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ITER will be equipped with four EC (Electron Cyclotron) Upper Launchers (UL) of 8 MW microwave power each with the aim to counteract plasma instabilities during operation. These launcher antennas will be installed into four upper ports of the ITER vacuum vessel. Beside their functional purpose the port plugs which are the structural system of the launchers, have to provide as much shielding as possible in order to protect adjacent components from neutrons and photons and to minimize the shutdown dose rate in the port interspace and the port cell, being located further back in the ITER Tokamak building. Thus appropriate shielding blocks shall be installed at proper positions inside the plug. In addition several structural components will be dressed up geometrically in order to provide maximum shielding capability. This paper presents the general design of the shielding elements and their technical integration into the EC Upper Launcher.

The present work introduces the first architectural energetics analysis of a medieval tumulus from the Eurasian/Pontic steppe. In contrast to New World earthworks, tumuli on the steppe were constructed 1) with sod taken from the environment immediately surrounding the construction site, 2) with the use of draft animals and metal tools, and 3) in identifiable phases as part of funerary rituals over a period of weeks or months. These variables introduce problems which are confronted through 1) the application of novel historically attested rates for construction and 2) the creation of new, replicable mathematical methods for modeling materials transport.

The surface of a ceramic substrate can be modified locally by introducing a second phase into a melt pool generated by a laser beam. CuO and WO"3 powders with nano-sized particles were used to laser-alloy alumina and a low-temperature co-fired ceramic (LTCC). A composite with complex multiphase microstructure was developed with particle agglomerates, small crystals as well as grains covered with reaction phase, in parts with typical length scales down to the submicron range. The geometry of the modified area could be controlled by the process parameters as well. A significant change of the thermal and electrical properties could be established for the laser-alloyed tracks in comparison with that of the ceramic substrate. The developed composites showed an electrical conductivity with a negative temperature coefficient for resistivity, i.e. resistivity decreases with increase in temperature, which is typical for semiconductors. An enhancement of thermal conductivity could be established as well. Especially for the WO"3 powder, it could be increased about 50% compared to the unmodified LTCC substrate.

Tribological properties of a system are very important for saving energy or increasing service life as in automotive industry. It is known that wear and friction behaviour is strongly influenced by the topography of the mated surfaces. In case of lubricated sliding contact the tribological properties can be improved by generating a defined surface structure in form of small channels or isolated pits. Depending on the structure it may act as a reservoir for the lubricant and hampers the drain of the lubricant. In addition, wear particles can be removed from the contact area and can be collected inside the structures. In the present paper, a Nd:YAG-laser was used to generate different structures on ceramic (Al 2 O 3 ) and steel (100Cr6) surfaces. Microchannels and micropits were generated onto an otherwise flat surface by a laser ablation process. Due to the high flexibility of the laser system, structural features such as size, density and orientation could be varied easily by changing the laser parameters. The effects of different topographies on friction and wear behaviour were examined using a cylinder/plate tribometer for lubricated and reversed sliding contact. Laser structured 100Cr6 and alumina surfaces mated to 100Cr6 cylinders showed that a reduction of friction could be achieved in comparison to the polished surfaces. Dependent on the kind of the surface structure the coefficient of friction could be reduced up to 30%, especially in the initial period of the tribological experiment. The results show that the laser technique is an effective tool to optimise the topography of tribological surfaces.

The objective of this work is the development of a laser-supported process that allows to modify the electric and thermal properties of ceramics on a local scale. The principle of the process is based on local melting of the ceramic by a CO 2 laser beam and application of an additive to the molten area on the surface. During solidification, a metal–ceramic composite is formed with modified material properties compared to the bulk material. Different alumina samples were treated with metal powders of tungsten, copper, and oxides of these metals. Scanning electron microscopy (SEM) and energy-dispersive X-ray microanalysis (EDX) analysis reveal that the physical and chemical properties of a peripheral zone are changed in the heated region down to a depth of approximately 500 μm. The resulting resistance of the laser tracks can be adjusted from semi-conducting to metallic behavior with a resistivity down to 2×10 −6 Ω/m. The modified ceramic can be used for heating elements working at operation temperatures of up to 1000 °C, high current resistance which can be loaded with current of up to 100 A.

