Invisible supernovas called 'bosenovas' may be exploding all around us, new research suggests

Paul Sutter

LIVE SCIENCE
Tue, July 25, 2023

A wispy red bubble of matter on a dense background of stars. 

A Hubble image of a supernova.

All around the universe, invisible stars may be dying in high-energy explosions, and new research suggests how scientists could actually detect these unseen catastrophes.

In a paper published June 28 in the preprint database arXiv, a team of astrophysicists explored what would happen when boson stars — theoretical large objects made of invisible dark matter — reached the ends of their lives. The result, they wrote, is a massive explosion similar to a supernova, only invisible: a "bosenova."
The invisible universe

Dark matter is a mysterious substance that makes up more than 85% of the mass of almost every galaxy in the universe. While astronomers have found multiple lines of evidence pointing to its existence, all of those lines depend on dark matter's gravitational influence on normal matter. We have yet to detect the presence of dark matter in any other way, so the identity of the particle that's responsible for dark matter remains in question.


Related: Strange star system may hold first evidence of an ultra-rare 'dark matter star'

For years, the leading theory was that the dark matter particle was heavy — as heavy, if not heavier than, particles like protons and neutrons. But searches for the interactions between heavy dark matter and normal matter have come up empty. So now, theorists are turning to models in which dark matter is extremely light.

For perspective, the lightest known particle is the neutrino, which is about 500,000 times lighter than an electron. In the most extreme models, the lightweight dark matter can be billions of times lighter than a neutrino.

If dark matter has such a small mass, it will behave in unexpected ways. For example, instead of zipping around the cosmos like particles, it would slosh around like waves. These waves could also bunch together into tight clumps in a phenomenon dubbed "boson stars," because in these models, dark matter is a kind of particle known as a boson.

These boson stars would maintain equilibrium through the interaction of two competing forces. On one hand is gravity, with the mass of the dark matter always wanting to pull the star into a tighter clump. But the dark matter has energy, which resists the pull of gravity, forming a stable star that would be completely invisible.

As the boson star aged, it would slowly gain mass, either by accumulating new dark matter or by merging with other boson stars, according to the new research. Eventually, the star's mass would increase to a critical tipping point where the energy of the dark matter could no longer resist the pull of gravity — so the boson star would begin to collapse.

This collapse would happen relatively slowly, and at first, nothing catastrophic would happen. But as the dark matter crammed together, individual particles would start to bump into each other, annihilating each other and releasing energy. The energy from the collapse would get released in the form of high-energy, high-velocity particles jetting away from the boson star. However, because these particles would be so incredibly light, they would appear as a burst of dark matter waves emitted by the dying boson star.

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— 1st image of our galaxy's 'black hole heart' unveiled

—Black holes may be swallowing invisible matter that slows the movement of stars

—What's the biggest black hole in the universe?

As an analogy, when normal stars die in supernovas, they release a tremendous number of photons, or particles of light. But because photons are massless, they appear as waves of electricity and magnetism — light.

By contrast, the hypothetical event described by the researchers, which they dubbed a "bosenova," would be completely invisible. Bosenovas might even be going off near our own solar system, and we would never know it.

The only way to detect a bosenova explosion would be through detectors designed to find ultralight dark matter. Many experiments around the globe are already searching for lightweight dark matter. A bosenova would appear to these detectors as a surge of dark matter coming from a specific direction in the sky, just like a traditional supernova appears as a surge of light. Now that the researchers have outlined what a bosenova signature would look like, they hope these experiments will find traces of those fleeting signals.

Mars rover is spying on the sun's far side to hunt for hidden, dangerous sunspots

Harry Baker
Wed, July 26, 2023

A picture of the Perseverance rover on Mars

In their quest to identify and track potentially dangerous sunspots hidden on the far side of the sun, scientists have turned to an unlikely ally: NASA's Perseverance rover on Mars.

Normally, the far side of the sun remains hidden from us and our space telescopes, which are positioned in orbit around Earth or at our planet's Lagrange points, where objects can be permanently stationed. This means that we do not have a clear view of what is happening on the far side of the solar surface. As a result, astronomers are often surprised by giant sunspots that appear suddenly on the sun's near side as our home star rotates at the heart of the solar system.


Large sunspots are more likely to spit out powerful solar flares and coronal mass ejections (CMEs) that can slam into Earth and trigger potentially dangerous geomagnetic storms, regardless of whether we can see the dark patches. This means we can be caught off guard by extreme space weather events. In January, for example, a hidden sunspot on the sun's far side spat out a surprise X-class flare — the most powerful class of solar flare — which narrowly missed Earth.

