Structural integrity of polymeric components produced by additive manufacturing (Am)—polymer applications

Funding Information: Authors acknowledge Funda??o para a Ci?ncia e a Tecnologia (FCT-MCTES) for its financial support via the project UIDB/00667/2020 (UNIDEMI) and project UIDB/00285/2020 (CEMMPRE). Funding Information: Funding: Authors acknowledge Fundação para a Ciência e a Tecnologia (FCT-MCTES) for its financial support via the project UIDB/00667/2020 (UNIDEMI) and project UIDB/00285/2020 (CEMMPRE). Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.In the work presented herein, the structural integrity of polymeric functional components made of Nylon-645 and Polylactic acid (PLA) produced by additive manufacturing (Fused Deposition Modelling, FDM) is studied. The PLA component under study was selected from the production line of a brewing company, and it was redesigned and analyzed using the Finite Element Method, 3D printed, and installed under real service. The results obtained indicated that, even though the durability of the 3D printed part was lower than the original, savings of about EUR 7000 a year could be achieved for the component studied. Moreover, it was shown that widespread use of AM with other specific PLA components could result in even more significant savings. Additionally, a metallic hanger (2700 kg/m3 ) from the cockpit of an airplane ATR 70 series 500 was successfully redesigned and additively manufactured in Nylon 645, resulting in a mass reduction of approximately 60% while maintaining its fit-for-purpose. Therefore, the components produced by FDM were used as fully functional components rather than prototype models, which is frequently stated as a major constraint of the FDM process.publishersversionpublishe

Sondas de ácido péptido nucleico, estojo e método para detectar espécies do género Lactobacillus spp. e/ou Gardnerella spp. e respectivas aplicações

O presente invento refere-se à concepção de duas sondas de ácido péptido nucleíco (PNA) para detectar as bactérias Lactobacillus e/ou Gardnerella spp.. Estas sondas são aplicadas a um processo baseado em técnicas de biologia molecular, nomeadamente de hibridação fluorescente in situ (FISH), aplicáveis no diagnóstico de vaginose bacteriana ou a detecção e quantificação destes géneros bacterianos em diversos tipos de amostras, incluindo sangue, alimentos, biopsias, fezes, água e outras amostras clínicas, ambientais ou provenientes da indústria agrícola ou alimentar

Comportamento de blocos de terra comprimida estabilizados com resíduos industriais

The construction of masonry with compressed earth blocks (CEBs) is a modern earth construction technique with current growing interest, but its environmental sustainability is many times depreciated by the use of traditional chemical stabilisation techniques (lime and cement addition). This paper presents an experimental program where the possibility of manufacturing CEBs using granitic residual soils (GRS) from northern Portugal is addressed. The GRS were shown to be inadequate and their use for manufacturing CEBs requires chemical stabilisation. A composition study involving stabilisation by addition of cement and addition of geopolymeric binders resulting from the alkaline activation of fly ash or of calcinated sludge was carried out. Then, CEBs stabilised with alkaline activation of fly ash were manufactured and their mechanical properties were tested. In addition, the compressive behaviour of masonry built with these CEBs was also characterized. In general, the stabilisation with alkaline activation of fly ash revealed excellent results with respect to the improvement in strength.A construção em alvenaria de blocos de terra comprimida (BTC) é uma técnica de construção em terra moderna com um atual interesse crescente, mas a sua sustentabilidade ambiental é muitas vezes desvalorizada pelo recurso a técnicas de estabilização química tradicionais (adição de cal e cimento). Este artigo apresenta um programa experimental onde é avaliada a possibilidade de se manufaturarem BTC com solo residual granítico (SRG) do Norte de Portugal. Mostrou-se que os SRG não são adequados e que o seu uso na produção de BTC requer estabilização química. Realizou-se um estudo de composição envolvendo estabilização por adição de cimento e de ligantes geopoliméricos à base da ativação alcalina de cinza volante ou lamas calcinadas. Em seguida, manufaturam-se BTC estabilizados com ativação alcalina de cinzas volantes e testaram-se as suas propriedades mecânicas. Além disto, caraterizou-se o comportamento em compressão da alvenaria construída com estes BTC. Em geral, a estabilização com ativação alcalina de cinzas volantes revelou excelentes resultados no que diz respeito ao melhoramento da resistência

Mechanical characterization of dry-stack masonry made of CEBs stabilised with alkaline activation

The increasing interest on earth construction as a sustainable building solution led to the development of modern earth construction techniques, in particular of masonry made of compressed earth blocks (CEBs). The traditional chemical stabilisation of the soil is a frequently used improvement process. However, such process increases significantly the embodied energy of the CEBs. This paper presents an alternative technique for the stabilisation of CEBs, based on alkali activation of fly ash. The mechanical behaviour of the CEBs and of the respective dry stack masonry is comprehensively investigated through an experimental program, during which this technique proved to be highly effective.The authors wish to express their gratitude to Mr. Pedro Esteves for his support in the experimental work and to Eng. Jorge Henriques, on behalf of the company PEGOP – Energia Eléctrica SA, for providing the fly ash. The financial support provided by the Portuguese Science and Technology Foundation through the project FCOMP-01-0124-FEDER-028864 (FCT-PTDC/ECM-EST/2396/2012) is also gratefully acknowledged.Fundação para a Ciência e a Tecnologia (FCT

