Search for dissertations about: "plant fibers"

Showing result 1 - 5 of 24 swedish dissertations containing the words plant fibers.

  1. 1. Molecular orientation in cellulose fibers and composites

    Author : Leo Svenningsson; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; composite; molecular orientation; lignin; solid-state NMR; Raman spectroscopy; fibers; X-ray scattering; carbon fibers; regenerated cellulose;

    Abstract : The scope of this thesis is to quantitatively investigate the molecular orientation distribution of regenerated cellulose fibers and composites. The molecular orientation is known to affect macroscopic properties such as tensile strength of the fiber. READ MORE

  2. 2. Cellulose-based Conducting 3D and 2D Composites for Applications in Plant Science and Responsive Systems

    Author : Vasileios Oikonomou; Eleni Stavrinidou; Magnus Berggren; Anna Herland; Linköpings universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; polymers; cellulose; conjugated polymers; volume changes; plant growth substrates;

    Abstract : Polymers (Greek: poly=many, meros=part) are large molecules made up of many small parts (monomers) in a repetitive way, as a term was introduced for the first time (1833) by the Swedish chemist, Jöns Jakob Berzelius. By the combination of different monomers, the resulting polymer can exhibit various properties, such as biodegradability, photosensitivity and electrical conductivity. READ MORE

  3. 3. Bio-based Composites from Soybean Oil Thermosets and Natural Fibers

    Author : Kayode Adekunle; Högskolan i Borås; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; bio-based thermoset resins; natural fibres; hybrid composites; renewable resources; mechanical analysis; compression molding; lyocell fiber; Energi och material; Resursåtervinning; Resource Recovery;

    Abstract : In order to reduce over-dependency on fossil fuels and to create an environment that is free of non-degradable plastics, and most importantly to reduce greenhouse gas emission, bio-based products are being developed from renewable resources through intense research to substitute conventional petrochemical-based plastics with renewable alternatives and to replace synthetic fibers with natural fibers. Many authors have done quite a lot of work on synthesizing polymers from renewable origin. READ MORE

  4. 4. Physico-Chemical Properties of Plant Polysaccharides Investigated with NMR Techniques

    Author : Åsa Östlund; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NMR diffusometry; Dissolution of cellulose; Chemical shift imaging; Fiber hornification; Xylan; Molecular weight; Pore size distribution; Cryoporometry; Cellulose solution; 19F NMR; Gelation of cellulose; Self-diffusion; Pulsed field gradient NMR; TBAF DMSO; 1H NMR;

    Abstract : In the lead of developing new biomaterials from plant sources it is of importance to be able to control and vary the properties, such as flexibility, strength, and hygroscopicity of the final material. These properties are highly directed by the interactions between constituents on a molecular level. READ MORE

  5. 5. Optical Phase Conjugation and All-Optical Demultiplexing using Four-Wave Mixing in Dispersion Shifted Fibers

    Author : Per Olof E Hedekvist; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; dispersion compensation; nonlinear fiber optics; high-speed communication; four-wave mixing; parametric amplification; noise figure; wavelength conversion; optical phase conjugation; all-optical demultiplexer; mid-span spectral inversion;

    Abstract : This thesis deals with two applications of four-wave mixing in optical dispersion-shifted fibers; optical phase conjugation and all-optical switching. The work is a part of an effort to study the upgradability of the existing fiber plant, which is of large economic interest. READ MORE