Product development: Ergonomic support tool for hydraulic bolting

This thesis is about product development and manufacturing based on ideas gathered from personal experience from the industry. By performing bolt inspection at the top flange in a wind turbine, where the operator manually holds the heavy torque wrench, an idea was formed to find a solution where the job could be done safer, faster and more comfortably. Both group members were interested in coming up with a project where they could be working with the theoretical aspects of development, design and calculations in combination with the physical manufacturing of a final product. The scientific approach of this thesis is based on Action based research, Case study research and Product Development Process (PDP), where the group have mainly depended on the principals and methods of the product development process. Through brain storming, discussions with other bolting operators from the work in the wind turbines and more formal interviews with the most experienced field engineer in Hytorc Norge, data was gathered to start the process of finding the key attributes of the support tool. After having generated and discarded different concepts, a final combination of attachment bracket and lift mechanism concepts were chosen. The design was based on using existing standard parts, such as the steel pipes used for the different tube sections of the body and piston, and the spring used to drive the piston. The first part that was chosen was the spring driving the piston, and from there the group could start choosing the other components. If the tool were to be designed without taking the dimensions of the standard components into account from the start, it would likely turn out very difficult or even impossible to manufacture. It would be a hard realization to find out that there are no springs available with a sufficient spring constant in the needed diameter and length after all other dimensions were set. Taking this approach has made a design that is highly over-dimensioned for buckling and plastic deformation, but it is a design that can be made with existing parts available on the market. Through the project the group has been working a lot with Autodesk Inventor. In the beginning for making the first drafts for the concepts, to in the end doing the full assemblies and final revisions of the drawings. Mechanical strength calculations have been made by a combination of “hand calculations” in MathCad Prime and Ansys Mechanical for buckling analysis and other calculations. For the manufacturing, a lot of different tools and techniques have been used. Additive layer manufacturing has been used for prototypes and final parts. For the remaining steel parts, everything has been manufactured by CNC machines. By making use of use of Marcus’ experience with machining, the CNC programs used has been created by the group itself. The manufacturing and the testing and refinement processes each had their unforeseen challenges. The group has done a lot of modifications and found creative solutions to the different challenges that iii arose. Dealing with these real-life challenges is a part of what makes this kind of thesis special. There are a lot more complications to doing actual manufacturing than to making a model to do analysis on in Inventor 3D-space. After a lot of work and modifications a final product was formed. The project has been very interesting and educational. New tools and techniques have been learned, and the process has given a lot of perspective regarding all the factors that needs to be taken to account to create a well-functioning product. Both the group and Hytorc were pleased with the final product. A demonstration of the work scenario and the finished tool can be seen on Vimeo: https://vimeo.com/826654158This thesis is about product development and manufacturing based on ideas gathered from personal experience from the industry. By performing bolt inspection at the top flange in a wind turbine, where the operator manually holds the heavy torque wrench, an idea was formed to find a solution where the job could be done safer, faster and more comfortably. Both group members were interested in coming up with a project where they could be working with the theoretical aspects of development, design and calculations in combination with the physical manufacturing of a final product. The scientific approach of this thesis is based on Action based research, Case study research and Product Development Process (PDP), where the group have mainly depended on the principals and methods of the product development process. Through brain storming, discussions with other bolting operators from the work in the wind turbines and more formal interviews with the most experienced field engineer in Hytorc Norge, data was gathered to start the process of finding the key attributes of the support tool. After having generated and discarded different concepts, a final combination of attachment bracket and lift mechanism concepts were chosen. The design was based on using existing standard parts, such as the steel pipes used for the different tube sections of the body and piston, and the spring used to drive the piston. The first part that was chosen was the spring driving the piston, and from there the group could start choosing the other components. If the tool were to be designed without taking the dimensions of the standard components into account from the start, it would likely turn out very difficult or even impossible to manufacture. It would be a hard realization to find out that there are no springs available with a sufficient spring constant in the needed diameter and length after all other dimensions were set. Taking this approach has made a design that is highly over-dimensioned for buckling and plastic deformation, but it is a design that can be made with existing parts available on the market. Through the project the group has been working a lot with Autodesk Inventor. In the beginning for making the first drafts for the concepts, to in the end doing the full assemblies and final revisions of the drawings. Mechanical strength calculations have been made by a combination of “hand calculations” in MathCad Prime and Ansys Mechanical for buckling analysis and other calculations. For the manufacturing, a lot of different tools and techniques have been used. Additive layer manufacturing has been used for prototypes and final parts. For the remaining steel parts, everything has been manufactured by CNC machines. By making use of use of Marcus’ experience with machining, the CNC programs used has been created by the group itself. The manufacturing and the testing and refinement processes each had their unforeseen challenges. The group has done a lot of modifications and found creative solutions to the different challenges that iii arose. Dealing with these real-life challenges is a part of what makes this kind of thesis special. There are a lot more complications to doing actual manufacturing than to making a model to do analysis on in Inventor 3D-space. After a lot of work and modifications a final product was formed. The project has been very interesting and educational. New tools and techniques have been learned, and the process has given a lot of perspective regarding all the factors that needs to be taken to account to create a well-functioning product. Both the group and Hytorc were pleased with the final product. A demonstration of the work scenario and the finished tool can be seen on Vimeo: https://vimeo.com/82665415

