Search results for "Solid"

Electrosynthesis of Sn-Co nanowires in alumina membranes

2010

A fabrication process of amorphous nanowires of Sn-Co alloys, based on electrodeposition into anodic alumina membranes, is described. It is shown that nanowires of tin-cobalt alloys with different compositions can be produced by varying electrodeposition time and concentration ratio of salts dissolved into the electrolytic bath. Importance of the chelating agent to produce amorphous Sn-Co alloys has also been addressed. Electrodepositions were carried out potentiostatically at -1 V versus Saturated Calomel Electrode and 60 degrees C for times ranging from 10 to 90 minutes; the atomic fraction of Co2+ in the aqueous electrolyte (Co2+/(Co2+ + Sn2+)) was varied from 0.33 to 0.67. Nanowires asp…

Dehydration of Fructose to 5-HMF over Acidic TiO2 Catalysts

2020

Different solid sulfonic titania-based catalysts were investigated for the hydrothermal dehydration of fructose to 5-hydroxymethylfurfural (5-HMF). The catalytic behavior of the materials was evaluated in terms of fructose conversion and selectivity to 5-HMF. The surface and structural properties of the catalysts were investigated by means of X-ray diffraction (XRD), N2 adsorption isotherms, thermo-gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and acid capacity measurements. Special attention was focused on the reaction conditions, both in terms of 5-HMF selectivity and the sustainability of the process, choosing water as the solvent. Among the various process condition…

Preliminary Estimation of Deoxynivalenol Excretion through a 24 h Pilot Study

2015

A duplicate diet study was designed to explore the occurrence of 15 Fusarium mycotoxins in the 24 h-diet consumed by one volunteer as well as the levels of mycotoxins in his 24 h-collected urine. The employed methodology involved solvent extraction at high ionic strength followed by dispersive solid phase extraction and gas chromatography determination coupled to mass spectrometry in tandem. Satisfactory results in method performance were achieved. The method"s accuracy was in a range of 68%108%, with intra-day relative standard deviation and inter-day relative standard deviation lower than 12% and 15%, respectively. The limits of quantitation ranged from 0.1 to 8 μg/Kg. The matrix effect w…

Infant exposure of perfluorinated compounds: Levels in breast milk and commercial baby food

2010

In this study, an analytical method to determine six previous termperfluorinatednext term compounds (PFCs) based on alkaline digestion and solid phase extraction (SPE) followed by liquid chromatography-quadrupole-linear ion trap mass spectrometry (LC-QqLIT-MS) was validated for the analysis of human breast milk, milk previous terminfantnext term formulas and cereals baby food. The average recoveries of the different matrices were in general higher than 70% with a relative standard deviation (RSD) lower than 21% and method limits of detection (MLOD) ranging from 1.2 to 362 ng/L for the different compounds and matrices. The method was applied to investigate the occurrence of PFCs in 20 sample…

Trace element systematics of tourmaline in pegmatitic and hydrothermal systems from the Variscan Schwarzwald (Germany): The importance of major eleme…

2013

article An extensive data set on the compositional variation of tourmaline from granitic pegmatites, from migmatitic gneisses and from various types of hydrothermal veins from the Schwarzwald, Germany, is provided. The investigated tourmalines are members of the alkali and X-vacant groups representing mostly dravite- schorl solid solutions with some analyses belonging to the foitite-Mg-foitite series. Oxygen isotope data on quartz-tourmaline pairs indicate formation temperatures between 550 and 350 °C for most of the quartz-tourmaline veins. Most of the tourmalines show strong sector zonation, fractionating certain major (e.g., Na, Mg), minor (e.g., Ti, Ca) and trace elements (e.g., Sr, Pb,…

Extraction and trace enrichment of genotoxicants from environmental samples by solid-phase adsorption on blue pearls

1988

Trace element behavior in the fluidized bed gasification of solid recovered fuels

2013

Gasification of biomass and recycled fuels is of particular interest for the efficient production of power and heat. Trace elements present as impurities in the product gas should be removed very efficiently. The objective of this work has been to develop and test thermodynamic models for the reactions of trace elements with chlorine and sulfur in the gasification processes of recycled fuels. In particular, the chemical reactions of trace elements with main thermochemical conversion products, main ash components, and bed and sorbent material are implemented into the model. The possibilities of gas cleaning devices in condensing and removing the trace element compounds are studied by establi…

Más cerca del caos

2001

Rapid nucleus-scale reorganization of chromatin in neurons enables transcriptional adaptation for memory consolidation

2020

AbstractThe interphase nucleus is functionally organized in active and repressed territories defining the transcriptional status of the cell. However, it remains poorly understood how the nuclear architecture of neurons adapts in response to behaviorally relevant stimuli that trigger fast alterations in gene expression patterns. Imaging of fluorescently tagged nucleosomes revealed that pharmacological manipulation of neuronal activity in vitro and auditory cued fear conditioning in vivo induce nucleus-scale restructuring of chromatin within minutes. Furthermore, the acquisition of auditory fear memory is impaired after infusion of a drug into auditory cortex which blocks chromatin reorganiz…

DC Bias Abatement in Dual Active Bridge Converter using Covalent Active and Passive Components

2022

The Dual Active Bridge (DAB) converter is the most attractive bidirectional DC-DC converter topology in the distribution network. However, the DC bias is the most common issue in the dual active bridge converter due to the sudden change in internal or external phase shift angles to regulate the power signal. Consequently, it will increase conduction losses, a core saturation problem of High-Frequency Transformer (HFT), and loss of Zero Voltage Switching (ZVS) operation. Therefore, this paper presents the DC bias abatement in the DAB converter using covalent active and passive components to alleviate these problems. The proposed method employs the series capacitor in the windings of HFT as t…