Optimization and Testing of a 1H/3He Double-Nuclear Quadrature Transmit Coil, Applying the Analytical Method at 0.06T

2020 ◽  
Vol 10 (11) ◽  
pp. 2699-2706
Author(s):  
Yan Dou ◽  
Jinzhang Xu ◽  
Yuxia Hu ◽  
Liangliang Hu ◽  
Yi Wang ◽  
...  
Keyword(s):  
Radio Frequency ◽  
Design Method ◽  
Noble Gas ◽  
Simulation Method ◽  
Pso Algorithm ◽  
Optimization Method ◽  
Complex Model ◽  
Rf Coil ◽  
Low Field ◽  
Em Field

Application of polarized noble gas technology in lung functional magnetic resonance imaging (fMRI) has garnered attention for its unique advantages, such as high resolution and a lack of radiation exposure. This paper presents a 4-channel radio frequency (RF) coil design method for applications of an 1H/3He MRI system at the ultra-low field of 0.06T. For the complex model of the double-nuclear 1H/3He coil, the analytical optimization method (based on the theories of Biot-Savart law and PSO algorithm) and the electromagnetic (EM) field and radio frequency (RF) circuit co-simulation method was implemented to optimize the analysis, resulting in an effective evaluation. The simulation results demonstrated that the proposed model has the potential for imaging of the lung with the 1H/3He MRI system at an ultra-low field.

Studying on the Technique of Integration Analysis to Rigid-Flexible Mixture Virtual Prototyping in Complex Mechanic System

2012 ◽  
Vol 220-223 ◽  
pp. 53-56
Author(s):  
Bin Lin ◽  
Yong Kui Zhu ◽  
Li Jun Cai
Keyword(s):  
Mechanical System ◽  
Mechanical Design ◽  
Design Method ◽  
Virtual Prototyping ◽  
Simulation Method ◽  
Optimization Method ◽  
Parametric Modeling ◽  
Complex Mechanical System ◽  
Whole Process ◽  
Optimization And Simulation

Mechanical design have experienced a long process of development, the improvement of design method and optimization method have always been the pursuit of any designer. In recent years, introduction of CAD/CAE have increased greatly the speed of design and experiment, making mechanical design undergo a fundamental leap. However, the whole process: design-trial-improve- ment, still needs manual control to complete, designers still face the problem of complex repeating process. In views of this bottleneck, we will conduct parametric modeling on complex mechanical system in PRO/E, and let key parts import into ANSYS to be flexible .Then, we will build and analyze rigid-flexible mixture virtual prototyping in automatic dynamic analysis of mechanical systems. At last, we will integrate this process in ISIGHT3.5, exploring design-trial-improvement integrated optimization and simulation method through the optimization of the size of key parts of complex mechanical system.

Destruction of water-in-oil emulsions in electromagnetic fields in a dynamic mode

2012 ◽  
Vol 9 (1) ◽  
pp. 110-115
Author(s):  
L.A. Kovaleva ◽  
R.R. Zinnatullin ◽  
V.N. Blagochinnov ◽  
A.A. Musin ◽  
Yu.I. Fatkhullina ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Radio Frequency ◽  
Electromagnetic Fields ◽  
Dynamic Mode ◽  
Droplet Dynamics ◽  
Oil Emulsion ◽  
Numerical Studies ◽  
Em Field ◽  
Oil Emulsions ◽  
Water In Oil Emulsion

Some results of experimental and numerical studies of the influence of radio-frequency (RF) and microwave (MW) electromagnetic (EM) fields on water-in-oil emulsions are presented. A detailed investigation of the dependence of the dielectric properties of emulsions on the frequency of the field makes it possible to establish the most effective frequency range of the EM influence. The results of water-in-oil emulsion stability in the RF EM field depending on their dielectric properties are presented. The effect of the MW EM field on the emulsion in a dynamic mode has been studied experimentally. In an attempt to understand the mechanism of emulsion destruction the mathematical model for a single emulsion droplet dynamics in radio-frequency (RF) and microwave (MW) electromagnetic fields is formulated.

scholarly journals Erosion Transportation Processes as Influenced by Gully Land Consolidation Projects in Highly Managed Small Watersheds in the Loess Hilly–Gully Region, China

