Team Recycles Previously Unrecyclable Plastic

Researchers have discovered a way to chemically recycle PVC into usable material, finding a way to use the phthalates in the plasticizers -- one of PVC's most noxious components -- as the mediator for the chemical reaction.

From:  University of Michigan

November 30, 2022 -- PVC, or polyvinyl chloride, is one of the most produced plastics in the United States and the third highest by volume in the world.

PVC makes up a vast amount of plastics we use on a daily basis. Much of the plastic used in hospital equipment -- tubing, blood bags, masks and more -- is PVC, as is most of the piping used in modern plumbing. Window frames, housing trim, siding and flooring are made of, or include, PVC. It coats electrical wiring and comprises materials such as shower curtains, tents, tarps and clothing.

It also has a zero percent recycling rate in the United States.

Now, University of Michigan researchers, led by study first author Danielle Fagnani and principal investigator Anne McNeil, have discovered a way to chemically recycle PVC into usable material. The most fortuitous part of the study? The researchers found a way to use the phthalates in the plasticizers -- one of PVC's most noxious components -- as the mediator for the chemical reaction. Their results are published in the journal Nature Chemistry.

"PVC is the kind of plastic that no one wants to deal with because it has its own unique set of problems," said Fagnani, who completed the work as a postdoctoral researcher in the U-M Department of Chemistry. "PVC usually contains a lot of plasticizers, which contaminate everything in the recycling stream and are usually very toxic. It also releases hydrochloric acid really rapidly with some heat."

Plastic is typically recycled by melting it down and reforming it into the lower quality materials in a process called mechanical recycling. But when heat is applied to PVC, one of its primary components, called plasticizers, leach out of the material very easily, McNeil says.

They then can slip into other plastics in the recycling stream. Additionally, hydrochloric acid releases easily out of PVC with heat. It could corrode the recycling equipment and cause chemical burns to skin and eyes -- not ideal for workers in a recycling plant.

What's more, phthalates -- a common plasticizer -- are highly toxic endocrine disruptors, which means they can interfere with the thyroid hormone, growth hormones and hormones involved with reproduction in mammals, including humans.

So, to find a way to recycle PVC that does not require heat, Fagnani began exploring electrochemistry. Along the way, she and the team discovered that the plasticizer that presents one of the major recycling difficulties could be used in the method to break down PVC. In fact, the plasticizer improves the efficiency of the method, and the electrochemical method resolves the issue with hydrochloric acid.

"What we found is that it still releases hydrochloric acid, but at a much slower, more controlled rate," Fagnani said.

PVC is a polymer with a hydrocarbon backbone, Fagnani says, composed of single carbon-carbon bonds. Attached to every other carbon group is a chlorine group. Under heat activation, hydrochloric acid rapidly pops off, resulting in a carbon-carbon double bond along the polymer's backbone.

But the research team instead uses electrochemistry to introduce an electron into the system, which causes the system to have a negative charge. This breaks the carbon-chloride bond and results in a negatively charged chloride ion. Because the researchers are using electrochemistry, they can meter the rate at which electrons are introduced into the system -- which controls how quickly hydrochloric acid is produced.

The acid can then be used by industries as a reagent for other chemical reactions. The chloride ions can also be used to chlorinate small molecules called arenes. These arenes can be used in pharmaceutical and agricultural components. There is material left from the polymer, for which McNeil says the group is still looking for a use. Fagnani says the study shows how scientists might think about chemically recycling other difficult materials.

"Let's be strategic with the additives that are in plastics formulations. Let's think about the during-use and end-of-use from the perspective of the additives," said Fagnani, who is now a research scientist at Ashland, a company focused on making biodegradable specialty additives to consumer goods such as laundry detergents, sunscreens and shampoos. "Current group members are trying to improve the efficiency of this process even more."

The focus of McNeil's lab has been to develop ways to chemically recycle different kinds of plastics. Breaking plastics into their constituent parts could produce non-degraded materials that industry can incorporate back into production.

"It's a failure of humanity to have created these amazing materials which have improved our lives in many ways, but at the same time to be so shortsighted that we didn't think about what to do with the waste," McNeil said. "In the United States, we're still stuck at a 9% recycling rate, and it's only a few types of plastics. And even for the plastics we do recycle, it leads to lower and lower quality polymers. Our beverage bottles never become beverage bottles again. They become a textile or a park bench, which then ends up in a landfill."

        https://www.sciencedaily.com/releases/2022/11/221130114529.htm 

2022 Ürümqi Fire

On 24 November 2022, a fire broke out in a residential high-rise in Ürümqi, Xinjiang, China.  Ten people were killed and an additional nine were injured.  Journalists raised questions that China's strict enforcement of the zero-COVID policy prevented residents from leaving the building, or interfered with the efforts of firefighters.  Authorities denied these claims.  The fire was seen by observers as a trigger of protests in several cities across China over the following days, which targeted the zero-COVID policy but in several instances also called for an end to the Chinese Communist Party rule and for its leader Xi Jinping to step down.

Background

Ürümqi is the capital city of Xinjiang, home to the Uyghur population.  Since August 2022, COVID-19 has spread to many parts of Xinjiang, and the local government had formulated several epidemic prevention policies in response, such as lockdowns and mandatory testing. Before the fire, the Jixiangyuan community was designated as a "low-risk area", and residents could go out for one to two hours each day while having to stay at home for the rest. It was unclear whether people were allowed to leave their compounds.

Fire

On 24 November 2022, at around 7:49 p.m. (11:49 a.m. GMT) a fire broke out on the 15th floor of a 21-story apartment building known as Jixiangyuan community building 8, unit 2, room 1502.

