Sökning: "frost damage"

Visar resultat 16 - 20 av 31 avhandlingar innehållade orden frost damage.

  1. 16. Bark lesions and sensitivity to frost in beech and Norway spruce

    Författare :Anna Maria Jönsson; Institutionen för naturgeografi och ekosystemvetenskap; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Picea abies; Multiple stress; Mineral nutrient balance; Liming; Lichen indices; Fagus sylvatica; Cryptococcus fagisuga; Excess nitrogen; Vitality fertilization; Plant ecology; Växtekologi;

    Sammanfattning : Strong temperature fluctuations and pathogen attacks can cause bark lesions, visible signs of wounds in the phloem and cambium. Pathogenic insects and fungi are able to invade lesions that have not healed, further increasing the damage. LÄS MER

  3. 17. Degradation of rock and shotcrete due to ice pressure and frost shattering

    Författare :Anna Andrén; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Mining and Rock Engineering; Gruv- och berganläggningsteknik;

    Sammanfattning : In recent years the Swedish Rail Administration has observed an increased incidence of shotcrete and rock fall-outs in its tunnels, for which reason it has initiated several research projects, of which the present project entitled "Degradation of rock and shotcrete due to ice pressure and frost shattering" is one. The aim of this licentiate project was to bring together experience and information relating to ice formation and the effect of ice pressure on fault zones, cracks and, in particular, the shotcrete/rock interface. LÄS MER

  4. 18. Understanding the environmental regulation of tree phenology

    Författare :Tetiana Svystun; BECC: Biodiversity and Ecosystem services in a Changing Climate; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Phenological events; environmental cues; temperature response; phenological modelling; frost risk; gross primary production; climate change impact;

    Sammanfattning : In temperate and boreal climates, trees synchronise their annual growth cycles with seasonal changes in daylength and temperature. Understanding how environmental cues regulate tree phenology is important to our ability to capture the potential responses of trees to climate change, with implications for forest productivity. LÄS MER

  5. 19. Kalkputs : porstrukturens betydelse för beständighet

    Författare :Kristin Balksten; Tor Broström; Britt-Marie Steenari; Jan-Erik Lindkvist; Chalmers; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; kalkputs; kalkbruk; murning; putsning; hantverk; frostresistens; porstruktur; Conservation HGO ; Kulturvård HGO ;

    Sammanfattning : When restoring historic lime plaster it can be difficult to reach the required durability. Today newly made lime plaster can fall off due to frost damages after only a couple of winters. To understand and solve these problems, the subject has been studied from different perspectives. LÄS MER

  7. 20. Low Portland cement content concretes at freezing and subfreezing temperatures

    Författare :Ankit Kothari; Andrzej Cwirzen; Hans Hedlund; Karin Habermehl-Cwirzen; Aleksandra Radlinska; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Byggmaterial; Building Materials;

    Sammanfattning : Concrete is the most used building material. With the increasing growth of industries and urbanization globally; the demand for concrete is increasing significantly. Ordinary Portland Cement (PC) is the binder used to produce typical concrete. Unfortunately, for every ton of manufactured cement about 0. LÄS MER