Here is the latest American Chemical Society (ACS) News Service Weekly PressPac with news from ACS’ 36 peer-reviewed journals and Chemical & Engineering News.
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Researchers in Greece report design of a new material that almost meets the U.S. Department of Energy (DOE) 2010 goals for hydrogen storage and could help eliminate a key roadblock to practical hydrogen-powered vehicles. Their study on a way of safely storing hydrogen, an explosive gas, is scheduled for the Oct. 8 issue of ACS’ Nano Letters, a monthly journal.
Georgios K. Dimitrakakis, Emmanuel Tylianakis, and George E. Froudakis note that researchers long have sought ways of using carbon nanotubes (CNTs) to store hydrogen in fuel cell vehicles. CNTs are minute cylinders of carbon about 50,000 times thinner than the width of a human hair. Scientists hope to use CNTs as miniature storage tanks for hydrogen in the coming generation of fuel cell vehicles.
In the new study, the researchers used computer modeling to design a unique hydrogen-storage structure consisting of parallel graphene sheets — layers of carbon just one atom thick — stabilized by vertical columns of CNTs. They also added lithium ions to the material’s design to enhance its storage capacity. The scientists’ calculations showed that their so-called “pillared graphene” could theoretically store up to 41 grams of hydrogen per liter, almost matching the DOE’s target (45 grams of hydrogen per liter) for transportation applications. “Experimentalists are challenged to fabricate this material and validate its storage capacity,” the researchers note. — MTS
With nanotechnology yielding a burgeoning menagerie of microscopic pumps, motors, and other machines for potential use in medicine and industry, here is one good question: How will humans turn those devices on and off? In an advance toward giving humans that control, scientists in The Netherlands are reporting use of an external electrical signal to control an atomic-scale mechanical device that looks like the flippers on a pinball machine. Their report is scheduled for the Oct. 8 issue of ACS’ monthly journal Nano Letters.
In the study, Harold J. W. Zandvliet and colleagues point out that efforts to build ever-smaller mechanical devices have made scientists recognize the difficulty of exerting control over these nanomachines, which are too tiny for any conventional on-off-switch. They describe construction and successful testing of a device, “grown” on a wafer of germanium crystal, that responds to on-off stimuli.
Researchers say the device — so tiny that billions would fit on the head of a pin — resembles the arms or flippers on a pinball machine. The signals for the arms to move back and forth come from the tip of a scanning tunneling microscope. “By precisely controlling the tip current and distance, we make two atom pairs behave like the flippers on an atomic-sized pinball machine,” they state. “Our observations prove unambiguously that it is possible to control an atomic scale mechanical device using a simple electrical signal. A better understanding of similar devices can shed light on the future possibilities and opportunities for the application of atomic-scale devices.” — AD
In what may be an unintended consequence of efforts to make furniture safer and less flammable, residents of California have blood levels of potentially toxic flame retardants called PBDEs at levels nearly twice the national average, scientists from Massachusetts and California are reporting. Their study, the first to examine regional variations in PBDE levels in household dust and blood within the U.S., is scheduled for posting online Oct. 1 by ACS’ semi-monthly journal Environmental Science & Technology.
In the new study, Ami Zota and colleagues note that PBDEs (polybrominated diphenyl ethers) are widely used as flame retardants in upholstered furniture and electronics. The materials are released into the environment as dust particles, where they can accumulate in homes as well as human blood and tissue. Although their exact effects in humans are unclear, studies in animals suggest that PBDEs may cause thyroid, developmental, and reproductive problems. Since California has among the most stringent furniture flammability standards, the researchers suspected that state residents may have higher levels of PBDE dust exposure than others in the United States.
To find out, the scientists compared data on PBDE concentrations in house dust from 49 California homes with concentrations reported from 120 Massachusetts homes and several other areas. The researchers also compared data on blood levels of PBDEs in California residents to blood levels in residents of other regions. They found that PBDE levels in California homes were four to 10 times higher than other U.S. areas. They also found that blood levels of some PBDEs were significantly higher in California residents than the rest of the country. “These findings raise concern about pending regulations and performance standards that encourage the widespread use of chemical flame retardants, which are toxic or whose safety is uncharacterized,” the article states. — MTS and AD
Journal: Environmental Science & Technology
Journal Article: “Elevated House Dust and Serum Concentrations of PBDEs in California: Unintended Consequences of Furniture Flammability Standards?”
