Calcium silicates synthesised from industrial residues with the ability for CO2 sequestration

This work explored several synthesis routes to obtain calcium silicates from different calcium-rich and silica-rich industrial residues. Larnite, wollastonite and calcium silicate chloride were successfully synthesised with moderate heat treatments below standard temperatures. These procedures help to not only conserve natural resources, but also to reduce the energy requirements and CO2 emissions. In addition, these silicates have been successfully tested as carbon dioxide sequesters, to enhance the viability of CO2 mineral sequestration technologies using calcium-rich industrial by-products as sequestration agents. Two different carbon sequestration experiments were performed under ambient conditions. Static experiments revealed carbonation efficiencies close to 100% and real-time resolved experiments characterised the dynamic behaviour and ability of these samples to reduce the CO2 concentration within a mixture of gases. The CO2 concentration was reduced up to 70%, with a carbon fixation dynamic ratio of 3.2 mg CO2 per g of sequestration agent and minute. Our results confirm the suitability of the proposed synthesis routes to synthesise different calcium silicates recycling industrial residues, being therefore energetically more efficient and environmentally friendly procedures for the cement industry.Ministerio de Ciencia e Innovación CIT-440000-09-0

Probability estimation of a Carrington-like geomagnetic storm

Intense geomagnetic storms can cause severe damage to electrical systems and communications. This work proposes a counting process with Weibull inter-occurrence times in order to estimate the probability of extreme geomagnetic events. It is found that the scale parameter of the inter-occurrence time distribution grows exponentially with the absolute value of the intensity threshold defining the storm, whereas the shape parameter keeps rather constant. The model is able to forecast the probability of occurrence of an event for a given intensity threshold; in particular, the probability of occurrence on the next decade of an extreme event of a magnitude comparable or larger than the well-known Carrington event of 1859 is explored, and estimated to be between 0.46% and 1.88% (with a 95% confidence), a much lower value than those reported in the existing literature

Probability estimation of a Carrington-like geomagnetic storm

Altres ajuts: RecerCaixa 2015ACUP00129 i Fundación Santander UniversidadesIntense geomagnetic storms can cause severe damage to electrical systems and communications. This work proposes a counting process with Weibull inter-occurrence times in order to estimate the probability of extreme geomagnetic events. It is found that the scale parameter of the inter-occurrence time distribution grows exponentially with the absolute value of the intensity threshold defining the storm, whereas the shape parameter keeps rather constant. The model is able to forecast the probability of occurrence of an event for a given intensity threshold; in particular, the probability of occurrence on the next decade of an extreme event of a magnitude comparable or larger than the well-known Carrington event of 1859 is explored, and estimated to be between 0.46% and 1.88% (with a 95% confidence), a much lower value than those reported in the existing literature

Procedimiento optimizado para la preparación de silicatos de calcio con capacidad para captar CO2, silicatos así obtenidos y uso de los mismos

Procedimiento para la preparación de silicatos de calcio con capacidad para captar CO 2 , a partir de subproductos, coproductos o residuos agro industriales con contenido en calcio y en silicio. Como fuente de calcio se utiliza portlandita obtenida como residuo de la industria del acetileno o cloruro de calcio; como fuente de silicio se utiliza cascarilla de arroz coproducto o residuo agro-industrial de la industria arrocera o sílice en polvo. El proceso comprende la mezcla y homogeneización de una fuente de calcio y una de silicio y un posterior tratamiento térmico de la mezcla a temperaturas entre 400°C y 900°C. Asimismo, la presente invención se refiere al uso de silicatos de calcio preparados mediante este procedimiento como captadores selectivos de CO 2 en corrientes gaseosas, mediante proceso de carbonatación en condiciones húmedas a presión y temperatura ambiental, generando al mismo tiempo, calcitas con potencial aplicación industrial.Españ

Probability estimation of a Carrington-like geomagnetic storm

Intense geomagnetic storms can cause severe damage to electrical systems and communications. This work proposes a counting process with Weibull inter-occurrence times in order to estimate the probability of extreme geomagnetic events. It is found that the scale parameter of the inter-occurrence time distribution grows exponentially with the absolute value of the intensity threshold defining the storm, whereas the shape parameter keeps rather constant. The model is able to forecast the probability of occurrence of an event for a given intensity threshold; in particular, the probability of occurrence on the next decade of an extreme event of a magnitude comparable or larger than the well-known Carrington event of 1859 is explored, and estimated to be between 0.46% and 1.88% (with a 95% confidence), a much lower value than those reported in the existing literature

Calcium silicates synthesised from industrial residues with the ability for CO2 sequestration

