A new technique for better understanding how silver nanoparticles might affect the environment was announced in a July 30, 2018 news item on ScienceDaily,
Chemists at Ruhr-Universität Bochum have developed a new method of observing the chemical reactions of individual silver nanoparticles, which only measure a thousandth of the thickness of a human hair, in real time. The particles are used in medicine, food and sports items because they have an antibacterial and anti-inflammatory effect. However, how they react and degrade in ecological and biological systems is so far barely understood. The team in the Research Group for Electrochemistry and Nanoscale Materials showed that the nanoparticles transform into poorly soluble silver chloride particles under certain conditions. The group led by Prof Dr Kristina Tschulik reports on the results in the Journal of the American Chemical Society from July 11, 2018.
Even under well-defined laboratory conditions, current research has yielded different, sometimes contradictory, results on the reaction of silver nanoparticles. “In every batch of nanoparticles, the individual properties of the particles, such as size and shape, vary,” says Kristina Tschulik, a member of the Cluster of Excellence Ruhr Explores Solvation. “With previous procedures, a myriad of particles was generally investigated at the same time, meaning that the effects of these variations could not be recorded. Or the measurements took place in a high vacuum, not under natural conditions in an aqueous solution.”
The team led by Kristina Tschulik thus developed a method that enables individual silver particles to be investigated in a natural environment. “Our aim is to be able to record the reactivity of individual particles,” explains the researcher. This requires a combination of electrochemical and spectroscopic methods. With optical and hyperspectral dark-field microscopy, the group was able to observe individual nanoparticles as visible and coloured pixels. Using the change in the colour of the pixels, or more precisely their spectral information, the researchers were able to follow what was happening in an electrochemical experiment in real time.
Degradation of the particles slowed down
In the experiment, the team replicated the oxidation of silver in the presence of chloride ions, which often takes place in ecological and biological systems. “Until now, it was generally assumed that the silver particles dissolve in the form of silver ions,” describes Kristina Tschulik. However, poorly soluble silver chloride was formed in the experiment – even if only a few chloride ions were present in the solution.
“This extends the lifespan of the nanoparticles to an extreme extent and their breakdown is slowed down in an unexpectedly drastic manner,” summarises Tschulik. “This is equally important for bodies of water and for living beings because this mechanism could cause the heavy metal silver to accumulate locally, which can be toxic for many organisms.”
Further development planned
The Bochum-based group now wants to further improve its technology for analysing individual nanoparticles in order to better understand the ageing mechanisms of such particles. The researchers thus want to obtain more information about the biocompatibility of the silver particles and the lifespan and ageing of catalytically active nanoparticles in the future.
It seems to be to my week for being a day late. Here’s my Valentine Day (February 14, 2019) celebration posting. I’ve got two frog stories, news of a dating app for animals, and a bonus (not a frog story) at the end.
For the last few years I’ve been getting stories about new frog species in Central and South America. This one marks a change of geography. From a February 12, 2019 news item on ScienceDaily,
A new species of puddle frog (order: Anura, family: Phynobatrachidae, genus: Phrynobatrachus), has just been discovered at the unexplored and isolated Bibita Mountain in southwestern Ethiopia. The research team named the new species Phrynobatrachus bibita sp. nov., or Bibita Mountain dwarf puddle frog, inspired by its home.
In summer 2018, NYU Abu Dhabi Postdoctoral Associates Sandra Goutte and Jacobo Reyes-Velasco explored an isolated mountain in southwestern Ethiopia where some of the last primary forest of the country remains. Bibita Mountain was under the radars of the team for several years due to its isolation and because no other zoologist had ever explored it before
“Untouched, isolated, and unexplored”
“It had all the elements to spike our interest,” says Dr. Reyes-Velasco, who initiated the exploration of the mountain. “We tried to reach Bibita in a previous expedition in 2016 without success. Last summer, we used a different route that brought us to higher elevation,” he added.
Their paper, published in ZooKeys journal, reports that the new, tiny frog, 17 mm for males and 20 mm for females, is unique among Ethiopian puddle frogs. Among other morphological features, a slender body with long legs, elongated fingers and toes, and a golden coloration, set this frog apart from its closest relatives. “When we looked at the frogs, it was obvious that we had found a new species, they look so different from any Ethiopian species we had ever seen before!” explains Dr. Goutte.
Back in NYU Abu Dhabi, the research team sequenced tissue samples from the new species and discovered that Phrynobatrachus bibita sp. nov. is genetically different from any frog species in the region.
“The discovery of such a genetically distinct species in only a couple of days in this mountain is the perfect demonstration of how important it is to assess the biodiversity of this type of places. The Bibita Mountain probably has many more unknown species that await our discovery; it is essential for biologists to discover them in order to protect them and their habitat properly,” explains NYU Abu Dhabi Program Head of Biology and the paper’s lead researcher Stéphane Boissinot, who has been working on Ethiopian frogs since 2010.
About NYU Abu Dhabi
NYU Abu Dhabi is the first comprehensive liberal arts and science campus in the Middle East to be operated abroad by a major American research university. NYU Abu Dhabi has integrated a highly-selective liberal arts, engineering and science curriculum with a world center for advanced research and scholarship enabling its students to succeed in an increasingly interdependent world and advance cooperation and progress on humanity’s shared challenges. NYU Abu Dhabi’s high-achieving students have come from 120 nations and speak over 120 languages. Together, NYU’s campuses in New York, Abu Dhabi, and Shanghai form the backbone of a unique global university, giving faculty and students opportunities to experience varied learning environments and immersion in other cultures at one or more of the numerous study-abroad sites NYU maintains on six continents.
