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  1. 1. Modelling the Variability of Bending Strength in Structural Timber - Length and Load Configuration Effects

    Författare :Tord Isaksson; Avdelningen för Konstruktionsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; code; reliability-based design; Weibull; test standard; load configuration effect; length effect; weak section; machine grading; visual grading; variability; Structural timber; bending strength; simulation; monte carlo simulation.; Building construction; Byggnadsteknik;

    Sammanfattning : The load carrying capacity of a beam of structural timber is dependent both on the span of the beam and the type of loading. The longer the beam and the more uniform the moment distribution, the lower the load carrying capacity. This phenomenon is due to the variability of material properties within a piece of timber. LÄS MER

  3. 2. Estimation of wood fibre length distributions from censored mixture data

    Författare :Ingrid Svensson; Sara Sjöstedt - de Luna; Lennart Bondesson; Aila Särkkä; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; censoring; fibre length distribution; identifiability; increment core; length bias; mixture; stochastic EM algorithm; Mathematical statistics; Matematisk statistik;

    Sammanfattning : The motivating forestry background for this thesis is the need for fast, non-destructive, and cost-efficient methods to estimate fibre length distributions in standing trees in order to evaluate the effect of silvicultural methods and breeding programs on fibre length. The usage of increment cores is a commonly used non-destructive sampling method in forestry. LÄS MER

  4. 3. Resistance of cold-formed high strength steel sections : Effect of cold-formed angle

    Författare :Anh Tuan Tran; Lars Bernspång; Ove Lagerqvist; Torsten Höglund; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Stålbyggnad; Steel Structures;

    Sammanfattning : Cold-formed steel members are increasingly used in industrial and civil construction. Their use allows optimised member cross sections and shapes, thereby reducing the amount of steel used as well as the weight of the structures and, consequently, reducing harmful effects on the environment. LÄS MER

  5. 4. Contacts on Silicon Carbide by Use of Nickel and Tantalum ---Preparation and Characterisation

    Författare :Yu Cao; Chalmers tekniska högskola; []
    Nyckelord :Keywords: Silicon Carbide; Metal Contact; Thin Films; Preferential Etching; Interfacial Reaction; effect; Nickel; Tantalum; #955; Depth Profile; I-V Characteristics.;

    Sammanfattning : Silicon carbide (SiC) is one of the attractive semiconductors due to its good electrical, thermal and mechanical properties. It is a promising material for high temperature, high power and high frequency application. Reliable electrodes are always necessary to utilise SiC for electronic devices. LÄS MER

  7. 5. LIVING WITH PARASITES: AVIAN MALARIA, TELOMERE LENGTH AND LIFE HISTORY TRADE-OFFS

    Författare :Asghar Muhammad; MEMEG; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Avian malaria; Plasmodium; qPCR; parasitemia; life history; reproduction; survival; feather growth; MHC; telomere length; heritability; telomere loss; fitness; wild population; Acrocephalus arundinaceus; Delichon urbica;

    Sammanfattning : Haemosporidia is a well-studied group of parasites, which infect mammals, reptiles and birds and use blood sucking vectors for their transmission. By conducting natural population studies and experimental infections, We have been able to detect and quantify Haemosporidia from avian blood to investigate how these pathogens affect their avian hosts. LÄS MER