Networked intelligent devices and sensors can improve the energy efficiency of consumer products and buildings by monitoring their consumption in real time. Miniature devices like these being developed under the concept of the Internet of Things require energy sources that are as compact as possible in order to function autonomously. Monolithically integrated batteries that simultaneously generate, convert, and store energy in a single system could be used for this purpose.

A team of scientists at the University of Freiburg’s Cluster of Excellence Living, Adaptive, and Energy-Autonomous Materials Systems (livMatS) has developed a monolithically integrated photo battery consisting of an organic polymer-based battery and a multi-junction organic solar cell. The battery, presented by Rodrigo Delgado Andrés andDr. Uli Würfel, University Freiburg, and Robin Wessling and Prof. Dr. Birgit Esser, University of Ulm, is the first monolithically integrated photo battery made of organic materials to achieve a discharge potential of 3.6 volts. It is thus among the first systems of this kind capable of powering miniature devices. The team published their results in the journal Energy & Environmental Science.

Combination of a multi-junction solar cell and a dual-ion battery

The researchers developed a scalable method for the photo battery which allows them to manufacture organic solar cells out of five active layers. “The system achieves relatively high voltages of 4.2 volts with this solar cell,” explains Wessling. The team combined this multi-junction solar cell with a so-called dual-ion battery, which is capable of being charged at high currents, unlike the cathodes of conventional lithium batteries. With careful control of illumination intensity and discharge rates, a photo battery constructed in this way is capable of rapid charging in less than 15 minutes at discharge capacities of up to 22 milliampere hours per gram (mAh g^-1). In combination with the averaged discharge potential of 3.6 volts, the devices can provide an energy density of 69 milliwatt hours per gram (mWh g^-1) and a power density of 95 milliwatts per gram (mW g^-1). “Our system thus lays the foundation for more in-depth research and further developments in the area of organic photo batteries,” says Wessling.

A recent theme in material physics research has been the use of intense laser light to modify the properties of magnetic materials. By carefully engineering the laser light’s properties, researchers have been able to drastically modify the electrical conductivity and optical properties of different materials. However, this requires continuous stimulation by high-intensity lasers and is associated with some practical problems, mainly that it is difficult to stop the material from heating up. Researchers are therefore looking for ways to gain similar control over materials using light, but without employing intense lasers.

Now theoreticians at the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) in Hamburg, Germany, Stanford University and the University of Pennsylvania (both in the USA) have come up with a fundamentally different approach to change a real material’s magnetic properties in a cavity — without the use of any laser light. Their collaboration shows that the cavity alone is enough to turn the zigzag antiferromagnet α-RuCl₃ into a ferromagnet.

Crucially, the team demonstrates that even in an apparently dark cavity, α-RuCl₃ senses modifications of the electromagnetic environment and changes its magnetic state accordingly. This is a purely quantum mechanical effect, arising from the fact that within quantum theory the empty cavity (technically called the vacuum state) is never really empty. Instead, the light field fluctuates so that light particles pop in and out of existence which, in turn, affects the properties of the material.

“The optical cavity confines the electromagnetic field to a very small volume, thereby enhancing the effective coupling between the light and the material,” explains lead author Emil Viñas Boström, a postdoctoral researcher in the MPSD Theory Group. “Our results show that carefully engineering the vacuum fluctuations of the cavity electric field can lead to drastic changes in a material’s magnetic properties.” As no light excitation is needed, the approach in principle circumvents the problems associated with continuous laser driving.

This is the first work demonstrating such cavity control over magnetism in a real material, and follows previous investigations into cavity control of ferroelectric and superconducting materials. The researchers hope that designing specific cavities will help them realize new and elusive phases of matter, and to better understand the delicate interplay between light and matter.

These preparative mass spectrometers can be used to produce chemical compounds in a new way. The researchers recently synthesised a new compound from a charged molecular fragment and nitrogen from the air, which has a wide range of potential applications in building new molecular structures. They have published their new findings in the journal Angewandte Chemie. The journal cover visualizes the concept of “harvesting” molecules that were composed from fragments in a seed box-like approach in the gas phase of a mass spectrometer directly into a chemical flask that would typically be employed for conventional synthesis.

