PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

In probing mysteries of glass, researchers find a key to toughness

2013-02-26
(Press-News.org) New Haven, Conn. — In a paper published online Feb. 26 in the journal Nature Communications, a Yale University team and collaborators propose a way of predicting whether a given glass will be brittle or ductile — a desirable property typically associated with metals like steel or aluminum — and assert that any glass could have either quality.

Ductility refers to a material's plasticity, or its ability to change shape without breaking.

"Most of us think of glasses as brittle, but our finding shows that any glass can be made ductile or brittle," said Jan Schroers, a professor of mechanical engineering and materials science at Yale, who led the research with Golden Kumar, a professor at Texas Tech University. "We identified a special temperature that tells you whether you form a ductile or brittle glass."

The key to forming a ductile glass, they said, is cooling it fast. Exactly how fast depends on the nature of the specific glass.

Focusing on a new group of glasses known as bulk metallic glasses (BMGs) — metal alloys, or blends, that can be extremely pliable yet also as strong as steel — researchers studied the effect of a so-called critical fictive temperature (CFT) on the glasses' mechanical properties at room temperature.

When forming from liquid, there is a temperature at which glass becomes too viscous for reconfiguration and freezes. This temperature is called the glass transition temperature. Based on experiments with three representative bulk metallic glasses, the researchers said there is also, for each distinct alloy, a critical temperature that determines the brittleness or plasticity of the glass. This is the CFT.

Researchers said it's possible to categorize glasses in two groups — those that will be brittle because in liquid form their CFT is above the glass transition temperature, and those that will be ductile, because in liquid form their CFT is below the glass transition temperature.

They previously thought a liquid's chemical composition alone would determine whether a glass would be brittle or ductile.

"That's not the case," Schroers said. "We can make any glass theoretically ductile or brittle. And it is the critical fictive temperature which determines how experimentally difficult it is to make a ductile glass. That is the major contribution of this work."

The finding applies theoretically to all glasses, not metallic glasses only, he said.

"A glass can have completely different properties depending on the rate at which you cool it," Schroers said. "If you cool it fast, it is very ductile, and if you cool it slow it¹s very brittle. We anticipate that our finding will contribute to the design of ductile glasses, and in general contribute to a deeper understanding of glass formation."

### The paper's lead author is Golden Kumar of Texas Tech University. Pascal Neibecker of the University of Augsburg in Germany and Yanhui Liu of Yale are co-authors.

The U.S. Department of Energy provided support for the research. END


ELSE PRESS RELEASES FROM THIS DATE:

Connecting the (quantum) dots

2013-02-26
PITTSBURGH—Recent research offers a new spin on using nanoscale semiconductor structures to build faster computers and electronics. Literally. University of Pittsburgh and Delft University of Technology researchers reveal in the Feb. 17 online issue of Nature Nanotechnology a new method that better preserves the units necessary to power lightning-fast electronics, known as qubits (pronounced CUE-bits). Hole spins, rather than electron spins, can keep quantum bits in the same physical state up to 10 times longer than before, the report finds. "Previously, our group ...

American Chemical Society podcast: New super-nutritious puffed rice for breakfast cereals, snacks

2013-02-26
The latest episode in the American Chemical Society's (ACS') award-winning Global Challenges/Chemistry Solutions podcast series reports a new process for blowing up grains of rice to produce a super-nutritious form of puffed rice, with three times more protein and a rich endowment of other nutrients. That makes it ideal for breakfast cereals, snack foods and nutrient bars for school lunch programs. Based on a report by Syed S.H. Rizvi, Ph.D., and colleagues in ACS' Journal of Agricultural and Food Chemistry, the new podcast is available without charge at iTunes and from ...

Persistent negative attitude can undo effectiveness of exposure therapy for phobias

2013-02-26
COLUMBUS, Ohio – Because confronting fear won't always make it go away, researchers suggest that people with phobias must alter memory-driven negative attitudes about feared objects or events to achieve a more lasting recovery from what scares them the most. Ohio State University psychology researchers determined that people who retained negative attitudes about public speaking after exposure therapy were more likely to experience a return of their fear a month later than were people whose attitudes were less negative. The fear returned among those with unchanged attitudes ...

Kauai, the Petrified Forest, Costa Rica, and more: New GSA Bulletin articles now online

2013-02-26
Boulder, Colo., USA – New GSA Bulletin articles cover wind erosion and sediment traps in the Qaidam basin; rain erosion on Kauai; new insights from the Petrified Forest, USA; a forearc sliver in Costa Rica; Quebec's St. Lawrence rift system; a new model for the development of Ries Crater Lake, Germany; bending and buckling mountain belts; a record of 22 large earthquakes in northern Fiordland, New Zealand; and the evolution of the ancient Montana landscape. GSA BULLETIN articles published ahead of print are online at http://gsabulletin.gsapubs.org/content/early/recent; ...

Novel combination therapy shuts down escape route, killing glioblastoma tumor cells

2013-02-26
February 26, 2013, New York, N.Y. and San Diego, Calif. – Glioblastoma, the most common and lethal form of brain tumor in adults, is challenging to treat because the tumors rapidly become resistant to therapy. As cancer researchers are learning more about the causes of tumor cell growth and drug resistance, they are discovering molecular pathways that might lead to new targeted therapies to potentially treat this deadly cancer. Scientists at the Ludwig Institute for Cancer Research in San Diego worked collaboratively across the laboratories of Drs. Paul Mischel, Web Cavenee ...

