Treatment of end-of-life concrete in an innovative heating-air classification system for circular cement-based products

A stronger commitment towards Green Building and circular economy, in response to environmental concerns and economic trends, is evident in modern industrial cement and concrete production processes. The critical demand for an overall reduction in the environmental impact of the construction sector can be met through the consumption of high-grade supplementary raw materials. Advanced solutions are under development in current research activities that will be capable of up-cycling larger quantities of valuable raw materials from the fine fractions of End-of-Life (EoL) concrete waste. New technology, in particular the Heating-Air classification System (HAS), simultaneously applies a combination of heating and separation processes within a fluidized bed-like chamber under controlled temperatures (±600 °C) and treatment times (25–40 s). In that process, moisture and contaminants are removed from the EoL fine concrete aggregates (0–4 mm), yielding improved fine fractions, and ultrafine recycled concrete particles (<0.125 mm), consisting mainly of hydrated cement, thereby adding value to finer EoL concrete fractions. In this study, two types of ultrafine recycled concrete (either siliceous or limestone EoL concrete waste) are treated in a pilot HAS technology for their conversion into Supplementary Cementitious Material (SCM). The physico-chemical effect of the ultrafine recycled concrete particles and their potential use as SCM in new cement-based products is assessed by employing substitutions of up to 10% of the conventional binder. The environmental viability of their use as SCM is then evaluated in a Life Cycle Assessment (LCA). The results demonstrated accelerated hydration kinetics of the mortars that incorporated these SCMs at early ages and higher mechanical strengths at all curing ages. Optimal substitutions were established at 5%. The results suggested that the overall environmental impact could be reduced by up to 5% when employing the ultrafine recycled concrete particles as SCM in circular cement-based products, reducing greenhouse gas emissions by as much as 41 kg CO2 eq./ton of cement (i.e. 80 million tons CO2 eq./year). Finally, the environmental impacts were reduced even further by running the HAS on biofuel rather than fossil fuel.The authors of the present paper, prepared in the framework ofthe Project VEEP "Cost-Effective Recycling of C&DW in High AddedValue Energy Efficient Prefabricated Concrete Components forMassive Retrofitting of our Built Environment", wish to acknowl-edge the European Commission for its support. This project hasreceived funding from the European Union’s Horizon 2020 researchand innovation programme under grant agreement No 723582.This paper reflects only the author’s view and the European Com-mission is not responsible for any use that may be made of theinformation it contains.The authors are also grateful to the Spanish Ministry of Science,Innovation and Universities (MICIU) and the European RegionalDevelopment Fund (FEDER) for funding this line of research(RTI2018-097074-B-C21)

Entorno de simulación de la gestión de una FPGA bidimensional, parte de un sistema computador de propósito general basado en HW

