Biopesticide is harmless to mammals but can wipe out colonies of wasps that benefit plants

Albeit less lethal than synthetic insecticides, this fungus-based substance is not detected by social insects and can spread spores to entire nests, threatening the survival of species that play a key role in pest control and pollination.

Peer-Reviewed Publication

FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO

 

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SOCIAL WASPS OF THE SPECIES MISCHOCYTTARUS METATHORACICUS DID NOT DISTINGUISH BETWEEN HEALTHY NESTMATES AND INDIVIDUALS INFECTED BY THE FUNGUS BEAUVERIA BASSIANA, WHICH CAN KILL ENTIRE COLONIES 

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CREDIT: ANDRÉ R. DE SOUZA

Some wasps and bees are able to recognize sick nestmates by smell and can prevent their entry into the nest to avert infection of the entire colony, assuring its survival and that of the species in the long run.

A study supported by FAPESP and described in an article published in the journal Environmental Science and Pollution Research shows that this recognition does not happen in paper wasps of the species Mischocyttarus metathoracicus infected by a biopesticide based on the fungus Beauveria bassiana.

The group of authors, led by researchers at the University of São Paulo’s Ribeirão Preto School of Philosophy, Sciences and Letters (FFCLRP-USP) in Brazil, determined through molecular, survival and behavioral assays that the biopesticide kills wasps, which benefit plants by feeding on pests and performing pollination. They also confirmed that wasps infected by the substance are not detected by nestmates.

The authors include scientists affiliated with the Luiz de Queiroz College of Agriculture (ESALQ-USP), São Paulo State University (UNESP) and the Federal University of Viçosa (UFV), also in Brazil.

“The synthetic insecticide [based on imidacloprid] kills in 24 hours and can quickly wipe out entire wasp colonies. The biopesticide is less lethal initially but kills over a period of 19 days, potentially infecting all the insects in a colony and threatening the long-term survival of the species,” said André Rodrigues de Souza, a researcher at FFCLRP-USP supported by FAPESP and corresponding author of the article.

The biopesticide has an advantage over the synthetic insecticide in that it contains spores of the fungus B. bassiana, which infects only insects, sparing mammals and other animals. The synthetic pesticide tested by the researchers is one of the most widely used and toxic to mammals. It is hazardous to humans if not properly used.

Defensive behavior

In the survival assay, about half the wasps exposed to the biopesticide died. The entire group exposed to the synthetic compound died. The imidacloprid-based pesticide was 50 times less concentrated than the biopesticide, showing how much more toxic it was to these insects.

A control group was exposed to an inert product or water. Under a quarter of these wasps died, further demonstrating the significant lethality of both pesticides.

In the behavioral assays, which were designed to find out whether wasps infected by the fungus were recognized (more attacked or avoided) by nestmates, the researchers used dead wasps as lures on sticks, which they brought near the nest so that resident wasps could interact physically with them. The resident wasps were able to distinguish nestmates from individuals belonging to other nests, which they attacked by biting and stinging. 

They recognized nestmates by detecting the odor of their cuticular hydrocarbons, chemical messengers present on the surface of these insects’ bodies and used for communication. Nest invasions are common in this competitive species, which defends itself aggressively. 

In the study, nestmates infected by the biopesticide and hence bearing fungal spores on the surface of their bodies continued to be accepted by the rest of the colony. “If they also attacked infected nestmates, the biopesticide wouldn’t be such a problem for the colony. They were allowed into the nest and probably remained there, so the 19-day period during which they coexisted with the fungus could be sufficient to transmit spores and infect other adults and larvae, potentially endangering the entire group,” Souza said.

Threatened allies

The biopesticide containing many fungal spores is sprayed onto crops so that the fungus can colonize and kill in a few days such pests as caterpillars, coffee borer beetles, red spider mites, eucalyptus weevils and silverleaf whiteflies, all of which feed on a wide array of crops. 

The wasps feed on caterpillars and can be key allies in the biological control of pests. Social insects are also important pollinators of both crops and wild plants.

For Souza, the results of the study serve as a warning not to avoid using biopesticides, but to test them as rigorously as synthetic pesticides and manage them adequately. 

For example, it would be advisable to avoid applying this biopesticide during the day, when the wasps go out to forage and could carry the spores back to the nest. 