But the Red Planet is currently positioned toward the opposite side of the sun as Earth is, which gives Perseverance a clear view of the sun's far side. Using images of the sun taken by the rover's two Mastcam-Z cameras, scientists can detect large sunspots before they become visible to us, thereby improving space weather predictions, Spaceweather.com recently reported.

Related: See the first clear images of 'sun rays' on Mars in eerie new NASA photos

An image of the sun with three large sunspots circles by a red ring

In recent weeks, Perseverance has spotted two major sunspots before they launched powerful solar storms toward Earth. The rover spotted a monster sunspot that eventually grew to be around 10 times wider than Earth and launched an X-class flare that hit our planet on July 2. Perseverance also glimpsed a sunspot that helped to launch a "cannibal CME" that hit our planet on July 18.

These sunspots, and others like them, can also be detected by a method known as helioseismology, which measures vibrations in the sun's magnetic field to produce an echo of the far side. However, this technique can often be unpredictable and fail to correctly identify the scale of larger sunspots, according to Spaceweather.com.

Perseverance's images have a low resoltuion, and they can be used only to identify sunspots that are more than 9,300 miles (15,000 kilometers) in diameter, or roughly as wide as 1.2 Earths. But this still allows the rover to catch around 40% of sunspots and most of the ones that could do us harm, which makes it a great tool to use alongside helioseismology when Mars is orientated in the right place, researchers wrote in a paper published in the Bulletin of the American Astronomical Society in January.

The sun setting on Mars

This is even more helpful considering the sun is currently ramping up toward the solar maximum, the most active phase of the roughly 11-year solar cycle, which could hit us sooner and harder than initially expected. As a result, the number of sunspots is higher than it has been in more than 20 years.

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Perseverance's view of the sun's far side will actually improve in the coming months as Mars becomes even more aligned with the side of the sun hidden from Earth, which will help the robot to track increasingly powerful storms. However, the rover will likely be unable to assist us during some of the peak months of the solar maximum.

This is not the first time that scientists have turned to the Red Planet to track sunspots. In 2015, in the months following the previous solar maximum, scientists used NASA's Curiosity rover to snap pictures of the sun's far side, Live Science's sister site Space.com reported at the time. But Curiosity's images had a lower resolution than Perseverance's pics, and solar activity was already starting to slow down by then.

NASA picks Lockheed Martin to develop nuclear rocket

AFP
Wed, July 26, 2023 

"These more powerful and efficient nuclear thermal propulsion systems can provide faster transit times between destinations," said Kirk Shireman, vice president of Lunar Exploration Campaigns at Lockheed Martin Space (MANDEL NGAN)

NASA and the US military said Wednesday they had selected defense contractor Lockheed Martin to develop a nuclear powered rocket, with a view to using the technology for missions to Mars.

The Demonstration Rocket for Agile Cislunar Operations (DRACO) program may launch as soon as 2027, officials said on a call.

Nuclear thermal propulsion (NTP) systems could cut journey times, increase fuel efficiency, and require less propellant, meaning future spacecraft could carry larger payloads than today's best chemical rockets.

NTP works by pumping a liquid propellant, in DRACO's case cryogenic hydrogen, through a reactor core, where uranium atoms split apart through fission.

The process super heats the propellant, converting it into a gas and funneling it through a nozzle to produce thrust.

"These more powerful and efficient nuclear thermal propulsion systems can provide faster transit times between destinations," said Kirk Shireman, vice president of Lunar Exploration Campaigns at Lockheed Martin Space.

"Reducing transit time is vital for human missions to Mars to limit a crew's exposure to radiation," he added.

BWX Technologies will be responsible for developing the nuclear reactor and propellant.

For safety purposes, DRACO's reactor will not be turned on until the spacecraft has reached a high orbit.

Shireman added that the technology could also "revolutionize" future missions to the Moon, where NASA plans to build long term habitats as part of the Artemis program.

NASA conducted its last nuclear thermal rocket engine tests more than 50 years ago but the program was abandoned due to budget cuts and Cold War tensions.

ia/tjj

New Image Reveals Dusty Clumps That Could Be the Source of Gas Giants

Isaac Schultz

GIZMONDO
Tue, July 25, 2023 

Combined SPHERE and ALMA images of the material surrounding V960 Mon.

