In a new study, researchers from the University of Illinois Urbana-Champaign report that automated high-resolution electron imaging can capture the nanoscale deformation events that lead to metal failure and breakage at the origin of metal failure. The new method helps scientists to rapidly predict the fatigue strength of any alloy, and design new materials for engineering systems subject to repeated loading for medical, transportation, safety, energy and environmental applications.

The findings of the study, led by materials science and engineering professors Jean-Charles Stinville and Marie Charpagne, are published in the journal Science.

Fatigue of metals and alloys — such as the repeated bending of a metal paperclip that leads to its fracture — is the root cause of failure in many engineering systems, Stinville said. Defining the relationship between fatigue strength and the microstructure is challenging because metallic materials display complex structures with features ranging from the nanometer to the centimeter scale.

“This multiscale issue is a long-standing problem because we’re trying to observe sparse, nanometer-sized events that control macroscopic properties and can be captured only by investigating large areas with fine resolution,” Charpagne said. “The current method for determining fatigue strength in metals uses traditional mechanical testing that is costly, time-consuming and does not provide a clear picture of the root cause of failure.”

In the current study, the researchers found that the statistical investigation of the nanoscale events that appear at the metal surface when deformed can inform fatigue strength of metals. The team is the first to uncover this relationship using automated high-resolution digital image correlation collected in the scanning electron micrsocope — a technique that compiles and compares a series of images recorded during deformation, Stinville said. The researchers demonstrated this relation on alloys of aluminum, cobalt, copper, iron, nickel, steel and refractory alloys used in a large variety of key engineering applications.

“What is remarkable is that the nanoscale deformation events that appear after a single deformation cycle correlate with the fatigue strength that inform the life of a metallic part under a large number of cycles,” Stinville said. “Discovering this correlation is like having access to a unique deformation fingerprint that can help us rapidly predict the fatigue life of metallic parts.”

“Designing metallic materials with higher fatigue strength means safer, more resilient and durable materials,” Charpagne said. “This work has societal, environmental and economic impacts because it sheds light on the micro and nanoscale parameters to tune to design materials with a longer life. I think this work will define a new paradigm in alloy design.”

This study was performed in collaboration with researchers from the University of California, Santa Barbara and the Universite de Poitiers, France.

The Department of Defense, the Office of Naval Research and the department of materials science and engineering at Illinois supported this research.

Story Source:

Materials provided by University of Illinois at Urbana-Champaign, News Bureau. Original written by Lois Yoksoulian. Note: Content may be edited for style and length.

Currently, roughly a third of cereal crop production is used as animal feed, and about a quarter of captured fish aren’t used to feed people. Matti Kummu, an associate professor of global water and food issues at Aalto, led a team that investigated the potential of using crop residues and food by-products in livestock and aquaculture production, freeing up the human-usable material to feed people.

‘This was the first time anyone has collected the food and feed flows in this detail globally, from both terrestrial and aquatic systems, and combined them together. That let us understand how much of the food by-products and residues is already in use, which was the first step to determining the untapped potential,’ explains Kummu.

The team analysed the flow of food and feed, as well as their by-products and residues, through the global food production system. They then identified ways to shift these flows to produce a better outcome. For example, livestock and farmed fish could be fed food system by-products, such as sugar beet or citrus pulp, fish and livestock by-products or even crop residues, instead of materials that are fit for human use.

With these changes, up to 10-26% of total cereal production and 17 million tons of fish (~11% of the current seafood supply) could be redirected from animal feed to human use. Depending on the precise scenario, the gains in food supply would be 6-13% in terms of caloric content and 9-15% in terms of protein content. ‘That may not sound like a lot, but that’s food for up to about one billion people,’ says Aalto’s Vilma Sandström, the first author of the study.

These findings dovetail nicely with earlier work from Kummu’s group on reducing food loss throughout the supply chain, from production, transport and storage through to consumer waste. ‘In that study, we showed that reducing food loss and waste by half would increase the food supply by about 12%. Combined with using by-products as feed, that would be about one-quarter more food,’ he says.

