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Sample records for solid interstellar material

  1. Presolar/Interstellar Materials

    NASA Technical Reports Server (NTRS)

    Sandford, Scott A.; DeVincenzi, Donald (Technical Monitor)

    2002-01-01

    This talk will review much of our current understanding of the origins, nature, and evolution of materials in circumstellar and interstellar space. I will begin by familiarizing the audience with some of the nomenclature associated the field, reviewing the lifecycle of dust in space, and pointing out where the speakers that follow will address portions of the lifecycle in greater detail. I will then address the different techniques used to study interstellar materials, paying particular attention to (i) telescopic remote sensing of the dust currently in interstellar space, (ii) laboratory studies of individual interstellar grains found in meteorites and other extraterrestrial materials, and (iii) laboratory simulation experiments. To complete the talk, I will focus on the nature of interstellar organic compounds as a particular example of how these disparate techniques can be used to improve our understanding of interstellar matter. While interstellar organics will be addressed in general, particular attention will be made to that portion of the organic inventory that may play a role in the origin and evolution of life on planetary surfaces.

  2. Interstellar and interplanetary solids in the laboratory

    NASA Astrophysics Data System (ADS)

    Dartois, E.; Alata, I.; Engrand, C.; Brunetto, R.; Duprat, J.; Pinot, T.; Quirico, E.; Remusat, L.; Bardin, N.; Briani, G.; Mostefaoui, S.; Morinaud, G.; Crane, B.; Szwec, N.; Delauche, L.; Jamme, F.; Sandt, C.; Dumas, P.

    2015-01-01

    The composition of the interstellar matter is driven by environmental parameters (e.g. elemental abundance, density, reactant nature, radiations, temperature, time scales) and results also from external interstellar medium physico-chemical conditions. Astrochemists must rely on remote observations to monitor and analyze the com­position of interstellar solids. These observations give essentially access to the molecular functionality of the solids, rarely elemental composition constraints and isotopic fractionation only in the gas phase. Astrochemists bring additional information from the study of analogues produced in the laboratory, placed in simulated space environments. Planetologists and cosmochemists can have access and spectroscopically examine collected extra-terrestrial material directly in the laboratory. Observations of the diffuse interstellar medium (DISM) and molecular clouds (MC) set constraints on the composition of organic solids and large molecules, that! can then be compared with collected extraterrestrial materials analyses, to shed light on their possible links.

  3. Interstellar material in the solar system

    NASA Technical Reports Server (NTRS)

    Wood, J. A.

    1986-01-01

    All the substance of the Earth and other terrestrial planets once existed in the form of interstellar grains and gas. A major aspect of solar system formation (and undoubtedly of star formation generally) is the complex series of processes that converted infalling interstellar grains into planets. A cryptic record of these processes is preserved in certain samples of planetary materials, such as chondritic meteorites, that were preserved in a relatively unchanged form since the beginning. It is to be expected that some of these primitive materials might contain or even consist of preserved presolar interstellar grains. The identification and study of such grains, the ancestors of our planetary system, is a matter of intense interest. Types of primitive material accessible or potentially accessible, and component of or relationship to presolar interstellar grains are discussed.

  4. Les Johnson Views Interstellar Sail Material

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Engineers at Marshall Space Flight Center's (MSFC) Interstellar Propulsion Research department are proposing different solutions to combustion propellants for future space travel. One alternative being tested is the solar sail. The idea is, once deployed, the sail will allow solar winds to propel a spacecraft away from Earth and towards its destination. This would allow a spacecraft to travel indefinitely without the need to refuel during its ong journey. Thin reflective sails could be propelled through space by sunlight, microwave beams, or laser beams, just as the wind pushes sailboats on Earth. The sail will be the largest spacecraft ever built, sparning 440 yards, twice the diameter of the Louisiana Super Dome. Construction materials are being tested in a simulated space environment, where they are exposed to harsh conditions to test their performance and durability in extremely hot and cold temperatures. A leading candidate for the construction material is a carbon fiber material whose density is less than 1/10 ounce per square yard, the equivalent of flattening one raisin to the point that it covers a square yard. In space, the material would unfurl like a fan when it is deployed from an expendable rocket. This photo shows Les Johnson, manager of MSFC's Interstellar Propulsion Research Center holding the rigid, lightweight carbon fiber. An artist's concept of the sail is on the right. Mankind's first venture outside of our solar system is proposed for launch in a 2010 timeframe. An interstellar probe, powered by the fastest spacecraft ever flown, will zoom toward the stars at 58 miles per second. It will cover the distance from New York to Los Angeles in less than a minute and will travel over 23 billion miles beyond the edge of the solar system.

  5. Graphene, the Ultimate Interstellar Solar Sail Material?

    NASA Astrophysics Data System (ADS)

    Matloff, G. L.

    Graphene (a carbon molecular monolayer) is a wonder material of great interest to materials researchers. Its molecular-layer thickness, finite fractional absorption, high melting point, and impermeability to gases coupled with the fact that doped materials, additives and multiple layers increase both fractional absorption and reflectivity indicates that it may be a superior material for application in solar-photon sailing. This paper first reviews relevant graphene physical and optical properties and then investigates the kinematics of interstellar solar sails constructed using this material. Two sail configurations are considered: thin-film probes and hollow-bodies sails. It is shown that graphene sail performance may be superior to that of beryllium sails. Less intense perihelion passes and accelerations may allow transit times to Alpha Centauri approximating a millennium. Future research should consider the interaction of graphene sails with the space environment and large-scale fabrication techniques.

  6. Chemical Evolution of Interstellar Dust into Planetary Materials

    NASA Technical Reports Server (NTRS)

    Fomenkova, M. N.; Chang, S.; DeVincenzi, Donald L. (Technical Monitor)

    1995-01-01

    Comets are believed to retain some interstellar materials, stored in fairly pristine conditions since-their formation. The composition and properties of cometary dust grains should reflect those of grains in the outer part of the protosolar nebula which, at least in part, were inherited from the presolar molecular cloud. However, infrared emission features in comets differ from their interstellar counterparts. These differences imply processing of interstellar material on its way to incorporation in comets, but C and N appear to be retained. Overall dust evolution from the interstellar medium (ISM) to planetary materials is accompanied by an increase in proportion of complex organics and a decrease in pure carbon phases. The composition of cometary dust grains was measured in situ during fly-by missions to comet Halley in 1986. The mass spectra of about 5000 cometary dust grains with masses of 5 x 10(exp -17) - 5 x 10(exp -12) g provide data about the presence and relative abundances of the major elements H, C, N, O,Na, Mg, Al, Si, S, Cl, K, Ca, Ti, Cr, Fe, Ni. The bulk abundances of major rock-forming elements integrated over all spectra were found to be solar within a factor of 2, while the volatile elements H, C, N, O in dust are depleted in respect to their total cosmic abundances. The abundances of C and N in comet dust are much closer to interstellar than to meteoritic and are higher than those of dust in the diffuse ISM. In dense molecular clouds dust grains are covered by icy mantles, the average composition of which is estimated to be H:C:N:O = 96:14:1:34. Up to 40% of elemental C and O may be sequestered in mantles. If we use this upper limit to add H, C, N and O as icy mantle material to the abundances residing in dust in the diffuse ISM, then the resulting values for H. C, and N match cometary abundances. Thus, ice mantles undergoing chemical evolution on grains in the dense ISM appear to have been transformed into less volatile and more complex organic

  7. The Inventory of Interstellar Materials Available for the Formation of the Solar System

    NASA Technical Reports Server (NTRS)

    Sandford, Scott A.; Witteborn, Fred C. (Technical Monitor)

    1996-01-01

    Dr. Derek Sears, the editor of the journal Meteoritics and Planetary Science, has established a policy of having each issue of the journal contain an invited review of an area that he deems to be of special cur-rent importance. Typically 20 to 25 pages of the beginning of the journal are devoted to each review. He has asked me to prepare such a review summarizing what we know about the composition and structure of interstellar materials. The attached paper is the result. This is a good time for such a review since tremendous progress has been made in the field of interstellar dust in recent years through the use of telescopic observations, theoretical studies, laboratory studies of analogs, and the study of actual interstellar samples found in meteorites. It is increasing clear that the interstellar medium (ISM) contains an enormous diversity of materials created by a wide range of chemical and physical processes. This understanding is a far cry from the picture of interstellar materials held as recently as two decades ago, a picture which incorporated only a few generic types of grains and few molecules. In the paper I review our current knowledge of the more abundant materials thought to exist in the ISM. The review concentrates on matter in interstellar dense molecular clouds since it is the materials in these environments from which new stars and planetary systems are formed, although materials in circumstellar environments and in the diffuse ISM are also discussed. The paper focuses largely on solid materials since they contain a major fraction of the heavier elements in clouds and because solids are most likely to survive incorporation into new planetary systems in identifiable form. The paper concludes with discussion of some of the implications resulting from the identification of these interstellar materials. I also present some new thoughts, the most intriguing being that meteoritic 'microdiamonds' may be the same material that modelers of the

  8. Solid Solution Model for Interstellar Dust Grains and Their Organics

    NASA Astrophysics Data System (ADS)

    Freund, Minoru M.; Freund, Friedemann T.

    2006-03-01

    We present a dust grain model based on the fundamental principle of solid solutions. The model is applicable to the mineral (silicate) component of the dust in the interstellar medium (ISM). We show that nanometer-sized mineral grains, which condense in the gas-rich outflow of late-stage stars or expanding gas shells of supernova explosions, do not consist of just high melting point oxides or silicates. Instead they form solid solutions with gas-phase components H2O, CO, and CO2 that are omnipresent in environments where the grains condense. Through a series of thermodynamically well-understood solid-state processes, these solid solutions become ``parents'' of organic matter that precipitates inside the grains. Thus, the mineral dust grains and their organics become part of the same thermodynamically defined solid phase and, hence, physically inseparable. This model can account for many astronomical observations, which no prior model can adequately address, specifically: (1) Organics in the diffuse ISM are identified by a 3.4 μm IR band, characteristic of aliphatic hydrocarbons composed of CH2 and of CH3 groups. (2) The methylene-to-methyl ratio is nearly constant, implying a CH2:CH3 ratio of ~5:2. (3) The intensity ratio between the 9.7 and the 3.4 μm band is nearly constant, implying a silicate-to-organics ratio of ~10:1. (4) In dense clouds the complex 3.4 μm band is replaced by a weak, featureless 3.47 μm band. (5) Whereas silicate grains identified by their 9.7 μm band tend to align in magnetic fields, grains with a strong 3.4 μm organic signature do not tend to align.

  9. Laboratory Formation and Analysis of the Materials Comprising Interstellar Dust

    NASA Astrophysics Data System (ADS)

    Scott, Alan Douglas

    The optical properties of interstellar dust analogs are investigated. Thin, solid, amorphous films are deposited on a substrate through excimer laser ablation. This process is analogous to the vapour deposition of atoms and ions which is thought to occur in stellar outflows and the interstellar medium (ISM). Refractive indices are calculated for typical polymeric hydrogenated amorphous carbon (HAC) films. Thickness dependent void structure is shown to influence the resultant density of the substance. Refractive indices are also determined for amorphous magnesium silicates in both the pyroxene (MgSiO3) and olivine (Mg2SiO4) composites. A plausible dust grain model is constructed which successfully reproduces the major features of the diffuse interstellar extinction. The effects of thermal annealing and dehydrogenation of HAC are investigated. The resulting graphitized HAC is shown to exhibit a spectral signature which is commonly associated with gas phase polycyclic aromatic hydrocarbons (PAHs). Thermal emission from HAC is observed for the first time and is shown to be an excellent match to various anomalous unidentified infrared (UIR) emitters. The emission from HAC closely resembles those rare sources labelled Type B UIR emitters in recent works by Geballe (1996) and Tokunaga (1996). Near threshold laser ionization mass spectroscopy (LIMS) of HAC is shown to produce large ionized molecular clusters including fullerenes. The astrophysical implications of these results are discussed.

  10. Origins of interstellar and solar system: Carbonaceous materials

    NASA Technical Reports Server (NTRS)

    Feigelson, Eric D.

    1994-01-01

    Carbon is a crucial atom in cosmochemistry. It is well-established that carbon is synthesized in stellar interiors after the main sequence, is ejected by red giants as small carbonaceous grains during their 'carbon star' phase, resides in the interstellar medium, and was later incorporated into the solar system. The mechanisms of carbon grain formation and later chemical processing are complex because, with only small thermodynamic differences, carbon can take on a bewildering variety of forms: diamond; oxides; carbides; graphite; aliphatic hydrocarbons; polycyclic aromatic hydrocarbons (PAH's); fullerenes; amorphous carbon; and other compounds. These are evidence for many of the forms of carbon found in astronomical observations. We seek to understand the possible astrophysical sites and conditions of the origins of different forms of carbon by combining state-of-the-art capabilities of carbon chemistry with astrophysical modeling. The work is a collaboration between Prof. Frenklach, a leading carbon materials scientist with both laboratory and computer modeling expertise and Prof. Feigelson, an astrophysicist with interests in star formation. The largest effort under this grant was devoted to developing this concept into a comprehensive quantitative model. In addition to explaining the astronomical properties of red giants producing carbonaceous grains, our model also can incorporate recent meteoritic findings. Finally, our induced nucleation grain formation model provides a natural explanation for the widespread presence of PAH emission bands in the Galactic interstellar medium. A brief synopsis of other activities sponsored under this grant and a list of publications from this grant is included.

  11. Origins of interstellar and solar system: Carbonaceous materials

    NASA Astrophysics Data System (ADS)

    Feigelson, Eric D.

    1994-10-01

    Carbon is a crucial atom in cosmochemistry. It is well-established that carbon is synthesized in stellar interiors after the main sequence, is ejected by red giants as small carbonaceous grains during their 'carbon star' phase, resides in the interstellar medium, and was later incorporated into the solar system. The mechanisms of carbon grain formation and later chemical processing are complex because, with only small thermodynamic differences, carbon can take on a bewildering variety of forms: diamond; oxides; carbides; graphite; aliphatic hydrocarbons; polycyclic aromatic hydrocarbons (PAH's); fullerenes; amorphous carbon; and other compounds. These are evidence for many of the forms of carbon found in astronomical observations. We seek to understand the possible astrophysical sites and conditions of the origins of different forms of carbon by combining state-of-the-art capabilities of carbon chemistry with astrophysical modeling. The work is a collaboration between Prof. Frenklach, a leading carbon materials scientist with both laboratory and computer modeling expertise and Prof. Feigelson, an astrophysicist with interests in star formation. The largest effort under this grant was devoted to developing this concept into a comprehensive quantitative model. In addition to explaining the astronomical properties of red giants producing carbonaceous grains, our model also can incorporate recent meteoritic findings. Finally, our induced nucleation grain formation model provides a natural explanation for the widespread presence of PAH emission bands in the Galactic interstellar medium. A brief synopsis of other activities sponsored under this grant and a list of publications from this grant is included.

  12. Stardust Interstellar Preliminary Examination VIII: Identification of crystalline material in two interstellar candidates

    NASA Astrophysics Data System (ADS)

    Gainsforth, Zack; Brenker, Frank E.; Simionovici, Alexandre S.; Schmitz, Sylvia; Burghammer, Manfred; Butterworth, Anna L.; Cloetens, Peter; Lemelle, Laurence; Tresserras, Juan-Angel Sans; Schoonjans, Tom; Silversmit, Geert; Solé, Vicente A.; Vekemans, Bart; Vincze, Laszlo; Westphal, Andrew J.; Allen, Carlton; Anderson, David; Ansari, Asna; Bajt, SašA.; Bastien, Ron K.; Bassim, Nabil; Bechtel, Hans A.; Borg, Janet; Bridges, John; Brownlee, Donald E.; Burchell, Mark; Changela, Hitesh; Davis, Andrew M.; Doll, Ryan; Floss, Christine; Flynn, George; Fougeray, Patrick; Frank, David; Grün, Eberhard; Heck, Philipp R.; Hillier, Jon K.; Hoppe, Peter; Hudson, Bruce; Huth, Joachim; Hvide, Brit; Kearsley, Anton; King, Ashley J.; Lai, Barry; Leitner, Jan; Leroux, Hugues; Leonard, Ariel; Lettieri, Robert; Marchant, William; Nittler, Larry R.; Ogliore, Ryan; Ong, Wei Ja; Postberg, Frank; Price, Mark C.; Sandford, Scott A.; Srama, Ralf; Stephan, Thomas; Sterken, Veerle; Stodolna, Julien; Stroud, Rhonda M.; Sutton, Steven; Trieloff, Mario; Tsou, Peter; Tsuchiyama, Akira; Tyliszczak, Tolek; von Korff, Joshua; Zevin, Daniel; Zolensky, Michael E.

