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Glacierized landscapes produce abundant fine-grained reactive minerals that play a pivotal role in high-altitude inorganic carbon cycling, mainly through geochemical weathering. However, our understanding of the relationship between glacially comminuted mineral dissolution, precipitation of secondary phases and inorganic carbon cycling in the world’s glacier-fed streams (GFSs) remains elusive. Here, we investigate first-order relationships between suspended sediment mineralogy, streamwater solute chemistry

Understanding the crystallisation of silicate melts at lower mantle conditions is essential for constraining the petrological and chemical evolution of planetary magma oceans. In this study, we investigated the solidification of a pyrolitic melt through fractional crystallisation experiments in the laser-heated diamond anvil cell coupled with thermodynamic modelling. Fifteen experiments were conducted to establish the melting phase diagrams of pyrolite at four lower mantle pressures (53, 87, 107, 133 GPa).

Mode I fracture toughness, KIc, is a key measure of rock strength. In volcanology, KIcis particularly relevant for dike propagation, as it quantifies the critical stress intensity factor required for fracture propagation under tensile stress. KIc has been extensively studied for rock types and construction materials relevant to civil engineering, mining, and hydrocarbon-related applications. However, there is a paucity of data for volcanic rock. In this study, we present KIcvalues for basalt samples of vary

Calcium silicate perovskite (CaPv) is the host for many large ion lithophile elements including the heat-producing elements in the lower mantle. Whether, when, and where it forms during the solidification of the magma ocean is fundamental to understanding the geochemical and geodynamical evolution of the early Earth and the trace element distribution in the lower mantle. In this study, we performed first-principles molecular dynamics simulations to investigate the partitioning behavior of Ca (alongside othe

Hydraulic fractures are driven by an internal fluid pressure exceeding the minimum compressive stress, propagating in a direction perpendicular to the latter. This class of tensile fractures has gained interest over the last fifty years due to the development of multiple engineering applications. Among these industrial applications are well-stimulation treatments by hydraulic fracturing used in the oil and gas industry to enhance the permeability of tight reservoirs. The same technique is used in geothermal

The stability of Nd-nickelate, considered as an alternative solid oxide fuel cell (SOFC) cathode material, was evaluated in this work on its tolerance towards contaminants. Symmetrical cells with Nd1.95NiO4+δ (NNO) electrodes on gadolinia-doped ceria electrolyte supports were monitored over time-spans of 1000 h under polarisation in an air-flux with deliberate chromium contamination. Impedance spectroscopy pointed out a polarization increase with time by the growth of the low frequency arc describing the el

Continuous hot-dip galvanization is a process during which steel sheets are coated with a layer of Zn-Al alloy to protect them against corrosion. As the name indicates, this is achieved by dipping the preheated sheet into a bath of molten alloy. The sheet ...

The aim of this thesis was to synthesise and control a nanostructured composite of copper/cobalt. Both the copper and cobalt oxalate exhibit a nanostructure. Attempts to produce nanocomposite particles in the size range of 10-70 nm were made via an oxalate co-precipitation route followed by the appropriate thermal treatment to finally obtain the metal nanocomposite. Much attention was focussed on the understanding of the copper oxalate precipitation and its further transformation into metal before the inves

The motivation of this work derives from the need of the cutting tool industry to improve its products in order to support harder and harder working conditions, namely increasing cutting speeds and working on stronger modern materials. The lifetime of the tools is limited by plastic deformation that occurs at the cutting edge under working conditions, which involve high temperatures and stresses. The high temperature deformation of the materials that are used for the production of cutting tools is studied.

Oriented films of tetracene and pentacene have been obtained by high vacuum sublimation onto oriented poly(tetrafluoroethylene) (PTFE) substrates. Polymorphism, orientation, and morphology of the pentacene and tetracene films are studied as a function of deposition parameters [substrate temperature (Ts), deposition time (t), and deposition rate (τ)] using X-ray and electron diffraction, transmission and scanning electron microscopies and atomic force microscopy (AFM). Oriented films of the tr

A method for the online calcn. of conversion rates and yield coeffs. under dynamic process conditions was developed. The method is based on cumulated mass balances using a moving av. method. Elemental balances were used to test the measured cumulated quantities for gross errors and inappropriate stoichiometry definition followed by data reconciliation and estn. of non-measured conversion rates, using a bioprocess set-up including multiple online anal. techniques. The quant. potential of the proposed method

A kinetic model for solid-state polycondensation of nylon-6 was developed by extrapolation of the melt chemistry to the amorphous phase of the solid polymer. In this way, a phenomenological description of the process was obtained that required examining al1 possible influences of the semicrystalline structure on the kinetics, equilibrium, and transport phenomena in the polymer granules. Particularly, dramatic apparent kinetics and equilibria changes were postulated due to the confinement of reactive species

In situ Fourier transform infrared (FTIR) absorption spectroscopy has been used to determine the fractional depletion of silane in a radio-frequency (ri) glow discharge. The technique used a simple single-pass arrangement and was implemented in a large-area industrial reactor for deposition of amorphous silicon. Measurements were made on silane plasmas for a range of excitation frequencies. It was observed that, at constant plasma power, the fractional depletion increased from 35% at 13.56 MHz to 70% at 70

The geochemical typology of natural subsurface waters of the Molasse basin is part of the AQUITYP project, initiated by the Geology Laboratory (GEOLEP) of the Swiss Federal Institute of Technology in Lausanne (EPFL). This study provides an overview of the variation in space of the hydrochemical parameters, especially of trace elements, in order to determine the geological origin of their aquifers. Our data base is mainly made up of two observation networks: a subsurface water network and a deep groundwater

The electrochem. behavior of the Ti/PtOx.TiO2 electrode in dil. HCl was studied as a function of the relative compns. of both oxides, which were deposited thermally at different temps. A max. was found of the catalytic activity of the electrode for Cl evolution at a ratio of PtOx/TiO2 of 10:1. [on SciFinder (R)]

Cumulat

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Rapid carbonation of silicate minerals drives atmospheric CO2 drawdown in glacier-fed stream waters

The petrological evolution of Earth’s solidifying magma ocean from experimental melting phase relations

The influence of porosity and microstructure on the fracture toughness of basalts from Mt. Etna: laboratory measurements

Formation of calcium silicate perovskite above the core-mantle boundary during solidification of Earth’s magma ocean

Ascent and movement of buoyant fluids in the lithosphere

Nd-Nickelate Solid Oxide Fuel Cell Cathode Sensitivity to Cr and Si Contamination

Texture Formation in Hot-Dip Galvanized Coatings : Nucleation and Growth of Anisotropic Grains in a Confined Geometry

Precipitation and transformation of nanostructured copper oxalate and copper/cobalt composite precursor synthesis

High temperature deformation mechanisms of cemented carbides and cermets

Orienting tetracene and pentacene thin films onto friction-transferred poly(tetrafluoroethylene) substrate

On-line stoichiometry and identification of metabolic state under dynamic process conditions

Kinetic studies and modeling of nylon-6 solid-state polycondensation

Degree of dissociation measured by FTIR absorption spectroscopy applied to VHF silane plasmas

Typologie des eaux souterraines de la molasse entre Chambéry et Linz (France, Suisse, Allemagne, Autriche)

Preparation and characterization of a new electrode of the type titanium/platinum oxide (PtOx).titanium dioxide