Sökning: "Pulp and Fiber Technology"

Visar resultat 26 - 30 av 269 avhandlingar innehållade orden Pulp and Fiber Technology.

1. 26. ANALYZING THE HYDRO DYNAMICS AND THE CHEMICAL REACTIONS IN PULP DIGESTER SYSTEMS USING CFD MODELLING

   Författare :Bijan Pourian; Erik Dahlquist; Laszlo Fuchs; Mälardalens högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; CFD; MODELLING; SIMULATION; PULP; DIGESTER. CHEMICAL; MULTIPHASE; Cellulose and paper engineering; Cellulosa- och pappersteknik; Energy- and Environmental Engineering; energi- och miljöteknik;

   Sammanfattning : The aim of this thesis is to use differential analysis and finite volume method (FVM) to model and analyze a continuous pulp digester in order to create a detailed picture of the flow behaviour and chemical reactions in the digester. This information will be used to optimize wood chip flow and reactions and to diagnose and avoid faults such as hang-ups and channelling. LÄS MER

3. 27. Micromechanics of Fiber Networks

   Författare :Svetlana Borodulina; Artem Kulachenko; Sören Östlund; Mikael Nygårds; Pierre J.J. Dumont; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Network simulation; Mechanical properties; Fibers; Fiber-to-fiber bonds; Free fiber length; Number of contacts; Contact density; Paper properties; X-ray microtomography; Hållfasthetslära; Solid Mechanics;

   Sammanfattning : The current trends in papermaking involve, but are not limited to, maintaining the dry strength of paper material at a reduced cost. Since any small changes in the process affect several factors at once, it is difficult to relate the exact impact of these changes promptly. LÄS MER

4. 28. Design of Cellulose-based Materials by Supramolecular Assemblies

   Författare :Tobias Benselfelt; Lars Wågberg; Torbjörn Pettersson; Joseph Schlenoff; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Adhesion; adsorption; alginate; assemblies; biodegradable; biomaterials; biopolymers; cellulose; cellulose nanofibrils; CNFs; gas barrier; hemicellulose; interfaces; ion-ion correlation; latex; layer-by-layer; metal-ligand complexes; montmorillonite; multivalent ions; packaging; PISA; polyelectrolyte multilayers; polyelectrolytes; polysaccharides; RAFT; renewable; specific ion effects; supramolecular; surfaces; sustainable; thin films; water-resilient; xyloglucan; Fiber- och polymervetenskap; Fibre and Polymer Science;

   Sammanfattning : Due to climate change and plastic pollution, there is an increasing demand for bio-based materials with similar properties to those of common plastics yet biodegradable. In this respect, cellulose is a strong candidate that is already being refined on a large industrial scale, but the properties differ significantly from those of common plastics in terms of shapeability and water-resilience. LÄS MER

5. 29. Preparation and characterization of nanoporous cellulose fibres and their use in new material concepts

   Författare :Anna Sjöstedt; Lars Wågberg; Akira Isogai; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fiber- och polymervetenskap; Fibre and Polymer Science;

   Sammanfattning : The overall objective of the work in this thesis is to better utilize the non-collapsed structure of the delignified wood-fibre cell wall in the preparation of new types of materials.In order to utilize the fibres in new materials, it is crucial to have a well-defined starting material and to know how it reacts to certain treatments of the fibres. LÄS MER

7. 30. Swelling of Cellulose Fibrillar Matrices and Gels

   Författare :Pernilla Karlsson; Lars Wågberg; Per Tomas Larsson; Eero Kontturi; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; swelling; hydrogel; cellulose; wood; cellulose fibrils; Fiber- och polymervetenskap; Fibre and Polymer Science;

   Sammanfattning : One of the major challenges of today´s society is to find a sustainable way to create a living based on the resources on earth. It is a challenge that includes a transition from fossil-based materials to renewable/biodegradable raw materials and also the creation of an environmentally friendly circular material flow. LÄS MER