    2014-09-01

    Using synchrotron-based X-ray diffraction measurements, we identified crystalline material in two particles of extraterrestrial origin extracted from the Stardust Interstellar Dust Collector. The first particle, I1047,1,34 (Hylabrook), consisted of a mosaiced olivine grain approximately 1 µm in size with internal strain fields up to 0.3%. The unit cell dimensions were a = 4.85 ± 0.08 Å, b = 10.34 ± 0.16 Å, c = 6.08 ± 0.13 Å (2σ). The second particle, I1043,1,30 (Orion), contained an olivine grain ≈ 2 µm in length and >500 nm in width. It was polycrystalline with both mosaiced domains varying over ≈ 20° and additional unoriented domains, and contained internal strain fields < 1%. The unit cell dimensions of the olivine were a = 4.76 ± 0.05 Å, b = 10.23 ± 0.10 Å, c = 5.99 ± 0.06 Å (2σ), which limited the olivine to a forsteritic composition >Fo65 (2σ). Orion also contained abundant spinel nanocrystals of unknown composition, but unit cell dimension a = 8.06 ± 0.08 Å (2σ). Two additional crystalline phases were present and remained unidentified. An amorphous component appeared to be present in both these particles based on STXM and XRF results reported elsewhere.

  13. The local interstellar medium. VII - The local interstellar wind and interstellar material in front of the nearby star Alpha Ophiuchi

    NASA Technical Reports Server (NTRS)

    Frisch, P. C.; York, D. G.; Fowler, J. R.

    1987-01-01

    IUE observations of Mg I 2852.127 A are used to search for warm interstellar gas in the direction of Alpha Oph. The data on Mg I are first presented, and Mg I as a diagnostic of warm gas is discussed. A cool H I feature found in the direction of Alpha Oph, and which is evidently the origin of most of the observed optical and ultraviolet lines, is discussed, and the cloud geometry is examined.

  14. First detection of line emission from the hot interstellar medium with solid state detectors

    NASA Technical Reports Server (NTRS)

    Schnopper, H. W.; Delvaille, J. P.; Rocchia, R.; Blondel, C.; Cheron, C.; Christy, J. C.; Ducros, R.; Koch, L.; Rothenflug, R.

    1981-01-01

    Previously reported enhanced soft X-ray emission from the North-Galactic Polar region supports the theory of a hot interstellar component. This paper reports the first detection of line emission from the hot interstellar component in the North-Galactic-Polar region. Measurements were made with solid state Si(Li) detectors aboard a spin-stabilized rocket launched from the White Sands Missile Range on March 22, 1980. Two features are clearly present in the low energy portion of the spectrum derived from the data. They correspond to emission lines from C V (300 eV) and C VI (360 eV), and from O VII (560 eV) and O VIII (650 eV). The detection of emission lines coming from these highly stripped ions is direct evidence for the thermal origin of the emission and confirms the presence of a hot (1-million K) component in the interstellar medium.

  15. Terrestrial atmospheric effects induced by counterstreaming dense interstellar cloud material

    NASA Astrophysics Data System (ADS)

    Yeghikyan, A.; Fahr, H.

    The Solar System during its life has encountered more than 10 times with dense interstellar clouds with particle concentrations about 10(8)-10(9) m(-3) and more suppressing the heliopause to dimensions smaller than 1 AU and bringing the Earth in immediate contact with the interstellar matter. For cloud's concentration greater than of 10(8) m(-3), the flow material at the Earth, completely shielded from solar wind protons would be only subject to solar photoionization processes. Previously published results were limited to consideration of processes outside of the accretion radius and have not been taken into account the photoionization. We have developed a 2D-2-fluid gasdynamical numerical code to describe the behavior of the incoming neutral matter near the Earth, taken into account both the photoionization and the gravity of the Sun. Increased neutral hydrogen fluxes ranging from 10(13) to 10(16) m(-2)s(-1) would cause an alteration of the terrestrial atmosphere. During immersion in the cloud the total incident flux of neutral hydrogen onto the terrestrial atmosphere in the steady state would be balanced by the upward escape flux of hydrogen and the downward flux of water, which is the product of hydrogen-oxygen chemistry via even-odd reaction schemes. In that case hydrogen acts as a catalyst for the destruction of oxygen atoms and causes the ozone concentration to diminish pronouncedly above 50 km from a factor of 1.5 at the stratopause to about a factor of 1000 and more at the mesopause. Thus, depending on the encounter parameters the large mixing ratio of hydrogen decreases the ozon concentration in the mesosphere and triggers an ice age of relatively long duration.

  16. Modelling interstellar physics and chemistry: implications for surface and solid-state processes.

    PubMed

    Williams, David; Viti, Serena

    2013-07-13

    We discuss several types of regions in the interstellar medium of the Milky Way and other galaxies in which the chemistry appears to be influenced or dominated by surface and solid-state processes occurring on or in interstellar dust grains. For some of these processes, for example, the formation of H₂ molecules, detailed experimental and theoretical approaches have provided excellent fundamental data for incorporation into astrochemical models. In other cases, there is an astrochemical requirement for much more laboratory and computational study, and we highlight these needs in our description. Nevertheless, in spite of the limitations of the data, it is possible to infer from astrochemical modelling that surface and solid-state processes play a crucial role in astronomical chemistry from early epochs of the Universe up to the present day. PMID:23734052

  17. The Abundances of Solid N2 and Gaseous CO2 in Interstellar Dense Molecular Clouds

    NASA Technical Reports Server (NTRS)

    Sandford, Scott A.; Bernstein, Max P.; Allamandola, Louis J.; Goorvitch, David; Teixeira, Teresa C. V. S.; DeVincenzi, D. (Technical Monitor)

    2000-01-01

    We present 2338-2322 per centimeter (4.277-4.307 micrometer) infrared spectra of a number of N2-containing mixed molecular ices and demonstrate that the strength of the infrared "forbidden" band due to the N=N stretch near 2328 per centimeter (4.295 micrometer) is extremely sensitive to the composition of the ice. The strength of the 2328 per centimeter N2 fundamental is significantly enhanced relative to that of pure N2 ice when NH3, H2O, or CO2 are present, but is largely unaffected by the presence of CO, CH4 or O2. We use the laboratory data in coil junction with ISO data that probes several lines-of-sight through dense molecular clouds to place limits on the abundance of interstellar solid phase N2 and the composition of the ices. Deriving upper limits is complicated by the presence of overlapping absorptions due to CO2 gas in the clouds and, in some cases, to photospheric CO in the background star. These upper limits are just beginning to be low enough to constrain interstellar grain models and the composition of possible N2-bearing interstellar ices. We outline the search criteria that will need to be met if solid interstellar N2 is to be detected in the future. We also discuss some of the implications of the presence of warm CO2 gas along the lines-of-sight to embedded protostars and demonstrate that its presence may help resolve certain puzzles associated with the previously derived gas/solid CO2 ratios and the relative abundances of polar and nonpolar ices towards these objects. Finally, we briefly comment on the possible implications of these results for the interpretation of N2 detections on outer solar system bodies.

  18. Studies of solid carbon dioxide in interstellar ice analogs subject to thermal processing

    NASA Astrophysics Data System (ADS)

    White, Douglas W.

    2010-09-01

    Solid CO2 has been detected in many lines of sight in the interstellar medium from infrared observatories. Spectral profiles from space-based observatories have suggested that CO2 on icy grain mantles is mixed with other common molecules such as H2O and CH 3OH in interstellar regions and that thermal annealing has occurred. The vibrational mode at 658 cm-1 (15.2 mum) is suspected to be a powerful diagnostic tool as to the composition of species on icy grain mantles as well as thermal histories. However, previous studies have not systematically investigated ice composition and temperature. Laboratory spectra of interstellar ice analogs have been created in this study order to better understand the physical properties of solid CO2 in these interstellar environments. Existing databases of ice composition studies and effects of ice thermal history were updated in this study to include a more systematic approach. The 658 cm-1 (15.2 mum) bending mode feature of CO2 is examined here and the subsequent astrophysical implications stated. In the first set of experiments, 47 mixtures of H2O,CH3OH, andCO2 were slowly warmed and mid-infrared absorption spectra were recorded at 5K intervals. The second set of experiments involved examining the CO2 bending mode feature of 10 different CO2-containing ice mixtures at different temperatures where ice segregation was suspected. In these experiments, the ice mixtures were slowly heated to the desired temperature for increasing time intervals before cooling down and recording mid-IR absorption spectra. These studies may be used to analyze IR data from space-based observatories such as the Spitzer Space Telescope Infrared Spectrograph as well other future IR observations of the interstellar medium. Finally, mass spectroscopy measurements were taken from temperature programmed desorption (TPD) experiments performed on several binary mixtures of H2O + CO2 and CH 3OH + CO2. Physical properties such as desorption energy of CO2 can be

  19. Laboratory and observational study of the interrelation of the carbonaceous component of interstellar dust and solar system materials

    NASA Technical Reports Server (NTRS)

    Allamandola, L. J.; Sanford, S. A.; Schutte, W. A.; Tielens, A. G. G. M.

    1991-01-01

    By studying the chemical and isotopic composition of interstellar ice and dust, one gains insight into the composition and chemical evolution of the solid bodies in the solar nebula and the nature of the material subsequently brought into the inner part of the solar system by comets and meteorites. It is now possible to spectroscopically probe the composition of interstellar ice and dust in the mid-infrared, the spectral range which is most diagnostic of fundamental molecular vibrations. We can compare these spectra of various astronomical objects (including the diffuse and dense interstellar medium, comets, and the icy outer planets and their satellites) with the spectra of analogs we produce in the laboratory under conditions which mimic those in these different objects. In this way one can determine the composition and abundances of the major constituents of the various ices and place general constraints on the types of organics coating the grains in the diffuse interstellar medium. In particular we have shown the ices in the dense clouds contain H2O, CH3OH, CO, perhaps some NH3 and H2CO, we well as nitriles and ketones or esters. Furthermore, by studying the photochemistry of these ice analogs in the laboratory, one gains insight into the chemistry which takes place in interstellar/precometary ices. Chemical and spectroscopic studies of photolyzed analogs (including deuterated species) are now underway. The results of some of these studies will be presented and implications for the evolution of the biogenic elements in interstellar dust and comets will be discussed.

  20. Interplanetary material as a guide to the composition of interstellar grains

    NASA Astrophysics Data System (ADS)

    Jones, A. P.; Williams, D. A.

    1987-01-01

    A compositional model for interstellar magnesium-iron silicate and iron-containing grains is derived under the constraint of elemental depletions, and using the composition of primitive solar system material as a paradigm of the interstellar particles. The solar system material invoked includes both chondritic porous aggregate interplanetary dust particles and unequilibrated ordinary chondritic meteorites. It is shown that the interstellar silicate grains are olivine rich (olivine-to-pyroxene grain mass ratio of greater than 0.8) and are iron rich (magnesium-to-iron atomic ratio of greater than 0.65). Iron not incorporated into silicates is assumed to be depleted into the iron sulphide pyrrhotite which makes up less than 6 percent of the refractory grain mass. The inclusion of grains of this magnetic sulphide into aggregate interstellar grains can explain the alignment of the grains responsible for the polarization in the visual.

  1. Do Carbynes Exist as Interstellar Material After All?

    NASA Astrophysics Data System (ADS)

    Gilkes, K. W. R.; Gaskell, P. H.; Russell, S. S.; Arden, J. W.; Pillinger, C. T.

    1992-07-01

    comparison with chaoite. An attempt has been made to obtain electron energy loss spectra (EELS) from individual crystals, so far without success because of their small size and fragility. EELS data with a characteristic carbon K edge, distinct from amorphous carbon, graphite, and diamond, have been obtained, however, from unspecified areas on the sample; the absence of any Si edges rules out the possibility of silicate contamination. Single crystals and microcrystalline material, having similar SAED patterns to the component found in meteorite residues, can be found in abundance in white carbon films deposited on a variety of substrates using plasma and arc techniques. Such materials are very low in Si abundance but contain some Fe. The existence of carbynes at the few percent level in acid residues from primitive meteorites in association with diamond, a material believed to be of presolar origin on the basis of isotopic characteristics, strongly suggests an analogous provenance to the linear carbon allotropes. Verchovsky et al. (this volume) have discussed the existence of an additional anomalous xenon host phase intimately coexisting with meteorite diamond. Given that if diamond is the carrier of Xe(HL), only one crystal in 3 x 10^6 actually contains a noble gas atom, carbynes may still have a role to play in understanding the first recognized noble gas isotope anomaly. A substantial body of astronomical observational data has been acquired documenting the presence of alternating single and triple carbon bonds in space: suggestions (Webster, 1980) that carbynes are a component of interstellar dust need to be further considered. The occurrence of triple- bonded species as grain material is particularly appealing, because cyano groups are common in interstellar molecules, and the exact location of istopically light nitrogen in primitive meteorite acid residues is still under active investigation (Russell et al., 1991). References: El Goresy A. and Donnay G. (1968) Science

  2. The Copernicus observations - Interstellar or circumstellar material. [UV spectra of early stars

    NASA Technical Reports Server (NTRS)

    Steigman, G.; Strittmatter, P. A.; Williams, R. E.

    1975-01-01

    It is suggested that the sharp absorption lines observed in the ultraviolet spectra of early-type stars by the Copernicus satellite may be entirely accounted for by the circumstellar material in the H II regions and associated transition zones around the observed stars. If this interpretation is correct, the Copernicus results yield little information on the state of any interstellar (as opposed to circumstellar) gas and, in particular, shed little light on the degree of element depletion in interstellar space.

  3. Identification of Crystalline Material in Two Interstellar Dust Candidates from the Stardust Mission

    NASA Technical Reports Server (NTRS)

    Gainsforth, Zack; Simionovici, Alexandra; Brenker, Frank E.; Schmitz, Sylvia; Burghammer, Manfred; Cloetens, Peter; Lemelle, Laurence; San Tresseras, Juan-Angel; Schoonjans, Tom; Silversmit, Geert; Sole, Vicente A.; Vekemans, Bart; Vincze, Laszlo; Achilles, Cheri; Allen, Carlton; Ansari, Asna; Bajt, Sasa; Bassim, Nabil; Bastien, Ron S.; Bechtel, H. A.; Borg, Janet; Bridges, John; Brownlee, Donald E.; Sandford, S. A.; Zolensky, Michael E.

    2012-01-01

    NASA's interstellar collector from the Stardust mission captured several particles that are now thought to be of interstellar origin. We analyzed two of these via nanodiffraction at the European Synchrotron Radiation Facility (ESRF) and found them to contain crystalline components. The unit cell of the crystalline material is determined from the diffraction patterns and the most likely mineral components are identified as olivine and spinel.

  4. Hydrocarbon Materials of Likely Interstellar Origin from the Paris Meteorite

    NASA Astrophysics Data System (ADS)

    Merouane, S.; Djouadi, Z.; Le Sergeant d'Hendecourt, L.; Zanda, B.; Borg, J.

    2012-09-01

    We have examined some grains from the Paris meteorite through infrared and Raman micro-spectroscopy in order to investigate their carbonaceous and mineralogical components. In the mid- as well as far-infrared regions, the raw and global spectra of Paris resemble those of CM meteorites. However, we have obtained rather peculiar infrared spectra for some aromatic-rich micron-sized fragments of Paris displaying a very good match between its organic signatures both in the 3.4 μm and 6 μm regions, and the ones observed from the diffuse interstellar medium infrared sources toward the Galactic center, suggesting that this meteorite may have indeed preserved some organic matter of interstellar origin.

  5. HYDROCARBON MATERIALS OF LIKELY INTERSTELLAR ORIGIN FROM THE PARIS METEORITE

    SciTech Connect

    Merouane, S.; Djouadi, Z.; D'Hendecourt, L. Le Sergeant; Borg, J.; Zanda, B. E-mail: zahia.djouadi@ias.u-psud.fr

    2012-09-10

    We have examined some grains from the Paris meteorite through infrared and Raman micro-spectroscopy in order to investigate their carbonaceous and mineralogical components. In the mid- as well as far-infrared regions, the raw and global spectra of Paris resemble those of CM meteorites. However, we have obtained rather peculiar infrared spectra for some aromatic-rich micron-sized fragments of Paris displaying a very good match between its organic signatures both in the 3.4 {mu}m and 6 {mu}m regions, and the ones observed from the diffuse interstellar medium infrared sources toward the Galactic center, suggesting that this meteorite may have indeed preserved some organic matter of interstellar origin.

  6. EXPLORING THE POTENTIAL FORMATION OF ORGANIC SOLIDS IN CHONDRITES AND COMETS THROUGH POLYMERIZATION OF INTERSTELLAR FORMALDEHYDE

    SciTech Connect

    Kebukawa, Yoko; Cody, George D.; David Kilcoyne, A. L. E-mail: yoko@ep.sci.hokudai.ac.jp

    2013-07-01

    Polymerization of interstellar formaldehyde, first through the formose reaction and then through subsequent condensation reactions, provides a plausible explanation for how abundant and highly chemically complex organic solids may have come to exist in primitive solar system objects. In order to gain better insight on the reaction, a systematic study of the relationship of synthesis temperature with resultant molecular structure was performed. In addition, the effect of the presence of ammonia on the reaction rate and molecular structure of the product was studied. The synthesized formaldehyde polymer is directly compared to chondritic insoluble organic matter (IOM) isolated from primitive meteorites using solid-state {sup 13}C nuclear magnetic resonance, Fourier transform infrared, and X-ray absorption near edge structure spectroscopy. The molecular structure of the formaldehyde polymer is shown to exhibit considerable similarity at the functional group level with primitive chondritic IOM. The addition of ammonia to the solution enhances the rate of polymerization reaction at lower temperatures and results in substantial incorporation of nitrogen into the polymer. Morphologically, the formaldehyde polymer exists as submicron to micron-sized spheroidal particles and spheroidal particle aggregates that bare considerable similarity to the organic nanoglobules commonly observed in chondritic IOM. These spectroscopic and morphological data support the hypothesis that IOM in chondrites and refractory organic carbon in comets may have formed through the polymerization of interstellar formaldehyde after planetesimal accretion, in the presence of liquid water, early in the history of the solar system.

