Microplastics found in Antarctic ice cores

by Bob Yirka , Phys.org

Credit: CC0 Public Domain

A team of researchers from the University of Tasmania has found evidence of microplastics in ice cores collected off the coast of Antarctica. In their paper published in the journal Marine Pollution Bulletin, the group describes their study of the cores and the plastics they found.


Last year, a team of researchers found examples of microplastics in Arctic ice floes, further evidence of the spread of the pollutants in the world's oceans. In this new effort, the team in Tasmania has found evidence of microplastics in ice cores collected in Antarctica ten years ago.

The cores were collected as part of work dedicated to better understanding the Antarctic—they were taken from sites approximately 2 kilometers from the Antarctic coast and have been in storage at a facility in Hobart, Tasmania, awaiting analysis. The cores were from ice that forms around the coast and thus, unlike pack ice, does not move.

Study of the cores (which were 1.1 meters long and 14 cm wide) revealed 96 particles from 14 kinds of microplastic, with an average of 12 pieces per liter of water—all of the particles were 5 mm or shorter. The most common type was polyethylene, which is used in a wide variety of products. The finding was the first for Antarctic ice—prior studies had found microplastics in water, snow and sediment.

The researchers also noted that the microplastic particles were surrounded by algae, a finding that suggests they may be eaten by krill, which feed on sea ice. And that further suggests that the particles are being consumed by whales when they eat the krill.

The source of the microplastics is not known, though the researchers suggest their size indicates that they are from relatively local sources. The longer microplastics remain in the sea, the smaller they become. They note that the ice cores were taken from the eastern side of the continent, which is visited less often than the west side. They suggest it is likely ice in more highly traveled areas has more microplastic particles in it. They also note that prior studies have shown that microplastics in ice can lead to melting due to heat absorption.


Explore further  Microplastics from ocean fishing can 'hide' in deep sediments

More information: A. Kelly et al. Microplastic contamination in east Antarctic sea ice, Marine Pollution Bulletin (2020). DOI: 10.1016/j.marpolbul.2020.111130

Journal information: Marine Pollution Bulletin



© 2020 Science X Network

New solution to capture microplastics before they enter waterways

by VTT Technical Research Centre of Finland

A scanning electron microscope shows how the microplastic particles are attached to the nanocellulose structure. The diameter of the plastic particles is 100 nanometers. Credit: VTT Technical Research Centre of Finland

A thousand liters of seawater can contain up to 8.3 million particles of microplastics. Until now, identifying these very small particles has been difficult—usually they are only detected once they have accumulated in the bodies of fish. A method developed at VTT utilizes nanocellulose structures for early particle identification. Nanocellulose would allow particles to be captured even before they enter waterways.


The properties of nanocellulose films and hydrogels support the identification and capture of very small microplastic particles.

"Nanocellulose has a mesh-like, porous structure and a large BET surface area. In the water, powerful capillary forces are generated in this structure, allowing particles to be transported inside the mesh and bound there," says Research Professor Tekla Tammelin from VTT.

The method provides a way to catch microplastic particles of a size that the human eye cannot detect. These are particles with a diameter of only 100 nanometers.

"Nanocellulose structures can be used to identify and analyze these particles and to obtain information about their behavior at an earlier stage. We can determine the concentration of particles in water and analyze, for example, whether particles are released into drinking water from plastic bottles."

Next step: filtration methods

The identification of microplastic particles with nanocellulose structures has been developed at VTT as part of the FinnCERES flagship project, which is exploring new bio-based material solutions. The next step could be to develop new and inexpensive filtration solutions utilizing the method.

"New filtration solutions would allow particles to be captured where they are generated. The solutions could be utilized, for example, in laundry, where microplastic particles are released from fleece clothing and other synthetic fibers. Similarly, we could develop filtration methods for any industry where there is a risk of microplastics being generated and released into waterways."


Explore further Lobster digestion of microplastics could further foul the food chain

Provided by VTT Technical Research Centre of Finland

Scientists develop first 3-D mass estimate of microplastic pollution in Lake Erie

by Luke Auburn, Rochester Institute of Technology

RIT scientists developed the first three-dimensional model to show where microplastic pollution is collecting in Lake Erie. This figure is the result of a half-year model simulation of particle count distribution in the lake's open water. Credit: RIT

Rochester Institute of Technology scientists have developed the first three-dimensional mass estimate to show where microplastic pollution is collecting in Lake Erie. The study examines nine different types of polymers that are believed to account for 75 percent of the world's plastic waste.

Plastic behaves differently in lakes than in oceans; previous studies on both have indicated the levels of plastic pollution found on the surface are lower than expected based on how much is entering the water. While massive floating "islands" of accumulated plastic waste have been found in oceans, previous studies have indicated the levels of plastic pollution found on the surface of Lake Erie are lower than expected based on how much is entering the water.

