Science

A research team led by Osaka University discovered that the new organic molecule thienyl diketone shows high-efficiency phosphorescence. It achieved phosphorescence that is more than ten times faster than traditional materials, allowing the team to elucidate this mechanism.

The paper is published in the journal Chemical Science.

Phosphorescence is a valuable optical function used in applications such as organic EL displays (OLEDs) and cancer diagnostics. Until now, achieving high-efficiency phosphorescence without using rare metals such as iridium and platinum has been a significant challenge. Phosphorescence, which occurs when a molecule transitions from a high-energy state to a low-energy state, often competes with non-radiative processes where the molecule loses energy as heat.

This competition can lead to slow phosphorescence and lower efficiency. While previous research indicated that incorporating certain structural elements into organic molecules could speed up phosphorescence, these efforts have not matched the speed and efficiency of rare metal-based materials.

The research team’s breakthrough with the new organic molecule thienyl diketone represents a significant advancement in the field. Yosuke Tani, senior author of the study, remarked, “We discovered this molecule by chance and initially did not understand why it demonstrated such superior performance. However, as our research progressed, we began to connect the pieces and deepen our understanding.”

“Our research has led to a clearer understanding of the mechanism behind this molecule’s performance than any previous organic phosphorescent material,” explains Dr. Tani. “Nonetheless, we believe there is still much to explore, and we are excited about its potential applications.”

This research provides new design guidelines for developing organic phosphorescent materials that do not rely on rare metals, offering the potential to surpass and replace these materials in various applications. The findings promise significant advancements in the fields of OLEDs, lighting, and medical diagnostics, among others.

Lunar swirls are light-colored, sinuous features on the moon’s surface, bright enough to be visible from a backyard telescope. Some people think they look like the brushstrokes in an abstract painting. But these are not mere artistic flourishes: NASA images show that the tendrils from some lunar swirls extend for hundreds of miles.

Lunar swirls have defied easy explanation, but recent modeling and spacecraft data shed light on the twisty mystery. The data shows that rocks in the swirls are magnetized, and these rocks deflect or redirect solar wind particles that constantly bombard the moon. Nearby rocks take the hit instead. Over time, neighboring rocks become darkened by chemical reactions caused by the collisions, while the swirls remain light colored.

But how did the rocks in lunar swirls get magnetized? The moon does not have a magnetic field today. No astronaut or rover has yet visited a lunar swirl to investigate.

“Impacts could cause these types of magnetic anomalies,” said Michael J. Krawczynski, an associate professor of Earth, environmental and planetary sciences in Arts & Sciences at Washington University in St. Louis. He notes that meteorites regularly deliver iron-rich material to areas on the moon’s surface. “But there are some swirls where we’re just not sure how an impact could create that shape and that size of thing.”

Krawczynski believes it’s more likely that something else has locally magnetized the swirls.

“Another theory is that you have lavas underground, cooling slowly in a magnetic field and creating the magnetic anomaly,” said Krawczynski, who designed experiments to test this explanation. His results are published in the Journal of Geophysical Research: Planets.

Krawczynski and study first author Yuanyuan Liang, who recently earned her Ph.D. in Earth, environmental and planetary sciences in Arts & Sciences, measured the effects of different combinations of atmospheric chemistry and magmatic cooling rates on a mineral called ilmenite to see if they could produce a magnetizing effect.

“Earth rocks are very easily magnetized because they often have tiny bits of magnetite in them, which is a magnetic mineral,” Krawczynski said. “A lot of the terrestrial studies that have focused on things with magnetite are not applicable to the moon, where you don’t have this hyper-magnetic mineral.”

But ilmenite, which is abundant on the moon, can also react and form particles of iron metal, which can be magnetized under the right conditions, Krawczynski and his team found.

“The smaller grains that we were working with seemed to create stronger magnetic fields because the surface area to volume ratio is larger for the smaller grains compared to the larger grains,” Liang said. “With more exposed surface area, it is easier for the smaller grains to undergo the reduction reaction.”

“Our analog experiments showed that at lunar conditions, we could create the magnetizable material that we needed. So, it’s plausible that these swirls are caused by subsurface magma,” said Krawczynski, who is a faculty fellow in the university’s McDonnell Center for the Space Sciences.

Determining the origin of lunar swirls is considered key in understanding what processes have shaped the lunar surface, the history of a magnetic field on the moon and even how the surfaces of planets and moons generally affect the space environment surrounding them.

This study will help interpret data acquired by future missions to the moon, especially those that explore magnetic anomalies on the lunar surface. NASA intends to send a rover to the lunar swirl area known as Reiner Gamma in 2025 as part of the Lunar Vertex mission.

