scholarly journals Simulation and Experimental Investigation of a Hollow, Bipolar Needle Electrode

2021 ◽  
Vol 7 (2) ◽  
pp. 21-24
Author(s):  
Jan Liu ◽  
Lina Hauser ◽  
Marcel Kappel ◽  
Chris Göhring ◽  
Peter P. Pott

Abstract Localized impedance measurements at the needle tip identifying the present tissue type could aid clinicians in needle procedures. To assess the sensitivity field of a hollow, bipolar needle electrode, a 3D finite element approach using COMSOL Multiphysics was chosen. The simulated bipolar needle electrode consists of two hypodermic needles (17 G and 23 G) with an insulating layer of polytetrafluoroethylene (PTFE) in between. Impedance values were recorded while steadily increasing the insertion depth of the needle electrode in a layered tissue structure of skin (dermis), fat, and blood. Simulation results reveal a highly local sensitivity volume around the needle tip that can be approximated by half a tri-axial ellipsoid with elliptic radii of 0.735 mm, 2.886 mm, and 1.774 mm. A comparison with simulated and measured impedance values shows great correspondence.

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Ivaná Đukic ◽  
Marija Ječmenica Dučić ◽  
Nikola Nikačević ◽  
Menka Petkovska

The goal of this work was to develop a 3D model of Electric Swing Adsorption pro- cess for carbon dioxide capture from effluent gasses from power plants. Detailed 3D model of the composite honeycomb monolithic adsorber was developed for a sin- gle monolith channel and can be used to simulate and represent different physical properties: velocity, concentration and temperature. The advantage of this model is the fact that all physical properties and results can be presented visually in the 3D domain. COMSOL Multiphysics software was used for solving partial differential equations and simulations of adsorption and electrothermal desorption processes. Some simulation results are presented in this work. The results obtained from 3D simulations will be used for the adsorber model reduction to the 1D model which will be used for modeling and optimization of the whole ESA cycle due to its sim- plicity and computational demands. Simulation and optimization runs based on the 1D model will be performed in g-Proms software.


2014 ◽  
Vol 989-994 ◽  
pp. 982-985
Author(s):  
Jun Chen ◽  
Xiao Jun Ye

ANSYS-LS/DYNA 3D finite element software projectile penetrating concrete target three-dimensional numerical simulation , has been the target characteristics and destroy ballistic missile trajectory , velocity and acceleration and analyze penetration and the time between relationship , compared with the test results , the phenomenon is consistent with the simulation results. The results show that : the destruction process finite element software can better demonstrate concrete tests revealed the phenomenon can not be observed , estimated penetration depth and direction of the oblique penetration missile deflection .


2021 ◽  
Vol 47 (2) ◽  
pp. 167-183
Author(s):  
Chenhao Chiu ◽  
Bryan Gick

Abstract Speech production requires temporal coordination between the actions of different functional groupings of muscles in the human body. Crucially, such functionally organized units, or “modules”, may be susceptible to disruption by an external stimulus such as a startling auditory stimulus (SAS; >120dB), enabling a possible window into the internal structure of learned speech movements. Following on the observation that SAS is known to accelerate the release of pre-planned actions, the current study examines lip kinematics in SAS-induced responses during speech movements to test whether this accelerated release applies on the scale of entire syllables or on the scale of smaller functional units. Production measures show that SAS-elicited bilabial movements in [ba] syllables are prone to disruption as measured by discontinuity in velocity profiles. We use a 3D finite element method (FEM) biomechanical model to simulate the temporal interaction between muscle groupings in speech. Simulation results indicate that this discontinuity can be accounted for as an instance of temporally decoupled coordination across neuromuscular modules. In such instances, the muscle groupings controlling lip compression and jaw opening, which normally fire sequentially, appear more likely to be activated synchronously.


