Healthier vegetable oil and tractor fuel to harvest it
Developing fruit of Euonymus alatus, or burning bush. The white seed endosperm produces novel acetyl triacylglycerols, or acTAGs, while the orange aril tissue around the seed produces normal vegetable oil. Photo courtesy of Timothy Durrett, MSU
Genetic discoveries from a shrub called the burning bush, known for its brilliant red fall foliage, could fire new advances in biofuels and low-calorie food oils, as per Michigan State University scientists.
New low-cost DNA sequencing technology applied to seeds of the species Euonymus alatus - a common ornamental planting - was crucial to identifying the gene responsible for its manufacture of a novel, high-quality oil. But despite its name, the burning bush is not a suitable oil crop.
Yet inserted into the mustard weed - well-known to scientists as Arabidopsis and a cousin to commercial oilseed canola - the burning bush gene encodes an enzyme that produces a substantial yield of unusual compounds called acetyl glycerides, or acTAGs. Related vegetable oils are the basis of the world's oilseed industry for the food and biofuels markets, but the oil produced by the burning bush enzyme claims unique and valuable characteristics.
One is its lower viscosity, or thickness.
"The high viscosity of most plant oils prevents their direct use in diesel engines, so the oil must be converted to biodiesel," explained Timothy Durrett, an MSU plant biology research associate. "We demonstrated that acTAGs possess lower viscosity than regular plant oils. The lower viscosity acTAGs could therefore be useful as a direct-use biofuel for a number of diesel engines".........
A "neodymium-YAG" laser will decompose VX nerve agent in this vinyl tile. Normally near-infrared, the laser turns ultraviolet as the frequency is increased. The UV light breaks the molecular bonds, decomposing the deadly nerve agent until it is just a harmless brown stain.
Credit: INL
Dhiren Barot was an al Qaeda operative involved in plots to blow up the London subway, among other targets. To maximize the damage and the terror, he planned to pack some of his bombs with toxic gas. Fortunately, in August 2004, British authorities nabbed Barot and his accomplices before they could carry out their attacks.
But the threat of a gas attack remains. Where Barot failed, at some point someone might succeed. The right response to such an attack could minimize exposure and save hundreds of thousands of American lives.
With funding and guidance from the Department of Homeland Security's Science and Technology Directorate (S&T), chemists at Idaho National Laboratory (INL) are researching ways to help the nation respond to and clean up after potential chemical attacks. They have been studying decontamination techniques for almost a decade.
Cleaning up chemical-contaminated structures can be difficult, costly, and time-consuming. For one thing, most preferred methods employ other chemicals, like bleach solutions, which can be corrosive and aggressive. A number of building materialslike cement and brickare extremely porous and getting contaminants off such surfaces is difficult, as contaminants will seep into cracks and pores.
As per Donald Bansleben, program manager in S&T's Chemical and Biological Division, lasers could one day play a big role. "Lasers could help to scrub chemical-contaminated buildings clean and become a tool in the toolbox to speed a facility's return to normal operations".........
Sourdough bread could be even tastier and more healthful thanks to a new strain of bacteria reported at the American Chemical Society meeting.
Credit: iStock
What better venue than San Francisco sourdough capital of the world to unveil a new natural sourdough ingredient that could replace conventional additives in a variety of other breads, while making them tastier and more healthful? And that's what researchers described today at the American Chemical Society's 239th National Meeting, being held here.
In the study, Maija Tenkanen, Ph.D., and his colleagues reported discovery and use of a new strain of bacteria that convert the sugars in bread dough into produce dextrans. Dextrans are sugar molecules associated withgether into long chains that improve the texture and taste of the sourdough and help keep the bread fresh. These bacteria are available commercially, but produce large amounts of lactic acid along with dextrans.
"The advantage of this new strain of bacteria is that while it produces 10 times more dextran than products on the market now, it doesn't produce large amounts of acid," Tenkanen said. "Because of this feature, and because the added amount of natural dextran could actually improve the flavor, this could be used in place of additives for a broad variety of breads".
She also said the new dextrans may act as so-called "prebiotics," non-digestible food ingredients that stimulate the growth or activity of bacteria in the digestive system which are beneficial to health.........
A graphene-oxide framework (GOF) is formed of layers of graphene connected by boron-carboxylic "pillars." GOFs such as this one are just beginning to be explored as a potential storage medium for hydrogen and other gases.
Credit: NIST
Graphenecarbon formed into sheets a single atom thicknow may be a promising base material for capturing hydrogen, as per recent research* at the National Institute of Standards and Technology (NIST) and the University of Pennsylvania. The findings suggest stacks of graphene layers could potentially store hydrogen safely for use in fuel cells and other applications.
Graphene has become something of a celebrity material in recent years due to its conductive, thermal and optical properties, which could make it useful in a range of sensors and semiconductor devices. The material does not store hydrogen well in its original form, as per a team of researchers studying it at the NIST Center for Neutron Research. But if oxidized graphene sheets are stacked atop one another like the decks of a multilevel parking lot, connected by molecules that both link the layers to one another and maintain space between them, the resulting graphene-oxide framework (GOF) can accumulate hydrogen in greater quantities.
Inspired to create GOFs by the metal-organic frameworks that are also under scrutiny for hydrogen storage, the team is just beginning to uncover the new structures' properties. "No one else has ever made GOFs, to the best of our knowledge," says NIST theorist Taner Yildirim. "What we have found so far, though, indicates GOFs can hold at least a hundred times more hydrogen molecules than ordinary graphene oxide does. The easy synthesis, low cost and non-toxicity of graphene make this material a promising candidate for gas storage applications".........
Simple oil droplets (in red) can navigate a complex maze using a special chemical approach that could lead to improved delivery of anti-cancer drugs.
Credit: American Chemical Society
Call them oil droplets with a brain or even "chemo-rats." Researchers in Illinois have developed a way to make simple oil droplets "smart" enough to navigate through a complex maze almost like a trained lab rat. The finding could have a wide range of practical implications, including helping cancer drugs to reach their target and controlling the movement of futuristic nano-machines, the researchers say. Their study is in the weekly Journal of the American Chemical Society
Bartosz Grzybowski and his colleagues note that the ability to solve a maze is a common scientific test of intelligence. Animals ranging from rats to humans can master the task. Researchers would like to pass along that same ability to anti-cancer drugs, for instance, to help these medications navigate complex mazes of blood vessels and reach the tumor.
The researchers describe an advance in that direction. They developed postage-stamp-sized mazes, and infused them with an alkaline solution, and placed a gel containing a strong acid at the exit. That created a pH gradient, a difference between the acid-alkaline levels. Oil droplets containing a weak acid placed at the entrance of the mazes developed convective flows in response to pH differences and propelled themselves along the gradient toward the exit. Since cancer cells are more acidic than other body cells, the experiment may serve as a model for designing new anti-cancer drugs that move along similar acid-based gradients to target diseased cells, the researchers suggest.........
A study by University of Michigan scientists offers new insight into what happens to mercury deposited onto Arctic snow from the atmosphere.
The work also provides a new approach to tracking mercury's movement through Arctic ecosystems.
Mercury is a naturally occurring element, but some 2000 tons of it enter the global environment each year from human-generated sources such as coal-burning power plants, incinerators and chlorine-producing plants.
"When released into the atmosphere in its reduced form, mercury is not very reactive. It can float around in the atmosphere as a gas for a year or more, and it's not really an environmental problem at the concentrations at which it occurs," said Joel Blum, the John D. MacArthur Professor of Geological Sciences.
But once mercury is oxidized, through a process that involves sunlight and often the element bromine, it becomes very reactive. Deposited onto land or into water, the mercury is picked up by microorganisms, which convert some of it to methylmercury, a highly toxic form that builds up in fish and the animals that eat them.
As bigger animals eat smaller ones, the methylmercury is concentrated. In wildlife, exposure to methylmercury can interfere with reproduction, growth, development and behavior and may even cause death. Effects on humans include damage to the central nervous system, heart and immune system. The developing brains of young and unborn children are particularly vulnerable.........
This tiny worm became temporarily paralyzed when scientists fed it a light-sensitive material, or "photoswitch," and then exposed it to ultraviolet light.
