Effect of gasketing and assembly design: a novel 10/3.5 mm multi-anvil assembly reaching perovskite pressures

A new design of multi-anvil assembly and modified gasket characteristics with octahedron and truncation edge lengths of 10 and 3.5 mm is presented for reaching pressures and temperatures over 24 GPa and 2000 °C, respectively. Partially dehydroxylated pyrophyllite half-gaskets with a tapered design fully nesting the octahedron have been employed to prevent excessive octahedron extrusion between the cubes. The assembly utilizes an axially placed thermocouple through the octahedral center, allowing two samples to be present at identical high P–T conditions on either side of the thermocouple during a run. A third sample can be used as a packing around the thermocouple, so long as that sample is inert with respect to the thermocouple and surrounding material. The temperature gradient within the sample locations has been well characterized using two-pyroxene thermometry in the CaO–MgO–SiO₂ system and numerical modeling calculations. The results indicate a good agreement in gradient shape, although the numerical model appears to under-estimate the magnitude of temperature change. The assembly maintains stable temperatures and provides low failure rates.     

Carbon Isotope Analysis in Urea at High 13C-Abundances Using the 13/12CO2-Breath Test Device Fanci2

Abstract

The increasing application of ¹³C-labelled urea in medicine requires simple and reasonable methods for measuring highly enriched ¹³C in urea. The combination: ultimate organic analysis—mass spectrometry so far prescribed is complicated and expensive. For medical diagnosis, however, isotope selective nondispersive infrared spectrometers (NDIRS) have been available for many years. One of these tools is FANci2 which is very reasonable and easily to be operated. By means of such devices also urea highly enriched in ¹³C can be analysed, provided that the samples are first diluted with a defined amount of urea of natural isotopic composition and then transformed into carbon dioxide by means of urease. The relative abundance of ¹³C in this carbon dioxide, measured by nondispersive infrared spectrometry, is then a measure of the ¹³C abundance in the initial urea sample. Comparison of results of such measurements with those attained by mass spectrometry proves that this procedure is feasible and yields precise results.     

Zum 100. Geburtstag von

Unter dem Aspekt, Anti-Tumor-Antikörper mit ^13lJod zu markieren und dabei deren immunologische Reaktivität (Präzipilationsfähigkeit in vitro) soweit wie möglich zu erhalten, werden Modellexperimente zur Markierung von Kaninchen-Gammaglobulin und Anti-Pferdeserumalbumin-Antikörpern beschrieben. Bis zu einem Substitutionsgrad von 1,2 Jodatomen pro Antikörpermoleküt ist ein Verlust an Präzipitationsvermögen der Antikörperpräparationen offenbar auf die Wirkung von im Überschuβ angewandtem Natriumdisulfit (Oxydations-Stop-Reagens für die Wirkung von Chloramin T) zurückzuführen.     

Frequency doubling of Nd:YAG- and GaAs-lasers by KNbO3: Ta crystals

Abstract

For KNb_1-xTa_xO₃ crystals the influence of the Ta-concentration on the phase-matching properties for optical second harmonic generation (SHG) was measured. For non-critical phase matched SHG of the Nd:YAG-laser (1064nm) the coefficient d₃₁ of the tensor of the nonlinear susceptibility was applied, while for the GaAs-laser (905 nm) the coefficient d₃₂ was used. For both laser wavelengths the phase-matching temperature decreases with increasing Ta-concentration. Non-critical phase-matching at room temperature can be reached with the GaAs-laser for a Ta-concentration of ≈9%. The corresponding value for the Nd:YAG-laser is ≈14%.     

On the evolution of the mass asymmetry in damped heavy-ion collisions

TotaT kinetic energy vs. fragment mass distributions have been measured in the reactions of⁶⁴Zn projectiles with¹¹⁴Sn,^natAg and¹³⁹La nuclei at incidence energies of 20–50% above the Coulomb barrier. Conclusions are drawn on the possible influence of nuclear structure effects on the energy dissipation and the mass drift behaviour of the present collision systems.     

Nitric oxide reduction by CO ON Rh(111): Temperature programmed reaction

The reaction of NO with CO on Rh(111) has been studied with temperature programmed reaction (TPR). Comparisons are made with the reaction of O₂ with CO and the reaction of NO with H₂. The rate-determining step for both CO oxidation reactions is CO(a) + O(a) → CO₂(g). Repulsive interactions between adsorbed CO and adsorbed nitrogen atoms lead to desorption of CO in a peak at 415 K which is in the temperature range where the reaction between CO(a) and O(a) produces CO₂(g). Thus the extent of reaction of CO(a) with NO(a) is less than that between CO(a) and O(a) due to the lower coverage of CO caused by adsorbed N atoms and NO. A similar repulsive interaction between NO(a) and H(a) suppresses the NO + H₂ reaction. CO + NO reaction behavior on Rh(111) is compared to that observed on Pt(111).     

Energy measurement at the Darmstadt unilac accelerator

The kinetic energy of⁸⁶Kr ions accelerated by UNILAC (GSI-Darmstadt) was measured using the recoil proton technique. A good agreement was found with the energy values obtained by the time-of-flight technique currently used at UNILAC.     

Low temperature heat capacity of electrotransported scandium

The heat capacity of two scandium samples containing 1.6 and <5 ppm atomic Fe was measured from 1 to 20 K. The weighted values for γ and θ_D are: 10.340 ± 0.018 mJ/g-at. K² and 346.1 ± 0.9 K, respectively. This is the first time anyone has obtained the same heat capacity results on two different scandium samples. The iron impurity concentration appears to be critical.     

Der einfluss des stanzens auf die magnetischen eigenschaften von elektroblech mit 1% silizium

The influence of punching on the magnetic properties of fully annealed electrical steel sheet with 1 % Silicon has been investigated. By comparing to an Epstein sample, which had its deformed edges carefully removed, it was found that the total power loss increases and the permeability decreases with increasing the specific cut edge. At a length of 100 m/kg the increase P 1.0 is about 30% when samples were cut with a sharp tool and even 40% for a blunt tool. The greatest change of the induction occurs in the range of maximum permeability. At 100 m/kg cut edge the decrease is about 70%: an influence of the clearance on the magnetic properties could not be shown clearly; the area of edge hardening was 0.35 mm in width; there was no influence of tool wear.Original magnetic properties have been obtained after box annealing at 700°C/1 h in dry nitrogen.