Characterization of agro-wastes to be used as aggregates for eco-efficient insulation boards

PD/BD/150579/2020This work derives from the awareness of the environmental impacts caused by the construction sector. Since building products are one of the main causes of this issue, the incremental use of local natural eco-friendly materials can moderate this problem, guaranteeing lower energy consumption for production and transport. Nowadays, research is increasingly focused on the possibility of using bio-wastes to produce several materials and products such as plasters, bricks, boards, binders and glues. They can secure both more sustainable building practices and contribute to solve the problems of disposal of wastes, another cause of the environmental impacts. The present work focuses on the characterization of some bio-wastes to assess their viability as aggregates for eco-efficient insulation boards. Knowing the properties of the raw materials allows making a more conscious choice of composite formulations according to the final requirements of the boards. For this reason, the bio-wastes from agricultural practices (agro-wastes) were studied individually. To evaluate their properties, the analysis was carried out according to RILEM Technical Committee 236-BBM, “Bio-aggregate-based building Materials” document, past literature studies and European Standards. The considered properties were loose bulk density, grain size distribution and thermal conductivity. Four agro-wastes were chosen: spent coffee grounds, grapes press waste, olives press waste and hazelnut shells. Maritime pine (Pinus pinaster Ait.) chips were included as control material. They have been considered both for their potential use to produce insulation composites and for their world production, focusing on Euro-Mediterranean countries. This region was chosen taking into account where the future research will be carried out and the advantages of employing local materials. In addition, buildings of Euro-Mediterranean countries have historically low insulation performance due to the mild climate; however, climate change and other factors have led to the recognition by the users of some periods of poor indoor hygrothermal comfort. The bibliographic research allowed identifying a gap as concerns the characterization of these agro-wastes. Both the testing methods and the properties of the considered materials are presented and discussed. In addition, the obtained results are compared with the ones of already studied materials, such as rice husk, hemp shiv and cork. Results show that the chosen materials do not have excellent insulating properties if considered individually but may probably be used to produce eco-efficient boards. The combination of them with other materials could guarantee building composites with good thermal insulation performances. The spent coffee ground differs greatly from the other bio-wastes and it seems to be more appropriate as a fine aggregate. Future research will deepen these studies and develop composites having adequate characteristics as insulation boards.publishersversionpublishe

Characterization tests for insulation boards made from corn cob and natural glues

In recent years there has been a growing interest in developing news solutions for more ecologic and efficient construction, including natural, renewable and local materials, thus contributing in the search for more efficient, economic and environmentally friendly construction. Several authors have assessed the possibility of using various agricultural sub products or wastes, as part of the effort of the scientific community to find alternative and more ecologic construction materials. Corn cob is an agricultural waste from a very important worldwide crop. Natural glues are made from natural materials, non-mineral, that can be used as such or after some modifications to achieve the behaviour and performance required. Two examples of these natural glues are casein and wheat flour-based glues that were used in the present study. Boards with different compositions were manufactured, having as variables the type of glue, the dimension of the corn cob particles and the features of the pressing process. The tests boards were characterized with physical and mechanical tests, such as thermal conductivity (λ) with a ISOMET 2104 and 60 mm diameter contact probe, density (ρ) based on EN 1602:2013, surface hardness (SH) with a PCE Shore A durometer, surface resistance (SR) with a PROCEQ PT pendular sclerometer, bending behaviour (σ) based on EN 12089:2013, compression behaviour (σ10) based on EN 826:2013 and resilience (R) based on EN 1094-1:2008, with a Zwick Rowell bending equipment with 2 kN and 50 kN load cells (Fig. 1), dynamic modulus of elasticity (Ed) with a Zeus Resonance Meter equipment (Fig. 5) based on NP EN 14146:2006 and water vapour permeability (δ) based on EN 12086:2013. The various boards produced were characterized according to the tests and the ones with the best results were C8_c8 (casein glue, grain size 2,38-4,76 mm, cold pressing for 8 hours), C8_c4 (casein glue, grain size 2,38-4,76 mm, cold pressing for 4 hours), F8_h0.5 (wheat flour glue, grain size 2,38-4,76 mm, hot pressing for 0,5 hours), FEV8_h0.5 (wheat flour, egg white and vinegar glue, grain size 2,38-4,76 mm, hot pressing for 0,5 hours) and FEVH68_c4 (wheat flour, egg white, vinegar and 6 g of sodium hydroxide glue, grain size 2,38-4,76 mm, cold pressing for 4 hours). Taking into account the various boards produced and respective test results the type of glue and the pressure and pressing time are very important factors which strongly influence the final product. The results obtained confirmed the initial hypotheses that these boards have potential as a thermal and, eventually, acoustic insulation material, to use as coating or intermediate layer on walls, floors or false ceilings. This type of board has a high mechanical resistance when compared with traditional insulating materials.The integrity of these boards seems to be maintained even in higher humidity environments. However, due to biological susceptibility and sensitivity to water, they would be more adequate for application in dry interior conditions.COST ACTION FP130