Credit: American Chemical Society
In an advance with overtones of Star Trek phasers and other sci-fi ray guns, researchers in Canada are reporting development of an internal on-off "switch" that paralyzes animals when exposed to a beam of ultraviolet light. The animals stay paralyzed even when the light is turned off. When exposed to ordinary light, the animals become unparalyzed and wake up. Their study appears in the Journal of the American Chemical Society (JACS). It reports the first demonstration of such a light-activated switch in animals.
Neil Branda and his colleagues point out that such "photoswitches" light-sensitive materials that undergo photoreactions have been available for years. Researchers use them in research. Doctors use light-sensitive materials and photoreactions in medicine in photodynamic treatment to treat certain forms of cancer. Those light-sensitive materials, however, do not have the reversibility that exists in photoswitching.
The JACS report describes development and successful testing of a photoswitch composed of the light-sensitive material, dithienylethene. The researchers grew transparent, pinhead-sized worms (C. elegans) and fed them a dithienylethene. When exposed to ultraviolet light, the worms turned blue and became paralyzed. When exposed to visible light, the dithienylethene became colorless again and the worms' paralysis ended. A number of of the worms lived through the paralyze-unparalyze cycle. Researchers were not sure how the switch causes paralysis. The study demonstrates that photoswitches may have great potential in turning photodynamic treatment on and off, and for other applications in medicine and research, they indicate.........
Synthesis of hydrogen fuel storage material may become less complicated
This image illustrates that an applied electric field polarizes hydrogen molecules and the substrate, inducing hydrogen absorption with good thermodynamics and kinetics. Image courtesy of Qian Wang, Ph.D./VCU.
An international team of scientists has identified a new theoretical approach that may one day make the synthesis of hydrogen fuel storage materials less complicated and improve the thermodynamics and reversibility of the system.
A number of scientists have their sights set on hydrogen as an alternative energy source to fossil fuels such as oil, natural gas and coal that contain carbon, pollute the environment and contribute to global warming. Known to be the most abundant element in the universe, hydrogen is considered an ideal energy carrier - not to mention that it's clean, environmentally friendly and non-toxic. However, it has been difficult to find materials that can efficiently and safely store and release it with fast kinetics under ambient temperature and pressure.
The team of scientists from Virginia Commonwealth University ; Peking University in Beijing; and the Chinese Academy of Science in Shanghai; have developed a process using an electric field that can significantly improve how hydrogen fuel is stored and released.
"Eventhough tremendous efforts have been devoted to experimental and theoretical research in the past years, the biggest challenge is that all the existing methods do not meet the Department of Energy targets for hydrogen storage materials. The breakthrough can only be achieved by exploring new mechanisms and new principles for materials design," said Qiang Sun, Ph.D., research associate professor with the VCU team, who led the study.........
Transforming lead into gold is an impossible feat, but a similar type of "alchemy" is not only possible, but cost-effective too. Three Penn State scientists have shown that certain combinations of elemental atoms have electronic signatures that mimic the electronic signatures of other elements. As per the team's leader A. Welford Castleman Jr., Eberly Distinguished Chair in Science and Evan Pugh Professor in the Departments of Chemistry and Physics, "the findings could lead to much cheaper materials for widespread applications such as new sources of energy, methods of pollution abatement, and catalysts on which industrial nations depend heavily for chemical processing".
The scientists also showed that the atoms that have been identified so far in these mimicry events can be predicted simply by looking at the periodic table. The team used advanced experimentation and theory to quantify these new and unexpected findings. "We're getting a whole new perspective of the periodic table," said Castleman. The team's findings would be reported in the 28 December 2009 early on-line issue of the journal Proceedings of the National Academy of Sciences, and at a later date in the print edition of the journal.
Castleman and his team -- which includes Samuel Peppernick, a former Penn State graduate student who now is a postdoctoral researcher at the Pacific Northwest National Laboratory, and Dasitha Gunaratne, a Penn State graduate student -- used a technique, called photoelectron imaging spectroscopy, to examine similarities between titanium monoxide and nickel, zirconium monoxide and palladium, and tungsten carbide and platinum. "Photoelectron spectroscopy measures the energy it takes to remove electrons from various electronic states of atoms or molecules, while simultaneously capturing snapshots of these electron-detachment events with a digital camera," said Castleman. "The method allows us to determine the binding energies of the electrons and also to observe directly the nature of the orbitals in which the electrons resided before they were detached. We observed that the amount of energy mandatory to remove electrons from a titanium-monoxide molecule is the same as the amount of energy mandatory to remove electrons from a nickel atom. The same is true for the systems zirconium monoxide and palladium and tungsten carbide and platinum. The key is that all of the pairs are composed of isoelectronic species, which are atoms with the same electron configuration." Castleman noted that, in this case, the term isoelectronic refers to the number of electrons present in the outer shell of an atom or molecule.........