FPGA Simulator 1.0 simula el comportamiento de una FPGA bidimensional dinámicamente reconfigurable. La simulación consiste en la gestión de una cola de tareas de tamaño rectangular (simple), con la posibilidad de multitarea, lo que permite ejecutar simultáneamente varias de estas tareas. La ubicación de las tareas dentro de la FPGA se lleva a cabo mediante un algoritmo previamente implementado que gestiona el espacio libre en la FPGA. Este algoritmo gestiona las tareas en espera de ejecución, las que están ejecutándose actualmente en la FPGA y las que han terminado de ejecutar. Nuestra solución FPGA Simulator 1.0 permite gestionar tanto la FPGA como la lista de tareas en espera a través de una sencilla e intuitiva interfaz gráfica. El algoritmo encargado de la ubicación de las tareas también puede ser configurado manualmente. Entre la diversidad de algoritmos existentes (p.e. First-Fit (FF), Best-Fit (BF), First-Fit-Decreasing (FFD) y Best-Fit-Decreasing (BFD)), el algoritmo utilizado en nuestra solución es el Bin Packing MER, que ubica las tareas en el MER (Maximun Empty Rectangle) o Máximo Rectángulo Vacío. Trabajar con distintas FPGAs y listas de tareas se convierte en una tarea sencilla gracias a la exportación de estos elementos a ficheros de texto, que permite tanto abrir y guardar como modificar los elementos involucrados en la simulación. A parte, el uso de ficheros incrementa la versatilidad del producto, permitiendo la exportación de elementos a otros ordenadores. FPGA Simulator 1.0 permite además guardar la configuración de una simulación concreta de manera que se pueda reproducir en cualquier momento. Dado el carácter determinista de los algoritmos utilizados, una misma configuración desemboca en un mismo resultado, de forma que el almacenamiento de resultados se simplifica con el uso de un fichero de texto absolutamente independiente, que también es completamente portable. A parte de la creación de un entorno de simulación, FPGA Simulator 1.0 proporciona además una idea general del comportamiento de la simulación por medio de métricas. Estas métricas, que deben ser utilizadas de manera orientativa, se basan en la utilización del espacio libre de la FPGA, y consisten en la ocupación media y la ocupación instantánea (en porcentaje) del espacio de la FPGA. La comparación de estas métricas como resultado de la ejecución de diferentes algoritmos sobre un mismo entorno de simulación nos puede dar un acercamiento al comportamiento real de los algoritmos. La versión actual de FPGA Simulator 1.0 sólo está disponible para plataformas Windows (windows 95, 98, NT, 2000 y XP) Implementando en Borland C++ Builder, este software presenta una gran estabilidad y rapidez de ejecución, al igual que un mínimo consumo de recursos de sistema. La posibilidad de incorporar manualmente nuevos algoritmos de ejecución convierte este producto en un software de gran utilidad en el campo de la investigación. [Abstract] FPGA Simulator 1.0 simulates the behavior of a dynamically reconfigurable bidimensional FPGA. Simulation consists of a rectangular task queue managemente (simple tasks) with a multitask posibility, which implies the simultaneous execution of several tasks. The task allocation within the FPGA is done through a previously programmed algorithm, which manages the free space in the FPGA. The task management involves the waiting for execution tasks, currently executing, and already finished ones. Our solution FPGA Simulator 1.0, enables the management of both the FPGA and the task queue throug an easy and intuitive graphic interface. The algorithm used to allocate the tasks con also be manually configured. Between many other existing ones (p.e. First-Fit (FF), Best-Fit (BF), First-Fit-Decreasing (FFD) y Best-Fit-Decreasing (BFD)),Bin Packing MER was the final algorithm used in our product. Bin Packing MER allocates tasks in the Maximum Empty Rectangle available at a given moment. The exportation of elements such as FPGAs and task queues to text files translates into a clear enhancement of the working capabilities, specially when working with different types of these kind of elements. The use of text files increases the product's versatility, as these elements can be exported to other copmputers with a minimum amount of space expense. FPGA Simulator 1.0 allows saving concrete simulatin configurations for later execution Given that the algorithms used are deterministic, two identical configurations imply same results. Thus, results storage is simplified by the use of absolutely independent text files, wich are also portable. Apart from creating a simulation environment, FPGA Simulator 1.0 offers a general view of the algorithms behavior trough the metrics. These metrics, which should be used only in an orientative way, are based on the available free space in the FPGA. The two metrics used are the current occupation and the average occupation (in percentage). The comparison of the metrics obtained out of the execution of different algorithms over the same simulation environment can give us an approximate idea of the real behavior of th algorithms. The current version of FPGA Simualtor 1.0 is only supported under Windows platforms (Windows 95, 98, NT, 2000 and XP). Programmed under Borland C++ Builder, this software displays a great stability and execution time, at the same time as it consumes a minimum amount of system resources. The possibility of adding manually new algorithms provides this software with a great utility withing the scope of investigation

