Abstract Only within the last decade, the works of Uruguay an Engineer Eladio Dieste (1917-2000) have been gaining international academic dissemination, one of whose main contributions in the realm of formal-structural conception within architecture and civil engineering reside in the iterative development of the structural typology of the gaussian vault shells in reinforced brickwork. However, there is not an established definition for this typology’s architectural geometry. Also, there is hardly any evidence of how such shells were designed. Therefore, the main objective, of this paper is to demonstrate the underlying geometric relationships in the discontinuous gaussian vault shells designed and built by Eladio Dieste in reinforced brickwork, the dominant typological variation within the object of study. This analysis was carried out by means of the parametric modeling and the polynomial regression of selected case studies from the primary sources, since such computational tools allow for the proper geometrical management of formally complex geometries. The expected contributions of this study reside in the deepening of the understanding of the relationship between the design process and the geometry of the object of study, as well as the understanding of the geometrical conformation of the structural typology conceived by Eladio Dieste. decade 19172000 1917 2000 (1917-2000 dissemination formalstructural formal brickwork However typologys s Also Therefore objective sources geometries 1917200 191 200 (1917-200 191720 19 20 (1917-20 19172 1 2 (1917-2 (1917- (1917 (191 (19 (1 (

Resumo Apenas na última década, a obra do engenheiro Uruguaio Eladio Dieste (1917-2000) vem ganhando disseminação acadêmica internacional, sendo que uma de suas principais contribuições para a concepção formal-estrutural na arquitetura e engenharia civil foi o desenvolvimento iterativo da tipologia estrutural das abóbadas gaussianas, cascas de dupla-curvatura estruturadas em cerâmica armada. Entretanto, não há registros de uma definição estabelecida para a geometria arquitetônica destas tipologias estruturais. Tampouco existem evidências concretas acerca da concepção e desenvolvimento projetual destas estruturas. Por conseguinte, o objetivo deste artigo é evidenciar as relações geométricas subjacentes nas abóbadas guassianas descontínuas projetadas e construídas por Eladio Dieste em cerâmica armada, a variação dominante desta tipologia estrutural. Esta análise foi conduzida através da modelagem paramétrica e da regressão polinomial de estudos de caso selecionados a partir de fontes primárias originais, justamente por estas ferramentas computacionais permitirem o correto manejo de geometrias tidas como formalmente complexas. A contribuição esperada para esta pesquisa reside em aprofundar o entendimento entre a relação do processo de projeto e a geometria resultante no objeto de estudo, assim como o entendimento da conformação geométrica desta tipologia estrutural desenvolvida por Eladio Dieste. década 19172000 1917 2000 (1917-2000 internacional formalestrutural formal gaussianas duplacurvatura dupla curvatura armada Entretanto estruturais estruturas conseguinte originais complexas estudo 1917200 191 200 (1917-200 191720 19 20 (1917-20 19172 1 2 (1917-2 (1917- (1917 (191 (19 (1 (

Abstract The identification of anomalies for damage mapping is a complex task that depends on knowledge of their manifestation. The purpose of this study is to propose criteria for detecting anomalies in mortar coatings by analyzing facade images, aiming to improve damage mapping. Specific parameters related to position (geometry), configuration, grouping, origin and nearby construction componentes are proposed to guide the identification of each damage, indicating what is most important to observe in each case. To apply the proposed method, six sections of building facades in Brasília - DF are selected. The main characteristics that aid in identifying the typology of each anomaly are obtained, and the applied methodology validates the proposed approach. The results show that the established criteria lead to precise anomaly identification, making the damage mapping process more efficient and reliable, contributing to the study of degradation. manifestation images geometry, geometry , (geometry) configuration grouping case method selected obtained approach reliable degradation (geometry

Resumo A identificação de anomalias para a elaboração de mapas de danos é uma tarefa complexa e depende do conhecimento das suas formas de manifestação. O objetivo deste estudo é propor critérios para a detecção de anomalias em revestimentos de argamassa, pela análise de imagens de fachadas, visando aperfeiçoar o mapeamento de danos. São propostos parâmetros específicos, relacionados a posição (geometria), configuração, agrupamento, origem e componentes construtivos próximos que direcionam para a identificação de cada dano, indicando o que é mais importante observar em cada caso. Para a aplicação do método proposto, são selecionados seis trechos de fachadas de edifícios de Brasília - DF. São obtidas as principais características que auxiliam na identificação da tipologia de cada anomalia e a aplicação realizada permite validar a abordagem proposta. Com os resultados alcançados, observa-se que os critérios estabelecidos conduzem para a identificação precisa das anomalias, tornando o processo de elaboração de mapas de danos mais eficiente e confiável, contribuindo para o estudo da degradação. manifestação argamassa específicos geometria, geometria , (geometria) configuração agrupamento dano caso proposto DF proposta alcançados observase observa se confiável degradação (geometria

Abstract There are several characteristics that influence fire resistance of load-bearing masonries, wherein stand out the bricks compressive strength. Verification of wall systems fire behavior was conducted as prescribed by NBR 5628. This research aims to comparatively analyze fire resistance in real scale load-bearing walls, considering thermal insulation, structural stability, and airtightness. The thickness of the coating and laying mortar were standardized for all specimens just varying brick geometry and septs design in blocks of EST 60, 100, and 140 class. The obtained results show that the compressive strength of the bricks can induce both the structural stability of the constructive systems and its thermal insulation, being a typically critical characteristic for clay brick walls in a building fire. The sample with the highest compressive strength obtained the shortest local displacement, contributing to mitigate the generation of fissures in the system, enhancing the thermal insulation of the clay brick wall, and, thereby, its fire resistance. loadbearing load bearing masonries 5628 airtightness 60 100 14 class displacement system thereby 562 6 10 1 56 5

Resumo Diversas características influenciam a resistência ao fogo de sistema de parede em alvenaria estrutural, dentre as quais pode se incluir sua resistência à compressão. O comportamento desse sistema é validado experimentalmente conforme a norma NBR 5628. Esse estudo tem como objetivo analisar comparativamente a resistência ao fogo obtida através de ensaios em escala real em alvenaria estrutural, envolvendo as características de isolamento térmico, estanqueidade a passagem de gases e fumaça e estabilidade estrutural. Foram avaliados componentes com a mesma configuração em termos de revestimento e assentamento, assumindo como variável a resistência a compressão dos blocos, tendo sido considerados neste estudo blocos de classe EST 60, 100 e 140. Os resultados obtidos apontam que a resistência à compressão da alvenaria pode influenciar, além da estabilidade estrutural do sistema, também seu isolamento térmico, critério tipicamente crítico para alvenarias de blocos cerâmicos em situação de incêndio. A amostra de maior resistência à compressão apresentou menor deslocamento horizontal, contribuindo para mitigar a geração de fissuras, aumentando a oposição da alvenaria à passagem da temperatura ao longo de sua seção transversal e assim aumentar sua resistência ao fogo. 5628 térmico assentamento 60 10 140 influenciar incêndio horizontal fissuras 562 6 1 14 56 5

Resumo A expansão desordenada das cidades é um desafio global que afeta o desenvolvimento urbano. Neste estudo, é analisado o crescimento urbano em uma cidade média durante cinco décadas, com enfoque na forma urbana e aplicação de mais de 20 métricas espaciais associadas à mensuração da geometria da expansão físico-territorial no ambiente construído. Os padrões de crescimento são analisados à luz do fenômeno espraiamento urbano e sob a perspectiva da teoria de Difusão-Coalescência. São discutidas as limitações inerentes às métricas existentes, assim como elencadas alternativas que as superam por mensuração das propriedades de Compacidade, Fragmentação, Complexidade e Dispersão concomitantemente. Os resultados demonstraram a ocorrência de fases distintas no crescimento urbano ao longo das décadas: Difusão de uma forma inicialmente compacta em partes menores nas periferias; e Transição para crescimento com agrupamento dessas partes, elevando a compacidade. Essa oscilação sugere aderência à teoria da Difusão-Coalescência, com ocorrência de espraiamento urbano (entre 1966 e 1976) seguida de aumento da compacidade nas décadas subsequentes (1976-2006). Após 2006 os resultados são ambíguos, possivelmente associados a fatores intervenientes de planejamento. A discussão dos resultados destaca a relevância da quantificação do crescimento urbano por meio de métricas, e traz conceitos importantes atualmente limitados à literatura internacional. estudo 2 físicoterritorial físico territorial construído DifusãoCoalescência. DifusãoCoalescência Coalescência. Coalescência Difusão-Coalescência existentes Compacidade Fragmentação concomitantemente periferias DifusãoCoalescência, Coalescência, entre 196 1976 19762006. 19762006 . (1976-2006) 200 ambíguos planejamento internacional 19 197 1976200 (1976-2006 1 197620 (1976-200 19762 (1976-20 (1976-2 (1976- (1976 (197 (19 (1 (

