Search

The application of protective coating systems is the major measure against the corrosion of steel structures for onshore wind turbines. The organic coatings are, however, susceptible to atmospheric exposure and tend to deteriorate during the operation. At the same time, onshore turbines become more powerful and require taller and more resistant tower structures. The inspection and condition monitoring of protective coating systems on large onshore turbines (in excess of 120 m height) is a demanding and time-consuming procedure and requires high human effort. The rapid developments in digitization and data analysis offer opportunities to notably increase the efficiency of monitoring processes and to develop (semi-)automated standardized procedures. The paper describes a data-oriented approach to utilize digital data for the monitoring and maintenance planning of surface protection systems of large onshore wind turbines. The proposed approach includes the following steps: the segmentation of an existing wind power structure into a number of reference areas based on an In-situ Virtual Twin; the definition of a local deterioration degree for each individual reference area; the annotation of image data; the use of heterogenous multi-modal data (image data, geodetical data, meteorological data, profile scanning data) as the sources for condition assessment and monitoring. An example procedure is exercised for a tower structure of an onshore wind power turbine in order to illustrate the practical relevance of the approach.

The effect of finely dispersed particles on the functional properties and morphology of thermally induced martensite in Co-Ni-Ga shape memory alloys has been already reported in literature, however, still important aspects are not fully understood. The current study focuses on the stress-induced martensitic transformation of solution-annealed, i.e. precipitate-free, and aged 〈001〉-oriented single crystals. In situ optical microscopy and neutron diffraction experiments show a significant influence of γ′-particles on the martensite variant selection and its morphology under pseudoelastic deformation. In addition, the results reveal detwinning upon loading in the presence of nanometric particles, which is experimentally proven for the first time.

Results are presented reporting on the martensite domain variant selection and stress-induced martensite morphology in [001]-oriented superelastic Co49Ni21Ga30 shape memory alloy (SMA) single crystals under tensile load. In situ neutron diffraction, as well as in situ optical- and confocal laser scanning microscopy were conducted focusing on three differently treated samples, i.e. in the as-grown, solution-annealed and aged condition. An aging treatment performed at 350 °C promotes the precipitation of nanoprecipitates. These second phase precipitates contribute to an increase of the number of habit plane interfaces, while reducing lamellar martensite plate thickness compared to the as-grown and solution-annealed (precipitate free) samples. During tensile loading, all samples show a stress-induced formation of martensite, characterized by one single domain variant (“detwinned”) and one set of parallel habit planes in a shear band. The results clearly show that γ’ nanoprecipitates do not necessarily promote multi-variant interaction during tensile loading. Thus, reduced recoverability in Co-Ni-Ga SMAs upon aging cannot be solely attributed to this kind of interaction as has been proposed in literature so far.

This data article presents a compilation of microstructural and mechanical data regarding the ternary single-phase FCC MnFeNi medium-entropy alloy (MEA). For the analysis, interpretation, and comparison of the data to literature values, the reader can refer to the original related research article entitled “Effect of Temperature and Texture on Hall-Petch Strengthening by Grain and Annealing Twin Boundaries in the MnFeNi Medium-Entropy Alloy”, see Schneider et al. (Metals 9, 2019, 84). The microstructural data reported here include: (i) raw backscatter electron (BSE) micrographs (tif-files) obtained using a scanning electron microscope (SEM) for nine different grain sizes with four images for each grain size and (ii) pdf reports and tables shown below presenting the distributions of the grain- (d, accounting for grain boundaries only) and crystallite- (c, which accounts for both grain and annealing twin boundaries) sizes and of the annealing twin thicknesses (t). These datasets may be useful to develop new algorithms for the automated evaluation of microstructural parameters in recrystallized alloys, i.e. with these benchmark data, an algorithm for image analysis could be trained to assess the above mentioned microstructural parameters. This would help to speed up the analysis of microstructures and improve its reliability. Additional tables describing the recrystallized microstructures and texture include the average number of annealing twin boundaries per grain (n), and the average Taylor factors (M). Raeisinia et al. (Model. Simul. Mater. Sc. 16, 2008, 025001) recently used a viscoplastic model to show that differences in the distribution of microstructural parameters affect the Hall-Petch parameters, but no attempt has been carried out so far to experimentally investigate this possibility since grain size distributions are rarely reported. Here, our benchmark data (e.g. distribution in grain/crystallite sizes, annealing twins per grain, distribution of annealing twin thicknesses) could be used to address these issues. The data describing the mechanical properties reported here are excel-sheets of raw stress-strain curves for temperatures ranging from 77 K to 873 K and different grain sizes. The yield stress (σ0.2%) and the normalized Hall-Petch parameters (σ0/G and ky/Gb2) are given for all temperatures. The normalized Hall-Petch parameters are reported here since they allow to better compare the strength and the magnitude of grain boundary strengthening of different alloys with the same crystallographic structure, see Cordero et al. (Int. Mater. Rev. 61, 2016, 495–512). Moreover, the Hall-Petch parameters as well as the mechanical data reported here could be used for data mining and implemented in programs used for alloy design.

