New process for efficient removal of steroid hormones from water

Micropollutants contaminate the water worldwide. Among them are steroid hormones that cannot be eliminated efficiently by conventional processes. Researchers of Karlsruhe Institute of Technology (KIT) have now developed an innovative filtration system that combines a polymer membrane with activated carbon. As the size of the carbon particles is very small, it is possible to reach the reference value of 1 nanogram estradiol — the physiologically most effective estrogen — per liter drinking water proposed by the European Commission. The improved method is reported in Water Research.

Supplying people with clean water is one of the biggest challenges of the 21st century worldwide. Often, drinking water is contaminated with micropollutants. Among them are steroid hormones that are used as medical substances and contraceptives. Their concentration in one liter water, into which treated wastewater is fed, may be a few nanograms only, but this small amount may already damage human health and affect the environment. Due to the low concentration and small size of the molecules, steroid hormones not only are difficult to detect, but also difficult to remove. Conventional sewage treatment technologies are not sufficient.

Reference Value of the European Commission Is Reached

Professor Andrea Iris Schäfer, Head of KIT’s Institute for Advanced Membrane Technology (IAMT) and her team have now developed an innovative method for the quick and energy-efficient elimination of steroid hormones from wastewater. Their technology combines a polymer membrane with activated carbon. “First, water is pressed through a semipermeable membrane that eliminates larger impurities and microorganisms,” Schäfer explains. “Then, water flows through the layer of carbon particles behind, which bind the hormone molecules.” At IAMT, researchers have further developed and improved this process together with filter manufacturer Blücher GmbH, Erkrath. Colleagues at KIT’s Institute of Functional Interfaces (IFG), Institute for Applied Materials (IAM), and the Karlsruhe Nano Micro Facility (KNMF) supported this further development by characterizing the material. This is reported by the scientists in Water Research. “Our technology allows to reach the reference value of 1 nanogram estradiol per liter drinking water proposed by the European Commission,” the Professor of Water Process Engineering says.

Particle Size and Oxygen Concentration Are Important

Scientists studied the processes in the activated carbon layer in more detail and used modified carbon particles (polymer-based spherical activated carbon — PBSAC). “It all depends on the diameter of the carbon particles,” Matteo Tagliavini of IAMT explains. He is the first author of the publication. “The smaller the particle diameter is, the larger is the external surface of the activated carbon layer available for adsorption of hormone molecules.” In an activated carbon layer of 2 mm thickness, the researchers decreased the particle diameter from 640 to 80 ?m and succeeded in eliminating 96% of the estradiol contained in the water. By increasing the oxygen concentration in the activated carbon, adsorption kinetics was further improved and a separation efficiency of estradiol of more than 99% was achieved. “The method allows for a high water flow rate at low pressure, is energy-efficient, and separates many molecules without producing any harmful by-products. It can be used flexibly in systems of variable size, from the tap to industrial facilities,” Schäfer says.

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New evidence for quantum fluctuations near a quantum critical point in a superconductor

Among all the curious states of matter that can coexist in a quantum material, jostling for preeminence as temperature, electron density and other factors change, some scientists think a particularly weird juxtaposition exists at a single intersection of factors, called the quantum critical point or QCP.

“Quantum critical points are a very hot issue and interesting for many problems,” says Wei-Sheng Lee, a staff scientist at the Department of Energy’s SLAC National Accelerator Laboratory and investigator with the Stanford Institute for Materials and Energy Sciences (SIMES). “Some suggest that they’re even analogous to black holes in the sense that they are singularities — point-like intersections between different states of matter in a quantum material — where you can get all sorts of very strange electron behavior as you approach them.”

Lee and his collaborators reported in Nature Physics today that they have found strong evidence that QCPs and their associated fluctuations exist. They used a technique called resonant inelastic X-ray scattering (RIXS) to probe the electronic behavior of a copper oxide material, or cuprate, that conducts electricity with perfect efficiency at relatively high temperatures.

These so-called high-temperature superconductors are a bustling field of research because they could give rise to zero-waste transmission of energy, energy-efficient transportation systems and other futuristic technologies, although no one knows the underlying microscopic mechanism behind high-temperature superconductivity yet. Whether QCPs exist in cuprates is also a hotly debated issue.