These are very small frogs with males growing to about 17mm, or 0.6 inches and females growing up to 20mm, or 0.8 inches.
First, here’s some background information. I wrote about Romeo, the Sehuencas water frog last year in my July 26,2018 posting: ‘Emergency!!! Lonely heart looking for love: Female. Stocky build. Height of 2 – 3 inches,’
“(Matias Careaga) [downloaded from https://www.smithsonianmag.com/smart-news/scientists-made-matchcom-profile-bolivias-loneliest-frog-180968140/]That is a very soulful look. How could any female Sehuencas water frog resist it? Sadly, that’s the problem. They havn’t found any female Sehuencas water frogs yet.
It’s not for want of trying. Back in February 2018 worldwide interest was raised when scientists as the Cochabamba Natural History Museum (Bolivia) started a campaign to find a mate and raise funds for a search. …”
Romeo was made for love, as all animals are. But for years he couldn’t find it. It’s not like there was anything wrong with Romeo. Sure he’s shy, eats worms, lacks eyelashes and is 10 years old, at least. But he’s aged well, and he’s kind of a special guy.
Romeo is a Sehuencas water frog, once thought to be the last one on the planet. He lives alone in a tank at the Museo de Historia Natural Alcide d’Orbigny in Bolivia.
A deadly fungal disease threatens his species and other frogs in the cloud forest where he was found a decade ago. When researchers brought him to the museum’s conservation breeding center, they expected to find another frog he could mate with and save the species from extinction. But they searched stream after stream, and nothing.
He needed a match before he croaked, so last year conservation groups partnered to create a Match.com profile for him. People related to Romeo’s romantic struggles, and on Valentine’s Day last year, the company and his fans raised $25,000 to send an expedition team out to the cloud forest to find his Juliet.
And for all the lonely lovers searching for that special someone, Teresa Camacho Badani, a herpetologist at the museum who found Juliet [emphasis mine], has another message: “Never give up searching for that happy ending.”
Here is Juliet,
If you don’t have much time, Klein’s article goes on to offer an engaging look at the successful expedition’s trip. For anyone who might like to keep digging, I have more. First, a video,
Global Wildlife Conservation has a January 15, 2019 posting (where I found the video) by Lindsay Renick Mayer which offers more detail via a Q&A (questions and answers) interview with Teresa Camacho Badani, the herpetologist who found Juliet. Here’s an excerpt to whet your appetite,
Q. What was the habitat like where you found the frogs? A. It is a well-preserved cloud forest where the climate is rainy, foggy and humid because of the streams, which are less than a meter in width with currents that form waterfalls, and ponds that are not very deep. Other biologists had looked here for the frog, even last year, with no success. We selected this spot after months of doing an analysis of historic records of where the species had originally been found—most of which have since been destroyed. Field evidence suggests that the frog is very, very rare and there are likely few left in the wild. And because it was clear that the threats to the frogs were so close in proximity—the streams around us were empty—we decided to rescue all five of these individuals for the conservation breeding program.
Q. What happens to these five frogs next? A. Right now they’re in quarantine at the K’ayara Center at the museum, where they are starting to acclimate to their new home. We’ll make sure they have the same quality of water and temperature as in the field. After they are used to their new habitat and they’re eating well, we will give them a preventive treatment for the deadly infectious disease, chytridiomycosis. We do not want Romeo to get sick on his first date! [emphasis mine] When the treatment is finished, we can finally give Romeo what we hope is a romantic encounter with his Juliet.
“It is an incredible feeling to know that thanks to everyone who believes in true love and donated for Valentine’s Day last year , we have already found a mate for Romeo and can establish a conservation breeding program with more than a single pair,” said Teresa Camacho Badani, the museum’s chief of herpetology and the expedition leader. “Now the real work begins—we know how to successfully care for this species in captivity, but now we will learn about its reproduction, while also getting back into the field to better understand if any more frogs may be left and if so, how many, where they are, and more about the threats they face. With this knowledge we can develop strategies to mitigate the threats to the species’ habitat, while working on a long-term plan to return Romeo’s future babies to their wild home, preventing the extinction of the Sehuencas water frog.”
These are the first Sehuencas water frogs that biologists have seen in the wild in a decade, though over the years (including in 2018) scientists had searched this area for the species with no success. This team, which had done careful analysis ahead of time to determine the best places to look for the frogs, still didn’t encounter the Sehuencas water frog until after failing for a few long days to find any frogs of any species in what seemed like perfect amphibian habitat—a well-protected stream in the Bolivian wilderness. …
Romeo became an international celebrity on Valentine’s Day in 2018 with a dating profile on Match, the world’s largest dating company. Now he is a powerful flagship for conservation in Bolivia. These expeditions were made possible by the individuals in more than 32 countries who made donations last year that were matched by Match for a total of $25,000. “Our entire Match community rallied behind Romeo and his search for love last year,” said Hesam Hosseini, CEO of Match. “We’re thrilled with this outcome for Romeo and his species. He now joins the list of millions of ‘members’ who have found meaningful relationships on Match.”
Do check out Romeo’s Twitter feed. You may find something appealing such as this link to a February 14, 2019 news item on the News for Kids blog which discusses dating apps for animals. Romeo’s story is recounted and then there’s this about an app for farm animals,
In the United Kingdom a company called Hectare has come up with “Tudder” – an unusual way for farm animals to find partners.