The new RIT estimate for the 3-D mass—381 metric tons—is more than 50 times greater than the previous estimates at the surface. The study also generated the first estimate of how much plastic is deposited on the bottom of the lake. It accounts for the unique properties of different types of plastics and shows that the three polymers with the lowest density—polyethylene, polypropylene and expanded polystyrene—accumulate on the surface of the lake while the other six polymers were concentrated in the sediment.

"Previously there was a focus on plastics modeled as neutrally buoyant for the most part in the beginning of plastics modeling," said Juliette Daily, a mathematical modeling Ph.D. student and author of the study. "In reality, plastic is probably almost never neutrally buoyant. It's probably always positively or negatively buoyant, which really changes how the particles behave."

The study shows other interesting patterns, such as plastic particles accumulating more heavily on the eastern shore of the lake, perhaps from the current moving predominantly west to east. This means that pollution could be pushed disproportionately to areas like Buffalo, N.Y. The authors hope other researchers will continue to build on this research and explore how factors like beaching can further explain where plastic particles end up.

"Trying to understand where plastic is going is important for people looking at mitigation or prevention and will be important for understanding what the most likely impacted areas are," said Matthew Hoffman, associate professor in the School of Mathematical Sciences and co-author of the paper. "Looking at things in the sediment or getting an idea of what is down in the lower levels of the lake will give us a better idea of what concentrations there are and what possible exposure levels are to this ecosystem."

The study is published in the May 2020 edition of the Marine Pollution Bulletin.

Explore furtherResearchers estimate 10,000 metric tons of plastic enter Great Lakes every year

More information: Juliette Daily et al, Modeling the three-dimensional transport and distribution of multiple microplastic polymer types in Lake Erie, Marine Pollution Bulletin (2020). DOI: 10.1016/j.marpolbul.2020.111024

Journal information: Marine Pollution Bulletin


Provided by Rochester Institute of Technology

Adsorbent material developed from PET bottles for the removal of antibiotics from water

by National Research Council of Science & Technology

The KIST research team observed magnetic porous carbon composite materials in the transmission electron microscope. Researchers tested the efficiency of the porous carbon composite in terms of its ability to adsorb "tetracycline," or the antibiotic used to treat bacterial infections, from the water. Tests showed that the newly developed material was able to remove 100% of the tetracycline in about 90 minutes under general water conditions (pH 6), with an adsorption rate of 671.14 mg/g, which is a rate superior to that of previously developed adsorbents. In order to assess the reusability of the porous carbon composite, the adsorption-desorption process was conducted five times. Even after repeated use, the material maintained 90% of its adsorption properties, indicating a high degree of stability and wide applicability for water treatment. Credit: Korea Institute of Science and Technology (KIST)

South Korea, with its high antibiotic use, is categorized as a country at high risk of the emergence of multi-drug-resistant bacteria, or so-called "super bacteria." According to the Ministry of Environment, antibiotic substances have been detected at livestock wastewater treatment facilities, sewage treatment plants and in rivers.

The Korea Institute of Science and Technology announced that a research team, led by researchers Jung Kyung-won and Choi Jae-woo, at KIST's Water Cycle Research Center, has developed a high-efficiency, adsorbent material using PET waste bottles. The new material is expected to help solve the problem of environmental toxins and antibiotic-resistant bacteria which are caused by leaks of antibiotics into water.

Currently, the most well-known method of effectively removing antibiotics from water uses porous carbon composite, synthesized by pyrolyzing metal-organic frameworks (MOF). Porous carbon composites adsorb antibiotics in the water, thereby removing them. However, since the organic ligand generally used to synthesize MOF is very expensive, the cost is a major obstacle to this method's widespread, practical application through mass production.

In order to develop a more cost-effective solution, the KIST research team turned its attention to the PET bottles that people use in their everyday lives. PET is a high-molecular compound obtained by polymerizing ethylene glycol and terephthalic acid, the latter of which is used as organic ligand for the syntheses of MOF. The KIST research team extracted high-purity organic ligand from PET waste bottles and used it to synthesize a high-efficiency adsorbent material that could effectively remove antibiotics from water in an environmentally and economically beneficial way.

The KIST research team extracted high-purity organic ligand from PET waste bottles and used it to synthesize a high-efficiency adsorbent material that could effectively remove antibiotics from water in an environmentally and economically beneficial way. During the development of this adsorbent material, an alkaline hydrolysis process was used to induce a neutralization reaction, resulting in the production of a high-purity terephthalic acid. Credit: Korea Institute of Science and Technology (KIST)

During the development of this adsorbent material, an alkaline hydrolysis process was used to induce a neutralization reaction, resulting in the production of a high-purity terephthalic acid. To maximize the efficiency of the alkaline hydrolysis process, the research team incorporated an ultrasound-assisted phase transfer catalyst process. By optimizing this process, the team was able to successfully extract 100% high-purity terephthalic acid, which they then used to develop a porous carbon composite. Iron-based MOF was used as a precursor in order to impart magnetism to the adsorbent material. In this way, the team was able to develop an eco-material that can be easily separated from the mixture after the adsorption process, using an external magnetic field.


