ABSTRACT Deformation intensity analysis for mechanical parts are very important data for machine design. For farm machines, these parameters present difficulties for determination due to its particularities. The Machinery industry searches for advanced technologies to determine the mechanical behavior of parts. This article shows the analysis of the reliability in the application of the laser triangulation technique (LTT) to determine the deformation of the mechanical elements of farm machines. A flat cutting disc with standardized dimension was selected as the object of study, as it is commonly used in farm machines, exhibiting a simple geometry made of steel, making the analysis procedure easier both for experimental execution and for data validation. Displacements of 1.0 mm to 10 mm were applied on the specimen. The theoretical behavior of specimen displacement was defined by finite element modelling with same condition of loading and dimension to compare the generated data by the experimental tests. Results indicated a displacement with maximum variation of 2.56% between experimental data and theoretical results and were considered satisfactory. LTT was able to determine deformation curve behavior of machine elements. It was concluded that Laser Triangulation Technique (LTT) was satisfactory to determine the deformation of a specimen. design machines particularities (LTT study steel validation 1 0 1. tests 256 2 56 2.56 25 5 2.5 2.

Abstract In housing, concrete masonry is one of the most used construction systems in Costa Rica. Under this construction system, beams and columns of equal width (12 or 15 cm) are usually required. In these cases, constructively, bending the reinforcing steel of the beam or column is used. This type of bend used “strangles” the reinforcement right in the section of maximum moment. Thus, it is relevant to experimentally investigate the behavior of these joints that are typically observed in constructions. The behavior of joints with two different reinforcement details and with 12 cm thick elements for use in housing was analyzed. Four joints were built, two with a “bottleneck” reinforcement detail (Type A Joint) and two with a 1:6 slope detail (Type B Joint). These were failed in the LanammeUCR Structures Laboratory under the application of a pseudo-dynamic cyclic load. Rotations were calculated and the hysteresis curve and elastoplastic curve were constructed for each joint. The behavior of the two types of joints was compared, as well as the experimental capacity results with respect to the expected theoretical capacity. The results obtained show that Type A Joints do not reach the calculated theoretical capacity and present a less ductile behavior than Type B Joints. It was concluded that it is preferable and advisable to use beam-column joints with the slope detail 1:6 as part of the earthquake-resistant system of a home.

Resumen En vivienda, la mampostería de concreto es uno de los sistemas constructivos más utilizados en Costa Rica. Bajo este sistema constructivo, se suelen requerir vigas y columnas de igual ancho (12 o 15 cm). En estos casos, constructivamente se recurre a doblar el acero de refuerzo de la viga o de la columna. Este tipo de doblez utilizado “estrangula” al refuerzo justo en la sección del máximo momento. De tal forma, resulta relevante investigar experimentalmente el comportamiento de estas uniones que típicamente se observan en las construcciones. Se analizó el comportamiento de uniones con dos distintos detalles de armado y con elementos de 12 cm de espesor para uso en vivienda. Se construyeron cuatro uniones, dos con un detalle de armado de “cuello de botella” (Unión Tipo A) y dos con detalle de pendiente 1:6 (Unión Tipo B). Estas se fallaron en el Laboratorio de Estructuras del LanammeUCR bajo la aplicación de una carga cíclica pseudo dinámica. Se calcularon rotaciones y se construyeron la curva de histéresis y la curva elastoplástica para cada unión. Se comparó el comportamiento de los dos tipos de uniones, así como, los resultados de capacidad experimentales con respecto a la capacidad teórica esperada. Los resultados obtenidos muestran que las Uniones Tipo A no alcanzan la capacidad teórica calculada y presentan un comportamiento menos dúctil que las Uniones Tipo B. Se logró concluir que es preferible y recomendable utilizar uniones viga-columna con el detalle de la pendiente 1:6 como parte del sistema sismorresistente de una vivienda.

