Sökning: "material variability"

Visar resultat 1 - 5 av 165 avhandlingar innehållade orden material variability.

  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. Climate, Conflict and Coping Capacity : The Impact of Climate Variability on Organized Violence

    Författare :Nina von Uexkull; Erik Melander; Hanne Fjelde; Jack A. Goldstone; Uppsala universitet; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; civil conflict; communal conflict; climate change; climate variability; Sub-Saharan Africa; Kenya; geo-referenced event data; agricultural dependence; vulnerability; Peace and Conflict Research; Freds- och konfliktforskning;

    Sammanfattning : Understanding the conflict potential of climate variability is critical for assessing and dealing with the societal implications of climate change. Yet, it remains poorly understood under what circumstances – and how – extreme weather events and variation in precipitation patterns affect organized violence. LÄS MER

  4. 3. Stream monitoring using near-infrared spectroscopy of epilithic material

    Författare :Jan Persson; Ingemar Renberg; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Streams; environmental monitoring; Water Framework Directive; water quality; biological impact; epilithic material; near-infrared spectroscopy; diatoms; Earth sciences; Geovetenskap;

    Sammanfattning : The European Union Water Framework Directive (WFD), with initiatives to manage surface water resources, has increased the need for fast and inexpensive methods for monitoring conditions in streams. The objective of this thesis is to assess the potential of near-infrared spectroscopy (NIRS) of epilithic material to become such method. LÄS MER

  5. 4. Mechanical Characterization of Engineering Materials by Modal Testing

    Författare :Daniel Larsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; material variability; modal testing; non-destructive test methods; damping ratios; timber beams; plastic panels; aluminium panel; elastic constants; concrete curing; wood-based panels; solids; high-strength concrete; anisotropic materials;

    Sammanfattning : This thesis deals with the use of modal testing for establishing elastic constants of engineering materials and for indicating material variability in terms of stiffness and damping properties. The methodology using modal testing techniques, is applied to timber beams, high strength concrete prisms, wood-based panels (oriented strand board and chipboard), an aluminium alloy panel and plastic laminate panels (high-pressure laminate). LÄS MER

  7. 5. Site variability and settlement patterns : an analysis of the hunter-gatherer settlement system in the Lule River Valley, 1500 B.C.-B.C./A.D

    Författare :Lars L. Forsberg; Umeå universitet; []
    Nyckelord :HUMANIORA; HUMANITIES; Hunter-gatherers; intrasite patterning; multivariate analysis; resource exploitation; settlement patterns; site function;

    Sammanfattning : This thesis deals with questions concerning prehistoric hunter-gatherer society on the River Luleälv in Northern Sweden from c. 1500 B.C. to B. LÄS MER