Prediction of the acoustic insulation of a prefabricated wooden-based system for collective buildings

Using wood, a renewable, carbon sink material with outstanding thermal properties associated with the prefabrication process and its benefits, a construction system for multi-storey multifamily buildings based on prefabricated wooden panels was developed to act as a tool for meeting the national carbon neutrality targets. It will contribute to the promotion of increasingly sustainable cities that optimise the use of materials and rely on highly energy-efficient buildings. This sustainable alternative to conventional construction materials was designed to comply with the Portuguese needs, regulations, and regulatory requirements regarding construction, structural, functional, and logistics demands. As the acoustic behaviour of wooden buildings is a sensitive subject due to the wood's lightweight and poor insulation performance for low-frequency sounds, this work aims to analyse the panels regarding their acoustic behaviour through INSUL software. The predictions showed favourable results for airborne insulation and partially favourable for impact sound insulation.This work was supported by national funds through FCT – Fundação para a Ciência e a Tecnologia, within the scope of a Ph.D. scholarship (PRT/BD/152841/2021) granted by MIT Portugal Program to the first author

Sistema construtivo em painéis modulares para edifícios coletivos com estrutura de madeira

Dissertação de mestrado em Construção e Reabilitação SustentáveisDado o alarmante cenário climático que revelou a urgência em reverter os padrões de consumo globais, alcançar a neutralidade carbónica até 2050 torna-se uma meta essencial para limitar o aquecimento global. Neste contexto, a construção em madeira assume um papel inovador e promissor na prossecução deste objetivo por parte do setor da construção. No entanto, existem lacunas de conhecimento substanciais acerca da utilização da madeira em edifícios que são decisivas na limitação do uso estrutural da madeira e que têm fomentado a disparidade dos seus avanços e incentivos comparativamente às tecnologias em betão e em aço. Este trabalho visa não apenas preencher estas lacunas de conhecimento, promovendo a maior aceitação e expansão ao uso da madeira, como oferecer uma solução sustentável alternativa aos materiais convencionais como ferramenta para o cumprimento dos objetivos nacionais de neutralidade carbónica e para o fortalecimento da bioeconomia local através do uso dos recursos florestais locais. A partir do uso da madeira, um material renovável, reservatório de carbono e com excelentes propriedades térmicas, em associação ao processo de pré-fabricação e seus benefícios, esta pesquisa propõe o desenvolvimento de um sistema construtivo para edifícios até 5 pisos recorrendo a painéis pré-fabricados de madeira com características concebidas e validadas para a aplicação bem sucedida no contexto português. Neste trabalho, o sistema construtivo é projetado, avaliado e otimizado em termos estruturais, funcionais e logísticos. São discutidas as estratégias de conceção de estruturas de madeira, bem como as necessidades e requisitos inerentes ao contexto português, a serem considerados na elaboração do sistema construtivo. Em seguida, definem-se as regras de conceção identificadas para os painéis, pormenorizando-os segundo cada camada constituinte e as suas propriedades. Os painéis são, então, avaliados quanto ao coeficiente de transmissão térmica (e proteção à humidade, para os painéis de fachada e cobertura) através do software Ubakus, quanto ao índice de redução sonora a sons aéreos e de percussão através do software INSUL e quanto à resistência e reação ao fogo. Através de um caso de estudo desenvolvido em parceria com a empresa PORTILAME - Engenharia e Madeira, Lda., avalia-se o comportamento estrutural dos componentes dos painéis para um edifício de 4 pisos através dos software RFEM e Calculatis.Given the climate scenario that revealed the urgency of reversing global consumption patterns, achieving carbon neutrality by 2050 becomes an essential target in limiting global warming. In this context, building up in wood plays an innovative and promising role in pursuing this goal by the construction sector. However, there are substantial knowledge gaps about using wood in buildings that are decisive in depriving the wood structural use and that have fostered the disparity of its advances and incentives regarding concrete and steel technologies. This work aims not only to fill these knowledge gaps, promoting greater acceptance and expansion of the use of wood, but also to promote a sustainable alternative solution to conventional materials, namely concrete and steel, as a tool for meeting the national carbon neutrality targets and for strengthening the local bioeconomy through the use of native forest resources. By using wood, a renewable, carbon sink material with excellent thermal properties in association with the prefabrication process and its benefits, this research proposes the development of a construction system for up to 5-storey buildings based on prefabricated wooden panels for successful application in the Portuguese context. In this work, the constructive system is designed, evaluated and optimized in structural, functional and logistical terms. Strategies for designing wooden structures are discussed, as well as the needs and requirements inherent in the Portuguese context, to be considered in the design of the construction system. Then, the design rules for the panels are defined and detailed according to each component layer and its properties. The panels are then evaluated for the coefficient of thermal transmission (and moisture protection, for the facade and roof panels) using the Ubakus software, for the noise reduction index to aerial and percussion sounds using the INSUL software and resistance and reaction to fire. Through a case study developed in partnership with the company PORTILAME - Engenharia e Madeira, Lda., the structural behavior of the components of the panels for a 4-storey building is evaluated using RFEM and Calculatis software

