Glasses and glass-ceramics in the CaO–MgO–SiO2 system: diopside containing compositions - a brief review

Among different silicate systems, CaO−MgO−SiO2 is the one of the most promising due to abundance of reagents, easier fabrication, improved performance, and wide range of application. Analysis of the current literature sources denotes that phase diagram of CaO−MgO−SiO2 system is regularly used by researchers worldwide as constitutive model for synthesis glass-ceramic materials (GCs) possessing an adequate combination of high chemical durability, mechanical and electrical properties. In recent years, materials from this system attracted extra interest for applications in bone tissue repair owing to their ability to induce hydroxyapatite formation in contact with body fluids and to be resorbed in controllable degradation rate. In this brief review diopside containing compositions are specifically discussed. The main goal is to provide critical analysis of the experimental trials directed on synthesis of GC materials in the CaO−MgO−SiO2 system. Glass compositions were analysed through the standpoint of their location in the relevant region, or phase field, within a phase diagram to guide GC production and to make educated choices of compositions and processing parameters. Apart from Introduction and Conclusions this review comprises five consecutive parts. In the first part, constitution of phase diagram of CaO−MgO−SiO2 system is comprehensively discussed with connection to melts’ crystallization path and crystalline phase formation. In the second part, special attentiveness is drawn towards diopside- containing GCs produced from wastes and non-expensive natural raw materials. In this regard and taking into consideration presence of Al2O3 in the majority types of wastes, cross sections of CaO−MgO−SiO2−Al2O3 system with 10, 15 and 20% of Al2O3 are suggested to utilize when anticipating ultimate crystalline phase(s) formation. The following parts of this review are mostly addressed to recent advancement in producing optimized diopside-containing glass–ceramic biomaterials for bone repair as well as innovative sealants for solid oxide fuel cells (SOFC). Likewise, some other active areas of research and application for diopside containing GC compositions are briefly discussed.publishe

Carbon dioxide emissions and heavy metal contamination analysis of stone mastic asphalt mixtures produced with high rates of different waste materials

The incorporation of waste materials in asphalt mixtures has driven several studies mainly focused on improving their mechanical performance while minimizing the use of virgin materials. However, these could only be considered cleaner solutions for road paving works if their production and application do not present additional risks for human health and the environment. Therefore, this study aims at assessing the carbon dioxide emissions and possible leachates of stone mastic asphalt mixtures produced with high rates of different waste materials for binder modification or material recycling. Thus, a chemical analysis of eluates that were in contact with those mixtures and an estimation of the carbon dioxide emissions associated with their production and transportation were carried out under different scenarios. In conclusion, these mixtures comply with the established specifications for hazardous leachates. The addition of waste materials to these mixtures decreases carbon dioxide emissions, especially for recycled stone mastic asphalt mixtures with 50% reclaimed asphalt pavement material and bitumens modified with waste materials. Thus, the studied mixtures are innovative solutions for future use in pavement maintenance and rehabilitation operations, in line with the circular economy concept.The authors gratefully acknowledge the funding by the Portuguese Government and EU/FSE within a Portuguese Foundation for Science and Technology (FCT) Ph.D. grant (SFRH/BD98379/2013), in the scope of POPH/QREN

Mechanical, surface and environmental evaluation of stone mastic asphalt mixtures with advanced asphalt binders using waste materials

The reuse of waste materials in asphalt mixtures has been recently investigated, in order to develop new sustainable solutions for the road-paving industry. Such materials should improve the mechanical performance and provide safe/comfortable pavement surface courses for road users, without compromising their environmental performance. Thus, the aim of this study is to evaluate the mechanical, surface and environmental properties of stone mastic asphalt (SMA) mixtures produced with forward-looking asphalt binders incorporating waste materials. These binders were designed to maximise the waste material content using motor oil, high-density polyethylene, styrene?butadiene?styrene and crumb rubber, while performing so well as a commercial modified bitumen. Finally, the overall performance of the SMA mixtures produced with the selected binders was evaluated. It was concluded that these mixtures improve the water sensitivity, fatigue cracking and permanent deformation performance. The requirements for macrotexture, skid resistance and presence of heavy metals in leachates of these mixtures were similarly fulfilled. Thus, this work shows that new asphalt mixtures with waste materials can be used in road-paving works to improve the performance without compromising human and environmental safety.Portuguese Government and EU/FSE within a PhD fellowship (SFRH/BD98379/2013) of the FCT, in the scope of POPH/QREN, by ERDF (European Regional Development Fund) funds through the Competitiveness Factors Operational Programme (COMPETE)info:eu-repo/semantics/publishedVersio

