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Zone plates are circular diffraction gratings that can provide diffraction-limited nano-focusing of x-ray radiation. When designing zone plates for X-ray Free Electron Laser (XFEL) sources special attention has to be made concerning the high intensity of the sources. Absorption of x-rays in the zone material can lead to significant temperature increases in a single pulse and potentially destroy the zone plate. The zone plate might also be damaged as a result of temperature build up and/or temperature fluctuations on longer time scales. In this work we simulate the heat transfer in a zone plate on a substrate as it is exposed to XFEL radiation. This is done in a Finite Element Method model where each new x-ray pulse is treated as an instantaneous heat source and the temperature evolution between pulses is calculated by solving the heat equation. We use this model to simulate different zone plate and substrate designs and source parameters. Results for both the 8 keV source at LCLS and the 12.4 keV source at the European XFEL are presented. We simulate zone plates made of high Z metals such as gold, tungsten and iridium as well as zone plates made of low Z materials such as diamond. In the case of metal zone plates we investigate the influence of substrate material by comparing silicon and diamond substrates. We also study the effect of different cooling temperatures and cooling schemes. The results give valuable indications on the temperature behavior to expect and can serve as a basis for future experimental investigations of zone plates exposed to XFEL radiation.

To study possible failure modes of the Hexis Galileo solid oxide fuel cell stack, various stack components such as nickel/yttria stabilised zirconia anodes, lanthanum strontium manganese cathodes, 3 mol%‐yttria stabilised zirconia electrolytes and chromium alloy metallic interconnectors have been characterised with respect to their thermo‐mechanical properties. Specifically, coefficients of thermal expansion, Young's moduli, bending strengths, Poisson's ratios and fracture toughnesses have been measured. Furthermore, the temperature‐dependent warpage of complete cells has been investigated by video analysis. All experimental data were taken as input parameters for a set of finite element models to analyse various thermo‐mechanical phenomena on different length scales. The simulations offer an explanation for the often observed ‘saddle‐like‘ deformations of cells at room temperature. They also show that cracks that first develop within the anode induce local tensile stresses within the electrolyte and hence represent a weakening mechanism for the cells. It is shown that the induced electrolyte stresses depend on the anode crack density. The electrolyte stresses decrease as the distances between the anode cracks become smaller.

Perovskite‐type materials have been synthesised and investigated with regards to their physical properties including specific surface area (BET), phase purity, sinter behaviour, coefficient of thermal expansion (CTE) and electrical conductivity. We investigated the effect of Sr variation on La1–xSrxFeO3–δthe influence of A‐site stoichiometry on (La0.8Sr0.2)yFeO3–δand the impact of substitution of iron by nickel or copper up to 20 mol%. The over‐stoichiometric compositions indicate secondary phases independent of the calcination temperature. Stoichiometric and understoichiometric compositions become single phase perovskites after calcination at 1,200 °C. The substitution of Fe by Ni or Cu on the B‐site, (La0.2Sr0.8)0.95Ni/CuxFe1–xO3, is viable, but limited to 20 mol%. Cu substitution and under‐stoichiometry lower the melting point and thus consequently influence the sintering temperature.

Solid oxide electrolyser cells (SOECs) have great potential for efficient and economical production of hydrogen fuel. Element diffusion between the Ni‐cermet electrode and the metal substrate of metal supported cells (MSC) is a known problem in fuel cell and electrolysis technology. In order to hinder this unintentional mass transport, different ceramic diffusion barrier layers (DBLs) are included in recent cell design concepts. This paper is based on wavelength dispersive X‐ray fluorescence investigations of different SOEC and focuses on Fe, Cr and Ni diffusion between the metal grains of the cathode and the metal substrate. Due to the low detection limits and therefore high analytical sensitivity, wavelength dispersive electron probe microanalysis (EPMA) provides a precise method to determine element distribution, absolute element concentration and changes between the reference material and aged cells on a microstructural level by element mappings and concentration profiles. The results of this work show considerable concentration gradients in the metal grains caused by mass exchange during cell operation. Diffusion can be inhibited significantly by integrating different ceramic DBLs of doped LaCrO3‐type or doped LaMnO3‐type perovskite, either by vacuum plasma spraying (VPS) or physical vapour deposition technique (PVD).

