Os cerca de 107.000 km de linhas de transmissão existentes no Brasil, nas tensões de 138/230/345/440/500/750 kV (corrente alternada), e 600 kV (corrente continua), atravessam parques nacionais ou estaduais, estradas, rios e parte se encontra com sobrecarga. O aumento da capacidade de carregamento das linhas de transmissão, se feito da forma tradicional, com a substituição ou reforço nas estruturas e fundações, em faixas que cruzam áreas consideradas de preservação ambiental permanente, exige obras adicionais que alteram o meio ambiente e desta forma, com os rigores da atual legislação ambiental, torna inviável tais alterações ou substituição. Uma das formas encontradas é a utilização de novas tecnologias em cabos condutores aéreos. Este trabalho tem a finalidade de pesquisar as necessidades do recondutoramento da linha de transmissão, com a minimização/eliminação dos danos ao meio ambiente. Uma das alternativas encontradas é a utilização de cabos especiais, que por se tratar de nova tecnologia em cabos, e considerando o desconhecimento de seu desempenho efetivo em condições reais, surge a necessidade da verificação de seu comportamento. Este trabalho apresenta a análise de casos no Brasil e o desenvolvimento piloto de um sistema de monitoramento em tempo real, através de medições diretas e indiretas, no trecho de linha de transmissão onde foi instalado um condutor de nova tecnologia, a fim de acompanhar o desempenho das características elétricas e mecânicas do novo condutor. Como resultado final foram validados os valores de projeto da ampliação da capacidade da linha de transmissão, sem impactos ao meio ambiente. / The approximately 107,000 km of transmission lines existing in Brazil, operating at 138 kV, 230 kV, 345 kV, 440 kV, 500 kV, 750 kV(ac) and 600 kV(dc), regularly encounter and cross state or national parks as well as highways, rivers and parks. Due to the ever increasing demand of power most of these transmission lines are at present overloaded. Increasing the loading capacity of these transmission lines in the traditional way (i.e. by substituting or reinforcing the structures and foundations in areas of permanent preservation) require additional works that may alter the environment; thus, making unfeasible the application of such alterations in view of the current strict environmental regulations. One way to cope with such a problem is through the utilization of new technologies applied to cables. Therefore, the objective of this work is to investigate the alternative of reconductoring a transmission line causing a minimum damage (and if possible eliminating this damage) to the environment. One of the alternatives found is the use of special cables which due to its relatively new introduction and technology to the power industry demands a thorough study on issues like the performance and verification of its behavior under real conditions. This work presents the development of a real-time monitoring system through direct and indirect measurements performed on a transmission line segment where a special conductor was installed. During the course of the research the performance of the new conductor regarding its electrical and mechanical characteristics was monitored. The measurements performed showed to be coherent with those obtained during the design of the transmission line.

The presented Master’s Thesis aims at determining stress and strain analysis of femur with fracture fixed by intramedullary nail and cerclage cable. The one of the goals of this work was create computational model which will be able simulate problem. Computational model consist of model of femur , it’s geometry was created on basis of CT data, than there was created model of intramedullary nail and cerclage cable on a basis of real objects. In this work was created simply model of femur with the same material features and characteristic proportions as analyzed model of femur. On this model was investigated direct impact of cerclage cables on deformation, respectively displacement in a surroundings of femoral fracture. On a final model were applied the real loads conditions. Preload in a cerclage cable was simulated by cooling down to a temperature from analytical calculation. Concluding analysis was powered by Finite Element Method (FEM) applied in system ANSYS Workbench 14.5 . Due to a results of analysis, we could say that using cerclage cables in combination with intramedullary nail is an effective way for healing femoral shaft fractures.

