Sökning: "Lattice structures"

Visar resultat 1 - 5 av 227 avhandlingar innehållade orden Lattice structures.

  1. 1. Design of flexible lattice structures : a design for additive manufacturing perspective

    Författare :Satabdee Dash; Innovation; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Design for additive manufacturing; DfAM; Lattice structures; Flexibility; Compuational methods; Numerical modelling; Engineering design process;

    Sammanfattning : Recent years has seen an unprecedented growth in emerging technologies like Additive manufacturing (AM), augmenting the manufacturing capabilities through a multitude of opportunities while also introducing unique constraints, such as support structures, and post-processing requirements. Taking full advantage of the potential of AM demands product designs to be optimised for both opportunities and constraints specific to AM, requiring evolution from the traditional design for manufacturing to design for additive manufacturing (DfAM). LÄS MER

  3. 2. Quasicrystal Approximants in the RE-Au-SM systems (RE = Gd, Tb, Ho, Yb; SM = Si, Ge) : Syntheses, structures and properties

    Författare :Girma Hailu Gebresenbut; Cesar Pay Gómez; Martin Sahlberg; Torbjörn Gustafsson; Alan I. Goldman; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Quasicrystal approximant; structure; physical property; Chemistry with specialization in Inorganic Chemistry; Kemi med inriktning mot oorganisk kemi; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : In this study, new Tsai-type 1/1 quasicrystal approximants (ACs) in the RE-Au-SM systems (RE = Gd, Tb, Ho, Yb; SM = Si, Ge) were synthesized using high temperature synthesis techniques such as self-flux, arc-melting-annealing and novel arc-melting-self-flux methods. The syntheses not only provided appropriate samples for the intended structural and physical property measurements but could also be adapted to other systems, especially where crystal growth is a challenge. LÄS MER

  4. 3. Periodic structures and lumped elements in microwave passives

    Författare :Dan Kuylenstierna; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Passive elements; Lumped elements; Photonic bandgap; Metamaterial; MMIC; Electromagnetic bandgap; Ferroelectric; Quadrature hybrid; Quadrature power splitter; Balun; Periodic structures;

    Sammanfattning : The ambition of this work is the incorporation of ferroelectric varactors as tuneable elements in Si integrated circuits (ICs). This thesis presents partialfulfillments of the work. LÄS MER

  5. 4. Understanding Physical Reality via Virtual Experiments

    Författare :Sergiu Arapan; Rajeev Ahuja; Börje Johansson; Chris Pickard; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; density functional theory; ab initio calculations; electronic structure; lattice dynamics; high-pressure phase transitions; high-temperature phase transitions; incommensurate structures; Condensed matter physics; Kondenserade materiens fysik;

    Sammanfattning : In this thesis I have studied some problems of condensed matter at high pressures and temperatures by means of numerical simulations based on Density Functional Theory (DFT).The stability of MgCO3 and CaCO3 carbonates at the Earth's mantle conditions may play an important role in the global carbon cycle through the subduction of the oceanic crust. LÄS MER

  7. 5. Voronoi-Based Coding

    Författare :Erik Agrell; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Voronoi diagram; linear block code; Gaussian channel; neighbor descent; nearest neighbor search algorithm; computational geometry; asymptotic theory; source coding; lattice; vector quantization; soft-decision decoding; index assignment; channel coding; complexity;

    Sammanfattning : The performance of a digital communication system can generally be improved by increasing the number of variables being jointly coded. In this sense, it is desirable to have, e.g., higher-dimensional quantizers, longer channel codes, and more users in a multiple-access system. LÄS MER