517 research outputs found

    Modelos gravimétricos y carta de isanómalas de aire libre sobre Banco Burdwood

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    Con los datos gravimétricos de la campaña “Islas Oreadas ” 13-14/77, y de otras campañas, se confeccionó una carta de isoanómalas de aire libre, la que muestra una orientación general este-oeste de las anomalías, con un máximo hacia el sur del Banco coincidente con el afloramiento de las capas de alta velocidad y densidad y hacia el norte un bajo gravimétrico asociado a la presencia de grandes espesores de sedimentos de baja velocidad. Sobre la carta se toman dos perfiles que se correlacionan con dos cortes sísmicos de refracción existentes. Se dan modelos de profundidades de corteza y de la interfase corteza - manto (Mohorovicic) para dichas secciones.With gravity data from the “Islas Oreadas”, cruise 13-14/77, and from other cruises, a map of free air anomalies has been made that shows an E-W trend of the anomalies, with a maximum to the South of the Burdwood Bank coincident with the outcropping of high speed and high density layers and with a gravity low to the North on an area of thick low speed sedimentary layers. Two profiles are studied from the map and correlated with two seismic refraction profiles. Models of crust depth and mantle-crust interface depth are given.Asociación Argentina de Geofísicos y Geodesta

    A Comprehensive Investigation on the Effects of Surface Finishing on the Resistance of Stainless Steel to Localized Corrosion

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    The present research investigates the influence of surface roughness imparted by cold surface finishing processes on the localized corrosion resistance of stainless steel. Five different alloys were studied: ferritic AISI 430, martensitic AISI 430F, austenitic AISI 303, AISI 304L, and AISI 316L. It was demonstrated that the grinding process, executed on previously cold drawn bars, leads to an improvement in corrosion resistance according to the results obtained with electrochemical tests, namely, potentiostatic and potentiodynamic tests in chloride-rich environments, the salt spray test, and long-term exposure in urban and marine atmospheres. This allowed us to establish a trend among the different alloys regarding the resistance to pitting corrosion, which was assessed according to pitting potentials, critical chloride contents, and pitting initiation time. All the tests confirmed that surface finishing, as well as alloy chemical composition, is an important factor in controlling the corrosion resistance of stainless steel

    First breeding record of kelp gull (<i>Larus dominicanus</i>) in samborombón bay, Buenos Aires Province, Argentina

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    Se describe una nueva colonia de Gaviota Cocinera (<i>Larus dominicanus</i>), la más septentrional de la costa atlántica argentina, ubicada en las cercanías de la Reserva Natural Punta Rasa, Bahía Samborombón. La colonia fue encontrada en una de las islas de la Ría San Clemente, cerca del puerto de pesca de San Clemente del Tuyú. La primera visita a la colonia se realizó durante la etapa de cortejo y formación de nidos el 3 de septiembre de 2005. Se realizó una segunda visita a la colonia durante el periodo de puesta de huevos del 24 al 26 de septiembre de 2005. Fueron hallados un total de 54 nidos, 50 de ellos ubicados sobre jume, 2 sobre cortadera y 2 sobre el barro, en un área de cuevas de cangrejo cavador. El 15 de diciembre de 2005 fueron cuantificados 64 pichones en los 54 nidos. Aunque la reproducción en este sitio no había sido descripta, los pescadores recuerdan la existencia de la colonia desde hace al menos 20 años. Su cercanía con el puerto de San Clemente sugiere que la presencia humana puede ser frecuente y que podría ocurrir ocasionalmente la recolección de huevos.We describe a new Kelp Gull (<i>Larus dominicanus</i>) colony, the most northern one along the Argentine Atlantic coast, located near Punta Rasa Reserve, Samborombón Bay. The colony was found on one of several island of the San Clemente’s tidal creek located near San Clemente del Tuyú Harbour. The first visit to the colony was made during courtship and nest formation in 3 September 2005. The second visit was made during the egg laying period between 24–26 September 2005. A total of 54 nests were found, 50 of them upon pickle weed, 2 upon dense-flowered pampas grass and 2 in the mud near a burrowing crab area. On 15 December 2005 we counted a total of 64 chicks in 54 nests. Although this is the first record of Kelp Gull reproduction in the area, local fishermen recall this colony being there since at least 20 years ago. Its location near San Clemente harbour suggests that human presence may be frequent and that egg collection could occur frequently

    The use of hematophagous insects for blood collection in birds : the Common Tern (Sterna hirundo) as a case study

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    El objetivo de este trabajo es actualizar la descripción de una técnica de obtención de muestras de sangre en aves y mostrar su eficiencia en una colonia de Gaviotín Golondrina (Sterna hirundo) situada en el lago Banter, Alemania. Las técnicas utilizadas actualmente involucran la captura y manejo de las aves y la extracción de sangre con agujas hipodérmicas, lo cual puede causar estrés en el individuo estudiado. En este trabajo se utilizó una técnica mínimamente invasiva usando insectos hematófagos del orden Heteroptera. Se describen las modificaciones del diseño original de la técnica y se muestra que existió una alta eficiencia en el muestreo, en términos de tiempo y número de muestras tomadas.The objective of this study is to update the description of a technique for obtaining blood samples in birds and to show its efficiency in a colony of Common Tern (Sterna hirundo) located in Lake Banter, Germany. The techniques currently used involve the capture and handling of birds and the extraction of blood with hypodermic needles, which can cause stress in the individual studied. In this study a minimally invasive technique was used using hematophagous insects of the order Heteroptera. The modifications of the original design of the technique are described and it was shown that there was a high efficiency in the sampling, in terms of time and number of samples taken

    Recent Advances in the Use of Green Corrosion Inhibitors to Prevent Chloride-Induced Corrosion in Reinforced Concrete

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    Inhibitors for the prevention of corrosion in reinforced concrete are chemical substances able to reduce carbon steel reinforcements corrosion without altering the overall properties of concrete. Today, many commercially available substances have a negative impact on human safety during either the inhibitor synthesis, their handling or application in field. Green corrosion inhibitors are nontoxic, biodegradable and environmentally biocompatible substances. They are generally made of extracts from natural plants or waste, which are abundantly available in several countries. The majority of green inhibitor molecules usually contain multiple bonds, aromatic rings, polar functional groups and electronegative atoms as P, N, S or O; the latter are able to coordinate with metal cations to form protective layers on the metallic surface of the reinforcements, so as to inhibit the development (initiation and/or propagation) of the corrosion process. In this review, the most recent achievements on the study and investigation of green corrosion inhibitors for concrete structures are presented and discussed. Inhibitors are classified based on their nature and inhibition mechanism. The inhibition effectiveness of the substances is compared with the well-established effective nitrite-based inhibitor, distinguishing between accelerated and long-term tests. Based on the available data, a summary of corrosion inhibitors efficiency is reported

    Interprofessional collaboration between different health care professions in emilia romagna

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    Background and aim of the work: Interprofessional collaboration in the healthcare sector contributes to the delivery of high quality and safe services to patients across different subdivisions of the healthcare system which is faced with constant challenges. The international literature offers a plethora of tools for assessing the collaboration between health workers, but only a few of these have been validated in the Italian language. One that has undergone such validation is the interprofessional collaboration (IPC) scale, which measures the perception of collaboration among health professionals. An advantage of this scale is that is addresses all workers within the system, and is not limited to specific professions. The aim of the present study was to apply the validated Italian version of the IPC scale, to a context different to the one used for its validation, to measure the level of collaboration between different health care workers. Method: A questionnaire-based study was conducted on a sample consisting of 329 health professionals working at Azienda USL-IRCCS in Reggio Emilia. The categorical and continuous variables were analysed using descriptive statistics (frequen-cies, percentages and standard deviations). Results: The IPC scale showed physicians to express the highest level of collaboration with other professionals, in line with the results of other studies in the literature. The values calculated for the factors “accommodation” and “communication” were higher than for “isolation”, de-picting a good level collaboration. The only case in which the isolation factor, which describes an absence of collaboration, was equal to the other two factors was in relation to the evaluation of midwives by nursing aides/orderlies. Conclusions: In conclusion, the Italian version of the IPC scale provides a useful instrument for measuring interprofessional collaboration between workers in the healthcare sector. In the present study, it revealed a satisfactory level of collaboration between health professionals in an organization located in Emilia Romagna, Italy. (www.actabiomedica.it)

