370 research outputs found
Microextraction of ochratoxin A in raw wheat with supramolecular solvents
II Encuentro sobre nanociencia y nanotecnología de investigadores y tecnólogos de la Universidad de Córdoba. NANOUC
Nanostructured-solvent for the extraction of ochratoxin A in Andalusian wines
II Encuentro sobre nanociencia y nanotecnología de investigadores y tecnólogos de la Universidad de Córdoba. NANOUC
Humic-like substances from urban waste as auxiliaries for photo-Fenton treatment: a fluorescence EEM-PARAFAC study
In this work, analysis of excitation-emission-matrices (EEM) has been employed to gain further insight into the characterization of humic like substances (HLS) obtained from urban wastes (soluble bio-organic substances, SBOs). In particular, complexation of these substances with iron and changes along a photo-Fenton process have been studied. Recorded EEMs were decomposed by using parallel factor analysis (PARAFAC). Three fluorescent components were identified by PARAFAC modeling of the entire set of SBO solutions studied. The EEM peak locations (λex/λem) of these components were 310?330 nm/400?420 nm (C1), 340?360 nm/450?500 nm (C2), and 285 nm/335?380 nm (C3). Slight variations of the maximum position of each component with the solution pH were observed. The interaction of SBO with Fe(III) was characterized by determining the stability constants of the components with Fe(III) at different pH values, which were in the order of magnitude of the ones reported for humic substances and reached their highest values at pH = 5. Photochemical experiments employing SBO and Fe(III), with and without H2O2, showed pH-dependent trends for the evolution of the modeled components, which exhibited a strong correlation with the efficiency reported for the photo-Fenton processes in the presence of SBO at different pH values.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada
Humic like substances for the treatment of scarcely soluble pollutants by mild photo-Fenton process
[EN] Humic-like substances (HLS) extracted from urban wastes have been tested as auxiliaries for the photo Fenton removal of thiabendazole (TBZ) under simulated sunlight. Experimental design methodology based on Doehlert matrices was employed to check the effects of hydrogen peroxide concentration, HLS amount as well as TBZ loading; this last parameter was studied in the range 25-100 mg/L, to include values below and above the limit of solubility at pH = 5. Very satisfactory results were reached when TBZ was above solubility if HLS and H2O2 amounts were high. This could be attributed to an interaction of HLS-TBZ that enhances the solubility of the pollutant. Additional evidence supporting the latter interaction was obtained by fluorescence measurements (excitation emission matrices) and parallel factor analysis (PARAFAC). (C) 2018 Elsevier Ltd. All rights reserved.Authors want to acknowledge the financial support of Spanish Ministerio de Economia y Competitividad (CTQ2015-69832-C04) and European Union (645551-RISE-2014, MAT4TREAT). The present work was partially supported by UNLP (11/X679), ANPCyT (PICT-2015-0374A) and CONICET (PIP: 12-2013-01-00236CO). B. Caram thank the CONICET for his research graduate grant. F. S. Garcia Einschlag is a research member of CONICET.Caram, B.; García-Ballesteros, S.; Santos-Juanes Jordá, L.; Arqués Sanz, A.; Garcia-Einschlag, FS. (2018). Humic like substances for the treatment of scarcely soluble pollutants by mild photo-Fenton process. Chemosphere. 198:139-146. https://doi.org/10.1016/j.chemosphere.2018.01.074S13914619
The space density distribution of galaxies in the absolute magnitude - rotation velocity plane: a volume-complete Tully-Fisher relation from CALIFA stellar kinematics
The space density distribution of galaxies in the absolute magnitude -
rotation velocity plane: a volume-complete Tully-Fisher relation from CALIFA
stellar kinematicsComment: Accepted to A&
Central star formation and metallicity in CALIFA interacting galaxies
We use optical integral-field spectroscopic (IFS) data from 103 nearby
galaxies at different stages of the merging event, from close pairs to merger
remnants provided by the CALIFA survey, to study the impact of the interaction
in the specific star formation and oxygen abundance on different galactic
scales. To disentangle the effect of the interaction and merger from internal
processes, we compared our results with a control sample of 80 non-interacting
galaxies. We confirm the moderate enhancement (2-3 times) of specific star
formation for interacting galaxies in central regions as reported by previous
studies; however, the specific star formation is comparable when observed in
extended regions. We find that control and interacting star-forming galaxies
have similar oxygen abundances in their central regions, when normalized to
their stellar masses. Oxygen abundances of these interacting galaxies seem to
decrease compared to the control objects at the large aperture sizes measured
in effective radius. Although the enhancement in central star formation and
lower metallicities for interacting galaxies have been attributed to tidally
induced inflows, our results suggest that other processes such as stellar
feedback can contribute to the metal enrichment in interacting galaxies.Comment: 9 pages, 9 figures. Accepted for publication in Astronomy &
Astrophysic
HII regions in the CALIFA survey: I. Catalog presentation
We present a new catalogue of H II regions based on the integral field spectroscopy (IFS) data of the extended CALIFA and PISCO samples. The selection of H II regions was based on two assumptions: a clumpy structure with high contrast of H α emission and an underlying stellar population comprising young stars. The catalogue provides the spectroscopic information of 26 408 individual regions corresponding to 924 galaxies, including the flux intensities and equivalent widths of 51 emission lines covering the wavelength range between 3745 and 7200 Å. To our knowledge, this is the largest catalogue of spectroscopic properties of H II regions. We explore a new approach to decontaminate the emission lines from diffuse ionized gas contribution. This diffuse gas correction was estimated to correct every emission line within the considered spectral range. With the catalogue of H II regions corrected, new demarcation lines are proposed for the classical diagnostic diagrams. Finally, we study the properties of the underlying stellar populations of the H II regions. It was found that there is a direct relationship between the ionization conditions on the nebulae and the properties of stellar populations besides the physicals condition on the ionized regions.Fil: Espinosa Ponce, Carlos. Universidad Nacional Autónoma de México; MéxicoFil: Sánchez, S. F.. Universidad Nacional Autónoma de México; MéxicoFil: Morisset, C.. Universidad Nacional Autónoma de México; MéxicoFil: Barrera Ballesteros, J. K.. Universidad Nacional Autónoma de México; MéxicoFil: Galbany, Lluís. Universidad de Granada; EspañaFil: García Benito, Rubén. Instituto de Astrofísica de Andalucía; España. Consejo Superior de Investigaciones Científicas; EspañaFil: Lacerda, E. A. D.. Universidad Nacional Autónoma de México; MéxicoFil: Mast, Damian. Archivo del Observatorio Astronomico de Cordoba ; Observatorio Astronomico de Cordoba ; Rectorado ; Universidad Nacional de Cordoba; . Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentin
Influence of solid loading on D-xylose production through dilute sulphuric acid hydrolysis of olive stones
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