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Jukka Vaari - One of the best experts on this subject based on the ideXlab platform.

  • A transient one-zone computer model for total Flooding Water mist fire suppression in ventilated enclosures
    Fire Safety Journal, 2002
    Co-Authors: Jukka Vaari
    Abstract:

    As Water mist fire fighting systems become increasingly common, there is a need to transform the accumulated practical experience to quantitative models. As a contribution to this process, this paper proposes a transient one-zone computer model for total Flooding Water mist fire suppression in ventilated enclosures. The one-zone approach is based on the experimentally observed ability of the Water sprays to mix the gas volume of the protected space. From this assumption, the model solves the time evolution of temperature, gas density, gas composition and Water mist concentration inside the protected space. The model incorporates a detailed description of the liquid phase (mist droplets) and the evaporation process. The extinguishment of a hydrocarbon flame is predicted based on the adiabatic flame temperature concept. The possibilities and limitations of the model are demonstrated by validation against experimental data from large-scale machinery space fire suppression tests.

  • A Study of Total Flooding Water Mist Fire Suppression System Performance Using a Transient One-Zone Computer Model
    Fire Technology, 2001
    Co-Authors: Jukka Vaari
    Abstract:

    Due to the intense R&D activity in the field of Water mist fire suppression during the past decade, the qualitative and quantitative understanding on the performance of Water mist has increased significantly. This development has led to a point in which quantitative theoretical models describing large-scale Water mist fire suppression systems begin to emerge. This paper describes the composition and validation of one such model, designed for total Flooding Water mist applications, especially against flammable liquid hazards in enclosures. The basic construction of the model is first described, followed by an example on the validation of the model using full-scale experimental data. The model is then used to investigate the limitations to the maximum possible mist concentration in the protected space. The potential of the model as an engineering tool is illustrated by making predictions on the scaling laws associated with Water mist systems in the framework of IMO MSC/Circ.668/728 as the enclosure volumes and ventilation conditions are varied. The predictions are found to be in agreement with what is indicated by the recent US Coast Guard test series in very large machinery spaces.

Rodríguez, Aixa Inés - One of the best experts on this subject based on the ideXlab platform.

  • Geología del cuaternario y Geofísica aplicada al diagnóstico ambiental-territorial en el valle de Tulum, provincia de San Juan, Argentina
    2020
    Co-Authors: Rodríguez, Aixa Inés
    Abstract:

