Element specific characterization of heterogeneous magnetism in (Ga,Fe)N films

We employ x-ray spectroscopy to characterize the distribution and magnetism of particular alloy constituents in (Ga,Fe)N films grown by metal organic vapor phase epitaxy. Furthermore, photoelectron microscopy gives direct evidence for the aggregation of Fe ions, leading to the formation of Fe-rich nanoregions adjacent to the samples surface. A sizable x-ray magnetic circular dichroism (XMCD) signal at the Fe L-edges in remanence and at moderate magnetic fields at 300 K links the high temperature ferromagnetism with the Fe(3d) states. The XMCD response at the N K-edge highlights that the N(2p) states carry considerable spin polarization. We conclude that FeN{\delta} nanocrystals, with \delta > 0.25, stabilize the ferromagnetic response of the films.Comment: 4 pages, 3 figures, 1 tabl

Schnellanalyse bei Chemieunfaellen und Braenden mit mobilem GC-MS-System Abschlussbericht

A mobile GC-MS-system for hazardous organics in fires or chemical accidents, which can be used by fire-fighters, was developed in cooperation with Bruker-Franzen Analytik Bremen. In case of fires or chemical accidents a rapid identification and correct assessment of hazard for the population and the environment is essential on-site. The objectives of this project are: 1. helicopter based emergency response with GC-MS, 2. simple procedures for sampling and 3. rapid and automatic analysis in 5 min. Since 1992 twenty German fire-brigades take part in a field study. Sampling equipment for air, water and soil is used. At 150 real incidents over 500 samples have been taken and analysed with rapid analyse methods by mobile GC-MS. The results are integrated in a database for further evaluation. Special MS-databases have been composed which operate hierarchical for fast and automatic identification with high reliability. Three analytical categories have been found: category I: chemical accident - single substance, category II: chemical accident - several substances, category III: fire - complex mixtures. The mobile GC-MS-system inclusive data system, mobile modem and power supply can be carried by 2-4 persons on a stretcher and will be transported by helicopters to the location of action. The results of analysis can be transmitted to center of expertise by wireless remote data transmission in a few minutes. (orig.)SIGLEAvailable from TIB Hannover: F95B2063+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

A protocol to examine the colour damage profile of bleach containing detergents

Abstract In the development of new and improved bleach systems for detergents there is a need for a reliable and generally accepted protocol to test colour and fibre damage. We here describe a protocol to screen detergents on colour damage/fading under European wash conditions, using a recently developed set of dyed fabrics. The test protocol has been evaluated in an inter-laboratory test and was found to be robust in the sense that it gave similar results in different laboratories. Hence the protocol described is recommended for testing the colour damage/fading properties of oxidative bleach containing detergents for the European market.</jats:p

Schnellanalyse bei Chemieunfaellen und Braenden mit mobilem GC-MS-System. Entwicklung und Erprobung von Standardverfahren in der Praxis Abschlussbericht

A new mobile GC/MS system (Bruker Model EM640) has been developed to analyze hazardous organic compound emissions. The aim of this project has been to design a semi-automatic GC/MS ststem and procedures that make it possible to perform sampling and analysis in less than 10 min. The instrumentation has to be suitable for installation in a container or a helicopter. Properly trained fire fighters, instead of analytical chemists, should be able to operate the system. A comprehensive kit for analytical field work has been developed. In a German nationwide research project based on the use of mobile GC/MS, standard operating procedures for the analysis of organic substances in air, water, soil and contaminated surfaces have been established. The focus is on simple sample treatment and fast compound enrichment techniques. A graphical user interface (GUI) has been designed especially for operation by skilled firefighters. This GUI is an easy-to-use data system with fixed analytical methods (sample description, parameters of GC and MS, identification and assessment). Further developments have been focussed on simple calibration procedures for air sampling and an on-line probe for on-line measurements and enrichment unit for programmed GC-cycles. Optimized data bases are used that contain mass spectra, retention indexes and response factors for identification and automatic semi-quantitative evaluation. A wireless data transfer system has been set up using the digital communication standard GSM. Files containing GC-MS data have been transferred to experts off-site for risk assessment. (orig.)Available from TIB Hannover: F98B1894+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

Standards for dielectric elastomer transducers

Financial support from COST—European Cooperation in Science and Technology, within the framework of ‘ESNAM —European Scientific Network for Artificial Muscles’ (COST Action MP1003), is gratefully acknowledged