16 research outputs found

    EGRET Spectral Index and the Low-Energy Peak Position in the Spectral Energy Distribution of EGRET-Detected Blazars

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    In current theoretical models of the blazar subclass of active galaxies, the broadband emission consists of two components: a low-frequency synchrotron component with a peak in the IR to X-ray band, and a high-frequency inverse Compton component with a peak in the gamma-ray band. In such models, the gamma-ray spectral index should be correlated with the location of the low-energy peak, with flatter gamma-ray spectra expected for blazars with synchrotron peaks at higher photon energies and vice versa. Using the EGRET-detected blazars as a sample, we examine this correlation and possible uncertainties in its construction.Comment: 17 pages including 1 figure, accepted for publication in The Astrophysical Journa

    Cuerpo y disciplina, orden y poder: Del Instructor Popular a los Tribunales Infantiles

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    A fines del siglo XIX, en la República Argentina, el periódico mendocino El Instructor Popular publica el intercambio epistolar entre dos graduados de la Escuela Normal de Paraná: Carlos Norberto Vergara y Ernesto A.Bavio. Reprender, reformar y corregir el error, las faltas y la ignorancia, fueron las justificaciones para hacer uso de punteros y palmetas e incorporar la pena, el dolor y la culpa como correctivos, en las instituciones educativas de "la letra con la sangre entra" en manos de "maestros normales que quieren gobernar con el lático". El espistolario visibiliza y reprueba ciertas prácticas que tuvieron al cuerpo infantil como territorio de anclaje para la institucionalización educativa. Puntear esa conjetura nos permite trazar continuidades y discontinuidades entre los "principios de la disciplina" y "los castigos corporales" como antecedentes para los "tribunales infantiles", implementados en la Escuela Quintana de la Provincia de Mendoza, por Florencia Fossatti, en las primeras décadas del siglo XX.Fil: Alvarado, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; Argentin

    Use of sonic tomography to detect and quantify wood decay in living trees.

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    Premise of the studyField methodology and image analysis protocols using acoustic tomography were developed and evaluated as a tool to estimate the amount of internal decay and damage of living trees, with special attention to tropical rainforest trees with irregular trunk shapes.Methods and resultsLiving trunks of a diversity of tree species in tropical rainforests in the Republic of Panama were scanned using an Argus Electronic PiCUS 3 Sonic Tomograph and evaluated for the amount and patterns of internal decay. A protocol using ImageJ analysis software was used to quantify the proportions of intact and compromised wood. The protocols provide replicable estimates of internal decay and cavities for trees of varying shapes, wood density, and bark thickness.ConclusionsSonic tomography, coupled with image analysis, provides an efficient, noninvasive approach to evaluate decay patterns and structural integrity of even irregularly shaped living trees

    Análisis sincrónico de la gobernanza universitaria: una mirada teórica a los años sesenta y setenta

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    Resumen Estudiar las perspectivas en el campo del gobierno de las universidades tiene cada día mayor preeminencia, especialmente si se toma en cuenta la incuestionable necesidad de avanzar hacía organizaciones más eficientes, conectadas con las expectativas que sobre ellas tiene la sociedad. Considerando este escenario, el trabajo se ha planteado como propósito central realizar un análisis de carácter sincrónico del concepto de gobernanza y la constitución de los gobiernos universitarios. Desde el punto de vista metodológico se utilizaron fuentes secundarias: una revisión de papers publicados esencialmente en revistas de habla inglesa. El estudio comprende las décadas del sesenta y el setenta. Se centra en las raíces del concepto de gobernanza universitaria, en la delineación de los actores que participan en sus gobiernos y en las relaciones de poder que fluyen entre ellos.Entre las principales conclusiones, se pueden destacar como el estamento académico desde el principio de las universidades ha ocupado el rol casi plenipotenciario en su respectivo gobierno, producto de esto, en el correr del desarrollo y mientras la complejidad organizacional se incrementaba, es que fue necesario incorporar nuevos actores a los sistemas de gestión; todo lo anterior, teniendo en cuenta que dos elementos han sido fundamentales para la sobrevivencia de este tipo de instituciones, la legitimidad otorgada por la sociedad y los principios de estrategias del ámbito de la gestión

    Data modeling for operation and maintenance of utility networks: Implementation and testing