    El valle de Tulum está ubicado en la provincia de San Juan, centro-oeste de Argentina. Sobre el mismo se encuentra ubicada la capital de la provincia y numerosos núcleos urbanos que ocupan el territorio de norte a sur. Desde el punto de vista geológico, se desarrolla en el frente de deformación activo de los Andes Centrales, con un régimen contraccional principal. Los relieves observados se asocian a fallas neotectónicas o con estructuras tectónicas antiguas, conformando un área de elevada actividad sísmica, de las mayores conocidas en el territorio Argentino. En este trabajo se realizó el Diagnóstico del medio físico del valle de Tulum. El diagnóstico del medio es una de las fases principales del Ordenamiento territorial (OT). Lo novedoso del presente estudio es la incorporación de la variable tectónica, no asociado a un ―riesgo geológico‖ sino como principal elemento para la delimitación de unidades ambientales requeridas en el OT. Este diagnóstico incorporó otras variables como geología del cuaternario, geomorfología, hidrogeología, hidrología, suelos y las relaciones gravimétricas y magnetométricas con estructuras tectónicas. Para estudiar el cuaternario se efectuaron trabajos de campo, también una importante recopilación de datos históricos en los archivos de la provincia, así como el manejo de imágenes satelitales y modelos digitales de elevación con distintas resoluciones, trabajadas con softwares específicos y procesados en diferentes oportunidades y según las necesidades. El uso de los métodos geofísicos como magnetismo y gravimetría permitió detectar anomalías asociadas a las estructuras geológicas, las cuales delimitaron zonas más o menos homogéneas del territorio, es decir Unidades ambientales (UA). Se utilizaron las bases de datos geofísicas del IGSV y del SEGEMAR, y además se realizaron nuevas mediciones. Se aplicaron procedimientos computacionales pertenecientes al ámbito de la geofísica como por ejemplo cálculo de correcciones y anomalías; cálculos de diferentes filtros para separar anomalías regionales de anomalías residuales. Se utilizaron las anomalías gravimétricas y magnéticas residuales que representan las estructuras más superficiales, para la correlación con la geología del Cuaternario. Para ello el procesamiento de datos se efectuó a través del software Oasis Montaj. Como complemento geofísico, se consiguieron modelos gravimétricos de inversión simples en 2D, basados en datos de mapeos geológicos y geomorfológicos. Las UA se adoptan como sectores territoriales básicos, tanto en el diagnóstico del medio físico como a lo largo del proceso de toma de decisiones, son unidades operacionales. El comportamiento actual de los subsistemas agua y suelo son particulares dentro de las unidades definidas. Resultaron 6 grandes Unidades Ambientales en base a límites dados por la tectónica: UA1 Alto del Abanico, UA2 Depocentro de cuenca; UA3 Altos del Tulum, UA4 Piedemonte fallado, UA5 Bajo Caucete, UA6 Sur Pie de Palo. A la vez en la unidad Piedemonte fallado se definieron subunidades en base al comportamiento de las cuencas superficiales analizadas morfométricamente con sistemas de información geográfica. En cada UA se evaluaron diversos parámetros referidos a su potencial de desarrollo territorial. Ellos son: topografía, unidad geomorfológica, pendiente, agua superficial, agua subterránea, valor ecológico, suelo y depósitos actuales. Además se evaluaron las sobrecargas sobre las unidades correspondientes. Las sobrecargas son características del medio físico que condicionan fuertemente la capacidad de acogida de la unidad. Para el valle de Tulum las sobrecargas fueron: erosión y depositación de detritos, sismicidad, licuefacción, inundación/crecientes, anegamiento, vulnerabilidad a la contaminación del agua, y del suelo, punto de interés geológico, viento zonda, yacimiento arqueológico-geológico-paleontológico, sitios de interés turístico-religioso, recarga de acuíferos subterráneos y riesgo de incendios. Los estudios realizados en esta tesis doctoral fueron integrados en un modelo final denominado ―ORDENAMIENTO TERRITORIAL CONTROLADO‖. El modelo consiste en desarrollar particularmente la etapa de diagnóstico del medio físico, encontrar las unidades ambientales que más unifiquen el comportamiento de los recursos naturales del territorio en cuestión, integrar los datos con los estudios sociales existentes (caso contrario generar un trabajo interdisciplinario con profesionales de las ciencias sociales o el área correspondiente a los estudios sociales de los municipios), exponer los resultados en tablas de UA con su mapa respectivo, haciendo uso de los actuales sistemas de información geográfica de uso abierto y finalmente exponer los resultados para la gestión.The Tulum Valley is located in San Juan province, central-western Argentina. The capital city and some urban centres place in this valley. People occupy the territory from north to south for his anthropic activities. From the geological point of view, it develops in the active deformation front of the Central Andes, with a main contractional regime. The observed reliefs are associated with neotectonic faults and with ancient tectonic structures, forming an area of high seismic activity, the largest known in Argentine. In this work, the physical environment Diagnosis of the Tulum Valley was carried out. The physical environment diagnosis is one of the major phases in land-use planning. The novel dimension in this study is the addition of the tectonic variable, it is not associated with a ―geological risk‖ but as the main element for delimitation of territorial areas or ―land units‖. Other variables such as quaternary geology, geomorphology, hydrogeology, hydrology, soils and the gravity and magnetic relationships with tectonic structures were incorporated into this analysis. In the Quaternary study, fieldwork and an important collection of historical data were made. Also, satellite images and digital terrain-elevation models were used. These were processed in geographic information systems and by using specific software. Geophysical methods, such as magnetism and gravity, allowed to determine the geophysical anomalies associated with geological structures. Land units were delimited from geological structures. Geophysical databases belonging to IGSV and SEGEMAR were used, and new data were also collected. Many computational Geophysical procedures were applied, such as the calculation of classical corrections to obtain anomalies and then, the use of different filters to separate regional and residual anomalies. The gravity and magnetic residual anomalies, are related with the most superficial structures, were used for the correlation with the Quaternary geology. The data processing was carried out with Oasis Montaj software. As a geophysical complement, 2D inversion gravimetric models based on geological and geomorphological mapping data were obtained. The land-units are adopted as operational areas. Water and the soils subsystems are distinctive within these units. The resulting land-units were six (based on tectonics): UA1 high fan, UA2 Depocenter; UA3 Tulum high, UA4 faulted ed piedmont, UA5 Caucete depresion, UA6 South Pie de Palo. Multiple parameters were evaluated in each unit. They are topography, geomorphology, slope, surface Water, groundWater, ecological value, soil and current deposits. In addition, the ―Overloads‖ were evaluated. The overloads limit the territory use. In the Tulum Valley, the overloads were: erosion and debris deposition, seismicity, liquefaction, Flooding, Water logging, Water and soil contamination vulnerability, geological interest point, Zonda wind, archaeological, geological or paleontological sites, tourist-religious sites, groundWater recharge areas and risk of fires. The studies carried out were integrated into a final model called ―Controlled Land-use planning‖. The model consists in to develop the stage of physical environment Diagnosis. This will allow to an adequate definition of a land unit to: -Find the environmental units that most unify the behaviour of the natural resources of the territory in question, -Integrate the environment data with the existing social studies (otherwise, generate an interdisciplinary work with professionals in the social sciences or municipalities), -Expose the results in tables of UA with their respective map, using geographic information systems and finally, -Expose the results to land-use management