Some of the changes, such as feeding crop residues to livestock, would lead to a drop in livestock productivity, but the researchers accounted for that in their analysis. Another challenge is that the human-edible food currently used in livestock production and aquaculture is different from the food people are used to. For example, a different variety of corn is used in feed industries and some of the grains are lower quality, while the fish used in fishmeal production tend to be small, bony fish that currently aren’t popular with consumers.

However, overcoming these hurdles could result in substantial gains. Realising these benefits would require some adjustments in supply chains. ‘For example, we’d need to reorganise the food system so that the industries and producers with by-products can find the livestock and aquaculture producers who would need them. And some of the by-products would need processing prior to using them as feed,’ says Sandström.

‘I don’t think there’s any serious problem with doing this. What we’re suggesting is already being done on a certain scale and in some areas, so it’s not something that would have to be developed from scratch. We just need to adjust the current system and increase the scale of those practices,’ Kummu concludes.

Story Source:

Materials provided by Aalto University. Note: Content may be edited for style and length.

“Previous research has shown face mask wearing can reduce the risk of spreading and contracting the disease. So, we wanted to create a mask that can detect the presence of virus in the air and alert the wearer,” says Yin Fang, the study’s corresponding author and a material scientist at Shanghai Tongji University.

Respiratory pathogens that cause COVID-19 and H1N1 influenza spread through small droplets and aerosols released by infected people when they talk, cough, and sneeze. These virus-containing molecules, especially tiny aerosols, can remain suspended in the air for a long time.

Fang and his colleagues tested the mask in an enclosed chamber by spraying the viral surface protein containing trace-level liquid and aerosols on the mask. The sensor responded to as little as 0.3 microliters of liquid containing viral proteins, about 70 to 560 times less than the volume of liquid produced in one sneeze and much less than the volume produced by coughing or talking, Fang says.

The team designed a small sensor with aptamers, which are a type of synthetic molecule that can identify unique proteins of pathogens like antibodies. In their proof-of-concept design, the team modified the multi-channel sensor with three types of aptamers, which can simultaneously recognize surface proteins on SARS-CoV-2, H5N1, and H1N1.

Once the aptamers bind to the target proteins in the air, the ion-gated transistor connected will amplify the signal and alert the wearers via their phones. An ion-gated transistor is a novel type of device that is highly sensitive, and thus the mask can detect even trace levels of pathogens in the air within 10 minutes.

“Our mask would work really well in spaces with poor ventilation, such as elevators or enclosed rooms, where the risk of getting infected is high,” Fang says. In the future, if a new respiratory virus emerges, they can easily update the sensor’s design for detecting the novel pathogens, he adds.

Next, the team hopes to shorten the detection time and further increase the sensitivity of the sensor by optimizing the design of the polymers and transistors. They are also working on wearable devices for a variety of health conditions including cancers and cardiovascular diseases.

“Currently, doctors have been relying heavily on their experiences in diagnosing and treating diseases. But with richer data collected by wearable devices, disease diagnosis and treatment can become more precise,” Fang says.

The work is supported by National Key Research and Development Program, National Natural Science Foundation of China, Science and Technology Commission of Shanghai Municipality, Shanghai Municipal Science and Technology Major Project and the Fundamental Research Funds for the Central Universities.

Story Source:

Materials provided by Cell Press. Note: Content may be edited for style and length.

A new study by Colorado State University civil engineers examines the hidden costs to building foundations due to sea level rise. They propose a method for inspection and repair to lower the cost associated with deterioration from saltwater corrosion.

The researchers, who are part of the NIST Center for Risk-Based Community Resilience Planning at CSU, say it is important to plan ahead — especially considering there are more than 16 million buildings along the U.S. Atlantic and Gulf coasts.

“This is a problem, and it’s going to cost a lot of money,” said Hussam Mahmoud, a professor in the Department of Civil and Environmental Engineering and co-author on the study.

One at-risk location

Engineers looked at nearly 137,000 residential buildings in low-lying regions in Mobile County, Alabama, and estimated probable foundation damage from saltwater corrosion.

As sea level rises, so does the groundwater table, and saltwater is more corrosive than freshwater. Using existing predictions for sea level rise and water table levels based on wells in Mobile, they predicted how long it would take for saltwater to reach the buildings’ foundations.

