1,721,052 research outputs found
Investigation of the use of iron in construction from antiquity to the technical revolution
Get PDFEn el contexto de la presente disertación, el uso del hierro en construcciones ha sido investigado.
Mediante el estudio de antiguos y modernos documentos disponibles sobre el tema, este trabajo
examina prácticas y conceptos asociados con el hierro en construcción civil desde su uso en la
antigüedad hasta la universal aceptación por los diseñadores, así como de observadores, en la
Revolución Industrial
Investigation of the use of iron in construction from antiquity to the technical revolution
Get PDFEn el contexto de la presente disertación, el uso del hierro en construcciones ha sido investigado.
Mediante el estudio de antiguos y modernos documentos disponibles sobre el tema, este trabajo
examina prácticas y conceptos asociados con el hierro en construcción civil desde su uso en la
antigüedad hasta la universal aceptación por los diseñadores, así como de observadores, en la
Revolución Industrial
Investigation of the use of iron in construction from antiquity to the technical revolution
No full textEn el contexto de la presente disertación, el uso del hierro en construcciones ha sido investigado.
Mediante el estudio de antiguos y modernos documentos disponibles sobre el tema, este trabajo
examina prácticas y conceptos asociados con el hierro en construcción civil desde su uso en la
antigüedad hasta la universal aceptación por los diseñadores, así como de observadores, en la
Revolución Industrial
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
A mixed micromechanical homogenisation scheme for the prediction of the 3D orthotropic elastic properties of different masonry bond typologies
Get PDFMasonry structures composed of two distinct material phases (units and mortar) with potentially
vastly different elastic properties are characterised by strong orthotropy. The variety of commonly
employed bond typologies for masonry walls, featuring unit groups and mortar joints with different
orientation with respect to the plane of the wall, result in complex stress and strain interactions between
the material phases.Postprint (published version
Derivation of the properties of masonry through micro-modeling techniques
No full textThe aim of this thesis is to present a framework for the application of micro-modeling techniques for the analysis of unreinforced masonry structures.
Finite element analyses of case studies from the literature are carried out in order to establish their capacity to predict the compressive strength of masonry. A critical review of the experimental inventory is carried out in parallel.
An experimental campaign involving masonry materials common in historical structures is presented. A parametric study on the modeling technique and the influence of material properties is also performed based on the finite element framework already presented.
A series of shear wall experiments are simulated using finite element models. The shear tests have been performed under a wide range of vertical prestress levels. The influence of the modeling technique is again investigated.
A micro-mechanical model for the analysis of masonry periodic unit cells is developed and presented, based on a critical analysis of the results of the preceding finite element analyses.
The model may be used for the derivation of the linear and nonlinear elastic properties of masonry walls ans pillars of a wide variety of typologies. The results of the model are compared against experimental results, finite element analysis benchmarks and closed form expressions.
The model also forms the basis for the development of a closed formexpression for the prediction of the compressive strength of masonry.
A complex masonry pillar is tested in compression. Its constituent materials are extensively characterized for the determination of their mechanical properties. The pillar test is simulated using a finite element micro-model for the purpose of highlighting the effect of the properties of its materials on its structural response. An analytical model for the prediction of the compressive strength of multi-leaf masonry is also proposed.El objetivo de esta tesis es presentar un esbozo de aplicación de técnicas de micro-modelado para el análisis de estructuras de fábrica sin refuerzo. Se han llevado a cabo análisis de elementos finitos de casos prácticos extraídos de la bibliografia para establecer su capacidad de predecir la resistencia a compresión de las estructures de fábrica. Paralelamente se ha realizado una revisión crítica del inventario experimental. Se expone una campaña experimental involucrando materiales de fábrica frecuentemente encontrado en estructuras históricas. Así mismo, se realiza un estudio paramétrico de las técnicas de modelado y la influencia de las propiedades de los materiales basado en el esbozo de anàlisis expuesto previamente. Se ha simulado por medio de modelos de elementos finitos una serie de experimentos realizados en muros a cortante. Los ensayos a cortante se han realizado bajo la acción de un amplio rango de niveles de pretensado vertical. La influencia de las técnicas de modelado es investigada. Se desarrolla y expone un modelo micro-mecánico para analizar células de fábrica periódicas, basado en un análisis crítico de los resultados obtenidos en los análisis de elementos finitos previamente realizados. El modelo puede ser usado para la deducción de las propiedades lineales y no lineales de una amplia variedad de tipologías tanto de muros y como de pilares de fábrica. Los resultados del modelo son comparados con resultados experimentales, estándares de comparación de análisis de elementos finitos y ecuaciónes analíticas. El modelo también establece las bases para el desarrollo de una nueva ecuación analítica para la predicción de la resistencia a compresión de estructuras de fábrica. Se realiza un ensayo de un complejo pilar de fábrica. Los materiales que lo componen son extensamente descritos para la definición de sus propiedades mecánicas. El ensayo del pilar es así mismo simulado por medio de un micro-modelo de elementos finitos con el objetivo de resaltar el efecto de las propiedades de los materiales en el comportamiento estructural. Se expone un modelo analítico para predecir la resistencia a compresión de fábrica de hoja múltiple.DOCTORAT EN ENGINYERIA DE LA CONSTRUCCIÓ (Pla 2007
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Design project of a low-cost data acquisition system for electromechanical testing of smart materials
Get PDFThis thesis aims to develop a low-cost data acquisition system to record electrical resistance and deformation data in self-sensing smart cement specimens. Subsequently, the developed system must be tested with cyclic load tests, a text file must be generated with the data obtained and said data must be analysed to extract conclusions about the performance of the system and the piezoresistive "smartness" of the materials. The most interesting application of this thesis is to implement the system designed in an intelligent cement for Structural Health Monitoring applications, where a structure can be continuously monitored to detect deformations and possible failures before they happen. For this reason, the research on this thesis’s state of the art has focused on the current applications of smart cement, current SHM systems and research about low-cost solutions. To achieve the thesis goals, fluent communication has been established between the thesis director and the author, both by exchanging emails and face-to-face meetings. In addition, face-to-face sessions have been held in the Resistance of Materials laboratory, such as preparing the test specimens and testing the data acquisition system at different points in the thesis. The results show that the developed system can record electrical resistance and deformation data and generate text files for its processing. The analysis of the obtained data also illustrates the linear relationship between the fractional change in the electrical resistance and the deformation, allowing in this way to characterize the specimens with their gauge factor and thus determine their "smartness”. To sum up, it can be established that this thesis manages to develop a low-cost system for the acquisition of reliable and replicable data and, due to its linear relationship, the cement can be considered "self-sensing" since the application of a load is translated into a change into the electrical resistance, eliminating in this way the need for off-the-shelf strain sensors in SHM systems
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