Major implications for polymer engineering — ScienceDaily


Researchers led by a staff from the College of Massachusetts Amherst not too long ago introduced a significant theoretical and experimental breakthrough that permits scientists to foretell, with an unprecedented precision, when a smooth materials will crack and fail. The findings, revealed within the Proceedings of the Nationwide Academy of Sciences, have rapid implications for the engineering and manufacture of a variety of polymers. In addition they present insights into how pure smooth supplies — such because the connective tissues in our our bodies and even our brains — break down.

It has proved devilishly complicated to foretell when a smooth materials, similar to a gel or elastomer, will crack and fail. “It has been a thriller,” says Alfred Crosby, professor of polymer science and engineering at UMass Amherst and one of many paper’s senior authors. As a result of scientists have not been capable of precisely predict when a smooth materials will fail, designers sometimes over-engineer their merchandise and advocate changing them earlier quite than later, simply to be secure. “But when we might predict precisely when a product would fail, and underneath what situations,” says Crosby, “we might engineer supplies in probably the most environment friendly technique to meet these situations.”

Cracking this specific nut, which was supported by the Workplace of Naval Analysis’s Naval Power Well being Safety program, concerned a multi-disciplinary effort between Alfred Crosby, Gregory Tew, additionally a professor of polymer science at UMass Amherst, and Robert Riggleman, professor of chemical and biomolecular engineering on the College of Pennsylvania. With a mix of extremely exact chemistry, detailed and progressive pc modeling, and fine-grained experimental information, the group modified an older idea, referred to as the Lake-Thomas Idea, with the assistance of a more recent molecular mannequin often called Actual Elastic Community Idea (RENT). “Consequently,” says Ipek Sacligil, graduate pupil in polymer science at UMass Amherst, and one of many paper’s co-lead authors, “utilizing solely the molecular components, we will now precisely predict when a smooth materials will fail at each the molecular and product ranges.”

Christopher Barney, one of many paper’s different co-lead authors and a graduate pupil at UMass on the time he accomplished this analysis says that “this venture highlights the significance of addressing trendy scientific issues from a number of views. By combining our efforts, we have been capable of craft a complete story that’s far higher than the sum of its components.”

“This advance offers a lacking hyperlink between chemistry and supplies science and engineering for polymer networks,” says Crosby, who notes that this analysis is a part of a a lot bigger, ongoing venture to know the mechanics of cavitation or the sudden, unstable crack-causing expansions inside smooth supplies and tissues.

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In Alaska, Beavers Are Engineering a New Tundra


This story initially appeared on Excessive Nation Information and is a part of the Local weather Desk collaboration.

Cyrus Harris hopped on a snowmobile in the future in early January and zoomed up a peninsula close to Kotzebue, Alaska, to interrupt path for his sled canines. “The primary beaver dam I’m operating into is about three miles from city,” he stated. “Close by that one is one other one, about 5 miles out is one other one, and that’s only one little space.” Harris (Inupiaq) was born in 1957 and spent his childhood throughout Kotzebue Sound in Sisualik. “Beavers had been actually simply unheard-of,” he stated. “It’s loopy the quantity of beaver coming in, they’re simply raiding the entire space.”

Beavers—as soon as seldom seen in northwest Alaska—began showing extra continuously within the ’80s and ’90s. Pastor Lance Kramer (Inupiaq) traps beavers as we speak, principally for making fur hats. He not too long ago requested an elder concerning the space’s first sightings. “They noticed this factor on the tundra, and it appeared like a wolverine, but it surely was a very lengthy beaver,” Kramer stated. “[It] had walked to this point on the tundra to rise up this manner that it wore out the underside of its tail.” 

Now the animals—and their ponds, dams, and lodges—are in all places. Utilizing satellite tv for pc pictures of the Kotzebue space, scientists discovered that the variety of beaver dams surged from two in 2002 to 98 in 2019, a 5,000 p.c soar. And it’s not simply Kotzebue: Beaver ponds doubled regionally since 2000, with 12,000 in northwestern Alaska now. Beavers, dubbed “ecosystem engineers” due to how they flood their environment, are remodeling the tundra.

North America’s largest rodent is transferring north partly due to local weather change: Because the tundra grows hotter and greener, it additionally turns into extra inviting to beavers, which want shrubs for meals, dams, and lodges. Their proliferation can also be linked to a inhabitants rebound: Beaver trapping, in style for hundreds of years, has tapered off, and the animals are thriving.

Beavers had been not too long ago cited as a “new disturbance” within the Nationwide Oceanic and Atmospheric Administration’s 2021 Arctic Report Card, a yearly report that tracks adjustments within the area. That’s as a result of they’re damming rivers and creating deeper, hotter ponds that open up new kinds of aquatic habitat. “The important thing query to ask, wherever you’re standing within the Arctic, is, ‘How lengthy will it’s till beavers get there?’” stated Ken Tape, an ecologist finding out beaver enlargement on the College of Alaska Fairbanks. “As a result of once they get there, it’ll by no means be the identical once more.”   

Harris worries that beavers swimming within the reservoir that provides Kotzebue’s consuming water might overwhelm the neighborhood water remedy plant. Beavers (and different animals) carry the giardia parasite, which they excrete into the setting, and water contaminated with their feces could cause intestinal infections. Harris and others used to drink instantly from rivers on their looking and fishing journeys, however as we speak they’re having second ideas. “If our water high quality will get broken, the place will we go from there?” Harris stated.