De mercenarios a héroes: un recorrido por la historia del periodismo Freelance

Los freelance son periodistas independientes que se distinguen de sus compañeros de plantilla en que trabajan para varios medios de comunicación sin pertenecer a la plantilla de ninguno de ellos. Las diferencias laborales son tantas que es necesario que la Universidad acepte la necesidad de impartir una formación específica para ellos, que les proporcione las armas intelectuales necesarias para luchar por sus derechos. Es impensable que iniciado ya el siglo XXI estos profesionales trabajen sin seguro en zonas de riesgo o que al darse de alta como autónomos tengan que renunciar casi al 50 % de sus ingresos. Todavía hoy día la mayor parte de los datos que conocemos sobre ellos es a través de sus trabajos, debido a la escasa documentación que hay sobre esta profesión. Y ello a pesar de que se lleva ejerciendo desde el mismo momento que el periodismo de plantilla.The freelance are independent journalists who differ from their companions of staff at which they are employed for several mass media without belonging to the staff of any of them. There are so many differences between them that it is necessary that the University accepts the need to give a specific formation for them, which provides to them the intellectual necessary weapon to fight for their rights. It is unthinkable that initiated the XXIst century these professionals are employed without assurance at zones of risk or that on having be given of discharge as autonomous they have to resign almost 50 % of their income. Still today most of the information that we know on them is across their works, due to the scanty documentation that exists on this profession. And it in spite of the fact that it exists from the same moment that the journalism of staff

Full factorial design to assess the concrete gas permeability

Novel composite material durability is mainly affectedby the transport of fluids and ions through thepore system which are potentially able to producedamage. Then, a key indicator of long-term durabilityof the structures can be the ease with which aggressiveagents are transported through the pore system,i.e. composite material permeability. The purpose ofthis paper is to broaden our knowledge of air permeabilitytesting conditions and, in particular, how it isaffected by the preconditioning temperature and testingpressure. Optimization of variables to determinatethe air permeability coefficient was done by using a 23full factorial design. Air permeability results are recordedin ∅150x70 mm3 concrete specimens. The airpermeability determination procedure gives reliableinformation about the quality of concrete with regardto its durability

Coal ash Portland Cement Mortars Sulphate Resistance

Coal fly ash (CFA), coal bottom ash (CBA) are residues produced in thermo-electrical power stations as result of the coal combustion in the same boiler. Therefore, some characteristics of the coal fly ash (CFA) are comparable with those of the coal bottom ash (CBA). Nevertheless, coal bottom ash size is larger than coal fly ash one. Consequently, it was found that it is necessary to grind the coal bottom ash (CBA) to reach a similar size to that one of the CFA. The objective of this paper is to evaluate the performance of Portland cement mortars made with coal fly ash (CFA), coal bottom ash (CBA) or mixes (CFA+CBA), against sulphate attack. The methodology is based on the expansion of slender bars submerged in a sodium sulphate solution (5%) according to the ASTM C-1012/C1012-13 standard. It has been found that mortars elaborated with CEM I 42.5 N (without ashes) presented the largest expansion (0.09%) after a testing period of 330 days. Mortars made with CEM II/A-V exhibited lower expansion (0.03%). Summing up, it can be established that mortar expansion decreases when the coal ash amount increases, independently of the type of coal ash employed. The novelty of this paper relies on the comparison between the performances of Portland cement mortars made with coal fly ash (CFA) or coal bottom ash (CBA) exposed to external sulphate attack. Doi: 10.28991/cej-2021-03091640 Full Text: PD

Efecto de la granulometría de los áridos en la permeabilidad al aire del hormigón

Great durability problems are being found in concrete structures related to the penetrability of aggressive agents through the concrete (ie. chloride penetration, sulphate attack, carbonation, freezing and thawing, and so on). Air permeability coefficient is used as an effective tool to estimate the potential durability of concrete structures due to its direct relation with the microstructure and the moisture content. This paper discusses the effect of the aggregate grading and water/cement ratio on the air permeability coefficient. An aggregate grading with more sand than coarse aggregates has resulted more beneficial from the point of view of concrete air permeability. This fact can be attributed to a denser skeleton formed by the finer aggregates. With fine aggregates, the higher water/cement ratio, the lower air permeability. However, the contrary was found with coarse aggregates. Overall, a temperature increase from 20 °C to 60 °C during preconditioning led to a Dair increase of 40–80%.Se han encontrado una gran cantidad de problemas de durabilidad de estructuras de hormigón relacionados con la penetración de agentes agresivos externos (es decir, penetración de cloruros, ataque por sulfatos, carbonatación, hielo-deshielo, etc.). El coeficiente de permeabilidad al aire se utiliza como una herramienta eficaz para estimar la durabilidad potencial de las estructuras de hormigón debido a su relación directa con su microestructura y contenido de humedad. Se discute el efecto de la gradación de los áridos y relación agua/cemento en el coeficiente de permeabilidad al aire. Con áridos más finos que gruesos, el resultado es más beneficioso, lo que se atribuye a que la arena forma un esqueleto más denso. Con áridos más finos, al aumentar la relación agua/cemento, disminuye la permeabilidad al aire; pero con áridos más gruesos se ha observado lo contrario. Cuando se pre-acondiciona de 20 °C a 60 °C, se produce un aumento del Dair del 40–80%

Simplified engineering design towards a competitive lipid-rich effluents valorization

Medium- and long-chain fatty acids and glycerol contained in the oily fraction of many food-industry effluents are excellent candidates to produce biobased high-value triacylglycerides (TAGs) and polyhydroxyalkanoates (PHAs). The typical process configuration for TAGs recovery from lipid-rich streams always includes two steps (culture enrichment plus storage compounds accumulation) whereas, for PHAs production, an additional pretreatment of the substrate for the obtainment of soluble volatile fatty acids (VFAs) is required. To simplify the process, substrate hydrolysis, culture enrichment, and accumulation (TAG and PHA storage) were coupled here in a single sequencing batch reactor (SBR) operated under the double growth limitation strategy (DGL) and fed in pulses with industrial waste fish oil during the whole feast phase. When the SBR was operated in 12 h cycles, it was reached up to 51 wt % biopolymers after only 6 h of feast (TAG:PHA ratio of 50:51; 0.423 CmmolBIOP/ CmmolS). Daily storage compound production was observed to be over 25% higher than the reached when enrichment and accumulation stages were carried in separate operational units. Increasing the feast phase length from 6 to 12 h (18 h cycle) negatively affected the DGL strategy performance and hence system storage capacity, which was recovered after also extending the famine phase in the same proportion (24 h cycle). Besides, the carbon influx during the feast phase was identified as a key operational parameter controlling storage compounds production and, together with the C/N ratio, culture selection. The different cycle configurations tested clearly modulated the total fungal abundances without no significant differences in the size of the bacterial populations. Several PHA and TAG producers were found in the mixed culture although the PHA and TAG productions were poorly associated with the increased relative abundances (RAs) of specific operational taxonomic units (OTUs).Spanish Government (AEI, Spain) through the TREASURE project CTQ 2017-83225-C2-1-R operative program FSE Galicia 2014-2020European Commissio

Auto Dealership Engagement Manual, Volume 1

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Influencia de la combinación de nano-SiO2 y nano-Fe2O3 en la resistencia a compresión, resistencia a tracción, porosidad y resistividad eléctrica de morteros de cemento.

The compressive strength, flexural strength, porosity and electrical resistivity properties of cement mortars with nano-Fe2O3 and nano-SiO2 are studied. Amorphous silica is the main component of pozzolanic materials due to its reaction with calcium hydroxide formed from calcium silicate (C3S and C2S) hydration. The pozzolanic reaction rate is not only proportional to the amount of amorphous silica but also to the surface area available for reaction. Subsequently, fine nano-Fe2O3 and nano-SiO2 particles in mortars are expected to improve mortar performance. The experimental results showed that the compressive strength of mortars with nano-Fe2O3 and nano-SiO2 particles were lower than those obtained with the reference mortar at seven and 28 days. It was shown that the nano-particles were not able to enhance mechanical strength on every occasion. The continuous microstructural progress monitored by mercury intrusion porosimetry (MIP) measurements, pore-size distribution (PSD), total porosity and critical pore diameter also confirmed such results.Se estudia la resistencia a compresión y flexión, porosidad y resistividad eléctrica de morteros de cemento con nano-Fe2O3 y nano-SiO2. La sílice amorfa reacciona con el hidróxido de calcio formado en la hidratación del C3S y C2S. La tasa de reacción puzolánica es proporcional a la cantidad de sílice amorfa y la superficie disponible para la reacción, esperando que las partículas finas de nano-Fe2O3 y nano-SiO2 mejoren las propiedades de los morteros. Los resultados experimentales han mostrado que la resistencia a compresión a siete y 28 días de morteros con partículas de nano-Fe2O3 y nano-SiO2 era, en ocasiones, inferior a la obtenida con el mortero de referencia. Se muestra que las nano-partículas no siempre son capaces de mejorar la resistencia de los morteros. Las medidas mediante porosimetría de intrusión de mercurio (PIM) de la distribución de tamaño de poro (DTP), porosidad total y diámetro de poro crítico confirmaron estos resultados

