Estudio de la relación variables de proceso, microestructura y propiedades del hierro grafito compacto.

Tesis (Maestría en Ciencias de la Ingeniería Mecánica con Especialidad en Materiales) UANL, 2011.

La construcción de equipamientos híbridos en altura como respuesta a un modelo de ciudad denso y compacto: una propuesta para la UPZ N°71 Tibabuyes en la localidad de Suba en Bogotá.

El interés de este trabajo de grado consiste en proponer la construcción de un equipamiento híbrido en altura como alternativa de solución frente al crecimiento poblacional y la escasez de suelo presentes en la Unidad de Planeamiento Zonal- 71 Tibabuyes en la localidad de Suba. Se planea esta propuesta en el marco de un modelo de ocupación territorial denso y compacto contemplado en el Plan de Ordenamiento Territorial de Bogotá. Por tanto, el equipamiento híbrido en altura busca disminuir el déficit y mejorar el acceso a los equipamientos urbanos colectivos por parte de los habitantes de este territorio con el propósito de replantearse la manera de concebir las edificaciones tradicionales que brindan los servicios sociales.

O problema do Hiker Dice em tabuleiro compacto: um estudo algorítmico

The Hiker Dice was a game recently proposed in a software designed by Mara Kuzmich and Leonardo Goldbarg. In the game a dice is responsible for building a trail on an n x m board. As the dice waits upon a cell on the board, it prints the side that touches the surface. The game shows the Hamiltonian Path Problem Simple Maximum Hiker Dice (Hidi-CHS) in trays Compact Nth , this problem is then characterized by looking for a Hamiltonian Path that maximize the sum of marked sides on the board. The research now related, models the problem through Graphs, and proposes two classes of solution algorithms. The first class, belonging to the exact algorithms, is formed by a backtracking algorithm planed with a return through logical rules and limiting the best found solution. The second class of algorithms is composed by metaheuristics type Evolutionary Computing, Local Ramdomized search and GRASP (Greed Randomized Adaptative Search). Three specific operators for the algorithms were created as follows: restructuring, recombination with two solutions and random greedy constructive.The exact algorithm was teste on 4x4 to 8x8 boards exhausting the possibility of higher computational treatment of cases due to the explosion in processing time. The heuristics algorithms were tested on 5x5 to 14x14 boards. According to the applied methodology for evaluation, the results acheived by the heuristics algorithms suggests a better performance for the GRASP algorithm

Projeto e montagem de um sistema compacto de cogeração: aplicação da análise exergoeconômica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Sistema compacto de cogeração com motor de combustão interna

Sistema compacto de cogeração com motor de combustão interna compreendendo a interligação mecânica de um motor de combustão interna (M), operando com gasolina e ou gás, com um gerador de eletricidade (G), e um trocador de calor água/água (TC1), onde a troca de calor ocorre entre a água proveniente do conjunto de refrigeração do motor (M) e a água a ser aquecida proveniente da rede de abastecimento...

Análise experimental e desenvolvimento de um modelo numérico simplificado para um trocador de calor compacto para resfriamento de componentes eletrônicos

Pós-graduação em Engenharia Mecânica - FEIS

Análise exergética e ecológica de um sistema compacto de cogeração operando com gás de síntese

The aim of this work is to make a qualitatively and ecologically evaluation of a compact cogeneration system that operates with synthesis gas obtained from a gasifier. Using the Eucalyptus Biomass as fuel, that passes through a wood gasifier (Drowndraft type) and supply the internal combustion engine. The compact cogeneration system is composed of two heat exchangers, an energy generator connected to an internal combustion engine and an absorption refrigeration system. The complete system is installed in the laboratory from the Energy Department at the University of Guaratinguetá. By the analysis related to the First and Second Thermodynamic Laws applied in this system, was possible to identify the mass flows in each point, energetic efficiency, irreversibility and exergetic efficiency. The components that have the biggest irreversibilities are the gasifier, followed by the internal combustion engine, which should be focused in future improvements. The system efficiency in energetic basis is 51,84% and in exergetic basis is 22,78%. Using the ecologic efficiency methodology was possible to identify the emissions rates, the pollution indicator associated to the combustion of the synthesis gas in the internal combustion engine. The ecologic efficiency considering the energectic analysis is 91,73%, while considering the exergetic analysis, 83,65%. It is concluded that the use of the synthesis gas in a compact cogeneration system is viable from the technical and ecological point of view, making possible to generate energy for isolated communities and promoting the decentralized electricity generation

Estudo teórico da contribuição a dose de partículas secundárias geradas por prótons de energias entre 100-200 MeV num phantom de osso compacto

