Scientific Earth Conscientious

Scientific progress makes moral progress a necessity; for if man's power is increased, the checks that restrain him from abusing it must be strengthened (Madame de Stael)

Archive for July, 2012

Concussions and head impacts may accelerate brain aging

Posted by Scientific Earth Conscientious on July 31, 2012

The photos compare images of two brains, one with and without head injury. The red areas indicates electrical activity in response to the task researchers asked study participants to perform, and non-injured brains show more red, thus more electrical activity during the task.
(Credit: Image courtesy of Steven Broglio)

Concussions and even lesser head impacts may speed up the brain’s natural aging process by causing signaling pathways in the brain to break down more quickly than they would in someone who has never suffered a brain injury or concussion.

Researchers from the University of Michigan School of Kinesiology and the U-M Health System looked at college students with and without a history of concussion and found changes in gait, balance and in the brain’s electrical activity, specifically attention and impulse control, said Steven Broglio, assistant professor of kinesiology and director of the Neurotrauma Research Laboratory.

The declines were present in the brain injury group up to six years after injury, though the differences between the study groups were very subtle, and outwardly all of the participants looked and acted the same.

Broglio, who is also affiliated with Michigan NeuroSport, stressed that the studies lay out a hypothesis where concussions and head impacts accelerate the brain’s natural aging process.

The study, “Cognitive decline and aging: The role of concussive and subconcussive impacts,” appears in the July issue of journal Exercise and Sport Sciences Reviews.

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Critically endangered whales sing like birds; new recordings hint at rebound — with audio By Nancy Gohring

Posted by Scientific Earth Conscientious on July 31, 2012

This bowhead whale is a member of the population that lives in the Alaskan Beaufort Sea. The bowheads that were the subject of this study are rarely seen.
Photo by Kate Stafford

When a University of Washington researcher listened to the audio picked up by a recording device that spent a year in the icy waters off the east coast of Greenland, she was stunned at what she heard: whales singing a remarkable variety of songs nearly constantly for five wintertime months.

Kate Stafford, an oceanographer with UW’s Applied Physics Lab, set out to find if any endangered bowhead whales passed through the Fram Strait, an inhospitable, ice-covered stretch of sea between Greenland and the northern islands of Norway. Only around 40 sightings of bowhead whales, which were hunted almost to extinction, have been reported there since the 1970s.

Stafford and colleagues put two hydrophones, or underwater microphones, on moorings attached to the seafloor in Fram Strait, leaving them there for as long as the batteries would last: nearly a year. Since the population of bowhead whales likely to pass through was thought to number in the tens, they didn’t anticipate much interesting data.

“We hoped to record a few little grunts and moans,” Stafford said. “We were not expecting to get five months of straight singing.”

Not only did they record singing nearly every hour of the day and night, they picked up more than 60 unique songs. A paper detailing their discoveries appears Tuesday (July 31) as the feature article in Endangered Species Research and is openly accessible online.

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Ecosystems reveal radiation secrets. The transfer of radioactive compounds is not straightforward

Posted by Scientific Earth Conscientious on July 31, 2012

A new study by Tiina Tuovinen, from the University of Eastern Finland, and her colleagues casts doubt over the validity of models used to assess the impact of radiation on human health. Their work is published online in Springer’s journal Hydrobiologia.The Chernobyl accident in 1986 led to a discharge of radioactive compounds into terrestrial, freshwater and marine environments. Over a period of time, these compounds have been taken up by organisms and have made their way into the food chain. Since the accident, the fall-out from the power plant accident has been used as a major source of information for models which predict the transfer of these radioactive compounds into ecosystems, estimating their doses and assessing their potential effects on human health and wildlife.The authors explain: “The ability of models to accurately predict concentrations and doses depends critically on the empirical data on the behavior of radioactive compounds in the biosphere and also on the correctness of basic assumptions used in the models.”Their analysis of the contamination of two Finnish lakes by radioactive compounds (137Cs in particular) suggests that the models used to predict consequences on human health are based on a false premise. Their work therefore questions the validity of the models used and the conclusions that can be drawn from them.The researchers collected data from two lakes in Northern Finland to investigate the transfer of 137Cs from lake water into fish during a twenty-year period after the Chernobyl nuclear power plant accident. Their results show that, contrary to what has been assumed until now, the transfer of the radioactive compounds is non-linear. In addition, the levels of these compounds appear to be three times higher in fish-eating species (piscivores) than in non-fish-eating species.

