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Breaking Down Polystyrene | Earth Wise

April 20, 2021 By EarthWise Leave a Comment

The proliferation of global plastic waste continues to be a growing problem for the world. Hundreds of millions of tons of plastics are produced each year and most of it is used once and then discarded. The properties that make plastics so attractive – durability and chemical stability – make it difficult to do anything with discarded plastics other than deposit them in landfills – where they don’t easily degrade over time – or burn them, which dumps carbon dioxide and various hazardous gases into the atmosphere.

Polystyrene is one of the most widely used plastics. It is found in foam packaging materials, disposable food containers, plastic cutlery, storage containers, and many other places.

Recycling plastics like polystyrene is generally not economically feasible. Sorting plastics by type is time and labor intensive and the chemical processes required to break down plastics into usable precursor materials require significant energy input and the use of toxic solvents.

Recently, a team of scientists at Ames Laboratory in Iowa has developed a process based on ball-milling that deconstructs commercial polystyrene in a single step, at room temperature, in ambient atmosphere, and in the absence of harmful solvents.

Ball-milling is a technique that places materials in a milling vial with metal ball bearings which is then agitated to initiate a chemical reaction. This approach is known as mechanochemistry.

The method represents an important breakthrough that enables dismantling of a polymer that includes its chemical breakdown without requiring solvents or the high temperatures generally needed to thermally decompose it. This discovery opens up new avenues for low-temperature recovery of monomers from polymer-based systems that include composites and laminates. It could be a very useful weapon in the battle against plastic waste.

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Polystyrene waste is everywhere, and it’s not biodegradable. Scientists just found a way to break it down.

Photo, posted December 11, 2010, courtesy of Warrenski via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Why Have Crocodiles Changed So Little Over Time? | Earth Wise

February 9, 2021 By EarthWise Leave a Comment

Crocodiles today look very similar to ones from the Jurassic period some 200 million years ago. In fact, there are very few species of crocodilians alive today – approximately two dozen to be exact. Many other species have achieved a diversity of many thousands of species in the same amount of time.

During prehistoric times, many more types of crocodiles roamed the earth, including some as big as dinosaurs and other serpentine forms that lived in the sea.

According to findings by scientists at the University of Bristol in the U.K., a stop-start pattern of evolution could explain why crocodiles have changed so little over time. In the study, which was recently published in the journal Nature Communications Biology, researchers describe how crocodiles follow a pattern of evolution known as “punctuated equilibrium.” In other words, crocodiles’ rate of evolution is generally slow, but occasionally picks up because the environment has changed.

According to the research team, this slow rate of evolution is how crocodile diversity became so limited. It appears crocodiles arrived at a body that was efficient and versatile. They didn’t need to continue to change in order to survive.

This efficiency and versatility could be an explanation for why crocodiles survived the meteor impact that wiped out the dinosaurs. Since crocodiles can’t control their body temperature and rely on the environment for warmth, they generally fare better in warm conditions. During the age of dinosaurs, the climate was warmer than it is today, which could explain why crocodile diversity was higher.

The scientists next step is to try to figure out why some prehistoric crocodiles died out while others did not.

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Why crocodiles have changed so little since the age of the dinosaurs

Photo, posted December 26, 2012, courtesy of Nicholas Smith via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Recyclable Wind Turbines | Earth Wise

January 1, 2021 By EarthWise Leave a Comment

The blades of modern wind turbines can be longer than the wing of a Boeing 747. Their useful lifetime is perhaps 20 years and after that, they can’t just be hauled away. They end up being cut up with special industrial saws to create pieces small enough to be strapped to a tractor-trailer. Then, they end up in landfills. There are thousands of blades being removed each year and those numbers are growing.

Wind turbine blades are currently manufactured using thermoset resin, which cannot be recycled. It is also energy-intensive and manpower-intensive to produce.

Researchers at the National Renewable Energy Laboratory in partnership with Arkema Inc of Pennsylvania have demonstrated the feasibility of using thermoplastic resin instead to make wind turbine blades. That material can be recycled and can also enable longer, lighter-weight, and lower-cost blades. Using thermoplastic could also allow manufacturers to build blades on site, alleviating the problems of transporting ever larger turbine blades.

