Saturday, September 05, 2020

 

Inequality of opportunity drags down everyone's motivation

UNIVERSITY COLLEGE LONDON

Research News

Unequal compensation reduces people's motivation to work, even among those who stand to benefit from unfair advantages, finds a new UCL-led study.

The researchers found that large disparities in rewards offered for the same task reduce people's happiness, which in turn reduce their willingness to work, in the study published in PLOS One.

Lead author, Dr Filip Gesiarz (UCL Psychology & Language Sciences) said: "Here we have shown the psychological impacts of inequality of opportunity, and how it can hurt the productivity and well-being of everyone involved.

"Our findings may shed light on how psychological mechanisms, apart from structural barriers, can contribute to higher unemployment and lower university application rates of people from disadvantaged backgrounds. It's more difficult to motivate yourself to work hard if you know that other people will be more generously rewarded for the same effort."

For the study, 810 participants were asked to complete a simple task in exchange for some money. In different scenarios across three experiments, participants were told that other people were being paid more or less than they were for the same task, to varying degrees of inequality. They were given the option of refusing to work on a given task, and in some of the trials, they were also asked how they were feeling.

The researchers found that when people were told there were wide disparities in pay between them and their peers, they were less willing to work, including participants who were told that other people were being paid much less than they were.

The findings show how people are less motivated to work if they are being paid less than others, but also if they perceive the whole system to be unjust.

Dr Gesiarz said: "People who are economically disadvantaged might face a two-fold reduction in motivation and well-being - first due to their lower relative position, and second due to their reaction to the unfair distribution of opportunities."

The findings showed that a large disparity in rewards brought about greater unhappiness, which was in turn associated with lower willingness to work. People were more likely to refuse to work in an unfair scenario, even if they would benefit, and despite their refusal being a private decision that had no impact on other people's rewards.

The researchers speculate that the negative feelings caused by arbitrary disparities may in part explain why disadvantaged people are more likely to experience anxiety and depression.

Co-author Dr Jan-Emmanuel De Neve (University of Oxford) said: "This study documents yet another example of a 'poverty trap': a situation in which being put at a disadvantage by random circumstances decreases a person's motivation to work, further worsening their situation."

Senior author Professor Tali Sharot (UCL Psychology & Language Sciences) said: "Whether inequality will negatively affect those at the top in 'the real world', outside the lab, remains to be studied. One thing to consider is that in our experiment, people were made aware that their position was randomly assigned. In the 'real world' people many times assume that their good fortune is justified by their talent and effort and therefore inequality might not have a negative influence on the motivation and well-being of privileged individuals in those situations. This is an important question that we hope to answer in the future."

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The study was funded by Wellcome.

 

Intelligent software for district renewable energy management

SWISS CENTER FOR ELECTRONICS AND MICROTECHNOLOGY - CSEM

Research News

New homes are increasingly being outfitted with solar panels, heat pumps, rechargeable batteries and other means of producing and storing heat, electricity and gas, all of which interconnect with the electrical grid. At the level of an entire neighborhood, these decentralized, intermittent energy sources form a complex network, which can also include energy-consuming installations such as electric vehicle charging stations.

Managing these multi-energy systems and optimizing energy costs raises a number of questions. Should energy be consumed when it is produced, sold to the grid, or stored for later use? And how should various energy sources be distributed if there are groups of consumers generating their own energy?

Orchestrating the production and consumption of energy

CSEM has developed smart, predictive software capable of providing real-time answers to these questions. Designed for non-specialists, it makes use of weather forecasts, data from local infrastructure, residents' consumption habits and market energy costs. As its name indicates, Maestro is like an orchestra conductor that automatically manages resources and keeps costs down. An online simulator, based on a building with eight family apartments, is available here.