In recent years, research has shown that mortality testing alone is insufficient to assess the hazardousness of any pesticide, synthetic or biological, for species other than those deliberately targeted by the product. Some compounds may not kill animals immediately but cause loss of fertility, for example, affecting survival of the species in the long run. In light of these findings, the researchers are now studying the effect on wasp fertility of an essential oil widely used as a biopesticide.

The study received funding from FAPESP via five other projects (22/07997-0, 19/08029-4, 21/00984-7, 20/06632–2 and 18/10996–0).

About São Paulo Research Foundation (FAPESP)

The São Paulo Research Foundation (FAPESP) is a public institution with the mission of supporting scientific research in all fields of knowledge by awarding scholarships, fellowships and grants to investigators linked with higher education and research institutions in the State of São Paulo, Brazil. FAPESP is aware that the very best research can only be done by working with the best researchers internationally. Therefore, it has established partnerships with funding agencies, higher education, private companies, and research organizations in other countries known for the quality of their research and has been encouraging scientists funded by its grants to further develop their international collaboration. You can learn more about FAPESP at www.fapesp.br/en and visit FAPESP news agency at www.agencia.fapesp.br/en to keep updated with the latest scientific breakthroughs FAPESP helps achieve through its many programs, awards and research centers. You may also subscribe to FAPESP news agency at http://agencia.fapesp.br/subscribe.

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JOURNAL

Environmental Science and Pollution Research

DOI

10.1007/s11356-023-29770-5 

ARTICLE TITLE

A predatory social wasp does not avoid nestmates contaminated with a fungal biopesticide

 

UVA Chemical Engineering team meets DOE challenge to innovate a better way to extract lithium

The ‘TELEPORT’ approach could solve one of the nation’s critical energy needs

Grant and Award Announcement

UNIVERSITY OF VIRGINIA SCHOOL OF ENGINEERING AND APPLIED SCIENCE

A research team led by members of the Department of Chemical Engineering faculty at the University of Virginia School of Engineering and Applied Science has found a way to extract lithium from geothermal brines — a potential answer to meeting some of the country’s critical energy needs as we transition from reliance on fossil fuels.

Lithium is an essential material in batteries for electric vehicles and grid-scale electricity storage.

Associate professors Geoffrey Geise and Gary Koenig and assistant professor Gaurav “Gino” Giri, with industry partner PowerTech Water, placed second in the U.S. Department of Energy’s American-Made Geothermal Lithium Extraction Prize in which they developed a prototype of their process, called Targeted Extraction of Lithium with Electroactive Particles for Recovery Technology (TELEPORT).

A Cleaner Alternative for a Clean-Energy Supply Chain

The DOE commissioned the prize to speed development of direct extraction of lithium from California’s Salton Sea to establish a domestic supply of the element that can be recovered safely and economically. The U.S. currently imports about 99% of its supply, according to a DOE news release announcing the competition’s winners.

Salton Sea geothermal power plants pump tens of thousands of gallons per minute of hot water containing salt, lithium and other minerals to the surface from deep wells to produce energy. These geothermal brines — a clean-energy byproduct — could supply 600,000 tons of lithium annually, according to the DOE, a volume exceeding U.S. demand today.

The problem is, conventional extraction by evaporation pools requires enormous land and water use. Finding the right technique for separating lithium from geothermal brines could reduce the consumption of groundwater, harmful chemicals and ecological disruptions associated with evaporative or land-mining methods in other locations.

The Geothermal Lithium Extraction Prize, administered by the National Renewable Energy Laboratory (NREL) and funded by DOE’s Geothermal Technologies Office, aimed to address this challenge by incentivizing academic researchers, entrepreneurs and industry partners to innovate new processes.

The TELEPORT Lithium Extraction Process

The TELEPORT process starts by flowing the brine — a primordial brew of mostly unwanted minerals and metals — through tubes packed with a crystalline material that acts like a lithium sponge. Atoms present in the material’s particles contain void space, explained Geise, the team captain.

Under conditions present in the brine solution, the particles will undergo a reaction that allows lithium into the material and to fit into those voids.

“The electrochemistry is nearly identical to what happens in a battery. You’re moving ions into the material similarly to the movement of ions into a battery cathode during discharge,” Geise said. “The molecular space within the particles is perfectly sized for lithium ions, and other contaminant ions just don’t fit well.”