“If you’re going to make magnetic anomalies by the methods that we describe, then the underground magma needs to have high titanium,” Krawczynski said. “We have seen hints of this reaction creating iron metal in lunar meteorites and in lunar samples from Apollo. But all of those samples are surface lava flows, and our study shows cooling underground should significantly enhance these metal-forming reactions.”

For now, his experimental approach is the best way to test predictions about how unseen lava may be driving the magnetic effects of the mysterious lunar swirls.

“If we could just drill down, we could see if this reaction was happening,” Krawczynski said. “That would be great, but it’s not possible yet. Right now, we’re stuck with the surface.”

Carbon in the atmosphere is a major driver of climate change. Now researchers from McGill University have designed a new catalyst for converting carbon dioxide (CO₂) into methane—a cleaner source of energy—using tiny bits of copper called nanoclusters. While the traditional method of producing methane from fossil fuels introduces more CO₂ into the atmosphere, the new process, electrocatalysis, does not.

“On sunny days you can use solar power, or when it’s a windy day you can use that wind to produce renewable electricity, but as soon as you produce that electricity you need to use it,” says Mahdi Salehi, Ph.D. candidate at the Electrocatalysis Lab at McGill University. “But in our case, we can use that renewable but intermittent electricity to store the energy in chemicals like methane.”

By using copper nanoclusters, says Salehi, carbon dioxide from the atmosphere can be transformed into methane and once the methane is used, any carbon dioxide released can be captured and “recycled” back into methane. This would create a closed “carbon loop” that does not emit new carbon dioxide into the atmosphere. The research, published recently in the journal Applied Catalysis B: Environment and Energy, was enabled by the Canadian Light Source (CLS) at the University of Saskatchewan (USask).

“In our simulations, we used copper catalysts with different sizes, from small ones with only 19 atoms to larger ones with 1000 atoms,” says Salehi. “We then tested them in the lab, focusing on how the sizes of the clusters influenced the reaction mechanism.”

“Our top finding was that extremely small copper nanoclusters are very effective at producing methane,” continues Salehi. “This was a significant discovery, indicating that the size and structure of the copper nanoclusters play a crucial role in the reaction’s outcome.”

The team plans to continue refining their catalyst to make it more efficient and investigate its large-scale, industrial applications. Their hope is that their findings will open new avenues for producing clean, sustainable energy.

Offering a foretaste of what’s to come once it is fully commissioned, ESA’s EarthCARE satellite has returned the first images from its broadband radiometer instrument. These initial images offer a tantalizing glimpse into the intricacies of our planet’s energy balance—a delicate balance that governs our climate.

Earth’s energy balance accounts the amount of energy it receives from the sun, solar radiation, and the amount of thermal radiation that Earth emits back out to space.

Influenced by numerous factors, including clouds, aerosols and greenhouse gases, this balance is vital for maintaining Earth’s relatively stable temperatures.

Although it is well-known that human activities are increasing greenhouse gas concentrations in the atmosphere, aerosols also enter the atmosphere from industrial plants, traffic and agricultural practices, as well as from natural sources.

Global temperatures are rising, so understanding and monitoring the radiation balance is crucial for studying and addressing climate-related issues, which is why ESA, together with the Japan Aerospace Exploration Agency, JAXA, built the EarthCARE satellite.

EarthCARE has been designed to measure various aspects of our atmosphere to help us understand how clouds and aerosols reflect incoming solar energy back out to space and how they trap outgoing infrared energy.

This information is crucial to understand climate change and to predict the rate at which clouds and aerosols could lose their current overall cooling effect in the future.

Remarkably, despite only being launched a little over a month ago, EarthCARE has already returned the first data from its cloud profiling radar.

And now, its broadband radiometer is also demonstrating its impressive capabilities.

ESA’s Director of Earth Observation Programs, Simonetta Cheli, said, “Of course we have never doubted the EarthCARE broadband radiometer’s potential, but here we see, at such an early stage in the mission, that the instrument is working very well and delivering excellent data.

“Each of the satellite’s different instruments has an extremely important role to play—and when all of them are working in harmony and the satellite is commissioned, then the scientific community and weather forecasters will have a powerful tool to advance our understanding of Earth’s energy balance, advance climate science and improve weather predictions.”

Crucial to the mission, the broadband radiometer measures radiative fluxes at the top of Earth’s atmosphere.

As the satellite travels along its orbit, the broadband radiometer is unique in the fact that it views the atmosphere from three directions simultaneously.

This information will allow scientists to accurately measure how much incoming energy from the sun is being reflected back out to space and how much thermal energy is being emitted from Earth’s surface at the same time.

The broadband radiometer’s three different viewing angles—one directly down from the satellite, one in front of the satellite’s path (forward) and one behind the satellite’s path (backward)—are key to capturing systematic three-dimensional views of both reflected and emitted radiation.

Comparing this to the radiation calculated from the combined measurements from the satellite’s other instruments will significantly improve our understanding of aerosol–cloud–radiation interactions.

The image above was taken on 18 July, just a few hours after the broadband radiometer started its measurements. It shows brightness in the forward view along EarthCARE’s orbital path across the western Mediterranean, around a 1,300 km stretch from northern Spain to Algeria.

The brightness indicates how much solar energy is reflected back to space. For example, white bright clouds reflect a lot of sunlight, shown in red, while the sea reflects little sunlight back to the satellite and appears dark, shown in blue.

While the data show a distinct transition between the coast of Spain and the Mediterranean Sea, there is little difference over the open sea. The switch from darker to brighter colors over the Algerian coast is down to the presence of aerosols and thin cloud.

The image below zooms into the Atlas Mountains where thunder clouds tower 10 km into the atmosphere. The broadband radiometer’s three different viewing angles capture the clouds from slightly different positions.

This can be seen in the apparent positions of the cloud’s shadows relative to the clouds: they seem to be north of the cloud for the forward view, east for the down view, and south for the backward view.

This combination of viewing angles is the instrument’s strength—one view only would not fully reveal the sunlight or the thermal radiation being reflected or emitted by cloud and other features. The view from multiple angles gathers information about the directional distribution of the energy that is seen at the top of the atmosphere.

Having this three-dimensional view globally, along with data from EarthCARE’s three other instruments—the cloud profiling radar, the atmospheric lidar and the multispectral imager—is key to advancing climate science.

An international team of researchers from the Universities of Tübingen (Dr. Armando Falcucci), Siena, and Bologna analyzed the cultural remains left by groups of early Homo sapiens at Grotta di Castelcivita in southern Italy, dating back to before the major eruption known as the Campanian Ignimbrite.

This explosive event, originating in the still-active Phlegraean Fields about 40,000 years ago, is considered the most powerful volcanic eruption ever recorded in the Mediterranean. Crucially, Grotta di Castelcivita is one of the rare archaeological sites where volcanic ash has sealed a high-resolution archaeological sequence.

By employing a set of cutting-edge methodologies to meticulously reconstruct the methods used in crafting stone tools—the most enduring artifacts unearthed in prehistoric excavations—the researchers demonstrated that cultural development at Castelcivita predates both the deposition of the volcanic layers and the sub-contemporaneous cold climate phase known as Heinrich Stadial 4, which lasted for about 2 millennia.

The most remarkable cultural innovation recorded at the site is the production of miniaturized stone points from rocks collected near the cave with the most suitable fracture properties. These micro-tools were likely intended to be hafted into multi-component projectile weapons.

This discovery challenges long-held speculations that natural disasters, such as volcanic eruptions and cooling events, were crucial drivers of major changes in the lifeways of hunter-gatherers throughout human prehistory.

The study, published in Scientific Reports, hypothesizes instead that cultural innovations among early Homo sapiens originated from mechanisms of cultural transmission and the establishment of large-scale networks that extended beyond the Alps.

Overall, this research represents a significant step towards understanding how Upper Paleolithic hunter-gatherer societies developed sophisticated strategies to thrive in changing environments.

Grotta di Castelcivita is one of the most important prehistoric deposits in Europe, containing a high-resolution stratigraphic sequence with evidence for the replacement of Neanderthals by early Homo sapiens groups about 43,000 years ago.

Excavations and research at this site are conducted with permission from the Italian Ministry of Culture by the Research Unit of Prehistory and Anthropology, Department of Physical Sciences, Earth, and Environment at the University of Siena, under the direction of Adriana Moroni.

If you scroll through the average student’s digital textbook or reading, you will probably see multi-colored streaks scattered everywhere. However, new research reveals that excessive highlighting may do more harm than good.

Researchers at Waterloo excel at creating new technologies, investigating human-technology interactions, and exploring how to mitigate harm. That’s why it’s no surprise that two computer scientists from Waterloo investigated whether technology controlling the number of words a user can highlight could affect their reading comprehension.

The work earned the duo the Best Paper Award at the Conference on Human Factors in Computing Systems (CHI 2024) one of the top-ranked conferences in computer science and the leading international HCI conference.

The research, “Constrained Highlighting in a Document Reader Can Improve Reading Comprehension,” was published in the Proceedings of the CHI Conference on Human Factors in Computing Systems.