In experiments at the UK’s Diamond Light Source, the team chilled the cuprate to temperatures below 90 kelvins (minus 183 degrees Celsius), where it became superconducting. They focused their attention on what’s known as charge order — alternating stripes in the material where electrons and their negative charges are denser or more sparse.

The scientists excited the cuprate with X-rays and measured the X-ray light that scattered into the RIXS detector. This allowed them to map out how the excitations propagated through the material in the form of subtle vibrations, or phonons, in the material’s atomic lattice, which are hard to measure and require very high-resolution tools.

At the same time, the X-rays and the phonons can excite electrons in the charge order stripes, causing the stripes to fluctuate. Since the data obtained by RIXS reflects the coupling between the behavior of the charge stripes and the behavior of the phonons, observing the phonons allowed the researchers to measure the behavior of the charge order stripes, too.

What the scientists expected to see is that when the charge order stripes grew weaker, their excitations would also fade away. “But what we observed was very strange,” Lee said. “We saw that when charge order became weaker in the superconducting state, the charge order excitations became stronger. This is a paradox because they should go hand in hand, and that’s what people find in other charge order systems.”

He added, “To my knowledge this is the first experiment about charge order that has shown this behavior. Some have suggested that this is what happens when a system is near a quantum critical point, where quantum fluctuations become so strong that they melt the charge order, much like heating ice increases thermal vibrations in its rigid atomic lattice and melts it into water. The difference is that quantum melting, in principle, occurs at zero temperature.” In this case, Lee said, the unexpectedly strong charge order excitations seen with RIXS were manifestations of those quantum fluctuations.

Lee said the team is now studying these phenomena at a wider range of temperatures and at different levels of doping — where compounds are added to change the density of freely moving electrons in the material — to see if they can nail down exactly where the quantum critical point could be in this material.

Thomas Devereaux, a theorist at SIMES and senior author of the report, noted that many phases of matter can be intertwined in cuprates and other quantum materials.

“Superconducting and magnetic states, charge order stripes and so on are so entangled that you can be in all of them at the same time,” he said. “But we’re stuck in our classical way of thinking that they have to be either one way or another.”

Here, he said, “We have an effect, and Wei-Sheng is trying to measure it in detail, trying to see what’s going on.”

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What factors influence the likelihood of fracking-related seismicity in Oklahoma?

The depth of a hydraulic fracturing well in Oklahoma, among other factors, increases the probability that fracking will lead to earthquake activity, according to a new report in the Bulletin of the Seismological Society of America.

The researchers hope their findings, published as part of an upcoming BSSA special issue on observations, mechanisms and hazards of induced seismicity, will help oil and gas operators and regulators in the state refine drilling strategies to avoid damaging earthquakes.

During hydraulic fracturing, well operators inject a pressurized liquid into a rock layer after drilling vertically and often horizontally through the rock. The liquid breaks apart — fractures — the rock layer and allows natural gas or petroleum to flow more freely. A growing number of studies suggest that this process can induce seismic activity large enough for people to feel, possibly by increasing fluid pressures within the rock that relieve stress on faults and allow them to slip.

In one rock layer examined in the BSSA study, the likelihood that hydraulic fracturing triggered seismic activity increased from 5 to 50 percent as well operations moved from 1.5 to 5.5 kilometers (0.9 to 3.4 miles) deep, the researchers found.

Although the exact mechanisms linking well depth and seismic probability are still being examined, Michael Brudzinski and colleagues suggest that the overpressure of fluids trapped inside the rock may be important.

“The deeper the rock layers are, the more rock that is sitting on top of a well, and that is going to potentially increase the fluid pressures at depth,” said Brudzinski, the study’s corresponding author from Miami University in Ohio.

Oklahoma has been at the center of a dramatic increase in earthquake activity over the past decade, mostly caused by oil and gas companies injecting wastewater produced by drilling back into deeper rock layers. However, a 2018 study identified places in the state where significant amounts of seismic activity were linked to nearly 300 hydraulic fracture wells.

