Sökning: "Velocity map imaging"

Visar resultat 1 - 5 av 11 avhandlingar innehållade orden Velocity map imaging.

1. 1. Near-ambient pressure velocity map imaging

   Författare :Tzu-En Chien; Dan Harding; Klas Engvall; Rainer Beck; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Catalyst; Surface reaction; Near-ambient pressure; CO; CO2; CO oxidation; Pd; Palladium; Instrument design; Velocity-map imaging; Katalysator; Ytreaktion; Näraomgivningstryck; CO; CO2; CO oxidation; Pd; Palladium; Instrumentdesign; Hastighetskartbildning; Chemical Engineering; Kemiteknik;

   Sammanfattning : Catalytic reactions on solid surfaces have been studied under Ultra-high vacuum (UHV) conditions for decades. These studies provide crucial information for catalytic reactions, such as surface structures, adsorption sites, and reaction mechanisms. LÄS MER

3. 2. Application of the Seismic Reflection Method in Mineral Exploration and Crustal Imaging : Contributions to Hardrock Seismic Imaging

   Författare :Omid Ahmadi; Christopher Juhlin; Alireza Malehmir; Gilles Bellefleur; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Seismic reflection; Hardrock; Mineral exploration; Crustal imaging; Interpretation; Modeling; Geofysik med inriktning mot fasta jordens fysik; Geophysics with specialization in Solid Earth Physics;

   Sammanfattning : The seismic reflection method has been used extensively in mineral exploration and for imaging crustal structures within hardrock environments. In this research the seismic reflection method has been used and studied to address problems associated with hardrock settings. LÄS MER

4. 3. Investigation of Ultrafast Molecular Dynamics via Covariance Mapping : A Tool for Intense XUV Light Sources

   Författare :Jan Lahl; Atomfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Covariance; Ultrafast; High-order harmonic generation; Extreme Ultraviolet; Pump probe; FLASH; Velocity map imaging; wavefront; FEL; photodissociation; Coulomb explosion; Fysicumarkivet A:2019:Lahl;

   Sammanfattning : The study of molecular dynamics involves observations of the motion of nuclei and electrons. While nuclear motion is usually on the picosecond or femtosecond timescale, attosecond precision is necessary to directly observe the motion of electrons. LÄS MER

5. 4. An Intense Attosecond Light Source - from Generation to Application

   Författare :Linnea Rading; Atomfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; High-order Harmonic Generation; Intense XUV pulses; Velocity map imaging spectrometer; Fysicumarkivet A:2017:Rading;

   Sammanfattning : Short and intense XUV pulses are important tools to study ultrafast dynamics and non-linear processes in matter. These pulses can be generated by free electron lasers (FELs) or by high-order harmonic generation (HHG), which are two complementary techniques. LÄS MER

7. 5. Power Doppler - Principles and Potential Clinical Applications

   Författare :Anders Nilsson; PG Lindgren; Torbjörn Andersson; Uppsala universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Radiology; Ultrasonography; Doppler studies; Power Doppler; Volume flow; Radiologisk forskning; Radiological research; Radiologisk forskning;

   Sammanfattning : The purpose of this work was to: a) Determine whether the amount of colour in a power Doppler image is dependent on the angle between the examined vessel and the soundbeam and/or on the velocity of the flow within the vessel; b) Investigate if a dependency on flow velocity could be used for the detection of volume flow differences and c) Define clinical applications utilising the improved sensitivity to low flow of PD.In the experimental studies (study I and II) a silicon tube in a water bath was insonated, the insonation angle and the volume flow changed and the resulting images stored, transferred to a personal computer and analysed with regard to the amount of colour present in the image. LÄS MER