Ductile Metallic Glasses in Supercooled Martensitic Alloys

We report ductile bulk metallic glasses based on martensitic alloys. The slowly cooled specimens contain a mixture of parent 'austenite' and martensite phase. The slightly faster cooled bulk metallic glasses with 2-5 nm sized 'austenite'-like crystalline cluster reveal high strength and large ductility (16%). Shear bands propagate in a slither mode in this spatially inhomogeneous glassy structure and undergo considerable 'thickening' from 5-25 nm. A 'stress induced displacive transformation' is proposed to be responsible for both plasticity and work-hardening-like behavior of these 'M-Glasses'

Pan-cancer analysis of whole genomes

Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale(1-3). Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter(4); identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation(5,6); analyses timings and patterns of tumour evolution(7); describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity(8,9); and evaluates a range of more-specialized features of cancer genomes(8,10-18).Peer reviewe

Genetic Design of Ultra High Strength Stainless Steels: Modelling and Experiments

Mechanics, Aerospace Structures and MaterialsAerospace Engineerin

Spatial model-aided indoor tracking

In order to address the problem of indoor pedestrian tracking, this thesis reports a research on spatial models' ability to reduce tracking error of a WiFi positioning system. There are three main objectives in this research. First, it is to build a suitable spatial model for tracking. Second, it is to develop a tracking algorithm that can make full use of the spatial model. Last, the tracking algorithm should be tested in a live environment. Based on literature study, a grid-based spatial model is chosen to be built because it is easy to design and maintain, has high flexibility, has accurate location data and is powerful for computation. The thesis explores various geometric, topological and semantic features of the grid model and select out the most useful features upon tracking purposes. Among geometric features, coordinate, buffer, orientation vector and Euclidean distance are used. Among semantic features, space, obstacle, and door are employed. Among topological features, the difference between straight-line distance and shortest path distance is chosen. We develop the tracking algorithm combining multiple tracking techniques. In addition to the spatial model and WiFi positioning system, the algorithm also includes magnetometers and grid filters. The former one measures the orientation of a pedestrian. The latter one allows integrating all selected features of the grid model with the measurements from both the WiFi positioning system and the magnetometer to compute the location recursively. To test the algorithm's performance, we built a tracking system with database, web service and mobile client. Several experiments are carried out using the system in a real environment. The experiment results show that the algorithm is able to determine locations at reasonable places (in the correct space, outside obstacles and connected to the previous location) and derive the accurate moving direction of a pedestrian.Geomatics \u96 for the built environmentGeomaticsArchitecture and The Built Environmen

Low-Power Readout IC for a PMUT-based bladder scanner

Electrical Engineering, Mathematics and Computer ScienceMicroelectronic

Leveraging spatial model to improve indoor tracking

In this paper, we leverage spatial model to process indoor localization results and then improve the track consisting of measured locations. We elaborate different parts of spatial model such as geometry, topology and semantics, and then present how they contribute to the processing of indoor tracks. The initial results of our experiment reveal that spatial model can support us to overcome problems such as tracks intersecting with obstacles and unstable shifts between two location measurements. In the future, we will investigate more exceptions of indoor tracking results and then develop additional spatial methods to reduce errors of indoor tracks.UrbanismArchitecture and The Built Environmen

Lateral resistance of polyurethane-reinforced ballast with the application of new bonding schemes: Laboratory tests and discrete element simulations

To mitigate the ballast flight risk in the high-speed railway, this paper presents three new polyurethane bonding schemes which have negligible influence to tamping operations. With the application of these bonding schemes, a series of laboratory tests indicated that the polyurethane-reinforced ballast exhibited much larger lateral resistance than the ordinary ballast by 31% at least. Discrete element simulation results further demonstrated that the polyurethane improved the load-bearing capacity of the ballast at the particle scale through effectively restraining the particle movement. Therefore, the proposed bonding schemes ensure adequate lateral ballast resistance and are effective measures for improving the ballast performance.Accepted Author ManuscriptRailway Engineerin

Analytical solutions for excess pore water pressures generated by TBM tunnelling in a semi-confined aquifer

Tunnel-boring machine (TBM) tunnelling through an aquifer will generate excess pore water pressures in the soil around the tunnel face. Accurately predicting the magnitude of the excess pore water pressures is significant because it directly determines the effective face support pressure. In this study, an analytical solution for transient cylindrical flow caused by TBM tunnelling considering the elastic storage of the aquifer is developed. Furthermore, a quasi-static solution to couple the effect of slurry infiltration with the elastic storage is presented. It is shown that the pore water pressures derived from the analytical solution match quite well with the measurements obtained in proximity to as well as far away from the TBM. The coupled quasi-static solution also agrees with the measurements for the places close to the tunnel face, but underestimates the observations far away from the tunnel face. The results also show that a larger infiltration distance leads to a slower dissipation of excess pore water pressures, which does not make a difference during excavation (when excavation velocity is faster than the pore fluid velocity).Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Geo-engineerin

Wind turbine load estimation using machine learning and transfer learning

Machine learning method has always been popular to solve wind turbine related problems at a data level. However, with the limitation of the availability of relevant data, transfer learning has gained increasing attention. In this study, traditional machine learning method of artificial neural networks (ANN), together with parameter-based transfer learning method has been used to estimate wind turbine load. First, ANN load model was built for DTU 10MW wind turbine as well as NREL 5MW wind turbine. Then, parameter-based transfer learning has been applied to the above-mentioned models to estimate load for a different turbine type or two mixed turbine types. Results indicate that ANN method provides good estimation on wind turbine fatigue load. For DTU 10MW ANN model, the trend of accuracy becomes steady as the number of input samples increases and 1500 samples is deemed as the optimal number of samples for training DTU 10MW. In addition, with transfer learning, it was succeeded in building NREL 5MW model with corresponding DTU 10MW pretrained model but failed in establishing mixed dataset model neither with DTU 10MW nor with NREL 5MW pretrained model.Wind Energ

A generic high-throughput microstructure classification and quantification method for regular SEM images of complex steel microstructures combining EBSD labeling and deep learning

We present an electron backscattered diffraction (EBSD)-trained deep learning (DL) method integrating traditional material characterization informatics and artificial intelligence for a more accurate classification and quantification of complex microstructures using only regular scanning electron microscope (SEM) images. In this method, EBSD analysis is applied to produce accurate ground truth data for guiding the DL model training. An U-Net architecture is used to establish the correlation between SEM input images and EBSD ground truth data using only small experimental datasets. The proposed method is successfully applied to two engineering steels with complex microstructures, i.e., a dual-phase (DP) steel and a quenching and partitioning (Q&P) steel, to segment different phases and quantify phase content and grain size. Alternatively, once properly trained the method can also produce quasi-EBSD maps by inputting regular SEM images. The good generality of the trained models is demonstrated by using DP and Q&P steels not associated with the model training. Finally, the method is applied to SEM images with various states, i.e., different imaging modes, image qualities and magnifications, demonstrating its good robustness and strong application ability. Furthermore, the visualization of feature maps during the segmenting process is utilised to explain the mechanism of this method's good performance.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Novel Aerospace Material