3-D models of electrical streamers

New work, described in Journal of Applied Physics, may be key to avoiding large-scale power outages

2013-09-27

(Press-News.org) WASHINGTON D.C. September 27, 2013 -- Streamers may be great for decorating a child's party, but in dielectrics, they are the primary origin of electric breakdown. They can cause catastrophic damage to electrical equipment, harm the surrounding environment, and lead to large-scale power outages.

Understanding streamers and the mechanisms behind their initiation, acceleration and branching is necessary to devise better solutions to avoid them. As recently reported in the Journal of Applied Physics, a team of researchers at MIT have developed an accurate 3-D model of streamer propagation that qualitatively and quantitatively describes the streamer development, an advance that may impact applications such as medical imaging, aerospace engineering, power transmission, atmospheric sensing, natural sciences, sensing technologies and large-scale industry.

Whether we realize it or not, every one of us experiences streamers in a phenomenon called electrostatic discharge. When you touch a piece of woolen cloth or a metallic object like the body of your car, it is very likely that you sense a tiny streamer discharge which is sometimes painful. These sparks may be the most common streamers that human beings experience in daily life. More than just being annoying, such streamers can be powerful enough to damage expensive electronic devices and even cause fires.

In their new paper, Jouya Jadidian and his team at the Massachusetts Institute of Technology (MIT) took a comprehensive approach to their study of streamers.

"Our modeling results are understandable even for someone without advanced knowledge of physics, since we have generated very intuitive 3-D plots of streamer tree structures that helps streamer branching mechanisms to be simply inferred," he said.

The model also relates the physical attributes of streamers to tangible circuit parameters measured in ordinary laboratories such as voltage, current and time-delay. The results have proven highly accurate given an extraordinary resemblance between modeling results and experimental images taken from the light emitting streamers. Jadidian's research in this area has been awarded the IEEE Guenther Award and the Chorafas Foundation Award in 2013.

The development of this model involves some real challenges. Although 3-D imagery in gases is doable using current technology, streamer imaging in liquid dielectrics is extremely difficult. Creating a comprehensive 3-D streamer model also imposes significant numerical burden that requires very efficient modeling code and powerful computational tools. "The molecular structure and behavior of liquids are more complex than gases and solids, and even in the purest liquids, there are trace amounts of impurities that make it difﬁcult to isolate the mechanisms behind electrical breakdown," Jadidian explained.

The next step in this research is applying these findings to challenges such as reducing the size of large medical machines such as MRIs and large power equipment such as power transformers, improving insulation materials, and identifying future potential of novel plasma treatment technologies such as industrial and medical sterilization of food, surgical equipment and even a surgeon's hands using plasmas.

The model offers great promise said Jadidian, "Another outcome of this research would be optimization of novel dielectric materials such as nanofluids that could suppress and even avoid streamer branching and consequently limit streamer acceleration and lowering the chance of electrical failure."

INFORMATION:

The article, "Stochastic and Deterministic Causes of Streamer Branching in Liquid Dielectrics" by Jouya Jadidian, Markus Zahn, Nils Lavesson, Ola Widlund and Karl Borg appears in the Journal of Applied Physics. See: http://dx.doi.org/10.1063/1.4816091

Authors of this paper are affiliated with MIT and ABB Corporate Research in Västerås, Sweden.

ABOUT THE JOURNAL

The Journal of Applied Physics, produced by AIP Publishing, is an influential international journal featuring significant new experimental and theoretical results of applied physics research. See: http://jap.aip.org

ELSE PRESS RELEASES FROM THIS DATE:

A new paradigm for nanoscale resolution MRI has been experimentally achieved

2013-09-27

A team from the University of Illinois at Urbana-Champaign and Northwestern University has devised a novel nuclear magnetic resonance imaging (MRI) technique that delivers a roughly 10¬nanometer spatial resolution. This represents a significant advance in MRI sensitivity -- modern MRI techniques commonly used in medical imaging yield spatial resolutions on the millimeter length scale, with the highest-resolution experimental instruments giving spatial resolution of a few micrometers. "This is a very promising experimental result," said U. of I. physicist Raffi Budakian, ...

Folic acid deficiency has multigenerational effects

2013-09-27

Researchers from the universities of Calgary and Cambridge, UK, have discovered that a mutation in a gene necessary for the metabolism of folic acid not only impacts immediate offspring but can also have detrimental health effects, such as spina bifida and heart abnormalities, on subsequent generations. The animal study, published this week in the journal Cell, also sheds light on the molecular mechanism of folic acid (also known as folate) during development. About one in 1,200 children are born with spina bifida. The detrimental effects of folic acid deficiency during ...

