147 research outputs found
Acerca del origen y de la cronologĂa de los cristales de roca llamados fatimĂes: el vidrio de Badajoz y la botella de Astorga
First contributions of Donato GarcĂa as Mineralogy Professor at the Royal Cabinet of Natural History of Madrid (Spain) in the Nineteenth Century
Donato GarcĂawas the mineralogy professor at the Royal Cabinet of Natural History and Central University of Madrid from 1816 to 1853. In addition to teaching mineralogy, he gathered geological and mineralogical material for didactic purposes, and for exhibitions in the hall of the Cabinet. He was a key figure in developing the subject matter of mineralogy in Spain during the first half of the nineteenth century. Donato Garcia likewise promoted the careers of very important future teachers at the Military Academy of Engineers, Natural Sciences Museums, and Universities, integrating oral lectures, mineral testing, visual recognition, and the use of crystallographic models. This paper investigates how the crystallographic system proposed by HaĂŒy (in the mid-thirties) was assimilated through unpublished documents of Donato GarcĂaâs mineralogical lessons from 1824 to 1825, obtained from Spainâs Archivo General de Palacio (Madrid). Hence, this manuscript can be considered the first scientific work reliably attributable to Donato and based on the notes of his pupil JosĂ© Musso y Valiente, which stands as an early attempt to create a handbook of mineralogy in Spanish. The novel approach to teaching mineralogy is furthermore compared with lessons published by disciple Antonio MarĂa Cisneros y Lanuza in 184
Mineralogical analysis of mortars in the walls of Ăvila (Spain) and its surroundings
The present article evaluated the mineralogical composition of 85 mortar samples from some emblematic monuments of Ăvila city (Spain), which were collected during the restoration of the monuments. The aim of this article is to try to extract the relationship between the composition and the origin of the raw materials, as well as to identify possible alterations in the samples. The study of the samples was carried out using visual and petrographic techniques such as stereoscopic microscope, XRD, and SEM/EDX analysis. The main components of the mortars were calcite, feldspar and quartz, although small amounts of phyllosilicates were also identified. The minerals of the mortars came from the surroundings of the city, and some of the samples presented evident alteration of the original materials due to humidity, salt concentration, and biological weathering, possibly inducted by unfortunate effects of the restoration. Finally, a study of the salts present in some mortars showed that most samples display contamination of soluble salts such as halite, thenardite, hexaedrite, and carnalite. This investigation offers fresh insight into historic building activity and related techniques, and should provide knowledge useful for restoration and conservation processes
Recognizing the importance of an urban soil in an open-air city museum: An opportunity in the city of Madrid, Spain
This article examines the presence of urban soil buried under anthropogenic debris in an air-museum park in the Madrid city center (Spain), and highlights the particularities of this singular urbanized setting to indicate ecological evaluation options for soils. The study of a soil profile (with a thickness of about 2.30 m), classified as Urbic Technosols, allowed us to devise that it is formed by a series of filled-in amounts of artifacts (construction debris and other anthropogenic waste) of about 10â30%, plus organic and mineral materials. These soilsâ composition and morphology depend on the natural conditions of the territory and also on anthropogenic activities. The soil properties (analyzed by conventional techniques) are moderate in acidity reaction and have relatively higher organic matter content. The Pb, Cu and Zn concentrations in anthropogenic horizons do not exceed the approximate permissible concentrations by 1.5â10-fold. Over the course of time, the soil profile has been transformed as a result of the impact of pedogenetic processes developing under the Mediterranean climate and manâs hand. Although urban environments present a certain complexity, at least the role of soil should be recognized regarding flood mitigation, recycling of wastes and toxins, filtering of nutrients or carbon storage and GHG regulation. The analysis of our results concludes the need to better perceive this soil profile and its green space to improve the urban ecosystem and to ensure better citizen well-bein
Ailanthus Altissima (Mill.) swingle, bioacumulated specie of contaminated soils
Ailanthus altissima (Mill.) Swingle) is one of the most widespread invasive alien species on a
global scale. Its current distribution is clearly linked to anthropized environments, where concentrations of
heavy metals or trace elements in their soils can reach levels of toxicity to other plant organisms. The
present research carried out in environments of the Community of Madrid (Spain) focuses on the
relationship between the presence in soil components such as arsenic (As), copper (Cu), chromium (Cr),
boron (B), vanadium (V), cobalt (Co), etc., harmful to some plant organisms, and the existence of
Ailanthus altissima. The results obtained identify that the species modifies the content of some minority
elements, a fact that must be taken into account for future soil fertility studies. Secondly, ailanto is capable
of absorbing toxic elements present in the soil environment, which shows its value as a phytoremediator
of contaminated soil