Influence of composition on physical performance and bio-susceptibility

This work was supported by Fundação para a Ciência e a Tecnologia (FCT) under DB-HERITAGE project (PTDC/EPH-PAT/4684/2014). The authors also acknowledge the EMBARRO Company for supplying the majority of the mortar materials and are grateful to Antonio Santos Silva, Miguel Teixeira, Sandra Noivo, Teresa Gonçalves and Vitor Silva for the support throughout the testing campaign. The support of COST Actions FP1303 “Performance of biobased building materials” and RILEM Technical Committees TCE, “Testing and Characterisation of Earth-based building materials and elements” and HDB, “Hygrothermal behaviour and Durability of Bio-aggregate based building materials”, are also acknowledged.An experimental campaign was developed to evaluate the properties of earth plastering mortars, not only at the level of workability and physic-mechanical performance but also their susceptibility for biological colonization. A ready-mixed earth mortar and several other mortars formulated with a raw clayish earth were produced. The influence of partial replacement of fine sand by a phase change material (PCM) and the addition of low amounts of oat fibres and hydrated air lime were assessed. The experimental campaign shows that the PCM completely changes the mortar workability, with a decrease on wet density. The addition of PCM and fibres decreases the bulk density and, consequently, increases the porosity of the mortars. The presence of PCM, fibres and air lime decreases the thermal conductivity. Earth mortars are susceptible to mould development, and the fibres or PCM seem to intensify their bio-susceptibility. A low addition of air lime increases pH and inhibits fungal growth though decreasing the mechanical properties. Mortars with PCM, fibres and air lime present a higher surface roughness in comparison to other mortars, including the ready-mixed earth mortar with fibres. Surface roughness was found to be an important factor influencing the level of colonization.authorsversionpublishe

Health educators and public health nurses: professional identities in the making

This is a study about São Paulo's health educators and public health nurses in the first half of the 20th century. These were occupations designed for women, who faced difficult challenges trying to demarcate a territory of decision and action that did not result solely from the medical profession´s benevolence toward them. The tools of historical sociology contributed, both theoretically and methodologically, to an appraisal of the relationships between institutions, power, and professional identities. Among the main conclusions, this article reveals the importance of the rising of a new professional field in health education and public health nursing. In addition, the work calls attention to the role played by the Rockefeller Foundation in opening up these new occupational tracks. The Foundation´s officers payed close attention to the setting of working conditions for the young professionals, helping them with human, technical, and financial resources.Este é um estudo sobre a história das educadoras sanitárias e das enfermeiras de saúde pública na primeira metade do século XX, em São Paulo. Tem por objetivo mostrar o desafio, às mulheres, de demarcar um território de decisões e atuação que não fosse simples poder delegável pela profissão médica. A sociologia histórica (no tocante às relações entre instituições, poder e identidades profissionais) proporcionou um instrumental teórico e metodológico para o presente trabalho. Entre as conclusões, destacamos a importância do surgimento de um novo campo profissional, relacionado à educação sanitária e à enfermagem de saúde pública. O texto destaca, brevemente, a participação da Fundação Rockefeller na organização do campo de saúde pública, uma vez que a Rockefeller apoiou a valorização do papel da mulher educadora e enfermeira em São Paulo, com recursos humanos e financeiros.17321

Bio-Wastes as Aggregates for Eco-Efficient Boards and Panels: Screening Tests of Physical Properties and Bio-Susceptibility

PD/BD/150579/2020 UIDB/04625/2020Screening tests were developed or adapted from RILEM recommendations, standards and past studies, and carried out to characterize some agro-industrial wastes and to assess their feasibility as aggregates for eco-efficient building composites. Spent coffee grounds, grape and olive press waste and hazelnut shells were used, as well as maritime pine chips as control material. Particle size distribution, loose bulk density, thermal conductivity and hygroscopicity properties were analysed. The selected bio-wastes did not show good thermal insulation properties if compared with some bio-wastes already studied and used for thermal insulation composites. Values of loose bulk density and thermal conductivity were between 325.6–550.5 kg/m3 and 0.078–0.107 W/(m·K); moisture buffering values higher than 2.0 g/(m2·%RH). Biological susceptibility to mould and termites were also tested, using not yet standardized methods. The low resistance to biological attack confirms one of the greatest drawbacks of using bio-wastes for building products. However, final products properties may be changed by adding other materials, pre-treatments of the wastes and the production process.publishersversionpublishe