Hydraulic fracturing is associated with a magnitude 4.6 earthquake in Canada and a magnitude 5.7 earthquake in China, although fracking-induced earthquakes tend to be smaller in magnitude than those caused by wastewater disposal. As a result, oil and gas operators and regulators would like to know more about why some wells trigger seismic activity, and how to adjust their operations to prevent damaging earthquakes.

Brudzinski and colleagues found the link between depth and seismic probability in their examination of data from 929 horizontal and 463 vertical hydraulic fracturing wells in Oklahoma. The scientists used publicly available data on injected volume at well sites, the number of wells on a drilling pad, what kind of fluid was injected, and the vertical depth of the well, among other features.

The total volume of injected liquid at the Oklahoma wells did not affect the probability of seismic activity near the wells — a surprising finding that differs from other studies of induced seismicity. Some previous hydraulic fracturing (and wastewater disposal) studies show an increase in seismic activity with increasing volume.

Most of the wells in the current study are single wells, however, and not multiple wells clustered on a drilling pad, Brudzinski noted. In some places in western Canada and Texas, where there is a link between the injected volume and seismicity, multiple wells on a pad are more common.

“So that’s where we started to think that perhaps that’s the difference between what we’re seeing in our study versus other studies,” Brudzinski said. “We’re proposing that multiple wells injecting next to each other may be why volume does matter in those cases, although we need to study it more.”

“It could be that volume does still matter, but more so in a cumulative way than for any given well,” he added. “An isolated well with a large volume may not have nearly as much of a [seismic] risk as a large volume well that is in close proximity to other large volume wells.”

The researchers also compared the probability of seismic activity in wells where the injected liquid was a gel versus “slickwater” — water with chemicals added to increase flow. They found a lower level of seismicity in gel operations compared to slickwater, although the difference wasn’t as statistically significant as the other trends.

Simulation studies suggest that the more viscous gel may not flow as far as the slickwater, limiting its effects on faults, Brudzinski said.

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New material mimics strength, toughness of mother of pearl

In the summer, many people enjoy walks along the beach looking for seashells. Among the most prized are those that contain iridescent mother of pearl (also known as nacre) inside. But many beachcombers would be surprised to learn that shimmery nacre is one of nature’s strongest, most resilient materials. Now, researchers reporting in ACS Nano have made a material with interlocked mineral layers that resembles nacre and is stronger and tougher than previous mimics.

Some mollusks, such as abalone and pearl oysters, have shells lined with nacre. This material consists of layers of microscopic mineral “bricks” called aragonite stacked upon alternating layers of soft organic compounds. Scientists have tried to replicate this structure to make materials for engineering or medical applications, but so far artificial nacre has not been as strong as its natural counterpart. Hemant Raut, Caroline Ross, Javier Fernandez and colleagues noticed that prior nacre mimics used flat mineral bricks, whereas the natural material has wavy bricks that interlock in intricate herringbone patterns. They wanted to see if reproducing this structure would create a stronger, tougher nacre mimic for sustainable medical materials.

Using the components of natural nacre, the team made their composite material by forming wavy sheets of the mineral aragonite on a patterned chitosan film. Then, they interlocked two of the sheets together, filling the space between the wavy surfaces with silk fibroin. They stacked 150 interlocked layers together to form a composite that was about the thickness of a penny. The material was almost twice as strong and four times as tough as previous nacre mimics — close to the strength and toughness reported for natural nacre. The artificial nacre was also biocompatible, which the researchers demonstrated by culturing human embryonic stem cells on its surface for one week. These features suggest that the material could be suitable for sustainable, low-cost medical uses, the researchers say.

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Gigantic, red and full of spots

Among the Sun’s most striking features are its sunspots, relatively darker areas compared to the rest of the surface, some of which are visible from Earth even without magnification. Numerous other stars, which like the Sun are in the prime of their lives, are also covered by spots. In red giants, on the other hand, which are in an advanced stage of stellar evolution, such spots were previously considered to be rare. The reason for this difference can be found deep in the interior of stars. In a dynamo process, the interplay of electrically conductive plasma currents and rotation generates a star’s magnetic field that is then washed up to its surface. In some places, particularly strong magnetic fields prevent hot plasma from flowing upwards. These regions appear dark and constitute starspots.