Estudio de materiales cerámicos de alta constante dielétrica basados en CaCu3Ti4O12

Tesis doctoral inédita. Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Química Inorgánica. Fecha de lectura: 16-12-201

Segmentación multiescala del Edema Macular Quístico en imágenes OCT

[Resumen] De entre todas las diferentes patologías oculares existentes, las más preocupantes son las que no provocan ningún signo o síntoma en el paciente. En particular, el Edema Macular Quístico (EMQ) no causa ningún síntoma hasta una etapa muy avanzada de la enfermedad y se caracteriza principalmente por la presencia de regiones quísticas (áreas llenas de líquido patológico) en la región macular. La Tomografía de Coherencia Óptica (OCT) es una técnica de diagnóstico por imagen no invasiva que utiliza ondas de luz para tomar imágenes tridimensionales y transversales detalladas de los tejidos oculares con resolución micrométrica. OCT es una herramienta útil y eficaz que es ampliamente utilizada por los oftalmólogos en el diagnóstico y seguimiento del EMQ. Una herramienta capaz de aislar y representar las distintas estructuras quísticas de la retina puede mejorar la calidad y eficacia de los procesos diagnósticos, permitiendo a los clínicos realizar estudios más precisos y tratamientos más adecuados de esta relevante patología ocular. Así, en este proyecto, se propone una novedosa y totalmente automática metodología para la segmentación multiescala de los EMQs a partir de imágenes OCT. En particular, la metodología propuesta utiliza 3 diferentes y complementarias aproximaciones: (i) Curvedness y Shape Index, (ii) Central Adaptive Medialness y (iii) la combinación entre ambas aproximaciones. Para la validación del sistema, se han realizado varios experimentos utilizando un conjunto de imágenes OCT etiquetadas por un experto clínico. Los resultados obtenidos han demostrado el correcto funcionamiento del sistema para las 3 aproximaciones y, por tanto, demuestran la solidez del sistema aplicado a la segmentación de quistes de diferentes tamaños y en el apoyo al proceso de toma de decisiones clínicas.Traballo fin de grao (UDC.FIC). Enxeñaría informática. Curso 2019/202

