The NOMAD Laboratory researchers have recently shed light on fundamental microscopic mechanisms that can help with tailoring materials for heat insulation. This development advances the ongoing efforts to enhance energy efficiency and sustainability.

The role of heat transport is crucial in various scientific and industrial applications, such as catalysis, turbine technologies, and thermoelectric heat converters that convert waste heat into electricity.

Particularly in the context of energy conservation and the development of sustainable technologies, materials with high thermal insulation capabilities are of utmost importance. These materials make it possible to retain and utilize heat that would otherwise go to waste. Therefore, improving the design of highly insulating materials is a key research objective in enabling more energy-efficient applications.

However, designing strongly heat insulators is far from trivial, despite the fact that the underlying fundamental physical laws have been known for nearly a century. At a microscopic level, heat transport in semiconductors and insulators was understood in terms of the collective oscillation of the atoms around their equilibrium positions in the crystal lattice. These oscillations, called “phonons” in the field, involve a huge number of atoms in solid materials and hence cover large, almost macroscopic length- and time-scales.

In a recent joined publication in Physical Review B and Physical Review Letters, researchers from the NOMAD Laboratory at the Fritz Haber Institute have advanced the computational possibilities to compute thermal conductivities without experimental input at unprecedented accuracy. They demonstrated that for strong heat insulators the above-mentioned phonon picture is not appropriate.

Using large-scale calculations on supercomputers at of the Max Planck Society, the North-German Supercomputing Alliance, and the Jülich Supercomputing Centre, they scanned over 465 crystalline materials, for which the thermal conductivity had not been measured yet. Besides finding 28 strong thermal insulators, six of which feature an ultra-low thermal conductivity comparable to wood, this study shed light on a hitherto typically overseen mechanism that allows one to systematically lower the thermal conductivity.

“We observed the temporary formation of defect structures that massively influences the atomic motion for an extremely short period of time,” says Dr. Florian Knoop (now Linköping University), first author of both publications.

“Such effects are typically neglected in thermal-conductivity simulations, since these defects are so short-lived and so microscopically localized compared to typical heat-transport scales, that they are assumed to be irrelevant. However, the performed calculations showed that they trigger lower thermal conductivities,” adds Dr. Christian Carbogno, a senior author of the studies.

These insights may offer new opportunities to fine-tune and design thermal insulators on a nanoscale level through defect engineering, potentially contributing to advances in energy-efficient technology.

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A long-dormant “supervolcano” in southern Italy is inching closer to a possible eruption — nearly six centuries after it last erupted, according to European researchers. 

The Campi Flegrei volcano, which is located near the city of Naples, has become weaker over time and as a result is more prone to rupturing, according to a peer-reviewed study conducted by researchers from England’s University College London and Italy’s National Research Institute for Geophysics and Volcanology. 

The study used a model of volcano fracturing to interpret the patterns of earthquakes and ground uplift. There have been tens of thousands of earthquakes around the volcano, and the town of Pozzuoli, which rests on top of Campi Flegrei, has been lifted by about 13 feet as a result of them. The quakes and rising earth have stretched parts of the volcano “nearly to the breaking point,” according to a news release about the study, and the ground seems to be breaking, rather than bending. 

The earthquakes are caused by the movement of fluids beneath the surface, the news release said. It’s not clear what those fluids are, but researchers said they may be molten rock, magma or natural volcanic gas. 

The earthquakes have taken place during the volcano’s active periods. While it last erupted in 1538, it has been “restless” for decades, with spikes of unrest occurring in the 1950s, 1970s and 1980s. There has been “a slower phase of unrest” in the past 10 years, researchers said, but 600 earthquakes were recorded in April, setting a new monthly record. 

According to LiveScience, Campi Flegrei is often referred to as a “supervolcano,” which can produce eruptions reaching a category 8 — the highest level on the Volcano Explosivity Index. However, Campi Flegrei’s biggest-ever eruption technically ranked as a category 7, which is still considered a very large and disastrous eruption, LiveScience reported.   

While Campi Flegrei — which means “burning fields” — may be closer to rupture, there is no guarantee that this will actually result in an eruption, the study concluded. 

“The rupture may open a crack through the crust, but the magma still needs to be pushing up at the right location for an eruption to occur,” said Professor Christopher Kilburn, who studies earth sciences at University College London and was the lead author of the study. 

Kilburn said that this is the first time the model has been applied to a volcano in real-time. Since first using the model in 2017, the volcano has behaved as predicted, Kilburn said, so researchers plan to expand the use of the model to look at other volcanoes that reawakened after long periods of dormancy. The goal is to establish more reliable criteria to decide if an eruption is likely and establish a model that can be applied to multiple volcanoes. 

“The study is the first of its kind to forecast rupture at an active volcano. It marks a step change in our goal to improve forecasts of eruptions worldwide,” Kilburn said.

Kerry Breen

Kerry Breen is a news editor and reporter for CBS News. Her reporting focuses on current events, breaking news and substance use.

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These underground mountain peaks are called ultra-low velocity zones or ULVZs.

The deep Earth contains mountains with peaks three to four times higher than Mount Everest, scientists have found. According to the BBC, a team of experts from Arizona State University used seismology centres in Antarctica and found these astonishingly huge mountains in the boundary between the core and mantle, around 2,900 kilometres deep inside our planet. 

“The mountain-like structures they revealed are utterly mysterious,” the BBC report read. Scientists explained that these underground mountain ranges – dubbed ultra-low velocity zones or ULVZs – had managed to escape the experts’ gaze all these years until earthquakes and atomic explosions generated enough seismic data to be spotted by them. 

Scientists believe that these huge mountain ranges are over 24 miles (38 kilometres) in height, while Mount Everest is around 5.5 miles (8.8 kilometres) from the surface. “Analysing 1000’s of seismic recordings from Antarctica, our high-definition imaging method found thin anomalous zones of material at the CMB [core-mantle boundary] everywhere we probed,” Arizona State University geophysicist Edward Garnero said in a statement.

“The material’s thickness varies from a few kilometres to 10’s of kilometres. This suggests we are seeing mountains on the core, in some places up to 5 times taller than Mt. Everest,” he added. 

Also Read | Stephen Hawking’s Famous Theory Could Mean That Entire Universe Is Doomed To Evaporate: Study

Further, as per the report, experts explained the possible reason behind the formation of these mysterious mountain peaks. They believe that these ancient formations were created when oceanic crusts were formed into Earth’s interior. They also argue that it might have begun with tectonic plates slipping down into our planet’s mantle and sinking to the core-mantle boundary. These then slowly spread out to form an assortment of structures, leaving a trail of both mountains and blobs. This would, therefore, mean that these mysterious mountains are made of ancient oceanic crust, which is a combination of basalt rock and sediments from the ocean floor. 

Now, with this recent discovery, scientists are seeking to argue that these underground mountains may play a critical role in how heat escapes the Earth’s core. “Seismic investigations, such as ours, provide the highest resolution imaging of the interior structure of our planet, and we are finding that this structure is vastly more complicated than once thought,” study co-author and University of Alabama geoscientist Samantha Hansen said in a statement.  

“Our research provides important connections between shallow and deep Earth structure and the overall processes driving our planet,” she added. 

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