Characterizing Aquitard Properties from the response of Grouted Vibrating Wire Piezometers to Surface Loading

Barometric Response Functions (BRF) are used to characterize the observed pore pressure response within grouted-in vibrating wire piezometers to changes in surface barometric pressure. The BRF facilitates determination of loading efficiency (λLE) which is a function of in situ compressibility. However, the mechanisms which control the characteristic shape of a BRF within a fully grouted borehole are not well understood. In this study, the transient pore pressure responses to both local instantaneous loading and transient barometric loading are used to improve our understanding of the BRF response. Two boreholes were each drilled to a depth of 200 m in a thick clay sequence in Southern Saskatchewan. One borehole was advanced through continuous coring while the other was drilled using rotary fluid circulation. Ten vibrating-wire piezometers (VWPs) were placed within each borehole at a 10m spacing. The pore pressure in all VWPs and barometric pressure was recorded concurrently for 3 years following installation. Multiple-linear regression was undertaken on both data sets to determine the BRF for each VWP. In addition, localized instantaneous surface loading was applied using heavy construction equipment. The coupled load-pore responses were simulated using a commercial coupled stress and water flow finite element model to evaluate the grout and formation hydraulic and mechanical properties. The BRF characteristics of the monitored depth profile were used to identify the limitations of linear-regression methods for determining λLE. Near-borehole influences, such as stress-release induced damage or mud filter-cake build-up, can influence the magnitude and timing of observed pore pressures. These limitations can be addressed by judicious selection of drilling methods, grouting procedures, and pressure sensor resolution. In addition, a more rigorous interpretation of the BRF can be used to obtain additional information about the in situ hydraulic and geomechanical properties of the aquitard. The rigorous analysis of measured pore pressure response to changes in external stress improves our understanding of in situ properties and the behavior of low-hydraulic conductivity and low-compressibility formations

Characterizing Aquitard Properties from the response of Grouted Vibrating Wire Piezometers to Surface Loading

Barometric Response Functions (BRF) are used to characterize the observed pore pressure response within grouted-in vibrating wire piezometers to changes in surface barometric pressure. The BRF facilitates determination of loading efficiency (λLE) which is a function of in situ compressibility. However, the mechanisms which control the characteristic shape of a BRF within a fully grouted borehole are not well understood. In this study, the transient pore pressure responses to both local instantaneous loading and transient barometric loading are used to improve our understanding of the BRF response. Two boreholes were each drilled to a depth of 200 m in a thick clay sequence in Southern Saskatchewan. One borehole was advanced through continuous coring while the other was drilled using rotary fluid circulation. Ten vibrating-wire piezometers (VWPs) were placed within each borehole at a 10m spacing. The pore pressure in all VWPs and barometric pressure was recorded concurrently for 3 years following installation. Multiple-linear regression was undertaken on both data sets to determine the BRF for each VWP. In addition, localized instantaneous surface loading was applied using heavy construction equipment. The coupled load-pore responses were simulated using a commercial coupled stress and water flow finite element model to evaluate the grout and formation hydraulic and mechanical properties. The BRF characteristics of the monitored depth profile were used to identify the limitations of linear-regression methods for determining λLE. Near-borehole influences, such as stress-release induced damage or mud filter-cake build-up, can influence the magnitude and timing of observed pore pressures. These limitations can be addressed by judicious selection of drilling methods, grouting procedures, and pressure sensor resolution. In addition, a more rigorous interpretation of the BRF can be used to obtain additional information about the in situ hydraulic and geomechanical properties of the aquitard. The rigorous analysis of measured pore pressure response to changes in external stress improves our understanding of in situ properties and the behavior of low-hydraulic conductivity and low-compressibility formations

Characterizing Aquitard Properties from the response of Grouted Vibrating Wire Piezometers to Surface Loading

Barometric Response Functions (BRF) are used to characterize the observed pore pressure response within grouted-in vibrating wire piezometers to changes in surface barometric pressure. The BRF facilitates determination of loading efficiency (λLE) which is a function of in situ compressibility. However, the mechanisms which control the characteristic shape of a BRF within a fully grouted borehole are not well understood. In this study, the transient pore pressure responses to both local instantaneous loading and transient barometric loading are used to improve our understanding of the BRF response. Two boreholes were each drilled to a depth of 200 m in a thick clay sequence in Southern Saskatchewan. One borehole was advanced through continuous coring while the other was drilled using rotary fluid circulation. Ten vibrating-wire piezometers (VWPs) were placed within each borehole at a 10m spacing. The pore pressure in all VWPs and barometric pressure was recorded concurrently for 3 years following installation. Multiple-linear regression was undertaken on both data sets to determine the BRF for each VWP. In addition, localized instantaneous surface loading was applied using heavy construction equipment. The coupled load-pore responses were simulated using a commercial coupled stress and water flow finite element model to evaluate the grout and formation hydraulic and mechanical properties. The BRF characteristics of the monitored depth profile were used to identify the limitations of linear-regression methods for determining λLE. Near-borehole influences, such as stress-release induced damage or mud filter-cake build-up, can influence the magnitude and timing of observed pore pressures. These limitations can be addressed by judicious selection of drilling methods, grouting procedures, and pressure sensor resolution. In addition, a more rigorous interpretation of the BRF can be used to obtain additional information about the in situ hydraulic and geomechanical properties of the aquitard. The rigorous analysis of measured pore pressure response to changes in external stress improves our understanding of in situ properties and the behavior of low-hydraulic conductivity and low-compressibility formations

Análise de sensibilidade do modelo de Caprio para simulação de evolução de resistência de pragas a toxinas BT.

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Development and validation of a riflescope mathematical model during recoil

The design, development, and production of new riflescopes have been driven by research and development into cutting-edge materials, techniques, and technology for use in the sport optics industry. With each evolution, the riflescope should be functionally evaluated to observe and acquire data on the riflescope's behavior during recoil. While assessing, field data is the most accurate and reliable way to certify a new product for commercial use. However, it is expensive to only verify all parameters after having a functional physical sample or prototype. A riflescope mathematical model would allow for more significant innovation while mitigating the risk of project failure. For this, the setup should be modeled, simplified for computational performance, and verified with field data. The Ansys platform will be used to model the design. The rifle/riflescope setup's recoil is fast and usually measured in milli or microseconds. Considering this, the mathematical model will have to be an explicit nonlinear simulation using Ansys Explicit Dynamics. Due to the complex phenomena occurring during the propellant ignition, projectile acceleration, and recoil wave traveling through the mechanical parts, the model needed simplification but was created with a rifle and riflescope assembly to absorb all the recoil energy reliably. This work uses data inputs such as chamber pressure curves to induce recoil for a specific caliber charge. This simplification eliminated the need to model the propellent, ignition, and explosion parameters. The projectile velocity and riflescope acceleration are output parameters used to verify the input chamber pressure curve and the model, respectively. In order to verify the mathematical model for accuracy, the simulation data results must be compared and approximated to known field data results. In this work, the simulation results are of similar magnitude to the experimental data obtained through data acquisition and analysis. The model is thus acceptable for testing innovative geometries, processes, and materials in riflescopes

Professor Pimenta Claro (1957-2018): Pioneer in dynamics of mechanical systems at the University of Minho

This work highlights the importance of Professor Pimenta Claro in the genesis and development of a new scientific area at the Department of Mechanical Engineering of the University of Minho, namely Dynamics of Mechanical Systems. Professor Pimenta Claro initiated his academic career in October 1980, coming from industry, where he was a well-recognized engineer in the field of mechanical design. Professor Pimenta Claro concluded his Pedagogical Aptitude and Scientific Capacity Tests (PAPCC) – MSc equivalent – in 1987, with dissertation title “Estudo Comparativo das Previsões Teóricas do Desempenho de Chumaceiras Radiais Hidrodinâmicas com Resultados Experimentais”. Professor Pimenta Claro received his doctorate degree in 1994 with thesis “Reformulação de Método de Cálculo de Chumaceiras Radiais Hidrodinâmicas – Análise do Desempenho Considerando Condições de Alimentação” under the mentorship of Professor Sousa Miranda, which was in fact the first PhD in Mechanical Engineering defended at the University of Minho. In 1997, Professor Pimenta Claro broken with his past background – classical tribology – to open a new research domain – Dynamics of Mechanical Systems. Since then, Professor Pimenta Claro has coordinated and participated in several scientific projects both with national and international partners, as well as projects with industrial partners. Professor Pimenta Claro was author of numerous publications, including scientific papers, books, conference papers, etc., and supervised PhD and MSc students. From 2007 to 2013 he coordinated the research group called Dynamics of Mechanical Systems. Professor Pimenta Claro was also pioneer and responsible for the creation of new courses on dynamics of mechanical systems offered in different degrees at the School of Engineering of the University of Minho. Thus, the main purpose of this work is to highlight Pimenta Claro’s contributions to the vast scientific area of Dynamics of Mechanical Systems at the Department of Mechanical Engineering of the University of Minho

Numerical simulation of capillary rise in millimetric cylindrical tubes

[Excerpt] Capillarity can be used in engineering nature-inspired slip-resistant surfaces, containing millimetric grooves, to provide an efficient grip on a solid floor with a small amount of liquid layer. Although literature has substantially reported analytical analysis and experimental data on capillary filling, numerical formulations provide the closest representation of the actual capillary filling process. Thus, in this work, a numerical model was developed to closely represent the natural filling of single-phase water inside a milli-metric-sized conduit of cylindrical shape, that demonstrates a single unit of the anti-slip surface matrix. A phase field numerical model was used to simulate the capillary imbibition of water inside the groove. [...]This work was supported by the Fundação para a Ciência e Tecnologia (FCT) project Bio Insole - Multi-Functional Bioinspired Slip Resistant Shoe-Sole (PTDC/EME-EME/7860/2020), and by the FCT reference projects UIDB/04436/2020 and UIDP/04436/2020. Susana O. Catarino thanks FCT for her contract funding provided through 2020.00215.CEECIND (DOI:10.54499/2020.00215.CEECIND/CP1600/CT0009

T.09 - Dinâmica de engrenagens

Neste documento aborda-se o tema da dinâmica de engrenagens, o qual é lecionado no âmbito da unidade curricular Órgãos de Máquinas II, do curso de Mestrado Integrado em Engenharia Mecânica da Universidade do Minho. Com efeito, inicia-se este assunto com uma breve abordagem ao conceito de diagrama do corpo livre e nomenclatura em dinâmica de engrenagens. Seguidamente apresenta-se a análise dinâmica de engrenagens cilíndricas de dentes retos e inclinados, engrenagens cónicas e de parafuse sem-fim. Finalmente, termina-se este documento com uma breve lista de questões de revisão de conhecimentos, assim como uma lista de referências bibliográficas.info:eu-repo/semantics/publishedVersio