Durability of Construction and Demolition Waste-Bearing Ternary Eco-Cements

In recent years, the development of ternary cements has become a priority research line for obtaining cements with a lower carbon footprint, with the goal to contribute to achieve climate neutrality by 2050. This study compared ordinary Portland cement (OPC) durability to the performance of ternary cements bearing OPC plus 7% of a 2:1 binary blend of either calcareous (Hc) or siliceous (Hs) concrete waste fines and shatterproof glass. Durability was measured further to the existing legislation for testing concrete water absorption, effective porosity, pressurized water absorption and resistance to chlorides and CO2. The experimental findings showed that the 7% blended mortars performed better than the reference cement in terms of total and effective porosity, but they absorbed more pressurized water. They also exhibited lower CO2 resistance, particularly in the calcareous blend, likely due to its higher porosity. Including the binary blend of CDW enhanced chloride resistance with diffusion coefficients of 2.9 × 10−11 m2 s−1 (calcareous fines-glass, 7%Hc-G) and 1.5 × 10−11 m2 s−1 (siliceous fines-glass, 7%Hs-G) compared to the reference cement’s 4.3 × 10−11 m2 s−1. The siliceous fines-glass blend out-performed the calcareous blend in all the durability tests. As the mortars with and without CDW (construction and demolition waste) performed to similar standards overall, the former were deemed viable for the manufacture of future eco-efficient cements.This research was conducted as part of a national project funded by the Spanish Ministry of Science, Innovation and Universities (MICIU), the Spanish National Research Agency (AEI) and the European Regional Development Fund (ERDF), grant number RTI2018-097074-B-C21 and C-22

Behaviour and Properties of Eco-Cement Pastes Elaborated with Recycled Concrete Powder from Construction and Demolition Wastes

This work analyses the influence of fine concrete fractions (<5 mm) of different natures —calcareous (HcG) and siliceous (HsT)—obtained from construction and demolition waste (C&DW) on the behaviour of blended cement pastes with partial replacements between 5 and 10%. The two C&DW fractions were characterised by different instrumental techniques. Subsequently, their limefixing capacity and the physico-mechanical properties of the blended cement pastes were analysed. Lastly, the environmental benefits of reusing these fine wastes in the manufacture of future ecoefficient cement pastes were examined. The results show that HsT and HcG exhibit weak pozzolanic activity, owing to their low reactive silica and alumina content. Despite this, the new cement pastes meet the physical and mechanical requirements of the existing regulations for common cements. It should be highlighted that the blended cement pastes initially showed a coarser pore network, but then they underwent a refinement process between 2 and 28 days, along with a gain in compressive strength, possibly due to the double pozzolanic and filler effect of the wastes. The environmental viability of the blended cements was evaluated in a Life Cycle Assessment (LCA) concluding that the overall environmental impact could be reduced in the same proportion of the replacement rate. This is in line with the Circular Economy goals and the 2030 Agenda for Sustainable Development.This research was funded by the Spanish Ministry of Science, Innovation and Un iversities (MICIU), the Spanish National Research Agency (AEI) and the European Regional Development Fund (ERDF), grant number RTI2018-097074- B-C21-22, as well as by the Spanish Training Program and the European Social Fund (MINECO/FSE) [grant number BES-2016-078454]

Servicio ubicuo de estimulación cognitiva orientado a personas con enfermedad de Parkinson

Este trabajo de investigación detalla el diseño y evaluación de un servicio de e-salud cuyo objetivo es mejorar la estimulación y seguimiento de personas con un trastorno cognitivo. Con este fin, se ha desarrollado un protocolo de transferencia de mensajes que facilita la provisión de un servicio telemático para personas afectadas de Parkinson, pudiendo así realizar estimulación cognitiva personalizada, de forma ubicua, mediante un dispositivo fácil de usar como un tablet Android. Asimismo, este servicio permite a los terapeutas adaptar y monitorizar de forma segura la terapia, vía web, beneficiándose así de una mejor calidad en el seguimiento efectivo de cada paciente. El sistema ha sido evaluado satisfactoriamente durante tres meses con 10 pacientes entre 59 y 77 años. La solución resultante es fácilmente integrable con otras terapias complementarias y puede ser adaptada para otros deterioros cognitivos, como el debido a la enfermedad de Alzheimer o el deterioro cognitivo leve