Analysis of sensory effects of chitosan-based coatings applied on frozen salmon over six-months storage

The 19th Gums & Stabilisers for the Food Industry Conference: Hydrocolloid MultifunctionalityDue to an increase in fish consumption over the past years, in combination with the perishable nature of fish, the fish industry has given an added focus on the improvement of the currently used fish preservation techniques. Chitosan coatings may add improvements to the traditional water glazing, namely in physical and anti-microbial protection, allowing for shelf life extension. This work was meant to determine the influence of chitosan coatings in the organoleptic characteristics of salmon. The effects of chitosan coatings on microbiological (Total Viable Count – TVC) and chemical (Total Volatile Base Nitrogen – TVB-N) parameters were also assessed. A 15 g/L solution of chitosan was used to coat frozen salmon samples, and its effect on the sensory properties of Atlantic salmon (Salmo salar) was compared with uncoated and water glazed samples, and was studied over six months of storage at -18 °C. Samples were dipped in the chitosan solution at 8 °C during 10 s; water glazing was applied at 0.5 °C, with a dipping time of 40 s. Textural properties were evaluated through Texture Profile Analysis (TPA), while sensory properties of frozen, frozen+thawed and frozen+thawed+cooked samples were assessed by a trained panel of judges. Microbiological stability was assessed through TVC (ISO 4833-1:2013 standard), and chemical stability was determined as TVB-N (NP 2930:2009 standard). TVC analysis showed an anti-microbial effect of chitosan in the coated samples (reduction of the number of microorganisms), while TVB-N results showed to remain stable during the experiment. Textural results from the TPA analysis showed no significant differences between different coatings. Results of the trained panel indicated that for frozen samples chitosan was the preferred choice, while no significant differences existed between chitosan-coated and glazed samples in thawed and cooked samples. Flavor diffusion from the chitosan coating to the samples was assessed by Principal Component Analysis and no correlation between coating type and sample flavor could be established, meaning that no chitosan flavor was detected by the panellists.info:eu-repo/semantics/publishedVersio

The importance of lipid conjugation on anti-fusion peptides against Nipah virus

© 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).Nipah virus (NiV) is a recently emerging zoonotic virus that belongs to the Paramyxoviridae family and the Henipavirus genus. It causes a range of conditions, from asymptomatic infection to acute respiratory illness and fatal encephalitis. The high mortality rate of 40 to 90% ranks these viruses among the deadliest viruses known to infect humans. Currently, there is no antiviral drug available for Nipah virus disease and treatment is only supportive. Thus, there is an urgent demand for efficient antiviral therapies. NiV F protein, which catalyzes fusion between the viral and host membranes, is a potential target for antiviral drugs, as it is a key protein in the initial stages of infection. Fusion inhibitor peptides derived from the HRC-domain of the F protein are known to bind to their complementary domain in the protein's transient intermediate state, preventing the formation of a six-helix bundle (6HB) thought to be responsible for driving the fusion of the viral and cell membranes. Here, we evaluated the biophysical and structural properties of four different C-terminal lipid-tagged peptides. Different compositions of the lipid tags were tested to search for properties that might promote efficacy and broad-spectrum activity. Fluorescence spectroscopy was used to study the interaction of the peptides with biomembrane model systems and human blood cells. In order to understand the structural properties of the peptides, circular dichroism measurements and molecular dynamics simulations were performed. Our results indicate a peptide preference for cholesterol-enriched membranes and a lipid conjugation-driven stabilization of the peptide α-helical secondary structure. This work may contribute for the development of highly effective viral fusion against NiV inhibitors.This work was financially supported by Fundação para a Ciência e a Tecnologia—Ministério da Ciência, Tecnologia e Ensino Superior (FCT-MCTES, Portugal), through projects PTDC/BBB-BQB/3494/2014, PTDC/QUI-BIQ/114774/2009, PTDC/CCI-BIO/28200/2017 and Pest-OE/EQB/LA0004/2011, and by National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIH), project R01AI114736, lead by Anne Moscona (Columbia University Medical Center, NY, USA). This work was also financially supported by Project LISBOA-01-0145-FEDER-007660 (Microbiologia Molecular, Estrutural e Celular) funded by FEDER funds through COMPETE2020-Programa Operacional Competitividade e Internacionalização (POCI) and by national funds through FCT-MCTES. MCM, PMS and DL were supported by FCT-MCTES fellowships SFRH/BPD/118731/2016, SFRH/BD/118413/2016 and SFRH/BPD/92537/2013, respectively.info:eu-repo/semantics/publishedVersio

Shear behaviour characterization of dry-stack masonry made of compressed earth blocks

