Universal Features of the Superfluid Transition of a Thin 4He Film on an Atomically Flat Substrate

We analyse recent observations, using a torsional oscillator, of the superfluid transition of a fluid ⁴ He bilayer, within the framework of a modified dynamic theory of the Kosterlitz-Thouless transition. A parametric plot of the real and imaginary parts of the complex superfluid density, determined from the measured period shift and dissipation, achieves a high degree of collapse of the experimental data at different coverages onto a universal curve. This is compared with the result of the recent theory.     

Generic remeshing of 3D triangular meshes with metric-dependent discrete voronoi diagrams

In this paper, we propose a generic framework for 3D surface remeshing. Based on a metric-driven Discrete Voronoi Diagram construction, our output is an optimized 3D triangular mesh with a user defined vertex budget. Our approach can deal with a wide range of applications, from high quality mesh generation to shape approximation. By using appropriate metric constraints the method generates isotropic or anisotropic elements. Based on point-sampling, our algorithm combines the robustness and theoretical strength of Delaunay criteria with the efficiency of entirely discrete geometry processing . Besides the general described framework, we show experimental results using isotropic, quadric-enhanced isotropic and anisotropic metrics which prove the efficiency of our method on large meshes, for a low computational cost.     

Recording and interpretation/analysis of tilt signals with five ASKANIA borehole tiltmeters at the KTB

In June 2003, a large scale injection experiment started at the Continental Deep Drilling site (KTB) in Germany. A tiltmeter array was installed which consisted of five high resolution borehole tiltmeters of the ASKANIA type, also equipped with three dimensional seismometers. For the next 11 months, 86 000 m(3) were injected into the KTB pilot borehole 4000 m deep. The average injection rate was approximately 200 l/min. The research objective was to observe and to analyze deformation caused by the injection into the upper crust at the kilometer range. A new data acquisition system was developed by Geo-Research Center Potsdam (GFZ) to master the expected huge amount of seismic and tilt data. Furthermore, it was necessary to develop a new preprocessing software called PREANALYSE for long-period time series. This software includes different useful functions, such as step and spike correction, interpolation, filtering, and spectral analysis. This worldwide unique installation offers the excellent opportunity of the separation of signals due to injection and due to environment by correlation of the data of the five stations with the ground water table and meteorological data.     

A short-term test using DDAVP for determination of the renal concentration capacity (author's transl)

A short-term test to determine renal concentrating ability without any water deprivation has been described. It consists of osmolatity determinations in three onehour urine portions from spontaneous voidings following an intranasal application of 7 microng of the synthetic analogue of vasopressin-DDAVP per 0,5 m2 body surface. The values of maximal urine osmalatity over 900 mosm/Kg H2O following DDAVP are considered normal whereas values under 600 mosm are consistent with impaired renal function. If, however, the maximal urine osmolality is in the so called "uncertain range" i.e. from 600 to 900 mosm, it is advisable to perform in the same patients also the classical concentration test based on a prolonged dehydration (26 h).     

Cristallogenese du 4-dimethylamino β-nitrostyrene

Single crystals of 4-dimethylamino β-nitrostyrene (DMNS) were grown from solution by a falling temperature technique. Growth conditions are given. The quality of crystals obtained was studied by X-ray diffraction methods.

$\text{DMNS : orthorhombic - class mmm - space group : Pcab}\text{a : b : c = 7,3 : 10,15 : 25,10}\text{A}\text{?}\text{Z=8}$

     

Complete structure of glycopeptides isolated from IgG immunoglobulins of cow colostrum

Bovine immunoglobulins (IgG1 type) have been isolated from colostral whey. Hydrolysis by pronase, trypsin and (or) chymotrypsin yield several glycopeptides structural studies of which lead to the following results. 1. IgG1 colostral immunoglobulins possess two glycan moieties which are linked to the peptidic chain by an N-(beta-aspartyl)-N-acetylglucosaminylamine bound. 2. The peptidic sequence around the linkage region has been determined by classical methods and is as follows: Thr-Lys-Pro-Arg-Glu-Glu-Gln-Phe-Asn(Glycan)-Ser-Thr-Tyr-Arg. 3. The following procedures: partial acidic hydrolysis, periodic oxidation, hydrazinolysis-nitrous deamination, methylation and use of specific glycosidases allowed us to determine the structure of the glycan moieties which fit with the general following scheme: (see article) Thus they could be related to the general glycan structure so-called of "N-acetyllactosamine type" because they possess the pentasaccharidic core common to numerous glycoproteins Man alpha 1 leads to [Man alpha 1 leads to 6] Man beta 1 leads to 4 GlcNAc beta 1 leads to 4 GlcNAc beta 1 leads to Asn on which are conjugated 2 N-acetyllactosamine residues. Besides they present a microheterogeneity which is due to the varying number of additional N-acetylneuraminic acid and fucose residues. 4. These structures are compared to various immunoglobulin structures proposed by others: bovine serum IgG and human serum IgG, IgE and IgA.     

IDR/UPM facilities for liquid bridge experimentation on Earth under microgravity conditions

Besides space laboratories for in-orbit experimentation, Earth based facilities for laboratory experimentation are of paramount importance for the enhancement on liquid bridge knowledge. In spite of the constraints imposed by simulated microgravity (which force to work either with very small size liquid bridges or by using the Plateau tank technique, amongst other techniques), the availability and accessibility of Earth facilities can circumvent in many cases the drawbacks associated with simulated microgravity conditions. To support theoretical and in orbit experimental studies on liquid bridges under reduced gravity conditions, several ground facilities were developed at IDR. In the following these ground facilities are briefly described, and main results obtained by using them are cited.     

10th GAMM-IMACS International Symposium on Scientific Computing,Computer Arithmetic,and Validated Numerics SCAN'2002

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