Two Kent State University professors are part of a team of scientists who recently uncovered a way to pack tetrahedra, considered to be the simplest shaped regular solids with its four triangular sides, more densely than ever before. Peter Palffy-Muhoray, professor of chemical physics and associate director of the Liquid Crystal Institute at Kent State, and Xiaoyu Zheng, assistant professor in Kent State's Department of Mathematical Sciences, along with four colleagues at the University of Michigan and one at Case Western Reserve University, have broken a world record for packing the most tetrahedra into a given volume.
Their findings will be featured in the Dec. 10 issue of Nature, one of the leading international scientific journals, in an article co-authored by the seven researchers. The article is titled "Disordered, quasicrystalline and crystalline phases of densely packed tetrahedra".
The scientists were able to obtain the highest packing fraction of 85.03, meaning tetrahedra fill 85.03 percent of the volume of the container. This shattered the prior record of 78.2 percent set by two Princeton University scientists in August 2009.
"The question of how best to pack shapes into a volume is an age-old question," Palffy-Muhoray said. "Johannes Kepler asked how to pack spheres in the early 1600s, and it was only recently proven in 2005 that the best way is to stack them like cannonballs. It is easy to understand how cubes can entirely fill space with no voids, but the packing problem is still unsolved for the simple tetrahedron. Though it's a simple object, it can't fill space like cubes, so we wondered how hard tetrahedra would pack when you squeezed them together".........
There is more to the snowflake than its ability to delight schoolchildren and snarl traffic.
The structure of the frosty flakes also fascinate ice chemists like Purdue University's Travis Knepp, a doctoral candidate in analytical chemistry who studies the basics of snowflake structure to gain more insight into the dynamics of ground-level, or "tropospheric," ozone depletion in the Arctic.
"A lot of chemistry occurs on ice surfaces," Knepp said. "By better understanding the physical structure of the snow crystal - how it grows and why it takes a certain shape - we can get a better idea of the chemistry that occurs on that surface."
His work on snowflake shape and how temperature and humidity affect it takes place in a special laboratory chamber no larger than a small refrigerator. Knepp can "grow" snow crystals year-round on a string inside this chamber. The chamber's temperature ranges from 100-110 degrees Fahrenheit down to minus 50 degrees Fahrenheit.
Knepp, under the direction of Paul Shepson, professor and head of Purdue's Department of Chemistry, is studying snow crystals and why sharp transitions in shape occur at different temperatures. The differences he sees not only explain why no two snowflakes are identical, but also hold implications for his ozone research in the Arctic Ocean region.........
Physicists have developed a new thermometry method suitable for measuring temperatures of ultracold atoms.
Credit: Illustration: Alan Stonebraker
As physicists strive to cool atoms down to ever more frigid temperatures, they face the daunting task of developing new, reliable ways of measuring these extreme lows. Now a team of physicists has devised a thermometer that can potentially measure temperatures as low as tens of trillionths of a degree above absolute zero. Their experiment is published in the current issue of Physical Review Letters and highlighted with a Viewpoint in the December 7 issue of Physics (http://physics.aps.org.).
Physicists can currently cool atoms to a few billionths of a degree, but even this is too hot for certain applications. For example, Richard Feynman dreamed of using ultracold atoms to simulate the complex quantum mechanical behavior of electrons in certain materials. This would require the atoms to be lowered to temperatures at least a hundred times colder than what has ever been achieved. Unfortunately, thermometers that can measure temperatures of a few billionths of a degree rely on physics that doesn't apply at these extremely low temperatures.
