## What Happens If I Use 2 Different Unit Systems in 1 Simulation?

##### Amit Patil December 6, 2017

Measurements and units make our professional and personal lives orderly and systematic. Different unit systems have been used over time, but today there are two dominant systems: the metric and English unit systems. What happens when both unit systems are used for the same application? In this blog post, we will shed light on two historical disasters brought about by the use of different unit systems and highlight unique features of the COMSOL Multiphysics® software for handling different unit systems.

### How to Model Optical Anisotropic Media with COMSOL Multiphysics®

##### Uttam Pal December 4, 2017

On a bright evening in 1669, Professor Erasmus Bartholinus looked through a piece of an Icelandic calcite crystal he had placed onto a bench. He observed when he covered text on the bench with the stone, it appeared as a double image. The observed optical phenomenon, called birefringence, involves a beam of light that splits into two parallel beams while emerging out of a crystal. Here, we demonstrate a modeling approach for this effect.

### Should I Fillet the Geometry in My Electromagnetic Heating Analysis?

##### Walter Frei November 30, 2017

To fillet or not to fillet, that is the question (that can bedevil the multiphysics analyst). When building finite element models, sharp edges can lead to local singularities and fields that are nonconvergent with mesh refinement. Rounding off these sharp edges by adding a fillet avoids this singularity. As it turns out, in many multiphysics models, these sharp edges and the resultant singularities do not necessarily negatively affect the results. Let’s find out more.

### Happy Birthday, Christian Doppler

##### Caty Fairclough November 29, 2017

You’re driving on the highway as an ambulance goes by, siren blaring. After the ambulance passes your car, you notice that the pitch of the siren suddenly drops. This happens due to the Doppler effect, which is named after physicist and mathematician Christian Doppler.

### How to Model Wet Chemical Etching in COMSOL Multiphysics®

##### Rasmus Karlsson November 27, 2017

Wet chemical etching is used to form patterns on surfaces, with applications including the production of integrated circuits, MEMS devices, and pressure sensors. This process has been around for hundreds of years, and was a favorite method of Old Master Rembrandt van Rijn. The optimization of chemical etching was historically a matter of trial and error, but in this blog post, we’ll show how to model the process in the COMSOL Multiphysics® software.

### Analyzing Magnetic Flow Meters for Blood Flow Measurement

##### Brianne Costa November 24, 2017

Magnetic flow meters are a noninvasive option for measuring blood flow. However, when patients move, displaced blood vessels can affect the sensitivity of the flow meter. Researchers from ABB Corporate Research used multiphysics modeling to study how the displacement of blood vessels in a moving patient impacts the performance of a magnetic flow meter.

### Happy Birthday, Johannes Diderik van der Waals

##### Caty Fairclough November 23, 2017

Throughout his lifetime, Johannes Diderik van der Waals worked toward increasing our understanding of liquids and gases. With his groundbreaking work, he made a name for himself in molecular science and earned a Nobel Prize in Physics.

### Optimizing a Microlens Design for Optogenetics Applications

##### Brianne Costa November 22, 2017

There is a lot we know about the brain, and a lot we don’t. Optogenetics is a relatively new area of study in which light is used to stimulate brain activity and study neurological behavior. Stimulating neurons with light is more precise than electrical stimulation — and safer. Researchers from Massachusetts Institute of Technology (MIT) used simulation to design an optical probe that can be implanted into the brain to stimulate nerve impulses.

### Award-Winning Posters from the COMSOL Conference 2017 Beijing

##### Yuhang Qin November 17, 2017

In early November, simulation engineers and professionals from across China gathered at the COMSOL Conference 2017 Beijing. More than 70 guests presented their simulation work during the conference presentation sessions. Attendees voted for their favorite posters and three of them earned Best Poster awards. Read on to learn how these posters stood out among a collection of innovative and inspiring projects.

### Top Papers and Posters from the COMSOL Conference 2017 Rotterdam

##### Gerard Hegemans November 16, 2017

At the COMSOL Conference 2017 Rotterdam, simulation specialists from across Europe (and some from as far away as Chile and South Korea) showcased their innovative research and modeling work. Among the many excellent user presentations, several made a special impression and were recognized with awards. Read on to learn about the top papers and posters from the COMSOL Conference 2017 Rotterdam.

### Focusing on Einzel Lenses with Particle Tracing Simulation

##### Caty Fairclough November 15, 2017

Einzel lenses are used to focus charged particle beams in cathode ray tubes (CRTs). To properly analyze an einzel lens, we need to study the charged particles in the lens subject to appropriate electrical excitation. Here, we discuss one such example that uses the Particle Tracing Module, an add-on product to the COMSOL Multiphysics® software.