Researchers working to improve and simplify models for how PFAS flows through the ground

Will Gnesda demonstrates a PFAS flow lab experiment. Gnesda is graduate student in the UW–Madison Department of Geosciences and lead author of a new study modeling PFAS flow through the ground. The experiment is designed to build on the modeling study.
Photo Credit: Will Cushman

As a growing number of communities are forced to confront PFAS contamination in their groundwater, a key hurdle in addressing this harmful group of chemicals lies in unraveling how they move through a region of the environment called the unsaturated zone — a jumble of soil, rock and water sandwiched between the ground’s surface and the water table below.

A new study by University of Wisconsin­–Madison researchers offers a simplified new way of understanding PFAS movement through this zone.

PFAS is an abbreviation for perfluoroalkyl and polyfluoroalkyl substances. The synthetic chemicals have been used for decades in products ranging from nonstick cookware to firefighting foams. Some PFAS chemicals are associated with health risks and can persist in the environment indefinitely. Modeling their flow through the unsaturated zone — also known as the vadose zone — is important because the chemicals can linger there for years or decades, all the while slowly leaching into aquifers many communities use to provide drinking water.

Researchers find decrease in crucial trace element preceded ancient mass extinction

The research group collecting samples.
Photo Credit Ben Gill

A decline in the element molybdenum across the planet’s oceans preceded a significant extinction event approximately 183 million years ago, new research from Florida State University shows.

The decrease may have contributed to the mass extinction, in which up to 90% of species in the oceans perished, and it suggests that much more organic carbon was buried in the extinction event than had been previously estimated. The work is published in AGU Advances.

“This research tells us more about what was happening with molybdenum during this extinction event, but we also take it a step further,” said Jeremy Owens, an associate professor in FSU’s Department of Earth, Ocean and Atmospheric Science and a paper co-author. “Our findings help us understand how much carbon was cycling through the system, and it’s much larger than previously thought — potentially on the scale of modern atmospheric and oceanic increases due to human activities.”

Previous research showed decreases in molybdenum during the main phase of the ancient mass extinction, but it was unclear how widespread the decrease was, how early it started or how long it lasted.

Webb Reveals an Exoplanet Atmosphere as Never Seen Before

The atmospheric composition of the hot gas giant exoplanet WASP-39 b has been revealed by the NASA/ESA/CSA James Webb Space Telescope. This graphic shows four transmission spectra from three of Webb’s instruments operated in four instrument modes. All are plotted on a common scale extending from 0.5 to 5.5 microns.  A transmission spectrum is made by comparing starlight filtered through a planet’s atmosphere as it moves in front of the star, to the unfiltered starlight detected when the planet is beside the star. Each of the data points (white circles) on these graphs represents the amount of a specific wavelength of light that is blocked by the planet and absorbed by its atmosphere. Wavelengths that are preferentially absorbed by the atmosphere appear as peaks in the transmission spectrum.  The blue line is a best-fit model that takes into account the data, the known properties of WASP-39 b and its star (e.g., size, mass, temperature), and assumed characteristics of the atmosphere. Researchers can vary the parameters in the model – changing unknown characteristics like cloud height in the atmosphere and abundances of various gases – to get a better fit and further understand what the atmosphere is really like.  At upper left, data from NIRISS shows fingerprints of potassium (K), water (H2O), and carbon monoxide (CO). At upper right, data from NIRCam shows a prominent water signature. At lower left, data from NIRSpec indicates water, sulfur dioxide (SO2), carbon dioxide (CO2), and carbon monoxide (CO). At lower right, additional NIRSpec data reveals all of these molecules as well as sodium (Na). 
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Credit: NASA, ESA, CSA, J. Olmsted (STScI)

The NASA/ESA/CSA James Webb Space Telescope just scored another first: a molecular and chemical portrait of a distant world’s skies. While Webb and other space telescopes, including the NASA/ESA Hubble Space Telescope, have previously revealed isolated ingredients of this heated planet’s atmosphere, the new readings provide a full menu of atoms, molecules, and even signs of active chemistry and clouds. The latest data also give a hint of how these clouds might look up close: broken up rather than as a single, uniform blanket over the planet.

The telescope’s array of highly sensitive instruments was trained on the atmosphere of WASP-39 b, a “hot Saturn” (a planet about as massive as Saturn but in an orbit tighter than Mercury) orbiting a star some 700 light-years away. This Saturn-sized exoplanet was one of the first examined by the NASA/ESA/CSA James Webb Space Telescope when it began regular science operations. The results have excited the exoplanet science community. Webb’s exquisitely sensitive instruments have provided a profile of WASP-39 b’s atmospheric constituents and identified a plethora of contents, including water, sulfur dioxide, carbon monoxide, sodium and potassium.