The thermal stability, fire retardancy and basic mechanical properties, as a function of the mass fractions of the poly(vinyl chloride) (PVC) compound ingredients, can be modelled using 2nd order Scheffé polynomials. The empirical models for each response variable can be determined using statistical experimental design. The particular models for each response variable, which are selected for predictive ability using k-fold cross validation, can be interpreted using statistical analysis of the model terms. The statistical analysis of the model terms can reveal the synergistic or antagonistic interactions between ingredients, some of which have not been reported in literature. The interaction terms in the models also mean that the effect of a certain ingredient is dependent on the mass fractions of the other ingredients. Sensitivity analysis can be used to examine the overall effect of a change in a particular formulation on the response variables. The empirical models can be used to minimise the cost of the PVC compound by varying the formulation. The optimum formulation is a function of the costs of the various ingredients and the limits which are placed on the response variables. To analyse the system as a whole, parametric analysis can be used. The number of different parametric analyses which can be done is very large and depends on the specific questions which need to be answered. Parametric analysis can be used to gain insight into the complex behaviour of the system with changing requirements, as a decision making tool in a commercial environment or to determine the completeness of the different measuring techniques used to describe the thermal stability and fire retardancy of the PVC compound. Statistical experimental design allows for the above methods to be used which leads to significant time and labour savings over attempting to reach the same conclusions using the traditional one-factor-at-a-time experiments with changes in the phr of an ingredient. It is recommended that the data generated for this investigation is analysed in more detail using the methods outlined for this investigation. This can be facilitated by making the analysis of the data (and therefore the data itself) more accessible through a usable interface. The data set itself can also be expanded to include new ingredients requiring very few additional experiments. If a PVC compound that contains none of the ingredients that were used in this investigation is of interest a new separate data set needs to be generated. This can be done by following the same procedure used in this investigation. In fact the method that is used in this investigation can be generalised to optimise the proportions of the ingredients of any mixture. / Dissertation (MEng)--University of Pretoria, 2017. / Chemical Engineering / MEng / Unrestricted

No description available.

El proyecto de investigación se realizó en la empresa P.Q. Servicios Generales EIRL, perteneciente al rubro de las telecomunicaciones. Se analizó la instalación de crecimientos horizontales de cable coaxial, estos tienen una gran demanda, sin embargo, no está cubierta totalmente, debido a elevados tiempos de las actividades del proceso, como el tensado de cable coaxial con un tiempo de 1 155,8 segundos, lo que hace que la productividad de mano de obra sea muy baja, actualmente de tan solo 20,88 metros/h x operario; por lo mencionado se genera unos ingresos no percibidos de S/8 321 al mes. A raíz de lo expuesto se plantea la siguiente interrogante, ¿Con el diseño de una máquina cabrestante se logrará reducir los ingresos no percibidos en la empresa P.Q. Servicios Generales EIRL? Se diseñó la máquina cabrestante con la ayuda del programa SolidWorks. Considerando el uso de la máquina en el proceso de instalación de cable coaxial, se logra una mejora muy significativa de los indicadores; el tiempo de tensado se reduce a 484,8 segundos; la productividad de mano de obra aumenta a 41,962 metros/h x operario; se reducen los ingresos no percibidos mensuales a S/ 4 735. La inversión en el proyecto tendrá un total de S/16 148,30; con una tasa interna de retorno del 183%; un VNA de S/103 176, 01 en un plazo de 5 años; y un periodo de recuperación de tan solo 196,3 días.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第21352号 / 工博第4511号 / 新制||工||1702(附属図書館) / 京都大学大学院工学研究科社会基盤工学専攻 / (主査)教授 八木 知己, 教授 清野 純史, 教授 高橋 良和 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