“Rotation and convection are both crucial ingredients for the formation of surface magnetic fields and starspots,” explains Dr. Federico Spada of MPS, co-author of the new study. “Stars with outer convective layers have the potential to generate surface magnetic fields via dynamo action, but only when the star rotates fast enough the magnetic activity becomes detectable,” he adds. Until now, researchers had assumed that almost all red giants rotate rather slowly around their own axis. After all, stars expand dramatically when they develop into red giants towards the end of their lives. As a result their rotation slows down, like a figure skater doing a pirouette with his arms stretched out. The new study led by scientists from MPS and New Mexico State University (USA) now paints a different picture. About eight percent of the observed red giants rotate quickly enough for starspots to form.

The research team scoured the measurement data of about 4500 red giants recorded by NASA’s Kepler space telescope from 2009 to 2013 for evidence of spots. Such spots reduce the amount of light that a star emits into space. Since they usually change only slightly over several months, they gradually rotate out of the telescope’s field of view — and then reappear after some time. This produces typical, regularly recurring brightness fluctuations.

In a second step, the scientists investigated the question why the spotted giants rotate so quickly. How do they muster the necessary energy? “To answer this question, we had to determine as many of the stars’ properties as possible and then put together an overall picture,” says Dr. Patrick Gaulme, lead author of the publication. At the Apache Point Observatory in New Mexico (USA), for example, the researchers studied how the wavelengths of starlight from some of the stars change over time. This allows conclusions about their exact movement. The team also looked at rapid fluctuations in brightness, which are superimposed on the slower ones caused by starspots. The faster fluctuations are the expression of pressure waves propagating through a star’s interior to its surface. They contain information on many internal properties such as the star’s mass and age.

The analysis revealed that approximately 15 percent of the spotted giants belong to close binary star systems, usually constituted of a red giant with a small and less massive companion. “In such systems, the rotational speeds of both stars synchronize over time until they rotate in unison like a pair of figure skaters,” says Gaulme. The slower red giant thus gains momentum and spins faster than it would have without a companion star.

The other red giants with starspots, about 85 percent, are on their own — and yet they rotate quickly. Those with a mass roughly equal to that of the Sun probably merged with another star or planet in the course of their evolution and thus gained speed. The somewhat heavier ones, whose masses are two to three times that of the Sun, look back on a different development. In the heyday of their lives before they became red giants, their internal structure prevented the creation of a global magnetic field that gradually carries particles away from the star. Unlike their magnetic counterparts, which therefore rotate slower and slower over time, their rotation has probably never slowed down significantly. Even as red giants, they still rotate almost as quickly as they did in their youth.

“In total, behind the common observational feature that some red giants have spots, we find three groups of rapidly rotating stars, each of which has a very different explanation. So it’s no wonder that the phenomenon is more widespread than we previously thought,” says Gaulme.

Studies like the present research shed light, among other things, on the evolution of rotation and magnetic activity in stars, and their complex interplay, including the impact on the habitability of the planetary systems they may host. These are among the prime objectives of ESA’s PLATO mission, whose launch is expected by the end of 2026. “We look forward to having the PLATO mission in space; with its unique long-duration observations we will be able to extend the study to other regions of the Milky Way,” concludes Spada.

This research was supported by the German Aerospace Center (DLR) under PLATO Data Center grant 50OO1501.

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Nanoplastics accumulate in land-plant tissues

As concern grows among environmentalists and consumers about micro- and nanoplastics in the oceans and in seafood, they are increasingly studied in marine environments, say Baoshan Xing at the University of Massachusetts Amherst and colleagues in China. But “little is known about the behavior of nanoplastics in terrestrial environments, especially agricultural soils,” they add.

Xing, an environmental scientist at UMass Amherst’s Stockbridge School of Agriculture, and collaborators at Shandong University, China, point out that until now, there had been no direct evidence that nanoplastics are internalized by terrestrial plants.

They state, “Our findings provide direct evidence that nanoplastics can accumulate in plants, depending on their surface charge. Plant accumulation of nanoplastics can have both direct ecological effects and implications for agricultural sustainability and food safety.” Both positively and negatively charged nanoplastics accumulate in the commonly used laboratory model plant, Arabidopsis thaliana.