  7. Exploring the Potential Formation of Organic Solids in Chondrites and Comets through Polymerization of Interstellar Formaldehyde

    NASA Astrophysics Data System (ADS)

    Kebukawa, Yoko; Kilcoyne, A. L. David; Cody, George D.

    2013-07-01

    Polymerization of interstellar formaldehyde, first through the formose reaction and then through subsequent condensation reactions, provides a plausible explanation for how abundant and highly chemically complex organic solids may have come to exist in primitive solar system objects. In order to gain better insight on the reaction, a systematic study of the relationship of synthesis temperature with resultant molecular structure was performed. In addition, the effect of the presence of ammonia on the reaction rate and molecular structure of the product was studied. The synthesized formaldehyde polymer is directly compared to chondritic insoluble organic matter (IOM) isolated from primitive meteorites using solid-state 13C nuclear magnetic resonance, Fourier transform infrared, and X-ray absorption near edge structure spectroscopy. The molecular structure of the formaldehyde polymer is shown to exhibit considerable similarity at the functional group level with primitive chondritic IOM. The addition of ammonia to the solution enhances the rate of polymerization reaction at lower temperatures and results in substantial incorporation of nitrogen into the polymer. Morphologically, the formaldehyde polymer exists as submicron to micron-sized spheroidal particles and spheroidal particle aggregates that bare considerable similarity to the organic nanoglobules commonly observed in chondritic IOM. These spectroscopic and morphological data support the hypothesis that IOM in chondrites and refractory organic carbon in comets may have formed through the polymerization of interstellar formaldehyde after planetesimal accretion, in the presence of liquid water, early in the history of the solar system.

  8. The Enigmatic Diffuse Interstellar Bands: A Reservoir of Organic Material

    NASA Astrophysics Data System (ADS)

    McCall, Benjamin

    2008-05-01

    The diffuse interstellar medium of our galaxy contains about 3 billion solar masses of atomic hydrogen, or ˜3x10^66 H atoms. The inventory of identified heavy-atom-containing molecules in diffuse clouds includes CH, CH^+, NH, OH, C2, CN, C2H, and C3H2, and totals to roughly ˜10^59 in number. However, a ubiquitous set of optical absorption lines known as the diffuse interstellar bands (DIBs) belies the likely presence of ˜10^58 large organic molecules that have yet to be identified. The first of the DIBs were observed in 1919, but despite many decades of intensive efforts by laboratory spectroscopists and astronomers the identities of the molecular carriers of the DIBs remain a mystery. After reviewing the history of the DIBs, I will discuss some preliminary results from a large-scale DIBs observing campaign that was conducted on over 119 nights between 1999 and 2003, using the 3.5-meter telescope at the Apache Point Observatory. This survey, undertaken by a collaboration led by Don York at the University of Chicago, has produced high-resolution, high signal-to-noise ratio spectra of over 160 stars, spanning the entire optical region from 3600--10200 å. In particular, I will focus on two ongoing efforts. The first is the generation of a comprehensive spectral atlas of the DIBs based on four heavily reddened sightlines; this atlas will be of great use to spectroscopists who wish to compare their laboratory spectra to interstellar spectra (in hopes of finding a match!). The second is the search for correlations among the different DIBs, and especially the search for sets of DIBs that always have the same relative intensities in different sightlines. Such sets would represent the electronic spectra of individual molecular carriers of the DIBs, and could provide hints about which species should be considered for additional laboratory spectroscopic studies.

  9. Modern solid state laser materials

    SciTech Connect

    Krupke, W.F.

    1984-06-20

    This document contains visual aids used in an invited talk entitled Modern Solid State Laser Materials, presented at the Conference on Lasers and Electro-Optics (CLEO) held in Anaheim, California, on June 20, 1984. Interest at LLNL in solid state lasers focuses on evaluating the potential of solid state laser media for high average power applications, including inertial fusion power production. This talk identifies the relevant bulk material parameters characterizing average power capacity and uses chromium and neodymium co-doped gadolinium scandium gallium garnet (Nd:Cr:GSGG) as an example of a laser material with improved laser properties relative to Nd:YAG (plausible large-scale growth, more efficient spectral coupling to xenon flashlamp radiation, reduced stimulated emission cross section, adequate thermal shock and optical damage threshold parameters, etc.). Recently measured spectroscopic, kinetic, and thermo-mechanical properties of Nd:Cr:GSGG are given.

  10. The 2140 cm-1 (4.673 microns) Solid CO Band: The Case for Interstellar O2 and N2 and the Photochemistry of Nonpolar Interstellar Ice Analogs

    NASA Astrophysics Data System (ADS)

    Elsila, Jamie; Allamandola, Louis J.; Sandford, Scott A.

    1997-04-01

    The infrared spectra of CO frozen in nonpolar ices containing N2, CO2, O2, and H2O and the UV photochemistry of these interstellar/precometary ice analogs are reported. The spectra are used to test the hypothesis that the narrow 2140 cm-1 (4.673 μm) interstellar absorption feature attributed to solid CO might be produced by CO frozen in ices containing nonpolar species such as N2 and O2. It is shown that mixed molecular ices containing CO, N2, O2, and CO2 provide a good match to the interstellar band at all temperatures between 12 and 30 K both before and after photolysis. The optical constants (real and imaginary parts of the index of refraction) in the region of the solid CO feature are reported for several of these ices. The N2 and O2 absorptions at 2328 cm-1 (4.296 μm) and 1549 cm-1 (6.456 μm), respectively, are also shown. The best matches between the narrow interstellar band and the feature in the laboratory spectra of nonpolar ices are for samples which contain comparable amounts of N2, O2, CO2, and CO. Co-adding the CO band from an N2:O2:CO2:CO=1:5:1/2:1 ice with that of an H2O:CO = 20:1 ice provides an excellent fit across the entire interstellar CO feature. The four-component, nonpolar ice accounts for the narrow 2140 cm-1 portion of the feature which is associated with quiescent regions of dense molecular clouds. Using this mixture, and applying the most recent cosmic abundance values, we derive that between 15% and 70% of the available interstellar N is in the form of frozen N2 along several lines of sight toward background stars. This is reduced to a range of 1%-30% for embedded objects with lines of sight more dominated by warmer grains. The cosmic abundance of O tied up in frozen O2 lies in the 10%-45% range toward background sources, and it is between 1% and 20% toward embedded objects. The amount of oxygen tied up in CO and CO2 frozen in nonpolar ices can be as much as 2%-10% toward background sources and on the order of 0.2%-5% for embedded

  11. The 2140 cm-1 (4.673 microns) solid CO band: the case for interstellar O2 and N2 and the photochemistry of nonpolar interstellar ice analogs

    NASA Technical Reports Server (NTRS)

    Elsila, J.; Allamandola, L. J.; Sandford, S. A.

    1997-01-01

    The infrared spectra of CO frozen in nonpolar ices containing N2, CO2, O2, and H2O and the UV photochemistry of these interstellar/precometary ice analogs are reported. The spectra are used to test the hypothesis that the narrow 2140 cm-1 (4.673 microns) interstellar absorption feature attributed to solid CO might be produced by CO frozen in ices containing nonpolar species such as N2 and O2. It is shown that mixed molecular ices containing CO, N2, O2, and CO2 provide a good match to the interstellar band at all temperatures between 12 and 30 K both before and after photolysis. The optical constants (real and imaginary parts of the index of refraction) in the region of the solid CO feature are reported for several of these ices. The N2 and O2 absorptions at 2328 cm-1 (4.296 microns) and 1549 cm-1 (6.456 microns), respectively, are also shown. The best matches between the narrow interstellar band and the feature in the laboratory spectra of nonpolar ices are for samples which contain comparable amounts of N2, O2, CO2, and CO. Co-adding the CO band from an N2:O2:CO2:CO = 1:5:1/2:1 ice with that of an H2O:CO = 20:1 ice provides an excellent fit across the entire interstellar CO feature. The four-component, nonpolar ice accounts for the narrow 2140 cm-1 portion of the feature which is associated with quiescent regions of dense molecular clouds. Using this mixture, and applying the most recent cosmic abundance values, we derive that between 15% and 70% of the available interstellar N is in the form of frozen N2 along several lines of sight toward background stars. This is reduced to a range of 1%-30% for embedded objects with lines of sight more dominated by warmer grains. The cosmic abundance of O tied up in frozen O2 lies in the 10%-45% range toward background sources, and it is between 1% and 20% toward embedded objects. The amount of oxygen tied up in CO and CO2 frozen in nonpolar ices can be as much as 2%-10% toward background sources and on the order of 0

  12. The 2140 cm-1 (4.673 microns) solid CO band: the case for interstellar O2 and N2 and the photochemistry of nonpolar interstellar ice analogs.

    PubMed

    Elsila, J; Allamandola, L J; Sandford, S A

    1997-04-20

    The infrared spectra of CO frozen in nonpolar ices containing N2, CO2, O2, and H2O and the UV photochemistry of these interstellar/precometary ice analogs are reported. The spectra are used to test the hypothesis that the narrow 2140 cm-1 (4.673 microns) interstellar absorption feature attributed to solid CO might be produced by CO frozen in ices containing nonpolar species such as N2 and O2. It is shown that mixed molecular ices containing CO, N2, O2, and CO2 provide a good match to the interstellar band at all temperatures between 12 and 30 K both before and after photolysis. The optical constants (real and imaginary parts of the index of refraction) in the region of the solid CO feature are reported for several of these ices. The N2 and O2 absorptions at 2328 cm-1 (4.296 microns) and 1549 cm-1 (6.456 microns), respectively, are also shown. The best matches between the narrow interstellar band and the feature in the laboratory spectra of nonpolar ices are for samples which contain comparable amounts of N2, O2, CO2, and CO. Co-adding the CO band from an N2:O2:CO2:CO = 1:5:1/2:1 ice with that of an H2O:CO = 20:1 ice provides an excellent fit across the entire interstellar CO feature. The four-component, nonpolar ice accounts for the narrow 2140 cm-1 portion of the feature which is associated with quiescent regions of dense molecular clouds. Using this mixture, and applying the most recent cosmic abundance values, we derive that between 15% and 70% of the available interstellar N is in the form of frozen N2 along several lines of sight toward background stars. This is reduced to a range of 1%-30% for embedded objects with lines of sight more dominated by warmer grains. The cosmic abundance of O tied up in frozen O2 lies in the 10%-45% range toward background sources, and it is between 1% and 20% toward embedded objects. The amount of oxygen tied up in CO and CO2 frozen in nonpolar ices can be as much as 2%-10% toward background sources and on the order of 0

  13. Accurate oscillator strengths for ultraviolet lines of Ar I - Implications for interstellar material

    NASA Technical Reports Server (NTRS)

    Federman, S. R.; Beideck, D. J.; Schectman, R. M.; York, D. G.

    1992-01-01

    Analysis of absorption from interstellar Ar I in lightly reddened lines of sight provides information on the warm and hot components of the interstellar medium near the sun. The details of the analysis are limited by the quality of the atomic data. Accurate oscillator strengths for the Ar I lines at 1048 and 1067 A and the astrophysical implications are presented. From lifetimes measured with beam-foil spectroscopy, an f-value for 1048 A of 0.257 +/- 0.013 is obtained. Through the use of a semiempirical formalism for treating singlet-triplet mixing, an oscillator strength of 0.064 +/- 0.003 is derived for 1067 A. Because of the accuracy of the results, the conclusions of York and colleagues from spectra taken with the Copernicus satellite are strengthened. In particular, for interstellar gas in the solar neighborhood, argon has a solar abundance, and the warm, neutral material is not pervasive.

  14. Isotopic Fractionation in Primitive Material: Quantifying the Contribution of Interstellar Chemistry

    NASA Technical Reports Server (NTRS)

    Charnley, Steven

    2010-01-01

    Anomalously fractionated isotopic material is found in many primitive Solar System objects, such as meteorites and comets. It is thought, in some cases, to trace interstellar matter that was incorporated into the Solar Nebula without undergoing significant processing. We will present the results of models of the nitrogen, oxygen, and carbon fractionation chemistry in dense molecular clouds, particularly in cores where substantial freeze-out of molecules on to dust has occurred. The range of fractionation ratios expected in different interstellar molecules will be discussed and compared to the ratios measured in molecular clouds, comets and meteoritic material. These models make several predictions that can be tested in the near future by molecular line observations, particularly with ALMA.

  15. FORMATION AND IDENTIFICATION OF INTERSTELLAR MOLECULE LINEAR C{sub 5}H FROM PHOTOLYSIS OF METHANE DISPERSED IN SOLID NEON

    SciTech Connect

    Wu Yujong; Chen Huifen; Hsu Shengchuan; Lin Mengyeh; Chou Shenglung; Cheng Bingming; Camacho, Cristopher; Witek, Henryk A.; Ogilvie, J. F.

    2009-08-10

    Photolysis of methane dispersed (1/1000) in solid Ne at 3 K with vacuum-ultraviolet light from a synchrotron produced infrared absorption lines of several products, including new lines at 3319.3 and 1955.5 cm{sup -1}. Based on experiments with isotopic labeling and results of quantum-chemical calculations, these lines are assigned to the C-H stretching and C=C stretching modes, respectively, of interstellar molecule linear C{sub 5}H radicals.

  16. Nanoprobes, nanostructured materials and solid state materials

    NASA Astrophysics Data System (ADS)

    Yin, Houping

    2005-07-01

    Novel templates have been developed to prepare nanostructured porous materials through nonsurfactant templated pathway. And new applications of these materials, such as drug delivery and molecular imprinting, have been explored. The relationship between template content and pore structure has been investigated. The composition and pore structures were studied in detail using IR, TGA, SEM, TEM, BET and XRD. The obtained mesoporous materials have tunable diameters in the range of 2--12 nm. Due to the many advantages of this nonsurfactant templated pathway, such as environment friendly and biocompatibility, controlled release of antibiotics in the nanoporous materials were studied. The in vitro release properties were found to depend on the silica structures which were well tuned by varying the template content. A controlled long-term release pattern of vancomycin was achieved when the template content was 30 wt% or lower. Nanoscale electrochemical probes with dimensions as small as 50 nm in diameter and 1--2 mum in length were fabricated using electron beam deposition on the apex of conventional micron size electrodes. The electroactive region was limited to the extreme tip of the nanoprobe by coating with an insulating polymer and re-opening of the coating at the extreme tip. The novel nanoelectrodes thus prepared were employed to probe neurons in mouse brain slice and the results suggest that the nanoprobes were capable of recording neuronal excitatory postsynaptic potential signals. Interesting solid state chemistry was found in oxygenated iron phthalocyanine. Their Mossbauer spectra show the formation of four oxygenated species apart from the unoxygenated parent compound. The oxygen-bridged compounds formed in the solid matrix bear no resemblance to the one formed by solution chemistry. Tentative assignment of species has been made with the help of Mossbauer and IR spectroscopy. An effort to modify aniline trimer for potential nanoelectronics applications and to

  17. Interstellar/Precometary Organic Material and the Photochemical Evolution of Complex Organics

    NASA Technical Reports Server (NTRS)

    Allamandola, Lou J.; Bernstein, Max; Sandford, Scott; Witteborn, Fred (Technical Monitor)

    1996-01-01

    During the past two decades ground-, air-, and space-based infrared spectroscopic observations, combined with realistic laboratory simulations, have revolutionized our understanding of interstellar ice and dust, the raw materials from which planets, comets and stars form. Most interstellar material is concentrated in Large molecular clouds where simple molecules are formed by dust grain and gas phase reactions. Gaseous species striking the cold (10 K) dust will stick, forming an icy grain mantle. This accretion, coupled with energetic particle bombardment and UV photolysis, will produce a complex chemical mixture containing volatile, non-volatile, and isotopically fractionated species. Ices in molecular clouds contain the very simple molecules H2O, CH3OH, CO, CO2, H2, and perhaps some NH3 and H2CO, as well as more complex species including nitriles and ketones or esters. The evidence for these compounds as well as carbon rich materials such as polycyclic aromatic hydrocarbons (PAHs), microdiamonds, and amorphous carbon will be reviewed and the possible connections with comets and meteorites will be presented in the first part of the talk. The second part of the presentation will focus on interstellar/precometary ice photochemical evolution. The chemical composition and photochemical evolution of realistic interstellar/pre-cometary ice analogs containing methanol will be discussed. ultraviolet photolysis of these ices produces H2, H2CO, CO2, CO, CH4, HCO, and more complex molecules. Infrared spectroscopy, H-1 and C-13 nuclear magnetic resonance (NMR) spectroscopy, and gas chromatography-mass spectrometry demonstrate that when ices representative of interstellar grains and comets are exposed to UV radiation at low temperature a series of moderately complex organic molecules are formed in the ice including: CH3CH2OH (ethanol), HC(=O)NH2 (formamide), CH3C(=O)NH2 (acetamide), and R-C(integral)N (nitriles). Several of these are already known to be in the interstellar

  18. NASA's IBEX Observes Interstellar Matter

    NASA Video Gallery

    The Interstellar Boundary Explorer (IBEX) has directly sampled multiple heavy elements from the Local Interstellar Cloud for the first time. It turns out that this interstellar material is not like...