An investigation discovered that resident Ayshem Memeteli (Chinese: 阿依仙木·買買提艾力) was steam showering in the bathroom, which tripped the circuit breaker.  After Ayshem reset the breaker, her daughter noticed sparks from an electronic socket. A power strip was also involved. After some firefighting efforts with community worker Deng Mingxing (Chinese: 鄧明星) and neighbors from the 14th floor, the fire spread out of control. They notified the 119 fire department and evacuated to the ground floor.  Officials said that a fireproof door on the 15th floor had been left open, which allowed the spread of the fire.

During the fire, epidemic prevention workers were unable to break down fences and barriers in time, and cars parked in the Jixiangyuan community blocked the fire trucks. Video footage posted to social media shows firetrucks unable to get close to the building and water from hoses unable to reach the structure fully. Other posted videos were reported to have recorded the screams of those trapped in the fire.

According to the local newspaper Xinjiang Daily, the Jixiangyuan community (Chinese: 吉祥苑小区), where the accident happened, lacked sufficient roadway for fire engines to pass, as a critical rescue passageway was blocked by fences and bollards for COVID crowd control and contact tracing measures.  

The fire was extinguished 3 hours later, around 10:35 p.m. (2:35 p.m. GMT), killed 10 people, including a three-year-old child, and injured nine, according to authorities.

Aftermath

After the fire, vigils and protests were held in Xinjiang, Shanghai, Nanjing and Beijing, criticizing the Chinese government's zero-COVID policy, with some calling on CCP leader Xi Jinping to resign.  Members of the public criticized the government's excessive epidemic prevention laws, which they suspect prevented firefighters from arriving at the scene.  

In the former French Concession neighborhood of Shanghai, protesters mourned the victims. They called for an end to the zero-COVID policy and for the ruling CCP and its general secretary Xi Jinping to step down.  

In Beijing and Nanjing, protesters held up blank pieces of paper to mourn the victims of the fire as well as criticize the censorship of their government.  Protests also occurred at universities and colleges such as Tsinghua University, Peking University, and Sun Yat-sen University.

Response by Chinese Government

Ürümqi mayor Memtimin Qadir apologized to the city's residents on the evening of 25 November during a press conference, and promised an investigation.

Li Wensheng, head of the Urumqi City Fire Rescue Department, said that some residents' abilities to rescue themselves were "too weak" and that they had "failed to escape in time".  Political scientist Dali Yang from the University of Chicago proposed that the comments by authorities on residents having been able to go downstairs and escape may have further fuelled public anger for having been perceived as victim blaming.  On 27 November 2022, Xinjiang officials promised to ease the lockdown measures without acknowledging the existence of the protest.

Response by the Uyghur Emigrant Community

Washington-based Uyghur academic Tahir Imin told The New York Times that the fire department response was terrible, and the fire wasn't under control for three hours despite having available facilities and equipment.

Abdulhafiz Maimaitimin, an Uyghur exile living in Switzerland, told journalists his aunt Qemernisa Abdurahman (also transliterated as Haiernishahan Abdureheman) and four family members in China were not rescued in time due to living in an Uyghur-majority neighborhood. They also raised concerns that the number of victims was being underreported by Chinese officials.

Merhaba Muhammad, an Uyghur emigrant living in Turkey, is also a relative of Abdurahman.  She told Newsweek that she lost contact with her family in 2016, after she left Xinjiang for international study. She claimed more than 44 people had died in the fire, citing her social media circles. She also emphasized that the local fire department did not prioritize saving Uyghurs.  

Mohammad and Sharapat Mohammad Ali, also relatives of Abdurahman, expressed their grief over the accident.

See also

• Chinese government response to COVID-19
• 2022 COVID-19 protests in China

        https://en.wikipedia.org/wiki/2022_%C3%9Cr%C3%BCmqi_fire

 

Many New Lakes on Earth

The number of lakes on our planet has increased substantially in recent decades, according to a unique global survey of 3.4 million lakes. There has been a particular increase in the number of small lakes, which unfortunately, emit large amounts of greenhouse gas. The development is of great importance for Earth's carbon account, global ecosystems, and human access to water resources.

From:  University of Copenhagen - Faculty of Science

November 28, 2022 -- Bacteria and fungi feeding on dead plants and animals at the bottom of a lake emit vast amounts of CO_2, methane, nitrous oxide, and other gases. Some of these gases end up in the atmosphere. This mechanism causes lakes to act like greenhouse gas factories. In fact, freshwater lakes probably account for 20% of all global CO₂ fossil fuel emissions into Earth's atmosphere. Forecasts suggest that climate change will cause lakes to emit an ever-greater share of greenhouse gases in the future.

This is just one of the reasons why it is important to know how many and how big these lakes are, as well as how they develop. Until now, this information was unknown. Scientific researchers from the University of Copenhagen and other universities have now prepared a more accurate and detailed map of the world's lakes than has ever existed. The researchers mapped 3.4 million lakes and their evolution over the past four decades using high-resolution satellite imagery combined with artificial intelligence.

The survey shows that between 1984 and 2019, the area of global lake surfaces grew by over 46,000 km² -- slightly more than the surface area of Denmark.

"There have been major and rapid changes with lakes in recent decades that affect greenhouse gas accounts, as well as ecosystems and access to water resources. Among other things, our newfound knowledge of the extent and dynamics of lakes allows us to better calculate their potential carbon emissions," explains Jing Tang, an Assistant Professor at the Department of Biology and co-author of the study, which is now published in Nature Communications.

