It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
The Appalachian Mountains that tower over East Tennessee, Western North Carolina and Southwest Virginia are hundreds of miles from the coast. But when hurricane season ramps up, residents in the region still need to pay attention.
That’s the message from Dr. Andrew Joyner, Tennessee’s official climatologist and a faculty member in the Department of Geosciences at East Tennessee State University.
“We may not get direct hits from hurricanes like coastal areas do,” said Joyner. “But the remnants of those storms can still bring serious impacts, especially when the season is active.”
How hurricane season might affect the Appalachian region
And the season is, indeed, expected to be active.
Forecasters at Colorado State University are predicting an above-average number of storms for 2025. That follows a volatile 2024 season that saw numerous hurricanes tear through the Caribbean and brush the American Southeast.
For Appalachia, the threat isn’t wind so much as water.
“Flash flooding is our biggest concern,” said Joyner. “With these systems, it’s not uncommon to see significant rainfall spread hundreds of miles inland, and the narrow valleys and steep terrain of our region make us especially vulnerable.”
Hurricane season begins June 1 and runs through Nov. 30.
Hurricane Helene’s impact on Appalachia
The mountains can both catch and concentrate rain.
At its peak, streamflow in Embreeville, Tennessee, reached more than 80,000 cubic feet per second — more than 130 times the average.
“It’s a generational event, and one we’ll be studying for years,” said Joyner. “These types of storms have impacted Appalachia before but may become more frequent and more intense, and we need to plan accordingly.”
As part of that reflection, ETSU launched the “Rising with Hope” video series, spotlighting stories of resilience and recovery in the wake of Helene’s destruction.
ETSU’s role in preparing the region for extreme weather
ETSU is playing a leading role in preparation for extreme weather. The university is home to Tennessee’s Climate Office, where researchers are helping shape public policy, plan emergency mitigation strategies, and educate the public.
ETSU scientists contributed heavily to the state’s most recent hazard mitigation plan, which emphasizes the growing risks of extreme precipitation events and rapid-onset droughts. It’s part of what makes the university the flagship institution of Appalachia.
As for what individuals can do?
“Understand your local flood risk,” said Joyner. “Pay attention to forecasts, have a plan and remember that even if we’re not in a coastal zone, hurricanes can still hit home in ways that matter.”
Hitting the right notes to play music by ear
Waterloo human-computer interaction study analyzes YouTube music lessons to create better digital tools for music students
Learning to play music by ear is challenging for most musicians, but research from a team at the University of Waterloo may help musicians-in-training find the right notes.
The Waterloo team analyzed a range of YouTube videos that focused on learning music by ear and identified four simple ways music learning technology can better aid prospective musicians – helping people improve recall while listening, limiting playback to small chunks, identifying musical subsequences to memorize, and replaying notes indefinitely.
“There are a lot of apps and electronic tools out there to help learn by ear from recorded music,” said Christopher Liscio, a recent Waterloo master’s graduate in computer science and the study’s lead author.
“But we see evidence that musicians don’t appear to use them very much, which makes us question whether these tools are truly well-suited to the task. By studying how people teach and learn how to play music by ear in YouTube videos, we can try to understand what might actually help these ear-learning musicians.”
The team studied 28 YouTube ear-learning lessons, breaking each down to examine how the instructors structured their teaching and how students would likely retain what they heard. Surprisingly, they found that very few creators or viewers were using existing digital learning tools to loop playback or manipulate playback speed despite their availability for over two decades.
“We started this research planning to build a specific tool for ear learners, but then we realized we might be reinforcing a negative pattern of building tools without knowing what users actually want,” said Dan Brown, professor of Computer Science at Waterloo. “Then we got excited when we realized YouTube could be a helpful resource for that research process.”
These devices could pack three times as much energy per pound as today’s best EV batteries, offering a lightweight option for powering trucks, planes, or ships.
Batteries are nearing their limits in terms of how much power they can store for a given weight. That’s a serious obstacle for energy innovation and the search for new ways to power airplanes, trains, and ships. Now, researchers at MIT and elsewhere have come up with a solution that could help electrify these transportation systems.