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Sandia National Laboratories’ wind energy researchers are re-evaluating vertical axis wind turbines (VAWTs) to help solve some of the problems of generating energy from offshore breezes.

Posted by Scientific Earth Conscientious on July 31, 2012

Basing their work on decades of wind energy research and experience, Sandia engineers are creating several concept designs, running those designs through modern modeling software and narrowing those design options down to a single, most-workable design for a VAWT turbine-blade. Results aren’t in, but the early favorite for further testing is the Darrieus design.
Credit: (Illustration by Josh Paquette and Matt Barone)

Sandia National Laboratories’ wind energy researchers are re-evaluating vertical axis wind turbines (VAWTs) to help solve some of the problems of generating energy from offshore breezes.

Though VAWTs have been around since the earliest days of wind energy research at Sandia and elsewhere, VAWT architecture could transform offshore wind technology.

The economics of offshore windpower are different from land-based turbines, due to installation and operational challenges. VAWTs offer three big advantages that could reduce the cost of wind energy: a lower turbine center of gravity; reduced machine complexity; and better scalability to very large sizes.

A lower center of gravity means improved stability afloat and lower gravitational fatigue loads.

Additionally, the drivetrain on a VAWT is at or near the surface, potentially making maintenance easier and less time-consuming. Fewer parts, lower fatigue loads and simpler maintenance all lead to reduced maintenance costs.

Elegant in their simplicity

Sandia is conducting the research under a 2011 Department of Energy (DOE) solicitation for advanced rotor technologies for U.S. offshore windpower generation. The five-year, $4.1 million project began in January of this year.

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IBBME researchers invent new tissue engineering tool

Posted by Scientific Earth Conscientious on July 31, 2012

Photo; The Institute of Biomaterials and Biomedical Engineering
University of Toronto

Imagine a machine that makes layered, substantial patches of engineered tissue—tissue that could be used as grafts for burn victims or vascular patches. Sounds like science fiction? According to researchers at the University of Toronto, it’s a growing possibility.

Along with graduate students from their labs—Lian Leng, Boyang Zhang, and Arianna McAllister— Associate Professor Axel Guenther of the Department of Mechanical and Industrial Engineering, cross-appointed to the Institute of Biomaterials and Biomedical Engineering (IBBME), and Associate Professor Milica Radisic, core professor at IBBME and the Department of Chemical Engineering and Applied Chemistry, have invented a new device that may allow for the uniform, large-scale engineering of tissue.

“There’s a lot of interest in soft materials, particularly biomaterials,” explains Guenther of the materials that help create functional tissue cultures, “but until now no one has demonstrated a simple and scalable one-step process to go from microns to centimeters.”

The invention, presented in a cover article for the journal Advanced Materials this month, is currently being commercialized by MaRS Innovations in collaboration with the Innovations and Partnerships Office (IPO) of the University of Toronto, where Radisic and Guenther’s labs have filed two patents on the device.

But how exactly does a machine grow a large patch of living tissue?

Scientists manipulate biomaterials into the micro-device through several channels. The biomaterials are then mixed, causing a chemical reaction that forms a “mosaic hydrogel”—a sheet-like substance compatible with the growth of cells into living tissues, into which different types of cells can be seeded in very precise and controlled placements.

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Method of carbon capture and storage. Current techniques for post-combustion carbon capture filter out CO2 from a power plant’s flue gases as they travel up a chimney

Posted by Scientific Earth Conscientious on July 31, 2012

CaO readily forms a shell of calcium hydroxide when exposed to water in the air (right). Due to differences in atomic congurations (top left) between the oxide and hydroxides, enormous strains develop due to the interface. These strains of 0.78% lead to stresses 20 times higher than the rupture strength of the hydroxide leading to rupture and the generation of nanoparticles.
Deconvolution of the data generated by Diamond (bottom left) allows the Leeds team to determine the size and strain in these layers, from the breadth of the peaks (the peaks from CaOH are far narrower than CaO). Conventional X-ray sources would have considerable peak overlap, making this type of analysis almost impossible.

