Sökning: "Waves"

Visar resultat 1 - 5 av 950 avhandlingar innehållade ordet Waves.

  1. 1. On steady waves in two-layer fluids and ferrofluids

    Författare :Dag Nilsson; Partiella differentialekvationer; []
    Nyckelord :Internal waves; ferrofluids; partial differential equation; nonlinear waves; travelling waves; solitary waves; dynamical systems; Hamiltonian systems; non-local equations;

    Sammanfattning : This thesis concerns travelling waves in a two-layer fluid and on a ferrofluid jet. We prove existence of several types of such waves by reformulating the corresponding governing equation as an infinite dimensional dynamical system, where an unbounded spatial coordinate is used as time. LÄS MER

  3. 2. Steady waves in local and nonlocal models for water waves

    Författare :Tien Truong; Matematik (naturvetenskapliga fakulteten); []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; The steady Euler equations; the Whitham equation; solitary waves; highest waves; periodic waves; transverse dynamics; The steady Euler equations; the Whitham equation; solitary waves; highest waves; periodic waves; transverse dynamics;

    Sammanfattning : We study the steady Euler equations for inviscid, incompressible, and irrotational water waves of constant density. The thesis consists of three papers. The first paper approaches the Euler equations through a famous nonlocal model equation for gravity waves, namely the Whitham equation. LÄS MER

  4. 3. Making waves : A study of the patterns and consequences of non-state actor participation in global fisheries governance

    Författare :Matilda Petersson; Henrik Österblom; Lisa Dellmuth; Robert Blasiak; Megan Bailey; Stockholms universitet; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Global fisheries governance; regional fisheries management organizations RFMOs ; non-state actors; non-governmental organizations NGOs ; transnational partnerships; participation; influence; effectiveness; process tracing; Sustainability Science; vetenskap om hållbar utveckling;

    Sammanfattning : States have established regional fisheries management organizations (RFMOs) to manage transboundary fish stocks. However, the effectiveness of these bodies has been questioned. Problems with overfishing, illegal, unreported, and unregulated (IUU) fishing, and bycatch remain persistent and difficult to solve. LÄS MER

  5. 4. Ultrasonic Arrays for Sensing and Beamforming of Lamb Waves

    Författare :Marcus Engholm; Tadeusz Stepinski; Paul D. Wilcox; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; imaging; array processing; guided waves; Lamb waves; dispersive waves; multi-modal waves; spatial filtering; mode suppression; resonant ultrasound; transducer design; direction of arrival estimation; adaptive beamforming; Signal processing; Signalbehandling; Electronic measurement and instrumentation; Elektronisk mät- och apparatteknik;

    Sammanfattning : Non-destructive testing (NDT) techniques are critical to ensure integrity and safety of engineered structures. Structural health monitoring (SHM) is considered as the next step in the field enabling continuous monitoring of structures. LÄS MER

  7. 5. Waves in space plasmas : Lower hybrid cavities and simple-pole distribution functions

    Författare :Anders Tjulin; Mats André; Hans Pécseli; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Space and plasma physics; space physics; plasma; waves; dispersion relations; lower hybrid cavities; Cluster; magnetosphere; Rymd- och plasmafysik; Space physics; Rymdfysik;

    Sammanfattning : Waves are a fundamental feature in many parts of physics, since they transport energy without transporting matter. This is the case also in space physics. Waves are responsible for energy transport both between different parts of space and between different particles in the space plasma. LÄS MER