68 research outputs found
Free-form, form finding and anisotropic grid shell
p. 966-876The new geometrical developments open new perspectives for free-form design, making it possible to escape from planar triangular or quadrilateral discretizations. Recent advances in theory algorithms allow for the discretization of any surface using only single curvature panels thus allowing the realisation of smooth double curvature glazed envelops of any form.
Grid shell structures usually present a nearly in plane uniform behaviour, but previous
realisations have shown that grid shells can be designed also according to an anisotropic inplane arrangement. The control of principal direction and the fine tuning of the stiffness of the different structural elements (arcs, cables etc.) is a tool for adjusting the form-finding thus controlling the resulting geometry. Moreover, the form-finding can also be performed without researching a constant stress (self weight); in this case an even wider range of forms become possible.
These new geometrical and structural approaches have been coupled together and tested in re-designing, as a case study, the glazed roof of the Neumunster Abbey in Luxembourg. Such approach allowed for the conception of an efficient structure supporting a smooth double curvature glass skin, made out of only single curvature panels, perfectly coherent with the perimeter of the courtyard i.e. matching all the edges without any gaps.Baldassini, N.; Raynaud, J. (2010). Free-form, form finding and anisotropic grid shell. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/696
North, South, East and West: The Environmental Approach to Transparent Design
Architecture has always been interested in transparency but this characteristic hasstrong implications for energy performance. For many years architecture hasneglected this factor but today, in a time when society has developed an awarenessof the carbon footprint, architecture must restructure its approach and process.Transparency is still possible but its implications must be taken into considerationfrom the very beginning of the process: when façades are designed with respectsolar exposure and the advantages of internal natural ventilation, transparencybecomes sustainable in terms of energy balance in addition to contributing toarchitectural expression
Benthic foraminiferal record of paleoenvironmental changes in the Langhian St. Peter’s Pool section (Malta Island)
Elementos conceptuales y metodolĂłgicos para la evaluaciĂłn de impactos ambientales acumulativos (eiaac) en bosques subtropicales : el caso del este de salta, argentina
163-178Northern Argentina experienced an unprecedented deforestation rate of xerophitic forests as a consequence of agricultural expansion. In the Province of Salta, 26 percent of the forest were removed between 1977 and 2008. At the end of 2007, just before the No. 26331 Law of Native Forest Protection was voted by the Congress, the highest annual rate of deforestation was registered, reaching a value of 2.1 percent. Regarding this situation, indigenous people of Eastern Salta along with the "criollos" (local small ranchers) appealed to the National Supreme Court of Justice for legal protection. The Court requested the province to elaborate a Cumulative Environmental Effects Assessment (CEEA) regarding the process of logging and deforestation in four departments of Salta Province (San MartĂn, Rivadavia, Santa Victoria, and Orán). The aim of this work is to present a conceptual framework to conduct a CEEA in eastern Salta and to present the evidences and existing methodologies to characterize the impacts of deforestation. The conceptual framework suggested depends on the quantitative characterization of the changes in the provision level of key ecosystem services as a function of the stress and/or disturbance level (in this case deforestation). Based on the literature and our own data, the effects of deforestation on four key ecosystem services have been assessed: C dynamics, energy balance and greenhouse gases emissions, water dynamics and landscape structure. Deforestation produced emissions of 2000 t of CH 4, 200 t of N 2O, above 20 Gg of C/year, a 1.1 watt/m2 reduction in reflected radiation and 4400 TJ radiative energy emissions caused by deforestation fires, increases in the risk of soil salinization and landscape fragmentation. Considering these aspects of the structure and functioning of the ecosystems provides objective elements to evaluate management alternatives and to elaborate monitoring programmes. To consider such management and monitoring alternatives arises technical challenges but also institutional and political ones
Adherence issues related to sublingual immunotherapy as perceived by allergists
Objectives: Sublingual immunotherapy (SLIT) is a viable alternative to subcutaneous immunotherapy to treat allergic rhinitis and asthma, and is widely used in clinical practice in many European countries. The clinical efficacy of SLIT has been established in a number of clinical trials and meta-analyses. However, because SLIT is self-administered by patients without medical supervision, the degree of patient adherence with treatment is still a concern. The objective of this study was to evaluate the perception by allergists of issues related to SLIT adherence. Methods: We performed a questionnaire-based survey of 296 Italian allergists, based on the adherence issues known from previous studies. The perception of importance of each item was assessed by a VAS scale ranging from 0 to 10. Results: Patient perception of clinical efficacy was considered the most important factor (ranked 1 by 54% of allergists), followed by the possibility of reimbursement (ranked 1 by 34%), and by the absence of side effects (ranked 1 by 21%). Patient education, regular follow-up, and ease of use of SLIT were ranked first by less than 20% of allergists. Conclusion: These findings indicate that clinical efficacy, cost, and side effects are perceived as the major issues influencing patient adherence to SLIT, and that further improvement of adherence is likely to be achieved by improving the patient information provided by prescribers. © 2010 Scurati et al, publisher and licensee Dove Medical Press Ltd
Grid Shells
Con il termine di gusci a griglia (Grid Shells in inglese o Gitterschale in tedesco) si indicano quelle coperture costituite da una trama sottile di aste metalliche organizzate su superfici a doppia o semplice curvatura mediante maglie quadrangolari o triangolari. La struttura metallica è autoportante, indipendentemente dal manto di copertura il quale è sistematicamente costituito da lastre di vetro. La trasparenza e l’effetto di filigrana sono le caratteristiche peculiari di queste coperture e la loro esaltazione presuppone necessariamente un processo molto spinto di ottimizzazione della leggerezza strutturale la quale, a sua volta, richiede una accurata, non arbitraria, ricerca della forma
A framework for the optimisation of glazed gridshells in the early design stage under structural and energy-based criteria
While it is of primary importance to deliver high performance architecture within constraints of time and money, the integration between structural and energy-based aspects presents significant challenges for the organisation of the design process, especially in the early stages. In the case of complex envelopes, such as glazed gridshells, these engineering-related aspects should be considered from multiple points of view from the very beginning of the concept development, exploiting the potential conflicts between architects and engineers to let creative solutions emerge, and thus avoiding expensive and time-consuming design modifications downstream. This paper aims to define the framework required to integrate a multi-objective optimisation capable of combining such aspects into an integrated flow of information. Such an integrated analysis presents difficulties because, in the early design phases, conceptual changes happen faster than computational capacity; so, to overcome this obstacle it is necessary to define an iterative flow of information between structural and energy-based procedures, while at the same time taking into account the aesthetic requirements. This particular flow not only guarantees a correct passage of technical data among different software tools, but it also allows for a better communication and comprehension of information between diverse actors, such as architects and engineers. Based on this specific plan, a conceptual framework for optimising gridshells under structural, geometrical and energy-based criteria is developed and presented. The final goal of such a procedure is not, clearly, to replace the designer, but to give guidance to transform potential conflict into creative discussion and improve the efficiency of the later phases of the design process
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