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Apr 24, 2019

Controlling instabilities gives closer look at chemistry from hypersonic vehicles

Posted by in categories: chemistry, engineering, transportation

While studying the chemical reactions that occur in the flow of gases around a vehicle moving at hypersonic speeds, researchers at the University of Illinois used a less-is-more method to gain greater understanding of the role of chemical reactions in modifying unsteady flows that occur in the hypersonic flow around a double-wedge shape.

“We reduced the pressure by a factor of eight, which is something experimentalists couldn’t do,” said Deborah Levin, researcher in the Department of Aerospace Engineering at the University of Illinois at Urbana-Champaign. “In an actual chamber, they tried to reduce the pressure but couldn’t reduce it that much because the apparatuses are designed to operate within a certain region. They couldn’t operate it if the pressure was too low. When we reduced the pressure in the simulation, we found that the instabilities in the calmed down. We still had a lot of the kind of vortical structure—separation bubbles and swirls—they were still there. But the data were more tractable, more understandable in terms of their time variation.”

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Apr 24, 2019

New type of silicon promises cheaper solar technology

Posted by in categories: solar power, sustainability

An international research team led by The Australian National University (ANU) has made a new type of silicon that better uses sunlight and promises to cut the cost of solar technology.

The researchers say their world-first invention could help reduce the costs of renewable electricity below that of existing coal power stations, as well as lead to more efficient solar cells.

Senior researcher ANU Professor Jodie Bradby said was used as the raw material for solar cells because of its abundance, low-cost and non-toxicity.

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Apr 24, 2019

NASA’s Aqua Satellite catches Tropical Cyclone Lorna organizing

Posted by in category: space

Visible satellite imagery from NASA’s Aqua satellite revealed the recently formed Tropical Storm Lorna was getting organized in the Southeastern Indian Ocean.

Lorna developed into a on April 23 at 11 a.m. EDT (1500 UTC) and was named Tropical Cyclone 25S. On April 24, it received the name Lorna. At 4:15 a.m. EDT (0815 UTC) on April 24, the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard Aqua captured a visible image of Lorna. The Joint Typhoon Warning Center or JTWC forecasters noted “persistent deep convection to the west of, and obscuring, the low level circulation center.”

By 11 a.m. EDT (1500 UTC) on April 24, Tropical Storm Lorna had maximum sustained winds near 40 knots (46 mph/74 kph). Lorna was centered near 10.9 degrees south latitude and 84.6 degrees east longitude, approximately 743 nautical miles southeast of Diego Garcia. Lorna has tracked to the east-southeast.

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Apr 24, 2019

On-chip drug screening for identifying antibiotic interactions in eight hours

Posted by in categories: biotech/medical, computing

A KAIST research team developed a microfluidic-based drug screening chip that identifies synergistic interactions between two antibiotics in eight hours. This chip can be a cell-based drug screening platform for exploring critical pharmacological patterns of antibiotic interactions, along with potential applications in screening other cell-type agents and guidance for clinical therapies.

Antibiotic susceptibility testing, which determines types and doses of antibiotics that can effectively inhibit , has become more critical in recent years with the emergence of antibiotic-resistant pathogenic bacteria strains.

To overcome the , combinatory therapy using two or more kinds of antibiotics has been gaining considerable attention. However, the major problem is that this therapy is not always effective; occasionally, unfavorable antibiotic pairs may worsen results, leading to suppressed antimicrobial effects. Therefore, combinatory testing is a crucial preliminary process to find suitable antibiotic pairs and their concentration range against unknown pathogens, but the conventional testing methods are inconvenient for concentration dilution and sample preparation, and they take more than 24 hours to produce results.

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Apr 24, 2019

Polymer reversibly glows white when stretched

Posted by in categories: chemistry, materials

Researchers at the University of Fribourg’s Adolphe Merkle Institute (AMI) and Hokkaido University in Japan have developed a method to tailor the properties of stress-indicating molecules that can be integrated into polymers and signal damages or excessive mechanical loads with an optical signal.

As part of their research activities within the National Center of Competence in Research Bio-inspired Materials, Professor Christoph Weder, the chair of Polymer Chemistry and Materials at AMI, and his team are investigating polymers that change their color or characteristics when placed under mechanical load. The prevailing approach to achieve this function is based on specifically designed sensor that contain weak chemical bonds that break when the applied mechanical force exceeds a certain threshold. This effect can cause a color change or other pre-defined responses. A fundamental limitation of this approach, however, is that the weak bonds can also break upon exposure to light or heat. This lack of specificity reduces the practical usefulness of stress-indicating polymers. It normally also makes the effect irreversible.

Addressing this problem, Weder and Dr. Yoshimitsu Sagara—a Japanese researcher who spent two years in Weder’s group at AMI before joining Hokkaido University as an Assistant Professor—devised a new type of sensor molecule that can only be activated by mechanical force. Unlike in previous force-transducing molecules, no chemical bond breaking takes place. Instead, the new sensor molecules consist of two parts that mechanically interlock. This interconnection prevents the separation of the two parts, while still allowing them to be pushed together or pulled away from each other. Such molecular pushing and pulling causes the molecule’s fluorescence to change from off to on.

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Apr 24, 2019

Creating sustainable bioplastics from electricity-eating microbes

Posted by in categories: biotech/medical, food, sustainability

Electricity harvested from the sun or wind can be used interchangeably with power from coal or petroleum sources. Or sustainably produced electricity can be turned into something physical and useful. Researchers in Arts & Sciences at Washington University in St. Louis have figured out how to feed electricity to microbes to grow truly green, biodegradable plastic, as reported in the Journal of Industrial Microbiology and Biotechnology.

“As our planet grapples with rampant, petroleum-based plastic use and plastic waste, finding sustainable ways to make bioplastics is becoming more and more important. We have to find new solutions,” said Arpita Bose, assistant professor of biology in Arts & Sciences.

Renewable energy currently accounts for about 11% of total U.S. energy consumption and about 17% of electricity generation.

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Apr 24, 2019

Dark matter detector observes rarest event ever recorded

Posted by in categories: alien life, particle physics

How do you observe a process that takes more than one trillion times longer than the age of the universe? The XENON Collaboration research team did it with an instrument built to find the most elusive particle in the universe—dark matter. In a paper to be published tomorrow in the journal Nature, researchers announce that they have observed the radioactive decay of xenon-124, which has a half-life of 1.8 × 1022 years.

“We actually saw this decay happen. It’s the longest, slowest process that has ever been directly observed, and our was sensitive enough to measure it,” said Ethan Brown, an assistant professor of physics at Rensselaer, and co-author of the study. “It’s an amazing to have witnessed this process, and it says that our detector can measure the rarest thing ever recorded.”

The XENON Collaboration runs XENON1T, a 1,300-kilogram vat of super-pure liquid xenon shielded from cosmic rays in a cryostat submerged in water deep 1,500 meters beneath the Gran Sasso mountains of Italy. The researchers search for (which is five times more abundant than ordinary matter, but seldom interacts with ordinary matter) by recording tiny flashes of light created when particles interact with xenon inside the detector. And while XENON1T was built to capture the interaction between a dark matter particle and the nucleus of a xenon atom, the detector actually picks up signals from any interactions with the xenon.

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Apr 24, 2019

Marine Skin dives deeper for better monitoring

Posted by in categories: health, materials

A new and greatly improved version of an electronic tag, called Marine Skin, used for monitoring marine animals could revolutionize our ability to study sea life and its natural environment, say KAUST researchers.

Marine Skin is a thin, flexible, lightweight polymer-based material with integrated electronics which can track an animal’s movement and diving behavior and the health of the surrounding . Early versions of the sensors, reported previously, proved their worth when glued onto the swimming crab, Portunus pelagicus.

The latest and much more robust version can operate at unprecedented depths and can also be attached to an animal using a noninvasive bracelet or jacket. This can, when necessary, avoid the need for any glues that might harm an animal’s sensitive skin.

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Apr 24, 2019

A faster method for multiplying very big numbers

Posted by in categories: computing, education, information science, mathematics

The multiplication of integers is a problem that has kept mathematicians busy since Antiquity. The “Babylonian” method we learn at school requires us to multiply each digit of the first number by each digit of the second one. But when both numbers have a billion digits each, that means a billion times a billion or 1018 operations.

At a rate of a billion operations per second, it would take a computer a little over 30 years to finish the job. In 1971, the mathematicians Schönhage and Strassen discovered a quicker way, cutting calculation time down to about 30 seconds on a modern laptop. In their article, they also predicted that another algorithm—yet to be found—could do an even faster job. Joris van der Hoeven, a CNRS researcher from the École Polytechnique Computer Science Laboratory LIX, and David Harvey from the University of New South Wales (Australia) have found that algorithm.

They present their work in a new article that is available to the through the online HAL archive. But one problem raised by Schönhage et Strassen remains to be solved: proving that no quicker method exists. This poses a new challenge for theoretical science.

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Apr 24, 2019

Treatment turns tumors into cancer vaccine factories

Posted by in category: biotech/medical

Researchers at Mount Sinai have developed a novel approach to cancer immunotherapy, injecting immune stimulants directly into a tumor to teach the immune system to destroy it and other tumor cells throughout the body.

The “in situ vaccination” worked so well in patients with advanced-stage lymphoma that it is also undergoing trials in breast and head and neck cancer patients, according to a study published in Nature Medicine in April.

The treatment consists of administering a series of immune stimulants directly into one tumor site. The first stimulant recruits important immune cells called dendritic cells that act like generals of the immune army. The second stimulant activates the dendritic cells, which then instruct T cells, the immune system’s soldiers, to kill cancer cells and spare non-cancer cells. This immune army learns to recognize features of the tumor cells so it can seek them out and destroy them throughout the body, essentially turning the tumor into a cancer vaccine factory.

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