Reibungsversuche mit Krypton bei niedrigen Drücken

Tests of a linear Equation on the Evaluation of Krypton Friction Experiments at low Pressures and Connections to Viscosity Effects The coefficient of viskosity is nearly constant in the region with STP conditions and is independent of the pressure. This coefficient decreases with lowering the pressure until the region of molecular flow is reached. There we have free molecular‐ or vacuum viscosity. Experiments with the friction of gas have to take in the gas between surfaces which are movabel and parallel. Reactions of the gas with the moving surface cannot be neglected. We made our lab‐examinations of gas friction effects between two rotating cylinders. Generally there is a linear equation of the reciprocal values of viscosities and pressures. Our experiments show a region, where this linear relation is valid. This region has a low limit with coming to molecular flow and an upper limit if the gas is warmed up by friction at higher pressures.     

Hochbelastbare kohlenstoffbasierte Mehrschichtsysteme für die Umformtechnik

Carbon based multilayer systems for highly loaded forming tools Amorphous hydrogenated carbon (metal‐free a‐C:H and metal‐containing a‐C:H:Me) films respond very sensitively to local overloads. For example during forming tool operations, hard abrasive particles and locally high stresses on the coating surface can cause crack initiation and early coating failure. Compared to the high hardness, wear resistance and excellent friction properties, in many cases the adhesion of a‐C:H films is relatively insufficient. Adhesion and overload resistance of a‐C:H and a‐C:H:Me, prepared by reactive sputtering, can be influenced in a wide range by different interlayer systems. In the present report the wear mechanism of amorphous carbon coatings and the influence of different metallic, metal nitride and metal carbide interlayers on the growth structure, the adhesion and the load resistance will be reported. Two well adapted multi‐coating systems, successfully tested for highly loaded tools and components, will be presented.     

Eye tracking — A new interface for visual exploration

Eye-tracking technology offers a natural and immediate way of communicating human intentions to a computer. Eye movements reflect interests and may be analysed to drive computer functionality in games, image and video search, and other visual tasks. This paper examines current eye tracking technologies and their applications. Experiments are described that show that target images can be identified more rapidly by eye tracking than using a mouse interface. Further results show that an eye-tracking technology provides an efficient interface for locating images in a large database. Finally the paper speculates about how the technology may enter the mass market as costs decrease.     

Methods and results of tests of a large model of the TUK-84 container

Tests of a prototype model of TUK-84 and the corresponding experimental procedures used at the test center of the All-Russia Research Institute of Technical Physics are described. The results are presented, and it is shown that the prototype withstood the tests. __________ Translated from Atomnaya énergiya, Vol. 100, No. 6, pp. 441–445, June, 2006.     

Hartstoffschichten für das Pressen und Prägen von Gläsern bei hohen Temperaturen

Hard and wear resistant coatings for the moulding and embossing of glasses at elevated temperatures Hard and wear resistant coatings of Titanium Aluminium Nitride TiAlN were deposited on various substrates by the application of different reactive deposition processes: RF-magnetron-sputtering, ion beam-sputtering and by the energetic cluster impact (ECI) process. The deposition of the coatings was performed under variation of biasing conditions and of process parameters such as pressures and flow rates of the process gases argon and nitrogen as well as of energies of species hitting the substrate surfaces. The microstructure particularly the growth morphology of several films was investigated by pictures of film cross sections recorded by transmission electron microscopy. Residual intrinsic film stresses were analyzed by measuring deflections of substrates in an interference optical microscope before and after the deposition of the coatings. By heating coated substrates and in-situ observation of deflections at elevated temperatures dependencies of thermally induced stresses on temperatures and variations of intrinsic stresses due to changes within the films could be analyzed and related to microstructure and growth conditions. In the paper specific characteristics of the deposition processes occuring on the scale both of atoms and of clusters which may contain several thousand of atoms are described and related to microstructure, residual stress states and damaging conditions. Different contributions to residual film stresses are analyzed on the base of theoretical considerations taking into account deposition kinetics and thermomecanical properties. The significance of achieved film properties for application, i. e. for the coating of tools for the manufacturing of optical components by moulding and embossing of glasses is discussed.     

A new ZVS-PWM unity power factor rectifier with reduced conductionlosses

This paper introduces a new single-phase high power factor rectifier, which features regulation by conventional PWM, soft commutation and instantaneous average line current control. Furthermore, thanks to the use of a single converter, instead of the conventional configuration composed of a four-diode front-end rectifier followed by a boost converter, a significant reduction in the conduction losses is achieved. A prototype rated at 1.6 kW, operating at 70 kHz, with an input AC voltage of 220 Vrms and an output voltage of 400 V_DC has been implemented in the laboratory. An efficiency of 97.8 % at 1.6 kW has been measured. Analysis, design, and the control circuitry are also presented in the paper     

In-utero transplantation of parental CD34 haematopoietic progenitor cells in a patient with X-linked severe combined immunodeficiency (SCIDXI)

BACKGROUND: X-linked severe combined immunodeficiency (SCIDXI) is an inherited immune defect which leads to death in infancy from severe infections. The defect is caused by mutations of the IL-2RG gene that encodes for the common gamma chain shared by several cytokine receptors. The disease is characterised by lack of T and NK cells with normal numbers of B cells. SCIDXI can be cured by bone marrow transplantation (BMT) or prevented by abortion after prenatal diagnosis. METHODS: A male fetus was diagnosed as having SCIDXI by molecular, immunophenotypic, and functional analyses. The fetus was injected intraperitoneally under ultrasound guidance with CD34 haematopoietic progenitor cells purified from paternal bone marrow and T-cell depleted by E rosetting. Chimerism analysis was by HLA-DQ alpha typing and gamma-chain staining on cord blood. FINDINGS: A healthy 3.6 kg boy was delivered by caesarean section at 38 weeks of gestation with no clinical or laboratory signs of graft-versus-host disease. Engraftment of donor-derived CD2 cells was found at birth. At 3.5 months of age the infant is well and his T-cell counts and function are normal. INTERPRETATION: In-utero transplantation of haematopoietic progenitor cells allowed immune reconstitution of a fetus with SCIDXI and may be an alternative to elective abortion. Our report should encourage applications of this method to other inherited disorders curable by BMT.     

Pollinosis

Pollinosis is an extremely common disorder affecting between 10 to 30% of the population. There are regional and seasonal variations with allergies occurring between february (in south of France) and autumn. Pollen calenders allow one to identify the pollens specific to each region. Treatment is based on the utilisation of antihistaminic and local antiinflammatory agents. Specific desensitization is efficacious when quality extracts are used, but should be reversed for particular cases as the therapeutic risk should in no case exceed that of the illness.