Scientific American - Chemistry

Sinking Global Warming: Is There a Reliable Way to Track Atmospheric Carbon Dioxide Levels?

Wed, 18 Nov 2009 16:31:00 EST

The planet soaks up excess carbon dioxide via oceans, plants and soils, among other natural systems, locking away some of the greenhouse gases emitted by burning fossil fuels . In fact, every year these natural "sinks" absorb a larger and larger tonnage of emissions--but thanks to the increasing amount of CO 2 and other greenhouse gases dumped in the atmosphere by human activity, the proportion that is reabsorbed is beginning to dwindle, according to new studies. [More]

Beyond the Still: 6 Bioscapes Contest Videos

Wed, 18 Nov 2009 13:29:00 EST

The entrants in the 2009 Olympus BioScapes International Digital Imaging Competition provide fitting tribute to nearly 1,000 years of making the invisible visible. These six videos include one winner and five Honorable Mentions.

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Ultrathin, Now Ultraflat: Ripple-Free Graphene May Hold Key to Material's Mysteries

Wed, 18 Nov 2009 13:01:00 EST

Graphene has been a hot topic in physics and materials science since its discovery five years ago . The sheets of carbon, just an atom thick, have a host of intriguing properties , including transparency, strength and a structure that lets electrons zip through almost unimpeded. Graphene's characteristics and near two-dimensionality recommend it for use in next-generation displays, electronics or structural composites , but like many materials du jour, it has yet to find applications on a significant scale. [More]

More important than Copenhagen? U.S.-China deal on energy and climate

Tue, 17 Nov 2009 14:31:00 EST

When the presidents of the two nations that are responsible for 40 percent of Earth's climate-changing greenhouse gases sit down to talk, big things can happen. In the case of Barack Obama and Hu Jintao on Monday and Tuesday, that meant flatly stating that emission reduction targets should be set at an international negotiation on climate change in Copenhagen this December, along with financial assistance figures to help poorer countries mitigate emissions and adapt to a changing climate. Oh, and the world should cut back on deforestation. [More]

Why Bangladesh Water Contains Arsenic

Mon, 16 Nov 2009 09:29:08 EST

It seemed like a good idea--because rivers and ponds in Bangladesh were contaminated with bacteria, Bangladeshis switched to wells. But soon after, in the early ‘80s, researchers realized those wells were harming Bangladeshis with a new poison--arsenic.

The underground sediment of the Ganges Delta contains arsenic. In 2002 M.I.T. researchers determined that microbes digesting organic carbon were freeing that trapped arsenic. But where did the carbon come from and how was the arsenic getting into the water supply? The M.I.T. team now thinks they have the answers, which they report in the journal Nature Geoscience .

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Heavy Metal: Researchers Try to Get the Lead out of Piezoelectronics

Thu, 12 Nov 2009 16:50:00 EST

Gadget makers often rely on piezoelectricity --the ability that some solids have to produce voltage when pressure is applied to them--to power tiny embedded systems, such as a BlackBerry Storm 2's touch screen or a car's airbag sensor . Whereas lead-based compounds typically have the greatest piezoelectric potential, the heavy metal has fallen out of favor as device-makers push to eliminate it from all electronics in an attempt to reduce toxic waste . [More]

Fact or Fiction: Generic Drugs Are Bad for You

Thu, 12 Nov 2009 10:00:00 EST

As we cope with the economic recession, we've all had to make concessions. It's been "good-bye" to European vacations, organic milk and magazine subscriptions. But there are those things we can't give up without risking serious illness or death, one of which is prescription medication. [More]

Planets May Affect the Chemistry of Their Stars

Wed, 11 Nov 2009 13:01:00 EST

Planets are, by and large, at the mercy of their stars. Not only do stars provide a ready energy source of radiated light and heat, but the mass and gravitational pull of stars flat-out dwarfs the summed masses and pulls of any orbiting companions. In our solar system, which has more planets--regardless of where one stands on the Pluto debate--than any other planetary system we know of so far, the sun still makes up more than 99.8 percent of its system's mass. [More]

Judging a Book by Its Odor

Wed, 11 Nov 2009 10:26:08 EST

“This book stinks!” is really a bad review. But even a classic work can start to smell when it gets old enough. Now chemists have developed a technique that identifies what kind of degradation process an old book or historical document is going through, based on the odors it gives off. The report appears in the American Chemical Society journal Analytical Chemistry .