Now a team at the MIT-Harvard Center for Ultra-Cold Atoms has developed a thermometer that can work in this unprecedentedly cold regime. The trick is to place the system in a magnetic field, and then measure the atoms' average magnetization. By determining a handful of easily-measured properties, the physicists extracted the temperature of the system from the magnetization. While they demonstrated the method on atoms cooled to one billionth of a degree, they also showed that it should work for atoms hundreds of times cooler, meaning the thermometer will be an invaluable tool for physicists pushing the cold frontier.........
WHOI chemist Scott Doney led a team that developed ocean-model simulations for estimating the historical variations in air-sea CO2 fluxes. (Tom Kleindinst, Woods Hole Oceanographic Institution)
The annual rate of increase in carbon dioxide emissions from fossil fuels has more than tripled in this decade, in comparison to the 1990s, reports an international consortium of scientists, who paint a bleak picture of the Earth's future unless "CO2 emissions [are] drastically reduced".
These CO2 emissions increased at a rate of 3.4% per year from 2000 to 2008, in contrast to 1% each year in the prior decade, researchers from the Global Carbon Project report in the current issue of Nature Geoscience. The team comprises some 30 scientists from around the world, including Scott C. Doney, senior scientist at the Woods Hole Oceanographic Institution (WHOI) and Richard A. Houghton, senior scientist and acting director of the Woods Hole Research Center (WHRC).
Since 2000, the researchers documented an overall increase of 29% in global CO2 emissions. They attributed the rise to increasing production and trade of manufactured products, especially from emerging economies, the gradual shift from oil to coal and the planet's waning capacity to absorb CO2.
Doney led a team that developed ocean-model simulations for estimating the historical variations in air-sea CO2 fluxes.
"Over the last decade, CO2 emissions have continued to climb despite efforts to control emissions," Doney said. "Preliminary evidence suggests that the land and ocean appears to be becoming less effective at removing CO2 from the atmosphere, which could accelerate future climate change".........
This schematic shows the structure of the new material, Xe(H2)7. Freely rotating hydrogen molecules (red dumbbells) surround xenon atoms (yellow).
Credit: Nature Chemistry
Researchers at the Carnegie Institution have found for the first time that high pressure can be used to make a unique hydrogen-storage material. The discovery paves the way for an entirely new way to approach the hydrogen-storage problem. The scientists observed that the normally unreactive, noble gas xenon combines with molecular hydrogen (H2) under pressure to form a previously unknown solid with unusual bonding chemistry. The experiments are the first time these elements have been combined to form a stable compound. The discovery debuts a new family of materials, which could boost new hydrogen technologies. The paper is reported in the November 22, 2009, advanced online publication of Nature Chemistry
Xenon has some intriguing properties, including its use as an anesthesia, its ability to preserve biological tissues, and its employment in lighting. Xenon is a noble gas, which means that it does not typically react with other elements.
As main author Maddury Somayazulu, research scientist at Carnegie's Geophysical Laboratory, explained: "Elements change their configuration when placed under pressure, sort of like passengers readjusting themselves as the elevator becomes full. We subjected a series of gas mixtures of xenon in combination with hydrogen to high pressures in a diamond anvil cell. At about 41,000 times the pressure at sea level (1 atmosphere), the atoms became arranged in a lattice structure dominated by hydrogen, but interspersed with layers of loosely bonded xenon pairs. When we increased pressure, like tuning a radio, the distances between the xenon pairs changedthe distances contracted to those observed in dense metallic xenon".........
Is there an easy way to memorise all 112 elements? Yes, there is. You could make up a melody, and sing them. Melody is a great mnemonic device. The idea was used by Carleton...
Visualization of helium-4 and beryllium nuclei. Image: Peter Mueller (Argonne National Lab)
A recent experiment at the Department of Energy's Thomas Jefferson National Accelerator Facility has observed that a proton's nearest neighbors in the nucleus of the atom may modify the proton's internal structure.
When comparing large nuclei to small nuclei, past measurements have shown a clear difference in how the proton's constituent particles, called quarks, are distributed. This difference is called the EMC Effect.
A number of models of the EMC Effect predict that it is caused by the mass or density of the nucleus in which the proton resides. To test these predictions, experimenters made precise new measurements of the EMC effect in a variety of light nuclei, such as isotopes of helium.