Empleo de la técnica de difracción por rayos X, en el estudio de terracotas arquitectónicas romanas de Ampurias y Tarraco
Identidades profesionales en educación desde una perspectiva de género
Este trabajo presenta los resultados de una investigaciĂłn sobre los perfiles y trayectorias profesionales de pedagogos/as. Fundamentado en los planteamientos de la teorĂa feminista y en la lĂnea de los estudios de gĂ©nero, el objetivo cientĂfico ha sido descubrir las formas cualitativamente distintas en que los profesionales experimentan, perciben y comprenden su realidad profesional. Conocer esta diversidad de caminos y perfiles que definen la identidad profesional de un/una pedagogo/a introduce datos novedosos para la construcciĂłn de una imagen ajustada a la actual prĂĄctica profesional de la pedagogĂa, asĂ como para el anĂĄlisis y reflexiĂłn sobre la heterogeneidad de modelos y trayectorias profesionales en educaciĂłn, superando concepciones y modelos tradicionales, normativos y esterotipados respecto al ejercicio de una profesiĂłn.This paper presents the outcomes of an research focused on educatorsâ profiles and professional trajectories. Starting from feminist theory and gender studies, the main aim is to study the qualitatively different ways that professionals feel, perceive and understand their professional activity settings. To know this diversity of trajectories and profiles constituents of the educatorâs professional identity introduce valuable data for the construction of a realistic picture of the current professional practise, as well as for the analysis and reflection on the heterogeneity of models and professional routes in education. This involves breaking traditional, standard and stereotyped models of the professional practise
Recycling of Waste Paper Sludge in Cements: Characterization and Behavior of New Eco-Efficient Matrices
The cement manufacturing process, because of its nature, is one of the major industries that release large amounts of greenhouse gases. It is estimated that releases between 800-1000 kg of CO2 per ton of clinker into the atmosphere. One of its priorities is the search for new materials that can be used as active additions, which have a direct impact on reducing gas pollutants.
Recently, the Council of Ministers of the EU has adopted a directive that will introduce more stringent limits in order to reduce industrial emissions from 2016, and also wants to improve the health of the citizens as well as environmental protection.
According to their intrinsic composition, paper sludge wastes can be used in many different ways such as agriculture, ceramics or even as an alternative combustible. During the last decade, a group of researchers from different Spanish institutions (Instituto Eduardo Torroja CSIC, Tecnalia and Universidad AutĂłnoma de Madrid) have established the scientific, technical and environmental bases for the use of thermally activated paper sludges as pozzolanic additions in order to obtain ecoefficient portland cement manufacture.
According to available data in Europe, its said that around 2.5 million tons of paper de-inking sludges are produced annually. These sludges are classified as inert wastes and for this reason, in most of countries are deposited in landfills with consequent environmental and social problems.
The chapter of the book address the following concepts
âą Characterization of paper de-inking sludges
âą Activation process and its influence on the mineralogy of the activated products
âą Evaluation of the pozzolanic properties of the products obtained
âą Studies of reaction kinetics in various systems, pozzolan / lime and pozzolan / cement
âą Physical-mechanical behavior of the new cements
âą Aspects of durabilityProyectos Nacionales refs: MAT2003-06479-CO3; CTM2006-12551-CO3 y MAT2009-10874-CO3Peer reviewe
Cements based on kaolinite waste
The cement industry involves high-energy consumption that generates high CO2 emissions into the atmosphere. Environmental concerns can be addressed by replacing parts of Portland cement clinkers with pozzolanic materials in mortars and concrete. Slag, fly ash and silica fume are materials considered for the planned replacement. Research studies on clay minerals, such as kaolinite, are being followed with special attention by the scientific community and the cement industry. It is well known that these minerals require an activation process to transform kaolinite (K) into metakaolinite (MK). MK is an amorphous material from the transformation of K with high pozzolanic activity, which is its capacity to react with the portlandite released during the hydration of Portland cement, generating compounds such as CâSâH gels and some aluminum-phase hydrates. One of the MK production methods is heat treatment controlled by kaolinite at temperatures in the range of 600â900°C. Different residues have been used (coal mining, paper sludge and waste from a drinking water treatment plant) activated at 600°C for 2h to elaborate blended cements. Due to their good behaviour as future eco-efficient additions, this research is a study by x-ray fluorescence (XRF), x-ray diffraction (XRD) and scanning electron microscopy (SEM) of their influence on the performances of blended cement mixtures (binary and ternary one), with substitutions of pozzolan ratio at 28 days of hydration. The porosity of pozzolanic cements decreases because of the formation of hydrated phases during pozzolanic reaction.the Spanish Ministry of the Economy and Competitiveness under coordinated projects BIA2015-65558C3-1-2-3R (MINECO/FEDER
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