Researchers in Iran are publishing what they describe as the first study on a fungus that can remove sulfur — a major source of air pollution — from crude oil more effectively than conventional refining methods. The finding could help reduce air pollution and acid rain caused by the release of sulfur components in gasoline and may help oil companies meet tougher emission standards for fuel, the scientists say. Their study is scheduled for the Oct. 1 issue of ACS’ Industrial & Engineering Chemistry Research, a bi-weekly journal.
Jalal Shayegan and colleagues point out that existing processes for refining so-called “heavy,” or high-sulfur, crude oil convert sulfur to hydrogen sulfide gas at high temperatures and pressures. However, they leave behind some kinds of sulfur-based compounds, which wind up in gasoline and other fuels. Scientists long have known that certain microbes can remove sulfur from oil. But nobody had tried using these microbes in so-called biodesulfurization of heavy crude oil until now, they indicate.
In the new study, the scientists describe isolation and testing of the first fungus capable of removing sulfur from heavy crude oil. The fungus, called Stachybotrys, removed 65-76 percent of the sulfur present in certain heavy crude oil from two different oil fields. The process does not need high temperatures and high-energy consumption because it occurs slightly above room temperature, they scientists note. — MTS
Just as a credit crunch is reshaping the global economic landscape, an often-unheralded shortage of clean water is confronting business and industry with a range of profound new challenges and opportunities, according to an article scheduled for the October 6 issue of Chemical & Engineering News, ACS’ weekly news magazine.
The cover story, written by C&EN Senior Business Editor Melody Voith, points out that big industrial companies, such as Dow Chemical, General Electric, Nalco, and Ashland, must manage day-to-day operations in ways that conserve and reuse water. Once regarded as a cheap and inexhaustible resource, clean water increasingly is in short supply around the world, Voith explains, noting that lack of clean water is “a growing risk” to industry.
“There is just no replacement for good, clean water — and it is getting harder to come by,” Voith states. At the same time, companies that supply water purification and conservation technology are taking advantage of new opportunities. The articles explain how companies are investing in new technologies to meet the evolving demand for water treatment chemicals, services, and equipment.
Activities will be held in communities around the United States Oct. 19-25 during National Chemistry Week, the American Chemical Society’s annual showcase of chemistry’s central role in everyday life. The theme will be “Having a Ball with Chemistry,” emphasizing the role chemistry plays in fitness and athletics. Thousands of students will learn about chemistry’s role in providing new materials and technology to improve athletic equipment and performance, and the importance of nutrition and maintaining an active lifestyle. For more information, including the location of local NCW events, please visit http://www.chemistryweek.org.
It's never too late to explore a treasure trove of news sources, background material and story ideas available from the ACS' latest National Meeting, which was held in Philadelphia from August 17-21, 2008. Reporters can view press releases, search an archive with abstracts of more than 9,000 scientific presentations and hundreds of non-technical summaries of those presentations, and access other resources at: www.eurekalert.org/acsmeet.php.
The ACS Office of Public Affairs also offers recorded video versions of its national meeting "chat room" briefings and accompanying chat transcripts by going to http://www.ustream.tv/channel/acslive. To use this site, you must first register with Ustream.tv by going to http://ustream.tv/sign-up-step-1. It's free and only takes a minute or two to sign up. To view the archived chat room sessions, proceed by clicking the "Login" button at the top right of the Ustream window and then selecting "Past Clips." Please note that Ustream requires the latest version of Adobe Flash, which can be downloaded without charge at http://www.adobe.com/products/flashplayer.
Don’t miss this special series of ACS podcasts on some of the 21st Century’s most daunting challenges, and how cutting-edge research in chemistry matters in the quest for solutions. This sweeping panorama of challenges includes topics such as providing a hungry, thirsty world with ample supplies of safe food and clean water; developing alternatives to petroleum to fuel the global economy; preserving the environment and assuring a sustainable future for our children; and improving human health. An ongoing saga of chemistry for life — chemistry that truly matters — Global Challenges debuts June 25 with new episodes through December. Subscribe at iTunes or listen and access other resources at the ACS web site www.acs.org/GlobalChallenges.
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PressPac information is intended for your personal use in news gathering and reporting and should not be distributed to others. Anyone using advance PressPac information for stocks or securities dealing may be guilty of insider trading under the federal Securities Exchange Act of 1934.
The American Chemical Society — the world’s largest scientific society — is a nonprofit organization chartered by the U.S. Congress and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.
Journal: Chemical & Engineering News
Journal Article: “The Other Scarce Resource”