462 research outputs found

    Characterization of organic compounds in weathered stones

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    3 pages, 3 figures, 1 table, 8 references. Trabajo presentado al citado Simposio, celebrado del 13-16, junio, 1989, en Bologna, Italia.Solvent extraction and pyrolysis of the black sulfated crusts obtained from the Custom House, a 18th century building located in Dublin, Ireland, revea1ed common products upon gas chromatography-mass spectrometry analysis. Both methods yielded aliphatic hydrocarbons, polycyclic aromatic hydrocarbons and triterpanes. The differences were the presence of fatty acids and diterpenoids (as methyl esters) and dialkyl phthalates in the solvent extract. On the contrary, low molecular weight compounds were identified as pyrolysis products, as denoted by their absence in the solvent extract. The origin of the identified compounds to related to urban and industrial activities.This research has been supported by the C.E.C. through contract EV4V 0061 E and the C.I.Y.T., Spain.Peer reviewe

    Comparison of humic and fulvic acids from different soils by pyrolysis-mass spectrometry

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    7 pages, 3 figures, 11 references.[EN]: Several recent publications showed the usefulness of pyrolysis mass spectrometry for the characterization of the organic matter of total soil samples and of soil organic matter fractions. Soil humic and fulvic acidS were pyrolyzed by the Curiepoint pyrolysis technique and were analyzed with a fast scanning low voltage electron impact mass spectrometer. Humic acids from different soil types and geographical distribution were characterized by series of homologous compounds, which were derived from protein, polysaccharides, alkanes, and lignin phenols. Fulvic acids showed great similarities and few variations in the relative abundance of pyrolysis products, with major peaks arising from polysaccharides: Aromatics and phenols were scanty or hardly detected.[ES]: Publicaciones recientes han mostrado la utilidad de la pirólisis-espectrometría de masas para la caracterización de la materia orgánica del suelo y sus fracciones. Ácidos húmicos y fúlvicos fueron pirolizados usando la técnica de la pirólisis por punto de Curie y analizados con un espectrómetro de masas de impacto electrónico a bajo voltaje. Los ácidos húmicos de diferentes tipos de suelos y orígenes geográficos se caracterizaron por series de compuestos homólogos, encontrándose derivados de proteínas, polisacáridos, alcanos y fenoles procedentes de la lignina. Los ácidos fúlvicos se mostraron muy similares y con pocas variaciones en la abundancia relativa de productos de pirólisis, hallándose que los picos mayores procedían de la pirólisis, de polisacáridos, mientras que, por el contrario, los compuestos aromáticos y fenoles fueron escasos y difícilmente detectables.This work was made possible by research grants from the Deutsche Forschungsgemeinschaft, the Dutcb Foundation Research on Matter (F.O.M) und the Dutch Ministry of Health and Environmental Hygiene.Peer reviewe

    Pyrolysis-gass chromatography-mass spectrometry of soil humic fractions: II. The high boiling point compounds

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    4 pages, 1 figure, 1 table, 16 references.-- Publicado en el apartado: Division S-3-Soil Microbiology and Biochemistry.Pyrolysis-gas chromatography-mass spectrometry studies of soil fulvic and humic acids were made. The high boiling point compounds produced by pyrolysis were separated in a column packed with Chromosorb AW DMCS 80-100 mesh coated with 10% FFAP. Humic acids with a high nitrogen content yielded a complex variety of protein derivatives, such as alkylpyridines, alkylpyrroles, alkylbenzonitriles, indoles, piperidines, pyrazines, and pyrrolidones. Humic acids with low N content yielded a smaller number of heterocyclic nitrogen compounds. Lignin derivatives were also identified, but the amount varied in different samples. Furanes were not as prominent as protein and lignin fragments. Acid hydrolysis released proteins, polysaccharides, and lignins, which could be considered as companion materials of a humic "core". The majority of the pyrolysis compounds from the residue after hydrolysis were identified as alkylbenzenes, alkylnaphthalenes, phenols, benzofuranes, indenes, and fluorenes. Alkanes and alkenes were noted in trace amounts. Pyrolysis behavior of fulvic acids differed from that of humic acids. They produced poorly resolved pyrograms with smaller number and a lower intensity of peaks, from which only furfurals, phenols, benzofuranes, and naphthalenes could be identified.Peer reviewe

