Sample records for hot atom chemistry

  1. Hot atom chemistry and radiopharmaceuticals

    NASA Astrophysics Data System (ADS)

    Krohn, Kenneth A.; Moerlein, Stephen M.; Link, Jeanne M.; Welch, Michael J.

    2012-12-01

    The chemical products made in a cyclotron target are a combined result of the chemical effects of the nuclear transformation that made the radioactive atom and the bulk radiolysis in the target. This review uses some well-known examples to understand how hot atom chemistry explains the primary products from a nuclear reaction and then how radiation chemistry is exploited to set up the optimal product for radiosynthesis. It also addresses the chemical effects of nuclear decay. There are important principles that are common to hot atom chemistry and radiopharmaceutical chemistry. Both emphasize short-lived radionuclides and manipulation of high specific activity nuclides. Furthermore, they both rely on radiochromatographic separation for identification of no-carrieradded products.

  2. Hot hydrogen atoms - Initiators of reactions of interest in interstellar chemistry and evolution

    NASA Technical Reports Server (NTRS)

    Hong, K.-Y.; Hong, J.-H.; Becker, R. S.

    1974-01-01

    Hot hydrogen atoms possess kinetic (or translational) energy in excess of that to be expected if the atoms were in thermal equilibrium with the surroundings. In the investigation reported the hot hydrogen atoms were generated by the photolysis of donor molecules. The light sources for the photolysis were 1000-watt xenon or 500-watt mercury lamps combined with a filter system. The experiments show that hot hydrogen atoms can initiate reactions among simple molecules to produce biomolecules of significance.

  3. Hot Atom Chemistry of the Alkyl Bromides; Absence of Effects Due to High Radiation Density; Isotope Separation in Solids

    Microsoft Academic Search

    Frank S. Rowland; W. F. Libby

    1953-01-01

    A 30-curie polonium-beryllium neutron source which gives less than 0.1 roentgen per hour in close contact was used to study the hot atom chemistry of a selection of alkyl bromides. Comparison of the results with those obtained with ordinary neutron sources containing gamma rays in abundance up to 700 roentgen\\/hour equivalent strongly indicates that the essential phenomena reported are free

  4. Physics and chemistry of hot molecular cores

    E-print Network

    Henrik Beuther

    2006-10-13

    Young massive star-forming regions are known to produce hot molecular gas cores (HMCs) with a rich chemistry. While this chemistry is interesting in itself, it also allows to investigate important physical parameters. I will present recent results obtained with high-angular-resolution interferometers disentangling the small-scale structure and complexity of various molecular gas components. Early attempts to develop a chemical evolutionary sequence are discussed. Furthermore, I will outline the difficulty to isolate the right molecular lines capable to unambiguously trace potential massive accretion disks.

  5. Cold Light from Hot Atoms and Molecules

    SciTech Connect

    Lister, Graeme [OSRAM SYLVANIA, CRSL, 71 Cherry Hill Drive, Beverly, MA (United States); Curry, John J. [National Institute of Standards and Technology, Gaithersburg, MD (United States)

    2011-05-11

    The introduction of rare earth atoms and molecules into lighting discharges led to great advances in efficacy of these lamps. Atoms such as Dy, Ho and Ce provide excellent radiation sources for lighting applications, with rich visible spectra, such that a suitable combination of these elements can provide high quality white light. Rare earth molecules have also proved important in enhancing the radiation spectrum from phosphors in fluorescent lamps. This paper reviews some of the current aspects of lighting research, particularly rare earth chemistry and radiation, and the associated fundamental atomic and molecular data.

  6. Cold Light from Hot Atoms and Molecules

    NASA Astrophysics Data System (ADS)

    Lister, Graeme; Curry, John J.

    2011-05-01

    The introduction of rare earth atoms and molecules into lighting discharges led to great advances in efficacy of these lamps. Atoms such as Dy, Ho and Ce provide excellent radiation sources for lighting applications, with rich visible spectra, such that a suitable combination of these elements can provide high quality white light. Rare earth molecules have also proved important in enhancing the radiation spectrum from phosphors in fluorescent lamps. This paper reviews some of the current aspects of lighting research, particularly rare earth chemistry and radiation, and the associated fundamental atomic and molecular data.

  7. COLD AND HOT ATOMIC VAPORS: A TESTBED FOR ASTROPHYSICS?

    E-print Network

    CHAPTER 5 COLD AND HOT ATOMIC VAPORS: A TESTBED FOR ASTROPHYSICS? Q. Baudouin, W. Guerin and R- scattering of light in hot and cold atomic vapors, random lasing in cold atoms and light-induced long, we would like to point out the possible applications of cold-atom experiments and, more generally

  8. Liquid-metal atomization for hot working preforms

    NASA Technical Reports Server (NTRS)

    Grant, N. J.; Pelloux, R. M.

    1974-01-01

    Rapid quenching of a liquid metal by atomization or splat cooling overcomes the major limitation of most solidification processes, namely, the segregation of alloying elements, impurities, and constituent phases. The cooling rates of different atomizing processes are related to the dendrite arm spacings and to the microstructure of the atomized powders. The increased solubility limits and the formation of metastable compounds in splat-cooled alloys are discussed. Consolidation of the powders by hot isostatic compaction, hot extrusion, or hot forging and rolling processes yields billets with properties equivalent to or better than those of the wrought alloys. The application of this powder processing technology to high-performance alloys is reviewed.

  9. Modeling hot spring chemistries with applications to martian silica formation

    USGS Publications Warehouse

    Marion, G.M.; Catling, D.C.; Crowley, J.K.; Kargel, J.S.

    2011-01-01

    Many recent studies have implicated hydrothermal systems as the origin of martian minerals across a wide range of martian sites. Particular support for hydrothermal systems include silica (SiO2) deposits, in some cases >90% silica, in the Gusev Crater region, especially in the Columbia Hills and at Home Plate. We have developed a model called CHEMCHAU that can be used up to 100??C to simulate hot springs associated with hydrothermal systems. The model was partially derived from FREZCHEM, which is a colder temperature model parameterized for broad ranges of temperature (<-70 to 25??C), pressure (1-1000 bars), and chemical composition. We demonstrate the validity of Pitzer parameters, volumetric parameters, and equilibrium constants in the CHEMCHAU model for the Na-K-Mg-Ca-H-Cl-ClO4-SO4-OH-HCO3-CO3-CO2-O2-CH4-Si-H2O system up to 100??C and apply the model to hot springs and silica deposits.A theoretical simulation of silica and calcite equilibrium shows how calcite is least soluble with high pH and high temperatures, while silica behaves oppositely. Such influences imply that differences in temperature and pH on Mars could lead to very distinct mineral assemblages. Using measured solution chemistries of Yellowstone hot springs and Icelandic hot springs, we simulate salts formed during the evaporation of two low pH cases (high and low temperatures) and a high temperature, alkaline (high pH) sodic water. Simulation of an acid-sulfate case leads to precipitation of Fe and Al minerals along with silica. Consistency with martian mineral assemblages suggests that hot, acidic sulfate solutions are plausibility progenitors of minerals in the past on Mars. In the alkaline pH (8.45) simulation, formation of silica at high temperatures (355K) led to precipitation of anhydrous minerals (CaSO4, Na2SO4) that was also the case for the high temperature (353K) low pH case where anhydrous minerals (NaCl, CaSO4) also precipitated. Thus we predict that secondary minerals associated with massive silica deposits are plausible indicators on Mars of precipitation environments and aqueous chemistry. Theoretical model calculations are in reasonable agreement with independent experimental silica concentrations, which strengthens the validity of the new CHEMCHAU model. ?? 2011 Elsevier Inc.

  10. Femtosecond two-photon photoassociation of hot magnesium atoms: A quantum dynamical study using thermal random phase wavefunctions

    SciTech Connect

    Amaran, Saieswari; Kosloff, Ronnie [Fritz Haber Research Centre and The Department of Physical Chemistry, Hebrew University, Jerusalem 91904 (Israel)] [Fritz Haber Research Centre and The Department of Physical Chemistry, Hebrew University, Jerusalem 91904 (Israel); Tomza, Micha?; Skomorowski, Wojciech; Paw?owski, Filip; Moszynski, Robert [Department of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw (Poland)] [Department of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw (Poland); Rybak, Leonid; Levin, Liat; Amitay, Zohar [The Shirlee Jacobs Femtosecond Laser Research Laboratory, Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa 32000 (Israel)] [The Shirlee Jacobs Femtosecond Laser Research Laboratory, Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa 32000 (Israel); Berglund, J. Martin; Reich, Daniel M.; Koch, Christiane P. [Theoretische Physik, Universität Kassel, Heinrich-Plett-Straße 40, 34132 Kassel (Germany)] [Theoretische Physik, Universität Kassel, Heinrich-Plett-Straße 40, 34132 Kassel (Germany)

    2013-10-28

    Two-photon photoassociation of hot magnesium atoms by femtosecond laser pulses, creating electronically excited magnesium dimer molecules, is studied from first principles, combining ab initio quantum chemistry and molecular quantum dynamics. This theoretical framework allows for rationalizing the generation of molecular rovibrational coherence from thermally hot atoms [L. Rybak, S. Amaran, L. Levin, M. Tomza, R. Moszynski, R. Kosloff, C. P. Koch, and Z. Amitay, Phys. Rev. Lett. 107, 273001 (2011)]. Random phase thermal wavefunctions are employed to model the thermal ensemble of hot colliding atoms. Comparing two different choices of basis functions, random phase wavefunctions built from eigenstates are found to have the fastest convergence for the photoassociation yield. The interaction of the colliding atoms with a femtosecond laser pulse is modeled non-perturbatively to account for strong-field effects.

  11. Femtosecond two-photon photoassociation of hot magnesium atoms: A quantum dynamical study using thermal random phase wavefunctions

    E-print Network

    Saieswari Amaran; Ronnie Kosloff; Micha? Tomza; Wojciech Skomorowski; Filip Pawlowski; Robert Moszynski; Leonid Rybak; Liat Levin; Zohar Amitay; J. Martin Berglund; Daniel M. Reich; Christiane P. Koch

    2013-10-31

    Two-photon photoassociation of hot magnesium atoms by femtosecond laser pulses, creating electronically excited magnesium dimer molecules, is studied from first principles, combining \\textit{ab initio} quantum chemistry and molecular quantum dynamics. This theoretical framework allows for rationalizing the generation of molecular rovibrational coherence from thermally hot atoms [L. Rybak \\textit{et al.}, Phys. Rev. Lett. {\\bf 107}, 273001 (2011)]. Random phase thermal wave functions are employed to model the thermal ensemble of hot colliding atoms. Comparing two different choices of basis functions, random phase wavefunctions built from eigenstates are found to have the fastest convergence for the photoassociation yield. The interaction of the colliding atoms with a femtosecond laser pulse is modeled non-perturbatively to account for strong-field effects.

  12. Collisional-radiative average-atom model for hot plasmas

    Microsoft Academic Search

    Balazs F. Rozsnyai

    1997-01-01

    A collisional-radiative {open_quotes}average-atom{close_quotes} (AA) model is presented for the calculation of opacities of hot plasmas that are not in the condition of local thermodynamic equilibrium (LTE). The electron impact and radiative rate constants are calculated using the dipole oscillator strengths of the average atom. A key element of the model is the photon escape probability, which at present is calculated

  13. The early days of atomic absorption spectrometry in clinical chemistry

    NASA Astrophysics Data System (ADS)

    Willis, J. B.

    1999-12-01

    An account is given of the first applications of atomic absorption spectrometry in clinical chemistry. These include the determination of calcium and magnesium in blood serum and of these elements, together with a range of heavy metals, in urine.

  14. Sounding rocket observation of a hot atomic oxygen geocorona

    NASA Technical Reports Server (NTRS)

    Cotton, Daniel M.; Gladstone, G. Randall; Chakrabarti, Supriya

    1993-01-01

    A sounding rocket measurement of the ultraviolet, atomic oxygen dayglow reveals an excess of emission compared to standard thermospheric model calculations at exospheric altitudes. We explore two explanations for this discrepancy: a breakdown of the radiative transfer model due to nonlocal thermal equilibrium (non-LTE) conditions above the exobase and a hot atomic oxygen geocorona. In particular, the effects of non-LTE on the 3P2, 1, 0 sublevel populations are modeled, and a hot O component in the upper thermosphere and lower exosphere is added to investigate the effects on the modeled emissions. For both cases, the data are reanalyzed and compared with the results using a standard LTE model. A hot O geocorona having a peak density of 10(exp 6)/cc at 550 km and a temperature of 4000 K is consistent with the data and appears to be the most reasonable explanation of the high-altitude enhanced emissions observed in the data.

  15. H atom probes of radiation chemistry: Solids and liquids

    SciTech Connect

    Trifunac, A.D.; Shkrob, I.A. [Argonne National Lab., IL (United States). Chemistry Div.

    1998-12-31

    H atoms are ubiquitous in radiation chemistry. Radiolysis of most substances yield H atoms and studies of the mechanisms of their production are as old as the field of radiation chemistry. The problem is that study or products does not easily reveal the chemical mechanisms involved even with the clever use of isotopes. Time-resolved pulsed electron paramagnetic resonance (EPR) was used to study formation and decay kinetics of spin-polarized mobile H atoms in radiolysis of wet fused silica containing {approximately} 1,200 ppm of SiOH groups. Two reactions of H atoms can be distinguished: a slow component corresponding to scavenging of H atoms by metastable paramagnetic centers and a fast component which is ascribed to a reaction of a short-lived small polaron (intrinsic hole) with H atoms.

  16. Hot hydrogen atom reactions moderated by H2 and He

    NASA Technical Reports Server (NTRS)

    Aronowitz, S.; Scattergood, T.; Flores, J.; Chang, S.

    1986-01-01

    Photolysis experiments were performed on the H2-CD4-NH3 and He-CD4-NH3 systems. The photolysis (1849 A) involved only NH3. Mixtures of H2:CD4:NH3 included all combinations of the ratios (200,400,800):(10,20,40):4. Two He:CD4:NH3 mixtures were examined where the ratios equalled the combinations 100:(10,20):4. Abstraction of a D from CD4 by the photolytically produced hot hydrogen from ammonia was monitored by mass spectrometric determination of HD. Both experiment and semiempirical hot-atom theory show that H2 is a very poor thermalizer of hot hydrogens with excess kinetic energy of about 2 eV. Applications of the hard-sphere collision model to the H2-CD4-NH3 system resulted in predicted ratios of net HD production to NH3 decomposition that were two orders of magnitude smaller than the experimental ratios. On the other hand, helium is found to be a very efficient thermalizer; here, the classical model yields reasonable agreement with experiments. Application of a semiempirical hot-atom program gave quantitative agreement with experiment for either system.

  17. Students' use of atomic and molecular models in learning chemistry

    Microsoft Academic Search

    Eileen Ann O'Connor

    1997-01-01

    The objective of this study was to investigate the development of introductory college chemistry students' use of atomic and molecular models to explain physical and chemical phenomena. The study was conducted during the first semester of the course at a University and College II. Public institution (Carnegie Commission of Higher Education, 1973). Students' use of models was observed during one-on-one

  18. Alloys Fabricated by Gas Atomization and Hot Extrusion

    NASA Astrophysics Data System (ADS)

    Madavali, Babu; Kim, Hyo-Seob; Hong, Soon-Jik

    2014-06-01

    In this research, n-type (Bi2Te3)1- x (Bi2Se3) x -based thermoelectric (TE) materials were produced through a gas atomization process, and subsequently hot extruded with an extrusion ratio of 10:1 at 400 °C. The effect of chemical composition on TE properties was investigated. The microstructure of all extruded bars showed a homogeneous and fine distribution of grains due to the dynamic recrystallization during the hot extrusion process. With increasing Bi2Te3 content, from 0.85 to 0.90, both electrical resistivity and Seebeck coefficient values were increased. The maximum figure of merit ( ZT) 0.673 was obtained at room temperature for (Bi2Te3)0.90(Bi2Se3)0.10 alloys due to them exhibiting higher seebeck coefficient and lower thermal conductivity than other compositions.

  19. Effects of surface chemistry on hot corrosion life

    NASA Technical Reports Server (NTRS)

    Fryxell, R. E.; Gupta, B. K.

    1984-01-01

    Hot corrosion life prediction methodology based on a combination of laboratory test data and field service turbine components, which show evidence of hot corrosion, were examined. Components were evaluated by optical metallography, scanning electron microscopy (SEM), and electron micropulse (EMP) examination.

  20. EleyRideal and hot-atom reactions of H,,D... atoms with D,,H...-covered Cu,,111... surfaces; quasiclassical studies

    E-print Network

    Persson, Mats

    Eley­Rideal and hot-atom reactions of H,,D... atoms with D,,H...-covered Cu,,111... surfaces to form HD via the Eley­Rideal mechanism, or trap onto the surface. These trapped hot atoms can react are computed and compared with experiment. Hot-atom pathways to product formation are shown to make significant

  1. Effects of surface chemistry on hot corrosion life

    NASA Technical Reports Server (NTRS)

    Fryxell, R. E.; Leese, G. E.

    1985-01-01

    This program has its primary objective: the development of hot corrosion life prediction methodology based on a combination of laboratory test data and evaluation of field service turbine components which show evidence of hot corrosion. The laboratory program comprises burner rig testing by TRW. A summary of results is given for two series of burner rig tests. The life prediction methodology parameters to be appraised in a final campaign of burner rig tests are outlined.

  2. Opacity of Hot and Dense Plasmas of a Mixture using an Average-Atom Approach

    Microsoft Academic Search

    Jian-Min Yuan

    2002-01-01

    An average-atom model is proposed to calculate the opacities of hot and dense plasmas of a mixture. A self-consistent scheme is used to reach the requirements of the same temperature and chemical potential for all kinds of atoms in the mixtures, the same electron density at the boundaries between the atoms, and the electrical neutrality within each atomic sphere. The

  3. Infusing the Chemistry Curriculum with Green Chemistry Using Real-World Examples, Web Modules, and Atom Economy in Organic Chemistry Courses

    ERIC Educational Resources Information Center

    Cann, Michael C.; Dickneider, Trudy A.

    2004-01-01

    Green chemistry is the awareness of the damaging environmental effects due to chemical research and inventions. There is emphasis on a need to include green chemistry in synthesis with atom economy in organic chemistry curriculum to ensure an environmentally conscious future generation of chemists, policy makers, health professionals and business…

  4. The Relation Between Alloy Chemistry and Hot-Cracking

    NASA Technical Reports Server (NTRS)

    Nunes, A. C., Jr.; Talia, J. E.

    2000-01-01

    Hot cracking is a problem in welding 2195 aluminum-lithium alloy. Weld wire additives seem to reduce the problem. This study proposes a model intended to clarify the way alloying elements affect hot-cracking. The brittle temperature range of an alloy extends wherever the tensile stress required to move the meniscus of the liquid film at the grain/dendrite boundaries is less than the bulks flow stress Sigma(sub B) of the grains: 2gamma/delta <= sigma(sub B) + P where gamma is boundary film surface tension delta= boundary film thickness P = gas pressure (Some alloys outgas.) If the above condition is not met, the grains deform under stress and the liquid film remains in place. Curves of 2gamma/delta and sigma(sub B) vs. temperature in the range just below the melting temperature determine the hot cracking susceptibility of an alloy. Both are zero at onset of solidification. sigma(sub B) rises as the thermal activation of the slip mechanism is reduced. 2gamma/delta rises as the film thickness delta which can be estimated from the Scheil equation, drops. But, given an embrittled alloy, whether the alloy actually cracks is determined by the strain imposed upon it in the embrittled condition. A critical strain is estimated, Epsilon(sub C) on the order of Epsilon(sub C) is approximately delta/l where L = grain size and where the the volume increment due to the strain, concentrated at the liquid film, is on the order of the liquid film volume. In the early 80's an empirical critical strain cracking envelope Epsilon(sub C)(T) was incorporated into a damage criterion to estimate the effect of welding parameters on the formation of microfissures in a superalloy with good results. These concepts, liquid film decoherence vs. grain bulk deformation and critical strain, form the key elements of a quantitative theory of hot-cracking applicable for assessing the effect of alloying elements on hot-cracking during welding.

  5. Equilibrium Chemistry Calculations for Model Hot-Jupiter Atmospheres

    NASA Astrophysics Data System (ADS)

    Blumenthal, Sarah; Harrington, Joseph; Bowman, M. Oliver; Blecic, Jasmina

    2014-11-01

    Every planet in our solar system has different elemental abundances from our sun's. It is thus necessary to explore a variety of elemental abundances when investigating exoplanet atmospheres. Composition is key to unraveling a planet's formation history and determines the radiative behavior of an atmosphere, including its spectrum (Moses et al. 2013). We consider here two commonly discussed situations: [C]/[O] > 1 and 10x and 100x heavy-element enrichment. For planets above 1200 K, equilibrium chemistry is a valid starting point in atmospheric analysis. For HD 209458b, this assumption was verified by comparing the results of a robust kinetics code (non-ideal behavior) to the results of an equilibrium chemistry code (ideal behavior). Both codes output similar results for the dayside of the planet (Agundez et al. 2012). Using NASA's open-source Chemical Equilibrium Abundances code (McBride and Gordon 1996), we calculate the molecular abundances of species of interest across the dayside of model planets with a range of: elemental abundance profiles, degree of redistribution, relevant substellar temperatures, and pressures. We then explore the compositional gradient of each model planet atmosphere layer using synthetic abundance images of target spectroscopic species (water, methane, carbon monoxide). This work was supported by the NASA Planetary Atmospheres grant NNX12AI69G and NASA Astrophysics Data Analysis Program NNX13AF38G.

  6. Unraveling the complex chemistry using dimethylsilane as a precursor gas in hot wire chemical vapor deposition.

    PubMed

    Toukabri, Rim; Shi, Yujun

    2014-05-01

    The gas-phase reaction chemistry when using dimethylsilane (DMS) as a source gas in a hot-wire chemical vapor deposition (CVD) process has been studied in this work. The complex chemistry is unraveled by using a soft 10.5 eV single photon ionization technique coupled with time-of-flight mass spectrometry in combination with the isotope labelling and chemical trapping methods. It has been demonstrated that both free-radical reactions and those involving silylene/silene intermediates are important. The reaction chemistry is characterized by the formation of 1,1,2,2-tetramethyldisilane (TMDS) from dimethylsilylene insertion into the Si-H bond of DMS, trimethylsilane (TriMS) from free-radical recombination, and 1,3-dimethyl-1,3-disilacyclobutane (DMDSCB) from the self dimerization of either dimethylsilylene or 1-methylsilene. At low filament temperatures and short reaction time, silylene chemistry dominates. The free-radical reactions become more important with increasing temperature and time. The same three products have been detected when using tantalum and tungsten filaments, indicating that changing the filament material from Ta to W does not affect much the gas-phase reaction chemistry when using DMS as a source gas in a hot-wire CVD reactor. PMID:24647875

  7. Effects of surface chemistry on hot corrosion life

    NASA Technical Reports Server (NTRS)

    Fryxell, R. E.

    1985-01-01

    Burner rig tests were conducted under the following conditions: 900 C, hourly thermal cycling, 0.5 ppm sodium as MaCl in the gas stream, velocity 0.3 Mach. The alloys are Udiment 700, Rene 80, uncoated and with RT21, Codep, or NiCoCrAlY coatings. These tests were completed for specimens in the as-processed condition and after aging at 1100 C in oxidizing or inert evnivronments for time up to 600 hours. Coil inductance changes used for periodic nondestructive inspection of specimens were useful in following the course of corrosion. Typical sulfidation was observed in all cases, structurally similar to that observed for service-run turbine components. Aging at cuased a severe decrease in hot corrosion life of RT21 and Codep coatings and a significant but less decrease in the life of the NiCoCrAlY coating. The extent of these decreases was much greater for all three coatings on U700 substrates than on Rene 80 substrates. Coating/substrate interdiffusion rather than by surface oxidation.

  8. Testing grain-surface chemistry in hot core regions

    NASA Astrophysics Data System (ADS)

    Bisschop, Suzanne E.; Jørgensen, Jes K.; van Dishoeck, Ewine F.

    Many complex organic molecules have been detected in star-forming regions like CH3OCH3 and CH3CH2CN. Studying their chemistry is important, since these species may eventually be incorporated into circumstellar disks and thus become part of the material from which future planetary systems are made. Two scenarios for their formation have been proposed: grain-surface formation and high-temperature gas-phase reactions (van Dishoeck & Hogerheijde 1999). In the former case, grain-surface reactions during the cold pre-stellar and protostellar phases are thought to lead to the formation of various hydrogenated molecules, which subsequently evaporate into the gas when the young star heats its surroundings. In the latter scenario, high-temperature gas-phase reactions involving evaporated molecules (primarily CH3OH) produce complex organic species (Charnley et al. 1992). The resulting molecules from these two schemes are also known as "first generation" and "second generation" species, respectively. Currently, it is very difficult to distinguish between these two scenarios since the rates of even some of the most basic surface reactions are not known. Accordingly, we have started a combined laboratory and observational program to test the scenarios. The basic scheme for grain surface chemistry has been outlined by Tielens & Hagen (1982) and Tielens & Charnley (1997). The first step is hydrogenation of the main species that accrete from the gas onto the grains, i.e., C, N, O and CO, leading to CH4, NH3, H2O, H2CO and CH3OH. These molecules can react further in the ice with C, H, N, and O creating several more complicated species. In the warm regions close to the protostars the grain mantles can evaporate, returning many of the "first generation" molecules into the gas phase. Deep JCMT searches for a set of molecules have been performed for 1 low mass and 7 high mass young stellar objects (YSOs) (e.g. Figure 1). The focus is on relatively nearby sources with narrow line widths to avoid confusion. The molecules studied are HCO, H2CO, CH3OH, CH2CO, CH3CHO, C2H5OH, HNCO and NH2CHO. HNCO, CH3OH, H2CO and C2H5OH are detected for most or all sources, whereas NH2CHO, CH2CO and HCOOH are detected for some and HCO and CH3CHO are not detected at all. For HCO the reason is likely due to its low intrinsic line strength, however CH3CHO has previously been detected by Ikeda et al. (2002). The rotational temperatures found by Ikeda et al. are only 20-30 K and thus much lower than the lowest rotational transition of 71 K that can be probed with the JCMT. Initial correlations between the abundances with respect to CO of these species have been studied, and a more detailed analysis using radiative transfer models will follow. The correlation between the abundances relative to CO are found to be strong for CH3OH, H2CO, C2H5OH, and HNCO (see for example Figure 1 for HNCO and C2H5OH), whereas no clear trends are yet found for the abundances of HCOOH, NH2CHO, and CH2CO. The strong trends found for four of these molecules indicate that they are either present in the same environment or share a common formation mechanism. The resulting branching ratios can be compared with various models. For example, pure gas-phase models by Lee et al. (1996) predict CH2CO/CH3CHO/CH3CH2OH ratios of ~1 : 10-3 : 10-5, whereas grain-surface chemistry predicts ratios much closer to unity. Our inferred branching ratios are found to be much closer to the latter values, indicating that grain-chemistry plays an important role.

  9. Hydrogen atom initiated chemistry. [chemical evolution in planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Hong, J. H.; Becker, R. S.

    1979-01-01

    H Atoms have been created by the photolysis of H2S. These then initiated reactions in mixtures involving acetylene-ammonia-water and ethylene-ammonia-water. In the case of the acetylene system, the products consisted of two amino acids, ethylene and a group of primarily cyclic thio-compounds, but no free sulfur. In the case of the ethylene systems, seven amino acids, including an aromatic one, ethane, free sulfur, and a group of solely linear thio-compounds were produced. Total quantum yields for the production of amino acids were about 3 x 10 to the -5th and about 2 x 10 to the -4th with ethylene and acetylene respectively as carbon substrates. Consideration is given of the mechanism for the formation of some of the products and implications regarding planetary atmosphere chemistry, particularly that of Jupiter, are explored.

  10. Quantum interference effects on the collisional excitation of the Fermi doublet states of CO sub 2 by hot electrons and hot H(D) atoms

    SciTech Connect

    Zhu, L.; Hewitt, S.A.; Flynn, G.W. (Department of Chemistry Columbia Radiation Laboratory, Columbia University, New York, New York (US))

    1991-03-01

    The vibrational excitation probability of the Fermi doublet states of CO{sub 2} has been determined following collisions with hot electrons and hot H(D) atoms. Similar, though not identical excitation probabilities are found for the two strongly mixed Fermi states in hot H(D) atom scattering; however, there is a dramatic preference for the upper energy member of this Fermi mixed pair in electron scattering experiments.

  11. Water chemistry of hot waters of Umut geothermal field (SW Turkey)

    NASA Astrophysics Data System (ADS)

    Av?ar, Özgür; Türe, Orkun

    2014-05-01

    Umut geothermal field is located on Menderes graben which is one of the most active geothermal regions of Turkey. In order to delineate the chemistry of the waters of Umut geothermal field, fourteen samples were taken from four wells and ten from hot springs. Discharge temperatures of the waters range from 20 to 120 °C. According to the results of chemical analyses, the waters are Na+K - HCO3 type. Cation geothermometer calculations revealed a reservoir temperature greater than 200 °C for Umut geothermal field waters. Stable isotope analyses results indicates that the waters are meteoric in origin.

  12. Evolution of the Atomic Concept and the Beginnings of Modern Chemistry

    NSDL National Science Digital Library

    Fowler, Michael

    This website from the University of Virginia provides an overview of the advancements in chemistry and physics that led to the atomic model of matter. The ideas of Galileo, Dalton, Gay-Lussac, Avogadro, and others are presented in order to describe the development of kinetic theory, element patterns, and other concepts in modern chemistry. Also, the site quotes nineteenth century scientists who opposed the atomic model.

  13. Atomic-resolution characterization of interface structure and chemistry in the STEM

    SciTech Connect

    Browning, N.D.; McGibbon, M.M.; McGibbon, A.J.; Chisholm, M.F.; Pennycook, S.J. [Oak Ridge National Lab., TN (United States); Ravikumar, V.; Dravid, V.P. [Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science and Engineering

    1994-03-01

    Combination of Z-contrast imaging and EELS (electron energy loss spectroscopy) allows the local structure and chemistry of interfaces to be determined on the atomic scale. In this paper, these two complementary techniques are used to analyze the structure and chemistry of a nominally 25 degree [100] symmetric tilt boundary in an electroceramic SrTiO{sub 3} bicrystal.

  14. Electronic Friction Dominates Hydrogen Hot-Atom Relaxation on Pd(100) M. Blanco-Rey,1,2

    E-print Network

    Muiño, Ricardo Díez

    Electronic Friction Dominates Hydrogen Hot-Atom Relaxation on Pd(100) M. Blanco-Rey,1,2 J. I initio molecular dynamics simulations that include a friction force to account for the energy transfer finding provides a new perspective for the study of hot atom (HA) relaxation on metal surfaces, which

  15. On the role of 'hot' atoms in plasma-assisted ignition.

    PubMed

    Starikovskiy, Andrey Yu

    2015-08-13

    This paper discusses the processes leading to the formation of 'hot' atoms and radicals possessing excessive translational energy in high-voltage NS pulse discharges. It is shown that the formation of such 'hot' atoms occurs efficiently both in the dissociation of molecules by direct electron impact, and in the collisional quenching of electronically excited states. Depending on the magnitude of the reduced electric field in the discharge, reactions of these 'hot' atoms increase the initial concentration of radicals in the discharge afterglow two to three times when compared with the values calculated without effects of translational non-equilibrium. The role of thermally non-equilibrium excitation has been demonstrated in the formation of the initial distribution of the chemically active components in the mixture and its influence on the kinetics of ignition initiation at low and high temperatures. It was found that in undiluted mixtures the presence of 'hot' atoms can significantly decrease an ignition threshold and accelerate a low-temperature oxidation. PMID:26170429

  16. Average-atom models of line broadening in hot dense plasmas

    Microsoft Academic Search

    J. Stein; D. Shalitin; Akiva Ron

    1985-01-01

    We present a method for estimating line broadening in the framework of a general average-atom model. This method is an extension of our previous work [Phys. Rev. A 29, 2789 (1984)]. It can reproduce the overall shapes of the ``hilly features'' present in spectra of hot dense plasmas in local thermodynamic equilibrium. Calculations are presented for a hafnium plasma, and

  17. Evidence of Catalytic Production of Hot Atomic Hydrogen in RF Generated Hydrogen/Helium Plasmas

    E-print Network

    Jonathan Phillips; Chun-Ku Chen; Toshi Shiina

    2005-09-14

    A study of the line shapes of hydrogen Balmer series lines in RF generated low pressure H2/He plasmas produced results suggesting a catalytic process between helium and hydrogen species results in the generation of 'hot' (ca. 28 eV) atomic hydrogen. Even far from the electrodes 'hot' atomic hydrogen was predominant in H2/He plasmas. Line shapes, relative line areas of cold and hot atomic hydrogen (hot/cold>2.5), were very similar for areas between the electrodes and far from the electrodes for these plasmas. In contrast, in H2/Xe only 'warm' (<5 eV) hydrogen (warm/cold<1.0) was found between the electrodes, and only cold hydrogen away from the electrodes. Earlier postulates that preferential hydrogen line broadening in plasmas results from the acceleration of ionic hydrogen in the vicinity of electrodes, and the special charge exchange characteristics of Ar/H2+ are clearly belied by the present results that show atomic hydrogen line shape are similar for H2/He plasmas throughout the relatively large cylindrical (14 cm ID x 36 cm length) cavity.

  18. Preliminary considerations of high temperature aqueous chemistry for representative hot springs in Guangdong, China

    NASA Astrophysics Data System (ADS)

    Lu, G.; Liu, R.; Gu, R.; Wang, Y.

    2013-12-01

    This presentation aims at helping understand general physical and chemical conditions that control geothermal flow to the ground surface. Conditions directly under the ground surface play critical roles in determining the pattern of geothermal flow fields. Controlling factors include structural features, source temperature, hydraulic properties, chemical conditions etc. However, they are hardly measured in a comprehensive way in laboratory or field experimental conditions. There are needs for characterizing conditions evolving during upward thermal flow and to relate physics and chemistry to heat distribution. Geothermal flow depends on exactly how heat diffusion works in the deep ground (the heat conductivity and convection), and the physics and chemistry behind this is complex and not well understood. We employed aqueous geochemistry methods to study heat and geochemistry behavior in deep underground. We develop scheme to relate elevated temperatures and heat to chemistry. The setup for elevated heat is expected to expand the capability of numerical models, so that the temperature effect can be more completely described. The heat has a significant effect on the speciation of water, tending to be more acidic and at more reduced state at an elevated temperature. For example, given an average pH 8.3 for spring outflow cooled down to 25oC, the corresponding hot water at 200oC could have pH as low as 5.8. The findings show that the numerical model effectively simulates chemical behavior in deep ground.

  19. Reactive simulation of the chemistry behind the condensed-phase ignition of RDX from hot spots.

    PubMed

    Joshi, Kaushik L; Chaudhuri, Santanu

    2015-07-01

    Chemical events that lead to thermal initiation and spontaneous ignition of the high-pressure phase of RDX are presented using reactive molecular dynamics simulations. In order to initiate the chemistry behind thermal ignition, approximately 5% of RDX crystal is subjected to a constant temperature thermal pulse for various time durations to create a hot spot. After application of the thermal pulse, the ensuing chemical evolution of the system is monitored using reactive molecular dynamics under adiabatic conditions. Thermal pulses lasting longer than certain time durations lead to the spontaneous ignition of RDX after an incubation period. For cases where the ignition is observed, the incubation period is dominated by intermolecular and intramolecular hydrogen transfer reactions. Contrary to the widely accepted unimolecular models of initiation chemistry, N-N bond dissociations that produce NO2 species are suppressed in the condensed phase. The gradual temperature and pressure increase in the incubation period is accompanied by the accumulation of short-lived, heavier polyradicals. The polyradicals contain intact triazine rings from the RDX molecules. At certain temperatures and pressures, the polyradicals undergo ring-opening reactions, which fuel a series of rapid exothermic chemical reactions leading to a thermal runaway regime with stable gas-products such as N2, H2O and CO2. The evolution of the RDX crystal throughout the thermal initiation, incubation and thermal runaway phases observed in the reactive simulations contains a rich diversity of condensed-phase chemistry of nitramines under high-temperature/pressure conditions. PMID:26123323

  20. Atomic Orbitals, Molecular Orbitals and Related Concepts: Conceptual Difficulties among Chemistry Students.

    ERIC Educational Resources Information Center

    Tsaparlis, Georgios

    1997-01-01

    Investigates the impact an undergraduate quantum chemistry course has on students' knowledge and understanding of atomic orbitals, molecular orbitals, and related concepts. Analysis reveals that students do not have a clear understanding of these concepts and confuse the various atomic orbital representations. Includes some suggestions and…

  1. Dry soldering with hot filament produced atomic hydrogen

    DOEpatents

    Panitz, Janda K. G. (Edgewood, NM); Jellison, James L. (Albuquerque, NM); Staley, David J. (Los Lunas, NM)

    1995-01-01

    A system for chemically transforming metal surface oxides to metal that is especially, but not exclusively, suitable for preparing metal surfaces for dry soldering and solder reflow processes. The system employs one or more hot, refractory metal filaments, grids or surfaces to thermally dissociate molecular species in a low pressure of working gas such as a hydrogen-containing gas to produce reactive species in a reactive plasma that can chemically reduce metal oxides and form volatile compounds that are removed in the working gas flow. Dry soldering and solder reflow processes are especially applicable to the manufacture of printed circuit boards, semiconductor chip lead attachment and packaging multichip modules. The system can be retrofitted onto existing metal treatment ovens, furnaces, welding systems and wave soldering system designs.

  2. Production of OH Molecules by Hot Oxygen Atoms in the Upper Atmospheres of Terrestrial Planets

    NASA Astrophysics Data System (ADS)

    Gacesa, M.; Kharchenko, V.

    2012-12-01

    Photodissociation of CO2 and O2 molecules and dissociative recombination of oxygen molecular ions are among the most important sources of suprathermal oxygen atoms in the upper atmospheres of terrestrial planets. The produced hot oxygen atoms can transfer energy in collisions with thermal atmospheric gases and perturb local equilibrium conditions or induce non-thermal chemical reactions. One such process is the reaction of hot O atoms with hydrogen molecules, leading to production of highly rotationally-vibrationally excited OH molecules. We report the results of extensive reactive quantum scattering calculations of O + H2(v, j) ? H + OH(v', j') and corresponding non-thermal rate coefficients at the atmospheric conditions found on Earth and Mars for different solar conditions. Possible implications of this comparative study on the physics of upper atmospheres of terrestrial planets are discussed.

  3. Phase equilibria constraints on the chemistry of hot spring fluids at mid-ocean ridges

    SciTech Connect

    Seyfried, W.E. Jr.; Ding, K.; Berndt, M.E. (Univ. of Minnesota, Minneapolis (United States))

    1991-12-01

    Recent advances in experimental and theoretical geochemistry have made it possible to assess both homogeneous and heterogeneous equilibria involving a wide range of aqueous species at temperatures and pressures appropriate to model hydrothermal alteration processes at mid-ocean ridges. The authors have combined selected aspects of the chemistry of hot spring fluids with constraints imposed by a geologically reasonable assemblage of minerals in the system Na{sub 2}O-K{sub 2}O-CaO-MgO-FeO-Fe{sub 2}O{sub 3}-Al{sub 2}O{sub 3}-SiO{sub 2}-H{sub 2}O-HCl-H{sub 2}S to assess the effect of temperature on the composition of the aqueous phase and the activities of mineral components in plagioclase and epidote solid solutions. Assuming fO{sub 2(g)} and fS{sub 2(g)} controlled by pyrite-pyrrhotite-magnetite equilibria, a constant dissolved Ca concentration, and a dissolved Cl concentration equivalent to that of seawater, increasing temperature from 250 to 400C at 500 bars results in systematic changes in the composition of mineral phases, which in turn constrain pH and the distribution of aqueous species. The model predicts that dissolved concentrations of Fe, SiO{sub 2}, K, H{sub 2}S, and H{sub 2} increase, while Na and pH{sub (25C)} decrease with increasing temperature. That many hot springs vent fluids are characterized by variable degrees of conductive heat loss renders measured temperatures unreliable as indicators of the maximum temperature of subseafloor hydrothermal alteration processes. The implications of this are significant for hot spring fluids which reveal large Cl variations relative to seawater, since likely mechanisms to account for such variability typically require temperatures in excess of those inferred for subseafloor reaction zones by simply correcting measured temperatures for the effects of adiabatic cooling.

  4. Possibility of nonexistence of hot and superhot hydrogen atoms in electrical discharges

    SciTech Connect

    Loureiro, J. [Instituto de Plasmas e FuSao Nuclear-Laboratorio Associado, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, 1049-001 Lisboa (Portugal); Amorim, J. [Laboratorio Nacional de Ciencia e Tecnologia do Bietanol (CTBE), Caixa Postal 6170, CEP 13083-970 Campinas, SP (Brazil)

    2010-09-15

    Recently, the existence of extremely energetic hydrogen atoms in electrical discharges has been proposed in the literature with large controversy, from the analysis of the anomalous broadening of hydrogen Balmer lines. In this paper, the velocity distribution of H atoms and the profiles of the emitting atom lines created by the exothermic reaction H{sub 2}{sup +}+H{sub 2}{yields}H{sub 3}{sup +}+H+{Delta}E are calculated, as a function of the internal energy defect {Delta}E. The shapes found for the non-Maxwell-Boltzmann distributions resulting in non-Gaussian line profiles raise serious arguments against the existence of hot and superhot H atoms as it has been proposed, at least with those temperatures.

  5. Symmetry in chemistry from the hydrogen atom to?proteins

    PubMed Central

    Kellman, Michael?E.

    1996-01-01

    The last 2 decades have seen discoveries in highly excited states of atoms and molecules of phenomena that are qualitatively different from the “planetary” model of the atom, and the near-rigid model of molecules, characteristic of these systems in their low-energy states. A unified view is emerging in terms of approximate dynamical symmetry principles. Highly excited states of two-electron atoms display “molecular” behavior of a nonrigid linear structure undergoing collective rotation and vibration. Highly excited states of molecules described in the “standard molecular model” display normal mode couplings, which induce bifurcations on the route to molecular chaos. New approaches such as rigid–nonrigid correlation, vibrons, and quantum groups suggest a unified view of collective electronic motion in atoms and nuclear motion in molecules. PMID:8962040

  6. Study of Photochemical Escape of Hot Atomic Carbon in Mars’ Upper Thermosphere and Exosphere

    NASA Astrophysics Data System (ADS)

    Lee, Yuni; Combi, M. R.; Tenishev, V.; Bougher, S. W.

    2012-10-01

    The production of energetic particles results in the formation of hot atom coronae on the Martian atmosphere. We have carried out the study of the hot carbon in Mars’ upper thermosphere and exosphere using our Monte Carlo calculations. The most important reactions for producing hot atomic carbon are expected to be photodissociation of CO and dissociative recombination (DR) of CO+ ion. The dominant source of the nonthermal escape of hot carbon from Mars is found to be photodissociation of CO, which is sensitive to solar activity and occurs mostly deep in the dayside thermosphere of Mars. The escape flux of hot carbon from dissociative recombination of CO+ has also been estimated using the latest available branching ratio and appropriate choice of rate coefficient. In this study, the calculated total global escapes of hot carbon from all dominant photochemical processes at different solar activities and Martian seasons are presented. To describe self-consistently the exosphere and the upper thermosphere, a combination of our 3D Direct Simulation Monte Carlo (DSMC) model [Valeille, A., Combi, M., Bougher, S., Tenishev, V., Nagy, A., 2009. J. Geophys. Res. 114, E11006. doi:10.1029/2009JE003389] and the 3D Mars Thermosphere General Circulation Model (MTGCM) [Bougher, S.W., Bell, J.M., Murphy, J.R., Lopez-Valverde, M.A., Withers, P.G., 2006. Geophys. Res. Lett. 32, doi: 10.1029/2005GL024059. L02203] is used. Profiles of density and temperature, atmospheric loss rates and return fluxes are studied using the model for the cases considered. Comparisons of DSMC model outputs will be made with those from other recent exosphere model studies.

  7. Two-color ghost interference with photon pairs generated in hot atoms

    SciTech Connect

    Ding Dongsheng; Zhou Zhiyuan; Shi Baosen; Zou Xubo; Guo Guangcan [Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026 (China)

    2012-09-15

    We report on an experimental observation of a two-photon ghost interference experiment. A distinguishing feature of our experiment is that the photons are generated via a non-degenerated spontaneous four-wave mixing process in a hot atomic ensemble; therefore the photon has narrow bandwidth. Besides, there is a large difference in frequency between two photons in a pair. Our works may be important to achieve more secure, large transmission capacity long-distance quantum communication.

  8. Scattering of cold-atom coherences by hot atoms: frequency shifts from background-gas collisions.

    PubMed

    Gibble, Kurt

    2013-05-01

    Frequency shifts from background-gas collisions currently contribute significantly to the inaccuracy of atomic clocks. Because nearly all collisions with room-temperature background gases that transfer momentum eject the cold atoms from the clock, the interference between the scattered and unscattered waves in the forward direction dominates these frequency shifts. We show they are ? 10 times smaller than in room-temperature clocks and that van der Waals interactions produce the cold-atom background-gas shift. General considerations allow the loss of the Ramsey fringe amplitude to bound this frequency shift. PMID:23683186

  9. Experimental Constraints on Hot Spring Fluid Chemistry in Back Arc Basins

    NASA Astrophysics Data System (ADS)

    Schaen, A. T.; Saccocia, P. J.; Seewald, J.

    2010-12-01

    Many axial hot springs from back-arc basins are characterized by low pH and high metal concentrations compared to fluids from the mid-ocean ridge. Such differences are likely related to the presence of felsic crust and the involvement of acidic magmatic fluids in back-arc hydrothermal systems. Previous experiments that reacted fresh andesite with seawater at elevated T and P yielded pH values significantly higher than those observed in back-arc basin hot springs. Moreover, ocean drilling beneath back-arc basin hot springs revealed acid-sulfate alteration assemblages, suggesting at least transient involvement of magmatic fluids. Here we report the results of two laboratory experiments designed to assess fluid chemistry in equilibrium with acid-sulfate alteration assemblages at sub-seafloor conditions typically associated with back-arc hot springs. Both experiments reacted a K-Ca-Na-Cl fluid with a pyrophyllite-pyrite-anhydrite-quartz assemblage (PPAQ). In addition, alunite was added to the assemblage in one experiment (PPAQA). Both experiments were conducted in a flexible-cell hydrothermal apparatus utilizing an inert Au-Ti reaction cell. Fluid samples were withdrawn from the reaction cell as a function of time and temperature and analyzed for major anions, cations, pH (25C), H2, and H2S to monitor reaction progress. In the PPAQ experiment, pH varied from 3.1 to 3.4 from 350 to 365C at 0.25 Kb. At 385C, 0.26 Kb, pH dropped to 2.74, close to the value observed in many BAB hot springs. H2S varied from 2 mmol/kg at 350C, 0.25 Kb to 11 mmol/kg at 385C, 0.26 Kb. In general, K decreased and Ca increased with increasing T and decreasing P while SO4 remained low (<1 mmol/kg). In the PPAQA experiment, fluid pH was much lower, varying from 2.2 to 1.5 from 250 to 350C, 0.25 Kb. H2S was low (<1 mmol/kg) at these same conditions. Similarly, H2 was <0.003 mmol/kg, consistent with relatively oxidizing conditions. K concentration remained nearly constant while Ca increased with decreasing T. SO4 varied inversely with Ca, varying from 35 to 4 mmol/kg from 350 to 250C, respectively. Thus, the presence of alunite in the alteration assemblage yields an extremely acid fluid, depleted in H2S and enriched in SO4 compared to fluids from the PPAQ experiment. These results suggest that the composition of hot spring fluids from back-arc environments is consistent with fluid-mineral equilibria involving acid-sulfate mineral assemblages. Such assemblages may be produced by previous episodes of magmatic degassing. Accordingly, the presence of highly acidic vent fluids may reflect an important role for magmatic fluids during crustal alteration processes, but does not require the presence of an actively degassing magma chamber.

  10. Simulation of Ionic Populations in Hot Dense Plasmas via a New Method beyond the Average Atom Model

    Microsoft Academic Search

    Min-Sheng Wang; Ling-Tao Liu; Jia-Ming Li

    2005-01-01

    In theoretical simulations and analysis of diagnostic measurements for hot dense plasmas in the inertial confinement fusion researches, it is usually necessary to consider thousands of transition arrays between a huge number of ionic energy states. Average atom models are adopted for practical purposes. In order to calculate ionic populations of hot dense plasmas more accurately either in local thermodynamic

  11. Atomic structure and chemistry of human serum albumin

    NASA Technical Reports Server (NTRS)

    He, Xiao M.; Carter, Daniel C.

    1992-01-01

    The three-dimensional structure of human serum albumin has been determined crystallographically to a resolution of 2.8 A. It comprises three homologous domains that assemble to form a heart-shaped molecule. Each domain is a product of two subdomains that possess common structural motifs. The principal regions of ligand binding to human serum albumin are located in hydrophobic cavities in subdomains IIA and ILIA, which exhibit similar chemistry. The structure explains numerous physical phenomena and should provide insight into future pharmacokinetic and genetically engineered therapeutic applications of serum albumin.

  12. Ab initio quantum chemistry in the molecular model of atomic collisions

    Microsoft Academic Search

    A. Macías; A. Riera

    1982-01-01

    We present an introduction to the application of ab initio methods of Quantum Chemistry to the molecular model of atomic collisions. This includes the choice and calculation of molecular wavefunctions using the well known Self Consistent Field and Configuration Interaction methods; the calculation of dynamical couplings and a detailed study of diabatic states. To make the article self contained, we

  13. The Materials Chemistry of Atomic Oxygen with Applications to Anisotropic Etching of Submicron Structures in Microelectronics and the Surface Chemistry Engineering of Porous Solids

    SciTech Connect

    Koontz, S.L.; Leger, L.J.; Wu, C.; Cross, J.B.; Jurgensen, C.W. [Los Alamos National Lab., NM (United States); [Bell Telephone Labs., Inc., Murray Hill, NJ (United States)

    1994-05-01

    Neutral atomic oxygen is the most abundant component of the ionospheric plasma in the low Earth orbit environment (LEO; 200 to 700 kilometers altitude) and can produce significant degradation of some spacecraft materials. In order to produce a more complete understanding of the materials chemistry of atomic oxygen, the chemistry and physics of O-atom interactions with materials were determined in three radically different environments: (1) The Space Shuttle cargo bay in low Earth orbit (the EOIM-3 space flight experiment), (2) a high-velocity neutral atom beam system (HVAB) at Los Alamos National Laboratory (LANL), and (3) a microwave-plasma flowing-discharge system at JSC. The Space Shuttle and the high velocity atom beam systems produce atom-surface collision energies ranging from 0.1 to 7 eV (hyperthermal atoms) under high-vacuum conditions, while the flowing discharge system produces a 0.065 eV surface collision energy at a total pressure of 2 Torr. Data obtained in the three different O-atom environments referred to above show that the rate of O-atom reaction with polymeric materials is strongly dependent on atom kinetic energy, obeying a reactive scattering law which suggests that atom kinetic energy is directly available for overcoming activation barriers in the reaction. General relationships between polymer reactivity with O atoms and polymer composition and molecular structure have been determined. In addition, vacuum ultraviolet photochemical effects have been shown to dominate the reaction of O atoms with fluorocarbon polymers. Finally, studies of the materials chemistry of O atoms have produced results which may be of interest to technologists outside the aerospace industry. Atomic oxygen `spin-off` or `dual use` technologies in the areas of anisotropic etching in microelectronic materials and device processing, as well as surface chemistry engineering of porous solid materials are described.

  14. Self-consistent average-atom scheme for electronic structure of hot and dense plasmas of mixture

    Microsoft Academic Search

    Jianmin Yuan

    2002-01-01

    An average-atom model is proposed to treat the electronic structures of hot and dense plasmas of mixture. It is assumed that the electron density consists of two parts. The first one is a uniform distribution with a constant value, which is equal to the electron density at the boundaries between the atoms. The second one is the total electron density

  15. Global Dynamics of Hot Atomic Oxygen in Mars' Upper Atmosphere and Comparison with Recent Observation

    NASA Astrophysics Data System (ADS)

    Lee, Y.; Combi, M. R.; Tenishev, V.; Bougher, S. W.

    2012-12-01

    The production of energetic particles in Mars's upper thermosphere and exosphere results in the formation of hot atom coronae. Dissociative recombination (DR) of O2+ ion is the dominant source of the production of hot atomic oxygen and the most important reaction for the exosphere on Mars, which occurs mostly deep in the dayside thermosphere of Mars. In this investigation, we have carried out the study of the global dynamics of energetic particles in Mars' upper atmosphere using our newly developed self-consistent Monte-Carlo model. The calculated total global escapes of hot oxygen are presented for different solar activities (solar maximum and minimum) and Martian seasons (aphelion, equinox, and perihelion). To describe self-consistently the exosphere and the upper thermosphere, a combination of our 3D Direct Simulation Monte Carlo (DSMC) model [Valeille, A., Combi, M., Bougher, S., Tenishev, V., Nagy, A., 2009. J. Geophys. Res. 114, E11006. doi:10.1029/2009JE003389] and the 3D Mars Thermosphere General Circulation Model (MTGCM) [Bougher, S.W., Bell, J.M., Murphy, J.R., Lopez-Valverde, M.A., Withers, P.G., 2006. Geophys. Res. Lett. 32, doi: 10.1029/2005GL024059. L02203] is used. Profiles of density and temperature, atmospheric loss rates, and return fluxes are studied using the model for the cases considered. Progress in updating the model physics is also described. Along with comparisons of our DSMC model outputs with those from other recent exosphere model studies, we present a comparison of our model results with the derived neutral oxygen density from atomic oxygen emission at 1304Å that was detected by Alice instrument on board European Space Agency's Rosetta spacecraft [Feldman, P., Steffl, A., Parker, J, A'Hearn, M., Bertaux, J., Stern, S., Weaver, H., Slater, D., Versteeg, M., Throop, H., Cunningham, N., Feaga, L., 2011. Icarus. 214, 2, 394-399, doi:10.1016/j.icarus.2011.06.013].

  16. Atomic and Molecular Quantum Theory Course Number: C561 Chemistry, Indiana University C-14 c 2003, Srinivasan S. Iyengar (instructor)

    E-print Network

    Iyengar, Srinivasan S.

    Atomic and Molecular Quantum Theory Course Number: C561 Chemistry, Indiana University C-14 c 2003, Srinivasan S. Iyengar (instructor) #12;Atomic and Molecular Quantum Theory Course Number: C561 D A little bit (instructor) #12;Atomic and Molecular Quantum Theory Course Number: C561 2. Using these ket vectors the Sz

  17. Generating Molecular Rovibrational Coherence by Two-Photon Femtosecond Photoassociation of Thermally Hot Atoms

    E-print Network

    Leonid Rybak; Saieswari Amaran; Liat Levin; Michal Tomza; Robert Moszynski; Ronnie Kosloff; Christiane P. Koch; Zohar Amitay

    2011-11-16

    The formation of diatomic molecules with rotational and vibrational coherence is demonstrated experimentally in free-to-bound two-photon femtosecond photoassociation of hot atoms. In a thermal gas at a temperature of 1000 K, pairs of magnesium atoms, colliding in their electronic ground state, are excited into coherent superpositions of bound rovibrational levels in an electronically excited state. The rovibrational coherence is probed by a time-delayed third photon, resulting in quantum beats in the UV fluorescence. A comprehensive theoretical model based on ab initio calculations rationalizes the generation of coherence by Franck-Condon filtering of collision energies and partial waves, quantifying it in terms of an increase in quantum purity of the thermal ensemble. Our results open the way to coherent control of a binary reaction.

  18. Generating Molecular Rovibrational Coherence by Two-Photon Femtosecond Photoassociation of Thermally Hot Atoms

    SciTech Connect

    Rybak, Leonid; Levin, Liat; Amitay, Zohar [Shirlee Jacobs Femtosecond Laser Research Laboratory, Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa 32000 (Israel); Amaran, Saieswari; Kosloff, Ronnie [Institute of Chemistry, Hebrew University, Jerusalem 91904 (Israel); Tomza, Michal; Moszynski, Robert [Department of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw (Poland); Koch, Christiane P. [Institut fuer Theoretische Physik, Freie Universitaet Berlin, Arnimallee 14, 14195 Berlin (Germany); Theoretische Physik, Universitaet Kassel, Heinrich-Plett-Strasse 40, 34132 Kassel (Germany)

    2011-12-30

    The formation of diatomic molecules with rotational and vibrational coherence is demonstrated experimentally in free-to-bound two-photon femtosecond photoassociation of hot atoms. In a thermal gas at a temperature of 1000 K, pairs of magnesium atoms, colliding in their electronic ground state, are excited into coherent superpositions of bound rovibrational levels in an electronically excited state. The rovibrational coherence is probed by a time-delayed third photon, resulting in quantum beats in the UV fluorescence. A comprehensive theoretical model based on ab initio calculations rationalizes the generation of coherence by Franck-Condon filtering of collision energies and partial waves, quantifying it in terms of an increase in quantum purity of the thermal ensemble. Our results open the way to coherent control of a binary reaction.

  19. Kinetic study on hot-wire-assisted atomic layer deposition of nickel thin films

    SciTech Connect

    Yuan, Guangjie, E-mail: ygjhzh@dpe.mm.t.u-tokyo.ac.jp; Shimizu, Hideharu; Momose, Takeshi; Shimogaki, Yukihiro [Department of Materials Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)

    2014-01-15

    High-purity Ni films were deposited using hot-wire-assisted atomic layer deposition (HW-ALD) at deposition temperatures of 175, 250, and 350?°C. Negligible amount of nitrogen or carbon contamination was detected, even though the authors used NH{sub 2} radical as the reducing agent and nickelocene as the precursor. NH{sub 2} radicals were generated by the thermal decomposition of NH{sub 3} with the assist of HW and used to reduce the adsorbed metal growth precursors. To understand and improve the deposition process, the kinetics of HW-ALD were analyzed using a Langmuir-type model. Unlike remote-plasma-enhanced atomic layer deposition, HW-ALD does not lead to plasma-induced damage. This is a significant advantage, because the authors can supply sufficient NH{sub 2} radicals to deposit high-purity metallic films by adjusting the distance between the hot wire and the substrate. NH{sub 2} radicals have a short lifetime, and it was important to use a short distance between the radical generation site and substrate. Furthermore, the impurity content of the nickel films was independent of the deposition temperature, which is evidence of the temperature-independent nature of the NH{sub 2} radical flux and the reactivity of the NH{sub 2} radicals.

  20. Surface chemistry and tip-sample interactions in atomic force microscopy

    Microsoft Academic Search

    Tim J. Senden; Calum J. Drummond

    1995-01-01

    Microfabricated silicon nitride cantilevers with integral tips are commonly employed in atomic force microscopy. The link between surface chemistry, including surface group acid-base dissociation and counterion complexation, and tip-sample interaction in aqueous electrolyte solution is examined. Silicon nitride tip interaction with “flat plate” samples of both muscovite mica and silicon nitride as a function of aqueous solution pH and electrolyte

  1. Chemistry of the heaviest elements--one atom at a time

    SciTech Connect

    Hoffman, Darleane C.; Lee, Diana M.

    2000-01-01

    In keeping with the goal of the Viewpoint series of the Journal of Chemical Education, this article gives a 75-year perspective of the chemistry of the heaviest elements, including a 50-year retrospective view of past developments, a summary of current research achievements and applications, and some predictions about exciting, new developments that might be envisioned within the next 25 years. A historical perspective of the importance of chemical separations in the discoveries of the transuranium elements from neptunium (Z=93) through mendelevium (Z=101) is given. The development of techniques for studying the chemical properties of mendelevium and still heavier elements on the basis of measuring the radioactive decay of a single atom (''atom-at-a-time'' chemistry) and combining the results of many separate experiments is reviewed. The influence of relativistic effects (expected to increase as Z{sup 2}) on chemical properties is discussed. The results from recent atom-at-a-time studies of the chemistry of the heaviest elements through seaborgium (Z=106) are summarized and show that their properties cannot be readily predicted based on simple extrapolation from the properties of their lighter homologues in the periodic table. The prospects for extending chemical studies to still heavier elements than seaborgium are considered and appear promising.

  2. How in Spite of the Rhetoric, History of Chemistry Has Been Ignored in Presenting Atomic Structure in Textbooks.

    ERIC Educational Resources Information Center

    Rodriguez, Maria A.; Niaz, Mansoor

    2002-01-01

    Reports on a study designed to: (a) show how the importance of the history of chemistry has been recognized in the classroom; (b) demonstrate how criteria based on history and philosophy of science can be used to evaluate the presentation of atomic structure in general chemistry textbooks; and (c) compare new (1970-1992) and old textbooks…

  3. Revealing the planar chemistry of two-dimensional heterostructures at the atomic level.

    PubMed

    Chou, Harry; Ismach, Ariel; Ghosh, Rudresh; Ruoff, Rodney S; Dolocan, Andrei

    2015-01-01

    Two-dimensional (2D) atomic crystals and their heterostructures are an intense area of study owing to their unique properties that result from structural planar confinement. Intrinsically, the performance of a planar vertical device is linked to the quality of its 2D components and their interfaces, therefore requiring characterization tools that can reveal both its planar chemistry and morphology. Here, we propose a characterization methodology combining (micro-) Raman spectroscopy, atomic force microscopy and time-of-flight secondary ion mass spectrometry to provide structural information, morphology and planar chemical composition at virtually the atomic level, aimed specifically at studying 2D vertical heterostructures. As an example system, a graphene-on-h-BN heterostructure is analysed to reveal, with an unprecedented level of detail, the subtle chemistry and interactions within its layer structure that can be assigned to specific fabrication steps. Such detailed chemical information is of crucial importance for the complete integration of 2D heterostructures into functional devices. PMID:26099196

  4. Resonance enhanced multiphoton ionization probing of H atoms and CH3 radicals in a hot lament chemical vapour deposition reactor

    E-print Network

    Bristol, University of

    hot ®lament (HF) reactor, or plasma (e.g. microwave) enhanced. The formation of H atoms chemical vapour deposition reactor James A. Smith, Moray A. Cook, Stephen R. Langford, Stephen A. Redman reactor used for diamond chemical vapour deposition (CVD). Parameters varied include the hydrocarbon (CH4

  5. Analytical Chemistry Laboratory (ACL) procedure compendium. Volume 7, Safety operation procedure for hot cell

    SciTech Connect

    Not Available

    1993-08-01

    This volume contains the interim change notice for the safety operation procedure for hot cell. It covers the master-slave manipulators, dry waste removal, cell transfers, hoists, cask handling, liquid waste system, and physical characterization of fluids.

  6. The atmospheric chemistry of methyl salicylate—reactions with atomic chlorine and with ozone

    NASA Astrophysics Data System (ADS)

    Canosa-Mas, Carlos E.; Duffy, Justin M.; King, Martin D.; Thompson, Katherine C.; Wayne, Richard P.

    Methyl salicylate is one of a number of semiochemicals, signal molecules, emitted by herbivore-infested plants. These signal molecules attract predators of the herbivore, and the chemicals thus act indirectly as part of the defence mechanism of the plant. Previous studies have shown that ozone damage to plants can also elicit the emission of signal molecules. The fate of these signal molecules in the atmosphere is not known. Preliminary studies have been undertaken to examine the atmospheric chemistry of methyl salicylate for the first time. Rate coefficients for the reaction of methyl salicylate with atomic chlorine and with ozone have been determined; the values are (2.8±0.3)×10 -12 and ˜4×10 -21 cm 3 molecule -1 s -1. These results suggest that neither reaction with atomic chlorine nor reaction with ozone will provide important loss routes for methyl salicylate in the atmosphere. The possible importance of photolysis of methyl salicylate in the atmosphere is considered.

  7. On the molecular complexity of the hot cores in Orion A - Grain surface chemistry as 'The last refuge of the scoundrel'

    NASA Technical Reports Server (NTRS)

    Charnley, S. B.; Tielens, A. G. G. M.; Millar, T. J.

    1992-01-01

    We have modeled the gas phase chemistry of warm molecular material around protostars that is seeded with evaporating grain mantles. We show that the release of simple molecules into the gas drives ion-molecule and neutral chemistries which can account for many of the complex O-bearing and N-bearing molecules observed in hot cores. Initial grain mantle components and secondary product molecules are identified, and the observational consequences are discussed.

  8. Interpenetrating network hydrogels via simultaneous "click chemistry" and atom transfer radical polymerization.

    PubMed

    Xu, L Q; Yao, F; Fu, G D; Kang, E T

    2010-07-12

    Simultaneous interpenetrating polymer networks (sIPNs) from concurrent copper(I)-catalyzed azide-alkyne cycloaddition "click chemistry" and atom transfer radical polymerization (ATRP) are described. Semi-sIPN of poly(ethylene glycol)/poly(2-hydroxyethyl methacrylate) (semi-PEG/PHEMA-sIPN) was first prepared via simultaneous "click chemistry" and ATRP from a mixture of poly(ethylene glycol)-diazide (N3-PEG-N3, Mn=4000 g/mol), tetrakis(2-propynyloxymethyl)methane (TPOM), ethyl-2-bromobutyrate (EBB), CuBr, pentamethyldiethylenetriamine (PMDETA), and 2-hydroxyethyl methacrylate (HEMA) in dimethylformamide (DMF). Full sIPN of PEG/PHEMA (full-PEG/PHEMA-sIPN) was then prepared via simultaneous "click chemistry" and ATRP from a mixture of N3-PEG-N3 (Mn=4000 g/mol), TPOM, EBB, CuBr, PMDETA, HEMA, and poly(ethylene glycol) diacrylate) (PEGDA, Mn=575) in DMF. Both the semi- and full-sIPNs exhibit a fast gelation rate and high gel yield. The sIPNs also exhibit high swelling ratios and good mechanical and antifouling properties. The morphology and thermal behavior of the sIPNs were studied by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). These sIPNs could find applications as biomaterials for contact lenses, biomedical materials, artificial organs, and drug delivery systems. PMID:20518556

  9. Thermal chemistry of the Cu-KI5 atomic layer deposition precursor on a copper surface

    SciTech Connect

    Ma, Qiang; Zaera, Francisco, E-mail: zaera@ucr.edu [Department of Chemistry, University of California, Riverside, California 92521 (United States)

    2015-01-01

    The thermal chemistry of a Cu(I) ketoiminate complex, Cu-KI5, resulting from the modification of the known Air Products CupraSelect{sup ®} copper CVD precursor Cu(hfac)(tmvs) designed to tether the two ligands via an isopropoxide linker, was studied under ultrahigh vacuum on a Cu(110) single-crystal surface by using a combination of temperature programmed desorption (TPD) and x-ray photoelectron spectroscopy. Adsorption at low temperatures was determined to take place via the displacement of the vinyl ligand by the surface. Molecular desorption was seen at 210?K, and the evolution of Cu(II)-KI5{sub 2} was established to take place at 280?K, presumably from a disproportionation reaction that also leads to the deposition of Cu(0). Other sets of desorption products were seen at 150, 250, and 430?K, all containing copper atoms and small organic moieties with molecular masses below 100 amu. The latter TPD peak in particular indicates significant fragmentation of the ligands, likely at the C–N bond that holds the vinylsilane-isopropoxide moiety tethered to the ketoimine fragment, and possibly also at the union between the vinylsilane and the alkoxide linker. The 430?K temperature measured for this chemistry may set an upper limit for clean Cu film deposition, but since reactivity on the surface was also found to be inhibited at higher surface coverages, it may be delayed to higher temperatures under atomic layer deposition conditions.

  10. Hot precursor reactions during the collisions of gas-phase oxygen atoms with deuterium chemisorbed on Pt(100).

    PubMed

    Kan, Heywood H; Shumbera, R Bradley; Weaver, Jason F

    2007-04-01

    We utilized direct rate measurements and temperature programmed desorption to investigate reactions that occur during the collisions of gaseous oxygen atoms with deuterium-covered Pt(100). We find that both D2O and D2 desorb promptly when an oxygen atom beam impinges upon D-covered Pt(100) held at surface temperatures ranging from 90 to 150 K, and estimate effective cross sections of 12 and 1.8 A2, respectively, for the production of gaseous D2O and D2 at 90 K. The yields of D2O and D2 that desorb at 90 K are about 13% and 2%, respectively, of the initial D atom coverage, though most of the D2O product molecules (approximately 80%) thermalize to the surface rather than desorb at the surface temperatures studied. Increasing the surface temperature from 90 to 150 K causes the D2O desorption rate to decay more quickly during O atom exposures to the surface and results in lower yields of gaseous D2O. We attribute the production of D2O and D2 in these experiments to reactions involving intermediates that are not thermally accommodated to the surface, so-called hot precursors. The results are consistent with the production of hot D2O involving first the generation of hot OD groups from the reaction O*+D(a)-->OD*, where the asterisk denotes a hot precursor, followed by the parallel pathways OD*+D(a)-->D2O* and OD*+OD(a)-->D2O*+O(a). The final reaction contributes significantly to hot D2O production only later in the reaction period when thermalized OD groups have accumulated on the surface, and it becomes less important at higher temperature due to depletion of the OD(a) concentration by thermally activated D2O production. PMID:17430053

  11. Chemistry of the organic-rich hot core G327.3-0.6

    NASA Technical Reports Server (NTRS)

    Gibb, E.; Nummelin, A.; Irvine, W. M.; Whittet, D. C.; Bergman, P.; Ferris, J. P. (Principal Investigator)

    2000-01-01

    We present gas-phase abundances of species found in the organic-rich hot core G327.3-0.6. The data were taken with the Swedish-ESO Submillimetre Telescope (SEST). The 1-3 mm spectrum of this source is dominated by emission features of nitrile species and saturated organics, with abundances greater than those found in many other hot cores, including Sgr B2 and OMC-1. Population diagram analysis indicates that many species (CH3CN, C2H3CN, C2H5CN, CH3OH, etc.) have hot components that originate in a compact (2") region. Gas-phase chemical models cannot reproduce the high abundances of these molecules found in hot cores, and we suggest that they originate from processing and evaporation of icy grain mantle material. In addition, we report the first detection of vibrationally excited ethyl cyanide and the first detection of methyl mercaptan (CH3SH) outside the Galactic center.

  12. Hot-atom versus Eley-Rideal dynamics in hydrogen recombination on Ni(100). I. The single-adsorbate case.

    PubMed

    Martinazzo, R; Assoni, S; Marinoni, G; Tantardini, G F

    2004-05-01

    We compare the efficiency of the Eley-Rideal (ER) reaction with the formation of hot-atom (HA) species in the simplest case, i.e., the scattering of a projectile off a single adsorbate, considering the Hydrogen and Hydrogen-on-Ni(100) system. We use classical mechanics and the accurate embedded diatomics-in-molecules potential to study the collision system over a wide range of collision energies (0.10-1.50 eV), both with a rigid and a nonrigid Ni substrate and for impact on the occupied and neighboring empty cells. In the rigid model metastable and truly bound hot-atoms occur and we find that the cross section for the formation of bound hot-atoms is considerably higher than that for the ER reaction over the whole range of collision energies examined. Metastable hot-atoms form because of the inefficient energy transfer to the adsorbate and have lifetimes of the order 0.1-0.7 ps, depending on the collision energy. When considering the effects of lattice vibrations we find, on average, a consistent energy transfer to the substrate, say 0.1-0.2 eV, which forced us to devise a two-step dynamical model to get rid of the problems associated with the use of periodic boundary conditions. Results for long-lived HA formation due to scattering on the occupied cell at a surface temperature of 120 K agree well with those of the rigid model, suggesting that in the above process the substrate plays only a secondary role and further calculations at surface temperatures of 50 and 300 K are in line with these findings. However, considerably high cross sections for formation of long-lived hot-atoms result also from scattering off the neighboring cells where the energy transfer to the lattice cannot be neglected. Metastable hot-atoms are reduced in number and have usually lifetimes shorter than those of the rigid-model, say less than 0.3 ps. In addition, ER cross sections are only slightly affected by the lattice motion and show a little temperature dependence. Finally, we find also that absorption and reflection strongly depend on the correct consideration of lattice vibrations and the occurrence of trapping. PMID:15267808

  13. Hot wire chemical vapor deposition chemistry in the gas phase and on the catalyst surface with organosilicon compounds.

    PubMed

    Shi, Yujun

    2015-02-17

    CONSPECTUS: Hot wire chemical vapor deposition (HWCVD), also referred to as catalytic CVD (Cat-CVD), has been used to produce Si-containing thin films, nanomaterials, and functional polymer coatings that have found wide applications in microelectronic and photovoltaic devices, in automobiles, and in biotechnology. The success of HWCVD is largely due to its various advantages, including high deposition rate, low substrate temperatures, lack of plasma-induced damage, and large-area uniformity. Film growth in HWCVD is induced by reactive species generated from primary decomposition on the metal wire or from secondary reactions in the gas phase. In order to achieve a rational and efficient optimization of the process, it is essential to identify the reactive species and to understand the chemical kinetics that govern the production of these precursor species for film growth. In this Account, we report recent progress in unraveling the complex gas-phase reaction chemistry in the HWCVD growth of silicon carbide thin films using organosilicon compounds as single-source precursors. We have demonstrated that laser ionization mass spectrometry is a powerful diagnostic tool for studying the gas-phase reaction chemistry when combined with the methods of isotope labeling and chemical trapping. The four methyl-substituted silane molecules, belonging to open-chain alkylsilanes, dissociatively adsorb on W and Ta filaments to produce methyl radical and H2 molecule. Under the typical deposition pressures, with increasing number of methyl substitution, the dominant chemistry occurring in the gas phase switches from silylene/silene reactions to free-radical short chain reactions. This change in dominant reaction intermediates from silylene/silene to methyl radicals explains the observation from thin film deposition that silicon carbide films become more C-rich with a decreasing number of Si-H bonds in the four precursor molecules. In the case of cyclic monosilacyclobutanes, we have shown that ring-opening reactions play a vital role in characterizing the reaction chemistry. On the other hand, exocyclic Si-H(CH3) bond cleavages are more important in the less-puckered disilacyclobutane molecules. Metal filaments are essential in HWCVD since they serve as catalysts to decompose precursor gases to reactive species, which initiate gas-phase reaction chemistry and thin film growth. We discuss the structural changes in metal filaments when exposed to various precursor gases. Depending on the nature of the radical intermediates formed from the hot-wire decomposition and subsequent gas-phase reactions, metal silicides and carbides can be formed. Overall, study of the gas-phase reaction chemistry in HWCVD provides important knowledge of the chemical species produced prior to their deposition on a substrate surface. This helps in identifying the major contributor to alloy formation on the filament itself and the film growth, and consequently, in determining the properties of the deposited films. An integrated knowledge of the gas-phase reaction chemistry, filament alloy formation, and thin film deposition is required for an efficient deposition of high-quality thin films and nanomaterials. PMID:25586211

  14. Breakdown into nanoscale of graphene oxide: Confined hot spot atomic reduction and fragmentation

    NASA Astrophysics Data System (ADS)

    Gonçalves, Gil; Vila, Mercedes; Bdikin, Igor; de Andrés, Alicia; Emami, Nazanin; Ferreira, Rute A. S.; Carlos, Luís D.; Grácio, José; Marques, Paula A. A. P.

    2014-10-01

    Nano-graphene oxide (nano-GO) is a new class of carbon based materials being proposed for biomedical applications due to its small size, intrinsic optical properties, large specific surface area, and easy to functionalize. To fully exploit nano-GO properties, a reproducible method for its production is of utmost importance. Herein we report, the study of the sequential fracture of GO sheets onto nano-GO with controllable lateral width, by a simple, and reproducible method based on a mechanism that we describe as a confined hot spot atomic fragmentation/reduction of GO promoted by ultrasonication. The chemical and structural changes on GO structure during the breakage were monitored by XPS, FTIR, Raman and HRTEM. We found that GO sheets starts breaking from the defects region and in a second phase through the disruption of carbon bonds while still maintaining crystalline carbon domains. The breaking of GO is accompanied by its own reduction, essentially by the elimination of carboxylic and carbonyl functional groups. Photoluminescence and photothermal studies using this nano-GO are also presented highlighting the potential of this nanomaterial as a unique imaging/therapy platform.

  15. Minor and trace element chemistry of Lake Baikal, its tributaries, and surrounding hot springs

    Microsoft Academic Search

    K. Kenison Falkner; M. Church; G. LeBaron; D. Thouron; C. Jeandel; M. C. Stordal; G. A. Gill; R. Mortlock; P. Froelich; L.-H. Chan

    1997-01-01

    A Russian-American fieldwork effort on Lake Baikal, its tributaries, and surrounding hot springs was undertaken in June-July 1991. Here we report on aspects of major ion (Ca 2+, Mg2+, Na+, K+, Alk, Cl-, SOJ2-) and several minor and trace element (Li isotopes, Sr isotopes, Ba, Al, V, Cr, Ni, Cu, Ge, Cd, Hg, U) cycles. Our riverine data for major

  16. Evidence of the production of hot hydrogen atoms in RF plasmas by catalytic reactions between hydrogen and oxygen species

    E-print Network

    Jonathan Phillips; Chun Ku Chen; Randell Mills

    2005-08-31

    Selective H-atom line broadening was found to be present throughout the volume (13.5 cm ID x 38 cm length) of RF generated H2O plasmas in a GEC cell. Notably, at low pressures (ca. hydrogen was 'hot' with energies greater than 40 eV with a pressure dependence, but only a weak power dependence. The degree of broadening was virtually independent of the position studied within the GEC cell, similar to the recent finding for He/H2 and Ar/H2 plasmas in the same GEC cell. In contrast to the atomic hydrogen lines, no broadening was observed in oxygen species lines at low pressures. Also, in control Xe/H2 plasmas run in the same cell at similar pressures and adsorbed power, no significant broadening of atomic hydrogen, Xe, or any other lines was observed. Stark broadening or acceleration of charged species due to high electric fields can not explain the results since (i) the electron density was insufficient by orders of magnitude, (ii) the RF field was essentially confined to the cathode fall region in contrast to the broadening that was independent of position, and (iii) only the atomic hydrogen lines were broadened. Rather, all of the data is consistent with a model that claims specific, predicted, species can act catalytically through a resonant energy transfer mechanism to create hot hydrogen atoms in plasmas.

  17. Getting Physical with Your Chemistry: Mechanically Investigating Local Structure and Properties of Surfaces with the Atomic Force Microscope

    ERIC Educational Resources Information Center

    Heinz, William F.; Hoh, Jan H.

    2005-01-01

    Atomic force microscope (AFM) investigates mechanically the chemical properties of individual molecules, surfaces, and materials using suitably designed probes. The current state of the art of AFM in terms of imaging, force measurement, and sample manipulation and its application to physical chemistry is discussed.

  18. Use of a COâ pellet non-destructive cleaning system to decontaminate radiological waste and equipment in shielded hot cells at the Bettis Atomic Power Laboratory

    Microsoft Academic Search

    Bench

    1997-01-01

    This paper details how the Bettis Atomic Power Laboratory modified and utilized a commercially available, solid carbon dioxide (COâ) pellet, non-destructive cleaning system to support the disposition and disposal of radioactive waste from shielded hot cells. Some waste materials and equipment accumulated in the shielded hot cells cannot be disposed directly because they are contaminated with transuranic materials (elements with

  19. Chemistry

    NSDL National Science Digital Library

    K-12 Outreach,

    Chemistry is the scientific study of matter and its interaction with other matter and with energy. It is the branch of natural science that deals with the composition of substances and their properties and reactions.

  20. Microelectrode studies of interstitial water chemistry and photosynthetic activity in a hot spring microbial mat

    SciTech Connect

    Revsbech, N.P.; Ward, D.M.

    1984-08-01

    Microelectrodes were used to measure oxygen, pH, and oxygenic photosynthetic activity in a hot spring microbial mat (Octopus Spring, Yellowstone National Park), where the cyanobacterium Synechoccus lividus and the filamentous bacteria Chloroflexus aurantiacus are the only known phototrophs. The data showed very high biological activities in the topmost layers of the microbial mat, resulting in extreme values for oxygen and pH. At a 1-mm depth at a 55 C site, oxygen and pH reached 900 micro M and 9.4, respectively, just after solar noon, whereas anoxic conditions with pH of 7.2 were measured before sunrise. Although diurnal changes between these extremes occurred over hours during a diurnal cycle microbial activity was great enough to give the same response in 1 to 2 mm after artificial shading. Oxygenic photosynthesis was confined to a 0.5- to 1.1-mm layer at sites with temperatures at or above about 50 C, with maximum activities in the 55 to 60 C region. The data suggest that S. lividus is the dominant primary producer of the mat. 30 references, 5 figures.

  1. The chemistry of sodium chloride involvement in processes related to hot corrosion. [in gas turbine engines

    NASA Technical Reports Server (NTRS)

    Stearns, C. A.; Kohl, F. J.; Fryburg, G. C.

    1979-01-01

    Thermodynamic and mass transport calculations, and laboratory experiments elucidating the behavior of sodium chloride in combustion environments, in the deposition process, and in reactions with certain oxides on the surfaces of superalloys are summarized. It was found that some of the ingested salt is separated out of the air stream by the compressor. However, sodium chloride does pass from the compressor to the combustor where numerous chemical reactions take place. Here some of the salt is vaporized to yield gaseous sodium chloride molecules. Hydrogen and oxygen atoms present in the combustion products react with some sodium chloride to yield other gaseous species such as sodium, and a fraction of the salt remains as particulates. Both the gas phase and condensed sodium chloride can lead to sodium sulfate formation by various routes, all of which involve reaction with sulfur oxides and oxygen. In addition to contributing to the formation of sodium sulfate, the sodium chloride can contribute to corrosion directly.

  2. Probing the Chemistry and Dynamics of Hot Molecular Cores Using Highly Excited Cyanopolyynic Transitions

    NASA Astrophysics Data System (ADS)

    Loughnane, Robert John; Lique, François; Singh, Navtej; Kurtz, Stan

    2014-06-01

    A hyperfine line fitting program is presented, which decomposes an observed rotational transition into its individual hyperfine components. The fit is optimized by the use of the Levenberg-Marquardt algorithm (for non-linear fitting) or Caruana's algorithm (linearization of the Gaussian function). From the optimal fit, various parameters from the decomposed components are derived such as the linewidth dispersion, peak brightness temperature and peak position in velocity units. The closeness in frequency units of two neighbouring hyperfine components within a rotational transition spectrum allows the derivation of a more credible estimate of the optical depth for the observed source of emission. Effective smoothing of the data subsequent to the fitting procedure greatly reduces the perceived error in the determination of various physical conditions of the observed region. The technique has been employed in observations of massive hot molecular cores (HMCs), considered to be the birthplace of high mass stars. In particular, observations of the cyanopolyynes HC_3N and HC_5N, each of which include a quadrupole hyperfine structure, as well as methyl cyanide, CH_3CN, have been analysed with this technique and modelled with a radiative transfer code incorporating non-LTE conditions, in order to derive abundances and column densities for a total of 10 HMCs and 5 massive cores. Using these derived parameters for each core, we have been able to test the time-dependent chemical models presented for these species by Chapman et al. (2009) and thus verify the suitability of their usefulness as "chemical clocks" by which to constrain the ages of the observed objects. In addition to this work, a detailed study of the magnetic hyperfine structure of a selection of inversion transitions of NH_3 is presented. As part of the continuing preparatory work for Herschel, SOFIA and, in particular, ALMA - improved rest frequencies for this commonly used kinetic temperature detecting species in star-forming cores will be forthcoming.

  3. Doing Chemistry

    NSDL National Science Digital Library

    Brooks, David W.

    This website includes over 150 chemistry experiments in the following areas: Atomic Structure, Bonding, Chemical Reactions, Colligative Properties, Condensed States, Electrochemistry, Equilibrium Gases, Instrumentation, Limiting Reactant and more.

  4. Ultraslow Group Velocity and Enhanced Nonlinear Optical Effects in a Coherently Driven Hot Atomic Gas

    Microsoft Academic Search

    Michael M. Kash; Vladimir A. Sautenkov; Alexander S. Zibrov; L. Hollberg; George R. Welch; Mikhail D. Lukin; Yuri Rostovtsev; Edward S. Fry; Marlan O. Scully

    1999-01-01

    We report the observation of small group velocities of order 90 m\\/s and large group delays of greater than 0.26 ms, in an optically dense hot rubidium gas ( ~360 K). Media of this kind yield strong nonlinear interactions between very weak optical fields and very sharp spectral features. The result is in agreement with previous studies on nonlinear spectroscopy

  5. Influence of atomic layer deposition chemistry on high- k dielectrics for charge trapping memories

    NASA Astrophysics Data System (ADS)

    Nikolaou, Nikolaos; Dimitrakis, Panagiotis; Normand, Pascal; Ioannou-Sougleridis, Vassilios; Giannakopoulos, Konstantinos; Mergia, Konstantina; Kukli, Kaupo; Niinistö, Jaakko; Ritala, Mikko; Leskelä, Markku

    2012-02-01

    In this work we report the performance of the SiO 2/Si 3N 4/HfO 2 and SiO 2/Si 3N 4/ZrO 2 stacks with emphasis on the influence of atomic layer deposition chemistry used for forming the HfO 2 and ZrO 2 blocking layers. Two Hf precursors were employed - tetrakis(ethylmethylamino)hafnium (TEMAH) and bis(methylcyclopentadienyl)methoxymethyl hafnium (HfD-04). For ZrO 2, tetrakis(ethylmethylamino)zirconium (TEMAZ) and bis(methylcyclopentadienyl)methoxymethyl zirconium (ZrD-04) were used as metal precursors. Ozone was used as the oxygen source. The structural characteristics of the stacks were examined by transmission electron microscopy and grazing incidence X-ray diffraction. The electrical properties of the stacks were studied using platinum-gated capacitor structures. The memory performance of the stacks was evaluated by write/erase (W/E) measurements, endurance and retention testing. Endurance measurements revealed the most important difference between the stacks. The films grown from TEMAH and TEMAZ could withstand a significantly higher number of W/E pulses (>3 × 10 5 in the 10 V/-11 V, 10 ms regime), in comparison to the stacks made from HfD-04 and ZrD-04 precursors (<5 × 10 3 W/E cycles). This difference in endurance characteristics is attributed mainly to the different deposition temperatures suited for these two precursors and the nature of the layer formed at the Si 3N 4/HfO 2 and the Si 3N 4/ZrO 2 interfaces.

  6. Competition of silene/silylene chemistry with free radical chain reactions using 1-methylsilacyclobutane in the hot-wire chemical vapor deposition process.

    PubMed

    Badran, I; Forster, T D; Roesler, R; Shi, Y J

    2012-10-18

    The gas-phase reaction chemistry of using 1-methylsilacyclobutane (MSCB) in the hot-wire chemical vapor deposition (CVD) process has been investigated by studying the decomposition of MSCB on a heated tungsten filament and subsequent gas-phase reactions in a reactor. Three pathways exist to decompose MSCB on the filament to form ethene/methylsilene, propene/methylsilylene, and methyl radicals. The activation energies for forming propene and methyl radical, respectively, are determined to be 68.7 ± 1.3 and 46.7 ± 2.5 kJ·mol(-1), which demonstrates the catalytic nature of the decomposition. The secondary gas-phase reactions in the hot-wire CVD reactor are characterized by the competition between a free radical chain reaction and the cycloaddition of silene reactive species produced either from the primary decomposition of MSCB on the filament or the isomerization of silylene species. At lower filament temperatures of 1000-1100 °C and short reaction time (t ? 15 min), the free radical chain reaction is equally important as the silene chemistry. With increasing filament temperature and reaction time, silene chemistry predominates. PMID:22934960

  7. Environmental Assessment for decontaminating and decommissioning the General Atomics Hot Cell Facility. Final [report

    SciTech Connect

    NONE

    1995-08-01

    This EA evaluates the proposed action to decontaminate and decommission GA`s hot cell facility in northern San Diego, CA. This facility has been used for DOE and commercial nuclear R&D for > 30 years. About 30,000 cubic feet of decontamination debris and up to 50,000 cubic feet of contaminated soil are to be removed. Low-level radioactive waste would be shipped for disposal. It was determined that the proposal does not constitute a major federal action significantly affecting the human environment according to NEPA; therefore, a finding of no significant impact is made, and an environmental impact statement is not required.

  8. Atomic-scale control of TiO6 octahedra through solution chemistry towards giant dielectric response

    PubMed Central

    Hu, Wanbiao; Li, Liping; Li, Guangshe; Liu, Yun; Withers, Ray L.

    2014-01-01

    The structures of many important functional oxides contain networks of metal-oxygen polyhedral units i.e. MOn. The correlation between the configurations and connectivities of these MOn to properties is essentially important to be well established to conduct the design, synthesis and application of new MOn-based functional materials. In this paper, we report on an atomic-scale solution-chemistry approach that for the first time enables TiO6 octahedral network control starting from metastable brookite TiO2 through simultaneously tuning pH values and interfering ions (Fe3+, Sc3+, and Sm3+). The relationship between solution chemistry and the resultant configuration/connectivity of TiO6 octahedra in TiO2 and lepidocrocite titanate is mapped out. Apart from differing crystalline phases and morphologies, atomic-scale TiO6 octahedral control also endows numerous defect dipoles for giant dielectric responses. The structural and property evolutions are well interpreted by the associated H+/OH? species in solution and/or defect states associated with Fe3+ occupation within TiO6 octahedra. This work therefore provides fundamental new insights into controlling TiO6 octahedral arrangement essential for atomic-scale structure-property design. PMID:25301286

  9. Chemistry of Hot Spring Pool Waters in Calamba and Los Banos and Potential Effect on the Water Quality of Laguna De Bay

    NASA Astrophysics Data System (ADS)

    Balangue, M. I. R. D.; Pena, M. A. Z.; Siringan, F. P.; Jago-on, K. A. B.; Lloren, R. B.; Taniguchi, M.

    2014-12-01

    Since the Spanish Period (1600s), natural hot spring waters have been harnessed for balneological purposes in the municipalities of Calamba and Los Banos, Laguna, south of Metro Manila. There are at more than a hundred hot spring resorts in Brgy. Pansol, Calamba and Tadlac, Los Banos. These two areas are found at the northern flanks of Mt. Makiling facing Laguna de Bay. This study aims to provide some insights on the physical and chemical characteristics of hot spring resorts and the possible impact on the lake water quality resulting from the disposal of used water. Initial ocular survey of the resorts showed that temperature of the pool water ranges from ambient (>300C) to as high as 500C with an average pool size of 80m3. Water samples were collected from a natural hot spring and pumped well in Los Banos and another pumped well in Pansol to determine the chemistry. The field pH ranges from 6.65 to 6.87 (Pansol springs). Cation analysis revealed that the thermal waters belonged to the Na-K-Cl-HCO3 type with some trace amount of heavy metals. Methods for waste water disposal are either by direct discharge down the drain of the pool or by discharge in the public road canal. Both methods will dump the waste water directly into Laguna de Bay. Taking in consideration the large volume of waste water used especially during the peak season, the effect on the lake water quality would be significant. It is therefore imperative for the environmental authorities in Laguna to regulate and monitor the chemistry of discharges from the pool to protect both the lake water as well as groundwater quality.

  10. Contribution of the E2 transitions to the opacity of hot and dense plasmas of heavy elements by an average-atom approach

    Microsoft Academic Search

    Jinsong Miao; Jianmin Yuan

    2004-01-01

    The contribution of electric quadrupole (E2) transitions to the opacity of hot and dense plasmas is taken into account by using an average-atom model. As an example, the increase of the opacity of Au due to the E2 transition is shown to range from less than 1% to more than 10% depending on density and temperature. It reaches 15% when

  11. The Atomic and Molecular Universe: Collisions in Hot Plasmas to the Building Blocks of Life

    NASA Astrophysics Data System (ADS)

    Chutjian, Ara

    2010-03-01

    Basic atomic and molecular collision phenomena are operative at the core of an enormous range of astrophysical plasmas, including the interstellar medium (ISM), protostellar regions, stars, our Sun, and planetary atmospheres, ionospheres, & magnetospheres. Laboratory measurements of cross sections and lifetimes are needed to establish plasma charge-state distributions. A required database includes absolute electron- impact excitation, ionization, and recombination cross sections in highly-charged ions (HCIs); photoionization cross sections; and absolute single- and multiple charge-exchange cross sections between a neutral target and an HCI, as when a solar/stellar wind meets a circumstellar cloud or passing comet to generate X- rays via charge exchange. Since satellites and spacecraft often detect photons from the astronomical object, the infrared-to-X- ray emissions are governed by a balance between collisional excitation and radiative decay, so that accurate lifetimes, branching fractions, and Einstein A and B coefficients are also needed. On yet another level, observations in the infrared-to- millimeter wave region from, for example, the Green Bank Telescope, Spitzer, Sofia, Herschel, and the James Webb Telescope provide information on molecular formation in the ISM and protostellar regions. Over 144 atomic, molecular, and ionic species have been identified to date. Recent laboratory results will be given on formation of some of these polyatomic molecules in superthermal, ground-state H- and O-atom collisions with simple, grain-adsorbed species, and results compared to the impressive array of space spectroscopic data.

  12. REVIEW ARTICLE: Atomic scale study of the chemistry of oxygen, hydrogen and water at SiC surfaces

    NASA Astrophysics Data System (ADS)

    Amy, Fabrice

    2007-10-01

    Understanding the achievable degree of homogeneity and the effect of surface structure on semiconductor surface chemistry is both academically challenging and of great practical interest to enable fabrication of future generations of devices. In that respect, silicon terminated SiC surfaces such as the cubic 3C-SiC(1 0 0) 3 × 2 and the hexagonal 6H-SiC(0 0 0 1) 3 × 3 are of special interest since they give a unique opportunity to investigate the role of surface morphology on oxygen or hydrogen incorporation into the surface. In contrast to silicon, the subsurface structure plays a major role in the reactivity, leading to unexpected consequences such as the initial oxidation starting several atomic planes below the top surface or the surface metallization by atomic hydrogen.

  13. Chemistry of the outer planets

    NASA Technical Reports Server (NTRS)

    Scattergood, Thomas W.

    1992-01-01

    Various aspects were studied of past or present chemistry in the atmospheres of the outer planets and their satellites using lab simulations. Three areas were studied: (1) organic chemistry induced by kinetically hot hydrogen atoms in the region of Jupiter's atmosphere containing the ammonia cirrus clouds; (2) the conversion of NH3 into N2 by plasmas associated with entry of meteors and other objects into the atmosphere of early Titan; and (3) the synthesis of simple hydrocarbons and HCN by lightning in mixtures containing N2, CH4, and NH3 representing the atmospheres of Titan and the outer planets. The results showed that: (1) hot H2 atoms formed from the photodissociation of NH3 in Jupiter's atmosphere could account for some of the atmospheric chemistry in the ammonia cirrus cloud region; (2) the thermalization of hot H2 atoms in atmospheres predominated by molecular H is not as rapid as predicted by elastic collision theory; (3) the net quantum loss of NH3 in the presence of a 200 fold excess of H2 is 0.02, much higher than was expected from the amount of H2 present; (4) the conversion of NH3 into N2 in plasmas associated with infalling meteors is very efficient and rapid, and could account for most of the N2 present on Titan; (5) the yields of C2H2 and HCN from lightning induced chemistry in mixtures of CH4 and N2 is consistent with quenched thermodynamic models of the discharge core; and (6) photolysis induced by the UV light emitted by the gases in the hot plasmas may account for some, if not most, of the excess production of C2H6 and the more complex hydrocarbons.

  14. Photon pair production from a hot atomic ensemble in the diamond configuration

    NASA Astrophysics Data System (ADS)

    Willis, Richard Thomas

    This thesis discusses four-wave mixing (4WM) in a warm ensemble of rubidium using the diamond configuration level structure. Both classical 4WM and nonclassical photon-pair production are investigated. Quantum information science has spawned a great amount of experimental work on the interaction of light with collective modes of excitation in atomic ensembles. Plans to build quantum networks and quantum repeaters with atom ensembles take advantage of nonlinear interactions to produce and store non-classical states of light. These technologies will require photon sources that not only generate nonclassical light, but also resonant, narrow band light. Here we investigate a system which could be used as such a source. We take advantage of the 4WM interaction in a warm ensemble of Rubidium atoms. Our scheme utilizes the diamond energy level configuration which, in rubidium, allows for correlated pairs at telecommunications wavelengths. We start by examining the properties of classical 4WM in the system. We measure the resonance structure and see that it can be understood in terms of velocity class selective resonant enhancement and power splitting effects. The efficiency of the process is low and limited by linear absorption of the pumps. Our observations agree with a semi-classical Maxwell-Bloch theoretical treatment. Next we observe pair generation by spontaneous 4WM from the warm ensemble. The temporal profile of the cross-correlation function (CCF) for the photons depends on pump-laser power and detuning. This allows us to produce biphotons with controllable spectra. A simple quantum optical theoretical treatment based on linear filtering gives qualitative agreement with the data. We show that the photon pairs are polarization entangled, clearly violating Bell's Inequality. A perturbative quantum optical treatment predicts the polarization state of the pairs and agrees with our measurements. We analyze the photon statistics of the source and find the largest violation of the two beam Cauchy-Schwarz inequality from a warm atomic source yet. We cast the system as a heralded single photon source at telecommunications wavelengths and see that it is competitive with other systems in terms of spectral brightness.

  15. High Metallicity and Non-Equilibrium Chemistry in the Dayside Atmosphere of Hot-Neptune Gj 436b

    E-print Network

    Madhusudhan, Nikku

    We present a detailed analysis of the dayside atmosphere of the hot-Neptune GJ 436b, based on recent Spitzer observations. We report statistical constraints on the thermal and chemical properties of the planetary atmosphere, ...

  16. How in Spite of the Rhetoric, History of Chemistry has Been Ignored in Presenting Atomic Structure in Textbooks

    NASA Astrophysics Data System (ADS)

    Rodríguez, María A.; Niaz, Mansoor

    Recent research in science education has recognized the importance of history and philosophy of science. This study has the following objectives:(a) To show how the importance of history of chemistry has been recognized in theclassroom, starting from the 1920s to the present; (b) How criteria based on history andphilosophy of science can be used to evaluate presentation of atomic structure in generalchemistry textbooks; (c) Comparison of the new (1970-1992) and old textbooks (1929-1967)with respect to the presentation of atomic structure. Results obtained show thatmost of the new and old textbooks not only ignore the history and philosophy of sciencebut also present experimental findings as a `rhetoric of conclusions'. It isconcluded that such presentations are not conducive towards a better understanding of scientificprogress. It is suggested that history and philosophy of science can be introduced in theclassroom not necessarily through formal courses in the history of chemistry or commentsand anecdotes, but rather by incorporating the `heuristic principles' that guided thescientists to elaborate their theories.

  17. Bonds Between Metal Atoms: A New Mode of Transition Metal Chemistry.

    ERIC Educational Resources Information Center

    Cotton, F. Albert; Chisholm, Malcolm H.

    1982-01-01

    Discusses polynuclear metal clusters (containing two or more metal atoms bonded to one another as well as to nonmetallic elements), including their formation and applications. Studies of bonds between metal atoms reveal superconductors, organic-reaction catalysts, and photosensitive complexes that may play a role in solar energy. (JN)

  18. Atomic carbon emission from photodissociation of CO2. [planetary atmospheric chemistry

    NASA Technical Reports Server (NTRS)

    Wu, C. Y. R.; Phillips, E.; Lee, L. C.; Judge, D. L.

    1978-01-01

    Atomic carbon fluorescence, C I 1561, 1657, and 1931 A, has been observed from photodissociation of CO2, and the production cross sections have been measured. A line emission source provided the primary photons at wavelengths from threshold to 420 A. The present results suggest that the excited carbon atoms are produced by total dissociation of CO2 into three atoms. The cross sections for producing the O I 1304-A fluorescence through photodissociation of CO2 are found to be less than 0.01 Mb in the wavelength region from 420 to 835 A. The present data have implications with respect to photochemical processes in the atmospheres of Mars and Venus.

  19. Hot atom reactions involving multivalent and univalent species. Progress report, February 1980-January 1981

    SciTech Connect

    Tang, Y.N.

    1981-01-01

    Major progress was made in the study of recoil /sup 31/Si reactions. The most significant discovery is that monomeric /sup 31/SiF/sub 2/ adds to two molecules of C/sub 2/H/sub 4/ to give 1,1-difluorosilacyclopentane as a final product. When radical scavengers were added, the yield of this product was not altered. When 1,3-butadiene was added to the above recoil /sup 31/Si system to compete with C/sub 2/H/sub 4/ for the available /sup 31/SiF/sub 2/, a nearly complementary relationship was found between 1,1-difluorosilacyclopent-3-ene-/sup 31/Si, the butadiene product, and 1,1-difluorosilacyclopentane-/sup 31/Si. Quantitatively, it was deduced that butadiene is about ten times more reactive than C/sub 2/H/sub 4/ for the trapping of /sup 31/SiF/sub 2/. When Ne was added as a moderator to the 5:1 C/sub 2/H/sub 4/:butadiene competition system, the two product ratio shifts from 1:2 in favor of butadiene to 10:1 in favor of C/sub 2/H/sub 4/. This indicates that it is the lower energy /sup 31/SiF/sub 2/ species which is captured by C/sub 2/H/sub 4/, while it is favorable for the more energetic /sup 31/SiF/sub 2/ to be captured by butadiene. In the systems reacting recoil /sup 31/Si atoms with C/sub 2/H/sub 4/ in the presence of PF/sub 3/, four unidentified products with yields less than that of 1,1-difluorosilacyclopentane were also observed. Two of them were also formed when either PH/sub 3/ or (CH/sub 3/)/sub 3/P were used as the /sup 31/Si precursor. This means that they are likely to be direct /sup 31/Si atom reaction products. When recoil /sup 31/Si atoms reacted with C/sub 2/H/sub 4/ in the presence of (CH/sub 3/)/sub 3/P, the main product was identified as /sup 31/SiH(CH/sub 3/)/sub 2/CH = CH/sub 2/. This might mean the formation of dimethylsilene, /sup 31/Si(CH/sub 3/)/sub 2/, and the addition of it to CH/sub 2/ = CH/sub 2/ to give the product. In addition, catalytic C-F hydrogenolysis of CH/sub 2/ = CHF, CH/sub 3/CH/sub 2/F, CHF = CHF, CH/sub 2/ = CF/sub 2/, CH/sub 3/CHF/sub 2/, and CH/sub 3/CF/sub 3/ were studied at temperatures ranging from 75/sup 0/ to 400/sup 0/C. The apparent activation energies and the A factors have been evaluated.

  20. Hot atom reactions involving multivalent and univalent species. Progress report, February 1979-January 1980

    SciTech Connect

    Tang, Y.N.

    1980-01-01

    The major progress during this period was in the study of recoil /sup 31/Si and recoil /sup 11/C reactions and in the initiation of the studies on the interaction of molecular tritium on solid surfaces. For the recoil /sup 31/Si systems, heterogeneous hydrogenation experiments have been designed to positively confirm that a major unknown product, derived from the interaction of /sup 31/Si atoms with 1,3-butadiene, is 1-silacyclopenta-2,4-diene. This compound has been shown to be very sensitive to ..gamma..-ray irradiation and to be thermally unstable at a temperature higher than 100/sup 0/C. Another recoil /sup 31/Si experiment was designed to review the mechanism of the /sup 31/Si abstraction reactions. From the fact that high yields of (/sup 31/Si)-1-fluorosilacyclopent-3-ene were obtained as a product from a mixture of PH/sub 3/ and PF/sub 3/ together with 1,3-butadiene, the stepwise abstraction mechanism is definitely much more predominant than the possible simultaneous abstraction. Other recoil /sup 31/Si works involved a detailed systematic composition study of /sup 31/SiF/sub 2/ reactions with 1,3-butadiene, some neon moderator studies, and the continuation of the studies on the reactions of /sup 31/SiF/sub 2/ and /sup 31/SiH/sub 2/ with conjugated hexadienes. By using 2-/sup 14/C-propanone and 1,3-/sup 14/C-propanone, the mechanism of solvent-free oxidative cleavage of propanone by KMnO/sub 4/ was elucidated. Information thus derived was used to degradate the /sup 11/C-labelled propadiene derived from the reactions of recoil /sup 11/C atoms with ethylene. Results indicate that 73% of the /sup 11/C-labelled propadiene was center-labelled. This value was observed to change with additives. Various mechanistic studies on the heterogeneous interactions of molecular T/sub 2/ on solid surfaces such as Pd supported on active carbon have been initiated.

  1. A large atomic chlorine source inferred from mid-continental reactive nitrogen chemistry

    E-print Network

    mercury1 and hydrocarbons such as the greenhouse gas methane2 . Chlorine atoms also influence cycles) represents a terminal NOx sink in the lower troposphere, whereas reaction (1b) recycles NOx through ClNO2

  2. Reactions of hot deuterium atoms with OCS in the gas phase and in OCS--DI complexes

    SciTech Connect

    Boehmer, E.; Mikhaylichenko, K.; Wittig, C. (University of Southern California, Department of Chemistry, Los Angeles, California 90089-0482 (United States))

    1993-11-01

    Reactions of photolytically prepared hot deuterium atoms with OCS have been investigated: (i) under gas phase, single collision, arrested relaxation (i.e., bulk) conditions; and (ii) by photoinitiating reactions within weakly bound OCS--DI complexes. Nascent SD([ital X] [sup 2][Pi], [ital v]=0) rotational, spin--orbit, and [Lambda]-doublet populations were obtained for the photolysis wavelengths 250, 225, and 223 nm by using [ital A] [sup 2][Sigma][l arrow][ital X] [sup 2][Pi] laser induced fluorescence (LIF). The reason for using deuterium is strictly experimental: [ital A] [sup 2][Sigma] predissociation rates are considerably smaller for SD than for SH. The SD ([ital v]=0) rotational distribution was found to be very cold and essentially the same for both bulk and complexed conditions; the most probable rotational energy is [similar to]180 cm[sup [minus]1]. No bias in [Lambda]-doublet populations was detected. Spin--orbit excitation for bulk conditions was estimated to be [[sup 2][Pi][sub 1/2

  3. The H + OCS hot atom reaction - CO state distributions and translational energy from time-resolved infrared absorption spectroscopy

    NASA Technical Reports Server (NTRS)

    Nickolaisen, Scott L.; Cartland, Harry E.

    1993-01-01

    Time-resolved infrared diode laser spectroscopy has been used to probe CO internal and translational excitation from the reaction of hot H atoms with OCS. Product distributions should be strongly biased toward the maximum 1.4 eV collision energy obtained from 278 nm pulsed photolysis of HI. Rotations and vibrations are both colder than predicted by statistical density of states theory, as evidenced by large positive surprisal parameters. The bias against rotation is stronger than that against vibration, with measurable population as high as v = 4. The average CO internal excitation is 1920/cm, accounting for only 13 percent of the available energy. Of the energy balance, time-resolved sub-Doppler line shape measurements show that more than 38 percent appears as relative translation of the separating CO and SH fragments. Studies of the relaxation kinetics indicate that some rotational energy transfer occurs on the time scale of our measurements, but the distributions do not relax sufficiently to alter our conclusions. Vibrational distributions are nascent, though vibrational relaxation of excited CO is unusually fast in the OCS bath, with rates approaching 3 percent of gas kinetic for v = 1.

  4. He-Ion and Self-Atom Induced Damage and Surface-Morphology Changes of a Hot W Target

    SciTech Connect

    Meyer, Fred W [ORNL; Hijazi, Hussein Dib [ORNL; Krstic, Predrag S [ORNL; Dadras, Mostafa Jonny [ORNL; Meyer III, Harry M [ORNL; Parish, Chad M [ORNL; Bannister, Mark E [ORNL

    2014-01-01

    We report results of measurements on the evolution of the surface morphology of a hot tungsten surface due to impacting low-energy (80 12,000 eV) He ions and of simulations of damage caused by cumulative bombardment of 1 and 10 keV W self-atoms. The measurements were performed at the ORNL Multicharged Ion Research Facility (MIRF), while the simulations were done at the Kraken supercomputing facility of the University of Tennessee. At 1 keV, the simulations show strong defect-recombination effects that lead to a saturation of the total defect number after a few hundreds impacts, while sputtering leads to an imbalance of the vacancy and interstitial number. On the experimental side, surface morphology changes were investigated over a broad range of fluences for both virgin and pre-damaged W-targets. At the lowest accumulated fluences, small surface-grain features and near-surface He bubbles are observed. At the largest fluences, individual grain characteristics disappear in FIB/SEM scans, and the entire surface is covered by a multitude of near-surface bubbles with a broad range of sizes, and disordered whisker growth, while in top-down SEM imaging the surface is virtually indistinguishable from the nano-fuzz produced on linear plasma devices. These features are evident at progressively lower fluences as the He-ion energy is increased.

  5. Kinematics and Chemistry of the Hot Molecular Core in G34.26+0.15 at High Resolution

    E-print Network

    B. Mookerjea; E. Casper; L. G. Mundy; L. W. Looney; ;

    2007-01-29

    (abridged) We present high angular resolution (~ 1") multi-tracer spectral line observations toward the hot core associated with G34.26+0.15 between 87--109 GHz. We have mapped emission from (i) complex nitrogen- and oxygen-rich molecules like CH3OH, HC3N, C2H5CN, NH2CHO, CH3OCH3, HCOOCH3; (ii) sulfur-bearing molecules like OCS, SO and SO2; and (iii) the recombination line H53 beta. The high angular resolution enables us to directly probe the hot molecular core associated with G34.26+0.15 at spatial scales of 0.018 pc. At this resolution we find no evidence for the hot core being internally heated. The continuum peak detected at lambda=2.8 mm is consistent with the free-free emission from component C of the ultracompact H II region. Velocity structure and morphology outlined by the different tracers suggest that the hot core is primarily energized by component C. Emission from the N- and O-bearing molecules peak at different positions within the innermost regions of the core; none is coincident with the continuum peak. Based on the brightness temperatures of optically thick lines in our sample, we estimate the kinetic temperature of the inner regions of the HMC to be 160+-30 K. Comparison of the observed abundances of the different species in G34.26+0.15 with existing models does not produce a consistent picture.

  6. Analysis of the Essential Nutrient Strontium in Marine Aquariums by Atomic Absorption Spectroscopy: An Undergraduate Analytical Chemistry Laboratory Exercise

    NASA Astrophysics Data System (ADS)

    Gilles de Pelichy, Laurent D.; Adam, Carl; Smith, Eugene T.

    1997-10-01

    An undergraduate atomic absorption spectroscopy (AAS) laboratory experiment is presented involving the analysis of the essential nutrient strontium in a real-life sample, sea water. The quantitative analysis of strontium in sea water is a problem well suited for an undergraduate analytical chemistry laboratory. Sea water contains numerous components which prevent the direct quantitative determination of strontium. Students learn first hand about the role of interferences in analytical measurements, and about the method of standard addition which is used to minimize these effects. This laboratory exercise also introduces undergraduate students to practical problems associated with AAS. We encourage students as a part of this experiment to collect and analyze marine water samples from local pet shops.

  7. Shippingport Atomic Power Station steam generator tube damage and water chemistry control (1965--1975)

    Microsoft Academic Search

    Singley

    1978-01-01

    The four stainless steel tubed steam generators in the Shippingport Atomic Power Station were replaced in 1964 with larger, horizontal, NiCrFe Alloy 600 tubed units consistent with a power uprating of the plant. Each of the four Alloy 600 tubed units experienced tube leakage attributed to corrosion by water treatment chemicals (sodium phosphates) which concentrated locally on the tubes in

  8. CHEMISTRY 3020-43256 PHYSICAL CHEMISTRY I

    E-print Network

    Findley, Gary L.

    CHEMISTRY 3020-43256 PHYSICAL CHEMISTRY I Fall 2013 8:00 am - 8:50 am, MWF SUGAR 259 INSTRUCTOR interpretations of the physical principles of chemistry. Goals/ Objectives: CHEM 3020 presents chemical principles foundations of modern chemistry. Topics covered include: introduction to quantum theory, atomic structure

  9. Chemistry of glass-ceramic to metal bonding for header applications: III. Treatment of Inconel 718 to eliminate hot cracking during laser welding

    SciTech Connect

    Moddeman, W.E.; Jones, W.H.; Koeller, T.L.; Craven, S.M.; Kramer, D.P.

    1987-04-24

    A study was conducted to determine the weldability of Inconel 718 shells. Two pieces of Inconel 718 were welded together with a Hastelloy B-2 filler. The Inconel surface condition was varied by heat-treating and by using several different cleaning processes. The surface chemistry following each modification was determined by Auger spectroscopy. Each conditioned Inconel hollow cylinder (shell) was also checked for pulsed laser weldability by looking for hot cracking. Abraded and solvent-cleaned Inconel shells were found to have thin surface oxides and were also found to be weldable. Heat-treated shells were shown to have a thick complex oxide layer consisting primarily of chromium, titanium, aluminum, and niobium, and were not found to be weldable. Variations of an ''oxide removal'' treatment were used and found to be ineffective in removing all of the heat-treated surface oxides. The predominant oxide left after the various removal treatments was a thick aluminum oxide laced with alkali, alkaline earth and nickel oxides, sulfides (or sulfates), and/or chlorides. Inconel shells after being treated by these oxide removal steps and variations were also found not be be laser weldable. This oxide was finally removed by electropolishing, and the resulting surface was found to be crack-free after welding. Auger analysis of fractured surfaces in hot-cracked regions revealed that the surfaces consisted of an oxide similar to that left after the removal steps, but without the aluminum oxide. Thus, it was concluded that hot cracking in heat-treated, oxide-removed Inconel 718 is due to one or all of the following: alkali, alkaline earth and nickel oxides, sulfides (or sulfates), and/or chlorides that accumulate in the cracked area.

  10. What`s new/hot/exciting: Using PC/PLC atuomatic balancing systems and advanced reagent chemistry for coal preparation

    SciTech Connect

    Zinkan, K.J. [O`Brien Industries, Inc., Twinsburg, OH (United States)

    1995-08-01

    If we were to select one product or service which will be a hot topic over the next five years, it would be the selection and automatic addition and balancing of the proper coal recovery chemistries. Currently there are a number of automatic chemical feeding and control systems available to the preparation manager. However, no one seems completely satisfied by either the technology or the results. There are a number of areas where automation is beginning to come into use in preparation plants: polymer addition; coal chemicals addition for recovery; and finally freeze proofing of coal (where necessary). Also, in some cases, an overall plant operational system is either in place or has been evaluated with either partial or totally automatic control over various or all phase of plant operation. Since we want to limit the scope of this discussion, we are only to look at the topic involving the coal recovery process. Further, we have selected to focus on only one of our areas of expertise: automatic feeding and control of the frother(s) and new frother chemistry. The areas that will all be tied together in order to insure customers recover the highest possible quality and quantity of coal possible are discussed.

  11. Hot Canyon

    SciTech Connect

    None

    2012-06-18

    This historical film footage, originally produced in the early 1950s as part of a series by WOI-TV, shows atomic research at Ames Laboratory. The work was conducted in a special area of the Laboratory known as the "Hot Canyon."

  12. Hot Canyon

    SciTech Connect

    None

    2012-01-01

    This historical film footage, originally produced in the early 1950s as part of a series by WOI-TV, shows atomic research at Ames Laboratory. The work was conducted in a special area of the Laboratory known as the "Hot Canyon."

  13. Hot Canyon

    ScienceCinema

    None

    2013-03-01

    This historical film footage, originally produced in the early 1950s as part of a series by WOI-TV, shows atomic research at Ames Laboratory. The work was conducted in a special area of the Laboratory known as the "Hot Canyon."

  14. Biophysical evaluation of cells on nanotubular surfaces: the effects of atomic ordering and chemistry

    PubMed Central

    Shokuhfar, Tolou; Hamlekhan, Azhang; Chang, Jen-Yung; Choi, Chang Kyoung; Sukotjo, Cortino; Friedrich, Craig

    2014-01-01

    After the implantation of a biomaterial in the body, the first interaction occurs between the cells in contact with the biomaterial surface. Therefore, evaluating the cell–substrate interface is crucial for designing a successful implant. In this study, the interaction of MC3T3 osteoblasts was studied on commercially pure and alloy (Ti6Al4V) Ti surfaces treated with amorphous and crystalline titanium dioxide nanotubes. The results indicated that the presence of nanotubes increased the density of osteoblast cells in comparison to bare surfaces (no nanotubes). More importantly, our finding shows that the chemistry of the substrate affects the cell density rather than the morphology of the cells. A novel approach based on the focused ion beam technique was used to investigate the biophysical cell–substrate interaction. The analysis revealed that portions of the cells migrated inside the crystalline nanotubes. This observation was correlated with the super hydrophilic properties of the crystalline nanotubes. PMID:25143725

  15. Calculation of the Relative Chemical Stabilities of Proteins as a Function of Temperature and Redox Chemistry in a Hot Spring

    PubMed Central

    Dick, Jeffrey M.; Shock, Everett L.

    2011-01-01

    Uncovering the chemical and physical links between natural environments and microbial communities is becoming increasingly amenable owing to geochemical observations and metagenomic sequencing. At the hot spring known as Bison Pool in Yellowstone National Park, the cooling of the water in the outflow channel is associated with an increase in oxidation potential estimated from multiple field-based measurements. Representative groups of proteins whose sequences were derived from metagenomic data also exhibit an increase in average oxidation state of carbon in the protein molecules with distance from the hot-spring source. The energetic requirements of reactions to form selected proteins used in the model were computed using amino-acid group additivity for the standard molal thermodynamic properties of the proteins, and the relative chemical stabilities of the proteins were investigated by varying temperature, pH and oxidation state, expressed as activity of dissolved hydrogen. The relative stabilities of the proteins were found to track the locations of the sampling sites when the calculations included a function for hydrogen activity that increases with temperature and is higher, or more reducing, than values consistent with measurements of dissolved oxygen, sulfide and oxidation-reduction potential in the field. These findings imply that spatial patterns in the amino acid compositions of proteins can be linked, through energetics of overall chemical reactions representing the formation of the proteins, to the environmental conditions at this hot spring, even if microbial cells maintain considerably different internal conditions. Further applications of the thermodynamic calculations are possible for other natural microbial ecosystems. PMID:21853048

  16. Environmental Chemistry 2.1 INTRODUCTION

    E-print Network

    Kammen, Daniel M.

    I CHAPTER 2 Environmental Chemistry 2.1 INTRODUCTION 2.2 STOICHIOMETRY 2.3 ENTHALPY IN CHEMICAL SYSTEMS 2.4 CHEMICAL EQUILIBRIA 2.S ORGANIC CHEMISTRY 2.6 NUCLEAR CHEMISTRY PROBLEMS REFERENCES It often #12;40 Chapter 2 Environmental Chemistry TABLE 2.1 Atomic Numbers andAtomic Weights Atomic Atomic

  17. Probing the Structure and Chemistry of Perylenetetracarboxylic Dianhydride on Graphene Before and After Atomic Layer Deposition of Alumina

    PubMed Central

    Johns, James E.; Karmel, Hunter J.; Alaboson, Justice M. P.; Hersam, Mark C.

    2012-01-01

    The superlative electronic properties of graphene suggest its use as the foundation of next generation integrated circuits. However, this application requires precise control of the interface between graphene and other materials, especially the metal oxides that are commonly used as gate dielectrics. Towards that end, organic seeding layers have been empirically shown to seed ultrathin dielectric growth on graphene via atomic layer deposition (ALD), although the underlying chemical mechanisms and structural details of the molecule/dielectric interface remain unknown. Here, confocal resonance Raman spectroscopy is employed to quantify the structure and chemistry of monolayers of 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) on graphene before and after deposition of alumina with the ALD precursors trimethyl aluminum (TMA) and water. Photoluminescence measurements provide further insight into the details of the growth mechanism, including the transition between layer-by-layer growth and island formation. Overall, these results reveal that PTCDA is not consumed during ALD, thereby preserving a well-defined and passivating organic interface between graphene and deposited dielectric thin films. PMID:22905282

  18. Probing the oxidation chemistry of half-sandwich iridium complexes with oxygen atom transfer reagents.

    PubMed

    Turlington, Christopher R; Harrison, Daniel P; White, Peter S; Brookhart, Maurice; Templeton, Joseph L

    2013-10-01

    The new complexes [Ir(Cp*)(phpy)3,5-bis(trifluoromethyl)benzonitrile](+) (1-NCAr(+)) and [Ir(Cp*)(phpy)(styrene)](+) (1-Sty(+), Cp* = ?(5)-pentamethylcyclopentadienyl, phpy = 2-phenylene-?C(1')-pyridine-?N) were prepared as analogues of reported iridium water oxidation catalysts, to study their reactions with oxygen atom transfer (OAT) reagents at low temperatures. In no case was the desired product, an Ir(V)oxo complex, observed by spectroscopy. Instead, ligand oxidation was implicated. Oxidation of 1-NCAr(+) with the OAT reagent dimethyldioxirane (DMDO) yielded dioxygen when analyzed by GC, but formation of a heterogeneous or paramagnetic species was simultaneously observed. This amplifies uncertainty over the actual identity of iridium catalysts in the harsh oxidizing conditions required for water oxidation. Catalyst stability was then assessed for a reported styrene epoxidation mediated by [Ir(Cp*)(phpy)(OH2)](+) (1-OH2(+)). It was found that the OAT reagent iodosobenzene (PhIO) extensively oxidized the organic ligands of 1-OH2(+). Acetic acid was detected as a decomposition product. In addition, both the molecular structure and the aqueous electrochemistry of 1-OH2(+) are described for the first time. Oxidative scans revealed rapid decomposition of the complex. All of the above experiments indicate that degradation of the organic ligands in catalysts built with the Ir(Cp*)(phpy) framework are facile under oxidizing conditions. In separate experiments designed to promote ligand substitution, an unexpected silver-bridged, dinuclear Ir(III) species with terminal hydrides, [{Ir(Cp*)(phpy)H}2Ag](+) (2), was discovered. The source of Ag(+) for complex 2 was identified as AgCl. PMID:24063760

  19. LASER ABLATION-INDUCTIVELY COUPLED PLASMA-ATOMIC EMISSION SPECTROSCOPY STUDY AT THE 222-S LABORATORY USING HOT-CELL GLOVE BOX PROTOTYPE SYSTEM

    SciTech Connect

    LOCKREM LL; OWENS JW; SEIDEL CM

    2009-03-26

    This report describes the installation, testing and acceptance of the Waste Treatment and Immobilization Plant procured laser ablation-inductively coupled plasma-atomic emission spectroscopy (LA-ICP-AES) system for remotely analyzing high-level waste samples in a hot cell environment. The 2005-003; ATS MP 1027, Management Plan for Waste Treatment Plant Project Work Performed by Analytical Technical Services. The APD group at the 222-S laboratory demonstrated acceptable turnaround time (TAT) and provide sufficient data to assess sensitivity, accuracy, and precision of the LA-ICP-AES method.

  20. LASER ABLATION-INDUCTIVELY COUPLED PLASMA-ATOMIC EMISSION SPECTROSCOPY STUDY AT THE 222-S LABORATORY USING HOT-CELL GLOVE BOX PROTOTYPE SYSTEM

    SciTech Connect

    SEIDEL CM; JAIN J; OWENS JW

    2009-02-23

    This report describes the installation, testing, and acceptance of the Waste Treatment and Immobilization Plant (WTP) procured laser ablation-inductively coupled plasma-atomic emission spectroscopy (LA-ICP-AES) system for remotely analyzing high-level waste (HLW) samples in a hot cell environment. The work was completed by the Analytical Process Development (APD) group in accordance with Task Order 2005-003; ATS MP 1027, Management Plan for Waste Treatment Plant Project Work Performed by Analytical Technical Services. The APD group at the 222-S Laboratory demonstrated acceptable turnaround time (TAT) and provide sufficient data to assess sensitivity, accuracy, and precision of the LA-ICP-AES method.

  1. New precursors and chemistry for the growth of transition metal films by atomic layer deposition

    NASA Astrophysics Data System (ADS)

    Knisley, Thomas Joseph

    The advancing complexity of advanced microelectronic devices is placing rigorous demands on currently used PVD and CVD deposition techniques. The ALD deposition method is proposed to meet the film thickness and conformality constraints needed by the semiconductor industry in future manufacturing processes. Unfortunately, there is a limited number of chemical precursors available that have high thermal stability, reactivity, and vapor pressure suitable for ALD film growth to occur. These properties collectively contribute to the lack of suitable transition metal precursors available for use in ALD. In this thesis, we report the discovery of a series of novel transition metal diazadienate precursors that promising properties deemed suitable for ALD. The volatility and thermal stability of the new transition metal diazadienyl compounds were studied by preparative sublimation and capillary tube melting point/decomposition experiments. Thermogravimetric analyses (TGA) demonstrate precursor residues of less than 4% at 500 °C. In addition, sublimation data, melting points, and decomposition temperatures for all complexes are presented. The manganese diazadienyl complex has the highest decomposition temperature of the series of complexes produced (325 °C). During preparative sublimations, the product recoveries of all transition metal diazadienyl complexes were greater than 92.0% with nonvolatile residues of less than 7.0%. This is an excellent indication that these complexes may be suitable candidates as metal precursors for ALD. Nickel nitride (NixN) films have been studied as an intermediate material for the formation of both nickel metal and nickel silicide using chemical vapor deposition. Herein, we describe the ALD growth of nickel nitride thin films from bis(1,4-di-tert-butyl-1,3-diazabutadiene) nickel(II) (Ni(tBu2DAD)2) and 1,1-dimethylhydrazine. An ALD window for the deposition of nickel nitride films on 500 nm thermal SiO2 substrates was observed between 225 and 240 °C with a constant growth rate of 0.70 Å/cycle. X-Ray photoelectron spectroscopy (XPS) showed all expected ionizations with carbon concentrations below the detection limit after argon ion sputtering. Due to preferential nitrogen sputtering in XPS, Rutherford backscattering spectrometry (RBS) and nuclear reaction analysis (NRA) were performed and subsequently revealed Ni:N ratios between 2-4 for films deposited within the ALD window. AFM measurements revealed a RMS roughness value of 10.8 nm on an as-deposited film at 225°C. All as-deposited films were amorphous as determined by X-ray diffraction. Copper is the primary interconnect material in microelectronics devices, due to its high conductivity and low affinity towards electromigration. With transistor gate lengths scheduled to reach 14 nm by 2014, there are severe demands upon the current film growth techniques used in device fabrication. The ALD film growth method is ideally suited for future microelectronics manufacturing, since it inherently provides highly conformal thin films, even in high aspect ratio nanoscale features, and allows sub-nanometer control over film thicknesses. In Chapter 4, we describe the atomic layer deposition of high purity, low resistivity copper metal thin films using a three precursor sequence entailing Cu(dmap)2, formic acid, and hydrazine. In this process, Cu(dmap) 2 is unreactive towards hydrazine but is transformed to copper(II) formate, which is then readily reduced to copper metal by subsequent hydrazine exposure. The present work therefore addresses a central problem with the ALD growth of metal thin films: low reactivity of metal precursors toward common reducing agents. A constant growth rate of 0.47-0.50 Å/cycle upon prime grade Si(100) was observed at substrate temperatures between 100 and 170 °C. Compositional analyses (XPS and TOF-ERDA) revealed copper films with low levels of carbon, oxygen, nitrogen, and hydrogen. Powder X-ray diffraction spectra of all films showed polycrystalline copper. The resistivities of films grown between 100 and 140 °C ranged b

  2. Theoretical Modeling of Interstellar Chemistry

    NASA Technical Reports Server (NTRS)

    Charnley, Steven

    2009-01-01

    The chemistry of complex interstellar organic molecules will be described. Gas phase processes that may build large carbon-chain species in cold molecular clouds will be summarized. Catalytic reactions on grain surfaces can lead to a large variety of organic species, and models of molecule formation by atom additions to multiply-bonded molecules will be presented. The subsequent desorption of these mixed molecular ices can initiate a distinctive organic chemistry in hot molecular cores. The general ion-molecule pathways leading to even larger organics will be outlined. The predictions of this theory will be compared with observations to show how possible organic formation pathways in the interstellar medium may be constrained. In particular, the success of the theory in explaining trends in the known interstellar organics, in predicting recently-detected interstellar molecules, and, just as importantly, non-detections, will be discussed.

  3. Chemistry touches your life every day, from the air you breathe to the food you eat. The science of chemistry examines the atomic and

    E-print Network

    Miles, Will

    features to the chemical and physical properties of substances. Its practical applications are many, from and industrial work. A Distinctive Program The Stetson chemistry department is approved by the American Chemical in fields ranging from semiconductors to forensics. Academics and Research Independent research Each

  4. The role of NaCl in flame chemistry, in the deposition process, and in its reactions with protective oxides as related to hot corrosion

    NASA Technical Reports Server (NTRS)

    Kohl, F. J.; Stearns, C. A.

    1979-01-01

    Sodium chloride is believed to be the primary source of turbine engine contamination that contributes to hot corrosion. The behavior of NaCl-containing aerosols ingested with turbine intake air is very complex; some of the NaCl may vaporize during combustion while some may remain as particulates. The NaCl can lead to Na2SO4 formation by several possible routes or it can contribute to corrosion directly. Hydrogen or oxygen atom reaction with NaCl(c) was shown to result in the release of Na(g). Gaseous NaCl in flames can be partially converted to gaseous Na2SO4 by homogeneous reactions. The remaining gaseous NaCl and other Na-containing molecules can act as sodium carriers for condensate deposition of Na2SO4 on cool surfaces. A frozen boundary layer theory was developed to predict the rates of deposition. The condensed phase NaCl can be converted directly to condensed Na2SO4 by reaction with sulfur oxides and O2. Reaction of gaseous NaCl with Cr2O3 results in the vapor phase transport of chromium by the formation of complex Cr-containing gaseous molecules. Similar gaseous complexes are formed with molybdenum. The presence of gaseous NaCl was shown to affect the oxidation kinetics of Ni-Cr alloys. It also causes changes in the surface morphology of Al2O3 scales formed on Al-containing alloys.

  5. Atoms Chemistry review

    NSDL National Science Digital Library

    McKinnon

    2009-06-11

    See the videos we watched in class (or review for your next exam) here To play the review game we will do in class, click below then click on Periodic Table Review Eureeka home To watch videos Sodium Video Element song Element song Alkali metal video Brainiac metalsSchool Island ...

  6. Hot Sauce Hot Spots

    NSDL National Science Digital Library

    2012-06-26

    In this activity, learners model hot spot island formation, orientation and progression with condiments. Learners squirt a thick condiment sauce on a coarsely woven fabric to model how volcanic island hot spots form.

  7. Chemistry Activities

    NSDL National Science Digital Library

    This collection of resource features demonstrations, laboratory investigations, teaching tips, worksheets and other chemistry-related activities. Materials include investigations of mols, nuclear energy, the periodic table, weight and mass, elements, calculations, equations, pH, atomic weight, half-lives, and reactions.

  8. Chemistry on Stamps.

    ERIC Educational Resources Information Center

    Schreck, James O.

    1986-01-01

    Suggests how postage stamps can be incorporated into chemistry teaching. Categories considered include emergence of chemistry as a science, metric system, atoms (and molecules and ions), stoichiometry, energy relationships in chemical systems, chemical bonding, nuclear chemistry, biochemistry, geochemistry, matter (gases, liquids, and solids),…

  9. Rydberg Matter clusters of alkali metal atoms: the link between meteoritic matter, polar mesosphere summer echoes (PMSE), sporadic sodium layers, polar mesospheric clouds (PMCs, NLCs), and ion chemistry

    E-print Network

    Olofson, Frans; Holmlid, Leif

    2010-01-01

    A material exists which links together the influx of meteoritic matter from interplanetary space, the polar mesosphere summer echoes (PMSE), the sporadic sodium layers, the polar mesospheric clouds (PMCs, NLCs), and the observed ion chemistry in the mesosphere. The evidence in these research fields is here analyzed and found to agree well with the properties of Rydberg Matter (RM). This material has been studied with numerous methods in the laboratory. Alkali atoms, mainly Na, reach the mesosphere in the form of interplanetary (meteoritic, cometary) dust. The planar RM clusters NaN usually contain N = 19, 37 or 61 atoms, and have the density of air at 90 km altitude where they float. The diameters of the clusters are 10-100 nm from laboratory high precision radio frequency spectroscopic studies. Such experiments show that RM clusters interact strongly with radar frequencies: this explains the radio frequency heating and reflection studies of PMSE layers. The clusters give the low temperature in the mesosphere...

  10. Use of a CO{sub 2} pellet non-destructive cleaning system to decontaminate radiological waste and equipment in shielded hot cells at the Bettis Atomic Power Laboratory

    SciTech Connect

    Bench, T.R.

    1997-05-01

    This paper details how the Bettis Atomic Power Laboratory modified and utilized a commercially available, solid carbon dioxide (CO{sub 2}) pellet, non-destructive cleaning system to support the disposition and disposal of radioactive waste from shielded hot cells. Some waste materials and equipment accumulated in the shielded hot cells cannot be disposed directly because they are contaminated with transuranic materials (elements with atomic numbers greater than that of uranium) above waste disposal site regulatory limits. A commercially available CO{sub 2} pellet non-destructive cleaning system was extensively modified for remote operation inside a shielded hot cell to remove the transuranic contaminants from the waste and equipment without generating any secondary waste in the process. The removed transuranic contaminants are simultaneously captured, consolidated, and retained for later disposal at a transuranic waste facility.

  11. Pressure and electrical resistivity measurements on hot expanded nickel: comparisons with quantum molecular dynamics simulations and average atom approaches

    Microsoft Academic Search

    Jean Clerouin; Charles Starrett; Gerald Faussurier; Christophe Blancard; Pierre Noiret; Patrick Renaudin

    2010-01-01

    We present experimental results on pressure and resistivity on expanded nickel at low density (0.1,\\/cm^3) and high temperature (1-3,V). These data, corresponding to the warm dense matter (WDM) regime, are used to benchmark different theoretical approaches. A comparison is presented between fully 3-dimensional quantum molecular dynamics (QMD) methods, based on density functional theory, with average atom (AA) methods, that are

  12. Pressure and electrical resistivity measurements on hot expanded nickel: Comparisons with quantum molecular dynamics simulations and average atom approaches

    Microsoft Academic Search

    Jean Clérouin; Charles Starrett; Gérald Faussurier; Christophe Blancard; Pierre Noiret; Patrick Renaudin

    2010-01-01

    We present experimental results on pressure and resistivity on expanded nickel at a density of 0.1g\\/cm3 and temperature of a few eV. These data, corresponding to the warm dense matter regime, are used to benchmark different theoretical approaches. A comparison is presented between fully three-dimensional quantum molecular dynamics (QMD) methods, based on density functional theory, with average atom methods, that

  13. Deuterium chemistry of dense gas in the vicinity of low-mass and massive star-forming regions

    NASA Astrophysics Data System (ADS)

    Awad, Zainab; Viti, Serena; Bayet, Estelle; Caselli, Paola

    2014-09-01

    The standard interstellar ratio of deuterium to hydrogen (D/H) atoms is ˜1.5 × 10-5. However, the deuterium fractionation is in fact found to be enhanced, to different degrees, in cold, dark cores, hot cores around massive star-forming regions, lukewarm cores, and warm cores (hereafter hot corinos) around low-mass star-forming regions. In this paper, we investigate the overall differences in the deuterium chemistry between hot cores and hot corinos. We have modelled the chemistry of dense gas around low-mass and massive star-forming regions using a gas-grain chemical model. We investigate the influence of varying the core density, the depletion efficiency of gaseous species on to dust grains, the collapse mode and the final mass of the protostar on the chemical evolution of star-forming regions. We find that the deuterium chemistry is, in general, most sensitive to variations of the depletion efficiency on to grain surfaces, in agreement with observations. In addition, the results showed that the chemistry is more sensitive to changes in the final density of the collapsing core in hot cores than in hot corinos. Finally, we find that ratios of deuterated sulphur bearing species in dense gas around hot cores and corinos may be good evolutionary indicators in a similar way as their non-deuterated counterparts.

  14. The role of organic haze in Titan's atmospheric chemistry. I. Laboratory investigation on heterogeneous reaction of atomic hydrogen with Titan tholin

    NASA Astrophysics Data System (ADS)

    Sekine, Yasuhito; Imanaka, Hiroshi; Matsui, Takafumi; Khare, Bishun N.; Bakes, Emma L. O.; McKay, Christopher P.; Sugita, Seiji

    2008-03-01

    In Titan's atmosphere consisting of N 2 and CH 4, large amounts of atomic hydrogen are produced by photochemical reactions during the formation of complex organics. This atomic hydrogen may undergo heterogeneous reactions with organic aerosol in the stratosphere and mesosphere of Titan. In order to investigate both the mechanisms and kinetics of the heterogeneous reactions, atomic deuterium is irradiated onto Titan tholin formed from N 2 and CH 4 gas mixtures at various surface-temperatures of the tholin ranging from 160 to 310 K. The combined analyses of the gas species and the exposed tholin indicate that the interaction mechanisms of atomic deuterium with the tholin are composed of three reactions; (a) abstraction of hydrogen from tholin resulting in gaseous HD formation (HD recombination), (b) addition of D atom into tholin (hydrogenation), and (c) removal of carbon and/or nitrogen (chemical erosion). The reaction probabilities of HD recombination and hydrogenation are obtained as ?=1.9(±0.6)×10×exp(-300/T) and ?=2.08(±0.64)×exp(-1000/T), respectively. The chemical erosion process is very inefficient under the conditions of temperature range of Titan's stratosphere and mesosphere. Under Titan conditions, the rates of hydrogenation > HD recombination ? chemical erosion. Our measured HD recombination rate is about 10 times (with an uncertainty of a factor of 3-5) the prediction of previous theoretical model. These results imply that organic aerosol can remove atomic hydrogen efficiently from Titan's atmosphere through the heterogeneous reactions and that the presence of aerosol may affect the subsequent organic chemistry.

  15. Partial characterization of a novel amphibian hemoglobin as a model for graduate student investigation on peptide chemistry, mass spectrometry, and atomic force microscopy.

    PubMed

    Bemquerer, Marcelo P; Macedo, Jéssica K A; Ribeiro, Ana Carolina J; Carvalho, Andréa C; Silva, Débora O C; Braz, Juliana M; Medeiros, Kelliane A; Sallet, Lunalva A P; Campos, Pollyanna F; Prates, Maura V; Silva, Luciano P

    2012-01-01

    Graduate students in chemistry, and in biological and biomedical fields must learn the fundamentals and practices of peptide and protein chemistry as early as possible. A project-oriented approach was conducted by first-year M.Sc and Ph.D students in biological sciences. A blind glass slide containing a cellular smear and an aqueous cellular extract were offered to the students. Qualitative and quantitative cell morphological parameters were analyzed by atomic force microscopy. The fractionation of the aqueous extract was conducted by reversed-phase chromatography followed by analysis of the isolated and partially purified proteins and peptides by mass spectrometry (MS). The proteins were treated by peptidases and the obtained peptide fragments were sequenced by de novo MS/MS, together with peptides already present in the extract. The most abundant protein fractions were identified as the alpha and beta chains of hemoglobin from an amphibian of the Leptodactylus genera. Two of the peptides sequenced by the students were synthesized by the solid-phase methodology, one of those being obtained by the split-and-pool library synthesis method. Thus, the students were able to learn some advanced principles and practices of protein chemistry and bionanotechnology in a 6-weeks project-oriented approach. PMID:22419593

  16. Average atom transport properties for pure and mixed species in the hot and warm dense matter regimes

    SciTech Connect

    Starrett, C. E.; Kress, J. D.; Collins, L. A.; Hanson, D. E. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87545 (United States); Clerouin, J. [CEA, DAM, DIF, 91297 Arpajon Cedex (France); Recoules, V. [CEA, DAM, DIF, 91297 Arpajon Cedex (France); LUTH UMR8102, Observatoire de Paris, CNRS, Universite Paris Diderot, 92195 Meudon (France)

    2012-10-15

    The Kubo-Greenwood formulation for calculation of optical conductivities with an average atom model is extended to calculate thermal conductivities. The method is applied to species and conditions of interest for inertial confinement fusion. For the mixed species studied, the partial pressure mixing rule is used. Results including pressures, dc, and thermal conductivities are compared to ab initio calculations. Agreement for pressures is good, for both the pure and mixed species. For conductivities, it is found that the ad hoc renormalization method with line broadening, described in the text, gives best agreement with the ab initio results. However, some disagreement is found and the possible reasons for this are discussed.

  17. CHEMISTRY IN EVAPORATING ICES-UNEXPLORED TERRITORY

    SciTech Connect

    Cecchi-Pestellini, Cesare [INAF-Osservatorio Astronomico di Cagliari, Strada n.54, Loc. Poggio dei Pini, 09012 Capoterra (Italy); Rawlings, Jonathan M. C.; Viti, Serena; Williams, David A., E-mail: ccp@ca.astro.i, E-mail: jcr@star.ucl.ac.u, E-mail: sv@star.ucl.ac.u, E-mail: daw@star.ucl.ac.u [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom)

    2010-12-20

    We suggest that three-body chemistry may occur in warm high-density gas evaporating in transient co-desorption events on interstellar ices. Using a highly idealized computational model we explore the chemical conversion from simple species of the ice to more complex species containing several heavy atoms, as a function of density and of adopted three-body rate coefficients. We predict that there is a wide range of densities and rate coefficients in which a significant chemical conversion may occur. We discuss the implications of this idea for the astrochemistry of hot cores.

  18. Nobody Can See Atoms: Science Camps Highlighting Approaches for Making Chemistry Accessible to Blind and Visually Impaired Students

    ERIC Educational Resources Information Center

    Wedler, Henry B.; Boyes, Lee; Davis, Rebecca L.; Flynn, Dan; Franz, Annaliese; Hamann, Christian S.; Harrison, Jason G.; Lodewyk, Michael W.; Milinkevich, Kristin A.; Shaw, Jared T.; Tantillo, Dean J.; Wang, Selina C.