This concentrates the lithium into a compact space until the next stage of the process and allows for immediate removal of lithium from the brine.

“So we manage to quickly get rid of the ions that are problematic from the brine perspective,” Geise said. “We also greatly reduce the physical space needed for the subsequent purification process, which is economical, and the way that our special sponges work is unique compared to similar approaches because they minimize the need to add acids or other chemicals.”

That last point matters because the leftover brine will be injected back into the ground and could contaminate the wells.

The lithium is released from the sponges as lithium chloride or lithium sulfate in a solution, which is converted in TELEPORT’s next stage to bicarbonate or hydroxide, the desired form of lithium electrolyte for use in batteries.

The conversion is made in an electrolysis cell by pulling the solution across a selective membrane using electricity. This leaves the undesired molecules on one side of the cell and pairs the lithium with bicarbonate, or in Team TELEPORT’s case, hydroxide, on the other.

The final TELEPORT stage dries the lithium hydroxide that comes out of the membrane process — by now reduced in volume by many orders of magnitude from the original brine — into the powdered crystal material manufacturers need to make a battery cathode.

Integrating Expertise for Success

Two years ago, UVA Engineering’s Team TELEPORT was a semifinalist from an initial field of 40 teams in the competition’s first phase. Semifinalists won $40,000 to develop their concepts in the second phase — from which Team TELEPORT emerged as one of five finalists with $280,000 in prize money to fund the work in phase three: Fabricate and test their prototypes.

Three final winners were chosen, with a first-place prize of $1 million and two second-place prizes of $500,000 awarded to continue the teams’ research.

Team TELEPORT’s three-phase approach capitalizes on their labs’ respective strengths — Geise’s work with advanced polymer membranes, Koenig’s expertise in the electrochemistry of battery systems and Giri’s use of crystallization for purification and separations technologies.

“Others have suggested lithium extraction and conversion via an all-membrane process or other particle-based approaches,” Geise said.

“Our idea was that coupling the particle- and membrane-based processes together could lead to a unique, economic and environmentally attractive solution.”

 

Study on battery recycling shows China is in 1st place

China is ahead of Europe and the US in using recycling to meet its needs for lithium, cobalt and nickel for batteries for electric vehicles

Peer-Reviewed Publication

UNIVERSITY OF MÜNSTER

With the increase in the production of batteries for electric vehicles, demand is also rising for the necessary raw materials. In view of risks to the supply chain, environmental problems and precarious working conditions which are all associated with the mining and transportation of these materials, the recycling of battery materials has become an important issue in research, politics and industry. Prof. Stephan von Delft from the University of Münster (Germany) heads a team of researchers from the fields of science and the automotive and battery industries who have therefore been investigating when the demand for the three most important raw materials for batteries – lithium, cobalt and nickel – can be met entirely through recycling in Europe, the US and China; in other words, when a completely circular economy will be possible in these regions. The team’s conclusion is that China will achieve this first, followed by Europe and the US.

In detail, the results show that China is expected to be able to employ recycling to meet its own demand for primary lithium for electric vehicles, obtained through mining, from 2059 onwards; in Europe and the US, this will not happen until after 2070. As far as cobalt is concerned, recycling is expected to ensure that China will be able to meet its needs after 2045, at the earliest; in Europe this will happen in 2052 and in the US not until 2056. As regards nickel: China can probably meet demand through recycling in 2046 at the earliest, with Europe following in 2058 and the US from 2064 onwards.

Although earlier research looked at the supply of recycled raw materials for batteries and the demand for them, it had not so far been clear when complete circularity would be achieved, with supply and demand being equal (“break-even point”). The team of researchers also looked at the question of whether there are any possibilities of achieving equilibrium sooner than is predicted by current developments. “Yes, there are,” says Stephan von Delft. “Our research shows that, in particular, a faster rate of electrification in the automotive industry, as is currently being discussed in the EU, will play a role in the process. The reason is that the faster electric vehicles spread throughout the automotive market, the sooner there will be sufficient quantities of batteries available for recycling.” As PhD student Jannis Wesselkämper adds, “The demand for raw materials could also be met much earlier by recycling as a result of a reduction in battery size and by avoiding a so-called ‘second life’ for batteries – for example as stationary storage units for solar power.”

The researchers made use of a so-called dynamic material flow analysis to calculate both future demand and the recyclable raw materials then available. The data basis the team used consisted of data from current research work and market forecasts regarding developments in battery production and sales and the associated demand for raw materials.

