Sökning: "gamma-ray technique"

Visar resultat 1 - 5 av 12 avhandlingar innehållade orden gamma-ray technique.

  1. 1. A model for heat and mass transfer in timber structures during fire: a theoretical, numerical and experimental study

    Detta är en avhandling från Lund University, Department of Fire Safety Engineering

    Författare :Bertil Fredlund; [1988]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wood; pyrolysis; temperature; pressure; moisture content; finite element method; mass flow; permeability; gamma-ray technique; specific heat; charring; rate of heat release; heat production;

    Sammanfattning : A model has been formulated for the pyrolysis of wood. This model includes heat and mass transfer. Heat transfer in the material is assumed to take place by thermal conduction and convection. Mass transfer of volatile pyrolysis products and water vapour occurs under the influlence of gradients in to tal pressure. LÄS MER

  2. 2. Characterisation of the Neutron Wall and of Neutron Interactions in Germanium-Detector Systems

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Joa Ljungvall; Uppsala universitet.; [2005]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nuclear physics; High-purity Ge detectors; Liquid scintillator detectors; Neutron scattering; Digital electronics; Time-of-flight technique; Pulse-shape simulation and analysis; Monte Carlo simulations; Geant4; Gamma-ray tracking; AGATA; Neutron Wall; Kärnfysik; NATURAL SCIENCES Physics Nuclear physics; NATURVETENSKAP Fysik Kärnfysik;

    Sammanfattning : A Monte Carlo simulation of the Neutron Wall detector system has been performed using Geant4, in order to define optimum conditions for the detection and identification of multiple neutrons. Emphasis was put on studying the scattering of neutrons between different detectors, which is the main source of the apparent increase of the number of detected neutrons. LÄS MER

  3. 3. Applications of Gamma Ray Spectroscopy of Spent Nuclear Fuel for Safeguards and Encapsulation

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Christofer Willman; Uppsala universitet.; [2006]
    Nyckelord :Nuclear physics; gamma radiation; spectroscopy; spent nuclear fuel; safeguards; HRGS; MOX; Kärnfysik;

    Sammanfattning : Nuclear energy is currently one of the world’s main sources of electricity. Closely connected to the use of nuclear energy are important issues such as the nonproliferation of fissile material that may potentially used in nuclear weapons (safeguards), and the management of the highly radioactive nuclear waste. LÄS MER

  4. 4. Collective Excitations in Transitional Nuclei Studied by Means of gamma-ray Spectroscopy and Lifetime Measurements

    Detta är en avhandling från Stockholm : KTH Royal Institute of Technology

    Författare :Hongjie Li; KTH.; [2015]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Despite that it is more than 100 years since the atomic nucleus was first dis- covered by Ernest Rutherford and coworkers, many of its features still elude our understanding. The fact that the fundamental interactions between the nuclear constituents; nucleons, and ultimately quarks, are not yet known in detail, and the complexity of the nuclear many-body system compound the great challenges facing theoretical interpretations of experimental data. LÄS MER

  5. 5. Studies of collective phenomena in neutron deficient nuclei by means of lifetime measurements, angular correlation measurements and the recoil-decay tagging technique

    Detta är en avhandling från Stockholm : KTH

    Författare :Karin Andgren; KTH.; [2008]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; heavy-ion reactions; multi-detector arrays; recoil separator; in-beam gamma-ray spectroscopy; high spin states; lifetime measurements; recoil-decay tagging; nuclear shape; NATURAL SCIENCES Physics Nuclear physics; NATURVETENSKAP Fysik Kärnfysik;

    Sammanfattning : The nucleus is a mesoscopic system that retains features from both the quantum and macroscopic worlds. A basic property of a macroscopic body is its shape. Nuclear shapes can be deduced from experimental data as they influence the excitation mode of the nucleus and hence the energies and lifetimes of its excited levels. LÄS MER