The KIST research team tested the efficiency of the porous carbon composite in terms of its ability to adsorb "tetracycline," or the antibiotic used to treat bacterial infections, from the water. Tests showed that the newly developed material was able to remove 100% of the tetracycline in about 90 minutes under general water conditions (pH 6), with an adsorption rate of 671.14 mg/g, which is a rate superior to that of previously developed adsorbents. In order to assess the reusability of the porous carbon composite, the adsorption-desorption process was conducted five times. Even after repeated use, the material maintained 90% of its adsorption properties, indicating a high degree of stability and wide applicability for water treatment.

Dr. Jung Kyung-won at KIST said, "This porous carbon composite is applicable to a wide range of water treatment areas as it uses waste plastics to prevent environmental pollution and maintains its high adsorption properties even after repeated use."

KIST's Dr. Choi Jae-woo said, "The porous carbon composite developed through this research is applicable to various fields, ranging from eco-materials to energy materials, and I expect that it will soon be highly regarded as a value-added eco-material."


Explore further 

Researchers develop high-capacity EV battery materials that double driving range

More information: Ju‐Myung Kim et al, Ecofriendly Chemical Activation of Overlithiated Layered Oxides by DNA‐Wrapped Carbon Nanotubes, Advanced Energy Materials (2020). DOI: 10.1002/aenm.201903658

Journal information: Advanced Energy Materials


Provided by National Research Council of Science & Technology

The best material for homemade face masks may be a combination of two fabrics

by American Chemical Society  APRIL 24, 2020

Credit: CC0 Public Domain

In the wake of the COVID-19 pandemic, the U.S. Centers for Disease Control and Prevention recommends that people wear masks in public. Because N95 and surgical masks are scarce and should be reserved for health care workers, many people are making their own coverings. Now, researchers report in ACS Nano that a combination of cotton with natural silk or chiffon can effectively filter out aerosol particles—if the fit is good.

SARS-CoV-2, the new coronavirus that causes COVID-19, is thought to spread mainly through respiratory droplets when an infected person coughs, sneezes, speaks or breathes. These droplets form in a wide range of sizes, but the tiniest ones, called aerosols, can easily slip through the openings between certain cloth fibers, leading some people to question whether cloth masks can actually help prevent disease. Therefore, Supratik Guha at the University of Chicago and colleagues wanted to study the ability of common fabrics, alone or in combination, to filter out aerosols similar in size to respiratory droplets.

The researchers used an aerosol mixing chamber to produce particles ranging from 10 nm to 6 μm in diameter. A fan blew the aerosol across various cloth samples at an airflow rate corresponding to a person's respiration at rest, and the team measured the number and size of particles in air before and after passing through the fabric. One layer of a tightly woven cotton sheet combined with two layers of polyester-spandex chiffon—a sheer fabric often used in evening gowns—filtered out the most aerosol particles (80-99%, depending on particle size), with performance close to that of an N95 mask material. Substituting the chiffon with natural silk or flannel, or simply using a cotton quilt with cotton-polyester batting, produced similar results. The researchers point out that tightly woven fabrics, such as cotton, can act as a mechanical barrier to particles, whereas fabrics that hold a static charge, like certain types of chiffon and natural silk, serve as an electrostatic barrier. However, a 1% gap reduced the filtering efficiency of all masks by half or more, emphasizing the importance of a properly fitted mask.

Explore further

Neither surgical nor cotton masks effectively filter SARS-CoV-2

More information: "Aerosol Filtration Efficiency of Common Fabrics Used in Respiratory Cloth Masks" ACS Nano (2020). http://pubs.acs.org/doi/abs/10 … 1021/acsnano.0c03252
Journal information: ACS Nano


Provided by American Chemical Society

A study looks at how to disinfect your mask at home
by Roland Yan, Steve Chillrud, Debra Magadini, and Beizhan Yan, Columbia University

A new study suggests that disposable surgical masks can be disinfected with heat multiple times without harming their effectiveness. A homemade plastic nose clip, used here, may add another layer of protection. Credit: Beizhan Yan

Due to the unknown numbers of asymptomatic people infected with the SARS-CoV-2, the Centers for Disease Control and Prevention has recommended that all citizens wear face coverings when in public. More recently, some states have mandated face coverings. Many people are wearing homemade coverings, but these mandates potentially increase demand for medical face masks, exacerbating shortages for first responders and medical staff.

One way to to extend the supply of disposable masks is to disinfect them and reuse them. We have just published a paper in the Journal of the International Society for Respiratory Protection that looks into whether disposable masks can be disinfected by heating them without compromising their effectiveness. We also compared the effectiveness of medical-grade masks with homemade ones, and looked into the feasibility of improving masks with homemade nose clips.

Prior work by others on disinfection of disposable masks has shown that heating for 30 minutes at 158 degrees F (70 C) or above can effectively destroy SARS, influenza and the novel SARS-CoV-2 coronavirus. This can be done in a home oven. As such, we did no testing with viruses. Instead we focused on whether repeated heat disinfection affected how well the masks worked for removing particles in the same size range as coronavirus.
To do this, we put masks onto mannequin heads, and rigged the heads to "breathe" through their noses and mouths, using a vacuum pump. We then exposed the mannequins to black carbon (i.e, soot) from a kerosene lamp, which generates particles that overlap in size with those of the coronavirus. We determined filtration efficiency by comparing black-carbon levels on both sides of the masks worn by the mannequins. We did this with two brands of disposable N95 respirators and one brand of disposable surgical mask, as well as with one design of homemade face covering. We tried this out repeatedly, and in a variety of ways.

One of three homemade face coverings tested out by the researchers. The silicone headform was a donation from Joshua Turi. Credit: Beizhan Yan

First, to measure the maximum filtration efficiency and resilience of the disposable masks, each disposable mask type was tested while taped or modified to tightly fit a plastic mannequin's face when new, and again after each heating cycle. We found that one N95 brand (3M) and a surgical mask (HSl brand) stood up to the 10 cycles of heat disinfection and reuse, with no reduction in performance. Filtration efficiency was greater than 95 percent over all 10 cycles for N95 respirators, and greater than 70 percent for surgical masks. (In contrast, we found that the nose-pad of another N95 brand, the Moldex, was unable to withstand multiple cycles of being put on and off the mannequin, whether or not it was heated in between uses.)


These tests show the maximum filtration efficiency possible, but they are not representative of how people normally wear masks, where the fit can be much looser. So, for a second set of tests, we obtained a head form covered in soft silicone to mimic the pliability of the human face. We then assessed the effectiveness of the masks as they are commonly worn, by simply putting the elastic straps around the head or ears without additional tightening. As expected, the filtration efficiency of all the disposable masks decreased substantially, to around 40 percent. This confirms that the effectiveness of such masks relies upon a tight fit, and this may be hard for many people to achieve.

We also tested the filtration efficiency of three homemade cloth coverings made following instructions on the CDC website. We made one from a cotton dress, one from a cotton sweater, and the third from polyester cloth. All three were worn in a normal mode on the silicone head form as directed by the CDC. The filtration efficiency of the cotton homemade cloth coverings in normal use was 55 percent, while the polyester covering came in at near 40 percent—about the same as loosely fitted medical-grade masks. This suggests that homemade cotton masks might actually work better than loosely fitted disposable masks, while polyester might be about the same.

We heated up the homemade masks for disinfection, which appeared to not affect the filtration efficiency. The CDC recommends washing and drying such coverings at home and we anticipate negligible effects on efficiency from this as well. When disinfecting your masks at home, we recommend you to place masks in an oven bag or a pressure cooker during heating, rather than directly put masks inside of the oven (see the instruction video below for details).

Finally, to see if we could improve the fit for the public, we designed a process that uses heat-moldable plastic strips to make homemade customized nose clips molded to an individual's face. By adding the customized nose clip to a normally worn disposable mask on a silicone head form, the filtration efficiency of the 3M N95 returned to greater than 95 percent, and the filtration efficiency of the surgical masks was measured at 88 percent. The nose clips passed two five-hour wearing tests for comfort. But due to the use of heat moldable plastic, the customized nose clips cannot be disinfected with heat; rather, they must be disinfected by soaking in solutions of alcohol or bleach.

This work has certain limitations. For one, our tests were all done under static conditions at a constant flow rate of air similar to how an adult breathes when sitting. We did not take into account the increase in breathing, nor the reduction in fit that can occur when someone is talking or active.

Our study is just one of many looking into how masks may be disinfected and reused. Others have been carried out or are in progress using not only heat, but ultraviolet light, vaporized hydrogen peroxide, or soaking in ethyl alcohol or bleach solutions. Most of these are aimed at medical personnel using specialized equipment. The soaking methods have been shown to reduce the effectiveness of certain types of N95 masks. Ours is a relatively modest effort aimed at everyday usage. Far more work needs to be done, but everything we know so far suggests that wearing almost any kind of mask in public is better than nothing; that a tight fit is best; and that, with certain limits, many types of masks can be reused outside of medical settings.



Explore furtherFollow the latest news on the coronavirus (COVID-19) outbreak

More information: Developing home-disinfection and filtration efficiency improvement methods for N95 respirators and surgical facial masks: stretching supplies and better protection during the ongoing COVID-19 pandemic. Journal of the International Society for Respiratory Protection. https://www.isrp.com/the-isrp- … 20-pp-19-35-yan/file

Provided by Columbia University

Warming climate undoes decades of knowledge of marine protected areas
by Lancaster University APRIL 24, 2020

A parrotfish feeding on degraded coral. Credit: Shaun Wilson, Department of Biodiversity, Conservation and Attractions in Australia, and the University of Western Australia

Climate change and warming seas are transforming tropical coral reefs and undoing decades of knowledge about how to protect these delicate and vital ecosystems.