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1540
Author(s):  
Qianqian Ji ◽  
Zhe Gao ◽  
Xingyao Li ◽  
Jian’en Gao ◽  
Gen’guang Zhang ◽  
...  
Keyword(s):  
Similarity Theory ◽  
Design Method ◽  
Simulation Method ◽  
Practical Significance ◽  
Land Consolidation ◽  
Small Watershed ◽  
Flood Peak ◽  
Erosion Area ◽  
The Impact ◽  
Erosion Environment

The Loess Hilly–Gully region (LHGR) is the most serious soil erosion area in the world. For the small watershed with high management in this area, the scientific problem that has been paid attention to in recent years is the impact of the land consolidation project on the erosion environment in the gully region. In this study, the 3D simulation method of vegetation, eroded sediment and pollutant transport was innovated based on the principles of erosion sediment dynamics and similarity theory, and the impacts of GLCP were analyzed on the erosion environment at different scales. The verification results show that the design method and the scale conversion relationship (geometric scale: λl = 100) were reasonable and could simulate the transport process on the complex underlying surface of a small watershed. Compared with untreated watersheds, a significant change was the current flood peak lagging behind the sediment peak. There were two important critical values of GLCP impact on the erosion environment. The erosion transport in HMSW had no change when the proportion was less than 0.85%, and increased obviously when it was greater than 3.3%. The above results have important theoretical and practical significance for watershed simulation and land-use management in HMSW.

scholarly journals Lightweight and maintainable rotary-wing UAV frame from configurable design to detailed design

2021 ◽  
Vol 13 (7) ◽  
pp. 168781402110349
Author(s):  
Huiqiang Guo ◽  
Mingzhe Li ◽  
Pengfei Sun ◽  
Changfeng Zhao ◽  
Wenjie Zuo ◽  
...  
Keyword(s):  
Design Method ◽  
Geometric Model ◽  
Optimization Method ◽  
Frame Structure ◽  
Manufacturing Cost ◽  
Detailed Design ◽  
High Manufacturing Cost ◽  
The Military ◽  
Rotary Wing ◽  
Novel Design

Rotary-wing unmanned aerial vehicles (UAVs) are widespread in both the military and civilian applications. However, there are still some problems for the UAV design such as the long design period, high manufacturing cost, and difficulty in maintenance. Therefore, this paper proposes a novel design method to obtain a lightweight and maintainable UAV frame from configurable design to detailed design. First, configurable design is implemented to determine the initial design domain of the UAV frame. Second, topology optimization method based on inertia relief theory is used to transform the initial geometric model into the UAV frame structure. Third, process design is considered to improve the manufacturability and maintainability of the UAV frame. Finally, dynamic drop test is used to validate the crashworthiness of the UAV frame. Therefore, a lightweight UAV frame structure composed of thin-walled parts can be obtained and the design period can be greatly reduced via the proposed method.

scholarly journals Surrogate-Based Optimization of Horizontal Axis Hydrokinetic Turbine Rotor Blades

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 4045
Author(s):  
David Menéndez Arán ◽  
Ángel Menéndez
Keyword(s):  
Turbine Blade ◽  
Design Method ◽  
Optimization Method ◽  
Turbine Rotor ◽  
Computational Effort ◽  
Rotor Blades ◽  
Linear Functions ◽  
Cavitation Inception ◽  
Hydrokinetic Turbine ◽  
Blade Geometry

A design method was developed for automated, systematic design of hydrokinetic turbine rotor blades. The method coupled a Computational Fluid Dynamics (CFD) solver to estimate the power output of a given turbine with a surrogate-based constrained optimization method. This allowed the characterization of the design space while minimizing the number of analyzed blade geometries and the associated computational effort. An initial blade geometry developed using a lifting line optimization method was selected as the base geometry to generate a turbine blade family by multiplying a series of geometric parameters with corresponding linear functions. A performance database was constructed for the turbine blade family with the CFD solver and used to build the surrogate function. The linear functions were then incorporated into a constrained nonlinear optimization algorithm to solve for the blade geometry with the highest efficiency. A constraint on the minimum pressure on the blade could be set to prevent cavitation inception.