Diamond Light Source is being used to improve low cost methods for carbon capture. Scientists from the University of Leeds are using the UK’s national synchrotron to investigate the efficiency of calcium oxide (CaO) based materials as carbon dioxide (CO2) sorbents. Their results, published in the journal of Energy & Environmental Science, provide an explanation for one of the key mechanisms involved. This new knowledge will inform efforts to improve the efficiency of this economically viable method of carbon capture and storage.

Current techniques for post-combustion carbon capture filter out CO2 from a power plant’s flue gases as they travel up a chimney. The filter is a solvent that absorbs the CO2, before being heated, releasing water vapour and leaving behind the CO2. In pre-combustion, the CO2 is filtered out by use of a catalytic converter before the fossil fuel is burned and the CO2 is diluted by other flue gases. These methods can prevent 80% to 90% of a power plant’s carbon emissions from entering the atmosphere.

CaO based materials have a large range of applications including pre- and post-combustion carbon capture technologies and thermochemical fuel upgrading. They are low cost, high abundance, have a large sorption capacity and fast reaction rates during the chemical process. They capture CO2 in the temperature range 400-800 °C via the formation of calcium carbonate (CaCO3) which can be regenerated with subsequent release of CO2, ready for compression and storage. However, after multiple capture and regeneration cycles, the materials’ capacity for capture decreases due to the loss of surface area through sintering, a process that fuses powders together to create a single solid object. Although the surface area can be restored through hydration, the material suffers a reduction in mechanical strength. If these problems can be overcome, CaO based materials could provide a low cost answer for carbon capture on a very large scale.

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Adding a ‘3D print’ button to animation software. Tool developed at Harvard turns animated characters into fully articulated action figures

Posted by Scientific Earth Conscientious on July 31, 2012

G.I. Joe may have finally met his match.
(Photo courtesy of Moritz Bächer.)

Watch out, Barbie: omnivorous beasts are assembling in a 3D printer near you.

A group of graphics experts led by computer scientists at Harvard have created an add-on software tool that translates video game characters—or any other three-dimensional animations—into fully articulated action figures, with the help of a 3D printer.

The project is described in detail in the Association for Computing Machinery (ACM) Transactions on Graphics and will be presented at the ACM SIGGRAPH conference on August 7.

Besides its obvious consumer appeal, the tool constitutes a remarkable piece of code and an unusual conceptual exploration of the virtual and physical worlds.

“In animation you’re not necessarily trying to model the physical world perfectly; the model only has to be good enough to convince your eye,” explains lead author Moritz Bächer, a graduate student in computer science at SEAS. “In a virtual world, you have all this freedom that you don’t have in the physical world. You can make a character so anatomically skewed that it would never be able to stand up in real life, and you can make deformations that aren’t physically possible. You could even have a head that isn’t attached to its body, or legs that occasionally intersect each other instead of colliding.”

Returning a virtual character to the physical world therefore turns the traditional animation process on its head, in a sort of reverse rendering, as the image that’s on the screen must be adapted to accommodate real-world constraints.

Bächer and his coauthors demonstrated their new method using characters from Spore, an evolution-simulation video game. Spore allows players to create a vast range of creatures with numerous limbs, eyes, and body segments in almost any configuration, using a technique called procedural animation to quickly and automatically animate whatever body plan it receives.

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Never again a flat vehicle battery: RUB researchers develop early warning system. Battery management permanently checks the age, state of charge and operational reliability

Posted by Scientific Earth Conscientious on July 31, 2012

Test of the battery management system
Credit: Ruhr-University Bochum

Never again a flat battery

RUB researchers develop an early warning system for vehicle batteries Battery management permanently checks the age, state of charge and operational reliability

A flat battery can turn an unsuspecting car driver into an unintentional pedestrian. The fact that vehicle batteries go flat all of a sudden is a well-known problem, but one that can also be avoided in future. Scientists from the RUB working group for Energy Systems Technology and Power Mechatronics headed by Professor Dr. Constantinos Sourkounis and Philip Dost have now developed an effective early warning system together with the Isabellenhütte Heusler GmbH & Co. KG.

Means of avoiding threatened total breakdown

The new battery management system for lead-acid accumulators is intended to prevent drivers from a total breakdown. The car driver is informed via the on-board computer that a change of battery or a new vehicle battery is imminent. Compared to previous battery management systems, no subsequent reprogramming is required in the garage. “During the first journey the system automatically measures and recognizes at the same time the current battery parameters”, said Professor Sourkounis. Information is provided about the age, the charge and functionality of the vehicle battery. This intelligent control is urgently required as modern cars require more and more energy. Apart from the combustion motor and headlights, dozens of small electrical motors and sensors need electric power.

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Study: Conciliatory tactics more effective than punishment in reducing terrorism

Posted by Scientific Earth Conscientious on July 31, 2012

Photo by Gípics on Flickr (CC)

Policies that reward abstinence from terrorism are more successful in reducing such acts of violence than tactics that aim to punish terrorists, suggests a new study in the August issue of the American Sociological Review.

Titled, “Moving Beyond Deterrence: The Effectiveness of Raising the Expected Utility of Abstaining from Terrorism in Israel,” the study looked specifically at the Israeli-Palestinian conflict and found that between 1987 and 2004, Israeli policies and actions that encouraged and rewarded refrain from terrorist acts were more successful in reducing terrorism than policies focused on punishment.

“Our argument begins to challenge the very common view that to combat terrorism, you have to meet violence with violence,” said Erica Chenoweth, study co-author and Assistant Professor at the Josef Korbel School of International studies at the University of Denver.

The study is the first to empirically evaluate the potential of conciliatory tactics in reducing terrorism. It relies on data from the Center for the Study of Terrorism and Response to Terrorism’s (START) Global Terrorism Database (GTD) and from the Government Actions in a Terrorist Environment-Israel (GATE-Israel) dataset. The GTD records global terrorist attacks, including Palestinian terrorist acts, while the GATE-Israel dataset, which the study authors developed, identifies counterterrorism strategies that Israel used against Palestinian targets and places them on a seven point scale from violent acts resulting in death to conciliatory acts involving peaceful gestures.

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Stem cell therapy could offer new hope for defects and injuries to head, mouth

Posted by Scientific Earth Conscientious on July 31, 2012

In the first human study of its kind, researchers found that using stem cells to re-grow craniofacial tissues—mainly bone—proved quicker, more effective and less invasive than traditional bone regeneration treatments.

Researchers from the University of Michigan School of Dentistry and the Michigan Center for Oral Health Research partnered with Ann Arbor-based Aastrom Biosciences Inc. in the clinical trial, which involved 24 patients who required jawbone reconstruction after tooth removal.

Patients either received experimental tissue repair cells or traditional guided bone regeneration therapy. The tissue repair cells, called ixmyelocel-T, are under development at Aastrom, which is a U-M spinout company.

“In patients with jawbone deficiencies who also have missing teeth, it is very difficult to replace the missing teeth so that they look and function naturally,” said Darnell Kaigler, principal investigator and assistant professor at the U-M School of Dentistry. “This technology and approach could potentially be used to restore areas of bone loss so that missing teeth can be replaced with dental implants.”

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Researchers at Duke University Medical Center have now discovered that mutations in one gene cause the disease in the majority of patients with a diagnosis of AHC (Alternating hemiplegia of childhood), and because of the root problem they discovered, a treatment may become possible.

Posted by Scientific Earth Conscientious on July 30, 2012

Magnetic resonance imaging of the AHC patients (A, C, and E: T2-weighted images, B, D, and F: T1-weighted images). (A–D) Patient 1 at age 18 years. Atrophy of frontal lobe (A) and cerebellum (B and D) and high signal changes in the hippocampus (C) are noted. (E and F) Patient 2 at age 5 years. Cerebellar atrophy is present (F), but otherwise there are no abnormal findings (E).

Alternating hemiplegia of childhood (AHC) is a very rare disorder that causes paralysis that freezes one side of the body and then the other in devastating bouts that arise at unpredictable intervals. Seizures, learning disabilities and difficulty walking are common among patients with this diagnosis.

Researchers at Duke University Medical Center have now discovered that mutations in one gene cause the disease in the majority of patients with a diagnosis of AHC, and because of the root problem they discovered, a treatment may become possible.

The study was published online on July 29 in Nature Genetics.

