75 research outputs found

    On the applications of IBA techniques to biological samples analysis: PIXE and RBS

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    The analyticaltechniques based on ion beamsorIBA techniquesgive quantitativeinformationonelemental concentrationin samples of awide variety of nature. In this work, weinformation on elemental concentrationin samples of awide variety of nature. In this work, weinformation on elemental concentrationin samples of awide variety of nature. In this work, weinformation on elemental concentrationin samples of awide variety of nature. In this work, wefocus on PIXE technique,analyzingthick target biologicalspecimens (TTPIXE),using 3MeVfocus on PIXE technique,analyzingthick target biologicalspecimens (TTPIXE),using 3MeVfocus on PIXE technique,analyzingthick target biologicalspecimens (TTPIXE),using 3MeVfocus on PIXE technique,analyzingthick target biologicalspecimens (TTPIXE),using 3MeVprotons producedby an electrostaticaccelerator.Anuclear microprobewas used performingprotons producedby an electrostaticaccelerator.Anuclear microprobewas used performingprotons producedby an electrostaticaccelerator.Anuclear microprobewas used performingprotons producedby an electrostaticaccelerator.Anuclear microprobewas used performingPIXEandRBSsimultaneously,inordertosolvetheuncertaintiesproducedintheabsolutePIXEPIXEandRBSsimultaneously,inordertosolvetheuncertaintiesproducedintheabsolutePIXEPIXEandRBSsimultaneously,inordertosolvetheuncertaintiesproducedintheabsolutePIXEPIXEandRBSsimultaneously,inordertosolvetheuncertaintiesproducedintheabsolutePIXEquantifying. Theadvantages of using both techniquesand anuclear microprobearediscussed.quantifying.Theadvantages of using both techniquesand anuclear microprobearediscussed.quantifying.Theadvantages of using both techniquesand anuclear microprobearediscussed.quantifying.Theadvantages of using both techniquesand anuclear microprobearediscussed.Quantitative resultsare shown to illustrate themultielemental resolutionof the PIXE technique;Quantitativeresults are shown to illustrate themultielemental resolutionof the PIXE technique;Quantitativeresults are shown to illustrate themultielemental resolutionof the PIXE technique;Quantitativeresults are shown to illustrate themultielemental resolutionof the PIXE technique;forthis,abloodstandardwasused.forthis,abloodstandardwasused.forthis,abloodstandardwasused.forthis,abloodstandardwasused

    Thermal Diffusivity Measurements In Vegetable Oils With Thermal Lens Technique

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    The thermal lens technique to measure the thermal diffusivity in vegetable oils was discussed. The Amazonian species and olive oils were used as samples. The time resolved spectra were measured using an automatic system and the obtained data were used to solve the thermal property of each oil.741 II697699Gordon, J.P., Leite, R.C.C., Moore, R.S., Porto, S.P.S., Whinery, J.R., (1965) J. Appl. Phys., 36, p. 3Andrade, A.A., Tenorio, E., Catunda, T., Baesso, M.L., Cassanho, A., Jenssen, H.P., (1999) J. Opt. Soc. Am. B, 16, p. 395Baesso, M.L., Bento, A.C., Andrade, A.A., Sampaio, J.A., Pecorato, E., Nunes, L.A.O., Catunda, T., Gama, S., (1998) Phys. Rev. B, 57, p. 10545Brown, S.M., Baesso, M.L., Shen, J., Snook, R.D., (1993) Anal. Chim. Acta, 282, p. 711Bento, A.C., Palangana, A.J., Evangelista, L.R., Baesso, M.L., Pereira, J.R.D., Da Silva, E.C., Mansanares, A.M., (1996) Appl. Phys. Lett., 68, p. 3371Pereira, J.R.D., Mansanares, A.M., Palangana, A.J., Baesso, M.L., (1999) Mol. Cryst. Liq. Cryst. Sci. Technol., Sect. A, 332, p. 3079Shen, J., Love, R.D., Snook, R.D., (1992) Chem. Phys., 165, p. 385Baesso, M.L., Shen, J., Snook, R.D., (1992) Chem. Phys. Lett., 197, p. 25

