Artist rendering of NASA’s Parker Solar Probe observing the sun. Credit: NASA/Wikimedia Commons.
One of the most logically-baffling solar mysteries is the fact that the sun’s surface is close to 10,000 degrees Fahrenheit while its outer atmosphere is several million degrees hotter. The body of the heat’s source itself is cooler than the atmosphere surrounding the fireball — and that’s simply against the common sense of physics.
Some physicists think that the terrific, intense heat displayed in the outer limits of the sun’s atmosphere may be explained by magnetic waves traveling to and from the solar surface, bouncing off the upper atmosphere (otherwise known as the corona) of the star. Recent studies have suggested that this activity could be tied to the sun’s zone of preferential ion heating. In this zone, ions reach scorching temperatures exceeding those at the very core of the sun.
Another element which has a role to play in this outlying solar vortex are Alfven waves. These waves are low-frequency oscillations traveling through a plasma in a magnetic field. Scientists think that these waves are making solar wind particles to collide and ricochet off one another. But once it hits the outskirts of the zone of preferential heating, the solar wind sweeps by at an extremely fast pace. Thus, it manages to evade the Alfven waves from there on out.
Researchers at trying to definitively mark the extent to which the superheating effect reaches beyond the sun. Recent research has brought light to a connection between the Alfven point (the point of altitude beyond the solar surface that permits solar wind particles to break free of the sun) and the outskirts of the zone of preferential heating. These two fields have fluctuated in unison. They shall continue their dance, and in 2021, NASA’s Parker Solar Probe, christened in honor of physicist Eugene Parker, should come in contact with the two boundaries.
The spacecraft includes instruments capable of recording a number of significant data pertaining to those solar fields. The information it would collect in some two years to come would be invaluable in this particular study.
The Parker Solar Probe was launched in August 2018. It made its second successful fly-by of our sun in early April with the follow-up perihelion (the point at which it gets closest to the sun) scheduled to occur on September 1. Visit NASA’s page on the Parker Solar Probe to learn more about it and its mission. To learn of interesting updates, check out the website of Parker Solar Probe Science Gateway.
Shipwrecks are coming — soon, to a museum near you. And it’s all thanks to nanotechnology.
“The Wreck”, Knud-Andreassen Baade. Image via Wikimedia.
A novel approach hopes to turn the damp, pitted wood of ancient shipwrecks into a showstopper. The team is currently using ‘smart’ nanocomposites to conserve the 16th-century British warship, the Mary Rose, and its artifacts. Should the process prove effective, museums will be able to display salvaged wrecks in all their glory without them rotting away.
The old that is strong does not wither
Thousands of shipwrecks have come to rest on ocean floors through the centuries. These drowned leviathans spark the passion of both researchers — who can learn a lot about past battles and ways of life from the wrecks — and public alike.
However, it’s very risky to go in and try to recover shipwrecks. Metal ships tend to weather the years underwater with some grace, but the wooden ones quickly rot away — after roughly a century, the only parts that remain are those that were buried in silt or sand soon after the sinking. Even worse, these timber skeletons quickly deteriorate once brought up to the surface.
While underwater, sulfur-reducing bacteria from the sea floor move into the wood and secrete hydrogen sulfide. This reacts with iron ions (rust) from items like nails or cannonballs, forming iron sulfide. This compound remains stable in environments that sport low levels of oxygen but binds with the gas to form acids that attack the wood.
In a paper being presented today at the 256th National Meeting & Exposition of the American Chemical Society (ACS), one team of researchers detail their efforts to keep wooden shipwrecks intact after recovery.
“This project began over a glass of wine with Eleanor Schofield, Ph.D., who is head of conservation at the Mary Rose Trust,” recalls Serena Corr, Ph.D., the project’s principal investigator.
“She was working on techniques to preserve the wood hull [of the Mary Rose] and assorted artifacts and needed a way to direct the treatment into the wood. We had been working with functional magnetic nanomaterials for applications in imaging, and we thought we might be able to apply this technology to the Mary Rose.”