AHC is almost always a sporadic disease, which means that typically no one else in the family has the disease, said Erin Heinzen, Ph.D., co-author of the study and Assistant Professor of Medicine in the Section of Medical Genetics. “Knowing that we were looking for genetic mutations in children with this disease that were absent in the healthy parents, we carefully compared the genomes of seven AHC patients and their unaffected parents. When we found new mutations in all seven children in the same gene we knew we had found the cause of this disease.”

All of the mutations were found in a gene that encodes ATP1A3, one piece of a key transporter molecule that normally would move sodium and potassium ions across a channel between neurons (nerve cells) to regulate brain activity.

In a remarkably broad international collaborative effort, the authors partnered with three family foundations (USA, Italy and France), including scientists from 13 different countries, to study an additional 95 patients and showed over 75 percent had disease-causing mutations in the gene for ATP1A3.

“This study is an excellent example of how genetic research conducted on a world-wide scale really can make a difference for such a rare disorder as AHC,” said Arn van den Maagdenberg, Ph.D., and co-author on the study and geneticist from Leiden University Medical Centre in the Netherlands. “It truly was an effort from many research groups that led to this remarkable discovery.”

“This kind of discovery really brings home just what the human genome project and next-generation sequencing have made possible,” said David Goldstein, Ph.D., Director of the Duke Center for Human Genome Variation and co-senior author on the study. “For a disease like this one with virtually no large families to study, it would have been very difficult to find the gene before next-generation sequencing.”

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According to a new study by scientists at Duke and Baylor Water pollution from surface coal mining has degraded more than 22 percent of streams and rivers in southern West Virginia to the point they may now qualify as impaired under state criteria

Posted by Scientific Earth Conscientious on July 30, 2012

A West Virginia stream polluted by coal mine drainage
(Photo courtesy iLoveMountains.org)

Water pollution from surface coal mining has degraded more than 22 percent of streams and rivers in southern West Virginia to the point they may now qualify as impaired under state criteria, according to a new study by scientists at Duke and Baylor.

The study, published this week in the peer-reviewed journal Environmental Science & Technology, documents substantial losses in aquatic insect biodiversity and increases in salinity linked to sulfates and other pollutants in runoff from mines often located miles upstream.

“Our findings offer concrete evidence of the cumulative impacts surface mining is having on a regional scale,” said Emily S. Bernhardt, associate professor of biogeochemistry at Duke’s Nicholas School of the Environment. “The relationship is clear and direct. The more mining you have upstream, the higher the biological loss and salinity levels will be downstream, and the farther they will extend.”

Numerous recent studies have demonstrated the water-quality problems caused at or near the site of individual surface coal mines, Bernhardt noted. She and her team “set out to understand how the large and growing number of surface mines is affecting water quality throughout Appalachia.”

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New international study led by the University of Colorado Boulder shows the onset of the Later Stone Age in South Africa likely began some 44,000 to 42,000 years ago

Posted by Scientific Earth Conscientious on July 30, 2012

New research led by CU-Boulder on South Africa’s Border Cave shows the Later Stone Age emerged more than 20,000 years than previously thought.
Credit: Courtesy Paola Villa, University of Colorado

The Later Stone Age emerged in South Africa more than 20,000 years earlier than previously believed — about the same time humans were migrating from Africa to the European continent, says a new international study led by the University of Colorado Boulder.

The study shows the onset of the Later Stone Age in South Africa likely began some 44,000 to 42,000 years ago, said Paola Villa, a curator at the University of Colorado Museum of Natural History and lead study author. The new dates are based on the use of precisely calibrated radiocarbon dates linked to organic artifacts found at Border Cave in the Lebombo Mountains on the border of South Africa and Swaziland containing evidence of hominid occupation going back 200,000 years.

The Later Stone Age is synonymous to many archaeologists with the Upper Paleolithic Period, when modern humans moved from Africa into Europe roughly 45,000 years ago and spread rapidly, displacing and eventually driving Neanderthals to extinction. The timing of the technological innovations and changes in the Later Stone Age in South Africa are comparable to that of the Upper Paleolithic, said Villa.

