Thursday, September 17, 2026

 

Study: Why colder temps can be better for removing ice






University of Texas at Dallas

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University of Texas at Dallas mechanical engineering research associate Dr. Yao Ren exposes an ice-covered metal surface to dry ice to cool it further. Researchers found that a material’s thermal properties play a critical role in determining whether ice remains attached to a surface — a discovery that may lead to the design of future deicing systems for aircraft and wind turbines.

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Credit: The University of Texas at Dallas





Deicing technologies often rely on heat to melt ice. But University of Texas at Dallas researchers have found that, under extreme cold, making ice even colder can weaken its grip on surfaces.

“Our work shows that under extremely cold conditions, rapid cooling can actually make ice much easier to remove,” said Dr. Hongbing Lu, professor of mechanical engineering and the Louis Beecherl Jr. Chair in the Erik Jonsson School of Engineering and Computer Science.

The discovery, published online May 29 in the journal Newton, reveals that a material’s thermal properties play a critical role in determining whether ice remains attached to a surface. The finding could guide the design of future deicing systems for aircraft, wind turbines and other applications in extreme cold.

Lu, who directs the Mechanics of Advanced Materials Laboratory, is a co-corresponding author of the study with Dr. Xianming “Simon” Dai, associate professor of engineering technology and industrial distribution at Texas A&M University and a former associate professor of mechanical engineering at UT Dallas.

Ice accumulation on aircraft, wind turbines and power infrastructure can ground flights, reduce energy production and damage equipment. While heating can be an effective method for removing ice, supplying enough heat in very cold environments can be difficult and energy intensive.

In addition to using heat to melt ice, deicing procedures also can involve changing the chemistry of surfaces to prevent ice from sticking. Those methods, however, become less effective in extremely cold conditions, when ice still can form strong bonds with the surface.

Cracks formed in the ice on this metal sample show how rapidly cooling ice can weaken its grip on the surface in extreme-cold conditions.

UT Dallas researchers made their discovery while conducting experiments to develop ice-resistant surfaces for cold environments.

The team cooled ice on metal, glass and plastic surfaces to minus 76 degrees Fahrenheit (minus 60 degrees Celsius) to investigate whether rapid temperature changes could weaken ice adhesion. Many materials, including solid ice, contract as they get colder, but how much they change size depends on the material.

Metal and glass have similar thermal expansion properties, so researchers expected the ice to behave similarly on both surfaces. Instead, the ice released easily from the cooled metal but remained firmly attached to the glass.

At first, the result didn’t make sense.

“It puzzled us for a long time,” Lu said.

As team members looked for explanations for the unexpected behavior, they determined that the thermal conductivity of the surface played a critical role in whether the ice would detach.

In particular, the way a surface transfers heat determines the temperature change at the ice-surface interface. In general, materials that transfer heat more efficiently can cool the ice more rapidly.

“We determined that the observed behavior is the result of differences in thermal conductivity of the substrate,” Lu said. “So, simply put, the ice touching steel gets colder much faster than ice touching glass.”

Because the metal conducted heat more efficiently than glass or plastic, the ice on the metal surface cooled and contracted more than on the other surfaces. This created stresses that fractured the ice, reducing its adhesion to nearly zero.

“The ice wants to shrink more than the steel does, but because they are bonded together, the steel holds it back, putting the ice under tensile stress,” Lu said.

The study’s findings challenge conventional thinking by showing that the speed at which a surface conducts heat is an important factor in determining whether ice will detach.

“On a surface with very high thermal conductivity, we don’t want to warm the ice — we may actually want to cool it,” Lu said. “The larger temperature drop creates greater stresses in the ice, which, combined with the mismatch in how the materials contract, can cause the ice to fracture.”

The researchers developed a model that predicts how different materials will behave during rapid cooling, which could help engineers design future deicing systems.

The researchers also tested composite materials relevant to aircraft and wind turbine blades and found that carbon fiber composites, which have higher thermal conductivity than glass fiber composites, created weaker ice interfaces, making ice easier to detach.

Although additional research will be needed before the approach could be incorporated into practical deicing systems, the findings suggest that in extremely cold environments, making ice colder rather than warmer may be a better approach.

“Conventional wisdom says we need to introduce heat,” Lu said. “In some cases, however, the colder the better.”

Other UT Dallas-affiliated authors of the article were Jyotirmoy Sarma MS’18, PhD’22; Dylan Boylan PhD’25; and mechanical engineering research associate Dr. Yao Ren; from Texas A&M, postdoctoral researcher Deepak Monga PhD’24 and graduate student Meiying He contributed to the work.

Lu received funding for the research from the U.S. Department of Energy (DOE) (NA0003962, NA0003525) and the National Science Foundation (NSF) (2219347). Dai received support from the Army Research Office (W911NF1910416), DOE (EE0011217), the Defense Advanced Research Projects Agency (D23AP00160) and the NSF (2044348).


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Dr. Yao Ren holds an ice-covered metal sample to demonstrate how the ice forms cracks when exposed to even colder temperatures.

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Cracks formed in the ice on this metal sample show how rapidly cooling ice can weaken its grip on the surface in extreme-cold conditions.

Credit

The University of Texas at Dallas







 

Study challenges estimates used to guide Atlantic menhaden fishing



Reanalysis of a historic tagging study could help managers better balance commercial harvests with the needs of coastal food webs




University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Science

Study challenges estimates used to guide Atlantic menhaden fishing

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Atlantic menhaden (Brevoortia tyrannus) form large schools in the Atlantic Ocean and bay areas. Photo: NOAA Fisheries

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Credit: NOAA Fisheries






Virginia Key, Fl. — Atlantic menhaden (Brevoortia tyrannus) supports a major commercial fishery along the U.S. East Coast and serves as essential prey for fishes, seabirds, and marine mammals, may be less able to sustain fishing pressure than some assessments suggest. A new study finds that a key estimate of deaths from natural causes was substantially overstated, potentially making the population appear more productive than its biology supports.

Led by Jerald Ault, professor emeritus at the University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Science, with co-author Jiangang Luo, a scientist at the Rosenstiel School’s Cooperative Institute for Marine and Atmospheric Studies, the study revisits a landmark federal tagging experiment. The research, published in the journal Fisheries Research, examines how historical records and assumptions about tag recovery influence estimates used to guide fisheries management.

Why it matters

Managers rely on population assessments to determine how much fishing a species can sustain. A central input is natural mortality, the rate at which fish die from causes other than fishing. Setting that rate too high can underestimate fishing’s impact and overestimate the size of the breeding population, leading to overly optimistic harvest advice.

“Getting this number right matters for both the fishery and the coastal ecosystems that depend on menhaden,” said Ault. “If natural mortality is set too high, the population can appear able to support more fishing than its biology allows.”

The researchers estimated a natural mortality rate of 0.50 per year, less than half the 1.17 estimate reported in a 2019 reanalysis by Liljestrand et al., which was incorporated into the SEDAR 69 benchmark stock assessment by the Atlantic States Marine Fisheries Commission. The new result was also substantially below the corrected value of 0.92 adopted in a 2025 stock assessment update.

Ault and Luo returned to original records from a federal tagging program conducted from 1966 through 1971 along the Atlantic coast, from Massachusetts to Florida. The experiment involved more than 1 million tagged menhaden and more than 100,000 recovered tags.

Over approximately three years, they reconstructed two versions of the historical data, checked release and recovery counts, rebuilt fishing-effort records and examined how tags were detected at fish-processing plants.

“Our investigation identified discrepancies involving the numbers of released and recovered tagged fish, reconstruction of historical fishing effort, treatment of tag-detection efficiency at processing plants, and aspects of the statistical model,” said Ault.

A critical issue was the performance of magnets used to recover metal tags from harvested fish. Detection varied widely among plants and over time. After correcting the underlying records, the researchers found that accounting for this variation was the principal reason their mortality estimate differed from earlier analyses.

Models that allowed tag-detection efficiency to vary by location and month better matched the recovery records. Both reconstructed datasets produced natural mortality estimates near 0.50 per year. Additional computer simulations tested uncertainty in the assumptions, with the best-fitting results consistently supporting a similar value.

The estimate also aligned with earlier research and biological evidence showing that Atlantic menhaden historically lived at least 10 years.

The findings concern a historical estimate, rather than a newly observed change in survival. The authors recommend that future assessments evaluate natural mortality values centered at 0.50 per year while accounting for uncertainty. The study does not establish a new catch limit.

“If natural mortality is high, fishing appears to account for a smaller share of population change. If it is closer to 0.5, as this study and earlier historical estimates suggest, fishing may account for a larger share of the losses,” added Ault. “For a species that is both heavily harvested and ecologically central, that distinction matters not only to the menhaden fishery but to the many managed predators that rely on menhaden.”

The study titled “Investigation of Atlantic menhaden mortality rates” was published on September 16, 2026 in the journal Fisheries Research. The authors are Jerald S. Ault and Jiangang Luo of the University of Miami Rosenstiel School.

