406 research outputs found
Aurea hymnorum totius anni expositio
Texto a dos col., con apostillas marginalesPort. calc. arq
Homilie diuersorum authorum in segme[n]ta ex quattuor eua[n]gelistis excerpta : que diebus dominicis in re diuina per totum annum ca[n]tantur
Texto con apostillas marginalesPort. calc. arq
Editorial: New Findings on the Use of Biosorbents and Technically-Based Sorbents to Control Soil and Water Pollution
Integral field spectroscopy of selected areas of the Bright Bar and Orion-S cloud in the Orion Nebula
We present integral field spectroscopy of two selected zones in the Orion
Nebula obtained with the Potsdam Multi-Aperture Spectrophotometer (PMAS),
covering the optical spectral range from 3500 to 7200 A and with a spatial
resolution of 1". The observed zones are located on the prominent Bright Bar
and on the brightest area at the northeast of the Orion South cloud, both
containing remarkable ionization fronts. We obtain maps of emission line fluxes
and ratios, electron density and temperatures, and chemical abundances. We
study the ionization structure and morphology of both fields, which ionization
fronts show different inclination angles with respect to the plane of the sky.
We find that the maps of electron density, O+/H+ and O/H ratios show a rather
similar structure. We interpret this as produced by the strong dependence on
density of the [OII] lines used to derive the O+ abundance, and that our
nominal values of electron density-derived from the [SII] line ratio-may be
slightly higher than the appropriate value for the O+ zone. We measure the
faint recombination lines of OII in the field at the northeast of the Orion
South cloud allowing us to explore the so-called abundance discrepancy problem.
We find a rather constant abundance discrepancy across the field and a mean
value similar to that determined in other areas of the Orion Nebula, indicating
that the particular physical conditions of this ionization front do not
contribute to this discrepancy.Comment: 15 pages, 10 figures. Accepted for publication in MNRA
Cr(VI) sorption/desorption on untreated and mussel-shell-treated soil materials: fractionation and effects of pH and chromium concentration
We used batch-type experiments to study Cr(VI) sorption/desorption on granitic material, forest soil, pyritic material, mussel shell, and on forest soil and granitic material amended with 12 t ha−1 (1.2 kg m −2) shell, considering the effects of varying Cr(VI) concentration and pH. Sequential extractions were carried out to fractionate adsorbed Cr(VI) and to determine the stability of Cr(VI) retention. The pyritic material had the highest Cr(VI) retention capacity, whereas the granitic material showed the lowest retention potential. When high Cr concentrations were added, some saturation of the adsorbent surfaces became apparent, but Cr release remained low. The highest Cr retention was achieved at a very acid pH value, with release progressively increasing as a function of increasing pH. The amendment with 12 t ha−1 mussel shell did not cause marked changes in Cr(VI) retention. Sorption data were satisfactory adjusted to the Freundlich model. Regarding Cr(VI) fractionation, the soluble fraction (weakly bound) was dominant in mussel shell and in the unamended and amended granitic material, whereas more stable fractions dominated in the pyritic material (residual fraction) and in the forest soil (oxidizable fraction). In conclusion, the pyritic material presented the highest Cr(VI) retention capacity, while the retention was low and weak on the granitic material; mussel shell was not characterized by a marked Cr(VI) retention potential, and it did not cause remarkable increase in Cr(VI) retention when used to amend the granitic material or the forest soil.This study was funded by the Ministerio de Economía y Competitividad (Government of Spain), grant numbers CGL2012-36805-C02-01-02S
Sulfadiazine, sulfamethazine and sulfachloropyridazine removal using three different porous materials: Pine bark, “oak ash” and mussel shell
