40 research outputs found

    Creep–Fatigue Interaction of Inconel 718 Manufactured by Electron Beam Melting

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    Electron beam melting of Ni-base superalloy Inconel 718 allows producing a columnar-grained microstructure with a pronounced texture, which offers exceptional resistance against high-temperature loading with severe creep–fatigue interaction arising in components of aircraft jet engines. This study considers the deformation, damage, and lifetime behavior of electron-beammelted Inconel 718 under in-phase thermomechanical fatigue loading with varying amounts of creep–fatigue interaction. Strain-controlled thermomechanical fatigue tests with equal-ramp cycles, slow–fast cycles, and dwell time cycles are conducted in the temperature range from 300 to 650 °C. Results show that both dwell time and slow–fast cycles promote intergranular cracking, gradual tensile stress relaxation, as well as precipitate dissolution and coarsening giving rise to cyclic softening. The interplay of these mechanisms leads to increased lifetimes in both dwell time and slow–fast tests compared to equal ramp tests at higher strain amplitudes. Conversely, at lower mechanical strain amplitudes, the opposite is observed. A comparison with results of conventional Inconel 718 indicates that the electron-beam-melted material exhibits superior resistance against strain-controlled loading at elevated temperatures such as thermomechanical fatigue

    Exploitation of the Timing Capabilities of Metallic Magnetic Calorimeters for a Coincidence Measurement Scheme

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    In this report, we compare two filter algorithms for extracting timing information using novel metallic magnetic calorimeter detectors, applied to the precision X-ray spectroscopy of highly charged ions in a storage ring. Accurate timing information is crucial when exploiting coincidence conditions for background suppression to obtain clean spectra. For X-rays emitted by charge-changing interactions between ions and a target, this is a well-established technique when relying on conventional semiconductor detectors that offer a good temporal resolution. However, until recently, such a coincidence scheme had never been realized with metallic magnetic calorimeters, which typically feature much longer signal rise times. In this report, we present optimized timing filter algorithms for this type of detector. Their application to experimental data recently obtained at the electron cooler of CRYRING@ESR at GSI, Darmstadt is discussed

    Towards an Intrinsic Doppler Correction for X-ray Spectroscopy of Stored Ions at CRYRING@ESR

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    We report on a new experimental approach for the Doppler correction of X-rays emitted by heavy ions, using novel metallic magnetic calorimeter detectors which uniquely combine a high spectral resolution with a broad bandwidth acceptance. The measurement was carried out at the electron cooler of CRYRING@ESR at GSI, Darmstadt, Germany. The X-ray emission associated with the radiative recombination of cooler electrons and stored hydrogen-like uranium ions was investigated using two novel microcalorimeter detectors positioned under 0∘ and 180∘ with respect to the ion beam axis. This new experimental setup allowed the investigation of the region of the N, M → L transitions in helium-like uranium with a spectral resolution unmatched by previous studies using conventional semiconductor X-ray detectors. When assuming that the rest-frame energy of at least a few of the recorded transitions is well-known from theory or experiments, a precise measurement of the Doppler shifted line positions in the laboratory system can be used to determine the ion beam velocity using only spectral information. The spectral resolution achievable with microcalorimeter detectors should, for the first time, allow intrinsic Doppler correction to be performed for the precision X-ray spectroscopy of stored heavy ions. A comparison with data from a previous experiment at the ESR electron cooler, as well as the conventional method of conducting Doppler correction using electron cooler parameters, will be discussed

    GSE LAND- GEOINFORMATION SERVICES FOR URBAN DEVELOPMENT, SPATIAL PLANNING, WATER QUALITY AND IRRIGATION FOR EUROPE

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    The paper summarises the results of GMES Land Monitoring activities carried out by ESA’s GMES Service Element Land. This project has developed services aimed to serve the needs of European public institutions supporting their efforts to report and manage their natural resources according to European directives and policies. These services comprise two general elements: (1) high quality generic land cover information (mapping and monitoring services) which is directly derived by EO data analysis in very high to high resolution from IKONOS, SPOT and IRS data and the monitoring of the seasonal vegetation development by medium-resolution MERIS imagery. (2) the so-called downstream services combining user-side data with land cover information for environmental modelling focusing on water quality, irrigation, soil sealing, soil erosion, spatial planning and urban services. 1

    Ka-InSAR: Application and System Requirement Analysis Report

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    Detailed Application and System Requirement Analysis for a Ka-band interferometric SAR mission

    Relationship of Canopy Cover with TanDEM-X Features in a Tropical Peat Swamp Forest. GI_Forum 2013 – Creating the GISociety|

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    Monitoring of tropical forests and peat swamp forests becomes increasingly important in order to reduce carbon emissions from deforestation and forest degradation. SAR systems are suitable for that purpose due to their weather independence and sensitivity for changes in time series. The TanDEM-X mission delivers global datasets of a single-pass SAR interferometer, which provides more information in comparison to normal X-band SAR acquisitions. In particular the interferometric coherence can be regarded as useful information because it is dependent on tree height and canopy cover representing stand structure, which are important parameters for monitoring of forests
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