Developing new ways to break and reform chemical bonds is one of the main tasks of basic chemical research. “When a bond in a charged molecule is broken, the result is often a chemically ‘aggressive’ fragment, which we call a reactive fragment. These fragments are difficult to control using established methods of chemical synthesis. You can think of them as untamed beasts that attack anything in their path. In a mass spectrometer, there are many ways to break certain bonds and generate fragments,” says Dr Warneke, describing the processes in mass spectrometers. According to him, the “beasts” are kept under special conditions because there is a vacuum inside the mass spectrometer. This means that there is nothing for them to attack, thus preventing uncontrolled chemical reactions. “If we then offer a certain molecule, for example nitrogen, which is normally unreactive and doesn’t bind, the beast is satisfied with it because it has no other choice,” he says. In this way, molecules that are very difficult to bind, such as nitrogen, can be easily incorporated into a new substance,” Warneke continues.

In the past, the research team has used this approach to bring reactive fragments into very unusual reactions, for example, with noble gases, which are the most difficult of all chemical elements to bind. “The basic strategy of controlling chemical beasts in mass spectrometers is not new,” says Warneke. It has been used for decades to analyse the properties of reactive fragments. However, the new compounds found in this way could not be further used. Mass spectrometers show what is happening inside them, but the new substances are only produced in tiny quantities and cannot usually be extracted. They are often simply destroyed when the signal used for analyses is generated.

This is why researchers usually come away from experiments with mass spectrometers with “great knowledge” but “empty hands.” “They have the beast under control. Exactly what they were hoping for happens, they observe the new molecule with potentially fascinating properties, and then it’s gone,” says Warneke, describing chemical experiments in conventional mass spectrometers. The new publication could fundamentally change this view of chemical reactions in mass spectrometers. The research team produced a new substance from an aggressive fragment and unreactive nitrogen and collected it with preparative mass spectrometers in sufficient quantities so that it could be seen with the naked eye, handled and further experimented with.

The amount of substance produced by this method will remain limited to thin film technology applications for some time to come. However, preparative mass spectrometry could soon open up completely new possibilities for these applications, for example, in the production of microchips, solar cells or biologically active coatings. The junior research group has now reached an important milestone in its project, which has been funded by the Volkswagen Foundation’s Freigeist Fellowship since 2020.

The scientists from The Ohio State University have reported in the Journal of Medical Entomology on the state’s first known established population of Asian longhorned ticks, and are now conducting research focused on monitoring and managing these pests.

So far, these ticks are not deemed to be a threat to human health. They tend to favor large livestock and wildlife, such as cattle and deer. Just a handful of the hundred ticks from the farm screened for infectious agents tested positive for pathogens, including one, Anaplasma phagocytophilium, that can cause disease in animals and humans. Elsewhere this tick carries another pathogen, Theileria orientalis, that affects cattle, and cases of bovine theileriosis have been reported in Ohio.

Researchers say the tiny brown ticks — the size of a sesame seed in some life stages and pea-sized when engorged — are persistent, however: Surveillance showed they returned the following summer to the farm despite the application of pesticides in 2021.

“They are going to spread to pretty much every part of Ohio and they are going to be a long-term management problem. There is no getting rid of them,” said Risa Pesapane, senior author of the paper and an assistant professor of veterinary preventive medicine at Ohio State.

“The good news about the ticks, though, is that most tick control agents that we currently have seem to kill them. Still, managing them is not easy because of how numerous they are and how easily they can come back.”

Asian longhorned ticks originate from East Asia and were first detected in the United States in New Jersey in 2017. When Pesapane joined Ohio State in 2019 as a tick-borne disease ecologist, the ticks were reported in West Virginia — meaning it was only a matter of time before they crossed the river into Ohio, she said.

She found the first of these ticks in Ohio, on a stray dog in Gallia County in 2020, and another was collected from a cow in Jackson County in June 2021. And then a farmer from Monroe County called Ohio State later that summer to report three of his 18 cattle, heavily infested with ticks, had died.