    Análisis cuantitativo de ácidos grasos en harina de Prosopis laevigata

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    Ripe mesquite pods are widely consumed by humans and animals in arid and semi-arid areas for their protein, carbohydrate, crude fiber and fat contents. The goal of this work is to identify and to quantify the fatty acid profile of flour from mesquite pods. Structural assignments were confirmed by the analysis of fragmentation patterns of mass spectra obtained by GC-MS. The results showed that 75% of the fatty acids were unsaturated, of which linoleic acid was predominant, while palmitic and stearic acids, and saturated fatty acids were found in minor proportions.Las vainas de mezquite maduro son ampliamente consumidas por humanos y animales en las zonas áridas y semiáridas por su contenido de proteínas, carbohidratos, fibra cruda y grasas. El propósito de este trabajo es identificar y cuantificar el perfil de ácidos grasos de harinas de vainas mezquite. La estructura química fue confirmada mediante el análisis de los fragmentos del espectro de masas obtenidos por GC-MS. Los resultados mostraron que el 75% de los ácidos grasos fueron insaturados, de los cuales, el ácido linoleico predomina mientras que el ácido pálmico y esteárico, ambos ácidos grasos saturados, fueron encontrados en menor proporción

    Dynamical Boson Stars

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    The idea of stable, localized bundles of energy has strong appeal as a model for particles. In the 1950s John Wheeler envisioned such bundles as smooth configurations of electromagnetic energy that he called {\em geons}, but none were found. Instead, particle-like solutions were found in the late 1960s with the addition of a scalar field, and these were given the name {\em boson stars}. Since then, boson stars find use in a wide variety of models as sources of dark matter, as black hole mimickers, in simple models of binary systems, and as a tool in finding black holes in higher dimensions with only a single killing vector. We discuss important varieties of boson stars, their dynamic properties, and some of their uses, concentrating on recent efforts.Comment: 79 pages, 25 figures, invited review for Living Reviews in Relativity; major revision in 201

    Global transpiration data from sap flow measurements: The SAPFLUXNET database

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    Plant transpiration links physiological responses of vegetation to water supply and demand with hydrological, energy, and carbon budgets at the land-atmosphere interface. However, despite being the main land evaporative flux at the global scale, transpiration and its response to environmental drivers are currently not well constrained by observations. Here we introduce the first global compilation of whole-plant transpiration data from sap flow measurements (SAPFLUXNET, https://sapfluxnet.creaf.cat/, last access: 8 June 2021). We harmonized and quality-controlled individual datasets supplied by contributors worldwide in a semi-automatic data workflow implemented in the R programming language. Datasets include sub-daily time series of sap flow and hydrometeorological drivers for one or more growing seasons, as well as metadata on the stand characteristics, plant attributes, and technical details of the measurements. SAPFLUXNET contains 202 globally distributed datasets with sap flow time series for 2714 plants, mostly trees, of 174 species. SAPFLUXNET has a broad bioclimatic coverage, with woodland/shrubland and temperate forest biomes especially well represented (80% of the datasets). The measurements cover a wide variety of stand structural characteristics and plant sizes. The datasets encompass the period between 1995 and 2018, with 50% of the datasets being at least 3 years long. Accompanying radiation and vapour pressure deficit data are available for most of the datasets, while on-site soil water content is available for 56% of the datasets. Many datasets contain data for species that make up 90% or more of the total stand basal area, allowing the estimation of stand transpiration in diverse ecological settings. SAPFLUXNET adds to existing plant trait datasets, ecosystem flux networks, and remote sensing products to help increase our understanding of plant water use, plant responses to drought, and ecohydrological processes. SAPFLUXNET version 0.1.5 is freely available from the Zenodo repository (10.5281/zenodo.3971689; Poyatos et al., 2020a). The "sapfluxnetr"R package-designed to access, visualize, and process SAPFLUXNET data-is available from CRAN. © 2021 Rafael Poyatos et al.This research was supported by the Minis-terio de Economía y Competitividad (grant no. CGL2014-55883-JIN), the Ministerio de Ciencia e Innovación (grant no. RTI2018-095297-J-I00), the Ministerio de Ciencia e Innovación (grant no. CAS16/00207), the Agència de Gestió d’Ajuts Universitaris i de Recerca (grant no. SGR1001), the Alexander von Humboldt-Stiftung (Humboldt Research Fellowship for Experienced Researchers (RP)), and the Institució Catalana de Recerca i Estudis Avançats (Academia Award (JMV)). Víctor Flo was supported by the doctoral fellowship FPU15/03939 (MECD, Spain)
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