24 research outputs found
Cassiodorus and the reluctant provinciales of Dalmatia
No full textLetters from Cassiodorus Variae directed to the provinciales of Dalmatia show a general understanding and description of this area as inhabited by people that try to avoid taxation. This example show how the different area subjected to Theoderic's power are typified through a selection of letters which insist on the same topic
Transformabilidad en las estructuras adaptativas de Frei Otto y más allá
No full text[EN] Adaptive structures can conform to external changing conditions, in order to improve their functional, energy related and/or load-bearing behavior. Structural adaptation can be depicted in the work of Frei Otto on lightweight tensile structures and elastic gridshells of reduced structural mass and materials with high strength and relatively low elastic modulus respectively. The main developments achieved were based on transformability in the structural simulation and erection process. Representative examples include the Olympic Stadium in Munich in 1972 and the Mannheim Multihalle in 1975 respectively. With the rise of digital and numerical technology in the last 20 years, Frei Otto s ideas and concepts are even more important and relevant today than they were half a century ago when they first emerged. Meanwhile, research and development of actual adaptive structures are based on the afore-mentioned principles of form variation and lightweight, as well as on aspects of flexibility, controllability and simplicity in kinematics. In achieving this, the development of adaptive structures with minimum embedded actuation and maximum possible output structural states, gains significance. Selected prototype developments demonstrate related achievements in the area.[ES] Las estructuras adaptativas pueden adaptarse a condiciones externas cambiantes para mejorar su comportamiento funcional, energético y/o de carga. La adaptación estructural puede representarse en los trabajos de Frei Otto sobre estructuras ligeras de tracción y cáscaras de rejilla elásticas de masa estructural reducida y materiales de alta resistencia y módulo elástico relativamente bajo, respectivamente. Los principales avances logrados se basaron en la transformabilidad en el proceso de simulación y montaje estructural. Algunos ejemplos representativos son el Estadio Olímpico de Múnich en 1972 y el Multihalle de Mannheim en 1975, respectivamente. Con el auge de la tecnología digital y numérica en los últimos 20 años, las ideas y conceptos de Frei Otto son aún más importantes y relevantes hoy que hace medio siglo, cuando surgieron por primera vez. Mientras tanto, la investigación y el desarrollo de estructuras adaptativas reales se basan en los principios antes mencionados de variación de forma y ligereza, así como en aspectos de flexibilidad, controlabilidad y simplicidad en la cinemática. Para lograrlo, cobra importancia el desarrollo de estructuras adaptables con un mínimo de actuación incorporada y un máximo de estados estructurales de salida posibles. Una selección de prototipos demuestra los logros alcanzados en este campo.C. Phocas, M.; Matheou, M. (2024). Transformability in adaptive structures of Frei Otto and beyond. VLC arquitectura. Research Journal. 11(2):237-249. https://doi.org/10.4995/vlc.2024.21914OJS23724911
Beihammer, Constantinou, and Parani (eds.), Court Ceremonies and Rituals of Power in Byzantium and the Medieval Mediterranean: Comparative Perspectives (Brill, 2013)
No full textReview of Alexander Beihammer, Stavroula Constantinou, and Maria G. Parani, eds., Court Ceremonies and Rituals of Power in Byzantium and the Medieval Mediterranean: Comparative Perspectives (Leiden: Brill, 2013)
Water-Harvesting Envelopes - Integration of Sorption-based Atmospheric Water Harvesting in a Façade System
No full textFaced with increasing water scarcity each year, regions with arid-hot climates are having a hard time collecting fresh water due to the limited rainfall or the geographic and technological difficulty of desalination of sea water. Atmospheric water harvesting (AWH) technology comes as a renewable water source that has a lot of methodologies, one of which is sorption-based AWH (SAWH). This thesis explores the potential of the integration of SAWH technology on building facades in arid-hot climates. Giving the fact that SAWH depends on low relative humidity and an abundant sorbent material it becomes a sustainable water resource that meets other façade functions like thermal and visual comforts in these regions. Using parametric design tools, the thesis explores the suggested design’s potential as architectural envelope for a variety of building uses while maintaining the visual and thermal comfort
Dynamics of the moderately stable boundary layer
No full textTese de doutoramento, Ciências Geofísicas e da Geoinformação (Meteorologia), Universidade de Lisboa, Faculdade de Ciências, 2018This project was divided in two main components. The first component consisted in modeling the very stable boundary layer using a large-eddy simulation (LES) model. Therefore, a novel LES model setup was developed to overcome the difficulties imposed on numerical models by the stable stratification and the associated reduction in the energetic scales in combination with the large anisotropy of turbulent motions. A series of stable boundary layers with weak geostrophic winds and strong surface cooling rates is explored. The surface heat flux is dynamically computed by resolving the surface layer since the often-used Monin–Obukhov similarity theory cannot represent very stable conditions. This requires the use of very high grid resolutions. Thus, Δ = 0.05 and 0.10 m was used. Two stability regimes can be identified based on vertical profiles of the gradient Richardson