About the University of Miami and Rosenstiel School of Marine, Atmospheric and Earth Science

 The University of Miami is a private research university and academic health system with a distinct geographic capacity to connect institutions, individuals, and ideas across the hemisphere and around the world. The University’s vibrant academic community comprises 12 schools and colleges serving more than 19,000 undergraduate and graduate students in more than 180 majors and programs. Located within one of the most dynamic and multicultural cities in the world, the University is building new bridges across geographic, cultural, and intellectual borders, bringing a passion for scholarly excellence, a spirit of innovation, and a commitment to tackling the challenges facing our world. The University of Miami is a member of the prestigious Association of American Universities (AAU).

 Founded in 1943, the Rosenstiel School of Marine, Atmospheric, and Earth Science is one of the world’s premier research institutions in the continental United States. The School’s basic and applied research programs seek to improve understanding and prediction of Earth’s geological, oceanic, and atmospheric systems by focusing on four key pillars:

*Saving lives through better forecasting of extreme weather and seismic events. 

*Feeding the world by developing sustainable wild fisheries and aquaculture programs. 

*Unlocking ocean secrets through research on climate, weather, energy and medicine. 

*Preserving marine species, including endangered sharks and other fish, as well as protecting and restoring threatened coral reefs. www.earth.miami.edu.

 

 

The depths of the ocean aren’t immune to human debris



A survey of the never-before-seen sea floor of a submarine canyon found plastic and other waste, indicating that it is not as distant as it may seem


PLOS

Out of sight, hidden into the deep: Marine litter in the Mar del Plata Submarine Canyon (southwestern Atlantic) revealed by ROV survey

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Examples of deep-sea litter found in the Mar del Plata Submarine Canyon. (A) Medium-sized plastic wrapper, 2,109 m. (B) Rubber boot, 2,598 m. (C) Food wrapper, 1,920 m. (D) Snack wrapper, 3,231 m. (E) Tissue paper wrapper, 3,814 m. (F) Sediment-filled plastic bag, 3,739 m. (G) Highly degraded plastic fragment, 3,709 m. (H) Nylon cord with a hook, 1,949 m. (I) White plastic cup and bag (arrows), 3,243 m. Scale bars: 10 cm. All images courtesy of Schmidt Ocean Institute/ ROV SuBastian (CC BY 4.0), expedition FKt250712.

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Credit: Teso et al., 2026, PLOS One, CC-BY 4.0 (https://creativecommons.org/licenses/by/4.0/)






It’s no secret that plastic and other human trash are a problem for marine life, but our understanding has long focused on the ocean’s surface. Now, a more complete picture is coming into focus, revealing that even some of our planet’s greatest depths have become home to our debris. As described in a study published on September 16, 2026 in the open access journal PLOS One, an international team led by Dr. Daniel Lauretta of Argentina’s natural science museum surveyed the Mar Del Plata Submarine Canyon in the southwestern Atlantic, finding that our trash has accumulated in a part of the planet we typically consider pristine.

The ocean’s depths remain one of Earth’s greatest unknowns, but­ as the fish swims—or as the debris sinks—the sea floor is not all that distant. On average, our oceans are just a few miles deep, and thus, not so far from human influence. This study, which took place in summer of 2025, marked the first time scientists had taken images of the seafloor within the Mar Del Plata Submarine Canyon. They documented approximately 40 species that may be new to science but also some more familiar sights.

Across 10 of the 17 dives with a remotely operated submersible, the researchers saw 29 identifiably manmade objects. The vast majority were plastic, along with a few rubber items. They ranged from fishing gear to plastic bags and food wrappers and even a boot. Some were buried in the sediment, while others were trapped in rocks or still drifting. The researchers observed more litter inside the canyon compared to the surrounding area, suggesting the geography and currents funneled these items into the fissure.

Researchers observed some animals also interacted with the waste. Mobile creatures like crustaceans had transient interactions while more stationary creatures—like starfish  and corals—had attached to some debris, often partially subsumed plastic packaging and fishing ropes. Though life was present, the team cautioned that we can’t assume these objects are suitable habitats.

This is not the only time scientists have found traces of our trash so far below the surface. Just a few months before the expeditions in the Mar Del Plata Submarine Canyon, a plastic bag was found in the Mariana Trench, the planet’s deepest fissure. The sinking of organic material is essential to life beyond the reaches of sunlight, but this new study adds to emerging evidence that nutrients aren’t the only matter pulled to the ocean floor.

The authors add: "Unveiling a species previously unknown to science in the endless darkness of the deep sea may be one of the most extraordinary experiences a marine biologist can have."

 

 

Author interview: https://plos.io/4ys71Nz

In your coverage, please use this URL to provide access to the freely available article in PLOS One: https://plos.io/3UwaXhS

Citation: Teso V, Urteaga D, Bozzano G, Bigatti G, Brogger MI, Brusa F, et al. (2026) Out of sight, hidden into the deep: Marine litter in the Mar del Plata Submarine Canyon (southwestern Atlantic) revealed by ROV survey. PLoS One 21(9): e0357098. https://doi.org/10.1371/journal.pone.0357098

Author countries: Argentina, Ecuador, USA.