Many of the world's coral reefs are seeing biodiversity plunge in the face of repeated coral bleaching events.

Protected areas, called marine reserves, are an effective and long-established tool in the conservation toolbox. Marine reserves have been used for decades to enhance biodiversity and fish biomass by preventing damage and over-exploitation by fishing.

However, a new study highlights that tropical coral reef marine reserves can offer little defence in the face of climate change impacts. And the changes that are being observed will force scientists, conservationists and reserve managers to rethink the role these protected areas can bring.

"Climate change is so fundamentally changing the structure and composition of coral reef ecosystems, that the way the ecosystem functions and responds to common management and conservation approaches needs to be carefully re-evaluated," explains Professor Nick Graham of Lancaster University and lead author of the study. "The rules we have come to rely on, no longer apply."

Algal dominated reef in Seychelles. Credit: Nick Graham, Lancaster University

Bleaching occurs when seas become too warm, causing corals to expel their colourful algae. This disrupts the ecosystem and reduces the availability of food and shelter for many fish species.

Some coral reefs are able to recover over time, while others are transformed and become dominated by seaweed.

The new study, published in the journal Nature Communications, focused on reefs and marine reserves in Seychelles. Coral reefs in Seychelles were badly affected by a bleaching event in 1998, when around 90% of the coral died. Scientists used data from 21 reefs over a 20-year time period, spanning the 1998 bleaching event, to explore how reefs have changed and how this has affected the role of marine reserves.

Professor Graham explains: "Our long-term records of Seychelles' coral reefs show that before the bleaching event marine reserves contained high coral cover, a very biodiverse range of fish, and high biomass of carnivorous and herbivorous fish.


"Following the bleaching event, the role of the marine reserves changed substantially. They no longer supported higher coral cover compared to adjacent fished areas, and their role in enhancing biodiversity decreased. Plant-loving fish, such as rabbitfish and parrotfish, dominated fish communities. This was the case for reefs where corals were recovering, as well as reefs transformed and dominated by seaweed."

A recovering reef in Seychelles. Credit: Nick Graham, Lancaster University

Reduced numbers of carnivorous predators, such as grouper and snapper species, show reserves are much less effective at protecting the tops of food webs in the years following bleaching events. These population drops are likely due to fewer fish for them to prey on after the loss of coral reef structures.

Dr. Shaun Wilson, of the Department of Biodiversity, Conservation and Attractions in Western Australia, a co-author on the study, said: "Despite these climate-driven transformations, marine protected areas still have a role to play in ocean conservation. It is encouraging that marine reserves continue to protect some species, especially when these species are critical for local fisheries."

Gilberte Gendron of the Seychelles National Parks Authority, adds: "Although these reordered marine reserves are less biodiverse, they are still important to maintain. This is because, when compared to openly fished areas, they still protect higher levels of fish biomass of species that are important to our local fisheries. For example, the protected herbivorous fish can spill out into openly fished areas and help support adjacent fisheries."

If the goal is to protect biodiversity then it may be better to target new marine reserves around those coral reefs where the rate of warming is slowest, or those where recovery from bleaching is more likely.

While the scientists say marine reserves still have an important role to play in protecting fish biomass, they call in their paper for urgent reductions in global greenhouse gas emissions, as well as other pressures such as poor land practices that input nutrients and pollutants to coastal waters, to protect tropical coral reefs.

Explore furtherCan coral reefs 'have it all'?

More information: Changing Role of Coral Reef Marine Reserves in a Warming Climate, Nature Communications (2020). DOI: 10.1038/s41467-020-15863-z

Journal information: Nature Communications

Making wind power more predictable

by Gabe Cherry, University of Michigan
 

A mesonet monitoring station located near Guthrie, Texas. It is one of 132 stations that make up the West Texas Mesonet. Credit: University of Michigan
A computer model that uses existing weather data to map long-term wind patterns at prospective wind turbine sites could help energy companies set up wind turbines more quickly and less expensively. The model eliminates the need to deploy dedicated wind monitoring stations. It could also make wind energy more reliable by enabling networks of turbines that are strategically placed to generate a more consistent stream of energy.


A team led by U-M assistant professor of industrial operations and engineering Eunshin Byon developed the model. We sat down with Byon recently to learn more about her work.

Is siting wind turbines really more complicated than just finding a windy spot?

As wind becomes a more and more important part of our energy supply, finding a windy spot will no longer be enough. We'll need to predict how the wind patterns at a given site will vary from day to day and month to month.

Currently, the only way to get a year of wind data for a specific site is to set up a meteorological station on that site and collect data for a year. That's not practical from a financial or time standpoint, especially as deployment of wind turbines continues to ramp up. And we believe we've found a better way.

Why is it important to have longer-term data about wind patterns?

The wind isn't always blowing in a given spot, but it's always blowing somewhere. If power companies can predict where and when the wind will blow, they can design their networks so that, when one turbine is likely to be idle, another is likely to be generating power

How does your method measure wind patterns without setting up a measuring station?