Abstract The disorderly expansion of cities is a global challenge that impacts urban development. In this paper, we analyse the urban growth in a medium-sized city over five decades, focusing on urban form and employing more than 20 spatial metrics associated with the geometry of physical-territorial expansion in the built environment. We examine the growth patterns in the context of the urban sprawl phenomenon and the Diffusion-Coalescence theory perspective. We discuss the inherent limitations of existing metrics and raise alternatives that simultaneously address the properties of Compactness, Fragmentation, Complexity, and Dispersion. The results reveal distinct phases in urban growth over the decades, from diffusion of an initially compact form into smaller parts on the periphery; to a transition towards more compact growth. This oscillation suggests adherence to the Diffusion-Coalescence theory, with urban sprawl occurring between 1966 and 1976, followed by increased compactness in subsequent decades (1976-2006). After 2006, the results became ambiguous, possibly due to intervening planning factors. The discussion of the findings underscores the importance of quantifying urban growth using metrics and introduces concepts that have been hitherto limited to international literature. development paper mediumsized medium sized 2 physicalterritorial physical territorial environment DiffusionCoalescence Diffusion Coalescence perspective Compactness Fragmentation Complexity Dispersion periphery 196 1976 19762006. 19762006 2006 . (1976-2006) ambiguous factors literature 19 197 1976200 200 (1976-2006 1 197620 (1976-200 19762 (1976-20 (1976-2 (1976- (1976 (197 (19 (1 (

Resumen: Las clases de Geometría son complicadas de entender para los estudiantes porque es difícil imaginarse las formas de las figuras que se estudian y sus características. En esta investigación, se diseñaron clases basadas en el constructivismo, que fueron aplicadas a estudiantes de una carrera de educación. El objetivo fue validar esta propuesta de clases, que hacen énfasis en la participación activa del estudiante en su formación, donde se proponen actividades que incentivan el aprendizaje mediante el uso de materiales manipulables, software educativo y aplicaciones de la geometría a la vida cotidiana. La investigación fue un estudio de caso que tuvo un enfoque cualitativo. Se diseñaron 4 clases y se intervino a un grupo de 40 estudiantes de una carrera de educación y mediante un grupo focal se reflexionó sobre su experiencia con la propuesta. Como resultado, los estudiantes mencionaron que les motivó trabajar con métodos activos y en colaboración con sus compañeros; que la manipulación de recursos didácticos concretos y virtuales les facilita la comprensión de temas que usualmente son complejos. En conclusión, el desarrollo de clases constructivistas plantea al docente el uso de nuevas metodologías y recursos educativos, que incentiven a los estudiantes a lograr aprendizajes significativos y duraderos.

Abstract: Geometry classes are always complicated for students to understand, because it is difficult to imagine the shapes of the figures being studied and their characteristics. In this research, classes based on constructivism were designed, which were then applied to students of an education career, the objective was to validate this proposal for classes that emphasize the active participation of the student in their training, where activities are proposed that encourage learning through the use of manipulatives, educational software and applications of geometry to everyday life. The research is a case study that had a qualitative approach, 4 classes were designed and a group of 40 students from an education degree were interviewed, then, using the focus group technique, they reflected on their experience with the new classes. As a result, the students mentioned that they are motivated to work with active methods and in collaboration with their classmates, that the manipulation of concrete and virtual teaching resources makes it easier for them to understand topics that are usually complex. In conclusion, the development of constructivist classes proposes to the teacher the use of new methodologies and educational resources, which motivate and encourage students to achieve significant and lasting learning.

