Sökning: "peak-to-valley methods"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden peak-to-valley methods.

  1. 1. On-line Mobile in situ Gamma Spectrometry

    Författare :Thomas Hjerpe; Lund Medicinsk strålningsfysik; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; radiobiologi; Kärnfysik; Nuclear physics; radiation protection.; 137Cs; peak-to-valley method; depth distribution; orphan source search; orphan sources; emergency preparedness; mobile gamma spectrometry; nuclear accidents; Nuclear medicine; radiobiology; Nukleärmedicin;

    Sammanfattning : Mobile in situ gamma spectrometry is an important instrument in the emergency preparedness for nuclear accidents. This work contributes through the development of strategies and analysis methods for two applications: an on-line search for gamma-emitting orphan sources and on-line estimation of the depth distribution of 137Cs. LÄS MER

  3. 2. Methods for localizing and quantifying radionuclide sources and deposition using in situ gamma spectrometry : Critical review of the peak-to-valley method based on experimental studies and applications in Georgia and Japan

    Författare :Karl Östlund; Malmö Medicinsk strålningsfysik; []
    Nyckelord :In situ gamma spectrometry;

    Sammanfattning : This thesis describes investigations made on mobile and stationary gammaspectrometry made both under laboratory conditions and in situ. The objective hasbeen to identify and quantify radionuclides in the form of point sources,contamination and widespread deposition in situations where the measurementgeometry is not known beforehand. LÄS MER

  4. 3. Methods for Characterisation of Pressing Die Surfaces

    Författare :Johan C Berglund; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; finish milling; scale-sensitive fractal analysis; surface characterisation; polishing; functional correlation; : pressing dies; functional filtration; surface roughness; functional surface;

    Sammanfattning : Design and manufacture of dies and moulds is a critical aspect of many production systems since the manufacturing and try-out of new dies and moulds often is essential in determining the lead-time and quality of a new production system. In the automotive industry, many new car models are introduced each year and for each of these models, a new set of pressing dies has to be designed and manufactured. LÄS MER

  5. 4. Electrical Characterization of Silicon Nanogaps

    Författare :Jonas Berg; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Organic molecules; Molecular electronics; Surface leakage currents; Low-frequency noise; Soft breakdown; TSRAM; Resonant tunneling diodes; Selective etching; Silicon nanogaps; Nanocontacts;

    Sammanfattning : We have designed and manufactured silicon nanogaps aimed at electrically interfacing molecules, utilizing the precision thickness control in an oxidation process. An insulating layer was formed on a silicon wafer, and then polysilicon was deposited on top. LÄS MER

  7. 5. Quantum Devices from the Assembly of Zero- and One-Dimensional Building Blocks

    Författare :Claes Thelander; Fasta tillståndets fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; quantum devices; classical mechanics; quantum mechanics; relativity; statistical physics; thermodynamics; Matematisk och allmän teoretisk fysik; klassisk mekanik; kvantmekanik; relativitet; gravitation; termodynamik; statistisk fysik; Mathematical and general theoretical physics; single-electron transistor; nanowires; AFM; carbon nanotubes; Fysicumarkivet A:2003:Thelander;

    Sammanfattning : This thesis describes novel methods for the fabrication of nanometer-scale electronic devices, such as single-electron transistors and resonant tunneling diodes, from wire- and dot-shaped building blocks. The first part of the thesis describes the manipulation of metal nanoparticles and carbon nanotubes using an atomic force microscope. LÄS MER