Under the most extreme sea level rise projections, they estimated the annual repair cost for foundations in Mobile could total $90 million by 2100.

“The significance here is that this value that we found for one of the saltwater intrusion scenarios is just for 137,000 buildings in Mobile,” Mahmoud said. “If you calculated the cost for the entire East Coast — or from the East to the West Coast — it would be staggering.”

Providing a solution

The engineers developed a formula to help building owners determine when to inspect and repair their buildings based on building location and the probability of saltwater corrosion. They say waiting for the right time to repair the foundation — but not so long that damage has been done — will save building owners money.

They also proposed the use of low-cost sensors to monitor the water table level near a building’s foundation and protect against uncertainties.

The researchers chose to study Mobile because it is an industrial port city with a large economically disadvantaged population. They have started investigating the impact of natural disasters on Mobile’s vulnerable communities to figure out the best way to allocate resources to help them recover in an emergency.

“In order for us to assess social and economic impact, we have to have a good understanding of the impact of the hazard on the built environment,” Mahmoud said.

Next, the team plans to examine structural performance beyond the foundation and how that affects people in the area. For example, how much wind and water surge during a hurricane can a structure withstand before alternative housing or shelters are needed?

“This work will allow us to be proactive about finding solutions quickly to help those in need, instead of waiting until it’s bad,” Mahmoud said.

Helping communities recover from natural disasters is the focus of the CSU-led Center for Risk-Based Community Resilience Planning, a $20 million partnership with the National Institute of Standards and Technology that involves collaborators from more than a dozen other universities.

Story Source:

Materials provided by Colorado State University. Original written by Jayme DeLoss. Note: Content may be edited for style and length.

Now, researchers at Stevens Institute of Technology have developed an algorithm that can accurately track patients’ level of consciousness based on simple physiological markers that are already routinely monitored in hospital settings. Though still in its early stages, the team’s work — published in the Sept. 15 issue of Neurocritical Care — promises to significantly ease the strain on medical staff, and could also provide vital new data to guide clinical decisions and enable the development of new treatments.

“Consciousness isn’t a light switch that’s either on or off — it’s more like a dimmer switch, with degrees of consciousness that change over the course of the day,” said Samantha Kleinberg, an associate professor in Stevens’ department of Computer Science. “If you only check patients once per day, you just get one data point. With our algorithm, you could track consciousness continuously, giving you a far clearer picture.”

To develop their algorithm, Kleinberg and her Ph.D. student Louis A. Gomez partnered with Jan Claassen, director of Critical Care Neurology at Columbia University, to collect data from a range of ICU sensors — from simple heart rate monitors up to sophisticated devices that measure brain temperature — and used it to forecast the results of a clinician’s assessment of a patient’s level of consciousness. The results were startling: using only the simplest physiological data, the algorithm proved as accurate as a trained clinical examiner, and only slightly less accurate than tests conducted with expensive imaging equipment such as fMRI machines.

“That’s hugely important, because it means this tool could potentially be deployed in virtually any hospital setting — not just neurological ICUs where they have more sophisticated technology,” Kleinberg explained. The algorithm could be installed as a simple software module on existing bedside patient-monitoring systems, she noted, making it relatively cheap and easy to roll out at scale.

Besides giving doctors better clinical information, and patients’ families a clearer idea of their loved ones’ prognosis, continuous monitoring could help to drive new research and ultimately improve patient outcomes.

“Consciousness is incredibly hard to study, and part of the reason is that there simply isn’t much data to work with,” said Kleinberg. “Having round-the-clock data showing how patients’ consciousness changes could one day make it possible to treat these patients far more effectively.”

More work will be needed before the team’s algorithm can be rolled out in clinical settings. The team’s algorithm was trained based on data collected immediately prior to a clinician’s assessment, and further development will be needed to show that it can accurately track consciousness around the clock. Additional data will also be required to train the algorithm for use in other clinical settings such as pediatric ICUs.