Instead of measuring wind patterns at the actual wind turbine site, we've used existing data from automated weather stations called mesonets. We've built a computer model that can use their data to estimate wind patterns at any location within a radius of about 22 miles from the mesonet station.

Tell me more about these Mesonet stations. What are they used for today?

Mesonets are networks of relatively simple, automated weather monitoring stations that are used to monitor localized weather patterns. They're spread all over the country and generally run by universities and other public entities. Michigan State University operates one here in Michigan. For our study, we used data from the West Texas Mesonet, which is operated by the National Wind Institute at Texas Tech University.

How accurate is your model compared to an actual monitoring station?

We found that our model accurately measured wind speed to within one meter per second. So it's very accurate. We determined those figures by setting up a dedicated monitoring station at a test site and compared its actual wind data to the estimated data from our model for the same site.

Does generating a model like this require a lot of computing power?

A model that predicts wind patterns at a single site is not very computing-intensive and can be done on an ordinary laptop.

What else could this technology be used for?

These mesonet stations collect a variety of weather data, and that could be useful for modeling other properties, like solar radiation levels. That could help solar energy installers site their installations more effectively as well. Solar power is growing even faster than wind right now, so that could be very important.

What are the next steps for this research?

We're looking at adapting our models to use Numerical Weather Prediction data—this is the larger-scale data that's used to generate the weather forecasts we all rely on. That data could enable us to get predictions of more types of patterns that are even more accurate and available in more areas.

The work is detailed in a paper titled "Probabilistic Characterization of Wind Diurnal Variability for Wind Resource Assessment." It is published in the January 2020 issue of IEEE Transactions on Sustainable Energy.


Explore further

Supporting structures of wind turbines contribute to wind farm blockage effect

More information: Youngchan Jang et al. Probabilistic Characterization of Wind Diurnal Variability for Wind Resource Assessment, IEEE Transactions on Sustainable Energy (2020). DOI: 10.1109/TSTE.2020.2965444

Energy efficiency could prevent the need to build up to 50 power plants in Indonesia

by Virginie Letschert, and Michael McNeil, The Conversation

Saving energy can save money and the environment. Credit: Mohamed Hassan/ Pixabay
Indonesia's electricity demand is growing rapidly. Robust economic growth combined with unprecedented urbanisation and industrialisation are driving this demand.

Based on the Ministry of Energy and Mineral … esources statisctics, daily peak electricity demand is also increasing rapidly. It is officially projected to double by 2030 to over 160 gigawatts (GW).

Domestic appliances and equipment, such as air conditioners (ACs), lighting, refrigerators and TVs, will lead energy demand in Indonesia by 2030, representing as much as 70% of the load during peak time at 8pm.

To meet the rising demand, Indonesia plans to build 87GW of additional power – the equivalent of 175 medium-size (500 megawatt) power plants—by 2030.

However, our research identifies strategies to cut electricity consumption by 25GW by 2030, equal to 35% of the peak electricity consumption in that year. The adoption of efficient technologies would reduce electricity use in lamps, air conditioners, refrigerators and other appliances.

With these technologies, Indonesia can avoid building 50 of the planned power plants by 2030.

Efficient technologies to reduce load

Our model forecasts energy demand by appliance types and analyses different scenarios of technology adoption to understand their impacts on future electricity loads.

We found the efficient technologies provide the same service to the households (lighting, cooling, etc) but use less energy. This makes them as much as 50% less expensive for consumers to run.


For example, common technologies are LEDs (light-emitting diodes), which produce more light with less heat loss, inverter ACs, which allow the AC to work at variable speed, and increased refrigerator insulation, which will keep food compartments cold longer.

While some Indonesians have already chosen to buy efficient technologies, tens of millions of energy-consuming products are entering households for the first time in the coming years.

Therefore, it is important to have strong policies in place to eliminate inefficient products and promote efficient ones in the market.

In particular, with sales of air conditioners growing at 7.5% every year in Indonesia, we find over half of the potential savings could come from this product alone.

Further research by our team has shown efficient cooling technologies using an inverter drive are available in Indonesia at a cost not necessarily higher than the inefficient ones.

In terms of climate impacts, we found efficient appliances and lighting could achieve nearly 27% of the energy sector emission-reduction target. That's 84.5 million tons of CO₂ saved by 2030. This makes it an essential tool in reducing carbon emissions (decarbonisation) of Indonesia's energy sector, along with deployment of renewable energy.

The ministry has introduced the national sectoral targets for energy conservation into the National Elecricity Master Plan, or RUKN, to reduce energy consumption for the first time in 2019.

The plan stipulates that 37GW of the projected 166GW peak demand in 2030 can be avoided through energy conservation for the next ten years.

Energy conservation relies on energy-efficient technologies (this is what our research focuses on) as well as changes in consumer behaviours (such as turning off the light when you leave a room).

Recommendations

As electricity demand grows in Indonesia at the same time as the country pursues clean energy, energy efficiency is a critical tool for financial viability and energy security.