    2014-01-01

    Curricula for three chemistry camp experiences for blind and visually impaired (BVI) individuals that incorporated single- and multiday activities and experiments accessible to BVI students are described. Feedback on the camps from students, mentors, and instructors indicates that these events allowed BVI students, who in many cases have been…

  19. Dressed states of the high-frequency Floquet theory for atoms and molecules with standard computational quantum chemistry programs

    Microsoft Academic Search

    C. Pérez del Valle; R. Lefebvre; O. Atabek

    1997-01-01

    The multipole expansion of the electron - nucleus interaction in the so-called high-frequency limit of the Floquet theory in the Kramers - Henneberger frame is used to determine equivalent point-charge distributions. This allows the use of standard quantum chemistry programs to calculate the energies. It is found that satisfactory results can be obtained with a quadrupole approximation if the parameter

  20. Pressure and electrical resistivity measurements on hot expanded nickel: Comparisons with quantum molecular dynamics simulations and average atom approaches

    SciTech Connect

    Clerouin, Jean; Starrett, Charles; Faussurier, Gerald; Blancard, Christophe; Noiret, Pierre; Renaudin, Patrick [CEA-DAM-DIF, Bruyeres Le Chatel, 91297 Arpajon Cedex (France)

    2010-10-15

    We present experimental results on pressure and resistivity on expanded nickel at a density of 0.1 g/cm{sup 3} and temperature of a few eV. These data, corresponding to the warm dense matter regime, are used to benchmark different theoretical approaches. A comparison is presented between fully three-dimensional quantum molecular dynamics (QMD) methods, based on density functional theory, with average atom methods, that are essentially one dimensional. In this regime the evaluation of the thermodynamic properties as well as electrical properties is difficult due to the concurrence of density and thermal effects which directly drive the metal-nonmetal transition. Experimental pressures and resistivities are given in a tabular form with temperatures deduced from QMD simulations.

  1. CHEMISTRY 1220 General Chemistry II Syllabus Course Description

    E-print Network

    Simons, Jack

    ourselves. Instructors Dr. Charles H. Atwood MWF 11:50 AM ­ 12:40 PM Classroom HEB 2008 North Henry Eyring Henry Eyring Chemistry Building, Rm. 1011 (801) 581-7288 Textbooks Required: CHEMISTRY AN ATOMS FIRST

  2. The Origin of Carbon-bearing Volatiles in Surprise Valley Hot Springs in the Great Basin: Carbon Isotope and Water Chemistry Characterizations

    NASA Astrophysics Data System (ADS)

    Fu, Q.; Socki, R.; Niles, P. B.; Romanek, C. S.; Datta, S.; Darnell, M.; Bissada, A. K.

    2013-12-01

    There are numerous hydrothermal fields within the Great Basin of North America, some of which have been exploited for geothermal resources. With methane and other carbon-bearing compounds being observed, however, their origins and formation conditions remain unknown. Thus, studying hydrothermal springs in this area provides us an opportunity to understand subsurface (bio)chemical processes that generate organic compounds, and aid in future development and exploration of potential energy resources as well. While isotope measurement has long been used for identification of their origins, there are secondary processes that may generate variations in isotopic compositions: oxidation, re-equilibration of methane and other alkanes with CO2, mixing with compounds of other sources, etc. Therefore, in addition to isotopic analysis, other lines of evidence, including water chemistry and rock compositions, are necessary to identify origins of volatile compounds. Surprise Valley Hot Springs (SVHS, 41°32'N, 120°5'W), located in a typical basin and range province in northeastern California, is a terrestrial hydrothermal spring system of the Great Basin. Previous geophysical studies indicated the presence of clay-rich volcanic and sedimentary rocks of Tertiary age beneath the lava flows during late Tertiary and Quaternary. Water and gas samples were collected for a variety of chemical and isotope composition analyses, including in-situ pH, alkalinity, oxidation reduction potential (ORP), major and trace elements, and C and H isotope measurements. Fluids issuing from SVHS can be classified as Na-(Cl)-SO4 type, with the major cation and anion being Na+ and SO42-, respectively. Thermodynamic calculation using ORP and major element data indicated that sulfate is the most dominant sulfur species, which is consistent with anion analysis results. Aquifer temperatures at depth estimated by both dissolved SiO2 and Na-K-Ca geothermometers are in the range of 125.0 to 135.4 °C, and higher than the values measured at orifices (77.3 to 90.0 °C). CO2 and homologs of straight chain alkanes (C1-C5) were identified in gas samples. Carbon isotope values of alkanes increase with carbon numbers. The 13C fractionation between CO2 and dissolved inorganic carbon suggests they are out of carbon isotope equilibrium. The hypothesis regarding the formation of carbon-bearing compounds in SVHS may involve two processes: 1) Under high heat flow conditions caused by regional faulting and crustal extension, original high molecular weight organic compounds (kerogens) in clay-rich rocks decomposed to generate methane and other alkanes. 2) The SVHS area is associated with outflow structures, and distant from the heat source. Anaerobic oxidation of methane with sulfate at shallow depth (< 90 °C) is suggested as being responsible for the generation of CO2 in SVHS.

  3. The Origin of Carbon-bearing Volatiles in Surprise Valley Hot Springs in the Great Basin: Carbon Isotope aud Water Chemistry Characterizations

    NASA Technical Reports Server (NTRS)

    Fu, Qi; Socki, Richard A.; Niles, Paul B.; Romanek, Christopher; Datta, Saugata; Darnell, Mike; Bissada, Adry K.

    2013-01-01

    There are numerous hydrothermal fields within the Great Basin of North America, some of which have been exploited for geothermal resources. With methane and other carbon-bearing compounds being observed, in some cases with high concentrations, however, their origins and formation conditions remain unknown. Thus, studying hydrothermal springs in this area provides us an opportunity to expand our knowledge of subsurface (bio)chemical processes that generate organic compounds in hydrothermal systems, and aid in future development and exploration of potential energy resources as well. While isotope measurement has long been used for recognition of their origins, there are several secondary processes that may generate variations in isotopic compositions: oxidation, re-equilibration of methane and other alkanes with CO2, mixing with compounds of other sources, etc. Therefore, in addition to isotopic analysis, other evidence, including water chemistry and rock compositions, are necessary to identify volatile compounds of different sources. Surprise Valley Hot Springs (SVHS, 41º32'N, 120º5'W), located in a typical basin and range province valley in northeastern California, is a terrestrial hydrothermal spring system of the Great Basin. Previous geophysical studies indicated the presence of clay-rich volcanic and sedimentary rocks of Tertiary age beneath the lava flows in late Tertiary and Quaternary. Water and gas samples were collected for a variety of chemical and isotope composition analyses, including in-situ pH, alkalinity, conductivity, oxidation reduction potential (ORP), major and trace elements, and C and H isotope measurements. Fluids issuing from SVHS can be classified as Na-(Cl)-SO4 type, with the major cation and anion being Na+ and SO4 2-, respectively. Thermodynamic calculation using ORP and major element data indicated that sulfate is the most dominant sulfur species, which is consistent with anion analysis results. Aquifer temperatures at depth estimated by both dissolved SiO2 and Na-K-Ca geothermometers are in the range of 125.0 to 135.4 oC, and higher than the values measured at orifices (77.3 to 90.0 oC). CO2 and homologs of straight chain alkanes (C1-C5) were identified in gas samples. Carbon isotope values of alkanes increase with carbon numbers. The 13C fractionation between CO2 and dissolved inorganic carbon suggests they are out of carbon isotope equilibrium. The hypothesis regarding the formation of carbon-bearing compounds in SVHS may involve two processes: 1) Under high heat flow conditions which are caused by regional faulting and crustal extension, original high molecular weight organic compounds (kerogens) in clay-rich rocks decomposed to generate methane and other alkane homologs. 2) The SVHS area is associated with outflow structures, and distant from the heat source. Anaerobic oxidation of methane (AOM) with sulfate at shallow depth (< 90 oC) is suggested as being responsible for the generation of CO2 in SVHS.

  4. The Origin of Carbon-bearing Volatiles in Surprise Valley Hot Springs in the Great Basin: Carbon Isotope and Water Chemistry Characterizations

    NASA Technical Reports Server (NTRS)

    Fu, Qi; Socki, Richard A.; Niles, Paul B.; Romanek, Christopher; Datta, Saugata; Darnell, Mike; Bissada, Adry K.

    2013-01-01

    There are numerous hydrothermal fields within the Great Basin of North America, some of which have been exploited for geothermal resources. With methane and other carbon-bearing compounds being observed, in some cases with high concentrations, however, their origins and formation conditions remain unknown. Thus, studying hydrothermal springs in this area provides us an opportunity to expand our knowledge of subsurface (bio)chemical processes that generate organic compounds in hydrothermal systems, and aid in future development and exploration of potential energy resources as well. While isotope measurement has long been used for recognition of their origins, there are several secondary processes that may generate variations in isotopic compositions: oxidation, re-equilibration of methane and other alkanes with CO2, mixing with compounds of other sources, etc. Therefore, in addition to isotopic analysis, other evidence, including water chemistry and rock compositions, are necessary to identify volatile compounds of different sources. Surprise Valley Hot Springs (SVHS, 41 deg 32'N, 120 deg 5'W), located in a typical basin and range province valley in northeastern California, is a terrestrial hydrothermal spring system of the Great Basin. Previous geophysical studies indicated the presence of clay-rich volcanic and sedimentary rocks of Tertiary age beneath the lava flows in late Tertiary and Quaternary. Water and gas samples were collected for a variety of chemical and isotope composition analyses, including in-situ pH, alkalinity, conductivity, oxidation reduction potential (ORP), major and trace elements, and C and H isotope measurements. Fluids issuing from SVHS can be classified as Na-(Cl)-SO4 type, with the major cation and anion being Na+ and SO4(2-), respectively. Thermodynamic calculation using ORP and major element data indicated that sulfate is the most dominant sulfur species, which is consistent with anion analysis results. Aquifer temperatures at depth estimated by both dissolved SiO2 and Na-K-Ca geothermometers are in the range of 125.0 to 135.4 C, and higher than the values measured at orifices (77.3 to 90.0 C). CO2 and homologs of straight chain alkanes (C1-C5) were identified in gas samples. Carbon isotope values of alkanes increase with carbon numbers. The C-13 fractionation between CO2 and dissolved inorganic carbon suggests they are out of carbon isotope equilibrium. The hypothesis regarding the formation of carbon-bearing compounds in SVHS may involve two processes: 1) Under high heat flow conditions which are caused by regional faulting and crustal extension, original high molecular weight organic compounds (kerogens) in clay-rich rocks decomposed to generate methane and other alkane homologs. 2) The SVHS area is associated with outflow structures, and distant from the heat source. Anaerobic oxidation of methane (AOM) with sulfate at shallow depth (< 90 C) is suggested as being responsible for the generation of CO2 in SVHS.

  5. Three-photon resonance ionization of atomic Mn in a hot-cavity laser ion source using Ti:sapphire lasers

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Gottwald, T.; Mattolat, C.; Wendt, K.

    2015-06-01

    Three-photon resonance ionization of atomic manganese (Mn) in a hot-cavity ion source using Ti:sapphire lasers has been demonstrated. Three-step ionization schemes employing different intermediate levels and Rydberg or autoionizing (AI) states in the final ionization step are established. Strong AI resonances were observed via the 3d54s5s f 6S5/2 level at 49 415.35 cm?1, while Rydberg transitions were reached from the 3d54s4d e 6D9/2,7/2,5/2 levels at around 47 210 cm?1. Analyses of the strong Rydberg transitions associated with the 3d54s4d e 6D7/2 lower level indicate that they belong to the dipole-allowed 4d ? nf 6F°9/2,7/2,5/2 series converging to the 3d54s 7S3 ground state of Mn II. From this series, an ionization potential of 59 959.56 ± 0.01 cm?1 is obtained for Mn. At high ion source temperatures the semi-forbidden 4d ? nf 8F°9/2,7/2,5/2 series was also observed. The overall ionization efficiency for Mn has been measured to be about 0.9% when using the strong AI transition in the third excitation step and 0.3% when employing an intense Rydberg transition. Experimental data indicate that the ionization efficiency was limited by the interaction of Mn atoms with ion source materials at high temperatures.

  6. Multi-Walled Carbon Nanotube (MWCNT) Dispersion and Aerosolization with Hot Water Atomization without Addition of Any Surfactant

    PubMed Central

    Kim, Sun-Man

    2011-01-01

    Objectives Carbon nanotubes are an important new class of technological materials that have numerous novel and useful properties. Multi-walled carbon nanotubes (MWCNTs), which is a nanomaterial, is now in mass production because of its excellent mechanical and electrical properties. Although MWCNTs appear to have great industrial and medical potential, there is little information regarding their toxicological effects on researchers and workers who could be exposed to them by inhalation during the handling of MWCNTs. Methods The generation of an untangled MWCNT aerosol with a consistent concentration without using surfactants that was designed to be tested in in vivo inhalation toxicity testing was attempted. To do this, MWCNTs were dispersed in deionized water without the addition of any surfactant. To facilitate the dispersion of MWCNTs in deionized water, the water was heated to 40?, 60?, and 80? depending on the sample with ultrasonic sonication. Then the dispersed MWCNTs were atomized to generate the MWCNT aerosol. After aerosolization of the MWCNTs, the shapes of the NTs were examined by transmission electron microscopy. Results The aerosolized MWCNTs exhibited an untangled shape and the MWCNT generation rate was about 50 mg/m3. Conclusion Our method provided sufficient concentration and dispersion of MWNCTs to be used for inhalation toxicity testing. PMID:22953189

  7. Zen Hot Dog Molecules

    NASA Astrophysics Data System (ADS)

    Ryan, Dennis

    2009-04-01

    Substituted cycloalkanes with one branch illustrating each topic in an instructional unit can serve as summaries or reviews in courses of organic chemistry. The hungry Zen master told the hot dog vendor to make him one with everything. You can do the same for your students.

  8. Zen Hot Dog Molecules

    ERIC Educational Resources Information Center

    Ryan, Dennis

    2009-01-01

    Substituted cycloalkanes with one branch illustrating each topic in an instructional unit can serve as summaries or reviews in courses of organic chemistry. The hungry Zen master told the hot dog vendor to make him one with everything. You can do the same for your students.

  9. Hot Science: Hot rocks

    NSDL National Science Digital Library

    This site explores two kinds of igneous rock, pumice and granite. Pumice is an example of extrusive igneous rock, while granite is an example of intrusive igneous rock. Intrusive indicates that the magma was forced close to the surface, but then cooled more slowly underneath the surface. The question, "How hot is Lava?" is linked to an explanation of the heat of lava, why it must be sampled when it is very hot, and how the samples are taken.

  10. Learning about Atoms, Molecules, and Chemical Bonds: A Case Study of Multiple-Model Use in Grade 11 Chemistry.

    ERIC Educational Resources Information Center

    Harrison, Allan G.; Treagust, David F.

    2000-01-01

    Reports in detail on a year-long case study of multiple-model use at grade 11. Suggests that students who socially negotiated the shared and unshared attributes of common analogical models for atoms, molecules, and chemical bonds used these models more consistently in their explanations. (Author/CCM)

  11. How Many Atomic Layers of Zinc Are in a Galvanized Iron Coating? An Experiment for General Chemistry Laboratory

    ERIC Educational Resources Information Center

    Yang, Shui-Ping

    2007-01-01

    This article describes an experiment using a novel gasometric assembly to determine the thickness and number of atomic layers of zinc coating on galvanized iron substrates. Students solved this problem through three stages. In the first stage, students were encouraged to find a suitable acidic concentration through the guided-inquiry approach. In…

  12. Multiply-charged ions and interstellar chemistry.

    PubMed

    Böhme, Diethard Kurt

    2011-11-01

    Gaseous molecules and ions, and even dust grains, can accumulate charge in the interstellar medium (ISM) by harvesting the energy of UV photons, cosmic rays, helium ions and metastable atoms. This Perspective views the various modes of gas-phase formation of multiply-charged cations and the possible impact of their reactions on the chemical and ionization structure of the ISM, in the light of what is still very limited knowledge. Emphasis is given to gas-phase reactions of multiply-charged cations with atoms, molecules and electrons that lead to charge reduction, charge separation and chemical bond formation and these are examined for multiply-charged atoms, small molecules, hydrocarbons, polycyclic aromatic hydrocarbons and fullerenes, primarily as dications but also as a function of charge state. The increased electrostatic interaction due to multiple charge is seen to promote bonding to individual charge sites on large molecules (e.g. fullerenes) and allow ensuing "surface" chemistry under the influence of Coulomb repulsion. The unique ability of multiply charged cations to undergo charge separation reactions, either unimolecular or bimolecular, can feature in the production in the ISM of internally cold, but translationally hot, cations of lower charge state or hot atoms that may provide the driving force for subsequent chemical reactions in what is otherwise an ultracold environment. Available chemical kinetic models that account for the role of multiply-charged ions in the ISM are few and of limited scope and the observation of these ions in the ISM has remained elusive. PMID:21869973

  13. Chemistry 321 Organic Chemistry

    E-print Network

    Wagner, Diane

    Chemistry 321 Organic Chemistry Fall 2010 MWF 1:00-2:00 Reichardt Bldg 202 Instructor: Thomas Dept.) Office Hours: By appointment Required Materials: Organic Chemistry 7th Ed., J. McMurry, Brooks/Cole OWL card RF classroom clicker Recommended: Study Guide & Solutions Manual for Org Chemistry HGS

  14. CHEMISTRY 11500 General Chemistry

    E-print Network

    Jiang, Wen

    CHEMISTRY 11500 General Chemistry Spring 2014 Professor Dr. John J. Nash; BRWN 4103C; phone: 494.edu (Lab) Required Course Materials Chemistry: The Molecular Nature of Matter and Change, 6th Ed., by M. S. Silberberg, McGraw-Hill, 2012. Chemistry 11500 Laboratory Manual, 2013-2014, Hayden-McNeil Publishing, Inc

  15. Oxygen-atom transfer chemistry and thermolytic properties of a di-tert-butylphosphate-ligated Mn4O4 cubane.

    PubMed

    Van Allsburg, Kurt M; Anzenberg, Eitan; Drisdell, Walter S; Yano, Junko; Tilley, T Don

    2015-03-16

    [Mn4O4{O2P(OtBu)2}6] (1), an Mn4O4 cubane complex combining the structural inspiration of the photosystem II oxygen-evolving complex with thermolytic precursor ligands, was synthesized and fully characterized. Core oxygen atoms within complex 1 are transferred upon reaction with an oxygen-atom acceptor (PEt3), to give the butterfly complex [Mn4O2{O2P(OtBu)2}6(OPEt3)2]. The cubane structure is restored by reaction of the latter complex with the O-atom donor PhIO. Complex 1 was investigated as a precursor to inorganic Mn metaphosphate/pyrophosphate materials, which were studied by X-ray absorption spectroscopy to determine the fate of the Mn4O4 unit. Under the conditions employed, thermolyses of 1 result in reduction of the manganese to Mn(II) species. Finally, the related butterfly complex [Mn4O2{O2P(pin)}6(bpy)2] (pin = pinacolate) is described. PMID:25676196

  16. Atmospheric chemistry of t-CF3CH=CHCl: products and mechanisms of the gas-phase reactions with chlorine atoms and hydroxyl radicals.

    PubMed

    Andersen, M P Sulbaek; Nielsen, O J; Hurley, M D; Wallington, T J

    2012-02-01

    FTIR-smog chamber techniques were used to study the products and mechanisms of the Cl atom and OH radical initiated oxidation of trans-3,3,3-trifluoro-1-chloro-propene, t-CF(3)CH=CHCl, in 700 Torr of air or N(2)/O(2) diluent at 296 ± 2 K. The reactions of Cl atoms and OH radicals with t-CF(3)CH=CHCl occur via addition to the >C=C< double bond; chlorine atoms add 15 ± 5% at the terminal carbon and 85 ± 5% at the central carbon, OH radicals add approximately 40% at the terminal carbon and 60% at the central carbon. The major products in the Cl atom initiated oxidation of t-CF(3)CH=CHCl were CF(3)CHClCHO and CF(3)C(O)CHCl(2), minor products were CF(3)CHO, HCOCl and CF(3)COCl. The yields of CF(3)C(O)CHCl(2), CF(3)CHClCOCl and CF(3)COCl increased at the expense of CF(3)CHO, HCOCl and CF(3)CHClCHO as the O(2) partial pressure was increased over the range 10-700 Torr. Chemical activation plays a significant role in the fate of CF(3)CH(O)CHCl(2) and CF(3)CClHCHClO radicals. In addition to reaction with O(2) to yield CF(3)COCl and HO(2) the major competing fate of CF(3)CHClO is Cl elimination to give CF(3)CHO (not C-C bond scission as previously thought). As part of this study k(Cl + CF(3)C(O)CHCl(2)) = (2.3 ± 0.3) × 10(-14) and k(Cl + CF(3)CHClCHO) = (7.5 ± 2.0) × 10(-12) cm(3) molecule(-1) s(-1) were determined using relative rate techniques. Reaction with OH radicals is the major atmospheric sink for t-CF(3)CH=CHCl. Chlorine atom elimination giving the enol CF(3)CH=CHOH appears to be the sole atmospheric fate of the CF(3)CHCHClOH radicals. The yield of CF(3)COOH in the atmospheric oxidation of t-CF(3)CH=CHCl will be negligible (<2%). The results are discussed with respect to the atmospheric chemistry and environmental impact of t-CF(3)CH=CHCl. PMID:22187719

  17. Department of Chemistry & Biochemistry UCLA Chemistry, Biochemistry & Chemistry Material Science

    E-print Network

    Levine, Alex J.

    ..............................................................................................................................................................11 Physical Chemistry ConcentrationDepartment of Chemistry & Biochemistry UCLA Chemistry, Biochemistry & Chemistry Material Science ...........................................................................................................................................4 Chemistry & Biochemistry Undergraduate Office

  18. Chemistry for Fuel Cells

    NSDL National Science Digital Library

    This presentation provides a basic introduction to the chemistry involved with fuel cell technology. The material covers chemical bonds, some basic atomic properties, the Noble Gas Theory and how the chemistry of fuel cells works.This document may be downloaded in Microsoft PowerPoint file format.

  19. Chemistry at corners and edges: Generation and adsorption of H atoms on the surface of MgO nanocubes

    SciTech Connect

    Sterrer, Martin; Berger, Thomas; Diwald, Oliver; Knoezinger, Erich; Sushko, Peter V.; Shluger, Alexander L. [Department of Chemical Physics, Fritz-Haber-Institute of the Max-Planck-Society, Faradayweg 4-6, D-14195 Berlin (Germany); Institute of Materials Chemistry, Vienna University of Technology, Veterinaerplatz 1/GA, A-1210 Vienna (Austria); Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom)

    2005-08-08

    We used UV light to generate site-selective O{sup -} hole centers at three-coordinated corner oxygen sites on MgO nanocubes. These highly reactive O{sup -} radicals split H{sub 2} homolytically and, in the course of this reaction, become hydroxylated and produce hydrogen atoms. The hydrogen atoms adsorb predominantly at cube edges and dissociate into surface-trapped electrons and protons. We propose that the experimentally observed (H{sup +})(e{sup -}) centers are formed adjacent to the hydroxyl groups generated in the homolytic splitting process and can be defined as (H{sup +}){sub 3C}{center_dot}{center_dot}{center_dot}(e{sup -})(H{sup +}){sub NC} centers where 3C and NC refer to the coordination numbers of the corresponding hydroxylated oxygen sites. Our ab initio embedded cluster calculations reveal that the electronic properties of (H{sup +}){sub 3C}{center_dot}{center_dot}{center_dot}(e{sup -})(H{sup +}){sub 4C} centers situated along MgO nanocube edges are consistent with both the electron-paramagnetic-resonance signal parameters and the reported optical-absorption properties. The transformation of corner O{sup -} centers into the (H{sup +}){sub 3C}{center_dot}{center_dot}{center_dot}(e{sup -})(H{sup +}){sub NC}-type centers prevents their recombination with electronic surface centers and, hence, significantly alters the electronic structure of MgO nanocubes by introducing shallow electron traps.

  20. Hot spacetimes for cold atoms

    Microsoft Academic Search

    Allan Adams; Koushik Balasubramanian; John McGreevy

    2008-01-01

    Building on our earlier work and that of Son, we construct string theory duals of non-relativistic critical phenomena at finite temperature and density. Concretely, we find black hole solutions of type IIB supergravity whose asymptotic geometries realize the Schrödinger group as isometries. We then identify the non-relativistic conformal field theories to which they are dual. We analyze the thermodynamics of

  1. A Coupled Chemistry-emission Model for Atomic Oxygen Green and Red-doublet Emissions in the Comet C/1996 B2 Hyakutake

    NASA Astrophysics Data System (ADS)

    Bhardwaj, Anil; Raghuram, Susarla

    2012-03-01

    The green (5577 Å) and red-doublet (6300, 6364 Å) lines are prompt emissions of metastable oxygen atoms in the 1 S and 1 D states, respectively, that have been observed in several comets. The value of the intensity ratio of green to red-doublet (G/R ratio) of 0.1 has been used as a benchmark to identify the parent molecule of oxygen lines as H2O. A coupled chemistry-emission model is developed to study the production and loss mechanisms of the O(1 S) and O(1 D) atoms and the generation of red and green lines in the coma of C/1996 B2 Hyakutake. The G/R ratio depends not only on photochemistry, but also on the projected area observed for cometary coma, which is a function of the dimension of the slit used and the geocentric distance of the comet. Calculations show that the contribution of photodissociation of H2O to the green (red) line emission is 30%-70% (60%-90%), while CO2 and CO are the next potential sources contributing 25%-50% (<5%). The ratio of the photoproduction rate of O(1 S) to O(1 D) would be around 0.03 (±0.01) if H2O is the main source of oxygen lines, whereas it is ~0.6 if the parent is CO2. Our calculations suggest that the yield of O(1 S) production in the photodissociation of H2O cannot be larger than 1%. The model-calculated radial brightness profiles of the red and green lines and G/R ratios are in good agreement with the observations made on the comet Hyakutake in 1996 March.

  2. A COUPLED CHEMISTRY-EMISSION MODEL FOR ATOMIC OXYGEN GREEN AND RED-DOUBLET EMISSIONS IN THE COMET C/1996 B2 HYAKUTAKE

    SciTech Connect

    Bhardwaj, Anil; Raghuram, Susarla, E-mail: bhardwaj_spl@yahoo.com, E-mail: anil_bhardwaj@vssc.gov.in, E-mail: raghuramsusarla@gmail.com [Space Physics Laboratory, Vikram Sarabhai Space Centre, Trivandrum 695022 (India)

    2012-03-20

    The green (5577 Angstrom-Sign ) and red-doublet (6300, 6364 Angstrom-Sign ) lines are prompt emissions of metastable oxygen atoms in the {sup 1}S and {sup 1}D states, respectively, that have been observed in several comets. The value of the intensity ratio of green to red-doublet (G/R ratio) of 0.1 has been used as a benchmark to identify the parent molecule of oxygen lines as H{sub 2}O. A coupled chemistry-emission model is developed to study the production and loss mechanisms of the O({sup 1}S) and O({sup 1}D) atoms and the generation of red and green lines in the coma of C/1996 B2 Hyakutake. The G/R ratio depends not only on photochemistry, but also on the projected area observed for cometary coma, which is a function of the dimension of the slit used and the geocentric distance of the comet. Calculations show that the contribution of photodissociation of H{sub 2}O to the green (red) line emission is 30%-70% (60%-90%), while CO{sub 2} and CO are the next potential sources contributing 25%-50% (<5%). The ratio of the photoproduction rate of O({sup 1} S) to O({sup 1} D) would be around 0.03 ({+-}0.01) if H{sub 2}O is the main source of oxygen lines, whereas it is {approx}0.6 if the parent is CO{sub 2}. Our calculations suggest that the yield of O({sup 1} S) production in the photodissociation of H{sub 2}O cannot be larger than 1%. The model-calculated radial brightness profiles of the red and green lines and G/R ratios are in good agreement with the observations made on the comet Hyakutake in 1996 March.

  3. Interstellar chemistry

    PubMed Central

    Klemperer, William

    2006-01-01

    In the past half century, radioastronomy has changed our perception and understanding of the universe. In this issue of PNAS, the molecular chemistry directly observed within the galaxy is discussed. For the most part, the description of the molecular transformations requires specific kinetic schemes rather than chemical thermodynamics. Ionization of the very abundant molecular hydrogen and atomic helium followed by their secondary reactions is discussed. The rich variety of organic species observed is a challenge for complete understanding. The role and nature of reactions involving grain surfaces as well as new spectroscopic observations of interstellar and circumstellar regions are topics presented in this special feature. PMID:16894148

  4. Manipulation of gold colloidal nanoparticles with atomic force microscopy in dynamic mode: influence of particle–substrate chemistry and morphology, and of operating conditions

    PubMed Central

    Darwich, Samer; Rao, Akshata; Gnecco, Enrico; Jayaraman, Shrisudersan; Haidara, Hamidou

    2011-01-01

    Summary One key component in the assembly of nanoparticles is their precise positioning to enable the creation of new complex nano-objects. Controlling the nanoscale interactions is crucial for the prediction and understanding of the behaviour of nanoparticles (NPs) during their assembly. In the present work, we have manipulated bare and functionalized gold nanoparticles on flat and patterned silicon and silicon coated substrates with dynamic atomic force microscopy (AFM). Under ambient conditions, the particles adhere to silicon until a critical drive amplitude is reached by oscillations of the probing tip. Beyond that threshold, the particles start to follow different directions, depending on their geometry, size and adhesion to the substrate. Higher and respectively, lower mobility was observed when the gold particles were coated with methyl (–CH3) and hydroxyl (–OH) terminated thiol groups. This major result suggests that the adhesion of the particles to the substrate is strongly reduced by the presence of hydrophobic interfaces. The influence of critical parameters on the manipulation was investigated and discussed viz. the shape, size and grafting of the NPs, as well as the surface chemistry and the patterning of the substrate, and finally the operating conditions (temperature, humidity and scan velocity). Whereas the operating conditions and substrate structure are shown to have a strong effect on the mobility of the particles, we did not find any differences when manipulating ordered vs random distributed particles. PMID:21977418

  5. How Iron-Containing Proteins Control Dioxygen Chemistry: A Detailed Atomic Level Description Via Accurate Quantum Chemical and Mixed Quantum Mechanics/Molecular Mechanics Calculations.

    SciTech Connect

    Friesner, Richard A.(Columbia University) [Columbia University; Baik, Mu-Hyun (Columbia University) [Columbia University; Gherman, Benjamin F.(Columbia University) [Columbia University; Guallar, Victor (Washington University) [Washington University; Wirstam, Maria E.(1836) [1836; Murphy, Robert B.(Schrodinger Inc) [Schrodinger Inc; Lippard, Stephen J.(Massachusetts Institute of Technology) [Massachusetts Institute of Technology

    2003-03-01

    Over the past several years, rapid advances in computational hardware, quantum chemical methods, and mixed quantum mechanics/molecular mechanics (QM/MM) techniques have made it possible to model accurately the interaction of ligands with metal-containing proteins at an atomic level of detail. In this paper, we describe the application of our computational methodology, based on density functional (DFT) quantum chemical methods, to two diiron-containing proteins that interact with dioxygen: methane monooxygenase (MMO) and hemerythrin (Hr). Although the active sites are structurally related, the biological function differs substantially. MMO is an enzyme found in methanotrophic bacteria and hydroxylates aliphatic C-H bonds, whereas Hr is a carrier protein for dioxygen used by a number of marine invertebrates. Quantitative descriptions of the structures and energetics of key intermediates and transition states involved in the reaction with dioxygen are provided, allowing their mechanisms to be compared and contrasted in detail. An in-depth understanding of how the chemical identity of the first ligand coordination shell, structural features, electrostatic and van der Waals interactions of more distant shells control ligand binding and reactive chemistry is provided, affording a systematic analysis of how iron-containing proteins process dioxygen. Extensive contact with experiment is made in both systems, and a remarkable degree of accuracy and robustness of the calculations is obtained from both a qualitative and quantitative perspective.

  6. Atmospheric chemistry of CF 3CH 2OCH 3: Reaction with chlorine atoms and OH radicals, kinetics, degradation mechanism and global warming potential

    NASA Astrophysics Data System (ADS)

    Østerstrøm, Freja From; Nielsen, Ole John; Sulbaek Andersen, Mads P.; Wallington, Timothy J.

    2012-02-01

    FTIR smog chamber techniques were used to measure k(Cl + CF3CH2OCH3) = (2.28 ± 0.44) × 10-11 and k(OH + CF3CH2OCH3) = (4.9 ± 1.3) × 10-13 cm3 molecule-1 s-1 in 700 Torr total pressure of air at 296 ± 2 K. The atmospheric lifetime of CF3CH2OCH3 is estimated at 25 days. Reaction of Cl atoms with CF3CH2OCH3 proceeds 79 ± 4% at the sbnd CH3 group and 22 ± 2% at the sbnd CH2sbnd group. Reaction with OH radicals proceeds 55 ± 5% at the sbnd CH3 group yielding CF3CH2OCHO and 45 ± 5% at the sbnd CH2sbnd group yielding COF2 and CH3OCHO as primary oxidation products. The infrared spectrum of CF3CH(O)OCH3 was measured and a global warming potential GWP100 = 8 was estimated. The atmospheric chemistry and environmental impact of CF3CH2OCH3 is discussed in context of the use of hydrofluoroethers as CFC substitutes.

  7. On the nature of interstellar organic chemistry

    NASA Astrophysics Data System (ADS)

    Charnley, Steven B.

    1997-01-01

    A theory for the origin of all organic molecules observed in regions of massive and low-mass star formation, as well as in dark molecular clouds is described. On dust grains, single atom addition reactions and stability of the intermediate radicals, mechanisms similar to those believed to form the organic component of the Murchison meteorite, lead to a very limited number of mantle compositions depending upon the degree of hydrogenation. The key step in the theory is the formation of the formyl radical by H atom addition (by quantum tunnelling) to CO. Subsequent H atom additions lead to formaldehyde and methanol, as previously suggested; C, N, and O atoms can also undergo additions to HCO. For increasing hydrogenation, the mantle types include one in which there is little contribution from formyl-initiated chemistry; one in which an acetylenic chain develops through C atom additions; and others where the acetylenic chain is increasingly hydrogenated to form aldehydes and alcohols. Following evaporation of grain mantles, such as occurs in protostellar hot cores, these molecules can form new organics, for example, by alkyl cation transfer from alcohols. In dark clouds, different mantles lead to different gas phase organics. This scenario accounts naturally for the formation of many interstellar organics for which none presently exists, predicts observable correlations between specific interstellar molecules, indicates the presence of many new organic molecules and why several others are not observed.

  8. Atomic-Scale Design of Iron Fischer-Tropsch Catalysts: A Combined Computational Chemistry, Experimental, and Microkinetic Modeling Approach

    SciTech Connect

    Manos Mavrikakis; James A. Dumesic; Amit A. Gokhale; Rahul P. Nabar; Calvin H. Bartholomew; Hu Zou; Brian Critchfield

    2006-03-03

    Efforts during this second year focused on four areas: (1) continued searching and summarizing of published Fischer-Tropsch synthesis (FTS) mechanistic and kinetic studies of FTS reactions on iron catalysts; (2) investigation of CO adsorption/desorption and temperature programmed hydrogenation (TPH) of carbonaceous species after FTS on unsupported iron and alumina-supported iron catalysts; (3) activity tests of alumina-supported iron catalysts in a fixed bed reactor; (4) sequential design of experiments, for the collection of rate data in a Berty CSTR reactor, and nonlinear-regression analysis to obtain kinetic parameters. Literature sources describing mechanistic and kinetic studies of Fischer-Tropsch synthesis on iron catalysts were compiled in a review. Temperature-programmed desorption/reaction methods (the latter using mass-spectrometry detection and also thermogravimetric analyzer (TGA)) were utilized to study CO adsorption/-desorption on supported and unsupported iron catalysts. Molecular and dissociative adsorptions of CO occur on iron catalysts at 25-150 C. The amounts adsorbed and bond strengths of adsorption are influenced by supports and promoters. That CO adsorbs dissociatively on polycrystalline Fe at temperatures well below those of FT reaction indicates that CO dissociation is facile and unlikely to be the rate-limiting step during FTS. Carbonaceous species formed after FT reaction for only 5 minutes at 200 C were initially hydrogenated under mild, isothermal condition (200 C and 1 atm), followed by TPH to 800 C. During the mild, isothermal hydrogenation, only about 0.1-0.2 mL of atomic carbon is apparently removed, while during TPH to 800 C multilayer equivalents of atomic, polymeric, carbidic, and graphitic carbons are removed. Rates of CO conversion on alumina-supported iron catalysts at 220-260 C and 20 atm are correlated well by a Langmuir-Hinshelwood expression, derived assuming carbon hydrogenation to CH and OH recombination to water to be rate-determining steps. In the coming year, studies will focus on quantitative determination of the rates of kinetically-relevant elementary steps on Fe catalysts with/without K and Pt promoters and at various levels of Al{sub 2}O{sub 3} support, providing a database for understanding (1) effects of promoter and support on elementary kinetic parameters and (2) for validation of computational models that incorporate effects of surface structure and promoters. Kinetic parameters will be incorporated into a microkinetics model, enabling prediction of rate without invoking assumptions, e.g. of a rate-determining step or a most-abundant surface intermediate. Calculations using periodic, self-consistent Density Functional Theory (DFT) methods were performed on two model surfaces: (1) Fe(110) with 1/4 ML subsurface carbon, and (2) Fe(110) with 1/4 ML Pt adatoms. Reaction networks for FTS on these systems were characterized in full detail by evaluating the thermodynamics and kinetics of each elementary step. We discovered that subsurface C stabilizes all the reactive intermediates, in contrast to Pt, which destabilizes most of them. A comparative study of the reactivities of the modified-Fe surfaces against pure Fe is expected to yield a more comprehensive understanding of promotion mechanisms for FTS on Fe.

  9. An Introduction to Chemistry: Nuclear Chemistry

    NSDL National Science Digital Library

    Mark Bishop

    This cost-free resource is a chapter from a textbook on introductory chemistry, developed for learners with little background in physics or chemistry. This chapter deals with the atomic nucleus and radiation, nuclear energy, and uses of radioactive substances. It is appropriate for teachers seeking additional content knowledge, high school physics and chemistry courses, and college-level preparatory chemistry. It builds a foundation to understand the physical forces in the nucleus (electrostatic force and strong force), and explains how chemical reactions differ from nuclear reactions. Graphs and diagrams depict what happens in radioactive decay. The section on chemical nuclear equations is straightforward and comprehensible for non-scientists. This collection is part of An Introduction to Chemistry, a set of resources developed by Mark Bishop which includes two textbooks, 15 animated tutorials, downloadable Power Point presentations for teachers, concept maps, and 3D molecular models.

  10. The Place of Macromolecules in Freshman Chemistry

    ERIC Educational Resources Information Center

    Wunderlich, Bernhard

    1973-01-01

    Discusses the inclusion of knowledge on macromolecules into a freshman chemistry course which emphasizes topics in organic chemistry, polymer science and biochemistry, atoms, chemical thermodynamics, and inorganic chemistry. Indicates that the program is the only way to keep chemistry education up to date. (CC)

  11. 3.091 Introduction to Solid State Chemistry, Fall 2002

    E-print Network

    Sadoway, Donald R.

    Basic principles of chemistry and their application to engineering systems. The relationship between electronic structure, chemical bonding, and atomic order. Characterization of atomic arrangements in crystalline and ...

  12. Chemistry 417 PHYSICAL CHEMISTRY LABORATORY

    E-print Network

    Richmond, Geraldine L.

    Chemistry 417 PHYSICAL CHEMISTRY LABORATORY Fall, 2008 Lecture: 13:00 Tuesday and Thursday 331 Senning tba 174 Klamath Required Texts: Chemistry 417: Physical Chemistry Laboratory - University.b.: This text is also used in Chemistry 429 Applied Mathematics for Physical Chemistry by James R. Barrante

  13. Average-atom quantum-statistical cell model for hot plasma in local thermodynamic equilibrium over a wide range of densities

    Microsoft Academic Search

    B. J. B. Crowley

    1990-01-01

    A method for numerically modeling hot plasma over a wide range of densities is described. The model generalizes the essential aspects of the Stewart-Pyatt model to plasmas comprising mixtures of elements and extends the treatment to include the effects of electron polarization and screening. A practical numerical prescription is provided that is a straightforward generalization of the ion-sphere cell model.

  14. Green Chemistry Teaching Resources

    NSDL National Science Digital Library

    The American Chemical Society (ACS) has created these excellent resources via the Green Chemistry Institute and the ACS Education Division. The goal of these materials is "to increase awareness and understanding of Green Chemistry principles, alternatives, practices, and benefits within traditional educational institutions and among practicing scientists." In the Online Resources section, visitors will find downloadable pocket guides to basic green chemistry principles, "Greener Education Materials for Chemists" from the University of Oregon, and more. Perhaps the best section of the site is Activities and Experiments, where visitors can look over activities like "Gassing Up Without Air Pollution" and "Cleaning Up With Atom Economy."

  15. Hot Groups.

    ERIC Educational Resources Information Center

    Vail, Kathleen

    1996-01-01

    Collaborators sparked by creative ideas and obsessed by a common task may not realize they're part of a "hot group"--a term coined by business professors Harold J. Leavitt and Jean Lipman-Blumen. Spawned by group decision making and employee empowerment, hot groups can flourish in education settings. They're typically small, short lived, and goal…

  16. Chemistry 675 Advanced Organic Chemistry

    E-print Network

    Doyle, Robert

    Fall 2014 Chemistry 675 Advanced Organic Chemistry MWF 10:35-11:30 AM 200 LSB Professor John D Description: CHE675 is a graduate-level organic chemistry course focused on physical organic chemistry, which in my office (CST 4-006) or my mailbox in the chemistry office (CST 1-014). Late problem sets will have

  17. Hot and Cold

    NSDL National Science Digital Library

    Oregon Museum of Science and Industry

    1997-01-01

    In this activity, learners explore temperature changes from chemical reactions by mixing urea with water in one flask and mixing calcium chloride with water in another flask. They observe that the urea flask gets cold and the calcium chloride flask gets hot. The main idea is that some chemical processes release heat energy and are exothermic, while some chemical processes absorb heat energy and are endothermic. This activity is currently used in the Nature of Matter Unit in OMSI's Chemistry Lab. Cost estimates are per 100 learners.

  18. The Great Ideas of Chemistry.

    ERIC Educational Resources Information Center

    Gillespie, Ronald J.

    1997-01-01

    Presents a list of six concepts that form the basis of modern chemistry and that should be included in introductory chemistry courses. Discusses atoms, molecules, and ions; the chemical bond; molecular shape and geometry; kinetic theory; the chemical reaction; and energy and entropy. (JRH)

  19. Hot Air

    NSDL National Science Digital Library

    The University of Texas McDonald Observatory

    2011-01-01

    In this activity, learners set up an experiment to investigate the effects of hot air on the path of a laser beam. They observe the wandering position of the laser beam spot on the wall after the light travels through hot air rising from the candle flame. Learners produce a table of observations from both the Cool Air and Hot Air experiments, and answer questions using evidence from their experiment. Apply what learners discover in this experiment to real-life by discussing why stars "twinkle."

  20. for Undergraduate CHEMISTRY MAJORS

    E-print Network

    Stuart, Steven J.

    and Petroleum Chemistry, Organic Chemistry, Physical Chemistry, Polymer Chemistry, Pulp and Paper Chemistry, RHANDBOOK for Undergraduate CHEMISTRY MAJORS DEPARTMENT OF CHEMISTRY Fall 2010 #12;#12;TABLE OF CONTENTS A Career in Chemistry - What It Means ___________________________________________ 4 What do

  1. Chemistry-nuclear chemistry division. Progress report, October 1979-September 1980

    SciTech Connect

    Ryan, R.R. (comp.)

    1981-05-01

    This report presents the research and development programs pursued by the Chemistry-Nuclear Chemistry Division of the Los Alamos National Laboratory. Topics covered include advanced analytical methods, atmospheric chemistry and transport, biochemistry, biomedical research, element migration and fixation, inorganic chemistry, isotope separation and analysis, atomic and molecular collisions, molecular spectroscopy, muonic x rays, nuclear cosmochemistry, nuclear structure and reactions, radiochemical separations, theoretical chemistry, and unclassified weapons research.

  2. Realization of atomically flat steps and terraces like surface of SrTiO3 (001) single crystal by hot water etching and high temperature annealing

    NASA Astrophysics Data System (ADS)

    Prakash, Bhanu; Chakraverty, S.

    2015-07-01

    We have successfully prepared atomically flat single-terminated SrTiO3(001) surface using a mild and reproducible etching technique combined with high temperature annealing. To achieve single terminated surface, deionised water at 60 °C was used to selectively etch SrO composites from the substrate surface. A clear step-and-terrace like surface morphology is observed by subsequent air annealing at 1000 °C. Atomic Force Microscopy suggests the step height (~0.4 nm) corresponding to the lattice parameter of SrTiO3, which confirms the formation of single-terminated surface. This chemical-free mild etching technique might be useful to prepare single-terminated surface, especially for the perovskites containing reactive elements.

  3. Modelling of non-LTE atomic physics processes in hot dense plasmas during the interaction with an intense short pulse laser

    NASA Astrophysics Data System (ADS)

    Davis, J.; Petrov, G. M.

    2014-05-01

    The implicit 2D3V particle-in-cell (PIC) code developed to study the interaction of intense lasers with matter (Petrov and Davis 2008 Comput. Phys. Commun. 179 868-80 2011 Phys. Plasmas 18 073102) has been extended to include atomic physics under extreme energy density conditions. The atomic physics model is applied to aluminium. Each ionization stage contains two levels: one ground and one lumped excited state, for which various atomic physics processes such as optical field ionization, collisional ionization, excitation, de-excitation and radiative decay describe the population density. Two-dimensional PIC simulations have been carried out for laser pulses with peak intensity 1 × 1020 W cm-2, pulse duration 60 fs, spot size 3 µm and energy 0.75 J interacting with ultrathin (0.2 µm) Al foil. Radiation emitted during the laser-target interaction is computed by accounting for both bound-bound transitions and bremsstrahlung radiation. We demonstrate that the radiation signature of laser-produced plasma can be used as a complementary tool to other diagnostic techniques used in laser-plasma interactions. Finally, results from the PIC model are compared to equilibrium calculations (Maxwell-Boltzmann and Saha). In the early stages of laser-plasma interactions (<100 fs) the plasma is far from equilibrium and equilibrium models can not be applied with confidence to model the plasma.

  4. Search for methylamine in high mass hot cores

    E-print Network

    Ligterink, N F W; van Dishoeck, E F

    2015-01-01

    We aim to detect methylamine, CH$_{3}$NH$_{2}$, in a variety of hot cores and use it as a test for the importance of photon-induced chemistry in ice mantles and mobility of radicals. Specifically, CH$_3$NH$_2$ cannot be formed from atom addition to CO whereas other NH$_2$-containing molecules such as formamide, NH$_2$CHO, can. Submillimeter spectra of several massive hot core regions were taken with the James Clerk Maxwell Telescope. Abundances are determined with the rotational diagram method where possible. Methylamine is not detected, giving upper limit column densities between 1.9 $-$ 6.4 $\\times$ 10$^{16}$ cm$^{-2}$ for source sizes corresponding to the 100 K envelope radius. Combined with previously obtained JCMT data analyzed in the same way, abundance ratios of CH$_{3}$NH$_{2}$, NH$_{2}$CHO and CH$_{3}$CN with respect to each other and to CH$_{3}$OH are determined. These ratios are compared with Sagittarius B2 observations, where all species are detected, and to hot core models. The observed ratios su...

  5. CHEMISTRY 521 GRADUATE PHYSICAL CHEMISTRY

    E-print Network

    Findley, Gary L.

    CHEMISTRY 521 GRADUATE PHYSICAL CHEMISTRY Fall Term, 1999 INSTRUCTOR INFORMATION Instructor: Dr@alpha.nlu.edu URL: http://www.nlu.edu/chemistry/findley/findley.html COURSE Content: A review of selected topics in Physical Chemistry. Goals/ Objectives: Introduction to quantum mechanics. Topics covered include

  6. CHEMISTRY 320 PHYSICAL CHEMISTRY I

    E-print Network

    Findley, Gary L.

    CHEMISTRY 320 PHYSICAL CHEMISTRY I Fall 2009 9:00 am - 10:30 am, MW CNSB 211 INSTRUCTOR INFORMATION of the physical principles of chemistry. Goals/ Objectives: CHEM 320 presents chemical principles from" or better in CHEM 108; PHYS 208; MATH 132. Text: Physical Chemistry, P. Atkins and J. de Paula, 8th ed. (W

  7. Environmental Chemistry II (Atmospheric Chemistry)

    E-print Network

    Dibble, Theodore

    SYLLABUS FOR Environmental Chemistry II (Atmospheric Chemistry) FCH 511 Fall 2013 Theodore S. Dibble Professor of Chemistry 421 Jahn Laboratory Syracuse, NY 13210 Phone: (315) 470-6596 Fax: (315) 470 Seinfeld, J. H. and Pandis, S. N. Atmospheric Chemistry and Physics: From Air Pollution to Climate Change

  8. CHEMISTRY 322 PHYSICAL CHEMISTRY II

    E-print Network

    Findley, Gary L.

    CHEMISTRY 322 PHYSICAL CHEMISTRY II Spring 2010 10:00 am - 11:30 am, MW CNSB 211 INSTRUCTOR interpretations of the physical principles of chemistry. Goals/ Objectives: CHEM 322, which is a continuation of CHEM 320, focuses of the quantum theoretical foundations of modern chemistry. Topics covered include

  9. Chemistry 419 PHYSICAL CHEMISTRY LABORATORY

    E-print Network

    Richmond, Geraldine L.

    Chemistry 419 PHYSICAL CHEMISTRY LABORATORY Spring, 2008 Lecture/Discussion 1:00 Tuesday, Brittney Young Required Text: Chemistry 419 - Physical Chemistry Laboratory - University Bookstore. Students are required to perform seven laboratories from among those offered this quarter. The first week

  10. Shape-selective catalysts for Fischer-Tropsch chemistry : atomic layer deposition of active catalytic metals. Activity report : January 1, 2005 - September 30, 2005

    Microsoft Academic Search

    Cronauer

    2011-01-01

    Argonne National Laboratory is carrying out a research program to create, prepare, and evaluate catalysts to promote Fischer-Tropsch (FT) chemistry - specifically, the reaction of hydrogen with carbon monoxide to form long-chain hydrocarbons. In addition to needing high activity, it is desirable that the catalysts have high selectivity and stability with respect to both mechanical strength and aging properties. The

  11. Green Chemistry

    NSDL National Science Digital Library

    2002-01-01

    This special feature page from the American Chemical Society (ACS) showcases the up-and-coming field of "green chemistry," that is, the development of chemical products and processes that eliminate or reduce the use and generation of hazardous substances. A list of principles behind green chemistry, a searchable bibliography of green chemistry references, green chemistry links (including conferences), and an online preview of the ACS-published book Real-World Cases in Green Chemistry are all found at the site. Five video clips on green chemistry from the standpoint of academia, industry, and small business are also featured (Windows Media Player). This page comes from ACS's Green Chemistry Project, a three-year educational project to develop and disseminate green chemistry educational materials for graduate and undergraduate chemistry students. Check back often for updates.

  12. Image Storage in Hot Vapors

    E-print Network

    L. Zhao; T. Wang; Y. Xiao; S. F. Yelin

    2007-10-22

    We theoretically investigate image propagation and storage in hot atomic vapor. A $4f$ system is adopted for imaging and an atomic vapor cell is placed over the transform plane. The Fraunhofer diffraction pattern of an object in the object plane can thus be transformed into atomic Raman coherence according to the idea of ``light storage''. We investigate how the stored diffraction pattern evolves under diffusion. Our result indicates, under appropriate conditions, that an image can be reconstructed with high fidelity. The main reason for this procedure to work is the fact that diffusion of opposite-phase components of the diffraction pattern interfere destructively.

  13. ENVIRONMENTAL CHEMISTRY

    EPA Science Inventory

    Environmental chemistry is applied to estimating the exposure of ecosystems and humans to various chemical environmental stressors. Among the stressors of concern are mercury, pesticides, and arsenic. Advanced analytical chemistry techniques are used to measure these stressors ...

  14. Chemistry Notes

    ERIC Educational Resources Information Center

    School Science Review, 1976

    1976-01-01

    Described are eight chemistry experiments and demonstrations applicable to introductory chemistry courses. Activities include: measure of lattice enthalpy, Le Chatelier's principle, decarboxylation of soap, use of pocket calculators in pH measurement, and making nylon. (SL)

  15. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1978

    1978-01-01

    Describes experiments, demonstrations, activities and ideas relating to various fields of chemistry to be used in chemistry courses of secondary schools. Three experiments concerning differential thermal analysis are among these notes presented. (HM)

  16. Chemistry Open Textbook

    NSDL National Science Digital Library

    This free chemistry textbook from Boundless Learning is based off openly available educational resources such as "government resources, open educational repositories, and other openly licensed websites." The textbook contains 25 chapters such as Introduction to Chemistry, Atoms, Molecules, and Ions, and Mass Relationships and Chemical Equations. The textbook can be browsed on this page or downloaded as a pdf. Students can register for a free Boundless account to access a search engine and other study tools to efficiently find specific topics and master the content.

  17. Chemistry of Transactinides

    NASA Astrophysics Data System (ADS)

    Kratz, J. V.

    In this chapter, the chemical properties of the man-made transactinide elements rutherfordium, Rf (element 104), dubnium, Db (element 105), seaborgium, Sg (element 106), bohrium, Bh (element 107), hassium, Hs (element 108), and copernicium, Cn (element 112) are reviewed, and prospects for chemical characterizations of even heavier elements are discussed. The experimental methods to perform rapid chemical separations on the time scale of seconds are presented and comments are given on the special situation with the transactinides where chemistry has to be studied with single atoms. It follows a description of theoretical predictions and selected experimental results on the chemistry of elements 104 through 108, and element 112.

  18. HOT AIR

    NSDL National Science Digital Library

    HOT AIR -- The graphical home page of THE ANNALS OF IMPROBABLE RESEARCH FROM MIT provides a different look at scientific research. Check out a schedule of AIR events, an art gallery, and SharewAIR--an interactive and up-to-the-minute moderated forum.

  19. Martian corona: Nonthermal sources of hot heavy species

    Microsoft Academic Search

    F. Cipriani; F. Leblanc; J. J. Berthelier

    2007-01-01

    We have studied the production of hot O and C atoms, and hot CO2 and CO molecules in the Martian upper atmosphere and exosphere by dissociative recombination (DR) of O2+ and CO+ ions, and sputtering of the atmosphere by incident O+ pick-up ions. Production and collisional thermalization of the hot particles in the upper atmosphere are described by using a

  20. Forensic Chemistry

    Microsoft Academic Search

    Suzanne Bell

    2009-01-01

    Forensic chemistry is unique among chemical sciences in that its research, practice, and presentation must meet the needs of both the scientific and the legal communities. As such, forensic chemistry research is applied and derivative by nature and design, and it emphasizes metrology (the science of measurement) and validation. Forensic chemistry has moved away from its analytical roots and is

  1. Biochemistry chemistry &

    E-print Network

    Morgan, Stephen L.

    Biochemistry chemistry & A n A ly t i c A l B i o l o g i c A l i n o r g A n i c o r g A n i c P h of South Carolina..........................1 Department of Chemistry and Biochemistry....2 The Graduate Program in Chemistry and Biochemistry.........................................................3 Ph

  2. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1982

    1982-01-01

    Presents background information, laboratory procedures, classroom materials/activities, and experiments for chemistry. Topics include superheavy elements, polarizing power and chemistry of alkali metals, particulate carbon from combustion, tips for the chemistry laboratory, interesting/colorful experiments, behavior of bismuth (III) iodine, and…

  3. Chemistry Links

    NSDL National Science Digital Library

    Charnine, Michael

    This compiled site contains titles and links to over 40 sites, journal articles, course and tutorial materials, simulations, batteries, and other resources. Definitions of chemistry, theoretical chemistry, organic, physical and nuclear chemistry are integrated with the links to outside materials. A number of useful keywords are included to help users navigate the materials.

  4. The atomic structure and chemistry of Fe-rich steps on antiphase boundaries in Ti-doped Bi{sub 0.9}Nd{sub 0.15}FeO{sub 3}

    SciTech Connect

    MacLaren, Ian, E-mail: ian.maclaren@glasgow.ac.uk; Craven, Alan J.; Schaffer, Bernhard [SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom); SuperSTEM Laboratory, SciTech Daresbury, Keckwick Lane, Warrington WA4 4AD (United Kingdom); Wang, LiQiu [SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Ramasse, Quentin M. [SuperSTEM Laboratory, SciTech Daresbury, Keckwick Lane, Warrington WA4 4AD (United Kingdom); Kalantari, Kambiz; Reaney, Ian M. [Department of Materials Science and Engineering, University of Sheffield, Mappin St, Sheffield S1 3JD (United Kingdom)

    2014-06-01

    Stepped antiphase boundaries are frequently observed in Ti-doped Bi{sub 0.85}Nd{sub 0.15}FeO{sub 3}, related to the novel planar antiphase boundaries reported recently. The atomic structure and chemistry of these steps are determined by a combination of high angle annular dark field and bright field scanning transmission electron microscopy imaging, together with electron energy loss spectroscopy. The core of these steps is found to consist of 4 edge-sharing FeO{sub 6} octahedra. The structure is confirmed by image simulations using a frozen phonon multislice approach. The steps are also found to be negatively charged and, like the planar boundaries studied previously, result in polarisation of the surrounding perovskite matrix.

  5. Forensic Chemistry

    NASA Astrophysics Data System (ADS)

    Bell, Suzanne

    2009-07-01

    Forensic chemistry is unique among chemical sciences in that its research, practice, and presentation must meet the needs of both the scientific and the legal communities. As such, forensic chemistry research is applied and derivative by nature and design, and it emphasizes metrology (the science of measurement) and validation. Forensic chemistry has moved away from its analytical roots and is incorporating a broader spectrum of chemical sciences. Existing forensic practices are being revisited as the purview of forensic chemistry extends outward from drug analysis and toxicology into such diverse areas as combustion chemistry, materials science, and pattern evidence.

  6. Computational Chemistry for Chemistry Educators

    NSDL National Science Digital Library

    Shodor Computational Science Institute

    This is a 15-session course on the technologies, techniques, and tools of computational chemistry. By using the same computational tools as research computational chemists, educators will have the opportunity to study chemistry in a manner very different than traditional teaching and education in chemistry.

  7. 148 Chemistry/Chinese Chemistry 347 (3)--Advanced Organic Chemistry

    E-print Network

    Dresden, Gregory

    ,organometalliccatalyticprocesses,andsolid statechemistry.Uffelman. Spring 2008 and alternate years Chemistry 365 (3)--Advanced Physical Chemistry148 Chemistry/Chinese Chemistry 347 (3)--Advanced Organic Chemistry Prerequisite: Chemistry 242,syntheticmethodology,mod- ernsyntheticreactions,protectinggroups,naturalprod- uctssynthesis,andcombinatorialchemistry.France. Spring Chemistry

  8. Uranium triamidoamine chemistry.

    PubMed

    Gardner, Benedict M; Liddle, Stephen T

    2015-07-01

    Triamidoamine (Tren) complexes of the p- and d-block elements have been well-studied, and they display a diverse array of chemistry of academic, industrial and biological significance. Such in-depth investigations are not as widespread for Tren complexes of uranium, despite the general drive to better understand the chemical behaviour of uranium by virtue of its fundamental position within the nuclear sector. However, the chemistry of Tren-uranium complexes is characterised by the ability to stabilise otherwise reactive, multiply bonded main group donor atom ligands, construct uranium-metal bonds, promote small molecule activation, and support single molecule magnetism, all of which exploit the steric, electronic, thermodynamic and kinetic features of the Tren ligand system. This Feature Article presents a current account of the chemistry of Tren-uranium complexes. PMID:26035690

  9. Vulcan Hot Springs known geothermal resource area: an environmental analysis

    Microsoft Academic Search

    S. G. Spencer; B. F. Russell

    1979-01-01

    The Vulcan Hot Springs known geothermal resource area (KGRA) is one of the more remote KGRAs in Idaho. The chemistry of Vulcan Hot Springs indicates a subsurface resource temperature of 147°C, which may be high enough for power generation. An analysis of the limited data available on climate, meteorology, and air quality indicates few geothermal development concerns in these areas.

  10. Polymeric nanocoatings by hot-wire chemical vapor deposition (HWCVD)

    Microsoft Academic Search

    Kenneth K. S. Lau; Y. Mao; Hilton G. Pryce Lewis; Shashi K. Murthy; Brad D. Olsen; Leslie S. Loo; Karen K. Gleason

    2006-01-01

    Hot-wire chemical vapor deposition (HWCVD) of polymers affords the ability to coat objects of complex shape and nanoscale features. Using hot filaments to drive the gas phase chemistry has enabled the deposition of true linear polymers rather than the highly cross-linked organic networks typically associated with plasma enhanced CVD. The HWCVD method is particularly valuable for creating ultrathin layers of

  11. Failure analysis of boiler cold and hot reheater tubes

    Microsoft Academic Search

    Khalil Ranjbar

    2007-01-01

    An analysis was made on the failure and shut down of boiler cold and hot reheater tubes by chemical analysis of sediments, metallographic examinations, XRD, SEM and EDX studies. The mode of operation, maintenance, and feed water chemistry were also checked. It is concluded that the bad maintenance and feed water chemistry are the main causes of the failure, leading

  12. Atom, atom-type and total molecular linear indices as a promising approach for bioorganic and medicinal chemistry: theoretical and experimental assessment of a novel method for virtual screening and rational design of new lead anthelmintic

    Microsoft Academic Search

    Yovani Marrero-Ponce; Juan A. Castillo-Garit; Ervelio Olazabal; Hector S. Serrano; Alcidez Morales; Nilo Castañedo; Froylán Ibarra-Velarde; Alma Huesca-Guillen; Alicia M. Sánchez; Francisco Torrens; Eduardo A. Castro

    2005-01-01

    Helminth infections are a medical problem in the world nowadays. In this paper a novel atom-level chemical descriptor has been applied to estimate the anthelmintic activity. Total and local linear indices and linear discriminant analysis were used to obtain a quantitative model that discriminates between anthelmintic and non-anthelmintic drug-like compounds. The discriminant model has an accuracy of 90.11% in the

  13. Hot Meetings

    NASA Technical Reports Server (NTRS)

    Chiu, Mary

    2002-01-01

    A colleague walked by my office one time as I was conducting a meeting. There were about five or six members of my team present. The colleague, a man who had been with our institution (The Johns Hopkins Applied Physics Lab, a.k.a. APL) for many years, could not help eavesdropping. He said later it sounded like we we re having a raucous argument, and he wondered whether he should stand by the door in case things got out of hand and someone threw a punch. Our Advanced Composition Explorer (ACE) team was a hot group, to invoke the language that is fashionable today, although we never thought of ourselves in those terms. It was just our modus operandi. The tenor of the discussion got loud and volatile at times, but I prefer to think of it as animated, robust, or just plain collaborative. Mary Chiu and her "hot" team from the Johns Hopkins Applied Physics Laboratory built the Advanced Composition Explorer spacecraft for NASA. Instruments on the spacecraft continue to collect data that inform us about what's happening on our most important star, the Sun.

  14. 5.61 Physical Chemistry, Fall 2004

    E-print Network

    Griffin, Robert Guy

    Introductory quantum chemistry; particles and waves; wave mechanics; atomic structure and the Periodic Table; valence and molecular orbital theory; molecular structure; and photochemistry. From the course home page: Course ...

  15. Chem 681 Quantum Chemistry Chemistry 681

    E-print Network

    Chem 681 Quantum Chemistry Chemistry 681 Introduction to Quantum Chemistry Fall 2003 Course outline-consistent field (Hartree-Fock) theory. G.S. Ezra 1 Cornell University #12;Chem 681 Quantum Chemistry 8. Molecules

  16. Nuclear Chemistry, Science (Experimental): 5316.62.

    ERIC Educational Resources Information Center

    Williams, Russell R.

    This nuclear chemistry module includes topics on atomic structure, instability of the nucleus, detection strengths and the uses of radioactive particles. Laboratory work stresses proper use of equipment and safe handling of radioactive materials. Students with a strong mathematics background may consider this course as advanced work in chemistry.…

  17. Electron scattering in hot-dense plasmas

    NASA Astrophysics Data System (ADS)

    Zammit, Mark C.; Fursa, Dmitry V.; Bray, Igor

    2012-11-01

    Hot-dense plasmas have direct industrial applications in inertial confinement fusion. We have used the convergent close-coupling (CCC) method to investigate electron scattering off hydrogen and helium atoms in a hot-dense weakly coupled (Debye) plasma. The Yukawa-type Debye-Hückel potential has been used to describe the plasma screening effects. Integrated excitation, total ionization and total cross sections have been calculated over a broad range of energies and various Debye lengths, D.

  18. Hot tub folliculitis

    MedlinePLUS

    Hot tub folliculitis is an infection of the skin around the lower part of the hair shaft (hair follicles). ... Hot tub folliculitis is caused by bacteria that survives in hot tubs, especially tubs made of wood.

  19. Hot Weather Tips

    MedlinePLUS

    HOT Weather Tips Printer-friendly version We all suffer in hot weather. However, for elderly and disabled people and ... stress and following these tips for dealing with hot weather. Wear cool clothing: See that the person ...

  20. Real-time Quantum Chemistry

    E-print Network

    Moritz P. Haag; Markus Reiher

    2012-08-18

    Significant progress in the development of efficient and fast algorithms for quantum chemical calculations has been made in the past two decades. The main focus has always been the desire to be able to treat ever larger molecules or molecular assemblies---especially linear and sub-linear scaling techniques are devoted to the accomplishment of this goal. However, as many chemical reactions are rather local, they usually involve only a limited number of atoms so that models of about two hundred (or even less) atoms embedded in a suitable environment are sufficient to study their mechanisms. Thus, the system size does not need to be enlarged, but remains constant for reactions of this type that can be described by less than two hundred atoms. The question then arises how fast one can obtain the quantum chemical results. This question is not directly answered by linear-scaling techniques. In fact, ideas such as haptic quantum chemistry or interactive quantum chemistry require an immediate provision of quantum chemical information which demands the calculation of data in "real time". In this perspective, we aim at a definition of real-time quantum chemistry, explore its realm and eventually discuss applications in the field of haptic quantum chemistry. For the latter we elaborate whether a direct approach is possible by virtue of real-time quantum chemistry.

  1. Circumstellar chemistry

    NASA Technical Reports Server (NTRS)

    Glassgold, Alfred E.; Huggins, Patrick J.

    1987-01-01

    The study of the outer envelopes of cool evolved stars has become an active area of research. The physical properties of CS envelopes are presented. Observations of many wavelengths bands are relevant. A summary of observations and a discussion of theoretical considerations concerning the chemistry are summarized. Recent theoretical considerations show that the thermal equilibrium model is of limited use for understanding the chemistry of the outer CS envelopes. The theoretical modeling of the chemistry of CS envelopes provides a quantitive test of chemical concepts which have a broader interest than the envelopes themselves.

  2. Cooperative Chemistry

    NSDL National Science Digital Library

    Allan A. Gahr

    2003-02-01

    Concept mapping in the organic chemistry laboratory can supplant cookbook activities with higher cognitive exercises. The common thread of most organic lab experiments is the synthesis, isolation, purification, and characterization of a carbon compound. T

  3. Radioanalytical Chemistry

    NSDL National Science Digital Library

    Hardy, James K.

    This website provides a course on the use of radionuclides in analytical chemistry. Types of radioactive decay are discussed as well as the techniques of scintillation counting, neutron activation analysis, and gamma spectroscopy.

  4. Precolumbian Chemistry.

    ERIC Educational Resources Information Center

    Robinson, Janet Bond

    1995-01-01

    Describes the content and development of a curriculum that provides an approach to descriptive chemistry and the history of technology through consideration of the pottery, metallurgy, pigments, dyes, agriculture, and medicine of pre-Columbian people. (DDR)

  5. Green Chemistry

    NSDL National Science Digital Library

    2011-03-02

    Learn about a study in which participants discovered contaminants in their homes, and how green chemistry may provide alternatives to such everyday toxins, in this video adapted from Contaminated Without Consent.

  6. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1981

    1981-01-01

    Describes 13 activities, experiments and demonstrations, including the preparation of iron (III) chloride, simple alpha-helix model, investigating camping gas, redox reactions of some organic compounds, a liquid crystal thermometer, and the oxidation number concept in organic chemistry. (JN)

  7. Stratospheric chemistry

    SciTech Connect

    Brune, W.H. (USAF, Geophysics Laboratory, Hanscom AFB, MA (United States))

    1991-01-01

    Advances in stratospheric chemistry made by investigators in the United States from 1987 to 1990 are reviewed. Subject areas under consideration include photochemistry of the polar stratosphere, photochemistry of the global stratosphere, and assessments of inadvertent modification of the stratosphere by anthropogenic activity. Particular attention is given to early observations and theories, gas phase chemistry, Antarctic observations, Arctic observations, odd-oxygen, odd-hydrogen, odd-nitrogen, halogens, aerosols, modeling of stratospheric ozone, and reactive nitrogen effects.

  8. Chemistry-Nuclear Chemistry Division. Progress report, October 1980-September 1981

    SciTech Connect

    Ryan, R.R. (comp.)

    1982-05-01

    This report describes major progress in the research and development programs pursued by the Chemistry-Nuclear Chemistry Division of the Los Alamos National Laboratory during FY 1981. Topics covered include advanced analytical methods, atmospheric chemistry and transport, biochemistry, biomedical research, medical radioisotopes research, element migration and fixation, nuclear waste isolation research, inorganic and structural chemistry, isotope separation, analysis and applications, the newly established Nuclear Magnetic Resonance Center, atomic and molecular collisions, molecular spectroscopy, nuclear cosmochemistry, nuclear structure and reactions, pion charge exchange, radiochemical separations, theoretical chemistry, and unclassified weapons research.

  9. The World of Chemistry

    NSDL National Science Digital Library

    1990-01-01

    One doesn't have to be a Glenn Seaborg or a Lord Ernest Rutherford to learn about chemistry, though it probably couldn't help to have some of their curiosity about the world of chemistry. Young chemists and their teachers will definitely benefit from this nice resource offered by the Annenberg Media project. This original video series was produced by the University of Maryland and the Educational Film Center, and it consists of 26 half-hour programs. With industrial and research chemists demonstrating a number of high-intensity experiments and processes, the series is quite a find. The installments include such titles as "Modeling the Unseen", "The Atom", and "The Busy Electron".

  10. Chemistry makes graphene beyond graphene.

    PubMed

    Liao, Lei; Peng, Hailin; Liu, Zhongfan

    2014-09-01

    Although graphene is extremely inert in chemistry because of the giant delocalized ? electron system, various methods have been developed to achieve its efficient chemical modification. Covalent chemistry is effective to modulate the physical properties of graphene. By converting the sp(2) hybridized carbon atoms to sp(3) ones, new two-dimensional (2D) materials and 2D superlattices with fascinating features beyond mother graphene could be built from the graphene scaffold, greatly expanding the graphene family and its attraction. In this Perspective, the power of covalent chemistry is demonstrated from the viewpoint of tailoring graphene's energy band structure as well as creating new 2D materials and 2D superlattices. A specific focus is laid on the general consideration and understanding of covalent graphene chemistry toward electronic devices and material science. PMID:25126670

  11. Atom, atom-type and total molecular linear indices as a promising approach for bioorganic and medicinal chemistry: theoretical and experimental assessment of a novel method for virtual screening and rational design of new lead anthelmintic.

    PubMed

    Marrero-Ponce, Yovani; Castillo-Garit, Juan A; Olazabal, Ervelio; Serrano, Hector S; Morales, Alcidez; Castañedo, Nilo; Ibarra-Velarde, Froylán; Huesca-Guillen, Alma; Sánchez, Alicia M; Torrens, Francisco; Castro, Eduardo A

    2005-02-15

    Helminth infections are a medical problem in the world nowadays. In this paper a novel atom-level chemical descriptor has been applied to estimate the anthelmintic activity. Total and local linear indices and linear discriminant analysis were used to obtain a quantitative model that discriminates between anthelmintic and non-anthelmintic drug-like compounds. The discriminant model has an accuracy of 90.11% in the training set, with a high Matthews' correlation coefficient (MCC=0.80). To assess the robustness and predictive power of the obtained model, internal (leave-n-out) and external validation process was performed. The QSAR model correctly classified 88.55% of compounds in this external prediction set, yielding a MCC of 0.77. Another LDA model was carried out to outline some conclusions about the possible modes of action of anthelmintic drugs. It has an accuracy of 93.50% in the training set, and 80.00% in the external prediction set. After that, the developed model was used in the virtual--in silico--screening and several compounds from the Merck Index, Negwer's Handbook and Goodman and Gilman were identified by the model as anthelmintic. Finally, the experimental assay of an organic chemical (a furylethylene derivative) by an in vivo test permits us to carry out an assessment of the model. An accuracy of 100% with the theoretical predictions was observed. These results suggest that the proposed method will be a good tool for studying the biological properties of drug candidates during the early state of the drug-development process. PMID:15670908

  12. Atomic and molecular supernovae

    NASA Technical Reports Server (NTRS)

    Liu, Weihong

    1997-01-01

    Atomic and molecular physics of supernovae is discussed with an emphasis on the importance of detailed treatments of the critical atomic and molecular processes with the best available atomic and molecular data. The observations of molecules in SN 1987A are interpreted through a combination of spectral and chemical modelings, leading to strong constraints on the mixing and nucleosynthesis of the supernova. The non-equilibrium chemistry is used to argue that carbon dust can form in the oxygen-rich clumps where the efficient molecular cooling makes the nucleation of dust grains possible. For Type Ia supernovae, the analyses of their nebular spectra lead to strong constraints on the supernova explosion models.

  13. Atmospheric chemistry of isoflurane, desflurane, and sevoflurane: kinetics and mechanisms of reactions with chlorine atoms and OH radicals and global warming potentials.

    PubMed

    Sulbaek Andersen, Mads P; Nielsen, Ole J; Karpichev, Boris; Wallington, Timothy J; Sander, Stanley P

    2012-06-21

    The smog chamber/Fourier-transform infrared spectroscopy (FTIR) technique was used to measure the rate coefficients k(Cl + CF(3)CHClOCHF(2), isoflurane) = (4.5 ± 0.8) × 10(-15), k(Cl + CF(3)CHFOCHF(2), desflurane) = (1.0 ± 0.3) × 10(-15), k(Cl + (CF(3))(2)CHOCH(2)F, sevoflurane) = (1.1 ± 0.1) × 10(-13), and k(OH + (CF(3))(2)CHOCH(2)F) = (3.5 ± 0.7) × 10(-14) cm(3) molecule(-1) in 700 Torr of N(2)/air diluent at 295 ± 2 K. An upper limit of 6 × 10(-17) cm(3) molecule(-1) was established for k(Cl + (CF(3))(2)CHOC(O)F). The laser photolysis/laser-induced fluorescence (LP/LIF) technique was employed to determine hydroxyl radical rate coefficients as a function of temperature (241-298 K): k(OH + CF(3)CHFOCHF(2)) = (7.05 ± 1.80) × 10(-13) exp[-(1551 ± 72)/T] cm(3) molecule(-1); k(296 ± 1 K) = (3.73 ± 0.08) × 10(-15) cm(3) molecule(-1), and k(OH + (CF(3))(2)CHOCH(2)F) = (9.98 ± 3.24) × 10(-13) exp[-(969 ± 82)/T] cm(3) molecule(-1); k(298 ± 1 K) = (3.94 ± 0.30) × 10(-14) cm(3) molecule(-1). The rate coefficient of k(OH + CF(3)CHClOCHF(2), 296 ± 1 K) = (1.45 ± 0.16) × 10(-14) cm(3) molecule(-1) was also determined. Chlorine atoms react with CF(3)CHFOCHF(2) via H-abstraction to give CF(3)CFOCHF(2) and CF(3)CHFOCF(2) radicals in yields of approximately 83% and 17%. The major atmospheric fate of the CF(3)C(O)FOCHF(2) alkoxy radical is decomposition via elimination of CF(3) to give FC(O)OCHF(2) and is unaffected by the method used to generate the CF(3)C(O)FOCHF(2) radicals. CF(3)CHFOCF(2) radicals add O(2) and are converted by subsequent reactions into CF(3)CHFOCF(2)O alkoxy radicals, which decompose to give COF(2) and CF(3)CHFO radicals. In 700 Torr of air 82% of CF(3)CHFO radicals undergo C-C scission to yield HC(O)F and CF(3) radicals with the remaining 18% reacting with O(2) to give CF(3)C(O)F. Atmospheric oxidation of (CF(3))(2)CHOCH(2)F gives (CF(3))(2)CHOC(O)F in a molar yield of 93 ± 6% with CF(3)C(O)CF(3) and HCOF as minor products. The IR spectra of (CF(3))(2)CHOC(O)F and FC(O)OCHF(2) are reported for the first time. The atmospheric lifetimes of CF(3)CHClOCHF(2), CF(3)CHFOCHF(2), and (CF(3))(2)CHOCH(2)F (sevoflurane) are estimated at 3.2, 14, and 1.1 years, respectively. The 100 year time horizon global warming potentials of isoflurane, desflurane, and sevoflurane are 510, 2540, and 130, respectively. The atmospheric degradation products of these anesthetics are not of environmental concern. PMID:22146013

  14. Final Report on Atomic Database Project

    Microsoft Academic Search

    Yuan; Moses

    2006-01-01

    Atomic physics in hot dense plasmas is essential for understanding the radiative properties of plasmas either produced terrestrially such as in fusion energy research or in space such as the study of the core of the sun. Various kinds of atomic data are needed for spectrum analysis or for radiation hydrodynamics simulations. There are many atomic databases accessible publicly through

  15. Ion chemistry in space.

    PubMed

    Larsson, M; Geppert, W D; Nyman, G

    2012-06-01

    We review the gas-phase chemistry in extraterrestrial space that is driven by reactions with atomic and molecular ions. Ions are ubiquitous in space and are potentially responsible for the formation of increasingly complex interstellar molecules. Until recently, positively charged atoms and molecules were the only ions known in space; however, this situation has changed with the discovery of various molecular anions. This review covers not only the observation, distribution and reactions of ions in space, but also laboratory-based experimental and theoretical methods for studying these ions. Recent results from space-based instruments, such as those on the Cassini-Huygens space mission and the Herschel Space Observatory, are highlighted. PMID:22790651

  16. Atmospheric Pseudohalogen Chemistry

    NASA Technical Reports Server (NTRS)

    Lary, David John

    2004-01-01

    Hydrogen cyanide is not usually considered in atmospheric chemical models. The paper presents three reasons why hydrogen cyanide is likely to be significant for atmospheric chemistry. Firstly, HCN is a product and marker of biomass burning. Secondly, it is also likely that lightning is producing HCN, and as HCN is sparingly soluble it could be a useful long-lived "smoking gun" marker of lightning activity. Thirdly, the chemical decomposition of HCN leads to the production of small amounts of the cyanide (CN) and NCO radicals. The NCO radical can be photolyzed in the visible portion of the spectrum yielding nitrogen atoms (N). The production of nitrogen atoms is significant as it leads to the titration of total nitrogen from the atmosphere via N+N->N2, where N2 is molecular nitrogen.

  17. CHEMISTRY 108-01 GENERAL CHEMISTRY II

    E-print Network

    Findley, Gary L.

    CHEMISTRY 108-01 GENERAL CHEMISTRY II Fall Term, 2002 10:00 - 10:50 am, MWThF CNSB 243 INSTRUCTOR-1835 Email: findley@ulm.edu URL: www.ulm.edu/chemistry/findley COURSE Content: Principles of modern chemistry. Goals/ Objectives: CHEM 108 is the second semester of a fundamental introduction to chemistry

  18. CHEMISTRY 107-01 GENERAL CHEMISTRY I

    E-print Network

    Findley, Gary L.

    CHEMISTRY 107-01 GENERAL CHEMISTRY I Spring 2002 8:00 am - 8:50 am, MTuWTh Rm. CNSB 243 INSTRUCTOR-1835 Email: chfindley@ulm.edu URL: http://www.ulm.edu/chemistry/findley COURSE Content: Principles of modern chemistry. Goals/ Objectives: CHEM 107 is the first semester of a fundamental introduction to chemistry

  19. Chem 681 Quantum Chemistry Chemistry 681

    E-print Network

    ]. The physical chemistry text by McQuarrie & Simon [3] (used in Chem 390) also has relevant material. The third] McQuarrie and Simon, Physical Chemistry (University Science Books). [4] R.P. Feynman, R.B. LeightonChem 681 Quantum Chemistry Chemistry 681 Introduction to Quantum Chemistry Fall 2003 BIBLIOGRAPHY

  20. CHEMISTRY 321 PHYSICAL CHEMISTRY LABORATORY I

    E-print Network

    Findley, Gary L.

    CHEMISTRY 321 PHYSICAL CHEMISTRY LABORATORY I Fall 2009 2:00 - 5:00 pm, F CNSB 142 INSTRUCTOR techniques of physical chemistry. Goals/ Objectives: Physical Chemistry Laboratory introduces the student analysis software and IEEE-488 electronic devices. The focus for Physical Chemistry Laboratory I

  1. CHEMISTRY 323 PHYSICAL CHEMISTRY LABORATORY II

    E-print Network

    Findley, Gary L.

    CHEMISTRY 323 PHYSICAL CHEMISTRY LABORATORY II Spring 2010 2:00 - 5:00 pm, F CNSB 142 INSTRUCTOR techniques of physical chemistry. Goals/ Objectives: Physical Chemistry Laboratory introduces the student analysis software and IEEE-488 electronic devices. The focus for Physical Chemistry Laboratory II

  2. Using Computational Chemistry Activities to Promote Learning and Retention in a Secondary School General Chemistry Setting

    ERIC Educational Resources Information Center

    Ochterski, Joseph W.

    2014-01-01

    This article describes the results of using state-of-the-art, research-quality software as a learning tool in a general chemistry secondary school classroom setting. I present three activities designed to introduce fundamental chemical concepts regarding molecular shape and atomic orbitals to students with little background in chemistry, such as…

  3. Chemistry Now

    NSDL National Science Digital Library

    2012-08-17

    The National Science Foundation (NSF) recently teamed up with NBC and the National Science Teachers Association to celebrate the International Year of Chemistry. Their big joint project was to create Chemistry Now, a weekly online video series that uncovers and explains the science of common, physical objects. There are over two dozen short films here that cover topics like the chemistry of salt, grapheme, safety glass, and the common cheeseburger. All of the videos are lively and interesting, and they can be used in a wide range of classroom settings to provide visual and audio reinforcement of topics that might be addressed in course lectures and other activities. The videos are completely free and the site includes links to other organizations that have created similar videos.

  4. Chemistry & Industry

    NSDL National Science Digital Library

    1997-01-01

    Chemistry and Industry Magazine, a bimonthly product of the Society of Chemical Industry, provides selected full-text articles from the print magazine in the areas of news, commentary, features, latest results from chemical literature, and highlights from the latest European patents. In addition, there is a searchable and browsable archive of past issues, a daily news section, and searchable jobs and meetings databases. The Society of Chemical Industry is "an international association of about 6000 members aimed at furthering applied chemistry." One of the highlights of its web site is its publication section, where, under "electronic publications," readers can find updated daily news, jobs and meetings listings on chemistry, pharmaceuticals, biotechnology, and the environment.

  5. Polymer Chemistry

    NASA Technical Reports Server (NTRS)

    Williams, Martha; Roberson, Luke; Caraccio, Anne

    2010-01-01

    This viewgraph presentation describes new technologies in polymer and material chemistry that benefits NASA programs and missions. The topics include: 1) What are Polymers?; 2) History of Polymer Chemistry; 3) Composites/Materials Development at KSC; 4) Why Wiring; 5) Next Generation Wiring Materials; 6) Wire System Materials and Integration; 7) Self-Healing Wire Repair; 8) Smart Wiring Summary; 9) Fire and Polymers; 10) Aerogel Technology; 11) Aerogel Composites; 12) Aerogels for Oil Remediation; 13) KSC's Solution; 14) Chemochromic Hydrogen Sensors; 15) STS-130 and 131 Operations; 16) HyperPigment; 17) Antimicrobial Materials; 18) Conductive Inks Formulations for Multiple Applications; and 19) Testing and Processing Equipment.

  6. Surface chemistry of a Cu(I) beta-diketonate precursor and the atomic layer deposition of Cu{sub 2}O on SiO{sub 2} studied by x-ray photoelectron spectroscopy

    SciTech Connect

    Dhakal, Dileep, E-mail: dileep.dhakal@zfm.tu-chemnitz.de [Center for Microtechnologies – ZfM, Technische Universität Chemnitz, D-09107 Chemnitz (Germany); Waechtler, Thomas; Schulz, Stefan E.; Gessner, Thomas [Center for Microtechnologies – ZfM, Technische Universität Chemnitz, D-09107 Chemnitz, Germany and Fraunhofer Institute for Electronic Nano Systems - ENAS, Technologie-Campus 3, D-09126 Chemnitz (Germany); Lang, Heinrich; Mothes, Robert; Tuchscherer, André [Institute of Chemistry, Inorganic Chemistry, Technische Universität Chemnitz, D-09107 Chemnitz (Germany)

    2014-07-01

    The surface chemistry of the bis(tri-n-butylphosphane) copper(I) acetylacetonate, [({sup n}Bu{sub 3}P){sub 2}Cu(acac)] and the thermal atomic layer deposition (ALD) of Cu{sub 2}O using this Cu precursor as reactant and wet oxygen as coreactant on SiO{sub 2} substrates are studied by in-situ x-ray photoelectron spectroscopy (XPS). The Cu precursor was evaporated and exposed to the substrates kept at temperatures between 22?°C and 300?°C. The measured phosphorus and carbon concentration on the substrates indicated that most of the [{sup n}Bu{sub 3}P] ligands were released either in the gas phase or during adsorption. No disproportionation was observed for the Cu precursor in the temperature range between 22?°C and 145?°C. However, disproportionation of the Cu precursor was observed at 200?°C, since C/Cu concentration ratio decreased and substantial amounts of metallic Cu were present on the substrate. The amount of metallic Cu increased, when the substrate was kept at 300?°C, indicating stronger disproportionation of the Cu precursor. Hence, the upper limit for the ALD of Cu{sub 2}O from this precursor lies in the temperature range between 145?°C and 200?°C, as the precursor must not alter its chemical and physical state after chemisorption on the substrate. Five hundred ALD cycles with the probed Cu precursor and wet O{sub 2} as coreactant were carried out on SiO{sub 2} at 145?°C. After ALD, in-situ XPS analysis confirmed the presence of Cu{sub 2}O on the substrate. Ex-situ spectroscopic ellipsometry indicated an average film thickness of 2.5?nm of Cu{sub 2}O deposited with a growth per cycle of 0.05?Å/cycle. Scanning electron microscopy and atomic force microscopy (AFM) investigations depicted a homogeneous, fine, and granular morphology of the Cu{sub 2}O ALD film on SiO{sub 2}. AFM investigations suggest that the deposited Cu{sub 2}O film is continuous on the SiO{sub 2} substrate.

  7. Chemistry 320N Organic Chemistry II

    E-print Network

    Chemistry 320N Organic Chemistry II for Prehealth Professionals Unique number: 52365 Spring 2013 M students can access the information. #12;Required Text: Brown, Foote, Iverson, & Anslyn Organic Chemistry

  8. Magnetohydrodynamic Simulations of Hot Jupiter Thermospheres

    NASA Astrophysics Data System (ADS)

    Christie, Duncan; Arras, Phil; Li, Zhi-Yun

    2015-01-01

    The majority of models of atmospheric escape from hot Jupiters have focused on one-dimensional, spherically-symmetric models. We present the results from 2-dimensional axisymmetric simulations of hot Jupiters including tidal gravity and magnetic fields as well as photo-ionization and photoelectric heating due to multiple atomic species. Escape is suppressed in polar and equatorial regions by tidal gravity and magnetic fields, respectively, reducing mass-loss estimates achieved through 1-dimensional models. For sufficiently large magnetic field strengths, an equatorial magnetic dead zone creates a static reservoir of hot gas extending to multiple planetary radii and exhibiting temperatures hotter than found within the escaping gas. The possibility of observing this reservoir of gas is discussed, as well as the influence of heavy atoms on the result.

  9. Interactive Teaching Units: Green Chemistry

    NSDL National Science Digital Library

    As more and more organizations go "green," it makes sense that a number of educational institutions are participating as well. One such institution is the University of Glasgow, which has developed this series of "green" chemistry teaching exercises known as Interactive Teaching units (ITUs). Currently, the site contains four ITUs, including "The Age of Refrigeration," "Titanium and the Titanium Dioxide Industry," and "The Atom Economy." The modules all draw on the concept of problem based learning to introduce key concepts of green chemistry and sustainability in an industrial context. All of these materials can be used in the college classroom in order to develop both teamwork and communication skills.

  10. Carbon Chemistry in interstellar clouds

    E-print Network

    Maryvonne Gerin; David Fosse; Evelyne Roueff

    2002-12-03

    We discuss new developments of interstellar chemistry, with particular emphasis on the carbon chemistry. We confirm that carbon chains and cycles are ubiquitous in the ISM and closely chemically related to ea ch other, and to carbon. Investigation of the carbon budget in shielded and UV illuminated gas shows that the inventory of interstellar molecules is not complete and more complex molecules with 4 or more carbon atoms must be present. Finally we discuss the consequences for the evolution of clouds and conclude that the ubiquitous presence of carbon chains and cycles is not a necessary consequence of a very young age for interstellar clouds.

  11. Interactive Teaching Units: Green Chemistry

    NSDL National Science Digital Library

    As more and more organizations go "green", it makes sense that a number of educational institutions are participating as well. One such institution is the University of Glasgow which has developed this series of "green" chemistry teaching exercises known as Interactive Teaching units (ITUs). Currently, the site contains four ITU's, including "The Age of Refrigeration", "Titanium and the Titanium Dioxide Industry", and "The Atom Economy". The modules all draw on the concept of problem based learning to introduce key concepts of green chemistry and sustainability in an industrial context. All of these materials can be used in the college classroom in order to develop both teamwork and communication skills.

  12. Chemistry Notes

    ERIC Educational Resources Information Center

    School Science Review, 1976

    1976-01-01

    Describes several chemistry projects, including solubility, formula for magnesium oxide, dissociation of dinitrogen tetroxide, use of 1-chloro-2, 4-dinitrobenzene, migration of ions, heats of neutralizations, use of pocket calculators, sonic cleaning, oxidation states of manganese, and cell potentials. Includes an extract from Chemical Age on…

  13. Nuclear Chemistry

    NSDL National Science Digital Library

    This page, from the University of North Carolina - Chapel Hill Chemistry Fundamentals program and the Shodor Education Foundation, discusses five different types of radioactive decay: alpha, beta negative, gamma, positron emission, and electron capture. After examining the numerous equations, students can test their dating skills by solving three practice problems. Solutions are included.

  14. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1980

    1980-01-01

    Presents 12 chemistry notes for British secondary school teachers. Some of these notes are: (1) a simple device for testing pH-meters; (2) portable fume cupboard safety screen; and (3) Mass spectroscopy-analysis of a mass peak. (HM)

  15. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1978

    1978-01-01

    Describes some laboratory apparatus, chemistry experiments and demonstrations, such as a Kofler block melting point apparatus, chromatographic investigation of the phosphoric acid, x-ray diffraction, the fountain experiment, endothermic sherbet, the measurement of viscosity, ionization energies and electronic configurations. (GA)

  16. Green Chemistry

    NSDL National Science Digital Library

    WGBH Educational Foundation

    2010-02-12

    This audio segment from PRI's The World Science Podcast explores the science of Green Chemistry. Hear about companies that are developing greener chemicals, and learn why they are fast becoming an attractive alternative for the multi-billion dollar chemical industry.

  17. Countertop Chemistry

    NSDL National Science Digital Library

    Chemistry activities and demonstrations that use common household items and kitchen chemicals. There are activities appropriate for students in elementary school, middle school, and high school. The activities were designed and tested by the Science House, the science and mathematics learning outreach program of North Carolina State University.

  18. Analytical Chemistry

    NSDL National Science Digital Library

    Hardy, James K.

    This site features lecture notes for first and second level courses in analytical chemistry. Topics include titrations, gravimetry, kinetics and electrochemistry (redox). Potentiometry, coulometry, voltammetry, spectroscopic and separation methods are presented as well, and are illustrated with QuickTime animations.

  19. Common Chemistry

    NSDL National Science Digital Library

    Chemical Abstracts Service (CAS)

    A web resource that contains Chemical Abstracts Service (CAS) Registry Numbers for approximately 7,800 chemicals of widespread general public interest. Common Chemistry is helpful to non-chemists who know either a name or CAS Registry Number® of a common chemical and want to pair both pieces of information.

  20. Atmospheric Chemistry

    NSDL National Science Digital Library

    This set of links provides access to resources on atmospheric chemistry, especially acid deposition, air pollution, and air quality. The sites include personal and government pages, universities and research groups, non-governmental organizations and meetings, and products and services. There are also links to related search topics.

  1. Chemistry Notes

    ERIC Educational Resources Information Center

    School Science Review, 1972

    1972-01-01

    Short articles on the kinetics of the hydrogen peroxide-iodide ion reaction, simulation of fluidization catalysis, the use of Newman projection diagrams to represent steric relationships in organic chemistry, the use of synthetic substrates for proteolytic enzyme reactions, and two simple clock reactions"--hydrolysis of halogenoalkanes and…

  2. Fall 2011 Chemistry 676

    E-print Network

    Mather, Patrick T.