Tudder is a “dating” app which allows farmers to easily find mates for their cows and bulls. Farmers can post pictures of their animals to the app, and swipe through pictures and descriptions to see other animals in need of a mate.
Tudder may sound a bit silly, but farmers say it saves them time and money because they don’t have to travel with their animals to find them a mate.
Funny thing is, I was wondering about Romeo just the other day and so, thanks is owed to the Beakerhead Twitter feed where I stumbled across the Romeo update. Thank you
I have two furry bonuses. First, the cats,
The excerpt is from the CBC (Canadian Broadcasting Corporation’s February 15, 2019 article by Devon Murphy about ‘Catwalk: Tales From The Cat Show Circuit’, a CBC documentary as is this excerpt,
Her hair is perfect, freshly washed, blow-dried, and combed, and her eyes are shining. She’s ready to compete and is calm as the judge approaches. Then, he takes a feather and twitches it in front of her face, and she turns on her back, furry stomach exposed, and bats at it with her immaculate paws.
That dog knows she’s a champion, whether or not she’s the fastest on the course. On February 10, 2019, she was a furry streak of lightning … in the 8″ division of the Westminster Dog Show’s Masters Agility Championship competition. Belated Happy Valentine’s Day.
Caption: A magnified photograph of a glass Whispering Gallery Resonator. The bubble is extremely small, less than the width of a human hair. Credit: OIST (Okinawa Institute of Science and Technology Graduate University)
It was the reference to a whispering gallery which attracted my attention; a July 11, 2018 news item on Nanowerk is where I found it,
Technology created by researchers at the Okinawa Institute of Science and Technology Graduate University (OIST) [Japan] is literally shedding light on some of the smallest particles to detect their presence – and it’s made from tiny glass bubbles.
The technology has its roots in a peculiar physical phenomenon known as the “whispering gallery,” described by physicist Lord Rayleigh (John William Strutt) in 1878 and named after an acoustic effect inside the dome of St Paul’s Cathedral in London. Whispers made at one side of the circular gallery could be heard clearly at the opposite side. It happens because sound waves travel along the walls of the dome to the other side, and this effect can be replicated by light in a tiny glass sphere just a hair’s breadth wide called a Whispering Gallery Resonator (WGR).
When light is shined into the sphere, it bounces around and around the inner surface, creating an optical carousel. Photons bouncing along the interior of the tiny sphere can end up travelling for long distances, sometimes as far as 100 meters. But each time a photon bounces off the sphere’s surface, a small amount of light escapes. This leaking light creates a sort of aura around the sphere, known as an evanescent light field. When nanoparticles come within range of this field, they distort its wavelength, effectively changing its color. Monitoring these color changes allows scientists to use the WGRs as a sensor; previous research groups have used them to detect individual virus particles in solution, for example. But at OIST’s Light-Matter Interactions Unit, scientists saw they could improve on previous work and create even more sensitive designs. The study is published in Optica.
Today, Dr. Jonathan Ward is using WGRs to detect minute particles more efficiently than ever before. The WGRs they have made are hollow glass bubbles rather than balls, explains Dr. Ward. “We heated a small glass tube with a laser and had air blown down it – it’s a lot like traditional glass blowing”. Blowing the air down the heated glass tube creates a spherical chamber that can support the sensitive light field. The most noticeable difference between a blown glass ornament and these precision instruments is the scale: the glass bubbles can be as small as 100 microns- a fraction of a millimeter in width. Their size makes them fragile to handle, but also malleable.
Working from theoretical models, Dr. Ward showed that they could increase the size of the light field by using a thin spherical shell (a bubble, in other words) instead of a solid sphere. A bigger field would increase the range in which particles can be detected, increasing the efficacy of the sensor. “We knew we had the techniques and the materials to fabricate the resonator”, said Dr. Ward. “Next we had to demonstrate that it could outperform the current types used for particle detection”.
To prove their concept, the team came up with a relatively simple test. The new bubble design was filled with a liquid solution containing tiny particles of polystyrene, and light was shined along a glass filament to generate a light field in its liquid interior. As particles passed within range of the light field, they produced noticeable shifts in the wavelength that were much more pronounced than those seen with a standard spherical WGR.
With a more effective tool now at their disposal, the next challenge for the team is to find applications for it. Learning what changes different materials make to the light field would allow Dr Ward to identify and target them, and even control their activity.
Despite their fragility, these new versions of WGRs are easy to manufacture and can be safely transported in custom made cases. That means these sensors could be used in a wide verity of fields, such as testing for toxic molecules in water to detect pollution, or detecting blood borne viruses in extremely rural areas where healthcare may be limited.
For Dr. Ward however, there’s always room from improvement: “We’re always pushing to get even more sensitivity and find the smallest particle this sensor can detect. We want to push our detection to the physical limits.”
It’s been over seven years since I first started writing about Duke University’s Center for the Environmental Implications of Nanotechnology and mesocosms (miniature ecosystems) and the impact that nanoparticles may have on plants and water (see August 11, 2011 posting). Since then, their focus has shifted from silver nanoparticles and their impact on plants, fish, bacteria, etc. to a more general examination of metallic nanoparticles and water. A June 25, 2018 news item on ScienceDaily announces some of their latest work,
The last 10 years have seen a surge in the use of tiny substances called nanomaterials in agrochemicals like pesticides and fungicides. The idea is to provide more disease protection and better yields for crops, while decreasing the amount of toxins sprayed on agricultural fields.