An old book’s familiar musty smell is due to hundreds of different volatile organic compounds gassing out from the paper and other materials, such as the binding. The particular blend of compounds results from specific degradation pathways. Conventional analysis techniques require small samples of the work for testing, further damaging the book. But analyzing the gases coming off of the old books is noninvasive.

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Pollution's Toll on the Brain

Wed, 11 Nov 2009 09:00:00 EST

In these days of hybrid cars and carbon credits, it is common knowledge that substances exhaled by autos and coal plants are harmful to our respiratory system. What may be surprising is the degree to which they may harm the brain--in some instances, as much as exposure to lead. A recent string of studies from all over the world suggests that common air pollutants such as black carbon, particulate matter and ozone can negatively affect vocabulary, reaction times and even overall intelligence.

The most recent of these studies found that New York City five-year-olds who were exposed to higher levels of urban air pollutants known as polycyclic aromatic hydrocarbons (PAH) while in the womb exhibited an IQ four points lower than those subjected to less PAH. Alarmingly, “the drop was similar to that seen in exposure to low levels of lead,” says epidemiologist Frederica Perera, director of the Columbia Center for Children’s Environmental Health and head author of the study, in which mothers wore personal air monitors during their pregnancy. The IQ change was enough of a dip to affect school performance and scores on standardized tests.

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Sewage Industry Fights Phosphorus Pollution

Tue, 10 Nov 2009 09:00:00 EST

Tucked away in Oregon’s Willamette Valley, three massive metal cones could help address the world’s dwindling supply of phosphorus, the crucial ingredient of fertilizers that has made modern agriculture possible. The cones make consistently high-quality, slow-release fertilizer pellets from phosphorus recovered at the Durham Advance Wastewater Treatment Facility, less than 10 miles from downtown Portland. By generating about one ton of pellets every day, they are changing the view that such recycling could not be done efficiently. Ostara, the firm that makes the reactors and sells the pellets as Crystal Green, thinks that Durham is one of hundreds of facilities that could use the technology.

Humans excrete some 3.3 million tons of phosphorus annually. In fact, phosphorus from domestic sewage, in addition to fertilizer runoff, has traditionally been a nuisance, because it triggers blooms of algae that deplete local waters of oxygen. In some wastewater plants the element can also bind with ammonia and magnesium to form a mineral called struvite, which keeps phosphorus out of waterways but clogs pipes at the facilities. The growing recognition that cheap supplies of phosphorus will grow scarce in the coming decades has led some nations to consider conservation. Sweden has mandated that 60 percent of phosphate be recycled from wastewater by 2015. In 2008 China slapped a 135 percent export tariff on phosphate.

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First Look at Carbon Capture and Storage in a West Virginia Coal-Fired Power Plant [Slide Show]

Fri, 06 Nov 2009 15:01:00 EST

NEW HAVEN, W.Va.--A 100-story smokestack belches a roiling, white cloud of water vapor, carbon dioxide and other leftover gases after burning daily as much as 12,000 tons of coal at the Mountaineer Power Plant --a total of 3.5 million tons a year. The facility just outside the town of New Haven boasts a single 65-meter-high boiler capable of generating enough steam to pump out 1,300 megawatts of electricity--enough to power nearly one million average American homes a month--continuously. And now roughly 1.5 percent of the CO 2 billowing from its stack is being captured in an industrial unit rising from the concrete in its shadow and then pumped underground for storage. In case you were wondering, this last phase is called "clean coal". [More]

Can Closing the Ozone Hole Also Help Combat Climate Change?

Thu, 05 Nov 2009 16:31:00 EST

Carbon dioxide is the primary greenhouse culprit in human-generated global warming , most scientists agree, but CO 2 itself, and a handful of other substances, are now being promoted as good alternatives to commonly used refrigerants that threaten Earth's atmosphere and climate. [More]

How Threatened Are Killer Whales in the Wild?

Tue, 03 Nov 2009 13:00:00 EST

Dear EarthTalk: How are populations of the world’s orca whales faring these days? Are we still in danger of losing them all in the wild? --J. Witham, Bangor, ME [More]

How Noise Can Help Quantum Entanglement

Tue, 03 Nov 2009 08:00:00 EST

Wouldn’t it be nice to be an electron? Then you, too, could take advantage of the marvels of quantum mechanics, such as being in two places at once--very handy for juggling the competing demands of modern life. Alas, physicists have long spoiled the fantasy by saying that quantum mechanics applies only to microscopic things.