Auto Dealership Engagement Manual, Volume 2

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La nueva norma europea de especificaciones de cementos comunes UNE-EN 197-1:2011

In this paper, the novelties of European standard EN 197-1:2011 which has been aprobed on 6th August, 2011 are presented. The european standard EN 197-1:2011 has been published in the Official Journal of the European Union on 19th June, 2012 (C 176/1). The UNEEN 197-1:2011 will be published in Spain in the Official Journal of Spain (B.O.E.). The date of applicability (DAV) of the standard as a harmonised European standard is on 1st of July, 2012 and the date of the end of the coexistence period is on 1st of July, 2013. The former EN 197-1:2000 has been the first European standard in the field of the Construction Products Directive (CPD) and this first revision include the requirements needed for a common cement to be, in addition, sulphate resisting cement. Therefore, the mandate given by the European Commission to CEN to prepare harmonised standards in the cement field (mandate M114) has been fulfilled.En este artículo se presentan las novedades de la nueva norma europea de especificaciones de cementos comunes UNE-EN 197-1:2011 aprobada el 6 de agosto de 2011 como EN 197-1:2011 y publicada el 19 de junio de 2012 en el Diario Oficial de la Unión Europea (DOUE). Esta norma se publicará en el Boletín Oficial del Estado (BOE) antes de final de año. La fecha de disponibilidad (date of applicability, DAV) es el 1 de julio de 2012 y el periodo de coexistencia finalizará el 1 de julio de 2013. La UNE-EN 197-1:2000 fue la primera norma armonizada dentro del campo de la Directiva de Productos de la Construcción (DPC) europea y esta primera revisión incorpora unos nuevos requisitos para establecer cuándo un cemento común, además, es resistente a la acción de los sulfatos. De esta forma, se completa el mandato dado por la Comisión Europea a CEN para la elaboración de normas armonizadas de cementos (mandato M114)

Exploring the production of bio-succinic acid from apple pomace using an environmental approach

This is the accepted manuscript of the following article: González-García, S., Argiz, L., Míguez, P., Gullón, B., 2018. Exploring the production of bio-succinic acid from apple pomace using an environmental approach. Chemical Engineering Journal 350, 982-991Fermentation-derived bio-succinic acid (BioSA) is a valuable intermediate; it is used as a chemical building block, and has multiple industrial applications as an alternative to petroleum counterparts. The aim of this study was to develop a full-scale plant to produce BioSA fromapple pomace, a low-cost solid waste from the cider- and juice-making industry, based on abiorefineryconcept, and to determine its environmental profile using acradleto-factory-gate, scaled-up LCA approach. Foreground data used in this LCA were based on mass and energy flows, modelled in detail. The production process was divided into three stages: i) reconditioning and storage; ii) fermentation with Actinobacillus succinogenes; and iii) purification. The results indicate that the use of enzymes is responsible for the highest environmental burdens, due to their highly energy-intensive background production processes. When these were excluded from the analysis (following other studies available in the literature), the purification stage played an environmentally significant role, due to the extraction and distillation units involved. The electricity use and the requirements for organic solvents in these operations make up the largest environmental burdens. Thus, approaches with the highest potential for improvement must involve both operations. Alternatives for improvement are proposed that offer interesting potential reductions in the environmental profile, especially at the purification stage.This research has been partially supported the STAR-ProBio project funded by the European Union’s Horizon 2020 Program (Grant agreement No.727740) andbyaproject granted byXunta de Galicia(project ref.ED431F2016/001). Dr. S.González-Garcia an dDr.B.Gullón would like to express their gratitude to the Spanish Ministry of Economy and Competitiveness for financial support (Grant references RYC-201414984 and IJCI-2015-25305). The authors (S. González-Garcia and Dr. B. Gullón) belong to the Galician Competitive Research Group GRC 2013-032 and to CRETUS Strategic Partnership (AGRUP2015/02). All these programmes are co-funded by Xunta de Galicia and FEDER (EU)S