Development and application of a microsurfacing mix design method to assess the influence of the emulsion type

Microsurfacing asphalt mixtures are a preventive maintenance technology comprising the application of a slurry (produced with a modified asphalt emulsion), aggregate, filler, and water on top of an existing pavement at ambient temperature. Although it is a widely used technology, further studies on the mix design procedures are necessary to ensure an adequate composition. Thus, this study contributes to developing an improved mix design procedure for microsurfacing asphalt mixtures. Different mixtures were prepared, and the influence of the type and amount of asphalt emulsion and the amount of added water and filler (cement) on the characteristics of the mixture were evaluated. Two preliminary tests, referred to as the “pizza test” and the “ball test”, were proposed to determine the initial proportions of added water and cement in the mixture, respectively. Then, consistency, cohesion, and shaking abrasion tests were performed to determine the optimum content of each component and evaluate their influence on the mixture characteristics. The results showed that these tests are essential to optimize the mix composition, even though it was found that the mix design of microsurfacings is a complex task because the mixture is a system with chemical interactions strongly influenced by its composition.This research was funded by Fundação para a Ciência e a Tecnologia through a Ph.D. grant (number 2021.08004.BD). This work was also partly financed by FCT/MCTES through national funds (PIDDAC) under the R&D Unit Institute for Sustainability and Innovation in Structural Engineering (ISISE), reference UIDB/04029/2020, and under the Associate Laboratory Advanced Production and Intelligent Systems ARISE, reference LA/P/0112/2020

Valorização de resíduos plásticos na modificação de betumes para pavimentos rodoviários

Com o aumento do tráfego rodoviário são colocadas maiores exigências aos pavimentos, surgindo a necessidade de melhorar o seu desempenho. Um método que pode melhorar significativamente a qualidade dos pavimentos flexíveis é a adição de polímeros aos ligantes/misturas betuminosas. Assim, foram produzidos ligantes modificados com polímeros reciclados, em diferentes condições, cujo desempenho foi comparado com o de ligantes convencionais e de um ligante modificado comercial. Os resultados dos ensaios laboratoriais serão utilizados na seleção de resíduos plásticos e das condições de produção do betume modificado para otimizar o seu comportamento, salientando-se que este estudo procura promover a reutilização de resíduos de uma forma mais ecológica e económica.Financiado por Fundos FEDER através do Programa Operacional Fatores de Competitividade – COMPETE e por Fundos Nacionais através da FCT – Fundação para a Ciência e a Tecnologia no âmbito do projeto PLASTIROADS (PTDC/ECM/119179/2010) e do projeto estratégico UI 4047 – 2011-2012

Support for automatic refactoring of business logic

Software’s structure profoundly affects its development and maintenance costs. Poor software’s structure may lead to well-known design flaws, such as large modules or long methods. A possible ap- proach to reduce a module’s complexity is the Extract Method refactor- ing technique. This technique allows the decomposition of a large and complex method into smaller and simpler ones, while reducing the orig- inal method’s size and improving its readability and comprehension. The OutSystems platform is a low-code platform that allows the de- velopment of web and mobile applications that rely on a set of visual Domain-Specific Languages (DSLs). Even low-code languages when im- properly used can lead to software that has maintenance issues like long methods. Thus, the purpose of this paper is to present the research and devel- opment done to provide the OutSystems platform with a tool that au- tomatically suggests Extract Method refactoring opportunities. The re- search combines program slicing techniques with code complexity metrics to calculate the best refactoring opportunities that preserve programs’ functionality. The proposed approach was tested on typical OutSystems apps and was shown to be able to reduce the overall applications’ complexity.info:eu-repo/semantics/publishedVersio