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JOURNAL

Resources Conservation and Recycling

DOI

10.1016/j.resconrec.2023.107218 

METHOD OF RESEARCH

Meta-analysis

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

battery value chain independent of primary raw materials: Towards circularity in China, Europe and the US.

ARTICLE PUBLICATION DATE

6-Dec-2023

 

Biases in large image-text AI model favor wealthier, Western perspectives

AI model that pairs text, images performs poorly on lower-income or non-Western images, potentially increasing inequality in digital technology representation

Reports and Proceedings

UNIVERSITY OF MICHIGAN

Images

In a study evaluating the bias in OpenAI's CLIP, a model that pairs text and images and operates behind the scenes in the popular DALL-E image generator, University of Michigan researchers found that CLIP performs poorly on images that portray low-income and non-Western lifestyles.

 

"During a time when AI tools are being deployed across the world, having everyone represented in these tools is critical. Yet, we see that a large fraction of the population is not reflected by these applications—not surprisingly, those from the lowest social incomes. This can quickly lead to even larger inequality gaps," said Rada Mihalcea, the Janice M. Jenkins Collegiate Professor of Computer Science and Engineering, who initiated and advised the project. 

 

AI models like CLIP act as foundation models, or models trained on a large amount of unlabeled data that can be adapted to many applications. When AI models are trained with data reflecting a one-sided view of the world, that bias can propagate into downstream applications and tools that rely on the AI.

 

"If a software was using CLIP to screen images, it could exclude images from a lower-income or minority group instead of truly mislabeled images. It could sweep away all the diversity that a database curator worked hard to include," said Joan Nwatu, a doctoral student in computer science and engineering. 

 

Nwatu led the research team together with Oana Ignat, a postdoctoral researcher in the same department. They co-authored a paper presented at the Empirical Methods in Natural Language Processing conference Dec. 8 in Singapore.

 

The researchers evaluated the performance of CLIP using Dollar Street, a globally diverse image dataset created by the Gapminder Foundation. Dollar Street contains more than 38,000 images collected from households of various incomes across Africa, the Americas, Asia and Europe. Monthly incomes represented in the dataset range from $26 to nearly $20,000. The images capture everyday items, and are manually annotated with one or more contextual topics, such as "kitchen" or "bed."

 

CLIP pairs text and images by creating a score that is meant to represent how well the image and text match. That score can then be fed into downstream applications for further processing such as image flagging and labeling. The performance of OpenAI's DALL-E relies heavily on CLIP, which was used to evaluate the model's performance and create a database of image captions that trained DALL-E. 

 

The researchers assessed CLIP's bias by first scoring the match between the Dollar Street dataset's images and manually annotated text in CLIP, then measuring the correlation between the CLIP score and household income.

 

"We found that most of the images from higher income households always had higher CLIP scores compared to images from lower income households," Nwatu said. 

 

The topic "light source," for example, typically has higher CLIP scores for electric lamps from wealthier households compared to kerosene lamps from poorer households.

 

CLIP also demonstrated geographic bias as the majority of the countries with the lowest scores were from low-income African countries. That bias could potentially eliminate diversity in large image datasets and cause low-income, non-Western households to be underrepresented in applications that rely on CLIP. 

 

"Many AI models aim to achieve a 'general understanding' by utilizing English data from Western countries. However, our research shows this approach results in a considerable performance gap across demographics," Ignat said. 

 

"This gap is important in that demographic factors shape our identities and directly impact the model's effectiveness in the real world. Neglecting these factors could exacerbate discrimination and poverty. Our research aims to bridge this gap and pave the way for more inclusive and reliable models."

 

The researchers offer several actionable steps for AI developers to build more equitable AI models:

 

• Invest in geographically diverse datasets to help AI tools learn more diverse backgrounds and perspectives. 

• Define evaluation metrics that represent everyone by taking into account location and income.
• Document the demographics of the data AI models are trained on.

 

"The public should know what the AI was trained on so that they can make informed decisions when using a tool," Nwatu said.

 

The research was funded by the John Templeton Foundation (#62256) and the U.S. Department of State (#STC10023GR0014).