Determining the best time to consume energy

"All of Maestro's decisions are based on cost management," says Tomasz Gorecki, one of CSEM's engineers behind the system. "When a solar panel is in use, for example, the software can tell you whether it's more advantageous to charge your electric vehicle, store the energy, or sell it to the grid. The system works for individual homes, but it could also prove to be very useful for a self-sufficient community, sharing various renewable energy sources across several homes," he adds. The system has already been successfully installed in two private homes and in an apartment building in collaboration with Soleco. Negotiations are underway to fit out an entire neighborhood currently under construction in Zurich. Maestro was also presented at the IFAC World Congress in Berlin.

How Maestro works

The software is easy to use and can be quickly adapted to individual neighborhoods. To start with, parameters such as solar panel size, buildings' surface area, battery storage capacity and user preferences and priorities are fed into a planning tool.

Production data from energy installations, provided by sensors, are then sent to the cloud, where Maestro automatically compares possible consumption decisions and identifies the most cost-effective one. Instructions are sent back to the computer, which carries them out on site.

Maestro can incorporate boilers, heat pumps and electric vehicle charging stations, as well as electric batteries, renewable energy sources such as solar panels and wind turbines, power-to-gas facilities, thermal storage tanks, and more.

To learn more and test the online simulator, go to: https://www.csem.ch/page.aspx?pid=126438

Specific questions

What sets Maestro apart from other energy management systems?

Other systems on the market are designed only for individual homes and often employ a very simple mechanism of increasing power consumption whenever solar energy is produced. Maestro, on the other hand, can be used just as well for an entire neighborhood, where the network is more complex. It can also accommodate other energy-consuming installations such as electric vehicle charging stations and home heating and cooling systems. What's more, Maestro looks at weather forecasts for the coming days, which means that it can factor future needs into its consumption decisions. More broadly, the system is designed to keep costs down.

Could this focus on cost actually lead to increased energy consumption?

No, that shouldn't happen. Whenever surplus energy is produced, for example, the system will sell it to the grid if storing it for later use wouldn't be possible or cost-efficient. In making this decision, the system takes into account the losses that would be incurred by storing the energy in batteries. It's all about determining the best time and most rational way to use the energy.

What sort of cost savings are possible?

The cost savings will vary from home to home and user to user. A preliminary study on the first house running Maestro revealed an approximately 20% reduction in heating costs alone.


 

A chemist from RUDN developed a green catalyst for pharmaceutical and industrial chemistry

RUDN UNIVERSITY

Research News

IMAGE

IMAGE: MANY PRODUCTION FACILITIES (E.G. PLASTIC MANUFACTURERS, PHARMA COMPANIES, AND OTHERS) USE NANOCATALYSTS THAT CONTAIN PALLADIUM--AN EXPENSIVE COMPONENT THAT IS NOT SUSTAINABLY PRODUCED. A CHEMIST FROM RUDN UNIVERSITY FOUND A WAY... view more 

CREDIT: RUDN UNIVERSITY

Many production facilities (e.g. plastic manufacturers, pharma companies, and others) use nanocatalysts that contain palladium--an expensive component that is not sustainably produced. A chemist from RUDN University found a way to reduce palladium consumption and to make its manufacture more eco-friendly. He developed a catalyst based on a substance that comes from plant waste. Using his invention, manufacturers could cut palladium consumption in half. Moreover, new catalysts can be reused multiple times without any decrease in efficiency. The results of the study were published in the journal Molecular Catalysis.

Cross-coupling is a type of reaction that involves combining carbon atoms from different organic molecules. Cross-coupling reactions are most widely spread ones in industrial chemistry. They are used to synthesize plastics, medicinal drugs, and other compounds and account for 17% of all reactions in medical chemistry only. The main component of cross-coupling is palladium nanoparticles. Palladium is one of the rarest elements on Earth, which makes it a very expensive catalyst. Moreover, it is mainly produced at mining facilities that pose a considerable threat to the environment. A chemist from RUDN University suggested solving all these issues with one new approach.

The consumption of palladium in cross-coupling reactions increases because the particles of palladium-containing catalysts tend to bind together. There are two ways to stop this. One could modify the chemical properties of the particles to weaken the reaction between their surfaces when they come in contact. Alternatively, the metal could be held in place physically with a framework or a grid. The chemist from RUDN University chose the second method and locked metal particles in their respective places using a multilayer shell with a magnetic core.

The core of the new nanocatalyst consists of iron oxide with high magnetic properties. The coating is made of a catechol-based polymer. Catechol is a substance that is found in plant cell walls and is produced from plant waste. Both these layers are ancillary and have no catalytic activity. The catalytic properties of the compound come from palladium nanoparticles that are incorporated into the second layer. The polymer fixes the particles in place and prevents them from binding together.

The new catalyst structure requires twice as little palladium as the old one: 1.5% of the total nanoparticle weight as opposed to 3-6%. Moreover, after a couple of production cycles, the core of the nanocomposite material can be cleaned up and reused. This method is not only good for the environment but also economically feasible, as it will make the production of medicinal drugs, plastics, and other products cheaper.

"Today chemists are especially interested in green catalysts. Our nanocatalysts contain a product of plant waste recycling and at the same time efficiently work in cross-coupling reactions. Therefore, not only are they able to reduce palladium consumption and make the production process cheaper, but also are beneficial for the environment. Moreover, we managed to showcase the universal nature of polymers based on plant catechols. The same approach can be used when working with other metals including platinum, silver, or gold, or with catalysts of other organic reactions," said Rafael Luque, PhD, Head of the Molecular Design and Synthesis of Innovative Compounds for Medicine Science Center at RUDN University.

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Autophagy: the beginning of the end

Scientists reveal key steps in the formation of the recycling centers of the cell

UNIVERSITY OF VIENNA

Research News

Autophagosomes first form as cup-shaped membranes in the cell, which then grow to engulf the cellular material designated for destruction. The formation of these membranes is catalyzed by a complex machinery of proteins. "We have a very good knowledge of the factors involved in autophagosomes formation", explains group leader Sascha Martens, "but how they come together to initiate the formation of these membranes has so far been enigmatic".

One of the factors is Atg9, a protein whose importance in the process was known, but whose role was not clear. Atg9 is found in small intracellular vesi-cles. Researchers Justyna Sawa-Makarska, Verena Baumann and Nicolas Coudevylle from the Martens lab now show that they form a platform on which the autophagy machinery can assemble to build the autophagosome. "Atg9 vesicles are abundant in the cell, which means they can be rapidly recruited when autophagosomes are needed", explains group leader Sascha Martens.

Cells encapsulate cargo in vesicles, so that they can be correctly transported and degraded in a chemical environment that is different to the one normally found in cells. Autophagosomes therefore consist of a double membrane made of phospholipids. This greasy envelope creates a waterproof package that separates material from the aqueous surroundings of the cell and marks it for degradation. However, Atg9 vesicles do not supply the bulk of the lipids to the growing autophagosome.

To understand a complex machinery like the cell, it often helps to take it apart and rebuild it. The biogenesis of autophagosome involves numerous proteins. By isolating and characterizing 21 of these components, the scientists have been able to rebuild parts of the autophagy machinery in the 'test tube' - an ar-duous process that took Sascha Martens and his team almost ten years. "With this approach we could reconstitute the early steps of autophagosome biogen-esis in a controlled manner", he says. With the elaborate toolkit the Martens lab has developed, the scientists now aim to unravel the next steps in the biogene-sis of the autophagosome. The research project was a collaboration of the Martens lab with Gerhard Hummer and Soeren von Bülow from the Max Planck Institute for Biophysics in Frankfurt and Martin Graef from the Max Planck In-stitute for Biology of Ageing in Cologne.

