Is Carbonic Acid the Source of Carbon Dioxide on Icy Moons?

CARBONIC ACID AS A RESERVE OF CARBON DIOXIDE ON ICY MOONS: THE FORMATION OF CARBON DIOXIDE (CO2) IN A POLAR ENVIRONMENT

Authors:

Jones et al

Abstract:

Carbon dioxide (CO2) has been detected on the surface of several icy moons of Jupiter and Saturn via observation of the ν3 band with the Near-Infrared Mapping Spectrometer on board the Galileo spacecraft and the Visible-Infrared Mapping Spectrometer on board the Cassini spacecraft. Interestingly, the CO2 band for several of these moons exhibits a blueshift along with a broader profile than that seen in laboratory studies and other astrophysical environments. As such, numerous attempts have been made in order to clarify this abnormal behavior; however, it currently lacks an acceptable physical or chemical explanation. We present a rather surprising result pertaining to the synthesis of carbon dioxide in a polar environment. Here, carbonic acid was synthesized in a water (H2O)-carbon dioxide (CO2) (1:5) ice mixture exposed to ionizing radiation in the form of 5 keV electrons. The irradiated ice mixture was then annealed, producing pure carbonic acid which was then subsequently irradiated, recycling water and carbon dioxide. However, the observed carbon dioxide ν3 band matches almost exactly with that observed on Callisto; subsequent temperature program desorption studies reveal that carbon dioxide synthesized under these conditions remains in solid form until 160 K, i.e., the sublimation temperature of water. Consequently, our results suggest that carbon dioxide on Callisto as well as other icy moons is indeed complexed with water rationalizing the shift in peak frequency, broad profile, and the solid state existence on these relatively warm moons.

Novel Ice Chemistry in the Outer Solar System

ICE CHEMISTRY ON OUTER SOLAR SYSTEM BODIES: CARBOXYLIC ACIDS, NITRILES, AND UREA DETECTED IN REFRACTORY RESIDUES PRODUCED FROM THE UV PHOTOLYSIS OF N2:CH4:CO-CONTAINING ICES

Authors:

Materese et al

Abstract:

Radiation processing of the surface ices of outer solar system bodies may result in the production of new chemical species even at low temperatures. Many of the smaller, more volatile molecules that are likely produced by the photolysis of these ices have been well characterized by laboratory experiments. However, the more complex refractory material formed in these experiments remains largely uncharacterized. In this work, we present a series of laboratory experiments in which low-temperature (15-20 K) N2:CH4:CO ices in relative proportions 100:1:1 are subjected to UV irradiation, and the resulting materials are studied with a variety of analytical techniques including infrared spectroscopy, X-ray absorption near-edge structure spectroscopy, gas chromatography coupled with mass spectrometry, and high-resolution mass spectroscopy. Despite the simplicity of the reactants, these experiments result in the production of a highly complex mixture of molecules from relatively low-mass volatiles (tens of daltons) to high-mass refractory materials (hundreds of daltons). These products include various carboxylic acids, nitriles, and urea, which are also expected to be present on the surface of outer solar system bodies, including Pluto and other transneptunian objects. If these compounds occur in sufficient concentrations in the ices of outer solar system bodies, their characteristic bands may be detectable in the near-infrared spectra of these objects.

Carbyne: Carbon Stronger Than Diamond or Graphene

Chemists have calculated that chains of double or triple-bonded carbon atoms, known as carbyne, should be stronger and stiffer than any known material

The sixth element, carbon, has given us an amazing abundance of extraordinary materials. Once there was simply carbon, graphite and diamond. But in recent years chemists have added buckyballs, nanotubes and any number of exotic shapes created out of graphene, the molecular equivalent of chickenwire.

So it’s hard to believe that carbon has any more surprises up its sleeve. And yet today, Mingjie Liu and pals at Rice University in Houston calculate the properties of another form of carbon that is stronger, stiffer and more exotic than anything chemists have seen before.

The new material is called carbyne. It is a chain of carbon atoms that are linked either by alternate triple and single bonds or by consecutive double bonds.

Carbyne is something of a mystery. Astronomers believe they have detected its signature in interstellar space but chemists have been bickering for decades over whether they had ever created this stuff on Earth. A couple of years ago, however, they synthesised carbyne chains up to 44 atoms long in solution.