 

Study: Bridging the Digital Divide: Performance Variation across Socio-Economic Factors in Vision-Language Models (DOI: 10.48550/arXiv.2311.05746)

 

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DOI

10.48550/arXiv.2311.05746 

Battle of the AIs in medical research: ChatGPT vs Elicit

Efforts to streamline the process of academic research collection in the medical field using generative AI

Peer-Reviewed Publication

OSAKA METROPOLITAN UNIVERSITY

 

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ACCURACY AND EFFICIENCY LEVELS DIFFER DEPENDING ON THE AI USED

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CREDIT: OSAKA METROPOLITAN UNIVERSITY

Can AI save us from the arduous and time-consuming task of academic research collection? An international team of researchers investigated the credibility and efficiency of generative AI as an information-gathering tool in the medical field.

The research team, led by Professor Masaru Enomoto of the Graduate School of Medicine at Osaka Metropolitan University, fed identical clinical questions and literature selection criteria to two generative AIs; ChatGPT and Elicit. The results showed that while ChatGPT suggested fictitious articles, Elicit was efficient, suggesting multiple references within a few minutes with the same level of accuracy as the researchers.

“This research was conceived out of our experience with managing vast amounts of medical literature over long periods of time. Access to information using generative AI is still in its infancy, so we need to exercise caution as the current information is not accurate or up-to-date.” Said Dr. Enomoto. “However, ChatGPT and other generative AIs are constantly evolving and are expected to revolutionize the field of medical research in the future.”

Their findings were published in Hepatology Communications.

 

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About OMU 

Osaka Metropolitan University is the third largest public university in Japan, formed by a merger between Osaka City University and Osaka Prefecture University in 2022. OMU upholds "Convergence of Knowledge" through 11 undergraduate schools, a college, and 15 graduate schools. For more research news, visit https://www.omu.ac.jp/en/ or follow us on Twitter: @OsakaMetUniv_en, or Facebook. 

 

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JOURNAL

Hepatology Communications

DOI

10.1097/HC9.0000000000000336 

METHOD OF RESEARCH

Meta-analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Collaborating with AI in Literature Search – An Important Frontier

ARTICLE PUBLICATION DATE

7-Dec-2023

COI STATEMENT

Cheng-Hao Tseng is on the speakers’ bureau for Roche. Yao-Chun Hsu consults, advises, is on the speakers’ bureau, and received grants from Gilead. He is on the speakers’ bureau and received grants from AbbVie, Bristol-Myers Squibb, and Roche. He advises Sysmex and is on the speakers’ bureau for MSD. Mindie Nguyen consults and received grants from Gilead, GlaxoSmithKline, and Exact Science. She consults for Intercept and Exelixis. She received grants from Pfizer, Enanta, AstraZeneca, Delfi, Innogen, Curve Bio, Vir, Healio, NCI, and Glycotest. The remaining authors have no conflicts to report.

Veins of bacteria could form a self-healing system for concrete infrastructure

Drexel University's ‘BioFiber’ can stabilize and heal damaged concrete

Peer-Reviewed Publication

DREXEL UNIVERSITY

 

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SEM IMAGES OF THE BIOFIBER'S CORE FIBER WITH HYDROGEL COATING.

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CREDIT: DREXEL UNIVERSITY

In hopes of producing concrete structures that can repair their cracks, researchers from Drexel University’s College of Engineering are putting a new twist on an old trick for improving the durability of concrete. Fiber reinforcement has been around since the first masons were mixing horsehair into their mud. But the Drexel research team is taking this method to the next level by turning reinforcing fibers into a living tissue system that rushes concrete-healing bacteria to the site of cracks to repair the damage.

Recently reported in the journal Construction and Building Materials, Drexel’s “BioFiber” is a polymer fiber encased in a bacteria-laden hydrogel and a protective, damage-responsive shell. The team reports that a grid of BioFibers embedded within a concrete structure can improve its durability, prevent cracks from growing and enable self-healing.

“This is an exciting development for the ongoing efforts to improve building materials using inspiration from nature,” said Amir Farnam, PhD, an associate professor in the College of Engineering who was a leader of the research team. “We are seeing every day that our ageing concrete structures are experiencing damage which lowers their functional life and requires critical repairs that are costly. Imagine, they can heal themselves? In our skin, our tissue does it naturally through multilayer fibrous structure infused with our self-healing fluid — blood. These biofibers mimic this concept and use stone-making bacteria to create damage-responsive living self-healing concrete.”