“There are lots of theories in psychology that show having constraints is really beneficial, especially for encouraging creativity,” says Nikhita Joshi (MMath ’20), a Ph.D. student specializing in human-computer interaction (HCI) research at the David R. Cheriton School of Computer Science.

“Traditionally, software constraints were mainly used for error-proofing. However, my research focuses on using constraints to influence positive outcomes for users, which I call ‘bounded interactions.'”

These theories inspired Joshi and her supervisor Dr. Daniel Vogel to recruit 127 participants to read a short story. After 24 hours, they completed a reading comprehension test, answering 20 multiple-choice questions within five minutes. The participants were divided into three groups: no highlights, limited highlights of 150 words and unlimited highlights.

The duo chose this restraint after running a similar experiment where participants were assigned different conditions such as 50 words, 150 words and 250 words. The group capped at 150 words had the highest test results, leading to promising research directions.

For this study, Joshi designed a web-based document reader using React JS in JavaScript, which hosted the reading and test interfaces. This tool can notify how many words a user highlights and if they are exceeding the limit.

Notably, the group with limited highlights scored the highest on the reading comprehension test, with scores 11% higher than the unlimited highlights, and 19% higher than the no highlights groups. This difference is equivalent to one to two letter grades. There were also no noticeable differences in each group’s reading time, showing that highlighting restraints does not impede a user’s mental demand, effort or frustration.

This research was the first to prove that restricted highlighting can boost reading comprehension. It is also the first to explore user interface constraints for text marking. Excessive highlighting has been a long-standing problem in pedagogy. Although many researchers have proposed solutions such as in-person self-regulation training, it can be time-consuming and strenuous. As a result, this innovative technology may be a faster and easier solution for better study habits.

In a follow-up questionnaire, most of the participants stated that the cap prompted them to concentrate on the most important parts of the story. Their highlights were shorter and focused on keywords like nouns, which are strategies recommended by some university learning centers.

What surprised the researchers the most was that some participants were reluctant to delete highlights despite having the option. Instead, they were more mindful, adopting different tactics like “highlighting a noun at the beginning of the sentence and using this as a bookmark to refer to later in the document,” Joshi shares.

This research comes at a time when literacy scores are declining across the globe. “There are concerns that the development of students’ cognitive skills may be declining, especially with the development of tools like ChatGPT,” Joshi says. “Reading is core to other cognitive skills like self-reflection, self-regulation, and critical thinking. All of that is super important to human intelligence.”

In the future, the group may launch a prototype of their current work. Joshi also wants to conduct a similar experiment but with non-fiction documents like academic papers or news articles. However, she would investigate and impose a different condition since 150 words may be too restrictive for long and complex reading.

One idea is to have a limit relative to the document structure. “Instead of having this one encompassing limit for the entire research paper, we would split the limit into different sections,” she says. “Perhaps the related work section can have a lower highlight limit, but the result sections could be higher since that’s the most important part of the paper.”

NASA is preparing for a new mission, dubbed Landolt Space Mission, by the end of the decade, that will place a satellite which will function just like an artificial star. The main objective of the mission is to improve the precision of ground-based telescopes, increasing our knowledge of the Universe. The satellite will launch in early 2029 and will be about the size of a loaf of bread. 

The lab will house eight lasers that will provide everything from the light of stars to that of a supernova. This satellite will function as a new calibration technique for astronomers to fine-tune their telescopes and other instruments in observatories. This will enable them to take more accurate measurements of real celestial objects.

The artificial star satellite will be placed 35,785 kilometres above Earth. This distance will allow it to sit in a geosynchronous orbit, which will be stationary when viewed from the Earth. According to a newsroom post by George Mason University, the principal investigator for the mission, Peter Plavchan said that the distance is intended to make the satellite appear like a real star. Further, the geosynchronous positioning will keep placed over the US in the first year, enabling better observation by NASA and other independent observatories in the country.

The artificial star will be invisible to the naked eye but will be easily detectable by typical telescopes that use digital cameras to capture images. If adopted, such a setup could help astronomers hone in on changes in stellar luminosity and related attributes with increased precision. Named after Arlo Landolt, a key player in creating stellar brightness catalogs, the mission was approved by NASA in February and disclosed to the public on June 10. The effort, the company says, would require 30 people and have an approximate price tag of $19,500,000 (roughly Rs. 162.8 crore).

The Landolt Space Mission is a breakthrough in space exploration. As a more constant and well-known sky ‘landmark’ it will allow scientists to better calibrate their methods and secure more exact data with every observation — effectively revealing more of the mystery of the cosmos.