This work focuses on studying the efficacy of three different by-products to adsorb three antibiotics (sulfadiazine, SDZ; sulfamethazine, SMT; sulfachloropyridazine, SCP). These antibiotics can be considered pollutants of the environment when they reach water, as well as in cases where they are spread on soils through irrigation or contained in sewage sludge or livestock manure. In this study, batch-type adsorption/desorption experiments were performed for each of the three sulfonamides, adding 7 different concentrations of the antibiotics, going from 1 to 50 μmol L−1, and with contact time of 24 h. The results indicate that pine bark is the most efficient bioadsorbent among those studied, as it adsorbs up to 95% of the antibiotics added, while desorption is always less than 11%. However, for “oak ash” and mussel shell the adsorption is always lower than 45 and 15%, respectively, and desorption is high, reaching up to 49% from “oak ash” and up to 81% from mussel shell. Adsorption data showed good fitting to the Linear and Freundlich models, with R2 values between 0.98 and 1.00 in both cases. Kd and KF adsorption parameters showed similar values for the same sorbent materials but were much higher for pine bark than for the other two bioadsorbents. The Freundlich's n parameter showed values in the range 0.81–1.28. The highest KF values (and therefore the highest adsorption capacities) were obtained for the antibiotic SCP in pine bark. Pine bark showed the highest capacity to adsorb each of the antibiotics, increasing as a function of the concentration added. When the concentration of sulfonamide added was 50 μM, the amounts adsorbed were 780 μmol kg−1 for SDZ, 890 μmol kg−1 for SMT, and 870 μmol kg−1 for SCP. “Oak ash” and mussel shell have low adsorption capacity for all three sulfonamides, showing values always lower than 150 μmol kg−1 (oak ash) and 20 μmol kg−1 (mussel shell) when a concentration of 50 μmol L−1 of antibiotic is added. The results of this study could aid to make an appropriate management of the by-products studied, in order to facilitate their valorization and recycling in the treatment of environmental compartments polluted with sulfonamide antibiotics.Agencia Estatal de Investigación | Ref. RTI2018-099574-B-C21Agencia Estatal de Investigación | Ref. RTI2018-099574-B-C2
Alpha band disruption in the AD-continuum starts in the subjective cognitive decline stage: a MEG study
The consideration of Subjective Cognitive Decline (SCD) as a preclinical stage of AD remains still a matter of debate. Alpha band alterations represent one of the most significant changes in the electrophysiological profile of AD. In particular, AD patients exhibit reduced alpha relative power and frequency. We used alpha band activity measured with MEG to study whether SCD and MCI elders present these electrophysiological changes characteristic of AD, and to determine the evolution of the observed alterations across AD spectrum. The total sample consisted of 131 participants: 39 elders without SCD, 41 elders with SCD and 51 MCI patients. All of them underwent MEG and MRI scans and neuropsychological assessment. SCD and MCI patients exhibited a similar reduction in alpha band activity compared with the no SCD group. However, only MCI patients showed a slowing in their alpha peak frequency compared with both SCD and no SCD. These changes in alpha band were related to worse cognition. Our results suggest that AD-related alterations may start in the SCD stage, with a reduction in alpha relative power. It is later, in the MCI stage, where the slowing of the spectral profile takes place, giving rise to objective deficits in cognitive functioning.This study was supported by two projects from the Spanish Ministry of Economy and Competitiveness, PSI2009-14415-C03-01 and PSI2012-38375-C03-01, a predoctoral fellowship from the Ministry of Economy and Competitiveness to DLS (PSI2012-38375-C03-01), and three predoctoral fellowships from the Ministry of Education to RB,NS,ICRR (FPU13/06009, FPU14/07164, FPU13/02064)
Studying the electronic and charge transport properties of two cyclocarbazole derivates