Yet that is a myth. In the modern view that has gained traction in the past decade, you don’t see quantum effects in everyday life not because you are big, per se, but because those effects are camouflaged by their own sheer complexity. They are there if you know how to look, and physicists have been realizing that they show up in the macroscopic world more than they thought. “The standard arguments may be too pessimistic as to the survival of quantum effects,” says Nobel laureate physicist Anthony Leggett of the University of Illinois.

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EPA tests porous pavement to combat contaminated rain runoff

Fri, 30 Oct 2009 07:00:00 EST

In an effort to prevent polluted parking lot rain runoff from contaminating surrounding soil and underground water, the U.S. Environmental Protection Agency on Thursday said it has launched decadelong test of permeable materials to find one that can filter out impurities in rainwater before it flows to its final destination. [More]

Novel Analysis Confirms Climate "Hockey Stick" Graph

Wed, 28 Oct 2009 08:00:00 EST

The “hockey stick” graph has been both a linchpin and target in the climate change debate. As a plot of average Northern Hemisphere temperature from two millennia ago to the present, it stays relatively flat until the 20th century, when it rises up sharply, like the blade of an upturned hockey stick. Warming skeptics have long decried how the temperatures were inferred, but a new reconstruction of the past 600 years, using an entirely different method, finds similar results and may help remove lingering doubts.

The hockey stick came to life in 1998 thanks to the work of Michael Mann, now at Pennsylvania State University, and his colleagues (and many other climate scientists who subsequently refined the graph). Reconstructing historical temperatures is difficult: investigators must combine information from tree rings, coral drilling, pinecones, ice cores and other natural records and then convert them to temperatures at specific times and places in the past. Such proxies for temperature can be sparse or incomplete, both geographically and through time. Mann’s method used the overlap, where it exists, of recent proxy data and instrument data (such as from thermometers) to estimate relations between them. It calculates earlier temperatures using a mathematical extrapolation technique [see “ Behind the Hockey Stick ,” by David Appell, Insights; Scientific American, March 2005].

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Staying Out of a Jam: Air Force Looks at Nanotube Sheets for Electromagnetic Shielding

Mon, 26 Oct 2009 16:10:00 EST

Aerospace and aircraft companies as well as the military have been challenged to find ways of effectively shielding sensitive electronic equipment such as radar and radios from electromagnetic interference (EMI) without adding a lot of weight to aircraft and satellites (the more massive they are, the more fuel they need to stay in the air or achieve orbit, respectively). Whereas EMI can lead to headaches like erased data and loss of connectivity for casual computer and cell phone users, the problem is far more serious in aircraft, where interference can jam cockpit radio and radar signals, preventing pilots from sending and receiving crucial information. [More]

Nerd a Vacation?: Travel with The Geek Atlas

Fri, 23 Oct 2009 08:00:00 EST

After five years of gallivanting across the globe, Charles Darwin settled down at Down House in Downe, England. Other than day trips to London, he hardly left his neighborhood for the remaining 45 years of his life. After three days at a conference in London this past summer, I took a day trip to Downe to see Darwin’s house, which is now a small museum. What I did not know at the time was that I was visiting site number 043 in The Geek Atlas: 128 Places Where Science & Technology Come Alive (O’Reilly Media, 2009).

Author John Graham-Cumming holds a doctorate in computer security and is described in the book as “a wandering programmer.” (That background probably explains the zeroes that give all his site numbers three digits. Not to mention the choice of 128 places--programmers can’t resist powers of 2.) Graham-Cumming secured his own geek status by contributing to Linux Magazine . And he became a supergeek with his previous book, published in 2008, a guide to the software program GNU Make. That’s right, Graham-Cumming is the author of GNU Make Unleashed , which, he notes, “saturated its target market of 100 readers.”

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Red Wine with Fish? Iron-ic Answer

Thu, 22 Oct 2009 10:23:08 EST

[ The following is an exact transcript of this podcast. ]

It’s one of the most vexing problems in modern science: which wine to order with the Chilean sea bass. One thing’s for sure, though--you’d only ever order a white wine, never a red wine with fish. The flavors just clash. But now researchers have pinpointed the problem with red wine and seafood. And some reds may actually go fine with fish.

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