But when combined with nutrient runoff from fertilized cropland and manure-filled pastures, these “nanopesticides” could also mean more toxic algae outbreaks for nearby streams, lakes and wetlands, a new study finds.
Too small to see with all but the most powerful microscopes, engineered nanomaterials are substances manufactured to be less than 100 nanometers in diameter, many times smaller than a hair’s breadth.
Their nano-scale gives them different chemical and physical properties from their bulk counterparts, including more surface area for reactions and interactions.
Those interactions could intensify harmful algal blooms in wetlands, according to experiments led by Marie Simonin, a postdoctoral associate with biology professor Emily Bernhardt at Duke University.
Carbon nanotubes and teeny tiny particles of silver, titanium dioxide and other metals are already added to hundreds of commercial products to make everything from faster, lighter electronics, self-cleaning fabrics, and smarter food packaging that can monitor food for spoilage. They are also used on farms for slow- or controlled-release plant fertilizers and pesticides and more targeted delivery, and because they are effective at lower doses than conventional products.
These and other applications have generated tremendous interest and investment in nanomaterials. However the potential risks to human health or the environment aren’t fully understood, Simonin said.
Most of the 260,000 to 309,000 metric tons of nanomaterials produced worldwide each year are eventually disposed in landfills, according to a previous study. But of the remainder, up to 80,400 metric tons per year are released into soils, and up to 29,200 metric tons end up in natural bodies of water.
“And these emerging contaminants don’t end up in water bodies alone,” Simonin said. “They probably co-occur with nutrient runoff. There are likely multiple stressors interacting.”
Algae outbreaks already plague polluted waters worldwide, said Steven Anderson, a research analyst in the Bernhardt Lab at Duke and one of the authors of the research.
Nitrogen and phosphorous pollution makes its way into wetlands and waterways in the form of agricultural runoff and untreated wastewater. The excessive nutrients cause algae to grow out of control, creating a thick mat of green scum or slime on the surface of the water that blocks sunlight from reaching other plants.
These nutrient-fueled “blooms” eventually reduce oxygen levels to the point where fish and other organisms can’t survive, creating dead zones in the water. Some algal blooms also release toxins that can make pets and people who swallow them sick.
To find out how the combined effects of nutrient runoff and nanoparticle contamination would affect this process, called eutrophication, the researchers set up 18 separate 250-liter tanks with sandy sloped bottoms to mimic small wetlands.
Each open-air tank was filled with water, soil and a variety of wetland plants and animals such as waterweed and mosquitofish.
Over the course of the nine-month experiment, some tanks got a weekly dose of algae-promoting nitrates and phosphates like those found in fertilizers, some tanks got nanoparticles — either copper or gold — and some tanks got both.
Along the way the researchers monitored water chemistry, plant and algae growth and metabolism, and nanoparticle accumulation in plant tissues.
“The results were surprising,” Simonin said. The nanoparticles had tiny effects individually, but when added together with nutrients, even low concentrations of gold and copper nanoparticles used in fungicides and other products turned the once-clear water a murky pea soup color, its surface covered with bright green smelly mats of floating algae.
Over the course of the experiment, big algal blooms were more than three times more frequent and more persistent in tanks where nanoparticles and nutrients were added together than where nutrients were added alone. The algae overgrowths also reduced dissolved oxygen in the water.
It’s not clear yet how nanoparticle exposure shifts the delicate balance between plants and algae as they compete for nutrients and other resources. But the results suggest that nanoparticles and other “metal-based synthetic chemicals may be playing an under-appreciated role in the global trends of increasing eutrophication,” the researchers said.
It seems to me that I stumbled across quite a few carbon nanotube (CNT) stories in 2018. This one comes courtesy of Japan (from a June 28, 2018 news item on Nanowerk),
Researchers at Tokyo Tech have developed flexible terahertz imagers based on chemically “tunable” carbon nanotube materials. The findings expand the scope of terahertz applications to include wrap-around, wearable technologies as well as large-area photonic devices.
Here’s a peek at an imager,
Figure 1. The CNT-based flexible THz imager (a) Resting on a fingertip, the CNT THz imager can easily wrap around curved surfaces. (b) Just by inserting and rotating a flexible THz imager attached to the fingertip, damage to a pipe was clearly detected. Courtesy Tokyo Tech
Carbon nanotubes (CNTs) are beginning to take the electronics world by storm, and now their use in terahertz (THz) technologies has taken a big step forward.
Due to their excellent conductivity and unique physical properties, CNTs are an attractive option for next-generation electronic devices. One of the most promising developments is their application in THz devices. Increasingly, THz imagers are emerging as a safe and viable alternative to conventional imaging systems across a wide range of applications, from airport security, food inspection and art authentication to medical and environmental sensing technologies.
The demand for THz detectors that can deliver real-time imaging for a broad range of industrial applications has spurred research into low-cost, flexible THz imaging systems. Yukio Kawano of the Laboratory for Future Interdisciplinary Research of Science and Technology, Tokyo Tech, is a world-renowned expert in this field. In 2016, for example, he announced the development of wearable terahertz technologies based on multiarrayed carbon nanotubes.
Kawano and his team have since been investigating THz detection performance for various types of CNT materials, in recognition of the fact that there is plenty of room for improvement to meet the needs of industrial-scale applications.
Now, they report the development of flexible THz imagers for CNT films that can be fine-tuned to maximize THz detector performance.
Publishing their findings in ACS Applied Nano Materials, the new THz imagers are based on chemically adjustable semiconducting CNT films.
By making use of a technology known as ionic liquid gating1, the researchers demonstrated that they could obtain a high degree of control over key factors related to THz detector performance for a CNT film with a thickness of 30 micrometers. This level of thickness was important to ensure that the imagers would maintain their free-standing shape and flexibility, as shown in Figure 1 [see above].
“Additionally,” the team says, “we developed gate-free Fermi-level2 tuning based on variable-concentration dopant solutions and fabricated a Fermi-level-tuned p-n junction3 CNT THz imager.” In experiments using this new type of imager, the researchers achieved successful visualization of a metal paper clip inside a standard envelope (see Figure 2.)
A measure of the electrochemical potential for electrons, which is important for determining the electrical and thermal properties of solids. The term is named after the Italian–American physicist Enrico Fermi.
I received this January 4, 2018 announcement from the Metcalf Institute at the University of Rhode Island (URI; US) in my email this morning. In other words, this is fresh off the email,
Get Science Tools to Break Stories About Global Change & Water Resources
Apply for Metcalf Institute’s Career-Changing Science Immersion Fellowship tuition, room and board, and travel support included
Global Change Impacts and Water According to the United Nations, water is the “primary medium through which we will feel the effects of climate change” and water scarcity alone affects nearly half the global population.
you have the science tools to make the connection between shrinking
water supplies, water quality, food production and climate change? Are
you looking for story ideas to convey these global change impacts to
your news audience? Would you like to build your confidence in
discerning the credibility of scientific sources?
Call for Applications The University of Rhode Island’s Metcalf Institute is accepting applications for its 21th Annual Science Immersion Workshop for Journalists, June 2-7, 2019. Ten journalists will be awarded Workshop fellowships, which include tuition, room and board, and travel support, thanks to the generosity of private donors and Metcalf Institute’s endowment. Two of the ten slots will be awarded to journalists based outside of the U.S.
About the Workshop
The Metcalf Institute Annual Science Immersion Workshop provides
professional journalists with hands-on experience in field and
laboratory science with expertise from leading scientists and
policymakers who are working to project the impacts of global change,
identify adaptation measures, and investigate the most effective ways to
communicate these challenges. The workshop will address water resource
and climate change topics of global significance while focusing on local
and regional case studies in and around Narragansett Bay, among the
world’s best studied estuaries. Held at the URI Graduate School of
Oceanography, one of the nation’s premier oceanographic research
institutions, the Metcalf Workshop provides an intense week of learning
in the field, classroom and lecture hall.
Metcalf Fellows will:
Receive a comprehensive overview of climate science and global change
Gain a deeper understanding of how scientists conduct research and handle scientific uncertainty
Develop the skills and confidence to interpret and translate the language of scientific journals for news audiences
Build confidence in their abilities to discern the credibility of scientific sources
Board a research vessel to study the impacts of rising water temperatures and ocean acidification on coastal ecosystems
Explore the study of “emerging contaminants” such as PFAS that affect freshwater and marine ecosystems and public health
wetlands, shorelines, and coastal communities to better understand
adaptive management efforts and solutions in response to sea level rise
and coastal storms
Discover new ways to write about global change to build audience understanding and engagement
Cultivate new sources by interacting with leading researchers and policy experts in an informal, off-deadline atmosphere
Network and develop lasting relationships with journalists from around the globe
Metcalf Institute has helped nearly 900 journalists cover the
environment with greater accuracy and nuance since its first program in
1999. Metcalf alumni represent all media types and a wide variety of
large and small news organizations ranging from local and regional
newspapers and broadcast outlets to online and national/international
outlets such as the Los Angeles Times, Reuters, National Geographic,
China Global Television Network, Marketplace, Politico and PBS NewsHour.
Metcalf Institute alumni hail from the U.S. and around the world,
including Pakistan, Brazil, Nigeria, Israel, Egypt, Italy, South Africa,
“This experience has changed my entire outlook on covering the environment and climate science. I may have only been in Rhode Island for a week, but the tools I gained during my Metcalf fellowship will stay with me for the entirety of my career.” Tony Briscoe, Chicago Tribune reporter and 2018 Annual Workshop alumnus.
“Metcalf has greatly enhanced my ability to break down complex issues for my audience. Not only am I headed back home with a bunch of great story ideas, but the ability to set them against an international background and draw broader connections between issues in my region and the rest of the world.” Tegan Wendland, New Orleans Public Radio interim news director, lead coastal reporter, and 2017 Annual Workshop alumna.
Note for journalists applying from outside of the U.S. While the Workshop addresses environmental topics of global significance, it focuses on U.S. case studies and a U.S. perspective on environmental policies. Metcalf Institute receives applications from journalists worldwide. However, due to funding limitations, only two of the ten fellowships will be awarded to journalists based outside of the U.S.
Eligibility The Fellowship is designed for early- to mid-career, full-time journalists from all media who are looking to start or expand their coverage of the environment. Applicants must demonstrate a clear need for scientific training in topics relating to global change in coastal environments, specifically related to climate change and water resources. The fellowship includes room, board, tuition, and travel reimbursement paid after the program in the amount of up to US$500 for U.S.-based journalists and up to US$1,000 for journalists based outside of the U.S. Journalists applying from outside the U.S. must provide written assurance that they have full travel funds and can obtain the appropriate visa. Applications for the 2019 Annual Science Immersion Workshop for Journalists must be submitted by February 18, 2019.
