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New Environmental Chemistry Resources
- Posted at 12:59 PM on Jul. 2, 2009 by ausetute in website update AUS-e-TUTE has just added new environmental chemistry resources! Each tutorial has links to test, exams and games.
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Soot and Global Warming
- Posted at 10:33 AM on Jul. 1, 2009 by ausetute in Chemistry Update Soot absorbs solar energy and according to recent atmospheric models, it is second only to carbon dioxide in its ability to contribute to the enhanced greenhouse effect. Common sources of soot in the atmosphere are fires and the burning of fossil fuels. In a new study by the University of California San Diego, the size, chemical composition and optical properties of atmospheric aerosols were measured over time. The study shows that fresh soot quickly becomes coated with a shell of other chemicals such as sulfates, nitrates and organic carbon, in light-driven chemical reactions. The coating acts like a lens enhancing the absorption of light by the soot particles. Unlike carbon dioxide, which stays in the atmosphere for hundreds of years, soot falls from the sky in days. So, reducing the levels of soot in the atmosphere could quickly reduce its impact on global warming. University of California - San Diego (2009, June 30). Particulate Pollution Combined With Airborne Soot Adds To Global Warming. ScienceDaily. Retrieved July 1, 2009, from http://www.sciencedaily.com /releases/2009/06/090629200808.htm |
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Rydberg Atoms
- Posted at 10:20 AM on Jun. 29, 2009 by ausetute in Chemistry Update A Rydberg atom is an atom that has at least one electron orbiting the nucleus at a very large distance. When 2 Rydberg atoms approach each other an additional electrical field can change the orbit of the electrons resulting in a change in the forces acting between the Rydberg atoms so the atoms are attracted to each other. The bond length in these molecules can be very large compared to the bond length in more traditional molecules. The properties of molecules made out of Rydberg atoms can be tailored by applying an electric field. Researchers at the University of Oklahoma have discovered giant Rydberg molecules with a bond as large as a red blood cell. University of Oklahoma (2009, June 24). Giant Molecules Made Of Rydberg Atoms Discovered. ScienceDaily. Retrieved June 29, 2009, from http://www.sciencedaily.com /releases/2009/06/090624111913.htm |
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White Phosphorus Made Safer
- Posted at 11:21 AM on Jun. 26, 2009 by ausetute in Chemistry Update White phosphorus, which reacts violently and spontaneously with air has finally be made safer to handle and transport. White phosphorus is an important industrial chemical because it is used to produce:
Researchers have created a container molecule to stabilize white phosphorus indefinitely, rendering it safe until it is released from the container by the action of an agent such as benzene. Although this research has important implications for the safe handling and transport of phosphorus, the same container molecules could also be used to clean up phosphorus spills in industrial accidents or in war zones. University of Cambridge (2009, June 25). White Phosphorous Can Be Safely Handled And Transported With New Technique, Researchers Say. ScienceDaily. Retrieved June 26, 2009, from http://www.sciencedaily.com /releases/2009/06/090625141452.htm |
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How Do You Make 1 Drop of Hydrochloric Acid?
- Posted at 11:09 AM on Jun. 24, 2009 by ausetute in Chemistry Update Chemists have discovered that it requires exactly 4 water molecules and 1 hydrogen chloride molecule to form 1 droplet of hydrochloric acid. The study was conducted on single molecules of water and hydrogen chloride cooled to -272.8oC, just a little above absolute zero, using infra-red spectroscopy to follow the reaction. When water molecules are added to the hydrogen chloride molecule, no reaction occurs until the fourth water molecule has attached to the hydrogen chloride molecule. At this point a proton (H+) from the hydrogen chloride molecule is transferred to a water molecule to form the hydronium ion (H3O+). The reaction mechanism is called aggregation induced dissociation. Anna Gutberlet, et al. Below 1 K: The Smallest Droplet of Acid Aggregation-Induced Dissociation of HCl(H2O)4. Science, 324, 1545 (2009) DOI: 10.1126/science.1171753 |
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New Atmospheric Carbon Dioxide Study
- Posted at 9:55 AM on Jun. 22, 2009 by ausetute in Chemistry Update Atmospheric carbon dioxide levels for the last 2.1million years have been reconstructed in the greatest detail yet by analyzing the shells of single-celled plankton buried in the Atlantic Ocean off the coast of Africa. The study has found that a drop in carbon dioxide is not the cause for earth's ice ages growing longer and more intense about 850,000 years ago, but it confirms that higher carbon dioxide levels coincide with warmer intervals. Peak carbon dioxide levels over the past 2.1million years averaged about 280ppm, but today carbon dioxide is at 385ppm, 38% higher. About 55 million years ago a large and rapid increase in carbon dioxide caused large scale extinctions in bottom-dwelling ocean creatures and dissolved a lot of shells as the ocean became more acidic. The researchers now believe they will have to find a way to study these carbon dioxide changes in greater detail further back in the past. Atmospheric Carbon Dioxide Concentrations Across the Mid-Pleistocene Transition. Science, June 19, 2009 |