  • Geología del cuaternario y Geofísica aplicada al diagnóstico ambiental-territorial en el valle de Tulum, provincia de San Juan, Argentina
    2020
    Co-Authors: Rodríguez, Aixa Inés
    Abstract:

    El valle de Tulum está ubicado en la provincia de San Juan, centro-oeste de Argentina. Sobre el mismo se encuentra ubicada la capital de la provincia y numerosos núcleos urbanos que ocupan el territorio de norte a sur. Desde el punto de vista geológico, se desarrolla en el frente de deformación activo de los Andes Centrales, con un régimen contraccional principal. Los relieves observados se asocian a fallas neotectónicas o con estructuras tectónicas antiguas, conformando un área de elevada actividad sísmica, de las mayores conocidas en el territorio Argentino. En este trabajo se realizó el Diagnóstico del medio físico del valle de Tulum. El diagnóstico del medio es una de las fases principales del Ordenamiento territorial (OT). Lo novedoso del presente estudio es la incorporación de la variable tectónica, no asociado a un ―riesgo geológico‖ sino como principal elemento para la delimitación de unidades ambientales requeridas en el OT. Este diagnóstico incorporó otras variables como geología del cuaternario, geomorfología, hidrogeología, hidrología, suelos y las relaciones gravimétricas y magnetométricas con estructuras tectónicas. Para estudiar el cuaternario se efectuaron trabajos de campo, también una importante recopilación de datos históricos en los archivos de la provincia, así como el manejo de imágenes satelitales y modelos digitales de elevación con distintas resoluciones, trabajadas con softwares específicos y procesados en diferentes oportunidades y según las necesidades. El uso de los métodos geofísicos como magnetismo y gravimetría permitió detectar anomalías asociadas a las estructuras geológicas, las cuales delimitaron zonas más o menos homogéneas del territorio, es decir Unidades ambientales (UA). Se utilizaron las bases de datos geofísicas del IGSV y del SEGEMAR, y además se realizaron nuevas mediciones. Se aplicaron procedimientos computacionales pertenecientes al ámbito de la geofísica como por ejemplo cálculo de correcciones y anomalías; cálculos de diferentes filtros para separar anomalías regionales de anomalías residuales. Se utilizaron las anomalías gravimétricas y magnéticas residuales que representan las estructuras más superficiales, para la correlación con la geología del Cuaternario. Para ello el procesamiento de datos se efectuó a través del software Oasis Montaj. Como complemento geofísico, se consiguieron modelos gravimétricos de inversión simples en 2D, basados en datos de mapeos geológicos y geomorfológicos. Las UA se adoptan como sectores territoriales básicos, tanto en el diagnóstico del medio físico como a lo largo del proceso de toma de decisiones, son unidades operacionales. El comportamiento actual de los subsistemas agua y suelo son particulares dentro de las unidades definidas. Resultaron 6 grandes Unidades Ambientales en base a límites dados por la tectónica: UA1 Alto del Abanico, UA2 Depocentro de cuenca; UA3 Altos del Tulum, UA4 Piedemonte fallado, UA5 Bajo Caucete, UA6 Sur Pie de Palo. A la vez en la unidad Piedemonte fallado se definieron subunidades en base al comportamiento de las cuencas superficiales analizadas morfométricamente con sistemas de información geográfica. En cada UA se evaluaron diversos parámetros referidos a su potencial de desarrollo territorial. Ellos son: topografía, unidad geomorfológica, pendiente, agua superficial, agua subterránea, valor ecológico, suelo y depósitos actuales. Además se evaluaron las sobrecargas sobre las unidades correspondientes. Las sobrecargas son características del medio físico que condicionan fuertemente la capacidad de acogida de la unidad. Para el valle de Tulum las sobrecargas fueron: erosión y depositación de detritos, sismicidad, licuefacción, inundación/crecientes, anegamiento, vulnerabilidad a la contaminación del agua, y del suelo, punto de interés geológico, viento zonda, yacimiento arqueológico-geológico-paleontológico, sitios de interés turístico-religioso, recarga de acuíferos subterráneos y riesgo de incendios. Los estudios realizados en esta tesis doctoral fueron integrados en un modelo final denominado ―ORDENAMIENTO TERRITORIAL CONTROLADO‖. El modelo consiste en desarrollar particularmente la etapa de diagnóstico del medio físico, encontrar las unidades