scholarly journals Conductivity Variation during Irreversible Electroporation

2021 ◽  
Vol 271 ◽  
pp. 01032
Author(s):  
Chao Xu ◽  
Lei Yang
Keyword(s):  
Low Voltage ◽  
Irreversible Electroporation ◽  
Low Frequency ◽  
Massive Bleeding ◽  
Element Analysis ◽  
Important Conclusion ◽  
Tissue Conductivity ◽  
The Finite Element Analysis ◽  
Sink Effect ◽  
Major Factors

Irreversible electroporation (IRE) is an emerging tumour ablation technique, which utilizes non thermoelectric pulse to ablate tumours. Compared with the common tumour treatment methods, e.g., surgery, chemotherapy and radiotherapy, IRE has advantages of short action time, no massive bleeding of tissue during ablation, avoiding heat sink effect, etc. However, the process of IRE will be affected by the distribution of E-field of the tissue. The major factors which affect E-field distribution are parameters of the electrical pulse and characteristics of the tissue, e.g., the conductivity of the tissue. We utilized the finite element analysis software COMSOL Multiphysics 5.4 to calculate the variation in liver tissue conductivity during IRE. In this study, there is a Low-Voltage High-Frequency (LVHF) pulse involves 3500 unipolar and bipolar pulses, and a High-Voltage Low-Frequency (HVLF) pulse involves eight unipolar and bipolar pulses. The results show that the conductivity change of the HVLF pulse is higher than that of the LVHF pulse due to the higher strength of E-field. The most important conclusion is that the LVHF pulse can only change the tissue conductivity near the electrode tip. The HVLF pulse will significantly change the conductivity in the tissue between the electrodes.

scholarly journals Burst Strength Analysis of Casing With Geometrical Imperfections

2006 ◽  
Vol 129 (4) ◽  
pp. 763-770 ◽  
Author(s):  
Xiaoguang Huang ◽  
Yanyun Chen ◽  
Kai Lin ◽  
Musa Mihsein ◽  
Kevin Kibble ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Strength Analysis ◽  
Element Analysis ◽  
Burst Strength ◽  
The Finite Element Analysis ◽  
Geometrical Imperfections ◽  
Major Factors

Accurately predicting the burst strength is very important in the casing design for the oil and gas industry. In this paper, finite element analysis is performed for an infinitely long thick walled casing with geometrical imperfections subjected to internal pressure. A comparison with a series of full-scale experiments was conducted to verify the accuracy and reliability of the finite element analysis. Furthermore, three predictive equations were evaluated using the test data, and the Klever equation was concluded to give the most accurate prediction of burst strength. The finite element analysis was then extended to study the effects of major factors on the casing burst strength. Results showed that the initial eccentricity and material hardening parameter had important effects on the burst strength, while the effect of the initial ovality was small.

scholarly journals Muffler structure improvement based on acoustic finite element analysis

2019 ◽  
Vol 38 (2) ◽  
pp. 415-426 ◽  
Author(s):  
Jun Fu ◽  
Minghui Xu ◽  
Zengfeng Zhang ◽  
Wenjie Kang ◽  
Yong He
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Transmission Loss ◽  
Low Frequency ◽  
Analysis Method ◽  
Acoustic Attenuation ◽  
Element Analysis ◽  
Acoustic Performance ◽  
Finite Element Analysis Method ◽  
The Finite Element Analysis

Aiming to obtain the acoustic attenuation performance of exhaust muffler of diesel engine and the influence of main structural parameters on its acoustic attenuation characteristics, the finite element analysis method and acoustic theory were adopted to numerically investigate the acoustic attenuation performance under the boundary condition of acoustic adiabatic propagation and muffler wall. It suggested that the noise cancellation effect of muffler was poor at the middle and low frequency in range of 0–3000 Hz, and the transfer loss of muffler was basically 0 dB pass frequency at 1100 Hz. According to previous single-factor study experience, the structural factors, such as the expansion ratio, insertion length of outlet perforated pipe, the distance between the diaphragm and the front part of muffler, have influences on the acoustic performance of muffler at low frequency. Thus, they were taken as the starting point to study the influence of multiple interaction factors on the muffling performance by using orthogonal design method combined with the finite element analysis method. The influence degree of different structure parameters on the acoustic performance of muffler and the optimized structure parameters were obtained. Through the analysis on the acoustic characteristic of the optimized muffler, it indicated that the transmission loss of the improved muffler had significant increase in other frequency range except the range of 650–800 Hz and 2500–2700 Hz, especially at frequency of 1100 Hz compared with the original muffler. In the range of 0–3000 Hz, the mean of transmission loss of the improved muffler was about 9.8 dB larger than that of original muffler, which indicated that better noise cancellation effect was achieved. The improved muffler also provided a certain reference for the structural improvement of similar muffler.