Lengthening the lifespan of concrete is not just a benefit for the building sector, it’s become a priority for countries around the world that are working to reduce greenhouse gas. The process of making the ingredients of concrete — burning a mixture of minerals, such as limestone, clay or shale at temperatures in excess of 2,000 degrees Fahrenheit — accounts for 8% of global greenhouse gas emissions.

Concrete structures can degrade in as little as 50 years depending on their environment. Between replacements and the growing demand for new buildings, concrete is the most consumed and most in-demand building material in the world.

Producing concrete that can last longer would be a big step in reducing its contribution to global warming, not to mention reducing the long-term cost of infrastructure repairs, which is why the U.S. Department of Energy has recently launched efforts focused on improving it.

Over the last decade, Drexel has led the way in looking at how to improve concrete’s sustainability and durability, and Farnam’s lab is part of a team participating in a Department of Defense effort to fortify its aging structures.

“For several years, the concept of bio-self-healing cementitious composites has been nurtured within the Advanced Infrastructure Materials Lab,” said Mohammad Houshmand, a doctoral candidate in Farnam’s lab who was the lead author of the research. “The BioFiber project represents a collaborative, multidisciplinary endeavor, integrating expertise from the fields of civil engineering, biology, chemistry, and materials science. The primary objective is to pioneer the development of a multifunctional self-healing BioFiber technology, setting new standards at the intersection of these diverse disciplines.”

The team’s approach in creating BioFibers was inspired by skin tissue’s self-healing capability and vasculature system’s role in helping organisms heal their own wounds. And it uses a biological technique they developed to enable self-repairing in concrete infrastructure with the help of biomineralizing bacteria.

In collaboration with research teams led by Caroline Schauer, PhD, the Margaret C. Burns Chair in Engineering, Christopher Sales, PhD, an associate professor, and Ahmad Najafi, PhD, an assistant professor, all from the College of Engineering, the group identified a strain of Lysinibacillus sphaericus bacteria as a bio-healing agent for the fiber. The durable bacteria, typically found in the soil, has the ability to drive a biological process called microbial induced calcium carbonate precipitation to create a stone-like material that can stabilize and harden into a patch for exposed cracks in concrete.

When induced into forming an endospore the bacteria can survive the harsh conditions inside concrete, lying dormant until called into action.

“One of the amazing things about this research is how everyone comes at the problem from their different expertise and the solutions to creating novel BioFibers are so much stronger because of that,” Schauer said. “Selecting the right combination of bacteria, hydrogel and polymer coating was central to this research and to the functionality of BioFiber. Drawing inspiration from nature is one thing, but translating that into an application comprised of biological ingredients that can all coexist in a functional structure is quite an undertaking — one that required a multifaced team of experts to successfully achieve.”

To assemble the BioFiber, the team started with a polymer fiber core capable of stabilizing and supporting concrete structures. It coated the fiber with a layer of endospore-laden hydrogel and encased the entire assembly with a damage-responsive polymer shell, like skin tissues. The entire assembly is a little over half a millimeter thick.

Placed in a grid throughout the concrete as it is poured, the BioFiber acts as a reinforcing support agent. But its true talents are revealed only when a crack penetrates the concrete enough to pierce the fiber’s outer polymer shell.

As water makes its way into the crack, eventually reaching the BioFiber, it causes the hydrogel to expand and push its way out of the shell and up toward the surface of the crack. While this is happening, the bacteria are activated from their endospore form in the presence of carbon and a nutrient source in the concrete. Reacting with the calcium in the concrete, the bacteria produce calcium carbonate which acts as a cementing material to fill the crack all the way to the surface.

The healing time ultimately depends on the size of the crack and activity of the bacteria — a mechanism the team is currently studying — but early indications suggest the bacteria could do its job in as little as one to two days.

“While there is much work to be done in examining the kinetics of self-repair, our findings suggest that this is a viable method for arresting formation, stabilizing and repairing cracks without external intervention,” Farnam said. “This means that BioFiber could one day be used to make a ‘living’ concrete infrastructure and extend its life, preventing the need for costly repairs or replacements.”

Drexel's BioFiber system uses a structural core fiber coated in bacteria-laden hydrogel encapsulated in a polymer shell to enable self-repairing concrete.

A scanning electron microscopic image of Drexel's BioFiber self-healing concrete system, showing a structural core fiber with hydrogel coating and polymer shell.