Joslin identifies immune cells that promote growth of beta cells in type 1 diabetes

2013-09-27

BOSTON - (September 27, 2013) - Joslin researchers have identified immune cells that promote growth of beta cells in type 1 diabetes. This study provides further evidence of a changed role for immune cells in type 1 diabetes pathology. The study appears online today and will also appear in the January issue of Diabetes. In type 1 diabetes, the immune system infiltrates pancreatic islets and destroys insulin-producing beta cells. However, previous studies in non-obese diabetic (NOD) mice have suggested that immune cells can also contribute to preserving beta cells. This ...

Study: New medical device extremely effective at preventing HIV in women

2013-09-27

It's often said that the HIV/AIDS epidemic has a woman's face. The proportion of women infected with HIV has been on the rise for a decade; in sub-Saharan Africa, women constitute 60 percent of people living with disease. While preventative drugs exist, they have often proven ineffective, especially in light of financial and cultural barriers in developing nations. A new intravaginal ring filled with an anti-retroviral drug could help. Developed with support from the National Institute of Allergy and Infectious Diseases by Northwestern University visiting associate professor ...

Oncogenic signatures mapped in TCGA a guide for the development of personalized therapy

2013-09-27

New York, September 27, 2013 -- Clinical trial design for new cancer therapies has historically been focused on the tissue of origin of a tumor, but a paper from researchers at Memorial Sloan-Kettering Cancer Center published on September 26 in Nature Genetics supports a new approach: one based on the genomic signature of a tumor rather than the tissue of origin in the body. It is well known that the emergence of cancer is a multi-step process, but because of the efforts of The Cancer Genome Atlas (TCGA), funded by the US National Institutes of Health, and other large-scale ...

Setting blurred images in motion improves perception

2013-09-27

Philadelphia, Pa. (September 26, 2013) - Blurred images that are unidentifiable as still pictures become understandable once the images are set in motion. That's because of a phenomenon called "optic flow"—which may be especially relevant as a source of visual information in people with low vision, reports a study 'With an Eye to Low Vision: Optic Flow Enables Perception Despite Image Blur' (published online ahead of print, September 3, 2013) in the October issue of Optometry and Vision Science official journal of the American Academy of Optometry. The journal is published ...

Study examines health of kidney donors

2013-09-27

Washington, DC (September 26, 2013) — The short-term risks associated with kidney donation are relatively modest, but because many donors have additional medical conditions, it is important to evaluate their ongoing health. That's the conclusion of a study appearing in an upcoming issue of the Clinical Journal of the American Society of Nephrology (CJASN). In more than a third of kidney transplantations performed in the United States, the transplanted organs come from live donors. Research suggests that there are minimal health consequences for donors, but only a few ...

NASA Mars rover Curiosity finds water in first sample of planet surface

2013-09-27

Troy, N.Y. – The first scoop of soil analyzed by the analytical suite in the belly of NASA's Curiosity rover reveals that fine materials on the surface of the planet contain several percent water by weight. The results were published today in Science as one article in a five-paper special section on the Curiosity mission. Rensselaer Polytechnic Institute Dean of Science Laurie Leshin is the study's lead author. "One of the most exciting results from this very first solid sample ingested by Curiosity is the high percentage of water in the soil," said Leshin. "About 2 ...

Wildlife face 'Armageddon' as forests shrink

2013-09-27

Singapore, 27 September 2013 – Species living in rainforest fragments could be far more likely to disappear than was previously thought, says an international team of scientists. In a study spanning two decades, the researchers witnessed the near-complete extinction of native small mammals on forest islands created by a large hydroelectric reservoir in Thailand. "It was like ecological Armageddon," said Luke Gibson from the National University of Singapore, who led the study. "Nobody imagined we'd see such catastrophic local extinctions." The study, just published ...

Pan-cancer studies find common patterns shared by different tumor types

2013-09-27

Cancer encompasses a complex group of diseases traditionally defined by where in the body it originates, as in lung cancer or colon cancer. This framework for studying and treating cancer has made sense for generations, but molecular analysis now shows that cancers of different organs have many shared features, while cancers from the same organ or tissue are often quite distinct. The Pan-Cancer Initiative, a major effort to analyze the molecular aberrations in cancer cells across a range of tumor types, has yielded an abundance of new findings reported in 18 forthcoming ...

3-D models of electrical streamers

ELSE PRESS RELEASES FROM THIS DATE:

LAST 30 PRESS RELEASES: