Sökning: "NATURVETENSKAP Fysik Atom- och molekylfysik"

Visar resultat 1 - 5 av 608 avhandlingar innehållade orden NATURVETENSKAP Fysik Atom- och molekylfysik.

  1. 1. Spectral Mammography with X-Ray Optics and a Photon-Counting Detector

    Detta är en avhandling från Stockholm : KTH

    Författare :Erik Fredenberg; KTH.; [2009]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; mammography; x-ray optics; photon counting; spectral shaping; spectral imaging; collimation; radiation dose; signal-to-noise ratio; quantum noise; anatomical noise; spatial resolution; x-ray flux; ; TECHNOLOGY; TEKNIKVETENSKAP; TECHNOLOGY Engineering physics; TEKNIKVETENSKAP Teknisk fysik; TECHNOLOGY Engineering physics Optical physics; TEKNIKVETENSKAP Teknisk fysik Optisk fysik; TECHNOLOGY Engineering physics Other engineering physics; TEKNIKVETENSKAP Teknisk fysik Övrig teknisk fysik; TECHNOLOGY Electrical engineering; electronics and photonics; TEKNIKVETENSKAP Elektroteknik; elektronik och fotonik; TECHNOLOGY Other technology Medical engineering; TEKNIKVETENSKAP Övriga teknikvetenskaper Medicinsk teknik; MEDICINE Physiology and pharmacology Radiological research; MEDICIN Fysiologi och farmakologi Radiologisk forskning;

    Sammanfattning : Early detection is vital to successfully treating breast cancer, and mammography screening is the most efficient and wide-spread method to reach this goal. Imaging low-contrast targets, while minimizing the radiation exposure to a large population is, however, a major challenge. LÄS MER

  2. 2. Synchrotron radiation studies of gas phase molecules from hydrogen to DNA sugars

    Detta är en avhandling från Stockholm : KTH

    Författare :Gemma Vall-llosera; KTH.; [2008]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURAL SCIENCES Physics Atomic and molecular physics; NATURVETENSKAP Fysik Atom- och molekylfysik; KTH thesis; synchrotron radiation; gas phase; bio molecules;

    Sammanfattning : This thesis summarises experimental results on the molecular spectroscopy of gas phase molecules excited by synchrotron radiation in the VUV and soft X-ray regions. We have used three different detection techniques, photon induced fluorescence spectroscopy, photoionisation mass spectroscopy and near edge X-ray absorption fine structure spectroscopy to study molecular deuterium, hydrogen sulphide, ammonia, methanol, pyridine, pyridazine, pyrimidine, pyrazine, s-triazine, and 2-deoxy-D-ribose, the last one also known as the DNA sugar. LÄS MER

  3. 3. Radial profiling using local and line integrated spectroscopic measurements

    Detta är en avhandling från Stockholm : KTH

    Författare :Mattias Kuldkepp; KTH.; [2005]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Atomic and molecular physics; Atom- och molekylfysik; NATURAL SCIENCES Physics Atomic and molecular physics; NATURVETENSKAP Fysik Atom- och molekylfysik;

    Sammanfattning : .... LÄS MER

  4. 4. Development and applications of theoretical algorithms for simulations of materials at extreme conditions

    Detta är en avhandling från Linköping : Linköping University Electronic Press

    Författare :Igor Mosyagin; Linköpings universitet.; Linköpings universitet.; [2017]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Materials at extreme conditions exhibit properties that differ substantially from ambient conditions. High pressure and high temperature expose anharmonic, non-linear behavior, and can provoke phase transitions among other effects. Experimental setups to study that sort of effects are typically costly and experiments themselves are laborious. LÄS MER

  5. 5. Fiber-laser-based noise-immune cavity-enhanced optical heterodyne molecular spectrometry

    Detta är en avhandling från Umeå : Umeå University

    Författare :Aleksandra Foltynowicz; Umeå universitet.; [2009]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; absorption spectrometry; frequency modulation; cavity enhancement; NICE-OHMS; Laser frequency stabilization; fiber laser; Fabry-Perot cavities; sub-Doppler spectroscopy; trace gas detection; NATURAL SCIENCES Physics; NATURVETENSKAP Fysik; NATURAL SCIENCES Physics Atomic and molecular physics Molecular physics; NATURVETENSKAP Fysik Atom- och molekylfysik Molekylfysik; fysik; Physics;

    Sammanfattning : Noise-immune cavity-enhanced optical heterodyne molecular spectro-metry (NICE-OHMS) is one of the most sensitive laser-based absorption techniques. The high sensitivity of NICE-OHMS is obtained by a unique combination of cavity enhancement (for increased interaction length with a sample) with frequency modulation spectrometry (for reduction of noise). LÄS MER