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Publication in "Science":

Justyna Sawa-Makarska, Verena Baumann, Nicolas Coudevylle, Sören von Bu?low, Veronika Nogellova, Christine Abert, Martina Schuschnig, Martin Graef, Gerhard Hummer und Sascha Martens: Reconstitution of autophagosome nucleation defines Atg9 vesicles as seeds for membrane formation. Science 2020

DOI:10.1126/science.aaz7714

 

Images of captive torment in art

Japanese war camps highlight 'lost' part of history

FLINDERS UNIVERSITY

Research News

IMAGE

IMAGE: ANON., FIGURES KISSING, 1942-45, WOOD, APPROXIMATE HEIGHT = 40?CM. COURTESY OF BARMERA VISITOR INFORMATION CENTRE, SOUTH AUSTRALIA. view more 

CREDIT: COURTESY OF BARMERA VISITOR INFORMATION CENTRE, SOUTH AUSTRALIA.

Between the arrival of pearl divers and war brides - long after Japanese performers toured Australia 150 years ago - an untold chapter of World War Two history has emerged in a new study of wartime art made by almost 5000 prisoners of war in Australia and New Zealand.

Focusing on internment camps set up across Australia and NZ, Canterbury University and Flinders University art historians Richard Bullen and Tets Kimura examine some exquisite Japanese artworks produced during the extended period of war incarceration.

It gives a fascinating insight into the lives of these ethnic and part-Japanese PoWs and civilians, at a time of enforced detention at remote locations such as Cowra and Hay (NSW), Tatura in Victoria, Loveday and Woolenook camp (SA) and Featherston, Pahiatua and Somes Island in New Zealand.

"Australasian Japanese internment camps remain largely unheard of, and the art made by the internees has received no attention until the current research," they say in the new paper. "Although there were some very crudely made items made by the Japanese held in Australasia, many of the works are of surprising quality and suggest a level of artistic confidence and training."

Including the Cowra breakout and a standoff at the Featherston facility, the record of camp life focuses more on a narrative of violence, misunderstanding, racism, than the social history and isolating and traumatic experience of internment.

In the largely all-male camp environment, many of the works depict alluring female figures, with the cultural symbols of kimono, geisha and umbrella depicted in various ways.The paper outlines the stories of several such artworks, including the attached:

Editors - the images can be downloaded from the article, except Figure 3 which is privately owned and requires permission.

Read the article, Japanese Art in Australasia During the Second World War, by Richard Bullen and Tets Kimura, in the Australian and New Zealand Journal of Art, 2020, vol 20, 1, 107-124 DOI: 10.1080/14434318.2020.1764232.

For more details on personal stories of WWII detainees, see a comprehensive camp history in Australia by Flinders University Professor Peter Monteath, Captured Lives: Australia's Wartime Internment Camps (Canberra: NLA Publishing, 2018).

 

The case of ibuprofen: evidence of huge impact of COVID-19 misinformation when coming from credible sources

The case of ibuprofen

UNIVERSITAT OBERTA DE CATALUNYA (UOC)

Research News

In March, in the early days of the coronavirus pandemic in Europe, a tweet from the French Health Minister, Olivier Verán, advised patients with COVID-19 not to take ibuprofen, an anti-inflammatory drug with analgesic and antipyretic properties. He even warned that taking it would increase mortality among COVID-19 patients, even though the statement was not backed by any scientifically valid evidence. In spite of this information's spuriousness, it subsequently spread to a number of countries. UOC doctoral student Sergi Xaudiera and Ana Sofía Cardenal, a researcher at the Faculty of Law and Political Science, have studied the digital reach of this unverified, Twitter-propagated information in Germany, France, Spain, the Netherlands and Italy. The results show that misinformation has a huge impact when credible sources take part in propagating it. Based on a case study of Catalonia, the project also highlights the importance of local channels in disseminating or deactivating misinformation as, according to the study's conclusions, it is precisely the regional channels that have greatest impact in each territory.