The wood moisture factor on the biological deterioration of wooden structures

With sustainability as a growing concern, the rehabilitation of buildings arises as one of the main forms of support for the construction sector. Rehabilitation, in comparison with new construction, is seen as a path to minimize the negative impacts of this activity by reducing, for example, the energy consumption of buildings and its consequent impact on energy production (still meeting the current needs for comfort) and the extraction of raw materials. Wood has a high potential for numerous purposes, also, it is a natural, renewable, and sustainable resource, presenting itself as a promising construction material with enormous importance for the bio-based economy. However, despite being a traditional material, reliable service life prediction of wooden structures continues to be a challenge. Like other biobased materials, wood can be subject to biological deterioration by fungi and insects. The biological agents, when combined with favourable conditions (e.g., temperature, air relative humidity, wood moisture content, etc.), can lead to simply aesthetic damage, reduction in indoor air quality, or compromising its resistant load capacity, creating a risk to human health and safety, in addition to an increase of repair and maintenance costs. Many approaches consider wood moisture content as the key factor to control the activation of the decay process, since fungal colonization of wood requires a minimum moisture content of around 20%. Moreover, though subterranean termites (one of the most damaging wood insects) are able to infest dry wood, contact to moisture is fundamental for effective installation of the colonies. This paper addresses moisture as a conditioning factor in the degradation of wood in construction. The role of water on the development of the biodeterioration processes, the transport of water within wooden elements, as well as how the current normative references address the issue are discussed. Finally, this work presents some of the exiting methods for continuous moisture content monitoring systems that, associated with regular maintenance, can be an alternative to chemical treatments, increasingly limited due to current environmental legislation- (undefined

Mechanical characterization of Iroko wood using small specimens

Despite their favorable physical and mechanical properties for structural use, tropical woods, such as Iroko (Milicia excelsa), present knowledge gaps to be filled mainly about their mechanical characterization, which currently limit their use or result in under- or overdimensioned structural elements. Visual classification, one of the most used methods for characterizing wood, is inaccurate in the case of Iroko due to the wide variety of geographical locations in which this species can be found. In addition, mechanical characterization using test pieces with structural dimensions leads to high and impractical costs. In this context, this study aims to verify the mechanical properties of Iroko (imported from the Republic of the Congo) from small size specimens, a process that is currently standardized only for softwoods, and to verify the correlation of different properties through bending properties and ultrasound tests. Prior to the bending tests, the speed of propagation of ultrasonic waves was measured using the direct method. The results obtained show a good correlation between density and bending properties and the velocity of propagation of ultrasonic waves

Assessment of the density loss in anobiid infested pine using X-ray micro-computed tomography