Abstract: Introduction: Although there are elements to guide intraoperative analgesia, there is no standardized tool that is also a predictor of postoperative pain. Surgical Pleth Index (SPI) could be that diagnostic test. Objective: To establish a cut-off value for SPI to predict moderate to severe postoperative pain. Material and methods: 60 patients who underwent elective surgery with balanced general anesthesia were evaluated. The analyzed variables: heart rate, mean arterial pressure and state entropy (SE) were recorded every 2 minutes during the last 10 minutes of surgery and upon awakening. During recovery, postoperative pain was measured using the numerical rating scale (NRS) every 3 minutes for 15 minutes. Results: The data obtained were analyzed using a ROC curve that revealed an optimal intraoperative cut-off value of 36 SPI, discriminating between patients without pain or mild pain (NRS = 0-3) vs patients with moderate to severe pain (NRS = 4-10) in the postoperative period. For this cut-off value, both the negative predictive value and the positive predictive value were high (80 and 88.7%, respectively). Conclusions: An SPI value of 36 can be a useful predictor of postoperative pain, with greater effectiveness than the hemodynamic variables analyzed.

Resumen: Introducción: Aunque existen elementos para guiar la analgesia en el transoperatorio, no hay una herramienta estandarizada que además sea predictora de dolor en el postoperatorio. El Surgical Pleth Index (SPI) podría ser esa prueba diagnóstica. Objetivo: Establecer un valor de corte para SPI para predecir el dolor postoperatorio de moderado a intenso. Material y métodos: Fueron evaluados 60 pacientes, sometidos a cirugía programada con anestesia general balanceada. Las variables analizadas: frecuencia cardíaca, presión arterial media y entropía de estado (SE) se registraron cada dos minutos durante los últimos 10 minutos de la cirugía y al despertar. Durante la recuperación, se midió el dolor postoperatorio mediante la escala numérica análoga (ENA), cada tres minutos durante 15 minutos. Resultados: Se analizaron los datos obtenidos mediante una curva ROC que reveló un valor de corte óptimo intraoperatorio de 36 SPI discriminando entre pacientes sin dolor o dolor leve (ENA = 0-3) vs pacientes con dolor moderado a severo (ENA = 4-10) en el postoperatorio. Para este valor corte, tanto el valor predictivo negativo, como el valor predictivo positivo, fueron altos, (80 y 88.7%, respectivamente). Conclusiones: Un valor de SPI de 36 puede ser un predictor útil de dolor postoperatorio, con mayor efectividad que las variables hemodinámicas analizadas.

Abstract: This study attempts to obtain the approximate fatigue vulnerability of a steel arch bridge from the Colombian national road network. It establishes the interaction between the demand and the available capacity through the Weibull probability equation, and an AASHTO remaining-time equation indicated in (FHWA, 2015). However, the available capacity in terms of the S-N curve obtained from available international references was modified to account for the effects of corrosion present in elements and/or joints in the bridge. The load demand was modeled as the controlled action of the fatigue truck reported in AASHTO, which was systematically located on a structural model represented by Shell and Frame type finite elements, which represented the information available in drawings (in the current Colombian bridge management system), and the one obtained from structural survey activities. The structural model was further calibrated by a parametric study on the modulus of elasticity of steel, which included the minimization of the error difference in the vertical deflections of a bridge load test, keeping the magnitude within the expected ranges established in a protocol. Such reports of actual deflections were achieved using distance meters at important points of the bridge. This model allowed for estimating the magnitude of stresses in the structural elements of the bridge, especially in an area of interest for the study where chemical and physical elements of structural deficiency were determined. The results show an inverse relationship between the probability of failure and remaining service life. The effect of corrosion on the remaining capacity and the probability of failure of the structural elements is clear.