About Metcalf Institute Metcalf Institute is a global leader in environmental science training for journalists and communication training for scientists and other science communicators, as well as provider of science resources for journalists and free public programs and webinars on environmental topics. Metcalf Institute was established at the University of Rhode Island’s Graduate School of Oceanography in 1997 with funding from three media foundations: the Belo Corporation, the Providence Journal Charitable Foundation and the Philip L. Graham Fund, with additional support from the Telaka Foundation. In 2017, the Institute joined the URI College of the Environment and Life Sciences.
Metcalf Institute Funding Metcalf programming is underwritten by federal and foundation grants, as well as donations from individuals and an endowment managed by the University of Rhode Island Foundation.
The breakthrough material reduces a noise level by 100% more efficient comparing to standard analogs, cutting the level of noise transmission by 20-22 dB. The new foam reacts to sound waves not only of high but also of low frequencies, which can damage human health. A young scientist from the Far Eastern Federal University (FEFU) took part in the development.
Alexey Zavjalov, postdoc, researcher at the Academic Department of Nuclear Technologies School of Natural Science, FEFU, worked as a part of the international team of Russian and South Korean scientists under professor S.P. Bardakhanov. Alexey’s research performance led to the creation of nanofoam – the new noise-absorbing composite material. The results of the work are published in ‘Applied Acoustics’.
‘The problem of noise is the problem of modern technogenic civilization. In South Korea, cities are equipped with round-the-clock working stationary and mobile networks for noise levels monitoring. The urbanization level of such territorially small countries as South Korea is much higher than in Russia. However, in our country this problem is still crucial for big cities,’ – explained Alexey Zavjalov. – ‘The development of new noise-absorbing materials is especially interesting for the automotive industry. Modern people spend a lot of time driving cars and the noise level inside the vehicles’ directly determines the quality of life. For East Asian countries, the issue of noise control is relevant for high-speed rail lines.’ Porous materials are excellent sound absorbers but their noise-absorbing properties can be significantly enhanced by nanoporous grit injected into the foam structure and formed internal channels in it. Alexey Zavjalov has developed approaches for saturation of macroporous foam material with nanoporous grit.
HARMFULNESS OF THE LOW FREQUENCIES NOISES.
Along with the rapid development of nanotechnology, there have been many attempts to mix nano- and microsized materials to create a modified material with enhanced strength, elastic, dynamical and vibrational properties. The acoustic parameters of such materials could not be fundamentally enhanced thus far.
Foam materials are most often used for soundproofing purposes. They provide the proper quality at a reasonable cost, but until today have been effective against high-frequency noise only. At the same time, low frequencies can be much more harmful to human health.
Infra- and low-frequency vibrations and noise (less than 0.4 kHz) are most harmful and dangerous for human health and life. Especially unfavorable is their long-lasting impact, since leads to serious diseases and pathologies. Complaints on such oppressions exceed 35% of the sum total of complaints on harmful environmental conditions.
The foam material, developed by Russian and Korean scientists, demonstrated promising results at medium frequencies and, therefore, more specialized low-frequency noise tests are needed.
CHEAPER AND EASIER FOR APPLICATION THAN AEROGEL.
The improved acoustic characteristics of the newest hybrid nanofoam were obtained by additional impregnation of the standard off-the-shelf sound-absorbing foam with porous granules of silica and magnetite nanoparticles. The porous foam was immersed in nanopowder suspensions in the liquid, subjected to ultrasonic treatment and dried.
The nanoparticles granules formed in the result can be compared structurally to a widely known class of materials – aerogel. It has not only excellent thermal insulation properties but also has a good noise-proof. However, aerogels are quite expensive and complex when used in structures. The new material, created according to the scheme developed by the FEFU researcher, is structurally similar to aerogel but is free of such shortcomings as a high price and engineering problems.
The mechanism of sound absorption of a new foam is based on the fact that its sound-absorbing surface is significantly scaled due to the presence of a large number of nanopores in the particles injected, as well as the location of these particles in the foam matrix in the form of distinct channels. Nanoparticles dissipate the energy of a sound wave transforming it into heat. The soundproof properties of the material increase.
Scientists found out that the composite structure is most effective for noise reduction. Thin layers of foam impregnated with nanoparticles are connected to each other in a “sandwich”-construction. This design significantly improves the soundproof properties of the resulting material. The outcome of the study also suggests that the more foamy material is impregnated with nanoparticles, the better it’s sound absorption is.
‘In some approximation, any material can be represented as a network of weights connected by springs. Such a mechanical system always has its own frequency bands, in which the oscillations propagate in the system relatively freely. There are also forbidden frequency bands in which the oscillations rapidly fade out in the system. To effectively extinguish the transmission of oscillations, including sound waves, the materials should be alternated in such a way that the fluctuations that propagate freely in the first material would be in the forbidden band for the second layer,’- commented Alexey Zavjalov. – ‘Of course, for our foam material, this idealization is too crude. However, it allows us to clearly illustrate the fundamentally conditioned necessity of creating a “sandwich” structure.’
