217 research outputs found
ELIMINACIÓN DE PINTURAS EN AEROSOL SOBRE SOPORTES POROSOS. REVISIÓN DE METODOLOGÍAS Y NUEVAS PROPUESTAS
Se desarrolla aquí una investigación que parte del conocimiento de los materiales presentes en los monumentos y su estado de conservación, así como del análisis al fenómeno del graffiti, las resinas sintéticas y las metodologías actuales de limpieza, para seguidamente desarrollar un proceso experimental sobre eliminación de graffitis.Reina De La Torre, A. (2009). ELIMINACIÓN DE PINTURAS EN AEROSOL SOBRE SOPORTES POROSOS. REVISIÓN DE METODOLOGÍAS Y NUEVAS PROPUESTAS. http://hdl.handle.net/10251/1450
Aproximación al estudio de la relación mujer-economía en los libros de texto de la España democrática : análisis comparativo entre el periodo de la transición y los primeros años del siglo XXI
La relación entre mujer y cultura económica en el panorama español ha sido poco estudiada por
los historiadores, mucho menos si la vinculamos a la socialización recibida durante los años de
formación escolar obligatoria, que creemos que influyen en la futura elección profesional. Los
libros de texto, recursos didácticos muy utilizados por el profesorado, pueden proporcionar
importantes pistas acerca de la toma de decisiones de las mujeres con relación a las actividades
que van a desempeñar dentro del campo económico, puesto que reflejan los estereotipos e
ideologías que caracterizan la mentalidad dominante de una determinada época y sociedad. Este
será el objetivo de nuestro trabajo: observar el papel de las mujeres respecto al ámbito
económico, mediante un análisis de contenido tanto de las imágenes como de los textos escritos
de manuales utilizados en la etapa de obligatoriedad escolar comparando dos períodos: la
Transición y los primeros años de la democracia.Historians have not deeply explored the relationship between women and economic culture in the
Spanish panorama, much less, if we link it to the socialization received during compulsory
schooling years which influences future career choices. Textbooks have dominated over other
resources at school and they can provide important clues about women's decision-making in
relation to their economic activities, as they incorporated the underpinnings of social, cultural and
economic mainstream. Likewise, we think that sexist stereotypes abound in textbooks too. This
paper presents a content analysis of textbooks, both of the illustrations and the text itself. The aim
of this research is to observe the economic role of women rendered in primary studies textbooks
after Franco’s regime, comparing those used during the early years of democracy, also called
“Transición” and nowaday’s Spain
Rheological and hydration characterization of calcium sulfoaluminate cement pastes
Calcium sulfoaluminate (CSA) cements are currently receiving a lot of attention because their manufacture produces less CO2 than ordinary Portland cement (OPC). However, it is essential to
understand all parameters which may affect the hydration processes. This work deals with the study of the effect of several parameters, such as superplasticizer (SP), gypsum contents (10, 20 and 30 wt%) and w/c ratio (0.4 and 0.5), on the properties of CSA pastes during early hydration. This characterization has been performed through rheological studies, Rietveld quantitative phase
analysis of measured x-ray diffraction patterns, thermal analysis and mercury porosimetry for
pastes, and by compressive strength measurements for mortars. The effect of the used SP on the
rheological properties has been established. Its addition makes little difference to the amount of
ettringite formed but strongly decreases the large pore fraction in the pastes. Furthermore, the SP role on compressive strength is variable, as it increases the values for mortars containing 30 wt% gypsum but decreases the strengths for mortars containing 10 wt% gypsum.This work has been supported by Spanish Ministry of Science and Innovation through MAT2010-
16213 research grant, which is co-funded by FEDER, and Ramón y Cajal Fellowship (RYC-2008-
03523)
Hydration studies of calcium sulfoaluminate cements blended with fly ash
The main objective of this work is to study the hydration and properties of calciumsulfoaluminate cement pastes
blended with fly ash (FA) and the corresponding mortars at different hydration ages. Laboratory X-ray powder
diffraction, rheological studies, thermal analysis, porosimetry and compressive strength measurements were
performed. The analysis of the diffraction data by Rietveld method allowed quantifying crystalline phases and
overall amorphous contents. The studied parameters were: i) FA content, 0, 15 and 30 wt.%; and ii) water addition,
water-to-CSA mass ratio (w/CSA = 0.50 and 0.65), and water-to-binder mass ratio (w/b = 0.50). Finally,
compressive strengths after 6 months of 0 and 15 wt.% FA [w/CSA = 0.50] mortars were similar: 73 ± 2 and
72 ± 3 MPa, respectively. This is justified by the filler effect of the FA as no strong evidences of reactivity of FA
with CSA were observed. These results support the partial substitution of CSA cements with FA with the economic
and environmental benefitsThis work has been supported by Spanish MINECO through MAT2010-16213 research grant, which is co-funded by FEDER. I. Santacruz thanks a Ramón y Cajal fellowship, RYC-2008-03523
Rietveld Quantitative Phase Analysis of OPC Clinkers, Cements and Hydration Products
Universidad de Málaga. Campus de Excelencia Interacional. Andalucía Tech
Economía y mujer en la manualística escolar de la España democrática: análisis comparativo entre el período de la Transición y los primeros años del siglo XXI
A lo largo de los años, los manuales escolares han sido uno de los recursos didácticos más utilizados por
el profesorado. El libro escolar es, además de un soporte curricular a través del cual se transmite el conocimiento
académico que las instituciones han de propagar, un reflejo de la sociedad que lo produce en
cuanto a que en él se vehiculan valores, actitudes, estereotipos e ideologías que caracterizan la mentalidad
dominante de una determinada época o, lo que es lo mismo, el imaginario colectivo que configura el
currículum explícito, y también el oculto. Dicho imaginario ha sostenido la persistencia de una sociedad
patriarcal, en la que la mujer aparece en un lugar secundario con respecto al hombre, y con unos roles
prefijados conectados a una visión esencialista de la condición femenina.
Cabría pensar que España, tras el fin de la dictadura franquista, ha experimentado una evolución significativa
en la forma de concebir las funciones políticas, económicas y sociales adjudicadas a ambos
sexos, intentando evitar desigualdades perniciosas. Dicha evolución debería verse reflejada en los libros
de texto que el alumnado maneja en las aulas. A través de este trabajo, y mediante análisis tanto cuantitativo
como cualitativo tanto de las imágenes como de los textos verbales, queremos observar si dicha
evolución ha existido, sobre todo desde el punto de vista de la denominada «cultura económica», analizando
manuales escolares utilizados en la etapa de obligatoriedad escolar en dos períodos: la Transición
y los primeros años del siglo XXI. Se trata de establecer cambios y permanencias, lo que nos permitirá
dar recomendaciones de cara a la confección y/o uso de e ste tipo de recurso en la escuela.Over the years, textbooks have dominated over other resources at school. Textbooks are also a conduit for
the academic content that institutions want to deliver, a reflection of society in that the mainstream social
attitudes, values and stereotypes and ideologies are reflected in their pages. It is a well-known fact that the
established mindset is disseminated with them, hence shaping an overt and covert curriculum. Textbooks
therefore reproduce the collective imagination dominated by a patriarchal society, one in which women play
a second position and play traditional female roles. Altogether, it paints the essentialist female condition.
Post-Franco Spain put an end to dictatorial manners and now new social, economic and political reality
should prevail and harmful sex inequality should have vanished too. Textbooks should replicate this
new lifestyle. This paper presents a content analysis of textbooks, both of the illustrations and the text
itself. We want to test if this change has taken place a tall, with a particular analysis of the economic
culture. We therefore compare textbooks of the time right after the dictatorship, some forty years ago
with the textbooks in use now at the turn of the century. We explore differences and similarities which
may inspire new textbooks for the present time
Identidad profesional y socialización de género: un estudio desde la manualística escolar en la España democrática
The construction of professional identity is a concept that holds interest for a variety of disciplines such as Anthropology, Psychology or Pedagogy. From the perspective of social constructivism, it has a narrative, dynamic character and is shaped by the interaction of the subject with current socio-historical discourses and their interiorization. During the decade of the nineteen seventies, the labor market in Spain experienced a massive incorporation of women, brought about by social and legislative advances in education and employment. The years of Spanish democracy are essential in the configuration and renewal of female identity in the economic field. This article focuses on the influence of the school textbook - the main didactic resource used in formal education - in this configuration. It presents models and stereotypes linked to gender, with a potential influence on the transmission and configuration of a biased socio-labor culture. In order to study this influence, our research examines a total of 20 elementary education textbooks in the areas of Language and Social Sciences in two periods of democratic Spain —the so-called Transition period and the current moment—, to explore the professional identity of women linked to the economic socialization as this is conveyed through this educational tool. Our results reveal a minimal inclusion of women as economic subjects in the textbooks; the underrepresentation of females performing paid activities, as well the lack of professional diversity serve to highlight a substantial inequality in the socialization processes between men and women, contrary to the goals of coeducational teaching values. La construcción de la identidad profesional es un tema de interés para diferentes disciplinas como la antropología, la psicología o la educación. Siguiendo el enfoque del constructivismo social, entendemos que esta tiene un carácter narrativo y dinámico y que se forma a partir de la interiorización de discursos sociohistóricos vigentes en las situaciones con las que el sujeto interacciona. Durante la década de los años setenta del siglo XX, el mercado laboral en España experimentó una masiva incorporación de las mujeres, promovida por progresos sociales y legislativos en educación y empleo. Los años de democracia española han resultado fundamentales en la configuración y renovación de la identidad femenina en el ámbito económico. El manual escolar, principal recurso didáctico utilizado en la educación formal, se presenta como un instrumento socializador con poder relevante en la transmisión y configuración de una cultura sociolaboral sesgada en caso de contener estereotipos de género. Nuestra investigación examina un total de veinte libros de texto de Educación Primaria de las áreas de Lengua y Sociales en dos periodos de la España democrática - Transición política y actualidad -, estudiando la identidad profesional femenina vinculada a la socialización económica difundida mediante este material. Los resultados desvelan una escasa participación de las mujeres como sujetos económicos en los manuales, mostrando una insuficiente representación femenina en el desempeño de actividades remuneradas, así como una falta de diversidad profesional que pone en relieve una gran desigualdad en los procesos de socialización entre hombres y mujeres contrarios a valores coeducativos.