Resumo O estudo fundamenta-se em uma análise geral das geociências do colapso nos campos de cultivo de Santa María Zacatepec, na cidade de Juan C. Bonilla, México. A técnica de sensoriamento remoto é aplicada no desenvolvimento, permitindo a interpretação de combinações de bandas e a determinação da geometria, geologia, geomorfologia e cartografia do local. É apresentada uma análise resumida do trabalho realizado, além de modelos de simulação do gasto hidrológico e da aceleração da água nos taludes estruturais de escoamento. Esses dados foram utilizados para o mapeamento final e a modelagem gráfica. Foi realizado um estudo geomorfológico, geológico e topográfico do local, utilizando técnicas telemétricas aéreas e de satélite. Também foi utilizado um software especializado para levantamentos geodésicos e mapeamento em modelos 2D e 3D da área de análise. Os levantamentos do local foram realizados com o objetivo de conhecer o formato da estrutura e identificar áreas de risco potencial para a população próxima ao colapso. Foram obtidas ortofotos para calcular e determinar a inclinação por distância-elevação, aceleração-altura, fluxo de água e força, o que serviu para concluir as possíveis causas que levaram ao colapso e para ter dados técnicos suficientes que foram compartilhados com as autoridades de proteção civil.

Abstract This paper presents a general analysis from the geosciences of structural collapses. The analysis was conducted in the crop fields of Santa María Zacatepec, in the city of Juan C. Bonilla, Mexico. The analysis implemented the Remote Sensing technique, facilitating the interpretation of band combinations and determining the geometry, geology, geomorphology and cartography of the site under study. A summary analysis of the work performed is presented, in addition to showing simulation models of the hydrological outflow and water acceleration in the runoff structural slopes, data that were used for the final mapping and graphic modeling. A geomorphological, geological, and topographical study of the site was conducted, using satellite and aerial telemetric techniques. Specialized software was also used for geodetic surveys, mapping in 2D and 3D models of the analysis area. Surveys of the site were carried out to determine the shape of the structure and identify potentially risk areas for the population near the collapse events. Orthophotos were obtained to calculate and determine the slope by distance-elevation, acceleration-height, water flow and force, which served to conclude the possible causes that led to the collapses and have sufficient technical data that were shared with the civil protection authorities.

Resumen El trabajo se basa en un análisis general desde las geociencias del colapso en los campos de cultivo de Santa María Zacatepec, de la ciudad Juan C. Bonilla. En el desarrollo se aplica la técnica de Percepción Remota, permitiendo interpretar combinaciones de bandas y determinar la geometría, geología, geomorfología y cartografía del sitio. Se presenta un análisis resumido del trabajo que se realizó, además de mostrar modelos de simulación del gasto hidrológico y la aceleración del agua en las pendientes estructurales de escorrentía, datos que se usaron para la cartografía y modelado gráfico finales. Se realizó un estudio geomorfológico, geológico y topográfico del lugar, con técnicas telemétricas satelitales y aéreas; también se utilizó software especializado que se aplicó para levantamientos geodésicos, realizando cartografía en modelos 2D y 3D del área de análisis. Las prospecciones del lugar se realizaron con el objetivo de conocer la forma de la estructura e identificar áreas potencialmente riesgosas para la población cercana al colapso. Se obtuvieron ortofotos para calcular y determinar la pendiente por distanciaelevación, la aceleración-altura, el gasto y la fuerza del agua; que sirvió para concluir las posibles causas que ocasionaron el colapso, y contar con datos técnicos suficientes que se compartieron con las autoridades de protección civil.

An investigation into moving electromagnetic near-field hotspots inside a resonant cavity is presented. The investigation focused on simulating an alternative approach to microwave thermal ablation of tumours by manipulating the interaction between electromagnetic near fields instead of utilising an interstitial antenna. The methodology comprised comparing various electromagnetic field solvers, verifying the simulation techniques, characterising a rectangular resonant cavity, and attempting to manipulate the position of its hotspots by introducing a feed phase shift. The effects of dielectric media were also investigated. Progressive hotspot movement was achieved using input phase manipulation between 2.55 and 2.7 GHz with the feeds on opposite walls. No pattern change was evident at the system's eigenfrequencies, indicating a constant field pattern at its resonant peaks. Furthermore, it was determined that the characteristic modes of the system were narrowband, such that the addition of dielectric material altered the system's resonance. Therefore, the application of this method to thermal ablation, which requires high precision, accuracy and control, was deemed impractical. Future recommendations include using adjustable geometry to design field patterns, comparing dielectric media with significant thermal mass, and investigating the 'inverse problem' to create a specific current distribution around the resonant cavity and induce the desired hotspot patterns.