Xing adds that widespread global use and persistence in the environment result in an “enormous” amount of plastic waste. He says, “Our experiments have given us evidence of nanoplastics uptake and accumulation in plants in the laboratory at the tissue and molecular level using microscopic, molecular and genetic approaches. We have demonstrated this from root to shoot.” Details are in Nature Nanotechnology this week.

Xing points out that nanoplastic particles can be as small as a protein or a virus. Weathering and degradation change plastic’s physical and chemical properties and imparts surface charges, so environmental particles are different from the pristine polystyrene nanoplastics often used in the lab. “This is why we synthesized polystyrene nanoplastics with either positive or negative surface charges for use in our experiments.”

He helped to design the study, interpret the results, evaluate and revise the manuscript while a large team at Shandong University led by Xian-Zheng Yuan and Shu-Guang Wang conducted the experiments.

They grew Arabidopsis plants in soil mixed with differently charged, fluorescently labeled nanoplastics to assess plant weights, height, chlorophyll content and root growth. After seven weeks, they observed that plant biomass and height were lower in plants exposed to nanoplastics than in controls, for example.

“Nanoplastics reduced the total biomass of model plants,” Xing adds. “They were smaller and the roots were much shorter. If you reduce the biomass, it’s not good for the plant, yield is down and the nutritional value of crops may be compromised.”

He adds, “We found that the positively charged particles were not taken up so much, but they are more harmful to the plant. We don’t know exactly why, but it’s likely that the positively charged nanoplastics interact more with water, nutrients and roots, and triggered different sets of gene expressions. That needs to be explored further in crop plants in the environment. Until then, we don’t know how it may affect crop yield and food crop safety.”

The team also analyzed seedlings to investigate sensitivity of the roots to charged nanoplastics. Exposed for 10 days, seedling growth was inhibited compared with that of control seedlings. To identify molecular mechanisms responsible, the researchers used RNA-Seq transcriptomic analyses of roots and shoots, then verified results with a quantitative PCR assay on three root genes and four shoot genes.

“Regardless of the surface charge, Arabidopsis can take up and transport nanoplastics with sizes of less than 200 nm,” they write. Further, “In this study, we mainly demonstrate that the pathway of uptake and transport of nanoplastics in root tissues differed between differentially charged nanoplastics.”

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Gravitational waves could prove the existence of the quark-gluon plasma

Neutron stars are among the densest objects in the universe. If our Sun, with its radius of 700,000 kilometres were a neutron star, its mass would be condensed into an almost perfect sphere with a radius of around 12 kilometres. When two neutron stars collide and merge into a hyper-massive neutron star, the matter in the core of the new object becomes incredibly hot and dense. According to physical calculations, these conditions could result in hadrons such as neutrons and protons, which are the particles normally found in our daily experience, dissolving into their components of quarks and gluons and thus producing a quark-gluon plasma.

In 2017 it was discovered for the first time that merging neutron stars send out a gravitational wave signal that can be detected on Earth. The signal not only provides information on the nature of gravity, but also on the behaviour of matter under extreme conditions. When these gravitational waves were first discovered in 2017, however, they were not recorded beyond the merging point.

This is where the work of the Frankfurt physicists begins. They simulated merging neutron stars and the product of the merger to explore the conditions under which a transition from hadrons to a quark-gluon plasma would take place and how this would affect the corresponding gravitational wave. The result: in a specific, late phase of the life of the merged object a phase transition to the quark-gluon plasma took place and left a clear and characteristic signature on the gravitational-wave signal.

Professor Luciano Rezzolla from Goethe University is convinced: “Compared to previous simulations, we have discovered a new signature in the gravitational waves that is significantly clearer to detect. If this signature occurs in the gravitational waves that we will receive from future neutron-star mergers, we would have a clear evidence for the creation of quark-gluon plasma in the present universe.”

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Journal Reference:

  1. Lukas R. Weih, Matthias Hanauske, Luciano Rezzolla. Post-merger gravitational wave signatures of phase transitions in binary mergers. Physical Review Letters, 2020 DOI: 10.1103/PhysRevLett.124.171103

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Goethe University Frankfurt. “Gravitational waves could prove the existence of the quark-gluon plasma: Computer models of merging neutron stars predicts how to tell when this happens.” ScienceDaily. ScienceDaily, 30 April 2020. <>.