The contribution of the total dose due to deposition of secondary energy particles caused by nuclear inelastic processes (n, 2H, 3H, 3He and  ) in proton therapy is an opened problem and in discussion. In the calculations of plans implemented for routine treatment, the paid dose is calculated whereas that the proton loses energy by ionization and or coulomb excitement. The contribution of inelastic processes associated with nuclear reactions is not considered, mainly due to the difficulty of processing targets consisting of various materials. In this sense, there are only estimates for pure materials or simple composition (water, for example).This work presents the results of simulations by the Monte Carlo method employing the code MCNPX v2.50 (Monte Carlo N-Particle eXtended) of the contribution to the total dose of secondary particles. The study was implemented in a cylindrical phantom composed by compact bone, for monochromatic beams of protons between 100 and 200 MeV with pencil beam form

Sobre a dimensão do quadrado de um espaço métrico compacto X de dimensão n e o conjunto dos mergulhos de X em R2n

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Adaptação do aparelho de amplificação sonora no SUS comparado com um modelo de adaptação compacto

In the present days it is critical to identify the factors that contribute to the quality of the audiologic care provided. The hearing aid fitting model proposed by the Brazilian Unified Health System (SUS) implies multidisciplinary care. This leads to some relevant and current questions. OBJECTIVE: To evaluate and compare the results of the hearing aid fitting model proposed by the SUS with a more compact and streamlined care. METHOD: We conducted a prospective longitudinal study with 174 participants randomly assigned to two groups: SUS Group and Streamline Group. For both groups we assessed key areas related to hearing aid fitting through the International Outcome Inventory for Hearing Aids (IOI-HA) questionnaire, in addition to evaluating the results of Speech Recognition Index (SRI) 3 and 9 months after fitting. RESULTS: Both groups had the same improvement related to the speech recognition after nine months of AASI use, and the IOI-HA didn't show any statically significant difference on three and nine months. CONCLUSION: The two strategies of care did not differ, from the clinical point of view, as regards the hearing aid fitting results obtained upon the evaluation of patients in the short and medium term, thus changes in the current model of care should be considered.

Contribution to the Analysis, Design and Assessment of Compact Antenna Test Ranges At Millimeter Wavelengths - Contribución al Análisis, Diseño y Caracterización de Sistemas de Medida de Antenas en Rango Compacto para Frecuencias Milimétricas

This Doctoral Thesis entitled Contribution to the analysis, design and assessment of compact antenna test ranges at millimeter wavelengths aims to deepen the knowledge of a particular antenna measurement system: the compact range, operating in the frequency bands of millimeter wavelengths. The thesis has been developed at Radiation Group (GR), an antenna laboratory which belongs to the Signals, Systems and Radiocommunications department (SSR), from Technical University of Madrid (UPM). The Radiation Group owns an extensive experience on antenna measurements, running at present four facilities which operate in different configurations: Gregorian compact antenna test range, spherical near field, planar near field and semianechoic arch system. The research work performed in line with this thesis contributes the knowledge of the first measurement configuration at higher frequencies, beyond the microwaves region where Radiation Group features customer-level performance. To reach this high level purpose, a set of scientific tasks were sequentially carried out. Those are succinctly described in the subsequent paragraphs. A first step dealed with the State of Art review. The study of scientific literature dealed with the analysis of measurement practices in compact antenna test ranges in addition with the particularities of millimeter wavelength technologies. Joint study of both fields of knowledge converged, when this measurement facilities are of interest, in a series of technological challenges which become serious bottlenecks at different stages: analysis, design and assessment. Thirdly after the overview study, focus was set on Electromagnetic analysis algorithms. These formulations allow to approach certain electromagnetic features of interest, such as field distribution phase or stray signal analysis of particular structures when they interact with electromagnetic waves sources. Properly operated, a CATR facility features electromagnetic waves collimation optics which are large, in terms of wavelengths. Accordingly, the electromagnetic analysis tasks introduce an extense number of mathematic unknowns which grow with frequency, following different polynomic order laws depending on the used algorithmia. In particular, the optics configuration which was of our interest consisted on the reflection type serrated edge collimator. The analysis of these devices requires a flexible handling of almost arbitrary scattering geometries, becoming this flexibility the nucleus of the algorithmia’s ability to perform the subsequent design tasks. This thesis’ contribution to this field of knowledge consisted on reaching a formulation which was powerful at the same time when dealing with various analysis geometries and computationally speaking. Two algorithmia were developed. While based on the same principle of hybridization, they reached different order Physics performance at the cost of the computational efficiency. Inter-comparison of their CATR design capabilities was performed, reaching both qualitative as well as quantitative conclusions on their scope. In third place, interest was shifted from analysis - design tasks towards range assessment. Millimetre wavelengths imply strict mechanical tolerances and fine setup adjustment. In addition, the large number of unknowns issue already faced in the analysis stage appears as well in the on chamber field probing stage. Natural decrease of dynamic range available by semiconductor millimeter waves sources requires in addition larger integration times at each probing point. These peculiarities increase exponentially the difficulty of performing assessment processes in CATR facilities beyond microwaves. The bottleneck becomes so tight that it compromises the range characterization beyond a certain limit frequency which typically lies on the lowest segment of millimeter wavelength frequencies. However the value of range assessment moves, on the contrary, towards the highest segment. This thesis contributes this technological scenario developing quiet zone probing techniques which achieves substantial data reduction ratii. Collaterally, it increases the robustness of the results to noise, which is a virtual rise of the setup’s available dynamic range. In fourth place, the environmental sensitivity of millimeter wavelengths issue was approached. It is well known the drifts of electromagnetic experiments due to the dependance of the re sults with respect to the surrounding environment. This feature relegates many industrial practices of microwave frequencies to the experimental stage, at millimeter wavelengths. In particular, evolution of the atmosphere within acceptable conditioning bounds redounds in drift phenomena which completely mask the experimental results. The contribution of this thesis on this aspect consists on modeling electrically the indoor atmosphere existing in a CATR, as a function of environmental variables which affect the range’s performance. A simple model was developed, being able to handle high level phenomena, such as feed - probe phase drift as a function of low level magnitudes easy to be sampled: relative humidity and temperature. With this model, environmental compensation can be performed and chamber conditioning is automatically extended towards higher frequencies. Therefore, the purpose of this thesis is to go further into the knowledge of millimetre wavelengths involving compact antenna test ranges. This knowledge is dosified through the sequential stages of a CATR conception, form early low level electromagnetic analysis towards the assessment of an operative facility, stages for each one of which nowadays bottleneck phenomena exist and seriously compromise the antenna measurement practices at millimeter wavelengths.