    Fall 2011 Chemistry 676 "Introduction to organic synthesis: Methodology" T chemistry, olefination reactions, cross coupling chemistry, and modern transition metal are due by 1200 (noon) in my office (CST 3-008) or my mailbox in the chemistry

  3. Chemistry of superheavy elements.

    PubMed

    Schädel, Matthias

    2006-01-01

    The number of chemical elements has increased considerably in the last few decades. Most excitingly, these heaviest, man-made elements at the far-end of the Periodic Table are located in the area of the long-awaited superheavy elements. While physical techniques currently play a leading role in these discoveries, the chemistry of superheavy elements is now beginning to be developed. Advanced and very sensitive techniques allow the chemical properties of these elusive elements to be probed. Often, less than ten short-lived atoms, chemically separated one-atom-at-a-time, provide crucial information on basic chemical properties. These results place the architecture of the far-end of the Periodic Table on the test bench and probe the increasingly strong relativistic effects that influence the chemical properties there. This review is focused mainly on the experimental work on superheavy element chemistry. It contains a short contribution on relativistic theory, and some important historical and nuclear aspects. PMID:16365916

  4. Highly charged ions in hot, dense plasmas

    SciTech Connect

    Osterheld, A.L.; Walling, R.S.; Young, B.K.F.; Goldstein, W.H.; Shimkaveg, G.; MacGowan, B.J.; Da Silva, L.; Keane, C.; Hammel, B.; London, R.; Stewart, R.E.

    1992-09-01

    Highly-charged ions play a critical role in hot, dense plasmas. They affect the energy balance and hydrodynamic evolution of transient plasmas. The radiation emitted by highly charged ions may be used in several practical applications, such as inertial confinement fusion, short wavelength lasers, and x-ray sources for lithography and microscopy applications. This radiation may also be used to diagnose the conditions in plasmas. In recent years, models have been developed to describe the atomic kinetics of complex ionization states of highly charged ions in plasmas. However, reliable atomic calculations and careful experiments which test both the fundamental atomic physics and the assumptions of the plasma emission models are required.

  5. Highly charged ions in hot, dense plasmas

    SciTech Connect

    Osterheld, A.L.; Walling, R.S.; Young, B.K.F.; Goldstein, W.H.; Shimkaveg, G.; MacGowan, B.J.; Da Silva, L.; Keane, C.; Hammel, B.; London, R.; Stewart, R.E. (Lawrence Livermore National Laboratory, L-59, P.O. Box 808, Livermore, California 94550 (United States))

    1993-06-05

    Highly-charged ions play a critical role in hot, dense plasmas. They affect the energy balance and hydrodynamic evolution of transient plasmas. The radiation emitted by highly charged ions may be used in several practical applications, such as inertial confinement fusion, short wavelength lasers, and x-ray sources for lithography and microscopy applications. This radiation may also be used to diagnose the conditions in plasmas, In recent years, models have been developed to describe the atomic kinetics of complex ionization states of highly charged ions in plasmas. However, reliable atomic calculations and careful experiments which test both the fundamental atomic physics and the assumptions of the plasma emission models are required.

  6. Hot oxygen corona of Mars

    SciTech Connect

    Ip, W.H.

    1988-10-01

    Electron dissociative recombination of O2(+) ions in the Venus ionosphere, which may be an important source of suprathermal atomic oxygen, is presently considered as a factor in the Mars exosphere; due to the weaker surface gravitational attraction of Mars, a hot oxygen corona thus formed would be denser than that of Venus at altitudes greater than 2000 km despite Mars' lower ionospheric content. If such an extended oxygen corona does exist on Mars, its collisional interaction with Phobos would lead to the formation of an oxygen gas torus whose average number density is of the order of only 1-2/cu cm along the Phobos orbit. 51 references.

  7. Hot Flow Anomalies at Venus

    NASA Technical Reports Server (NTRS)

    Collinson, G. A.; Sibeck, David Gary; Boardsen, Scott A.; Moore, Tom; Barabash, S.; Masters, A.; Shane, N.; Slavin, J.A.; Coates, A.J.; Zhang, T. L.; Sarantos, M.

    2012-01-01

    We present a multi-instrument study of a hot flow anomaly (HFA) observed by the Venus Express spacecraft in the Venusian foreshock, on 22 March 2008, incorporating both Venus Express Magnetometer and Analyzer of Space Plasmas and Energetic Atoms (ASPERA) plasma observations. Centered on an interplanetary magnetic field discontinuity with inward convective motional electric fields on both sides, with a decreased core field strength, ion observations consistent with a flow deflection, and bounded by compressive heated edges, the properties of this event are consistent with those of HFAs observed at other planets within the solar system.

  8. Experimental Atomic Physics Research in the Budker Group

    E-print Network

    Pines, Alexander

    , Armenia, and Russia], [LANL, NIST, LBNL, UCB Chemistry,...] · Each student has their own project · Lots in in dysprosium ' ~ 3-2000 MHz atomic beam PM T atomic freq. standard rf freq. generator fluor. E-field plates

  9. Translationally hot neutrals in etching discharges Timothy J. Sommerer and Mark J. Kushner

    E-print Network

    Kushner, Mark

    Translationally hot neutrals in etching discharges Timothy J. Sommerer and Mark J. Kushner in these plasmas. Neutral species may, however, become translationally hot through either charge exchange and effects of translationally hot neutral atoms and molecules in CF, etching plasmas. We lind

  10. Resin Chemistry

    Microsoft Academic Search

    Louis Pilato

    2010-01-01

    \\u000a During the ensuing years since the last phenolic resins book was published, many new and remarkable developments have occurred\\u000a in the realm of phenolic chemistry and are given in this chapter.\\u000a \\u000a \\u000a A critical examination of the first step or addition step (methylolation) in the preparation of resoles is described and how\\u000a it can be controlled and compared with the typical

  11. Identification of hot spot residues at protein-protein interface.

    PubMed

    Li, Lei; Zhao, Bing; Cui, Zhanhua; Gan, Jacob; Sakharkar, Meena Kishore; Kangueane, Pandjassarame

    2006-01-01

    It is known that binding free energy of protein-protein interaction is mainly contributed by hot spot (high energy) interface residues. Here, we investigate the characteristics of hot spots by examining inter-atomic sidechain-sidechain interactions using a dataset of 296 alanine-mutated interface residues. Results show that hot spots participate in strong and energetically favorable sidechain-sidechain interactions. Subsequently, we describe a novel, yet simple 'hot spot' prediction model with an accuracy that is similar to many available approaches. The model is also shown to efficiently distinguish specific protein-protein interactions from non-specific interactions. PMID:17597870

  12. Identification of hot spot residues at protein-protein interface

    PubMed Central

    Li, Lei; Zhao, Bing; Cui, Zhanhua; Gan, Jacob; Sakharkar, Meena Kishore; Kangueane, Pandjassarame

    2006-01-01

    It is known that binding free energy of protein-protein interaction is mainly contributed by hot spot (high energy) interface residues. Here, we investigate the characteristics of hot spots by examining inter-atomic sidechain-sidechain interactions using a dataset of 296 alanine-mutated interface residues. Results show that hot spots participate in strong and energetically favorable sidechain-sidechain interactions. Subsequently, we describe a novel, yet simple ‘hot spot’ prediction model with an accuracy that is similar to many available approaches. The model is also shown to efficiently distinguish specific protein-protein interactions from non-specific interactions. PMID:17597870

  13. Chemistry on Polycyclic Aromatic Hydrocarbons

    NASA Astrophysics Data System (ADS)

    Hornekaer, Liv

    Chemistry on Polycyclic Aromatic Hydrocarbons Even though Polycyclic Aromatic Hydrocarbons (PAHs) are ubiquitous in the interstellar medium, the role they play as catalysts for interstellar chemistry is still largely unexplored. However, existing experimental data and theoretical calculations indicate that PAHs may well play a very active role, in particular in connection with the formation of molecular hydrogen. These findings may explain observations of increased molecular hydrogen formation rates in Photodissociation regions with high PAH abundances. In my talk I will present temperature programmed desorption data demonstrating the formation of highly super-hydrogenated PAHs via hydrogen addition reactions and catalytic formation of molecular hydrogen via abstraction reactions at a wide range of H atom temperatures. Approximate cross-sections for these reactions derived via model simulations will be presented. The implications for the role played by PAHs in interstellar chemistry will be discussed.

  14. Modelling Hot Air Balloons.

    ERIC Educational Resources Information Center

    Brimicombe, M. W.

    1991-01-01

    A macroscopic way of modeling hot air balloons using a Newtonian approach is presented. Misleading examples using a car tire and the concept of hot air rising are discussed. Pressure gradient changes in the atmosphere are used to explain how hot air balloons work. (KR)

  15. Chemistry 411/611 Inorganic Chemistry (2010)

    E-print Network

    Mather, Patrick T.

    2010-01-01

    1 Chemistry 411/611 Inorganic Chemistry (2010) Instructor: Assistant Professor Mathew M. Maye: M-W 4:00-5:00, and by appointment Credits: 3 Text: (Required) Shriver & Atkins, "Inorganic Chemistry. (Suggested for CHE611 Students pursuing Inorganic) Huheey, "Inorganic Chemistry: Principles of Structure

  16. CHEMISTRY 3022-63067 PHYSICAL CHEMISTRY II

    E-print Network

    Findley, Gary L.

    CHEMISTRY 3022-63067 PHYSICAL CHEMISTRY II Spring 2014 8:00 am - 8:50 am, MWF CNSB 211 INSTRUCTOR interpretations of the physical principles of chemistry. Goals/ Objectives: CHEM 3022 presents chemical principles: Physical Chemistry, R. Stephen Berry, Stuart A. Rice and John Ross, 2nd ed. (Oxford Univ. Press, New York

  17. CHEMISTRY 1010 CHEMISTRY, HUMANITY AND ENVIRONMENT

    E-print Network

    Simons, Jack

    CHEMISTRY 1010 CHEMISTRY, HUMANITY AND ENVIRONMENT Spring 2006 Instructor: Dr. Laya Kesner, HEB - 002 H ST 205 11:50 a.m.-12:40 p.m. Teaching Assistant: Chem 1010-002 Michelle Taliaferro, michelle@chemistry; 9:30 a.m. - 5:30 p.m. Textbook: Chemistry for Changing Times, 10th Edition, Hill & Kolb, Prentice

  18. Chemistry 211 General Chemistry Laboratory II

    E-print Network

    Nickrent, Daniel L.

    Chemistry 211 General Chemistry Laboratory II Fall 2014 Instructor Dr. Michelle Greene Office: Neckers 295 Office Hours: by appointment Phone: TBA E-mail: mgreene@chem.siu.edu Text Chemistry 211 University Carbondale) Course Description "General Chemistry Laboratory II" is an introductory level

  19. CHEMISTRY 162 GENERAL CHEMISTRY II SPRING 2008

    E-print Network

    Vonessen, Nikolaus

    1 of 10 CHEMISTRY 162 GENERAL CHEMISTRY II SPRING 2008 Lead Instructor Professor Mark S. Cracolice survey of chemistry. We follow the standard curriculum in the United States, as suggested by the American an introduction to the principles of physical and inorganic chemistry appropriate for the level of knowledge

  20. SYLLABUS for CHEMISTRY 2310 ORGANIC CHEMISTRY 1

    E-print Network

    Simons, Jack

    SYLLABUS for CHEMISTRY 2310 ORGANIC CHEMISTRY 1 Lectures: Monday, Wednesday and Friday 8:35 AM-9 Chemistry" by Janice Gorzynski Smith, McGraw Hill, 3rd Edition, 2010 [2nd Edition will suffice]. The ebook · Highly Recommended Equipment: Turning Point Clicker · Highly Recommended: (1) "Organic Chemistry I

  1. CHEMISTRY 3020-42232 PHYSICAL CHEMISTRY I

    E-print Network

    Findley, Gary L.

    CHEMISTRY 3020-42232 PHYSICAL CHEMISTRY I Fall 2011 8:00 am - 8:50 am, MWF CNSB 211 INSTRUCTOR interpretations of the physical principles of chemistry. Goals/ Objectives: CHEM 3020 presents chemical principles.) REQUIREMENTS Prerequisites: "C" or better in CHEM 1008; PHYS 2008; MATH 1032. Text: Physical Chemistry, P

  2. CHEMISTRY DEPARTMENT Chem 315 (Honors Organic Chemistry)

    E-print Network

    Lawson, Catherine L.

    CHEMISTRY DEPARTMENT Chem 315 (Honors Organic Chemistry) Fall 2014 Important Registration Information Admission to Honors Organic Chemistry (Fall 2014) is restricted to the following students: Students who received an A in both semesters of General Chemistry (159 and 160 OR 161 and 162 OR 163

  3. CHEMISTRY 3022-62169 PHYSICAL CHEMISTRY II

    E-print Network

    Findley, Gary L.

    CHEMISTRY 3022-62169 PHYSICAL CHEMISTRY II Spring 2012 8:00 am - 8:50 am, MWF CNSB 211 INSTRUCTOR interpretations of the physical principles of chemistry. Goals/ Objectives: CHEM 3022, which is a continuation of CHEM 3020, focuses of the quantum theoretical foundations of modern chemistry. Topics covered include

  4. Chemistry 224 Fall 2008 Honors General Chemistry

    E-print Network

    Richmond, Geraldine L.

    Chemistry 224 Fall 2008 Honors General Chemistry Dr. Greg Williams Office hours: Onyx 182 Tu and Th 110 Required Materials: Textbook General Chemistry: Principles and Modern Applications by R. Petrucci Prerequisites: One year of high school chemistry and one year of high school physics are the minimum

  5. CHEMISTRY CONNECTION Northwestern University Department of Chemistry

    E-print Network

    Grzybowski, Bartosz A.

    CHEMISTRY CONNECTION Northwestern University Department of Chemistry In this Issue Faculty News 2. The team, representing four departments and schools at Northwestern (Chemistry, Kellogg/ Business, Law is stored in motor vehicle gas tanks. Omar Farha, Chemistry Research Associate Professor, along with Chris

  6. Position: Assistant Professor of Chemistry, Physical Chemistry

    E-print Network

    John Grey Position: Assistant Professor of Chemistry, Physical Chemistry Email: jkgrey of Physical Chemistry C (2010) ACS ASAP. 2. "Resonance Raman Spectroscopic- and Photocurrent Imaging of Polythiophene/Fullerene Solar Cells" Y.Gao, T.P. Martin, A.K. Thomas, J.K. Grey. Journal of Physical Chemistry

  7. Azulene Chemistry

    NSDL National Science Digital Library

    The month's featured molecules come from the paper An Azulene-Based Discovery Experiment: Challenging Students To Watch for the "False Assumption" by Charles Garner illustrating some of the chemistry of a substituted azulene. Azulene is a structural isomer of naphthalene and differs from it in several important ways, the most obvious being azulene's intense blue color, which arises from the S0 ? S2 transition. Another unusual feature of this molecule is that its fluorescence arises from the reverse of this transition rather than from S1 ? S0.

  8. Chemistry References

    NSDL National Science Digital Library

    Kim

    2007-08-08

    This site highlights chemistry resources that we consider essentiala fabulous periodic table, a database of chemical compounds, a set of demonstrations of chemical reactions that are just plain spectacular, and, dont forget, laboratory safety. Articles from the web sites Whats That Stuff? and Science News for Kids can be used as supplemental reading all through the year. This site explains the history and characteristics of over 20 substances, such as sunscreen, Cheese Whiz, baseballs, fluoride, new car smell, ink, lipstick, bug spray, and licorice. The individual articles are nontechnical for the most part and are presented in a fun way that readers will enjoy. Also, if a ...

  9. Interaction of hydrogen, methane, ethylene, and cyclopentane with hot tungsten: Implications for the growth of diamond films

    SciTech Connect

    Winters, H.F.; Seki, H. (IBM Research Division, Almaden Research Center, 650 Harry Road, San Jose, California 95120-6099 (United States)); Rye, R.R.; Coltrin, M.E. (Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States))

    1994-07-15

    The production of hydrogen atoms from H[sub 2] was found to be largest on clean tungsten, less on carburized tungsten, and not observable on graphite. Evaporation of tungsten from carburized tungsten was seen at temperatures below 2500 [degree]C but not below 2200 [degree]C. XPS measurements indicated that slightly carburized tungsten contained some graphite in the surface region while heavily carburized tungsten contained much more graphite. The surface concentration of carbon was found to depend in a complicated manner on the balance between carbide and graphite growth and carbon evaporation. The reaction probability of the incident gas is also a determining factor. In addition, computer simulations were used to calculate the concentrations of various species in the gas phase under conditions which are typical of those used in diamond hot-filament CVD reactors. Calculated gas-phase species distributions near the substrate for carbon-atom/H[sub 2] mixtures are found to be similar for most species to those calculated for CH[sub 4]/H[sub 2] mixtures. It appears that the fast H[sub 2] and H chemistry determines the equilibrium mixture and that it is nearly independent of the type of carbon containing species introduced near the filament. Literature results obtained in typical diamond hot-filament CVD reactors are compared and interpreted on the basis of the present data.

  10. Syllabus Chemistry 1225

    E-print Network

    Simons, Jack

    Syllabus Chemistry 1225 Summer 2013 Instructor: David Thomas: You must obtain a copy of the Chemistry 1225 lab manual Experiments in General Chemistry Featuring MeasureNet® from the University Bookstore, 2nd

  11. Computational Chemistry List

    NSDL National Science Digital Library

    The Computational Chemistry List (CCL) was established as an independent electronic forum for chemistry researchers and educators from around the world. The discussions cover all aspects of computational chemistry.

  12. Science Update: Inorganic Chemistry

    ERIC Educational Resources Information Center

    Rawls, Rebecca

    1978-01-01

    This first in a series of articles describing the state of the art of various branches of chemistry reviews inorganic chemistry, including bioinorganic, photochemistry, organometallic, and solid state chemistries. (SL)

  13. 3.091 Introduction to Solid State Chemistry, Fall 2004

    E-print Network

    Sadoway, Donald

    This course explores the basic principles of chemistry and their application to engineering systems. It deals with the relationship between electronic structure, chemical bonding, and atomic order. It also investigates ...

  14. Chemistry by the Case: Integrated Case Teaching and Team Learning.

    ERIC Educational Resources Information Center

    Dinan, Frank J.

    2002-01-01

    Introduces a chemistry unit, the "Evolving Atom", based on a problem-based learning approach designed for non-science majors. Uses the case method to address memory loss in mice during instruction. (Contains 14 references.) (YDS)

  15. Tropospheric Chemistry

    NASA Technical Reports Server (NTRS)

    Mohnen, V.

    1984-01-01

    The fundamental processes that control the chemical composition and cycles of the global troposphere and how these processes and properties affect the physical behavior of the atmosphere are examined. The long-term information needs for tropospheric chemistry are: to be able to predict tropospheric responses to perturbations, both natural and anthropogenic, of these cycles, and to provide the information required for the maintenance and effective future management of the atmospheric component of our global life support system. The processes controlling global tropospheric biogeochemical cycles include: the input of trace species into the troposphere, their long-range transport and distribution as affected by the mean wind and vertical venting, their chemical transformations, including gas to particle conversion, leading to the appearance of aerosols or aqueous phase reactions inside cloud droplets, and their removal from the troposphere via wet (precipitation) and dry deposition.

  16. HotBot

    NSDL National Science Digital Library

    HotBot, a service of HotWired Ventures, uses the Inktomi search engine as the heart of its new Internet search service. It claims to index the full text contents of 50 million Web pages, as well as Usenet news and mailing lists. This would make it the largest search engine on the Internet. HotBot supports Boolean AND/OR/NOT, and phrase searching. It provides relevance feedback with retrieval. It also supports chronological, domain, and geographic searches, as well as media type searches such as Java, VRML, and Acrobat. HotBot is a public "beta" site and encourages feedback and bug reports.

  17. Atomic Physics

    NSDL National Science Digital Library

    Christopher Griffith

    This collection provides a basic introduction to Atomic Physics. It reviews the building blocks of atomic structure, explores atomic isotopes, explains Einstein's famous equation E = mc2, and introduces the various types of radiation.

  18. Science Update: Inorganic Chemistry.

    ERIC Educational Resources Information Center

    Rawls, Rebecca

    1981-01-01

    Describes areas of inorganic chemistry which have changed dramatically in the past year or two, including photochemistry, electrochemistry, organometallic complexes, inorganic reaction theory, and solid state chemistry. (DS)

  19. Chemistry Bachelor of Science in Chemistry 4 YEAR TYPICAL

    E-print Network

    Carter, John

    Chemistry Bachelor of Science in Chemistry 4 YEAR TYPICAL PROGRAM OF STUDY 2013-2014 DEGREE OF SCIENCE & ENGINEERING Department of Chemistry | Office: Bannan 516 chemistry@seattleu.edu | www.seattleu.edu/scieng/chemistry

  20. Microscale Effects from Global Hot Plasma Imagery

    NASA Technical Reports Server (NTRS)

    Moore, T. E.; Fok, M.-C.; Perez, J. D.; Keady, J. P.

    1995-01-01

    We have used a three-dimensional model of recovery phase storm hot plasmas to explore the signatures of pitch angle distributions (PADS) in global fast atom imagery of the magnetosphere. The model computes mass, energy, and position-dependent PADs based on drift effects, charge exchange losses, and Coulomb drag. The hot plasma PAD strongly influences both the storm current system carried by the hot plasma and its time evolution. In turn, the PAD is strongly influenced by plasma waves through pitch angle diffusion, a microscale effect. We report the first simulated neutral atom images that account for anisotropic PADs within the hot plasma. They exhibit spatial distribution features that correspond directly to the PADs along the lines of sight. We investigate the use of image brightness distributions along tangent-shell field lines to infer equatorial PADS. In tangent-shell regions with minimal spatial gradients, reasonably accurate PADs are inferred from simulated images. They demonstrate the importance of modeling PADs for image inversion and show that comparisons of models with real storm plasma images will reveal the global effects of these microscale processes.

  1. Chemistry Research

    NASA Technical Reports Server (NTRS)

    1987-01-01

    Philip Morris research center scientists use a computer program called CECTRP, for Chemical Equilibrium Composition and Transport Properties, to gain insight into the behavior of atoms as they progress along the reaction pathway. Use of the program lets the scientist accurately predict the behavior of a given molecule or group of molecules. Computer generated data must be checked by laboratory experiment, but the use of CECTRP saves the researchers hundreds of hours of laboratory time since experiments must run only to validate the computer's prediction. Philip Morris estimates that had CECTRP not been available, at least two man years would have been required to develop a program to perform similar free energy calculations.

  2. 6. HOT AIR PORTION OF DAMPERS. Hot Springs National ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. HOT AIR PORTION OF DAMPERS. - Hot Springs National Park, Bathhouse Row, Lamar Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

  3. Simulations of the chemistry of shocked energetic materials on the nanosecond timescale

    NASA Astrophysics Data System (ADS)

    Fried, Laurence

    2013-06-01

    The initiation of chemistry by a shock wave occurs through complex interactions between chemical and mechanical mechanisms. The first few nanoseconds after shock arrival is a crucial time period, where the initiation of exothermic chemical reactions leads to the growth of local hot spots. We are simulating these mechanisms in two ways. First, we are performing atomistic simulations of shocked TATB using a modified version of the ReaxFF force field. We have found that modification of ReaxFF is necessary in order to accurately model charge transfer and ionization under sustained high density conditions. We have simulated overdriven detonation waves in TATB using the multi-scale shock technique (MSST). In our simulations of overdriven shocked TATB, we find that large-scale graphitic structures encompassing thousands of atoms form after 1 ns. A second simulation technique uses continuum mechanics with an anisotropic crystal-level plasticity model for shocked HMX. We use a thermochemical approach to model the equation of state and chemistry of the shocked energetic material. In the simulations a pore is compressed by a shock wave, resulting in material deformation and chemistry. We find that simulations with crystal-level plasticity predict chemistry that is localized in fluid regions. The results of the crystal plasticity model will be compared with a more traditional treatment of plasticity in HMX via shock viscosity. The initiation of chemistry by a shock wave occurs through complex interactions between chemical and mechanical mechanisms. The first few nanoseconds after shock arrival is a crucial time period, where the initiation of exothermic chemical reactions leads to the growth of local hot spots. We are simulating these mechanisms in two ways. First, we are performing atomistic simulations of shocked TATB using a modified version of the ReaxFF force field. We have found that modification of ReaxFF is necessary in order to accurately model charge transfer and ionization under sustained high density conditions. We have simulated overdriven detonation waves in TATB using the multi-scale shock technique (MSST). In our simulations of overdriven shocked TATB, we find that large-scale graphitic structures encompassing thousands of atoms form after 1 ns. A second simulation technique uses continuum mechanics with an anisotropic crystal-level plasticity model for shocked HMX. We use a thermochemical approach to model the equation of state and chemistry of the shocked energetic material. In the simulations a pore is compressed by a shock wave, resulting in material deformation and chemistry. We find that simulations with crystal-level plasticity predict chemistry that is localized in fluid regions. The results of the crystal plasticity model will be compared with a more traditional treatment of plasticity in HMX via shock viscosity. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  4. Hot air balloon engine

    Microsoft Academic Search

    Ian Edmonds

    2009-01-01

    This paper describes a solar powered reciprocating engine based on the use of a tethered hot air balloon fuelled by hot air from a glazed collector. The basic theory of the balloon engine is derived and used to predict the performance of engines in the 10kW to 1MW range. The engine can operate over several thousand metres altitude with thermal

  5. Solar Hot Box

    NSDL National Science Digital Library

    In this lesson, students explore different aspects of solar energy by building a solar hot box and testing various colors and materials to find the maximum temperature that can be reached. They will review the basic needs for alternative energy sources, identify three materials and colors that will produce maximum heat, and solve a design problem for the hot box.

  6. Hot Air Balloon

    NSDL National Science Digital Library

    Oakland Discovery Centers

    2012-01-01

    In this activity, learners build a hot air balloon using just a few sheets of tissue paper and a hair dryer. Use this activity to demonstrate how hot air rises due to density and how the volume of gas increases with temperature (Charles's Law).

  7. Hot Spot at Yellowstone

    ERIC Educational Resources Information Center

    Dress, Abby

    2005-01-01

    Within this huge national park (over two million acres spread across Wyoming, Montana, and Idaho) are steaming geysers, hot springs, bubbling mudpots, and fumaroles, or steam vents. Drives on the main roads of Yellowstone take tourists through the major hot attractions, which also include Norris Geyser Basin, Upper and Lower Geyser Basin, West…

  8. Index to the Understanding the Atom Series.

    ERIC Educational Resources Information Center

    Atomic Energy Commission, Oak Ridge, TN. Div. of Technical Information.

    This index was prepared for the set of 51 booklets in the "Understanding the Atom Series" published by the U. S. Atomic Energy Commission for high school students and their teachers. In addition to the index, a complete list of the series is provided in which the booklets are grouped into the categories of physics, chemistry, biology, nuclear…

  9. Digital Resource Package for Teaching Atomic Structure

    NSDL National Science Digital Library

    Laura Moin

    This digital resource package is a collection of online sources to help K-12 teachers create lessons on the Chemistry subject of atomic structures. Topics include The History of the Atom, Reference Material, Tutorials, Simulations, Questions and Activities, Periodic Tables, and resources for more advanced learners.

  10. Richard T. Oakley FRSC, Professor of Chemistry

    E-print Network

    Le Roy, Robert J.

    -doctoral Fellow, 1976-78, Univ. of Wisconsin and Stanford University The design and synthesis of single component. Chemistry, electrochemistry, EPR spectroscopy, electronic and magnetic properties of molecular radicals. Heavy atom radicals as multifunctional molecular conductors and magnetic materials. Academic Background

  11. A materials informatics approach for crystal chemistry

    Microsoft Academic Search

    Chang Sun Kong

    2009-01-01

    This thesis addresses one of the fundamental questions in materials crystal chemistry, namely why do atoms arrange themselves in the way they do? The ability to broadly design and predict new phases [i.e. crystal structures] can be partly met using concepts that employ phase homologies. Homologous series of compounds are those that seem chemically diverse but can be expressed in

  12. Polyhedra in physics, chemistry and geometry

    E-print Network

    Michael Atiyah; Paul Sutcliffe

    2003-03-31

    In this article we review some problems in physics, chemistry and mathematics that lead naturally to a class of polyhedra which include the Platonic solids. Examples include the study of electrons on a sphere, cages of carbon atoms, central configurations of gravitating point particles, rare gas microclusters, soliton models of nuclei, magnetic monopole scattering and geometrical problems concerning point particles.

  13. Trace Chemistry

    NASA Technical Reports Server (NTRS)

    Radhakrishnan, Krishnan; Whitefield, Philip

    1999-01-01

    The goals of the trace chemistry group were to identify the processes relevant to aerosol and aerosol precursor formation occurring within aircraft gas turbine engines; that is, within the combustor, turbine, and nozzle. The topics of discussion focused on whether the chemistry of aerosol formation is homogeneous or heterogeneous; what species are important for aerosol and aerosol precursor formation; what modeling/theoretical activities to pursue; what experiments to carry out that both support modeling activities and elucidate fundamental processes; and the role of particulates in aerosol and aerosol precursor formation. The consensus of the group was that attention should be focused on SO2, SO3, and aerosols. Of immediate concern is the measurement of the concentration of the species SO3, SO2, H2SO4 OH, HO2, H2O2, O, NO, NO2, HONO, HNO3, CO, and CO2 and particulates in various engines, both those currently in use and those in development. The recommendation was that concentration measurements should be made at both the combustor exit and the engine exit. At each location the above species were classified into one of four categories of decreasing importance, Priority I through IV, as follows: Combustor exit: Priority I species - SO3:SO2 ratio, SO3, SO2, and particulates; Priority II species: OH and O; Priority III species - NO and NO2; and Priority IV species - CO and CO2. For the Engine exit: Priority I species - SO3:SO2 ratio, SO3, SO2,H2SO4, and particulates; Priority II species: OH,HO2, H2O2, and O; Priority III species - NO, NO2, HONO, and HNO3; and Priority IV species - CO and CO2. Table I summarizes the anticipated concentration range of each of these species. For particulate matter, the quantities of interest are the number density, size distribution, and composition. In order to provide data for validating multidimensional reacting flow models, it would be desirable to make 2-D, time-resolved measurements of the concentrations of the above species and, in addition, of the pressure, temperature, and velocity. A near term goal of the experimental program should be to confirm the nonlinear effects of sulfur speciation, and if present, to provide an explanation for them. It is also desirable to examine if the particulate matter retains any sulfur. The recommendation is to examine the effects on SOx production of variations in fuel-bound sulfur and aromatic content (which may affect the amount of particulates formed). These experiments should help us to understand if there is a coupling between particulate formation and SO, concentration. Similarly, any coupling with NOx can be examined either by introducing NOx into the combustion air or by using fuel-bound nitrogen. Also of immediate urgency is the need to establish and validate a detailed mechanism for sulfur oxidation/aerosol formation, whose chemistry is concluded to be homogeneous, because there is not enough surface area for heterogeneous effects. It is envisaged that this work will involve both experimental and theoretical programs. The experimental work will require, in addition to the measurements described above, fundamental studies in devices such as flow reactors and shock tubes. Complementing this effort should be modeling and theoretical activities. One impediment to the successful modeling of sulfur oxidation is the lack of reliable data for thermodynamic and transport properties for several species, such as aqueous nitric acid, sulfur oxides, and sulfuric acid. Quantum mechanical calculations are recommended as a convenient means of deriving values for these properties. Such calculations would also help establish rate constants for several important reactions for which experimental measurements are inherently fraught with uncertainty. Efforts to implement sufficiently detailed chemistry into computational fluid dynamic codes should be continued. Zero- and one-dimensional flow models are also useful vehicles for elucidating the minimal set of species and reactions that must be included in two- and three-dimensional modeling studies.

  14. Chemistry and Chemical Biology

    E-print Network

    Linhardt, Robert J.

    Chemistry and Chemical Biology AT RENSSELAER ONE WORD To Drive Discovery -- RENSSELAER What is the best Chemistry Ph.D. program for you? Choosing the right Ph.D. Chemistry program depends on many interests, we encourage you consider the Department of Chemistry and Chemical Biology at Rensselaer. WHY

  15. Atomic Structure

    NSDL National Science Digital Library

    The Concord Consortium

    2011-12-11

    In this activity students explore the structure and properties of atoms. They construct models of atoms with properties of particular mass and charge; create models of atoms with different stabilities by adding or subtracting neutrons, protons, and electrons to a model atom; and determine that the same element may have varying number of neutrons and these form isotopes.Students will be able to:

  16. Atom Chips

    E-print Network

    Ron Folman; Peter Krüger; Donatella Cassettari; Björn Hessmo; Thomas Maier; Jörg Schmiedmayer

    1999-12-23

    Atoms can be trapped and guided using nano-fabricated wires on surfaces, achieving the scales required by quantum information proposals. These Atom Chips form the basis for robust and widespread applications of cold atoms ranging from atom optics to fundamental questions in mesoscopic physics, and possibly quantum information systems.

  17. Rotational and vibrational state distributions of HNC(0 v{Sup 1 ovr sub 2} 0) from the hot H atom reaction : H + (CN){sub 2}{yields}HNC + CN.

    SciTech Connect

    Macdonald, R. G.; Chemistry

    2000-11-16

    The reaction dynamics of the five-atom system, H + (CN){sub 2}, was investigated by probing the minor product channel producing the transient HNC molecule. The complete initial energy disposition, translation, rotation, and vibration was determined for the HNC(0v{sup 1}{sub 2} 0), v{sup 1}{sub 2} = 0{sup 0},1{sup -1}, product. The reaction was studied under bulk conditions and was initiated by energetic H atoms with a mean translational energy of 92 kJ mol{sup -1}. The HNC molecule was monitored by time- and frequency-resolved absorption spectroscopy with sub-Doppler resolution. The initial rotational state distribution of each HNC(0 v{sup 1}{sub 2} 0) vibrational level was measured and found to be well-described by a Boltzmann distribution. Only two vibrational levels were detected so that the initial HNC product vibrational level distribution was determined as well. The absolute reaction cross section for the title reaction was measured to be 2 x 10{sup -18} cm{sup -2} for H atoms with a nominal translational energy of 113 kJ mol.{sup -1}.

  18. Real-time Quantum Chemistry

    E-print Network

    Haag, Moritz P

    2012-01-01

    Significant progress in the development of efficient and fast algorithms for quantum chemical calculations has been made in the past two decades. The main focus has always been the desire to be able to treat ever larger molecules or molecular assemblies---especially linear and sub-linear scaling techniques are devoted to the accomplishment of this goal. However, as many chemical reactions are rather local, they usually involve only a limited number of atoms so that models of about two hundred (or even less) atoms embedded in a suitable environment are sufficient to study their mechanisms. Thus, the system size does not need to be enlarged, but remains constant for reactions of this type that can be described by less than two hundred atoms. The question then arises how fast one can obtain the quantum chemical results. This question is not directly answered by linear-scaling techniques. In fact, ideas such as haptic quantum chemistry or interactive quantum chemistry require an immediate provision of quantum che...

  19. ACS Green Chemistry Institute

    NSDL National Science Digital Library

    This special feature page from the American Chemical Society (ACS) showcases the up-and-coming field of "green chemistry," that is, the development of chemical products and processes that eliminate or reduce the use and generation of hazardous substances. A list of principles behind green chemistry, a searchable bibliography of green chemistry references, and green chemistry links (including conferences). This page comes from ACS's Green Chemistry Project, a three-year educational project to develop and disseminate green chemistry educational materials for graduate and undergraduate chemistry students.

  20. CHEMISTRY COURSE OFFERINGS SPRING, 2013 CHEM 0001-01 CHEMICAL FUNDAMENTALS W/LAB

    E-print Network

    Kounaves, Samuel P.

    CHEMISTRY COURSE OFFERINGS SPRING, 2013 (10/31/12) CHEM 0001-01 CHEMICAL FUNDAMENTALS W/LAB Atomic, and thermochemistry. Additional topics may include qualitative thermodynamics and equilibrium and chemistry of materials. Three lectures, one laboratory, one recitation. Only one of Chemistry 1, 11, or 16 may be counted

  1. Enhancing Adaptive Middleware for Quantum Chemistry Applications with a Database Framework

    E-print Network

    Sosonkina, Masha

    Enhancing Adaptive Middleware for Quantum Chemistry Applications with a Database Framework: mark,mike@si.msg.chem.iastate.edu Abstract-- Quantum chemistry applications such as the General Atomic molecular quantum chemistry calculations. These calculations include a wide range of Hartree-Fock(HF) wave

  2. Atom Interferometers

    E-print Network

    Alexander D. Cronin; Joerg Schmiedmayer; David E. Pritchard

    2007-12-21

    Interference with atomic and molecular matter waves is a rich branch of atomic physics and quantum optics. It started with atom diffraction from crystal surfaces and the separated oscillatory fields technique used in atomic clocks. Atom interferometry is now reaching maturity as a powerful art with many applications in modern science. In this review we first describe the basic tools for coherent atom optics including diffraction by nanostructures and laser light, three-grating interferometers, and double wells on AtomChips. Then we review scientific advances in a broad range of fields that have resulted from the application of atom interferometers. These are grouped in three categories: (1) fundamental quantum science, (2) precision metrology and (3) atomic and molecular physics. Although some experiments with Bose Einstein condensates are included, the focus of the review is on linear matter wave optics, i.e. phenomena where each single atom interferes with itself.

  3. Delights of Chemistry

    NSDL National Science Digital Library

    Developed by the University of Leeds, the Delights of Chemistry promotes the art of chemistry demonstrations. Users can find illustrations and explanations of forty chemistry experiments. Many animations of demonstrations including the magnesium lamp, thermite reaction, and the volcano reaction are available. The website is full of pictures of chemistry equipment and scientists at work. Through this site, students and educators are able to explore fun chemistry experiments without having to worry about the many hazards associated with working with chemicals.

  4. Legendre Functions Quantum Chemistry: Chemistry 180-345A

    E-print Network

    Ronis, David M.

    Legendre Functions Quantum Chemistry: Chemistry 180-345A In class we showed that the the angular Fall 2003 #12;Quantum Chemistry -2- Chemistry 180-345A which is divergent at x = ±1 (i.e., at = 0 Chemistry -3- Chemistry 180-345A Hydrogen orbitals for l = 0, 1 Fall 2003 #12;Quantum Chemistry -4

  5. Accurate theoretical chemistry with coupled pair models.

    PubMed

    Neese, Frank; Hansen, Andreas; Wennmohs, Frank; Grimme, Stefan

    2009-05-19

    Quantum chemistry has found its way into the everyday work of many experimental chemists. Calculations can predict the outcome of chemical reactions, afford insight into reaction mechanisms, and be used to interpret structure and bonding in molecules. Thus, contemporary theory offers tremendous opportunities in experimental chemical research. However, even with present-day computers and algorithms, we cannot solve the many particle Schrodinger equation exactly; inevitably some error is introduced in approximating the solutions of this equation. Thus, the accuracy of quantum chemical calculations is of critical importance. The affordable accuracy depends on molecular size and particularly on the total number of atoms: for orientation, ethanol has 9 atoms, aspirin 21 atoms, morphine 40 atoms, sildenafil 63 atoms, paclitaxel 113 atoms, insulin nearly 800 atoms, and quaternary hemoglobin almost 12,000 atoms. Currently, molecules with up to approximately 10 atoms can be very accurately studied by coupled cluster (CC) theory, approximately 100 atoms with second-order Møller-Plesset perturbation theory (MP2), approximately 1000 atoms with density functional theory (DFT), and beyond that number with semiempirical quantum chemistry and force-field methods. The overwhelming majority of present-day calculations in the 100-atom range use DFT. Although these methods have been very successful in quantum chemistry, they do not offer a well-defined hierarchy of calculations that allows one to systematically converge to the correct answer. Recently a number of rather spectacular failures of DFT methods have been found-even for seemingly simple systems such as hydrocarbons, fueling renewed interest in wave function-based methods that incorporate the relevant physics of electron correlation in a more systematic way. Thus, it would be highly desirable to fill the gap between 10 and 100 atoms with highly correlated ab initio methods. We have found that one of the earliest (and now almost forgotten) of this class of methods, the coupled-electron pair approximation (CEPA), performs exceedingly well in chemical applications. In this Account, we examine the performance of CEPA in chemical applications. One attractive feature of CEPA, in addition to its surprising accuracy that surpasses that of DFT and MP2 theory, is a simplicity that allows for straightforward and very efficient approximations and extensions to be developed; these are much more difficult or even impossible with the more rigorous CC theory. Thus, approximate CEPA methods can be implemented efficiently enough to allow for calculations on molecules of 50-100 atoms, perhaps the most common range in contemporary chemical research. PMID:19296607

  6. CSA Hot Topics Series

    NSDL National Science Digital Library

    The Hot Topics series provides a free sampling of the resources in Cambridge Scientific Abstracts (CSA) and the Internet Database Service (IDS). The 30 topics span subjects in the humanities, engineering, environmental policy, and medicine. Each Hot Topic gives an overview of the subject, key citations with abstracts, a list of Websites, a glossary, a comment form so that users can correspond with the editors, and a "source" section, which explains from which of CSA's paid services the resources were culled. The latest hot topic is MicroElectroMechanical systems (MEMS), "small integrated devices or systems that combine electrical and mechanical components."

  7. Industrial Chemistry and School Chemistry: Making Chemistry Studies More Relevant

    ERIC Educational Resources Information Center

    Hofstein, Avi; Kesner, Miri

    2006-01-01

    In this paper, we present the development and implementation over the period of more than 15 years of learning materials focusing on industrial chemistry as the main theme. The work was conducted in the Department of Science Teaching at the Weizmann Institute of Science, Israel. The project's general goal was to teach chemistry concepts in the…

  8. Chemistry Rocks: Redox Chemistry as a Geologic Tool.

    ERIC Educational Resources Information Center

    Burns, Mary Sue

    2001-01-01

    Applies chemistry to earth science, uses rocks in chemistry laboratories, and teaches about transition metal chemistry, oxidation states, and oxidation-reduction reactions from firsthand experiences. (YDS)

  9. MChem (Single Honours Degrees) Chemistry with External Placement

    E-print Network

    Brierley, Andrew

    with Mathematics MSci (Joint Honours Degree) Chemistry and Physics BSc (Single Honours Degrees) Chemistry Chemistry62 Chemistry MChem (Single Honours Degrees) Chemistry Chemistry with External Placement Chemistry with Medicinal Chemistry Chemistry with Medicinal Chemistry and External Placement Materials Chemistry Materials

  10. Are "Hot Spots" Hot? An Overview Gillian R. Foulger

    E-print Network

    Foulger, G. R.

    Are "Hot Spots" Hot? ­ An Overview Gillian R. Foulger Dept. Earth Sciences, Univ. of Durham, Durham DH1 3LE, U.K. g.r.foulger@durham.ac.uk The term "hot spot" is taken variously to imply a) the presence of excessive volcanism, or b) that the melt formed in an unusually hot source. Case b

  11. 21 CFR 862.2850 - Atomic absorption spectrophotometer for clinical use.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Laboratory Instruments § 862.2850 Atomic absorption...

  12. Charmonium in Hot Medium 

    E-print Network

    Zhao, Xingbo

    2012-02-14

    We investigate charmonium production in the hot medium created by heavy-ion collisions by setting up a framework in which in-medium charmonium properties are constrained by thermal lattice QCD (lQCD) and subsequently implemented into kinetic...

  13. Modelling hot air balloons

    Microsoft Academic Search

    N. W. Brimicombe

    1991-01-01

    Hot air balloons can be modelled in a number of different ways. The most satisfactory, but least useful model is at a microscopic level. Macroscopic models are easier to use but can be very misleading.

  14. Reactor hot spot analysis

    SciTech Connect

    Vilim, R.B.

    1985-08-01

    The principle methods for performing reactor hot spot analysis are reviewed and examined for potential use in the Applied Physics Division. The semistatistical horizontal method is recommended for future work and is now available as an option in the SE2-ANL core thermal hydraulic code. The semistatistical horizontal method is applied to a small LMR to illustrate the calculation of cladding midwall and fuel centerline hot spot temperatures. The example includes a listing of uncertainties, estimates for their magnitudes, computation of hot spot subfactor values and calculation of two sigma temperatures. A review of the uncertainties that affect liquid metal fast reactors is also presented. It was found that hot spot subfactor magnitudes are strongly dependent on the reactor design and therefore reactor specific details must be carefully studied. 13 refs., 1 fig., 5 tabs.

  15. Hot Accretion Disks Revisited

    NASA Astrophysics Data System (ADS)

    Bjoernsson, Gunnlaugur; Abramowicz, Marek A.; Chen, Xingming; Lasota, Jean-Pierre

    1996-08-01

    All previous studies of hot (Tp 1010-1012 K), optically thin accretion disks have neglected either the presence of e+ e- pairs or advective cooling. Thus all hot disk models constructed previously have not been self-consistent. In this paper we calculate local disk models including pair physics, relevant radiative processes in the hot plasma, and the effect of advective cooling. We use a modification of the Björnsson & Svensson mapping method. We find that the role of e+ e- pairs in the structure of hot, optically thin accretion disks is far less significant than was previously thought. The improved description of the radiation-matter interactions provided in the present paper modify the previously obtained values of the critical parameters characterizing advectively dominated flows.

  16. Hot Springs Creek

    USGS Multimedia Gallery

    USGS scientist Jennifer Lewicki measures the discharge along a tributary to Hot Springs Creek, Akutan Island, Alaska. Steam (upper left) rises from 3 high-temperature springs that discharge into the tributary....

  17. The Hot Tub Mystery

    NSDL National Science Digital Library

    House, Herbert

    This case study sets up a mystery and asks students to solve it using science: why was the couple found dead in their hot tub? The material asks students to connect seemingly unrelated factors, such as blood pressure, hot water and alcohol. The material would be most appropriate for lower level undergraduate students. The case study and teaching notes may be downloaded in PDF format. The site also includes a section for instructor feedback where general comments may be read and contributed.

  18. TU KAISERSLAUTERN DEPARTMENT OF CHEMISTRY

    E-print Network

    Madlener, Klaus

    ............................................................................................44 PHYSICAL CHEMISTRY: Prof. Dr. M. Gerhards ....................................................................................................46 PHYSICAL CHEMISTRY: Prof. Dr. Dr. G. Niedner-Schatteburg...............................................................................48 PHYSICAL CHEMISTRY: PD Dr. C. Riehn ...........................................................................

  19. Supercritical Burning of Liquid Oxygen (LOX) Droplet with Detailed Chemistry

    E-print Network

    Heil, Matthias

    Supercritical Burning of Liquid Oxygen (LOX) Droplet with Detailed Chemistry J. DAOU,* P of the supercritical combustion of a liquid oxygen (LOX) droplet in a stagnant environment of hot hydrogen is carried. The conditions under which such a supercritical regime is reached, have been the purpose of recent investigations

  20. Hot Carbon Corona in Mars’ Upper Thermosphere and Exosphere

    NASA Astrophysics Data System (ADS)

    Lee, Yuni; Combi, M.; Tenishev, V.; Bougher, S.

    2013-10-01

    The production of energetic particles results in the formation of the hot corona, where the most of the escape of neutral atoms occur, in the Martian upper atmosphere. In order to investigate the dynamics of these energetic neutral atoms, we have carried out a study that provides a self-consistent global description of the hot corona in the upper thermosphere and exosphere by employing a self-consistent global kinetic model coupled with a thermosphere/ionosphere model. In this work, we evaluate the carbon atom inventory by studying the production and distribution of energetic carbon atoms. The most important source reactions for hot atomic carbon are expected to be photodissociation of CO and dissociative recombination of CO+, which are highly sensitive to solar activity and occur mostly deep in the dayside of the thermosphere. The latest available branching ratios is adopted, and appropriate choices of the rate coefficient and the photodissociation frequencies are made. In this study, we simulate the variations of the hot carbon corona over the solar cycle and seasons. The spatial distributions and profiles of density and temperature, atmospheric loss rates are discussed for the cases considered. The total global escape of hot carbon from all dominant photochemical processes is computed and compared with those from other previous models. To describe self-consistently the upper thermosphere and exosphere, a combination of our 3D Direct Simulation Monte Carlo (DSMC) model [Valeille, A., Combi, M., Bougher, S., Tenishev, V., Nagy, A., 2009. J. Geophys. Res. 114, E11006. doi:10.1029/2009JE003389] and the 3D Mars Thermosphere General Circulation Model (MTGCM) [Bougher, S. W., Bell, J. M., Murphy, J. R., Lopez-Valverde, M. A., Withers, P. G., 2006. Geophys. Res. Lett. 32, doi: 10.1029/2005GL024059. L02203] is used. Finally, our computed global total escape rate of hot carbon ranges ~ (5.2 - 57.1) × 1023 s-1 for the aphelion solar low to perihelion solar high case.

