Field observations were carried out in the East China Sea (ECS) in October 2000, May 2001 and April–May 2002. Biogenic silica (BSi) in core sediments, sediment traps, and suspended particulate matter (SPM) was measured; silicate profiles in pore waters were examined. The concentration of BSi in SPM was high in coastal areas. The content of BSi in ECS sediments is less than 1%, as the result of ...

The present study describes for the first time the synthesis of silica nanoparticles starting from sodium silicate and oleic acid (OLA). The interactions between OLA and sodium silicate require an optimal OLA/OLANa molar ratio able to generate vesicles that can stabilize silica particles obtained by the sol-gel process of sodium silicate. The optimal molar ratio of OLA/OLANa can be ensured by a...

Context. Studying the composition of dust in the interstellar medium (ISM) is crucial for understanding the cycle of dust in our galaxy. Aims. The mid-infrared spectral signature of amorphous silicates, the most abundant dust species in the ISM, is studied in different lines-of-sight through the Galactic plane, thus probing different conditions in the ISM. Methods. We have analysed ten spectra ...

The origin of silicate carbon stars has been a mystery ever since their discovery. We discuss here a full grating spectrum between 2.4 and 45 μm of the silicate carbon star V778 Cyg obtained by the ISO/SWS. The spectrum, taken about 14 years after the IRAS LRS observation, confirms the complex nature of the object. The spectrum is clearly divided into a short wavelength (λ < 6.5 μm), carbon-ric...

Istituto Nazionale di GEOFISICA e VULCANOLOGIA The GaME workshop: " Gases in Magmatic Evolution: from depth to atmosphere, from micro to macro-scale, from calculation to observation " " Flory-Huggins, Quasi-Chemical and Polymeric model analogies in the treatment of reactivity and mixing properties of melts " 10:10-10:30: Christian De Capitani (Univ. Basel, Switzerland) " The Computation of Equi...

A method for controlling the gastric pH of rabbits to low acidity (pH > 4) by using different antacids was investigated, and the physiological state of rabbits during gastric-acidity control and repeated bioavailability tests was also examined in terms of hemocytological and clinicobiochemical parameters. Neither dried aluminum hydroxide gel (DAH) nor synthetic aluminum silicate (SAS) could ele...

The present study firstly proposed a method of integrated utilization of sewage sludge (SS) and coal gangue (CG), two waste products, for cement clinker products with the aim of heat recovery and environment protection. The results demonstrated that the incremental amounts of SS and CG addition was favorable for the formation of tricalcium silicate (C₃S) during the calcinations, but excess amou...

Introduction: The presence and amount of Si in Earth's core has important implications for models of the processes and chemistry of core segregation. A metal core containing 5 to 7 wt. % Si can be produced when assuming continuous accretion and equili-bration along the silicate liquidus terminating at ~35 GPa and ~3,000 K, and with a concomitant increase in fO 2 from 4 to 2 log units below IW [...

Introduction: The compositional characteristics of the Earth's core-mantle system are best described by a model that recognizes that the present upper mantle is not in equilibrium with the core and that metal-silicate differentiation was in response to secular changes in equilibrium conditions [1-5 and references therein]. Au) that are ~100-fold depleted relative to chondritic meteorites [6-7]....

Arsenic (As) contaminated aquifers contain iron minerals and clays that strongly bind As at their surfaces. It was suggested that As mobilization is driven by natural organic matter (including fulvic acids (FA) and humic acids (HA)) present in the aquifers either via providing reducing equivalents for reductive dissolution of Fe(III) (hydr)oxides or via competitive desorption of As from the min...