According to the study's calculations, the annual increase of CO₂ emissions from lakes during the period is 4.8 teragrams (10^12, trillion) of carbon -- which equals to the CO₂ emission increase of the United Kingdom in 2012.

Small lakes, large CO₂ emissions

More and more small lakes (<1 km2) have appeared since 1984. The number of these small lakes is especially important according to the researchers, because they emit the most greenhouse gas in relation to their size. While small lakes account for just 15% of total lake area, they account for 25% of CO₂ and 37% of methane emissions. Furthermore, they also contribute to 45% and 59% of the net increases of the lake CO₂ and CH₄ emissionsover the period 1984-2019.

"Small lakes emit a disproportionate amount of greenhouse gases because they typically accumulate more organic matter, which is converted into gases. And also, because they are often shallow. This makes it easier for gases to reach the surface and up into the atmosphere," explains Jing Tang, who continues:

"At the same time, small lakes are much more sensitive to changes in climate and weather, as well as to human disturbances. As a result, their sizes and water chemistry fluctuate greatly. Thus, while it is important to identify and map them, it is also more demanding. Fortunately, we've been able to do justify that."

The mapping also reveals that there are two main reasons for Earth's many new lakes: climate change and human activities. Reservoirs account for more than half of increased lake area -- i.e., artificial lakes. The other half are primarily created by melting glaciers or thawing permafrost.

New figures sent to the UN

According to the researchers, the new dataset offers a range of regional and global applications.

"I have sent our new greenhouse gas emission estimates to the people responsible for calculating the global carbon budget, those who are behind the UN's IPCC climate reports. I hope they include them in updating the global emission numbers," says Jing Tang.

She adds:

"Furthermore, the dataset can be used to make better estimates of water resources in freshwater lakes and to better assess the risk of flooding, as well as for better lake management -- because lake area impacts biodiversity too."

Facts

• In the study, researchers mapped 3.4 million lakes (with the lowest lake size down to 0.03 km²) and how their sizes developed between 1984-1999, 2000-2009 and 2010-2019.
• The GLAKES dataset constructed in this study is based on high-resolution satellite imagery and a deep learning algorithm. The dataset is publicly available.
• The research results have been published in the scientific journal Nature Communications.
• The first authors of the study are Xuehui Pi and Qiuqi Luo from Southern University of Science and Technology, Shenzhen, China and The University of Hong Kong, Hong Kong SAR, China.
• Yang Xu, Rasmus Fensholt and Martin Brandt of the University of Copenhagen's Department of Geosciences and Natural Resource Management also contributed to the study.

Background

• 49.8% of the total global lakes and 23.6% of the global lake area lies above the 60th parallel north.
• Lakes created by melting glaciers or thawing permafrost make up 30% of the world's lake area. Hotspots for these types of lakes include Greenland, the Tibetan Plateau, and the Rocky Mountains.
• Also observed during the period under review, were lakes that shrank due to drought and the consumption of water resources, among other things. These were observed across the Western US, Central Asia, Northern China, Southern Australia and elsewhere.

        https://www.sciencedaily.com/releases/2022/11/221128101212.htm

 

New Catalyst Could Be Key for Hydrogen Economy

Inexpensive catalyst uses energy from light to turn ammonia into hydrogen fuel

From:  Rice University

November 25, 2022 -- Rice University researchers have engineered a key light-activated nanomaterial for the hydrogen economy. Using only inexpensive raw materials, a team from Rice's Laboratory for Nanophotonics, Syzygy Plasmonics Inc. and Princeton University's Andlinger Center for Energy and the Environment created a scalable catalyst that needs only the power of light to convert ammonia into clean-burning hydrogen fuel.

The research is published online today in the journal Science.

The research follows government and industry investment to create infrastructure and markets for carbon-free liquid ammonia fuel that will not contribute to greenhouse warming. Liquid ammonia is easy to transport and packs a lot of energy, with one nitrogen and three hydrogen atoms per molecule. The new catalyst breaks those molecules into hydrogen gas, a clean-burning fuel, and nitrogen gas, the largest component of Earth's atmosphere. And unlike traditional catalysts, it doesn't require heat. Instead, it harvests energy from light, either sunlight or energy-stingy LEDs.

The pace of chemical reactions typically increases with temperature, and chemical producers have capitalized on this for more than a century by applying heat on an industrial scale. The burning of fossil fuels to raise the temperature of large reaction vessels by hundreds or thousands of degrees results in an enormous carbon footprint. Chemical producers also spend billions of dollars each year on thermocatalysts -- materials that don't react but further speed reactions under intense heating.

"Transition metals like iron are typically poor thermocatalysts," said study co-author Naomi Halas of Rice. "This work shows they can be efficient plasmonic photocatalysts. It also demonstrates that photocatalysis can be efficiently performed with inexpensive LED photon sources."

"This discovery paves the way for sustainable, low-cost hydrogen that could be produced locally rather than in massive centralized plants," said Peter Nordlander, also a Rice co-author.

The best thermocatalysts are made from platinum and related precious metals like palladium, rhodium and ruthenium. Halas and Nordlander spent years developing light-activated, or plasmonic, metal nanoparticles. The best of these are also typically made with precious metals like silver and gold.

Following their 2011 discovery of plasmonic particles that give off short-lived, high-energy electrons called "hot carriers," they discovered in 2016 that hot-carrier generators could be married with catalytic particles to produce hybrid "antenna-reactors," where one part harvested energy from light and the other part used the energy to drive chemical reactions with surgical precision.