This thesis is based on a research project to monitor the temperature profile along a power cable using the fibre optic Distributed Temperature Sensing (DTS) technology. Based on the temperature measured by a DTS system, real time condition monitoring of power cables can be achieved. In this thesis, there are three main research themes. 1. Develop a DTS system for industrial applications. The entire hardware system and measuring software are developed to be an industrial product. Multiple functions are provided for the convenience of users to conduct temperature monitoring, temperature history logging and off-line simulation. 2. Enhance the robustness of the DTS system. An algorithm for signal compensation is developed to eliminate the signal fluctuation due to disturbance from the hardware and its working environment. It ensures robustness of the system in industrial environments and applicability to different system configurations. 3. Improve the accuracy of the DTS system. A calibration algorithm based on cubic spline fitting is developed to cope with non-uniform fibre loss in the system, which greatly improved the accuracy of the temperature decoding in real applications with unavoidable nonlinear characteristics. The developed DTS system and the algorithms have been verified by continuous experiments for about one year and achieved a temperature resolution of 0.1 degree Celsius, a spatial resolution of 1 meter, and a maximum error of 2 degree Celsius in an optic fibre with the length of 2910 metres.

This thesis proposes a method to simulate the dynamics of an autonomous underwater vehicle towing another autonomous underwater vehicle of equivalent size using a marine cable in the vertical and horizontal plane. There is a coupling effect between the two vehicles because the towed vehicle is of equivalent size. This means that the towed vehicle cannot be modeled as just a payload but rather, must incorporate the forces and moments experienced and acting on it. In this work, only AUVs with symmetrical hulls are considered, where the towing AUV is moving at a constant velocity with a set thrust while the towed AUV has no thrust. The rope system is another important component that needs to be modeled correctly because the rope material and type significantly impact the motion of the vehicles. The rope system in this study is modeled using a numerical approach called the lumped mass spring damper method which is easy to understand and computationally inexpensive. The rope model accounts for buoyancy differences in different ropes and permits cable flexibility. This thesis enables us to study the motion of multiple combinations of different ropes and axi-symmetric types of underwater vehicles with any fixed or movable fin configuration. / M.S. / This thesis studies the motion of an autonomous underwater vehicle towing another autonomous underwater vehicle which is a large as it is. The towed vehicle cannot be assumed to be just a mass attached to the towing vehicle. There is an interaction between the two vehicle. The towed vehicle places a force on the towed vehicle and the towed vehicle likewise places a force on the towing vehicle. This interaction needs to be modeled correctly to fully capture the impact of both vehicles and their appendages. Additionally, the rope system poses a huge impact on the two vehicle depending on what type of rope is selected. Multiple factors affect the performance of a rope such as the shape and the elasticity. Some ropes may also be denser due to their material type and are less buoyant than others. These factors are considered in the modeling of the overall system and allows us to study different combinations of ropes and symmetric hulled autonomous underwater vehicles.

En el presente trabajo se diseñó un prototipo de brazo robótica háptico teleoperado de 4 grados de libertad para la exploración marina hasta una profundidad máxima de 500m. Se diseñó el brazo robótica esclavo en un software de diseño, se analizó la estática y dinámica de dicho robot y se realizaron análisis de esfuerzos en los principales componentes. El robot tendrá un alcance máximo de 900mm y contará con sensores de posicionamiento y fuerza para el control de posición y fuerza. Además el brazo robótico contará con una cámara cerca al efector final con el motivo de tener una mejor visión para el operador. El trabajo incluye también el diseño del manipulador maestro que será controlado por el operador y que incluirá una realimentación de fuerza (force feedback). Se escogieron los motores y controladores indicados para el correcto funcionamiento del robot así como el tipo de comunicación que tendrá el robot con el computador. En el primer capítulo se presentará la problemática actual de los manipuladores robóticos submarinos, los cuales en su mayoría son hidráulicos y el costo de operación de dichos robots son altos. En el segundo capítulo se mencionarán los requerimientos físicos-mecánicos, requerimientos electrónicos y requerimientos de control del robot. Además se presentará el concepto de solución del sistema mecatrónico que será una alternativa de solución a la problemática presentada. En el tercer capítulo presentará el sistema mecatrónico completo. Se explicará el diagrama de funcionamiento del sistema mecatrónico, los sensores y actuadores presentes en el trabajo, planos de ensamble de los manipuladores, diagramas de circuitos y el diagrama de control del sistema mecatrónico. En el cuarto capítulo se presentará el presupuesto total del proyecto, el cual incluirá el presupuesto de los componentes mecánicos y electrónicos. Por último en el quinto capítulo se presentarán las conclusiones obtenidas del proyecto.