The thinking until now has been that carbyne must be extremely unstable. In fact some chemists have calculates that two strands of carbyne coming into contact would react explosively.

Nevertheless, nanotechnologists have been fascinated with potential of this material because it ought to be both strong and stiff and therefore useful. But exactly how strong and how stiff, no one has been quite sure.

This is where Liu and co step in. These guys have calculated from first principles the bulk properties of carbyne and the results make for interesting reading.

Chemical Reaction, Atom by Atom, Bond by Bond

When Felix Fischer of the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) set out to develop nanostructures made of graphene using a new, controlled approach to chemical reactions, the first result was a surprise: spectacular images of individual carbon atoms and the bonds between them.

“We weren’t thinking about making beautiful images; the reactions themselves were the goal,” says Fischer, a staff scientist in Berkeley Lab’s Materials Sciences Division (MSD) and a professor of chemistry at the University of California, Berkeley. “But to really see what was happening at the single-atom level we had to use a uniquely sensitive atomic force microscope in Michael Crommie’s laboratory.” Crommie is an MSD scientist and a professor of physics at UC Berkeley.

What the microscope showed the researchers, says Fischer, “was amazing.” The specific outcomes of the reaction were themselves unexpected, but the visual evidence was even more so. “Nobody has ever taken direct, single-bond-resolved images of individual molecules, right before and immediately after a complex organic reaction,” Fischer says.

The researchers report their results online in the May 30, 2013 edition of Science Express.

DOE's Joint Bio Energy Institute and NERSC Advance Cellulosic Biofuel Production

Advanced biofuels – liquid fuels synthesized from the sugars in cellulosic biomass – offer a clean, green and renewable alternative to gasoline, diesel and jet fuels. Bringing the costs of producing these advanced biofuels down to competitive levels with petrofuels, however, is a major challenge. Researchers at the U.S. Department of Energy (DOE)'s Joint BioEnergy Institute (JBEI), a bioenergy research center led by Berkeley Lab, have taken another step towards meeting this challenge with the development of a new technique for pre-treating cellulosic biomass with ionic liquids - salts that are liquids rather than crystals at room temperature. This new technique requires none of the expensive enzymes used in previous ionic liquid pretreatments, and makes it easier to recover fuel sugars and recycle the ionic liquid.

"Most of our ionic liquid efforts at JBEI have focused on using enzymes to liberate fermentable sugars from lignocellulosic biomass after pretreatment, but with this new enzyme-free approach we use an acid as the catalyst for hydrolyzing biomass polysaccharides into a solution containing fermentable sugars," says Blake Simmons, a chemical engineer who heads JBEI's Deconstruction Division and was the leader of this research. "We're then able to separate the pretreatment solution into two phases, a sugar-rich water phase for recovery and a lignin-rich ionic liquid phase for recycling. As an added bonus, our new pretreatment technique uses a lot less water than previous pretreatments."

Simmons is the corresponding author of a paper describing this research that has been published in the journal Biotechnology for Biofuels. The paper is titled "Production and extraction of sugars from switchgrass hydrolyzed in ionic liquids." Co-authoring it were Ning Sun, Hanbin Liu Noppadon Sathitsuksanoh, Vitalie Stavila, Manali Sawant, Anaise Bonito, Kim Tran, Anthe George, Kenneth Sale, Seema Singh and Bradley Holmes.

With the burning of fossil fuels continuing to add 9 billion metric tons of excess carbon dioxide to the atmosphere each year, the need for carbon neutral, cost-competitive renewable alternative fuels has never been greater. Advanced biofuels, produced from the microbial fermentation of sugars in lignocellulosic biomass, could displace gasoline, diesel and jet fuel on a gallon-for-gallon basis and be directly dropped into today's engines and infrastructures without impacting performance. If done correctly, the use of advanced biofuels would not add excess carbon to the atmosphere.

Environmentally benign ionic liquids are used as green chemistry substitutes for volatile organic solvents. While showing great potential as a biomass pretreatment for dissolving lignocellulose and helping to hydrolyze the resulting aqueous solution into fuel sugars, the best of these ionic liquids so far have required the use of expensive enzymes. Recent studies have shown that acid catalysts, such as hydrochloric or Brønsted, can effectively replace enzyme-based hydrolysis, but the subsequent separation of sugars and ionic liquids becomes a difficult and expensive problem can require the use of significant amounts of water.