The present study aims at evaluating the impact of anobiid damage on pine timber elements. Anobiid attack produces a diffuse damage of the elements with a set of tunnels in random directions and sizes, thus confusing quantification. Therefore, a method was developed based on X-ray micro-computed tomography (μ-XCT) to obtain, for naturally infested timber samples, an empirical correlation between lost material percentage (consumed by beetles) and timber apparent density (original, before degradation—OTD and residual, after degradation—RTD). The quantified density loss can then be used in further assessment of the structure. The results of the tests performed showed high correlation between original apparent density and lost material percentage (r2 = 0.60) and between residual apparent density and lost material percentage (r2 = 0.83), which confirms μ-XCT as a valuable tool to the required quantification. The loss of density results can be further applied on the definition of an assessment method for the evaluation of the residual strength of anobiids infested timber, thus contributing to reducing unnecessary replacement. The optimized procedure of the μ-XCT study for infested Maritime pine (Pinus pinaster) is presented and discussed in this article.The authors acknowledge the support given by Portuguese Foundation for Science and Technology (FCT) within research projects: PTDC/EPH-PAT/4684/2014 (DB-HERITAGE), PTDC/ECM-EST/1072/2014 (Pro-Timber), Pest-OE/CTE/UI4028/2011 (CERENA) and UIDB/ 04625/2020 (CERIS)

The potential of CEB reinforced masonry technology for (re)construction in the context of disasters

More than 226 million people are affected by some type of disaster every year in various dimensions of human life, both in the short and long term. In this context, housing provision plays a leading role when it comes to basic needs and the choice of construction technologies and materials are determinant for a well-succeeded housing provision process. This work aims to analyze the viability of reinforced masonry technology with cement-stabilized compressed earth blocks as an alternative for the (re)construction process in situations that involve disaster risk reduction (DRR). To address this issue, a discussion from the literature and the main results obtained during the investigations carried out within the scope of the Simple Housing Solution (SHS) Project are presented. In the sequence, analyses are performed under United Nations Development Program/International Recovery Platform sustainability recommendations: environmental, technical, financial and socio-organizational aspects. It is concluded that the technology of Compressed Earth Blocks (CEBs) reinforced structural masonry has a high potential to be successfully applied in DRR situations, especially when associated with the community construction system in a joint effort.The SHS Project counted on financial support from Fundação Carlos Chagas Filho de AmparoàPesquisado Estado do Rio de Janeiro (FAPERJ) during Phase 1 (2009–2012), grant number E-26/190.212/2009

Impactos da gravidez na saúde mental das adolescentes: Impacts of pregnancy on the mental health of adolescents

Introdução: A experiência da gravidez não planejada traz sentimento de perda, podendo repercutir negativamente na saúde física e mental das jovens, principalmente por alterarem sua imagem corporal. Objetivo geral: Identificar os impactos da gravidez na adolescência e conhecer os fatores de risco para o desenvolvimento de transtornos na saúde mental das adolescentes.  Método: Trata-se de uma revisão integrativa teve como critérios de inclusão ensaios clínicos, ensaio randomizado controlado aleatório, metanálises, pesquisas qualitativas e estudos de prevalência publicados entre os anos de 2017 e 2022 nos idiomas português e inglês, excluídos estudos incompletos, resumos, livros, capítulos de livros, teses, dissertações, trabalhos de conclusão de curso e revisões de literatura. As buscas por estudos foram realizadas nas bases de dados PubMed, Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS) e na Base de Dados de Enfermagem (BDENF), sendo selecionados 6 estudos para compor esta revisão. Resultados: Foi identificado que o status socioeconômico e o uso de substâncias estão ligados à gravidez na adolescência, sendo fatores de risco para o desenvolvimento de problemas relacionados à saúde mental. Discussão: As adolescentes mais vulneráveis a uma gravidez na adolescência sofreram algum tipo de negligência na infância e maior parte relatam ter sofrido abuso sexual, sendo evidente que o apoio social é importante para a adolescente vivenciar a maternidade com estabilidade. Conclusão: O abuso pode impactar negativamente na saúde psicológica e reprodutiva das adolescentes, destacando-se a importância de pesquisas que tenham como foco a vulnerabilidade de adolescentes grávidas e dos impactos na saúde mental.&nbsp