Simulation of the Attrition of Recycled Concrete Aggregates during Concrete Mixing

Concrete mixing can lead to mechanical degradation of aggregates, particularly when dealing with recycled concrete aggregates. In this work, the attrition of such materials during mixing is studied by means of experiments and simulations. The effect of the presence of fines, water addition, flow configuration of the mixer (co- or counter-current) and impeller frequency is discussed. Experiments were performed in a laboratory Eirich mixer. Discrete element numerical simulations (DEM) were performed on the same geometry by mimicking the behaviour of the material and, in particular, the cohesion induced by water and the cement paste using either Hertz–Mindlin or Hertz–Mindlin with Johnson–Kendall–Roberts (JKR) contact laws. The combination of the collision energy spectra extracted from the DEM simulations and an attrition model allowed the prediction of the mass loss due to attrition in 1-min experiments. Semi-quantitative agreement was observed between experiments and simulations, with a mean relative error of 26.4%. These showed that higher mass losses resulted from operation at the highest impeller speeds, co-current operation, and also with the wet aggregate. Mixing of the agglomerate in the concrete mix resulted in a significant reduction in attrition when compared to mixing aggregates alone. With further validation, the proposed simulation approach can become a valuable tool in the optimization of mixing by allowing the effects of material, machine and process variables to be studied on the mass loss due to attritionThis research was partially funded by the Brazilian Research Agency CNPq (grant number 310293/2017-0)

ACT-Discover: identifying karyotype heterogeneity in pancreatic cancer evolution using ctDNA

Circulating tumour DNA; Pancreatic cancer; Tumour evolutionADN tumoral circulant; Càncer de pàncrees; Evolució tumoralADN tumoral circulante; Cáncer de páncreas; Evolución tumoralBackground Liquid biopsies and the dynamic tracking of somatic mutations within circulating tumour DNA (ctDNA) can provide insight into the dynamics of cancer evolution and the intra-tumour heterogeneity that fuels treatment resistance. However, identifying and tracking dynamic changes in somatic copy number alterations (SCNAs), which have been associated with poor outcome and metastasis, using ctDNA is challenging. Pancreatic adenocarcinoma is a disease which has been considered to harbour early punctuated events in its evolution, leading to an early fitness peak, with minimal further subclonal evolution. Methods To interrogate the role of SCNAs in pancreatic adenocarcinoma cancer evolution, we applied whole-exome sequencing of 55 longitudinal cell-free DNA (cfDNA) samples taken from 24 patients (including 8 from whom a patient-derived xenograft (PDX) was derived) with metastatic disease prospectively recruited into a clinical trial. We developed a method, Aneuploidy in Circulating Tumour DNA (ACT-Discover), that leverages haplotype phasing of paired tumour biopsies or PDXs to identify SCNAs in cfDNA with greater sensitivity. Results SCNAs were observed within 28 of 47 evaluable cfDNA samples. Of these events, 30% could only be identified by harnessing the haplotype-aware approach leveraged in ACT-Discover. The exceptional purity of PDX tumours enabled near-complete phasing of genomic regions in allelic imbalance, highlighting an important auxiliary function of PDXs. Finally, although the classical model of pancreatic cancer evolution emphasises the importance of early, homogenous somatic events as a key requirement for cancer development, ACT-Discover identified substantial heterogeneity of SCNAs, including parallel focal and arm-level events, affecting different parental alleles within individual tumours. Indeed, ongoing acquisition of SCNAs was identified within tumours throughout the disease course, including within an untreated metastatic tumour. Conclusions This work demonstrates the power of haplotype phasing to study genomic variation in cfDNA samples and reveals undiscovered intra-tumour heterogeneity with important scientific and clinical implications. Implementation of ACT-Discover could lead to important insights from existing cohorts or underpin future prospective studies seeking to characterise the landscape of tumour evolution through liquid biopsy.This work was supported by the European Research Council (ERC) no. 670582 (Call: ERC-2014-ADG) to Dr. Hidalgo. R.A.T is supported by the Miguel Servet-II Research Award and the 2021 call for Proyectos de generación de conocimiento by the Institute of Health Carlos III (ISCIII) of the Ministry of Economy [CP17/00199], the Olga Torres Foundation Award to emerging researchers [2017, to R.A.T, 2601], and received research grants from Novartis, Astrazeneca, and Beigene pharmaceuticals, not related to this study. N.M is a Sir Henry Dale Fellow, jointly funded by the Wellcome Trust and the Royal Society (Grant Number 211179/Z/18/Z), and also receives funding from Cancer Research UK Lung Cancer Centre of Excellence, Rosetrees, and the NIHR BRC at University College London Hospitals

