Silicon oxide thin films obtained by Ar+ bombardment of Si(100) in oxygen atmosphere at room temperature

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Predicting the induced change of fluid pressure in an unsaturated porous medium during undrained loading/unloading processes is challenging because two different fluids (a liquid and a gaseous solution) and a mixture of solid particles are involved. The relative presence of the two fluids and solid particles in the medium of interest, their stiffness, and the initial conditions in terms of liquid and gaseous pressure can play a crucial role in dictating the fluid pressures to be expected at the end of an un

MoMuCAMS (Modular, Multiplatform-Compatible Air Measurement System) is a newly developed system for aerosol and trace gas measurements in the lower atmosphere, which offers possibilities for detailed analysis at the interface of the boundary layer and free troposphere. This tethered-balloon system has been developed to address the need for more aerosol vertical observations to help our process understanding and eventually improve aerosol transport in models. This poster is a characterization of the system.

The diffusion of gases, dry and moist, had been studied in 1874 by Louis Dufour, who observed a pressure difference across a porous wall separating moist air and a vessel containing either water or a desiccant. 70 years later, Heinrich Greinacher (1880-1974) claimed to have built the first Diffusion Hygrometer, proposed a theory and got a patent for it. Two different models were produced by firms of Lausanne, TESA and Rüeger. Eventually, they were a commercial failure. We found one exemplar of each maker in

In DEMO reactor to produce electricity, a total installed power up to 150 MW is considered. In the heating mix, neutral beam (NB) injectors of high neutral particle energy (0.8-1 MeV) with high wall-plug efficiency (η in the range of 50% to 60%) will be required. Present design considered a NB system delivering in total 50 MW. In the Siphore NB concept [1], one of the promising candidates to meet these challenging requirements, negative ions will be extracted from a long, thin ion source 3 m high and 15 cm

Combinatorial high-vacuum chemical vapor deposition (HV-CVD) was used to identify the conditions required to obtain hafnium-doped lithium niobate thin films on sapphire {001} substrates. Niobium tetraethoxydimethylaminoethoxide (Nb(OEt)(4)(dmae)), lithium tert-butoxide (Li(OBut)), and hafnium tert-butoxide (Hf(OBut)(4)) were used as precursors. X-ray diffraction (XRD) and transmission electron microscopy (TEM) indicated that a single phase of textured {001} Hf-doped lithium niobate film was obtained under c

A new type of Nafion/Fe structured membrane ensuring faster kinetics, higher efficiency, and mechanical properties has been prepared and will be compared in its performance with the Fe-exchanged commercial Dupont 117 Nafion/Fe membrane during the abatement of model organic compounds. During the casting of the laboratory Nafion sample, the iron ions were introduced directly into the Nafion oligomer solution. This novel laboratory Nafion/Fe was tested as an immobilized catalyst in the degradation of several t

The surface active Fe-sites in HZSM-5 with low content of iron (

We used pulsed laser deposition, with a Bi2Sr2CaCu2O8+x target, to grow films ranging from (1/4) to 10 unit cells thick. We studied these films, and reference Bi2Sr2CaCu2O8+x single crystal samples, using angle-integrated photoemission, core level photoemission, and x-ray diffraction. The data indicate that all films exhibit a metallic-like Fermi edge in the photoemission data. More strikingly, a structural phase transition occurs at a nominal Bi2Sr2CaCu2O8+x thickness of approximately one unit cell, conver

We performed angle-resolved photoelectron spectroscopy (ARPES) and resistivity measurements on the layered metal 1T-TiTe2. We determined the quasiparticle dispersion and lifetime. In particular, we could characterize and separately evaluate the effects of the electron-electron and electron-phonon interactions on the experimental spectra. The good correlation between transport and spectroscopic scattering rates indicates that this material behaves as a model Fermi liquid system.

Flow in a elbow draft tube is a turbulent complex unsteady flow caused by its rotating nature and the draft tube's geometry. The understanding of the main phenomena that could appear near the BEP and at off-design conditions is important to master the instability of the machine. The results shown in this work are a summary of a very large experimental database. The aim of this investigation work is to analyze the steady and unsteady pressure fields at the wall of the draft tube through extensive pressure me

The work presents the effect of K-doping on V/Ti-oxides taking into account: the surface acid–base properties and the structure of surface vanadia species in respect to the catalyst performance and deactivation. The structure of active surface species determines redox properties, which are related to the catalytic performance by the Mars–van Krevelen mechanism. The reducibility of surface vanadia is studied by temperature-programmed reduction (TPR) in H2. The molecular structure of surface vanadia is determ

First-principles total energy calculations are carried out to investigate the relative energetics of several neutral oxygen species in alpha-quartz and amorphous SiO2. We considered both atomic and molecular oxygen, as interstitial and network species. The interstitial O-2 molecule is found to be the most stable oxygen species, both in alpha-quartz and amorphous SiO2. The formation energy of the interstitial O-2 molecule shows a strong correlation with the size of the interstitial void, strongly decreasing

We report on X-ray photoemission of core levels, valence band studies using angle-integrated photoemission, and magnetization measurements of ruthenocuprate and SrRuO3 polycrystalline samples. The data indicate that the RuO2 planes are the source of the energetics of the magnetic ordering. We also find that adding hydrogen leads to changes in the many-body response on both the CuO2 and EuO planes.

