MO-FG-303-01: FEATURED PRESENTATION and BEST IN PHYSICS (THERAPY): Automating LINAC QA: Design and Testing of An Image Acquisition and Processing System Utilizing a Combination of Radioluminescent Phosphors, Embedded X-Ray Markers and Optical Measurements

2015 ◽  
Vol 42 (6Part29) ◽  
pp. 3566-3567
Author(s):  
C Jenkins ◽  
D Naczynski ◽  
S Yu ◽  
L Xing
Keyword(s):  
Image Acquisition ◽  
Processing System ◽  
Optical Measurements ◽  
X Ray ◽  
Design And Testing

Scanning x-ray fluorescence microscopy and principal component analysis

1992 ◽  
Vol 50 (2) ◽  
pp. 1752-1753
Author(s):  
Brian Cross
Keyword(s):  
Principal Component Analysis ◽  
Fluorescence Microscopy ◽  
Spatial Resolution ◽  
High Speed ◽  
Image Acquisition ◽  
Principal Component ◽  
Fluorescence Microscope ◽  
Acquisition Rate ◽  
X Ray ◽  
Speed Up

A relatively new entry, in the field of microscopy, is the Scanning X-Ray Fluorescence Microscope (SXRFM). Using this type of instrument (e.g. Kevex Omicron X-ray Microprobe), one can obtain multiple elemental x-ray images, from the analysis of materials which show heterogeneity. The SXRFM obtains images by collimating an x-ray beam (e.g. 100 μm diameter), and then scanning the sample with a high-speed x-y stage. To speed up the image acquisition, data is acquired "on-the-fly" by slew-scanning the stage along the x-axis, like a TV or SEM scan. To reduce the overhead from "fly-back," the images can be acquired by bi-directional scanning of the x-axis. This results in very little overhead with the re-positioning of the sample stage. The image acquisition rate is dominated by the x-ray acquisition rate. Therefore, the total x-ray image acquisition rate, using the SXRFM, is very comparable to an SEM. Although the x-ray spatial resolution of the SXRFM is worse than an SEM (say 100 vs. 2 μm), there are several other advantages.

scholarly journals Upconversion Spectral Rulers for Transcutaneous Displacement Measurements

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3554
Author(s):  
Melissa M. Suckey ◽  
Donald W. Benza ◽  
John D. DesJardins ◽  
Jeffrey N. Anker
Keyword(s):  
Optical Measurement ◽  
Optical Measurements ◽  
Small Displacement ◽  
Simple Method ◽  
Low Background ◽  
X Ray ◽  
Optical Displacement ◽  
Spectral Peaks ◽  
Displacement Measurements ◽  
Minimal Intensity

We describe a method to measure micron to millimeter displacement through tissue using an upconversion spectral ruler. Measuring stiffness (displacement under load) in muscles, bones, ligaments, and tendons is important for studying and monitoring healing of injuries. Optical displacement measurements are useful because they are sensitive and noninvasive. Optical measurements through tissue must use spectral rather than imaging approaches because optical scattering in the tissue blurs the image with a point spread function typically around the depth of the tissue. Additionally, the optical measurement should have low background and minimal intensity dependence. Previously, we demonstrated a spectral encoder using either X-ray luminescence or fluorescence, but the X-ray luminescence required an expensive X-ray source and used ionizing radiation, while the fluorescence sensor suffered from interference from autofluorescence. Here, we used upconversion, which can be provided with a simple fiber-coupled spectrometer with essentially autofluorescence-free signals. The upconversion phosphors provide a low background signal, and the use of closely spaced spectral peaks minimizes spectral distortion from the tissue. The small displacement noise level (precision) through tissue was 2 µm when using a microscope-coupled spectrometer to collect light. We also showed proof of principle for measuring strain on a tendon mimic. The approach provides a simple method to study biomechanics using implantable sensors.

Towards a revisitation of vesuvianite-group nomenclature: the crystal structure of Ti-rich vesuvianite from Alchuri, Shigar Valley

2016 ◽  
Vol 72 (5) ◽  
pp. 744-752 ◽  
Author(s):  
Sergey M. Aksenov ◽  
Nikita V. Chukanov ◽  
Vyacheslav S. Rusakov ◽  
Taras L. Panikorovskii ◽  
Ramiza K. Rastsvetaeva ◽  
...  
Keyword(s):  
Octahedral Site ◽  
Structure Refinement ◽  
Optical Measurements ◽  
Transition Elements ◽  
X Ray ◽  
Cell Parameters ◽  
Tetragonal Unit Cell ◽  
Northern Areas ◽  
Shigar Valley