Mary Rose in its specially-designed building at the Historic Dockyard in Portsmouth, United Kingdom. Image via Wikimedia.
The Mary Rose was one of the first sailing ships built for war. Work on the wooden carrack (three-masted ship) began in 1510, and she was set to sea in July 1511. She remained one of the largest ships in the English navy for over three decades, during which she fought against the French, Scottish, and Brythonic navies — a task at which the Mary Rose excelled. The ship bristled with heavy cannons that popped out from gun-ports (which were cutting-edge technology at the time), and one of the first ships in the world capable of firing a full broadside.
Still, for reasons not yet clear, the ship sank in 1545 off the south coast of England. It was re-discovered in 1971 and recovered in 1982 by the Mary Rose Trust, along with over 19,000 artifacts and pieces of timber. The wreck helped provide a unique snapshot of seafaring and daily life in the Tudor period. It was displayed in a museum in Portsmouth, England, alongside the recovered artifacts.
Only 40% of the initial wooden structure survived the centuries underwater, and even this was rapidly degrading on the surface. So the Trust set out to preserve their invaluable wreck.
Corr’s goal was to avoid acid production by removing free iron ions from the wreck. She and her team at the University of Glasgow started by spraying the wood with cold water to keep it from drying out, which prevented further microbial activity, they explain. Afterward, they applied different types of polyethylene glycol (PEG) — a common polymer — to the wreck. The PEG replaced water in the wood’s cells, forming a more robust outer layer.
The team, alongside researchers from the University of Warwick, are also working on a new family of magnetic nanoparticles to help in the conservation effort. They analyzed the sulfur species in the wood before the PEG treatment was applied, and then periodically as the ship dried.
This process will help the team design new targeted treatments to scrub sulfur compounds from the wood of the Mary Rose.
The next step, Schofield says, will be to use a nanocomposite material — based on magnetic iron oxide nanoparticles coated in active chemical agents — to remove these sulfur and iron ions. The nanoparticles will be applied directly to the wood and later guided through its pores to any particular areas using external magnetic fields. Such an approach should allow the team to completely remove the ions from the wood, they say.
“Conservators will have, for the first time, a state-of-the-art quantitative and restorative method for the safe and rapid treatment of wooden artifacts,” Corr says. “We plan to then transfer this technology to other materials recovered from the Mary Rose, such as textiles and leather.”
Crystals have caught the eye of humans since the dawn of time. Some scientists have even speculated that the origins of life on Earth may trace its origins to crystals. It shouldn’t come as a surprise that these gleaming mineral formations appear frequently in pop culture often as having supernatural powers (even though they don’t). A few examples of this reoccurring theme are the Silmarils in the Lord of the Rings universe and the sunstones in James Gurney’s Dinotopia.
The atoms which make up a crystal lie in a lattice which repeats itself over and over. There are several methods for generating crystals artificially in a lab, with superheating being the most common process. Likewise, in nature, a hot liquid (eg: magma) cools down, and as this happens, the molecules are attracted to each other, bunching up and forming that repeating pattern which leads to crystal formation.
Quartz is one of the most abundant minerals found on the planet. This mineral is known to be transparent or have the hues of white, yellow, pink, green, blue, or even black. It is also the most common form of crystalline silica which has a rather high melting point and can be extremely dangerous if inhaled in its powdered form. This mineral compound is present in the majority of igneous rocks. Some quartzes are considered semiprecious stones. Aside from mere bedazzlement, they have been used in countless industries.
Industrial, not magical uses
If a pressure is applied to the surface of a quartz crystal, it can give off a small electrical charge. This effect is the result of the electrically charged atoms (the ions) dispersing and spreading away from the area to which the pressure is being applied. This can be done in a number of ways, including simply squeezing the crystal. It also dispenses an electric current if a precise cut is made at an angle to the axis.
Since it possesses this property, quartz has been a component of devices such as radios, TV’s, and radar systems. Some quartz crystals are capable of transmitting ultraviolet light better than glass (by the way, quartz sand is used in making glass). Because of this, low-quality quartz is often used for making specific lenses; optical quartz is made exclusively from quartz crystals. Quartz which is somewhat clouded or which is not as transparent as the stuff used for optics is frequently incorporated into lab instrumentation.
Scientists have employed quartz for many things, and they have considered its role in the Earth sciences a crucial one. Some have stated it directly brings about the reaction which forms mountains and causes earthquakes! It continues to be used in association with modern technology, and it likely will lead us to more discoveries in the future.
The full extent of Japan’s 2011 Fukushima meltdown is still being uncovered, with measured levels of contamination increasing in previously identified sites throughout the North American coast. While it’s still too low to threaten human or ocean life, this confirms that the power plant continues to leak radioactive isotopes researchers report.
Image via deviantart
The Fukushima Daiichi nuclear plant saw wide-scale equipment failure following the 11 March 2011 earthquake and tsunami. The ensuing triple reactor meltdowns and escape of radioactive material on the 12th were so severe that the accident is considered as being second only to the one at Chernobyl.
Researchers at the non-profit Woods Hole Oceanographic Institution have been taking samples of Pacific Ocean water and analyzing them in an effort to monitor and document the aftermath of the accident. The results show that the Fukushima reactors still leaks radioactive isotopes (especially cesium-134) four years after the meltdowns, reports marine radiochemist Ken Buesseler. Trace amounts of these atoms have been found in several hundreds of miles-wide areas of the Oregon, Washington and California coasts as well as offshore of Vancouver Island.
Another isotope, cesium-137, a radioactive reminder of the nuclear weapons tests conducted between 1950 and 1970, was found at low levels in nearly every seawater sample tested.
“Despite the fact that the levels of contamination off our shores remain well below government-established safety limits for human health or to marine life, the changing values underscore the need to more closely monitor contamination levels across the Pacific,” Buesseler said.
In 2014 the Institute reported detecting isotope contamination about 100 miles (160 km) off the norther coast of California as well as off Canada’s shorelines. The latest readings measured the highest radiation levels outside Japanese waters to date some 1,600 miles (2,574 km) west of San Francisco.
The figures also confirm that the spread of radiation to North American waters is not isolated to a handful of locations, but rather a along a stretch of more than 1,000 miles (1,600 km) of shoreline. Currently, reported levels in these areas shouldn’t be dangerous to organisms, but this may change in the future.
Tawny crazy ants (Nylanderia fulva) attacked by rivaling fire ants (Solenopsis invicta). To protect itself against the deadly fire ant venom, crazy ants secret a venom of their own that cancels the other. When the two mix, a new substance whose class has never been encountered in nature emerges. Photo: Ed LeBrun
Ionic liquids (IL) are basically liquid salts with very low melting points. These are heavily used in industry as solvents for chemical processes or as performance enhancers, part of electrolytes or lubricants. It’s only recently that an ionic liquid has been found to occur in nature, after a team of researchers at University of South Alabama found that the substances forms when two ant species mix their venom.
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The team led by Prof. James Davis was studying two ant species fighting over territory: fire ants (Solenopsis Invicta) and tawny crazy ants (Nylanderia fulva). Fire ants and tawny crazy ants are native to South America, where their battle may have raged for thousands of years. Fire ants arrived in the United States first, sometime in the 1930s. The crazy ants didn’t start to show up until the early 2000s.
When the fire ants would sprinkle the tawny crazies with their venom, the latter would respond by secreting formic acid, their own venom, to groom and rid themselves of the poisonous attack. When the two substances mix, a viscous ionic liquid containing a mixture of different cations along with formate anions forms.
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The properties of the resulting mixed-cation ammonium formate milieu are consistent with its classification as a protic IL. Seeing how the IL was discovered by accident, it’s very much likely that other naturally occurring ILs might be discovered.
It’s interesting to see how well the crazy ants have adapted to fire ants’ venom. In a separate study, Edward LeBrun, a researcher at the Fire Ant Research and Management Project at the University of Texas at Austin, found when crazy ants were prevented from secreting the antidote after being brushed with a bit of nail polish on their abdomens, 48% of them died when exposed to fire ants. When they were allowed to secrete the antidote, 98% survived.
Finding appeared in the journal Angewandte Chemie International.
In a breakthrough moment, researchers at Harvard School of Engineering and Applied Sciences have developed a novel material resembling a simple transparent disk, which the researchers applied an electrical signal to and used it to play music. This is no ordinary speaker, though. The disk consists of a thin sheet of rubber sandwiched between two layers of a saltwater gel, and represents the first demonstration that electrical charges carried by ions, rather than electrons, can be put to meaningful use in fast-moving, high-voltage devices.
Using ionic materials for high voltage applications has been thought to be intractable in the past, due to the high number of constraints. High voltages can set off electrochemical reactions in ionic materials, producing gases and burning up the materials. Also, ions, being much larger than electrons, take longer to propagate through a circuit affecting signal quality. The system developed at Harvard overcomes both of these challenges, all while exposing a number of benefits inaccessible to traditional, electron carrying conductors.
Jeong-Yun Sun (left) and Christoph Keplinger show off an ionically conductive material that is very stretchy and completely transparent. Photo by Eliza Grinnell/SEAS Communications
And, we’re not talking here just about sound speakers. The researchers chose to design a speaker with their compound material simply because its the best proof of concept. To produce sound in the whole human audible spectrum – 20 Hz to 20kHz – a speaker needs to carry high voltage and be capable of contracting rapidly to produce vibrations and push the air in a specific manner, producing what we commonly refer to as sound. This wasn’t though possible in the past for ionic conductors.
“It must seem counterintuitive to many people, that ionic conductors could be used in a system that requires very fast actuation, like our speaker,” said Sun. “Yet by exploiting the rubber layer as an insulator, we’re able to control the voltage at the interfaces where the gel connects to the electrodes, so we don’t have to worry about unwanted chemical reactions. The input signal is an alternating current, and we use the rubber sheet as a capacitor, which blocks the flow of charge carriers through the circuit. As a result, we don’t have to continuously move the ions in one direction, which would be slow; we simply redistribute them, which we can do thousands of times per second.”
Ions that play music
Since it can suit the high demands a speaker poses, the material is versatile enough to be used in other applications, where other options aren’t available. Key traits of the Harvard ionic conductor include: the capacity to stretch to many times their normal area without an increase in resistivity (common issue in stretchy electronics); transparency (high reward of optics apps); bio-compatibility (!).
A video demonstration of the gel-based audio speaker can be seen in the video embedded below.
Immediate applications includes devices that need a soft, transparent layer that deforms in response to electrical stimuli — for example, on the screen of a TV, laptop, or smartphone to generate sound or provide localized haptic feedback. Smart windows are also a highly interesting and appealing idea – you could potentially place this speaker on a window and achieve active noise cancellation, with complete silence inside.
“With wearable computing devices becoming a reality, you could imagine eventually having a pair of glasses that toggles between wide-angle, telephoto, or reading modes based on voice commands or gestures,” suggested Sam Liss, director of business development in Harvard’s Office of Technology Development
The term capabilities of the technology are far more interesting, however. The electrical signal that relays information to and fro the brain is actually carried by charged ions, not electrons. Seeing how the ionic conductor developed at Harvard is also biocompatible, it’s not difficult to imagine high-tech biotechnology like artificial muscles, limbs or organs meshing in this novel material.
“The big vision is soft machines,” said co-lead author Christoph Keplinger, who worked on the project as a postdoctoral fellow at SEAS and in the Department of Chemistry and Chemical Biology. “Engineered ionic systems can achieve a lot of functions that our body has: They can sense, they can conduct a signal, and they can actuate movement. We’re really approaching the type of soft machine that biology has to offer.”
The ion conductor was described in a paper published in the journal Science.