Sökning: "noise 2012"

Visar resultat 16 - 20 av 105 avhandlingar innehållade orden noise 2012.

  1. 16. Noise Applications in Light Water Reactors with Traveling Perturbations

    Författare :Victor Dykin; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Green s function technique; transit times; decay ratio; cross-correlation function; void fraction; global and regional instabilities; propagating density perturbation; BWR stability; reduced order models; non-white driving force; local component; Monte Carlo; space-dependent neutron noise; density wave oscillations;

    Sammanfattning : Neutron noise induced by perturbations traveling with the coolant of light water reactors (LWRs) is investigated. Different methods to simulate the effect of propagating perturbations are considered. The studies are performed in both open- and closed-loop systems and summarized in three chapters. LÄS MER

  3. 17. Graded index sonic crystal noise barriers: An introduction to design and optimization

    Författare :Bart van der Aa; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Shape optimal design; Broadband acoustic lens; Optimization; Outdoor sound propagation; Sonic crystal noise barrier; Graded index sonic crystal;

    Sammanfattning : Environmental noise pollution and its impact on human beings remains to be an important topic in acoustics. Conservative estimations of the World Health Organization have shown that traffic related noise alone causes a loss of approximately one million healthy life years, only within Western Europe. LÄS MER

  4. 18. The influence of modelling parameters on the simulation of car tyre rolling losses and rolling noise

    Författare :Carsten Hoever; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; rolling resistance; modelling parameters; parameter study; radiation; tyre road noise; tyres; tyre road interaction; waveguide finite element;

    Sammanfattning : Due to legislative changes within the EU there is an increased demand for improvement in car tyre rolling resistance and noise generation. Yet, apart from empirical data based on measurements, there is little information concerning the relationship between rolling resistance and rolling noise generation. LÄS MER

  5. 19. Ultra-Low Noise InP HEMTs for Cryogenic Amplification

    Författare :Joel Schleeh; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; cryogenic; DC power dissipation; MMIC; LNA; InP HEMT; ALD;

    Sammanfattning : InGaAs/InAlAs/InP High Electron Mobility Transistors (InP HEMTs), are today the best devices to design cryogenic low noise amplifiers. However, reported progress in reducing the noise has been slow in the last decade. LÄS MER

  7. 20. Cognitive performance and restoration in open-plan office noise

    Författare :Helena Jahncke; Mats Nilsson; Staffan Hygge; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Teknisk psykologi; Engineering Psychology;

    Sammanfattning : This dissertation presents four experimental studies (in four papers) with the overall aim to investigate the effects of office noise on cognitive performance and restoration. In the first two papers the focus was on the effects of different sound levels (i.e. LÄS MER