Vesuvianite containing 5.85 wt% TiO2from an Alpine-cleft-type assemblage outcropped near Alchuri, Shigar Valley, Northern Areas, has been investigated by means of electron microprobe analyses, gas-chromatographic analysis of H2O, X-ray powder diffraction, single-crystal X-ray structure refinement,27Al NMR,57Fe Mössbauer spectroscopy, IR spectroscopy and optical measurements. Tetragonal unit-cell parameters are:a= 15.5326 (2),c= 11.8040 (2) Å, space groupP4/nnc. The structure was refined to finalR1= 0.031,wR2= 0.057 for 11247I> 2σ(I). A general crystal-chemical formula of studied sample can be written as follows (Z= 2):[8–9](Ca17.1Na0.9)[8]Ca1.0[5](Fe2+0.44Fe3+0.34Mg0.22)[6](Al3.59Mg0.41)[6](Al4.03Ti2.20Fe3+1.37Fe2+0.40) (Si18O68) [(OH)5.84O2.83F1.33]. The octahedral siteY2 is Al-dominant and does not contain transition elements. Another octahedral siteY3 is also Al-dominant and contains Fe2+, Fe3+and Ti. The siteY1 is split intoY1aandY1bpredominantly occupied by Fe2+and Fe3+, respectively. The role of theY1 site in the diversity of vesuvianite-group minerals is discussed.

scholarly journals Low-temperature hydrothermal synthesis of hierarchical flower-like CuB2O4 superstructures

2020 ◽  
Vol 14 (2) ◽  
pp. 113-118
Author(s):  
Daniel Ursu ◽  
Anamaria Dabici ◽  
Marinela Miclau ◽  
Nicolae Miclau
Keyword(s):  
Thermal Stability ◽  
Low Temperature ◽  
Self Assembly ◽  
Hydrothermal Solution ◽  
Optical Measurements ◽  
Oriented Attachment ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
One Step

We report for the first time the fabrication of hierarchical ordered superstructure CuB2O4 with flower-like morphology via a one-step, low temperature hydrothermal method. The tetragonal structure of CuB2O4 was determined by X-ray diffraction and high-resolution transmission electron microscopy. Optical measurements attested of the quality of the fabricated CuB2O4 and high temperature X-ray diffraction confirmed its thermal stability up to 600 ?C. The oriented attachment growth and the hierarchical self-assembly of micrometer-sized platelets producing hierarchical superstructures with flower-like morphology are designed by pH of the hydrothermal solution. The excellent band gap, high thermal stability and hierarchical structure of the CuB2O4 are promising for the photovoltaic and photocatalytic applications.

Relationships between molecular structure and physical properties in bent-core mesogens

2006 ◽  
Vol 364 (1847) ◽  
pp. 2657-2679 ◽  
Author(s):  
Wolfgang Weissflog ◽  
H.N Shreenivasa Murthy ◽  
Siegmar Diele ◽  
Gerhard Pelzl
Keyword(s):  
Optical Measurements ◽  
Polar Phase ◽  
X Ray Diffraction ◽  
Aromatic Rings ◽  
Scanning Calorimetry ◽  
Polarizing Microscopy ◽  
X Ray ◽  
Smectic Phases ◽  
Collective Rotation ◽  
Clear Change

New five-ring bent-core mesogens that possess only ester connecting groups between the aromatic rings and different lateral substituents at the central phenyl ring are presented. The mesophases have been assigned by polarizing microscopy, differential scanning calorimetry, X-ray diffraction and electro-optical measurements. It is shown that the mesophase behaviour depends strongly on the position of the lateral substituents. Compounds, which are derived from 4-cyano-, 4-chloro- and 4,6-dichloro-resorcinol, show polymorphism variants where polar phases (SmAP, SmCP) occur together with nematic and conventional smectic phases, e.g. SmA–SmAP, SmA–SmC S P A –Col ob –SmC S P A , N–SmA–SmCP A , SmA–SmC–SmCP A and SmC–SmCP A . On the basis of the behaviour of two series of materials, the occurrence of different polar-switching mechanisms could be demonstrated. Apart from the usual mechanism by director rotation around the tilt cone, the polar switching can also take place through collective rotation of the molecules around their long axes, which corresponds to a field-induced switching of the layer chirality. A remarkable finding is the polar switching in the crystalline modification of long-chain, bent-core compounds with a methyl group in 2-position, which is accompanied by a clear change of the optical texture and by a relatively high switching polarization (approx. 600 nC cm −2 ). It was found for selected bent-core compounds that, above the transition temperature of a polar to a non-polar phase, the non-polar phase can be transformed to the polar phase by application of an electric field, which was proved for the transitions isotropic–SmCP F , SmA–SmCP F and isotropic–CrII polar.

High-Speed Visible Image Acquisition and Processing System for Plasma Shape and Position Control of EAST Tokamak

2018 ◽  
Vol 46 (5) ◽  
pp. 1312-1317 ◽  
Author(s):  
Heng Zhang ◽  
Bingjia Xiao ◽  
Zhengping Luo ◽  
Qin Hang ◽  
Jianhua Yang
Keyword(s):  
High Speed ◽  
Position Control ◽  
Image Acquisition ◽  
Processing System ◽  
Visible Image
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