Stories tagged Structure of Matter

Apr
16
2008

Taking some of the poison out of wine: Don't worry--the snake died happy.
Taking some of the poison out of wine: Don't worry--the snake died happy.Courtesy niko si
South African entrepreneur and former pro rugby player, Guy Kebble, has supposedly invented a method of purifying wine that could eliminate some of the negative side effects of drinking. The side effects in question include headaches and nausea, which nobody likes. There’s still no word as to whether the new wine filtering technique will have any affect on some of the other side effects of drinking, like dangerously creative dancing, or telling that dude what you really think of his fauxhawk.

Before we get into the specifics of Guy’s technique, let’s learn a little bit about hangovers.

As we all know, hangovers are primarily the result of an epic scale battle of wills between the mind and the body. Always at war, a night of drinking might be considered a specific “battleground” between the armies of the brain and the body, an opportunity for each faction to make the other do something it knows is a bad idea. The desolation of the morning after, however, has time and time again shown that, in war, no one wins.

Ethyl alcohol is the active component of beer wine and liquor. We drink it, and things get a little goofy. Ethyl alcohol, or ethanol, is not to be confused with methyl alcohol. Methyl alcohol, or methanol, can be distilled from wood, and differs from ethanol by a single carbon atom and a couple of hydrogens. When we drink methanol, however, things get really goofy. Like, we go blind and die.

Aside from the goofy stuff, ethanol is a diuretic—it makes us pee more. Because of all this peeing, we get dehydrated after boozing it up. Dehydration gives us dry mouths and aching heads. Also, being dehydrated can cause or little brains to shrink slightly and pull away from the sides of the skull, which is kind of unsettling.

Along with dehydration, when our body metabolizes alcohol things get a little crazy. Shortly after consuming alcohol, our bodies turn it into acetaldehyde. Acetaldehyde is a flammable, fruity smelling liquid, and it’s found naturally in fruit, coffee, and fresh bread. And it causes hangovers. The acetaldehyde is then converted in the liver to acetic acid, a reaction that redirects glucose (sugar) from our brains, and when our brains don’t get their sugar fix, they get angry. Also, they get tired, weak, moody, and unable to concentrate.

Finally, the presence of other chemicals mixed in with the alcohol, called congeners, can cause trouble. Congeners are products of fermentation, and are sometimes added to drinks to enhance flavor. They also can make us sick.

This is where the South African wine scheme comes in. Most wine, it seems, has sulphites added to it, to help preserve it from spoiling. Some people are intensely allergic to sulphites, but most of us just get headaches from them. But the alternative is drinking spoiled wine. Or no wine at all, if you want to get technical.

Guy Kebble claims to have invented a machine that purifies liquids using “ultra-violet technology,” making it unnecessary—in wine—to add sulphites to kill the little wine-dwelling microbes. And without the sulphites, all that stands in the way of joyful mornings-after are dehydration, acetaldehyde poisoning, and hypoglycemia.

That’s all? This Guy’s going to be rich.

Mar
30
2008

Graphene potentially 100x better than silicon

Graphene computer chips: The slightly darker purple area is the graphene, and the lighter purple is the substrate material (SiO2/Si).
Graphene computer chips: The slightly darker purple area is the graphene, and the lighter purple is the substrate material (SiO2/Si).Courtesy S. Cho and M. S. Fuhrer, University of Maryland
Graphene could replace silicon as the material of choice for many applications like high-speed computer chips and biochemical sensors.

Michael Fuhrer in a paper published online in Nature Nanotechnology explains that in graphene, the intrinsic limit to the mobility, a measure of how well a material conducts electricity, is higher than any other known material at room temperature.

If other extrinsic factors that limit mobility in graphene, such as impurities and lattice vibrations in the substrate on which graphene sits, could be eliminated, the intrinsic mobility in graphene would be more than 100 times higher than silicon.

The low resistivity and extremely thin nature of graphene makes it ideal for applications like touch screens, photovoltaic cells, and chemical and biochemical sensors. The research group was led by principal investigator Michael Fuhrer of the University of Maryland's Center for Nanophysics and Advanced Materials and the Maryland NanoCenter.

Better than silver or gold

Fuhrer said the electrical current in graphene is carried by only a few electrons moving much faster than the electrons in a metal like silver.

"Our current samples of graphene are fairly 'dirty' due to some extraneous sources of resistivity,"
"Once we remove that dirt, graphene, at room temperature, should have about 35 percent less resistivity than silver, the lowest resistivity material known at room temperature."

Roadmap for progress

Because graphene is only one atom thick, current samples must sit on a substrate, in this case silicon dioxide. The electron mobility within the graphene is effected by the substrate. Trapped electrical charges in the silicon dioxide (a sort of atomic-scale dirt) and vibrations of the silicon dioxide atoms can also have an effect on the graphene which are stronger than the effect of graphene's own atomic vibrations.

"We believe that this work points out the importance of these extrinsic effects, and creates a roadmap for finding better substrates for future graphene devices in order to reduce the effects of charged impurity scattering and remote interfacial phonon scattering." Fuhrer said.

Source:University of Maryland news release

Feb
24
2008

Grand Challenges for Engineering in the 21st Century

Want to know what to do with your life. A diverse committee of experts from around the world, at the request of the U.S. National Science Foundation, identified 14 challenges that, if met, would improve how we live.

Here is their list in no particular order. You can learn more about each challenge by clicking on it.

You can vote for which is most important

The committee decided not to rank the challenges. NAE is offering the public an opportunity to vote on which one they think is most important and to provide comments at the Engineering Challenges website

Feb
05
2008

Nano (not!): Built for the 1958 Brussels World's Fair, this model of a body-centred cubic crystal is similar to the nano crystal created with DNA except it is magnified 165 billion times.
Nano (not!): Built for the 1958 Brussels World's Fair, this model of a body-centred cubic crystal is similar to the nano crystal created with DNA except it is magnified 165 billion times.Courtesy John Kerno

First step toward three-dimensional catalytic, magnetic, and/or optical nanomaterials

Assembling structures that are 1000 times smaller than a human hair is difficult. One technique that works is known as "self assembly". A random mixture of microscopic parts can be coaxed into assembling spontaneously into a desired structure by attaching appropriate segments of DNA to various parts. Complementary DNA strands want to "pair up". This is how nano structures are assembled in living organisms.

"researchers at the U.S. Department of Energy's Brookhaven National Laboratory have for the first time used DNA to guide the creation of three-dimensional, ordered, crystalline structures of nanoparticles.

Nanomaterials: Golden handshake

The team from Brookhaven and another group from Northwestern University in Evanston, US, both started with tiny spheres of gold around 10 nanometres across, and attached short strands of DNA. By varying the length of the DNA strands, their flexibility,and the types of sticky ends, they are working toward reliably binding them together in particular ways. This is the first step toward building three-dimensional catalytic, magnetic, and/or optical nanomaterials.

Sources:

Dec
18
2007

Burning methane hydrate
Burning methane hydrateCourtesy United States Geological Survey

What is Methane ice?

Huge amounts of methane are being found on the ocean floor, trapped within cages of water molecules.

Methane clathrate, also called methane hydrate or methane ice, is a solid form of water that contains a large amount of methane within its crystal structure (a clathrate hydrate). wikipedia

Geologists estimate that significantly more hydrocarbons are bound in the form of methane hydrate than in all known reserves of coal, natural gas and oil combined. India and China plan to spend hundreds of millions of dollars learning how to tap into this huge reservoir of energy (Spiegel online).

Carbon curse or cure

Relying on this carbon based energy instead of renewable energy sources could worsen global warming by releasing more greenhouse gases. To be carbon neutral the carbon dioxide from burning carbon fuels needs to be captured and sequestered (locked up). Harvesting methane ice offers just this opportunity.

When a certain amount of pressure is applied to the cage-like crystal structure, carbon dioxide can penetrate the layer of ice, at which point it displaces the methane. Then a new cage of frozen water molecules forms around the carbon dioxide. Klaus Wallmann, Uni Kiel

Wallman is also impressed by the ratio at which the gases are exchanged. For each dissolved molecule of methane released, up to five molecules of carbon dioxide disappear into the ice cage. Wallmann hopes to see, in the not-too-distant future, tankers filled with CO2 heading out to sea to pump their climate-damaging cargo into the depths.

You might also read about research being done at Columbia University, "Carbon Neutral Methane Production Via Hydrates".

Dec
08
2007

Killer robots are everywhere!: And soon they'll be even unstoppabler. More unstoppable.
Killer robots are everywhere!: And soon they'll be even unstoppabler. More unstoppable.Courtesy SoulCookie
I hate to bring up killer robots so frequently (no, wait, “hate” isn’t the right word), but the news this week demands it – New Scientist featured a story a few days ago on self-healing composite materials.

Granted, the article never directly mentions killer robot technology, but when you’re dealing with self-healing materials, I think killer-robotics is pretty much the implied subject.

Ostensibly, the article is about how new materials could make things like bridges and passenger planes more safe. Large constructions like these gradually develop tiny fractures from simple fatigue. These can become dangerous as they add up, and there’s not a lot that can be done about damage from fatigue (because you can’t exactly put a brace over a microscopic crack). Self-healing materials, however, might be a solution to structural fatigue.

Self-healing composites work by being permeated with tiny capsules of liquid adhesive. When little fractures develop, the capsules break open, and cause the separating pieces to fuse together again. Most experiments with self-healing materials have used adhesive chemicals that require UV light or high heat to set, making them impractical in many applications. An alternative method is to use a liquid adhesive and a catalyst, like a two part epoxy. A “ring hydrocarbon called dicyclopentadiene” and a “ruthenium solvent” work very well, except that ruthenium is quite rare – a single airbus plane made of this particular type of self healing composite, for example, would require a substantial fraction of the world’s supply of ruthenium.

Now, we all know that when the article says “airbus” it means “army of self-healing killer robots.” While robots are hardly known for altruism (and therefore would have no qualms over consuming the planet’s precious ruthenium), their armies must be vast, and so it would not work to manufacture their self-healing bodies with ruthenium. Accordingly, the human thralls of the robot empire have been hard at work on the problem.

In their most recent advance, the scientist-servants have accidentally (more or less) discovered that certain solvents seem to work very well at mending fractures even in the absence of a catalyst. They appear to work by dissolving the surrounding composite material, which allows it to mix and bond again. Using the solvent chlorobenzene, researchers have observed fractured materials regaining up to 100% of their original strength.

To the further satisfaction of the robots, no doubt, chlorobenzene turns out to be pretty toxic. It affects the kidneys, liver, and brain, and can cause “headaches, nausea, sleepiness, numbness, and vomiting,” as well as “unconsciousness, tremors, restlessness, and death,” depending on the type and duration of exposure.

Just imagine: an army of killer robots, whose skin – as it spontaneously heals itself – releases clouds of deadly chlorobenzene. We won’t stand a chance.

On the plus side, however, chlorobenzene is supposed to have a pleasant, almond-like odor, so the robot apocalypse should at least have that fresh-from-the-oven smell to it. We can look forward to that.

Nov
25
2007

At least one person is concerned about nanotech: somewhere.
At least one person is concerned about nanotech: somewhere.Courtesy andymiah
Nanotechnology is the wave of the future (or one of them), especially here around Science Buzz. Sure, it’s a small wave, but it’s very powerful, like Mighty Mouse, or Dr. Ruth. According to at least one new study, however, most people are pretty much unaware of the possible risks associated with the technology.

The new survey, coming out of the University of Wisconsin, Madison, shows that experts are far more concerned about the potential health and environmental risks of nanotechnology than the general public is

“Nanotechnology is starting to emerge on the policy agenda,” says one of the authors of the study. “But with the public, it's not on their radar,"

Nanotechnology has a vast range of potential applications (check out some of the Buzz’s nano-related stories here), and scientists want the public to be conscious of its potential ramifications, good and bad, before they’re actually exposed to the fruits of nanotech research.

It can be difficult for scientists to predict all the effects of the nano-sized materials they work with (their toxicity to the human body, for example), because, on such a small scale, substances can behave very differently than what we might normally expect.

This study, like most studies, has got me worried. Worried, and thinking, and thinking worriedly. There are a lot of potential nano problems out there, ones that even the scientists probably haven’t thought of. Like, if I ever spilled a bowl of some nano stuff, they’d be totally hard to find again. Because they’re so small.

Or, what about this: I hate glitter. I hate it because it’s so small and it gets stuck on my fingers. It makes it look like I’ve been giving David Bowie a face massage. What if there were nano-glitter? I think it would be worse.

And, sure, nanobots might be able to rebuild my body someday, but what if they rebuilt it, you know, really ugly?

Or did you ever see that movie Innerspace? That’s probably the first thing some scientists would do – build nano-submarines to float around inside your body. If I wanted Dennis Quiad swimming around my brain, I’d just go buy a poster. But I’m not sure that I do want that.

The future is a nerve-racking place.

Nov
19
2007

Garrett Lisi, a 39-year-old surfer, hiking guide and construction worker (with a PhD in theoretical physics), believes he may have solved the biggest problem in all of science – how are all the particles of matter and forces of nature related to one another? Scientists since Einstein have been trying to figure it out, with little success. (The current theory involves outrageously tiny “strings” vibrating in 11-dimensional space. The mathematics, they say, is beautiful, but it cannot be tested or verified.) Lisi’s breakthrough came when he noticed that the formulas that describe something called the E8 pattern -- a complex, geometrical design with 248 points – also describe many of the fundamental forces and particles. His theory is that nature follows the same formulas as E8, and that the figure can be used to predict particles that have not yet been discovered. If he's right, he will have finally shown that everything in the universe is related, and basically just different manifestations of the same essence.

Rad, dude.

Oct
16
2007

A denrimer molceule: Image from Wikimedia Commons.
A denrimer molceule: Image from Wikimedia Commons.

New treatments for AIDS and cancer, based on nanoparticles, are about to go into human trials. Both treatments use dendrimers, molecules with multiple arms. Each arm can be designed to do different things. In the case of the AIDS treatment, the arms clasp onto docking sites on the virus’s coating, preventing it from attaching to and infecting healthy cells. In the cancer treatment, some of the arms hold folic acid, which cancer cells absorb; the other arms hold an anti-cancer drug, which is then released inside the cancerous cell.

Dendrimers were invented 30 years ago, but have had few practical applications, since they are difficult and expensive to make. But new processes promise to speed up production, perhaps unlocking the promise of these molecules.

To see images of dendrimers, go here.

Oct
07
2007

Ultra plastic: Just think - a Lunchable that you could see, but never get to.  (Image courtesy of the University of Michigan)
Ultra plastic: Just think - a Lunchable that you could see, but never get to. (Image courtesy of the University of Michigan)
Using a technique similar to the natural processes involved in the formation of seashells, scientists at the University of Michigan at Ann Arbor have created a plastic based material as thin as a sheet of paper, but as strong as steel.

What’s the secret? It has to do with that magic word that we love so much around the science museum: nano.

Nano-sized sheets of plastic are stacked by a robotic arm, and stuck together with a mortar made of “clay and a non-toxic glue similar to that used in school classrooms.” The plastic layers are so thin that even after 300 of them are stacked, the resulting sheet is still paper-thin and transparent. The reason why the material is so strong is because the layers are stacked in alternating patterns, and because the glue/mortar immediately creates new bonds as soon as others are broken. Again, this is all very similar to the way that abalone shells (known for their strength) form – in the case of the shells, crystals are stacked in alternating patterns, and cemented together with an organic mortar.

Currently the material is only being produced in pieces a few centimeters large, but the Ann Arbor researchers are already building a machine in their lab that could make pieces as large as one meter by one meter.

Although it’s still several years away from commercial applications, the material has potential uses ranging from microtechnology to creating stronger, lighter body armor.