Assessment of Radiation Background Suppression Using Phoswich Detectors for In Vivo Pb-210 Measurements: A Simulation Study

2021 ◽  
pp. 1-8
Author(s):  
Xiangpeng Meng ◽  
Yuanyuan Liu ◽  
Bin Wu ◽  
Jianping Cheng ◽  
Li Wang ◽  
...  
Keyword(s):  
Simulation Study ◽  
Background Suppression ◽  
Radiation Background ◽  
Phoswich Detectors

scholarly journals Effects of Loading and Boundary Conditions on the Performance of Ultrasound Compressional Viscoelastography: A Computational Simulation Study to Guide Experimental Design

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2590
Author(s):  
Che-Yu Lin ◽  
Ke-Vin Chang
Keyword(s):  
Boundary Conditions ◽  
Simulation Study ◽  
Viscoelastic Properties ◽  
Measurement Accuracy ◽  
Computational Simulation ◽  
Vertical Direction ◽  
Fixation Method ◽  
Element Analysis ◽  
Sample Container

Most biomaterials and tissues are viscoelastic; thus, evaluating viscoelastic properties is important for numerous biomedical applications. Compressional viscoelastography is an ultrasound imaging technique used for measuring the viscoelastic properties of biomaterials and tissues. It analyzes the creep behavior of a material under an external mechanical compression. The aim of this study is to use finite element analysis to investigate how loading conditions (the distribution of the applied compressional pressure on the surface of the sample) and boundary conditions (the fixation method used to stabilize the sample) can affect the measurement accuracy of compressional viscoelastography. The results show that loading and boundary conditions in computational simulations of compressional viscoelastography can severely affect the measurement accuracy of the viscoelastic properties of materials. The measurement can only be accurate if the compressional pressure is exerted on the entire top surface of the sample, as well as if the bottom of the sample is fixed only along the vertical direction. These findings imply that, in an experimental validation study, the phantom design should take into account that the surface area of the pressure plate must be equal to or larger than that of the top surface of the sample, and the sample should be placed directly on the testing platform without any fixation (such as a sample container). The findings indicate that when applying compressional viscoelastography to real tissues in vivo, consideration should be given to the representative loading and boundary conditions. The findings of the present simulation study will provide a reference for experimental phantom designs regarding loading and boundary conditions, as well as guidance towards validating the experimental results of compressional viscoelastography.

Simulation Study of a Combined Pair Production – Compton Camera for In-Vivo Dosimetry During Therapeutic Proton Irradiation

2015 ◽  
Vol 62 (5) ◽  
pp. 2023-2030 ◽  
Author(s):  
H. Rohling ◽  
C. Golnik ◽  
W. Enghardt ◽  
F. Hueso-Gonzalez ◽  
T. Kormoll ◽  
...  
Keyword(s):  
Pair Production ◽  
Simulation Study ◽  
Proton Irradiation ◽  
In Vivo Dosimetry ◽  
Compton Camera

scholarly journals Characterization of prompt gamma ray emission for in vivo range verification in particle therapy: A simulation study

2019 ◽  
Vol 62 ◽  
pp. 20-32 ◽  
Author(s):  
Melek Zarifi ◽  
Susanna Guatelli ◽  
Yujin Qi ◽  
David Bolst ◽  
Dale Prokopovich ◽  
...  
Keyword(s):  
Simulation Study ◽  
Gamma Ray ◽  
Particle Therapy ◽  
Prompt Gamma ◽  
Gamma Ray Emission ◽  
Range Verification

Heparin-reduced graphene oxide nanocomposites for curcumin delivery: in vitro, in vivo and molecular dynamics simulation study

2019 ◽  
Vol 7 (3) ◽  
pp. 1011-1027 ◽  
Author(s):  
Xiaoqun Shi ◽  
Yang Wang ◽  
Haiyan Sun ◽  
Yujuan Chen ◽  
Xingzhen Zhang ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Graphene Oxide ◽  
Molecular Dynamics Simulation ◽  
Reduced Graphene Oxide ◽  
Simulation Study ◽  
Dynamics Simulation ◽  
Reduced Graphene

We fabricated novel rGO-based nanocomposites and analyzed their interaction with drug and proteins via a molecular dynamics study.

scholarly journals Simultaneous SAXS/SANS Method at D22 of ILL: Instrument Upgrade

2021 ◽  
Vol 11 (13) ◽  
pp. 5925
Author(s):  
Ezzeldin Metwalli ◽  
Klaus Götz ◽  
Tobias Zech ◽  
Christian Bär ◽  
Isabel Schuldes ◽  
...  
Keyword(s):  
Structural Model ◽  
Structural Information ◽  
High Energy ◽  
Scattering Data ◽  
Background Suppression ◽  
Experimental Conditions ◽  
Radiation Background ◽  
Saxs Data ◽  
X Ray ◽  
Sans Data

A customized portable SAXS instrument has recently been constructed, installed, and tested at the D22 SANS instrument at ILL. Technical characteristics of this newly established plug-and-play SAXS system have recently been reported (J. Appl. Cryst. 2020, 53, 722). An optimized lead shielding arrangement on the SAXS system and a double energy threshold X-ray detector have been further implemented to substantially suppress the unavoidable high-energy gamma radiation background on the X-ray detector. The performance of the upgraded SAXS instrument has been examined systematically by determining background suppression factors (SFs) at various experimental conditions, including different neutron beam collimation lengths and X-ray sample-to-detector distances (SDDX-ray). Improved signal-to-noise ratio SAXS data enables combined SAXS and SANS measurements for all possible experimental conditions at the D22 instrument. Both SAXS and SANS data from the same sample volume can be fitted simultaneously using a common structural model, allowing unambiguous interpretation of the scattering data. Importantly, advanced in situ/real time investigations are possible, where both the SAXS and the SANS data can reveal time-resolved complementary nanoscale structural information.

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