Performance-based selection of sustainable construction solutions for external walls

This research is focused on the integration of sustainability and functional performance in architecture. While having an important contribution in terms of environmental impact, construction solutions also play a significant role in the reduction of energy use during the use phase of buildings. Therefore a careful, although simple, analysis of construction solutions integrating environmental and functional performance is needed to support the decision process in architectural design. A simplified methodology, using an environmental indicator and an energy-related functional indicator is implemented to assess how a set of construction solutions for external walls would perform in face of different objectives. The environmental indicator is obtained through the aggregation of the individual normalized values for the embodied energy and the carbon footprint. The functional indicator characterizes the energy performance of the wall, by aggregating the individual normalized values of the heat transfer coefficient and the net superficial thermal mass. These indicators are then integrated in a final weighted index to allow for a straightforward, yet effective understanding of the environmental impact of functional construction solutions. The set of construction solutions comprises different materials for cavity as well as single walls that are common in the building construction sector: ceramic brick masonries, reinforced concrete, mortar render and plasterboard as internal coating, synthetic or natural materials applied in two thicknesses for thermal insulation. Different combinations of these materials form the set of 90 heavyweight external walls that were calculated. Results show that it is possible to select construction solutions with a good environmental and functional performance. There is however a conflict between the objectives of reducing embodied environmental impact and increasing thermal inertia. This later may be an important comfort factor in the cooling season in residential architecture. The proposed methodology can be a comprehensive support tool to architects at the moment of selecting construction solutions, so that the principles of a sustainable construction are increasingly becoming a reality in architectural design.info:eu-repo/semantics/publishedVersio

Análise multicritério das técnicas de reforço locais: aplicação ao frontal de edifícios Pombalinos

As dinâmicas da reabilitação do património Pombalino em Lisboa (1755-1880) envolvem três macro-fatores interdependentes: i) o artefacto histórico; ii) os proprietários e utilizadores; iii) os agentes especializados. A dicotomia entre a integração e a integralidade do Património cultural (PC) deriva das diferentes atribuições de valor (cultural, histórico, funcional, económico) ao edifício histórico e da coexistência de objetivos contraditórios. De facto, o domínio da reutilização e da reabilitação dos imóveis históricos (na qual se pode incluir o reforço estrutural) é marcado pela complexidade na seleção das soluções de intervenção, de projeto e técnicas. Este artigo aborda o estudo comparativo in itinere das técnicas de reforço da parede mista (frontal) através de métodos de análise de decisão multicritério (MCDA). O estudo visa propor um modelo de seleção das atuais técnicas de reforço utilizando como critérios a compatibilidade material, a autenticidade arquitectónica e estrutural e a perda de material original. Os critérios de avaliação das práticas de reforço estrutural e as combinações das variantes de reforço são brevemente discutidos. Salienta-se que a reflexão sobre o impacto das intervenções no património histórico e a necessidade de introduzir transparência no processo decisório representam prioridades no cenário contemporâneo lisboeta, bem como no contexto internacional.info:eu-repo/semantics/publishedVersio

Gaiola vs Borbone system: a comparison between 18th Century anti-seismic case studies

This article briefly discusses the seismic-resistant heritage of the 18th century, circumscribed in Lisbon's Baixa Pombalina (post 1755) and case baraccate of Southern Italy (post 1783).A comparison of these anti-seismic systems is discussed through the architectural principles and the mechanical behavior. It is shown that, despite the wide diversity of cases and the different geo-historical conditioning, both systems arise from an intuition of the compound seismic efficiency, the typical pragmatism of the enlightenment period and an interpretation of the classic composition code.Two specific case studies, a private building in Baixa Pombalina (Lisbon) and the Bishop's Palace of Mileto (Calabria region) are compared. We briefly analyze: (i) configuration and structural principles; (ii) characteristics of the materials; and (iii) seismic behavior.A standardized spatial morphology closely linked to traditional construction techniques positively determines the seismic response and it is one of the key common factors in this heritage to be preserved.In both cases, the architectural and structural choices are crucial to the seismic response of the building and must be respected as an identity of a specific technical knowledge. Moreover, this materiality represents a historical continuity of the community's memory that requires transdisciplinary, critical understanding, and preservation.info:eu-repo/semantics/submittedVersio

Fault detection in the Tennessee Eastman benchmark process using dynamic principal components analysis based on decorrelated residuals (DPCA-DR)

Current multivariate control charts for monitoring large scale industrial processes are typically based on latent variable models, such as principal component analysis (PCA) or its dynamic counterpart when variables present auto-correlation (DPCA). In fact, it is usually considered that, under such conditions, DPCA is capable to effectively deal with both the cross- and auto-correlated nature of data. However, it can easily be verified that the resulting monitoring statistics (T2 and Q, also referred by SPE) still present significant auto-correlation. To handle this issue, a set of multivariate statistics based on DPCA and on the generation of decorrelated residuals were developed, that present low auto-correlation levels, and therefore are better positioned to implement SPC in a more consistent and stable way (DPCA-DR). The monitoring performance of these statistics was compared with that from other alternative methodologies for the well-known Tennessee Eastman process benchmark. From this study, we conclude that the proposed statistics had the highest detection rates on 19 out of the 21 faults, and are statistically superior to their PCA and DPCA counterparts. DPCA-DR statistics also presented lower auto-correlation, which simplifies their implementation and improves their reliability

The MACBETH approach to evaluate strategies for the conservation of architectural heritage

The critical appraisal of alternative strategies in conservation projects of historical buildings is often a complex task that requires balancing a variety of conflicting criteria related to multiple stakeholders and requirements. The main purpose of this study is to make the case for the use of multi-criteria decision analysis in supporting a consistent and transparent, inter-disciplinary decision-making process, using the case study of repair and strengthening techniques of timber frame walls. The MACBETH approach is particularly suitable in this field of research since the judgment procedures allow for an appropriate analysis of intangible values such as the ones at stake in architectural heritage.info:eu-repo/semantics/acceptedVersio

Exploring viral infection using single-cell sequencing.

Single-cell sequencing (SCS) has emerged as a valuable tool to study cellular heterogeneity in diverse fields, including virology. By studying the viral and cellular genome and/or transcriptome, the dynamics of viral infection can be investigated at single cell level. Most studies have explored the impact of cell-to-cell variation on the viral life cycle from the point of view of the virus, by analyzing viral sequences, and from the point of view of the cell, mainly by analyzing the cellular host transcriptome. In this review, we will focus on recent studies that use single-cell sequencing to explore viral diversity and cell variability in response to viral replication

Back and forth between social and technical: A collective experience in the transdisciplinary making of sustainable artifacts

