.
308

Optimal air and fuel-path control of a diesel engine

Yang, Zhijia January 2014 (has links)
The work reported in this thesis explores innovative control structures and controller design for a heavy duty Caterpillar C6.6 diesel engine. The aim of the work is not only to demonstrate the optimisation of engine performance in terms of fuel consumption, NOx and soot emissions, but also to explore ways to reduce lengthy calibration time and its associated high costs. The test engine is equipped with high pressure exhaust gas recirculation (EGR) and a variable geometry turbocharger (VGT). Consequently, there are two principal inputs in the air-path: EGR valve position and VGT vane position. The fuel injection system is common rail, with injectors electrically actuated and includes a multi-pulse injection mode. With two-pulse injection mode, there are as many as five control variables in the fuel-path needing to be adjusted for different engine operating conditions.
309

Comportamento geotécnico de um solo coluvionar de São Vendelino (RS) / Geotechnical behavior of a colluvium soil from São Vendelino (RS, Brazil)

Silveira, Rodrigo Moraes da January 2008 (has links)
Nesta tese foram executados diversos ensaios geotécnicos em um solo coluvionar de uma encosta em que ocorreu uma ruptura translacional, seguida de liquefação e corrida de detritos, em São Vendelino (RS). Na mesma área ocorreram dezenas de rupturas de taludes em dezembro de 2000, durante um evento pluviométrico com chuvas de 148 mm medidas em 2 h. Os taludes da região apresentam declividades em torno de 27-36° com uma camada superficial de solo coluvionar (aproximadamente 2 m). Os solos amostrados foram retirados junto da cicatriz de um destes movimentos, o qual uma testemunha ocular descreveu como uma ruptura de grande mobilidade e fluidez. No trabalho é apresentada (a) uma caracterização geral das propriedades geotécnicas dos solos coluvionares da área de estudo, a partir de um conjunto de ensaios realizados em amostras deformadas e indeformadas coletadas em campo; (b) resultados do monitoramento de poro-pressões por piezômetros elétricos e um pluviômetro, instalados na encosta; (c) ensaios de condutividade hidráulica de laboratório e de campo (permeâmetro de Guelph, piezômetros de Casagrande e cilindros concêntricos); (d) um conjunto de resultados de ensaios de cisalhamento direto, ensaios de compressão triaxial CID, CIU, CID-U e CSD (constant shear drained) e (e) um conjunto de ensaios hollow cylinder. Os ensaios de condutividade hidráulica realizados em laboratório com amostras indeformadas forneceram valores entre 2,5x10-4 e 5,4x10-3 cm/s. Os resultados dos ensaios de cisalhamento resultaram em valores c =4-10 kPa e f = 26º (remoldados ou indeformados) e c =0-10 kPa e f =25,8-36,9º (triaxiais em solo remoldado). Os ensaios hollow cylinder realizados mostraram que há uma grande influência da rotação das tensões principais nos parâmetros de resistência ao cisalhamento e no comportamento do solo pré e pós-ruptura. Os resultados também sugerem que análises de estabilidade de taludes baseadas nos parâmetros de resistência ao cisalhamento obtidos a partir de ensaios de compressão triaxial não são conservativas. Análises de fluxo de água e de estabilidade da encosta sugerem que somente chuvas com intensidade de magnitude semelhante à de dezembro de 2000 podem provocar rupturas na encosta estudada. / In this thesis several geotechnical tests were performed in a colluvium soil from a slope in which a translational slide occurred, followed by liquefaction and debris flow, in São Vendelino, RS, Brazil. In the same area several other slope failures occurred in December 2000 during a rain event with precipitation of 148mm in 2 hours. The inclination of the slopes in the region are in the range of 27-36o with a surficial layer of colluvium soil (approximately 2 m). The soil samples soil were collected close to a scar generated by one of those movements, which an eye-witness described as a failure with great mobility. This thesis presents (a) a basic characterization of colluvium soils from the studied area, using disturbed and undisturbed samples; (b) monitored values of in-situ pore-pressure using electric piezometers and results of a pluviometer installed in the studied area; (c) results of hydraulic conductivity from laboratory and field tests (Guelph permeameter, Casagrande piezometers and concentric cylinders); (d) results from direct shear and triaxial tests (CID, CIU, CID-U and CSD) and (e) a set of hollow cylinder tests. The laboratory conductivity hydraulic tests carried out on undisturbed samples showed values variyng from 2.5x10-4 to 5.4x10-3 cm/s. The direct shear results resulted in c =4-10 kPa e f =26º (undisturbed or reconstituted samples) and triaxial tests resulted in c =0-10 kPa and f =25.8-36.9º (reconstituted samples). The hollow cylinder tests showed that there is a strong influence of principal stress rotation in the shear strength and in the soil behavior pre and post failure. The results also suggest that slope stability analyses based on shear strength parameters obtained from triaxial tests are not conservative. Seepage and slope stability analyses suggest that only rains of great intensity, similar to the event of December 2000, may generate failures in the studied slope.
310