Published in the Harvard Kennedy School (HKS) Misinformation Review, the research forms part of Sergi Xaudiera's doctoral thesis, in which he studies cases of misinformation in emergency situations. "Until now, most misinformation campaigns were instigated by unauthoritative users or partisan media. However, this case stands out for the fact that the fake news was echoed by political representatives (specifically, the French Health Minister) and respectable media outlets, who took it to a broader audience," the researcher explained.

From a WhatsApp voice message to the French Minister's Twitter account

The spark that spread the false news about ibuprofen to other European countries was the message posted by the French Minister on Twitter. However, the UOC researchers traced the story's trail back to a WhatsApp voice message in Germany. Following the digital footprint on the microblogging network, they also analysed how, over a period of two weeks, the story spread from its country of origin to users in the Netherlands, France and, finally, Spain and Italy. They looked at the role played by credible sources, such as political representatives and respected media outlets, in giving greater prominence to the misinformation.

The importance of official sources in matters such as these can be seen in the differences in how the information spread between France and Germany. "Even though the message originated in Germany, nobody took it seriously. The voice message was forwarded to different users but, as it was not possible to identify who originally recorded it, it lost credibility and the general tone of comments was basically to debunk it or make jokes about it," the research project's author highlighted. However, in France, where the message was sponsored by a credible source, the fake news had the greatest impact of all the countries studied and the comments refuting the information were virtually non-existent. Indeed, the project showed how other reliable sources, such as the media, reproduced the Minister's tweet without fact-checking, helping to take the information to greater segments of the population.

"Misinformation supported by reliable sources is particularly dangerous because their very credibility induces people to accept the recommendations without doubting or questioning the information on which they are based. In addition, these types of action, occurring during emergency situations, are particularly sensitive and, if treated incorrectly, they may have irreversible consequences," the researcher continued.

The other territories included in the study fall between these two extremes, combining messages that reproduced the fake news with others that said that it was not true. In Spain and Italy, the media and journalists were the first to debunk the misinformation, citing the French Minister's subsequent statements to disprove it. On 18 March, a second wave appeared in all the territories, and was quickly rejected by users. In spite of this, the news re-emerged in Italy and spread quickly between 20 and 23 March.

The power of local media in spreading information

Tracking the path taken by this information highlights the importance of governments' active presence on social media. "By practising active listening to detect conversations about how the emergency is being handled, governments can act quickly whenever inaccurate information attains a certain level of visibility," Xaudiera explained. The study's researchers also found that even though supragovernmental agencies such as the World Health Organization and the European Medicines Agency dismissed the information as untrue, the fake information continued to spread unabated until it was denied by each region's official channels. According to the authors, this points to a strong regional dimension in the dissemination of information.

With the goal of determining the effectiveness of local official sources in discrediting fake news, the researchers studied the specific case of Catalonia. The results showed that most of the Catalan users who contributed to spreading unverified information were not following official sources when the information was published. However, the vast majority of those who shared messages that contributed to discrediting the misinformation were following official channels.

"Misinformation is counteracted most effectively by local sources. When a false narrative starts to circulate in a region, it is the local channels that must help in checking the information and exposing it as fake when necessary. We have seen that following local official channels has a positive effect. However, when it is these channels that are putting out fake information, the region's citizens may become impervious to accurate information," Xaudiera said. In such cases, social media's role becomes particularly complex. "Social platforms (in this case, Twitter) can and must do more to prevent fake information from circulating in their ecosystems. This is particularly critical in cases such as that studied by us, as they are credible, verified channels that are disseminating incorrect information on the platform," he stressed.

Faced with fake information such as the statements about ibuprofen, the researchers recommend following official sources and viewing the information we receive critically, checking it on several sources from different, geographically separate origins, if possible. In addition, on the institutional level, they propose approaching cybersecurity from an information and communication viewpoint. "Until now, cybersecurity was seen purely as a technology issue. However, these cases show that the threat involves much more than technology and the social aspects must be studied as well," Xaudiera concluded.