  19. Nebular and Interstellar Materials in a Giant Cluster IDP of Probable Cometary Origin

    NASA Technical Reports Server (NTRS)

    Messenger, S.; Brownlee, D. E.; Joswiak, D. J.; Nguyen, A. N.

    2015-01-01

    Comets contain a complex mixture of materials with presolar and Solar System origins. Chondritic porous interplanetary dust particles (CP-IDPs) are associated with comets by their fragile nature, unequilibrated anhydrous mineralogy and high abundances of circumstellar grains and isotopically anomalous organic materials. Comet 81P/Wild 2 samples returned by the Stardust spacecraft contain presolar materials as well as refractory 16O-rich Ca-Al-rich inclusion- (CAI), chondrule-, and AOA-like materials. We are conducting coordinated chemical, mineralogical, and isotopic studies of a giant cluster CP-IDP (U2-20-GCA) to determine the proportions of inner Solar System and interstellar materials. We previously found that this IDP contains abundant presolar silicates (approx. 1,800 ppm) and 15N-rich hotspots [6].

  20. The 2140 cm(exp -1) (4.673 Microns) Solid CO Band: The Case for Interstellar O2 and N2 and the Photochemistry of Non-Polar Interstellar Ice Analogs

    NASA Technical Reports Server (NTRS)

    Elsila, Jamie; Allamandola, Louis J.; Sandford, Scott A.; Witteborn, Fred C. (Technical Monitor)

    1996-01-01

    The infrared spectra of CO frozen in non-polar ices containing N2, CO2, O2, and H2O, and the ultraviolet photochemistry of these interstellar/precometary ice analogs are reported. The spectra are used to test the hypothesis that the narrow 2140/cm (4.673 micrometer) interstellar absorption feature attributed to solid CO might be produced by CO frozen in ices containing non-polar species such as N2 and O2. It is shown that mixed molecular ices containing CO, N2, O2, and CO2 provide a very good match to the interstellar band at all temperatures between 12 and 30 K both before and after photolysis. The optical constants (real and imaginary parts of the index of refraction) in the region of the solid CO feature are reported for several of these ices.

  1. An attempt to detect scattering from tenuous diffuse interstellar material in an elliptical galaxy

    NASA Astrophysics Data System (ADS)

    Michard, R.; Marchal, J.

    1991-03-01

    An attempt has been made to observe the phenomenon described by Jura (1978), who predicted that if a sufficient amount of tenuous interstellar material would be presented in an elliptical galaxy, it could be detected by the linear polarization associated with Rayleigh scattering. An admittedly too crude experiment gives an upper limit of about 0.0005 for the degree of the corresponding polarization in red light in NGC 3377. It appears that there is no large scale pattern of polarization at a level of 0.001 in this galaxy.

  2. Quenched Carbonaceous Composite: a laboratory analog for carbonaceous material in the interstellar medium.

    PubMed

    Tokunaga, A T; Wada, S

    1997-01-01

    We review the properties of Quenched Carbonaceous Composite (QCC), a residue produced from a hydrocarbon plasma, and the properties of its derivatives. A. Sakata and his colleagues have shown that QCC has a 220 nm absorption band, visible fluorescence matching the extended red emission seen in reflection nebulae, and infrared absorption bands that correspond to the infrared emission features in reflection nebulae, HII regions, and planetary nebulae. These properties make QCC a strong candidate material as a laboratory analog to the carbonaceous material in the interstellar medium. QCC is distinguished from the PAH hypothesis in that (1) it is a condensate composed of aromatic and aliphatic molecules, as well as radicals; (2) it exhibits a 220 nm absorption that is very similar in wavelength to the 217 nm absorption in the interstellar medium; (3) it exhibits visible fluorescence consistent with that seen in reflection nebulae; and (4) the bands at 7.7 and 8.6 microns are caused by ketone bands in oxidized QCC. The aromatic component in QCC is thought to be typically 1-4 rings, with the majority being about 1-2 rings. PMID:11541327

  3. Solid oxide materials research accelerated electrochemical testing

    SciTech Connect

    Windisch, C.; Arey, B.

    1995-08-01

    The objectives of this work were to develop methods for accelerated testing of cathode materials for solid oxide fuel cells under selected operating conditions. The methods would be used to evaluate the performance of LSM cathode material.

  4. Isotopic Fractionation in Primitive Materials: Quantifying the Contribution of Interstellar Chemistry

    NASA Astrophysics Data System (ADS)

    Charnley, Steven

    We propose to continue theoretical studies aimed at elucidating the contribution of astrochemical processes to the isotopic fractionation measured in carbonaceous meteoritic material, interplanetary dust particles (IDPs) and comets, including the dust samples returned by the Stardust mission. Prior work has focused on the fractionation chemistry of 15N, 13C, and D in cold, isolated dense cores. We now propose to extend these studies to cores residing in stellar clusters, more energetic conditions that better reflect the birth environment of the Solar System. We will undertake four studies: In cold molecular cores, the computation of 13C, 15N and D fractionation in small and large hydrocarbons that could be precursors to meteoritic organic material A definitive study of isotopic fractionation in candidate presolar cores illuminated by strong ultraviolet radiation from nearby stars in a stellar cluster. A new model of isotopic chemistry in dense cores exposed to greatly enhanced fluxes of cosmic-ray particles due to their proximity to a supernovae. These theoretical models will make predictions that will testable by astronomical observation and so an interdisciplinary approach can be advantageous. We therefore also propose to perform a program of radioastronomical observations to definitively measure the isotopic fractionation of 15N in interstellar molecules. In each environment, we will evaluate the maximum degree of stable-isotope enhancement or depletion present in specific molecular functional groups, which could have been precursor reservoirs of cometary and asteroidal material. For the theoretical projects we will employ comprehensive chemical fractionation networks and astrochemistry codes previously developed with Origins support. These studies will allow us, for the first time, to compare and contrast the effect of irradiation environment and so uniquely delineate astronomical contributions to isotopic fractionation in primitive Solar System materials. In

  5. Protective glove material permeation by organic solids.

    PubMed

    Fricker, C; Hardy, J K

    1992-12-01

    A method has been developed for the determination of permeation characteristics of glove materials by organic solids. The system employs a stainless steel exposure cell and allows rapid and uniform contact of either solid disks or powders with minimal membrane bowing. A gas chromatograph equipped with a flame ionization detector was used for monitoring the permeation process, which provided detection limits of 0.9-1.2 ng for the organic solids evaluated. By using an automated system for instrument control and data collection, breakthrough times, steady-state times, and steady-state permeation rates have been determined for five common glove materials when exposed to nine organic solids. PMID:1471595

  6. Dry pulverized solid material pump

    DOEpatents

    Meyer, John W.; Bonin, John H.; Daniel, Jr., Arnold D.

    1984-07-31

    Apparatus is shown for substantially increasing the feed rate of pulverized material into a pressurized container. The apparatus includes a rotor that is mounted internal to the pressurized container. The pulverized material is fed into an annular chamber defined by the center of the rotor. A plurality of impellers are mounted within the annular chamber for imparting torque to the pulverized material.

  7. Formation of Nitrogen and Hydrogen-bearing Molecules in Solid Ammonia and Implications for Solar System and Interstellar Ices

    NASA Astrophysics Data System (ADS)

    Zheng, Weijun; Jewitt, David; Osamura, Yoshihiro; Kaiser, Ralf I.

    2008-02-01

    We irradiated solid ammonia (NH3) in the temperature range of 10-60 K with high-energy electrons to simulate the processing of ammonia-bearing ices in the interstellar medium and in the solar system. By monitoring the newly formed molecules online and in situ, the synthesis of hydrazine (N2H4), diazene (N2H2 isomers), hydrogen azide (HN3), the amino radical (NH2), molecular hydrogen (H2), and molecular nitrogen (N2) has been confirmed. Our results show that the production rates of hydrazine, diazene, hydrogen azide, molecular hydrogen, and molecular nitrogen are higher in amorphous ammonia than those in crystalline ammonia; this behavior is similar to the production of molecular hydrogen, molecular oxygen, and hydrogen peroxide found in electron-irradiated water ices. However, the formation of hydrazine in crystalline ammonia does not show any temperature dependence. Our experimental results give hints to the origin of molecular nitrogen in the Saturnian system and possibly in the atmospheres of proto-Earth and Titan; our research may also guide the search of hitherto unobserved nitrogen-bearing molecules in the interstellar medium and in our solar system.

  8. Materials for solid state lighting

    SciTech Connect

    Johnson, S.G.; Simmons, J.A.

    2002-03-26

    Dramatic improvement in the efficiency of inorganic and organic light emitting diodes (LEDs and OLEDs) within the last decade has made these devices viable future energy efficient replacements for current light sources. However, both technologies must overcome major technical barriers, requiring significant advances in material science, before this goal can be achieved. Attention will be given to each technology associated with the following major areas of material research: (1) material synthesis, (2) process development, (3) device and defect physics, and (4) packaging. The discussion on material synthesis will emphasize the need for further development of component materials, including substrates and electrodes, necessary for improving device performance. The process technology associated with the LEDs and OLEDs is very different, but in both cases it is one factor limiting device performance. Improvements in process control and methodology are expected to lead to additional benefits of higher yield, greater reliability and lower costs. Since reliability and performance are critical to these devices, an understanding of the basic physics of the devices and device failure mechanisms is necessary to effectively improve the product. The discussion will highlight some of the more basic material science problems remaining to be solved. In addition, consideration will be given to packaging technology and the need for the development of novel materials and geometries to increase the efficiencies and reliability of the devices. The discussion will emphasize the performance criteria necessary to meet lighting applications, in order to illustrate the gap between current status and market expectations for future product.

  9. The Evolution of Interstellar Gas: Massive Stars and the Dispersal of Neutral Material

    NASA Technical Reports Server (NTRS)

    Federman, Steven R.

    2003-01-01

    We studied the effects of newly formed O and B stars on their surrounding interstellar material through a combination of observations and theoretical modeling. The observational data came from measurements of absorption seen in the spectra of background, newly formed stars. Particular attention was given to stellar radiation which converts molecular to atomic material. Laboratory data on absorption cross sections relevant to the analysis and interpretation of carbon monoxide formed part of the effort. The grant supported Postdoctoral Fellows, Drs. Min Yan and Yaron Sheffer, and a laboratory technician. Though the students themselves were not supported. one M.S. Thesis and two Ph.D. dissertations from the University of Toledo were based on the research done under the grant. The research accomplished under this grant led directly to other funded programs. An observing proposal to study the chemistry of diffuse molecular clouds in the Large and Small Magellanic Clouds with ESO s Very Large Telescope was another example of a successful outcome of my LTSA program.

  10. Hydrogenation process for solid carbonaceous materials

    DOEpatents

    Cox, John L.; Wilcox, Wayne A.

    1979-01-01

    Coal or other solid carbonaceous material is contacted with an organic solvent containing both hydrogen and a transition metal catalyst in solution to hydrogenate unsaturated bonds within the carbonaceous material. This benefaction step permits subsequent pyrolysis or hydrogenolysis of the carbonaceous fuel to form gaseous and liquid hydrocarbon products of increased yield and quality.

  11. APPARATUS FOR HANDLING MIXTURES OF SOLID MATERIALS

    DOEpatents

    Hubbell, J.P.

    1959-08-25

    An apparatus is described for handling either a mixture of finely subdivided materials or a single material requiring a compacting action thereon preparatory to a chemical reducing process carried out in a crucible container. The apparatus is designed to deposit a mixture of dust-forming solid materials in a container while confining the materials against escape into the surrounding atmosphere. A movable filling tube, having a compacting member, is connected to the container and to a covered hopper receiving the mixture of materials. The filling tube is capable of reciprocating in the container and their relative positions are dependent upon the pressure established upon the material by the compacting member.

  12. Laboratory Studies of Solid Carbon Dioxide in Planetary and Interstellar Ices

    NASA Technical Reports Server (NTRS)

    White, Douglas; Sandford, Scott A.; Mastrapa, Rachel M.

    2012-01-01

    Laboratory spectra have shown that CO2. is a powerful diagnostic tool for analyzing infrared data from remote observations, as it has been detected on icy moons in the outer solar system as well as dust grain surfaces in the interstellar medium. IR absorption profiles of CO2 wi thin ice mixtures containing H2O and CH30H change with respect to tem perature and mixture ratios. In this particular study, the CO2 stretch mode around 235O cm (exp -1) (4.3 rricrons) is systematically observ ed in different mixtures with H2O and CH30H in temperature ranges from 15K to 150 K, as well as vibrational modes in the near-IR such as th e combination bands near 3700 cm (exp -1) (2.7 microns) and 5080 (exp -1) (2.0 microns). Additionally, some high?temperature deposits (T > 50 K) of H2O, CH30H, and CO2 ice mixtures were performed to determine the maximum temperatures at which CO2 will deposit on the sample win dow. These data may then be used to interpret spectra obtained from remote IR observations. This research was sponsored by Oak Ridge Associ ated Universities (ORAU) through the NASA Postdoctoral Program (NPP) as well as Ames Research Center and the SETI institute who provided fa cilities and equipment.

  13. Solid C triple bond N bearing material on outer solar system bodies.

    PubMed

    Cruikshank, D P; Allamandola, L J; Hartmann, W K; Tholen, D J; Brown, R H; Matthews, C N; Bell, J F

    1991-01-01

    Using telescopic observations by ourselves and other observers, we have identified cyano-group containing molecules in the very dark solids on the surfaces of a few D-class asteroids, the dust of some comets, and low-albedo hemisphere of Iapetus, and the rings of Uranus, through spectroscopic detection of the 2.2-micrometers overtone of the C triple bond N stretching fundamental mode. The occurrence of this band on all four classes of small Solar System bodies may be diagnostic of the duration of exposure and degree of modification of surface materials, and may also establish a link between outer Solar System and interstellar materials. PMID:11538090

  14. Advanced materials for solid oxide fuel cells

    SciTech Connect

    Armstrong, T.R.; Stevenson, J.

    1995-08-01

    The purpose of this research is to improve the properties of the current state-of-the-art materials used for solid oxide fuel cells (SOFCs). The objectives are to: (1) develop materials based on modifications of the state-of-the-art materials; (2) minimize or eliminate stability problems in the cathode, anode, and interconnect; (3) Electrochemically evaluate (in reproducible and controlled laboratory tests) the current state-of-the-art air electrode materials and cathode/electrolyte interfacial properties; (4) Develop accelerated electrochemical test methods to evaluate the performance of SOFCs under controlled and reproducible conditions; and (5) Develop and test materials for use in low-temperature SOFCs. The goal is to modify and improve the current state-of-the-art materials and minimize the total number of cations in each material to avoid negative effects on the materials properties. Materials to reduce potential deleterious interactions, (3) improve thermal, electrical, and electrochemical properties, (4) develop methods to synthesize both state-of-the-art and alternative materials for the simultaneous fabricatoin and consolidation in air of the interconnections and electrodes with the solid electrolyte, and (5) understand electrochemical reactions at materials interfaces and the effects of component composition and processing on those reactions.

  15. Fracture of Materials Undergoing Solid-Solid Phase Transformation

    NASA Astrophysics Data System (ADS)

    Penmecha, Bharat

    A large number of technologically important materials undergo solid-solid phase transformations. Examples range from ferroelectrics (transducers and memory devices), zirconia (Thermal Barrier Coatings) to nickel superalloys and (lithium) iron phosphate (Li-ion batteries). These transformations involve a change in the crystal structure either through diffusion of species or local rearrangement of atoms. This change of crystal structure leads to a macroscopic change of shape or volume or both and results in internal stresses during the transformation. In certain situations this stress field gives rise to cracks (tin, iron phosphate etc.) which continue to propagate as the transformation front traverses the material. In other materials the transformation modifies the stress field around cracks and effects crack growth behavior (zirconia, ferroelectrics). These observations serve as our motivation to study cracks in solids undergoing phase transformations. Understanding these effects will help in improving the mechanical reliability of the devices employing these materials. In this thesis we present work on two problems concerning the interplay between cracks and phase transformations. First, we consider the directional growth of a set of parallel edge cracks due to a solid-solid transformation. We conclude from our analysis that phase transformations can lead to formation of parallel edge cracks when the transformation strain satisfies certain conditions and the resulting cracks grow all the way till their tips cross over the phase boundary. Moreover the cracks continue to grow as the phase boundary traverses into the interior of the body at a uniform spacing without any instabilities. There exists an optimal value for the spacing between the cracks. We ascertain these conclusion by performing numerical simulations using finite elements. Second, we model the effect of the semiconducting nature and dopants on cracks in ferroelectric perovskite materials, particularly

  16. Stability of solid oxide fuel cell materials

    SciTech Connect

    Armstrong, T.R.; Bates, J.L.; Chick, L.A.