"What we found is that there is a large modification of the quark structure in helium-4, and there was a much smaller effect in helium-3. And even though they were both light nuclei, they had a very different EMC Effect," said John Arrington, a spokesperson for the experiment and a nuclear physicist at DOE's Argonne National Lab.
The results, Arrington added, rules out the idea that the size of the EMC effect scales with the mass of the nucleus.
Next, the experimenters turned their attention to density. They compared the EMC Effect in beryllium to various other nuclei. Beryllium has a mass similar to carbon but a much lower density, roughly the same as helium-3. They observed that the size of the EMC Effect in beryllium is similar to that of carbon, which is twice as dense.........
Shane Stephens-Romero built a computer model called STREET that foresees the effects of alternative transportation fuels. Photo by Daniel A. Anderson / University Communications
It's the year 2060, and 75 percent of drivers in the Greater Los Angeles area have hydrogen fuel cell vehicles that emit only water vapor.
Look into Shane Stephens-Romero's crystal ball - a computer model called STREET - and find that air quality has significantly improved. Greenhouse gas emissions are more than 60 percent lower than in 2009, and levels of microscopic soot and ozone are about 15 percent and 10 percent lower, respectively.
"For the first time, we can look at these future fuel scenarios and say how they're going to impact things like ozone and particulate matter, which have severe effects on people's lungs and quality of life," said Stephens-Romero, a UC Irvine doctoral candidate in the Advanced Power & Energy Program.
His 2060 analysis appeared online recently in Environmental Science & Technology. It's the first peer-evaluated test of the computer model, which has caught the attention of California policymakers and auto industry leaders trying to integrate alternative fuels into the transportation system.
"We're transitioning to new technologies. How do we do this while maintaining our lifestyle and keeping our economy robust?" Stephens-Romero said. "We don't know how these changes could affect the future".
The Spatially & Temporally Resolved Energy & Environment Tool, he says, can help.........
An unusual "trigonal bipyramidal coordination" of manganese compounds was used to create a new blue pigment that is safe to produce, durable and environmentally benign.
An accidental discovery in a laboratory at Oregon State University has apparently solved a quest that over thousands of years has absorbed the energies of ancient Egyptians, the Han dynasty in China, Mayan cultures and more - the creation of a near-perfect blue pigment.
Through much of recorded human history, people around the world have sought inorganic compounds that could be used to paint things blue, often with limited success. Most had environmental or durability issues. Cobalt blue, developed in France in the early 1800s, can be carcinogenic. Prussian blue can release cyanide. Other blue pigments are not stable when exposed to heat or acidic conditions.
But chemists at OSU have discovered new compounds based on manganese that should address all of those concerns. They are safer to produce, much more durable, and should lead to more environmentally non-malignant blue pigments than any being used now or in the past. They can survive at extraordinarily high temperatures and don't fade after a week in an acid bath.
The findings were just reported in the Journal of the American Chemical Society, and a patent has been applied for on the composition of the compound and the process used to create it. The research was funded by the National Science Foundation.........
Pacific Northwest National Laboratory scientist David Heldebrant demonstrates how a new process called reversible acid gas capture works to pull more than just carbon dioxide out of power plant emissions.
The Department of Energy's Pacific Northwest National Laboratory has developed a reusable organic liquid that can pull harmful gases such as carbon dioxide or sulfur dioxide out of industrial emissions from power plants. The process could directly replace current methods and allow power plants to capture double the amount of harmful gases in a way that uses no water, less energy and saves money.
"Power plants could easily retrofit to use our process as a direct replacement for existing technology," said David Heldebrant, PNNL's lead research scientist for the project.
Harmful gases such as carbon dioxide or sulfur dioxide are called "acid gases". The new scrubbing process uses acid gas-binding organic liquids that contain no water and appear similar to oily compounds. These liquids capture the acid gases near room temperature. Researchers then heat the liquid to recover and dispose of the acid gases properly.
These recyclable liquids require much less energy to heat but can hold two times more harmful gases by weight than the current leading liquid absorbent used in power plants. It is a combination of water and monoethanolamine, a basic organic molecule that grabs the carbon dioxide.
PNNL's prior work with the all-organic liquids focused on pulling only carbon dioxide out of emissions from power plants. New work will show how the process can be applied to other acid gases such as sulfur dioxide.........
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