Sökning: "numerical ring"

Visar resultat 1 - 5 av 41 avhandlingar innehållade orden numerical ring.

  1. 1. The Theory of Polynomial Functors

    Författare :Qimh Xantcha; Torsten Ekedahl; Vincent Franjou; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; numerical ring; polynomial map; strict polynomial map; numerical map; polynomial functor; strict polynomial functor; numerical functor; maze; multi-set; multation; Algebra and geometry; Algebra och geometri; Mathematics; matematik;

    Sammanfattning : Polynomial functors were introduced by Professors Eilenberg and Mac Lane in 1954, who used them to study certain homology rings. Strict polynomial functors were invented by Professors Friedlander and Suslin in 1997, in order to develop the theory of group schemes. LÄS MER

  2. 2. Moisture-induced stress and distortion of wood : A numerical and experimental study of wood's drying and long-term behaviour

    Författare :Sara Florisson; Sigurdur Ormarsson; Johan Vessby; Kent Persson; Linnéuniversitetet; []
    Nyckelord :AGRICULTURAL SCIENCES; LANTBRUKSVETENSKAPER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; LANTBRUKSVETENSKAPER; ENGINEERING AND TECHNOLOGY; AGRICULTURAL SCIENCES; analytical method; calibration; controlled climate; creep; distortion; experimental methodology; FEM; fibre orientation; mechano-sorption; moisture transport; natural climate; Norway spruce; numerical model; three-dimensional; timber beam; validation; wood; Byggteknik; Civil engineering; Forestry and Wood Technology; Skog och träteknik;

    Sammanfattning : With the current advances made in three-dimensional modelling of wood, it is possible to provide an overall picture of moisture flow, and moisture-induced stress and deformations, whereas previously, experiments only provided local measurements. The main aim of the doctoral thesis is to investigate the possibilities of the developed three-dimensional numerical model to predict the behaviour of wood when simultaneously exposed to a mechanical load and a particular climate. LÄS MER

  3. 3. Friction in Piston Ring - Cylinder Liner Contacts

    Författare :Markus Söderfjäll; Peder Klit; Luleå tekniska universitet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Machine Elements; Maskinelement;

    Sammanfattning : With today’s striving towards reduction of fuel consumption it is moreimportant than ever to understand the function of different componentsin the internal combustion engine. There is a need to develop and usetools to investigate and predict the result of specific design changesmade on the components. LÄS MER

  4. 4. Semi-deterministic numerical simulations of wear on various scales : From chemo-mechanical effects to the wear of components in orbital type hydraulic motors

    Författare :Joel Furustig; Luleå tekniska universitet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Maskinelement; Machine Elements;

    Sammanfattning : A costly effect, caused by the relative motion of machine components in contact, is wear. Solid surfaces come into contact when the lubricant film thickness is thin, resulting in locally high pressures and high wear rates. Components and machines will, due to this wear, eventually lose their functionality. LÄS MER

  5. 5. Numerical study of flows related to aerated stirred tanks

    Författare :Dragana Arlov; Strömningsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; plasma; fluiddynamik; Gaser; plasmas; fluid dynamics; Gases; Lattice Boltzmann method; Volume of Fluid; Aerated stirred tank; Large Eddy Simulation; Eulerian-Lagrangian model; Energy research; Energiforskning; Mechanical engineering; hydraulics; vacuum technology; vibration and acoustic engineering; Maskinteknik; hydraulik; vakuumteknik; vibrationer; akustik;

    Sammanfattning : The overall purpose with this work is to investigate the bubbly flow in a aerated stirred tank using numerical simulations. Aerated stirred tanks are commonly used in chemical processes for producing for example insulin and antibiotics. LÄS MER