    1996-04-01

    Interconnection materials in a solid oxide fuel cell are exposed to both highly oxidizing conditions at the cathode and to highly reducing conditions at the anode. The thermal expansion characteristics of substituted lanthanum and yttrium chromite interconnect materials were evaluated by dilatometry as a function of oxygen partial pressures from 1 atm to 10{sup -18} atm, controlled using a carbon dioxide/hydrogen buffer.

  17. Thermal testing of solid neutron shielding materials

    SciTech Connect

    Boonstra, R.H.

    1992-09-01

    Two legal-weight truck casks the GA-4 and GA-9, will carry four PWR and nine BWR spent fuel assemblies, respectively. Each cask has a solid neutron shielding material separating the steel body and the outer steel skin. In the thermal accident specified by NRC regulations in 10CFR Part 71, the cask is subjected to an 800[degree]C environment for 30 minutes. The neutron shield need not perform any shielding function during or after the thermal accident, but its behavior must not compromise the ability of the cask to contain the radioactive contents. In May-June 1989 the first series of full-scale thermal tests was performed on three shielding materials: Bisco Products NS-4-FR, and Reactor Experiments RX-201 and RX-207. The tests are described in Thermal Testing of Solid Neutron Shielding Materials, GA-AL 9897, R. H. Boonstra, General Atomics (1990), and demonstrated the acceptability of these materials in a thermal accident. Subsequent design changes to the cask rendered these materials unattractive in terms of weight or adequate service temperature margin. For the second test series, a material specification was developed for a polypropylene based neutron shield with a softening point of at least 280[degree]F. The neutron shield materials tested were boronated (0.8--4.5%) polymers (polypropylene, HDPE, NS-4). The Envirotech and Bisco materials are not polypropylene, but were tested as potential backup materials in the event that a satisfactory polypropylene could not be found.

  18. Thermal testing of solid neutron shielding materials

    SciTech Connect

    Boonstra, R.H.

    1992-09-01

    Two legal-weight truck casks the GA-4 and GA-9, will carry four PWR and nine BWR spent fuel assemblies, respectively. Each cask has a solid neutron shielding material separating the steel body and the outer steel skin. In the thermal accident specified by NRC regulations in 10CFR Part 71, the cask is subjected to an 800{degree}C environment for 30 minutes. The neutron shield need not perform any shielding function during or after the thermal accident, but its behavior must not compromise the ability of the cask to contain the radioactive contents. In May-June 1989 the first series of full-scale thermal tests was performed on three shielding materials: Bisco Products NS-4-FR, and Reactor Experiments RX-201 and RX-207. The tests are described in Thermal Testing of Solid Neutron Shielding Materials, GA-AL 9897, R. H. Boonstra, General Atomics (1990), and demonstrated the acceptability of these materials in a thermal accident. Subsequent design changes to the cask rendered these materials unattractive in terms of weight or adequate service temperature margin. For the second test series, a material specification was developed for a polypropylene based neutron shield with a softening point of at least 280{degree}F. The neutron shield materials tested were boronated (0.8--4.5%) polymers (polypropylene, HDPE, NS-4). The Envirotech and Bisco materials are not polypropylene, but were tested as potential backup materials in the event that a satisfactory polypropylene could not be found.

  19. Thermal testing of solid neutron shielding materials

    SciTech Connect

    Boonstra, R.H. )

    1990-03-01

    The GA-4 and GA-9 spent fuel shipping casks employ a solid neutron shielding material. During a hypothetical thermal accident, any combustion of the neutron shield must not compromise the ability of the cask to contain the radioactive contents. A two-phase thermal testing program was carried out to assist in selecting satisfactory shielding materials. In the first phase, small-scale screening tests were performed on nine candidate materials using ASTM procedures. From these initial results, three of the nine candidates were chosen for inclusion in the second phase of testing, These materials were Bisco Products NS-4-FR, Reactor Experiments 201-1, and Reactor Experiments 207. In the second phase, each selected material was fabricated into a test article which simulated a full-scale of neutron shield from the cask. The test article was heated in an environmental prescribed by NRC regulations. Results of this second testing phase showed that all three materials are thermally acceptable.

  20. Sealant materials for solid oxide fuel cells

    SciTech Connect

    Krumpelt, M.

    1995-08-01

    The objective of this work is to complete the development of soft glass-ceramic sealants for the solid oxide fuel cell (SOFC). Among other requirements, the materials must soften at the operation temperature of the fuel cell (600-1000{degrees}C) to relieve stresses between stack components, and their thermal expansions must be tailored to match those of the stack materials. Specific objectives included addressing the needs of industrial fuel cell developers, based on their evaluation of samples we supply, as well as working with commercial glass producers to achieve scaled-up production of the materials without changing their properties.

  1. Solid materials for removing arsenic and method thereof

    SciTech Connect

    Coronado, Paul R.; Coleman, Sabre J.; Sanner, Robert D.; Dias, Victoria L.; Reynolds, John G.

    2010-09-28

    Solid materials have been developed to remove arsenic compounds from aqueous media. The arsenic is removed by passing the aqueous phase through the solid materials which can be in molded, granular, or powder form. The solid materials adsorb the arsenic leaving a purified aqueous stream. The materials are aerogels or xerogels and aerogels or xerogels and solid support structure, e.g., granulated activated carbon (GAC), mixtures. The species-specific adsorption occurs through specific chemical modifications of the solids tailored towards arsenic.

  2. Solid materials for removing arsenic and method thereof

    DOEpatents

    Coronado, Paul R.; Coleman, Sabre J.; Sanner, Robert D.; Dias, Victoria L.; Reynolds, John G.

    2008-07-01

    Solid materials have been developed to remove arsenic compounds from aqueous media. The arsenic is removed by passing the aqueous phase through the solid materials which can be in molded, granular, or powder form. The solid materials adsorb the arsenic leaving a purified aqueous stream. The materials are aerogels or xerogels and aerogels or xerogels and solid support structure, e.g., granulated activated carbon (GAC), mixtures. The species-specific adsorption occurs through specific chemical modifications of the solids tailored towards arsenic.

  3. Alternative materials for solid oxide fuel cells

    SciTech Connect

    Stevenson, J.W.; Armstrong, T.R.

    1994-08-01

    The purpose of this research is to develop alternative materials for solid oxide fuel cell (SOFC) interconnections and electrodes with improved electrical, thermal, and electrochemical properties. A second objective is to develop synthesis and fabrication methods for these materials whereby they can be processed in air into SOFCs. The approach is to (1) develop modifications of the current, state-of-the-art materials used in SOFCs, (2) minimize the number of cations used in the SOFC materials to reduce potential deleterious interactions, (3) improve thermal, electrical, and electrochemical properties, (4) develop methods to synthesize both state-of-the-art and alternative materials for the simultaneous fabrication and consolidation in air of the interconnections and electrodes with the solid electrolyte, and (5) understand electrochemical reactions at materials interfaces and the effects of component composition and processing on those reactions. This paper summarizes a comprehensive study that assessed the effect of ambient oxygen partial pressure on the stability of air-sinterable chromites and the sintering behavior of doped lanthanum manganites.

  4. Interstellar Alcohols

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

    We have investigated the gas-phase chemistry in dense cores where ice mantles containing ethanol and other alcohols have been evaporated. Model calculations show that methanol, ethanol, propanol, and butanol drive a chemistry leading to the formation of several large ethers and esters. Of these molecules, methyl ethyl ether (CH3OC2H5) and diethyl ether (C2H5)2O attain the highest abundances and should be present in detectable quantities within cores rich in ethanol and methanol. Gas-phase reactions act to destroy evaporated ethanol and a low observed abundance of gas-phase C,H,OH does not rule out a high solid-phase abundance. Grain surface formation mechanisms and other possible gas-phase reactions driven by alcohols are discussed, as are observing strategies for the detection of these large interstellar molecules.

  5. Optical studies of interstellar material in low density regions of the Galaxy

    NASA Technical Reports Server (NTRS)

    Sembach, K. R.; Danks, A. C.

    1994-01-01

    We analyze high-resolution Na I and Ca II interstellar absorption line data obtained in an earlier spectroscopic survey of 57 stars along extended sight lines through the Galactic disk and halo. We find that the Na I lines trace a diffuse cloudy medium and the CA II lines trace both the cloudy medium and a more extended (intercloud) medium. High latitude and interarm sight lines that do not cross spiral arms have clouds that are more diffuse on average than those along sight lines that cross spiral arms. Spiral structure may play an important role in determinating the average absorption properties along extended sight lines and/or interesting physical differences may exist between sight lines that cross spiral arms and those that do not. These might include a harder radiation field and/or higher electron tempertures along the high latitude and 'clean' interarm sight lines. On average, 10% of the Ca II column density occurs at velocities forbidden by the Galactic rotation law by more than 10 km/s. In contrast, only a small precentage of the Na I column density occurs at these velocites. The Ca II to Na I ratio increases by a factor of 15 over forbidden velocities from 0 to 50 km/s and rises rapidly thereafter. A two component model of the Ca II column density per unit velocity over the range l = 325 deg to 360 deg indicates that two distinct distributions exists, one with sigma = 8 km/s and one with sigma = 21 km/s. As much as 60% of the Ca II column density at forbidden velocities may be associated with the faster distribution, which we attribute to warm intercloud material. We estimate expontential scale heights of 0.4-0.5 kpc for the neutral gas traced by the E(B-V), Na I, and H I distributions along the low density sight lines, and we find that Ca II has a larger scale height of 0.8 kpc.

  6. Solid materials for removing metals and fabrication method

    DOEpatents

    Coronado, Paul R.; Reynolds, John G.; Coleman, Sabre J.

    2004-10-19

    Solid materials have been developed to remove contaminating metals and organic compounds from aqueous media. The contaminants are removed by passing the aqueous phase through the solid materials which can be in molded, granular, or powder form. The solid materials adsorb the metals and the organics leaving a purified aqueous stream. The materials are sol-gel and or sol-gel and granulated activated carbon (GAC) mixtures. The species-specific adsorption occurs through specific chemical modifications of the solids tailored towards the contaminant(s). The contaminated solid materials can then be disposed of or the contaminant can be removed and the solids recycled.

  7. Complex Molecules in the Interstellar Medium

    NASA Technical Reports Server (NTRS)

    Sandford, Scott

    1996-01-01

    A brief review of the current state of knowledge concerning the composition of complex molecules in the interstellar medium (ISM) is given. The materials in interstellar dense molecular clouds is also discussed. As well as the formation of stars and planetary systems. A concentration on solids are addressed, because they contain a major fraction of the heavier elements in these clouds and because these materials are the most likely to survive incorporation into new planetary systems and participate in the subsequent formation and evolution of life. However, dense clouds are not well-defined, long-lived entities but are dynamic objects that are formed from materials in the diffuse ISM and destroyed on time scales of 10(exp 6)-10(exp 8) years. As a result, materials in space are probably constantly being mixed between the dense ISM and the more diffuse intercloud ISM, and some discussion of the materials found in the diffuse ISM is also merited.

  8. Space aging of solid rocket materials

    NASA Technical Reports Server (NTRS)

    Lester, Dean M.; Jones, Leon L.; Smalley, R. B., Jr.; Ord, R. Neil

    1991-01-01

    Solid rocket propellant and rocket motor components were aged in a vented container on the interior of the LDEF. The results of aging IPSM-II/PAM-DII space motor components are presented. Ballistic and mechanical properties of the space aged main propellant, igniter propellant, and ignition system were compared with similar data from preflight and ground aged samples. Mechanical properties of the composite materials and bonded joints used in the motor case, insulation, liner, nozzle, exit cone, and skirt were similarly evaluated. The space aging results are compared to data collected in a ground based vacuum aging program on similar components.

  9. Copernicus studies of interstellar material in the Perseus II complex. III - The line of sight to Zeta Persei

    NASA Technical Reports Server (NTRS)

    Snow, T. P., Jr.

    1977-01-01

    Ultraviolet spectrophotometric data obtained with Copernicus are used to analyze the distribution, composition, density, temperature, and kinematics of the interstellar material along the line of sight to Zeta Persei. The far-UV extinction curve for the star is evaluated along with the kinematics of the interstellar gas, observations of atomic and molecular hydrogen, curves of growth for neutral and ionized species, atomic abundances and depletions, ionization equilibria, and observations of CO and OH lines. The results show that there are apparently three clouds along the line of sight to Zeta Persei: a main cloud at approximately +13 km/s which contains most of the material and forms all the neutral and molecular lines as well as most of the ionic lines, a second component at +22 km/s which must contribute to the strong UV lines of most ions, and a third component at roughly +2 km/s which gives rise to a strong Si III line at 1206 A. It is also found that the UV extinction curve has a somewhat steep far-UV rise, indicating the presence of a substantial number of small grains, and that about 30% of the hydrogen nuclei over the entire line of sight are in molecular form.

  10. Space aging of solid rocket materials

    NASA Technical Reports Server (NTRS)

    Lester, Dean M.; Jones, Leon L.; Smalley, R. B., Jr.; Ord, R. Neil

    1992-01-01

    Solid rocket propellant and rocket motor components were aged in a vented container on the interior of the LDEF. This paper will present the results of aging the Improved Performance Space Motor-II/Payload Assist Module-Delta II (IPSM-II/PAM-DII) space motor components. Ballistic and mechanical properties of the space aged main propellant, igniter propellant, and ignition system were compared with similar data from preflight and ground aged samples. Mechanical properties of the composite materials and bonded joints used in the motor case, insulation, liner, nozzle, exit cone, and skirt were similarly evaluated. The space aging results will be compared to data collected in a ground based vacuum aging program on similar components. The operation of the vacuum actuated venting valve and pressure actuated resealing of the container will also be addressed. The materials tested showed no significant changes due to space aging. These results indicate that properly designed solid rocket motors can be expected to perform reliably after extended periods of exposure to a space environment.

  11. Interstellar Dust - A Review

    NASA Technical Reports Server (NTRS)

    Salama, Farid

    2012-01-01

    The study of the formation and the destruction processes of cosmic dust is essential to understand and to quantify the budget of extraterrestrial organic materials. Although dust with all its components plays an important role in the evolution of interstellar physics and chemistry and in the formation of organic materials, little is known on the formation and destruction processes of carbonaceous dust. Laboratory experiments that are performed under conditions that simulate interstellar and circumstellar environments to provide information on the nature, the size and the structure of interstellar dust particles, the growth and the destruction processes of interstellar dust and the resulting budget of extraterrestrial organic molecules. A review of the properties of dust and of the laboratory experiments that are conducted to study the formation processes of dust grains from molecular precursors will be given.

  12. Solid freeform fabrication of biological materials

    NASA Astrophysics Data System (ADS)

    Wang, Jiwen

    This thesis investigates solid freeform fabrication of biological materials for dental restoration and orthopedic implant applications. The basic approach in this study for solid freeform fabrication of biological materials is micro-extrusion of single or multiple slurries for 3D components and inkjet color printing of multiple suspensions for functionally graded materials (FGMs). Common issues associated with micro-extrusion and inkjet color printing are investigated. These common issues include (i) formulation of stable slurries with a pseudoplastic property, (ii) cross-sectional geometry of the extrudate as a function of the extrusion parameters, (iii) fabrication path optimization for extrusion process, (iv) extrusion optimization for multi-layer components, (v) composition control in functionally graded materials, and (vi) sintering optimization to convert the freeform fabricated powder compact to a dense body for biological applications. The present study clearly shows that the rheological and extrusion behavior of dental porcelain slurries depend strongly on the pH value of the slurry and extrusion conditions. A slurry with pseudoplastic properties is a basic requirement for obtaining extruded lines with rectangular cross-sections. The cross-sectional geometry of the extrudate is also strongly affected by extrusion parameters including the extrusion nozzle height, nozzle moving speed, extrusion rate, and critical nozzle height. Proper combinations of these extrusion parameters are necessary in order to obtain single line extrudates with near rectangular cross-sections and 3D objects with dimensional accuracy, uniform wall thickness, good wall uprightness, and no wall slumping. Based on these understandings, single-wall, multi-wall, and solid teeth have been fabricated via micro-extrusion of the dental slurry directly from a CAD digital model in 30 min. Inkjet color printing using stable Al2O3 and ZrO 2 aqueous suspensions has been developed to fabricate

  13. Method and apparatus for semi-solid material processing

    DOEpatents

    Han, Qingyou; Jian, Xiaogang; Xu, Hanbing; Meek, Thomas T.