“One of those was a healthy male bull, about 5 years old. Enormous. To have been taken down by exsanguination by ticks, you can imagine that was tens of thousands of ticks on one animal,” said Pesapane, who also has a faculty appointment in Ohio State’s School of Environment and Natural Resources.

Pesapane and colleagues collected almost 10,000 ticks within about 90 minutes on the farm, leading her to speculate that there were more than 1 million of them in the roughly 25-acre pasture.

Asian longhorned ticks’ secret colonization weapon is the ability to reproduce asexually, with each female laying up to 2,000 eggs at a time — and all 2,000 of those female offspring able to do the same.

“There are no other ticks in North America that do that. So they can just march on, with exponential growth, without any limitation of having to find a mate,” Pesapane said. “Where the habitat is ideal, and anecdotally it seems that unmowed pastures are an ideal location, there’s little stopping them from generating these huge numbers.”

Because of their ability to hide in vegetation, Asian longhorned ticks also can escape pesticides that kill only when coming into direct contact with a pest.

“It would be wisest to target them early in the season when adults become active, before they lay eggs, because then you would limit how many will hatch and reproduce in subsequent years. But for a variety of reasons, I tell people you cannot spray your way out of an Asian longhorned tick infestation — it will require an integrated approach,” Pesapane said.

She and colleagues are working as rapidly as they can at filling in knowledge gaps about these invaders and developing training materials and policy recommendations for affected industries. As one example, Pesapane said, tick inspections of livestock could provide a window for application of an antiparasitic agent to eliminate the risk of transporting the exotic arachnids across multiple state lines.

Ohioans are encouraged to help with research efforts: People who think they’ve spotted an Asian longhorned tick can email ticks@osu.edu for instructions on how to collect the specimen and send it to Ohio State scientists as part of ongoing surveillance. To date, the lab has received Asian longhorned ticks from residents of 11 Ohio counties.

More information about spotting Asian longhorned ticks and preventing tick exposure is available on Ohio State’s Bite Site.

This work was supported by the U.S. Department of Agriculture. Co-authors on the study were Andreas Eleftheriou, Julia Beckett and Ningzhu Bai, all of Ohio State.

Maintaining species-rich and resilient ecosystems is key to preserving biodiversity and mitigating climate change. Here, megafauna — the part of the animal population in an area that is made up of the largest animals — plays an important role. In a new study published in the scientific journal One Earth, an international research team, of which Lund University is a part, has investigated the intricate interplay between the number of voracious herbivores and the diversity of trees in the world’s protected areas.

“Our findings reveal a fascinating and complex story of how large herbivorous animals shape the world’s natural landscapes. The tree cover in these areas is sparser, but the diversity of the tree cover is much higher than in areas without large herbivores,” says Lanhui Wang, a researcher in physical geography and ecosystem science at Lund University.

“In our global analysis, we find a substantial association between the biomass of large herbivores and varied tree cover in protected areas, notably for browsers and mixed-feeders such as elephants, bison and moose and in non-extreme climates,” explains the study’s senior author, Jens-Christian Svenning, professor at Aarhus University.

Hereby, the study supports that large wild herbivores promote a diverse vegetation structure, creating a rich habitat for many other species. This is due to the animals’ consumption of vegetation as well as physical disturbances.

According to Lanhui Wang, these new research findings highlight the need to integrate large herbivores into restoration and conservation strategies. Not only for the sake of the animals themselves but also for the vital role they play in shaping landscapes and influencing biodiversity. The researchers argue that this aspect is not sufficiently considered within the framework of sustainable land management and ecosystem restoration.

“At a time when global initiatives are intensely focused on combating climate change and biodiversity loss, our findings highlight the need for a broader and more nuanced discussion about ecosystem management and conservation measures. It is of utmost importance to integrate understanding of the ecological impact of megafauna into this,” says Lanhui Wang.

The UN has declared the 2020s as the decade of ecosystem restoration. In total, 115 countries have agreed to restore up to 100,000 square kilometres of nature in total. To achieve this, more wild-living large herbivores are needed worldwide, says Lanhui Wang.