Instead of a battery, the new concept is a kind of fuel cell — which is similar to a battery but can be quickly refueled rather than recharged. In this case, the fuel is liquid sodium metal, an inexpensive and widely available commodity. The other side of the cell is just ordinary air, which serves as a source of oxygen atoms. In between, a layer of solid ceramic material serves as the electrolyte, allowing sodium ions to pass freely through, and a porous air-facing electrode helps the sodium to chemically react with oxygen and produce electricity.
In a series of experiments with a prototype device, the researchers demonstrated that this cell could carry more than three times as much energy per unit of weight as the lithium-ion batteries used in virtually all electric vehicles today. Their findings are being published today in the journal Joule, in a paper by MIT doctoral students Karen Sugano, Sunil Mair, and Saahir Ganti-Agrawal; professor of materials science and engineering Yet-Ming Chiang; and five others.
“We expect people to think that this is a totally crazy idea,” says Chiang, who is the Kyocera Professor of Ceramics. “If they didn’t, I’d be a bit disappointed because if people don’t think something is totally crazy at first, it probably isn’t going to be that revolutionary.”
And this technology does appear to have the potential to be quite revolutionary, he suggests. In particular, for aviation, where weight is especially crucial, such an improvement in energy density could be the breakthrough that finally makes electrically powered flight practical at significant scale.
“The threshold that you really need for realistic electric aviation is about 1,000 watt-hours per kilogram,” Chiang says. Today’s electric vehicle lithium-ion batteries top out at about 300 watt-hours per kilogram — nowhere near what’s needed. Even at 1,000 watt-hours per kilogram, he says, that wouldn’t be enough to enable transcontinental or trans-Atlantic flights.
That’s still beyond reach for any known battery chemistry, but Chiang says that getting to 1,000 watts per kilogram would be an enabling technology for regional electric aviation, which accounts for about 80 percent of domestic flights and 30 percent of the emissions from aviation.
The technology could be an enabler for other sectors as well, including marine and rail transportation. “They all require very high energy density, and they all require low cost,” he says. “And that’s what attracted us to sodium metal.”
A great deal of research has gone into developing lithium-air or sodium-air batteries over the last three decades, but it has been hard to make them fully rechargeable. “People have been aware of the energy density you could get with metal-air batteries for a very long time, and it’s been hugely attractive, but it’s just never been realized in practice,” Chiang says.
By using the same basic electrochemical concept, only making it a fuel cell instead of a battery, the researchers were able to get the advantages of the high energy density in a practical form. Unlike a battery, whose materials are assembled once and sealed in a container, with a fuel cell the energy-carrying materials go in and out.
The team produced two different versions of a lab-scale prototype of the system. In one, called an H cell, two vertical glass tubes are connected by a tube across the middle, which contains a solid ceramic electrolyte material and a porous air electrode. Liquid sodium metal fills the tube on one side, and air flows through the other, providing the oxygen for the electrochemical reaction at the center, which ends up gradually consuming the sodium fuel. The other prototype uses a horizontal design, with a tray of the electrolyte material holding the liquid sodium fuel. The porous air electrode, which facilitates the reaction, is affixed to the bottom of the tray.
Tests using an air stream with a carefully controlled humidity level produced a level of nearly 1,700 watt-hours per kilogram at the level of an individual “stack,” which would translate to over 1,000 watt-hours at the full system level, Chiang says.
The researchers envision that to use this system in an aircraft, fuel packs containing stacks of cells, like racks of food trays in a cafeteria, would be inserted into the fuel cells; the sodium metal inside these packs gets chemically transformed as it provides the power. A stream of its chemical byproduct is given off, and in the case of aircraft this would be emitted out the back, not unlike the exhaust from a jet engine.
But there’s a very big difference: There would be no carbon dioxide emissions. Instead the emissions, consisting of sodium oxide, would actually soak up carbon dioxide from the atmosphere. This compound would quickly combine with moisture in the air to make sodium hydroxide — a material commonly used as a drain cleaner — which readily combines with carbon dioxide to form a solid material, sodium carbonate, which in turn forms sodium bicarbonate, otherwise known as baking soda.
“There’s this natural cascade of reactions that happens when you start with sodium metal,” Chiang says. “It’s all spontaneous. We don’t have to do anything to make it happen, we just have to fly the airplane.”
As an added benefit, if the final product, the sodium bicarbonate, ends up in the ocean, it could help to de-acidify the water, countering another of the damaging effects of greenhouse gases.
Using sodium hydroxide to capture carbon dioxide has been proposed as a way of mitigating carbon emissions, but on its own, it’s not an economic solution because the compound is too expensive. “But here, it’s a byproduct,” Chiang explains, so it’s essentially free, producing environmental benefits at no cost.
Importantly, the new fuel cell is inherently safer than many other batteries, he says. Sodium metal is extremely reactive and must be well-protected. As with lithium batteries, sodium can spontaneously ignite if exposed to moisture. “Whenever you have a very high energy density battery, safety is always a concern, because if there’s a rupture of the membrane that separates the two reactants, you can have a runaway reaction,” Chiang says. But in this fuel cell, one side is just air, “which is dilute and limited. So you don’t have two concentrated reactants right next to each other. If you’re pushing for really, really high energy density, you’d rather have a fuel cell than a battery for safety reasons.”
While the device so far exists only as a small, single-cell prototype, Chiang says the system should be quite straightforward to scale up to practical sizes for commercialization. Members of the research team have already formed a company, Propel Aero, to develop the technology. The company is currently housed in MIT’s startup incubator,The Engine.
Producing enough sodium metal to enable widespread, full-scale global implementation of this technology should be practical, since the material has been produced at large scale before. When leaded gasoline was the norm, before it was phased out, sodium metal was used to make the tetraethyl lead used as an additive, and it was being produced in the U.S. at a capacity of 200,000 tons a year. “It reminds us that sodium metal was once produced at large scale and safely handled and distributed around the U.S.,” Chiang says.
What’s more, sodium primarily originates from sodium chloride, or salt, so it is abundant, widely distributed around the world, and easily extracted, unlike lithium and other materials used in today’s EV batteries.
The system they envisage would use a refillable cartridge, which would be filled with liquid sodium metal and sealed. When it’s depleted, it would be returned to a refilling station and loaded with fresh sodium. Sodium melts at 98 degrees Celsius, just below the boiling point of water, so it is easy to heat to the melting point to refuel the cartridges.
Initially, the plan is to produce a brick-sized fuel cell that can deliver about 1,000 watt-hours of energy, enough to power a large drone, in order to prove the concept in a practical form that could be used for agriculture, for example. The team hopes to have such a demonstration ready within the next year.
Sugano, who conducted much of the experimental work as part of her doctoral thesis and will now work at the startup, says that a key insight was the importance of moisture in the process. As she tested the device with pure oxygen, and then with air, she found that the amount of humidity in the air was crucial to making the electrochemical reaction efficient. The humid air resulted in the sodium producing its discharge products in liquid rather than solid form, making it much easier for these to be removed by the flow of air through the system. “The key was that we can form this liquid discharge product and remove it easily, as opposed to the solid discharge that would form in dry conditions,” she says.
Ganti-Agrawal notes that the team drew from a variety of different engineering subfields. For example, there has been much research on high-temperature sodium, but none with a system with controlled humidity. “We’re pulling from fuel cell research in terms of designing our electrode, we’re pulling from older high-temperature battery research as well as some nascent sodium-air battery research, and kind of mushing it together,” which led to the “the big bump in performance” the team has achieved, he says.
The research team also included Alden Friesen, an MIT summer intern who attends Desert Mountain High School in Scottsdale, Arizona; Kailash Raman and William Woodford of Form Energy in Somerville, Massachusetts; Shashank Sripad of And Battery Aero in California, and Venkatasubramanian Viswanathan of the University of Michigan. The work was supported by ARPA-E, Breakthrough Energy Ventures, and the National Science Foundation, and used facilities at MIT.nano.
From left, graduate student Parmit Singh Virdi and Professor Wei Guo work on a custom-built test facility used to measure the heat transfer coefficients of cryogenic working fluids in the National High Magnetic Field Laboratory. The data from these experiments is crucial for designing efficient heat exchangers that will be used in liquid hydrogen-powered aircraft.
Credit: Scott Holstein/FAMU-FSU College of Engineering
Researchers at the FAMU-FSU College of Engineering have designed a liquid hydrogen storage and delivery system that could help make zero-emission aviation a reality. Their work outlines a scalable, integrated system that addresses several engineering challenges at once by enabling hydrogen to be used as a clean fuel and also as a built-in cooling medium for critical power systems aboard electric-powered aircraft.
The study, published inApplied Energy, introduces a design tailored for a 100-passenger hybrid-electric aircraft that draws power from both hydrogen fuel cells and hydrogen turbine-driven superconducting generators. It shows how liquid hydrogen can be efficiently stored, safely transferred and used to cool critical onboard systems — all while supporting power demands during various flight phases like takeoff, cruising, and landing.
“Our goal was to create a single system that handles multiple critical tasks: fuel storage, cooling and delivery control,” said Wei Guo, a professor in the Department of Mechanical Engineering and corresponding author of the study. “This design lays the foundation for real-world hydrogen aviation systems.”
WHAT THEY DID Hydrogen is seen as a promising clean fuel for aviation because it packs more energy per kilogram than jet fuel and emits no carbon dioxide. But it’s also much less dense, meaning it takes up more space unless stored as a super-cold liquid at –253°C.
To address this challenge, the team conducted a comprehensive system-level optimization to design cryogenic tanks and their associated subsystems. Instead of focusing solely on the tank, they defined a new gravimetric index, which is the ratio of the fuel mass to the full fuel system. Their index includes the mass of the hydrogen fuel, tank structure, insulation, heat exchangers, circulatory devices and working fluids.
By repeatedly adjusting key design parameters, such as vent pressure and heat exchanger dimensions, they identified the configuration that yields the maximum fuel mass relative to total system mass. The resulting optimal configuration achieves a gravimetric index of 0.62, meaning 62% of the system’s total weight is usable hydrogen fuel, a significant improvement compared to conventional designs.
The system’s other key function is thermal management. Rather than installing a separate cooling system, the design routes the ultra-cold hydrogen through a series of heat exchangers that remove waste heat from onboard components like superconducting generators, motors, cables and power electronics. As hydrogen absorbs this heat, its temperature gradually rises, a necessary process since hydrogen must be preheated before entering the fuel cells and turbines.
HOW IT WORKS Delivering liquid hydrogen throughout the aircraft presents its own challenges. Mechanical pumps add weight and complexity and can introduce unwanted heat or risk failure under cryogenic conditions. To avoid these issues, the team developed a pump-free system that uses tank pressure to control the flow of hydrogen fuel.
The pressure is regulated using two methods: injecting hydrogen gas from a standard high-pressure cylinder to increase pressure and venting hydrogen vapor to decrease it. A feedback loop links pressure sensors to the aircraft’s power demand profile, enabling real-time adjustment of tank pressure to ensure the correct hydrogen flow rate across all flight phases. Simulations show it can deliver hydrogen at rates up to 0.25 kilograms per second, sufficient to meet the 16.2-megawatt electrical demand during takeoff or an emergency go-around.
The heat exchangers are arranged in a staged sequence. As the hydrogen flows through the system, it first cools high-efficiency components operating at cryogenic temperatures, such as high-temperature superconducting generators and cables. It then absorbs heat from higher-temperature components, including electric motors, motor drives and power electronics. Finally, before reaching the fuel cells, the hydrogen is preheated to match the optimal fuel cell inlet conditions.
This staged thermal integration allows liquid hydrogen to serve as both a coolant and a fuel, maximizing system efficiency while minimizing hardware complexity.
“Previously, people were unsure about how to move liquid hydrogen effectively in an aircraft and whether you could also use it to cool down the power system component,” Guo said. “Not only did we show that it’s feasible, but we also demonstrated that you needed to do a system-level optimization for this type of design.”