Como material de construção não normalizado, a terra é ainda associada à construção de subsistência dos países em desenvolvimento. Porém, as vantagens da construção em terra têm sido cada vez mais reconhecidas, nomeadamente a sua sustentabilidade. Esta mudança de paradigma tem levado ao desenvolvimento de técnicas modernas de construção em terra, particularmente a alvenaria de blocos de terra comprimida (BTC). A estabilização química tradicional do solo é um processo de melhoramento frequentemente utilizado, mas que também aumenta significativamente a energia incorporada dos BTC. Este artigo apresenta uma solução de estabilização alternativa para BTC, baseada na ativação alcalina de cinza volante. O comportamento mecânico dos BTC e da respetiva alvenaria de junta seca é estudado através de um programa experimental, que inclui a caraterização do comportamento ao corte da alvenaria.Raw earth, as a non-standard building material, is still associated to the poor construction from the developing countries. However, the advantages of earth construction have been increasingly recognized, namely its sustainability. This change of paradigm have been led to the development of modern earth construction techniques, in particular of the masonry made of compressed earth blocks (CEBs). The traditional chemical stabilization of the soil is an improvement process used frequently, but which increases significantly the embodied energy of the CEBs. This paper presents an alternative stabilisation technique for CEBs, based on the alkaline activation of fly ash. The mechanical behaviour of the CEBs and of the respective dry-stack masonry is investigated through an experimental program, which includes the characterization of the shear behaviour of the masonryFundação para a Ciência e a Tecnologia (FCT

CEBs stabilised with geopolymeric binders: mechanical performance of dry-stack masonry

The sustainability in the building industry is currently a sounding topic, seeking the development of more environmental friendly building materials. The incorporation of industrial wastes and the reuse of construction and demolition waste (CDW) in the production of building materials are methods being used to solve this problem. Furthermore, these methods contribute to fulfilling the targets defined by European Union for the valorisation of non-hazard waste. The construction with compressed earth blocks (CEBs) stabilised with geopolymeric binders is a solution that can contribute to this objective by incorporating both CDW (excavation soil) and industrial wastes. Despite some recent research done on this topic, it still deserves further investigation. This paper intends to contribute to the development of this topic by presenting an experimental program, continuing previous research. The experimental program is addressed to the mechanical characterisation of a dry-stack CEB (stabilised with geopolymer obtained from alkaline activation of fly ash) masonry system, and includes the evolution of the strength of the CEBs with the curing time. In general, the evolution of the strength of the CEBs cured under ambient condition was shown to be a slow process, which can have implications on the production process.Portuguese Science and Technology Foundation (FCT) through the project FCOMP-01-0124-FEDER-028864 (FCT-PTDC/ECM-EST/2396/2012)

Rammed earth construction with granitic residual soils: the case study of northern Portugal

Building in unstabilised rammed earth results in low environmental impact. However, northern Portugal has not historical tradition with this technique, and thus the suitability of the local granitic residual soils is unknown. This paper presents an experimental investigation, where this possibility is assessed. The results showed that these soils are unsuitable, and that rammed earth construction is only feasible if these soils go through a stabilising process. The alkaline activation of fly ash was investigated as an environmentally friendly stabilisation technique, and it proved to be capable of improving the performance of rammed earth

Mechanical performance of masonry made with CEB stabilised by alkali activated fly ashes

Ao longo dos últimos anos foi possível observar uma crescente preocupação ao nível da sustentabilidade e da preservação do meio ambiente. Este trabalho tem como principal objetivo prestar um contributo nesse sentido, nomeadamente através do desenvolvimento de ummaterial mais sustentável, com menor impacto ambiental, recorrendo a uma técnica que permite encarar os resíduos industriais como matérias-primas. A terra, como material de construção, tem já uma utilização milenar, comprovada pelos importantes monumentos que chegaram até aos nossos dias. A ativação alcalina, enquanto técnica para a produção de ligantes alternativos, tem demonstrado um grande potencial, evidenciado ao longo dos últimos anos. Através da utilização de solo e da ativação alcalina de cinzas volantes foi possível desenvolver um material para fabrico de blocos de terra compactada (BTC) com desempenho mecânico, quer a nível individual quer ao nível da própria alvenaria resultante, adequado ao funcionamento deste tipo de estrutura.Over the last years it was possible to observe an increasing concern in terms of sustainability and environmental preservation. This work aims to make a contribution in this direction, particularly through the development of a more sustainable material, with lower environmental impact, employing a technique that allows to face the industrial waste as raw materials. The earth as building material has a millenary use, proven by the important monuments that have survived till nowadays. The alkaline activation, while technique for the production of alternative binders, has shown a great potential, evidenced over the last years. Through the use of the soil and alkali activated fly ashes was possible to develop a material for the manufacture of compressed earth blocks (CEB) with mechanical performance, either individually or at the level of the masonry itself, suitable for use in this type of structure.FCT (Fundação para a Ciência e Ta ecnologia), através do ISISE, com o projeto IUD/ECI/04029/201