Researchers think they’ve gotten a glimpse at how gas giants like Jupiter form, thanks to a remarkable image of a distant star system.

At the heart of the system is V960 Mon, a young star about 5,000 light-years away, in the constellation Monoceros. The star brightened to about 20 times its normal levels in 2014, allowing a research team using the European Southern Observatory’s Spectro-Polarimetric High-contrast Exoplanet Research instrument, or SPHERE, to image it. The team’s research characterizing their findings was published today in The Astrophysical Journal Letters.

“Our group has been searching for signs of how planets form for over ten years, and we couldn’t be more thrilled about this incredible discovery,” said Sebastián Pérez, an astronomer at the University of Santiago, in an ESO release.

The SPHERE observations showed that the material surrounding V960 Mon was amassing in spiral arms stretching farther than the size of our own solar system.

Follow-up observations of the distant star system were made with the Atacama Large Millimeter/submillimeter Array (ALMA), which penetrated deeper into the dusty material surrounding the star.

“With ALMA, it became apparent that the spiral arms are undergoing fragmentation, resulting in the formation of clumps with masses akin to those of planets,” said Alice Zurlo, a researcher at the Universidad Diego Portales and co-author of the paper, in the same release.

SPHERE (left) and ALMA (right) images of the region around the star.

The imagery lends credence to one theory of how gas giants form: from the glomming together of material surrounding a star, a formation method known as gravitational instability. Gravitational instability posits that clumps of material contract and collapse, forming gassy planets. That differs from the more common theory for gas giant formation, called core accretion, in which grains of dust slowly come together to form these large worlds.

Observatories like the Webb Space Telescope can ogle distant gassy exoplanets for clues as to how they formed, but the V960 system offers an intimate glimpse at a possible setting for their formation.

The researchers hope to better understand the chemical composition of the clumps around such star systems, which will in turn inform them what kind of planets might form from the clumps.

As always, more observations of the V960 system and those like it will improve astronomers’ understanding of how planets like those in our own solar system form. The ESO’s Very Large Telescope is set to be succeeded by the Extremely Large Telescope in 2027.

The Extremely Large Telescope will be the largest visible and infrared light telescope in the world and will focus its science on exoplanets, black holes, galactic evolution, and the universe’s earliest days.

More: These Telescopes Will Change the Way We See Space

Could space (the final frontier) hold climate solutions for planet Earth?

Doug Johnson
Wed, July 26, 2023 

Thumbnail image: Seen in space in 2001, Canadarm2, launched aboard STS-100, is installed on the International Space Station. Here, Canadian Space Agency astronaut Chris Hadfield stands on one Canadian-built robot arm while working with Canadarm2. (NASA)

Off-world, on Earth’s moon and asteroids, lies a wealth of resources. For a long time, the ability to harvest these resources — which potentially includes elements vital for fuel and renewable sources of energy — was the purview of science fiction, or at least the movie Armageddon.

(The movie’s miners turned protagonists were using their skills to try and blow up a Texas-sized asteroid and save the world. But in theory their efforts could have pioneered a method for extracting rocks while in space.)

However, a future where humans mine other celestial bodies may not be that far off, proponents told The Weather Network. There would be environmental benefits to the approach and Canada is well-positioned to be an active part of this potential future, they added. That said, others are more skeptical about this so-called “space mining.”

In broad strokes, space mining could be an environmental boon in two ways. The first involves developing the ability to gather resources on Earth’s moon. Namely, these resources are helium-3, which is rare on Earth, to power nuclear fusion reactors; and moon dust, which contains ice particles.

Various researchers from around the world are seeking ways to split this ice into hydrogen and oxygen, the former being a potential source of fuel for spacecraft. Daniel Sax is the founder and CEO of the Canadian Space Mining Corporation (CSMC), one of a few Canadian companies in the field.

According to Sax, the future of space exploration will likely require a great deal of fuel and water. Take, for instance, the NASA-led Artemis Mission, which aims to establish a human presence on the moon, among other things.

Hauling water and fuel into space from Earth is difficult, considering they add weight to a spacecraft already subject to the drag from Earth’s atmosphere, and the planet’s gravity. The ability to collect and process moon dust in space could, as such, reduce the amount of fuel burned and greenhouse gasses emitted by enabling a spacecraft to access water and refuel in space — which isn’t normally done currently — with resources made there.