Resumen: El presente estudio busca obtener la vulnerabilidad aproximada a fatiga de un Puente de acero en arco que pertenece a la red de vías nacionales de Colombia. Se establece la interacción entre la demanda y la capacidad disponible de resistencia através de la ecuación de probabilidad de Weibull y la ecuación indicada en ela norma AASHTO para vida remanente en fatiga (FHWA, 2015). Sin embargo, la capacidad disponible con base en las curvas S-N de capacidad disponible, se modificaron para poder tener en cuenta los efectos de corrosión presentes en elementos y/o conexiones del puente. La carga se modeló mediante el camion de fatiga especificado en la AASHTO, el cual fue localizado de manera sistemática sobre los nudos de un modelo hecho en elementos finitos tipo Shell and Frame. Este modelo se construyó basado en planos disponibles y de algunas actividades de levantamiento estructural en campo. El modelo estructural fue calibrado mediante un proceso paramétrico en el modulo de elasticidad del acero, el cual minimizó el error entre las deflexiones verticales modealdas y las determinadas mediante una prueba de carga sobre el puente real. Las deflexiones reales fueron reportadas mediane el uso de distanciómetros localizados en puntos seleccionados del puente. El modelo calibrado sirvió para estimar la magnitud de los rangos de esfuerzo en los elementos modelados del Puente, especialmente en la zona de estudio, donde se determinó la presencia de corrosión. Los resultados presentan una relación inversa entre la probabilidad de falla por fatiga, y la vida remanente estimada por efectos de fatiga. Se pudo determinar con claridad el efecto de la corrosión en la capacidad del puente y la probabilidad de falla asociada.

In this paper we develop a physics-based model for lining erosion in steel ladles. The model predicts the temperature evolution in the liquid slag, steel, refractory bricks, and outer steel shell of the ladle. The flow of slag and steel is due to forced convection induced by inert gas injection, vacuum treatment (extreme bubble expansion), natural convection, and waves caused by the gas stirring. The lining erosion takes place by dissolution of refractory elements into the steel or slag. The mass and heat transfer coefficients inside the ladle during gas stirring are modelled based on wall functions which take the distribution of wall shear velocities as a critical input. The wall shear velocities are obtained from computational fluid dynamics (CFD) simulations for a sample of scenarios, spanning out the operational space, and a model is developed using curve fitting. The model is capable of reproducing both thermal and erosion evolution well. Deviations between model predictions and industrial data are discussed. The model is fast and has been tested successfully in a 'semi-online' application. The model source code is available to the public at [https://github.com/SINTEF/refractorywear].

ABSTRACT Metal oxide nanoparticles (NPs) possess antibacterial activities and can be used for the control of phytopathogenic bacteria. The objective of this work was to evaluate the antibacterial activity of pure and doped NPs against Dickeya zeae, Pantoea ananatis, and Xanthomonas vasicola pv. vasculorum in vitro, and to assess the efficacy of preventive and curative application of zinc oxide (ZnO), nickel oxide (NiO), and silver-doped zinc oxide (ZnO:Ag) NPs for the control of white spot (WS) and bacterial leaf streak (BLS) in vivo. Bacterial growth inhibition was first evaluated by measuring the diameter of the inhibition zone formed in Petri dishes. Subsequently, the severity of WS and BLS diseases was evaluated in a greenhouse calculating the area under the disease progress curve. The in vitro antibacterial activity was not influenced by the increase in the concentration of doping elements for most NPs. ZnO NPs doped with Ag, K, and Mo; ZnOCl doped with Ag, and pure NPs (Ag2O, CuO, and NiO) showed antibacterial activity against D. zeae, P. ananatis, and X. vasicola pv. vasculorum with relatively similar inhibition zones at different concentrations. Commercial copper showed antibacterial activity only against D. zeae. NiO NPs in preventive and curative applications reduced WS and BLS severities, whereas commercial copper application increased WS severity and reduced BLS severity. The use of NPs has promising applications and further evaluation of their formulation, application form, and timing is necessary for new strategies to control the activity of phytopathogenic bacteria. (NPs bacteria zeae ananatis pv ZnO, , (ZnO) NiO, (NiO) silverdoped silver ZnOAg Ag (ZnO:Ag (WS (BLS vivo dishes Subsequently curve K Mo Ag2O, Ag2O AgO O (Ag2O CuO D P X concentrations severities formulation form (ZnO (NiO

