454 research outputs found
Time indeterminacy and spatio-temporal building transformations: an approach for architectural heritage understanding
Nowadays most digital reconstructions in architecture and archeology describe buildings heritage as awhole of static and unchangeable entities. However, historical sites can have a rich and complex history, sometimes full of evolutions, sometimes only partially known by means of documentary sources. Various aspects condition the analysis and the interpretation of cultural heritage. First of all, buildings are not inexorably constant in time: creation, destruction, union, division, annexation, partial demolition and change of function are the transformations that buildings can undergo over time. Moreover, other factors sometimes contradictory can condition the knowledge about an historical site, such as historical sources and uncertainty. On one hand, historical documentation concerning past states can be heterogeneous, dubious, incomplete and even contradictory. On the other hand, uncertainty is prevalent in cultural heritage in various forms: sometimes it is impossible to define the dating period, sometimes the building original shape or yet its spatial position. This paper proposes amodeling approach of the geometrical representation of buildings, taking into account the kind of transformations and the notion of temporal indetermination
Seismic Response of a Platform-Frame System with Steel Columns
Timber platform-frame shear walls are characterized by high ductility and diffuse energy dissipation but limited in-plane shear resistance. A novel lightweight constructive system composed of steel columns braced with oriented strand board (OSB) panels was conceived and tested. Preliminary laboratory tests were performed to study the OSB-to-column connections with self-drilling screws. Then, the seismic response of a shear wall was determined performing a quasi-static cyclic-loading test of a full-scale specimen. Results presented in this work in terms of force-displacement capacity show that this system confers to shear walls high in-plane strength and stiffness with good ductility and dissipative capacity. Therefore, the incorporation of steel columns within OSB bracing panels results in a strong and stiff platform-frame system with high potential for low- and medium-rise buildings in seismic-prone areas
Failure of curvature-dimension conditions on sub-Riemannian manifolds via tangent isometries
We prove that, on any sub-Riemannian manifold endowed with a positive smooth
measure, the Bakry-\'Emery inequality for the corresponding sub-Laplacian
implies the existence of enough Killing vector fields on the tangent cone to
force the latter to be Euclidean at each point, yielding the failure of the
curvature-dimension condition in full generality. Our approach does not apply
to non-strictly-positive measures. In fact, we prove that the weighted Grushin
plane does not satisfy any curvature-dimension condition, but, nevertheless,
does admit an a.e. pointwise version of the Bakry-\'Emery inequality. As
recently observed by Pan and Montgomery, one half of the weighted Grushin plane
satisfies the RCD(0,N) condition, yielding a counterexample to gluing theorems
in the RCD setting.Comment: 25 page
A semantic-based platform for the digital analysis of architectural heritage
This essay focuses on the fields of architectural documentation and digital representation. We present a research paper concerning the development of an information system at the scale of architecture, taking into account the relationships that can be established between the representation of buildings (shape, dimension, state of conservation, hypothetical restitution) and heterogeneous information about various fields (such as the technical, the documentary or still the historical one). The proposed approach aims to organize multiple representations (and associated information) around a semantic description model with the goal of defining a system for the multi-field analysis of buildings
Bridging the Gap: long-term use and re-use of Bronze Age funerary areas at Ypsonas-Vounaros and Erimi-Laonin tou Porakou.
Time indeterminacy and spatio-temporal building transformations: an approach for architectural heritage understanding
Nowadays most digital reconstructions in architecture and archeology describe buildings heritage as awhole of static and unchangeable entities. However, historical sites can have a rich and complex history, sometimes full of evolutions, sometimes only partially known by means of documentary sources. Various aspects condition the analysis and the interpretation of cultural heritage. First of all, buildings are not inexorably constant in time: creation, destruction, union, division, annexation, partial demolition and change of function are the transformations that buildings can undergo over time. Moreover, other factors sometimes contradictory can condition the knowledge about an historical site, such as historical sources and uncertainty. On one hand, historical documentation concerning past states can be heterogeneous, dubious, incomplete and even contradictory. On the other hand, uncertainty is prevalent in cultural heritage in various forms: sometimes it is impossible to define the dating period, sometimes the building original shape or yet its spatial position. This paper proposes amodeling approach of the geometrical representation of buildings, taking into account the kind of transformations and the notion of temporal indetermination
Antiradical potential of ancient Italian apple varieties of Malus x domestica Borkh. in a peroxynitrite-induced oxidative process
Ancient apple cultivars may be an important source of genes for apple breeding programs and for the production of value-added apple cultivars. We evaluated the biochemical properties of six apple varieties grown in the Casentino area (Tuscany, Italy). Two commercial varieties (Golden Delicious and Stark Delicious) and four local varieties (Mora, Nesta, Panaia-red and Ruggine) were selected and their methanolic extracts were analysed for total phenolics and flavonoids. Moreover the content of catechin,
epicatechin, rutin, chlorogenic and caffeic acid, five major phenolic constituents, was determined through HPLC-UV analysis. The radical scavenging capacity of the methanolic extracts was assessed using two in vitro tests: the blanching of the stable DPPH radical and the inhibition of tyrosine nitration induced by peroxynitrite. Three of the four local varieties had the highest content of total phenols and flavonoids. Ruggine and Panaia-red apple had the highest content of the five phenolic compounds
investigated and the highest antioxidant activity towards both radicals. The commercial varieties were characterized by lower phenolic content and antioxidant activity compared to old varieties. Finally, a significant correlation between phenolic content and antioxidant activity was found
Comparative Analysis of Bearings for Micro-GT: An Innovative Arrangement
Microgas turbines are a widespread technology in cogenerative and propulsion applications. Bearings are a key factor in their design and development. The aim of the present research work is the development of the support system for a typical microturbine intended for power generation. To this goal, the present chapter defines the typical requirements of the machine and, afterward, describes the different technologies available to develop the support system of a reliable microturbine. Conventional (rolling element and oil-film) supports and cutting-edge (magnetic, aerodynamic, and aerostatic) bearings are reviewed. Particularly, their suitability to the operating conditions is compared by means of a literature review and elaboration of the relevant data. By analyzing all this information, a new concept for the design of a micro-GT support system is devised. Instead of using a single type of bearing as usual, the new system includes different types in order to take advantage of the best characteristics of each one and, simultaneously, to minimize the effects of the relevant flaws. The innovative support system requires a suitable bearing arrangement, which is compared with the conventional ones. The conceptual design of the innovation is completed by a discussion of its advantages, drawbacks, and prospective improvements
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