“Right now, it’s really inefficient to get to space and to stay there,” Sax told The Weather Network.

space stuff 3

NASA's Lunar Reconnaissance Orbiter captured this view on March 3, 2023. Malapert Massif, a lunar mountain and Artemis 3 candidate landing region, is shown at lower left. The mountain's highest point looms more than 16,400 feet (5000 meters) above its base. (NASA)
2023: A Space Ore-dyssey

It’s further in the future, but space mining could also be used to gather the critical minerals needed for renewable sources of energy, then ship them down to Earth. According to Sax, this means fewer emissions from terrestrial mining and fewer natural habitats degraded.

This could mean waiting for asteroids to hit the moon or by sending out a probe to grab a part of an asteroid and then having astronauts nearby collect it to return it to Earth. This latter idea was proposed, researched but ultimately canceled by NASA in 2017. Some desirable elements, like europium — which could be used in some types of solar panels — could also be mined on the moon.

“If you start looking at critical minerals and the energy transition, then you very quickly see that unless we start either recycling much more or consuming much less, the physical Earth does not have the capacity to provide us with all of the metals and minerals that we will need,” Elizabeth Steyn, a faculty member at the Western Institute for Earth and Space Exploration at Western University, told The Weather Network.

She added that bringing asteroids, or parts of them, back down to Earth for processing poses some technical challenges, including finding a way to wrangle it to solid ground. Right now, this approach is farther in the future, she said, but in theory, the concept of a space elevator (almost exactly what it sounds like) could make the process easier.

In space, no one can hear you ‘eh’

According to Sax, Canada is well-positioned to be an important part of space mining. This is because of the country’s wealth of experience in mining (on Earth) and in creating robotics that go off into space, such as the Canadarm.

Meanwhile, according to Steyn, the country’s regulations haven’t really caught up with the field’s technology. As it stands, only a few countries — including the United States, Japan and Luxembourg — have dedicated policies allowing for resource extraction in space.

That said, groups like the CMSC have been pushing for Canada to update its regulations. Plus the Canadian Space Agency consulted residents on topics such as resource extraction in space this year. “So we’re not quite there, but we may be moving in that direction,” Steyn said.

space stuff 2

In this image, published by NASA in 2018, the view from NASA’s Dawn mission is seen. It shows where ice has been detected in the northern wall of Ceres’ Juling Crater, which is in almost permanent shadow. (NASA)

However, it’s unclear how each country’s policies in this area would interact with international agreements, such as the UN’s Outer Space Treaty, which 113 parties have signed since it was introduced in 1967. In short, signatory nations agreed to not start wars in space and that no one country could claim celestial bodies like the moon. More recently, the non-binding Artemis Accords, which 27 nations signed so far, state that extracting resources from space doesn’t necessarily breach the Outer Space Treaty.
A long-ish time from now, in a galaxy really, really close…

However, not everyone is as enthusiastic about the future of space mining, and have doubts about the potential environmental boons it could offer. According to Katherine Moore, senior lecturer in critical and green technology metals at Exeter University, harvesting critical elements from asteroids would be tricky because there would need to be large amounts of them brought back to Earth in order for the effort to be economically viable.

Watch below: How solar panels in space can beam energy back to Earth
Click here to view the video

Moore added that, primarily, the main elements discussed as possibilities here are platinum group metals (PGMs), a group of six elements that sit close to the group’s namesake on the periodic table, and often appear together in mineral deposits.

Platinum could find use in some types of batteries, but the International Energy Agency considers PGMs “low need” materials for many energy transition technologies except for hydrogen power, for which they are “high need.” As such, mining asteroids for this class of element might not help reduce terrestrial mining, Moore said.

That said, some asteroids may contain other elements that could be useful in renewable energy technologies, such as gold.

Steyn added that the technologies and policies needed to extract resources in outer space might not come soon enough to be beneficial to the environment. Beyond policy debates at an international level, the technology needed to create hydrogen fuel from water crystals on the moon could still be a ways off. Further, the need for countries around the globe to decarbonize and invest in ways to limit their greenhouse gas emissions could mean less support for mining off-planet.

“I think the bottom line is that all of these things are technologically possible,” Moore told The Weather Network. “But whether they are economically and environmentally viable in a meaningful timeframe, is very open to question.”

 

Astronomers reveal new features of galactic black holes

International team of scientists reports in Nature the first detection of a quasi-periodic oscillation signal in the radio band from a Galactic black hole system.