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Students often do not question online information

The Internet and social media are among the most frequently used sources of information today. Students, too, often prefer online information rather than traditional teaching materials provided by universities. According to a study conducted by Johannes Gutenberg University Mainz (JGU) and Goethe University Frankfurt, students struggle to critically assess information from the Internet and are often influenced by unreliable sources. In this study, students from various disciplines such as medicine and economics took part in an online test, the Critical Online Reasoning Assessment (CORA). “Unfortunately, it is becoming evident that a large proportion of students are tempted to use irrelevant and unreliable information from the Internet when solving the CORA tasks,” reported Professor Olga Zlatkin-Troitschanskaia from JGU. The study was carried out as part of the Rhine-Main Universities (RMU) alliance.

Critical evaluation of online information and online sources are particularly important today

Learning using the Internet offers many opportunities, but it also entails risks. It has become evident that not only “fake news” but also “fake science” with scientifically incorrect information is being spread on the Internet. This problem becomes particularly apparent in the context of controversially discussed social issues such as the current corona crisis, but it actually goes much deeper. “Having a critical attitude alone is not enough. Instead, Internet users need skills that enable them to distinguish reliable from incorrect and manipulative information. It is therefore particularly important for students to question and critically examine online information so they can build their own knowledge and expertise on reliable information,” stated Zlatkin-Troitschanskaia.

To investigate how students deal with online information, Professor Olga Zlatkin-Troitschanskaia and her team have developed a new test based on the Civic Online Reasoning (COR) assessment developed by Stanford University. During the assessment, the test takers are presented with short tasks. They are asked to freely browse the Internet, focusing on relevant and reliable information that will help them to solve the tasks within the relatively short time frame of ten minutes, and to justify their solutions using arguments from the online information they used.

CORA testing requires complex and extensive analysis

The analysis of the results is based on the participants’ responses to the tasks. In addition, their web search activity while solving the tasks is recorded to examine their strengths and weaknesses in dealing with online information in more detail. “We can see which websites the students accessed during their research and which information they used. Analyzing the entire process requires complex analyses and is very time-consuming,” said Zlatkin-Troitschanskaia. The assessments have so far been carried out in two German federal states. To date, 160 students from different disciplines have been assessed; the majority of the participants studied medicine or economics and were in their first or second semester.

Critical online reasoning skills should be specifically promoted in higher education

The results are striking: almost all test participants had difficulties solving the tasks. On a scale of 0 to 2 points per task, the students scored only 0.75 points on average, with the results ranging from 0.50 to 1.38 points. “The majority of the students did not use any scientific sources at all,” said Zlatkin-Troitschanskaia, pointing out that no domain-specific knowledge was required to solve the CORA tasks. “We are always testing new groups of students, and the assessment has also been continued as a longitudinal study. Since we first started conducting these assessments two years ago, the results are always similar: the students tend to achieve low scores.” However, students in higher semesters perform slightly better than students in their first year of study. Critical online reasoning skills could therefore be promoted during the course of studies. In the United States, a significant increase in these kinds of skills was observed only a few weeks after implementing newly developed training approaches.

The study shows that most students do not succeed in correctly evaluating online sources in the given time and in using relevant information from reliable sources on the Internet to solve the tasks. “As we know from other studies, students are certainly able to adequately judge the reliability of well-known media portals and Internet sources. We could build on this fact and foster the skills required to critically evaluate new sources and online information and to use the Internet in a reflected manner to generate warranted knowledge,” concluded Professor Olga Zlatkin-Troitschanskaia.

In research on this topic, skills related to critically dealing with online information and digital sources are regarded as an essential prerequisite for learning in the 21st century. However, there are still very few training approaches and assessments available for students to foster these skills, especially online. “The RMU study is still in the early stages of development. We have only just developed the first test of this kind in Germany,” Zlatkin-Troitschanskaia pointed out. “We are currently in the process of developing teaching/learning materials and training courses and of testing their effectiveness. The analysis of the processing will be particularly useful when it comes to offering students targeted support in the future.

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Biometric devices help pinpoint factory workers’ emotions and productivity

Happiness, as measured by a wearable biometric device, was closely related to productivity among a group of factory workers in Laos, reveals a recent study.