The study showed the effectiveness of the method of foams impregnation with nanosilica or nanomagnetite, which form granules up to several hundred micrometers (in accordance with the pore sizes of the modified foam material) and having pores about 15 nm. This small addition provided a more complex and branched 3D network of nanochannels which led to an additional absorption of noise energy.
Due to the method used, the noise absorption efficiency was achieved in the range of 2.0-6.3 kHz and at lower frequencies 0.5-1.6 kHz. The degree of absorption was increased by 60-100% and the sound transmission was reduced by 20-22 dB, regardless of the type of nanofiller.
‘There is room to further improve the sound absorbing properties of the new material for medium and low frequencies using the” active control” strategy’. – Alexey Zavjalov comments on the plans for further development of such an important scientific topic. – ‘First of all, this refers to the materials obtained by using a magnetite nanopowder. Active noise protection systems have long been used in the world. The main idea is to detect the noise acoustic fields “online” and to generate sound waves in antiphase by means of loudspeakers. That allows achieving a significant reduction of noise in a given area. Concerning the nanofoam, it’s proposed to adapt this approach and to actively exert on a material saturated with granules of magnetite nanoparticles by magnetic fields. This will achieve even better noise reduction.’
I have heard of phytomining in soil remediation efforts (reclaiming nanoscale metals in plants near mining operations; you can find a more detailed definition here at Wiktionary) but, in this case, scientists have discovered plant tissues with nanoscale gold in an area which has no known deposits of gold. From a June 14, 2018 news item on Nanowwerk (Note: A link has been removed),
Plants containing the element gold are already widely known. The flowering perennial plant alfafa, for example, has been cultivated by scientists to contain pure gold in its plant tissue. Now researchers from the Sun Yat-sen University in China have identified and investigated the characteristics of gold nanoparticles in two plant species growing in their natural environments.
The study, led by Xiaoen Luo, is published in Environmental Chemistry Letters (“Discovery of nano-sized gold particles in natural plant tissues”) and has implications for the way gold nanoparticles are produced and absorbed from the environment.
Xiaoen Luo and her colleagues investigated the perennial shrub B. nivea and the annual or biennial weed Erigeron Canadensis. The researchers collected and prepared samples of both plants so that they could be examined using the specialist analytical tool called field-emission transmission electron microscope (TEM).
Gold-bearing nanoparticles – tiny gold particles fused with another element such as oxygen or copper – were found in both types of plant. In E. Canadensis these particles were around 20-50 nm in diameter and had an irregular form. The gold-bearing particles in B. nivea were circular, elliptical or bone-rod shaped with smooth edges and were 5-15 nm.
“The abundance of gold in the crust is very low and there was no metal deposit in the sampling area so we speculate that the source of these gold nanoparticles is a nearby electroplating plant that uses gold in its operations, “ explains Jianjin Cao who is a co-author of the study.
Most of the characteristics of the nanoparticles matched those of artificial particles rather than naturally occurring nanoparticles, which would support this theory. The researchers believe that the gold-bearing particles were absorbed through the pores of the plants directly, indicating that gold could be accumulated from the soil, water or air.
“Discovering gold-bearing nanoparticles in natural plant tissues is of great significance and allows new possibilities to clean up areas contaminated with nanoparticles, and also to enrich gold nanoparticles using plants,” says Xiaoen Luo.
The researchers plan to further study the migration mechanism, storage locations and growth patterns of gold nanoparticles in plants and also verify the absorbing capacity of different plants for gold nanoparticles in polluted areas.
For anyone who’d like to find out more about electroplating, there’s this January 25, 2018 article by Anne Marie Helmenstine for ThoughtCo.
Chlorociboria Aeruginascens fungus on a tree log. (Image: Oregon State University)
Apparently the pigment derived from the fungi you see in the above picture is used by visual artists and, perhaps soon, will be used by electronics manufacturers. From a June 5, 2018 news item on Nanowerk,
Researchers at Oregon State University are looking at a highly durable organic pigment, used by humans in artwork for hundreds of years, as a promising possibility as a semiconductor material.
Findings suggest it could become a sustainable, low-cost, easily fabricated alternative to silicon in electronic or optoelectronic applications where the high-performance capabilities of silicon aren’t required.
Optoelectronics is technology working with the combined use of light and electronics, such as solar cells, and the pigment being studied is xylindein.
“Xylindein is pretty, but can it also be useful? How much can we squeeze out of it?” said Oregon State University [OSU] physicist Oksana Ostroverkhova. “It functions as an electronic material but not a great one, but there’s optimism we can make it better.”
Xylindien is secreted by two wood-eating fungi in the Chlorociboria genus. Any wood that’s infected by the fungi is stained a blue-green color, and artisans have prized xylindein-affected wood for centuries.
The pigment is so stable that decorative products made half a millennium ago still exhibit its distinctive hue. It holds up against prolonged exposure to heat, ultraviolet light and electrical stress.
“If we can learn the secret for why those fungi-produced pigments are so stable, we could solve a problem that exists with organic electronics,” Ostroverkhova said. “Also, many organic electronic materials are too expensive to produce, so we’re looking to do something inexpensively in an ecologically friendly way that’s good for the economy.”
With current fabrication techniques, xylindein tends to form non-uniform films with a porous, irregular, “rocky” structure.
“There’s a lot of performance variation,” she said. “You can tinker with it in the lab, but you can’t really make a technologically relevant device out of it on a large scale. But we found a way to make it more easily processed and to get a decent film quality.”
