H. Cabrera, D.A. Zanin, L.G. De Pietro, A. Vindigni, U. Ramsperger, D. Pescia
Laboratory for Solid State Physics, ETH Zurich, Zurich, Switzerland
A sharp tip approached perpendicular to a conducting surface at subnanometer distances and biased with a small voltage builds a junction across which electrons can be transferred from the tip apex to the nearest surface atom by direct quantum mechanical tunneling. Such a junction is used e.g. in Scanning Tunneling Microscopy (STM). When the distance d between tip and collector is increased ...
Simulation of Helmholtz Resonators for Optical Gas Sensing: Comparison Between Pressure Acoustics and Thermoacoustics - new
B. Parvitte, C. Risser, R. Vallon, V. Zéninari
Université de Reims, Reims, France
Among optical gas sensing methods, photoacoustic (PA) spectroscopy combined with a laser source has proven to be a very robust and sensitive method for trace gas detection. COMSOL Multiphysics® software was used to calculate the frequency response of differential Helmholtz resonator cells in order to optimize the detection limit of PA sensors. Two different kind of simulation were performed: ...
L. Wright, G. Memoli, P. Jones, E. Stride
National Physical Laboratory, Teddington, UK
University College London, London, UK
University of Oxford, Oxford, UK
Understanding the interactions between microbubbles and surfaces is key to the successful deployment of microbubbles in a range of applications. Two important examples are their use as a drug delivery mechanism, and their potential use of acoustically-driven bubbles as microscale sensors. Drug delivery with bubbles involves sonication at high frequency close to a boundary, and sensing with ...
J. P. Mmbaga, F. Munoz, S. Dhir, R. Gupta, R. E. Hayes, M. Toledo
University of Alberta, Edmonton, AB, Canada
Departamento de Ingenieria Mecanica, Universidad Tecnica Federico Santa Maria, Valparaiso, Chile
Pyrolysis is a key step in the conversion of carbonaceous materials into useful products. In this study, we investigate the pyrolysis of asphaltene and oil shale, both experimentally and numerically. COMSOL Multiphysics® software is used to model the combined effects of fluid flow in porous media, mass transfer of species, heat transfer, and reaction kinetics. Gas evolution and the porosity ...
Conductivity Estimation of Breast Cancer Using COMSOL® Modeling of Microwave Scattering and Frechet Mean Estimate of Covariance - new
A. Jeremic, E. Khoshrowshahli
Electrical & Computer Engineering, McMaster University, Hamilton, ON, Canada
Biomedical Engineering, McMaster University, Hamilton, ON, Canada
Breast cancer detection is one of the most important problems in health care and it is second most frequent cancer according to WHO. It is recommended that women over fifty or even younger in some cases do a screening test every two years. Besides clinical breast examination, there are number of imaging methods used for this purpose, such as mammography, ultrasound and MRI. Among them, ...
Y. Ou, S. Weber
University of Pittsburgh, Pittsburgh, PA, USA
We have created and optimized a multiphysics model in COMSOL Multiphysics® software that studies sensitivity to ectopeptidase rates in the rat hippocampus. Ectopeptidases are membrane-bound enzymes whose catalytic domains face the extracellular space (ECS) (Figure 1). They have traditionally been accepted to inactivate peptides from the ECS. Recently, not only can these enzymes activate ...
T. J. Berger ,
 Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, NY, USA
The XENON Dark Matter Experiment utilizes ultra-pure xenon (Xe) as a target for particle interaction in the effort to detect dark matter particles. To measure the purity of Xe, a gas purity monitor (GPM) is being developed which drifts electrons through Xe gas to detect impurities that contribute to charge attenuation. An axially-symmetric model is used to simulate the electric field generated ...
刘佳琪 , 朴胜春 , 唐骏 
海洋覆盖了地球表面百分之七十以上的面积，其中蕴藏着丰富的生物矿产资源，日益受到世界各国的重视。声波作为海水中传输信号的唯一载体，在浅海波导中的传播受海底和海面影响很大，当声波在浅海波导中发生折射反射和散射时，如何预报复杂海底边界条件下浅海中的传播特性对海洋开发有重要意义。针对含有声速剖面的沉积层海底、楔形海底及实际弹性海底，利用有限元理论，对二维浅海声场的传播损失进行数值模拟。应用 COMSOL Multiphysics® 软件的声压接口和声结构耦合接口，把地形数据导入软件模拟真实海底的地形。把浅海波导简化成分层矩形，信号源以点声源的形式向外发射单频信号，在模型定义处添加完美匹配层模拟无限远距离处声压场情况；对于含有声速剖面情况的波导问题，在 COMSOL 中可以较为便捷地以添加内插函数的形式进行仿真，与其他声场建模软件形成对比，突显有限理论元理论计算浅海传播损失的优势 ...
Simulation of the Acoustic Environment for the Manufacture of Graded Porosity Materials by Sonication
C. Torres-Sanchez, and J. R. Corney
University of Strathclyde, United Kingdom
Many materials require functionally graded cellular microstructures whose porosity is engineered to meet specific requirements of diverse applications. It has been shown in previous work that the bubble growth rate of a polymeric foam can be influenced by the surrounding acoustic environment and, once solidified, produce a solid of graded porosity. Motivated by the desire to create a flexible ...
Y. Parikh, V. Penmatsa, J. Yang, and C. Wang
Department of Mechanical & Material Science Engineering, Florida International University, Miami, FL, USA
An Enzymatic Biofuel Cell (EBFC) converts the chemical energy in biological fuels into electricity. In this work, we optimize the performance of the Carbon-Micro Electro Mechanical system in an EBFC by using COMSOL Multiphysics. With a simple model, we realized that most of the glucose reacts with enzymes at the top of the electrode posts, while the bottoms of the posts remain deficient of the ...