number. Nevertheless, the Richardson number exceeds the critical value for all simulations. The buoyancy effects act on the small scales of the turbulent flow from the surface to the top for the most stable regime, and only in the upper part of the SBL for the other regime. Furthermore, the analysis of the anisotropy tensor shows that the flow is in an anisotropic state and is governed by the stream-wise component of the turbulent flux u′u′. In the second component of this project, a method to decompose the vertical turbulent flux based on the corresponding joint probability density function (JPD) is introduced. Thus, the JPD is partitioned into a joint Gaussian part and its complement, which represent, respectively, the local mixing and them coherent motions, such as updrafts and downdrafts. The flow decomposition is independent of the water condensate (cloud) and can be applied to dry convection, subcloud layer, and stratiform cloud layer. Moreover, the JPD-based method can be applied to observational or model data.Fundação para a Ciência e a Tecnologia (FCT), SFRH/BD/52555/201
Dynamics of the moderately stable boundary layer
No full textTese de doutoramento, Ciências Geofísicas e da Geoinformação (Meteorologia), Universidade de Lisboa, Faculdade de Ciências, 2018This project was divided in two main components. The first component consisted in modeling the very stable boundary layer using a large-eddy simulation (LES) model. Therefore, a novel LES model setup was developed to overcome the difficulties imposed on numerical models by the stable stratification and the associated reduction in the energetic scales in combination with the large anisotropy of turbulent motions. A series of stable boundary layers with weak geostrophic winds and strong surface cooling rates is explored. The surface heat flux is dynamically computed by resolving the surface layer since the often-used Monin–Obukhov similarity theory cannot represent very stable conditions. This requires the use of very high grid resolutions. Thus, Δ = 0.05 and 0.10 m was used. Two stability regimes can be identified based on vertical profiles of the gradient Richardson number. Nevertheless, the Richardson number exceeds the critical value for all simulations. The buoyancy effects act on the small scales of the turbulent flow from the surface to the top for the most stable regime, and only in the upper part of the SBL for the other regime. Furthermore, the analysis of the anisotropy tensor shows that the flow is in an anisotropic state and is governed by the stream-wise component of the turbulent flux u′u′. In the second component of this project, a method to decompose the vertical turbulent flux based on the corresponding joint probability density function (JPD) is introduced. Thus, the JPD is partitioned into a joint Gaussian part and its complement, which represent, respectively, the local mixing and them coherent motions, such as updrafts and downdrafts. The flow decomposition is independent of the water condensate (cloud) and can be applied to dry convection, subcloud layer, and stratiform cloud layer. Moreover, the JPD-based method can be applied to observational or model data.Fundação para a Ciência e a Tecnologia (FCT), SFRH/BD/52555/201
Dynamics of the moderately stable boundary layer
No full textTese de doutoramento, Ciências Geofísicas e da Geoinformação (Meteorologia), Universidade de Lisboa, Faculdade de Ciências, 2018This project was divided in two main components. The first component consisted in modeling the very stable boundary layer using a large-eddy simulation (LES) model. Therefore, a novel LES model setup was developed to overcome the difficulties imposed on numerical models by the stable stratification and the associated reduction in the energetic scales in combination with the large anisotropy of turbulent motions. A series of stable boundary layers with weak geostrophic winds and strong surface cooling rates is explored. The surface heat flux is dynamically computed by resolving the surface layer since the often-used Monin–Obukhov similarity theory cannot represent very stable conditions. This requires the use of very high grid resolutions. Thus, Δ = 0.05 and 0.10 m was used. Two stability regimes can be identified based on vertical profiles of the gradient Richardson number. Nevertheless, the Richardson number exceeds the critical value for all simulations. The buoyancy effects act on the small scales of the turbulent flow from the surface to the top for the most stable regime, and only in the upper part of the SBL for the other regime. Furthermore, the analysis of the anisotropy tensor shows that the flow is in an anisotropic state and is governed by the stream-wise component of the turbulent flux u′u′. In the second component of this project, a method to decompose the vertical turbulent flux based on the corresponding joint probability density function (JPD) is introduced. Thus, the JPD is partitioned into a joint Gaussian part and its complement, which represent, respectively, the local mixing and them coherent motions, such as updrafts and downdrafts. The flow decomposition is independent of the water condensate (cloud) and can be applied to dry convection, subcloud layer, and stratiform cloud layer. Moreover, the JPD-based method can be applied to observational or model data.Fundação para a Ciência e a Tecnologia (FCT), SFRH/BD/52555/201
REVIEW: Court Ceremonies and Rituals of Power in Byzantium and the Eastern Mediterranean. Comparative Perspectives. Edited by Alexander Beihammer, Stavroula Constantinou, & Maria Parani
No full textReview of the collected volume Court Ceremonies and Rituals of Power in Byzantium and the Eastern Mediterranean
Editorial - transformable structures and envelopes in architecture and civil engineering
No full text