Ostroverkhova and collaborators in OSU’s colleges of Science and Forestry blended xylindein with a transparent, non-conductive polymer, poly(methyl methacrylate), abbreviated to PMMA and sometimes known as acrylic glass. They drop-cast solutions both of pristine xylindein and a xlyindein-PMMA blend onto electrodes on a glass substrate for testing.
They found the non-conducting polymer greatly improved the film structure without a detrimental effect on xylindein’s electrical properties. And the blended films actually showed better photosensitivity.
“Exactly why that happened, and its potential value in solar cells, is something we’ll be investigating in future research,” Ostroverkhova said. “We’ll also look into replacing the polymer with a natural product – something sustainable made from cellulose. We could grow the pigment from the cellulose and be able to make a device that’s all ready to go.
“Xylindein will never beat silicon, but for many applications, it doesn’t need to beat silicon,” she said. “It could work well for depositing onto large, flexible substrates, like for making wearable electronics.”
This research, whose findings were recently published in MRS Advances, represents the first use of a fungus-produced material in a thin-film electrical device.
“And there are a lot more of the materials,” Ostroverkhova said. “This is just first one we’ve explored. It could be the beginning of a whole new class of organic electronic materials.”
I’m starting to have a collection of postings related to plastic nanoparticles and aquatic life (I have a listing below). The latest originates in Singapore (from a May 31, 2018 news item on ScienceDaily),
Plastic nanoparticles — these are tiny pieces of plastic less than 1 micrometre in size — could potentially contaminate food chains, and ultimately affect human health, according to a recent study by scientists from the National University of Singapore (NUS). They discovered that nanoplastics are easily ingested by marine organisms, and they accumulate in the organisms over time, with a risk of being transferred up the food chain, threatening food safety and posing health risks.
Ocean plastic pollution is a huge and growing global problem. It is estimated that the oceans may already contain over 150 million tonnes of plastic, and each year, about eight million tonnes of plastic will end up in the ocean. Plastics do not degrade easily. In the marine environment, plastics are usually broken down into smaller pieces by the sun, waves, wind and microbial action. These micro- and nanoplastic particles in the water may be ingested by filter-feeding marine organisms such as barnacles, tube worms and sea-squirts.
Using the acorn barnacle Amphibalanus amphitrite as a model organism, the NUS research team demonstrated for the first time that nanoplastics consumed during the larval stage are retained and accumulated inside the barnacle larvae until they reach adulthood.
“We opted to study acorn barnacles as their short life cycle and transparent bodies made it easy to track and visualise the movement of nanoplastics in their bodies within a short span of time,” said Mr Samarth Bhargava, a PhD student from the Department of Chemistry at the NUS Faculty of Science, who is the first author of the research paper.
“Barnacles can be found in all of the world’s oceans. This accumulation of nanoplastics within the barnacles is of concern. Further work is needed to better understand how they may contribute to longer term effects on marine ecosystems,” said Dr Serena Teo, Senior Research Fellow from the Tropical Marine Science Institute at NUS, who co-supervised the research.
Studying the fate of nanoplastics in marine organisms
The NUS research team incubated the barnacle larvae in solutions of their regular feed coupled with plastics that are about 200 nanometres in size with green fluorescent tags. The larvae were exposed to two different treatments: ‘acute’ and ‘chronic’.
Under the ‘acute’ treatment, the barnacle larvae were kept for three hours in a solution that contained 25 times more nanoplastics than current estimates of what is present in the oceans. On the other hand, under the ‘chronic’ treatment, the barnacle larvae were exposed to a solution containing low concentrations of nanoplastics for up to four days.
The larvae were subsequently filtered from the solution, and examined under the microscope. The distribution and movement of the nanoplastics were monitored by examining the fluorescence from the particles present within the larvae over time.
“Our results showed that after exposing the barnacle larvae to nanoplastics in both treatments, the larvae had not only ingested the plastic particles, but the tiny particles were found to be distributed throughout the bodies of the larvae,” said Ms Serina Lee from the Tropical Marine Science Institute at NUS, who is the second author of the paper.
Even though the barnacles’ natural waste removal pathways of moulting and excretion resulted in some removal of the nanoplastics, the team detected the continued presence of nanoplastics inside the barnacles throughout their growth until they reached adulthood.
“Barnacles may be at the lower levels of the food chain, but what they consume will be transferred to the organisms that eat them. In addition, plastics are capable of absorbing pollutants and chemicals from the water. These toxins may be transferred to the organisms if the particles of plastics are consumed, and can cause further damage to marine ecosystems and human health,” said marine biologist Dr Neo Mei Lin from the Tropical Marine Science Institute at NUS, who is one of the authors of the paper.
The team’s research findings were first published online in the journal ACS Sustainable Chemistry & Engineering in March 2018. The study was funded under the Marine Science Research and Development Programme of the National Research Foundation Singapore.
The NUS research team seeks to further their understanding of the translocation of nanoparticles within the marine organisms and potential pathways of transfer in the marine ecosystem.
“The life span and fate of plastic waste materials in marine environment is a big concern at the moment owing to the large amounts of plastic waste and its potential impact on marine ecosystem and food security around the world. The team would like to explore such topics in the near future and possibly to come up with pathways to address such problems,” explained Associate Professor Suresh Valiyaveettil from the Department of Chemistry at the NUS Faculty of Science, who co-supervised the research.
The team is currently examining how nanoplastics affect other invertebrate model organisms to understand the impact of plastics on marine ecosystems.