© 2014 The Author(s). This work explored several synthesis routes to obtain calcium silicates from different calcium-rich and silica-rich industrial residues. Larnite, wollastonite and calcium silicate chloride were successfully synthesised with moderate heat treatments below standard temperatures. These procedures help to not only conserve natural resources, but also to reduce the energy requirements and CO2 emissions. In addition, these silicates have been successfully tested as carbon dioxide sequesters, to enhance the viability of CO2 mineral sequestration technologies using calcium-rich industrial by-products as sequestration agents. Two different carbon sequestration experiments were performed under ambient conditions. Static experiments revealed carbonation efficiencies close to 100% and real-time resolved experiments characterised the dynamic behaviour and ability of these samples to reduce the CO2 concentration within a mixture of gases. The CO2 concentration was reduced up to 70%, with a carbon fixation dynamic ratio of 3.2 mg CO2 per g of sequestration agent and minute. Our results confirm the suitability of the proposed synthesis routes to synthesise different calcium silicates recycling industrial residues, being therefore energetically more efficient and environmentally friendly procedures for the cement industry.Peer Reviewe

Relación entre exposición a riesgos psicosociales y salud: un estudio de cohorte mediante el COPSOQ-Istas21

Objetivo: Estimar las relaciones prospectivas entre la exposición a las dimensiones de riesgos psicosociales incluidas en el COPSOQ-Istas21 y el deterioro de la salud general, la salud mental y los problemas del sueño entre personas trabajadoras residentes en España. Método: Cohorte cuya línea base corresponde a la Encuesta de Riesgos Psicosociales de 2016, con una nueva medición al cabo de 1 año. Resultados: Las dimensiones de capital social y de relaciones interpersonales y liderazgo, así como el conflicto trabajo-vida, se relacionaron con todas las variables de salud. Las de organización y contenido del trabajo lo hicieron especialmente con la salud mental, las exigencias cuantitativas con la salud general y las emocionales con la salud mental. Las dimensiones relacionadas con la inseguridad laboral no mostraron relación con la salud. Conclusiones: Los resultados obtenidos refuerzan el papel del COPSOQ-Istas21 como un instrumento útil para la evaluación y la prevención de los riesgos psicosociales en el trabajo.Objective: To estimate the prospective relationships between exposure to psychosocial risks dimensions included in the COPSOQ-Istas21 and the deterioration of general and mental health and sleep problems among workers residing in Spain. Method: Cohort whose baseline corresponds to the 2016 Psychosocial Risks Survey with a new measurement after one year. Results: Social capital and interpersonal relations and leadership dimensions, as well as work̶life conflict, were related to all health variables. Dimensions of work organization and job contents did it especially with the mental health, the quantitative demands with the general health and the emotional ones with the mental health. The dimensions related to job insecurity did not show relationships with health. Conclusions: The results obtained reinforce the role of the COPSOQ-Istas21 as a useful instrument for the evaluation and prevention of psychosocial risks at work

Assessing the Underestimation of HIV Risk Infection among Young Men Who Have Sex with Men in Argentina

The aim of this study is to describe the discordance between the self-perceived risk and actual risk of HIV among young men who have sex with men (YMSM) and its associated factors. An online, cross-sectional study was conducted with 405 men recruited from an Argentinian NGO in 2017. Risk discordance (RD) was defined as the expression of the underestimation of risk, that is, as a lower self-perception of HIV risk, as measured with the Perceived Risk of HIV Scale, than the current risk of HIV infection, as measured by the HIV Incidence Risk Index. Multivariate logistic regression models were used to analyze the associations between the RD and the explanatory variables. High HIV risk was detected in 251 (62%), while 106 (26.2%) showed high self-perceived risk. RD was found in 230 (56.8%) YMSM. The predictors that increased RD were consistent condom use with casual partners (aOR = 3.8 [CI 95:1.5-11.0]), the use of Growler to meet partners (aOR = 10.38 [CI 95:161-121.94]), frequenting gay bars (aOR = 1.9 [95% CI:1.1-3.5]) and using LSD (aOR = 5.44 [CI 95:1.32-30.29]). Underestimation of HIV risk in YMSM is associated with standard HIV risk behavior and modulated by psychosocial aspects. Thus, prevention campaigns aimed at YMSM should include these factors, even though clinical practice does not. Health professionals should reconsider adapting their instruments to measure the risk of HIV in YMSM. It is unknown what score should be used for targeting high-risk YMSM, so more research is needed to fill this gap. Further research is needed to assess what score should be used for targeting high-risk in YMSM

Probability estimation of a Carrington-like geomagnetic storm

Altres ajuts: RecerCaixa 2015ACUP00129 i Fundación Santander UniversidadesIntense geomagnetic storms can cause severe damage to electrical systems and communications. This work proposes a counting process with Weibull inter-occurrence times in order to estimate the probability of extreme geomagnetic events. It is found that the scale parameter of the inter-occurrence time distribution grows exponentially with the absolute value of the intensity threshold defining the storm, whereas the shape parameter keeps rather constant. The model is able to forecast the probability of occurrence of an event for a given intensity threshold; in particular, the probability of occurrence on the next decade of an extreme event of a magnitude comparable or larger than the well-known Carrington event of 1859 is explored, and estimated to be between 0.46% and 1.88% (with a 95% confidence), a much lower value than those reported in the existing literature