Current blades are made primarily of composite materials like fiberglass infused with thermoset resin. The manufacturing process requires additional heat to cure the resin, which adds cost and time. Thermoplastic resin cures at room temperature and requires less labor. With regard to recycling, thermoplastic resin, when heated above a certain temperature, melts into its original liquid resin and can be reused.

NREL has demonstrated the feasibility of the thermoplastic resin system by manufacturing nearly identical blades using both the standard materials and the thermoplastics. NREL has also developed a technoeconomic model to evaluate the cost benefits of using thermoplastic resin.

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News Release: NREL Advanced Manufacturing Research Moves Wind Turbine Blades Toward Recyclability

Photo, posted June 28, 2008, courtesy of Patrick Finnegan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Finding Methane Leaks from Space | Earth Wise

December 23, 2020 By EarthWise Leave a Comment

There is growing concern about the climate effects of methane leaking from oil and gas wells. The 20-year global warming potential of methane is 84, meaning that over a 20-year period, it traps 84 times more heat per mass unit than carbon dioxide. Global methane concentrations have increased by nearly a factor of 3 since the industrial revolution.

More than a century of oil and gas drilling has left behind millions of abandoned wells, many of which are leaching pollutants into the air and water. In the U.S. alone, more than 3.2 million abandoned oil and gas wells emitted 280,000 tons of methane just in 2018. And the data is incomplete.

Part of the problem is finding out which wells are leaking. Ground-based sensors or airplanes and drones are effective ways to find leaks but considering how many wells there are to check, the costs are considerable, and the process is time consuming and complicated.

New technology is coming along that uses satellites to detect methane leaks. A Canadian company called GHGSat recently used satellites to detect what it has called the smallest methane leak ever seen from space and has begun selling data to emitters interested in pinpointing leaks.

Another company, New York-based Bluefield Technologies, plans a group of satellites for launch in 2023 that promises even finer resolution. The Environmental Defense Fund, with support from Jeff Bezos’ Earth Fund, plans to launch MethaneSAT in the next couple of years, which is designed to find small sources of methane.

Research at Stanford University determined that just 5% of methane leaks produce around half the total leakage.

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New Technology Claims to Pinpoint Even Small Methane Leaks From Space

Photo, posted June 8, 2011, courtesy of Jeremy Buckingham via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Shrinking Ice In The Bering Sea | Earth Wise

October 19, 2020 By EarthWise Leave a Comment

The Bering Sea forms the divide between the two largest landmasses on Earth: Eurasia and the Americas. Recent analysis of vegetation from a Bering Sea island has determined that the extent of sea ice in the region is the lowest it has been for over 5,000 years.

St. Matthew Island, a small island in the middle of the Bering Sea, has essentially been recording what is happening in the ocean and atmosphere around it, in the form of the composition of peat layers on the island. By analyzing the chemical composition of peat core samples, scientists can estimate how sea ice in the region has changed over the course of time.

Changes in the relative amounts of two oxygen isotopes in the sediment and plant debris trapped in the peat on the island reflect the nature of precipitation during the period when the peat layers formed. That ratio is correlated with the amount of sea ice in the region. Satellite data acquired over the past 40 years confirms this correlation.

Analysis of the data shows that the current ice levels are unprecedented in the last 5,500 years. These long-term findings affirm that reductions in Bering Sea ice are due to more than recent higher temperatures associated with global warming. Atmospheric and ocean currents, which have also been altered by climate change, play a large role in the presence of sea ice.

Summertime sea ice in the Arctic was expected to reach its second-lowest extent in September in 40 years of observation. Sea ice typically builds up again each winter, but the changes in ice extents actually lag behind changes in greenhouse gas level by decades. Future ice loss is already built into the system.

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Bering Sea ice extent is at most reduced state in last 5,500 years

Photo, posted December 2, 2012, courtesy of Bering Land Bridge National Preserve via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Permanent Time Observation | Earth Wise

September 25, 2020 By EarthWise Leave a Comment

Americans have debated the value of daylight savings time going all the way back to Benjamin Franklin. As a country, we adopted the practice of changing our clocks twice a year in 1918.