Kleinberg also hopes to improve the algorithm’s accuracy by cross-referencing different kinds of physiological data, and studying the way they coincide or lag one another over time. Some such relationships are known to correlate with consciousness, potentially making it possible to validate the algorithm’s consciousness ratings during periods when assessments by human clinicians aren’t available.

For now, though, the Stevens’ team is thrilled to have found a simple, broadly applicable model for automatically assessing patient consciousness in clinical settings. “It was a high-risk, high-reward project,” Kleinberg said. “It was extremely exciting to find we could use these signals to classify patients’ levels of consciousness.”

Story Source:

Materials provided by Stevens Institute of Technology. Note: Content may be edited for style and length.

Biologists at the University of Cincinnati found that it’s not just the size of its head and body that puts almost everything on a python’s menu. They evolved super-stretchy skin between their lower jaws that allows them to consume prey up to six times larger than similar-sized snakes.

The study, funded in part by a grant from the National Science Foundation, was published in the journal Integrative Organismal Biology.

Since most snakes swallow prey whole, they must have wide mouths to accommodate a meal. Unlike our lower jawbone, the lower jawbones of snakes are not connected, allowing them to open wide.

“The stretchy skin between left and right lower jaws is radically different in pythons. Just over 40% of their total gape area on average is from stretchy skin,” lead author and UC biology professor Bruce Jayne said. “Even after you correct for their large heads, their gape is enormous.”

Pythons are constrictors. They bite their prey and wrap their powerful coils around it, fatally cutting off the animal’s vital blood flow, before consuming it whole at their leisure.

The bigger the prey, the more energy a snake derives from a meal. For pythons, that means not having to hunt as often, which can carry extensive risk in a world full of busy roads and dangerous predators.

Along with pythons, Jayne studied the gape size of brown tree snakes, a mildly venomous arboreal specialist that hunts birds and other animals in the forest canopy. Brown tree snakes were introduced in the 1950s to Guam, wiping out many bird species.

Besides measuring the snakes, Jayne also measured the dimensions and weight of potential prey animals. This allowed Jayne to use snake size to predict the maximal size of its prey and the relative benefits of consuming different types such as alligators, chickens, rats or deer.

Small snakes derive greater benefits in relative prey mass from a modest increase in gape size, the study found. This gives python babies an early advantage in taking on a broader range of prey compared to other snakes their size, Jayne said.

Being big also helps snakes avoid becoming meals themselves. Snakes fall prey to everything from wading birds to minks and raccoons to alligators and other snakes.

“Once those pythons get to a reasonable size, it’s pretty much just alligators that can eat them,” Jayne said. “And pythons eat alligators.”

Like invasive brown tree snakes in Guam, Burmese pythons are wreaking havoc on the ecology of Everglades National Park where they were introduced due to the release of captive animals from the exotic pet trade in the 1980s.

Study co-author Ian Bartoszek works as an environmental science project manager for the Conservancy of Southwest Florida, where he has led a project to track pythons. They implant radio transmitters in male snakes during breeding season to find females before they can lay more clutches of eggs. A big female python can lay more than 100 eggs.

Researchers routinely find deer hooves and the remains of other big animals in their stomachs. Bartoszek photographed one python regurgitating a full-grown white-tailed deer.

“The Everglades ecosystem is changing in real time based on one species, the Burmese python,” Bartoszek said.

The good news is that pythons rarely attack people. Bartoszek said the only defensive encounters he’s had with wild pythons are with females guarding their nests.

“It’s way more dangerous to drive there than to work with the snakes,” he said.

Story Source:

Materials provided by University of Cincinnati. Original written by Michael Miller. Note: Content may be edited for style and length.

“We picked the Jezero Crater for Perseverance to explore because we thought it had the best chance of providing scientifically excellent samples — and now we know we sent the rover to the right location,” said Thomas Zurbuchen, NASA’s associate administrator for science in Washington. “These first two science campaigns have yielded an amazing diversity of samples to bring back to Earth by the Mars Sample Return campaign.”

Twenty-eight miles (45 kilometers) wide, Jezero Crater hosts a delta — an ancient fan-shaped feature that formed about 3.5 billion years ago at the convergence of a Martian river and a lake. Perseverance is currently investigating the delta’s sedimentary rocks, formed when particles of various sizes settled in the once-watery environment. During its first science campaign, the rover explored the crater’s floor, finding igneous rock, which forms deep underground from magma or during volcanic activity at the surface.