    2007-05-15

    A method of forming a material includes the steps of: vibrating a molten material at an ultrasonic frequency while cooling the material to a semi-solid state to form non-dendritic grains therein; forming the semi-solid material into a desired shape; and cooling the material to a solid state. The method makes semi-solid castings directly from molten materials (usually a metal), produces grain size usually in the range of smaller than 50 .mu.m, and can be easily retrofitted into existing conventional forming machine.

  14. Method and apparatus for semi-solid material processing

    DOEpatents

    Han, Qingyou [Knoxville, TN; Jian, Xiaogang [Knoxville, TN; Xu, Hanbing [Knoxville, TN; Meek, Thomas T [Knoxville, TN

    2009-02-24

    A method of forming a material includes the steps of: vibrating a molten material at an ultrasonic frequency while cooling the material to a semi-solid state to form non-dendritic grains therein; forming the semi-solid material into a desired shape; and cooling the material to a solid state. The method makes semi-solid castings directly from molten materials (usually a metal), produces grain size usually in the range of smaller than 50 .mu.m, and can be easily retrofitted into existing conventional forming machine.

  15. Method and apparatus for semi-solid material processing

    DOEpatents

    Han, Qingyou [Knoxville, TN; Jian, Xiaogang [Knoxville, TN; Xu, Hanbing [Knoxville, TN; Meek, Thomas T [Knoxville, TN

    2009-11-24

    A method of forming a material includes the steps of: vibrating a molten material at an ultrasonic frequency while cooling the material to a semi-solid state to form non-dendritic grains therein; forming the semi-solid material into a desired shape; and cooling the material to a solid state. The method makes semi-solid castings directly from molten materials (usually a metal), produces grain size usually in the range of smaller than 50 .mu.m, and can be easily retrofitted into existing conventional forming maching.

  16. Impact of solids on composite materials

    NASA Technical Reports Server (NTRS)

    Bronson, Arturo; Maldonado, Jerry; Chern, Tzong; Martinez, Francisco; Mccord-Medrano, Johnnie; Roschke, Paul N.

    1987-01-01

    The failure modes of composite materials as a result of low velocity impact were investigated by simulating the impact with a finite element analysis. An important facet of the project is the modeling of the impact of a solid onto cylindrical shells composed of composite materials. The model under development will simulate the delamination sustained when a composite material encounters impact from another rigid body. The computer equipment was installed, the computer network tested, and a finite element method model was developed to compare results with known experimental data. The model simulated the impact of a steel rod onto a rotating shaft. Pre-processing programs (GMESH and TANVEL) were developed to generate node and element data for the input into the three dimensional, dynamic finite element analysis code (DYNA3D). The finite element mesh was configured with a fine mesh near the impact zone and a coarser mesh for the impacting rod and the regions surrounding the impacting zone. For the computer simulation, five impacting loads were used to determine the time history of the stresses, the scribed surface areas, and the amount of ridging. The processing time of the computer codes amounted from 1 to 4 days. The calculated surface area were within 6-12 percent, relative error when compated to the actual scratch area.

  17. Interstellar molecules

    NASA Astrophysics Data System (ADS)

    Smith, D.

    1987-09-01

    Some 70 different molecular species have so far been detected variously in diffuse interstellar clouds, dense interstellar clouds, and circumstellar shells. Only simple (diatomic and triatomic) species exist in diffuse clouds because of the penetration of destructive UV radiations, whereas more complex (polyatomic) molecules survive in dense clouds as a result of the shielding against this UV radiation provided by dust grains. A current list of interstellar molecules is given together with a few other molecular species that have so far been detected only in circumstellar shells. Also listed are those interstellar species that contain rare isotopes of several elements. The gas phase ion chemistry is outlined via which the observed molecules are synthesized, and the process by which enrichment of the rare isotopes occurs in some interstellar molecules is described.

  18. Advanced Materials and Solids Analysis Research Core (AMSARC)

    EPA Science Inventory

    The Advanced Materials and Solids Analysis Research Core (AMSARC), centered at the U.S. Environmental Protection Agency's (EPA) Andrew W. Breidenbach Environmental Research Center in Cincinnati, Ohio, is the foundation for the Agency's solids and surfaces analysis capabilities. ...

  19. The Composition of Organics and Volatiles in the Interstellar Medium

    NASA Technical Reports Server (NTRS)

    Sandford, Scott A.; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    Tremendous progress has been made in our understanding of the composition of interstellar dust through the combined use of telescopic observations, theoretical models, laboratory studies of analogs, and the analysis of interstellar samples found in meteorites. It is increasingly clear that the interstellar medium (ISM) contains an enormous diversity of materials created by a wide range of chemical and physical processes. This paper reviews some of our current knowledge of the organic and volatile materials thought to exist in the ISM. These compounds supply a significant portion of the material that makes up the interstellar dense molecular clouds from which new stars and planetary systems are formed, and thus represents an important reservoir of material that could play key roles in the formation and evolution of life. This paper will largely focus on solid materials, as opposed to gases, since solids contain a major fraction of the heavier elements in clouds and because solids are most likely to survive incorporation into new planetary systems in identifiable form. The paper concludes with a brief discussion of the astrobiological relevance of some of the compounds now known or suspected to be present in the ISM.

  20. Pipelining particulate solid material as stable foam slurry

    SciTech Connect

    Fitch, J.L.

    1980-04-29

    A method of transporting particulate solid material through a pipeline in the form of a stable foam slurry is described. A pumpable slurry is formed of the particulate solid material in a stable foam carrier medium and the slurry is flowed through the pipeline to a receiving point. A method of transporting particulate solid materials through a pipeline is described wherein a pumpable slurry is formed of the particulate solid material. The particulate material is present in the stable foam in an amount of at least 20% by volume based on the total volume of the stable foam slurry. The particulate solid material may be coal particles, other forms of particulate carbonaceous material, such as coke, lignite and pitch, ores, and still other particulate material which is insoluble in the stable foam. The foam may be formed from a liquid, usually water, gas, and a foam stabilizing agent, such as a soap or a surfactant. 4 claims.

  1. Interstellar Deuterium Chemistry

    NASA Technical Reports Server (NTRS)

    Sandford, S. A.

    2003-01-01

    The presence of isotopic anomalies is the most unequivocal demonstration that meteoritic material contains circumstellar or interstellar components. In the case of organic compounds in meteorites and interplanetary dust particles (IDPs), the most useful isotopic tracer of interstellar components has been deuterium (D) excesses. In some cases these enrichments are seen in bulk meteoritic materials, but D enrichments have also been observed in meteoritic subfractions and even within specific classes of molecular species, such as amino and carboxylic acids. These anomalies are not thought to be the result of nucleosynthetic processes, but are instead ascribed to chemical and physical processes occurring in the interstellar medium (ISM). The traditional explanation of these D excesses has been to invoke the presence of materials made in the ISM by low temperature gas phase ion-molecule reactions. Indeed, the DM ratios seen in the simple interstellar gas phase molecules in cold dense clouds amenable to measurement using radio spectral techniques are generally considerably higher than the values seen in enriched Solar System materials. However, the true linkage between the DM ratios in interstellar and meteoritic materials is obscured by several effects. First, current observations of D enrichment in the ISM have been made of only a few simple molecules, molecules that are not the main carriers of D in Solar System materials. Second, some of the interstellar D enrichment is likely to reside on labile moieties that will have exchanged to some degree with more isotopically normal material during incorporation into the warm protosolar nebula, parent body processing, delivery, recovery, and analysis. Third, ion-molecule reactions represent only one of at least four processes that can produce strong D-H fractionation in the ISM.

  2. Laboratory Astrochemistry: Interstellar PAHs

    NASA Technical Reports Server (NTRS)

    Salama, Farid; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are now considered to be an important and ubiquitous component of the organic material in space. PAHs are found in a large variety of extraterrestrial materials such as interplanetary dust particles (IDPs) and meteoritic materials. PAHs are also good candidates to account for the infrared emission bands (UIRs) and the diffuse interstellar optical absorption bands (DIBs) detected in various regions of the interstellar medium. The recent observations made with the Infrared Space Observatory (ISO) have confirmed the ubiquitous nature of the UIR bands and their carriers. PAHs are thought to form through chemical reactions in the outflow from carbon-rich stars in a process similar to soot formation. Once injected in the interstellar medium, PAHs are further processed by the interstellar radiation field, interstellar shocks and energetic particles. A major, dedicated, laboratory effort has been undertaken to measure the physical and chemical characteristics of these complex molecules and their ions under experimental conditions that mimic the interstellar conditions. These measurements require collision-free conditions where the molecules and ions are cold and chemically isolated. The spectroscopy of PAHs under controlled conditions represents an essential diagnostic tool to study the evolution of extraterrestrial PAHs. The Astrochemistry Laboratory program will be discussed through its multiple aspects: (1) objectives, (2) approach and techniques adopted, (3) adaptability to the nature of the problem(s), and (4) results and implications for astronomy as well as for molecular spectroscopy. A review of the data generated through laboratory simulations of space environments and the role these data have played in our current understanding of the properties of interstellar PAHs will be presented. The discussion will also introduce the newest generation of laboratory experiments that are currently being developed in order to provide a

  3. Stability of solid oxide fuel cell materials

    SciTech Connect

    Armstrong, T.R.; Bates, J.L.; Coffey, G.W.; Pederson, L.R.

    1996-08-01

    Chromite interconnection materials in an SOFC are exposed to both highly oxidizing conditions at the cathode and to highly reducing conditions at the anode. Because such conditions could lead to component failure, the authors have evaluated thermal, electrical, chemical, and structural stabilities of these materials as a function of temperature and oxygen partial pressure. The crystal lattice of the chromites was shown to expand for oxygen partial pressures smaller than 10{sup {minus}10} atm, which could lead to cracking and debonding in an SOFC. Highly substituted lanthanum chromite compositions were the most susceptible to lattice expansion; yttrium chromites showed better dimensional stability by more than a factor of two. New chromite compositions were developed that showed little tendency for lattice expansion under strongly reducing conditions, yet provided a good thermal expansion match to other fuel cell components. Use of these new chromite interconnect compositions should improve long-term SOFC performance, particularly for planar cell configurations. Thermodynamic properties of substituted lanthanum manganite cathode compositions have been determined through measurement of electromotive force as a function of temperature. Critical oxygen decomposition pressures for Sr and Ca-substituted lanthanum manganites were established using cells based on a zirconia electrolyte. Strontium oxide and calcium oxide activities in a lanthanum manganite matrix were determined using cells based on strontium fluoride and calcium fluoride electrolytes, respectively. The compositional range of single-phase behavior of these ABO{sub 3}-type perovskites was established as a function of A/B cation ratios and the extent of acceptor doping. Before this work, very little thermodynamic information was in existence for substituted manganite compositions. Such information is needed to predict the long-term stability of solid oxide fuel cell assemblies.

  4. Interstellar Antifreeze: Ethylene Glycol

    NASA Astrophysics Data System (ADS)

    Hollis, J. M.; Lovas, F. J.; Jewell, P. R.; Coudert, L. H.

    2002-05-01

    Interstellar ethylene glycol (HOCH2CH2OH) has been detected in emission toward the Galactic center source Sagittarius B2(N-LMH) by means of several millimeter-wave rotational torsional transitions of its lowest energy conformer. The types and kinds of molecules found to date in interstellar clouds suggest a chemistry that favors aldehydes and their corresponding reduced alcohols-e.g., formaldehyde (H2CO)/methanol (CH3OH), acetaldehyde (CH3CHO)/ethanol (CH3CH2OH). Similarly, ethylene glycol is the reduced alcohol of glycolaldehyde (CH2OHCHO), which has also been detected toward Sgr B2(N-LMH). While there is no consensus as to how any such large complex molecules are formed in the interstellar clouds, atomic hydrogen (H) and carbon monoxide (CO) could form formaldehyde on grain surfaces, but such surface chemistry beyond that point is uncertain. However, laboratory experiments have shown that the gas-phase reaction of atomic hydrogen (H) and solid-phase CO at 10-20 K can produce formaldehyde and methanol and that alcohols and other complex molecules can be synthesized from cometary ice analogs when subject to ionizing radiation at 15 K. Thus, the presence of aldehyde/reduced alcohol pairs in interstellar clouds implies that such molecules are a product of a low-temperature chemistry on grain surfaces or in grain ice mantles. This work suggests that aldehydes and their corresponding reduced alcohols provide unique observational constraints on the formation of complex interstellar molecules.

  5. Interstellar Antifreeze: Ethylene Glycol

    NASA Technical Reports Server (NTRS)

    Hollis, J. M.; Lovas, F. J.; Jewell, P. R.; Coudert, L. H.

    2002-01-01

    Interstellar ethylene glycol (HOCH2CH2,OH) has been detected in emission toward the Galactic center source Sagittarius B2(N-LMH) by means of several millimeter-wave rotational torsional transitions of its lowest energy conformer. The types and kinds of molecules found to date in interstellar clouds suggest a chemistry that favors aldehydes and their corresponding reduced alcohols-e.g., formaldehyde (H2CO)/methanol (CH3OH), acetaldehyde (CH3CHO)/ethanol (CH3CH2OH). Similarly, ethylene glycol is the reduced alcohol of glycolaldehyde (CH2OHCHO), which has also been detected toward Sgr B2(N-LMH). While there is no consensus as to how any such large complex molecules are formed in the interstellar clouds, atomic hydrogen (H) and carbon monoxide (CO) could form formaldehyde on grain surfaces, but such surface chemistry beyond that point is uncertain. However, laboratory experiments have shown that the gas-phase reaction of atomic hydrogen (H) and solid-phase CO at 10-20 K can produce formaldehyde and methanol and that alcohols and other complex molecules can be synthesized from cometary ice analogs when subject to ionizing radiation at 15 K. Thus, the presence of aldehyde/ reduced alcohol pairs in interstellar clouds implies that such molecules are a product of a low-temperature chemistry on grain surfaces or in grain ice mantles. This work suggests that aldehydes and their corresponding reduced alcohols provide unique observational constraints on the formation of complex interstellar molecules.

  6. Interstellar Optics

    NASA Technical Reports Server (NTRS)

    Gwinn, C. R.; Britton, M. C.; Reynolds, J. E.; Jauncey, D. L.; King, E. A.; McCulloch, P. M.; Lovell, J. E. J.; Preston, R. A.

    1998-01-01

    We discuss the effects of finite source size on the diffraction pattern produced by scattering in a thin screen, particularly as applied to radio-wave scattering, by density fluctuations in the interstellar plasma.

  7. System for chemically digesting low level radioactive, solid waste material

    DOEpatents

    Cowan, Richard G.; Blasewitz, Albert G.

    1982-01-01

    An improved method and system for chemically digesting low level radioactive, solid waste material having a high through-put. The solid waste material is added to an annular vessel (10) substantially filled with concentrated sulfuric acid. Concentrated nitric acid or nitrogen dioxide is added to the sulfuric acid within the annular vessel while the sulfuric acid is reacting with the solid waste. The solid waste is mixed within the sulfuric acid so that the solid waste is substantilly fully immersed during the reaction. The off gas from the reaction and the products slurry residue is removed from the vessel during the reaction.

  8. 76 FR 8658 - Bulk Solid Hazardous Materials: Harmonization With the International Maritime Solid Bulk Cargoes...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-15

    ...), 1974, as amended, that carry bulk solid cargoes other than grain. The final rule (75 FR 64586) allows... SECURITY Coast Guard 46 CFR Part 148 RIN 1625-AB47 Bulk Solid Hazardous Materials: Harmonization With the International Maritime Solid Bulk Cargoes (IMSBC) Code AGENCY: Coast Guard, DHS. ACTION: Rule;...

  9. 75 FR 34682 - Bulk Solid Hazardous Materials: Harmonization With the International Maritime Solid Bulk Cargoes...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-18

    ... SECURITY Coast Guard 46 CFR Parts 97 and 148 RIN 1625-AB47 Bulk Solid Hazardous Materials: Harmonization With the International Maritime Solid Bulk Cargoes (IMSBC) Code; Correction AGENCY: Coast Guard, DHS... proposed rule published in the Federal Register on June 17, 2010, entitled ``Bulk Solid Hazardous...

  10. Solid lubricant materials for high temperatures: A review

    NASA Technical Reports Server (NTRS)

    Sliney, Harold E.

    1985-01-01

    Solid lubricants that can be used above 300 C in air are discussed, including coatings and self-lubricating composite bearing materials. The lubricants considered are representative dichalcogenides, graphite, graphite fluoride, polyimides, soft oxides, oxidatively stable fluorides, and hard coating materials. A few general design considerations revelant to solid lubrication are interspersed.

  11. Youth Solid Waste Educational Materials List, November 1991.

    ERIC Educational Resources Information Center

    Cornell Univ., Ithaca, NY. Cooperative Extension Service.

    This guide provides a brief description and ordering information for approximately 300 educational materials for grades K-12 on the subject of solid waste. The materials cover a variety of environmental issues and actions related to solid waste management. Entries are divided into five sections including audiovisual programs, books, magazines,…

  12. Interfacial material for solid oxide fuel cell

    DOEpatents

    Baozhen, Li; Ruka, Roswell J.; Singhal, Subhash C.

