644 research outputs found

    Market Opportunities of Water Treatments Powered by Solar Micro Gas Turbines: Chile and Ecuador Case Studies

    Get PDF
    Throughout the last decades the developments on desalination field have been focused on energy consumption and costs reduction. However, water recovery and brine disposal are becoming a matter of concern to desalination industry. In this work, a Zero Liquid Discharge (ZLD) unit coupled with a Solar Micro Gas Turbine (SMGT) system is presented to address, among others, the challenges of mining industry in remote areas, in particular, fossil fuel dependence, water availability and pollution derived from effluents disposal. As a way to assess the feasibility of the proposal, a techno-economic analysis of the application in two Southern American regions (Chile and Ecuador) of photovoltaic modules, wind turbines and Solar Micro Gas Turbines is performed. Afterwards, the main novel feature of the new system—i.e., the ZLD unit—is described and a sensitivity analysis on its functioning whilst coupled with the SMGT is carried out. The aim is to propose a preliminary design of the ZLD process. The selection of the optimal ratio between exhaust gases and brine mass flow rates is analyzed, as well as variation in inlet salinity and temperatures. Furthermore, the water which could be recovered from effluents, at the same time that the heat of exhaust gases from SMGT is harvested, is quantified. Lastly, according to the results obtained, a preliminary design of a 10 kWe rated power SMGT system, coupled to Reverse Osmosis (RO) and ZLD units, is proposed.Ministerio de Ciencia, Innovación y Universidades - Agencia Estatal de Investigación (AEI) - Fondo Europeo de Desarrollo Regional (FEDER) RTI2018-102196-B-100FEDER - Interreg Atlantic Area (EERES4WATER project) EAPA 1058/2018Universidad de Sevilla 2019/0000035

    Análisis de la prevención de riesgos laborales en procesos mecánicos de la construcción de trenes

    Get PDF
    Visión del mundo ferroviario desde el punto de vista de la Ingeniería Mecánica, relacionando los procesos mecánicos de forja y soldadura aluminotérmica que tienen lugar para la obtención de ruedas de tren y de carriles ferroviarios, respectivamente, con los riesgos laborales que estos procedimientos pueden presentar. <br /

    Tournament en el mercado español de fondos de inversión de renta variable nacional

    Get PDF
    En este Trabajo de Fin de Grado he analizado la existencia de comportamiento tournament entre los gestores de fondos de inversión de renta variable nacional domiciliados en España en el periodo 2006-2018. Para ello, siguiendo a Brown et al. (1996), he estudiado si los gestores “perdedores” en la primera parte del año, aumentan en mayor grado que los “ganadores” el riesgo que asumen en su gestión durante la segunda parte, con el objetivo de alcanzar mejores posiciones en los rankings de performance financiera al final del año.De forma adicional, para testar la robustez del estudio, he analizado de las siguientes maneras la muestra de datos: por sub-muestras temporales (la primera del 2006-2012 y la segunda del 2013-2018), excluyendo del análisis original el mes de diciembre para controlar por efecto window-dressing y según el tamaño de los fondos de inversión.Los resultados obtenidos varían según el periodo considerado para la primera parte del año. De este modo, en todos los test realizados, observo que cuando se considera la ventana (5-7) existe evidencia significativa de tournament. Sin embargo, esta evidencia no se da para el resto de ventas analizadas (4-8), (6-6), (7-5) y (8-4). Este mismo resultado se observa para fondos grandes y pequeños, por lo que se puede concluir que el tamaño del fondo no afecta al comportamiento de los gestores analizados. Además, cuando controlo por window-dressing observo que también hay evidencia significativa de tournament para la ventana (4-8) y cuando analizo las diferentes submuestras temporales, la evidencia de tournament es más fuerte entre los años 2006-2012.<br /

    Uso potencial de arcillas modificadas con metales para la obtención de formulaciones de liberación lenta de herbicidas.