BaZr0.9Y0.1O3‐δhas been synthesised by three different methods: the solid‐state reaction, the spray pyrolysis and the spray drying. Significantly different apparent lattice parameters (between 0.4192 nm for the sample prepared by the solid‐state reaction method and sintered at 1,500 °C and 0.4206 nm for the sample prepared by the solid‐state reaction method and sintered at 1,720 °C) are observed after calcination and sintering, depending on the synthesis method and the sintering temperature. The bulk conductivity values also vary over several orders of magnitude (–7.2< log σb<–3.6 at 300 °C) depending on the synthesis method and the sintering temperature. These variations of the bulk conductivity and also the activation energy are correlated with variations of the apparent lattice parameter. The influence of the preparation method on the electrical properties is discussed. The grain boundaries are more resistive than the bulk. The variation of the grain boundary conductivity could be correlated to the microstructure in terms of the grain size.

The ability to predict load-bearing capacity during the consolidation phase in distraction osteogenesis by non-invasive means would represent a significant advance in the management of patients undergoing such treatment. Measurements of stiffness have been suggested as a promising tool for this purpose. Although the multidimensional characteristics of bone loading in compression, bending and torsion are apparent, most previous experiments have analysed only the relationship between maximum load-bearing capacity and a single type of stiffness. We have studied how compressive, bending and torsional stiffness are related to the torsional load-bearing capacity of healing callus using a common set of samples of bone regenerate from 26 sheep treated by tibial distraction osteogenesis.Our findings showed that measurements of torsional, bending and compressive stiffness were all suitable as predictors of the load-bearing capacity of healing callus. Measurements of torsional stiffness performed slightly better than those of compressive and bending stiffness.

The in situFourier transform infrared (FT-IR) spectrum of gas-phase SiO produced in silicon oxynitride fiber growth has been quantitatively analyzed. Both absorption and emission FT-IR spectra at a spectral resolution of 0.5 cm−1were produced from the reaction zone at 1450 °C. The fundamental and hot bands were observed with vibrational levels up to v= 7. For the purposes of quantitative analysis the individual vibration–rotation integrated line strengths for the three main isotopes, 28SiO, 29SiO, and 30SiO, were calculated based on ab initioquantum chemical calculations of the electric dipole moment function and the transition moment. Vibrational anharmonicity and Hermann–Wallis correction factors were also incorporated. From the line strengths at specific temperatures and the known Dunham coefficients, the absorbance spectrum was simulated with best fits giving the averaged SiO concentration in the 400 mm reaction zone of 1.0 × 1017molecules/cm3. Such quantitative measurements demonstrate the power of in situinfrared (IR) spectroscopy combined with quantum chemical calculations. The rapid determination of synthetic calibration datasets for chemometric analysis can thus lead to correlation of gas-phase species concentrations with fiber growth properties and subsequently to real-time process control.

Abstract. Purpose: About 40% of non-small cell lung cancer (NSCLC) patients are candidates for systemic chemotherapy, despite the fact that at diagnosis most NSCLC are usually chemoresistant both in vivo and ex vivo. It is important to develop sufficient methods of prediction of the response to chemotherapy and to find molecular markers that may prognose this response. Therefore, a study on the relationship of p53 gene status to the ex vivo chemosensitivity of primary human NSCLC was performed. Methods: Three drug combinations (carboplatin/etoposide, cyclophosphamide/etoposide/epirubicin, and paclitaxel/carboplatin) were tested in a modified ATP cell viability assay. A group of 28 cases of primary human NSCLC was assessed. Results: Ex vivo chemosensitivity testing showed that tumors with p53 mutations were significantly more resistant to the cyclophosphamide/etoposide/epirubicin regimen than with normal p53 gene (P = 0.012). However, no correlation was observed for two other treatment regimens. Conclusion: Mutations in the p53 gene can lead to enhanced chemoresistance, confirming the hypothesis that the p53 gene may serve as a marker of tumor response to treatment in NSCLC. However, the data also illustrate that some additional factors might contribute to drug resistance of the examined tumors.

Abstract:: Using 50 fs ( ∼ 2×1018 W/cm2) and 2 ps ( ∼ 5×1016 W/cm2) pulses from a Ti:Sa multi-TW laser at 800 nm wavelength large Xe-clusters ( 105...106 atoms per cluster) have been excited. Absolute yield measurements of EUV-emission in a wavelength range between 10 nm and 15 nm in combination with cluster target variation were carried out. The ps-laser pulse has resulted in about 30% enhanced and spatially more uniform EUV-emission compared to fs-laser excitation. Circularly polarized laser light instead of linear polarization results in enhanced emission which is probably caused by electrons gaining higher energies by the polarization dependent optical field ionization process. An absolute emission efficiency at 13.4 nm of up to 0.8% in 2π sr and 2.2% bandwidth has been obtained.