Halas, Nordlander, their students and collaborators have worked for years to find non-precious metal alternatives for both the energy-harvesting and reaction-speeding halves of antenna reactors. The new study is a culmination of that work. In it, Halas, Nordlander, Rice alumnus Hossein Robatjazi, Princeton engineer and physical chemist Emily Carter, and others show that antenna-reactor particles made of copper and iron are highly efficient at converting ammonia. The copper, energy-harvesting piece of the particles captures energy from visible light.

"In the absence of light, the copper-iron catalyst exhibited about 300 times lower reactivity than copper-ruthenium catalysts, which is not surprising given that ruthenium is a better thermocatalyst for this reaction," said Robatjazi, a Ph.D. alumnus from Halas' research group who is now chief scientist at Houston-based Syzygy Plasmonics. "Under illumination, the copper-iron showed efficiencies and reactivities that were similar to and comparable with those of copper-ruthenium.

Syzygy has licensed Rice's antenna-reactor technology, and the study included scaled-up tests of the catalyst in the company's commercially available, LED-powered reactors. In laboratory tests at Rice, the copper-iron catalysts had been illuminated with lasers. The Syzygy tests showed the catalysts retained their efficiency under LED illumination and at a scale 500 times larger than lab setup.

"This is the first report in the scientific literature to show that photocatalysis with LEDs can produce gram-scale quantities of hydrogen gas from ammonia," Halas said. "This opens the door to entirely replace precious metals in plasmonic photocatalysis."

"Given their potential for significantly reducing chemical sector carbon emissions, plasmonic antenna-reactor photocatalysts are worthy of further study," Carter added. "These results are a great motivator. They suggest it is likely that other combinations of abundant metals could be used as cost-effective catalysts for a wide range of chemical reactions."

Halas is Rice's Stanley C. Moore Professor of Electrical and Computer Engineering and a professor of chemistry, bioengineering, physics and astronomy, and materials science and nanoengineering. Nordlander is Rice's Wiess Chair and Professor of Physics and Astronomy, and professor of electrical and computer engineering, and materials science and nanoengineering. Carter is Princeton's Gerhard R. Andlinger Professor in Energy and Environment at the Andlinger Center for Energy and the Environment, senior strategic adviser for sustainability science at the Princeton Plasma Physics Laboratory, and professor of mechanical and aerospace engineering and of applied and computational mathematics. Robatjazi is also an adjunct professor of chemistry at Rice.

Halas and Nordlander are Syzygy co-founders and hold an equity stake in the company.

The research was supported by the Welch Foundation (C-1220, C-1222), the Air Force Office of Scientific Research (FA9550-15-1-0022), Syzygy Plasmonics, the Department of Defense and Princeton University.

Additional co-authors include Yigao Yuan, Jingyi Zhou, Aaron Bales, Lin Yuan, Minghe Lou and Minhan Lou of Rice, Linan Zhou of both Rice and South China University of Technology, Suman Khatiwada of Syzygy Plasmonics, and Junwei Lucas Bao of both Princeton and Boston College.

        https://www.sciencedaily.com/releases/2022/11/221125132041.htm

 

 

525-Million-Year-Old Fossil Defies Textbook Explanation for Brain Evolution

According to a new study, fossils of a tiny sea creature with a delicately preserved nervous system solve a century-old debate over how the brain evolved in arthropods, the most species-rich group in the animal kingdom. Combining detailed anatomical studies of the fossilized nervous system with analyses of gene expression patterns in living descendants, they conclude that a shared blueprint of brain organization has been maintained from the Cambrian until today.

From:  University of Arizona

November 25, 2022 -- Fossils of a tiny sea creature that died more than half a billion years ago may compel a science textbook rewrite of how brains evolved.

A study published in Science -- led by Nicholas Strausfeld,a Regents Professor in the University of Arizona Department of Neuroscience, and Frank Hirth, a reader of evolutionary neuroscience at King's College London -- provides the first detailed description of Cardiodictyon catenulum, a wormlike animal preserved in rocks in China's southern Yunnan province. Measuring barely half an inch (less than 1.5 centimeters) long and initially discovered in 1984, the fossil had hidden a crucial secret until now: a delicately preserved nervous system, including a brain.

"To our knowledge, this is the oldest fossilized brain we know of, so far," Strausfeld said.

Cardiodictyon belonged to an extinct group of animals known as armored lobopodians, which were abundant early during a period known as the Cambrian, when virtually all major animal lineages appeared over an extremely short time between 540 million and 500 million years ago. Lobopodians likely moved about on the sea floor using multiple pairs of soft, stubby legs that lacked the joints of their descendants, the euarthropods -- Greek for "real jointed foot." Today's closest living relatives of lobopodians are velvet worms that live mainly in Australia, New Zealand and South America.

A debate going back to the 1800s

Fossils of Cardiodictyon reveal an animal with a segmented trunk in which there are repeating arrangements of neural structures known as ganglia. This contrasts starkly with its head and brain, both of which lack any evidence of segmentation.

"This anatomy was completely unexpected because the heads and brains of modern arthropods, and some of their fossilized ancestors, have for over a hundred years been considered as segmented," Strausfeld said.

According to the authors, the finding resolves a long and heated debate about the origin and composition of the head in arthropods, the world's most species-rich group in the animal kingdom. Arthropods include insects, crustaceans, spiders and other arachnids, plus some other lineages such as millipedes and centipedes.

"From the 1880s, biologists noted the clearly segmented appearance of the trunk typical for arthropods, and basically extrapolated that to the head," Hirth said. "That is how the field arrived at supposing the head is an anterior extension of a segmented trunk."

