J. Knox ,
 NASA Marshall Space Flight Center, Huntsville, AL, USA
In a recent publication (Limitations of Breakthrough Curve Analysis in Fixed-Bed Adsorption, Ind. Eng. Chem. Res. 2016, 55, 4734-4748) the authors discussed the a priori prediction of the axial dispersion coefficient from available correlations versus obtaining it and also mass transfer information from experimental breakthrough data and the consequences that may arise when doing so based on ...
J. T. Fong ,
 National Institute of Standards and Technology, Gaithersburg, MD, USA
In a magnetic resonance imaging (MRI) system, it is necessary to excite the nuclei of a patient into coherent precession for imaging. This requires a coupling between the nuclei and a source of radio frequency (RF) power using a transmitter. To receive a meaningful signal, we also need a coupling between the nuclei and an external circuitry known as the receiver. Both the transmitter and the ...
安琪 , 潘绍丰 , 栾兴龙 ,
生命现象中存在许多复杂的时空调节机制，以便对一些生物活性因子进行合理分配。其中，最为常见的是动态的时空浓度梯度，即随着时间积累，空间各处浓度将不断地发生变化；这一过程对于生物体来说是十分重要的。 本文受生物体系中，扩散过程中快速可逆的超分子结合作用调控浓度梯度的启发，报道水凝胶材料中快速可逆超分子结合调控物质浓度梯度的概念。在接有环糊精的水凝胶基质中，客体分子偶氮苯的扩散受超分子结合的影响，产生与自由扩散不同的浓度梯度分配。 模拟过程运用了Comsol Multiphysics 5.2中化学反应工程下的稀物质传递模块。建立一个长5mm、宽2mm、高0.5mm的三维几何体，作为水凝胶基底的模型。然后将2*0.5mm截面的某一面设置为具有恒定浓度的边界，其物质为对氨基偶氮苯，作为对氨基偶氮苯溶液与水凝胶的边界；对氨基偶氮苯的两种顺反异构体与beta-环糊精的结合常数具有一定的差异 ...
M. Weber, T. Kletschkowski, and B. Samtleben
Helmut-Schmidt-University Hamburg, Germany
An inverse finite element method for noise source identification in an aircraft cabin is presented. If all sound sources are located on the boundary of the cabin, the equation system resulting from a matching FE model can be re-sorted in such a way that computation of the unknown boundary data is possible from measurement data taken in the cavity. The method is first validated using a simplified ...
COMSOL Grab Bag: How to Use a Versatile CFD Code to Model Interesting Problems from Cryogenic Storage to Biofuel Production
Senior Research Engineer,
NASA Glenn Research Center, Cleveland, OH, USA
Emily Nelson received her PhD in Mechanical Engineering from the University of California at Berkeley. She is a senior research engineer at NASA Glenn Research Center and specializes in the formulation and solution of problems in microgravity science, multiphase flow, porous media, risk analysis, and gravitational biology. This leads her to fundamental and applied approaches on a range of issues ...
Dept. of Mechanics and Machine Design, Research Centre on Choral and Instrumental Music (MUSICOS), University of Genoa, Italy
The paper attempts to give a contribution to the dynamic analysis of musical instruments. A multidisciplinary approach oriented to the study of mechanical, structural, vibratory and acoustical phenomena related to stringed instruments is discussed. The case study focused in this paper concerns the violins family: the geometry and the vibratory propagation of this instrument is very complicated ...
F. Dewarrat, L. Falco, A. Caduff, and M. Talary
Solianis Monitoring AG, Zürich, Switzerland
Impedance spectroscopy is a measurement technique that has been investigated in a wide variety of medical applications. An example is the measurement of the dielectric properties of the skin and underlying tissue using sensors placed in contact with human skin with capacitive fringing field electrodes. The aim of this work is to use finite element methods for optimizing the sensor design ...
Two-dimensional Analysis of Triple Coupled Physics of Structural Mechanics, Diffusion and Heat Transfer in a Gas Pipe
P. Lee-Sullivan, and M. Haghighi-Yazdi
Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, Ontario, Canada
In this study, a 2-D model has been built using COMSOL Multiphysics® to analyze a triple coupled physics problem involving simultaneous gas diffusion, heat transfer, and structural mechanics in a pipe due to the flow of high-pressure carbon dioxide. The problem geometry and boundary conditions were based on the analysis by Rambert et al. who have published the most advanced modeling work in ...
W. Vetterling, and Z. Peng
Zink Imaging, Inc., Bedford, Massachusetts, USA
This document describes a method for maintaining the long-term calibration of a full color direct thermal printer. An essential component of the system is a thermal model created using COMSOL Multiphysics that allows fitting of color data recorded at different temperatures and exposure times to model results for the same conditions. The fitted results reveal the depth and thickness of color dye ...
R. Escarela-Perez, E.A. Gutierrez-Rodriguez, J.C. Olivares-Galvan, M.S. Esparza-González, and E. Campero-Littlewood
Departamento de Energia, Universidad Autonoma Metropolitana - Azcapotzalco, Mexico D.F., Mexico
Instituto Tecnologico de Aguscalientes, Aguascalientes, Mexico
This work is concerned with the study of the asymmetrical phenomenon observed in three-phase transformers during the standard short-circuit test. The purpose of our work is to see if the asymmetric measurements can be predicted with the use of 2D finite-element models. To this end, we use the AC/DC Module of COMSOL Multiphysics. A multi-port network impedance is then determined to explain the ...