    Get PDF
    9 páginas., 5 gráficos, 2 tablas y 9 referencias. Versión extendida de la comunicación presentada en la "XIX Reunión Científica de la Sociedad Española de Arcillas - SEA05", celebrada en Salamanca del 26 al 28 de Septiembre de 2005. Enlace a la web de la Sociedad Española de Arcillas http://www.sea-arcillas.es/publicacionesSEA.htm[EN]Abstract A slow release system of the herbicide imazapyr was designed by adsorption on pillared clays. Pillared clays based on aluminum and mixed aluminum-copper solutions were synthesized. The aim was to check whether the introduction into the pillars of a metal complexing the herbicide molecules enhanced the sorption and release properties of the clay for the herbicide. A commercial aluminum pillared clay was also examined as a potential sorbent. The chemical analysis data as well as those of X-ray diffraction show that copper from pillaring solutions was partially introduced, and the basal spacing were increased about 9 Å in good agreement with the size of the Keggin ion. The textural properties indicate a reduction in the micro- and mesoporosity of the pillared clays after pillaring with copper solutions. The largest the copper content in the mixed Al-Cu pillared clays the largest the decrease in the surface area. However, imazapyr adsorption increased up to three-fold compared to the commercial pillared clay, and desorption percentages from the Cu-Al pillared clays were three-fold lower than the commercial one, whose desorption was completely reversible. These preliminary results show the potential use of Cu-Al pillared clays for the development of slow release formulations of the herbicide imzapyr, unlike those whose pillars are only made of aluminum.[ES]Resumen En el presente trabajo se ha intentado desarrollar un sistema de liberación lenta del herbicida imazayr mediante su adsorción en arcillas pilareadas. Se han sintetizado arcillas pilareadas con aluminio y con soluciones mixtas Cu-Al, a fin de comprobar si la formación de pilares mixtos de aluminio con un metal complejante del herbicida mejoraba las propiedades de adsorción y liberación del mismo. También se ha estudiado el empleo potencial de una arcilla pilareada comercial formada con pilares exclusivos de aluminio. Los resultados de análisis químico así como de difracción de rayos X muestran que parte del cobre de las soluciones pilareantes se ha introducido en las arcillas finales, cuyos espaciados basales presentan un incremento de aproximadamente 9 Å, que se corresponde con el tamaño del ión Keggin. Las propiedades texturales indican una disminución tanto de la microporosidad como de la mesoporosidad en las arcillas tras su pilarización con soluciones de Cu-Al, que es tanto mayor cuanto mayor es el contenido de Cu. A pesar de la reducción en la superficie de estas arcillas sintetizadas con Cu, la adsorción de imazapyr incrementaba hasta 3 veces con respecto a la arcilla pilareada comercial. A su vez los porcentajes de desorción en la arcillas pilareadas con Cu-Al eran hasta tres veces inferiores a los correspondientes a la arcilla pilareada comercial, cuya desorción era prácticamente reversible. Estos resultados preliminares avalan el uso potencial de arcillas pilareadas con Cu-Al para el desarrollo de formulaciones de liberación lenta del herbicida imazapyr, a diferencia de aquellas en las que los pilares se encuentran formados únicamente por aluminio.Peer Reviewe

    Circulating Undercarboxylated Osteocalcin as Estimator of Cardiovascular and Type 2 Diabetes Risk in Metabolic Syndrome Patients

    Get PDF
    Undercarboxylated osteocalcin (ucOC) could be a biomarker of glucose disturbances and cardiovascular risk. Our study aimed to determine the association between serum levels of ucOC and cardiovascular risk in metabolic syndrome (MetS) patients and to analyse its potential role as estimator of type 2 diabetes (T2D) risk in this population. This cross-sectional study included 235 patients with MetS, 53.2% women, aged 55–75 years. Circulating ucOC levels were measured by ELISA. Cardiovascular risk was determined as Z-score of the diagnostic criteria for MetS (CV-ZS). Linear regression model was performed to analyse the association between circulating ucOC and CV-ZS. A receiver operating curve (ROC) was performed to analyse the usefulness of ucOC as T2D risk estimator. Patients above the CV-ZS median showed signifcant lower ucOC levels. We found an inverse association between ucOC levels and CV-ZS in MetS patients without T2D. Patients with ucOC levels below the 25th percentile showed worse cardiometabolic profle and higher cardiovascular and T2D risk. The area under the curve performed better when ucOC levels were included along with the classic T2D risk factors. The measurement of circulating ucOC could be a useful tool to identify increased cardiovascular and T2D risk in MetS patients without T2D.Junta de Andalucia PI-0207-2016European Union (EU) PI18-00803 PI18-0123