"But Cardiodictyon shows that the early head wasn't segmented, nor was its brain, which suggests the brain and the trunk nervous system likely evolved separately," Strausfeld said.

Brains do fossilize

Cardiodictyon was part of the Chengjiang fauna, a famous deposit of fossils in the Yunnan Province discovered by paleontologist Xianguang Hou. The soft, delicate bodies of lobopodians have preserved well in the fossil record, but other than Cardiodictyon none have been scrutinized for their head and brain, possibly because lobopodians are generally small. The most prominent parts of Cardiodictyon were a series of triangular, saddle-shaped structures that defined each segment and served as attachment points for pairs of legs. Those had been found in even older rocks dating back to the advent of the Cambrian.

"That tells us that armored lobopodians might have been the earliest arthropods," Strausfeld said, predating even trilobites, an iconic and diverse group of marine arthropods that went extinct around 250 million years ago.

"Until very recently, the common understanding was 'brains don't fossilize,'" Hirth said. "So you would not expect to find a fossil with a preserved brain in the first place. And, second, this animal is so small you would not even dare to look at it in hopes of finding a brain."

However, work over the last 10 years, much of it done by Strausfeld, has identified several cases of preserved brains in a variety of fossilized arthropods.

A common genetic ground plan for making a brain

In their new study, the authors not only identified the brain of Cardiodictyon but also compared it with those of known fossils and of living arthropods, including spiders and centipedes. Combining detailed anatomical studies of the lobopodian fossils with analyses of gene expression patterns in their living descendants, they conclude that a shared blueprint of brain organization has been maintained from the Cambrian until today.

"By comparing known gene expression patterns in living species," Hirth said, "we identified a common signature of all brains and how they are formed."

In Cardiodictyon, three brain domains are each associated with a characteristic pair of head appendages and with one of the three parts of the anterior digestive system.

"We realized that each brain domain and its corresponding features are specified by the same combination genes, irrespective of the species we looked at," added Hirth. "This suggested a common genetic ground plan for making a brain."

Lessons for vertebrate brain evolution

Hirth and Strausfeld say the principles described in their study probably apply to other creatures outside of arthropods and their immediate relatives. This has important implications when comparing the nervous system of arthropods with those of vertebrates, which show a similar distinct architecture in which the forebrain and midbrain are genetically and developmentally distinct from the spinal cord, they said.

Strausfeld said their findings also offer a message of continuity at a time when the planet is changing dramatically under the influence of climatic shifts.

"At a time when major geological and climatic events were reshaping the planet, simple marine animals such as Cardiodictyon gave rise to the world's most diverse group of organisms -- the euarthropods -- that eventually spread to every emergent habitat on Earth, but which are now being threatened by our own ephemeral species."

Funding for this work was provided by the National Science Foundation, the University of Arizona Regents Fund, and the UK Biotechnology and Biological Sciences Research Council.

        https://www.sciencedaily.com/releases/2022/11/221125132137.htm

 

  

Less Intensively Managed Grasslands Have Higher Plant Diversity and Better Soil Health

Researchers have shown -- for the first time -- that less intensively managed British grazed grasslands have on average 50% more plant species and better soil health than intensively managed grassland. The new study could help farmers increase both biodiversity and soil health, including the amount of carbon in the soil of the British countryside.

From:  UK Centre for Ecology & Hydrology

November 25, 2022 -- Grazed grassland makes up a large proportion of the British countryside and is vital to farming and rural communities. This land can be perceived as only being about food production, but this study gives more evidence that it could be key to increasing biodiversity and soil health. indicating ploughing/reseeding and fertiliser and slurry application), to grassland with higher levels of species and lower levels of soil phosphorus. The plots were sampled as part of the UKCEH Countryside Survey, .

Researchers at the UK Centre for Ecology & Hydrology (UKCEH) studied 940 plots of grassland, comparing randomly selected plots which sampled the range of grassland management across Great Britain; from intensively- managed land with a few sown grassland species and high levels of soil phosphorus (nationally representative long-term dataset.

The study counted the number of plant species in sample areas and analysed co-located soil samples for numbers of soil invertebrates and carbon, nitrogen and phosphorus levels.

Researchers found that less intensively managed grassland had greater diversity of plant species and, strikingly, this correlated with better soil health, such as increased nitrogen and carbon levels and increased numbers of soil invertebrates such as springtails and mites.

In the same study, the researchers used the same methods to examine the plant diversity and soil from grasslands on 56 mostly beef farms from the Pasture Fed Livestock Association (PFLA) -- a farmer group that has developed standards to manage and improve soil and pasture health.

The researchers found that plots of land from PFLA farms had greater plant diversity -- on average an additional six plant species, including different types of grasses and herbaceous flowering plants, compared to intensively farmed plots from the Countryside Survey. In addition, grassland plants on these farms were often taller, a quality which is proven to be beneficial to butterflies and bees.

Pasture Fed Livestock Association grasslands did not yet show increased soil health, but the research indicated that this may be due to a time lag between increasing numbers of plant species and changes in soil health, particularly on farms which have been intensively managed in the past.

Lead author Dr Lisa Norton, Senior Scientist at UKCEH, says: "We've shown for the first time, on land managed by farmers for production, that a higher diversity of plants in grasslands is correlated with better soil health. This work also tells us that the Pasture Fed Livestock Association members are on the right track to increase biodiversity, though it may take longer to see improvements in soil health.

"Grassland with different types of plants able to grow tall and flower is associated with improved soil health measures, and is beneficial for creepy crawlies below and above ground. Having this abundance of life in our grasslands can in turn support small mammals and birds of prey, and farmers have told us that they are seeing voles and mice in their fields for the first time."