    1999-01-01

    Solid oxide fuel cells having improved low-temperature operation are disclosed. In one embodiment, an interfacial layer of terbia-stabilized zirconia is located between the air electrode and electrolyte of the solid oxide fuel cell. The interfacial layer provides a barrier which controls interaction between the air electrode and electrolyte. The interfacial layer also reduces polarization loss through the reduction of the air electrode/electrolyte interfacial electrical resistance. In another embodiment, the solid oxide fuel cell comprises a scandia-stabilized zirconia electrolyte having high electrical conductivity. The scandia-stabilized zirconia electrolyte may be provided as a very thin layer in order to reduce resistance. The scandia-stabilized electrolyte is preferably used in combination with the terbia-stabilized interfacial layer. The solid oxide fuel cells are operable over wider temperature ranges and wider temperature gradients in comparison with conventional fuel cells.

  13. Process for hot briquetting of organic solid materials

    SciTech Connect

    Janusch, A.

    1982-11-23

    For the purpose of briquetting organic solid materials, such as brown coal or bituminous coal, the materials are heated by hot water and/or steam and under super-atmospheric pressure to temperatures exceeding 160/sup 0/ C. After discharging the organic solid materials, which have become dried to a great extent, the generated steam is separated by sucking off the steam without substantially cooling effect, bitumen-forming substances present within the organic solid materials thereby rapidly becoming homogeneously distributed. These homogeneously distributed binding agents give the compressed briquettes obtained a high strength and good mechanical properties when using substantially reduced compacting pressures as compared with known briquetting processes.

  14. THE REINCARNATION OF INTERSTELLAR DUST: THE IMPORTANCE OF ORGANIC REFRACTORY MATERIAL IN INFRARED SPECTRA OF COMETARY COMAE AND CIRCUMSTELLAR DISKS

    SciTech Connect

    Kimura, Hiroshi

    2013-09-20

    We consider the reincarnation of interstellar dust to be reborn in protoplanetary disks as aggregates consisting of submicron-sized grains with a crystalline or amorphous silicate core and an organic-rich carbonaceous mantle. We find that infrared spectra of reincarnated interstellar dust reproduce emission peaks at correct wavelengths where the peaks were observed in cometary comae, debris disks, and protoplanetary disks if the volume fraction of organic refractory meets the constraints on elemental abundances. We discuss what we can learn from the infrared spectra of reincarnated interstellar dust in cometary comae and circumstellar disks.

  15. The Reincarnation of Interstellar Dust: The Importance of Organic Refractory Material in Infrared Spectra of Cometary Comae and Circumstellar Disks

    NASA Astrophysics Data System (ADS)

    Kimura, Hiroshi

    2013-09-01

    We consider the reincarnation of interstellar dust to be reborn in protoplanetary disks as aggregates consisting of submicron-sized grains with a crystalline or amorphous silicate core and an organic-rich carbonaceous mantle. We find that infrared spectra of reincarnated interstellar dust reproduce emission peaks at correct wavelengths where the peaks were observed in cometary comae, debris disks, and protoplanetary disks if the volume fraction of organic refractory meets the constraints on elemental abundances. We discuss what we can learn from the infrared spectra of reincarnated interstellar dust in cometary comae and circumstellar disks.

  16. Optical studies of interstellar material in low density regions of the Galaxy. I - A survey of interstellar Na I and Ca II absorption toward 57 distant stars

    NASA Technical Reports Server (NTRS)

    Sembach, K. R.; Danks, A. C.; Savage, B. D.

    1993-01-01

    We present high-resolution spectra of the Na I D and Ca II K lines toward 57 late-O and early-B stars along extended (d greater than 1 kpc) low-density paths through the Milky Way disk and halo. The sight lines preferentially sample diffuse gas in the interstellar medium (ISM) along interarm, Galactic center, and high latitude directions. We measure equivalent widths, apparent column densities, and absorption component structure. The Ca II to Na I ratios presented as a function of velocity for each sight line exhibit variations due to elemental depletion, ionization, and density enhancements. Absorption along high latitude sight lines is kinematically simpler than it is along interarm and Galactic center sight lines. Galactic rotation noticeably broadens the absorption profiles of distant stars located in these latter directions. Along several sight lines, we see Ca II absorption at velocities corresponding to large distances (/z/ about 1 kpc) from the Galactic plane. The effects of differences in the Ca II and Na I scale heights and nonzero velocity dispersions are readily apparent in the data. Brief notes are given for several sight lines with interesting absorption properties.

  17. Molecular Structure and Infrared Spectrum of Solid Amino Formate (HCO2NH2): Relevance to Interstellar Ices

    NASA Astrophysics Data System (ADS)

    Khanna, R. K.; Lowenthal, M. S.; Ammon, H. L.; Moore, M. H.

    2002-06-01

    We report the infrared spectrum of the reaction product of isocyanic acid (HNCO) and water (H2O) at 20 K. The reaction is catalyzed by hydrochloric acid (HCl) even at low temperatures. The resulting product is identified to be amino formate (HCO2NH2). This identification has been achieved by comparison of the IR spectrum of the product with the corresponding spectra of formic acid (HCO2H), methyl formate (HCO2CH3), and formamide (HCONH2), all of which have the HCO group. The results of ab initio quantum mechanical calculations of the harmonic frequencies and the infrared intensities of the most stable structure containing NH2OCHO groups also agree with the laboratory data. Such complex organics may be produced on the cold interstellar grains and on planetary objects by radiation and/or catalytically induced reactions involving simple C-, H-, N-, and O-containing species.

  18. Four Interstellar Dust Candidates from the Stardust Interstellar Dust Collector

    NASA Technical Reports Server (NTRS)

    Westphal, A. J.; Allen, C.; Bajt, S.; Bechtel, H. A.; Borg, J.; Brenker, F.; Bridges, J.; Brownlee, D. E.; Burchell, M.; Burghammer, M.; Butterworth, A. L.; Cloetens, P.; Davis, A. M.; Floss, C.; Flynn, G. J.; Fougeray, P.; Frank, D.; Gainsforth, Z.; Grun, E.; Heck, P. R.; Jillier, J. K.; Hoppe, P.; Howard, L.; Hudson, B.; Huss, G. R.

    2011-01-01

    In January 2006, the Stardust sample return capsule returned to Earth bearing the first solid samples from a primitive solar system body, Comet 81P/Wild2, and a collector dedicated to the capture and return of contemporary interstellar dust. Both collectors were approx. 0.1 sq m in area and were composed of aerogel tiles (85% of the collecting area) and aluminum foils. The Stardust Interstellar Dust Collector (SIDC) was exposed to the interstellar dust stream for a total exposure factor of 20 sq m/day. The Stardust Interstellar Preliminary Examination (ISPE) is a consortium-based project to characterize the collection using nondestructive techniques. The goals and restrictions of the ISPE are described . A summary of analytical techniques is described.

  19. Ultrafast laser spectroscopy in complex solid state materials

    SciTech Connect

    Li, Tianqi

    2014-12-01

    This thesis summarizes my work on applying the ultrafast laser spectroscopy to the complex solid state materials. It shows that the ultrafast laser pulse can coherently control the material properties in the femtosecond time scale. And the ultrafast laser spectroscopy can be employed as a dynamical method for revealing the fundamental physical problems in the complex material systems.

  20. Stability of solid oxide fuel cell materials

    SciTech Connect

    Armstrong, T.R.; Pederson, L.R.; Stevenson, J.W.; Raney, P.E.

    1995-08-01

    The phase stability and sintering behavior of materials used in SOFCs has been evaluated. The sintering behavior of Ca and Sr doped lanthanum. manganite (the preferred SOFC cathode material) is highly dependent on the relative proportion of A and B site cations in the material. Ca and Sr doped lanthanum chromite (the preferred interconnect material) have been shown to rapidly expand in reducing atmospheres at temperatures as low as 700{degrees}C. This expansion is due to the reduction of Cr{sup 4+} to Cr{sup 3+} in reducing environments.

  1. Chemical digestion of low level nuclear solid waste material

    DOEpatents

    Cooley, Carl R.; Lerch, Ronald E.

    1976-01-01

    A chemical digestion for treatment of low level combustible nuclear solid waste material is provided and comprises reacting the solid waste material with concentrated sulfuric acid at a temperature within the range of 230.degree.-300.degree.C and simultaneously and/or thereafter contacting the reacting mixture with concentrated nitric acid or nitrogen dioxide. In a special embodiment spent ion exchange resins are converted by this chemical digestion to noncombustible gases and a low volume noncombustible residue.

  2. Apparatus and methods for filtering granular solid material

    NASA Technical Reports Server (NTRS)

    Backes, Douglas J. (Inventor); Poulter, Clay B. (Inventor); Godfrey, Max R. (Inventor); Tolman, Dennis K. (Inventor); Dutton, Melinda S. (Inventor)

    2011-01-01

    Apparatuses for screening granular solid particulate material include a generally planar first screen and a second screen. A plurality of apertures extends through the first screen. At least a portion of the second screen is oriented at an angle to the first screen, and apertures extend through a perforated region of the second screen. The second screen includes at least one region configured to prevent at least some particles of solid material from passing through the second screen.

  3. Interstellar Panspermia Reconsidered

    NASA Astrophysics Data System (ADS)

    Zubrin, R.

    The absence of free-living microorganisms simpler than bacteria on Earth is evidence that life did not originate on Earth, but immigrated. The question then arises as to whether life was imported from a point of origin in our solar system, most likely Mars, of whether the solar system was seeded from interstellar sources. The search for fossil or extant prebacterial organisms (prebacteria) on Mars can resolve this question. However, to understand the likelihood of interstellar panspermia, we also need to consider whether the Earth itself has served as an efficient source for the spread of microorganisms. Close encounters with other stars due to random stellar motion occur with a frequency of 1/20 Myr, in fair agreement with the observed frequency of major impact events and mass extinctions. Such events are estimated to eject unsterilized material into interstellar space at a time-averaged rate of 10 tonnes per year. A number of mechanisms for the interstellar dissemination of bacteria along with this material are considered. It is shown that transmission of microbial life from one solar system to another is highly probable.

  4. Nanocrystalline cerium oxide materials for solid fuel cell systems

    DOEpatents

    Brinkman, Kyle S

    2015-05-05

    Disclosed are solid fuel cells, including solid oxide fuel cells and PEM fuel cells that include nanocrystalline cerium oxide materials as a component of the fuel cells. A solid oxide fuel cell can include nanocrystalline cerium oxide as a cathode component and microcrystalline cerium oxide as an electrolyte component, which can prevent mechanical failure and interdiffusion common in other fuel cells. A solid oxide fuel cell can also include nanocrystalline cerium oxide in the anode. A PEM fuel cell can include cerium oxide as a catalyst support in the cathode and optionally also in the anode.

  5. Apparatus for removing hydrocarbon contaminants from solid materials

    DOEpatents

    Bala, G.A.; Thomas, C.P.

    1996-02-13

    A system is described for removing hydrocarbons from solid materials. Contaminated solids are combined with a solvent (preferably terpene based) to produce a mixture. The mixture is washed with water to generate a purified solid product (which is removed from the system) and a drainage product. The drainage product is separated into a first fraction (consisting mostly of contaminated solvent) and a second fraction (containing solids and water). The first fraction is separated into a third fraction (consisting mostly of contaminated solvent) and a fourth fraction (containing residual solids and water). The fourth fraction is combined with the second fraction to produce a sludge which is separated into a fifth fraction (containing water which is ultimately reused) and a sixth fraction (containing solids). The third fraction is then separated into a seventh fraction (consisting of recovered solvent which is ultimately reused) and an eighth fraction (containing hydrocarbon waste). 4 figs.

  6. Method for removing hydrocarbon contaminants from solid materials

    DOEpatents

    Bala, G.A.; Thomas, C.P.

    1995-10-03

    A system is described for removing hydrocarbons from solid materials. Contaminated solids are combined with a solvent (preferably terpene based) to produce a mixture. The mixture is washed with water to generate a purified solid product (which is removed from the system) and a drainage product. The drainage product is separated into a first fraction (consisting mostly of contaminated solvent) and a second fraction (containing solids and water). The first fraction is separated into a third fraction (consisting mostly of contaminated solvent) and a fourth fraction (containing residual solids and water). The fourth fraction is combined with the second fraction to produce a sludge which is separated into a fifth fraction (containing water which is ultimately reused) and a sixth fraction (containing solids). The third fraction is then separated into a seventh fraction (consisting of recovered solvent which is ultimately reused) and an eighth fraction (containing hydrocarbon waste). 4 figs.

  7. Method for removing hydrocarbon contaminants from solid materials

    DOEpatents

    Bala, Gregory A.; Thomas, Charles P.

    1995-01-01

    A system for removing hydrocarbons from solid materials. Contaminated solids are combined with a solvent (preferably terpene based) to produce a mixture. The mixture is washed with water to generate a purified solid product (which is removed from the system) and a drainage product. The drainage product is separated into a first fraction (consisting mostly of contaminated solvent) and a second fraction (containing solids and water). The first fraction is separated into a third fraction (consisting mostly of contaminated solvent) and a fourth fraction (containing residual solids and water). The fourth fraction is combined with the second fraction to produce a sludge which is separated into a fifth fraction (containing water which is ultimately reused) and a sixth fraction (containing solids). The third fraction is then separated into a seventh fraction (consisting of recovered solvent which is ultimately reused) and an eighth fraction (containing hydrocarbon waste).

  8. Apparatus for removing hydrocarbon contaminants from solid materials

    DOEpatents

    Bala, Gregory A.; Thomas, Charles P.

    1996-01-01

    A system for removing hydrocarbons from solid materials. Contaminated solids are combined with a solvent (preferably terpene based) to produce a mixture. The mixture is washed with water to generate a purified solid product (which is removed from the system) and a drainage product. The drainage product is separated into a first fraction (consisting mostly of contaminated solvent) and a second fraction (containing solids and water). The first fraction is separated into a third fraction (consisting mostly of contaminated solvent) and a fourth fraction (containing residual solids and water). The fourth fraction is combined with the second fraction to produce a sludge which is separated into a fifth fraction (containing water which is ultimately reused) and a sixth fraction (containing solids). The third fraction is then separated into a seventh fraction (consisting of recovered solvent which is ultimately reused) and an eighth fraction (containing hydrocarbon waste).

  9. Solid electrolyte material manufacturable by polymer processing methods

    DOEpatents

    Singh, Mohit; Gur, Ilan; Eitouni, Hany Basam; Balsara, Nitash Pervez

    2012-09-18

    The present invention relates generally to electrolyte materials. According to an embodiment, the present invention provides for a solid polymer electrolyte material that is ionically conductive, mechanically robust, and can be formed into desirable shapes using conventional polymer processing methods. An exemplary polymer electrolyte material has an elastic modulus in excess of 1.times.10.sup.6 Pa at 90 degrees C. and is characterized by an ionic conductivity of at least 1.times.10.sup.-5 Scm-1 at 90 degrees C. An exemplary material can be characterized by a two domain or three domain material system. An exemplary material can include material components made of diblock polymers or triblock polymers. Many uses are contemplated for the solid polymer electrolyte materials. For example, the present invention can be applied to improve Li-based batteries by means of enabling higher energy density, better thermal and environmental stability, lower rates of self-discharge, enhanced safety, lower manufacturing costs, and novel form factors.

  10. Evolution of Interstellar Grains

    NASA Technical Reports Server (NTRS)

    Allamandola, Lou J.; DeVincenzi, Donald L. (Technical Monitor)

    1998-01-01

    During the past two decades observations combined with laboratory simulations, have revolutionized our understanding of interstellar ice and dust, the raw materials from which planets, comets and stars form. Most interstellar material is concentrated in large molecular clouds where simple molecules are formed by dust-grain and gas-phase reactions. Gaseous species striking the cold (10K) dust stick, forming an icy grain mantle. This accretion, coupled with UV photolysis, produces a complex chemical mixture containing volatile, non-volatile, and isotopically fractionated species. Ices in molecular clouds contain the very simple molecules H2O, CH3OH, CO, CO2, H2, and perhaps some NH3 and H2CO, as well as more complex species. The evidence for these compounds, as well as carbon-rich materials, will be reviewed and the possible connections with comets and meteorites will be presented in the first part of the talk . The second part of the presentation will focus on interstellar/precometary ice photochemical evolution and the species likely to be found in comets. The chemical composition and photochemical evolution of realistic interstellar/pre-cometary ice analogs will be discussed. Ultraviolet photolysis of these ices produces H2, H2CO, CO2, CO, CH4, HCO, and more complex molecules. When ices representative of interstellar grains and comets are exposed to UV radiation at low temperature a series of moderately complex organic molecules are formed in the ice including: CH3CH2OH (ethanol), HC(=O)NH2 (formamide), CH3C(=O)NH2 (acetamide), and R-C=N (nitriles). Several of these are already known to be in the interstellar medium, and their presence indicates the importance of grain processing. After warming to room temperature an organic residue remains. This is composed primarily of hexamethylenetetramine (HMT, C6H12N4), with lesser amounts of polyoxymethylene-related species (POMs), amides, and ketones. This is in sharp contrast to the organic residues produced by

  11. Interstellar grains

    NASA Technical Reports Server (NTRS)

    Snow, T. P.