In-situ Molibdenum X-ray powder diffraction study of the early hydration of cementitious systems on a humidity chamber
The durability of cement-based construction materials depends on the environmental conditions during their service
life. A further factor is the microstructure of the cement bulk, established by formation of cement hydrates. The
development of the phases and microstructure under given conditions is responsible of the high strength of cementitious
materials. The investigation on the early hydration behavior of cements and cementing systems has been for a long time
a very important area of research: understanding the chemical reactions that lead to hardening is fundamental for the
prediction of performances and durability of the materials.
The production of 1 ton of Ordinary Portland Cement, OPC, releases into the atmosphere ~0.97 tons of CO2. This
implies that the overall CO2 emissions from the cement industry are 6% of all anthropogenic carbon dioxide. An
alternative to reduce the CO2 footprint consists on the development of eco-cements composed by less calcite demanding
phases, such as belite and ye'elimite. That is the case of Belite-Ye’elimite cements (BY). Since the reactivity of belite is
not quick enough, these materials develop low mechanical strengths at intermediate hydration ages. A possible solution
to this problem goes through the production of cements which jointly contain alite with the two previously mentioned
phases, named as Belite-Alite-Ye’elimite (BAY) cements. The reaction of alite and ye'elimite with water will develop
cements with high mechanical strengths at early ages, while belite will contribute to later values.
The final goal is to understand the hydration mechanisms of a variety of cementing systems (OPC, BAY and pure
phases) as a function of water content, superplasticizer additives and type and content of sulfate source. In order to do
so, in-situ laboratory humidity chambers with Molybdenum X-ray Powder diffraction are employed. In the first 2h of
hydration, reaction degree (α) of ye'elimite had been decreased for superplasticizer.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Effect of calcium sulfate source on the hydration of calcium sulfoaluminate eco-cement
The availability of cements, including eco-cements, with tailored mechanical properties is very important
for special applications in the building industry. Here we report a full study of the hydration of calcium
sulfoaluminate eco-cements with different sulfate sources (gypsum, bassanite and anhydrite) and two
water/cement ratios (0.50 and 0.65). These parameters have been chosen because they are known to
strongly modify the mechanical properties of the resulting mortars and concretes. The applied multitechnique
characterization includes: phase assemblage by Rietveld method, evolved heat, conductivity,
rheology, compressive strength and expansion/retraction measurements. The dissolution rate of the sulfate
sources is key to control the hydration reactions. Bassanite dissolves very fast and hence the initial
setting time of the pastes and mortars is too short (20 min) to produce homogeneous samples. Anhydrite
dissolves slowly so, at 1 hydration-day, the amount of ettringite formed (20 wt%) is lower than that in
gypsum pastes (26 wt%) (w/c = 0.50), producing mortars with lower compressive strengths. After 3
hydration-days, anhydrite pastes showed slightly larger ettringite contents and hence, mortars with
slightly higher compressive strengths. Ettringite content is the chief parameter to explain the strength
development in these eco-cements.Universidad de Málaga. Campus de Excelencia Interncaional Andalucía Tech
Rietveld quantitative phase analyses of SRM 2686a: a standard Portland clinker
SRM 2686a is a NIST reference Portland clinker with reported mineralogical analysis from powder diffraction and electron microscopy. This sample is used in ASTM C1365 test method for Rietveld quantitative phase analysis validation procedure. Here, we have analysed SRM 2686a by using three state-of-the-art powder diffraction configurations: i) strictly monochromatic CuKα 1 radiation in flat reflection geometry; ii) strictly monochromatic MoKα 1 radiation in flat transmission geometry; and iii) synchrotron radiation in rotating capillary transmission geometry. The silicate and aluminate enriched residues have also been studied by CuKα 1 powder diffraction. All the powder patterns were analysed by Rietveld method with the best available protocols. The results indicate that belite in SRM 2686a is composed of two polymorphs (- and α’H-) that must be included in the analyses. The use of a unique phase for describing belite (-polymorph) and improper peak shape modelling could explain the problems found for implementing ASTM C1365 in some cement manufacturing plants. Furthermore, all the patterns are deposited as open data access at Zenodo, so interested laboratories can analyse these data to verify their protocols.This work has been supported by Spanish MINECO through
BIA2014-57658-C2-2-R, which is co-funded by FEDER, and BIA2014-
57658-C2-1-R. We also thank ALBA synchrotron for providing beam
time at BL04-MSPD beamline
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