For rare event searches, such as the direct dark matter search experiment CRESST (Cryogenic Rare Event Search with Superconducting Thermometers), highly sensitive cryogenic detectors are indispensable. A very low energy threshold ( ≪ 100 eV ) and excellent energy resolution are required to increase the experimental sensitivity, particularly for low mass dark matter particles ( m DM 5 GeV/c 2 ), and to differentiate between these rare events and natural radioactive backgrounds. For background suppression, CRESST benefits from using simultaneously two detection channels from scintillating calorimeters , in this case of heat and light. Measuring a heat signal and its corresponding scintillating light, allows event-by-event particle identification down to certain energies. Therefore, the development of cryogenic light detectors that can achieve single photon sensitivity, have high radio-purity and excellent energy resolution, is a key point to improve the experiment’s sensitivity at low energies. In this contribution we explain and report on novel ways to improve the light collection efficiency through a preliminary study on Nb films sputtered on Sapphire and through highly doped Si as cryogenic light detectors.

Spring wheat (Triticum aestivum L. cv. Triso) was grown in a free-air CO2 enrichment (FACE) field experiment in order to gain information on CO2-induced effects on grain composition and quality at maturity. A proteome analysis was performed using two-dimensional gel electrophoresis (2-DE) and protein identification was done with mass spectrometry (MALDI-TOF MS). In elevated CO2 (526 μl l−1), an increase of 13.5% in grain yield was observed relative to 375 μl l−1 at a low level of significance (P = 0.528). Total grain protein concentration was decreased by 3.5% at a high level of statistical significance. Most importantly, a number of statistically significant changes within the grain proteome were observed, as the levels of 32 proteins were affected by elevated CO2: 16 proteins were up-regulated and 16 were down-regulated. Our experiment demonstrates that high-CO2 can markedly affect the proteome of mature wheat grain. The potential role of the proteins, changed in response to CO2 enrichment, is discussed as some may affect grain quality. For the task of selecting cultivars resistant to CO2-induced quality loss, we propose to consider the proteins affected by elevated CO2 identified in this work here.

We have characterised the expression of a subfamily of genes that encode sucrose phosphate synthase (SPS), the plant enzyme responsible for sucrose synthesis. cDNA fragments from four genes were cloned from diploid Actinidia chinensis Planch. var. chinensis. Three genes are highly similar (94–96% nucleotide identity in the overlapping region of the reading frame) and all belong to Family A, with the fourth gene (67% nucleotide identity) belonging to Family B. The A2 gene encodes a longer open reading frame than the other two A family genes, with a C-terminal extension of 102 amino acids. We compared transcript abundance of these four genes using RT-PCR. The three A genes were expressed in all tissues, but only A1 was present at high abundance and responded to developmental and environmental stimuli. The A1 transcript increased in fruit in response to treatment with exogenous ethylene and again during the ripening climacteric, but was not affected by low temperature. A1 expression was also high in senescent leaves, stems and in flower buds. The B family transcript was detectable in roots, albeit at very low levels and in all other tissues examined. It also increased in low temperature and in fruit at the climacteric (but not with applied ethylene). This is the first demonstration of differential expression patterns for highly homologous SPS genes in any plant species.