    The colored Hanbury Brown--Twiss effect

    Full text link
    The Hanbury Brown--Twiss effect is one of the celebrated phenomenologies of modern physics that accommodates equally well classical (interferences of waves) and quantum (correlations between indistinguishable particles) interpretations. The effect was discovered in the late thirties with a basic observation of Hanbury Brown that radio-pulses from two distinct antennas generate signals on the oscilloscope that wiggle similarly to the naked eye. When Hanbury Brown and his mathematician colleague Twiss took the obvious step to propose bringing the effect in the optical range, they met with considerable opposition as single-photon interferences were deemed impossible. The Hanbury Brown--Twiss effect is nowadays universally accepted and, being so fundamental, embodies many subtleties of our understanding of the wave/particle dual nature of light. Thanks to a novel experimental technique, we report here a generalized version of the Hanbury Brown--Twiss effect to include the frequency of the detected light, or, from the particle point of view, the energy of the detected photons. In addition to the known tendencies of indistinguishable photons to arrive together on the detector, we find that photons of different colors present the opposite characteristic of avoiding each others. We postulate that fermions can be similarly brought to exhibit positive (boson-like) correlations by frequency filtering.Comment: 18 pages, includes supplementary material of the derivation

    IAPT chromosome data 28

    Get PDF
    [EN] Veronica angustifolia (Vahl) Bernh.; Veronica austriaca subsp. jacquinii (Baumg.) Watzl; Veronica dalmatica N.Pad.Gar., Rojas-Andrés, López-González &amp; M.M.Mart.Ort.; Veronica kindlii Adam.; Veronica orsiniana Ten.; Veronica prostrata L.; Veronica rosea Desf.; Veronica sennenii (Pau) M.M.Mart.Ort. &amp; E.Rico; Veronica tenuifolia subsp. javalambrensis (Pau) Molero &amp; J.Pujadas; Veronic tenuifolia Asso subsp. tenuifolia; Veronica teucrium L.; Veronica thracica Velen.. In: K. Marhold &amp; J. Kucera, IAPT chromosome data 28

    Does Seipin Play a Role in Oxidative Stress Protection and Peroxisome Biogenesis? New Insights from Human Brain Autopsies

    Get PDF
    Seipin is a widely expressed protein but with highest levels found in the brain and testes. Seipin function is not yet completely understood, therefore the aim of this study was to evaluate the expression of BSCL2 transcripts in the central nervous system (CNS) of humans and investigate the effect of their overexpression on a neuron model and their relationship with oxidative stress protection, as well as shed light on the pathogenic mechanisms of Celia’s Encephalopathy. We analyzed the expression of BSCL2 transcripts using real-time RT– PCR in samples across the brain regions of subjects who underwent necropsy and from a case with Celia’s Encephalopathy. The transcript encoding the long seipin isoform (BSCL2-203, 462 aa) is expressed primarily in the brain and its expression is inversely correlated with age in the temporal lobe, amygdala, and hypothalamus. Strong positive correlations were found between BSCL2 expression and some genes encoding protective enzymes against oxidative stress including SOD1 and SOD2, as well as peroxisome proliferator-activated receptor gamma (PPARG) in the amygdala. These results were experimentally corroborated by overexpressing BSCL2 transcripts in SH-SY5Y cells with lentiviral transduction and assessing their effects on neuron differentiated cells. Confocal microscopy studies showed that both seipin and PEX16 are closely expressed in the hypothalami of healthy human brains, and PEX16 was absent in the same region of the PELD case. We hypothesize that seipin has specific CNS functions and may play a role in peroxisome biogenesis.This work was supported by the Instituto de Salud Carlos III and the European Regional Development Fund, FEDER (grants number PI10/02873 and PI13/00314), by the Consellería de Industria, Xunta de Galicia (grants number 10PXIB208013PR and ED341b2017/19), and by Fundación Mutua Madrileña (Call 2015)S
    corecore