Energy efficiency means using less energy to perform the same task. Technologies now offer us the benefits of energy efficiency. Energy-efficiency policies support the deployment of these technologies.

We recommend that Indonesia consider energy efficiency as a resource for meeting the country's future energy needs.

Even with low coal prices, energy efficiency is the cheapest way to provide electricity to the Indonesian people.

Typically, we have found the cost of saving a unit of electricity (kWh) is around 2-3 cents, compared to the typical household electricity rate of 10-11 cents/kWh in Indonesia.

Energy efficiency will also help with the integration of renewable energy (like solar PV) by reducing the evening peak demand and the need for energy storage systems or expensive plants that are run only for high demand, such as gas-fired "peaker" plants.

Because of the shape of the load—high peak demand at 8pm—the system will need additional capacity that baseload cannot meet, i.e. coal.

We recommend the Ministry of Energy and Mineral Resources turn to the 37GW energy conservation target to help the country meet its climate commitments of 29% unconditional emission reduction by 2030.

We hope our research can help prioritise policy action and track progress towards the country's clean energy and climate goals.

Implementing these targets will help save the government money, reduce local and global pollution, and ultimately will reduce costs for Indonesian consumers.

Explore furtherGeothermal energy storage system to reduce peak electricity demand

Provided by The Conversation

Ultraviolet light can be used against coronavirus — just not in the way Trump imagines

Jon Ward Senior Political Correspondent, Yahoo News•April 25, 2020

WASHINGTON — President Trump’s mention Thursday of treating COVID-19 with ultraviolet light was part of a rambling digression that included speculation about administering disinfectants to patients, prompting confusion and alarm from medical experts.

The president’s invocation of pseudoscience — which he claimed on Friday had been a joke intended “sarcastically” to provoke reporters — overshadowed the news from the briefing about evidence, first reported last week by Yahoo News, that ultraviolet light does destroy the coronavirus. Researchers have shown it can be used to disinfect surfaces and kill viruses in ambient air in ways that could be used to reduce transmission in public spaces.

“Continuous very low dose-rate far-UVC light in indoor public locations is a promising, safe and inexpensive tool to reduce the spread of airborne-mediated microbial diseases,” wrote a team of researchers in a 2018 paper published in Scientific Reports.

Transmission of the coronavirus is thought to be more common through particles spread through the air than by contact with hard surfaces, but scientists are still working to understand how the virus spreads.

Yet if commercially available UV products were to mitigate some of the risk of contracting the coronavirus, that might help ease the transition out of a total lockdown. “This approach may help limit seasonal influenza epidemics, transmission of tuberculosis, as well as major pandemics,” the scientific researchers wrote in 2018.

The key is advances in UV lighting technology, specifically the advent of “far-UVC” lamps, which operate at a wavelength of 222 nanometers, a frequency that doesn’t penetrate skin or the outer layer of the human eye. Previously, disinfecting ultraviolet could not be used in public spaces because the wavelengths used, of 254 nanometers and up, can cause skin cancer and damage the eyes.

A pedestrian in Madrid on Friday. (Samuel de Roman/Getty Images)

By contrast, the 2018 paper found that “far-UVC light cannot penetrate even the outer (non living) layers of human skin or eye” but that “because bacteria and viruses are of micrometer or smaller dimensions, far-UVC can penetrate and inactivate them.”

David Brenner, director of Columbia University’s Center for Radiological Research, said earlier this week that far-UVC light “can be safely used in occupied public spaces, and it kills pathogens in the air before we can breathe them in.”

“Most approaches focus on fighting the virus once it has gotten into the body. Far-UVC is one of the very few approaches that has the potential to prevent the spread of viruses before they enter the body,” Brenner said.

A group of researchers at the Center for Radiological Research published a study in 2017 that “tested the hypothesis that there exists a narrow wavelength window in the far-UVC region, from around 200-222 nm, which is significantly harmful to bacteria, but without damaging cells in tissues.”

A UV sanitizer wand. (Kirk McKoy/Los Angeles Times via Getty Images)

The study found that far-UVC light kills pathogens “without the skin damaging effects associated with conventional germicidal UV exposure.”

Two other studies have examined the impact of far-UV light on skin using mice and found that “222 nm-UVC lamps can be safely used for sterilizing human skin.”

One company, Healthe, is already selling a few different UV light products, including far-UV lights meant to be used in public spaces. One is a downlight that can be installed in the ceiling of an average room. There is also a portal, similar to a metal detector, that claims it “inactivates over 90% of contaminants” if a person stands — arms up — inside the portal for 10 to 12 seconds.

The company says another way to use ultraviolet is to irradiate air as it passes through a sealed unit, like a building air-conditioning system. Since that doesn’t expose people to the rays, it can use different, more powerful wavelengths.

Despite these advances, public attention was distracted on Friday by the continued controversy over the president’s remarks the previous day.