Novel Low-Frequency Rectangular-Loop Piezoelectric Energy Harvester

2014 ◽  
Vol 635-637 ◽  
pp. 928-931
Author(s):  
Shuai Yuan ◽  
Bing Jiang ◽  
Li Juan Chen ◽  
Yu Guo Hao ◽  
Jian Bo Xin ◽  
...  
Keyword(s):  
Resonant Frequency ◽  
Output Voltage ◽  
Energy Harvester ◽  
Low Frequency ◽  
Effective Bandwidth ◽  
Response Analysis ◽  
Element Analysis ◽  
Piezoelectric Energy ◽  
The Finite Element Analysis ◽  
Harmonic Response Analysis

The ambient energy harvesting based on piezoelectric has become an important subject in recent research publications. A new rectangular-loop piezoelectric energy harvester(RLPEH) is proposed. The characteristic is analyzed by the finite element analysis (FEA) which includes the static analysis, modal analysis and harmonic response analysis. The analysis results show that the RLPEH could reduce the resonant frequency and improve the output voltage. The three order resonant frequency is 18.6Hz, 40.8Hz and 85.4Hz. The output voltage is 42V under 3m/s2 of acceleration and the effective bandwidth is 18.7Hz with output voltage above 10V.

Model Analysis of Micro-Feed Tool Holder Based on Finite Element Simulation

2010 ◽  
Vol 44-47 ◽  
pp. 1350-1354
Author(s):  
Jie Mei ◽  
Yu Zhen ◽  
Ding Fang Chen ◽  
Wen Feng Li
Keyword(s):  
Finite Element ◽  
Vibration Mode ◽  
Model Analysis ◽  
Element Analysis ◽  
Theoretical Derivation ◽  
Important Conclusion ◽  
Tool Holder ◽  
Improvement Measure ◽  
Element Simulation ◽  
The Finite Element Analysis

The theoretical derivation of model analysis is elaborated first in the paper. Then combined with the developed micro-feed tool holder, the structure’s first ten order vibration mode is analyzed through the finite element analysis software. From the analysis results, the natural frequency in every mode is finally obtained. After the analysis, an important conclusion is put forward. Based on the conclusion, an improvement measure for the micro-feed tool holder structure is proposed.

Low-Frequency Shaking of the Construction Machine Cab and Design of Vibration Isolators for Protecting

2011 ◽  
Vol 141 ◽  
pp. 49-53
Author(s):  
Xiao Juan Sun ◽  
Jian Run Zhang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Static Analysis ◽  
Silicone Oil ◽  
Low Frequency ◽  
Practical Application ◽  
Element Analysis ◽  
Vibration Isolators ◽  
Construction Machine ◽  
The Finite Element Analysis

Focusing on low-frequency shaking of the construction machine cab, the article analyzes reasons of the shaking and shows several improved isolator designs to reduce the effect of shaking on drivers’ comfort. Firstly according to previous 4 modes below 26 Hz from the finite element analysis of an excavator cab with 6 cab mounts, reasons for low-frequency shaking are analyzed. Then two improved measures of isolator designs for keeping the shaking small effectively are considered. Static analysis on one silicone-oil-sealed-type rubber mount, which can improve drivers’ comfort effectively according to practical application, is done. Besides, perfect setting approaches of isolators can greatly alleviate the cab shaking, which is confirmed by finite element modal analysis of the excavator cab, the first natural frequency of cab increased to 15.55Hz from 6.91Hz.

scholarly journals Analysis of Coil Parameters and Comparison of Circular, Rectangular, and Hexagonal Coils Used in WPT System for Electric Vehicle Charging

2021 ◽  
Vol 12 (1) ◽  
pp. 45
Author(s):  
Tasnime Bouanou ◽  
Hassan El Fadil ◽  
Abdellah Lassioui ◽  
Ouidad Assaddiki ◽  
Sara Njili
Keyword(s):  
Electric Vehicle ◽  
Wireless Power Transfer ◽  
Power Transfer ◽  
Wireless Power ◽  
Element Analysis ◽  
Electric Vehicle Charging ◽  
Inner Radius ◽  
The Finite Element Analysis ◽  
Vehicle Charging ◽  
Major Factors

In this paper, the major factors that affect the performance of wireless power transfer systems, such as coil inner radius and coil number of turns, are discussed. A comparison of three coil shapes covering the coreless case, the case with ferrite, and the case with ferrite and aluminum is also carried out. Another comparison is proposed by addressing the combination of different coil shapes in the wireless power transfer (WPT)system. The analysis covers the coupling coefficient, the mutual inductance, and the self-inductance. Due to the complexity of calculating these parameters, the finite element analysis (FEA) method is adopted by using the Ansys Maxwell software. An introduction to the typical WPT system for electric vehicle charging is also presented.