SHS (Simple Housing Solution) Methodology: Community (Re) Building in Critical Situations

The SHS - Simple Housing Solution - methodology helps to facilitate the process of (re) construction in critical situations (post-disaster, post-conflict, refugee settlement, relocation of populations from risk areas, among others). It was conceived with the philosophy of gathering basic knowledge that can be useful in the (re) construction of housing units and basic collective equipment (such as schools, health clinics), in a joint effort (community working system), using low cost constructive technologies. The idea is to help communities that are victims of disasters and conflicts to better organize their own recovery, and provide help via the guidance and supervision of qualified technical assistants (engineers and / or architects) who can be hired by the local community, government or NGOs, for these purposes. This paper aims to present the Simple Housing Solution methodology and the main results of SHS Project, focusing on investigations related to the construction technology of partially reinforced masonry with soil-cement bricks. Currently, new research is being conducted to improve the existing model of residency for critical situations, seeking to broaden its working range. After the current phase is concluded, the next step will be the construction of a prototype house in natural scale, on a seismic platform, to study the effects of simulated seismic actions on the house. In order to achieve this task, financial support is sought from sponsors, as well as technical cooperation with LNEC - National Laboratory of Civil Engineering, in Portugal. Keywords: Disaster recovery, housing recovery, conflict recovery, refugee settlements, risk managemen

Citogenotoxic response of juvenile cobia Rachycentron canadum (Linnaeus, 1766) reared in two different systems

A produção da aquicultura vem crescendo em todo o mundo e o cultivo de peixes marinhos no Brasil é ainda muito recente. Condições intensivas de aquicultura podem causar estresse fisiológico ao organismo do cultivo, o que pode ser avaliado por biomarcadores citogenotóxicos. O objetivo desse estudo foi avaliar o efeito genotóxico das condições de cultivo nos eritrócitos de juvenis de beijupirás Rachycentron canadum usando o ensaio cometa e o ensaio de micronúcleo e outras anormalidades nucleares. Juvenis de beijupirá foram cultivados por 13 semanas em um tanque indoor com circulação aberta de água e em um tanque-rede. O ensaio comera e o ensaio de anormalidades nucleares detectaram um maior dano ao DNA e uma maior frequência de anormalidades nucleares em eritrócitos de peixes cultivados no tanque indoor. Results showed that two methods are complementary. Além disso, beijupirás foram injetados com β-naftoflavona (BNF) nas concentrações de 2mgkg-1 e 10mgkg-1 em condições controladas de laboratório e mantidos por 7 dias em tanques separados para um melhor entendimento dos mecanismos de resposta dessa espécie a uma substância tóxica. O ensaio cometa não detectou nenhuma diferença significativa entre os peixes injetados com BNF e os da condição controle, enquanto que o ensaio das anormalidades nucleares apresentaram diferenças significativas entre peixes injetados com BNF e os do controle. Os danos identificados pelo ensaio cometa são quebras reparáveis na fita do DNA, enquanto que as anormalidades nucleares são permanentes. Possivelmente, o período de de manutenção dos peixes nos tanques após a injeção foi suficiente para limpar a BNF dos organismos e reparar as quebras na fita do DNA. Como os beijupirás parecem responder muito bem a compostos genotóxicos, o ensaio cometa e o ensaio de anormalidades nucleares podem ser ferramentas úteis para monitorar as condições de cultivo.Aquaculture production is continuously growing worldwide, and marine fish farming in Brazil is still in its infancy. Intensive farming conditions may cause physiological stress to the cultured organism, which can be evaluated by citogenotoxic biomarkers. The aim of this study was to assess the genotoxic effect of the rearing conditions in red blood cells of juvenile cobia Rachycentron canadum by using comet assay and micronucleus and other nuclear abnormalities assay. Juvenile cobia were reared for 13 weeks in indoor tank with open water circulation and in near shore cage. The comet assay and the nuclear abnormalities assay detected higher DNA damage and higher nuclear abnormalities frequency in erythrocytes of fish reared in the indoor tank. Results showed that two methods are complementary. Additionally, cobia were injected with ß-naphthoflavone (BNF) at concentrations of 2mgkg-1 and 10mgkg-1 in laboratory controlled conditions, and maintained for 7 days in separate tanks to better understand the response mechanisms of this species to a toxic substance. The comet assay did not detect any significant differences between BNF injected and control fish, whereas nuclear abnormalities assay showed significant differences between BNF injected and the control groups. The damages identified by the comet assay are repairable breaks in the DNA strands, whereas nuclear abnormalities may be permanent. Possibly the period of maintenance after injection was enough to clean BNF from the organisms and to repair the breaks in the DNA strands. As cobia seems to respond very well to genotoxic elements, comet assay and nuclear abnormalities assay would be useful tools to monitor farming conditions