Smart mobility: a survey

Internet of Things (IoT) describes a world where everyday objects are always connected to the Internet, allowing them to communicate and interact with each other. By connecting these everyday objects to the Internet and making them available everywhere at any time, IoT allows to remotely monitor, manage, and gather status information about them and their surrounding environment. IoT is a revolutionary concept that brought new experiences to everyday life and enabled Smart City initiatives all over the world. These initiatives are using a combination of technology paired with physical infrastructure and services, to improve people’s quality of life. One of the high priority domain to support the Smart City’s vision is the field of Smart Mobility. This paper reviews the current IoT approaches and concepts related to Smart Cities and Smart Mobility. In addition, it analyzes distinct features and numerous applications covering both Intelligent Transportation and Real Time Traffic Management Systems.info:eu-repo/semantics/publishedVersio

Assessment of different adhesives

Publisher Copyright: © 2023 The AuthorsLaboratory tests were carried out to evaluate the feasibility of producing boards or coating panels with good hygrothermal performance by using different agro-industrial wastes (grape and olive press wastes, hazelnut shells, spent coffee and pine) and adhesives (gypsum-based binder, sodium silicate solution and starch-based glue). Hygrothermal properties and resistance to mould growth, including the effect of citric acid, were evaluated. The results highlighted the benefits and drawbacks of each adhesive: the binder seems more adequate to produce bio-based plastering mortars than boards; the other adhesives seem efficient solutions to produce boards with good hygrothermal properties; for the natural glue the bio-susceptibility needs improvement.publishersversionpublishe

Eco-efficient boards with agro-industrial wastes – Assessment of different adhesives

Laboratory tests were carried out to evaluate the feasibility of producing boards or coating panels with good hygrothermal performance by using different agro-industrial wastes (grape and olive press wastes, hazelnut shells, spent coffee and pine) and adhesives (gypsum-based binder, sodium silicate solution and starch-based glue). Hygrothermal properties and resistance to mould growth, including the effect of citric acid, were evaluated. The results highlighted the benefits and drawbacks of each adhesive: the binder seems more adequate to produce bio-based plastering mortars than boards; the other adhesives seem efficient solutions to produce boards with good hygrothermal properties; for the natural glue the bio-susceptibility needs improvement.info:eu-repo/semantics/publishedVersio

Histórias de vida: o pioneirismo de Gilberto Freyre

The article attempts to show the importance of oral and life history as a data collection procedure in Gilberto Freyre’s social science. In his Ordem e Progresso, published in 1959, Freyre worked with oral narratives and written documents, collected in the 1930’s and 40’s, from Brazilians who had witnessed the disintegration of the patriarchal and slave-holding society. By comparing the statements of so many different people he was able to interview, Freyre tried to understand and interpret the “intimacy” ofsocial relationships and ways of life during that period of Brazilian history. The social life he described was that of persons from all social classes, from the very illustrious andfamous groups of the Brazilian society, to the world of the working classes and the destitute. In Brazil, the author was a pioneer in the use of oral and life histories as an empirical procedure in the social sciences, a technique that only much later, during the 1980's, became widespread among historians and his fellow social scientists. Furthermore, this essay calls attention to Gilberto Freyre’s multidisciplinary approaches, methods and techniques of social study, which opened way to his pioneering use of oral and life histories in Brazil.Cet article a pour objet démontrer I ’importance des histoires de vie dans les etudes de Sciences Sociales de Gilberto Freyre. En “Ordre etProgrès”, Freyre travaille avec des témoignages, oraux et écrits, récueillis entre 1930 et 1940, de brésiliens qui ont vécu et observé la désintégration de la société patriarchale et esclavagiste au Brésil. Atravers la comparaison des réponses, Freyre apu comprendre et, principalment, interpreter le mode de vie intime de la société brésilienne de cette période de notre histoire. L ’auteur voulait des rapports et des informations de personnalités illutres de notre société, autant que des classes populaires. En ce sens, il a inaugure une méthode de connaissance des relations sociales qui, seulement à partir des années 80, gagnera d'importance entre historiens et chercheurs sociaux au Brésil. En plus, te travail attire Tattention pour la fléxibilité de I'auteur dans I'utilisation d'autres méthodes d'appréhension de la réalité, en dehors de I’histoire oral, dans laquelle il a été le pionnier.O presente artigo procura mostrar a importância das histórias de vida na ciência social de Gilberto Freyre. Em Ordem e Progresso, Freyre trabalha com testemunhos orais e escritos, colhidos entre 1930 e 40, de brasileiros que viveram e observaram a desintegração da sociedade patriarcal e escravocrata no Brasil. Através da comparação das respostas, Freyre pôde compreender e, principalmente, interpretar o modo íntimo de vida da sociedade brasileira naquele período de nossa história. O autor queria relatos e informações de pessoas ilustres e famosas de nossa sociedade, mas também de membros das classes populares. Neste sentido, inaugurou uma técnica de conhecimento das relações sociais que só a partir da década de 80 ganhou relevância entre historiadores e cientistas sociais no Brasil. Além disso, o trabalho chama a atenção para a flexibilidade do autor no uso de outras técnicas de apreensão da realidade, além da história oral em que pioneiramente trabalhou