Conservation of a Wooden Tomb-Marker from the Jewish Cemetery of Algarrobos in Argentina

The state of conservation of some tombs in the Jewish Cemetery of Algarrobos in ColoniaMauricio, Buenos Aires, Argentina was evaluated. A lot of material was found, but only twotomb-markers were done on wood. They were in a state of serious deterioration, so these were definedas an object of study. The tomb-markers, which had been established by the Jewish immigrants fromRussia at the end 19th century, were made of South American tree known as Aspidosperma QuebrachoBlanco and suffered both biological (from fungal decay and insect attack) and mechanical deterioration(cracks and fissures due to weathering, and discoloration due to ultraviolet radiation). Thus, the aimof this paper was the conservation of one of the two remaining wooden tomb-markers found,using impregnant based on non-toxic siloxanes employing sol-gel technology in order to increasethe readability of epitaphs and reliefs found at the tomb-marker. The treatment with this moderntechnology resulted in the excellent performance of wooden tomb-maker conservation. The structuralconsolidation and cracks sealing were achieved. It avoided the detachment of material and theappearance of natural veins; furthermore, it improved the reading of the epitaphs and reliefs.Fil: Alfieri, Paula Vanesa. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Lofeudo, Rosana. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Canosa, Guadalupe. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; ArgentinaFil: Iloro, Fabian. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Traversa, Luis Pascual. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentin

Biological growth on white mortar artificial stone: Assesment, cleaning and protection techniques

Los revestimientos de muros exteriores, además de las agresiones de la intemperie, están sujetos al  desarrollo de diversos organismos como: cianobacterias, microalgas, hongos y líquenes, que además del impacto estético, pueden deteriorar el material por medios físicos y químicos. Un buen procedimiento de limpieza debe contemplar la eliminación de estos microorganismos evitando dañar el material e incluir tratamientos que demoren el desarrollo de nuevas colonias. Con esa finalidad, se ensayaron diversos mecanismos de limpieza en un muro con revestimiento símil piedra correspondiente a un edificio de la ciudad de La Plata construido en la década de 1930; el revestimiento se encuentra colonizado por diversos organismos. Se tomaron muestras para identificar los micro organismos y se realizó un muestreo previo mediante la técnica del número más probable para calcular cuántas unidades formadoras de colonias (UFC). Para la limpieza se emplearon distintas técnicas: hidrolavado a presión controlada, cepillado con cloro al 40% y cepillado con detergente de pH neutro. En todos los casos se procedió a un enjuague con abundante agua, se dejó secar durante tres días, colocándose con posterioridad hidrorepelentes con base de silanos en solvente. La eficacia de las técnicas y el sistema de protección fue evaluada mediante conteos microbiológicos a 1, 3, 6, 9 y 12 meses. En general, se hallaron números de UFC bajos, excepto en los sectores hidrolavados únicamente y cepillados con detergente pH neutro. Los hidrorepelentes mostraron un efecto protector, sin mayores diferencias entre los productos utilizados.Cement plasters covering exterior walls, besides being exposed to weather conditions, are also subject to the development of organisms like cyanobacteria, microalgae, fungi and lichens, that apart from the aesthetic impact, may deteriorate the material by physical and chemical mechanisms. A good cleaning process must eliminate these microorganisms but avoid damage to the material and include treatments that delay the growth of new colonies. With this aim, different cleaning mechanisms were tested on a wall covered with a stone imitation white mortar colonized by different organisms from a building in La Plata city built in the 1930s, in order to find the best cleaning method that delays for as long as possible the growth of new colonies. Samples were obtained to identify these organisms and a previous sampling using the most probable number technique to calculate how many colony-forming units (CFU) existed in the place. Cleaning was performed in limited sectors, using different techniques: hydrojet washing with controlled pressure, hydrojet washing, brushing with sodium hypochlorite 40% and with one neutral pH detergent. Once the wall was cleaned, it was rinsed with abundant water, allowed to dry during three days and each sector was subdivided in three. In one sector a hydro- repelling agent with a base of sylane in solvent was applied; in other, a product with a base of syloxanes and alcoxisyloxanes in solvents; whereas the third was left without treatment as control. New microbiological counts were performed after 1, 3, 6, 9 y 12 months. In general, low CFU numbers, except the sectors cleaned with hydrojet- washing and brushed with pH neutral detergent, whereas the hydro-repelling agents showed a protective effect, without great differences between the products.Fil: Rosato, Vilma Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Iloro, Fabian Horacio. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Lofeudo, Rosana. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentin