Navigation Links
Outside a vacuum: Model predicts movement of charged particles in complex media

Picture two charged particles in a vacuum. Thanks to laws of elementary electrostatics, we can easily calculate the force these particles exert upon one another, and therefore predict their movements.

Submerge those particles in a simple medium say, water and the calculation grows more complex. The charged particles' movements influence the water, which in turn may slow, speed, or otherwise alter the particles' paths. In this environment a prediction must also consider the water's reaction, or its dielectric response.

But in real biological and material systems, media are also complex: plant cells and blood cells, for instance, are made up of several media and may be oddly shaped. This heterogeneity has made predicting the movement of charged particles in complex environments extremely challenging for theoretical physicists.

Now researchers at Northwestern University's McCormick School of Engineering have developed a model that can predict the reactions of charged particles in any media. Their computational discovery, which takes cues from nature, could find applications in biology, medicine, and synthetic materials research.

The model is the culmination of seven years of work by Monica Olvera de la Cruz, Lawyer Taylor Professor of Materials Science and Engineering, Chemistry, and (by courtesy) Chemical and Biological Engineering at the McCormick School of Engineering, with partners from Arizona State University.

Creating molecular simulations in heterogeneous media requires two steps: measuring the effects of the medium's dielectric response on the charged particles and measuring the effects of the charged particles on the medium's dielectric response. In previous attempts at such simulations, models treated the two calculations separately, completing one set of calculations before turning to the next. This process required solving a differential equation that governs the motion of the charged particles namely, the Poisson equation at each step of the simulation.

The Northwestern researchers have developed a new, faster way that avoids the Poisson equation entirely. Using insight gleamed from nature, they have reframed the electrostatic problem as an energy-minimizing problem.

"Nature doesn't wait to figure out the response of the medium in order to move the charged particles, nor does it wait to position the particles before determining the response of the medium," said Olvera de la Cruz. "The dielectric response and the motion of the charged particles are inherently coupled, and our model mirrors that."

The researchers formulated a new function that gives the correct response of the medium and produces the true energy of the charged particles. This enabled them to update the position of the charged particles and the medium's response in the same simulation time step. Within this theoretical framework and simulation design, they were able to attack problems that were previously intractable.


Contact: Megan Fellman
Northwestern University

Related biology news :

1. Fat outside of arteries may influence onset of coronary artery disease
2. Hyenas that think outside the box solve problems faster
3. First model of how buds grow into leaves
4. Parkinsons disease stopped in animal model
5. New method for estimating parameters may boost biological models
6. Bone marrow transplant arrests symptoms in model of Rett syndrome
7. 3-D RNA modeling opens scientific doors
8. NCEAS researchers offer new ecological model for deep-water oil spills
9. Patel recognized with NSF Career Award for computer-modeling research on cell membranes
10. Model forecasts long-term impacts of forest land-use decisions
11. A cells first steps: Building a model to explain how cells grow
Post Your Comments:
(Date:11/16/2015)... 2015  Synaptics Inc. (NASDAQ: SYNA ), ... announced expansion of its TDDI product portfolio with ... and display driver integration (TDDI) solutions designed to ... TDDI products add to the previously-announced TD4300 ... resolution), and TD4322 (FHD resolution) solutions. All four ...
(Date:11/11/2015)... Minn. , Nov. 11, 2015   MedNet Solutions ... entire spectrum of clinical research, is pleased to announce that ... in Clinical Trials (PCT) event, to be held November ... be able to view live demonstrations of iMedNet ... and learn how iMedNet has been able to ...
(Date:11/9/2015)... Nov. 9, 2015  Synaptics Inc. (NASDAQ: SYNA ... announced broader entry into the automotive market with a ... the pace of consumer electronics human interface innovation. Synaptics, ... ideal for the automotive industry and will be implemented ... Europe , Japan , ...
Breaking Biology News(10 mins):
(Date:11/24/2015)... , ... November 24, 2015 , ... The United States ... of the 2016 USGA Green Section Award. Presented annually since 1961, the USGA Green ... or her work with turfgrass. , Clarke, of Iselin, N.J., is an ...
(Date:11/24/2015)... , Nov. 24, 2015 /CNW/ - iCo Therapeutics ... today reported financial results for the quarter ended ... expressed in Canadian dollars and presented under International ... United States ," said Andrew Rae ... advancements regarding iCo-008 are not only value enriching ...
(Date:11/24/2015)... 2015 /PRNewswire/ - Aeterna Zentaris Inc. (NASDAQ:  AEZS) (TSX: AEZ) ... of the Toronto Stock Exchange, confirms that as of ... corporate developments that would cause the recent movements in ... --> About Aeterna Zentaris Inc. ... Aeterna Zentaris is a specialty biopharmaceutical company engaged ...
(Date:11/24/2015)... ... ... This fall, global software solutions leader SAP and AdVenture Capital brought together dozens ... BIG ideas to improve health and wellness in their schools. , Now, the top ... of SAP's Teen Innovator, an all-expenses paid trip to Super Bowl 50, and an ...
Breaking Biology Technology: