Sökning: "phase contrast"

Visar resultat 1 - 5 av 410 avhandlingar innehållade orden phase contrast.

  1. 1. High-resolution biomedical phase-contrast tomography

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

    Författare :William Twengström; KTH.; [2018]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; x-ray; x-ray imaging; biomedical; phase contrast; tomography; zebrafish; coronary artery; virtual histology; ring artifacts; phase retrieval; mummy; Physics; Fysik;

    Sammanfattning : Improved three-dimensional biomedical imaging can give a better understanding of tissue structure, growth and diseases. Most present imaging techniques that provide cellular spatial resolution are based on visible or infrared light. These methods cannot image deeper than a millimeter into tissue. LÄS MER

  2. 2. Laboratory X-Ray Phase-Contrast Imaging Methods and Comparisons

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

    Författare :Tunhe Zhou; KTH.; [2016]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; X-ray imaging; Phase-contrast; Liquid-metal-jet source; Propagation-based imaging; Grating-based imaging; Speckle-based imaging; Physics; Fysik;

    Sammanfattning : X-ray phase-contrast imaging has seen rapid development in recent decades due to its superior performance in imaging low-absorption objects, compared to traditional attenuation x-ray imaging. Having higher demand on coherence, x-ray phase-contrast imaging is performed mostly at synchrotrons. LÄS MER

  3. 3. Liquid-Jet-Target Microfocus X-Ray Sources Electron Guns, Optics and Phase-Contrast Imaging

    Detta är en avhandling från Stockholm : KTH

    Författare :Tomi Tuohimaa; KTH.; [2008]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; electron-impact; x-ray; brightness; liquid-jet-target; phase-contrast imaging; TECHNOLOGY Engineering physics; TEKNIKVETENSKAP Teknisk fysik;

    Sammanfattning : This Thesis describes the development of an electron-impact microfocus x-ray source and its application for phase-contrast imaging. The source is based on a novel, liquid-jet target concept. Stable and continuous operation can be achieved at substantially higher electron-beam power densities than conventional solid target based systems. LÄS MER

  4. 4. Phase Noise in Communication Systems--Modeling, Compensation, and Performance Analysis

    Detta är en avhandling från Stockholm : KTH

    Författare :M Reza Khanzadi; [2015]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; multiple antennas; distributed oscillators.; colored phase noise; free-running oscillator; Bayesian Cramér-Rao bound; Oscillator phase noise; phase noise model; channel capacity; mean square error; capacity achieving distribution; Wiener process; extended Kalman filter smoother; maximum a posteriori estimator; phase-locked loop;

    Sammanfattning : The continuous increase in demand for higher data rates due to applications with massive number of users motivates the design of faster and more spectrum efficient communication systems. In theory, the current communication systems must be able to operate close to Shannon capacity bounds. LÄS MER

  5. 5. Ultrasound Contrast Agents Loaded with Magnetic Nanoparticles Acoustic and Mechanical Characterization

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

    Författare :VeeraVenkata Satyanarayana Kothapalli; KTH.; [2013]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Ultrasound contrast agents; SPION nanoparticles; harmonic oscillation; backscattering power; attenuation coefficient; phase velocity; nonlinear equation of motion;

    Sammanfattning : The current methodologies in body scanning diagnostic uses different simultaneous imaging modalities like Ultrasound (US), magnetic resonance imaging (MRI), single photon emission tomography (SPECT) and positron emission tomography (PET). The field requires combination of different modalities for effective use in clinical diagnostics. LÄS MER