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Classification of Matter
- Posted at 3:57 PM on Jun. 17, 2009 by ausetute in website update AUS-e-TUTE has just added new resources (tutorials, tests, exams and games) on the classification of matter:
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Metals That Don't Expand When Heated
- Posted at 10:46 AM on Jun. 16, 2009 by ausetute in Chemistry Update Normal metals expand when heated but Caltech Scientists have created a metal alloy that does not expand when heated. The iron-palladium alloy, Pd3Fe, was squeezed between two diamond anvils at pressures 326,000 times greater than atmospheric pressure. The resultant alloy does not expand when heated. Metals that do not expand when heated were first discovered in 1896 by Charles Edouard Guillaume when he discovered an iron-nickel alloy that expands very little when heated. He called his alloy Invar alloy because the metals are invariant when heated. Invar alloys have been used in watches, toasters, light bulbs, electronic and scientific instruments, because they do not respond to temperature changes. Invar behaviour is caused by a change in the magnetic properties of alloys that cancel out the thermal expansion of the material. M. L. Winterrose, M. S. Lucas, A. F. Yue, I. Halevy, L. Mauger, J. A. Muñoz, Jingzhu Hu, M. Lerche, and B. Fultz. Pressure-Induced Invar Behavior in Pd3Fe. Physical Review Letters, 2009; 102 (237202) DOI: 10.1103/PhysRevLett.102.237202 |
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New Element Discovered
- Posted at 11:35 AM on Jun. 14, 2009 by ausetute in Chemistry Update Element 112, discovered at the Centre for Heavy Ion Research in Darmstadt, has been officially recognized as a new element by the International Union of Pure and Applied Chemistry (IUPAC). The new element is the heaviest element in the Periodic Table, about 277 times heavier than hydrogen. Element 112 is produced by accelerating zinc ions within the 120m long particle accelerator at GSI and firing them onto a lead target. The zinc and lead nuclei merge in a nuclear fusion reaction to form the nucleus of element 112. The GSI accelerator experiments have succeeded in producing 6 chemical elements since 1981:
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New Equilibrium Resources
- Posted at 9:58 AM on Jun. 11, 2009 by ausetute in website update AUS-e-TUTE has just new equilibrium resources including a tutorial, game, test and exam questions. You can always contact AUS-e-TUTE to tell us what resources you would like to see added to the website. |
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AUS-e-NEWS June 2009
- Posted at 9:43 AM on Jun. 3, 2009 by ausetute in AUS-e-NEWs The June edition of AUS-e-NEWS, AUS-e-TUTE's free quarterly newsletter, has been emailed out to members and subscribers. If you have not received your email, or if you would like to subscribe to the newsletter, please email 
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Structure of the AADase Enzyme
- Posted at 9:34 AM on Jun. 2, 2009 by ausetute in Chemistry Update In World War I, Chaim Weiszmann, isolated a bacterium that transforms cornstarch to a mixture of acetone (propanone) and a number of alcohols (alkanols). The bacterium uses AADase, an enzyme that catalyses the reaction that converts acetoacetate to acetone which could then be used in the production of cordite for explosives. Dr. Frank H. Westheimer used AADase to study the catalytic mechanism of enzymes in the 1960's. He hypothesised that a protein could control its own environment around the reaction, called the electrostatic perturbation hypothesis. X-ray crystallography as now been used to determine the atomic structure of AADase and has revealed a complex three-dimensional protein fold responsible for the catalytic mechanism of AADase. Meng-Chiao Ho, Jean-François Ménétret, Hiro Tsuruta, Karen N. Allen. The origin of the electrostatic perturbation in acetoacetate decarboxylase. Nature, 2009; 459 (7245): 393 DOI: 10.1038/nature07938 |
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New Biochemistry Resources
- Posted at 9:51 AM on May. 30, 2009 by ausetute in website update AUS-e-TUTE has just added new tutorials, tests, exams and games in the Biochemistry topic. |
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Turning Plants into Plastic
- Posted at 9:23 AM on May. 25, 2009 by ausetute in Chemistry Update Chemists have successfully converted cellulose directly into HMF, 5-hydroxymethylfurfural, the building block for plastics, in a one step process. The process generates a high yield of HMF and allows the use of raw cellulose as the feed material without the need to convert cellulose into simple sugars first. Using an ionic liquid to dissolve the cellulose and metal chloride catalysts , copper chloride and chromium chloride at 120oC, to speed up the reaction, the Chemists found they could convert 57% of the sugar content in cellulose to HMF, recovering more than 90% of the HMF formed with a purity of 96%. The ionic liquid and the catalysts can be reused multiple times without loss of effectiveness. It is hoped that advances such as this will reduce our reliance on fossil fuels. Y. Su, H.M. Brown, X. Huang, X.-d. Zhou, J.E. Amonette, Z.C. Zhang. Single-Step Conversion of Cellulose to 5-Hydroxymethylfurfural (HMF), a Versatile Platform Chemical. Applied Catalysis A: General, Online 9 April 2009 DOI: 10.1016/j.apcata.2009.04.002 |
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Sulfur and Mercury Removal