New study reveals high rates of iron deficiency in women during late-stage pregnancy

Photo Credit: Juan Encalada

Pregnant women may need to take more supplemental iron than current Health Canada guidelines recommend, after two UBC researchers found high rates of iron deficiency in a recent study.

The research investigated iron deficiency prevalence among 60 pregnant women in Metro Vancouver and found that over 80 per cent of them were likely iron-deficient in late pregnancy despite taking daily prenatal supplements that provided 100 per cent of the daily iron recommendation in pregnancy.

“This was much higher than I expected to see, which worries us because a woman who is iron-deficient in pregnancy is at higher risk for having an infant with iron deficiency,” said faculty of land and food systems professor Dr. Crystal Karakochuk (she/her), the study’s principal investigator.

Iron is an important nutrient during pregnancy and infancy as it supports optimal growth and development for the fetus and, eventually, the baby.

Kelsey Cochrane (she/her), a PhD candidate in the faculty of land and food systems and the study’s first author, explains that, for the first six months of their lives, babies rely on iron stores they built throughout gestation.

Limiting Global Warming Now Can Preserve Valuable Freshwater Resource

Spring snowmelt in the Ansel Adams Wilderness of the California Sierra Nevada. New research identifies how climate change could differentially alter spring snowmelt in iconic mountain landscapes of the American Cordillera.
Photo Credit: Alan Rhoades

Snowcapped mountains not only look majestic – They’re vital to a delicate ecosystem that has existed for tens of thousands of years. Mountain water runoff and snowmelt flows down to streams, rivers, lakes, and oceans – and today, around a quarter of the world depends on these natural “water towers” to replenish downstream reservoirs and groundwater aquifers for urban water supplies, agricultural irrigation, and ecosystem support.

But this valuable freshwater resource is in danger of disappearing. The planet is now around 1.1 degrees Celsius (1.9 degrees Fahrenheit) warmer than pre-industrial levels, and mountain snowpacks are shrinking. Last year, a study co-led by Alan Rhoades and Erica Siirila-Woodburn, research scientists in the Earth and Environmental Sciences Area of Lawrence Berkeley National Laboratory (Berkeley Lab), found that if global warming continues along the high-emissions scenario, low-to-no-snow winters will become a regular occurrence in the mountain ranges of the western U.S. in 35 to 60 years.

Now, in a recent Nature Climate Change study, a research team led by Alan Rhoades found that if global warming reaches around 2.5 degrees Celsius compared to pre-industrial levels, mountain ranges in the southern midlatitudes, the Andean region of Chile in particular, will face a low-to-no-snow future between the years 2046 and 2051 – or 20 years earlier than mountain ranges in the northern midlatitudes such as the Sierra Nevada or Rockies. (Low-to-no-snow occurs when the annual maximum water stored as snowpack is within the bottom 30% of historical conditions for a decade or more.)

Can a new technique for capturing ‘hot’ electrons make solar cells more efficient?

A scanning tunnelling microscope is used to study the dynamics of hot electrons through single molecule manipulation.
Photo Credit: Adrian Hooper

A new way of extracting quantitative information from state-of-the-art single molecule experiments has been developed by physicists at the University of Bath. Using this quantitative information, the researchers will be able to probe the ultra-fast physics of ‘hot’ electrons on surfaces – the same physics that governs and limits the efficacy of silicon-based solar cells.

Solar cells work by converting light into electrons, whose energy can be collected and harvested. A hot solar cell is a novel type of cell that converts sunlight to electricity more efficiently than conventional solar cells. However, the efficiency of this process is limited by the creation of energetic, or ‘hot’, electrons that are extremely short lived and lose most of their energy to their surrounding within the first few femtoseconds of their creation (1 femtosecond equals 1/1,000,000,000,000,000 of a second).

The ultra-short lifetime of hot electrons and the corresponding short distance they can travel mean probing and influencing the properties of hot electrons is experimentally challenging. To date, there have been a few techniques capable of circumventing these challenges, but none has proven capable of spatial resolution – meaning, they can’t tell us about the crucial connection between a material’s atomic structure and the dynamics of hot electrons within that material.