Since the energy crisis of the 1970s, there have been a number of initiatives aimed at making daylight savings time permanent. However, there is also a growing movement to eliminate the practice entirely.

In August, the American Academy of Sleep Medicine published a position statement calling for the abolishing of daylight savings time in favor of fixed, national, year-round standard time.

The statement describes the adverse effects of the annual abrupt switch to daylight savings time, which range from increased risk of stroke and hospital admissions to sleep loss and increased production of inflammatory markers, which are one of the body’s responses to stress. It also cites studies that show that traffic fatalities increase by as much as six percent in the first few days following the change to daylight savings time. Other research shows that there is an 18% increase in adverse medical events related to human error in the week after switching to daylight savings time.

In July, a survey by the academy of more than 2,000 U.S. adults found that 63% support the elimination of seasonal time changes in favor of a national, fixed year-round time, and only 11% oppose the idea, but many of those in favor of the idea actually want permanent daylight savings time.

The sleep academy contends that permanent standard time is the best choice to most closely match our circadian sleep-wake cycle while daylight saving time results in more darkness in the morning and more light in the evening, disrupting the body’s natural rhythm.

Residents of Arizona and Hawaii get to sit out this debate since they don’t change their clocks.

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American Academy of Sleep Medicine calls for elimination of daylight saving time

Photo, posted May 28, 2018, courtesy of Kis Akos via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Fabric To Keep You Cool | Earth Wise

September 1, 2020 By EarthWise Leave a Comment

About 10% of all electricity consumption in the U.S. is devoted to keeping us cool with air conditioning and other methods. Researchers at two universities in Shanghai, China have developed a new material that can be made into clothing that cools the wearer without using any electricity.

The new fabric transfers heat, allows moisture to evaporate from the skin, and repels water. Cooling off a person’s body is much more efficient than cooling off an entire room or a building. There have been textiles and types of clothing designed to perform the cooling function, but most of those have disadvantages. These include some combination of poor cooling capacity, high energy consumption, complex and time-consuming manufacturing, and high cost.

The researchers wanted to develop a personal cooling fabric that can efficiently transfer heat away from the body while at the same time being breathable, water resistant and easy to make.

The new fabric is made by electrospinning an ordinary polyurethane polymer with a water-repelling fluorinated version of polyurethane polymer along with a thermally conductive filler composed of boron nitride nanosheets. The resultant material is a nanofibrous membrane that repels water from the outside but has large enough pores to allow sweat to evaporate from the skin and air to circulate.

Tests of the membrane demonstrated higher thermal conductivity than other conventional or high-tech fabrics. Used in clothing, the material would be more effective than previous fabrics in conducting heat away from the body. It may be possible to beat the heat without turning on the AC. These membranes could also be useful for solar energy collection, seawater desalination, and thermal management of electronic devices.

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New fabric could help keep you cool in the summer, even without A/C

Photo courtesy of the American Chemical Society on Youtube.

Earth Wise is a production of WAMC Northeast Public Radio.

Engineering Mosquitoes | Earth Wise

February 21, 2020 By EarthWise Leave a Comment

Tropical regions grapple with the spread of diseases – such as dengue, yellow fever, zika, chikungunya, and malaria – by mosquitoes. A fairly successful strategy has been the Sterile Insect Technique, which is essentially insect birth control. The process involves rearing large quantities of sterilized male mosquitoes in dedicated facilities, and then releasing them to mate with females in the wild. As they do not produce any offspring, the insect population declines over time.

A problem with this approach is that while mosquitoes create health problems for people, they also play important roles in various ecosystems, such as providing food for bats and other animals. Eliminating mosquito populations on a large scale can trigger major changes in ecosystems.

Recently, an international team of scientists has synthetically engineered mosquitoes that halt the transmission of the dengue virus. They genetically engineered mosquitoes with an antibody “cargo” that gets expressed in the female mosquitoes that spread the dengue virus. Once the female mosquito takes in blood, the antibody is activated which hinders the replication of the virus and prevents its dissemination throughout the mosquito, thereby preventing its transmission to humans. Essentially, what the researchers have done is transfer genes from the human immune system to confer immunity to mosquitoes. The researchers are testing methods to neutralize mosquitoes against other viruses they spread.

This opens up a whole new approach to interrupt mosquito-borne human diseases. Mosquitoes are among the deadliest killers on the planet because they are the messengers that transmit deadly diseases. Until now, the only real solution has been to kill the messenger. The new approach may be a better way to deal with a serious problem.

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Mosquitoes engineered to repel dengue virus

Photo, posted June 20, 2014, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Volunteer Tourism | Earth Wise

February 13, 2020 By EarthWise 1 Comment

Spending vacation time in a disaster zone seems like a crazy idea, but so-called volunteer tourism can actually be a big help to communities trying to recover from natural disasters. It can also be a unique and rewarding experience for the volunteers.

Such volunteer tourism should not be confused with “disaster tourism”, the unfortunate practice of rushing to the scene of a calamity to gawk. That is certainly no help to anyone.

When disaster strikes a destination usually frequented by tourists, people naturally tend to stay away, leaving communities to deal with the loss of tourism income on top of the costs of repair and recovery.

A study by UTS, a technology university in Sydney, Australia, looked at the effects of volunteer tourism in the wake of the April 2015 earthquake in Nepal. They found that when it is done in an ethical matter than takes into account local conditions and the affected community, volunteer tourism can aid recovery and resilience.

In the months following the earthquake, most relief organizations asked international volunteers not to come unless they had specific expertise, such as medical skills, building skills, or emergency response experience. Eventually, Nepal relaxed conditions to include volunteers to help rebuild homes and schools, to intern in hospitals, and to support NGOs and to re-establish sustainable agriculture.

According to the Nepal Association of Tour and Travel Agents, almost one third of the tours booked to Nepal in the two years after the earthquake comprised groups who combined tourism with volunteering or philanthropy.

Volunteer tourism isn’t for everyone and for every situation, but for places that rely on tourism for their economy, building volunteer tourism into the recovery process can be a good strategy.

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Volunteer tourism can aid disaster recovery

Photo, posted July 2, 2015, courtesy of the World Humanitarian Summit via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Lighting Up Batteries

December 24, 2019 By EarthWise 2 Comments

One of the things that hampers the adoption of electric vehicles is range anxiety. Drivers worry that they will run out of charge before they get to the closest charging station. Range anxiety has lessened considerably in recent years as electric cars have incorporated larger and larger battery packs yielding driving ranges well over two hundred and even over three hundred miles.

With these extended driving ranges, drivers then turn their attention to how long it takes to charge. Tesla’s Superchargers have gotten to the point where a car can add 75 miles of charge in 5 minutes and 200 miles in less than half an hour. Fast charging systems are improving the charge times for other electric models as well.

Nevertheless, drivers would ideally like to reduce charging times to as little as possible in order to provide the convenience experienced in gasoline cars.

Researchers at Argonne National Laboratory have reported a mechanism for speeding up the charging of lithium-ion batteries for electric vehicles. By exposing the battery cathode to a beam of concentrated light, the charging time can be reduced by a factor of two or more. If this could be commercialized, it could be a real game changer for electric vehicles.

The research used specially crafted lithium-ion cells with transparent quartz windows. Shining white light into the windows caused a semiconductor material known as LMO to change its charge state and drive the charging reaction more quickly in the lithium ions of the battery.

Using this photo-assisted technology in vehicle batteries would require substantial redesign that would allow concentrated light to illuminate battery electrodes during charging. How practical that is remains to be seen, but the payoff would be substantial.

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Shedding new light on the charging of lithium-ion batteries

Photo, posted June 30, 2018, courtesy of Open Grid Scheduler via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

New Membranes For Carbon Capture

October 2, 2019 By EarthWise Leave a Comment

Drastically reducing the amount of carbon dioxide being emitted into the atmosphere is an essential goal in the effort to mitigate the effects of climate change. While the ultimate solution is to avoid combustion of fossil fuels by the use of clean alternative energy sources, that transition will take time – possibly more time than we have. As a result, there is a great deal of effort underway to develop techniques for capturing the carbon emitted by fossil fuel combustion and either recycling it or storing it.

There are multiple ways to capture carbon emissions, but the ultimate goal is to find a technique that is both inexpensive and scalable. One promising technique involves the use of high-performance membranes, which are filters that can specifically pick out CO2 from a mix of gases, such as those coming out of a factory smokestack.

Scientists at a Swiss laboratory have now developed a new class of high-performance membranes that exceeds the targeted performance for carbon capture by a significant margin. The membranes are based on single-layer graphene with a selective layer thinner than 20 nanometers – only about 40 atoms thick. The membranes are highly tunable in terms of chemistry, meaning that they can be designed to capture specific molecules.

The membranes are highly permeable – meaning that they don’t impede gas flow too much – but highly selective. The CO2/N2 separation factor is 22.5, which means that 22.5 times more nitrogen can get through the membrane than carbon dioxide.

The work is just at the laboratory stage at this point, but it is a very promising step towards developing a practical scheme for keeping carbon dioxide from escaping from power-plant and factory smokestacks.

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Next-gen membranes for carbon capture

Photo, posted December 28, 2010, courtesy of Emilian Robert Vicol via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Affordable Electric Cars

May 1, 2019 By EarthWise Leave a Comment

The main reasons that electric cars haven’t taken over are that they didn’t drive far enough on a charge, it took too long to charge them, and, most of all, they cost too much.

In recent years, the problem with driving range has steadily been disappearing as electric cars that can go over two hundred and even over three hundred miles on a charge have entered the market. Charging time has also become less of a problem. Tesla’s network of Superchargers can provide 200 miles worth of charge in half an hour and their next generation of chargers, which are just starting to appear, can cut that time much further.

As for cost, a new report by transportation analysts at Bloomberg New Energy Finance predicts that electric vehicles will be cost-competitive with combustion-engine cars by 2022.

The main reason is that the cost of EV batteries has been plummeting. In 2015, batteries made up 57% of the total cost of an electric vehicle. Today, that number is down to 33% and is expected to drop to 20% by 2025. In addition, the cost of electric powertrain systems is also dropping. The Bloomberg report predicts that over the next decade, costs for motors, inverters, and power electronics could be 25 to 30% cheaper than today.

The cost of electric vehicles has been dropping faster than predicted. Bloomberg’s report on the subject in 2017 predicted cost parity in 2026. Last year, they changed it to 2024. And now, they are saying 2022.

Given that electric cars are much cheaper to drive than gasoline cars, finding reasons not to drive them is getting harder to do.

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Electric Cars Could Be As Affordable as Conventional Vehicles In Just Three Years

Photo, posted November 17, 2018, courtesy of Jakob Harter via Flickr.

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The New Normal Weather

March 13, 2019 By EarthWise Leave a Comment

We often hear about how the weather is getting stranger all the time, but do most of us really think so? What kinds of weather do we really find remarkable and has that been changing?

A study led by the University of California, Davis used some very modern tools to examine the question of what people might consider to be “normal” weather. To reach their conclusions, they quantified the timeless pastime of talking about the weather by analyzing Twitter posts. They sampled over 2 billion geolocated tweets to determine what kind of events generated the most posts about the weather.

Unsurprisingly, they found that people most often tweet when temperatures are unusual for a particular place and time of year. However, if the same weather persisted year after year, it generated less comment on Twitter, indicating that people began to view it as normal in a relatively short amount of time.

The study indicates that people have short memories when it comes to what they consider normal weather. On average, most people base their idea of normal weather on what has happened in just the past two up to maybe eight years. This disconnect with the historical climate record may obscure the public’s perception of climate change.

After repeat exposures to historically-extreme temperatures, people talk less about the weather, even though particularly hot or cold weather conditions make them unhappy and grumpy. Even though we are experiencing conditions that are historically extreme, we might not consider them to be particularly unusual if we tend to forget what happened more than a few years ago. Things may be getting worse, but they apparently are just the new normal.

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