- Posted at 10:13 AM on May. 20, 2009 by ausetute in Chemistry Update Hydrodesulfurization is a catalytic process that is used to remove sulfur from natural gas (methane) and refined petroleum products such as petrol (gasoline), deisel and jet fuels. Scientists in the USA have developed a new material to improve the process of removing sulfur. The new material, cobalt-molybdenum-sulfur, a new class of chalcogels, is stable to air or water and can be used as a powder. A similar material made of cobalt, nickel, molybdenum and sulfur is a gel which is freeze dried, producing a sponge-like material with a vast surface area. This gel is capable of soaking up heavy metals, like mercury, from polluted water because the mercury binds with the sulfur. This gel can also remove carbon dioxide from hydrogen which could be useful in the development of hydrogen as a fuel. Spongy Chalcogels of Nonplatinum Metals Act as Effective Hydrodesulfurization Catalysts. Nature Chemistry, May 17, 2009 |
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Biomass to Bio-oil to Useful Alkanes
- Posted at 9:11 AM on May. 15, 2009 by ausetute in Chemistry Update A team of Scientists at the Technical University of Munich have developed a new "one pot" catalytic process to convert components of bio-oil directly into alkanes and methanol. Bio-oil is the product of conversion of biomass using processes such as pyrolysis or liquefaction. It is an aqueous, acidic, highly oxidised mixture that cannot be used directly as a fuel. It contains phenolic compounds (aromatic ring compounds made up of 6 carbon atoms and some hydroxy groups attached). Alkanes (paraffins) are used not only as fuels, but also as the starting materials for the production of plastics. The new catalyst, palladium metal on a carbon support with phosphoric acid as the proton source for the reaction, converts the phenolic components of bio-oil into cycloalkanes with a high degree of selectivity. Highly Selective Catalytic Conversion of Phenolic Bio-Oil to Alkanes. Angewandte Chemie International Edition 2009, 48, 4047%u20134050 DOI: 10.1002/anie.200900404 |
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Detergents Destroy Blood Traces
- Posted at 9:07 AM on May. 13, 2009 by ausetute in Chemistry Update Forensic Scientists have been using reagents such as
Recent studies have shown that when clothing is washed in modern detergents containing active oxygen, all the tests above show false negatives, ie, they do not show the presence of blood. Although Scientists are still unsure as to the reason why, they are suggesting that the active oxygen detergents contain sodium percarbonate and when this dissolves in water hydrogen peroxide is released which may be inhibiting the test reactions by depleting the haemoglobin in an attempt to eliminate the peroxide. Castelló et al. Active oxygen doctors the evidence. Naturwissenschaften, 2009; 96 (2): 303 DOI: 10.1007/s00114-008-0466-9 |
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New AUS-e-TUTE Resources
- Posted at 3:25 PM on May. 11, 2009 by ausetute in website update AUS-e-TUTE has just added new tutorials, tests, exams and games. Hess's Law |
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The Science Behind Invisibility
- Posted at 10:21 AM on May. 6, 2009 by ausetute in Chemistry Update Berkeley Scientists have created an invisibility cloak out of nanostructured silicon which conceals the presence of objects placed under it. While the cloak itself can be seen, the bulge of the object underneath it disappears from view. Previous attempts at an invisibility cloak using metallic metamaterials have succeeded in achieving invisibility cloaking at microwave frequencies. The new invisibility cloak, made out of dielectric materials which are often transparent at optical frequencies achieves invisibility for light between 1,400 and 1,800 nanometers in wavelength (the near-infrared part of the electromagnetic spectrum). Researchers are now confident that a dielectric approach to invisibility could lead to a material that operates for visible light. Valentine et al. An optical cloak made of dielectrics. Nature Materials, 2009; DOI: 10.1038/nmat2461 |
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Mass Spectrometry and Evolution
- Posted at 9:15 AM on May. 3, 2009 by ausetute in Chemistry Update Chemists have used Mass Spectrometry to produce evidence that birds and dinosaurs are evolutionarily related. Protein samples were extracted from preserved tissue and bone fragments of an 80 million year old hadrosaur (duck-billed dinosaur). These were analyzed using an ion trap mass spectrometer which captures and holds peptides through time so that after the collected peptides are measured for mass they are isolated and fragmented to reveal their amino acid sequence. A total of eight collagen peptides and 149 amino acids were sequenced. The collagen sequences were compared to a database of collagen sequences with the result that the hadrosaur was placed in the same family-tree branch with Tyrannosaurus rex, chickens and ostriches, and shown to be more distantly related to alligators and lizards. Mary H. Schweitzer, Wenxia Zheng, Chris L. Organ, Recep Avci, Zhiyong Suo, Lisa M. Freimark, Valerie S. Lebleu, Michael B. Duncan, Matthew G. Vander Heiden, John M. Neveu, William S. Lane, John S. Cottrell, John R. Horner, Lewis C. Cantley, Raghu Kalluri, and John M. Asara. Biomolecular Characterization and Protein Sequences of the Campanian Hadrosaur B. canadensis. Science, 2009; 324 (5927): 626 DOI: 10.1126/science.1165069 |
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