58 research outputs found

    Nano-mechanical properties of Fe-Mn-Al-C lightweight steels

    Get PDF
    High Al Low-density steels could have a transformative effect on the light-weighting of steel structures for transportation and achieving the desired properties with the minimum amount of Ni is of great interest from an economic perspective. In this study, the mechanical properties of two duplex low-density steels, Fe-15Mn-10Al-0.8C-5Ni and Fe-15Mn-10Al-0.8C (wt.%) were investigated through nano-indentation and simulation through utilization of ab initio formalisms in Density Functional Theory (DFT) in order to establish the hardness resulting from two critical structural features (ߢ-carbides and B2 intermetallic) as a function of annealing temperature (500 − 1050 ℃) and the addition of Ni. In the Ni-free sample, the calculated elastic properties of kappa-carbides were compared with those of the B2 intermetallic Fe3Al − L12, and the role of Mn in the kappa structure and its elastic properties were studied. The Ni-containing samples were found to have a higher hardness due to the B2 phase composition being NiAl rather than FeAl, with Ni-Al bonds reported to be stronger than the Fe-Al bonds. In both samples, at temperatures of 900 ℃ and above, the ferrite phase contained nano-sized discs of B2 phase, wherein the Ni-containing samples exhibited higher hardness, attributed again to the stronger Ni-Al bonds in the B2 phase. At 700 ℃ and below, the nano-sized B2 discs were replaced by micrometre sized needles of kappa in the Ni-free sample resulting in a lowering of the hardness. In the Ni-containing sample, the entire alpha phase was replaced by B2 stringers, which had a lower hardness than the Ni-Al nano-discs due to a lower Ni content in B2 stringer bands formed at 700 ℃ and below. In addition, the hardness of needle-like kappa-carbides formed in alpha phase was found to be a function of Mn content. Although it was impossible to measure the hardness of cuboid kappa particles in gamma phase because of their nano-size, the hardness value of composite phases, e.g. gamma + kappa was measured and reported. All the hardness values were compared and rationalized by bonding energy between different atoms

    Modern eminence and concise critique of solar thermal energy and vacuum insulation technologies for sustainable low-carbon infrastructure

    Get PDF
    A concise critique on harnessing the abundant solar thermal energy and improvement with vacuum insulation for the utilization and conversion is presented. This research implicates that the world is becoming a global solar smart city prompted by increasing daily demand of energy by the global population and land-use. Amongst all the renewable energy resources available, solar thermal energy collectors (STC) are the most copious because it is accessible in both direct and indirect modes with global solar thermal capacity in operation in 2019 was 479 GWth and annual energy yield estimated to be 389 TWh. Hybridization has been found to be the only way of improving the existing performance of (STC) such as hybrid photovoltaic thermal (PVT) with phase-change material (PCM) for energy storage and magneto-thermoelectric generators (MTEGs) and/or vacuum insulated TEG (VTEG) for waste heat energy conversion to electrical power. The concentrating solar power (CSP) technologies were also precisely studied and yet parabolic trough collector, dish sterling and solar tower are amongst the top solar thermal heat energy harvesters and its electrical power generation has also been comprehended. The modern eminence of vacuum insulation technologies on thermal comfort and sound insulation in sustainable low-carbon buildings is presented. The research implicates that there is still a scope of improving the building and construction sector and target to achieve not only zero-energy buildings (ZEB) but generating-energy buildings (GEB). A concise critique on vacuum insulated smart glazed windows is presented and the review implicates that the hybridization with PV and TEG and novelty in the constructional materials of vacuum glazing (VG) and translucent vacuum insulation panel (TVIP) are vital in the realistic move towards the GEB. The future of vacuum insulation is not only limited to GEB but vital applications occur in medical, imaging, mechatronics and manufacturing industries

    Pan-cancer analysis of whole genomes

    Get PDF
    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

    Coupled quasicrystals

    No full text
    corecore