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Chemistry's Feng Lin Lab is splitting water molecules for a renewable energy future

VIRGINIA TECH

Research News

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IMAGE: CHEMISTRY GRADUATE STUDENT ZHIJIE YANG IS OPERATING SYNCHROTRON MEASUREMENT COMPUTER AT ADVANCED PHOTON SOURCE OF THE ARGONNE NATIONAL LAB IN A PHOTO TAKEN BEFORE THE COVID-19 PANDEMIC. view more 

CREDIT: VIRGINIA TECH

The future economy based on renewable and sustainable energy sources might utilize battery-powered cars, large-scale solar and wind farms, and energy reserves stored in batteries and chemical fuels. Although there are examples of sustainable energy sources in use already, scientific and engineering breakthroughs will determine the timeline for widespread adoption.

One proposed paradigm for shifting away from fossil fuels is the hydrogen economy, in which hydrogen gas powers society's electrical needs. To mass produce hydrogen gas, some scientists are studying the process of splitting water -- two hydrogen atoms and one oxygen atom -- which would result in hydrogen fuel and breathable oxygen gas.

Feng Lin, an assistant professor of chemistry in the Virginia Tech College of Science, is focusing on energy storage and conversion research. This work is part of a new study published in the journal Nature Catalysis that solves a key, fundamental barrier in the electrochemical water splitting process where the Lin Lab demonstrates a new technique to reassemble, revivify, and reuse a catalyst that allows for energy-efficient water splitting. Chunguang Kuai, a former graduate student of Lin's, is first author of the study with Lin and co-authors chemistry graduate students Zhengrui Xu, Anyang Hu, and Zhijie Yang.

The core idea of this study goes back to a subject in general chemistry classes: catalysts. These substances increase the rate of a reaction without being consumed in the chemical process. One way a catalyst increases the reaction rate is by decreasing the amount of energy needed for the reaction to commence.

Water may seem basic as a molecule made up of just three atoms, but the process of splitting it is quite difficult. But Lin's lab has done so. Even moving one electron from a stable atom can be energy-intensive, but this reaction requires the transfer of four to oxidize oxygen to produce oxygen gas.

"In an electrochemical cell, the four-electron transfer process will make the reaction quite sluggish, and we need to have a higher electrochemical level to make it happen," Lin said. "With a higher energy needed to split water, the long-term efficiency and catalyst stability become key challenges."

In order to meet that high energy requirement, the Lin Lab introduces a common catalyst called mixed nickel iron hydroxide (MNF) to lower the threshold. Water splitting reactions with MNF work well, but due to the high reactivity of MNF, it has a short lifespan and the catalytic performance decreases quickly.

Lin and his team discovered a new technique that would allow for periodic reassembling to MNF's original state, thus allowing the process of splitting water to continue. (The team used fresh water in their experiments, but Lin suggests salt water - the most abundant form of water on Earth - could work as well.)

MNF has a long history with energy studies. When Thomas Edison tinkered with batteries more than a century ago, he also used the same nickel and iron elements in nickel hydroxide-based batteries. Edison observed the formation of oxygen gas in his nickel hydroxide experiments, which is bad for a battery, but in the case of splitting water, production of oxygen gas is the goal.

"Scientists have realized for a long time that the addition of iron into the nickel hydroxide lattice is the key for the reactivity enhancement of water splitting." Kuai said. "But under the catalytic conditions, the structure of the pre-designed MNF is highly dynamic due to the highly corrosive environment of the electrolytic solution."

During Lin's experiments, MNF degrades from a solid form into metal ions in the electrolytic solution -- a key limitation to this process. But Lin's team observed that when the electrochemical cell flips from the high, electrocatalytic potential to a low, reducing potential, just for a period of two minutes, the dissolved metal ions reassemble into the ideal MNF catalyst. This occurs due to a reversal of the pH gradient within the interface between the catalyst and the electrolytic solution.