RESUMO Nanopartículas de óxido metálico (NPs) possuem atividade antibacteriana e podem ser utilizadas para o controle de bactérias fitopatogênicas. O objetivo deste trabalho foi avaliar a atividade antibacteriana de NPs puras e dopadas contra Dickeya zeae, Pantoea ananatis e Xanthomonas vasicola pv. vasculorum in vitro, e avaliar a eficácia da aplicação preventiva e curativa de NPs de óxido de zinco (ZnO), óxido de níquel (NiO) e óxido de zinco dopado com prata (ZnO:Ag) para o controle da mancha branca (WS) e estria bacteriana (BLS) in vivo. A inibição do crescimento bacteriano foi primeiramente avaliada medindo o diâmetro da zona de inibição formada em placas de Petri e a severidade das doenças WS e BLS foi avaliada em casa de vegetação, calculando a área abaixo da curva de progresso da doença. A atividade antibacteriana in vitro não foi influenciada pelo aumento na concentração dos elementos dopantes para a maioria das NPs. NPs de ZnO dopadas com Ag, K e Mo; ZnOCl dopada com Ag e NPs puras (Ag2O, CuO e NiO) apresentaram atividade antibacteriana contra D. zeae, P. ananatis e X. vasicola pv. vasculorum com halos de inibição relativamente semelhantes em diferentes concentrações. O cobre comercial apresentou atividade antibacteriana apenas para D. zeae. NPs de NiO em aplicações preventivas e curativas reduziram a severidade de WS e BLS, enquanto a aplicação de cobre comercial aumentou a severidade de WS e reduziu a severidade de BLS. O uso de NPs tem aplicações promissoras na cultura do milho e estudos futuros avaliando sua formulação, forma de aplicação e época são necessários para novas estratégias de controle de bactérias fitopatogênicas. (NPs fitopatogênicas zeae pv ZnO, , (ZnO) (NiO ZnOAg (ZnO:Ag (WS (BLS vivo vegetação doença Mo Ag2O, Ag2O AgO (Ag2O D P X concentrações formulação (ZnO

Abstract This work aims to investigate the ultimate capacity of reinforced concrete elements in terms of cracking and stiffness loss. Nonlinear finite element analysis (NLFEA) was performed in the ATENA software and compared with a proposed numerical simulation of nonlinear static analysis (NLSA), where material cracking is evaluated based on the loss of tangent stiffness of the elements. The analysis was applied to a low-rise reinforced concrete frame with constant axial loads in the columns, and monotonic lateral load applied at the top beam level. Both methodologies showed good agreement regarding the capacity curve and crack patterns, and the numerical simulation NLSA allowed the identification of the sequence of elements' stiffness loss. The results indicated a substantial similarity between the numerical simulation NLFEA and NLSA and the experimental test, indicating a high potential in predicting the nonlinear behavior of reinforced concrete. (NLFEA NLSA, , (NLSA) lowrise low rise columns level patterns test (NLSA

Resumo Este trabalho tem como objetivo investigar a capacidade última de elementos em concreto armado em termos de fissuração e perda de rigidez. Uma análise não linear via método dos elementos finitos (MEF) foi realizada no programa ATENA e comparada com uma simulação numérica de análise estática não linear (AENL), onde a fissuração do material é avaliada com base na perda de rigidez tangente dos elementos. As análises foram aplicadas a um pórtico em concreto armado com cargas axiais constantes nos pilares, e carga lateral monotônica aplicada na viga superior. Ambas as metodologias mostraram boa concordância em relação à curva de capacidade e panorama de fissuração, e a simulação numérica AENL permitiu identificar a sequência de perda de rigidez dos elementos. Os resultados indicaram grande semelhança entre a simulação numérica FEM e AENL e ensaio experimental, indicando um alto potencial para prever o comportamento não linear do concreto armado. MEF (MEF AENL, , (AENL) pilares superior experimental (AENL