Guided by molecular dynamics simulations carried out at DOE's National Energy Research Scientific Computing Center (NERSC), Simmons and his colleagues at JBEI solved this problem by deploying the ionic liquid imidazolium chloride in tandem with an acid catalyst.

"Imidazolium is the most effective known ionic liquid for breaking down lignocellulose and the chloride anion is amenable with the acid catalyst," Simmons says. "The combination makes it easy to extract fermentable sugars that have been liberated from biomass and also easy to recover the ionic liquid for recycling. By eliminating the need for enzymes and decreasing the water consumption requirements of more traditional ionic liquid pretreatments we should be able to reduce the costs of sugar production from lignocellulose."

Complete separation of the pretreatment solution into sugar-rich water and lignin-rich ionic liquid phases was attained with the addition to the solution of sodium hydroxide. The optimized sodium hydroxide concentration for both phase separation and sugar extraction was 15-percent, resulting in the recovery of maximum yields of 54-percent glucose and 88-percent xylose. The JBEI researchers believe these sugar yields can be increased by optimizing the process conditions and using more advanced methods of phase separation and sugar recovery.

Photochemistry, Climate Forcing and Volcanoes

Volcanoes are well known for cooling the climate. But just how much and when has been a bone of contention among historians, glaciologists and archeologists. Now a team of atmosphere chemists, from the Tokyo Institute of Technology and the University of Copenhagen, has come up with a way to say for sure which historic episodes of global cooling were caused by volcanic eruptions.

The answer lies in patterns of isotopes found in ancient volcanic sulfur trapped in ice core, patterns due to stratospheric photochemistry. Their mechanism is published in the highly recognized journal PNAS.

Better history through atmospheric chemistry

Matthew Johnson is an associate professor at the Department of Chemistry, University of Copenhagen where he studies chemical mechanisms in the atmosphere. He is thrilled at the prospect of giving a more precise tool to historians studying cold spells.

"Historical records are not always so accurate. Some may have been written down long after the fact, or when a different calendar was in use by a different culture. But the chemistry does not lie", says Johnson.

Method reads height by analyzing effect of sunshine

Powerful volcanoes can shoot gases through the atmosphere and high into the stratosphere where it can affect climate globally for a year or more. Less powerful eruptions can also have powerful impacts, but only locally, and for shorter times. And here's the trick. High plumes spend longer in the harsh sunlight of the stratosphere, and that changes the chemical signature of the sulfur in the plume. The balance of various isotopes is changed according to very precise rules, explains Mathew Johnson.

"Using our method we can determine whether a given eruption was powerful enough for the plume to enter the stratosphere affecting global climate. If we can find material from ancient eruptions it can now be used to give an accurate record of global volcanic events extending many hundreds of thousands of years back in time.", says Johnson.

Clue to fires found in ice

Strangely, the best place to look for traces of the fiery events is in ice. Tracking climate history is performed on cores drilled from the ice shields of Greenland and Antarctica. Much like tree rings, the snows of each year is compacted into a layer representing that year. As you go further down in the borehole, you descend into deeper history.

If volcanic material shows up in a layer, you know there was an eruption in that year. Using the method developed by Johnson and his colleagues it is now possible to analyze exactly how powerful a given eruption was.

"With the sulfur isotope method, we now have a way to prove whether a given eruption was so explosive that it entered the stratosphere, affecting global climate and civilizations, or, whether a given eruption was confined to the troposphere and local in its effects" says Johnson and goes on: "There are many controversial eruptions. The Mediterranean island of Santorini blew apart and caused the end of the Minoan culture. But there is a huge debate about when exactly this occurred. 1601 was the 'year without a summer' - but nobody knows where the volcano was that erupted. There's debate over whether there was an eruption on Iceland in 527, or 535, or 541. The sulfur isotope trick is a definite method to solve debates like this and get the most information out of the ice core records" Says Matthew Johnson.