Funding: The oceanographic expedition FKt250712 was funded by the Schmidt Ocean Institute (SOI), the Nippon Foundation-Nekton Ocean Census Programme (https://oceancensus.org/), CORDAP Coral Accelerator Program under Award No. CAP-2023–1502, and the AZARA Foundation. Funding was also provided by PICT 2020-1169 (Agencia I+D+I), PICT 2020-1215 (Agencia I+D+I), PIBAA 2022-0410 (CONICET), PIBAA 2022-0433 (CONICET), PIP 2022-0277 (CONICET), and Fundación ProyectoSub. All funders have no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.



Faunal interactions with anthropogenic litter in the Mar del Plata Submarine Canyon (MPSC). (A) Degraded black plastic sheet, partially buried, with arthropods including Tetrachaelasma southwardi and an octocoral, 2,108 m. (B) Plastic bag with the asteroid Smilasterias sp., 3,243 m. (C) Fishing rope with tubicolous polychaetes, 2,054 m. (D) Nylon filament (probably fishing line) with Anthozoa polyp indet., 1,616 m. (E) White plastic container, partially buried, with the brittle star Ophioplinthus sp. and probable ascidian, 1,764 m. All images courtesy of Schmidt Ocean Institute/ ROV SuBastian (CC BY 4.0), expedition FKt250712.

Credit

Teso et al., 2026, PLOS One, CC-BY 4.0 (https://creativecommons.org/licenses/by/4.0/)




 

Harvesting hot electrons could break solar panel barrier




University of Groningen
Two effects are required to delay cooling of hot electrons

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The visual abstract of the paper in ACS Energy Letters, showing how two synergetic effects create a delay in the loss of energy from hot electrons:

1) The Hot Phonon Bottleneck

2) Band-filling, resulting in the Burnstein-Moss effect

 

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Credit: ACS Energy Letters






Physics predicts that no more than 33 percent of the solar energy that falls on a solar panel can be converted into electricity. However, experiments and simulations by scientists at the University of Groningen (the Netherlands) revealed a way to harvest extra energy from ‘hot electrons’, which could break this barrier.

When light falls on a solar panel, the energy of the photons brings electrons in the solar cell material into an excited state, thus transferring the energy to them. This reaction can free an electron from the solar cell material and create a voltage.

However, very energetic photons give the electrons extra energy, producing ‘hot electrons’. In theory, the extra energy these hot electrons carry could increase the voltage. In practice, the extra energy is lost as heat in a matter of picoseconds (0,000000000001 second). ‘This means that the energy is lost before the hot electron exits the solar cell material’, says Jan Anton Koster, Professor of Physics of Novel Semiconductors and Devices at the University of Groningen.

Scepticism about the claims

However, in an experimental setup, his colleague Maria Antonietta Loi, professor of Photophysics and Optoelectronics, managed to produce a delay in heat loss by hot electrons. She created a solar cell material called tin-based perovskite, and observed that the loss of extra energy is slowed down to nanoseconds, roughly a factor of 1,000. ‘The measurements were clear, but we didn’t understand the physics behind this’, says Koster. This led others in the field to question this claim. ‘We even started to doubt the measurements ourselves’, he admits.

In order to solve this conundrum, Koster and his PhD student Tim Faber used simulations to study the physics of this energy loss. They found that in perovskite solar cells, two different mechanisms combine to extend the time it takes hot electrons to lose the extra energy.

Nanosecond range

When energy is lost as heat, the environment surrounding the electrons will become warmer. Koster and Faber realised that this lingering heat can be reabsorbed by the electrons. ‘When we added this well-known process called Hot Phonon Bottleneck to the simulations, it slowed the loss of energy, but not enough to explain our measurements.’ This required adding a second mechanism to the simulation.

The extra energy of hot electrons can bring them into a number of excited states. Energy loss means that the excited state is reduced to a lower energy level in discrete steps. However, when the different steps in this process are already occupied, the way down to the lowest energy level is more difficult and takes more time. This is called the Burstein-Moss effect. Koster: ‘When we added this process to the simulation as well, we saw that energy loss was now in the nanosecond range, as seen in the experiments by Maria Loi.’

As both of these processes are present in tin-based perovskite solar cells, Koster and his team finally understood why the energy loss of hot electrons was slowed down. There are many other questions that still need answers, but in theory, this discovery could allow the creation of more efficient solar cells, beyond the theoretical limit of 33 percent.

Reference: Tim Faber et al.: The Physics of Ultra-Long Cooling Times in Metal Halide Perovskites. ACS Energy Letters, 11 September 2026.