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

Design and Implementation of Constraints for 3D Spatial Database: Using Climate City Campus Database as an Example

Nowadays the field of geo-information is undergoing major changes, and the transition from 2D to 3D is having a major influence. A significant amount of 3D datasets are stored in the database. Experts are aware that new quality control mechanisms need to be built into the database systems in order to secure and guarantee high-performing data. Constraints are effective in providing solutions needed to avoid errors and enable maintenance of data quality. Whereas constraints for 2D geographic datasets have already been the subject of several research projects, studies into 3D geo-data constraints are largely unexplored. This thesis research discovers a new approach to model, conceptualise and implement 3D geo-constraints which can function in the database. At the outset, constraints can be formulated using natural language. As natural language is subjective and varies between individuals, expressions can be ambiguous and can easily cause confusion. So spatial constraints are abstracted using geometry that depicts the exact shape, and also topology that reveals the spatial relationship between geometries. This step makes the meaning of a constraint clearer to others. Furthermore, using standardised UML diagrams and OCL expressions, geo-constraints can be formalised to an extent that not only humans, but also machines can understand them. With model-driven architecture supported by various softwares, OCL expressions can be automatically converted to other models/executable codes (e.g. PL/SQL) just by a few clicks. And with small modifications, database triggers can be formulated to carry out constraints check. A database including various topographic objects (e.g. buildings, trees, roads, grass, water-bodies and terrains) is used as a study case to apply the discovered approach. During this research, a first attempt to formulate 3D geo-constraints in OCL has been made. These expressions can be tested and translated to other models/implementations when the OCL standard is extended with spatial types and operations. In the implementation stage, the current 3D functions in Oracle Spatial database are found to be insufficient. A new 3D function using existing 2D functions - plus additional code relating to computational geometry - has been developed by the author to bridge the gap. Based upon this function, a large group of spatial constraints which apply to objects in 3D space can be checked. Bentley Map and Python IDLE are used to test the performance of constraints as well as the visualisation of warning messages to clients. Database error messages are immediately displayed on the front-ends when a modification that does not satisfy a constraint is attempted to commit to the database. During the case study, new classes of constraints are also discovered. They are higher-level constraints, parameterised constraints, constraints allowing exceptional instances, extra-check rules to detect conflicting constraints and constraints relating to multi-scale representations.MSc GeomaticsGIS-technologyOTB Research Institute for the Built Environmen

An approach to develop 3d Geo-DBMS topological operators by re-using existing 2d operators

Database systems are continuously extending their capabilities to store, process and analyse 3D data. Topological relationships which describe the interaction of objects in space is one of the important spatial issues. However, spatial operators for 3D objects are still insufficient. In this paper we present the development of a new 3D topological function to distinguish intersections of 3D planar polygons. The development uses existing 2D functions in the DBMS and two geometric transformations (rotation and projection). This function is tested for a real dataset to detect overlapping 3D city objects. The paper presents the algorithms and analyses the challenges. Suggestions for improvements of the current algorithm as well as possible extensions to handle more 3D topological cases are discussed at the end.OTB ResearchOTB Research Institute for the Built Environmen