CREDIT

Drexel University

JOURNAL

Construction and Building Materials

DOI

10.1016/j.conbuildmat.2023.133765 

METHOD OF RESEARCH

Experimental study

ARTICLE TITLE

Development of a nature-inspired polymeric fiber (BioFiber) for advanced delivery of self-healing agents into concrete

ARTICLE PUBLICATION DATE

8-Dec-2023

 

Time-tested magnesium oxide: Unveiling CO2 absorption dynamics

Peer-Reviewed Publication

DOE/OAK RIDGE NATIONAL LABORATORY

 

IMAGE: 

IN A PROPOSED CARBON-CAPTURE METHOD, MAGNESIUM OXIDE CRYSTALS ON THE GROUND BIND TO CARBON DIOXIDE MOLECULES FROM THE SURROUNDING AIR, TRIGGERING THE FORMATION OF MAGNESIUM CARBONATE. THE MAGNESIUM CARBONATE IS THEN HEATED TO CONVERT IT BACK TO MAGNESIUM OXIDE AND RELEASE THE CARBON DIOXIDE FOR PLACEMENT UNDERGROUND, OR SEQUESTRATION. CREDIT: ADAM MALIN/ORNL, U.S. DEPT. OF ENERGY

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CREDIT: ADAM MALIN/ORNL, U.S. DEPT. OF ENERGY

Magnesium oxide is a promising material for capturing carbon dioxide directly from the atmosphere and injecting it deep underground to limit the effects of climate change. But making the method economical will require discovering the speed at which carbon dioxide is absorbed and how environmental conditions affect the chemical reactions involved.

Scientists at the Department of Energy’s Oak Ridge National Laboratory analyzed a set of magnesium oxide crystal samples exposed to the atmosphere for decades, and another for days to months, to gauge the reaction rates. They found that carbon dioxide is taken up more slowly over longer time periods because of a reacted layer that forms on the surface of the magnesium oxide crystals.

“This reacted layer is a complicated mix of different solids, which limits the ability of carbon dioxide molecules to find fresh magnesium oxide to react with. To make this technology economical, we are now looking at ways to overcome this armoring effect,” said ORNL's Juliane Weber, the project’s principal investigator. Andrew Stack, a scientist at ORNL and team member on the project, followed: “If we can do so, this process might be able to achieve the Carbon Negative Energy Earthshot goal of capturing gigaton levels of carbon dioxide from air for less than $100 per metric ton of carbon dioxide.”

Most of the previous research, aimed at understanding how fast the magnesium oxide and carbon dioxide chemical reactions occur, relied on rough calculations rather than materials testing. The ORNL study marks the first time a multidecade test has been conducted to determine the reaction rate over long time scales. Using transmission electron microscopy at the Center for Nanophase Materials Science, or CNMS, at ORNL, the researchers found that a reacted layer forms. This layer consists of a variety of complex crystalline and amorphous hydrated and carbonate phases.

“Additionally, by performing some reactive transport modeling computer simulations, we determined that as the reacted layer builds up, it gets better and better at blocking carbon dioxide from finding fresh magnesium oxide to react with,” ORNL's researcher Vitaliy Starchenko said. “Thus, going forward, we are looking at ways to bypass this process to allow carbon dioxide to find fresh surface with which to react.”

The computer simulations help scientists and engineers understand how the reacted layer evolves and changes the way in which substances move through it over time. Computer models enable predictions concerning the reactions and movement of materials in natural and engineered systems, such as materials sciences and geochemistry.

The DOE Office of Science primarily supported the work. ORNL’s Laboratory Directed Research and Development program supported time-of-flight, or TOF, secondary ion mass spectrometry, or SIMS, and preliminary transmission electron microscopy, or TEM. Atomic force microscopy-TOF-SIMS and TEM characterizations were conducted as part of a user project at the CNMS, a DOE Office of Science user facility at ORNL.

UT-Battelle manages ORNL for DOE’s Office of Science, the single largest supporter of basic research in the physical sciences in the United States. The Office of Science is working to address some of the most pressing challenges of our time. For more information, please visit energy.gov/science.

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JOURNAL

Environmental Science & Technology

DOI

10.1021/acs.est.3c04690 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Armoring of MgO by a Passivation Layer Impedes Direct Air Capture of CO2