FUTURE STEPS AND COLLABORATORS While this study focused on design optimization and system simulation, the next phase will involve experimental validation. Guo and his team plan to build a prototype system and conduct tests at FSU’s Center for Advanced Power Systems.
The project is part of NASA’s Integrated Zero Emission Aviation program, which brings together institutions across the U.S. to develop a full suite of clean aviation technologies. Partner universities include Georgia Tech, Illinois Institute of Technology, University of Tennessee and University at Buffalo. FSU leads the effort in hydrogen storage, thermal management and power system design.
At FSU, key contributors include graduate student Parmit S. Virdi; professors Lance Cooley, Juan Ordóñez, Hui Li, Sastry Pamidi; and other faculty experts in cryogenics, superconductivity and power systems.
FUNDING This project was supported by NASA as part of the organization’s University Leadership initiative, which provides an opportunity for U.S. universities to receive NASA funding and take the lead in building their own teams and setting their own research agenda with goals that support and complement the agency’s Aeronautics Research Mission Directorate and its Strategic Implementation Plan.
Guo’s research was conducted at the FSU-headquartered National High Magnetic Field Laboratory, which is supported by the National Science Foundation and the State of Florida.
An artist's rendering of a 100-passenger hybrid-electric aircraft that uses hydrogen as fuel.
A schematic showing the design of a hydrogen-powered aircraft.
A new study published today in the journal Conservation Biology has found that songbirds modify their migration patterns when migrating through the vast agricultural landscape of the Midwest known as the "Corn Belt" in similar ways when crossing natural barriers like the Gulf of Mexico.
The research team analyzed five years of weather radar data from 47 stations across the eastern United States to examine how birds modify their migration patterns when crossing the Corn Belt compared to more forested landscapes. They found that birds fly faster and are more selective about flying with favorable tailwinds when crossing the Corn Belt—a vast agricultural region where more than 76% of the original forests and grasslands have been converted primarily to cornfields since the 1850s.
"Birds are showing clear behavioral changes when crossing this agricultural landscape compared to more forested landscapes," said lead author Fengyi Guo, a postdoctoral researcher at the Cornell Lab of Ornithology. "They increase their powered flight speed and carefully adjust their flight time and height to take advantage of tailwinds, much like they do when crossing natural barriers like the Gulf of Mexico."
However, unlike the trans-Gulf migration where birds must make a non-stop flight, the Corn Belt's scattered forest patches appear to serve as important "stepping stones" where birds can stop to rest and refuel.
“For those birds that do not cross the Corn Belt in a single flight, the radar pattern also shows that they are more likely to make stops in areas with more forest cover within the Corn Belt,” said Guo.
While not as formidable as crossing the Gulf of Mexico, this research shows that human changes to the landscape can alter migratory behavior. "What makes the Corn Belt a somewhat easier barrier to cross is its narrower width, the presence of forest fragments throughout the agricultural matrix, and the fact that birds can land if needed," explained Guo. "Still, we found that birds tend to concentrate in areas with more forest cover within the Corn Belt, highlighting how important these remaining woodlands are for migrating birds."
The researchers recommend protecting existing forest patches and restoring additional forest "stepping stones" within the Corn Belt to help birds successfully navigate this agricultural landscape. They also emphasize the importance of preserving woodlands along the Gulf Coast where birds make the first landfall after crossing that natural barrier.
"With continuing agricultural expansion and coastal development, both the Corn Belt and Gulf Coast are becoming increasingly challenging for migrating birds," said co-author Adriaan Dokter, research associate at the Cornell Lab of Ornithology. "Conservation efforts should focus on maintaining and creating high-quality stopover habitats in both regions to support the billions of birds that migrate through them each year."
F. Guo, J. J. Buler, A. M. Dokter, K. G. Horton, E. B. Cohen, D. Sheldon, J. A. Smolinksy, and D. S. Wilcove. (2025). Assessing the Corn Belt as an anthropogenic barrier to migrating landbirds in the United States. Conservation Biology
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