From Fablabs to Hackerspaces we now see the emergence of promising venues following open and collaborative frameworks mixing multiple types of knowledge and skills. They are supported by an accessibility of additive and subtractive fabrication machines, open source software and hardware, and many other personal manufacturing tools ushering in low-cost and DiY trends, to create anything from micro controllers and apps, to wearables and tangible devices in the hype of highly anticipated Internets of Everything. And, from academia, business or industry, to lay individuals or pro-amateurs, all are expected to benefit from these spaces and their material and conceptual platforms, as everyone here is ultimately encouraged to learn how to produce, use, share, copy and improve assorted objects or systems. This presentation will focus on a collective experience of learning and making in one of these spaces, by addressing both the final outputs, and the processes that led to, and occurred during STTF2013 Summer School “Sustainable Technologies and Transdisciplinary Futures: From Collaborative Design to Digital Fabrication” (http://sttf2013.iscte-iul.pt/), jointly organized by VitruviusFabLab-IUL (Digital Fabrication Laboratory) and CIES-IUL (Centre for Research and Studies in Sociology) of ISCTE-IUL (University Institute of Lisbon), with partners as the JRC-EC, and altLab - Lisbon’s hackerspace. Gathering graduate students, researchers, and professionals from STS, Design, Social Sciences, Humanities, Architecture, Computer Science, Communication and Management, the challenge was to engage all participants within a transdisciplinary collaboration model based on working groups, while generating sociotechnical debates and tangible outputs that could meet concrete social needs. From generative design, qualitative social data analysis, or ethical debates, to digital fabrication, physical computing, or open production exercises, STTF2013 participants worked in sociotechnical processes of discussion, design, and fabrication of environmentally, economically, socially and culturally sustainable prototypes for distinct social groups that pass by, use, or live near two Lisbon's waterfront territories, Cais do Sodré and Cacilhas, considering issues as cradle to cradle cycles, conviviality, empowerment, modularity, transparency, etc. Devising these prototypes through such processes allowed for each development stage to be reflected upon, worked, decided and envisioned through a broad spectrum of disciplinary views. And its particular mix of social and technical backgrounds and skills, with citizen needs and local knowledge, resulted in several routes for designing, producing, distributing, and using more appropriate artifacts. But adding issues or people often apart does not only allow methodological sharing or collective work, as it also requires careful attention to divergent goals and backgrounds, dissimilar learning needs, conflicting notions of cooperation, or disparate abilities to use available technical or social tools. The same logic that enables a transdisciplinary creation of artifacts from start to end, also provides insights on the most challenging aspects of mingling conceptual and material processes from social and technical fields in these emerging spaces. An experience such as STTF2013 present us the opportunity to rethink both the embedding of social questions and their connected stakeholders within technological outputs, and the paths that should precede some of the novel heuristic and fabrication frameworks of our nearest futures.info:eu-repo/semantics/acceptedVersio

A methodology to qualitatively select upcycled building materials from urban and industrial waste

The rising concern about climate change and other challenges faced by the planet led society to look for different design solutions and approaches towards a more balanced relationship between the built and natural environment. The circular economy is an effective alternative to the linear economic model inspired by natural metabolisms and the circular use of resources. This research explores how innovative strategies can be integrated for evaluating local urban and industrial wastes into sustainable building materials. A literature review is conducted focusing on circular design strategies, re-use, recycle, and waste transformation processes. Then, a methodology for the selection of upcycled and re-used building materials is developed based on Ashby’s method. A total of thirty-five types of partition walls, which include plastic, wood, paper, steel, aluminium, and agricultural wastes, are evaluated using a multi-criteria decision aid (M-MACBETH). Among these solutions, ten types of walls show high-performance thermal and sound isolation, fourteen types are effective for coating, and two exhibit structural reliability. Regardless of their functional limitations, the proposed solutions based on waste materials bear great potential within the construction industry.info:eu-repo/semantics/publishedVersio

Testing the Freeze/Thaw Cycles in Lime Mortar

2nd Historic Mortars Conference - HMC 2010 and RILEM TC 203-RHM Final Workshop, Prague, September 2010The purpose of this study is to evaluate the behaviour of lime mortars in cold climates, namely by the effect of freeze/thaw cycles. Twelve compositions of mortars were prepared by varying the type of binder (air lime, hydraulic lime and air lime plus cement) and the grain size distribution of the sand and by including an air entraining agent. Tests, including the open porosity, mechanical strength and resistance to freeze/thaw cycles, were conducted in order to evaluate the performance of lime mortars in cold climates. The analysis of results allowed the determination of relevant conclusions about the influence of the grain size of aggregate, the use of an air entraining agent and the behaviour of mortars with different types of binder to be drawn. The open porosity depends mainly on the granulometry of sands while the mechanical strength is correlated with the binder type. These two characteristics have a great influence on the strength of mortar during freeze/thaw cycles and consequently on their performance in cold climates