ambientales que más unifiquen el comportamiento de los recursos naturales del territorio en cuestión, integrar los datos con los estudios sociales existentes (caso contrario generar un trabajo interdisciplinario con profesionales de las ciencias sociales o el área correspondiente a los estudios sociales de los municipios), exponer los resultados en tablas de UA con su mapa respectivo, haciendo uso de los actuales sistemas de información geográfica de uso abierto y finalmente exponer los resultados para la gestión.The Tulum Valley is located in San Juan province, central-western Argentina. The capital city and some urban centres place in this valley. People occupy the territory from north to south for his anthropic activities. From the geological point of view, it develops in the active deformation front of the Central Andes, with a main contractional regime. The observed reliefs are associated with neotectonic faults and with ancient tectonic structures, forming an area of high seismic activity, the largest known in Argentine. In this work, the physical environment Diagnosis of the Tulum Valley was carried out. The physical environment diagnosis is one of the major phases in land-use planning. The novel dimension in this study is the addition of the tectonic variable, it is not associated with a ―geological risk‖ but as the main element for delimitation of territorial areas or ―land units‖. Other variables such as quaternary geology, geomorphology, hydrogeology, hydrology, soils and the gravity and magnetic relationships with tectonic structures were incorporated into this analysis. In the Quaternary study, fieldwork and an important collection of historical data were made. Also, satellite images and digital terrain-elevation models were used. These were processed in geographic information systems and by using specific software. Geophysical methods, such as magnetism and gravity, allowed to determine the geophysical anomalies associated with geological structures. Land units were delimited from geological structures. Geophysical databases belonging to IGSV and SEGEMAR were used, and new data were also collected. Many computational Geophysical procedures were applied, such as the calculation of classical corrections to obtain anomalies and then, the use of different filters to separate regional and residual anomalies. The gravity and magnetic residual anomalies, are related with the most superficial structures, were used for the correlation with the Quaternary geology. The data processing was carried out with Oasis Montaj software. As a geophysical complement, 2D inversion gravimetric models based on geological and geomorphological mapping data were obtained. The land-units are adopted as operational areas. Water and the soils subsystems are distinctive within these units. The resulting land-units were six (based on tectonics): UA1 high fan, UA2 Depocenter; UA3 Tulum high, UA4 faulted ed piedmont, UA5 Caucete depresion, UA6 South Pie de Palo. Multiple parameters were evaluated in each unit. They are topography, geomorphology, slope, surface Water, groundWater, ecological value, soil and current deposits. In addition, the ―Overloads‖ were evaluated. The overloads limit the territory use. In the Tulum Valley, the overloads were: erosion and debris deposition, seismicity, liquefaction, Flooding, Water logging, Water and soil contamination vulnerability, geological interest point, Zonda wind, archaeological, geological or paleontological sites, tourist-religious sites, groundWater recharge areas and risk of fires. The studies carried out were integrated into a final model called ―Controlled Land-use planning‖. The model consists in to develop the stage of physical environment Diagnosis. This will allow to an adequate definition of a land unit to: -Find the environmental units that most unify the behaviour of the natural resources of the territory in question, -Integrate the environment data with the existing social studies (otherwise, generate an interdisciplinary work with professionals in the social sciences or municipalities), -Expose the results in tables of UA with their respective map, using geographic information systems and finally, -Expose the results to land-use management.Fil: Rodríguez, Aixa Inés. Autor; . Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto Geofísico Sismológico Volponi; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentin

Rich Hansen - One of the best experts on this subject based on the ideXlab platform.

Mohamed Larbi Merroun - One of the best experts on this subject based on the ideXlab platform.

  • Metabolism-dependent bioaccumulation of uranium by Rhodosporidium toruloides isolated from the Flooding Water of a former uranium mine
    PLoS ONE, 2018
    Co-Authors: Ulrike Gerber, Rene Huebner, Andre Rossberg, Evelyn Krawczyk-baersch, Mohamed Larbi Merroun
    Abstract:

    Remediation of former uranium mining sites represents one of the biggest challenges worldwide that have to be solved in this century. During the last years, the search of alternative strategies involving environmentally sustainable treatments has started. Bioremediation, the use of microorganisms to clean up polluted sites in the environment, is considered one the best alternative. By means of culture-dependent methods, we isolated an indigenous yeast strain, KS5 (Rhodosporidium toruloides), directly from the Flooding Water of a former uranium mining site and investigated its interactions with uranium. Our results highlight distinct adaptive mechanisms towards high uranium concentrations on the one hand, and complex interaction mechanisms on the other. The cells of the strain KS5 exhibit high a uranium tolerance, being able to grow at 6 mM, and also a high ability to accumulate this radionuclide (350 mg uranium/g dry biomass, 48 h). The removal of uranium by KS5 displays a temperature- and cell viability-dependent process, indicating that metabolic activity could be involved. By STEM (scanning transmission electron microscopy) investigations, we observed that uranium was removed by two mechanisms, active bioaccumulation and inactive biosorption. This study highlights the potential of KS5 as a representative of indigenous species within the Flooding Water of a former uranium mine, which may play a key role in bioremediation of uranium contaminated sites.

Kazuhiko Kobayashi - One of the best experts on this subject based on the ideXlab platform.

  • Effect of free‐air CO2 enrichment (FACE) on CO2 exchange at the flood‐Water surface in a rice paddy field
    New Phytologist, 2001
    Co-Authors: Hiroshi Koizumi, Takeshi Kibe, Shigeru Mariko, Toshiyuki Ohtsuka, Toshie Nakadai, Hideshige Toda, Nishimura Seiichi, Kazuhiko Kobayashi
    Abstract:

    Summary •  Diurnal and seasonal changes in CO2 exchange between Flooding Water and the atmosphere are reported in a rice (Oryza sativa) paddy field under ambient and free-air CO2 enrichment (FACE) conditions. •  Measurements of CO2 exchange were made in a randomized complete-block design experiment with two CO2 mole fractions (ambient; FACE, ambient +200 mmol mol−1) and four blocks. •  Evolution of CO2 from the Flooding Water occurred throughout the entire day under ambient CO2, although the rate decreased in the daytime. By contrast, under FACE, CO2 evolution from the Flooding Water was observed at night, and CO2 absorption from the atmosphere was observed in the daytime. The time course of CO2 exchange was similar to that of solar radiation. •  The diurnal pattern is similar to that for photosynthesis of terrestrial plant communities. This suggests that photosynthesis of the free-floating weeds and algae in the Flooding Water is related to the CO2 exchange between the Flooding Water and the atmosphere. In addition, the amplitude of the diurnal cycle of CO2 exchange was larger under the FACE than under ambient conditions.