Sökning: "secondary cell wall"

Visar resultat 1 - 5 av 52 avhandlingar innehållade orden secondary cell wall.

1. 1. The cell wall ultrastructure of wood fibres : effects of the chemical pulp fibre line

   Författare :Jesper Fahlén; Ulf W. Gedde; Drek G. Gray; KTH; []
   Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; Chemical engineering; atomic force microscopy; cellulose; cell wall; drying; fiber; Kemiteknik; Chemical engineering; Kemiteknik;

   Sammanfattning : Knowledge of the ultrastructural arrangement within wood fibres is important for understanding the mechanical properties of the fibres themselves, as well as for understanding and controlling the ultrastructural changes that occur during pulp processing. The object of this work was to explore the use of atomic force microscopy (AFM) in studies of the cell wall ultrastructure and to see how this structure is affected in the kraft pulp fibre line. LÄS MER

3. 2. Programmed Cell Death in Xylem Development

   Författare :Laetitia Charleen Courtois-Moreau; Hannele Tuominen; Stefan Jansson; Christina Dixelius; Umeå universitet; []
   Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; PCD Programmed Cell Death ; Xylem; Apoptosis; Autophagy; Secondary Cell Walls; Microscopy; Microarrays; Comet Assay; TUNEL Assay; Cell and molecular biology; Cell- och molekylärbiologi;

   Sammanfattning : Concerns about climate changes and scarcity of fossil fuels are rising. Hence wood is becoming an attractive source of renewable energy and raw material and these new dimensions have prompted increasing interest in wood formation in trees, in both the scientific community and wider public. LÄS MER

4. 3. Interactions between Wood Polymers in Wood Cell Walls and Cellulose/Hemicellulose Biocomposites

   Författare :Jasna Stevanic Srndovic; Chalmers University of Technology; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; dynamic FTIR spectroscopy; viscoelasticity; orientation; Norway spruce; protein; glucomannan; xyloglucan; polymer interactions; pectin; imaging FTIR microscopy; primary cell wall; nanocomposite films; dynamic 2D FTIR spectroscopy; xylan; wood fibre; cellulose; secondary cell wall; DMA; lignin;

   Sammanfattning : A wood fibre is a complex multi component biocomposite that is hierarchically organised. The arrangement of a wood fibre on the ultrastructural level is highlycontrolled by the interactions between the main structural polymers, i.e. cellulose, various hemicelluloses and lignin, as well as in some parts also pectin and protein. LÄS MER

5. 4. Computerized Cell and Tissue Analysis

   Författare :Azadeh Fakhrzadeh; Gunilla Borgefors; Cris Luengo Hendriks; Lena Holm; Nasir Rajpoot; Uppsala universitet; []
   Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; NATURAL SCIENCES; NATURVETENSKAP; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Image processing; Cell; Tissue; Segmentation; Classification; Histology; Computerized Image Processing; Datoriserad bildbehandling;

   Sammanfattning : The latest advances in digital cameras combined with powerful computer software enable us to store high-quality microscopy images of specimen. Studying hundreds of images manually is very time consuming and has the problem of human subjectivity and inconsistency. LÄS MER

7. 5. Composition of lignin in outer cell-wall layers

   Författare :Maria Christiernin; Gunnar Henriksson; Gösta Brunow; KTH; []
   Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Lignin; thioacidolysis; primary wall; middle lamella; Populus balsamifera; Populus tremula L. x P. tremuloides Michx.; Picea abies; Picea glauca; Cellulose and paper engineering; Cellulosa- och pappersteknik;

   Sammanfattning : The composition of lignin in the outer cell-wall layers of spruce and poplar has been studied and the data obtained have been compared with those of the mature reference wood in which the secondary cell wall predominates. Materials with exclusively or predominantly outer cell-wall layers were examined. LÄS MER