Debido a su gran exibilidad, los cables suspendidos presentan un comportamiento dinámico complejo producto de la no linealidad geométrica característica, con alta sensibilidad al nivel de tensión mecánica. Asimismo, en torres arriostradas de telecomunicaciones y de transmisión de energía, la tensión de las riendas presenta un considerable nivel de incertidumbre, en cuanto puede verse afectada en el tiempo debido a eventos ambientales, acciones accidentales o deliberadas sobre la estructura. En ciertas con guraciones de torres arriostradas de comunicación, las riendas poseen un arreglo de aisladores que interrumpen su longitud en segmentos menores. En esos casos, la aplicación de los métodos existentes basados en frecuencias naturales para la determinación de la tensión podría conducir a errores signi cativos. En el presente trabajo se desarrollan dos metodologías para la estimación de la tensión en cables con complejidades. Por un lado, a través de un enfoque probabilístico se propone un esquema Bayesiano de inferencia. Adicionalmente, se aborda la resolución del problema a través de la implementación de una Red Neuronal Arti cial. Ambas metodologías son evaluadas a través de ensayos físicos y computacionales. En el contexto del estudio dinámico de cables y estructuras con cables, se incluye un análisis probabilístico de líneas de transmisión de energía eléctrica (LTEE). En estos sistemas, la carga asociada al viento constituye usualmente el factor más relevante en el diseño estructural. Se aborda el análisis probabilístico de LTEE mediante un enfoque Monte Carlo de propagación y cuanti cación de incertidumbre, considerando a la carga de viento como un campo dinámico estocástico con correlación espacial y temporal, y a la tensión de las riendas como variables aleatorias. Por medio de este enfoque, se deriva una representación robusta de la respuesta estructural. A través de la aplicación de la carga estática de reglamento, se de nen umbrales de referencia que sirven de base para un análisis de cont abilidad estructural de la respuesta estocástica. / Due to its great exibility, suspended cables exhibit a complex dynamic behavior associated to their characteristic geometrical nonlinearity, and high sensibility to their pretension level. At the same time, in guyed power and telecommunication towers, the mechanical tension of the guys presents a signi cant uncertainty level, since it could be a ected in time due to environmental or deliberated human actions against the structure. In some con guration of guyed communication towers, an arrangement of insulators is attached to the guys, breaking its total length in minor sub-spans. In those cases, the application of the existing vibration-based methods for the estimation of the tension force could lead to signi cant errors. Therefore, two separate methodologies are developed in the present investigation for the estimation of the tension force in cables with complexities. On one side, through a probabilistic approach, a Bayesian framework is proposed. Additionally, the problem is approached through the implementation of an Arti cial Neural Network (ANN). Both methodologies are evaluated through physical and simulated tests. Additionally, the application of cables in Power Transmission Lines (PTL) is studied. In these systems, the load due to wind acting on the structure usually de nes the structural design. In the present investigation, the probabilistic analysis of a PTL is performed by means of a Monte Carlo approach for uncertainty quanti cation and propagation, considering the wind-related load as a dynamical stochastic eld with spatial and temporal correlation. Moreover, the uncertainty in the guys tension is included in the study through the de nition of a statistical model for the tension in the four guy wires of the supporting structure. This approach allows the derivation of a robust representation of the system response. Moreover, through the application of the static-equivalent wind load suggested in an international design code, reference thresholds are de ned and used in a reliability analysis of the stochastic dynamical structural response. / TEXTO PARCIAL en período de teletrabajo