Dr Norton adds: "My hope for the future is that our grasslands can be managed less intensively -- with all the improvements in plant and animal biodiversity and soil health that brings -- but still remain productive for farmers."

The study was published in the journal Ecology Solutions and Evidence on 25 November, 2022, and was funded by the UK Research and Innovation Global Food Security Programme.

        https://www.sciencedaily.com/releases/2022/11/221125132024.htm

                                 

 

Uncrewed, Moon-orbiting Artemis I

Artemis 1, officially Artemis I, is an ongoing uncrewed Moon-orbiting mission and the first major spaceflight of NASA's Artemis program.  It is the first integrated flight test of the Orion spacecraft and Space Launch System rocket.  Artemis 1 was successfully launched from Kennedy Space Center on November 16, 2022, at 06:47:44 UTC (01:47:44 EST).  Its main objective is to test the Orion spacecraft, especially its heat shield, in preparation for subsequent Artemis missions. These missions will seek to reestablish a human presence on the Moon and demonstrate technologies and business approaches needed for future scientific studies, including exploration of Mars.

Formerly known as Exploration Mission-1 (EM-1), the mission was given its current name following the creation of the Artemis program. The mission lifted off from Launch Complex 39B at the Kennedy Space Center aboard the Space Launch System rocket.  The Orion spacecraft has been launched on a mission of 25 days.  After reaching Earth orbit and performing a trans-lunar injection (burn to the Moon), the mission deployed ten CubeSat satellites. The Orion spacecraft has completed one flyby of the Moon, on November 21, and will enter a distant retrograde orbit for six days with a planned second flyby on November 25.  The Orion spacecraft will then return and reenter the Earth's atmosphere with the protection of its heat shield and splash down in the Pacific Ocean. The mission aims to certify Orion and the Space Launch System for crewed flights beginning with Artemis 2.  After the Artemis 1 mission, Artemis 2 is scheduled to perform a crewed lunar flyby and Artemis 3, a crewed lunar landing, five decades after the last lunar Apollo mission.

The Orion spacecraft for Artemis 1 was stacked on October 20, 2021, marking the first time a super-heavy-lift vehicle has been stacked inside NASA's Vehicle Assembly Building (VAB) since the final Saturn V in 1973. On August 17, 2022, the fully stacked vehicle was rolled out for launch after a series of delays caused by difficulties in pre-flight testing. The first two launch attempts were canceled due to a faulty engine temperature reading on August 29, 2022, and a hydrogen leak during fueling on September 3, 2022.

Schedule of Remaining Flight Events

Nov 21–24      Transit to distant retrograde orbit (DRO)

Nov 25–30      In DRO

December 1, 21:53      DRO departure burn

Dec 1–4           Exiting DRO

December 5, 16:43      Return powered flyby

Dec 5–11         Return transit

December 11, 18:06    Entry and splashdown

        https://en.wikipedia.org/wiki/Artemis_1#cite_note-SN-20220903-18 

The Next Generation of Microscopes

A completely new type of microscope can take 3D images of cells -- while working in a natural environment. The new technology is significantly faster and better than before and will give researchers new opportunities.

From:  UiT The Arctic University of Norway

November 22, 2022 -- To observe living cells through a microscope, a sample is usually squeezed onto a glass slide. It then lies there calmly and the cells are observable. The disadvantage is that this limits how the cells behave and it only produces two-dimensional images.

Researchers from UiT The Arctic University of Norway and the University Hospital of North Norway (UNN) have now developed what they are referring to as the next generation microscope. The new technology can take pictures of much larger samples than before, while living and working in a more natural environment.

A major development

The technology provides 3D images where researchers can study the smallest details from several angles, clearly and visibly, sorted into different layers and all layers are in focus.

3D microscopes do already exist, but they work slowly and give poorer results. The most common type works by recording pixel after pixel in series, which are then assembled into a 3D image. This takes time and often they can't handle more than 1-5 shots a minute. It's not very practical if what you're going to photograph something that moves.

"With our technology, we can manage around 100 full frames per second. And we believe it is possible to increase this number. This is just what we have demonstrated with our prototype," says Florian Ströhl, researcher at UiT.

The new microscope is a so-called multifocus microscope, which provides completely clear images, sorted into different layers, where you can study the cells from all angles.

"It's a big deal. The fact that we manage to get all this in one take, it is a huge development," says Ströhl.

Can see behind objects

Ströhl explains that we are not talking about 3D in the form most of us know it. While in a traditional 3D image you will be able to perceive some kind of depth, with the new technology you are also be able to see behind objects.

Ströhl uses an example where you see a jungle scene in 3D at the cinema.

"In a normal 3D image, you can see that the forest has a depth, that some leaves and trees are closer than others. With the same technology used in our new 3D microscope, you are also able to see the tiger hiding behind the bushes. You are able to see and study several layers independently," says Ströhl.

Now you do not use a microscope to look for tigers in the jungle, but for researchers this can be an important tool when looking for answers in the minutest details.

Studying heart cells -- while they beat

Ströhl has collaborated with researchers and doctors from the University Hospital of North Norway (UNN) in the development of this technology.

Among other things, they work to understand and develop better treatment methods for various heart diseases.

Studying a living human heart is challenging, both for technical reasons and not least for ethical reasons. Thus, researchers have used stem cells that are manipulated so that they mimic heart cells. In this way, they can grow organic tissue that behaves as it would in a human heart, and they can study and test this tissue to understand more about what is happening.