Treated Cloth Separates Oil From Water in U Pittsburgh Lab

Caltech Team Develops Paleothermometer for Extinct Animals

Was Tyrannosaurus rex cold-blooded? Did birds regulate their body temperatures before or after they began to grow feathers? Why would evolution favor warm-bloodedness when it has such a high energy cost?

Questions like these—about when, why, and how vertebrates stopped relying on external factors to regulate their body temperatures and began heating themselves internally—have long intrigued scientists.

Now, a team led by researchers at the California Institute of Technology (Caltech) has taken a critical step toward providing some answers.

Reporting online this week in the early edition of the Proceedings of the National Academy of Sciences (PNAS), they describe the first method for the direct measurement of the body temperatures of large extinct vertebrates—through the analysis of rare isotopes in the animals' bones, teeth, and eggshells.

"This is not quite like going back in time and sticking a thermometer up a creature's back end," says John Eiler, Robert P. Sharp Professor of Geology and professor of geochemistry at Caltech. "But it's close."

Studying the mechanisms of and changes in temperature regulation in long-extinct animals requires knowing what their body temperatures were in the first place. But the only way scientists have had to study temperature regulation in such creatures was to make inferences based on what is known about their anatomy, diet, or behavior. Until now.

The technique the team has developed to measure body temperature in extinct vertebrates looks at the concentrations of two rare isotopes—carbon-13 and oxygen-18. "These heavy isotopes like to bond, or clump together, and this clumping effect is dependent on temperature," says Caltech postdoctoral scholar Robert Eagle, the paper's first author. "At very hot temperatures, you get a more random distribution of these isotopes, less clumping. At low temperatures, you find more clumping."

In living creatures, this clumping can be seen in the crystalline lattice that makes up bioapatite—the mineral from which bone, tooth enamel, eggshells, and other hard body parts are formed. "When the mineral precipitates out of the blood—when you create bone or tooth enamel—the isotopic composition is frozen in place and can be preserved for millions of years," he adds.

In addition, work in Eiler's lab has "defined the relationship between clumping and temperature," says Eagle, "allowing measurements of isotopes in the lab to be converted into body temperature." The method is accurate to within one or two degrees of difference.

"A big part of this paper is an exploration of what sorts of materials preserve temperature information, and where," notes Eiler.

To do this, the team looked at bioapatite from animals whose form of body-temperature regulation is already known. "We know, for instance, that mammals are warm-blooded; all the bioapatite in their bodies was formed at or near 37 degrees centigrade," says Eagle.

After showing proof of concept in living animals, the team looked at those no longer roaming the earth. For instance, the team was able to analyze mammoth teeth, finding body temperatures of between 37 and 38 degrees—exactly as expected.

Going back even further in time, they looked at 12-million-year-old fossils from a relative of the rhinoceros, as well as from a cold-blooded member of the alligator family tree. "We found we could measure the expected body temperature of the rhino-like mammal, and could see a temperature difference between that and the alligator relative, of about 6 degrees centigrade," Eagle says.

There are, however, limitations to this sort of temperature sleuthing. For one, the information that the technique provides is only a snapshot of a particular time and place, Eiler says, and not a lifelong record. "When we look at tooth enamel, for instance, what we get is a record of the head temperature of the animal when the tooth grew," he notes. "If you want to know what his big-toe temperature was two years later, too bad."

And, of course, the technique relies on the quality of the fossils available for testing. While teeth tend to withstand the rigors of burial and time, eggshells are "fragile and prone to recrystallization during burial," says Eiler. Finding good specimens can be difficult.

whoa.

Yes.

They are going after dinos next.

This will get...exciting.

Paper link.

Anoxygenic Photosynthesic Bacteria Dominated Early Earth

Anoxygenic photosynthesis modulated Proterozoic oxygen and sustained Earth's middle age

1. D. T. Johnston (a,b,1,2)
2. F. Wolfe-Simon (a,1,2)
3. A. Pearson (a,2)
4. A. H. Knoll (b,2)

a Department of Earth and Planetary Sciences, Harvard University, 20 Oxford Street, Cambridge, MA, 02138; and

b Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA, 02138

1 D.T.J. and F.W.-S. contributed equally to this work

2 To whom correspondence may be addressed. E-mail: johnston@eps.harvard.edu, wolfe@eps.harvard.edu, pearson@eps.harvard.edu, or aknoll@oeb.harvard.edu