Resumen Este artículo muestra el uso de recursos web para crear entornos para visualizar los poliedros de Arquímedes y los respectivos duales de Catalan. Estos entornos fueron creados utilizando recursos de Realidad Virtual (VR), que permiten al visitante manipular los poliedros y compararlos y sus duales. Para la construcción de las salas virtuales se utilizaron transformaciones geométricas de traslación y rotación, utilizando estructuras de jerarquías de páginas HTML, e insertando cada poliedro en su respectiva sala virtual. Los recursos presentados en este trabajo se pueden utilizar en el aula para visualizar poliedros con gafas inmersivas e incluso en Realidad Aumentada (RA) utilizando smartphones y tablets. Otros estudios que se pueden desarrollar con los poliedros modelados en este artículo son áreas, volúmenes, secciones planas y la relación de Euler. Este artículo muestra la posibilidad de crear materiales didácticos con una tecnología sencilla y gratuita que hace un gran aporte a la mejora de la enseñanza de la Geometría, así como de otras áreas que utilizan representaciones gráficas de objetos 3D.

Abstract This paper shows the use of web resources to create environments for visualizing Archimedean polyhedra and the respective Catalan duals. These environments were created using Virtual Reality (VR) resources, which allow the visitor to manipulate the polyhedra and compare the polyhedra and their duals. Geometric transformations of translation and rotation were used to build the virtual rooms, using HTML page hierarchies structures, and inserting each polyhedron in its respective virtual room. The resources presented in this work can be used in the classroom to visualize polyhedra with immersive goggles and even in Augmented Reality (AR) using smartphones and tablets. Other studies that can be developed with the polyhedra modeled in this article are areas, volumes, plane sections and the Euler relation. This article shows the possibility of creating teaching materials with a simple, free technology that makes a great contribution to improving the teaching of Geometry, as well as other areas that use graphic representations of 3D objects.

Geotechnical engineers are routinely tasked with advising suitable stand-off distances below high-risk sections of slopes in open-pit mines that are identified to have potential to deform or collapse. Accurate prediction of failed material runout can mean the difference between continuous safe mining and unwanted high-potential incidents that result in loss of production, equipment damage, injury, or loss of life. This paper updates previous empirical relationships presented by the authors for estimating the volume and runout distance of excavated slope failures, in an open-pit mine operation, using slope geometry as the primary predictor. Cases are sourced from varying slope geometries (fall heights up to 385 m, slope angles up to 80°) and a range of commodities (iron ore, coal, nickel, gold, copper, boron, and limestone), excavated in sedimentary, banded-sedimentary, epithermal, and copper-porphyry deposits, across all six inhabited continents. Analysis of these cases identified positive correlations between slope height and runout distance, and slope height and failed material volume. In general, negative correlations were identified between Fahrböschung angle and slope height, and Fahrböschung angle and failed material volume; however, significant scatter is observed in these datasets. A definitive relationship could not be derived comparing Fahrböschung angle with failed material runout. Slope angle was also found to be a poor indicator of runout. Of the parameters analysed, slope height (i.e., fall height) was found to be the simplest and best predictor of runout distance. This paper presents new charts for predicting failed material runout distance for rock slopes. Relationships are defined for structurally and rock-mass driven slope failure mechanisms at average, 75%, and 95% prediction intervals.