This tissue is almost like a small lump of live meat, about 1 cm in size. This makes for a very demanding test situation, where heart cells beat and are in constant motion along it the fact that the sample is too large to study with traditional microscopes. The new microscope handles this well.

"You have this pumping lump of meat in a bowl, which you want to take microscope pictures of. You want to view at the very smallest parts of this, and you want super high resolution. We have achieved this with the new microscope," says Ströhl.

Formula 1 division

Kenneth Bowitz Larsen heads a large laboratory with advanced microscopes that are used by all the research groups at the Faculty of Health at UiT. He has tested this new microscope, and is optimistic.

"The concept is brilliant, the microscope they have built does things that the commercial systems do not," Larsen explains. The laboratory he heads mainly uses commercial microscopes from suppliers such as Zeiss, Nikon, etc.

"Then we also collaborate with research groups like the one Florian Ströhl represents. They build microscopes and test optical concepts, they are in a way like the formula 1 division of microscopy," Larsen says. Larsen has great faith in the new microscope Ströhl has created.

The commercial microscopes must be usable for all kinds of possible samples, while the microscope Ströhl has developed is more tailored to a specific task.

"It is very photosensitive, and it can depict the specimen in various focuses. It can work its way through the sample and you can view both high and low. And it happens so fast that it can practically be seen in real time. It's an extremely fast microscope," Larsen says.

According to Larsen, the tests so far show that this works well, and he believes this type of microscope can eventually be used on all types of samples where you look at living things that move.

He also sees another advantage with the speed of this microscope.

"Bright lights are not kind to cells. Since this microscope is so fast, it exposes the cells to much shorter illumination and is therefore more gentle," he explains.

The technology is patented

The prototype of the microscope works and is operational. The researchers are currently working on creating an upgraded version that is easier to use, so that more people are able to operate and use the microscope.

The researchers have also applied for a patent and are also looking for industrial partners who will develop this into a microscope that will be available for sale.

In the meantime, the prototype will be made available to local partners who can benefit from the new technology.

"We will also offer it to others in Norway, if they have particularly demanding samples that they want examined," says Ströhl.

        https://www.sciencedaily.com/releases/2022/11/221122111441.htm

 

Scientists Estimate the Weight of Two Giant Extinct Amphibians

A team of Australian scientists led by UNSW Sydney palaeontologist Lachlan Hart has calculated the body mass of two ancient amphibians.

From:  UNSW Media/Australian Museum

November 21, 2022 -- The last of the temnospondyls – amphibians that look more like crocodiles – became extinct during the Cretaceous period, about 120 million years ago, after thriving on Earth for more than 200 million years.

Now a team of scientists led by Lachlan Hart, a palaeontologist and PhD candidate in the School of Biological, Earth & Environmental Sciences at UNSW Sydney, has assessed various methods of estimating the weight of these unique extinct animals. The team’s study is published in Palaeontology.

“Estimating mass in extinct animals presents a challenge, because we can’t just weigh them like we could with a living thing,” said Mr Hart. “We only have the fossils to tell us what an animal looked like, so we often need to look at living animals to get an idea about soft tissues, such as fat and skin.”

Temnospondyls as case studies

Mr Hart said temnospondyls were “very strange animals”.

“Some grew to enormous sizes, six or seven metres long. They went through a larval (tadpole) stage just like living amphibians. Some had very broad and round heads – such as Australia’s Koolasuchus, recently named as the Victorian State Fossil Emblem – and others, like the temnospondyls we used in this study, had heads that were more croc-like.”

The 1.8 metre-long Eryops megacephalus lived during the Permian period in what is now the USA, while the slightly longer Paracyclotosaurus davidi is known from the Triassic of Australia. The more aquatically inclined Paracyclotosaurus was the heftier of the two, tipping the scales at roughly 260 kilograms, where Eryops was a more modest 160 kilograms.

“The size of an animal is important for many aspects of their life,” said Mr Hart. “It impacts what they feed on, how they move and even how they handle cold temperatures. So naturally, palaeontologists are interested in calculating the body mass of extinct creatures so we can learn more about how they lived.

“There have been several studies on body mass estimation in other groups of extinct animals, such as dinosaurs, but not extensively on temnospondyls.

“They survived two of Earth’s Big Five mass extinction events which makes them a very interesting case study on how animals adapted following these global catastrophes,” Mr Hart said.

Because temnospondyls have no direct living relatives, the team of scientists had to assemble a selection of five modern ‘analogues’ (such as the Chinese Giant Salamander and the Saltwater Crocodile) to test a total of 19 different body mass estimation techniques to determine their suitability for use in temnospondyls.

“We found several methods which gave us consistently accurate body mass estimations in our five living animals, which included using mathematical equations and 3-dimensional digital models of the animals,” said Dr. Nicolas Campione from the University of New England, Armidale, an authority on body mass estimation who was also involved in the study. “We hypothesised that as these methods are accurate for animals which lived and looked like temnospondyls, they would also be appropriate for use with temnospondyls.”

Dr. Matthew McCurry, Senior Lecturer in Earth Science at UNSW, and co-author on the study said, “This work has shown there are multiple methods for estimating mass in temnospondyls.

“We don’t need the whole skeleton to do this, as some methods involve using the width of the skull or the circumference of the legs. The work will be useful for palaeontologists because many fossils we find are only of one or two parts of the skeleton.”

        https://newsroom.unsw.edu.au/news/science-tech/scientists-estimate-weight-two-giant-extinct-amphibians

  

Engineers Solve a Mystery on the Path to Smaller, Lighter Batteries

Branchlike metallic filaments can sap the power of solid-state lithium batteries. A new study explains how they form and how to divert them.

