Search results for "Oxide"

CO 2 output and δ 13 C(CO 2 ) from Mount Etna as indicators of degassing of shallow asthenosphere

1997

An estimated average CO2 output from Etna's summit craters in the range of 13±3 Mt/a has recently been determined from the measured SO2 output and measured CO2/SO2 molar ratios. To this amount the CO2 output emitted diffusely from the soil (≈ 1 Mt/a) and the amount of CO2 dissolved in Etna's aquifers (≈ 0.25 Mt/a) must be added. Data on the solubility of CO2 in Etnean magmas at high temperature and pressure allow the volume of magma involved in the release of such an amount of this gas to be estimated. This volume of magma (≈ 0.7 km3/a) is approximately 20 times greater than the volume of magma erupted annually during the period 1971–1995. On the basis of C-isotopic data of CO2 collected in…

CO2 release to the atmosphere from thermal springs of Sperchios Basin and northern Euboea (Greece): The contribution of “hidden” degassing

2020

Abstract Greece is a region characterised by intense geodynamic activity that favours the circulation of hydrothermal fluids in the crust transporting volatiles from either the deep crust or the mantle to the surface. Elevated heat flow values are detectable at Sperchios Basin and North Euboea (central Greece), two areas defined by a system of deeply rooted extensional faults and Quaternary volcanic activity. This setting contributed to the formation of numerous hydrothermal systems, which are mostly expressed as CO2-rich thermal springs with intense bubbling. The CO2 output from six bubbling pools has been determined by flux measurements with the use of the floating chamber method. The hig…

Glyphosate Sensor Based on Nanostructured Water-Gated CuO Field-Effect Transistor

2022

This research presents a comparative analysis of water-gated thin film transistors based on a copper oxide (CuO) semiconductor in the form of a smooth film and a nanostructured surface. A smooth CuO film was deposited through reactive magnetron sputtering followed by annealing in atmosphere at a temperature of 280 (Formula presented.) C. Copper oxide nanostructures were obtained by hydrothermal synthesis on a preliminary magnetron sputtered 2 nm thick CuO precursor followed by annealing at 280 (Formula presented.) C. An X-ray diffraction (XRD) analysis of the samples revealed the presence of a tenorite (CuO) phase with a predominant orientation of (002). Scanning electron microscopy (SEM) a…

Synthesis of a biocompatible aerogel based on graphene oxide and a modified polyethylene glycol

2016

The synthesis and self-assembly of a 3D aerogel built by graphene oxide (GO) and a modified polyethylene glycol (PEG) was achieved by a multi-step synthetic procedure, involving the preparation of an amino-terminated PEG (PEG-NH2) and the subsequent coupling with GO by carbodiimide in water, exploiting the carboxyl and epoxy moieties of GO and –NH2 terminations of the biopolymer. The resulting nanohybrid hydrogel was successively converted into an aerogel via dialysis plus freeze-drying [1] and fully characterized. FTIR, Raman, XPS, XRD and BET measurements were performed to confirm the successful modification for each reaction step, while morphological, mechanical and hemolytic tests were …

Graphene oxide and Fumed silica graphene oxide nanocomposites modification by thermal treatments

2014

In the present study we investigate post synthesis thermal treatments up to 400 °C of graphene oxide (GrO) prepared from commercial graphite and of GrO–silica nanocomposites prepared by a solution of commercial Fumed silica nanoparticles (average diameter 7 nm or 40 nm) and the GrO. The thermal treatments were carried out in air, vacuum or He atmosphere to highlight tunable changes. Two GrO batches with small differences in the D (~1350 cm–1) and G (~1580 cm–1) Raman bands have been employed to evaluate effects depending on preparation. Thermal effects have been monitored through the Raman spectroscopy focusing on D, G and 2D (2500–3500 cm–1) bands spectral ranges. The experiments evidenced…

IMPROVED STABILITY OF GRAPHENE OXIDE-SILICA NANOHYBRIDS AND RELATED POLYMER-BASED NANOCOMPOSITES

2014

Although its promising properties make the graphene oxide (GO) very interesting as filler for polymer matrices, some problems related to its thermal stability in the region which ranges from 80 to 200 °C, are crucial for the possibility to melt process GO together with practically all the polymers [1,2]. Moreover, above 100 °C GO lamellae were found to become stacked. In this work, two different ways to preserve the GO structure and ensure its dispersion within different polymer matrices have been investigated and schematized in Fig. 1. Exfoliation plays a key-role in the achievement of good mechanical properties since it preserves the GO from both stacking phenomena. The capability of sili…

Polyamide 6/Graphene Oxide Nanohybrids

2013

Facile and novel synthesis of Graphene oxide/Silica nanohybrids with tunable properties

2013

An Overview of Functionalized Graphene Nanomaterials for Advanced Applications

2021

Interest in the development of graphene-based materials for advanced applications is growing, because of the unique features of such nanomaterials and, above all, of their outstanding versatility, which enables several functionalization pathways that lead to materials with extremely tunable properties and architectures. This review is focused on the careful examination of relationships between synthetic approaches currently used to derivatize graphene, main properties achieved, and target applications proposed. Use of functionalized graphene nanomaterials in six engineering areas (materials with enhanced mechanical and thermal performance, energy, sensors, biomedical, water treatment, and c…

Using exomarkers to assess mitochondrial reactive species in vivo

2014

Background:\ud The ability to measure the concentrations of small damaging and signalling molecules such as reactive oxygen species (ROS) in vivo is essential to understanding their biological roles. While a range of methods can be applied to in vitro systems, measuring the levels and relative changes in reactive species in vivo is challenging.\ud \ud Scope of review:\ud One approach towards achieving this goal is the use of exomarkers. In this, exogenous probe compounds are administered to the intact organism and are then transformed by the reactive molecules in vivo to produce a diagnostic exomarker. The exomarker and the precursor probe can be analysed ex vivo to infer the identity and a…