Sökning: "Helmholtz"

Visar resultat 1 - 5 av 57 uppsatser innehållade ordet Helmholtz.

  1. 1. Decay Chains of Fast Alpha Emitters in the Actinide Region

    Magister-uppsats, Lunds universitet/Fysiska institutionen; Lunds universitet/Partikel- och kärnfysik

    Författare :Tanvir Sayed; [2024]
    Nyckelord :alpha decay; alpha emissions; fine structure; decay chain; decay scheme; alpha spectrometry; actinide; nucleus; nuclear structure; nuclear states; energy levels; uranium isotopes; U310 experiment; parasitic runs; decay station; TASISpec ; moving window deconvolution; digitisers; alpha-gamma coincidence; 221-Th decay; fine structure of alpha decay to 217-Ra; GSI; Gamow s theory; Geiger-Nuttall; chain search; short half-lives; Physics and Astronomy;

    Sammanfattning : With the advent of increasingly advanced spectroscopic instruments after the turn of the century, it has become accessible to unravel the structure of instantly ‘vanishing’ nuclei, with lifetimes as short as 1 μs, and responsible for pile-up events in analog electronics. Experimental data has been recorded by the Nuclear Structure Group at Lund University for 48Ca/50Ti + nat. LÄS MER

  3. 2. Moderling Acoustic Transmission in Towed Array Sonars : Computations of the coupled acoustic and elastic wave equations

    Master-uppsats, KTH/Matematik (Avd.)

    Författare :Bill Claesson; [2023]
    Nyckelord :;

    Sammanfattning : This thesis presents a method of solving the Helmholtz equation coupled with the Navier-Cauchy equation over a cross section of a Towed Array Sonar (TAS) modeled as a simplified cylindrical shell. The purpose of solving these equations is to estimate the transfer function of the pressure between the outside boundary and a position inside the TAS. LÄS MER

  4. 3. Dirichlet-to-Neumann maps and Nonlinear eigenvalue problems

    Kandidat-uppsats, KTH/Skolan för teknikvetenskap (SCI)

    Författare :Tindra Jernström; Anna Öhman; [2023]
    Nyckelord :Dirichlet-to-Neumann maps; Nonlinear eigenvalue problems; Absorbing boundary conditions;

    Sammanfattning : Differential equations arise frequently in modeling of physical systems, often resulting in linear eigenvalue problems. However, when dealing with large physical domains, solving such problems can be computationally expensive. LÄS MER

  5. 4. Analys av ljudabsorberande spaltpaneler med varierande spjälbredd : En studie med mål att tillförse mätdata samt analysera stående våg över spjälbredd

    Kandidat-uppsats, KTH/Skolan för elektroteknik och datavetenskap (EECS)

    Författare :Johan Wangärd; Arthur Öhman; [2023]
    Nyckelord :Akustik; Spaltpanel; Membranabsorbent; Ljudabsorption; Helmholtzresonans;

    Sammanfattning : This study is based on a hypothesis from Delta Akustik AB regarding standing waves in slotted panels and the requisite for measurement data regarding its sound absorption. The purpose is to acquire measurement data and to examine three types of slotted panels and the possibility of a standing wave vertically in the boards. LÄS MER

  7. 5. Implementation and study of boundary integral operators related to PDE:s in the plane

    Master-uppsats, Lunds universitet/Matematik LTH

    Författare :Erik Andersson; [2023]
    Nyckelord :Boundary integral equation; Singular integral operator; Product integration; Close evaluation; Numerical integration; MATLAB; Mathematics and Statistics;

    Sammanfattning : The method of solving boundary value problems of partial differential equations numerically by first reformulating the problem as a boundary integral equation has many advantages over other methods, but also some unique difficulties. Some of these difficulties stem from problems in evaluating singular or nearly singular integral operators, and solving these difficulties is an active field of research. LÄS MER