"During the low potential for two minutes, we demonstrated we not only get nickel and iron ions deposited back into the electrode, but mixing them very well together and creating highly active catalytic sites," Lin said. "This is truly exciting, because we rebuild the catalytic materials at the atomic length scale within a few nano-meter electrochemical interface."

Another reason that the reformation works so well is that the Lin Lab synthesized novel MNF as thin sheets that are easier to reassemble than a bulk material.

Validating findings through X-rays

To corroborate these findings, Lin's team conducted synchrotron X-ray measurements at the Advanced Photon Source of Argonne National Laboratory and at Stanford Synchrotron Radiation Lightsource of SLAC National Accelerator Laboratory. These measurements use the same basic premise as the common hospital X-ray but on a much larger scale.

"We wanted to observe what had happened during this entire process," Kuai said. "We can use X-ray imaging to literally see the dissolution and redeposition of these metal irons to provide a fundamental picture of the chemical reactions."

Synchrotron facilities require a massive loop, similar to the size of the Drillfield at Virginia Tech, that can perform X-ray spectroscopy and imaging at high speeds. This provides Lin high levels of data under the catalytic operating conditions. The study also provides insights into a range of other important electrochemical energy sciences, such as nitrogen reduction, carbon dioxide reduction, and zinc-air batteries.

"Beyond imaging, numerous X-ray spectroscopic measurements have allowed us to study how individual metal ions come together and form clusters with different chemical compositions," Lin said. "This has really opened the door for probing electrochemical reactions in real chemical reaction environments."

The work was supported by the Department of Chemistry startup funds and the Institute for Critical Technology and Applied Science.

Researchers find unexpected electrical current that could stabilize fusion reactions

DOE/PRINCETON PLASMA PHYSICS LABORATORY

Research News

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IMAGE: AN ARTIST'S RENDERING OF ELECTRICAL CURRENT FLOWING THROUGH A TOKAMAK FUSION FACILITY view more 

CREDIT: ELLE STARKMAN / PPPL OFFICE OF COMMUNICATIONS

Electric current is everywhere, from powering homes to controlling the plasma that fuels fusion reactions to possibly giving rise to vast cosmic magnetic fields. Now, scientists at the U.S. Department of Energy's (DOE) Princeton Plasma Physics Laboratory (PPPL) have found that electrical currents can form in ways not known before. The novel findings could give researchers greater ability to bring the fusion energy that drives the sun and stars to Earth.

"It's very important to understand which processes produce electrical currents in plasma and which phenomena could interfere with them," said Ian Ochs, graduate student in Princeton University's Program in Plasma Physics and lead author of a paper selected as a featured article in Physics of Plasmas. "They are the primary tool we use to control plasma in magnetic fusion research."

Fusion is the process that smashes together light elements in the form of plasma -- the hot, charged state of matter composed of free electrons and atomic nuclei -- generating massive amounts of energy. Scientists are seeking to replicate fusion for a virtually inexhaustible supply of power to generate electricity.

The unexpected currents arise in the plasma within doughnut-shaped fusion facilities known as tokamaks. The currents develop when a particular type of electromagnetic wave, such as those that radios and microwave ovens emit, forms spontaneously. These waves push some of the already-moving electrons, "which ride the wave like surfers on a surfboard," said Ochs.

But the frequencies of these waves matter. When the frequency is high, the wave causes some electrons to move forward and others backward. The two motions cancel each other out and no current occurs.

However, when the frequency is low, the waves pushes forward on the electrons and backward on the atomic nuclei, or ions, creating a net electrical current after all. Ochs found that researchers could surprisingly create these currents when the low-frequency wave was a particular type called an "ion acoustic wave" that resembles sound waves in air.