Quantum Properties in Hybrid Nanowire Devices

Quantum computing is a flourishing field of scientific and technological research. The development of quantum computing in the past decades is the so-called second quantum revolution, where various aspects of quantum physics, such as entanglement and superposition, are used to form the main building block of computation — the quantum bit, or qubit. With quantum technologies rapidly growing, people have been paying attention to a few promising implementation schemes for quantum computing, including schemes based on topological protection.Majorana bound states (MBSs) are predicted to be non-Abelian anyons that enable topological quantum computing, which uses the topological phase of matter to protect quantum information against noise from the environment. The search for MBSs has drawn enormous interests in condensed matter physics community, where hybrid semiconductor-superconductor nanowire systems are currently the most promising candidates. Great advances have been achieved in this field over the last decade, due to efforts ranging from material growth, to transport experiments and to theoretical understanding.When a hybrid nanowire undergoes a transition to a topologically nontrivial phase, two MBSs appear at the ends of the hybrid region. As a result, zero-bias peaks (ZBPs) should appear in tunneling spectroscopy performed on normal-conductor - semiconductor-nanowire - superconductor (N-nanowire-S) junctions. In this thesis, we firstly demonstrate large ZBPs in vapor-liquid-solid (VLS) InSb nanowires with epitaxial Al with heights on the order of 2e2/h. Besides the original Majorana interpretation of these ZBPs, we discuss alternative explanations such as quasi-Majoranas due to a smooth potential and random disorder. (Chapter 4)In the same system, we then demonstrate that the induced superconducting gap, the effective Landé g-factor and the spin-orbit coupling strength can be tuned by the electrostatic environment, i.e. applied gate voltage. The change of these quantities is dominated by the coupling between the semiconductor and the superconductor. (Chapter 5)The remaining part of the thesis focuses on selective area growth (SAG) InSb nanowires with epitaxial Al. Quantum transport results on these nanowires show high-quality phase-coherence, hard superconducting gap and 2e-Coulomb blockaded transport. We then study the properties on induced superconductivity as well as phase coherence in SAG nanowire networks. We establish a fitting model to extract the phase coherence length based on the temperature dependence of the Aharonov-Bohm (AB) effect. The SAG platform will allow scalable experiments for more complicated quantum transport, paving the way towards Majorana braiding. (Chapters 6-8)QRD/Kouwenhoven La

Method for removing methane from gas mixtures

The invention relates to a method for oxidizing methane, comprising passing a gaseous, methane containing mixture over a catalyst, comprising a carrier with a substrate surface which consists substantially of titanium dioxide with a combination of platinum and palladium thereon, in the presence of molecular oxygen, and to a catalyst suitable thereto.Applied Science

Numerical simulation of precipitation kinetics in multicomponent alloys

A universal numerical model based on the particle size distribution (PSD) approach has been developed for the simulation of precipitation kinetics in multicomponent alloys during isothermal ageing. Nucleation was implemented utilizing the classical nucleation theory (CNT). Growth and coarsening were modeled by a single growth kinetics equation, which is constructed based on the interfacial diffusion flux balance and the capillarity effect. Only partial off-diagonal terms in the diffusion matrix (diffusion of individual components in the matrix) were taken into account in the calculations to minimize the computational cost while coupling with CALPHAD to extract thermodynamics equilibrium around the interface. A new feature of the model is the incorporation of a more realistic spatial site distribution via a Voronoi construction in the characteristic cell, for the purpose of modifying the diffusion distance. Computational predictions of the precipitate dimensions and the precipitation kinetics were compared with the atom probe tomography (APT) measurements on ternary Ni-Al-Cr alloys isothermally aged at 873 K. It is found that the temporal evolution of the dimensions and composition of the precipitates is well captured, as is the dependence on changes in the alloy composition. The new modification with Voronoi construction demonstrates that the overall precipitation kinetics depends on the density and the spatial site distribution of precipitates. The ability to handle sophisticated alloy chemistries by quantitative equations, the compositional sensitivity of microstructural characteristics emerging from the simulation results, and the ability to visualize the spatial distribution of precipitates make the work very promising for multicomponent alloy design and optimization.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