From:  MIT News Office

By David L. Chandler

November 18, 2022 -- A discovery by MIT researchers could finally unlock the door to the design of a new kind of rechargeable lithium battery that is more lightweight, compact, and safe than current versions, and that has been pursued by labs around the world for years.

The key to this potential leap in battery technology is replacing the liquid electrolyte that sits between the positive and negative electrodes with a much thinner, lighter layer of solid ceramic material, and replacing one of the electrodes with solid lithium metal. This would greatly reduce the overall size and weight of the battery and remove the safety risk associated with liquid electrolytes, which are flammable. But that quest has been beset with one big problem: dendrites.

Dendrites, whose name comes from the Latin for branches, are projections of metal that can build up on the lithium surface and penetrate into the solid electrolyte, eventually crossing from one electrode to the other and shorting out the battery cell. Researchers haven’t been able to agree on what gives rise to these metal filaments, nor has there been much progress on how to prevent them and thus make lightweight solid-state batteries a practical option.

The new research, being published today in the journal Joule in a paper by MIT Professor Yet-Ming Chiang, graduate student Cole Fincher, and five others at MIT and Brown University, seems to resolve the question of what causes dendrite formation. It also shows how dendrites can be prevented from crossing through the electrolyte.

Chiang says in the group’s earlier work, they made a “surprising and unexpected” finding, which was that the hard, solid electrolyte material used for a solid-state battery can be penetrated by lithium, which is a very soft metal, during the process of charging and discharging the battery, as ions of lithium move between the two sides.

This shuttling back and forth of ions causes the volume of the electrodes to change. That inevitably causes stresses in the solid electrolyte, which has to remain fully in contact with both of the electrodes that it is sandwiched between. “To deposit this metal, there has to be an expansion of the volume because you’re adding new mass,” Chiang says. “So, there’s an increase in volume on the side of the cell where the lithium is being deposited. And if there are even microscopic flaws present, this will generate a pressure on those flaws that can cause cracking.”

Those stresses, the team has now shown, cause the cracks that allow dendrites to form. The solution to the problem turns out to be more stress, applied in just the right direction and with the right amount of force.

While previously, some researchers thought that dendrites formed by a purely electrochemical process, rather than a mechanical one, the team’s experiments demonstrate that it is mechanical stresses that cause the problem.

The process of dendrite formation normally takes place deep within the opaque materials of the battery cell and cannot be observed directly, so Fincher developed a way of making thin cells using a transparent electrolyte, allowing the whole process to be directly seen and recorded. “You can see what happens when you put a compression on the system, and you can see whether or not the dendrites behave in a way that's commensurate with a corrosion process or a fracture process,” he says.

The team demonstrated that they could directly manipulate the growth of dendrites simply by applying and releasing pressure, causing the dendrites to zig and zag in perfect alignment with the direction of the force.

Applying mechanical stresses to the solid electrolyte doesn’t eliminate the formation of dendrites, but it does control the direction of their growth. This means they can be directed to remain parallel to the two electrodes and prevented from ever crossing to the other side, and thus rendered harmless.

In their tests, the researchers used pressure induced by bending the material, which was formed into a beam with a weight at one end. But they say that in practice, there could be many different ways of producing the needed stress. For example, the electrolyte could be made with two layers of material that have different amounts of thermal expansion, so that there is an inherent bending of the material, as is done in some thermostats.

Another approach would be to “dope” the material with atoms that would become embedded in it, distorting it and leaving it in a permanently stressed state. This is the same method used to produce the super-hard glass used in the screens of smart phones and tablets, Chiang explains. And the amount of pressure needed is not extreme: The experiments showed that pressures of 150 to 200 megapascals were sufficient to stop the dendrites from crossing the electrolyte.

The required pressure is “commensurate with stresses that are commonly induced in commercial film growth processes and many other manufacturing processes,” so should not be difficult to implement in practice, Fincher adds.

In fact, a different kind of stress, called stack pressure, is often applied to battery cells, by essentially squishing the material in the direction perpendicular to the battery’s plates — somewhat like compressing a sandwich by putting a weight on top of it. It was thought that this might help prevent the layers from separating. But the experiments have now demonstrated that pressure in that direction actually exacerbates dendrite formation. “We showed that this type of stack pressure actually accelerates dendrite-induced failure,” Fincher says.

What is needed instead is pressure along the plane of the plates, as if the sandwich were being squeezed from the sides. “What we have shown in this work is that when you apply a compressive force you can force the dendrites to travel in the direction of the compression,” Fincher says, and if that direction is along the plane of the plates, the dendrites “will never get to the other side.”

That could finally make it practical to produce batteries using solid electrolyte and metallic lithium electrodes. Not only would these pack more energy into a given volume and weight, but they would eliminate the need for liquid electrolytes, which are flammable materials.

Having demonstrated the basic principles involved, the team’s next step will be to try to apply these to the creation of a functional prototype battery, Chiang says, and then to figure out exactly what manufacturing processes would be needed to produce such batteries in quantity. Though they have filed for a patent, the researchers don’t plan to commercialize the system themselves, he says, as there are already companies working on the development of solid-state batteries. “I would say this is an understanding of failure modes in solid-state batteries that we believe the industry needs to be aware of and try to use in designing better products,” he says.

The research team included Christos Athanasiou and Brian Sheldon at Brown University, and Colin Gilgenbach, Michael Wang, and W. Craig Carter at MIT. The work was supported by the U.S. National Science Foundation, the U.S. Department of Defense, the U.S. Defense Advanced Research Projects Agency, and the U.S. Department of Energy.