Resumen Las ciudades propician un alto impacto ambiental en el sitio y en el entorno por sus requerimientos energéticos. En este artículo analizamos la implementación de la tecnología solar fotovoltaica (PV) como alternativa de autoaprovisionamiento energético limpio en un sector de uso mixto-residencial en la ciudad ecuatorial andina de Cuenca, Ecuador. A partir de las demandas energéticas de las edificaciones de la zona seleccionada, a través de LiDAR se identifican techumbres que, por su geometría, orientación o emplazamiento, son adecuadas para la instalación de paneles PV. Se obtienen consumos energéticos reales y, usando el software SAM con datos climáticos locales, se simula la capacidad de autoabastecimiento con la integración de PVs para alcanzar la neutralidad energética en cada inmueble. Se determina la generación eléctrica conjunta y se establece que la demanda energética puede ser cubierta en un 94,88%, con la instalación de 427 placas PV de 335 Wp distribuidas en 29 predios y con requerimiento de ocupación espacial de 11,95% de las cubiertas disponibles. Finalmente, se concluye que por espacio en techumbres se puede autoabastecer la totalidad de la demanda eléctrica, siendo incluso esta una alternativa para cubrir demandas alternativas como cocción y transporte que actualmente se solventan con combustibles fósiles.

Abstract Cities have a high environmental impact on both the site and the surrounding area due to their energy requirements. In this article, we analyze the implementation of photovoltaic (PV) solar technology as a clean energy self-supply alternative in a mixed-residential sector in the Andean equatorial city of Cuenca, Ecuador. Based on the energy demands of the buildings in the selected area, LiDAR is used to identify rooftops that, due to their geometry, orientation, or location, are suitable for PV panel installation. Real energy consumption data is collected, and using SAM software with local climate data, the self-sufficiency capacity is simulated with the integration of PVs to achieve energy neutrality in each property. The combined electrical generation is determined and it is established that the energy demand can be met by 94.88%, with the installation of 427 PV panels of 335 Wp distributed across 29 properties and with a spatial occupation requirement of 11.95% of the available roofs. It is concluded that the entire electrical demand can be self-supplied through rooftop space, and this could even serve as an alternative to meet other demands such as cooking and transportation that are currently met with fossil fuels.

With the research discussed here I aimed to examine the effect of the COVID-19 pandemic on primary school mathematics teaching processes and specifically the teaching process of 1st-grade geometric shapes. A holistic multiple case study design was used in this qualitative research. The participants were primary school teachers who have taught both processes and geometric shapes in 1st grade primary school and were selected using purposive sampling. Semi-structured interviews based on an interview form developed by me was used as data collection instrument. In this form, questions about the 4 skills in the programme related to geometry were included. Lesson content, materials, and content related to the method of expression related to each skill were examined comparatively during and before the COVID-19 pandemic. Semi-structured interviews during which the questions on the form were asked, were conducted with participating teachers. The content analysis technique was used to analyse the obtained data. The results of the analysis show that the transition to online education during the COVID-19 pandemic had serious consequences. Positive and negative effects were found in both primary school mathematics teaching process and the teaching process of geometric shapes in the 1st grade.

ABSTRACT The generation of observation units of reduced dimensions and regular geometry is becoming increasingly important in spatial analysis. Following this line of work, the Institute of Statistics and Cartography of Andalusia has, for the last decade, developed information integrated into the statistical grid formed by regular cells of 250 x 250 meters, according to Eurostat guidelines. This article shows the results of the use of spatial distribution data of population and housing. Autocorrelation and spatial correlation analyses have been conducted to find out the relationship between the Smoothed Standardized Mortality Ratio and certain socioeconomic indicators, as well as certain housing characteristics. The results, along with the advantages of working at a territorial disaggregation level of reduced dimensions and with a homogeneous observation unit, are showing order to obtain a more exhaustive knowledge of the territory.

RESUMEN La generación de unidades de observación de dimensiones reducidas y geometría regular tiene cada vez más peso en el análisis espacial. Siguiendo esta línea de trabajo, el Instituto de Estadística y Cartografía de Andalucía elabora, desde hace diez años, información integrada en la malla estadística formada por celdas regulares de 250 x 250 metros según las directrices de Eurostat. En este artículo se muestran los resultados de la utilización de datos de distribución espacial de la población y de la vivienda. Se han realizado análisis de autocorrelación y de correlación espacial para conocer la relación que existe entre la Razón de Mortalidad Estandarizada Suavizada y determinados indicadores socioeconómicos y de algunas características de las viviendas. Se muestran los resultados y las ventajas de trabajar en un nivel de desagregación territorial de dimensiones reducidas y con una unidad de observación homogénea, para obtener así un conocimiento más exhaustivo del territorio.