  1. Hot off the press.

    PubMed

    Hill, Robert A; Sutherland, Andrew

    2015-01-28

    A personal selection of 32 recent papers is presented covering various aspects of current developments in bioorganic chemistry and novel natural products such as forazoline A from an Actinomadura species. PMID:25565355

  2. Hot off the press.

    PubMed

    Hill, Robert A; Sutherland, Andrew

    2013-06-01

    A personal selection of 33 recent papers is presented covering various aspects of current developments in bioorganic chemistry and novel natural products such as asperterpenoid A, a metabolite of an endophytic Aspergillus species. PMID:23652358

  3. Hot off the press.

    PubMed

    Hill, Robert A; Sutherland, Andrew

    2015-07-22

    A personal selection of 32 recent papers is presented covering various aspects of current developments in bioorganic chemistry and novel natural products such as eudistidine A from a marine ascidian Eudistoma sp. PMID:26138661

  4. Special Report: Brain Chemistry.

    ERIC Educational Resources Information Center

    Krassner, Michael B.

    1983-01-01

    Chemical actions in the brain result in cognitive, emotional, neuroendocrine, neuromuscular, and/or neurocirculatory effects. Developments in understanding brain chemistry are discussed, considering among others, neurotransmitter chemistry, neuropeptides, drugs and the brain, antidepressants, and actions of minor tranquilizers. (JN)

  5. Igniting Chemistry in Fireworks

    NSDL National Science Digital Library

    WGBH Educational Foundation

    2004-01-29

    Students learn about the concepts of spectral chemistry, combustion, and the nature of fire through the use of visually rich fireworks resources. Optional resources address chemical reactions for those who want a more advanced chemistry lesson.

  6. Computational chemistry research

    NASA Technical Reports Server (NTRS)

    Levin, Eugene

    1987-01-01

    Task 41 is composed of two parts: (1) analysis and design studies related to the Numerical Aerodynamic Simulation (NAS) Extended Operating Configuration (EOC) and (2) computational chemistry. During the first half of 1987, Dr. Levin served as a member of an advanced system planning team to establish the requirements, goals, and principal technical characteristics of the NAS EOC. A paper entitled 'Scaling of Data Communications for an Advanced Supercomputer Network' is included. The high temperature transport properties (such as viscosity, thermal conductivity, etc.) of the major constituents of air (oxygen and nitrogen) were correctly determined. The results of prior ab initio computer solutions of the Schroedinger equation were combined with the best available experimental data to obtain complete interaction potentials for both neutral and ion-atom collision partners. These potentials were then used in a computer program to evaluate the collision cross-sections from which the transport properties could be determined. A paper entitled 'High Temperature Transport Properties of Air' is included.

  7. 79Black Holes -Hot Stuff! Artist's impression of gas falling into a black hole

    E-print Network

    79Black Holes - Hot Stuff! Artist's impression of gas falling into a black hole Image credit: NASA / Dana Berry, SkyWorks Digital When gas flows into a black hole, it gets very hot and emits light. The gas is heated because the atoms collide with each other as they fall into the black hole. Far away

  8. Chemistry -Bachelor of Science (SCH) Chemistry: ACS Certified

    E-print Network

    Chemistry - Bachelor of Science (SCH) Chemistry: ACS Certified Total Credits Required: 128 Required of the following courses Course Credits CH 1110 University Chemistry I 4 Course Credits AND CH 4110 Pharmaceutical Chemistry I 3 CH 1111 University Chemistry Lab I 1 CH 4120 Pharmaceutical Chemistry II 3 OR CH 4320

  9. Chemistry -Bachelor of Science (SCH) Chemistry: ACS Certified

    E-print Network

    Chemistry - Bachelor of Science (SCH) Chemistry: ACS Certified Total Credits Required: 128 Required of the following courses Course Credits CH 1150 University Chemistry I AND 3 Course Credits CH 1151 University Chemistry Lab I AND 1 CH 4110 Pharmaceutical Chemistry I 3 CH 1153 University Chemistry I Recitation 1 CH

  10. B.A. DEGREE REQUIREMENTS FOR CHEMISTRY (CHEMISTRY TRACK)

    E-print Network

    Doyle, Robert

    ) CHE 346: Physical Chemistry Lecture I (3) CHE 347: Physical ­ Analytical Chemistry Laboratory (2) CHE 356: Physical Chemistry Lecture II (3) CHE 357: Physical Chemistry Laboratory (2) AND CHE 335 (1) CHE 427: Intermediate Organic Chemistry (3) CHE 436: Advanced Physical Chemistry (3) CHE 467

  11. Exploring Conceptual Frameworks of Models of Atomic Structures and Periodic Variations, Chemical Bonding, and Molecular Shape and Polarity: A Comparison of Undergraduate General Chemistry Students with High and Low Levels of Content Knowledge

    ERIC Educational Resources Information Center

    Wang, Chia-Yu; Barrow, Lloyd H.

    2013-01-01

    The purpose of the study was to explore students' conceptual frameworks of models of atomic structure and periodic variations, chemical bonding, and molecular shape and polarity, and how these conceptual frameworks influence their quality of explanations and ability to shift among chemical representations. This study employed a purposeful sampling…

  12. The Chemistry Hypermedia Project

    NSDL National Science Digital Library

    These materials and documents are typical of those presented in an undergraduate course in general chemistry, analytical chemistry, and analytical instrumentation. Resources for educators include Excel spreadsheet simulations for analytical and physical chemistry, prototype JavaScripts and PERL scripts, lists of web workshops and publications, and links to the most recent papers and presentations from the Chemistry Hypermedia Project. There are also tutorials for equilibrium practice problems and analytical spectroscopy.

  13. Zeeman slowing of thulium atoms

    E-print Network

    Chebakov, K; Akimov, A; Sukachev, D; Kanorsky, S; Kolachevsky, N; Sorokin, V

    2009-01-01

    We demonstrate laser slowing of a hot thulium atomic beam using the nearly closed cycling transition $4\\textrm{f}^{13}6\\textrm{s}^2(^2\\textrm{F}^\\circ)(J=7/2)\\leftrightarrow4\\textrm{f}^{12}(^3\\textrm{H}_5)5\\textrm{d}_{3/2}6\\textrm{s}^2(J=9/2)$ at 410.6 nm. Atoms are decelerated to velocities around 25 m/s by a 40 cm Zeeman slower. The flux of slowed atoms is evaluated as $10^7 \\textrm{s}^{-1}\\textrm{cm}^{-2}$. The experiment explicitly indicates the possibility of trapping Tm atoms in a magneto-optical trap.

  14. Atom interferometers and atom holography

    SciTech Connect

    Shimizu, Fujio; Mitake, Satoru [Institute for Laser Science and CREST, University of Electro-Communications, Chofu-shi 182-8585 (Japan); Fujita, Jun-ichi [NEC Fundamental Research Laboratories, 34 Miyukigaoka, Tsukuba 305-0841 (Japan); Morinaga, Makoto [Department of Applied Physics, University of Tokyo, Bunkyo-ku, Tokyo 113 (Japan); Kishimoto, Tetsuo [Institute for Laser Science and CREST, University of Electro-Communications, Chofu-shi 182-8585 (Japan); Department of Applied Physics, University of Tokyo, Bunkyo-ku, Tokyo 113 (Japan)

    1999-06-11

    Various techniques of atom manipulation with a binary hologram are discussed and demonstrated experimentally. An atomic beam of metastable neon in the 1s{sub 3} state and a SiN thin film with holes that expresses the transmission function of the hologram are used to demonstrate this technique. The gray-scale holography of atoms is demonstrated for the first time. Other possibilities of holographic manipulation of atoms are also discussed.

  15. Chemistry and Chemical Engineering

    E-print Network

    Paxton, Anthony T.

    2011 SCHOOL OF Chemistry and Chemical Engineering Information for Candidates APPOINTMENT OF PROFESSOR OF CHEMICAL ENGINEERING #12;#12;SCHOOL OF Chemistry and Chemical Engineering 3 Thank you for your 6-7 School of Chemistry and Chemical Engineering 8-9 Staff Profiles 10-11 Queen's and Northern

  16. CHEMISTRY 12500 Stephen Hoffmann

    E-print Network

    Jiang, Wen

    CHEMISTRY 12500 Fall 2014 Instructor Stephen Hoffmann Office = ARMS 1343 Phone = 765-494-5740 Email@purdue.edu Required Course Materials · Chemistry: The Molecular Nature of Matter and Change, 6th Edition, by M. S. Silberberg, McGraw-Hill, 2014. [ISBN: 978-1-2593-79567] · Chemistry 12500 Laboratory Manual, Fall 2014

  17. CHEMISTRY 12600 Spring 2014

    E-print Network

    Jiang, Wen

    CHEMISTRY 12600 Spring 2014 Professor Professor Gabriela C. Weaver WTHR laboratory each week. Required Course Materials Chemistry: The Molecular Nature of Matter and Change, 6th Ed., by M. S. Silberberg, McGraw-Hill, 2012. [ISBN: 978-0-07-340265-9] Chemistry 126 Laboratory

  18. Chemistry 171 Instructors

    E-print Network

    Chemistry 171 Fall 2004 Instructors Dr. George C. Schatz (lecturer) Nano 4018 (491-5657) schatz edition by Peter Atkins and Loretta Jones. General Chemistry Laboratory Manual, Stipes Publishing. Available through PLU (student chemistry group) or the Norris Center Bookstore: Laboratory notebook ­ must

  19. Chemistry & Biology Perspective

    E-print Network

    Williams, Loren

    Chemistry & Biology Perspective The Origin of RNA and ``My Grandfather's Axe'' Nicholas V. Hud,1,* Brian J. Cafferty,1 Ramanarayanan Krishnamurthy,2 and Loren Dean Williams1 1School of Chemistry, Atlanta, GA 30332, USA 2Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037, USA

  20. CHEMISTRY 450 Spring, 2009

    E-print Network

    Stuart, Steven J.

    CHEMISTRY 450 Spring, 2009 Gautam Bhattacharyya, 363 Hunter Labs, phone: 656-1356 gautamb. This course does NOT have a separate laboratory meeting time. Course Goals CH 450 is the Chemistry Capstone course intended for chemistry majors in their final year of study. The main objectives for this course

  1. Chemistry for a SUSTAINABLE

    E-print Network

    Selloni, Annabella

    Viewpointt Chemistry for a SUSTAINABLE FUTURE MIGUEL GARCIA-GARIBAY UNIVERSITY OF CALIFORNIA LOS ON SUSTAINABIL- ITY AND CHEMISTRY, MAY 30­JUNE 1, 2006, ARLINGTON, VA. VICKI H. GRASSIAN (CO-CHAIR) UNIVERSITY innovations do we need to achieve the goal of a sustainable future? Chemistry, a branch of science that deals

  2. Analytical chemistry instrumentation

    SciTech Connect

    Laing, W.R.

    1986-01-01

    In nine sections, 48 chapters cover 1) analytical chemistry and the environment 2) environmental radiochemistry 3) automated instrumentation 4) advances in analytical mass spectrometry 5) fourier transform spectroscopy 6) analytical chemistry of plutonium 7) nuclear analytical chemistry 8) chemometrics and 9) nuclear fuel technology.

  3. Analytical chemistry instrumentation

    SciTech Connect

    Laing, W.R. (ed.)

    1986-01-01

    Separate abstracts were prepared for 48 papers in these conference proceedings. The topics covered include: analytical chemistry and the environment; environmental radiochemistry; automated instrumentation; advances in analytical mass spectrometry; Fourier transform spectroscopy; analytical chemistry of plutonium; nuclear analytical chemistry; chemometrics; and nuclear fuel technology. (LEW)

  4. Green Chemistry and Education.

    ERIC Educational Resources Information Center

    Hjeresen, Dennis L.; Schutt, David L.; Boese, Janet M.

    2000-01-01

    Many students today are profoundly interested in the sustainability of their world. Introduces Green Chemistry and its principles with teaching materials. Green Chemistry is the use of chemistry for pollution prevention and the design of chemical products and processes that are environmentally benign. (ASK)

  5. Mechanisms in Photographic Chemistry

    ERIC Educational Resources Information Center

    Sahyun, M. R. V.

    1974-01-01

    Reviews current research interests in photographic chemistry, involving two proposed models for spectral sensitization of crystal defects and impurities in the photolysis reactivity and the mechanisms of development and complexation. Establishment of photographic chemistry in a chemistry curriculum is recommended. (CC)

  6. Chemistry For Kids.

    ERIC Educational Resources Information Center

    Smith, Patricia J., Ed.

    1985-01-01

    Desribes a chemistry course (taught in summer for graduate credit) for K-6 teachers to help promote teaching of chemistry as an experimental science at the elementary school level. Also describes another chemistry course for elementary school teachers, focusing on the laboratory component and experiments. (JN)

  7. Surface-enhanced Raman mapping of chemical hot spots

    NASA Astrophysics Data System (ADS)

    Voronine, Dmitri

    2015-03-01

    Surface-enhanced Raman spectroscopy (SERS) and atomic force microscopy (AFM) are used for simultaneous chemical-topographic mapping of Raman hot spots on dielectric, semiconductor and metal surfaces. Raman signals enhanced by electromagnetic and chemical mechanisms are separated. Several approaches of nanoscale surface analysis are compared. Future experimental advances for spatiotemporal imaging of surface dynamics using ultrafast lasers and multiple tips are discussed.

  8. Cavity Cooling with a Hot Cavity Vladan Vuletic

    E-print Network

    Vuletic, Vladan

    Cavity Cooling with a Hot Cavity Vladan Vuleti´c 1 Introduction Whereas from a classical point precision spectroscopy of anti-hydrogen, implement magnetic motors to move Bose-Einstein condensates to the atomic level structure [9], this cavity cooling technique holds promise for generalizing laser cooling

  9. Chemflex Overview: Common Chemistry core

    E-print Network

    Napier, Terrence

    see above Path A 28 see above and the following: 21 (for concentration) CHM 343 1 Physical chemistry laboratory CHM 341 4 Physical chemistry I CHM 342 4 Physical chemistry II CHM 334 3 Advanced chemistry Advanced chemistry elective BS Chemistry - Analytical/Physical Concentration Course Number Number

  10. IR Hot Wave

    SciTech Connect

    Graham, T. B.

    2010-04-01

    The IR Hot Wave{trademark} furnace is a breakthrough heat treatment system for manufacturing metal components. Near-infrared (IR) radiant energy combines with IR convective heating for heat treating. Heat treatment is an essential process in the manufacture of most components. The controlled heating and cooling of a metal or metal alloy alters its physical, mechanical, and sometimes chemical properties without changing the object's shape. The IR Hot Wave{trademark} furnace offers the simplest, quickest, most efficient, and cost-effective heat treatment option for metals and metal alloys. Compared with other heat treatment alternatives, the IR Hot Wave{trademark} system: (1) is 3 to 15 times faster; (2) is 2 to 3 times more energy efficient; (3) is 20% to 50% more cost-effective; (4) has a {+-}1 C thermal profile compared to a {+-}10 C thermal profile for conventional gas furnaces; and (5) has a 25% to 50% smaller footprint.

  11. Alcohol, Chemistry and You

    NSDL National Science Digital Library

    Developed by Kennesaw State University, ChemCases.com is a series of curriculum units that link responsible decision making in product development with chemical principles taught in college General Chemistry. Alcohol, Chemistry and You, by Dr. Bill Boggan, is the latest offering by the Web site, which "looks at the chemistry of beverage alcohol (ethyl alcohol) through the eyes of a General Chemistry student." The fourteen chapter lessons cover everything from what ethyl alcohol is to alcohol addiction, relating it to various principles learned in a general chemistry course.

  12. Rotational hot Brownian motion

    E-print Network

    Daniel Rings; Dipanjan Chakraborty; Klaus Kroy

    2012-03-14

    We establish an effective Markov theory for the rotational Brownian motion of hot nanobeads and nanorods. Compact analytical expressions for the effective temperature and friction are derived from the fluctuating hydrodynamic equations of motion. They are verified by comparison with recent measurements and with GPU powered parallel molecular dynamics simulations over a wide temperature range. This provides unique insights into the physics of hot Brownian motion and an excellent starting point for further experimental tests and applications involving laser-heated nanobeads, nanorods and Janus particles.

  13. Surface morphology and chemistry of Prunus laurocerasus L. leaves: a study using X-ray photoelectron spectroscopy, time-of-flight secondary-ion mass spectrometry, atomic-force microscopy and scanning-electron microscopy

    Microsoft Academic Search

    Mark C. Perkins; Clive J. Roberts; David Briggs; Martyn C. Davies; Adrian Friedmann; Clifford A. Hart; Gordon A. Bell

    2005-01-01

    The surface properties of the plant cuticle play a crucial role in plant–pathogen interactions and the retention and penetration of agriculturally important chemicals. This paper describes the use of X-ray photoelectron spectroscopy (XPS), time-of-flight secondary-ion mass spectrometry (ToF-SIMS), tapping-mode atomic force microscopy (TM-AFM) and scanning electron microscopy (SEM) to determine surface-specific chemical and material properties of the adaxial surface of

  14. Surface chemistry: a non-negligible parameter in determining optical properties of small colloidal metal nanoparticles

    Microsoft Academic Search

    Yugang Sun; Stephen K. Gray; Sheng Peng

    2011-01-01

    Surface chemistry can become pronounced in determining the optical properties of colloidal metal nanoparticles as the nanoparticles become so small (diameters <20 nm) that the surface atoms, which can undergo chemical interactions with the environment, represent a significant fraction of the total number of atoms although this effect is often ignored. For instance, formation of chemical bonds between surface atoms

  15. Hot helium flow test facility summary report

    SciTech Connect

    Not Available

    1980-06-01

    This report summarizes the results of a study conducted to assess the feasibility and cost of modifying an existing circulator test facility (CTF) at General Atomic Company (GA). The CTF originally was built to test the Delmarva Power and Light Co. steam-driven circulator. This circulator, as modified, could provide a source of hot, pressurized helium for high-temperature gas-cooled reactor (HTGR) and gas-cooled fast breeder reactor (GCFR) component testing. To achieve this purpose, a high-temperature impeller would be installed on the existing machine. The projected range of tests which could be conducted for the project is also presented, along with corresponding cost considerations.

  16. Historical Account And Branching To Rarefied Gas Dynamics Of Atomic and Molecular Beams : A Continuing And Fascinating Odyssey Commemorated By Nobel Prizes Awarded To 23 Laureates In Physics And Chemistry

    NASA Astrophysics Data System (ADS)

    Campargue, Roger

    2005-05-01

    This Historical Account derived in part from D. R. Herschbach was presented as an opening lecture of the Molecular Beam Session organized at the 24th International Symposium on Rarefied Gas Dynamics held in Bari, Italy, in July 2004. The emphasis is on the impressive results due to the molecular beam techniques in the last century. The first section summarizes the historical beam experiments performed by 14 Nobel Prize laureates having used the thermally effusive sources to establish the basic principles of Modern Physics. The second section is on the branching of Molecular Beams to Rarefied Gas Dynamics having permitted to investigate the physics of supersonic free jets and transform the molecular beam techniques. Finally, the last section relates the spectacular molecular beam experiments in helium free jet ultracooling, molecular spectroscopy, chemical reaction dynamics, clustering and modification of low density matter, and biomolecule mass spectrometry, rewarded by nine Nobel Prizes in Chemistry from 1986 to 2002.

  17. The hot-spring genesis of the Shimen realgar deposit, northwest Hunan

    Microsoft Academic Search

    Zhang Jingrong; Wang Wei; Yang Fan; Cai Tong

    1993-01-01

    The Shimen realgar deposit is characterized by the pipe-shaped orebody and the development of silica sinter and hydrothermal\\u000a explosive breccia which are typical of hot spring activity. Very similar trace-element associations are noticed between the\\u000a silica cap and the breccia and modern hot spring waters in the area. The chemistry of ore-forming solutions is also well comparable\\u000a with that of

  18. THE \\\\HOT SPOTS\\

    Microsoft Academic Search

    DAVID JERISON; NIKOLAI NADIRASHVILI

    x1. Introduction Consider a convex planar domain with two axes of symmetry. We show that the maximum and minimum of a Neumann eigenfunction with lowest nonzero eigen- value occur at points on the boundary only. We deduce J. Rauch's \\\\hot spots\\

  19. OECD Focus Hot File

    NSDL National Science Digital Library

    In each issue of the Organization for Economic Co-operation and Development (OECD)'s Focus Hot File, recent books and government reports of interest are listed with summaries and contact information. Past listings may be browsed by country in the Focus Compendium, and related publications are hyperlinked throughout.

  20. Keep It Hot!

    NSDL National Science Digital Library

    2014-09-18

    Student teams design insulated beverage bottles with the challenge to test them to determine which materials (and material thicknesses) work best at insulating hot water to keep it warm for as long as possible. Students test and compare their designs in still air and under a stream of moving air from a house fan.

  1. Hot piston ring tests

    NASA Technical Reports Server (NTRS)

    Allen, David J.; Tomazic, William A.

    1987-01-01

    As part of the DOE/NASA Automotive Stirling Engine Project, tests were made at NASA Lewis Research Center to determine whether appendix gap losses could be reduced and Stirling engine performance increased by installing an additional piston ring near the top of each piston dome. An MTI-designed upgraded Mod I Automotive Stirling Engine was used. Unlike the conventional rings at the bottom of the piston, these hot rings operated in a high temperature environment (700 C). They were made of a high temperature alloy (Stellite 6B) and a high temperature solid lubricant coating (NASA Lewis-developed PS-200) was applied to the cylinder walls. Engine tests were run at 5, 10, and 15 MPa operating pressure over a range of operating speeds. Tests were run both with hot rings and without to provide a baseline for comparison. Minimum data to assess the potential of both the hot rings and high temperature low friction coating was obtained. Results indicated a slight increase in power and efficiency, an increase over and above the friction loss introduced by the hot rings. Seal leakage measurements showed a significant reduction. Wear on both rings and coating was low.

  2. Hot Dog Champ Defeated

    E-print Network

    Hacker, Randi; Tsutsui, William; Bleier, R.H.

    2007-07-25

    Broadcast Transcript: Arthritic jaw? Recent wisdom tooth extraction? The universe saying "It is time"? Whatever. All we know is that Japan's six year domination of Nathan's Famous July 4th Hot Dog Eating contest at Coney Island came to an end...

  3. Kamchatka's thermal hot springs

    NSDL National Science Digital Library

    Vision of Kamchatka

    The Kamchatka Peninsula is featured in this website including information on geography, climate, fauna, flora, volcanoes, thermal springs, Valley of Geysers, native people, and options for travel in Kamchatka. This specific page highlights a selection of Kamchatka's hot springs, presenting basic information on temperature ranges, chemical and physical characteristics, surrounding vegetation, and general location.

  4. Some Like it Hot

    NSDL National Science Digital Library

    Henry Bortman

    NASA Astrobiologist Jack Farmer is featured in this web article that focuses on microrganisms found in Yellowstone hot springs and ocean floor hydrothermal vents. Included within the article are numerous links to concepts, resources, and further readings involving exobiology. and microbiology. Downloadable Quick time videos of a discussion with Farmer and hydrothermal vent activity at the ocean floor are also available.

  5. Editor's Note: Hot Properties

    NSDL National Science Digital Library

    Chris Ohana

    2008-01-01

    Properties are "hot," not in terms of real estate but in science class. Here, the editor highlights the feature articles related to this month's theme, Properties of Objects and Materials. With these articles as a guide, you can move students toward a deeper understanding of property. As you do so, they will build a strong foundation for future science learning.

  6. Atomic oxygen testing with thermal atom systems - A critical evaluation

    NASA Technical Reports Server (NTRS)

    Koontz, Steven L.; Albyn, Keith; Leger, Lubert J.

    1991-01-01

    The use of thermal atom (kinetic energy near 0.04 eV) test methods as a materials selection and screening technique for LEO spacecraft is critically evaluated in this paper. The physics and chemistry of the thermal atom environments are shown to produce specific mass loss rates (mg/sq cm per min) and reaction efficiencies (Re) radically different from those produced in the LEO environment. A response surface study shows that specific mass loss rates change rapidly with plasma-asher parameters and seldom agree with flight data. FEP Teflon is shown to react by a different mechanism than Kapton, polyethylene, or graphite. The Re (Re = volume of material removed/oxygen atom) of Kapton, polyethylene, Mylar, Tedlar, FEP Teflon, and graphite measured in a flowing afterglow apparatus are 0.001 to 0.0001 those measured with high-energy atoms (kinetic energy 1.5 eV or greater) in beam systems or in LEO. The effect of sample temperature and atom impact energy on Re is discussed. A simple kinetic model describing the reaction of atomic oxygen with polymer surfaces is developed. Guidelines and recommendations for thermal atom testing and interpretation of test results are presented.

  7. A model of hollow cathode plasma chemistry

    NASA Technical Reports Server (NTRS)

    Katz, I.; Anderson, J. R.; Polk, J. E.; Brophy, J. R.

    2002-01-01

    We have developed a new model of hollow cathode plasma chemistry based on the observation that xenon ion mobility is diffusion limited due to resonant charge exchange reactions. The model shows that vapor phase barium atoms are ionized almost immediately and electric fields accelerate the ions upstream from the emission zone. We have also applied the model to the orifice region, where the resultant ion generation profile correlates with previously reported orifice erosion.

  8. Hot Tub Rash (Pseudomonas Folliculitis)

    MedlinePLUS

    newsletter | contact Share | Hot Tub Rash ( Pseudomonas Folliculitis) Information for adults A A A This image displays follicular elevations of the skin and small pus-filled lesions. Overview Hot tub rash ( Pseudomonas folliculitis) is an infection of ...

  9. Atomic supersymmetry

    NASA Technical Reports Server (NTRS)

    Kostelecky, V. Alan

    1993-01-01

    Atomic supersymmetry is a quantum-mechanical supersymmetry connecting the properties of different atoms and ions. A short description of some established results in the subject are provided and a few recent developments are discussed including the extension to parabolic coordinates and the calculation of Stark maps using supersymmetry-based models.

  10. Exercising Safely in Hot Weather

    MedlinePLUS

    ... grouchy, acting strangely, staggering, or being unresponsive l Dry, flushed skin and a strong rapid pulse or a slow weak pulse l Not sweating even if it is hot Quick Tip For more hot weather tips, see the AgePage Hyperthermia: Too Hot for ...

  11. B.A. DEGREE REQUIREMENTS FOR CHEMISTRY (BIOLOGICAL CHEMISTRY TRACK)

    E-print Network

    Doyle, Robert

    326: Organic Chemistry Laboratory II (2) CHE 474: Structural and Physical Biochemistry I (3) 2: Intermediate Organic Chemistry (3) CHE 436: Advanced Physical Chemistry (3) CHE 467: Introduction to PhysicalB.A. DEGREE REQUIREMENTS FOR CHEMISTRY (BIOLOGICAL CHEMISTRY TRACK) Requirements include 21 credits

  12. Hot Tub Rash (Pseudomonas Dermatitis/Folliculitis)

    MedlinePLUS

    ... How Do I Protect Myself and My Family? "Hot Tub Rash" ( Pseudomonas Dermatitis / Folliculitis) Below are answers ... hot tub rash and healthy swimming. What is Hot Tub Rash? Hot tub rash, or dermatitis, is ...

  13. Chemistry 365 Useful Information

    E-print Network

    Ronis, David M.

    Chemistry 365 Quiz II Useful Information kB = 1. 380662 × 10-23 J/K h = 6. 6256 × 10-27 erg sec how your expression changes if you were to use HD instead of H2. March 20, 2002 #12;Chemistry 365 -2.11 * From, G. W. Castellan, Physical Chemistry What would the order be in the high temperature limit? Why? 4

  14. Middle School Chemistry

    NSDL National Science Digital Library

    Middle school science resource from ACS. It includes activity-based lesson plans for teaching basic chemistry concepts that cover all the main concepts in middle school chemistry. Each lesson also contains integrated animations and video that a teacher can use to help explain student observations on the molecular level. Online professional development will also be available to introduce and familiarize teachers with the demonstrations, activities, and chemistry content in the site.

  15. Science Update: Analytical Chemistry.

    ERIC Educational Resources Information Center

    Worthy, Ward

    1980-01-01

    Briefly discusses new instrumentation in the field of analytical chemistry. Advances in liquid chromatography, photoacoustic spectroscopy, the use of lasers, and mass spectrometry are also discussed. (CS)

  16. The Chemistry of Cocaine

    NSDL National Science Digital Library

    Brahmadeo Dewprashad

    2010-01-01

    This case study on the chemistry of cocaine is in the form of a classroom discussion between a professor and her students about cocaine, its addictive properties, a search for an addiction treatment, and the chemistry involved in the synthesis of cocaine in its various forms. The case can be used to teach nucleophilic addition reactions, nucleophilic acyl substitution, and cocaine metabolism. In addition, it provides students with experience in locating, reading, and analyzing a research paper.  The case was designed for the second course in a two-course sequence in undergraduate organic chemistry, but it could be adapted for medicinal chemistry classes.

  17. BachelorofScience/BachelorofEducation Chemistry/ScienceEducation

    E-print Network

    Morris, Joy

    - Organic Chemistry II ___ 6. Chemistry 2740 - Physical Chemistry List B - Elective Chemistry - Contemporary Chemistry ___Chemistry 3410 - Analytical Chemistry II ___Chemistry 3730 - Advanced PhysicalBachelorofScience/BachelorofEducation Chemistry/ScienceEducation This is a planning guide

  18. The Martian Hot Oxygen Corona at Ancient times

    NASA Astrophysics Data System (ADS)

    Lee, Y.; Combi, M. R.; Tenishev, V.; Bougher, S. W.; Dong, C.; Pawlowski, D. J.

    2014-12-01

    The evaluation of the global atomic oxygen loss rate and its changes over geologic time is necessary for a better understanding of the evolution of the Martian atmosphere. The recent surface geomorphological evidence suggests that water has played a key role in forming the present atmospheric environment. Throughout the planet's history, the inventory of water has been affected in part by changing solar radiation and solar wind conditions. In this study, we investigate the evolution of the oxygen atom inventory by simulating the hot oxygen corona for solar conditions appropriate to about 2.5 Gyr ago (about 3 times the current solar EUV flux). Dissociative recombination of O2+ion is assumed to remain as the dominant source of hot atomic oxygen at ancient times. To describe ancient Mars, we present the 3D self-consistent simulations of the Martian hot oxygen corona by one-way coupling our Adaptive Mesh Particle Simulator (AMPS) with the ancient thermosphere and ionosphere as simulated by the 3D Mars Global Ionosphere Thermosphere Model (M-GITM), a newly developed atmospheric model. The structure and composition of the Martian upper atmosphere and the hot oxygen corona during early solar conditions are compared with those at the current epoch to study the evolution of the macroscopic parameters and their effects on the hot oxygen corona. The coupled framework provides the density and escape probabilities of hot oxygen and estimates the global atmospheric loss rates for the conditions considered. These results are also being used as input into calculations of the global solar wind interaction with Mars' atmosphere, ionosphere and exosphere.

  19. STIS CCD Hot Pixel Annealing

    NASA Astrophysics Data System (ADS)

    Hernandez, Svea

    2013-10-01

    This purpose of this activity is to repair radiation induced hot pixel damage to theSTIS CCD by warming the CCD to the ambient instrument temperature and annealing radiation damaged pixels. Radiation damage creates hot pixels in the STIS CCD Detector. Many of these hot pixels can be repaired by warming the CCD from its normal operating temperature near-83 C to the ambient instrument temperature { +5 C} for several hours. The number of hot pixels repaired is a function of annealing temperature. The effectiveness of the CCD hot pixel annealing process is assessed by measuring the dark current behavior before and after annealing and by searching for any window contamination effects.

  20. Hot chocolate effect

    SciTech Connect

    Crawford, F.S.

    1982-05-01

    The ''hot chocolate effect'' was investigated quantitatively, using water. If a tall glass cylinder is filled nearly completely with water and tapped on the bottom with a softened mallet one can detect the lowest longitudinal mode of the water column, for which the height of the water column is one-quarter wavelength. If the cylinder is rapidly filled with hot tap water containing dissolved air the pitch of that mode may descend by nearly three octaves during the first few seconds as the air comes out of solution and forms bubbles. Then the pitch gradually rises as the bubbles float to the top. A simple theoretical expression for the pitch ratio is derived and compared with experiment. The agreement is good to within the 10% accuracy of the experiments.

  1. THE HOT CHOCOLATE EFFECT

    SciTech Connect

    Crawford, Frank S.

    1980-12-01

    The "hot chocolate effect" was investigated quantitatively, using water. If a tall glass cylinder is filled nearly completely with water and tapped on the bottom with a softened mallet one can detect the lowest longitudinal mode of the water column, for which the height of the water column is one quarter wavelength. If the cylinder is rapidly filled with hot tap water containing dissolved air the pitch of that mode may descend by nearly three octaves during the first few seconds as the air comes out of solution and forms bubbles. Then the pitch gradually rises as the bubbles float to the top. A simple theoretical expression for the pitch ratio is derived and compared with experiment. The agreement is good to within the ten percent accuracy of the experiments.

  2. The hot chocolate effect

    NASA Astrophysics Data System (ADS)

    Crawford, Frank S.

    1982-05-01

    The ''hot chocolate effect'' was investigated quantitatively, using water. If a tall glass cylinder is filled nearly completely with water and tapped on the bottom with a softened mallet one can detect the lowest longitudinal mode of the water column, for which the height of the water column is one-quarter wavelength. If the cylinder is rapidly filled with hot tap water containing dissolved air the pitch of that mode may descend by nearly three octaves during the first few seconds as the air comes out of solution and forms bubbles. Then the pitch gradually rises as the bubbles float to the top. A simple theoretical expression for the pitch ratio is derived and compared with experiment. The agreement is good to within the 10% accuracy of the experiments.

  3. Hot Billet Surface Qualifier

    SciTech Connect

    Tzyy-Shuh Chang

    2007-04-30

    OG Technologies, Inc. (OGT), developed a prototype of a Hot Billet Surface Qualifier (“Qualifier”) based on OGT’s patented HotEye™ technology and other proprietary imaging and computing technologies. The Qualifier demonstrated its ability of imaging the cast billets in line with high definition pictures, pictures capable of supporting the detection of surface anomalies on the billets. The detection will add the ability to simplify the subsequent process and to correct the surface quality issues in a much more timely and efficient manner. This is challenging due to the continuous casting environment, in which corrosive water, temperature, vibration, humidity, EMI and other unbearable factors exist. Each installation has the potential of 249,000 MMBTU in energy savings per year. This represents a cost reduction, reduced emissions, reduced water usage and reduced mill scale.

  4. Optimization of Hot Standby 

    E-print Network

    de Souza, J.; Holden, D.

    2004-01-01

    Utilities helps plant operations to find the correct trade-off between energy efficiency and reliability, such as: • Hot standby • Load shedding • Drive switching • Fuel selection • Electricity supply • Maintenance planning • Operator... over an extended period, usually a month, not the current instantaneous value Maintenance planning Correct maintenance plays an important part in maintaining system reliability. However, bringing equipment down for maintenance can also have a big...

  5. Session: Hot Dry Rock

    SciTech Connect

    Tennyson, George P. Jr.; Duchane, David V.; Ponden, Raymond F.; Brown, Donald W.

    1992-01-01

    This session at the Geothermal Energy Program Review X: Geothermal Energy and the Utility Market consisted of four presentations: ''Hot Dry Rock - Summary'' by George P. Tennyson, Jr.; ''HDR Opportunities and Challenges Beyond the Long Term Flow Test'' by David V. Duchane; ''Start-Up Operations at the Fenton Hill HDR Pilot Plant'' by Raymond F. Ponden; and ''Update on the Long-Term Flow Testing Program'' by Donald W. Brown.

  6. Optimization of Hot Standby

    E-print Network

    de Souza, J.; Holden, D.

    2004-01-01

    Utilities helps plant operations to find the correct trade-off between energy efficiency and reliability, such as: • Hot standby • Load shedding • Drive switching • Fuel selection • Electricity supply • Maintenance planning • Operator... over an extended period, usually a month, not the current instantaneous value Maintenance planning Correct maintenance plays an important part in maintaining system reliability. However, bringing equipment down for maintenance can also have a big...

  7. Hot refueling hazards.

    PubMed

    Hammer, D L

    1989-03-01

    Hot refueling in the special operations community has several potential hazards which can accompany the operation. The MC-130 Panel Operator's (PO) position is located in the exhaust of the number 3 engine, subjecting him to fumes, heat, and exhaust blast. The hypothesis was that time constraints should be implemented to the work load due to heat and carbon monoxide exposure. The hypothesis was confirmed for heat exposure but not for significant carbon monoxide exposure. PMID:2496343

  8. The ''hot'' patella

    SciTech Connect

    Kipper, M.S.; Alazraki, N.P.; Feiglin, D.H.

    1982-01-01

    Increased patellar uptake on bone scans is seen quite commonly but the possible or probable etiologies of this finding have not been previously well described. A review of 100 consecutive bone scans showed that the incidence of bilateral ''hot'' patellae is 15%. Identified etiologies include osteoarthritic degenerative disease (35%), fracture, possible metastatic disease, bursitis, Paget's disease, and osteomyelitis. The value of careful history, physical examination, and radiographs is stressed.

  9. Silicon chemistry in interstellar clouds

    NASA Technical Reports Server (NTRS)

    Langer, William D.; Glassgold, A. E.

    1990-01-01

    A new model of interstellar silicon chemistry is presented that explains the lack of SiO detections in cold clouds and contains an exponential temperature dependence for the SiO abundance. A key aspect of the model is the sensitivity of SiO production by neutral silicon reactions to density and temperature, which arises from the dependence of the rate coefficients on the population of the excited fine-structure levels of the silicon atom. As part of the explanation of the lack of SiO detections at low temperatures and densities, the model also emphasizes the small efficiencies of the production routes and the correspondingly long times needed to reach equilibrium. Measurements of the abundance of SiO, in conjunction with theory, can provide information on the physical properties of interstellar clouds such as the abundance of oxygen bearing molecules and the depletion of interstellar silicon.

  10. Microstructure Evolution of Gas Atomized Iron Based ODS Alloys

    SciTech Connect

    Rieken, J.R.; Anderson, I.E.; Kramer, M.J.; Anderegg, J.W.; Shechtman, D.

    2009-12-01

    In a simplified process to produce precursor powders for oxide dispersion-strength- ened (ODS) alloys, gas-atomization reaction synthesis (GARS) was used to induce a surface oxide layer on molten droplets of three differing erritic stainless steel alloys during break-up and rapid solidification. The chemistry of the surface oxide was identified using auger electron spectroscopy (AES) and scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS). The precursor iron-base powders were consolidated at 850 C and 1,300 C using hot isostatic pressing (HIPing). Consolidation at the lower temperature resulted in a fully dense microstructure, while preventing substantial prior particle-boundary-oxide dissociation. Microstructural analysis of the alloys consolidated at the higher temperature confirmed a significant reduction in prior-particle-boundary-oxide volume fraction, in comparison with the lower-temperature-consolidated sample. This provided evidence that a high-temperature internal oxygen-exchange reaction occurred between the metastable prior particle-boundary-oxide phase (chromium oxide) and the yttrium contained within each prior particle. This internal oxygen-exchange reaction is shown to result in the formation of yttrium-enriched oxide dispersoids throughout the alloy microstructure. The evolving microstructure was characterized using transmission electron microscopy (TEM) and high-energy X-ray diffraction (HE-XRD).

  11. Microstructure Evolution of Gas Atomized Iron Based ODS Alloys

    SciTech Connect

    Rieken, J.R.; Anderson, I.E.; Kramer, M.J.

    2011-08-09

    In a simplified process to produce precursor powders for oxide dispersion-strengthened (ODS) alloys, gas-atomization reaction synthesis (GARS) was used to induce a surface oxide layer on molten droplets of three differing erritic stainless steel alloys during break-up and rapid solidification. The chemistry of the surface oxide was identified using auger electron spectroscopy (AES) and scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS). The precursor iron-base powders were consolidated at 850 C and 1,300 C using hot isostatic pressing (HIPing). Consolidation at the lower temperature resulted in a fully dense microstructure, while preventing substantial prior particle-boundary-oxide dissociation. Microstructural analysis of the alloys consolidated at the higher temperature confirmed a significant reduction in prior-particle-boundary-oxide volume fraction, in comparison with the lower-temperature-consolidated sample. This provided evidence that a high-temperature internal oxygen-exchange reaction occurred between the metastable prior particle-boundary-oxide phase (chromium oxide) and the yttrium contained within each prior particle. This internal oxygen-exchange reaction is shown to result in the formation of yttrium-enriched oxide dispersoids throughout the alloy microstructure. The evolving microstructure was characterized using transmission electron microscopy (TEM) and high-energy X-ray diffraction (HE-XRD).

  12. Lithium chemistry in brown dwarfs and extrasolar gas giant planets

    NASA Astrophysics Data System (ADS)

    Lodders, K.

    1998-09-01

    Lithium chemistry (and that of all other naturally occurring elements) in brown dwarfs and gas giant planet atmospheres is being investigated by thermochemical equilibrium calculations, using the CONDOR code (Fegley and Lodders, 1994, Icarus 110, 117). The calculations are done for solar composition material over a wide pressure (P) and temperature (T) range appropriate for model atmospheres of Gl 229B, other brown dwarfs and putative extrasolar gas giant planets. Monatomic Li is the major Li gas at high T (but below the Li-Li+ boundary). As T decreases, Li (g) reacts to form LiCl. The abundances of LiH and LiOH also increase with decreasing T, but they are always less important than LiCl. The Li-LiCl boundary (equal abundance of these two gases) is given by the equation: 10,000/T ~ 6.565-0.3574 log P (bar). Between the Li-LiCl boundary and the Li_2S condensation line, which removes all Li from the gas at even lower T, monatomic Li is still present but at lower abundances than LiCl. The presence or absence of detectable monatomic Li in cool, low-mass objects is often used as a discriminant of whether or not the object has reached the stellar mass limit of 0.07-0.08 solar masses (Li absent) or has a lower substellar mass (Li present). However, this work shows that the Li-test for brown dwarf candidates suggested by Rebollo and coworkers (1992, ApJ. 389, L83) may only apply to objects with sufficiently hot atmospheres, where Li is dominantly in its monatomic form. In the coolest brown dwarfs and in gas giant planets low atomic Li abundances or the absence of Li occurs because Li forms LiCl gas or condenses out as Li_2S. Supported by NAG5-6366 from the NASA Planetary Atmospheres Program.

  13. Mechanical gate control for atom-by-atom cluster assembly with scanning probe microscopy.

    PubMed

    Sugimoto, Yoshiaki; Yurtsever, Ayhan; Hirayama, Naoki; Abe, Masayuki; Morita, Seizo

    2014-01-01

    Nanoclusters supported on substrates are of great importance in physics and chemistry as well as in technical applications, such as single-electron transistors and nanocatalysts. The properties of nanoclusters differ significantly from those of either the constituent atoms or the bulk solid, and are highly sensitive to size and chemical composition. Here we propose a novel atom gating technique to assemble various atom clusters composed of a defined number of atoms at room temperature. The present gating operation is based on the transfer of single diffusing atoms among nanospaces governed by gates, which can be opened in response to the chemical interaction force with a scanning probe microscope tip. This method provides an alternative way to create pre-designed atom clusters with different chemical compositions and to evaluate their chemical stabilities, thus enabling investigation into the influence that a single dopant atom incorporated into the host clusters has on a given cluster stability. PMID:25014188

  14. Quantum Chemistry at Finite Temperature

    E-print Network

    Liqiang Wei

    2006-05-23

    In this article, we present emerging fields of quantum chemistry at finite temperature. We discuss its recent developments on both experimental and theoretical fronts. First, we describe several experimental investigations related to the temperature effects on the structures, electronic spectra, or bond rupture forces for molecules. These include the analysis of the temperature impact on the pathway shifts for the protein unfolding by atomic force microscopy (AFM), the temperature dependence of the absorption spectra of electrons in solvents, and the temperature influence over the intermolecular forces measured by the AFM. On the theoretical side, we review advancements made by the author in the coming fields of quantum chemistry at finite temperature. Starting from the Bloch equation, we have derived the sets of hierarchy equations for the reduced density operators in both canonical and grand canonical ensembles. They provide a law according to which the reduced density operators vary in temperature for the identical and interacting many-body systems. By taking the independent particle approximation, we have solved the equations in the case of a grand canonical ensemble, and obtained an energy eigenequation for the molecular orbitals at finite temperature. The explicit expression for the temperature-dependent Fock operator is also given. They form a mathematical foundation for the examination of the molecular electronic structures and their interplay with finite temperature. Moreover, we clarify the physics concerning the temperature effects on the electronic structures or processes of the molecules, which is crucial for both theoretical understanding and computation. Finally, ....

  15. PREFACE: Hot Quarks 2004

    NASA Astrophysics Data System (ADS)

    Antinori, Federico; Bass, Steffen A.; Bellwied, Rene; Ullrich, Thomas; Velkovska, Julia; Wiedemann, Urs

    2005-04-01

    Why another conference devoted to ultra-relativistic heavy-ion physics? As we looked around the landscape of the existing international conferences and workshops, we realized that there was not a single one tailored to the people who are most directly involved with the actual research work: students, post-docs, and junior faculty/research scientists. Of course there are schools, but that was not what we had in mind. We wanted a meeting where young researchers could come together to discuss in depth the physics that they are working on without any hindrance. The major conferences have very limited time for discussions which is often shared amongst the most established. This leaves little room for young people to ask their questions and to get the detailed feedback which they deserve and which satisfies their curiosity. A discussion-driven workshop, centering on those without whom there will be no future—that seemed like what was needed. And thus the Hot Quarks workshop was born. The aim of Hot Quarks was to enhance the direct exchange of scientific information among the younger members of the community, from both experiment and theory. Participation was by invitation only in order to emphasize the contributions from junior researchers. This approach makes the workshop unique among the many forums in the field. For young scientists it represented an opportunity for exposure that they would not have had in one of the major conferences. The hope is that this meeting has helped to stimulate the next generation of scientists in our field and, at the same time, strengthened their sense of community. It all came together from 18 24 July 2004, when the 77 participants met at The Inn at Snakedance in the Taos Ski Valley, New Mexico, USA, for the first Hot Quarks workshop. Photograph Participants gather in the sunshine at the foot of the Taos Ski Valley chairlift. By all accounts, Hot Quarks 2004 was a great success. Every participant had the opportunity to present her or his research and we spent an entire week talking physics and having fun from breakfast in the morning until late at night. A symbolic award was instituted for the best presentation at the workshop, dedicated to the memory of Klaus Kinder-Geiger, a sharp and brilliant young theorist who perished in the crash of Swissair Flight 111 on 2 September 1998 off the coast of Nova Scotia. It went to Denesh Molnar from Ohio State University for his outstanding talk on parton coalescence. The organizers wish to extend their gratitude to all participants for the high quality presentations making Hot Quarks 2004 a notable event. We are also very grateful for the superb hospitality of the staff of the Snakedance Inn, in particular Mitch Daniels who worked sheer miracles. Given the success of the first Hot Quarks workshop we decided to organize a second one, possibly even turning Hot Quarks into a series. The next meeting will be held in the late spring of 2006, probably in Italy. We hope it will be as memorable as the first one! Last but not least, we wish to thank all the generous sponsors of the conference: Brookhaven National Laboratory, European Organization for Nuclear Research (CERN), Gesellschaft fA~ 1/4 r Schwerionenforschung (GSI), Institute of Physics Publishing, Los Alamos National Laboratory, National Science Foundation, and Vanderbilt University. We are grateful for their support and are particularly happy that this support came from institutions both in the US and in Europe and from all the main experimental facilities that pursue a prominent heavy-ion program. Their support was essential for the success of a workshop targeting young scientists.

