所谓近场声学，是相对于远场声学而言。传统的声学理论，通常只研究远离光源或者远离物体的声场分布，一般统称为远场声学。远场声学在原理上存在着一个远场衍射极限，限制了利用远场光学原理进行显微和其它光学应用时的最小分辨尺寸和最小标记尺寸。而近场声学则研究距离光源或物体一个波长范围内的光场分布。在近场声学研究领域，远场衍射极限被打破，分辨率极限在原理上不再受到任何限制，可以无限地小，从而基于近场声学原理可以提高显微成像与其它光学应用时的光学分辨率。 声学超材料自问世之日起就受到了国内外科学家们的广泛追捧，在很多领域都可以看到其踪迹，以声子晶体为代表的声超材料具有很多天然材料所不具备的声学特性，为声学信号处理带来了很多创新的思路和途径。 声超材料的突出特点在于采用尺寸远小于入射波长的人工结构构建出等效参数，利用等效参数实现“小尺寸结构调控大尺寸波长”的目的。 ...
Influence of Notches in Corners of Casement Windows on Stress Experienced in the Aluminum Profiles under Thermal Load
J. Arfaoui , L. Fromme 
 University of Applied Sciences Bielefeld, Department of Engineering Sciences and Mathematics, Bielefeld, Germany
Modern aluminum casement windows consist of an inner and outer profile made of aluminum, which are separated by an insulating bar made of polyamide (see Figure 1). Due to the low heat conductivity of the plastic material the thermal interaction between the living space and the surrounding is reduced significantly, but thermal expansion of the different materials could cause elastic or even ...
J. Drillet ,
 DECHEMA-Forschungsinstitut, Frankfurt, Germany
This work aims at the modelling of a 5 cm^2 Direct Methanol Fuel Cell (DMFC) with mixed serial/parallel serpentine flow fields in terms of current/voltage behavior. One of the main challenge to overcome consists on lowering the so-called methanol cross over from the anode through the polymer membrane to the cathode that is responsible for mixed-potential formation at the cathode where both ...
A. Frey , I. Kuehne , R. Großmann , T. Frommelt , L. Fromme , T. Koch ,
 Augsburg University of Applied Sciences, Augsburg, Bavaria, Germany
 Heilbronn University, Heilbronn, Germany
 Bielefeld University of Applied Sciences, Bielefeld, Germany
 COMSOL Multiphysics GmbH, Göttingen, Germany
Today, 90 percent of automation sensors are binary proximity detectors. Besides capacitive and optical types, inductive proximity sensors are essential for industrial applications. Compared to their mechanical counterparts, they offer almost ideal properties as contact-free and wear-free working principle as well as high switching frequency and precision. Inductive sensors cover a detection ...
J. Boon , H. Heuver , F. Velterop , H. van Veen , A. de Groot ,
 ECN, Petten, The Netherlands
 Pervatech, Rijssen, The Netherlands
Pervaporation is the selective evaporation of one component in a liquid mixture using a membrane. HybSi pervaporation membranes consist of porous ceramic support tubes with a thin selective layer on the inside or feed side. Modules for 7 and 19 membrane bundles (surface area up to 2.0 m2) are studied in COMSOL Multiphysics® for the absence of pressure drop on the permeate side. With a water flux ...
S. Bekemeier, L. Fromme, A. Genschel, K. Kröger
University of Applied Sciences Bielefeld, Department of Engineering Sciences and Mathematics, Bielefeld, Germany
Adequate cooling of beverages is a major issue in planning of several types of events, e.g. poster sessions at conferences. One crucial factor is the time needed to cool beverages from its initial temperature to the desired drinking temperature. We present a way to determine a close approximation for the cooling behavior of three types of commonly used beverage containers using COMSOL ...
L. T. Gritter , E. Dunlop , J. S. Crompton , K. C. Koppenhoefer 
 AltaSim Technologies, Columbus, OH, USA
 Pan Pacific Technologies Pty Ltd, Adelaide, South Australia, Australia
Photo-bioreactors generate biomass by providing a controlled environment for the cultivation of algae due to photosynthesis. Algae cultivation can be controlled through the operating parameters and bioreactor environment to allow for high productivity and the use of systems with large surface-to-volume ratios offers maximum efficiency in the use of light compared to alternative batch systems. ...
J. H. Al-Smail 
 King Fahd University of Petroleum & Minerals, Dhahran, Saudi Arabia
We develop a porosity-optimization problem to improve the electrochemical reactions taking place in hydrogen fuel cells. We introduce a mathematical model, which involves a system of conservation laws defined in a porous space domain. Our goal is to find the domain's optimal porosity function that can make the oxygen-hydrogen reaction as uniform as possible. The optimal porosity design ...
K. Gandhi ,
 University of California, Riverside, CA, USA
The delivery of chemotherapy for cancer into the central nervous system, in particular the brain, remains a challenge. This results in brain metastases commonly being a cause of death from cancer. Here, we look at the environment of the blood-brain barrier. Then, we explore two proteins (breast cancer resistance protein and p-glycoprotein) that may inhibit the transport of medications (erlotinib ...
S. L. Pinjare , V. S. Nagaraja , K. S. Rudresh ,
 Department of ECE , Nitte Meenakshi Institute of technology, Bangalore, Karnataka, India
A Piezoelectric Directional Microphone is demonstrated based on a bio-mimetic design inspired by the parasitoid fly Ormia ochracea using the PiezoMUMPs multi-user foundry. The device simulation was conducted using COMSOL Multiphysics® software which achieves a directional sound field response and frequency band of 3.5 KHz to 4.5KHz. The sensitivity of the device is 3.8nV/pa.