Friction effects on quasi-steady dam-break wave propagation on horizontal beds

The propagation of dam-break waves on different rough beds was observed to be quasi-steady in the range < [CDATA[11.3 < x/h dam, where is measured from the dam position. These quasi-steady propagation speeds converge with the steady ideal fluids model of Stoker (Water Waves, 1957, Interscience) when the tailwater depth becomes greater than, in the range <[CDATA[0.001< k_s/h_{dam}, where is the roughness and the depth behind the dam. Hence, this convergence encourages the use of Stoker's steady, ideal fluid solution to develop more general models, including friction effects due to bed roughness and/or viscosity. The new experimental data support a MacLaurin series for the celerity, in analogy with the series in terms of, derived for Stoker's model, being the tailwater depth. Compared with the retarding effect of the tailwater, 1 mm of roughness is found to be equivalent to 13 mm of tailwater, and 1 m of viscous length (, where is the kinematic viscosity and g the acceleration due to gravity) is equivalent to 1700 m of tailwater. While the MacLaurin series quantifies the similar effects of small roughness and small tailwater depths acting separately, the new data illustrate for the first time the complex interplay between tailwater and roughness on 'wet beds' with many details yet to be investigated. In particular, it was shown that a small amount of tailwater on a rough bed acts as a lubricant, so that is an increasing function of for <[CDATA[h 2. Hydraulic Structures and Flood Ris

Correction to: Are green buildings more liveable than conventional buildings? An examination from the perspective of occupants (Journal of Housing and the Built Environment, (2022), 10.1007/s10901-022-09983-9)

In the original publication of the article, the first affiliation “School of Public Administration, Hunan University, Changsha, China” was incorrectly repeated as fourth affiliation. The fourth affiliation should be “Building and Real Estate Dept. Hong Kong Polytechnic University, Hong Kong SAR”. The original article has been corrected.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.Technology, Policy and ManagementManagement in the Built EnvironmentHousing SystemsDesign & Construction Managemen

Slurry Tank Conditioning of Oil Sands: Tailings Behaviour

Slurry tank conditioning as an oil sands process step prior to extraction can be expected to produce a tailings material significantly different from conventional Clark hot water process tailings. Recycle water pond design and operation will depend upon the settling and consolidation properties of the fine tailings stream, and these properties in turn depend upon the chemical and physical conditions to which the oil sands are exposed in the extraction process. Slurry tank conditioning occurs at 50°C and without the addition of any process aides. The release of bitumen from the sand matrix is accomplished using mechanical agitation (stirring) in a tank, prior to desanding and flotation using conventional oil sands separation processes. This is in contrast to the Clark process which conditions the oil sand using tumblers, heat (80°C), and an alkaline water chemistry. The alkaline water chemistry serves to disperse the fine clays, as well as enhance the release of natural surfactants in the bitumen. Both of these effects result in rapid release of bitumen from the sand, allowing for very short residence times (5 to 10 min) in the tumblers. The non-alkanine water chemistry, and (longer residence time) mechanical conditioning in the slurry tank process results in a reduction in dispersion of the fine clays, as well as an increase in the flocculation and settling rate, compared to the Clark process tailings. The rapid flocculation and settling of the fine clays results in a fine tailings stream that begins settling without any induction time and that has a solids free release water. The slurry tank process tailings have an order of magnitude higher permeability than Clark hot water process tailings and they have a significantly improved capacity to support a sand surcharge which will provide a stress to further enhance dewatering, relative to the Clark tailings. The improved capacity to support a sand surcharge indicates that a lower calcium addition would be needed to create CT (relative to Clark tailings). Because of the similar water chemistry, slurry tank and OSLO tailings behaviour will be similar, with the additional potential benefit of tailoring the degree of mechanical conditioning in the slurry tank to maximize bitumen recovery, but minimize clay dispersion. The beneficial fine tailings properties result from both the water chemistry, as well as the more controlled mechanica! conditioning in the slurry tank. Depending upon the connate water chemistry of the oil sands, maintaining a non-alkaline environment after many years of recycle may require chemical treatment of the recycled water. For the lease 13 oil sands tested here, chemical treatment is not likely to he required to control the water chemistry. Toxicity of the release water is significantly lower for the slurry tank conditioned oil sands than for the Clark tailings, although it has some level of toxicity. This means that in any treat and release scenario, the slurry tank conditioned tailings will require less treatment than conventional Clark tailings