We summarize some of the main results on photoemission spectroscopy in the field of high T-c superconductivity, beginning with a discussion of several open questions. We then briefly analyze our experiments that illustrate the role of doping and of intentionally introduced disorder (by electron bombardment) in Bi2Sr2CaCu2O8+x single crystals.

The homogeneous hydrogenation of carbon dioxide into formate anion has been investigated in aqueous solution, using water soluble ruthenium(II)-phosphine (meta-monosulphonated triphenylphosphine, TPPMS; and 1,3,5-triaza-7-phosphaadamantane, PTA) complexes as catalysts. These reactions take place in amine free medium under mild conditions, bicarbonate anion is more active than carbon dioxide in the reduction. The initial turnover frequency of the reduction increases with increasing H-2 pressure, as it was ob

A review with 55 refs. Oxygen is a key substrate in animal cell metab. It has been reported that the oxygen uptake rate (OUR) is a good indicator of cellular activity, and even under some conditions, a good indicator of the no. of viable cells. The measurement of OUR is difficult due to many different reasons. In particular, the very low specific consumption rate (0.2*10-12 mol cell h-1), the sensitivity of the cells to variations in dissolved oxygen concn. and the difficulty to provide oxygen without damag

A new separation technique has been developed to determine the forward and backward running arterial pressure wave components. It takes into account friction as well as nonlinear effects due to convective acceleration and to the pressure dependence of the arterial compliance. The new method is a combination of two methods treating friction and nonlinearities separately. The method requires the measurements of pressure and flow at one location as well as the knowledge of the area-pressure relationship. The v

We demonstrated that polycrystalline cesium iodide (CsI) on large area Ni/Au coated printed board provides a quantum efficiency (QE) higher by a factor of 2 than the films deposited on the standard Cu/Au printed circuits. This is the most important result of the present systematic study of the QE lateral inhomogeneity for CsI on different substrates. We found a strong correlation between the QE lateral variation and the morphological homogeneity of the films. The QE was measured by UV photoelectron emission

Using the X-ray spectromicroscopy technique, we studied the primary and secondary electron photoemission of cesium iodide (CsI) films deposited on different substrates, such as copper, aluminum, stainless-steel, and gold-coated quartz. We found an increase of more than a factor of 2 in the secondary emission after exposing, for a few seconds in ultra-high-vacuum (3 X 10(-10) mbar), the sample surface to an X-ray dose-rate of about 5 X 10(11) photons/s cm2 at the Al Kalpha photon energy (1486.7 eV). The acti

The dramatic enhancement of the silicon room-temperature oxidation rate by a Na overlayer has been attributed to the spectator catalytic action of the alkali metal. In contrast, we show evidence that Na participates in the oxidation process binding an oxygen atom in a substoichiometric intermediate oxidation state. This causes preferential saturation of the semiconductor dangling bonds on the surface and a subsequent promotion of the oxide growth. We have, in fact, detected the Na 2p photoemission chemical

Silicon oxide thin films obtained by Ar+ bombardment of Si(100) in oxygen atmosphere at room temperature

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On predicting pore fluid pressure changes in unsaturated porous media subject to undrained processes

MoMuCAMS – A newly developed Helikite-based modular platform for aerosol and trace gas vertical measurements

The Diffusion Hygrometer: A late invention of H. Greinacher

A novel helicon plasma source for negative ion beams for fusion

Combinatorial High-Vacuum Chemical Vapor Deposition of Textured Hafnium-Doped Lithium Niobate Thin Films on Sapphire

Synthesis, Testing, and Characterization of a Novel Nafion Membrane with Superior Performance in Photoassisted Immobilized Fenton Catalysis

Transient response method for characterization of active sites in HZSM-5 with low content of iron during N2O decomposition

Structural phase transition in early growth of Bi2Sr2CaCu2O8+x films on SrTiO3 substrates

Quasiparticle scattering processes in a model Fermi liquid: 1T-TiTe2

Pressure Wall Measurements in the whole Draft Tube : Steady and Unsteady Analysis

Implication of the Acid-Base Properties of V/Ti-oxide Catalyst in Toluene Partial Oxidation

Energetics of oxygen species in crystalline and amorphous SiO2: a first-principles investigation

Electronic and magnetic properties of ruthenocuprates

Photoemission experiments on high-T-c superconductors: Recent progress and some open questions

Towards an easy carbon dioxide reduction in aqueous solution

Measurement of volumetric (OUR) and determination of specific (qO2) oxygen uptake rates in animal cell cultures

Separation of arterial pressure waves into their forward and backward running components

Morphological Effects in the Quantum Yield of Cesium Iodide

Spatially-Resolved X-Ray Spectroscopy of CsI Deposits

Na-Promoted Oxidation of Si - the Specific Oxidation Mechanism