Array Compacto De Monopolos Planos Con Plano De Tierra Ranurado Para Sistemas Mimo

A compact array of monopoles with a slotted ground plane is analyzed for being used in MIMO systems. Compact arrays suffer usually from high coupling which degrades significantly MIMO benefits. Through a matching network, main drawbacks can be solved, although it tends to provide a low bandwidth. The studied design is an array of monopoles with a slot in the ground plane. The slot shape is optimized with a Genetic Algorithm and an own electromagnetic software based on MoM in order to fulfill main figures of merit within a significant bandwidth

Trabajos virtuales. Un método compacto para el análisis práctico

La utilización del teorema de los trabajos virtuales para el estudio de los mecanismos de colapso de una estructura, permite resolver con elegancia y sencillez los problemas de diseño práctico. En este artículo se recuerdan los conceptos fundamentales y se resuelven algunos ejemplos.

Sistema de adquisición de datos compacto para medidas de extensiometría y posición

En este proyecto se trata el diseño y construcción de un sistema de adquisición de datos compacto y de bajo coste para medidas de extensiometría y posición. Dicho sistema irá embarcado en una bicicleta de montaña con el fin de medir determinados parámetros. Estos parámetros son a) Elongación de las suspensiones, b) Deformación en el cuadro. Para la medida de elongación de las suspensiones se diseña y construye un sensor casero de bajo coste basado en una transparencia y un par de diodos fotoemisor y fotorreceptor infrarrojos. Se imprime un gradiente y se emplean dos tubos coaxiales de PVC. La medida de extensiometría se realiza con galgas extensiométricas, puentes de Wheatstone y amplificador de instrumentación. Las muestras se digitalizan con el ADC del microcontrolador C8051F020 de la casa Silabs, que se usa en una placa de desarrollo, y se almacenan en una memoria flash serie. Se desarrolla un software para PC con LabView para poder recibir, procesar y visualizar las muestras obtenidas de los distintos canales con el fin de analizarlas. Se obtienen conclusiones de los resultados de pruebas básicas. ABSTRACT On this project, the design and construction of a compact, low cost, data adquisition system for strain and position measurements is dealt with. Such system will be embedded on a bicycle in order to measure certain parameters. These are a) Suspension elongation, b) Frame deformation. For suspension elongation measurements, a homemade, low cost sensor based on a photoemitter-photoreceiver diode couple and a transparent sheet is designed and built. A gradient is printed in the transparent sheet, and two coaxial PVC pipes are used. Strain measurements are carried out by means of a strain gage, Wheatstone bridges and an instrumentation amplifier. Samples are digitized with Silabs’ C8051F020’s ADC, which is used in a development board, and are stored in a serial flash memory. Software for PC on LabView is developed in order to receive, process and visualize the obtained samples from each channel in order to analyze them. Results are obtained from basic tests.

Novas metodologias no ensino do inglês : o ensino de línguas em disco compacto interactivo

Académico - Licenciaturas