Optimized 2-D NUFFTs for Spiral Scanning in MRI

2021 ◽  
Vol 2 ◽  
Keyword(s):  
Spiral Scanning

A silver/graphene oxide nanocomposite film as a flexible SERS substrate for reliable quantitative analysis using high-speed spiral scanning spectrometry

2017 ◽  
Vol 53 (73) ◽  
pp. 10108-10111 ◽  
Author(s):  
Yejung Choi ◽  
Si Won Song ◽  
Wytse Hooch Antink ◽  
Hyung Min Kim ◽  
Yuanzhe Piao
Keyword(s):  
Graphene Oxide ◽  
Quantitative Analysis ◽  
Nanocomposite Film ◽  
High Speed ◽  
Scanning System ◽  
Adhesive Tape ◽  
Sers Substrate ◽  
Spiral Scanning ◽  
System P

Excellent uniformity (∼1.5% RSD) in SERS signals was obtained from an Ag/GO decorated adhesive tape on a simple in-house cylindrical scanning system.

Трехмерная рентгеновская томография промышленных объектов при ограниченных размерах регистрирующего экрана

2021 ◽  
pp. 54-62
Author(s):  
В.П. Карих ◽  
Б.В. Певченко ◽  
А.В. Курбатов ◽  
А.А. Охотников ◽  
А.А. Скоков
Keyword(s):  
3D Reconstruction ◽  
Cross Section ◽  
Test Object ◽  
Reconstruction Algorithm ◽  
Scanning Method ◽  
Spiral Scanning ◽  
Arbitrarily Oriented Crack ◽  
Principal Possibility

The article investigates the possibilities of using a 3D tomograph with a limited-sizes registering screen for detecting arbitrarily oriented crack-like defects in large industrial objects. Circular and spiral scanning schemes are considered, the principal possibility of detecting defects in the case of two-pass spiral scanning and a registering screen covering half of the view field of the test object cross-section is shown. The performance of the 3D reconstruction algorithm for the selected scanning method has been demonstrated.

scholarly journals Precision controlled atomic resolution scanning transmission electron microscopy using spiral scan pathways

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Xiahan Sang ◽  
Andrew R. Lupini ◽  
Jilai Ding ◽  
Sergei V. Kalinin ◽  
Stephen Jesse ◽  
...  
Keyword(s):  
Linear Velocity ◽  
Atomic Resolution ◽  
Characteristic Functions ◽  
Precise Control ◽  
Spiral Scanning ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Spiral Scan ◽  
Aberration Corrected

Abstract Atomic-resolution imaging in an aberration-corrected scanning transmission electron microscope (STEM) can enable direct correlation between atomic structure and materials functionality. The fast and precise control of the STEM probe is, however, challenging because the true beam location deviates from the assigned location depending on the properties of the deflectors. To reduce these deviations, i.e. image distortions, we use spiral scanning paths, allowing precise control of a sub-Å sized electron probe within an aberration-corrected STEM. Although spiral scanning avoids the sudden changes in the beam location (fly-back distortion) present in conventional raster scans, it is not distortion-free. “Archimedean” spirals, with a constant angular frequency within each scan, are used to determine the characteristic response at different frequencies. We then show that such characteristic functions can be used to correct image distortions present in more complicated constant linear velocity spirals, where the frequency varies within each scan. Through the combined application of constant linear velocity scanning and beam path corrections, spiral scan images are shown to exhibit less scan distortion than conventional raster scan images. The methodology presented here will be useful for in situ STEM imaging at higher temporal resolution and for imaging beam sensitive materials.

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