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    The organisational data models that support the information needs of utility network managers are proprietary and domain-specific, while the emerging national standards in this field often lack lifecycle data representation capabilities. However, multiple types of utility networks can be comprehensively represented with the free and open-source Utility Network Application Domain Extension (ADE) of the international standard CityGML. The Operation & Maintenance (O&M) Domain Ontology is a proposed extended version of the Utility Network ADE that allows for consistent and comprehensive processing, storage and exchange of O&M-related utility network data. So far, this ontology has not yet been implemented in a spatial-relational database. Consequently, the support it offers during routine utility asset management tasks has remained untested. This paper, therefore, tests the support of the O&M domain ontology for asset management and proposes a database implementation of this data model. To this end, it models and loads two utility networks from the campus of the University of Twente, the Netherlands. It tests the ontology's support for asset management by simulating a street reconstruction project and retrieving necessary project information in relation to a utility's (a) maintenance history and performance, and (b) site conditions and valve locations. Results show that the implemented model supports projects with rapid, comprehensive, and consistent information about semantic details of utilities. Such data needs yet to be collected and registered systematically to enable future data-driven asset management practices

    Data modeling for operation and maintenance of utility networks: Implementation and testing

    Get PDF
    The organisational data models that support the information needs of utility network managers are proprietary and domain-specific, while the emerging national standards in this field often lack lifecycle data representation capabilities. However, multiple types of utility networks can be comprehensively represented with the free and open-source Utility Network Application Domain Extension (ADE) of the international standard CityGML. The Operation & Maintenance (O&M) Domain Ontology is a proposed extended version of the Utility Network ADE that allows for consistent and comprehensive processing, storage and exchange of O&M-related utility network data. So far, this ontology has not yet been implemented in a spatial-relational database. Consequently, the support it offers during routine utility asset management tasks has remained untested. This paper, therefore, tests the support of the O&M domain ontology for asset management and proposes a database implementation of this data model. To this end, it models and loads two utility networks from the campus of the University of Twente, the Netherlands. It tests the ontology's support for asset management by simulating a street reconstruction project and retrieving necessary project information in relation to a utility's (a) maintenance history and performance, and (b) site conditions and valve locations. Results show that the implemented model supports projects with rapid, comprehensive, and consistent information about semantic details of utilities. Such data needs yet to be collected and registered systematically to enable future data-driven asset management practices.Urban Data Scienc

    Mesoplastics and large microplastics along a use gradient on the Uruguay Atlantic coast: Types, sources, fates, and chemical loads

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    Plastic pollution is a global problem with great local and regional variability. Plastic litter reaches beaches directly and indirectly through different pathways, due to both terrestrial and marine pressures. In this study, we assess and characterize meso and microplastic pollution on four Uruguayan oceanic beaches along a gradient of tourist use within a complex regional coastal marine system. In Punta del Diablo we found a total mean density of 106 items m of different debris (pellets, fragments, and foams) with different polymeric compositions, and diverse persistent bioaccumulative and toxic chemicals (PAHs, PCBs, OCs, heavy metals). However, the trend of plastic debris densities along this gradient was not what was expected. Fabeiro, one of the sites furthest from the urban center, had the highest total mean density of plastics (292 items m) suggesting that marine influences (winds, currents, and beach orientation) have a preponderant role in the distribution of micro and mesoplastics. Meanwhile, the density in the urban site (Pueblo) was highest during summer (March, 201 items m), 200 times higher than the density observed in winter (July, 1 item m). Although this difference could be associated to the peak season (southern summer), the analysis of types of plastics (171 pellets m vs. 8 cigarette butts m) suggested a predominance of marine inputs. Seasonal changes in the configuration of the beaches due to natural geomorphological dynamics imply alternating states (Source or Sink of debris) that also affect the final density of plastics in the system. The relative importance of both sources is highly variable throughout the year and understanding them may directly improve beach management and stranded coastal plastic litter cleaning.With funding from the Spanish government through the "María de Maeztu Unit of Excellence" accreditation (MDM-2017-0737

    Use of sonic tomography to detect and quantify wood decay in living trees

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    PREMISE OF THE STUDY: Field methodology and image analysis protocols using acoustic tomography were developed and evaluated as a tool to estimate the amount of internal decay and damage of living trees, with special attention to tropical rainforest trees with irregular trunk shapes. METHODS AND RESULTS: Living trunks of a diversity of tree species in tropical rainforests in the Republic of Panama were scanned using an Argus Electronic PiCUS 3 Sonic Tomograph and evaluated for the amount and patterns of internal decay. A protocol using ImageJ analysis software was used to quantify the proportions of intact and compromised wood. The protocols provide replicable estimates of internal decay and cavities for trees of varying shapes, wood density, and bark thickness. CONCLUSIONS: Sonic tomography, coupled with image analysis, provides an efficient, noninvasive approach to evaluate decay patterns and structural integrity of even irregularly shaped living trees
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