Author(s):  
Mohamed B. Trabia ◽  
Woosoon Yim ◽  
Paul Weinacht ◽  
Venkat Mudupu

The objective of this paper is to explore a method for the design of fuzzy logic controller for a smart fin used to control the pitch and yaw attitudes of a subsonic projectile during flight. Piezoelectric actuators are an attractive alternative to hydraulic actuators commonly used in this application due to their simplicity. The proposed cantilever-shaped actuator can be fully enclosed within the hollow fin with one end fixed to the rotation axle of the fin while the other end is pinned at the trailing edge of the fin. The paper includes a dynamic model of the system based on the finite element approach. The model includes external moment due to aerodynamic effects. This paper presents a novel approach for automatically creating fuzzy logic controllers for the fin. This approach uses the inverse dynamics of the smart fin system to determine the ranges of the variables of the controllers. Simulation results show that the proposed controller can successfully drive smart fin under various operating conditions.


2019 ◽  
Vol 81 (5) ◽  
Author(s):  
Nur Fharahin Mukaiyin ◽  
Elmy Johana Mohamad ◽  
Zulkifli Mansor ◽  
Hanis Liyana Mohamad Ameran ◽  
Ruzairi Abdul Rahim ◽  
...  

The demand in an efficient technique to monitor the condition of the pipeline for oil and gas industries leads to research into alternative solutions. The conventional methods are often too expansive and require manpower to conduct an on-site inspection. Using the Eddy current testing as the main principle, this study aims to explore the capability of 8-coil channel EMT as pipeline imaging in a different analytical situation. The 2D 8-coil channel is developed using COMSOL Multiphysics and using 20 kHz sinusoidal frequency to detect the pipeline with different materials, which is alloy and aluminum. Simulation results proved that EMT is a capable tool for inspection of metallic pipelines. This paper also presented a comparison of the pipeline cross-sectional images from the simulation and experimental.


2010 ◽  
Vol 20-23 ◽  
pp. 1405-1408 ◽  
Author(s):  
Wei Hua Kuang ◽  
Qun Liu

Drawing process is an important technology in shaping products. In the paper, the geometric surfaces of tools and sheet were modeled by Pro/E software, and a 3D finite element model of the cylindrical drawing process was developed by DYNAFORM. Numerical simulation results showed the distribution of stress, strain and thickness. FLD showed no material was in crack area and risk crack area. The drawing process could be successfully completed in one stroke. The simulation results were helpful for the die design.


2015 ◽  
Vol 645-646 ◽  
pp. 1320-1325
Author(s):  
Xi Xin Ling ◽  
Da Hai Ren ◽  
Zheng You

Identification and characterization of CTCs can be used as a tool for the study of cancer metastases. A novel design of microfluidic chip used for enrichment of circulating tumor cells is presented in this paper. An integration of DLD method and negative enrichment method were designed to improve the throughput and recovery rate while getting intact CTCs. The DLD stage is used to separate CTCs from blood cells preliminarily, and the negative enrichment stage is used to acquire purified CTCs. Both of them were simulated with COMSOL Multiphysics. Simulation results showed that triangular micro-posts have better performance in DLD stage, and wave structures could generate better disturbance effect than herringbone structures. This chip provides a potential approach with high throughput and purity for the enrichment of CTCs.


2010 ◽  
Vol 156-157 ◽  
pp. 360-366
Author(s):  
Kun Zhong ◽  
Zhong Hua Du ◽  
Liang Zhou ◽  
Li Li Song

Based on the advantages and disadvantages of existing active protection system, this paper proposes a new type of airbag active protection system. The components and working process of the system is introduced. Then taking the physical process of airbag active protection system against a rocket projectile as an example, a 3D finite element model (FEM) of airbag and rocket projectile is set up. With the assistance of the software LS-DYNA3D, through performing the simulation when the rocket projectile touched the airbag with an angle 30° from the normal interface, the intercepting efficiency is calculated and analyzed in the simulation. Results show that airbag can deform and rupture the metal jet generated by the rocket projectile, thus greatly reduce its armor penetrating effect. Finally, it shows excellent protective effect of the airbag active protection system.


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