Abstract The application of swept frequency response analysis (SFRA) as a fault diagnosis tool in two autotransformers of a substation is described. Unlike power transformers, autotransformers have, in each phase of the high voltage winding, a series coil and a common coil, which must be tested separately in order to discriminate the state of each of them. The results obtained using the open circuit admittance configuration and sweeping from the frequency of 10 Hz to 1000 kHz are shown. Comparisons of the transference response functions were made between phases of the same autotransformer and the statistical method of Correlation Coefficients was applied to analyze the results. It was found that the occurrence of several short circuit events and poor operations, caused modifications in the geometry of the windings of both devices.

Resumen Se describe la aplicación del análisis de respuesta al barrido de frecuencia (SFRA) como herramienta de diagnóstico de fallas en dos autotransformadores de una subestación. A diferencia de los transformadores de potencia, los autotransformadores poseen, en cada fase del devanado de alta tensión, una bobina serie y otra común, que deben ensayarse por separado para poder discriminar el estado de cada una de ellas. Se muestran los resultados obtenidos empleando la configuración de admitancia de circuito abierto y realizando un barrido desde la frecuencia de 10 Hz hasta 1000 kHz. Las comparaciones de las funciones transferenciales de respuesta se hicieron entre fases de un mismo autotransformador y para el análisis de los resultados se aplicó el método estadístico de los Coeficientes de Correlación. Se comprobó que la ocurrencia de varios eventos de cortocircuitos y malas operaciones, provocaron modificaciones en la geometría de los devanados de ambos equipos.

Abstract: The main purpose of the paper was to study the effect of the geometry of recycled plastic fiber on the performance of mortar based on natural limestone residue. The used fibers were collected from plastic waste of polypropylene, resulting from domestic sweeps fabrication. The main test variables were the type of recycled fibers and the fiber fraction. Two types of recycled fibers were used, straight and crimped fibers, having the same length (20 ± 2mm) and the same diameter (0.45 ± 0.07mm). Four dosages of fibers were considered, 0.5%, 1%, 1.5% and 2 wt. %. The obtained results show that the geometry of recycled plastic fibers has an important effect on the performances of limestone residue mortar. The addition of recycled fibers to mortar decreases its workability and the decrease is higher with crimped fibers. The results reveal that the limited dosage of recycled plastic fiber necessary to obtain a workable mortar is 1% and 0.5% for straight and crimped fibers, respectively. The benefit of recycled plastic fibers is well observed on the flexural and compressive behavior of limestone residue mortar, but the strength’s values are higher in straight fibers mortar (SFM) than that in crimped fibers mortar (CFM). The microstructure analysis confirms the good performances of the fiber mortar

Abstract A continuous increase in levels of atmospheric pollution and emission restrictions has forced scientists and engineers to adopt new strategies to improve and develop internal combustion engines. One strategy is based on the development of new simulation methodologies using computational fluid dynamic (CFD) techniques, proposed in the present article. In this study,the dynamic loop methodology with ANSYS Fluent code is proposed to perform the numerical simulation ofa four-stroke spark ignition engine. The complexity of the real case was first simplified with three-dimensional CAD geometry, which was then discretized in ANSYS Meshing, whereby a hybrid mesh was created using prismatic and tetrahedral elements. Simulations for in-cylinder analyses were performed in cold flow and employing common flow parameters, such as swirl and tumble. The mesh quality results were classified as good or excellent, being higher than 0.79 for orthogonal quality criteria and lower than 0.36 for skewness criteria. Turbulent effects were introduced concerning the opening and closing of the valves. It was found that the turbulence increases during the intake stroke up to 90°, and during the power stroke, wherein the of the piston bowl, had a great contributionthat can be seen from the swirl and tumble profile for the engine cycle. In the case of the turbulence intensity, a sharp increase was registered during the admission step up to 90°, at which point the turbulence intensity was 4.0. It canbe concluded that this is an innovative approach, capable of simulating the engine motion profile in cold flow. engines CFD (CFD techniques article studythe study fourstroke four threedimensional three dimensional geometry Meshing elements incylinder cylinder parameters excellent 079 0 79 0.7 036 36 0.3 valves 90 90° bowl cycle 40 4 4.0 approach 07 7 0. 03 3 9 4.