Abstract Reinforced concrete structures, when subjected to fire, have their mechanical resistance reduced related to the behavioral change of the material. Many experimental and numerical research on the behavior of concrete exposed to fire have been carried out on beams and columns, with slabs being studied less frequently, mainly due to its size and consequently higher research costs. This paper carried out a numerical analysis of the thermomechanical behavior of reinforced concrete slabs exposed to fire, using finite element modeling. The parametric analysis carried out changing the aggregate type of concrete showed that when exposed to ISO834 fire curve, the displacement in the center of slab with siliceous aggregate was 47% higher than the slab with calcareous aggregate. Analyzing the crack opening, for slabs exposed to ISO834 fire curve, the first 1mm-cracks were noticed at 18min when using calcareous aggregate, while the slabs with siliceous aggregate started at 13min. structures material columns frequently costs modeling ISO ISO83 curve 47 opening 1mmcracks mmcracks 1mm cracks mm min 13min ISO8 4

Resumo Estruturas de concreto armado, quando submetidas ao fogo, têm sua resistência mecânica reduzida em função da mudança de comportamento do material. Muitas pesquisas experimentais e numéricas sobre o comportamento do concreto exposto ao fogo têm sido realizadas em vigas e pilares, sendo as lajes menos estudadas, principalmente devido à sua dimensão e consequentemente maiores custos de ensaio. Este artigo realizou uma análise numérica do comportamento termomecânico de lajes de concreto armado expostas ao fogo, utilizando modelagem por elementos finitos. A análise paramétrica realizada alterando o tipo de agregado do concreto mostrou que, quando exposta à curva de incêndio ISO834, o deslocamento no centro da laje com agregado silicioso foi 47% maior do que a laje com agregado calcário. Analisando a abertura de fissuras, para as lajes expostas à curva de incêndio ISO834, as primeiras fissuras de 1mm foram notadas aos 18min quando se utilizou agregado calcário, enquanto as lajes com agregado silicioso iniciaram aos 13min. material pilares estudadas ensaio finitos ISO834 ISO 47 calcário mm min 13min ISO83 4 ISO8

RESUMEN Las enfermedades infecciosas pueden convertirse en pandemias y constituir emergencias sanitarias. Desestabilizan los sistemas de salud, la vida económica, política, social y medioambiental de un país. En una situación de pandemia, se produce un aumento progresivo de las demandas asistenciales, que responden con la curva epidémica, y exige de los sistemas sanitarios la reorganización de sus recursos en función de la atención a los pacientes. En este trabajo se exponen las principales estrategias de dirección asumidas en el Hospital Militar Central “Dr. Luis Díaz Soto” en la preparación de la institución para el enfrentamiento a la COVID-19. Una vez esclarecida la tarea, se definió en la institución, la misión, visión, objetivos generales y política de calidad para la asistencia médica en esta situación sanitaria. Se realizaron 3 actividades fundamentales, la creación de un puesto de mando central, la definición de las áreas clasificadas como zona roja y la reorganización de las actividades asistenciales, que incluyó los elementos de garantía de la bioseguridad. Como indicadores hospitalarios para analizar mensualmente el resultado de la actividad asistencial se determinaron el índice de ocupación, el promedio de estadía, la letalidad y la mortalidad bruta y neta. La estrategia de dirección permitió la organización de la institución para el enfrentamiento a la pandemia.

ABSTRACT Infectious diseases can become pandemics and constitute health emergencies. They destabilize health systems and the economic, political, social and environmental life of a country. In a pandemic situation, there is a progressive increase in the demand for care, which responds to the epidemic curve and requires health systems to reorganize their resources in terms of patient care. This paper presents the main management strategies adopted at the Central Military Hospital "Dr. Luis Díaz Soto" in the preparation of the institution to face COVID-19. Once the task was clarified, the institution defined its mission, vision, general objectives and quality policy for medical assistance in this health situation. Three fundamental activities were carried out: the creation of a central command post, the definition of the areas classified as red zones and the reorganization of healthcare activities, which included the elements of biosafety assurance. The hospital indicators used to analyze the results of care activities on a monthly basis included the occupancy rate, average length of stay, case fatality, and gross and net mortality. The management strategy allowed the organization of the institution to face the pandemic.

