Search for dissertations about: "Heartwood"

Showing result 11 - 15 of 42 swedish dissertations containing the word Heartwood.

  2. 11. Moisture Transport in Porous Media. Modelling Based on Kirchhoff Potentials

    Author : Jesper Arfvidsson; Avdelningen för Byggnadsfysik; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; moisture distribtion; wood drying; wood; diffusion coefficient; numerical modelling; moisture flow; Moisture; transient measurements; periodic boundary condition; penetration depth; sorption coefficient; non-linear moisture flow; calculation model; anisitropy; Kirchhoff potentials; evaluation; moisture transport; Building construction; Byggnadsteknik;

    Abstract : The work presented in this thesis is focused on the development of the new concept to describe isothermal moisture transport using Kirchhoff potentials. The first four papers deal with moisture transport in porous media using Kirchhoff potentials. The last three papers deal with wood. READ MORE

  4. 12. X-ray measurement of properties of saw logs

    Author : Johan Oja; Luleå tekniska universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Träteknik; Wood Technology;

    Abstract : A nondestructive method of measuring knot parameters for research purposes has been compared to alternative, destructive methods. The method is based on automatic analysis of CT-images. The image analysis algorithms were adjusted to and evaluated on Norway spruce. READ MORE

  5. 13. Properties of solid wood : responses to drying and heat treatment

    Author : Margot Sehlstedt-Persson; Luleå tekniska universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wood Physics; Träfysik;

    Abstract : The hygro-thermal processes that wood is exposed to during drying and heat treatment lead to different reactions or responses in the wood material. The objective of this thesis has been to study the impact of different drying and heat-treatment strategies on various responses, such as strength, sorption/desorption behaviour, dimensional stability and colour changes. READ MORE

  6. 14. The initial phase of sodium sulfite pulping of softwood : A comparison of different pulping options

    Author : Raghu Deshpande; Ulf Germgård; Pedro Fardim; Karlstads universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Activation energy; acid sulfite pulping; bisulfite pulping; cellulose; delignification; dissolving pulp; extractives; glucomannan; hemicelluloses; lignin; lignin condensation; lignin carbohydrate complexes; pine; spruce; thiosulfate; total SO2; xylan; Chemical Engineering; Kemiteknik;

    Abstract : Single stage and two-stage sodium sulfite cooking were carried out on either spruce, pine or pure pine heartwood chips to investigate the influence of several process parameters on the initial phase of such a cook down to about 60 % pulp yield. The cooking experiments were carried out in the laboratory with either a lab-prepared or a mill-prepared cooking acid and the temperature and time were varied. READ MORE

  7. 15. Physical-mechanical properties and natural durability of lesser used wood species from Mozambique

    Author : Alexandre Charifo Ali; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Keywords : LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Abstract : The aim of this study is to assess properties of lesser used/known timbers from Mozambique. The studied species were ncurri (Icuria dunensis Wieringa), ntholo (Pseudolachnostylis maprounaefolia Pax), metil (Sterculia appendiculata K. Schum), namuno (Acacia nigrescens Oliv.) and muanga (Pericopsis angolensis Meeuwen). READ MORE