Peer-Reviewed Publication

UNIVERSITY OF NEVADA, LAS VEGAS

 

IMAGE: ARTIST'S DEPICTION OF MICROQUASAR EVENT CAPTURED BY FAST TELESCOPE. view more 

CREDIT: COURTESY PROFESSOR WEI WANG, WUHAN UNIVERSITY

LAS VEGAS – July 26, 2023 – Black holes are the most mysterious objects in the universe, with features that sound like they come straight from a sci-fi movie. 

Stellar-mass black holes with masses of roughly 10 suns, for example, reveal their existence by eating materials from their companion stars. And in some instances, supermassive black holes accumulate at the center of some galaxies to form bright compact regions known as quasars with masses equal to millions to billions of our sun. A subset of accreting stellar-mass black holes that can launch jets of highly magnetized plasma are called microquasars. 

An international team of scientists, including UNLV astrophysicist Bing Zhang, reports in the July 26 issue of Nature a dedicated observational campaign on the Galactic microquasar dubbed GRS 1915+105. The team revealed features of a microquasar system that have never before been seen. 

Using the massive Five-hundred-meter Aperture Spherical radio Telescope (FAST) in China, astronomers discovered a quasi-periodic oscillation (QPO) signal in the radio band for the first time from any microquasar systems. QPOs are a phenomenon that astronomers use to understand how stellar systems like black holes function. And while they have been observed in X-rays from microquasars, their presence outside of this manner — as part of the system’s radio emission — is unique.

“The peculiar QPO signal has a rough period of 0.2 seconds, or a frequency of about 5 Hertz,” said Wei Wang, a professor with China’s Wuhan University who led the team that made the discovery. “Such a signal does not always exist and only shows up under special physical conditions. Our team was lucky enough to catch the signal twice — in January 2021 and June 2022, respectively.”

According to UNLV’s Zhang, director of the Nevada Center for Astrophysics and one of the study’s corresponding authors, this unique feature may provide the first evidence of activity from a “jet” launched by a Galactic stellar-mass black hole. Under certain conditions, some black hole binary systems launch a jet — a mix of parallel beams of charged matter and a magnetic field that moves with a swiftness approaching the speed of light.  

“In accreting black hole systems, X-rays usually probe the accretion disk around the black hole while radio emission usually probes the jet launched from the disk and the black hole,” said Zhang. “The detailed mechanism to induce temporal modulation in a relativistic jet is not identified, but one plausible mechanism would be that the jet is underlying precession, which means the jet direction is regularly pointing towards different directions and returns to the original direction once every about 0.2 seconds.” 

Zhang said that a misalignment between the spin axis of the black hole and its accretion disk (extremely hot, bright spinning gasses surrounding the black hole) could cause this effect, which is a natural consequence of a dragging of spacetime near a rapidly spinning black hole. 

“Other possibilities exist, though, and continued observations of this and other Galactic microquasar sources will bring more clues to understand these mysterious QPO signals,” said Zhang. 

Publication Details

The study, “Sub-second periodic radio oscillation in a microquasar”, appeared July 26 in the journal Nature. The publication includes 21 co-authors from 13 institutions. Besides UNLV and Wuhan University, other institutions include National Astronomical Observatories of China (NAOC) and several other observatories and universities from China. 

---

JOURNAL

Nature

DOI

10.1038/s41586-023-06336-6 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Subsecond periodic radio oscillations in a microquasar

ARTICLE PUBLICATION DATE

26-Jul-2023

 

Using cosmic weather to study which worlds could support life

Study uses new code to test next-gen telescope abilities

Peer-Reviewed Publication

OHIO STATE UNIVERSITY

COLUMBUS, Ohio – As the next generation of giant, high-powered observatories begin to come online, a new study suggests that their instruments may offer scientists an unparalleled opportunity to discern what weather may be like on far-away exoplanets. 

Dubbed the extremely large telescopes (ELTs), these observatories, which include the Extremely Large Telescope (ELT), the Giant Magellan Telescope (GMT), and the Thirty Meter Telescope (TMT), will be some of the largest ground-based telescopes ever built, and their instruments are expected to exceed the capabilities of the James Webb Space Telescope.

Data collected with their powerful instruments will allow astronomers to use Doppler Imaging – a technique that can recreate 2D maps of an object’s surface – to make accurate measurements of the magnetism and chemistry of ultracool targets, or cosmic objects with temperatures less than 2700 K, such as brown dwarfs (BDs) or very low-mass stars (VLMs) –  and even some exoplanets.

