Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Radiation Pressure: Problem Solving01:09

Radiation Pressure: Problem Solving

702
The radiation pressure applied by an electromagnetic wave on a perfectly absorbing surface equals the energy density of the wave. The wave's momentum also gets transferred to the surface when an electromagnetic wave is entirely absorbed by it. The rate at which momentum is transmitted to an absorbing surface perpendicular to the propagation direction equals the force on the surface.
The average value of the rate of momentum transfer divided by the absorbing area represents the average force...
702
Method of Superposition01:20

Method of Superposition

1.6K
The method of superposition is a crucial technique in structural engineering, used to analyze the effect of multiple loads on beams. This approach involves calculating the deflection and slope for each load on a beam separately, and then summing these effects to determine the overall impact. It is applicable only when the beam material remains within its elastic limit, ensuring that deformations are linearly elastic.
When applying the method of superposition, each type of load—whether...
1.6K
Beams with Symmetric Loadings01:15

Beams with Symmetric Loadings

344
The moment-area method is an analytical tool used in structural engineering to determine the slope and deflection of beams under various loads. Consider a cantilever with a concentrated load and moment at the free end. The first step is constructing a free-body diagram to calculate the reactions at the fixed end. Next, the bending moment diagram is plotted to visualize how the bending moment varies along the beam's length, focusing on points where the bending moment equals zero.
The M/EI...
344
Beams with Unsymmetric Loadings01:17

Beams with Unsymmetric Loadings

322
Analyzing a supported beam under unsymmetrical loadings is essential in structural engineering to understand how beams respond to varied force distributions. This analysis involves calculating the deflection and identifying points where the slope of the beam is zero, which are crucial for ensuring structural stability and functionality.
The first moment-area theorem determines the slope at any point on the beam. This theorem indicates that the change in slope between two points on a beam...
322
Maxwell-Boltzmann Distribution: Problem Solving01:20

Maxwell-Boltzmann Distribution: Problem Solving

2.7K
Individual molecules in a gas move in random directions, but a gas containing numerous molecules has a predictable distribution of molecular speeds, which is known as the Maxwell-Boltzmann distribution, f(v).
This distribution function f(v) is defined by saying that the expected number N (v1,v2) of particles with speeds between v1 and v2 is given by
2.7K
Shearing Stresses in a Beam: Problem Solving01:14

Shearing Stresses in a Beam: Problem Solving

518
A cantilever beam with a rectangular cross-section under distributed and point loads experiences shearing stresses. The analysis begins by identifying the loads acting on the beam. Then, the reactions at the beam's fixed end are calculated using equilibrium equations. The vertical reaction is a combination of the distributed and point loads, while the moment reaction is the sum of their moments. The shear force distribution along the beam, resulting from these loads, is established by creating...
518

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Bilateral Macular Coloboma With Eccentric Fixation Confirmed by Microperimetry: A Case Report.

Cureus·2025
Same author

Respiratory-gated proton beam therapy for intrahepatic cholangiocarcinoma without fiducial markers.

Radiation oncology (London, England)·2024
Same author

Dose Evaluation in 2-Phase Method for Advanced Esophageal Cancer by Hybrid Irradiation Techniques.

International journal of particle therapy·2024
Same author

Use of Ranibizumab for evaluating focal laser combination therapy for refractory diabetic macular edema patients: an exploratory study on the RELAND trials.

Scientific reports·2023
Same author

Effectiveness of CT-image guidance in proton therapy for liver cancer and the importance of daily dose monitoring for tumors and organs at risk.

Medical physics·2023
Same author

Evaluation of Exposure Doses of Elective Nodal Irradiation in Chemoradiotherapy for Advanced Esophageal Cancer.

Cancers·2023

Related Experiment Video

Updated: Dec 17, 2025

Proton Therapy Delivery and Its Clinical Application in Select Solid Tumor Malignancies
08:34

Proton Therapy Delivery and Its Clinical Application in Select Solid Tumor Malignancies

Published on: February 6, 2019

20.9K

A robust optimization method for weighted-layer-stacking proton beam therapy.

Yusuke Sakamoto1, Yoshikazu Maeda2, Yukiko Yamada3,4

  • 1Advanced Technology R&D Center, Mitsubishi Electric Corporation, Hyogo, Japan.

Physics in Medicine and Biology
|June 23, 2020
PubMed
Summary
This summary is machine-generated.

A new weight optimization algorithm enhances proton therapy dose distribution robustness against layer depth variations. This improves target coverage and organ-at-risk sparing in layer-stacking proton beam therapy.

More Related Videos

Positron Emission Tomography-based Dose Painting Radiation Therapy in a Glioblastoma Rat Model using the Small Animal Radiation Research Platform
07:57

Positron Emission Tomography-based Dose Painting Radiation Therapy in a Glioblastoma Rat Model using the Small Animal Radiation Research Platform

Published on: March 24, 2022

3.0K
Dynamic Lung Tumor Tracking for Stereotactic Ablative Body Radiation Therapy
08:17

Dynamic Lung Tumor Tracking for Stereotactic Ablative Body Radiation Therapy

Published on: June 7, 2015

16.1K

Related Experiment Videos

Last Updated: Dec 17, 2025

Proton Therapy Delivery and Its Clinical Application in Select Solid Tumor Malignancies
08:34

Proton Therapy Delivery and Its Clinical Application in Select Solid Tumor Malignancies

Published on: February 6, 2019

20.9K
Positron Emission Tomography-based Dose Painting Radiation Therapy in a Glioblastoma Rat Model using the Small Animal Radiation Research Platform
07:57

Positron Emission Tomography-based Dose Painting Radiation Therapy in a Glioblastoma Rat Model using the Small Animal Radiation Research Platform

Published on: March 24, 2022

3.0K
Dynamic Lung Tumor Tracking for Stereotactic Ablative Body Radiation Therapy
08:17

Dynamic Lung Tumor Tracking for Stereotactic Ablative Body Radiation Therapy

Published on: June 7, 2015

16.1K

Area of Science:

  • Medical Physics
  • Radiation Oncology
  • Particle Therapy

Background:

  • Layer-stacking proton beam therapy utilizes mini-spread-out Bragg peaks (SOBP) for conformal dose distributions.
  • Robustness of dose distributions against variations in layer depth is crucial for treatment efficacy.

Purpose of the Study:

  • To demonstrate the effectiveness of a novel weight optimization algorithm for enhancing dose distribution robustness in layer-stacking proton therapy.
  • To improve stability against layer depth variations, ensuring precise dose delivery.

Main Methods:

  • A new robustness algorithm adapted layer weight limits and evaluated 620 weight sets.
  • An objective function based on a Gaussian function (σ = 3 mm) selected optimal weights for Water Equivalent Depth (WED) variation.
  • 1D depth dose and 3D dose distributions in a water phantom were evaluated using Monte Carlo (MC) calculations.

Main Results:

  • The robustness algorithm reduced dose distribution changes due to WED variation by approximately 75% compared to conventional methods.
  • 91.8% of samples maintained dose within 5% of maximum, versus 64.9% with the conventional algorithm.
  • MC calculations showed reduced high-dose volumes in organs at risk (OARs) and enhanced depth dose distribution stability.

Conclusions:

  • The developed robustness algorithm significantly improves dose distribution stability in layer-stacking proton therapy.
  • This method is beneficial for treatments requiring sharp distal falloff to spare OARs and maintain target dose coverage.