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Team of researchers has discovered the eating habits of Diplodocus using a three-dimensional model of the dinosaur’s skull

Posted by Scientific Earth Conscientious on July 30, 2012

Diplodocus Skull
Photo by Patti Heck

A team of researchers from the University of Bristol, Natural History Museum of London, the University of Missouri and Ohio University has discovered the eating habits of Diplodocus using a three-dimensional model of the dinosaur’s skull. The eating habits of the herbivore have been uncertain since its discovery more than 130 years ago. Understanding these behaviors could help scientists better understand extinct and modern ecosystems and what it takes to feed these giant herbivores, as well as today’s living animals.

Diplodocus was a giant, herbivorous sauropod dinosaur from the Jurassic period, which was around 150 million years ago. The dinosaur, which was more than 170 feet long and weighed more than 12 tons, was the longest animal ever to walk the planet. Its neck was about 20 feet in length.

“Since Diplodocus was such a huge animal, its eating habits and behavior have always been a question in the paleontology community,” said Casey Holliday, an assistant professor of pathology and anatomical sciences at MU. “With the 3D model of the skull, we were able to simulate three eating scenarios using a computer-based analysis to determine the stresses that the skull would experience in each situation.”

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MIT News Release: 10-year-old problem in theoretical computer science falls. Interactive proofs — mathematical games that underlie much modern cryptography — work even if players try to use quantum information to cheat

Posted by Scientific Earth Conscientious on July 30, 2012

Thomas Vidick
Postdoc at MIT’s Computer Science and Artificial Intelligence Laboratory

Interactive proofs, which MIT researchers helped pioneer, have emerged as one of the major research topics in theoretical computer science. In the classic interactive proof, a questioner with limited computational power tries to extract reliable information from a computationally powerful but unreliable respondent. Interactive proofs are the basis of cryptographic systems now in wide use, but for computer scientists, they’re just as important for the insight they provide into the complexity of computational problems.

Twenty years ago, researchers showed that if the questioner in an interactive proof is able to query multiple omniscient respondents — which are unable to communicate with each other — it can extract information much more efficiently than it could from a single respondent. As quantum computing became a more popular research topic, however, computer scientists began to wonder whether such multiple-respondent — or “multiprover” — systems would still work if the respondents were able to perform measurements on physical particles that were “entangled,” meaning that their quantum properties were dependent on each other.

At the IEEE Symposium on Foundations of Computer Science in October, Thomas Vidick, a postdoc at MIT’s Computer Science and Artificial Intelligence Laboratory, and Tsuyoshi Ito, a researcher at NEC Labs in Princeton, N.J., finally answer that question: Yes, there are multiprover interactive proofs that hold up against entangled respondents. That answer is good news for cryptographers, but it’s bad news for quantum physicists, because it proves that there’s no easy way to devise experiments that illustrate the differences between classical and quantum physical systems.

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A giant step in a miniature world: UZH researcher measures the electrical charge of nano particles

Posted by Scientific Earth Conscientious on July 30, 2012

This is a cross-section through two chip-sized glass plates in which a nano particle is trapped in an energy hole (or “potential well” to use the scientific term). The colored fields show the different charges in the electrostatic field. The red zone signifies a very low charge, while the blue edges have a strong charge.
Credit: Picture: University of Zurich

In order to observe the individual particles in a solution, Prof. Madhavi Krishnan and her co-workers «entice» each particle into an «electrostatic trap». It works like this: between two glass plates the size of a chip, the researchers create thousands of round energy holes. The trick is that these holes have just a weak electrostatic charge. The scientists than add a drop of the solution to the plates, whereupon each particle falls into an energy hole and remains trapped there. But the particles do not remain motionless in their trap. Instead, molecules in the solution collide with them continuously, causing the particles to move in a circular motion. «We measure these movements, and are then able to determine the charge of each individual particle», explains Prof. Madhavi Krishnan.

Put simply, particles with just a small charge make large circular movements in their traps, while those with a high charge move in small circles. This phenomenon can be compared to that of a light-weight ball which, when thrown, travels further than a heavy one. The US physicist Robert A. Millikan used a similar method 100 years ago in his oil drop experiment to determine the velocity of electrically charged oil drops. In 1923, he received the Nobel Prize in physics in recognition of his achievements. «But he examined the drops in a vacuum», Prof. Krishnan explains. «We on the other hand are examining nano particles in a solution which itself influences the properties of the particles».

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