    Polyacrylamide gel electrophoresis of humic and fulvic acids after acid hydrolysis

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    Two soil humic acids (HA), a marine sediment HA, and a soil fulvic acid (FA), were fractionated by polyacrylamide gel electrophoresis in the presence of denaturing agents before and after 6N HCl hydrolysis. After acid hydrolysis, the intensity of the high molecular size (MS) fraction decreased considerably in all HAs. On the other hand, a new high-MS fraction appeared in the FA after hydrolysis. The electrophoretic data indicate that acid hydrolysis produced a transformation in the humic macromolecule, inducing either depolymerization or condensation, depending on the nature of the humic fraction. Therefore, the advantages and disadvantages of using acid hydrolysis should be carefully considered before this treatment is carried out.Peer Reviewe

    The Seville Cathedral altarpiece: A microbiological and chemical survey of the dust

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    4 pages, 4 figures, 5 references.-- Proceedings of the International Congress on Science and Technology for the Conservation of Cultural Heritage, held 2-5 october, Santiago de Compostela, España.The altarpiece of the Seville Cathedral was built between 1481 and 1565 and has a total perimeter of 20.10 m and 23.41 m height, which makes this altarpiece the largest in the world. The last restoration was performed in 1977, centered on ensuring its structural stability and consolidation of wood structures and polychromy. A new intervention to appraise the state of conservation is currently in progress. Our study is centered on the assessment of the dust accumulated on the surface including a survey of significant alterations from biological origin. The approach carried out combined molecular biology methods and analytical procedures. The composition of the dust samples is very heterogeneous, comprising mineral particles resulting from the deterioration of the building materials, fragments of decorative elements particularly gold leaf from the gilded wood, products from air pollution (soot), as well as biological fragments of insects, arachnids and bird droppings, in addition to bacteria and fungal spores.The Cabildo Catedral de Sevilla supported this research through Agora S.L. The postdoctoral fellowship granted by the Portuguese Fundação para a Ciência e a Tecnologia to A.Z.M. (SFRH/BPD/63836/2009) is acknowledged. CEPGIST work was supported by PTDC/EATEAT/ 116700/2010 and PEst-OE/CTE/UI0098/2011.Peer reviewe

    La Red de Ciencia y Tecnología para la Conservación del Patrimonio Cultural como plataforma de colaboración

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    13 páginas, 15 referencias.-- Jornada celebrada los días 24-25 de mayo de 2012, en el contexto de la VIII Bienal de la Restauración y Gestión del Patrimonio AR&PA 2012, en Valladolid.-- Las Jornadas Técnicas Arespa-Investigación y Empresa, han sido promovidas por la Delegación del CSIC en Castilla y León, la Red de Ciencia y Tecnología para la Conservación del Patrimonio Cultural (TechoHeritage) y la Asociación Española de Empresas de Restauración del Patrimonio Histórico (Arespa).El carácter multidisciplinar de la investigación en conservación del patrimonio cultural hace especialmente adecuado y necesario el establecimiento de redes que pongan en contacto y permitan la colaboración de los distintos actores implicados: universidades, centros de investigación, instituciones culturales y empresas. Con este fin, se creó en 2011 la Red TechnoHeritage (Red de Ciencia y Tecnología para la Conservación del Patrimonio Cultural), con la financiación del Ministerio de Economía y Competitividad. TechnoHeritage aglutina en la actualidad a 80 grupos de los ámbitos citados. En la presente publicación se presentan los orígenes de la Red, las motivaciones para su puesta en marcha, los objetivos que se pretenden alcanzar y algunas de las actividades que se han llevado a cabo.Al Ministerio de Economía y Competitividad por la financiación de la Red dentro del Programa de Acciones Complementarias del Plan Nacional de I+D+i 2008-2011 (HAR2010-11432-E).Peer reviewe

    The microbiology of Lascaux Cave

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    Lascaux Cave (Montignac, France) contains paintings from the Upper Paleolithic period. Shortly after its discovery in 1940, the cave was seriously disturbed by major destructive interventions. In 1963, the cave was closed due to algal growth on the walls. In 2001, the ceiling, walls and sediments were colonized by the fungus Fusarium solani. Later, black stains, probably of fungal origin, appeared on the walls. Biocide treatments, including quaternary ammonium derivatives, were extensively applied for a few years, and have been in use again since January 2008. The microbial communities in Lascaux Cave were shown to be composed of human-pathogenic bacteria and entomopathogenic fungi, the former as a result of the biocide selection. The data show that fungi play an important role in the cave, and arthropods contribute to the dispersion of conidia. A careful study on the fungal ecology is needed in order to complete the cave food web and to control the black stains threatening the Paleolithic paintings. © 2010 SGM.We thank support from the Ministry of Culture and Communication, France, the Spanish project CGL2006-07424/BOS, and facilities from DRAC Aquitaine. This is a TCP CSD2007-00058 paper.Peer Reviewe

    Halotolerant bacteria in the efflorescences of a deteriorated church

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    7 pages, 6 figures, 3 tables, 18 references.--Proceedings of the 5th International Symposium, celebrado del 5-8, abril, 2000, en Sevilla, España.[EN]: A study on the composition of the efflorescences from the Church of Saint Jerome, Granada, Spain, and their influence on the distribution ofthe bacterial communities was carried out. The composition of the efflorescences varied depending on the location of the sampling point. The colony foming units (cfu) was related with the type of salt, with a clear difference between halite and epsomite/hexahydrite. The most abundant genera were Bacillus and Micrococcus and the abundance of bacilli could be explained by their osmotic adaptation to halophilic environments.[ES]: Se ha determinado la composición de las eflorescencias de la iglesia de San Jerónimo, en Granada, España, y relacionado con la presencia de comunidades específicas de bacterias. Existe una conexión entre el tipo de sales y las comunidades bacterianas; así, la epsomita, la sal más abundante en el templo, origina la selección de comunidades capaces de crecer a concentraciones de hasta,15% de esta sal. Sin embargo, las bacterias que basan su halotolerancia en la halita presentan un crecimiento comparativamente menor y no son significativamente estimuladas por la presencia de epsomita. Los géneros más abundantes son Bacillus y Micrococcus. La abundancia de bacilos se debe a su adaptación osmótica a ambientes salinos.This work was supported by the European Commission, project ENV4-CT98-0705, and the Research Groups RNM-179 and 201 from the Community of Andalusia.Peer reviewe

    Evolución y análisis filogenético de las comunidades microbianas desarrolladas como respuesta al aumento de los niveles de fenantreno en un suelo contaminado por PAHs

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    Trabajo presentado al citado Congreso que tuvo lugar del 21-24, de septiembre, 2009, en Almería, España.Las comunidades microbianas de los suelos contaminados con hidrocarburos aromáticos poli cíclicos (PAHs) presentan gran biodiversidad. Esta biodiversidad puede relacionarse con la respuesta a niveles elevados de PAHs. En este trabajo se presenta el estudio y la caracterización de las comunidades microbianas de un suelo contaminado principalmente con hidrocarburos aromáticos poli cíclicos (5LO), mediante técnicas basadas en ADN y técnicas de cultivo. Se ha estudiado la evolución de las comunidades como respuesta al aumento de la concentración de fenantreno.Peer reviewe

    Laboratory and in situ assays of digital image analysis based protocols for biodeteriorated rock and mural paintings recording

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    8 pages, 8 figures, 43 references.Rock art paintings, and in general mural paintings, are one of the many elements of cultural heritage complex systems. As the different elements of a system have diverse spatial positions, spatial recording allows understanding their interactions. Thus, a useful approach to mural paintings recording is to understand it as a microcartography issue, managing each element of the system as a cartographic coverage. The approach implemented emphasizes the utilization of data obtained by remote sensing techniques for extracting different kinds of information susceptible of being analysed, classified and plotted in a differentiate way by means of the possibility of reducing redundant data by Principal Component Analysis (PCA) and the elaboration of false-colour images from uncorrelated bands. A laboratory model was prepared in order to simulate biodeterioration of rock art. The samples were photographically recorded thereafter under different lighting conditions, and PCA applied to the resulting images. False-colour images obtained by combining Principal Component bands allowed us to reach results similar to those of an unsupervised classification. The method has been applied to Roman mural paintings from one of the tombs of Carmona Necropolis, obtaining good results.Peer reviewe
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