GENOTOXICITY OF SHALLOW WATERS NEAR THE BRAZILIAN ANTARCTIC STATION "COMANDANTE FERRAZ" (EACF), ADMIRALTY BAY, KING GEORGE ISLAND, ANTARCTICA

Series of biomonitoring surveys were undertaken weekly in February 2012 to investigate the genotoxicity of the shallow waters around the Brazilian Antarctic Station "Comandante Ferraz" (EACF). The comet assay was applied to assess the damage to the DNA of hemocytes of the crustacean amphipods Gondogeneia antarctica collected from shallow waters near the Fuel Tanks (FT) and Sewage Treatment Outflow (STO) of the research station, and compare it to the DNA damage of animals from Punta Plaza (PPL) and Yellow Point (YP), natural sites far from the EACF defined as experimental controls. The damage to the DNA of hemocytes of G. antarctica was not significantly different between sites in the biomonitoring surveys I and II. In survey III, the damage to the DNA of animals captured in shallow waters near the Fuel Tanks (FT) and Sewage Treatment Outflow (STO) was significantly higher than that of the control site of Punta Plaza (PPL). In biomonitoring survey IV, a significant difference was detected only between the FT and PPL sites. Results demonstrated that the shallow waters in front of the station may be genotoxic and that the comet assay and hemocytes of G. antarctica are useful tools for assessing genotoxicity in biomonitoring studies of Antarctic marine coastal habitats.Séries de biomonitoramentos foram executadas semanalmente, durante o mês de fevereiro de 2012, para se investigar a genotoxicidade de ambientes costeiros rasos no entorno da Estação Antártica "Comandante Ferraz (EACF). O ensaio cometa foi aplicado para se avaliar os danos ao DNA hemocitário de crustáceos anfípodes Gondogeneia antarctica coletados em áreas rasas próximas aos tanques de armazenamento de combustível (FT) e saída de efluentes da estação de tratamento de esgoto (STO), em comparação aos danos ao DNA de animais provenientes de Punta Plaza (PPL) e Yellow Point (YP), locais naturais distantes da EACF, definidos como controles experimentais. O dano ao DNA hemocitário de G. antarctica não foi significativamente diferente entre locais, nos biomonitoramentos I e II. No biomonitoramento III, o dano ao DNA de animais coletados em águas rasas próximas aos tanques de combustível e saída de efluentes de esgoto foi significativamente maior do que aquele do controle de Punta Plaza. No biomonitoramento IV, a diferença foi significativa somente entre os locais dos tanques de combustível e de Punta Plaza. Estes resultados demonstram que a contaminação das águas em frente à EACF pode ser genotóxica e que, tanto o ensaio cometa quanto os hemócitos de G. antarctica são ferramentas úteis na avaliação da genotoxicidade em estudos de biomonitoramento de habitats marinhos costeiros da Antártica