The metal-support interactions for a model silica-supported copper catalyst have been studied using temperature-programmed desorption, X-ray photoelectron and infrared reflection-absorption spectroscopies under ultrahigh vacuum conditions. The model catalyst support was prepared by synthesizing a thin SiO, film (_ 100 A) on a Mo(l10) surface. Copper was then evaporated onto the SiO, films. A sm...

Thermochemical and compressibility data are used to calculate the approximate pressures and temperatures required for the reaction of clinoenstatite to Mg•SiO• (spinel or olivine) or to periclase and stishovite, the reaction of forsteritc to Mg•SiO• (spinel) or periclase and stishovite, and the breakdown of Mg•SiO• (spinel) to periclase and stishovite. The calculated reaction lines for Mg•SiO• ...

We have used the Very Large Array (VLA) at 7 mm wavelength to image five rotational transitions (J = 1 − 0) from three SiO isotopologues towards Orion BN/KL: SiO v = 0, 1, 2; and SiO and SiO v = 0. For the first time, we have mapped the SiO and SiO J = 1− 0 emission, established the maser nature of the emission, and confirmed association with the deeply embedded high-mass young stellar object c...

We have investigated the influence of several line overlaps between 28 SiO , 29 SiO and 30 SiO on maser emission from the envelopes of late-type stars using the Large Velocity Gradient radiative transfer formalism modified to account for overlaps. Our model includes: (i) 40 rotational levels for each of the v = 0 to 4 vibrational states and each isotopic species; (ii) collisions with molecular ...

We report the first VLBI map of the 7 mm v=0 J=1–0 maser line of the 29 SiO isotopic substitution in the long period variable star IRC +10011. We have found that this maser emission is composed of multiple features distributed in an incomplete ring, suggesting that this maser is also amplified tangentially as already proposed in other SiO circumstellar masers. We present also the results for so...

Silicone oil (SiO) and fluorosilicone oil (FSiO) are useful in difficult cases of retinal detachment surgery. Unidentified low-molecular-weight components (LMWC) and residual catalysts in SiO and FSiO have been implicated in the adverse reactions of the oils in the eye. The authors analyzed LMWC of SiO and FSiO using a gas chromatograph (GC) equipped with a 6-ft x 2-mm column packed with 3% SP-...

We have observed with the IRAM interferom-eter at two different epochs and simultaneously the two transitions v = 0, J = 2 → 1 and v = 1, J = 2 → 1 of 29 SiO and 28 SiO in Orion IRc2. We have made the first maps of 29 SiO v = 0, J = 2 → 1 emission from Orion. These maps and properties of the 29 SiO spectra attest to maser emission. Our 28 SiO maps show the stable ring of maser spots observed in...

The first gas-phase infrared spectra of silicon monoxide cations (SiO)n , n = 3–5, using multiple photon dissociation in the 550–1250 cm 1 frequency range, are reported. All clusters studied here fragment via loss of a neutral SiO unit. The experimental spectra are compared to simulated linear absorption spectra from calculated low energy isomers for each cluster. This analysis indicates that a...

We present images of the HH 211 molecular jet in the SiO v=0, J=1–0 line at 43 GHz made with the Very Large Array at approximately 0.5 arcsec resolution. The SiO emission appears to trace primarily internal bowshocks in the outflow, suggesting that the dust and molecular gas are accelerated via prompt entrainment at internal working surfaces in the jet. There is also some evidence for limb-brig...

This retrospective study aimed to evaluate the influence of a temporary silicone oil (SiO) tamponade on intraocular pressure (IOP). We reviewed 131 procedures with a temporary SiO tamponade for different indications. Visual outcome and anatomic results after the SiO removal were also analyzed. Relatively good visual and anatomic results can be achieved by a temporary SiO tamponade with an accep...