scholarly journals Optimal Control of Thermal Damage to Targetted Regions in a Biological Material

Volume 4 ◽  
2004 ◽  
Author(s):  
F. Scott Gayzik ◽  
Elaine P. Scott ◽  
Tahar Loulou
Keyword(s):  
Objective Function ◽  
Thermal Damage ◽  
Numerical Technique ◽  
Damage Model ◽  
Gradient Algorithm ◽  
Bioheat Equation ◽  
Hyperthermia Treatment ◽  
Potential Applications ◽  
Damage Field ◽  
The Relationship

A numerical technique with potential applications in hyperthermia treatment planning is presented. The treatment is simulated using a 2D transient computational model of the Pennes bioheat equation within an optimization algorithm. The algorithm recovers the heating protocol which will lead to a desired damage field. The relationship between temperature, time and thermal damage is expressed as a first order rate process using the Arrhenius equation. The objective function of the control problem is based on this thermal damage model. The adjoint method in conjunction with the conjugate gradient algorithm is used to minimize the objective function. The results from a numerical simulation show good agreement between the optimal damage field and the damage field recovered by the algorithm. A comparison between the recovered damage field and the commonly used thermal dose is also made.

Experimental Research on the Thermal Damage of Concrete

2013 ◽  
Vol 351-352 ◽  
pp. 460-466
Author(s):  
Chao Chen ◽  
Ying She Luo ◽  
Song Hua Tang ◽  
Xuan Zhang
Keyword(s):  
Damage Evolution ◽  
Thermal Damage ◽  
Damage Model ◽  
Effect Of Temperature ◽  
Compression Tests ◽  
Thermal Compression ◽  
Relevant Reference ◽  
Different Temperatures ◽  
The Relationship ◽  
Fire Design

In order to investigate the effect of temperature (from normal temperature to 850°C) coursed by fire on the strength damage of concrete, thermal compression tests for concrete specimens named C35 have been performed under different temperature conditions. Emphasis is laid on the relationship between temperature and thermal damage strength; and the relevant formula is proposed in this paper. The regularity and mechanism of thermal damage evolution in concrete on strength under high temperature are analyzed. Combined the result of tests with the residual strength thermal damage model, we obtain the specific damage variable value D under different temperatures. Finally, we compare the fitting formula curve to relevant reference; there are some important conclusions which can be partly applied to fire design of concrete structure.

2-D Thermal Dose Optimization in High Intensity Focused Ultrasound Treatments Using the Adjoint Method

2000 ◽  
Author(s):  
Tahar Loulou ◽  
Elaine P. Scott
Keyword(s):  
Heat Source ◽  
Adjoint Method ◽  
Focused Ultrasound ◽  
Control Function ◽  
Numerical Technique ◽  
High Intensity Focused Ultrasound ◽  
Computational Method ◽  
Gradient Algorithm ◽  
Thermal Dose ◽  
Hyperthermia Treatment

Abstract A previously reported numerical technique, which uses adjoint method when optimizing 1D space variation of thermal dose in hyperthermia treatment is extended to the case of 2D problems [1]. Using a 2D transient computational model in the Penne’s bio-heat equation, optimization of thermal treatment during hyperthermia is shown to be effective and accurate. Numerical simulations are carried out with the 2D computational method to retrieve the prescribed thermal dose from the solution of an inverse thermal problem. The non-continuity of the temperature variation of thermal dose around the reference temperature is linearized over a small temperature interval. The adjoint method in conjunction with the conjugate gradient algorithm are employed to perform the optimization of the objective function. The results are obtained in terms of the computed thermal dose and the heat source to be applied. The numerical results, obtained for a simple treatment case show a good agreement between the estimated and desired thermal dose. However, the non-uniqueness of the obtained solution (the control function: heat source to be applied) is still under investigation and supports the need for further fundamental research.

NUMERICAL SIMULATION OF FRACTIONAL BIOHEAT EQUATION IN HYPERTHERMIA TREATMENT

2014 ◽  
Vol 14 (02) ◽  
pp. 1450018 ◽  
Author(s):  
R. S. DAMOR ◽  
SUSHIL KUMAR ◽  
A. K. SHUKLA
Keyword(s):  
Numerical Simulation ◽  
Finite Difference ◽  
Finite Difference Method ◽  
Fractional Derivative ◽  
Thermal Damage ◽  
Heating Time ◽  
Bioheat Equation ◽  
Hyperthermia Treatment ◽  
Implicit Finite Difference ◽  
Time Fractional Derivative

This paper deals with the study of fractional bioheat equation for hyperthermia treatment in cancer therapy with external electromagnetic (EM) heating. Time fractional derivative is considered as Caputo fractional derivative of order α ∈ (0, 1]. Numerical solution is obtained by implicit finite difference method. The effect of anomalous diffusion in tissue has been studied. The temperature profile and thermal damage over the entire affected region are obtained for different values of α.

Structure-properties relationship for energy storage redox polymers: a review

2020 ◽  
Vol 40 (5) ◽  
pp. 373-393 ◽  
Author(s):  
Narendra Singh Chundawat ◽  
Nishigandh Pande ◽  
Ghasem Sargazi ◽  
Mazaher Gholipourmalekabadi ◽  
Narendra Pal Singh Chauhan
Keyword(s):  
Energy Storage ◽  
Cost Efficiency ◽  
Energy Storage Materials ◽  
High Scale ◽  
Chemical Structures ◽  
Redox Active ◽  
Potential Applications ◽  
Intelligent Clothing ◽  
The Relationship ◽  
Structure Properties

AbstractRedox-active polymers among the energy storage materials (ESMs) are very attractive due to their exceptional advantages such as high stability and processability as well as their simple manufacturing. Their applications are found to useful in electric vehicle, ultraright computers, intelligent electric gadgets, mobile sensor systems, and portable intelligent clothing. They are found to be more efficient and advantageous in terms of superior processing capacity, quick loading unloading, stronger security, lengthy life cycle, versatility, adjustment to various scales, excellent fabrication process capabilities, light weight, flexible, most significantly cost efficiency, and non-toxicity in order to satisfy the requirement for the usage of these potential applications. The redox-active polymers are produced through organic synthesis, which allows the design and free modification of chemical constructions, which allow for the structure of organic compounds. The redox-active polymers can be finely tuned for the desired ESMs applications with their chemical structures and electrochemical properties. The redox-active polymers synthesis also offers the benefits of high-scale, relatively low reaction, and a low demand for energy. In this review we discussed the relationship between structural properties of different polymers for solar energy and their energy storage applications.

scholarly journals Changes in Optical Properties upon Dye–Clay Interaction: Experimental Evaluation and Applications

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 197
Author(s):  
Giorgia Giovannini ◽  
René M. Rossi ◽  
Luciano F. Boesel
Keyword(s):  
Optical Properties ◽  
Hybrid Materials ◽  
High Performance ◽  
Fluorescent Properties ◽  
Chemical Mechanisms ◽  
Strong Electrostatic Interaction ◽  
Potential Applications ◽  
Photochemical Properties ◽  
Physical And Chemical ◽  
The Relationship

The development of hybrid materials with unique optical properties has been a challenge for the creation of high-performance composites. The improved photophysical and photochemical properties observed when fluorophores interact with clay minerals, as well as the accessibility and easy handling of such natural materials, make these nanocomposites attractive for designing novel optical hybrid materials. Here, we present a method of promoting this interaction by conjugating dyes with chitosan. The fluorescent properties of conjugated dye–montmorillonite (MMT) hybrids were similar to those of free dye–MMT hybrids. Moreover, we analyzed the relationship between the changes in optical properties of the dye interacting with clay and its structure and defined the physical and chemical mechanisms that take place upon dye–MMT interactions leading to the optical changes. Conjugation to chitosan additionally ensures stable adsorption on clay nanoplatelets due to the strong electrostatic interaction between chitosan and clay. This work thus provides a method to facilitate the design of solid-state hybrid nanomaterials relevant for potential applications in bioimaging, sensing and optical purposes.

ANN-Based Structure Optimization with Fatigue Reliability Constrains

2012 ◽  
Vol 204-208 ◽  
pp. 3128-3131
Author(s):  
Li Rong Sha ◽  
Yue Yang
Keyword(s):  
Structural Optimization ◽  
Objective Function ◽  
Reliability Analysis ◽  
Response Surface ◽  
Minimum Weight ◽  
Structure Optimization ◽  
Fatigue Reliability ◽  
Ann Model ◽  
Surface Method ◽  
The Relationship

The ANN-based optimization for considering fatigue reliability requirements in structural optimization was proposed. The ANN-based response surface method was employed for performing fatigue reliability analysis. The fatigue reliability requirements were considered as constraints while the weight as the objective function, the ANN model was adopted to establish the relationship between the fatigue reliability and geometry dimension of the structure, the optimal results of the structure with a minimum weight was reached.

The relationship between the unmodified initial tissue pH of human tumours and the response to combined radiotherapy and local hyperthermia treatment

1989 ◽  
Vol 25 (1) ◽  
pp. 73-78 ◽  
Author(s):  
Adriaan P. Van Den Berg ◽  
Jennifer L. Wike-Hooley ◽  
M. Pia Broekmeyer-Reurink ◽  
Jacoba Van Der Zee ◽  
Hubert S. Reinhold
Keyword(s):  
Hyperthermia Treatment ◽  
Tissue Ph ◽  
Local Hyperthermia ◽  
Human Tumours ◽  
The Relationship

scholarly journals METHODS OF FORMULATING AND SOLVING OPTIMIZATION PROBLEMS OF CUTTING LOGS OF LARGE SIZE BY BAR-SAWING METHOD WITH CUTTING OUT ONE BAR AND FIVE PAIRS OF SIDE EDGING BOARDS WITH SUBSEQUENT SAWING LUMBER FOR EDGED BOARDS

2017 ◽  
Vol 7 (1) ◽  
pp. 137-150
Author(s):  
Агапов ◽  
Aleksandr Agapov
Keyword(s):  
Mathematical Model ◽  
Objective Function ◽  
Optimization Problem ◽  
Optimization Problems ◽  
Target Function ◽  
Cross Sectional ◽  
Optimization Task ◽  
Cutting Out ◽  
The Mathematical Model ◽  
The Relationship

For the first time the mathematical model of task optimization for this scheme of cutting logs, including the objective function and six equations of connection. The article discusses Pythagorean area of the logs. Therefore, the target function is represented as the sum of the cross-sectional areas of edging boards. Equation of the relationship represents the relationship of the diameter of the logs in the vertex end with the size of the resulting edging boards. This relationship is described through the use of the Pythagorean Theorem. Such a representation of the mathematical model of optimization task is considered a classic one. However, the solution of this mathematical model by the classic method is proved to be problematic. For the solution of the mathematical model we used the method of Lagrange multipliers. Solution algorithm to determine the optimal dimensions of the beams and side edging boards taking into account the width of cut is suggested. Using a numerical method, optimal dimensions of the beams and planks are determined, in which the objective function takes the maximum value. It turned out that with the increase of the width of the cut, thickness of the beam increases and the dimensions of the side edging boards reduce. Dimensions of the extreme side planks to increase the width of cut is reduced to a greater extent than the side boards, which are located closer to the center of the log. The algorithm for solving the optimization problem is recommended to use for calculation and preparation of sawing schedule in the design and operation of sawmill lines for timber production. When using the proposed algorithm for solving the optimization problem the output of lumber can be increased to 3-5 %.

scholarly journals Modelling semi-continuous data using mixture regression models with an application to cattle production yields

2011 ◽  
Vol 150 (1) ◽  
pp. 109-121 ◽  
Author(s):  
E. J. BELASCO ◽  
S. K. GHOSH
Keyword(s):  
Regression Models ◽  
Continuous Variable ◽  
Continuous Variables ◽  
Multivariate Models ◽  
Mixture Regression ◽  
Potential Applications ◽  
Mixture Regression Models ◽  
Mixture Regression Model ◽  
The Relationship ◽  
Positive Half

SUMMARYThe present paper develops a mixture regression model that allows for distributional flexibility in modelling the likelihood of a semi-continuous outcome that takes on zero value with positive probability while continuous on the positive half of the real line. A multivariate extension is also developed that builds on past multivariate models by systematically capturing the relationship between continuous and semi-continuous variables, while allowing for the semi-continuous variable to be characterized by a mixture model. The flexibility associated with this model provides potential applications in many production system studies. The empirical model is shown to provide a more accurate measure of mortality rates in cattle feedlots, both independently and within a system including other performance and health factors.

Optical-Thermal Response and Dynamic Thermal Damage of Bio-Tissue During Laser Thermotherapy

2003 ◽  
Author(s):  
G. M. Zhu ◽  
W. Liu ◽  
T. F. Zeng ◽  
K. Yang
Keyword(s):  
Thermal Injury ◽  
Thermal Damage ◽  
Tumor Tissue ◽  
Local Heating ◽  
Damage Model ◽  
Thermal Response ◽  
Tumor Treatment ◽  
Thermal Coagulation ◽  
Laser Head ◽  
Temperature Damage

Laser thermotherapy is a technique used for tumor treatment. It generates a local heating, causes thermal coagulation of living tissue and eliminates the tumor. Precise heating of tumor tissue with healthy minimum thermal injury to adjacent tissue is essential to thermotherapy. Understanding of heat transfer and optical-thermal interaction is important for control of temperature and design of thermotherapy. This study applies the Arrhenius damage model to describe the heat-induced change of optical properties. It calculates the distribution temperature, damage and optical-thermal response of bio-tissue during the laser treatment, and shows how these factors affect the effectiveness of laser thermotherapy. Similar research has been performed by Kim and coworkers [1996], Iizuka and coworkers [2000], and Whelan and coworkers [2000]. This study relaxes some conditions in previous investigations. It reveals the importance and the effect of size of the laser head.

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