“The delta, with its diverse sedimentary rocks, contrasts beautifully with the igneous rocks — formed from crystallization of magma — discovered on the crater floor,” said Perseverance project scientist Ken Farley of Caltech in Pasadena, California. “This juxtaposition provides us with a rich understanding of the geologic history after the crater formed and a diverse sample suite. For example, we found a sandstone that carries grains and rock fragments created far from Jezero Crater — and a mudstone that includes intriguing organic compounds.”

“Wildcat Ridge” is the name given to a rock about 3 feet (1 meter) wide that likely formed billions of years ago as mud and fine sand settled in an evaporating saltwater lake. On July 20, the rover abraded some of the surface of Wildcat Ridge so it could analyze the area with the instrument called Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals, or SHERLOC.

SHERLOC’s analysis indicates the samples feature a class of organic molecules that are spatially correlated with those of sulfate minerals. Sulfate minerals found in layers of sedimentary rock can yield significant information about the aqueous environments in which they formed.

What Is Organic Matter?

Organic molecules consist of a wide variety of compounds made primarily of carbon and usually include hydrogen and oxygen atoms. They can also contain other elements, such as nitrogen, phosphorus, and sulfur. While there are chemical processes that produce these molecules that don’t require life, some of these compounds are the chemical building blocks of life. The presence of these specific molecules is considered to be a potential biosignature — a substance or structure that could be evidence of past life but may also have been produced without the presence of life.

In 2013, NASA’s Curiosity Mars rover found evidence of organic matter in rock-powder samples, and Perseverance has detected organics in Jezero Crater before. But unlike that previous discovery, this latest detection was made in an area where, in the distant past, sediment and salts were deposited into a lake under conditions in which life could potentially have existed. In its analysis of Wildcat Ridge, the SHERLOC instrument registered the most abundant organic detections on the mission to date.

“In the distant past, the sand, mud, and salts that now make up the Wildcat Ridge sample were deposited under conditions where life could potentially have thrived,” said Farley. “The fact the organic matter was found in such a sedimentary rock — known for preserving fossils of ancient life here on Earth — is important. However, as capable as our instruments aboard Perseverance are, further conclusions regarding what is contained in the Wildcat Ridge sample will have to wait until it’s returned to Earth for in-depth study as part of the agency’s Mars Sample Return campaign.”

The first step in the NASA-ESA (European Space Agency) Mars Sample Return campaign began when Perseverance cored its first rock sample in September 2021. Along with its rock-core samples, the rover has collected one atmospheric sample and two witness tubes, all of which are stored in the rover’s belly.

The geologic diversity of the samples already carried in the rover is so good that the rover team is looking into depositing select tubes near the base of the delta in about two months. After depositing the cache, the rover will continue its delta explorations.

“I’ve studied Martian habitability and geology for much of my career and know first-hand the incredible scientific value of returning a carefully collected set of Mars rocks to Earth,” said Laurie Leshin, director of NASA’s Jet Propulsion Laboratory in Southern California. “That we are weeks from deploying Perseverance’s fascinating samples and mere years from bringing them to Earth so scientists can study them in exquisite detail is truly phenomenal. We will learn so much.”

More About the Mission

A key objective for Perseverance’s mission on Mars is astrobiology, including caching samples that may contain signs of ancient microbial life. The rover will characterize the planet’s geology and past climate, pave the way for human exploration of the Red Planet, and be the first mission to collect and cache Martian rock and regolith.

Subsequent NASA missions, in cooperation with ESA, would send spacecraft to Mars to collect these sealed samples from the surface and return them to Earth for in-depth analysis.

The Mars 2020 Perseverance mission is part of NASA’s Moon to Mars exploration approach, which includes Artemis missions to the Moon that will help prepare for human exploration of the Red Planet.

JPL, which is managed for NASA by Caltech, built and manages operations of the Perseverance rover.

For more about Perseverance: https://mars.nasa.gov/mars2020/