Disorientation of Cs(62P1/2) atoms, induced in collisions with noble gases

1976 ◽  
Vol 54 (7) ◽  
pp. 748-752 ◽  
Author(s):  
B. Niewitecka ◽  
L. Krause
Keyword(s):  
Cross Sections ◽  
Noble Gas ◽  
Zero Magnetic Field ◽  
Zero Field ◽  
Buffer Gas ◽  
Resonance Fluorescence ◽  
Circularly Polarized ◽  
Low Field ◽  
Good Agreement ◽  
Gas Pressures

The disorientation of 62P1/2 cesium atoms, induced in collisions with noble gas atoms in their ground states, was systematically investigated by monitoring the depolarization of cesium resonance fluorescence in relation to noble gas pressures. The Cs atoms, contained together with a buffer gas in a fluorescence cell and located in zero magnetic field, were excited and oriented by irradiation with circularly polarized 8943 Å resonance radiation, and the resonance fluorescence, emitted in an approximately backward direction, was analyzed with respect to circular polarization. The experiments yielded the following disorientation cross sections which have been corrected for the effects of nuclear spin: Cs–He: 4.9 ± 0.7 Å2; Cs–Ne: 2.1 ± 0.3 Å2; Cs–Ar: 5.6 ± 0.8 Å2; Cs–Kr: 5.8 ± 0.9 Å2; Cs–Xe: 6.3 ± 0.9 Å2. The results are in good agreement with most of the available zero-field and low-field data.

A Mathematical Principle and Application on Design of Planar Six-Bar Mechanism with unto Three-Ordered Intermission at Limit Position(s)

2010 ◽  
Vol 37-38 ◽  
pp. 9-13
Author(s):  
Hong Xin Wang ◽  
Ning Dai
Keyword(s):  
Design Method ◽  
Optimization Method ◽  
Basic Function ◽  
Mathematical Principle ◽  
Transmission Characteristics ◽  
Basic Functions ◽  
Combined Mechanism ◽  
Limit Position ◽  
Derivatives Of ◽  
Better Than

A non-iterative design method about high order intermittent mechanisms is presented. The mathematical principle is that a compound function produced by two basic functions, and then one to three order derivatives of the compound function are all zeroes when one order derivative of each basic function is zero at the same moment. The design method is that a combined mechanism is constructed by six bars; the displacement functions of the front four-bar and back four-bar mechanisms are separately built, let one order derivatives of two displacement functions separately be zero at the same moment, and then get geometrical relationships and solution on the intermittent mechanism. A design example shows that this method is simpler and transmission characteristics are better than optimization method.

Median Morphological Filter Design Based on the PSO Algorithm

2011 ◽  
Vol 128-129 ◽  
pp. 181-184
Author(s):  
You Lian Zhu ◽  
Cheng Huang
Keyword(s):  
Filter Design ◽  
Design Method ◽  
Signal To Noise Ratio ◽  
Pso Algorithm ◽  
Morphological Operations ◽  
Morphological Filter ◽  
Signal To Noise ◽  
Noise Ratio ◽  
The Cost ◽  
Filter Design Method

Design of morphological filter greatly depends on morphological operations and structuring elements selection. A filter design method used median closing morphological operation is proposed to enhance the image denoising ability and the PSO algorithm is introduced for structural elements selecting. The method takes the peak value signal-to-noise ratio (PSNR) as the cost function and may adaptively build unit structuring elements with zero square matrix. Experimental results show the proposed method can effectively remove impulse noise from a noisy image, especially from a low signal-to-noise ratio (SNR) image; the noise reduction performance has obvious advantages than the other.

Calculation and Design Method Study of the Coil-Wound Heat Exchanger

2014 ◽  
Vol 1008-1009 ◽  
pp. 850-860 ◽  
Author(s):  
Zhou Wei Zhang ◽  
Jia Xing Xue ◽  
Ya Hong Wang
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Heat Exchanger ◽  
Design Method ◽  
Fluid Velocity ◽  
Exchange Process ◽  
Three Dimensional ◽  
Simulation Method ◽  
Physical Parameters ◽  
Numerical Result

A calculation method for counter-current type coil-wound heat exchanger is presented for heat exchange process. The numerical simulation method is applied to determine the basic physical parameters of wound bundles. By controlling the inlet fluid velocity varying in coil-wound heat exchanger to program and calculate the iterative process. The calculation data is analyzed by comparison of numerical result and the unit three dimensional pipe bundle model was built. Studies show that the introduction of numerical simulation can simplify the pipe winding process and accelerate the calculation and design of overall configuration in coil-wound heat exchanger. This method can be applied to the physical modeling and heat transfer calculation of pipe bundles in coil wound heat exchanger, program to calculate the complex heat transfer changing with velocity and other parameters, and optimize the overall design and calculation of spiral bundles.

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