scholarly journals THERMAL LESION FORMATION AND DETERMINATION FOR EXTERNAL ULTRASOUND THERMAL THERAPY

2003 ◽  
Vol 15 (03) ◽  
pp. 124-132 ◽  
Author(s):  
HAO-LI LIU ◽  
YUNG-YAW CHEN ◽  
JIA-YUSH YEN ◽  
WIN-LI LIN
Keyword(s):  
Blood Perfusion ◽  
Heating System ◽  
Target Volume ◽  
Thermal Therapy ◽  
Bioheat Transfer ◽  
Heating Process ◽  
Thermal Lesion ◽  
Feedback Information ◽  
Temperature Feedback ◽  
Heating Pattern

The purpose of this paper is to investigate the relationship between the formation of the thermal lesion and the major parameters of the external ultrasound heating systems, and to propose a useful thermal lesion determination procedure, which is capable of specifying the range of a thermal lesion by temperature feedback in external ultrasound thermal therapy. This work is based on an ideal ultrasound power deposition formed by an external ultrasound heating system and the temperature distribution is calculated by the transient bioheat transfer equation. A simplified model was employed to determine the heating pattern for four most important parameters. Through the simplified power expression, the property of a new parameter, T300, which is defined as the maximal temperature corresponding to the thermal dose of 300 minutes, is also investigated. When the target volume is large enough such that the thermal conduction effect becomes negligible, the T300 value is almost independent of the system parameters and the heating strategies, and is dominated by the blood perfusion rate with a monotonic correlation. The method enables us to use feedback information in the ultrasound heating process and to pre-determine the heating range of the thermal lesion, which will be very useful in ultrasound treatment planning.

Studies on the Three-Dimensional Temperature Transients in the Canine Prostate During Transurethral Microwave Thermal Therapy

2000 ◽  
Vol 122 (4) ◽  
pp. 372-379 ◽  
Author(s):  
Jing Liu ◽  
Liang Zhu ◽  
Lisa X. Xu
Keyword(s):  
Three Dimensional ◽  
Blood Perfusion ◽  
Thermal Therapy ◽  
Bioheat Transfer ◽  
Target Tissue ◽  
Urethral Wall ◽  
Theoretical Predictions ◽  
Closed Form Analytical Solution ◽  
Good Agreement

Thermal therapy of benign prostatic hyperplasia requires accurate prediction of the temperature distribution induced by the heating within the prostatic tissue. In this study, the Pennes bioheat transfer equation was used to model the transient heat transfer inside the canine prostate during transurethral microwave thermal therapy. Incorporating the specific absorption rate of microwave energy in tissue, a closed-form analytical solution was obtained. Good agreement was found between the theoretical predictions and in-vivo experimental results. Effects of blood perfusion and the cooling at the urethral wall on the temperature rise were investigated within the prostate during heating. The peak intraprostatic temperatures attained by application of 5, 10, or 15 W microwave power were predicted to be 38°C,41°C, and 44°C. Results from this study will help optimize the thermal dose that can be applied to target tissue during the therapy. [S0148-0731(00)01004-9]

Multiobjective Optimization of the Heating Process for Forging Automotive Crankshaft

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Hong-Seok Park ◽  
Xuan-Phuong Dang
Keyword(s):  
Multiobjective Optimization ◽  
Heating System ◽  
Optimization Method ◽  
Heating Process ◽  
Temperature Deviation ◽  
Engineering Data ◽  
Optimization Of Process Parameters ◽  
Mathematical Approximation ◽  
Nondominated Sorting ◽  
Induction Heating System

This paper presents potential approaches that increase the energy efficiency of an in-line induction heating system for forging of an automotive crankshaft. Both heat loss reduction and optimization of process parameters are proposed scientifically in order to minimize the energy consumption and the temperature deviation in the workpiece. We applied the numerical multiobjective optimization method in conjunction with the design of experiment (DOE), mathematical approximation with metamodel, nondominated sorting genetic algorithm (GA), and engineering data mining. The results show that using the insulating covers reduces heat by an amount equivalent to 9% of the energy stored in the heated workpiece, and approximately 5.8% of the energy can be saved by process parameter optimization.

