scholarly journals Computer simulation of radiation-induced late effects by "system dynamics"

1986 ◽  
Vol 27 (2) ◽  
pp. 230-239 ◽  
Author(s):  
TAKASHI AOYAMA ◽  
AKIRA IMAMURA ◽  
HIDETOSHI MATSUBARA ◽  
TAKESHI IMAMURA ◽  
TSUTOMU SUGAHARA
Keyword(s):  
Computer Simulation ◽  
System Dynamics ◽  
Late Effects ◽  
Radiation Induced

А Computer Simulation of Radiation-Induced Structural Changes and Properties of Multiperiod ZrNx/MoNx System

2017 ◽  
Vol 9 (2) ◽  
pp. 02031-1-02031-5
Author(s):  
O. V. Sobol ◽  
◽  
A. A. Meylekhov ◽  
T. V. Bochulia ◽  
V. A. Stolbovoy ◽  
...  
Keyword(s):  
Computer Simulation ◽  
Structural Changes ◽  
Radiation Induced

scholarly journals Acute Skin Damage and Late Radiation-Induced Fibrosis and Inflammation in Murine Ears after High-Dose Irradiation

Cancers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 727 ◽  
Author(s):  
Annique C. Dombrowsky ◽  
Jannis Schauer ◽  
Matthias Sammer ◽  
Andreas Blutke ◽  
Dietrich W. M. Walsh ◽  
...  
Keyword(s):  
Transforming Growth Factor Beta ◽  
Late Effects ◽  
Transforming Growth Factor ◽  
Scoring Systems ◽  
High Dose ◽  
Skin Damage ◽  
Fractional Dose ◽  
Radiation Induced ◽  
Tissue Alterations ◽  
Dose Dependent

The use of different scoring systems for radiation-induced toxicity limits comparability between studies. We examined dose-dependent tissue alterations following hypofractionated X-ray irradiation and evaluated their use as scoring criteria. Four dose fractions (0, 5, 10, 20, 30 Gy/fraction) were applied daily to ear pinnae. Acute effects (ear thickness, erythema, desquamation) were monitored for 92 days after fraction 1. Late effects (chronic inflammation, fibrosis) and the presence of transforming growth factor beta 1 (TGFβ1)-expressing cells were quantified on day 92. The maximum ear thickness displayed a significant positive correlation with fractional dose. Increased ear thickness and erythema occurred simultaneously, followed by desquamation from day 10 onwards. A significant dose-dependency was observed for the severity of erythema, but not for desquamation. After 4 × 20 and 4 × 30 Gy, inflammation was significantly increased on day 92, whereas fibrosis and the abundance of TGFβ1-expressing cells were only marginally increased after 4 × 30 Gy. Ear thickness significantly correlated with the severity of inflammation and fibrosis on day 92, but not with the number of TGFβ1-expressing cells. Fibrosis correlated significantly with inflammation and fractional dose. In conclusion, the parameter of ear thickness can be used as an objective, numerical and dose-dependent quantification criterion to characterize the severity of acute toxicity and allow for the prediction of late effects.

Radiation-Induced Systemic and Local Bone Tumors: Two Types of Late Effects with Possible Different Origins?

1994 ◽  
Vol 138 (3) ◽  
pp. 415 ◽  
Author(s):  
W. A. Müller ◽  
A. Luz ◽  
U. Linzner ◽  
W. A. Muller
Keyword(s):  
Late Effects ◽  
Bone Tumors ◽  
Local Bone ◽  
Radiation Induced ◽  
Different Origins

Introduction to Computer Simulation—A System Dynamics Modeling Approach

1997 ◽  
Vol 48 (11) ◽  
pp. 1145-1145 ◽  
Author(s):  
N Roberts ◽  
D Anderson ◽  
R Deal ◽  
M Garet ◽  
W Shaffer
Keyword(s):  
Computer Simulation ◽  
System Dynamics ◽  
System Dynamics Modeling ◽  
Dynamics Modeling ◽  
Modeling Approach

Damped Absorber Optimization and Stability for Semi-Definite Systems Exhibiting Unstable Self-Excitation During Start-Up

1992 ◽  
Vol 114 (1) ◽  
pp. 47-53 ◽  
Author(s):  
J. R. Shadley ◽  
J. R. Sorem
Keyword(s):  
Computer Simulation ◽  
System Dynamics ◽  
Laboratory Testing ◽  
Submersible Pump ◽  
Safe Operation ◽  
Pump System ◽  
Electric Induction ◽  
First Case ◽  
Start Up ◽  
Electric Submersible Pump

Stability is examined with respect to the torque in the elastic element between motor and load in semi-definite systems exhibiting unstable self-excitation during start-up. Equations are provided for optimizing a motor-mounted damped absorber to minimize the torque fluctuations in the shafting between motor and load in semi-definite systems. Minimum damper inertia needed to stabilize the system is computed assuming optimum damping. Stability and damper optimization equations are applied to two cases involving unstable self-excitation in electric submersible pump systems. In the first case, unstable growth of torque amplitude in shafting between an electric induction motor and an inertial load was observed during start-up in laboratory testing. A computer simulation of the system dynamics demonstrated that the torque could be stabilized by adding a damped absorber to the motor. In a computer simulation for the second case, unstable torque fluctuations in the shafting of an electric submersible pump system were dramatically reduced by the addition of a damped absorber; however, stability was not achieved until the damper inertia was sufficiently increased. Stability is not always required for safe operation of electric submersible pumps. A computational model of the system dynamics during startup should be used to determine when stability is required.

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