Vertical distribution of PAHs in marine sediments (particulate fraction and interstitial water) from eight Iberian Mediterranean areas

Polycyclic aromatic hydrocarbons (PAHs) have been determined in sediment cores from eight Iberian Mediterranean coastal areas (Barcelona, Tarragona, Ebro Delta, Valencia, Castellón, Cartagena, Almería y Málaga), considering both interstitial water and solid fraction. Three sediment cores were taken in three different sampling sites per area by using a box corer. Cores were cut into 1-cm-thick sections between 0 and 18-cm depth, interstitial water was obtained by centrifugation and samples from every site were pooled. Fourteen polycyclic aromatic hydrocarbons (fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benz[a]anthracene, crysene, benzo[e]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, benzo[g,h,i]perylene, dibenzo[a,h]anthracene and indeno[1,2,3-c,d]pyrene) were determined in interstitial water by stir bar sorptive extraction coupled to GC/MS and solid fraction by Soxhlet extraction and HPLC with fluorescence detection. As result of PAHs hydrofobicity, their concentrations were several magnitude order higher in sediment (solid phase) than interstitial water. Total PAH concentration in sediment varied from 1 to 1321 g•kg-1 d.w and from 4.9 to 274 ng•L-1 in interstitial water. Vertical PAHs distributions in sediments were homogeneous in some areas, however, sharp concentration decreases were observed at deeper layers from some sampling sites. However, their maximum concentrations in interstitial water were found mainly in upper or in deeper layers, depending on the specific characteristics of the area and sediments.This work was supported by the Spanish Ministry of Environment (2-ESMARME and 2-2-ESMARME projects), the Spanish Inter-Ministerial Science and Technology Commission through the ‘IMPACTA’ (CICYT, CTM2013-48194-C3-1-R) project and the European Union through the European Regional Development Fund (ERDF)

Insuficiencia mitral severa secundaria a rotura del músculo papilar posteromedial

The prevalence of mechanical complications of infarction has decreased in recent years, however, mortality remains high. Echocardiography plays a fundamental role for early diagnosis and management of these complications.&nbsp; We present the case of a patient with ischemic rupture of the posteromedial papillary muscle and severe mitral regurgitation.La prevalencia de las complicaciones mecánicas del infarto se ha reducido en los últimos años, sin embargo, la mortalidad sigue siendo elevada. La ecocardiografía juega un papel fundamental para un diagnóstico y manejo precoz de estas complicaciones.&nbsp; Presentamos el caso de una paciente con rotura isquémica del músculo papilar posteromedial e insuficiencia mitral severa

Sea snail (Hexaplex trunculus) and sea cucumber (Holothuria polii) as potential sentinel species for organic pollutants and trace metals in coastal ecosystems

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