scholarly journals Research on Electromagnetic Sensitivity Properties of Sodium Chloride during Microwave Heating

2020 ◽  
Vol 39 (1) ◽  
pp. 54-62
Author(s):  
Hua Chen ◽  
Junjiang Chen ◽  
Weijun Wang ◽  
Huan Lin
Keyword(s):  
Sodium Chloride ◽  
Electric Field ◽  
Water Content ◽  
Heating Rate ◽  
Microwave Heating ◽  
Resonant Cavity ◽  
Relative Dielectric Constant ◽  
Heating System ◽  
Heating Process ◽  
Heating Efficiency

AbstractThe multimode resonant cavity is the most common cavity. The material often shows on selective heating performance during the heating process due to the effect of microwave heating having a closely relationship with the electromagnetism parameters. This paper is based on finite difference time domain method (FDTD) to establish the electromagnetic-thermal model. The electromagnetic sensitivity property parameters of sodium chloride including relative dielectric constant, loss angle tangent and water content of sodium chloride is studied during the heating and drying process. The heating rate and the electric field distribution of sodium chloride, at the different water content, were simulated with the electromagnetic characteristic parameters changing. The results show that with the electromagnetic sensitivity property parameters varying, the electric field strength, heating rate and steady-state temperature of the heating material will all have a variety in the cavity. Some measures are proposed to improve the heating efficiency and ensure the stability of the microwave heating system in the industrial application.

scholarly journals Infrared-Emitting QDs for Thermal Therapy with Real-Time Subcutaneous Temperature Feedback

2016 ◽  
Vol 26 (33) ◽  
pp. 6060-6068 ◽  
Author(s):  
Blanca del Rosal ◽  
Elisa Carrasco ◽  
Fuqiang Ren ◽  
Antonio Benayas ◽  
Fiorenzo Vetrone ◽  
...  
Keyword(s):  
Real Time ◽  
Thermal Therapy ◽  
Temperature Feedback

An Embedded Prototype for a Distributed and Automated Line Heating System

2009 ◽  
Vol 25 (04) ◽  
pp. 182-190 ◽  
Author(s):  
Jackyou Noh ◽  
Jong Gye Shin ◽  
Kwang Hee Ko ◽  
Jae An Chun
Keyword(s):  
Robot Control ◽  
Heating System ◽  
Heating Process ◽  
Current Line ◽  
Line Heating ◽  
Design Data ◽  
Heating Systems ◽  
Network Information ◽  
Automated Process ◽  
Automated Line

Automated line heating systems have been developed based on stand-alone operation with no consideration of the extensibility and maintainability. In the line heating shop, many of the line heating works are performed simultaneously; therefore, a collaborative and simultaneous automated line heating system is needed. In order to develop such a new line heating system, the current line heating process was analyzed, and then a distributed and automated process was determined, and the parts to be distributed and automated were identified to propose a distributed and automated line heating system based on modularization and network. Information and data flow from production design to robot control have been analyzed and integrated in the system. The system has two main processes: the calculation of the line heating information and execution of a working unit without calculation. A prototype of the system has been developed to study the feasibility of the system. Tests were carried out by using real production design data of a middle-sized Korean shipyard.

scholarly journals Thermodynamic and Economic Analyses of Reformative Design for High Back-Pressure Heating in Coal-Fueled Cogeneration Units

Entropy ◽  
2019 ◽  
Vol 21 (4) ◽  
pp. 342 ◽  
Author(s):  
Heng Chen ◽  
Yunyun Wu ◽  
Jidong Xu ◽  
Gang Xu ◽  
Yongping Yang ◽  
...  
Keyword(s):  
Power Output ◽  
Heating System ◽  
Back Pressure ◽  
Heating Process ◽  
Heat Output ◽  
Water Heating ◽  
Heating Steam ◽  
Economic Analyses ◽  
Novel Concept ◽  
Supply Water

High back-pressure (HBP) heating technology has been identified as an effective approach to improve the efficiency of combined heat and power (CHP). In this study, the novel concept of a HBP heating system with energy cascade utilization is developed and its probability examined. In the reformative design, the extracted heating steam from the intermediate-pressure turbine (IPT) is first drawn to an additional turbine where its excess pressure can be converted into electricity, then steam with a lower pressure can be employed to heat the supply water. As a consequence, the exergy destruction in the supply water heating process can be reduced and the efficiency of the cogeneration unit raised. A detailed thermodynamic investigation was performed based on a typical coal-fired HBP–CHP unit incorporating the proposed configuration. The results show that the artificial thermal efficiency (ATE) promotion was as much as 2.01 percentage points, with an additional net power output of 8.4 MW compared to the reference unit. This was attributed to a 14.65 percentage-point increment in the exergy efficiency of the supply water heating process caused by the suggested retrofitting. The influences of the unit power output, unit heat output, supply water and return water temperatures and turbine back pressure on the thermal performance of the modified system are discussed as well. In addition, the economic performance of the new design is assessed, indicating that the proposed concept is financially feasible.

scholarly journals Microwave-induced heating behavior of Y-TZP ceramics under multiphysics system

2020 ◽  
Vol 9 (1) ◽  
pp. 119-130
Author(s):  
Kaihui Cui ◽  
Tianqi Liao ◽  
Chen Qiu ◽  
Hua Chen ◽  
Junwen Zhou
Keyword(s):  
Numerical Model ◽  
Microwave Heating ◽  
Three Dimensional ◽  
Heating System ◽  
Dielectric Materials ◽  
Microwave Cavity ◽  
Heating Process ◽  
Highly Sensitive ◽  
Dimensional Distribution ◽  
Heating Behavior

AbstractThis paper aims to investigate the heating behaviors of Y-TZP arrays under microwave irradiation. In this study, a three-dimensional numerical model of the microwave heating system was developed by COMSOL Multiphysics software. The numerical model was verified by microwave heating experiment, and the average root means square errors (RMSE) between the simulation and experimental data also confirmed the reliability of the model. The varying position and arrays of materials were applied to predict and visualize the three-dimensional distribution of the electromagnetic field and temperature during the microwave heating process. The results show that the temperature field distribution in microwave cavity was highly sensitive to the dielectric materials, the arrangement of the Y-TZP array interfered with the distribution of standing waves. The results can serve as references for the study to design and optimize the ceramic’s application in terms of microwave heating.

scholarly journals A New Single-Phase Direct Frequency Controller Having Reduced Switching Count without Zero-Crossing Detector for Induction Heating System

Electronics ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 430
Author(s):  
Naveed Ashraf ◽  
Tahir Izhar ◽  
Ghulam Abbas ◽  
Ahmed Bilal Awan ◽  
Ali S. Alghamdi ◽  
...  
Keyword(s):  
Induction Heating ◽  
Heating System ◽  
Input Voltage ◽  
Heating Process ◽  
Zero Crossing ◽  
Pulse Width Modulated ◽  
Controlled Switching ◽  
Compact Size ◽  
Frequency Magnetic Field ◽  
Frequency Controller

Induction heating (IH) is an environmentally friendly solution for heating and melting processes. The required high-frequency magnetic field is accomplished through frequency controllers. Direct frequency controllers (DFC) are preferred to dual converters as they have low conversion losses, compact size, and simple circuit arrangement due to low component count. Numerous frequency controllers with complex switching algorithms are employed in the induction heating process. They have a complicated circuit arrangement, and complex control as their switching sequences have to synchronize with source voltage that requires the zero-crossing detection of the input voltage. They also have a shoot-through problem and poor power quality. Therefore, this research proposes a novel frequency controller with a low count of six controlled switching devices without a zero-crossing detector (ZCD) having a simple control arrangement. The required switching signals are simply generated by using any pulse-width-modulated (PWM) generator. The performance of the proposed topology is verified through simulation results obtained using the MATLAB/Simulink environment and experimental setup.

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