  16. Basic Chemistry Review

    NSDL National Science Digital Library

    Thomas Meixner

    This assignment reviews basic of chemistry for students who should have had 2 introductory semesters of basic chemistry prior to enrolling in the Fundamental of Water Quality course for which the assignment is used. Assignment reviews basic equation balancing and questions about valence and concentration conversion that students will confront regularly in any geochemistry course.

  17. Chemistry & Biology Brief Communication

    E-print Network

    Miranker, Andrew

    Chemistry & Biology Brief Communication A Peptidomimetic Approach to Targeting Pre Avenue, New Haven, CT 06520-8114, USA 2Department of Chemistry, Yale University, 225 Prospect Street, P., 1999). These amyloid plaques are composed primarily of fibers formed from islet amyloid polypep- tide

  18. Stratospheric chemistry and transport

    NASA Technical Reports Server (NTRS)

    Prather, Michael; Garcia, Maria M.

    1990-01-01

    A Chemical Tracer Model (CTM) that can use wind field data generated by the General Circulation Model (GCM) is developed to implement chemistry in the three dimensional GCM of the middle atmosphere. Initially, chemical tracers with simple first order losses such as N2O are used. Successive models are to incorporate more complex ozone chemistry.

  19. Chemistry 365 Useful Information

    E-print Network

    Ronis, David M.

    Chemistry 365 Quiz II Useful Information kB = 1. 380662 × 10-16 erg/K h = 6. 6256 × 10-27 erg sec homonuclear diatomic molecules. Assume that the nuclei have spin 1. March 18, 1994 over... #12;Chemistry 365

  20. Macromolecular Chemistry and Physics

    E-print Network

    Guo, John Zhanhu

    , Mansfield Road, Oxford, OX1 3TA, United Kingdom L. Sun Department of Chemistry and Biochemistry, Texas State2429 Full Paper Macromolecular Chemistry and Physics wileyonlinelibrary.com Macromol. Chem. Phys Wang, Luyi Sun, Zhanhu Guo* PP nanocomposites containing different carbon nanofillers (CNTs, CNFs, Gn

  1. Chemistry and Biology

    ERIC Educational Resources Information Center

    Wigston, David L.

    1970-01-01

    Discusses the relationship between chemisty and biology in the science curriculum. Points out the differences in perception of the disciplines, which the physical scientists favoring reductionism. Suggests that biology departments offer a special course for chemistry students, just as the chemistry departments have done for biology students.…

  2. WATER CHEMISTRY ASSESSMENT METHODS

    EPA Science Inventory

    This section summarizes and evaluates the surfce water column chemistry assessment methods for USEPA/EMAP-SW, USGS-NAQA, USEPA-RBP, Oho EPA, and MDNR-MBSS. The basic objective of surface water column chemistry assessment is to characterize surface water quality by measuring a sui...

  3. Sawyer Environmental Chemistry Research

    E-print Network

    Thomas, Andrew

    1 Sawyer Environmental Chemistry Research Laboratory Sawyer Environmental Research Center University of Maine #12;2 Mission Statement The Sawyer Environmental Chemistry Research Laboratory is a multi- disciplinary facility for environmental research and education at the University of Maine. The lab provides

  4. Environmental Chemistry Library

    NSDL National Science Digital Library

    This is an "everything" site for the teaching of environmental chemistry. The site contains some unique case studies, a list of textbooks, lab and modeling activities and other educational content. The content is still in development, but the material provided would be helpful in developing a unit or course on environmental chemistry.

  5. General Chemistry Online

    NSDL National Science Digital Library

    This educational site features: A searchable database of over 800 common compound names; Hyperlinked notes for first semester general chemistry; Interactive graphing, popup tables, and calculators; an index of self-guided tutorials, quizzes, and drills on specific topics; a searchable glossary; and a Chemistry Exam Survival Guide

  6. Secondary atomization

    Microsoft Academic Search

    D. R. Guildenbecher; C. López-Rivera; P. E. Sojka

    2009-01-01

    When a drop is subjected to a surrounding dispersed phase that is moving at an initial relative velocity, aerodynamic forces\\u000a will cause it to deform and fragment. This is referred to as secondary atomization. In this paper, the abundant literature\\u000a on secondary atomization experimental methods, breakup morphology, breakup times, fragment size and velocity distributions,\\u000a and modeling efforts is reviewed and

  7. Cold Atoms

    NASA Astrophysics Data System (ADS)

    Bellac, Michel Le

    2014-11-01

    This chapter and the following one address collective effects of quantum particles, that is, the effects which are observed when we put together a large number of identical particles, for example, electrons, helium-4 or rubidium-85 atoms. We shall see that quantum particles can be classified into two categories, bosons and fermions, whose collective behavior is radically different. Bosons have a tendency to pile up in the same quantum state, while fermions have a tendency to avoid each other. We say that bosons and fermions obey two different quantum statistics, the Bose-Einstein and the Fermi-Dirac statistics, respectively. Temperature is a collective effect, and in Section 5.1 we shall explain the concept of absolute temperature and its relation to the average kinetic energy of molecules. We shall describe in Section 5.2 how we can cool atoms down thanks to the Doppler effect, and explain how cold atoms can be used to improve the accuracy of atomic clocks by a factor of about 100. The effects of quantum statistics are prominent at low temperatures, and atom cooling will be used to obtain Bose-Einstein condensates at low enough temperatures, when the atoms are bosons.

  8. Radiological and Environmental Research Division annual report, October 1979-September 1980: fundamental molecular physics and chemistry

    SciTech Connect

    Inokuti, Mitio; Dehmer, P. M.; Pratt, S. T.; Poliakoff, E. D.; Dehmer, J. L.; Stockbauer, Roger; Dill, Dan; Parr, A. C.; Jackson, K. H.; Zare, R. N.; Person, J. C.; Nicole, P. P.; Fowler, D. E.; Codling, K.; West, J. B.; Ederer, D. L.; Cole, B. E.; Loomba, D.; Wallace, Scott; Swanson, J. R.; Poliakoff, E. D.; Spence, David; Chupka, W. A.; Stevens, C. M.; Shyn, W. T.; Sharp, W. E.; Kim, Y. K.; Eggarter, E.; Baer, T.; Hanson, J. D.; Shimamura, Isao; Dillon, Michael A.

    1981-09-01

    Research is reported on the physics and chemistry of atoms, ions, and molecules, especially their interactions with external agents such as photons and electrons. Individual items from the report were prepared separately for the data base. (GHT)

  9. Coherent control of atoms and molecules

    Microsoft Academic Search

    Randy Alan Bartels

    2002-01-01

    Whenever scientific tools are significantly advanced; new discoveries soon follow. My thesis work relies on advances in ultrafast laser technology that allow precise control over the shape of sub 20-fs laser pulses. This laser system enabled many new experiments that yielded significant advances in attosecond science, atomic physics; extreme nonlinear optics, quantum chemistry, coherent control, molecular physics, ultrafast optical phase

  10. Distributed Pore Chemistry in Porous Organic Polymers

    NASA Technical Reports Server (NTRS)

    Koontz, Steven L. (Inventor)

    1998-01-01

    A method for making a biocompatible polymer article using a uniform atomic oxygen treatment is disclosed. The sub-strate may be subsequently optionally grated with a compatibilizing compound. Compatibilizing compounds may include proteins, phosphorylcholine groups, platelet adhesion preventing polymers, albumin adhesion promoters, and the like. The compatibilized substrate may also have a living cell layer adhered thereto. The atomic oxygen is preferably produced by a flowing afterglow microwave discharge, wherein the substrate resides in a sidearm out of the plasma. Also, methods for culturing cells for various purposes using the various membranes are disclosed as well. Also disclosed are porous organic polymers having a distributed pore chemistry (DPC) comprising hydrophilic and hydrophobic region, and a method for making the DPC by exposing the polymer to atomic oxygen wherein the rate of hydrophilization is greater than the rate of mass loss.

  11. Organic Chemistry Resources Worldwide

    NSDL National Science Digital Library

    Van Aken, Koen

    1996-01-01

    Organic Chemistry Worldwide is an excellent organic chemistry metasite that is not to be missed. Geared toward synthetic organic chemists involved in academic or industrial research, Organic Chemistry Resources Worldwide has a mission to collect and independently annotate "all useful organic chemistry sites and to present them in an intuitive way." This extensive metasite is divided into sections on literature, laboratory resources, spectroscopy and spectrometry, nomenclature and teaching, and conferences and organizations. The Literature section contains links to over 75 journals (some restricted access), 14 free databases (and many more commercial), dissertation collections, reviews, guides, patents, and current awareness sources. Examples of resources for laboratory work include links to chemical product databases, laboratory safety bulletins (.pdf), products and services, etc. Highlights of the site are an in-depth section on mass spectrometry, with links to publications and databases, and a plethora of links to organic chemistry labs worldwide, from Armenia to Uruguay.

  12. Ethylene oxide and Acetaldehyde in hot cores

    E-print Network

    Occhiogrosso, A; Herbst, E; Viti, S; Ward, M D; Price, S D; Brown, W A

    2014-01-01

    [Abridged] Ethylene oxide and its isomer acetaldehyde are important complex organic molecules because of their potential role in the formation of amino acids. Despite the fact that acetaldehyde is ubiquitous in the interstellar medium, ethylene oxide has not yet been detected in cold sources. We aim to understand the chemistry of the formation and loss of ethylene oxide in hot and cold interstellar objects (i) by including in a revised gas-grain network some recent experimental results on grain surfaces and (ii) by comparison with the chemical behaviour of its isomer, acetaldehyde. We test the code for the case of a hot core. The model allows us to predict the gaseous and solid ethylene oxide abundances during a cooling-down phase prior to star formation and during the subsequent warm-up phase. We can therefore predict at what temperatures ethylene oxide forms on grain surfaces and at what temperature it starts to desorb into the gas phase. The model reproduces the observed gaseous abundances of ethylene oxid...

  13. Is It Time to Retire the Hybrid Atomic Orbital?

    ERIC Educational Resources Information Center

    Grushow, Alexander

    2011-01-01

    A rationale for the removal of the hybrid atomic orbital from the chemistry curriculum is examined. Although the hybrid atomic orbital model does not accurately predict spectroscopic energies, many chemical educators continue to use and teach the model despite the confusion it can cause for students. Three arguments for retaining the model in the…

  14. Energetic Metastable Oxygen and Nitrogen Atoms in the Terrestrial Atmosphere

    NASA Technical Reports Server (NTRS)

    Kharchenko, Vasili

    2003-01-01

    We have investigated the energy distributions of the metastable oxygen atoms in the terrestrial thermosphere. Nascent O(lD) atoms play a fundamental role in the energy balance and chemistry of the terrestrial atmosphere, because they are produced by photo-chemical reactions in the excited electronic states and carry significant translational energies.

  15. Atomic and Molecular Structure Codes with Lab View

    Microsoft Academic Search

    Edward Deveney

    2005-01-01

    Atomic and molecular electronic structure (AMES) computer codes yield spectroscopic and dynamic details about atomic and molecular electron states. This information plays a fundamental and practical role in physics, chemistry, biology and industry. Advances in AMES codes have progressed in parallel with quantum theory and computer technologies yet many of the codes continue to be developed in the original scientific

  16. Atoms in astronomy

    NASA Technical Reports Server (NTRS)

    Blanchard, P. A.

    1976-01-01

    Aspects of electromagnetic radiation and atomic physics needed for an understanding of astronomical applications are explored. Although intended primarily for teachers, this brochure is written so that it can be distributed to students if desired. The first section, Basic Topics, is suitable for a ninth-grade general science class; the style is simple and repetitive, and no mathematics or physics background is required. The second section, Intermediate and Advanced Topics, requires a knowledge of the material in the first section and assumes a generally higher level of achievement and motivation on the part of the student. These latter topics might fit well into junior-level physics, chemistry, or earth-science courses. Also included are a glossary, a list of references and teaching aids, class exercises, and a question and answer section.

  17. Art in Chemistry; Chemistry in Art.

    ERIC Educational Resources Information Center

    Greenberg, Barbara R.; Patterson, Dianne

    High school teachers are often challenged to motivate students who have little or no interest in a subject and are bored with traditional instruction. This unique book is designed to help educators make chemistry classes more interesting and links art curriculum to practical applications, integrating the two subjects through scores of hands-on…

  18. Korean Kimchi Chemistry: A Multicultural Chemistry Connection

    ERIC Educational Resources Information Center

    Murfin, Brian

    2009-01-01

    Connecting science with different cultures is one way to interest students in science, to relate science to their lives, and at the same time to broaden their horizons in a variety of ways. In the lesson described here, students make kimchi, a delicious and popular Korean dish that can be used to explore many important chemistry concepts,…

  19. Chemistry for Kids: Elementary School Chemistry Activities.

    ERIC Educational Resources Information Center

    Seager, Spencer L.; Swenson, Karen T.

    1987-01-01

    Describes a program in which six experiments in chemistry were used in an elementary school science program. Discusses the problems encountered in initiating the program, and some of the ways the problems were solved. Lists the six experiments, along with the reaction or process being studied, and the application of each. (TW)

  20. Chemistry for Kids: Summer Chemistry for Fun.

    ERIC Educational Resources Information Center

    Hufford, Kevin D.

    1984-01-01

    A five-week course for fourth- and fifth-grade students (titled "Chemistry for Kids") was developed. Each class session consisted of a brief lecture, a demonstration, and one or more experiments. An outline of concepts fostered, instructional strategies, and procedures used is provided. (JN)

  1. Hot Electrons Do the Impossible: Plasmon-Induced Dissociation of H2 Shaunak Mukherjee,,

    E-print Network

    Florian, Libisch

    the vacuum level and the work function of the metal. In this transient state, hot electrons can transfer and Aerospace Engineering, Program in Applied and Computational Mathematics, and the Andlinger Center for Energy ABSTRACT: Heterogeneous catalysis is of paramount importance in chemistry and energy applications

  2. INT 10-2A, Quantifying the Properties of Hot QCD Matter Week #8 -EM Probes

    E-print Network

    Washington at Seattle, University of - Department of Physics, Electroweak Interaction Research Group

    INT 10-2A, Quantifying the Properties of Hot QCD Matter Week #8 - EM Probes ALL TALKS IN ROOM C-421 Chatterjee, Variable Energy Cyclotron Centre "Elliptic Flow of EM Signals" 10:30 am ­ Rainer Fries, Texas A & M University "Jet Chemistry and Contributions to EM Signals" Thursday, July 15 9:00 am ­ Vincenzo

  3. Hot oiling spreadsheet

    SciTech Connect

    Mansure, A.J. [Sandia National Labs., Albuquerque, NM (United States). Geothermal Research Dept.

    1996-09-01

    One of the most common oil-field treatments is hot oiling to remove paraffin from wells. Even though the practice is common, the thermal effectiveness of the process is not commonly understood. In order for producers to easily understand the thermodynamics of hot oiling, a simple tool is needed for estimating downhole temperatures. Such a tool has been developed that was distributed as a compiled, public-domain-software spreadsheet. That spreadsheet has evolved into an interactive from on the World Wide Web and has been adapted into a Windows{trademark} program by Petrolite, St. Louis MO. The development of such a tools was facilitated by expressing downhole temperatures in terms of analytic formulas. Considerable algebraic work is required to develop such formulas. Also, the data describing hot oiling is customarily a mixture of practical units that must be converted to a consistent set of units. To facilitate the algebraic manipulations and to assure unit conversions are correct, during development parallel calculations were made using the spreadsheet and a symbolic mathematics program. Derivation of the formulas considered falling film flow in the annulus and started from the transient differential equations so that the effects of the heat capacity of the tubing and casing could be included. While this approach to developing a software product does not have the power and sophistication of a finite element or difference code, it produces a user friendly product that implements the equations solved with a minimum potential for bugs. This allows emphasis in development of the product to be placed on the physics.

  4. Web-Based Job Submission Interface for the GAMESS Computational Chemistry Program

    ERIC Educational Resources Information Center

    Perri, M. J.; Weber, S. H.

    2014-01-01

    A Web site is described that facilitates use of the free computational chemistry software: General Atomic and Molecular Electronic Structure System (GAMESS). Its goal is to provide an opportunity for undergraduate students to perform computational chemistry experiments without the need to purchase expensive software.

  5. The Hot Tub Mystery

    NSDL National Science Digital Library

    Herbert House

    2005-01-01

    Roma and Clint Underhill are relaxing after a stressful day in their hot tub with some wine. But tragedy strikes, and the next morning their lifeless bodies are found in the water by their housekeeper. The paramedics who respond to her frantic 911 call pronounce the couple dead at the scene and call in the police to investigate. Developed for use in a lower-level undergraduate course on human physiology, students work through the various parts of this interrupted case to discover the cause of death, and in the process learn about blood pressure regulation.

  6. Hot Off the Press

    NSDL National Science Digital Library

    Barry Schlegel

    2006-10-01

    Environmental Health Perspectives (EHP) , a peer-reviewed environmental health research journal (published by the National Institute of Environmental Health Sciences, part of the National Institutes of Health,) provides the EHP Student Edition for high school and college teachers and their students. Each edition contains news articles that summarize a wide variety of scientific information and original research, which are paired with complementary lessons that introduce students to hot-off-the-press science. This article presents ways to integrate EHP's online content in the classroom.

  7. Hot cell examination table

    DOEpatents

    Gaal, Peter S. (Monroeville, PA); Ebejer, Lino P. (Weston, MA); Kareis, James H. (Slickville, PA); Schlegel, Gary L. (McKeesport, PA)

    1991-01-01

    A table for use in a hot cell or similar controlled environment for use in examining specimens. The table has a movable table top that can be moved relative to a table frame. A shaft is fixedly mounted to the frame for axial rotation. A shaft traveler having a plurality of tilted rollers biased against the shaft is connected to the table top such that rotation of the shaft causes the shaft traveler to roll along the shaft. An electromagnetic drive is connected to the shaft and the frame for controllably rotating the shaft.

  8. MSFC hot air collectors

    NASA Technical Reports Server (NTRS)

    Anthony, K.

    1978-01-01

    A description of the hot air collector is given that includes a history of development, a history of the materials development, and a program summary. The major portion of the solar energy system cost is the collector. Since the collector is the heart of the system and the most costly subsystem, reducing the cost of producing collectors in large quantities is a major goal. This solar collector is designed to heat air and/or water cheaply and efficiently through the use of solar energy.

  9. Reaction studies of hot silicon and germanium radicals. Progress report, September 1, 1972--August 31, 1973

    SciTech Connect

    Gaspar, P.P.

    1973-01-01

    Progress was made in the following major areas: a. primary reactions of recoiling silicon atoms and the mode of formation of silylene; b. elucidation of the role of ionic reactions in the chemistry of recoiling silicon atoms; c. kinetics of addition of silyl radicals to olefins; d. flow-discharge kinetic measurements of the rates of reaction of /sup 2/P/sub 3/2 and /sup 2/P/sub 1/2 chlorine atoms with saturated and unsaturated substrates. (auth)

  10. Matthew F. Tuchler Associate Professor of Chemistry

    E-print Network

    Marsh, David

    of Chicago, 1989 Ph.D. in Physical Chemistry, University of Illinois at Urbana, 1995 PROFESSIONAL POSITIONS Chemistry 210 ­ Structure and Reactivity of Molecules Chemistry 261 ­ Physical Chemistry I: Thermodynamics, Kinetics and Statistics Chemistry 262 ­ Physical Chemistry II: Quantum Chemistry and Spectroscopy Chemistry

  11. Moderator Chemistry Program

    SciTech Connect

    Dewitt, L.V.; Gibbs, A.; Lambert, D.P.; Bohrer, S.R.; Fanning, R.L.; Houston, M.W.; Stinson, S.L.; Deible, R.W.; Abdel-Khalik, S.I.

    1990-11-01

    Over the past fifteen months, the Systems Chemistry Group of the Reactor Engineering Department has undertaken a comprehensive study of the Department`s moderator chemistry program at Savannah River Site (SRS). An internal review was developed to formalize and document this program. Objectives were as outlined in a mission statement and action plan. In addition to the mission statement and action plan, nine separate task reports have been issued during the course of this study. Each of these task reports is included in this document as a chapter. This document is an organized compilation of the individual reports issued by the Systems Chemistry Group in assessment of SRS moderator chemistry to determine if there were significant gaps in the program as ft existed in October, 1989. While these reviews found no significant gaps in that mode of operation, or any items that adversely affected safety, items were identified that could be improved. Many of the items have already been dear with or are in the process of completion under this Moderator Chemistry Program and other Reactor Restart programs. A complete list of the items of improvement found under this assessment is found in Chapter 9, along with a proposed time table for correcting remaining items that can be improved for the chemistry program of SRS reactors. An additional external review of the moderator chemistry processes, recommendations, and responses to/from the Reactor Corrosion Mitigation Committee is included as Appendix to this compilation.

  12. Moderator Chemistry Program

    SciTech Connect

    Dewitt, L.V.; Gibbs, A.; Lambert, D.P.; Bohrer, S.R.; Fanning, R.L.; Houston, M.W.; Stinson, S.L.; Deible, R.W.; Abdel-Khalik, S.I.

    1990-11-01

    Over the past fifteen months, the Systems Chemistry Group of the Reactor Engineering Department has undertaken a comprehensive study of the Department's moderator chemistry program at Savannah River Site (SRS). An internal review was developed to formalize and document this program. Objectives were as outlined in a mission statement and action plan. In addition to the mission statement and action plan, nine separate task reports have been issued during the course of this study. Each of these task reports is included in this document as a chapter. This document is an organized compilation of the individual reports issued by the Systems Chemistry Group in assessment of SRS moderator chemistry to determine if there were significant gaps in the program as ft existed in October, 1989. While these reviews found no significant gaps in that mode of operation, or any items that adversely affected safety, items were identified that could be improved. Many of the items have already been dear with or are in the process of completion under this Moderator Chemistry Program and other Reactor Restart programs. A complete list of the items of improvement found under this assessment is found in Chapter 9, along with a proposed time table for correcting remaining items that can be improved for the chemistry program of SRS reactors. An additional external review of the moderator chemistry processes, recommendations, and responses to/from the Reactor Corrosion Mitigation Committee is included as Appendix to this compilation.

  13. Surface Chemistry Research

    NSDL National Science Digital Library

    This Topic in Depth explores the field of surface chemistry. First, the American Chemical Society's (ACS) Division of Colloid and Surface Chemistry publicizes its members initiatives to "investigate the interaction of surfaces with fluids having molecular densities spanning the range from liquids to ultra-high vacuum" (1). Researchers can find out about upcoming meetings, awards, and membership opportunities. The second website presents Chalmers University of Technology's research activities in surfactants and microemulsions, environmental catalysis, fuels engineering, and metal working chemistry (2). Students and teachers can discover the basics of surface chemistry and its benefits to society. Next, University of Canterbury features its studies which "help in the development of portable devices in freshwater analysis, microelectrodes, chemically modified electrodes & biochips for sensors, nanoparticle assemblies for smart materials, [and] novel electrode material for catalysis of industrial processes" (3). Users can view posters detailing their research as well as articles describing the group's latest news and results. Fourth, the US Naval Research Lab describes its surface chemistry research interests, facilities, and its strengths (4). Individuals can find lists of the Lab's journal articles, reports, and technical papers. The fifth website, provided by the University of Virginia, addresses how the chemistry of aerogels makes them "attractive materials for use as catalysts, catalyst substrates, and adsorbents" (5). The website contains illustrations of the interaction between water and aerogel compounds. Sixth, the Environmental Molecular Sciences Laboratory presents its Ultra-high Vacuum (UHV) Surface Chemistry-High-Resolution Electron Energy Loss Spectroscopy (HREELS) System capabilities to "study the molecular-level chemistry of adsorbates on metal oxide surfaces" (6 ). The website offers a concise overview of sample preparation, handling, and manipulation. Lastly, the University of Michigan provides links to in-depth discussions and informational images of the research projects of its four surface chemistry research groups (7). Researchers can find slide show presentations of the group's work, lists of its publications, and information on the individual researchers' education and work. [RME

  14. Working in Hot Weather or Hot Workplace Environments Subject: Procedures and Guidelines for Working in Hot Environments

    E-print Network

    Lennard, William N.

    Working in Hot Weather or Hot Workplace Environments Subject: Procedures and Guidelines for Working in Hot Environments Applies to: All employees Number: 2010-06 Pages: 7 Effective Date: November 2010 is intended to prevent potential heat induced illness as a result of hot weather or hot workplace environments

  15. CHEMISTRY 213B: Introductory Physical Chemistry I. General Information

    E-print Network

    Ronis, David M.

    CHEMISTRY 213B: Introductory Physical Chemistry I. General Information Lectures: MWF 9:30 - 10 Chemistry. Supplementary Texts 1. P. A. Rock, Chemical Thermodynamics. 2. Gordon M. Barrow, Physical Chemistry. 3. R. Kubo, Thermodynamics (Physics orientation, advanced) Grades There will be approximately one

  16. Chemistry Bachelor of Science in Chemistry 2 YEAR TYPICAL

    E-print Network

    Carter, John

    Chemistry Bachelor of Science in Chemistry 2 YEAR TYPICAL PROGRAM OF STUDY 2013-2014 DEGREE completed a full year of General Chemistry, Calculus and Physics. If you have already taken a full year of Organic Chemistry, then your Junior year will be devoted to completing Math and Physics requirements

  17. Chemistry 436/636 Fall 2011 Advanced Physical Chemistry

    E-print Network

    Raina, Ramesh

    Chemistry 436/636 Fall 2011 Advanced Physical Chemistry Instructor: Prof. J. Goodisman 3-014E Sci. 16, 5:15-7:15 PM Text: T. Engel and P. Reid, Physical Chemistry, 2nd Edition (Prentice-Hall, 2010) or any other comprehensive physical chemistry text. Engel & Reid is used in the undergraduate physical

  18. CHEMISTRY 243: Introductory Physical Chemistry II. General Information

    E-print Network

    Ronis, David M.

    CHEMISTRY 243: Introductory Physical Chemistry II. General Information Lectures: Monday & Wednesday, Inc., 2006) J.R. Barrante, Applied Mathematics for Physical Chemistry, 3rd edition (Pearson Education, Inc., 2004) Supplementary Texts 1. G. W. Castellan, Physical Chemistry 3rd edition (Benjamin Cummings

  19. Chemistry 1010 -090 (Online) Chemistry, Humanity, and Environment

    E-print Network

    Simons, Jack

    Chemistry 1010 -090 (Online) Chemistry, Humanity, and Environment 1. Course Content The Online version of Chemistry 1010 (1010-090) supports the aims of the University of Utah General Education Mission Statement: The course has been designed for nonmajors and presupposes no background in chemistry. The course

  20. CHEMISTRY 3023-62170 PHYSICAL CHEMISTRY LABORATORY II

    E-print Network

    Findley, Gary L.

    CHEMISTRY 3023-62170 PHYSICAL CHEMISTRY LABORATORY II Spring 2012 2:00 - 5:00 pm, W CNSB 211.ulm.edu/~findley COURSE Content: Modern experimental techniques of physical chemistry. Goals/ Objectives: Physical for Physical Chemistry Laboratory II is on spectroscopy. REQUIREMENTS Prerequisite: "C" or better in CHEM 3021

  1. CHEMISTRY 3021-42233 PHYSICAL CHEMISTRY LABORATORY I

    E-print Network

    Findley, Gary L.

    CHEMISTRY 3021-42233 PHYSICAL CHEMISTRY LABORATORY I Fall 2011 2:00-2:50, W, CNSB 211 (Prelab) 3.ulm.edu/~findley COURSE Content: Modern experimental techniques of physical chemistry. Goals/ Objectives: Physical for Physical Chemistry Laboratory I is on thermodynamics and chemical kinetics. REQUIREMENTS Prerequisite: "C

  2. B.A. DEGREE REQUIREMENTS FOR CHEMISTRY (BIOLOGICAL CHEMISTRY TRACK)

    E-print Network

    Doyle, Robert

    326: Organic Chemistry Laboratory II (2) CHE 474: Structural and Physical Biochemistry I (3) 2: Organic Chemistry of Biological Molecules (3) CHE 436: Advanced Physical Chemistry (3) CHE 467: Introduction to Physical Chemistry Research Laboratory (3) CHE 546: Molecular Spectroscopy and Structure (1

  3. Materials Chemistry at SFU

    NSDL National Science Digital Library

    The Materials Science group at Simon Fraser University (SFU) developed this website to address the group's primary research interests in material synthesis, molecular, electronics, and photonics. Visitors will find explanations covering sixteen research topics including chemical sensors, lithography, non-linear optics, and supramolecular chemistry. Under each topic heading, users will find links discussing the faculties' current goals, recent publications, and patents. The site also features links to the Pacific Centre for Advanced Materials and Microstructures; a collaborative effort between the Materials Science group at SFU and the physics and chemistry departments at the University of British Columbia. Anyone searching for the latest investigations in materials chemistry will find this website very informative.

  4. The Chemistry of Cocaine

    NSDL National Science Digital Library

    Dewprashad, Brahmadeo

    This case study looks at cocaine, including its addictive properties and the chemistry involved in the synthesis of the drug in its different forms. The lesson can be used to teach nucleophilic addition reactions, nucleophilic acyl substitution, and cocaine metabolism. The material was designed for use in an undergraduate organic chemistry course but could also be used in medicinal chemistry coursework. The case study and teaching notes may be downloaded in PDF format. The site also includes a section for instructor feedback where general comments may be read and contributed.

  5. Atom Interferometry

    ScienceCinema

    Mark Kasevich

    2010-01-08

    Atom de Broglie wave interferometry has emerged as a tool capable of addressing a diverse set of questions in gravitational and condensed matter physics, and as an enabling technology for advanced sensors in geodesy and navigation. This talk will review basic principles, then discuss recent applications and future directions. Scientific applications to be discussed include measurement of G (Newton?s constant), tests of the Equivalence Principle and post-Newtonian gravity, and study of the Kosterlitz-Thouless phase transition in layered superfluids. Technology applications include development of precision gryoscopes and gravity gradiometers. The talk will conclude with speculative remarks looking to the future: Can atom interference methods be sued to detect gravity waves? Can non-classical (entangled/squeezed state) atom sources lead to meaningful sensor performance improvements?

  6. Atom Interferometry

    SciTech Connect

    Mark Kasevich

    2008-05-07

    Atom de Broglie wave interferometry has emerged as a tool capable of addressing a diverse set of questions in gravitational and condensed matter physics, and as an enabling technology for advanced sensors in geodesy and navigation. This talk will review basic principles, then discuss recent applications and future directions. Scientific applications to be discussed include measurement of G (Newton’s constant), tests of the Equivalence Principle and post-Newtonian gravity, and study of the Kosterlitz-Thouless phase transition in layered superfluids. Technology applications include development of precision gryoscopes and gravity gradiometers. The talk will conclude with speculative remarks looking to the future: Can atom interference methods be sued to detect gravity waves? Can non-classical (entangled/squeezed state) atom sources lead to meaningful sensor performance improvements?

  7. TCD-IISc Symposium "Chemistry & Chemical Biology"

    E-print Network

    O'Mahony, Donal E.

    TCD-IISc Symposium "Chemistry & Chemical Biology" Trinity College Clive Williams, Dean of Chemistry. Research areas include supramolecular organic and inorganic chemistry and medicinal chemistry, robotics, structure-function relationships. Sylvia Draper, Professor in Chemistry. Her research spans

  8. Silicon chemistry in interstellar clouds

    NASA Technical Reports Server (NTRS)

    Langer, William D.; Glassgold, A. E.

    1989-01-01

    Interstellar SiO was discovered shortly after CO but it has been detected mainly in high density and high temperature regions associated with outflow sources. A new model of interstellar silicon chemistry that explains the lack of SiO detections in cold clouds is presented which contains an exponential temperature dependence for the SiO abundance. A key aspect of the model is the sensitivity of SiO production by neutral silicon reactions to density and temperature, which arises from the dependence of the rate coefficients on the population of the excited fine structure levels of the silicon atom. This effect was originally pointed out in the context of neutral reactions of carbon and oxygen by Graff, who noted that the leading term in neutral atom-molecule interactions involves the quadrupole moment of the atom. Similar to the case of carbon, the requirement that Si has a quadrupole moment requires population of the J = 1 level, which lies 111K above the J = 0 ground state and has a critical density n(cr) equal to or greater than 10(6)/cu cm. The SiO abundance then has a temperature dependence proportional to exp(-111/T) and a quadratic density dependence for n less than n(cr). As part of the explanation of the lack of SiO detections at low temperatures and densities, this model also emphasizes the small efficiencies of the production routes and the correspondingly long times needed to reach equilibrium. Measurements of the abundance of SiO, in conjunction with theory, can provide information on the physical properties of interstellar clouds such as the abundances of oxygen bearing molecules and the depletion of interstellar silicon.

  9. Chemistry 120a AY 96 Problem Set 6

    E-print Network

    Goddard III, William A.

    Chemistry 120a AY 96 Problem Set 6 Due: Monday, November 13, 1995 at 2pm TA: Chris Kankel (kankel two­fold bridge sites. How would the hydrogen atoms split the degeneracies of the cluster orbitals of the positive or negative coordinate axes. How would the cluster orbitals split? b) Recall problem 4, parts b

  10. The origin of anti-wear chemistry of ZDDP.

    PubMed

    Martin, Jean Michel; Onodera, Tasuku; Minfray, Clotilde; Dassenoy, Fabrice; Miyamoto, Akira

    2012-01-01

    Molecular Dynamics has been used to simulate the anti-wear chemistry of zinc dialkyl dithiophosphate (ZDDP). The model simulates the digestion of abrasive particles into the zinc polyphosphate glass. The main result is that the driving force for the tribochemical reaction is not temperature but entropy due to mechanical mixing at the atomic scale. PMID:23285636

  11. Analytical Chemistry CHM1102H Biosensors & Chemical Sensors

    E-print Network

    Chan, Hue Sun

    will include specialized mass spectrometry techniques, including secondary ion, fast atom bombardment and ion cyclotron resonance mass spectrometry methods; GC/MS and LC/MS interfaces; a survey of surfaceAnalytical Chemistry CHM1102H Biosensors & Chemical Sensors (Cross-listed Undergraduate CHM414H

  12. Full of Hot Air: Hot Air Balloon Building

    NSDL National Science Digital Library

    Children's Museum of Houston

    2010-01-01

    In this activity, learners create a model of a hot air balloon using tissue paper and a hairdryer. Educators can use this activity to introduce learners to density and its role in why things float. This activity page features a fun how-to video that shows learners and educators how to make the hot air balloons.

  13. Emergences of supramolecular chemistry: from supramolecular chemistry to supramolecular science

    Microsoft Academic Search

    Jacques VicensQuentin Vicens; Quentin Vicens

    We describe the field of supramolecular chemistry as a consequence of the progress of chemistry from its premises to recent\\u000a achievements. Supramolecular chemistry has been claimed to be an emergent field of research taking its roots in chemistry.\\u000a According to the definitions of emergences related to hierarchy or more recently to scope, supramolecular chemistry is shown\\u000a to have bottom-up or

  14. Analytical Chemistry Applied Mathematics

    E-print Network

    Heller, Barbara

    .Admin./Marketing Communication Bus.Admin./Public Admin. Chemical Engineering Chem. Eng./Comp. Sci. Chemistry Civil Engineering Cyber Forensics Data Science Design Methods Electrical Engineering Electrical & Computer Engineering

  15. Magnetism in Chemistry

    ERIC Educational Resources Information Center

    Brookes, R. W.; McFadyen, W. D.

    1975-01-01

    Discusses the technical aspects of paramagnetism and an electrostatic model called Crystal Field Theory (CFT), very often used in the case of transition metal compounds. Suggests that this discussion be included as an option for college chemistry courses. (MLH)

  16. Chemistry with a Peel.

    ERIC Educational Resources Information Center

    Borer, Londa; Larsen, Eric

    1997-01-01

    Presents experiments that introduce natural product chemistry into high school classrooms. In the laboratory activities, students isolate and analyze the oil in orange peels. Students also perform a steam distillation and learn about terpenes. (DDR)

  17. Enzymes in Analytical Chemistry.

    ERIC Educational Resources Information Center

    Fishman, Myer M.

    1980-01-01

    Presents tabular information concerning recent research in the field of enzymes in analytic chemistry, with methods, substrate or reaction catalyzed, assay, comments and references listed. The table refers to 128 references. Also listed are 13 general citations. (CS)

  18. Chemistry Societies Network

    NSDL National Science Digital Library

    Users gain access to the heart of CSN's site through the site gateway which leads them to CSN's information arcade, education arcade, societies, chembytes, and conferences and events. The information arcade provides links to experts and specialists, and chemistry societies. The education arcade contains a wealth of information for educators in the chemistry arena. Societies lists chemical and chemistry-related societies, divided alphabetically by country. Chembytes provides access to a variety of news, including recent findings and discoveries, business updates, and news from around the globe. Chembytes also features a continuing series which looks in-depth at a topic recently in the news. Currently featured is NASA's attempt to return to the moon. Conferences and Events is searchable and browseable and contains a submission form so visitors can list an event. CSN's site also includes Useful Links, a listing of sites categorized and reviewed by Chemsoc and Science Park, which links to four companies offering chemistry related resources on the web.

  19. General Chemistry Multimedia Problems

    NSDL National Science Digital Library

    General Chemistry Multimedia Problems ask students questions about experiments they see presented using videos and images. The questions asked apply concepts from different parts of an introductory course, encouraging students to decompartmentalize the material.

  20. Sequencing General Chemistry

    NSDL National Science Digital Library

    B.J. Yoblinski

    2003-03-01

    The material in the authors' general chemistry curriculum has been rearranged into a sequence thought to be more logical to students than the traditional sequence. This fresh approach does not radically change course content but rather produces a systemat

  1. Chemistry for Kids.

    ERIC Educational Resources Information Center

    Sato, Sanae; Majoros, Bela

    1988-01-01

    Reports two methods for interesting children in chemistry. Describes a method for producing large soap bubbles and films for study. Examines the use of simple stories to explain common chemical concepts with example given. Lists titles of available stories. (ML)

  2. Chemistry 455 Chemical Nanotechnology

    E-print Network

    Rohs, Remo

    Chemistry 455 Chemical Nanotechnology 4 units Prof. Richard Brutchey, Fall 2014 (Lecture = 12:00­12:50 pm MWF) CHEM 455 is an upper-division undergraduate course in Chemical Nanotechnology. The intent

  3. Chemistry and Detective Fiction.

    ERIC Educational Resources Information Center

    Labianca, Dominick A.; Reeves, William J.

    1981-01-01

    Describes an interdisciplinary program consisting of two courses. The first course deals with the chemistry of drugs and poisons; the second course focuses on fictional works in which these drugs and poisons are central to the plots. (SK)

  4. Learn Chemistry: Chemistry Resources for Teachers

    NSDL National Science Digital Library

    The Royal Society of Chemistry has created this most useful website to help teachers and students of chemistry learn about the field via interactive experiments, diagrams, animations, and so on. The site includes over 3,300 resources. Visitors can get started by using the Resource Type tab. Here they can browse through ten different headings, including Worksheet, Quiz, Tutorial, and Podcast. The Experiments area is quite wonderful, as it includes over 340 different experiments that can be conducted in the classroom. A few highlights in this area include "Challenging Medicines: Making Medicines," "The Salt Cellar Mystery," and "Which solution is which?" Overall, it's a tremendous site and one that visitors will want to share with friends.

  5. CHEMISTRY 324W ORGANIC LABORATORY

    E-print Network

    Wagner, Diane

    1 Fall 2010 CHEMISTRY 324W ORGANIC LABORATORY Course Information Title: Chemistry 324W, Organic for multiple chemistry classes) $5 key deposit fee (refunded at end of semester with return of key) Course a scientific paper consistent with the format of the Journal of Organic Chemistry, American Chemical Society. 7

  6. Secondary water chemistry at Oconee

    Microsoft Academic Search

    S. G. Sawochka; W. L. Pearl; M. J. Bell; S. S. Choi

    1984-01-01

    As part of EPRI Program RP704-1, chemistry and OTSG corrosion data for Oconee were evaluated. Utility collected chemistry information was augmented by data collected during short and long term NWT sampling and analysis campaigns. Chemistry generally was controlled within Duke Power specifications; however, significant variations were observed with time and between units. Improvements in feedwater chemistry appear achievable by routing

  7. The Nobel Prize in Chemistry

    NSDL National Science Digital Library

    2001-01-01

    The first hundred years of Nobel Prizes for Chemistry give a beautiful picture of the development of modern chemistry. The prizes cover the whole spectrum of the basic chemical sciences, from theoretical chemistry to biochemistry, and also a number of contributions to applied chemistry.

  8. WESTERN UNIVERSITY DEPARTMENT OF CHEMISTRY

    E-print Network

    Sinnamon, Gordon J.

    WESTERN UNIVERSITY DEPARTMENT OF CHEMISTRY The Department of Chemistry invites applications for a probationary (tenure-track) faculty position at the rank of Assistant Professor in Inorganic Chemistry, externally funded research program, and to develop and teach innovative courses in chemistry

  9. Chem 793 Bibliography Chemistry 793

    E-print Network

    Chem 793 Bibliography Chemistry 793 QUANTUM MECHANICS I Fall 2000 BIBLIOGRAPHY The two volumes. Walter and G.E. Kimball, Quantum Chemistry (Wiley). [13] I. Levine, Quantum Chemistry (Allyn and Bacon). [14] G.C. Schatz and M. Ratner, Quantum Mechanics in Chemistry. [15] J. Simons and J. Nichols, Quantum

  10. Chemistry, Color, and Art

    NASA Astrophysics Data System (ADS)

    Orna, Mary Virginia

    2001-10-01

    Artists' colors have been intertwined with chemistry from antiquity, both in the extraction of them from raw materials and their production by the 'manufacturing chemists' of their day. In our own time, not only has chemistry made possible the enormous expension of the artist's palette, but also has provided methods to study it scientifically with a view to restoration, preservation, authentication, and understanding of works of art.

  11. Organic Chemistry Forum

    NSDL National Science Digital Library

    ChemWeb's Organic Chemistry Forum bills itself as a "free online club for the organic chemistry community." Users will need to complete a simple online form to obtain membership and access the site. One highlight of this site is free full-text access to Tetrahedron Letters. This rapid publication journal appears weekly. Along with free access to Beilstein Abstracts, the site includes jobs, a conference diary, news, discussion groups, and more.

  12. Organic Chemistry Forum

    NSDL National Science Digital Library

    2005-01-01

    ChemWeb's Organic Chemistry Forum bills itself as a "free online club for the organic chemistry community." Users will need to complete a simple online form to obtain membership and access the site. One highlight of this site is free full-text access to Tetrahedron Letters. This rapid publication journal appears weekly. Along with free access to Beilstein Abstracts, the site includes jobs, a conference diary, news, discussion groups, and more.

  13. UCLA: Organic Chemistry Tutorials

    NSDL National Science Digital Library

    Hardinger, Steven

    Steven Hardinger at the Department of Chemistry and Biochemistry at UCLA created these tutorials to assist students with the difficult concepts presented in introductory organic chemistry. Students can find tutorials dealing with acids and bases, carbocations, Lewis dot structures, and more. Within each tutorial, users can find links to a dictionary that adequately explain the unfamiliar terminology. The tutorials include example problems and exercises to challenge users.

  14. Acid-base chemistry

    SciTech Connect

    Hand, C.W.; Blewit, H.L.

    1985-01-01

    The book is not a research compendium and there are no references to the literature. It is a teaching text covering the entire range of undergraduate subject matter dealing with acid-base chemistry (some of it remotely) as taught in inorganic, analytical, and organic chemistry courses. The excellent chapters VII through IX deal in detail with the quantitative aspects of aqueous acid-base equilibria (salt hydrolysis and buffer, titrations, polyprotic and amphoteric substances).

  15. EPA Environmental Chemistry Laboratory

    NASA Technical Reports Server (NTRS)

    1993-01-01

    The Environmental Protection Agency's (EPA) Chemistry Laboratory (ECL) is a national program laboratory specializing in residue chemistry analysis under the jurisdiction of the EPA's Office of Pesticide Programs in Washington, D.C. At Stennis Space Center, the laboratory's work supports many federal anti-pollution laws. The laboratory analyzes environmental and human samples to determine the presence and amount of agricultural chemicals and related substances. Pictured, ECL chemists analyze environmental and human samples for the presence of pesticides and other pollutants.

  16. Chemistry in space research.

    NASA Technical Reports Server (NTRS)

    Landel, R. F. (editor); Rembaum, A.

    1972-01-01

    Chemistry in space is discussed together with aspects of chemistry in planetary atmospheres, the prebiological synthesis of organic compounds, and carbonaceous meteorites as possible sites of extraterrestrial life. Other subjects investigated include terrestrial and extraterrestrial stable organic molecules, thermally stable macromolecules, chemical aspects of ablation, low-temperature relaxations in amorphous polymers, and solid propellants. Liquid propellant rockets are also considered along with questions of spacecraft sterilization. Individual items are announced in this issue.

  17. Precision Measurements of Atomic Lifetimes and Hyperfine Energies in Alkali Like Systems

    Microsoft Academic Search

    Carol E

    2005-01-01

    Financial support of this research project has lead to advances in the study of atomic structure through precision measurements of atomic lifetimes, energy splittings, and transitions energies. The interpretation of data from many areas of physics and chemistry requires an accurate understanding of atomic structure. For example, scientists in the fields of astrophysics, geophysics, and plasma fusion depend on transition

  18. Electrical hot work safety program

    Microsoft Academic Search

    J. M. Gallagher; L. B. McClung

    1988-01-01

    An internal review of the safety practices for a large Canadian chemical plant indicated that the established procedures for electrical hot work needed to be expanded and formalized. The practices were expanded into a comprehensive electrical hot work program that included the philosophy, control, qualification, and safe work methods. The program resulted in changes that improved on an adequate chemicals

  19. SOURCE ASSESSMENT: ASPHALT HOT MIX

    EPA Science Inventory

    This report summarizes data on air emissions from the asphalt hot mix industry. A representative asphalt hot mix plant was defined, based on the results of an industrial survey, to assess the severity of emissions from this industry. Source severity was defined as the ratio of th...

  20. Solar powered hot air balloon

    Microsoft Academic Search

    Eshoo

    1979-01-01

    A solar powered hot air balloon is disclosed having an envelope with an opaque portion and a transparent portion arranged so as to utilize solar heating to heat air within the envelope. The solar heating air may either be sufficient to provide the entire free lift or may be combined with air from a hot air generating system carried by