The significance of this finding extends from the relatively small scale of the laboratory to the vast scale of the cosmos. "There are magnetic fields throughout the universe on different scales, including the size of galaxies, and we don't really know how they got there," Ochs said. "The mechanism we discovered could have helped seed cosmic magnetic fields, and any new mechanisms that can produce magnetic fields are interesting to the astrophysics community."

The results from the pencil-and-paper calculations consist of mathematical expressions that give scientists the ability to calculate how these currents, which occur without electrons directly interacting, develop and grow. "The formulation of these expressions was not straightforward," Ochs said. "We had to condense the findings so they would be sufficiently clear and use simple expressions to capture the key physics."

The results deepen understanding of a basic physical phenomenon and were also unexpected. They appear to contradict the conventional notion that current drives require electron collisions, Ochs said.

"The question of whether waves can drive any current in plasma is actually very deep and goes to the fundamental interactions of waves in plasma," said Nathaniel Fisch, a coauthor of the paper, professor and associate chair of the Department of Astrophysical Sciences, and director of the Program in Plasma Physics. "What Ochs derived in masterful, didactic fashion, with mathematical rigor, was not only how these effects are sometimes balanced, but also how these effects sometimes conspire to allow the formation of net electrical currents."

These findings lay the groundwork for future research. "What especially excites me," Fisch said, "is that the mathematical formalism that Ochs has built, together with the physical intuitions and insights that he has acquired, now put him in a position either to challenge or to put on a firm foundation even more curious behavior in the interactions of waves with resonant particles in plasma."

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PPPL, on Princeton University's Forrestal Campus in Plainsboro, N.J., is devoted to creating new knowledge about the physics of plasmas -- ultra-hot, charged gases -- and to developing practical solutions for the creation of fusion energy. The Laboratory is managed by the University for the U.S. Department of Energy's Office of Science, which is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit https://energy.gov/science

 

Plant protein discovery could reduce need for fertilizer

UNIVERSITY OF NOTTINGHAM

Research News

Researchers have discovered how a protein in plant roots controls the uptake of minerals and water, a finding which could improve the tolerance of agricultural crops to climate change and reduce the need for chemical fertilisers.

The research, published in Current Biology, shows that members of the blue copper proteins family, the Uclacyanins are vital in the formation of Casparian strips. These strips are essential structures that control mineral nutrient and water use efficiencies by forming tight seals between cells in plants, blocking nutrients and water leaking between.

This is the first evidence showing the implications of this family in the biosynthesis of lignin, one of the most abundant?organic polymers?on earth. This study reveals that the molecular machinery required for Casparian strip lignin deposition is highly ordered by forming nano-domains which can have a huge impact on plant nutrition, a finding that could help in the development of crops that are efficient in taking in the nutrients they need.

Food security represents a pressing global issue. Crop production must double by 2050 to keep pace with global population growth. This target is even more challenging given the impact of climate change on water availability and the drive to reduce fertilizer inputs to make agriculture become more environmentally sustainable. In both cases, developing crops with improved water and nutrient uptake efficiency would provide a solution and this.

Guilhem Reyt from the School of Biosciences and Future Food Beacon at the University of Nottingham has led this research project, he says: "This research is important in revealing the molecular mechanics underpinning efforts to improve mineral nutrient and water use efficiencies and enhanced stress tolerance, making crops more able to withstand flooding, drought, nutrient deficiencies and trace element toxicities.

Such improvements in agricultural and horticultural crops could also potentially benefit subsistence farmers with limited access to inorganic fertilizers which include nitrogen, phosphate and potassium and also sulphur and magnesium. This would help to reduce the cost burden such fertilizers impose and reduce the environmental and ecological damage their production and excess use causes. Improved water use efficiency and stress tolerance will also improve yields for subsistence farmers cultivating marginal lands.

An improved understanding of how roots acquire important trace element and minerals should provide an important molecular mechanistic underpinning to efforts to improve food quality by helping to increase the content of essential mineral nutrients and reduce toxic trace elements in food crops."

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