Sökning: "Tube shape"

Visar resultat 16 - 20 av 37 avhandlingar innehållade orden Tube shape.

  1. 16. Structural and Morphological Studies of Mesoporous Crystals

    Författare :Kristina Lund; Osamu Terasaki; Sven Lidin; Lars Eriksson; Mika Lindén; Stockholms universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Chemistry; Kemi; Structural Chemistry; strukturkemi;

    Sammanfattning : Mesoporous silica and carbon have been synthesised and characterised by X-ray diffraction (XRD), transmission and scanning electron microscopy (TEM and SEM) and nitrogen adsorption. Surface structure, size and shape (morphology) of particles have been of special interest in this work. LÄS MER

  3. 17. Charged Polymers: From DNA to Polyampholytes

    Författare :Malek O Khan; Beräkningskemi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; computational steering; DNA condensation; ion correlations; electrostatic interactions; colloidal stability; polyampholytes; Monte Carlo simulations; polyelectrolytes; Theoretical chemistry; quantum chemistry; Teoretisk kemi; kvantkemi;

    Sammanfattning : Three main themes are outlined in this thesis: Polyelectrolytes/DNA : In a living cell, DNA molecules have a compact conformation in order to fit in, while in a test tube they will take on an expanded cylindrical shape, due to the negative phosphate groups along the DNA molecule. With the help of computer simulations it has been shown that like-charged monomers of a poly- electrolyte can attract each other if the counterions are taken into account. LÄS MER

  4. 18. In-line rheology of cement grouts - Feasibility study of an ultrasound based non-invasive method

    Författare :Mashuqur Rahman; Stefan Larsson; Ulf Håkansson; Thomar Dalmalm; Lars-O Ericsson; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Järnvägsgruppen - Infrastruktur; Järnvägsgruppen - Infrastruktur;

    Sammanfattning : Grouting is used in underground construction to reduce the water flow into tunnels and caverns and to limit the lowering of the surrounding groundwater table. Due to their wide availability and low cost relative to other materials, cement based materials are commonly used as grouts and, in this context, the rheology of the cement grout is an important factor. LÄS MER

  5. 19. Energy concentration by converging shock waves in gases

    Författare :Malte Kjellander; Nicholas Apazidis; Gabi Ben-Dor; KTH; []
    Nyckelord :;

    Sammanfattning : Converging shock waves have been studied experimentally in a shock tube, and numerically using inviscid calculations and the theory of geometrical shock dynamics. The converging shock waves were created in a shocktube with two modular test sections designed to create cylindrical respectively spherical waves. LÄS MER

  7. 20. Studies of PoGOLite performance and background rejection capabilities

    Författare :Mózsi Kiss; Mark Pearce; Staffan Carius; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; Fysik;

    Sammanfattning : The Polarized Gamma-ray Observer (PoGOLite) is a balloon-borne instrument capable of measuring as low as 10% polarization from a 200 mCrab source in a sixhour °ight. A wide array of sources can be studied, including pulsars, neutron stars, accretion discs and jets from active galactic nuclei. LÄS MER