“I believe that we will need to protect and conserve large herbivores to achieve the UN goals. Megafauna are crucial for tree cover, which in turn promotes carbon sequestration and a diversity of habitats,” says Lanhui Wang.

“For many years now, I’ve been working with citizen stakeholders in the southeastern corner of Massachusetts,” says Boutt, “and in 2021, the Pine Barrens Alliance, an environmental group interested in preserving the area’s unique environmental character, approached me with an idea for a project to help assess how communities along the coast could best prepare for climate change.”

Boutt and his colleagues, including recent UMass graduate and research assistant Alexander Kirshen, undergraduates Rachel King and Carly Lombardo, graduate student Daniel Corkran and postdoctoral researcher Brendan Moran, jumped at the opportunity to apply their academic research to an urgent, real-world problem close to home.

Plymouth sits on top of a freshwater aquifer — the town’s sole source of water. Because Plymouth extends to the ocean’s edge, it is extremely susceptible to rising sea levels. For their study, Boutt, Kirshen and colleagues peeked underground to see what was happening.

Groundwater, flowing beneath the surface of the land, and the ocean’s water, which, likewise, flows subterraneanly, push against each other and reach an equilibrium state. A well sunk on the freshwater side will flow with sweet water, but one that drills down into the brackish meeting point between fresh and salt will come up briny. As the oceans rise, that sub-surface saltwater pushes farther inland, and wells that have delivered pure water for generations can suddenly turn salty.

While the theory might seem intuitive enough, actually mapping, to say nothing of predicting, the flows and interactions of both fresh and salt water is an enormously complex task.

To start, the team built a salinity database that gathered all the available data from groundwater wells and surface water, such as ponds and streams, in the Plymouth area and measured them for salinity. This gave them a baseline understanding of the current locations and likely sources of elevated water salinity.

Next, Boutt and Kirshen adopted an existing U.S. Geological Survey hydrogeological model, which only focused on the onshore half of the hydrogeology equation, by extending its reach five kilometers offshore. The model includes ponds, streams, terrestrial recharge — or the rate and amount of precipitation that seeps down into the aquifer — as well the various wells that draw from the aquifer and the wastewater that is returned to the aquifer via re-infiltration or septic systems.

Finally, they conducted a series of model runs that took into consideration various scenarios in terms of future precipitation, sea-level rise, groundwater usage and changes in water returned to the aquifer.

“We found that, under the high sea-level rise scenario, areas of the aquifer will increase in salinity by up to 17,000 milligrams per liter by 2100,” says Kirshen, “and the mixing zone between the ocean and freshwater will migrate inland by up to 200 meters.” While a few ponds might see significant rise in water elevation, by up to 1.8 meters, most ponds would not see their salinity increase from this source of salinization.

The team also learned that water returned to the aquifer by septic systems plays a major role in helping to limit saltwater intrusion. “About 66% of the water that gets pumped out of the aquifer ends up returning to it,” says Kirshen.

Perhaps the biggest surprise is that the highest levels of salinity today aren’t near the coast, but inland, and especially around the roads. “This surprised me,” says Boutt, “and it looks like road salt is one of the main sources of elevated salinity today.”

“In partnering with UMass Amherst, we were always thinking beyond the municipal boundaries of Plymouth,” says SEMPBA Vice President Frank Mand. “We share an aquifer and a geological foundation with over 30 communities in our ecoregion. So, though the news for Plymouth is good, more importantly we now have a scientific foundation — and new methods for evaluating susceptibility to saltwater intrusion — that are transferrable to those other communities and will help inform Plymouth’s and other communities’ planning for years to come.”

“We were not looking to science to help us recover from our mistakes,” Mand adds. “We were seeking to avoid problems in the future. That, in and of itself, was a worthy goal.”

To prepare for the future, Boutt and Kirshen recommend further, finer-grained analyses of the region’s hydrogeography, the creation of an early warning system to monitor the sites most vulnerable to saltwater intrusion, developing new wells in areas that are at the least risk of salt contamination and reconsidering practices, such as salting the roads in the winter, which are currently responsible for the majority of saltwater contamination in the area.