Besides helping to improve our understanding of some of the most mysterious objects in the universe, having the capability to study the chemical compositions of these objects in a more precise manner also offers greater insight into the search for life on other worlds, said Michael Plummer, lead author of the study and a graduate student in astronomy at The Ohio State University. 

“Learning about the atmospheres of other objects outside our solar system not only informs us how Earth’s atmosphere may behave but allows scientists to scale those concepts to study potentially habitable planets,” said Plummer.

The study was published this month in The Astrophysical Journal. 

Magnetism is especially important to search for worlds similar to our own as magnetic fields, specifically for smaller star systems, are considered necessary to support and influence whether a planet can support life on its surface.  

To aid in this hunt, Plummer and Ji Wang, co-author of the study and an assistant professor of astronomy at Ohio State, previously developed a publicly available analytical code called Imber to simulate and infer the presence of surface discrepancies like magnetic star spots, cloud systems, and other atmospheric phenomena such as hurricanes on distant objects.

In this study, they used the technique to estimate the scientific capabilities of various ELTs’ instruments to detect surface variations on six targets: the star of Trappist-1, a well-studied seven-planet system about 40 light-years from Earth, two brown dwarfs, and three exoplanets.        

They used their technique to investigate the abilities of the following instruments: the GMT’s Consortium Large Earth Finder (GMT/GCLEF), the ELT’s Mid-Infrared ELT Imager and Spectrograph (ELT/METIS) and the TMT’s Multi-Objective Diffraction-limited High-Resolution Infrared Spectrograph (MODHIS).

Researchers found that while discerning star spots on Trappist-1 was challenging for all three instruments due to its edge-on inclination – or its orbit in parallel to the rest of the sky – ELT and TMT could make high-resolution observations of the brown dwarfs and exoplanets over a single rotation. 

Conversely, GMT’s instruments required multiple rounds of observations to determine the presence of surface irregularities on the study’s chosen exoplanets. Overall, the study shows that their technique can provide an accurate estimation of ELTs future abilities and help determine if future targets would be worth investigating on a larger scale. 

Plummer also said their technique garnered interest from scientists looking to identify or confirm planetary bodies found using the radial velocity method – a way to find exoplanets by studying the slight gravitational effect an object has on the star it orbits. In essence, their research is the first step towards helping scientists use future astronomical instruments to the best of their abilities.

“The more we learn about other similar planets to Earth, the more those discoveries should inform Earth science itself,” said Plummer. “Our work is particularly well-suited to help make those real-world observations.” 

The study was supported by the National Science Foundation. 

#

Contact: Michael Plummer, Plummer.323@osu.edu

Written by: Tatyana Woodall, Woodall.52@osu.edu

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JOURNAL

The Astrophysical Journal

DOI

10.3847/1538-4357/accd5d 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Mapping the Skies of Ultracool Worlds: Detecting Storms and Spots with Extremely Large Telescopes

ARTICLE PUBLICATION DATE

27-Jul-2023

 

Unleashing the power of mixing: New electrode systems revolutionizing clean electricity generation

Peer-Reviewed Publication

RESEARCH

 

IMAGE: FIG. 1. ELECTRODE POTENTIAL ESTABLISHMENT OF A CARBON ELECTRODE IN AN AQUEOUS SOLUTION. view more 

CREDIT: RESEARCH

Did you know rivers carry about 40 trillion metric tons of river water into the ocean every year? This meeting point, known as the estuary, holds great potential for electricity generation. Mixing the two types of water -- seawater and river water containing different salt concentrations -- releases a substantial amount of Gibbs free energy, which can be converted to electricity using semipermeable membranes. However, the performance of membranes has limited the economic viability of membrane-based approaches, leaving the vast potential of this naturally abundant energy source largely untapped.

To overcome the challenges associated with the membranes, researchers have developed membrane-free technologies. Instead of using membranes to create a boundary between saltwater and freshwater for mixing, they mix directly in the nanopores of capacitive electrodes. In particular, mixing induces structural changes of the electric double layers (EDLs) that spontaneously form at a solid-electrolyte interface -- the surface of the pores in this case. When freshwater is introduced to a pore filled with seawater, the salt concentration in the pore will reduce, making the EDLs expand – much the same way as moving the two plates of a parallel-plate capacitor away from each other. As a result, the Gibbs free energy driving the expansion is converted to electrical energy stored in the EDLs. However, the low surface charge of existing electrode systems has been a major challenge for this concept to be a promising contender as an alternative to membrane-based approaches – the benefits of getting rid of membranes remain hypothetical.