New process developed to extract high purity rare earth element oxides

Pennsylvania stream impacted by acid mine drainage.
Photo Credit: Pennsylvania State University

Critical minerals, including rare earth elements, are used to power devices like smartphones and computers and are essential to our nation’s economy and national security. Penn State’s Center for Critical Minerals has developed a new purification process that extracts mixed rare earth oxides from acid mine drainage and associated sludges at purities of 88.5%

Critical minerals (CMs), including the 17 rare earth elements (REEs), are used in many common household products like smartphones and computers, and in many commercial products such as electric vehicles, batteries and solar panels. Demand for them has skyrocketed, and they are classified as critical because they have high economic importance, high supply risk, and their absence would have significant consequences on the economic and national security of the United States.

Acid mine drainage (AMD) and associated solids and precipitates resulting from AMD treatment have been found to be viable sources of multiple CMs, including REEs, aluminum, cobalt and manganese.

The U.S. Department of Energy (DOE) has funded efforts to demonstrate both the technical feasibility and economic viability of extracting, separating and recovering REEs and CMs from U.S. coal and coal by-product sources, with the goal of achieving mixed rare earth oxides from coal-based resources with minimum purities of 75%.

Flocks of assembler robots show potential for making larger structures

Researchers at MIT have made significant steps toward creating robots that could practically and economically assemble nearly anything, including things much larger than themselves, from vehicles to buildings to larger robots. The new system involves large, usable structures built from an array of tiny identical subunits called voxels (the volumetric equivalent of a 2-D pixel).
Photo Credit: Massachusetts Institute of Technology | Courtesy of the researchers

Researchers at MIT have made significant steps toward creating robots that could practically and economically assemble nearly anything, including things much larger than themselves, from vehicles to buildings to larger robots.

The new work, from MIT’s Center for Bits and Atoms (CBA), builds on years of research, including recent studies demonstrating that objects such as a deformable airplane wing and a functional racing car could be assembled from tiny identical lightweight pieces — and that robotic devices could be built to carry out some of this assembly work. Now, the team has shown that both the assembler bots and the components of the structure being built can all be made of the same subunits, and the robots can move independently in large numbers to accomplish large-scale assemblies quickly.

The new work is reported in the journal Nature Communications Engineering, in a paper by CBA doctoral student Amira Abdel-Rahman, Professor and CBA Director Neil Gershenfeld, and three others.

A fully autonomous self-replicating robot assembly system capable of both assembling larger structures, including larger robots, and planning the best construction sequence is still years away, Gershenfeld says. But the new work makes important strides toward that goal, including working out the complex tasks of when to build more robots and how big to make them, as well as how to organize swarms of bots of different sizes to build a structure efficiently without crashing into each other.

A Solution for Reclaiming Valuable Resources Flushed Down the Drain

A problem at sewage treatment plants - the buildup of 'brown grease' - could yield a bounty of biofuel, thanks to the work of UConn researchers
Photo Credit: kubinger

For the everyday products we use, a pattern has become numbingly familiar: Something is made, we use it, we throw it away. Yet, for a sustainable future – one where we don’t simply extract and toss resources – we need to make this linear process circular, says UConn Department of Chemical and Biomolecular Engineering Emeritus Professor Richard Parnas.

Parnas and his team research biodiesel and how to make it out of waste resources. Parnas also co-founded REA Resource Recovery Systems, which supported UConn Chemical Engineering graduate student Cong Liu Ph.D. ‘22 to develop technology to improve a critical process of removing sulfur from biodiesel made from waste materials. In this case, the materials originate from sewage, and the technology is being implemented in a project at Danbury’s John Oliver Memorial Sewer Plant scheduled to go into operation in January 2023 that will convert fats, oils, and grease into biodiesel whose lifecycle emissions are more than 74% lower than petroleum-based diesel.

Earth might be experiencing 7th mass extinction, not 6th

Diorama depicting Ediacaran-era sea creatures.
Photo Credit: Smithsonian Institution

Earth is currently in the midst of a mass extinction, losing thousands of species each year. New research suggests environmental changes caused the first such event in history, which occurred millions of years earlier than scientists previously realized.

Most dinosaurs famously disappeared 66 million years ago at the end of the Cretaceous period. Prior to that, a majority of Earth’s creatures were snuffed out between the Permian and Triassic periods, roughly 252 million years ago.

Thanks to the efforts of researchers at UC Riverside and Virginia Tech, it’s now known that a similar extinction occurred 550 million years ago, during the Ediacaran period. This discovery is documented in a Proceedings of the National Academy of Sciences paper.

Although unclear whether this represents a true “mass extinction,” the percentage of organisms lost is similar to these other events, including the current, ongoing one.

Researchers believe environmental changes are to blame for the loss of approximately 80% of all Ediacaran creatures, which were the first complex, multicellular life forms on the planet.