The team of researchers from the School of Economics at Hiroshima University conducted a study to examine relationships between toy painters’ productivity and on-the-job emotional states.

While employee productivity has already been linked to job conditions, mental health, and other demographic factors, this study adds to a deeper understanding of how emotional states affect productivity.

Professor Yoshihiko Kadoya, the lead researcher on the paper, said the findings have implications for both operational and human resources strategies.

“Organizations need to consider employees’ emotionality when producing workflow designs that could help ensure a pleasant working environment,” he said.

In the study, 15 workers answered a questionnaire and wore a device on their wrist with built-in sensors to detect movement, pulse waves, environmental ultraviolet light, body temperature, and sound through which it continuously recorded physical activity, beat-to-beat pulse intervals, skin temperature, and sleep. The device, Silmee(TM)W20, is produced by the TDK Corporation Tokyo, Japan.

Employees’ emotional states were measured for three working days through a complex process of beat-to-beat pulse intervals via custom software developed by NEC Corporation Tokyo, Japan. The researchers followed a common model in the field — Russel’s circumplex model — to measure employees’ emotion in four states: happy, angry, relaxed, and sad.

Using a random effect panel regression model, they found people’s happy emotional state was positively related to their productivity. Meanwhile, no other emotional states were found to be related to productivity.

“The use of wearable biometric devices, which can track employees’ emotional states provides an opportunity to examine more objective components of the emotion-productivity link,” Kadoya adds.

The study’s limitations included the possibility of device errors, the number of observations throughout the day, and the gender distribution (14 out of 15 workers in this study identified as female), therefore the results should not be over-generalized. In the future, however, researchers hope to apply similar methods to explore the links between emotional states and different types of work.

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Octopus-inspired robot can grip, move, and manipulate a wide range of objects

Of all the cool things about octopuses (and there’s a lot), their arms may rank among the coolest.

Two-thirds of an octopus’s neurons are in its arms, meaning each arm literally has a mind of its own. Octopus arms can untie knots, open childproof bottles, and wrap around prey of any shape or size. The hundreds of suckers that cover their arms can form strong seals even on rough surfaces underwater.

Imagine if a robot could do all that.

Researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and Beihang University have developed an octopus-inspired soft robotic arm that can grip, move, and manipulate a wide range of objects. Its flexible, tapered design, complete with suction cups, gives the gripper a firm grasp on objects of all shapes, sizes and textures — from eggs to iPhones to large exercise balls.

“Most previous research on octopus-inspired robots focused either on mimicking the suction or the movement of the arm, but not both,” said August Domel, a recent PhD graduate of Harvard and co-first author of the paper. “Our research is the first to quantify the tapering angles of the arms and the combined functions of bending and suction, which allows for a single small gripper to be used for a wide range of objects that would otherwise require the use of multiple grippers.”

The research is published in Soft Robotics.

The researchers began by studying the tapering angle of real octopus arms and quantifying which design for bending and grabbing objects would work best for a soft robot. Next, the team looked at the layout and structure of the suckers (yes, that is the scientific term) and incorporated them into the design.

“We mimicked the general structure and distribution of these suckers for our soft actuators,” said co-first author Zhexin Xie, a PhD student at Beihang University. “Although our design is much simpler than its biological counterpart, these vacuum-based biomimetic suckers can attach to almost any object.”

Xie is the co-inventor of the Festo Tentacle Gripper, which is the first fully integrated implementation of this technology in a commercial prototype.

Researchers control the arm with two valves, one to apply pressure for bending the arm and one for a vacuum that engages the suckers. By changing the pressure and vacuum, the arm can attach to an object, wrap around it, carry it, and release it.

The researchers successfully tested the device on many different objects, including thin plastic sheets, coffee mugs, test tubes, eggs, and even live crabs. The tapering also allowed the arm to squeeze into confined spaces and retrieve objects.

“The results from our study not only provide new insights into the creation of next-generation soft robotic actuators for gripping a wide range of morphologically diverse objects, but also contribute to our understanding of the functional significance of arm taper angle variability across octopus species,” said Katia Bertoldi, the William and Ami Kuan Danoff Professor of Applied Mechanics at SEAS, and co-senior author of the study.

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