Researchers at Texas A&M University-Corpus Christi, the University of Hawaii, and the Beijing Institute of Nanoenergy and Nanosystems have recently developed a new electrode system that demonstrated a much higher level of surface charge when submerged in aqueous electrolytic solutions (DOI: 10.34133/research.0173). By treating the surface of a porous, activated carbon material differently, the researchers were able to modify the surface molecular structures by attaching functional groups that induce opposite surface charges to the surface. In particular, when immersed in a sodium chloride solution, the surface groups on one electrode each loses one hydrogen atom while those on the other electrode each gains one hydrogen atom, creating oppositely charged electrodes. The opposite charges increase the electrostatic energy stored in the EDLs, allowing more Gibbs free energy to be converted to electricity. Under normal seawater and freshwater condition, the new electrode system could triple the areal power density of existing capacitive systems. The volumetric power density of the prototype device is on par with or even surpasses, that of membrane-based technologies. Amazingly, the system can retain 90% of its capacity after more than 50 thousand charging/discharging cycles, making it much more economically competitive. The researchers are confident that their approach has significant room for further development. This breakthrough opens up exciting possibilities for practical, economically viable solutions to harness this abundant source of renewable energy.

---

JOURNAL

Research

DOI

10.34133/research.0173 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Tuning Surface Molecular Design of Porous Carbon for Blue Energy Harvesting

ARTICLE PUBLICATION DATE

19-Jun-2023

COI STATEMENT

T.M. and J.Y. conceived the idea. T.M. and J.Y. designed all experiments. J.Y. fabricated the capacitors. J.Y. and T.M. performed measurements and data analysis. T.M., J.Y., and Z.-L.W. wrote the manuscript.

 

A new monograph by Lithuanian scientists explores circular economy patterns in small open economies

In the book, published by Springer Cham, the authors explore the implementation of the CE model in small open economies in Europe.

Book Announcement

KAUNAS UNIVERSITY OF TECHNOLOGY

 

IMAGE: CIRCULAR BUSINESS MODELS IN THE MANUFACTURING INDUSTRY PUBLISHED BY SPRINGER CHAM, THE AUTHORS EXPLORE THE IMPLEMENTATION OF THE CE MODEL IN SMALL OPEN ECONOMIES IN EUROPE. view more 

CREDIT: SPRINGER CHAM

More than half of the European Union countries are small open economies, and smooth circular transformation of the entire EU significantly depends on these countries as well. According to the Kaunas University of Technology (KTU), Lithuania scientists, in today’s rapidly changing economic environment, their role in shaping global trade patterns and circularity issues deserve special attention.

A shift to a circular economy (CE) can be an answer to many issues caused by the prevailing linear economy model characterised by the intensive use of natural resources and the amount of waste produced. However, CE is an inherently complex, systemic, and multidimensional concept, and the integration of CE principles and practices varies across countries and industries.

“The topic of circular business models is gaining a lot of attention both in practice and in the academic literature. The circular transformation raises many questions for business and society. Such as: when does a business model qualify as circular? What are the main barriers and challenges that manufacturing companies face? Why the uptake of circular business models is slow?” says prof. Dr Lina Dagilienė, a researcher at the KTU School of Economics and Business.

Dagilienė, one of the authors of the recently published monograph Circular Business Models in the Manufacturing Industry, believes that the shift towards circularity should be based on a business model transformation as the validation of a circular business is not about the single sale, but about the life cycle of the product aligned with successful multi-actor collaboration among business partners, consumers, government and civic society.

Smaller can be smarter

In the book, published by Springer Cham, the authors explore the implementation of the CE model in small open economies in Europe. In addition to a theoretical review of data from various sources, the monograph provides practical insights by investigating case studies on the textile, furniture, and plastics industries in Lithuania.

“While previous research on the circular economy has mainly focused on large economies such as the US, China, Japan, Germany and the UK, there is a growing realisation that small open economies have unique adaptive characteristics that can drive their circularity performance. It is time to recognise the important role of small open economies in the global economy, as they show how smaller can be smarter,” says Justina Banionienė a researcher at the KTU School of Economics and Business, Kaunas University of Technology, Lithuania.

She is convinced that the size of the economy is not the only determinant of productivity and growth. According to her, while small open economies (SOEs) have limited influence on global output levels and prices, they take advantage of their small size to make the most of their opportunities, thanks to their flexibility and speed of decision-making.