Ensino contextualizado de área e volume de cilindro

Binotti, Andréa Magalhães 03 September 2016 (has links)
Submitted by Alison Vanceto (alison-vanceto@hotmail.com) on 2017-01-16T10:42:26Z No. of bitstreams: 1 DissAMB.pdf: 5237889 bytes, checksum: 547281c2cd13bea74f0b9f0704bde106 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2017-01-17T12:27:12Z (GMT) No. of bitstreams: 1 DissAMB.pdf: 5237889 bytes, checksum: 547281c2cd13bea74f0b9f0704bde106 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2017-01-17T12:27:21Z (GMT) No. of bitstreams: 1 DissAMB.pdf: 5237889 bytes, checksum: 547281c2cd13bea74f0b9f0704bde106 (MD5) / Made available in DSpace on 2017-01-17T12:27:31Z (GMT). No. of bitstreams: 1 DissAMB.pdf: 5237889 bytes, checksum: 547281c2cd13bea74f0b9f0704bde106 (MD5) Previous issue date: 2016-09-03 / Não recebi financiamento / The study Geometry Metric Space is very important in high school. To observe, analyze and evaluate the student body to what I teach, we see the lack of interest and a lot of difficulties in relation to learning geometry, especially the spatial geometry. In order to stimulate the students and contribute to overcoming these difficulties we propose in this paper a contextualized teaching sequence for teaching such content. Because of the time available to carry out this project to go beyond the particular subject area and volume of right circular cylinders. The didactic sequence mix the use of official teaching materials of the State of São Paulo (Notebook student and teacher) and application activities leaves prepared for us. It consists of four lectures using the official materials, three classes for problem solving, four classes for implementation of activities leaves and two classes for socialization of results. In class prior to the implementation of activities leaves students must recognize circular cylinders that are part of everyday life, study the surface areas of concepts and volume of circular straight cylinder review simple rule of three, length measurement units, area and volume and method of rounding values. Then must solve problem situations to assess the understanding of the issues mentioned above. Regarding the implementation of activities leaves the students, in groups and with little intervention teacher, calculate the area of aluminum sheet required to build a pressure cooker and then check if the capacity specified by the manufacturer is real. They are then asked to find the minimum size of the pot with volume set, with the idea of getting material savings in manufacturing. After the implementation of activities leaves students with the mediation of the teacher, make the correction. This sequence was applied in two classes of the second high school grade of a school of the São Paulo State Education Network in a country town. It is important to note that this proposal adopts suggestions from the National Curriculum Guidelines for Secondary Education (PCNEM) and requires few resources and can be useful to other professionals. For validation of this research follow in general steps, the four phases of research methodology called Didactic Engineering. / O estudo da Geometria Métrica Espacial é muito importante no Ensino Médio. Ao observar, analisar e avaliar o corpo discente para qual leciono, percebe-se a falta de interesse e muitas dificuldades em relação ao aprendizado da Geometria, especialmente a Geometria Espacial. Com o intuito de estimular os estudantes e contribuir para a superação de tais dificuldades propomos neste trabalho uma sequência didática contextualizada para o ensino desses conteúdos. Devido ao tempo disponível para a realização deste projeto nos limitamos ao assunto particular de área e volume de cilindros circulares retos. A sequência didática mescla o uso do material didático oficial do Estado de São Paulo (Caderno do aluno e do professor) e aplicação de Folhas de Atividades elaboradas por nós. Consiste de quatro aulas expositivas utilizando o material oficial, três aulas para resolução de problemas, quatro aulas para aplicação das Folhas de Atividades e duas aulas para socialização dos resultados. Nas aulas que antecedem a aplicação das Folhas de Atividades os alunos devem reconhecer cilindros circulares que fazem parte do cotidiano, estudar os conceitos de áreas de superfície e volume de cilindros retos circulares, revisar regra de três simples, unidades de medidas de comprimento, área e volume e método de arredondamento de valores. Em seguida devem resolver situaçõesproblema para avaliar a compreensão dos assuntos mencionados anteriormente. Em relação a aplicação das Folhas de Atividades, os estudantes, em grupo e com pouca intervenção da professora, devem calcular a área da chapa de alumínio necessária para construir uma panela de pressão e depois verificar se a capacidade indicada pelo fabricante é real. Depois são solicitados a encontrar a área mínima da panela com volume fixado, com a ideia de obter economia de material na sua fabricação. Após a aplicação das Folhas de Atividades os alunos, com a mediação da professora, fazem a correção. Esta sequência foi aplicada em duas turmas da segunda série do Ensino Médio de uma escola da Rede Estadual de Ensino de São Paulo em uma cidade do interior. É importante destacar que esta proposta adota sugestões dos Parâmetros Curriculares Nacionais para o Ensino Médio (PCNEM) e requer poucos recursos, podendo ser útil a outros profissionais da área. Para validação deste trabalho de pesquisa seguimos, em passos gerais, as quatro fases da metodologia de investigação denominada Engenharia Didática.

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