Resumen: Las redes radiales de alta tensión son muy propensas a sufrir inestabilidades de tensión cuando se presentan fallas. Dentro de las acciones preventivas ante este tipo de eventos, la instalación de compensación de potencia reactiva en las zonas con más problemas de tensión es una alternativa económica y sencilla de aplicar. Trabajos previos han utilizado el método de las curvas QV basados en flujos de potencia en estados de contingencia para identificar tales zonas. Sin embargo, este procedimiento es criticado debido a que no contempla el efecto dinámico de elementos que cambian su comportamiento de acuerdo a los niveles de tensión, especialmente en escenarios de contingencia. Con el fin de subsanar esta crítica, este artículo propone el uso de las mismas curvas QV basándose en los puntos de operación resultantes de simulaciones dinámicas. Para evaluar la metodología propuesta, se utilizó el modelo de la red radial de alta tensión de la Patagonia, al sur de Argentina, por medio del software PSS/E en conjunto con el lenguaje de programación Python. Los resultados detectaron las zonas más propensas a la inestabilidad de tensión y el requerimiento de potencia reactiva necesaria para que la red opere en niveles de tensión aceptables. La metodología propuesta puede ser replicada en cualquier tipo de red. Por ejemplo, en el contexto latinoamericano, se podría utilizar en posibles futuras expansiones de red, especialmente en aquellas que vinculen países como Ecuador con Colombia o Perú, o también el Sistema Interconectado Centroamericano.

Abstract: Radial High-Voltage networks have problems ensuring voltage stability when a fault occurs. Among preventive actions for these events, installing reactive power compensation in the most vulnerable zones to voltage instability is an economical and simple alternative. Previous works have used the QV curves methodology based on contingency power flows to identify such zones. However, this method has been criticized because it does not consider the dynamical effect of some network elements that depend on the voltage levels, especially in contingency scenarios. This article proposes a QV curve analysis based on the operating point resulting from dynamic simulations to amend this critique. To evaluate the proposed procedure, the model of the Patagonian High-Voltage Network in southern Argentina is used through the PSS/E software with the help of the Python programming language. The results detect the most vulnerable areas to voltage instability after a fault occurs and the reactive power necessary to maintain voltage levels in an acceptable operating range. The proposed methodology can be applied to other networks. For example, it can be used in the Latin-American context to assess future network expansions, especially on those linking countries, such as Ecuador with Perú or Colombia, or even the Centro American Interconnected System.

Resumen Uno de los posibles usos de los vidrios calcogenuros es su aplicación en dispositivos de memoria de cambio de fase. El funcionamiento de estas memorias no volátiles se basa en el uso de una aleación con elementos calcogenuros como material sensible, aprovechando el gran contraste en la resistencia eléctrica entre los estados amorfo y cristalino. Se destaca la aleación Sb70Te30 (porcentaje atómico) entre los materiales calcogenuros con estas propiedades. Por otro lado, el conocimiento de los mecanismos microscópicos de la cristalización de aleaciones amorfas permite el control microestructural para optimizar propiedades. En este punto, la calorimetría diferencial de barrido (DSC) ha sido ampliamente utilizada para la determinación de la estabilidad térmica de las aleaciones amorfas. Previamente hemos comenzado el estudio de la cinética de cristalización de aleaciones amorfas Sb70Te30. En este trabajo se ha aplicado un procedimiento basado en la denominada hipótesis isocinética para realizar el análisis cinético de los datos calorimétricos de calentamiento continuo. En particular la denominada curva maestra de la cinética de cristalización de esta aleación es determinada.