It is evident that there is a direct link between economic disparities among various small open economies within the EU and the implementation of circular economy practices. Justina Banionienė gives examples, that economically stronger SOEs tend to exhibit more green innovation and higher resource productivity, while weaker ones prioritize improving social conditions for employees. Besides, SOEs holding leadership positions in industries tend to implement more circular activities. This suggests that industry leadership plays a role in driving circular practices “Besides, small open economies with leading industrial positions are more likely to implement circular economy activities overall. This suggests that industrial leadership plays an important role in promoting circular economy practices,” adds the researcher.

The relevant patterns of the CE in Lithuanian manufacturing companies

CREDIT

KT

Motivational factors to shift to circularity vary

According to Dagilienė, when moving towards circular business models, paradoxical contradictions arise for companies in different industries.

“Linear business model is validated when a certain level of sales of goods and services is sold. However, to verify a circular business model in practice is much complicated. Modifying product ingredients or switching to biodegradable packaging are minor changes that lead to new eco-efficiency practices, but do not fundamentally change the prevailing business model principles,” explains Prof Dagilienė.

The factors that can influence a manufacturing organisation’s shift to a circular business model are numerous. More importantly, sometimes the same factor can be both a motivator and a hindrance, depending on the industry, institutional environment and ecological values. For example, some manufacturing companies simply comply with existing legislation and decide to do nothing or do the minimum when the legislation is ambiguous. But other companies are taking a more responsible role and are involved in developing new rules, norms and practices for the future to ensure circular solutions.

Moreover, pressure from brands, global companies is seen to be more important than government regulation. This is due to the fact that many Lithuanian manufacturers are sub-contractors and need to adhere high level eco-standards in their value chains.

Dr Viktorija Varaniūtė, a KTU researcher and co-author of the book, among the factors that urge restructuring of the traditional supply chain, lists consumer pressure, institutional regulations and individual companies’ efforts to become more green or sustainable. The study, conducted by a team of researchers from KTU School of Economics and Business on 139 manufacturing companies in Lithuania, revealed that they mainly focus on the efficient use of materials and energy resources while aiming for circularity. However, the motivating factors depend on the nature of the industry.

“The companies, operating on a biological cycle (e.g. food companies) focus on introducing technological solutions, however, in Lithuania, the majority of manufacturing companies are based on the technical cycle (e.g. furniture, plastics, textiles). Moreover, most of them are involved in a global network of value chains, so the main motivating factor for them to change their circularity approach is influenced by the requirements that are set by industry leaders,” says Varaniūtė.

The data shows that reverse logistics or green public procurement are not very relevant motivating factors for Lithuanian manufacturing companies to make more circular decisions in their operations. Varaniūtė believes that this may be due to excessive bureaucratic burdens.

Circular business models are often industry-specific and context dependent

In the book Circular Business Models in the Manufacturing Industry, CE practices were analysed in three different industry sectors – textile, furniture, and plastics – in one of the small open economies, Lithuania. According to one of its co-authors, Dr Jurgita Bruneckienė, a Professor of the Sustainable Economy Research Group at KTU, the type of circular business model applied by a company depends on the specifics of the industry.

The Lithuanian textile manufacturers usually are export-orientated subcontractors and focus mostly on eco-efficiency through energy and material optimization, and cleaner production through adoption of technological innovations.

„From a circular economy point of view, Lithuanian textile manufacturers still lack eco-design solutions and novel business models orientated to product life-cycle extension,” says Dr Bruneckienė.

The furniture industry in Lithuania is highly technologically developed, with an increasing focus on digitalization. Business models embedded in the economics of Lithuanian furniture are orientated towards eco-efficiency through input material optimization and cleaner production processes. Although, among furniture manufacturers eco-design solutions are becoming more common, human-centred design, product integrity and sustainable materials issues are still need to get attention. According to the researcher, the greatest challenge for this industry’s shift to circularity is closing the loop, as furniture manufacturers sell to large furniture retailers and do not contribute to the reverse value chains.

However, according to the KTU scientists’ research, the Lithuanian plastics industry is highly technological with sufficient innovation to implement the circular economy principles. The plastics sector has sufficient cooperation with other industries through well-developed reverse logistics aimed at closed loops, even though they sell their products to other manufacturers or retailers.

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DOI

10.1007/978-3-031-28809-8