Tag: chemistry

Super-Tough Silicon Carbide Sensors Could Survive Inside a Volcano

By Andrew Moseman | September 21, 2010 12:40 pm

MagmaThe silicon from which most electronics are built is a useful, durable material up to about 350 degrees Fahrenheit (but don’t go sticking your iPhone in the oven). Three hundred fifty isn’t bad, says engineer Alton Horsfall of Newcastle University in the U.K., but not nearly good enough for his mission: monitoring volcanoes.  Horsfall and colleague Nick Wright say their research into a different material, silicon carbide (SiC), shows that it could work at temperatures in excess of 1,000 degrees F, and might be just what they need to keep watch on inhospitable places like the blazing-hot mouth of a volcano.

The silicon and carbon in silicon carbide bond very strongly, permitting them to survive extreme temperatures. But the material’s pricey and hard to work with for the same reason. So while organizations like NASA have done silicon carbide research, the material hasn’t spread to a multitude of applications.

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CATEGORIZED UNDER: Environment, Technology

When Caterpillars Attack, Tobacco Plants Use Their Own Spit Against Them

By Andrew Moseman | August 26, 2010 5:25 pm

Tobacco-hornwormIf you’re a tobacco hornworm caterpillar, your own spit can come back to bite you: That plant you tried to eat for dinner can use your own saliva to summon larger animals that might like to make you their dinner.

According to a study in Science, the tobacco plant has evolved a clever defense against hungry insects—it calls in the insects’ predators for help:

When a leaf is wounded, plants immediately release a “bouquet” of distress chemicals known as green leaf volatiles (GLVs) into the air. GLVs are formed when long fatty acid chains in the cell membranes are chopped up into six-carbon molecules as a result of damage. These molecules can exist in two different shapes, or isomers, depending on the position of a double bond between two of the carbons [The Scientist].

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CATEGORIZED UNDER: Living World

How to Turn a Frog Egg Into a Robot’s Artificial Nose

By Joseph Calamia | August 24, 2010 5:35 pm

robotsmellResearchers have found the secret to improving a robot’s sense of smell: Shove frog eggs up its nose. A team at the University of Tokyo has developed a sensor made from a genetically modified frog egg that can help a robot pick out insect smells and pheromones.

As useful as a moth-smelling robot may seem, researchers believe the study published yesterday in Proceedings of the National Academy of Sciences is just one step towards an inexpensive but sensitive chemical detector. Study coauthor Shoji Takeuchi explains that such a device could pick out gases like carbon dioxide:

“When you think about the mosquito, it is able to find people because of carbon dioxide from the human. So the mosquito has CO2 receptors. When we can (extract) DNA (from the mosquito) we can put this DNA into the frog eggs to detect CO2.” [Reuters]

Here’s how they did it.

Step 1 — Get Some Frog Eggs

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CATEGORIZED UNDER: Living World, Technology

Study: There's Water on the Lunar Surface, but Inside It's Bone Dry

By Andrew Moseman | August 6, 2010 9:18 am

moonWet. Dry. Wet. Dry. You’d think the moon were a vacuum cleaner infomercial.

A series of studies in the last few years has raised our hopes that the moon is not completely dry—researchers have said that it’s still drier than the driest places on Earth, but some small amount of water ice is there. Then, this afternoon, along comes another study to reassert that the interior of the moon is drier than bone-dry.

For his paper in Science, Zachary Sharp peered into the lunar samples brought back to Earth by the Apollo missions. Where previous studies of those Apollo rocks suggested water ice was locked inside the minerals, Sharp’s assessment focuses on the chlorine in the sample because it could tell him about the moon’s history.

Most scientists think the moon was born when a huge object roaming the inner solar system — something about the size of Mars — smashed into the embryonic Earth. Debris from the collision coalesced to form the moon. As it cooled, an ocean of magma covering its surface began to crystallize. Sharp and his colleagues studied what happened to two isotopes of the element chlorine during that process [Science News].

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CATEGORIZED UNDER: Space
MORE ABOUT: chemistry, moon, water

Spitzer Telescope Finds Buckyballs… in Spaaace!

By Joseph Calamia | July 22, 2010 5:08 pm

Looking at a planetary nebula 6,500 light years away, scientists recognized an old friend: the buckyball. The large, soccer ball-shaped molecule–made from bonding 60 carbon atoms together–was first seen in a lab in 1985. In a paper published today in Science, scientists confirm the first known extraterrestrial existence of the rare carbon balls.

buckyballsspace

The buckyballs’ planetary nebula, called TC 1, surrounds a white dwarf star. Using NASA’s Spitzer Space Telescope, a team led by Jan Cami of the University of Western Ontario observed traces of the the 60-atom balls and their 70-atom cousins while looking at light coming from the white dwarf.

When light hits molecules and atoms, they will vibrate in specific, measurable ways–a field of science known as spectroscopy. One of Cami’s colleagues, who was studying Tc 1, found some unfamiliar fingerprints in the nebula’s infrared light. Cami recognized them as carbon’s 60-atom configuration and its favored 70-atom carbon partner. [Discovery News]

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CATEGORIZED UNDER: Physics & Math, Space

Legal, Synthetic Marijuana Pleases Pot-Heads, Upsets State Governments

By Andrew Moseman | July 12, 2010 12:59 pm

k2Around the United States, state governments are rushing to enact bans on K2, the hot new (and still mostly legal) drug made with synthetic cannabinoids: lab-created compounds designed to mimic the effects of THC, the active ingredient in marijuana.

Often marketed as incense, K2 — which is also known as Spice, Demon or Genie — is sold openly in gas stations, head shops and, of course, online. It can sell for as much as $40 per gram. The substance is banned in many European countries, but by marketing it as incense and clearly stating that it is not for human consumption, domestic sellers have managed to evade federal regulation [The New York Times].

Missouri is the most recent state to move against K2, the origin of which dates back to the work of Clemson University scientist John Huffman, who was developing these synthetic compounds in the 1990s. Scientifically, the chemicals are interesting for their potential to mimic some of the pain-relieving aspects of marijuana, which advocates of medical marijuana legality point to, without the negative health effects that come with setting a plant on fire and inhaling the smoke. The chemical used in most varieties of K2 is called JWH-018.

Huffman was interviewed by The Guardian last year when K2 was spreading around Europe. Now in his late 70s, he seems to understand something that many politicians can’t seem to get through their heads: Risk-taking teenagers will go to about any length, legal or illegal, to get high. Huffman says he wouldn’t oblige the numerous enterprising types who asked him how to make his substances, and that the substances are always labeled not for human consumption. But he figured someone was going to figure it out sooner or later, especially considering the chemical doesn’t show up on drug tests.

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Can the Human Body Make Its Own Morphine?

By Andrew Moseman | April 28, 2010 2:32 pm

MorphineWho needs poppy plants to produce morphine? Last month scientists said they’d isolated the genes those plants use to synthesize the narcotic chemical and made it themselves in a lab. Now, in a study in the Proceedings of the National Academy of Sciences,  another team has suggested that we mammals might possess the pathway to create our own morphine.

Because we have receptors for the opiate in our brains (which makes it such an effective and addictive painkiller), and because morphine traces show up in our urine, scientists had long wondered if animals could produce the drug themselves. But studies using living animals yielded inconclusive results because of possible contamination from external sources of morphine in their food or in the environment [Nature]. In addition, the body breaks down and changes morphine, which complicates the task.

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CATEGORIZED UNDER: Health & Medicine, Mind & Brain

New Element Discovered! But Don't Ask About Its Name

By Smriti Rao | April 6, 2010 5:39 pm

element-117-279x300A little square that has been left blank on the periodic table for all these years might finally be filled in. A team of American and Russian scientists have just reported the synthesis of a brand new element–element 117. Says study coauthor Dawn Shaughnessy: “For a chemist, it’s so fundamentally cool” to fill a square in that table [The New York Times].

If other scientists confirm the discovery, the still-unnamed element will take its place between elements 116 and 118, both of which have already been tracked down. A paper about element 117 will soon be published in Physical Review Letters, and scientists say the new element appears to point the way toward a brew of still more massive elements with chemical properties no one can predict [The New York Times].

Element 117 was born in a particle accelerator in Russia, where the scientists smashed together calcium-48 — an isotope with 20 protons and 28 neutrons — and berkelium-249, which has 97 protons and 152 neutrons. The collisions spit out either three or four neutrons, creating two different isotopes of an element with 117 protons [Science News].

The new element 117, takes it place between two superheavy elements that scientists know to be very radioactive and that decay almost instantly. But many researchers think it is possible that even heavier elements may occupy an “island of stability” in which superheavy atoms stick around for a while [Science News]. If this theory holds up, scientists say, the work could generate an array of strange new materials with as yet unimagined scientific and practical uses [New York Times].

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CATEGORIZED UNDER: Physics & Math

Spacecraft-Collected Comet Dust Reveals Surprises From the Solar System's Boondocks

By Andrew Moseman | February 26, 2010 1:21 pm

stardustcometSince NASA’s Stardust mission returned in 2006 from its trip of billions of miles collecting the dust of a comet called Wild2 and dropped it samples down to Earth in the Utah desert, the samples have raised all sorts of questions about how comets formed and what the early solar system was like. In a study this week in Science, there’s a new surprise. Scientists say that the comet sample contains chemicals that must have formed in our home turf, the inner solar system.

Lead researcher Jennifer Matzel studies a tiny particle taken from Stardust’s sample, a piece just five micrometers across. In it her team found the mark of materials that would have formed under high temperatures. Matzel, who specializes in using the decay rates of radioactive chemical elements to assess ancient dates, determined that the Stardust particle must have crystallized just 1.7 million years after the oldest solid rocks in the solar system were forming [San Francisco Chronicle]. After that, the researchers says, the particle must have been flung out to the Kuiper Belt, the region of icy comets revolving around the sun at a distance far past Neptune.

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CATEGORIZED UNDER: Space

Study: Bacteria Can Make Avatar-Like Electrical Connections in Mud

By Andrew Moseman | February 25, 2010 1:14 pm

ElectricMudOnce again, laziness pays off. When microbiologist Lars Peter Nielsen and his team were studying marine sediments, they got a little sloppy about cleaning their beakers. But after letting samples sit around in the lab for a few weeks, they began to see weird chemical patterns in them that you just wouldn’t expect. As they saw changes in the surface of the mud quickly trigger other changes down below, the scientists came upon a startling idea: that the bacteria in the top layer and those deep down were somehow electrically linked. Their paper appears this week in Nature.

Specifically, Nielsen saw that hydrogen sulfide buried below the sediment’s surface (the stuff that makes it smell bad) was oxidizing and changing color. One problem, though: That shouldn’t be happening. Below the sediment surface there is plenty of hydrogen sulfide and carbon for bacteria to consume via oxidation, or removing electrons [Scientific American]. But the reaction can’t be sustained without access to dissolved oxygen, which carries away electrons produced by the reaction, and in these samples the oxygen was all up at the sediment’s surface. So the researchers hypothesize that the buried bacteria form a conductive chain to ferry the electrons up to the surface.

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CATEGORIZED UNDER: Environment, Living World
MORE ABOUT: bacteria, chemistry, ocean
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