Abstract One of the possible uses of chalcogenide glasses is their application in phase change memory devices. The operation of these non-volatile memories is based on the use of an alloy with chalcogenide elements as a sensitive material, taking advantage of the great contrast in electrical resistance between the amorphous and crystalline states. The Sb70Te30 (atomic percentage) alloy stands out among the chalcogenide materials with these properties. On the other hand, the knowledge of the microscopic mechanisms of the amorphous alloys crystallization allows microstructural control to optimize properties. At this point, differential scanning calorimetry (DSC) has been widely used for the determination of the thermal stability of amorphous alloys. Previously we have started the study of the crystallization kinetics of Sb70Te30 amorphous alloys. In this work, a procedure based on the so-called isokinetic hypothesis has been applied to carry out the kinetic analysis of the calorimetric data of continuous heating. In particular, the so-called master curve of the crystallization kinetics of this alloy is determined.

Abstract The maximum shear modulus (G0) and the modulus degradation curve (G/G0 versus γ) are important information in the evaluation of the soil mechanical behavior, both for dynamic and static loads. Dynamic tests (resonant column and cyclic triaxial tests) are not routinely performed in geotechnical practice in Brazil, and the geotechnical literature on the dynamic behavior of unsaturated tropical soils is limited. This paper presents and discusses seismic dilatometer (SDMT), resonant column, and triaxial test with bender elements and internal instrumentation to determine G0 and the modulus degradation curve in an unsaturated tropical sandy soil profile. It was observed that G0 tends to increase non-linearly with soil suction and net stress (σ - ua). It was also observed that the in situ G0 values determined with the SDMT were higher than those from laboratory tests (bender elements and resonant column). The modulus degradation curves determined with resonant column were used to define the reference curve via SDMT for the studied site. Soil suction influence in shear modulus degradation curves determined with unsaturated triaxial compression tests with local instrumentation is also presented and discussed. G (G0 G/G0 GG0 GG (G/G γ loads Brazil limited SDMT, , (SDMT) profile nonlinearly non linearly σ ua. ua . ua) column. column) site discussed (G G/G (SDMT

Abstract Understanding the dynamic behavior of soils is essential to the study of the influence of seismic loads on the instability of submarine slopes, an important issue in Brazil and other countries. The shear modulus and the damping ratio are two fundamental parameters for the study of this behavior. Determining these parameters for Speswhite kaolin clay is the object of the present study using resonant column tests and dynamic centrifuge tests with accelerometers and pairs of bender elements. The curves obtained in the laboratory are compared with empirical curves and comparable data in the literature. Good agreement was observed between experimental data and the empirical prediction for the degradation curve of the normalized shear modulus. The damping curve for very low strains, obtained with resonant column tests, was consistent with the empirical curve. However, consistent with a trend observed in the literature, the centrifuge test results presented considerable scatter (dispersion), attributable to the difficulty in modelling damping dissipation mechanisms in the centrifuge. slopes countries elements literature strains However dispersion, dispersion , (dispersion) (dispersion

RESUMO Para uma gestão eficiente da conservação da água e do solo, os aspectos de qualidade e quantidade devem ser integrados. No entanto, ainda faltam estudos com essa sinergia incluindo o processo de governança. Avaliamos aspectos de quali-quantidade (2010-2019) por 10 anos em um manancial de abastecimento de água e a implementação de Pagamentos por Serviços Ambientais (PSA), para entender a eficiência da política pública na área ambiental e seus efeitos sobre os recursos hídricos. O processo de governança foi investigado e análises estatísticas usadas para comparação de médias, análises gráficas (tendências, série temporal, curva de permanência, desvio padrão), correlação e multivariada para avaliar o comportamento dos parâmetros, após implementação do PSA. Nossos resultados mostraram que houve uma redução significativa na turbidez, DQO e sólidos suspensos totais. Além disso, a vazão, nitrogênio total, fósforo total e oxigênio dissolvido permaneceram estáveis, após a implementação de práticas de conservação, corroborada pela análise multivariada. O índice de qualidade da água (IQA) entre “Bom” e “Ótimo” e os parâmetros químicos e hidrobiológicos abaixo dos valores máximos permitidos, refletiram na manutenção da qualidade da água. A tomada de decisão participativa com base no diálogo entre as partes interessadas e a confiança no PSA foram os elementos-chave de sucesso. solo integrados entanto qualiquantidade quali 20102019 2010 2019 (2010-2019 1 PSA, , (PSA) hídricos médias tendências, tendências (tendências temporal permanência padrão, padrão padrão) turbidez totais disso vazão estáveis IQA (IQA Bom “Bom Ótimo “Ótimo permitidos elementoschave elementos chave sucesso 2010201 201 (2010-201 (PSA 201020 20 (2010-20 20102 2 (2010-2 (2010- (2010 (201 (20 (2 (