Macroweather is what you expect

Macroweather is what you expect
2013-02-26
While short-term weather is notoriously volatile, climate is thought to represent a kind of average weather pattern over a long period of time. This dichotomy provides the analytical framework for scientific thinking about atmospheric variability, including climate change. But the weather-climate dichotomy paints an incomplete picture – one that may be complicating efforts to untangle natural variations in climate from man-made effects, according to McGill University physics professor Shaun Lovejoy. In a paper published recently in the journal Eos, Transactions, American ...

Gender gap disappears in school math competitions, study shows

Gender gap disappears in school math competitions, study shows
2013-02-26
The idea that boys are better at math and in competitions has persisted for a long time, and now we know why: Nobody bothered to schedule the rematch. Most school math contests are one-shot events where girls underperform relative to their male classmates. But a new study by a Brigham Young University economist presents a different picture. Twenty-four local elementary schools changed the format to go across five different rounds. Once the first round was over, girls performed as well or better than boys for the rest of the contest. "It's really encouraging that seemingly ...

OHSU scientists first to grow liver stem cells in culture, demonstrate therapeutic benefit

2013-02-26
PORTLAND, Ore. — For decades scientists around the world have attempted to regenerate primary liver cells known as hepatocytes because of their numerous biomedical applications, including hepatitis research, drug metabolism and toxicity studies, as well as transplantation for cirrhosis and other chronic liver conditions. But no lab in the world has been successful in identifying and growing liver stem cells in culture -- using any available technique – until now. In the journal Nature, physician-scientists in the Papé Family Pediatric Research Institute at Oregon Health ...

Tweaking gene expression to repair lungs

Tweaking gene expression to repair lungs
2013-02-26
PHILADELPHIA — Lung diseases such as asthma and chronic obstructive pulmonary disease (COPD) are on the rise, according to the American Lung Association and the National Institutes of Health. These ailments are chronic, affect the small airways of the lung, and are thought to involve an injury-repair cycle that leads to the breakdown of normal airway structure and function. For now, drugs for COPD treat only the symptoms. "A healthy lung has some capacity to regenerate itself like the liver," notes Ed Morrisey, Ph.D., professor of Medicine and Cell and Developmental ...

Prenatal DHA reduces early preterm birth, low birth weight

2013-02-26
LAWRENCE — University of Kansas researchers have found that the infants of mothers who were given 600 milligrams of the omega-3 fatty acid DHA during pregnancy weighed more at birth and were less likely to be very low birth weight and born before 34 weeks gestation than infants of mothers who were given a placebo. This result greatly strengthens the case for using the dietary supplement during pregnancy. Susan CarlsonThe results are from the first five years of a 10-year, double-blind randomized controlled trial to be published in the April issue of the American Journal ...

LAST 30 PRESS RELEASES:

Toxic metals linked to impaired growth in infants in Guatemala

Being consistently physically active in adulthood linked to 30–40% lower risk of death

Nerve pain drug gabapentin linked to increased dementia, cognitive impairment risks

Children’s social care involvement common to nearly third of UK mums who died during perinatal period

‘Support, not judgement’: Study explores links between children’s social care involvement and maternal deaths

Ethnic minority and poorer children more likely to die in intensive care

Major progress in fertility preservation after treatment for cancer of the lymphatic system

Fewer complications after additional ultrasound in pregnant women who feel less fetal movement

Environmental impact of common pesticides seriously underestimated

The Milky Way could be teeming with more satellite galaxies than previously thought

New study reveals surprising reproductive secrets of a cricket-hunting parasitoid fly

Media Tip Sheet: Symposia at ESA2025

NSF CAREER Award will power UVA engineer’s research to improve drug purification

Tiny parasitoid flies show how early-life competition shapes adult success

New coating for glass promises energy-saving windows

Green spaces boost children’s cognitive skills and strengthen family well-being

Ancient trees dying faster than expected in Eastern Oregon

Study findings help hone precision of proven CVD risk tool

Most patients with advanced melanoma who received pre-surgical immunotherapy remain alive and disease free four years later

Introducing BioEmu: A generative AI Model that enables high-speed and accurate prediction of protein structural ensembles

Replacing mutated microglia with healthy microglia halts progression of genetic neurological disease in mice and humans

New research shows how tropical plants manage rival insect tenants by giving them separate ‘flats’

Condo-style living helps keep the peace inside these ant plants

Climate change action could dramatically limit rising UK heatwave deaths

Annual heat-related deaths projected to increase significantly due to climate and population change

Researchers discover new way cells protect themselves from damage

Rivers choose their path based on erosion — a discovery that could transform flood planning and restoration

New discovery reveals dopamine operates with surgical precision, not as a broad signal

New AI tool gives a helping hand to x ray diagnosis

New Leicester study reveals hidden heart risks in women with Type 2 Diabetes

[Press-News.org] In probing mysteries of glass, researchers find a key to toughness