Abstract:

Molecular oxygen (O2) began to accumulate in the atmosphere and surface ocean ca. 2,400 million years ago (Ma), but the persistent oxygenation of water masses throughout the oceans developed much later, perhaps beginning as recently as 580–550 Ma. For much of the intervening interval, moderately oxic surface waters lay above an oxygen minimum zone (OMZ) that tended toward euxinia (anoxic and sulfidic). Here we illustrate how contributions to primary production by anoxygenic photoautotrophs (including physiologically versatile cyanobacteria) influenced biogeochemical cycling during Earth's middle age, helping to perpetuate our planet's intermediate redox state by tempering O2 production. Specifically, the ability to generate organic matter (OM) using sulfide as an electron donor enabled a positive biogeochemical feedback that sustained euxinia in the OMZ. On a geologic time scale, pyrite precipitation and burial governed a second feedback that moderated sulfide availability and water column oxygenation. Thus, we argue that the proportional contribution of anoxygenic photosynthesis to overall primary production would have influenced oceanic redox and the Proterozoic O2 budget. Later Neoproterozoic collapse of widespread euxinia and a concomitant return to ferruginous (anoxic and Fe2+ rich) subsurface waters set in motion Earth's transition from its prokaryote-dominated middle age, removing a physiological barrier to eukaryotic diversification (sulfide) and establishing, for the first time in Earth's history, complete dominance of oxygenic photosynthesis in the oceans. This paved the way for the further oxygenation of the oceans and atmosphere and, ultimately, the evolution of complex multicellular organisms.

I'm reading and chewing on this one. Big time.

Quick Question

Has anyone ever done the calculation of just how much water has been lost from the Earth over the Phanerozoic? I mean through UV light slighting the water molecules up high and the hydrogen escaping because of its low mass and the Earth's warmth relative to gravity? I have heard discussions of this with respet to Venus, but not Earth...my google fu isn't so good today.

Quantum Computers Do Chem Sim better?

Quantum computers would likely outperform conventional computers in simulating chemical reactions involving more than four atoms, according to scientists at Harvard University, the Massachusetts Institute of Technology, and Haverford College. Such improved ability to model and predict complex chemical reactions could revolutionize drug design and materials science, among other fields.

Writing in the Proceedings of the National Academy of Sciences, the researchers describe "software" that could simulate chemical reactions on quantum computers, an ultra-modern technology that relies on quantum mechanical phenomena, such as entanglement, interference, and superposition. Quantum computing has been heralded for its potential to solve certain types of problems that are impossible for conventional computers to crack.

"There is a fundamental problem with simulating quantum systems -- such as chemical reactions -- on conventional computers," says Alán Aspuru-Guzik, assistant professor of chemistry and chemical biology in Harvard's Faculty of Arts and Sciences. "As the size of a system grows, the computational resources required to simulate it grow exponentially. For example, it might take one day to simulate a reaction involving 10 atoms, two days for 11 atoms, four days for 12 atoms, eight days for 13 atoms, and so on. Before long, this would exhaust the world's computational power."

Unlike a conventional computer, Aspuru-Guzik and his colleagues say, a quantum computer could complete the steps necessary to simulate a chemical reaction in a time that doesn't increase exponentially with the reaction's complexity.

"Being able to predict the outcomes of chemical reactions would have tremendous practical applications," says Ivan Kassal, a graduate student in chemical physics at Harvard. "A lot of research in drug design, materials science, catalysis, and molecular biology is still done by trial and error. Having accurate predictions would change the way these types of science are done."

The researchers demonstrate in PNAS that quantum computers would need to attain a size of about 100 qubits -- which are to quantum computers as bits are to conventional computers -- to outperform current classical supercomputers at a chemical simulation.

"This is still far beyond current prototype quantum computers," Kassal says. "And although it might take millions of quantum elementary operations on a few hundred quantum bits, our work suggests that with quantum computers that are as fast as modern conventional computers, one could simulate in seconds a chemical reaction that would take a conventional computer years."

Interesting. In a way it makes sense. I'd have to defer to the computational chem geeks on their opinions, but if its a power of n problem it does make sense.

Huh. Sounds a little similar to a coLabbie's work. HA! Same guys!