Molecular systems have proven to be efficient active materials in electronics, being possible alternatives to the inorganic semiconductors used nowadays in electronic devices. For this reason, organic electronics has emerged as a research field with great potential and interest. In this project, an experimental and theoretical study of two carbazole-based macrocycles is presented (Figure 1). Specifically, we investigated the impact of the inclusion of acetylene groups on the electronic and molecular structures of these macrocycles, as well as their potential as charge transporting materials. The first studied compound (Cz) is composed by four carbazole groups linked at their para position with respect to the nitrogen atom[1]. In the second compound (ACz), the carbazole units are connected through ethynylene groups[2]. For this study, Raman and UV-Vis absorption spectroscopies have been used in combination with theoretical calculations based on the density functional theory (DFT). In addition, the two studied compounds have been implemented in organic field-effect transistors (OFETs), to assess their potential as active materials in organic electronics. Overall, the inclusion of ethynylene groups as π-conjugated spacers is found to be a good strategy to improve the electronic delocalization in macrocycles.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Effect of the faique (Acacia macracantha) on the nutritional value of guinea grass (Panicum maximum Jacq.) in a silvopastoral system
Universidad Nacional Agraria La Molina. Escuela de Posgrado. Maestría en Producción AnimalEl objetivo del estudio fue determinar la tasa de crecimiento y calidad nutricional del pasto Guinea (Panicum maximum Jacq) bajo un sistema silvopastoril con el árbol faique (Acacia macracantha). Se evaluaron dos épocas (lluviosa y seca) y tres tratamientos: (1) bajo la copa del árbol joven, (2) bajo la copa del árbol mediano y (3) fuera de la copa del árbol. Los árboles se clasificaron según el diámetro a la altura al pecho. El crecimiento y calidad del pasto se midió por el método de corte y separación y posterior análisis de laboratorio. La tasa de crecimiento osciló de 71.09 a 51.15 kg MS/ha/d, fuera y dentro de la copa de los árboles, respectivamente, en la época lluviosa. La proteína cruda varió de 10.58, 12.79 y 13.88% (época lluviosa) y 8.93, 10.26 y 11.99% (época seca) fuera de la copa del árbol, bajo la copa del árbol joven y bajo la copa del árbol mediano, respectivamente (p<0.05). El contenido de calcio en el pasto fue estadísticamente (p<0.05) superior bajo la copa del árbol mediano (0.23%) que fuera de la copa del árbol (0.20%) en la época lluviosa. El fósforo en el pasto varió significativamente (p<0.05) entre 0.72, 0.83 y 0.91% (época lluviosa) y 0.73, 0.87 y 1.06% (época seca), fuera de la copa de los árboles, bajo la copa del árbol joven y bajo la copa del árbol mediano, respectivamente. El estudio reveló que la presencia de árboles leguminosos (Acacia macracantha) dentro de los potreros mejora la calidad nutricional de la pastura Panicum maximum Jacq.The aim of this study was to determine the growth rate and nutritional quality of Guinea grass (Panicum maximum Jacq) under a silvopastoral system with the faique tree (Acacia macracantha). The evaluation included two seasons (rainy and dry) and three treatments: (1) under the canopy of the young tree, (2) under the canopy of the mediumsize tree, and (3) outside the canopy of the tree. The trees were classified according to the diameter at chest height. The growth and quality of the grass were measured by the method of cutting and separation and subsequent laboratory analysis. The growth rate ranged from 71.09 to 51.15 kg DM/ha/d, outside and inside the tree canopy, respectively, in the rainy season. Crude protein varied from 10.58, 12.79 and 13.88% (rainy season) and 8.93, 10.26 and 11.99% (dry season) outside the tree canopy, under the young tree canopy and under the middle tree canopy respectively (p<0.05). The calcium content in the grass was statistically (p<0.05) higher under the middle tree canopy (0.23%) than outside the tree canopy (0.20%) in the rainy season. The phosphorus in the grass varied significantly (p<0.05) between 0.72, 0.83 and 0.91% (rainy season) and 0.73, 0.87 and 1.06% (dry season), outside the tree canopy, under the canopy of the young tree and under the canopy of the medium tree, respectively. The study revealed that the presence of leguminous trees (Acacia macracantha) within the paddocks improves the nutritional quality of the Panicum maximum Jacq pasture
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