ABSTRACT For the efficient management of water and soil conservation, quality and quantity aspects must be integrated. However, there is still a lack of studies with this synergy including governance processes. The present research evaluated for ten years (2010-2019) quality and quantity aspects of a water supply source and the Payment for Environmental Services (PES) implementation to investigate public policy efficiency and its effect on water resources. We used statistical analyses for comparing means, graphical analyses (trends, time series, duration curve, standard deviation), and correlation and multivariate analysis to evaluate parameters’ behavior after the PES implementation. Results showed that there was a significant reduction in turbidity, COD, and total suspended solids. Furthermore, water flow rate, total nitrogen, total phosphorus, and dissolved oxygen remained stable after the implementation of conservation practices, as confirmed by the multivariate analysis. Water quality index (WQI) between “Good” and “Great” and chemical and hydrobiological parameters below the maximum allowed values reflected on the water quality maintenance. Participative decision-making based on dialogue between stakeholders and trust in PES were key elements for success. integrated However processes 20102019 2010 2019 (2010-2019 (PES resources means trends, trends (trends series curve deviation, deviation , deviation) turbidity COD solids Furthermore rate nitrogen phosphorus practices WQI (WQI Good “Good Great “Great maintenance decisionmaking decision making success 2010201 201 (2010-201 201020 20 (2010-20 20102 2 (2010-2 (2010- (2010 (201 (20 (2 (

Neste trabalho utilizamos elementos de geometria diferencial, tais como vetores unitários, tangente e normal, e raio de curvatura, para estudar a compatibilidade de modelos mecânicos em dois problemas de perseguição. No primeiro estudo referente ao problema da curva tractriz, mostramos como a escolha de um modelo de duas partículas conectadas por uma haste rígida, em um primeiro momento, uma escolha aparentemente natural e intuitiva, é incompatível com os demais vínculos do problema. Logo em seguida ampliamos a discussão e consideramos o problema no qual as duas partículas obedecem à cinemática do problema de perseguição de Pierre Bouguer. Neste caso mostramos como a escolha de um modelo de haste hookeana extensível conectando ambas as partículas é compatível com os vínculos do referido problema de perseguição. O software gratuito Modellus é utilizado para simular o comportamento das forças necessárias para justificar a cinemática do sistema. Um interessante comportamento de mudança na orientação das forças atuantes ao longo do tempo é apresentado e discutido à luz dos vínculos a serem respeitados e através do conceito de velocidade relativa. diferencial unitários normal curvatura tractriz rígida momento intuitiva Bouguer sistema relativa

In this work, we use elements of differential geometry, such as unit vectors, tangent and normal, and radius of curvature, to study the compatibility of mechanical models in two pursuit problems. In the first study concerning the problem of the tractrix curve, we show how the choice of a model of two particles connected by a rigid stem, at first a natural and intuitive choice, is incompatible with the other constraints of the problem. Soon after, we expand the discussion and consider the situation in which the two particles obey the kinematics of Pierre Bouguer’s pursuit problem. In this case, we show how the choice of an extensible hookean stem model connecting both particles is compatible with the other constraints of the problem. The free software Modellus is used to simulate the behavior of the forces necessary to justify the system’s kinematics. An interesting behavior of changes in the orientation of the acting forces over time is presented and discussed in light of the constraints to be respected and through the concept of relative velocity. work geometry vectors normal curvature problems curve after Bouguers Bouguer s case systems system velocity