President Trump at the coronavirus task force daily briefing on Thursday. (Mandel Ngan/AFP)

“I was asking a question sarcastically to reporters like you, just to see what would happen,” Trump said in the Oval Office. “I was asking a sarcastic question to the reporters in the room about disinfectant on the inside.”

He claimed he had not asked his medical experts in the White House briefing room on Thursday to look into injecting disinfectants into the human body. “I thought it was clear,” he said.

But the president’s comments on Thursday were anything but clear. His remarks were so jumbled it was hard to know what exactly he meant at times.

Trump spoke on Thursday just after the head of the Science and Technology Directorate at the Department of Homeland Security, Bill Bryan, had spoken to reporters about the impact of sunlight on coronavirus particles in outdoor public spaces, and had also mentioned testing bleach as a disinfectant.

“So, supposing we hit the body with a tremendous — whether it’s ultraviolet or just very powerful light — and I think you said that that hasn’t been checked, but you’re going to test it. And then I said, supposing you brought the light inside the body, which you can do either through the skin or in some other way, and I think you said you’re going to test that too. It sounds interesting.

“And then I see the disinfectant, where it knocks it out in a minute. One minute. And is there a way we can do something like that, by injection inside or almost a cleaning. Because you see it gets in the lungs and it does a tremendous number on the lungs,” Trump said. “So it would be interesting to check that. So, that, you’re going to have to use medical doctors with. But it sounds — it sounds interesting to me. So we’ll see. But the whole concept of the light, the way it kills it in one minute, that’s — that’s pretty powerful.”

Later in the briefing, Trump asked Dr. Deborah Birx, a medical expert on his coronavirus task force, about the possibility of using heat or light to treat a COVID-19 infection — rather than kill the coronavirus in the environment.

“Not as a treatment,” she replied.

Sunlight destroys coronavirus quickly, say US scientists

This transmission electron microscope image shows SARS-CoV-2 -- also known as 2019-nCoV, the virus that causes COVID-19 -- isolated from a patient in the US. Virus particles are shown emerging from the surface of cells cultured in the lab. The spikes on the outer edge of the virus particles give coronaviruses their name, crown-like. Credit: NIAID-RML

The new coronavirus is quickly destroyed by sunlight, according to new research announced by a senior US official on Thursday, though the study has not yet been made public and awaits external evaluation.

William Bryan, science and technology advisor to the Department of Homeland Security secretary, told reporters at the White House that government scientists had found ultraviolet rays had a potent impact on the pathogen, offering hope that its spread may ease over the summer.

"Our most striking observation to date is the powerful effect that solar light appears to have on killing the virus, both surfaces and in the air," he said.

"We've seen a similar effect with both temperature and humidity as well, where increasing the temperature and humidity or both is generally less favorable to the virus."

But the paper itself has not yet been released for review, making it difficult for independent experts to comment on how robust its methodology was.

It has long been known that ultraviolet light has a sterilizing effect, because the radiation damages the virus's genetic material and their ability to replicate.

A key question, however, will be what the intensity and wavelength of the UV light used in the experiment was and whether this accurately mimics natural light conditions in summer.

"It would be good to know how the test was done, and how the results were measured," Benjamin Neuman, chair of biological sciences at Texas A&M University-Texarkana, told AFP.

"Not that it would be done badly, just that there are several different ways to count viruses, depending on what aspect you are interested in studying."

Virus inactivated

Bryan shared a slide summarizing major findings of the experiment that was carried out at the National Biodefense Analysis and Countermeasures Center in Maryland.

It showed that the virus's half-life—the time taken for it to reduce to half its amount—was 18 hours when the temperature was 70 to 75 degrees Fahrenheit (21 to 24 degrees Celsius) with 20 percent humidity on a non-porous surface.

This includes things like door handles and stainless steel.

But the half-life dropped to six hours when humidity rose to 80 percent—and to just two minutes when sunlight was added to the equation.

When the virus was aerosolized—meaning suspended in the air—the half-life was one hour when the temperature was 70 to 75 degrees with 20 percent humidity.

In the presence of sunlight, this dropped to just one and a half minutes.

Bryan concluded that summer-like conditions "will create an environment (where) transmission can be decreased."

He added, though, that reduced spread did not mean the pathogen would be eliminated entirely and social distancing guidelines cannot be fully lifted.

"It would be irresponsible for us to say that we feel that the summer is just going to totally kill the virus and then if it's a free-for-all and that people ignore those guides," he said.

Previous work has also agreed that the virus fares better in cold and dry weather than it does in hot and humid conditions, and the lower rate of spread in southern hemisphere countries where it is early fall and still warm bear this out.

Australia, for example, has had just under 7,000 confirmed cases and 77 deaths—well below many northern hemisphere nations.

The reasons are thought to include that respiratory droplets remain airborne for longer in colder weather, and that viruses degrade more quickly on hotter surfaces, because a protective layer of fat that envelops them dries out faster.

US health authorities believe that even if COVID-19 cases slow over summer, the rate of infection is likely to increase again in fall and winter, in line with other seasonal viruses like the flu.


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