For the operation of a refrigerator cryopump a roughing pump is necessary to provide a sufficient low starting pressure prior to cool-down. Usually oil lubricated rotary vane pumps are used for that purpose. However, the demand for a fully hydrocarbon-free high vacuum system does not allow that type of roughing pump. Therefore we performed investigations with a dry oil-free diaphragm pump as a roughing pump for a refrigerator cryopump. We were able to show that in spite of the high ultimate pressure a diaphragm pump can be used. The combination of a cryopump with a diaphragm pump meets the requirement of a hydrocarbon-free high vacuum system.

According to the PNEUROP-acceptance rules for cryopumps the crossover is defined as the maximum amount of nitrogen (mbar I) which can be pumped by the cryopump within a short interval, whereby the temperature of the cryopanels must not exceed 20 K. Measurements carried out with a standard refrigerator-cooled cryopump (intake flange DN 200) have shown that the present definition is not sufficient. The temperature rise caused by the gas flow mainly depends on the preloading of the pumping surfaces. The report proposes a new, more complete and practicable definition of the crossover.

We develop a theory of aggregation using statistical mechanical methods. An example of a complicated aggregation system with several levels of structures is peptide/protein self-assembly. The problem of protein aggregation is important for the understanding and treatment of neurodegenerative diseases and also for the development of bio-macromolecules as new materials. We write the effective Hamiltonian in terms of interaction energies between protein monomers, protein and solvent, as well as between protein filaments. The grand partition function can be expressed in terms of a Zimm-Bragg-like transfer matrix, which is calculated exactly and all thermodynamic properties can be obtained. We start with two-state and three-state descriptions of protein monomers using Potts models that can be generalized to include q-states, for which the exactly solvable feature of the model remains. We focus on n X N lattice systems, corresponding to the ordered structures observed in some real fibrils. We have obtained results on nucleation processes and phase diagrams, in which a protein property such as the sheet content of aggregates is expressed as a function of the number of proteins on the lattice and inter-protein or interfacial interaction energies. We have applied our methods to A{\beta}(1-40) and Curli fibrils and obtained results in good agreement with experiments., Comment: 13 pages, 8 figures, accepted to J. Chem. Phys

Despite the common use of the standard 12-lead ECG, its reliability as an indicator of coronary artery disease (CAD) is poor. The normal ECG is falsely negative in more than 50% of angiographically proven CAD. The waveform of the standard ECG, however, can be transformed mathematically by nonlinear signal transformation to enhance its interpretation by computer. Using such a process it is possible that abnormalities can be identified in "normal" ECGs that can be correlated with CAD, thus identifying high-risk patients. A computer template that represents grouped data of normal ECGs for patients who also have normal coronary angiography was developed. Unblinded, preliminary testing of the template on normal ECGs of 107 white patients who had normal or abnormal coronary angiograms was performed. The process identified presence or absence of CAD with 82% specificity and 71% sensitivity for 53 women, and with 82% specificity and 86% sensitivity for 54 men. These preliminary results are promising, but further refinement of the templates is required and blinded studies with larger numbers and varieties of patients are needed.

In order to enhance subtle changes not apparent in resting ECGs by conventional criteria, a computerized signal processing technique, biopotential coordinate transformation (BCT), has been developed to increase the physician's perceptibility of CAD in seemingly "normal" resting ECGs. ECGs initially read as normal then can be tested with this process to predict the presence or absence of CAD. A blinded, retrospective study of 93 Caucasian patients with normal ECGs was performed using coronary angiography as the test standard. The BCT process identified the presence or absence of CAD with an 84.3% sensitivity and 81.8% specificity in 62 men. Similarly, a 76.2% sensitivity and 80% specificity was obtained for 31 women. These results suggest that the BCT process may provide the emergency physician with a noninvasive screening test for the detection of CAD in patients with apparently normal resting ECGs. Further studies are necessary for process refinement and verification.