New Avenues for the chemical modification of 1D and 2D nanomaterials

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Química Orgánica. Fecha de lectura: 30-06-2017En este trabajo se presentan tres resultados principales: i) El uso de naftaleno bisimidas como motivo de reconocimeinto para la síntesis de derivados mecánicamente enlazados de SWNTs. La naturaleza de los enlaces mecánicos y y la formación de polímeros de NDI ha sido probada a través de técnicas analíticas, espectroscópicas (TGA, NMR, UV-vis-NIR y Raman) y los correspondientes experimentos control. Además ha sido posible observar la presencia de macrociclos individules alrededor de los nanotubos gracias al microscopio de transmisión electrónica. ii) El desarrolo de un metodo simple para la modificación covalente de grafeno con una cierta periodicidad, este método se basa en la adsorción selectiva de radicales de cianometilo (CH2CN•) producidos mediante ruptura homolítica de acetonitrilo (CH3CN), El cual presenta una gran selectividad para enlazar covalentemente sobre sitios atómicos específicos del grafeno crecido sobre Ru(0001). Los resultados expermientales obtenidos fueron confirmados a través de cálculos DFT. iii) El desarrollo de fotodetectores de alto rendimiento a través de funcionalziación no covalente reversible y reproducible de dispositivos de MoS2 mediante el uso de distintas moléculas. A través de este trabajo hemos obtenido un incremento de la fotorespuesta de cuatro órdenes de magnitud y responsividades de hasta 100AW-1.In this work we presented three main results: i) The use of naphthalene bisimides as recognition motifs for the synthesis of mechanicallyinterlocked derivatives of SWNTs. The mechanically interlocked nature and polymer wrapping of NDI was probed by analytical and spectroscopic techniques (TGA, NMR, UVvis- NIR and Raman) and adequate control experiments. Furthermore, individual macrocycles were be seen around the nanotubes under TEM scrutiny. ii) The development of a simple method for the covalent modification of graphene with strict spatial periodicity at the nanometer scale, based on selective adsorption of cyanomethyl radicals (CH2CN•) produced by homolytic breaking of acetonitrile (CH3CN), which present a nearly complete selectivity to bind covalently to graphene grown on Ru(0001) on specific atomic sites. The results obtained experimentally were validated through Density Functional Theory (DFT) calculations. iii) The development of a high performance photodetector through reversible, and reproducible noncovalent functionalization of MoS2-devices with molecular dyes. We found an enhancement of the photoresponse of four orders of magnitude and responsivities up to 100 AW-1

Catecolaminas cerebrales y sistema endocrino

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Ciencias Biológicas, leída en 1983.Fac. de Ciencias BiológicasTRUEProQuestpu

Catecolaminas cerebrales y sistema endocrino

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Ciencias Biológicas, leída en 1983.Fac. de Ciencias BiológicasTRUEProQuestpu

Experimental determination of the eutectic temperature in air of the CuO-TiO2 pseudobinary system

Eutectic temperature and composition in the CuO–TiO2 pseudobinary system have been experimentally determined in air by means differential thermal analysis (DTA), thermogravimetry (TG) and hot-stage microscopy (HSM). Samples of the new eutectic composition treated at different temperatures have been characterized by X-ray diffraction (XRD) and X-ray absorption near-edge structural spectroscopy (XANES) to identify phases and to determine the Cu valence state, respectively. The results show that the eutectic temperature in air is higher by 100 °C (∼1000 °C) for a Ti-richer composition (XTiO2=25 mol%) than the one calculated in the literature. The reduction of Cu2+ to Cu+ takes places at about 1030 °C. The existence of Cu2TiO3 and Cu3TiO4 has been confirmed by XRD in the temperature range between 1045 and 1200 °C

Effect of the Synthesis Route on the Microstructure and the Dielectric Behavior of CaCu3Ti4O12 Ceramics

CaCu3Ti4O12 (CCTO) was prepared by a conventional synthesis (CS) and through reaction sintering, in which synthesis and sintering of the material take place in one single step. The microstructure and the dielectric properties of CCTO have been studied by XRD, FE-SEM, EDS, AFM, and impedance spectroscopy to correlate structure, microstructure, and electrical properties. Samples prepared by reactive sintering show very similar dielectric behavior to those prepared by CS. Therefore, it is possible to prepare CCTO by means of a single-step processing method

Dielectric behaviour of Hf-doped CaCu₃Ti₄O₁₂ ceramics obtained by conventional synthesis and reactive sintering

CaCu₃ (Ti₄₋ₓ Hfₓ )O₁₂ ceramics ( x  = 0.04, 0.1 and 0.2) were prepared by conventional synthesis (CS) and through reactive sintering (RS), in which synthesis and sintering of the material take place in one single step. The microstructure and the dielectric properties of Hf-doped CCTO (CCTOHf) have been studied by XRD, FE-SEM, AFM, Raman and impedance spectroscopy (IS) in order to correlate the structure, microstructure and the electrical properties. Samples prepared by reactive sintering show slightly higher dielectric constant than those prepared by conventional synthesis in the same way than the pure CCTO. Dielectric constant and dielectric losses decrease slightly increasing Hf content. For CCTOHf ceramics with x  > 0.04 for CS and x  > 0.1 for RS, a secondary phase HfTiO₄ appears. As expected, the reactive sintering processing method allows a higher incorporation of Hf in the CCTO lattice than the conventional synthesis one.Facultad de Ciencias Exacta