    First breeding record of kelp gull (Larus dominicanus) in Samborombón Bay, Buenos Aires Province, Argentina

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    Se describe una nueva colonia de Gaviota Cocinera (Larus dominicanus), la más septentrional de la costa atlántica argentina, ubicada en las cercanías de la Reserva Natural Punta Rasa, Bahía Samborombón. La colonia fue encontrada en una de las islas de la Ría San Clemente, cerca del puerto de pesca de San Clemente del Tuyú. La primera visita a la colonia se realizó durante la etapa de cortejo y formación de nidos el 3 de septiembre de 2005. Se realizó una segunda visita a la colonia durante el periodo de puesta de huevos del 24 al 26 de septiembre de 2005. Fueron hallados un total de 54 nidos, 50 de ellos ubicados sobre jume, 2 sobre cortadera y 2 sobre el barro, en un área de cuevas de cangrejo cavador. El 15 de diciembre de 2005 fueron cuantificados 64 pichones en los 54 nidos. Aunque la reproducción en este sitio no había sido descripta, los pescadores recuerdan la existencia de la colonia desde hace al menos 20 años. Su cercanía con el puerto de San Clemente sugiere que la presencia humana puede ser frecuente y que podría ocurrir ocasionalmente la recolección de huevos.We describe a new Kelp Gull (Larus dominicanus) colony, the most northern one along the Argentine Atlantic coast, located near Punta Rasa Reserve, Samborombón Bay. The colony was found on one of several island of the San Clemente’s tidal creek located near San Clemente del Tuyú Harbour. The first visit to the colony was made during courtship and nest formation in 3 September 2005. The second visit was made during the egg laying period between 24–26 September 2005. A total of 54 nests were found, 50 of them upon pickle weed, 2 upon dense-flowered pampas grass and 2 in the mud near a burrowing crab area. On 15 December 2005 we counted a total of 64 chicks in 54 nests. Although this is the first record of Kelp Gull reproduction in the area, local fishermen recall this colony being there since at least 20 years ago. Its location near San Clemente harbour suggests that human presence may be frequent and that egg collection could occur frequently

    Contourite terraces along the Argentine continental margin : morphosedimentary and oceanographic implications

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    Un enorme Sistema Deposicional Contornítico, compuesto mediante rasgos deposicionales y erosivos, ha sido caracterizado en el margen continental Argentino. El presente trabajo se centra en los rasgos erosivos contorníticos y en concreto en uno de ellos: las terrazas contorníticas. Se identifican a lo largo del talud continental, y a diferentes profundidades, un conjunto de terrazas con una muy buena continuidad lateral. Esta terrazas son elementos morfológicos sub-horizontales sobre el actual fondo submarino desarrolladas durantes sucesivas fases constructivas (deposicionales) y erosivas mediante la acción de las masas de agua antárticas que interaccionan con el talud continental. Regionalmente la ubicación de las terrazas se correlaciona con la posición de las interfases entre las principales masas de agua. La presencia de las terrazas contorníticas implica cambios muy significativos en el perfil morfológico del talud, generando un perfil muy diferente al definido en los modelos conceptuales de los taludes para los márgenes continentalesA significant Contourite Depositional System on the slope of the Argentine margin was characterised, where several depositional and erosive features are well developed. This work is focused on one of these erosive features: the contourite terraces. A set of terraces with good lateral continuity has been described at different depths along the slope. They are sub-horizontal morphologic elements identified at the present sea-floor, which have developed over time in constructional (depositional) and erosive phases caused by the interaction of Antarctic water masses with the seafloor. Their location can be correlated with the main interfaces of water masses. Contourite terraces occurrence has conditioned a remark change in the slope morphologic profile very different to those defined in the conceptual models for continental margin
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