A two degrees of freedom comb capacitive-type accelerometer with low cross-axis sensitivity

2019 ◽  
Vol 13 (3) ◽  
pp. 5334-5346
Author(s):  
M. N. Nguyen ◽  
L. Q. Nguyen ◽  
H. M. Chu ◽  
H. N. Vu
Keyword(s):  
Degrees Of Freedom ◽  
Proof Mass ◽  
Vibration Modes ◽  
Electrode Structure ◽  
Element Analysis ◽  
Mechanical Coupling ◽  
Fully Differential ◽  
Mode Effects ◽  
The Finite Element Analysis ◽  
Cross Axis

In this paper, we report on a SOI-based comb capacitive-type accelerometer that senses acceleration in two lateral directions. The structure of the accelerometer was designed using a proof mass connected by four folded-beam springs, which are compliant to inertial displacement causing by attached acceleration in the two lateral directions. At the same time, the folded-beam springs enabled to suppress cross-talk causing by mechanical coupling from parasitic vibration modes. The differential capacitor sense structure was employed to eliminate common mode effects. The design of gap between comb fingers was also analyzed to find an optimally sensing comb electrode structure. The design of the accelerometer was carried out using the finite element analysis. The fabrication of the device was based on SOI-micromachining. The characteristics of the accelerometer have been investigated by a fully differential capacitive bridge interface using a sub-fF switched-capacitor integrator circuit. The sensitivities of the accelerometer in the two lateral directions were determined to be 6 and 5.5 fF/g, respectively. The cross-axis sensitivities of the accelerometer were less than 5%, which shows that the accelerometer can be used for measuring precisely acceleration in the two lateral directions. The accelerometer operates linearly in the range of investigated acceleration from 0 to 4g. The proposed accelerometer is expected for low-g applications.

Tread Depth Effects on Tire Rolling Resistance

2001 ◽  
Vol 29 (3) ◽  
pp. 134-154 ◽  
Author(s):  
J. R. Luchini ◽  
M. M. Motil ◽  
W. V. Mars
Keyword(s):  
Finite Element Analysis ◽  
Common Knowledge ◽  
Rolling Resistance ◽  
Test Method ◽  
Tire Model ◽  
Element Analysis ◽  
Truck Tires ◽  
The Finite Element Analysis ◽  
Equilibrium Test ◽  
Depth Effects

Abstract This paper discusses the measurement and modeling of tire rolling resistance for a group of radial medium truck tires. The tires were subjected to tread depth modifications by “buffing” the tread surface. The experimental work used the equilibrium test method of SAE J-1269. The finite element analysis (FEA) tire model for tire rolling resistance has been previously presented. The results of the testing showed changes in rolling resistance as a function of tread depth that were inconsistent between tires. Several observations were also inconsistent with published information and common knowledge. Several mechanisms were proposed to explain the results. Additional experiments and models were used to evaluate the mechanisms. Mechanisms that were examined included tire age, surface texture, and tire shape. An explanation based on buffed tread radius, and the resulting changes in footprint stresses, is proposed that explains the observed experimental changes in rolling resistance with tread depth.

Interactive Graphics for the Analysis of Tires

1985 ◽  
Vol 13 (3) ◽  
pp. 127-146 ◽  
Author(s):  
R. Prabhakaran
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Approximate Solutions ◽  
Interactive Graphics ◽  
Element Analysis ◽  
Analysis Process ◽  
Physical Problems ◽  
The Finite Element Analysis ◽  
Analysis Computer ◽  
Discretization Technique

Abstract The finite element method, which is a numerical discretization technique for obtaining approximate solutions to complex physical problems, is accepted in many industries as the primary tool for structural analysis. Computer graphics is an essential ingredient of the finite element analysis process. The use of interactive graphics techniques for analysis of tires is discussed in this presentation. The features and capabilities of the program used for pre- and post-processing for finite element analysis at GenCorp are included.

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