Utilization of waste materials to improve asphalt mixtures performance

This study aims to develop an innovative bitumen with large quantities of waste materials to improve asphalt mixtures performance. Different amounts of waste motor oil and waste HDPE were added to a new bitumen. The bitumen modified with 10% of waste motor oil and 5% of HDPE showed promising characteristics (high softening point temperatures and penetration slightly higher than the conventional bitumen). After the selection of the most promising modified bitumen, three asphalt mixtures were produced with different bitumens (namely conventional bitumen, commercial modified bitumen and the selected modified bitumen). Beyond that, this modified bitumen improved some mechanical characteristics of the asphalt mixture where it was used, in comparison to conventional and modified asphalt mixtures.Portuguese Government and EU/FSE within a PhD fellowship (SFRH/BD98379/2013) of the FCT, in the scope of POPH/QREN, by FEDER through the Competitiveness Factors Operational Programme (COMPETE) and by national funds through the Portuguese Foundation for Science and Technology (FCT) in the scope of PLASTIROAD Project (PTDC/ECM/119179/2010

A simple technique can reduce cardiopulmonary bypass use during lung transplantation

Cardiopulmonary bypass causes an inflammatory response and consumption of coagulation factors, increasing the risk of bleeding and neurological and renal complications. Its use during lung transplantation may be due to pulmonary hypertension or associated cardiac defects or just for better exposure of the pulmonary hilum. We describe a simple technique, or open pericardium retraction, to improve hilar exposure by lifting the heart by upward retraction of the pericardial sac. This technique permits lung transplantation without cardiopulmonary bypass when bypass use is recommended only for better exposure

Fast prototyping microfluidics: Integrating droplet digital lamp for absolute quantification of cancer biomarkers

UID/CTM/50025/2019 UID/Multi/04378/2019 Inn-INDIGO/0002/2015 PTDC/BTM-SAL/31201/2017 SFRH/BPD/124311/2016Microfluidic (MF) advancements have been leveraged toward the development of state-of-the-art platforms for molecular diagnostics, where isothermal amplification schemes allow for further simplification of DNA detection and quantification protocols. The MF integration with loop-mediated isothermal amplification (LAMP) is today the focus of a new generation of chip-based devices for molecular detection, aiming at fast and automated nucleic acid analysis. Here, we combined MF with droplet digital LAMP (ddLAMP) on an all-in-one device that allows for droplet generation, target amplification, and absolute quantification. This multilayer 3D chip was developed in less than 30 minutes by using a low-cost and extremely adaptable production process that exploits direct laser writing technology in “Shrinky-dinks” polystyrene sheets. ddLAMP and target quantification were performed directly on-chip, showing a high correlation between target concentration and positive droplet score. We validated this integrated chip via the amplification of targets ranging from five to 500,000 copies/reaction. Furthermore, on-chip amplification was performed in a 10 µL volume, attaining a limit of detection of five copies/µL under 60 min. This technology was applied to quantify a cancer biomarker, c-MYC, but it can be further extended to any other disease biomarker.publishersversionpublishe

Low-temperature performance of polymer-modified binders in stone mastic asphalts

When temperatures drop to significantly low levels, road pavements are subjected to thermally-induced stresses, resulting in the appearance of thermal cracking, among other distresses. In these situations, polymers can be used as asphalt binder modifiers to improve certain asphalt binder properties, such as elastic recovery, cohesion, and ductility. Polymers also minimize some of the problems of asphalt mixtures, such as thermal and fatigue cracking and permanent deformation. This work’s objective was to study the behavior of asphalt mixtures at low temperatures, mainly when using modified binders. Thus, three binders were selected and tested: a standard 50/70 penetration grade bitumen and two polymer-modified binders (PMB), obtained by adding, respectively, 2.5% and 5.0% of styrene–butadiene–styrene (SBS) in the 50/70 pen grade bitumen. Then, the PMBs were incorporated into stone mastic asphalt mixtures (namely SMA 11), which were subjected to low-temperature mechanical tests based on the most recent European Standards. The asphalt binders and mixtures evaluated in this work were tested for thermal cracking resistance, creep, elastic recovery, cohesive strength, and ductility strength. Overall, it is concluded that the studied asphalt mixtures with PMB, with just 2.5% SBS, performed adequately at low temperatures down to −20 °C.This research was funded by FCT/MCTES through national funds (PIDDAC) under the R&D Unit Institute for Sustainability and Innovation in Structural Engineering (ISISE), under reference code UIDB/04029/2020