    1986-01-01

    There are few aspects of interstellar grains that can be unambiguously defined. Very little can be said that is independent of models or presuppositions; hence issues are raised and questions categorized, rather than providing definitive answers. The questions are issues fall into three general areas; the general physical and chemical nature of the grains; the processes by which they are formed and destroyed; and future observational approaches.

  12. Development of solid thorium-232 reference materials

    SciTech Connect

    Engelder, P.R.; Donivan, S.; Chessmore, R.B.

    1985-05-01

    Thorium-232 reference materials having a matrix similar to soil and uranium-mill tailings are necessary for ensuring uniform standardization among measurements performed by remedial-action contractors. A task was undertaken by the Technical Measurements Center (TMC) to prepare some 200 pounds each of three different concentrations of Th-232 reference material by diluting a thorium ore with soil. Target values for Th-232 content were 70, 30, and 10 pCi/g. The recommended thorium-232 concentrations for the three reference materials are 71.2 +- 2.0 pCi/g, 30.5 +- 0.6 pCi/g, and 10.2 +- 0.3 pCi/g.

  13. Polarimetry of the Interstellar Medium

    NASA Technical Reports Server (NTRS)

    Sandford, Scott; Witteborn, Fred C. (Technical Monitor)

    1995-01-01

    The talk will review what is known about the composition of ices and organics in the dense and diffuse interstellar media (ISM). Mixed molecular ices make up a significant fraction of the solid materials in dense molecular clouds and it is now known that thermal and radiation processing of these ices results in the production of more complex organic species, some of which may survive transport into forming stellar systems and the diffuse ISM. Molecular species identified in interstellar ices include H2O, CH3OH, CO, CH4, CO2, and somewhat surprisingly, H2. Theoretical and laboratory studies of the processing of interstellar analog ices containing these species indicate that species like HCO, H2CO, CH3, and NH3 are readily made and should also be present. The irradiation of mixed molecular ices containing these species, when followed by warming, leads to the production of a large variety of more complex species, including ethanol (CH3CH2OH), formamide (HC(=O)NH2), acetamide (CH3C(=O)NH2), nitriles or isonitriles (R-CN or R-NC hexamethylenetetramine (HMT; C6H12N4), a number of polymeric species related to polyoxymethylene [POM,(-CH2O-)n], and ketones {R-C(=O)-R'}. Spectral studies of dust in the diffuse ISM indicate the presence of fairly complex organics, some of which may be related to the organics produced in dense molecular clouds. Spectral comparisons indicate that the diffuse ISM organics may be quite similar to meteoritic kerogens, i.e. they may consist largely of aromatic moieties interlinked by short aliphatic bridges. Interestingly, recent evidence indicates that the galactic distribution of this material closely matches that of silicates, but does not correlate directly with visual extinction. This implies that a large fraction of the visual extinction is caused by a material other than these organics and silicates and that this other material has a significantly different distribution within the galaxy.

  14. Prebiologically Important Interstellar Molecules

    NASA Astrophysics Data System (ADS)

    Kuan, Y.-J.; Huang, H.-C.; Charnley, S. B.; Tseng, W.-L.; Snyder, L. E.; Ehrenfreund, P.; Kisiel, Z.; Thorwirth, S.; Bohn, R. K.; Wilson, T. L.

    2004-06-01

    Understanding the organic chemistry of molecular clouds, particularly the formation of biologically important molecules, is fundamental to the study of the processes which lead to the origin, evolution and distribution of life in the Galaxy. Determining the level of molecular complexity attainable in the clouds, and the nature of the complex organic material available to protostellar disks and the planetary systems that form from them, requires an understanding of the possible chemical pathways and is therefore a central question in astrochemistry. We have thus searched for prebiologically important molecules in the hot molecular cloud cores: Sgr B2(N-LMH), W51 e1/e2 and Orion-KL. Among the molecules searched: Pyrimidine is the unsubstituted ring analogue for three of the DNA and RNA bases. 2H-Azirine and Aziridine are azaheterocyclic compounds. And Glycine is the simplest amino acid. Detections of these interstellar organic molecular species will thus have important implications for Astrobiology. Our preliminary results indicate a tentative detection of interstellar glycine. If confirmed, this will be the first detection of an amino acid in interstellar space and will greatly strengthen the thesis that interstellar organic molecules could have played a pivotal role in the prebiotic chemistry of the early Earth.

  15. X-ray characterization of solid small molecule organic materials

    SciTech Connect

    Billinge, Simon; Shankland, Kenneth; Shankland, Norman; Florence, Alastair

    2014-06-10

    The present invention provides, inter alia, methods of characterizing a small molecule organic material, e.g., a drug or a drug product. This method includes subjecting the solid small molecule organic material to x-ray total scattering analysis at a short wavelength, collecting data generated thereby, and mathematically transforming the data to provide a refined set of data.

  16. Interstellar grains within interstellar grains

    NASA Technical Reports Server (NTRS)

    Bernatowicz, Thomas J.; Amari, Sachiko; Zinner, Ernst K.; Lewis, Roy S.

    1991-01-01

    Five interstellar graphite spherules extracted from the Murchison carbonaceous meteorite are studied. The isotopic and elemental compositions of individual particles are investigated with the help of an ion microprobe, and this analysis is augmented with structural studies of ultrathin sections of the grain interiors by transmission electron microscopy. As a result, the following procedure for the formation of the interstellar graphite spherule bearing TiC crystals is inferred: (1) high-temperature nucleation and rapid growth of the graphitic carbon spherule in the atmosphere of a carbon-rich star, (2) nucleation and growth of TiC crystals during continued growth of the graphitic spherule and the accretion of TiC onto the spherule, (3) quenching of the graphite growth process by depletion of C or by isolation of the spherule before other grain types could condense.

  17. Detection of organic matter in interstellar grains.

    PubMed

    Pendleton, Y J

    1997-06-01

    Star formation and the subsequent evolution of planetary systems occurs in dense molecular clouds, which are comprised, in part, of interstellar dust grains gathered from the diffuse interstellar medium (DISM). Radio observations of the interstellar medium reveal the presence of organic molecules in the gas phase and infrared observational studies provide details concerning the solid-state features in dust grains. In particular, a series of absorption bands have been observed near 3.4 microns (approximately 2940 cm-1) towards bright infrared objects which are seen through large column densities of interstellar dust. Comparisons of organic residues, produced under a variety of laboratory conditions, to the diffuse interstellar medium observations have shown that aliphatic hydrocarbon grains are responsible for the spectral absorption features observed near 3.4 microns (approximately 2940 cm-1). These hydrocarbons appear to carry the -CH2- and -CH3 functional groups in the abundance ratio CH2/CH3 approximately 2.5, and the amount of carbon tied up in this component is greater than 4% of the cosmic carbon available. On a galactic scale, the strength of the 3.4 microns band does not scale linearly with visual extinction, but instead increases more rapidly for objects near the Galactic Center. A similar trend is noted in the strength of the Si-O absorption band near 9.7 microns. The similar behavior of the C-H and Si-O stretching bands suggests that these two components may be coupled, perhaps in the form of grains with silicate cores and refractory organic mantles. The ubiquity of the hydrocarbon features seen in the near infrared near 3.4 microns throughout out Galaxy and in other galaxies demonstrates the widespread availability of such material for incorporation into the many newly forming planetary systems. The similarity of the 3.4 microns features in any organic material with aliphatic hydrocarbons underscores the need for complete astronomical observational

  18. Materials research for passive solar systems: solid-state phase-change materials

    SciTech Connect

    Benson, D.K.; Webb, J.D.; Burrows, R.W.; McFadden, J.D.O.; Christensen, C.

    1985-03-01

    A set of solid-state phase-change materials is being evaluated for possible use in passive solar thermal energy storage systems. The most promising materials are organic solid solutions of pentaerythritol (C/sub 5/H/sub 12/O/sub 4/), pentaglycerinve (C/sub 5/H/sub 12/O/sub 3/), and neopentyl glycol (C/sub 5/H/sub 12/O/sub 2/). Solid solution mixtures of these compounds can be tailored so that they exhibit solid-to-solid phase transformations at any desired temperature betweeen 25/sup 0/C and 188/sup 0/C, and have latent heats of transformation between 20 and 70 cal/g. Transformation temperatures, specific heats, and latent heats of transformation have been measured for a number of these materials. Limited cyclic experiments suggest that the solid solutions are stable. These phase-change materials exhibit large amounts of undercooling; however, the addition of certain nucleating agents as particulate dispersions in the solid phase-change material greatly reduces this effect. Computer simulations suggest that the use of an optimized solid-state phase-change material in a Trombe wall could provide better performance than a concrete Trombe wall four times thicker and nine times heavier. Nevertheless, a higher cost of the phase-change materials (approx. =$0.70 per pound) is likely to limit their applicability in passive solar systems unless their performance can be significantly improved through further research.

  19. Tunable solid-state fluorescent materials for supramolecular encryption

    NASA Astrophysics Data System (ADS)

    Hou, Xisen; Ke, Chenfeng; Bruns, Carson J.; McGonigal, Paul R.; Pettman, Roger B.; Stoddart, J. Fraser

    2015-04-01

    Tunable solid-state fluorescent materials are ideal for applications in security printing technologies. A document possesses a high level of security if its encrypted information can be authenticated without being decoded, while also being resistant to counterfeiting. Herein, we describe a heterorotaxane with tunable solid-state fluorescent emissions enabled through reversible manipulation of its aggregation by supramolecular encapsulation. The dynamic nature of this fluorescent material is based on a complex set of equilibria, whose fluorescence output depends non-linearly on the chemical inputs and the composition of the paper. By applying this system in fluorescent security inks, the information encoded in polychromic images can be protected in such a way that it is close to impossible to reverse engineer, as well as being easy to verify. This system constitutes a unique application of responsive complex equilibria in the form of a cryptographic algorithm that protects valuable information printed using tunable solid-state fluorescent materials.

  20. Tunable solid-state fluorescent materials for supramolecular encryption

    PubMed Central

    Hou, Xisen; Ke, Chenfeng; Bruns, Carson J.; McGonigal, Paul R.; Pettman, Roger B.; Stoddart, J. Fraser

    2015-01-01

    Tunable solid-state fluorescent materials are ideal for applications in security printing technologies. A document possesses a high level of security if its encrypted information can be authenticated without being decoded, while also being resistant to counterfeiting. Herein, we describe a heterorotaxane with tunable solid-state fluorescent emissions enabled through reversible manipulation of its aggregation by supramolecular encapsulation. The dynamic nature of this fluorescent material is based on a complex set of equilibria, whose fluorescence output depends non-linearly on the chemical inputs and the composition of the paper. By applying this system in fluorescent security inks, the information encoded in polychromic images can be protected in such a way that it is close to impossible to reverse engineer, as well as being easy to verify. This system constitutes a unique application of responsive complex equilibria in the form of a cryptographic algorithm that protects valuable information printed using tunable solid-state fluorescent materials. PMID:25901677

  1. Materials for Intermediate-Temperature Solid-Oxide Fuel Cells

    NASA Astrophysics Data System (ADS)

    Kilner, John A.; Burriel, Mónica

    2014-07-01

    Solid-oxide fuel cells are devices for the efficient conversion of chemical energy to electrical energy and heat. Research efforts are currently addressed toward the optimization of cells operating at temperatures in the region of 600°C, known as intermediate-temperature solid-oxide fuel cells, for which materials requirements are very stringent. In addition to the requirements of mechanical and chemical compatibility, the materials must show a high degree of oxide ion mobility and electrochemical activity at this low temperature. Here we mainly examine the criteria for the development of two key components of intermediate-temperature solid-oxide fuel cells: the electrolyte and the cathode. We limit the discussion to novel approaches to materials optimization and focus on the fluorite oxide for electrolytes, principally those based on ceria and zirconia, and on perovskites and perovskite-related families in the case of cathodes.

  2. A room-temperature all-solid-state 4.7 THz multiplied LO source to enable the heterodyne observation of interstellar neutral oxygen

    NASA Astrophysics Data System (ADS)

    Siles, Jose

    emission and absorption, the models that predict the chemistry of ISM cannot be verified, revised and/or completed. Until this problem is solved, or in other words, until the fine OI atomic line is observed in high spectral and spatial resolution, the chemistry of oxygen in interstellar clouds and protostellar regions, essential for understanding the formation of stars and the incorporation of key molecules into forming planetary system, will not be fully understood. As a response to this problem, we will develop the first all-solid-state continuous coherent local oscillator (LO) source at 4.7 THz to enable very high-resolution heterodyne observation (R=»/”» > 1E6) of the 4.748 THz (63.1837 μm) fine structure line of neutral atomic oxygen (OI). This source will be broadband, frequency-agile, temperature and frequency stable and will operate at room-temperature (no need of cryogenic cooling). With hot electron bolometer detectors (HEB) already available, the proposed source is the only technological part that is still missing to provide the radio-astronomers with this highly necessary science data for the complete understanding of star and planetary systems formation processes.

  3. Solid freeform fabrication of highly loaded composite materials

    NASA Astrophysics Data System (ADS)

    Souvignier, Chad William

    Composites are known for their unique blend of modulus, strength, and toughness. This study focuses on two types of composites; organic-inorganic hybrids and the mineralization of highly swollen polymer gels. Both of these composite systems mimic the biological process of composite formation, known as biomineralization. Biomineralization allows for the control of the precipitating phase through an interaction with the organic matrix. This allows higher volume fractions of inorganic material than can be achieved by many traditional processing techniques. Solid freeform fabrication is a processing method that builds materials by the sequential addition of thin layers. As long as the material can easily be converted from a liquid to a solid, it should be amenable for this processing technique. Freeform fabrication has three distinctions from traditional processing techniques that may enable the formation of composite materials with improved mechanical properties. These are the sequential addition of layers, which allows a layer by layer influence of chemistry, the ability to form complex geometries, and finally, extrusion freeform fabrication has been shown to align fibers due to the extrusion of the slurry through a needle. Cracking and shrinkage still play a major role in forming solid parts. The use of an open mesh structure in combination with proper materials selection allowed the formation of highly loaded composite materials without cracking. The modulus values of these materials ranged from 0.1 GPa to 6.0 GPa. The mechanical properties of these materials were modeled.

  4. Chemistry and Evolution of Interstellar Clouds

    NASA Technical Reports Server (NTRS)

    Wooden, D. H.; Charnley, S. B.; Ehrenfreund, P.

    2003-01-01

    In this chapter we describe how elements have been and are still being formed in the galaxy and how they are transformed into the reservoir of materials present at the time of formation of our protosolar nebula. We discuss the global cycle of matter, beginning at its formation site in stars, where it is ejected through winds and explosions into the diffuse interstellar medium. In the next stage of the global cycle occurs in cold, dense molecular clouds, where the complexity of molecules and ices increases relative to the diffuse ISM.. When a protostar forms in a dense core within a molecular cloud, it heats the surrounding infalling matter warms and releases molecules from the solid phase into the gas phase in a warm, dense core, sponsoring a rich gas-phase chemistry. Some material from the cold and warm regions within molecular clouds probably survives as interstellar matter in the protostellar disk. For the diffuse ISM, for cold, dense clouds, and for dense-warm cores, the physio-chemical processes that occur within the gas and solid phases are discussed in detail.

  5. SRM (Solid Rocket Motor) propellant and polymer materials structural modeling

    NASA Technical Reports Server (NTRS)

    Moore, Carleton J.

    1988-01-01

    The following investigation reviews and evaluates the use of stress relaxation test data for the structural analysis of Solid Rocket Motor (SRM) propellants and other polymer materials used for liners, insulators, inhibitors, and seals. The stress relaxation data is examined and a new mathematical structural model is proposed. This model has potentially wide application to structural analysis of polymer materials and other materials generally characterized as being made of viscoelastic materials. A dynamic modulus is derived from the new model for stress relaxation modulus and is compared to the old viscoelastic model and experimental data.

  6. Modeling interfaces between solids: Application to Li battery materials

    NASA Astrophysics Data System (ADS)

    Lepley, N. D.; Holzwarth, N. A. W.

    2015-12-01

    We present a general scheme to model an energy for analyzing interfaces between crystalline solids, quantitatively including the effects of varying configurations and lattice strain. This scheme is successfully applied to the modeling of likely interface geometries of several solid state battery materials including Li metal, Li3PO4 , Li3PS4 , Li2O , and Li2S . Our formalism, together with a partial density of states analysis, allows us to characterize the thickness, stability, and transport properties of these interfaces. We find that all of the interfaces in this study are stable with the exception of Li3PS4/Li . For this chemically unstable interface, the partial density of states helps to identify mechanisms associated with the interface reactions. Our energetic measure of interfaces and our analysis of the band alignment between interface materials indicate multiple factors, which may be predictors of interface stability, an important property of solid electrolyte systems.

  7. HANDBOOK: MATERIAL RECOVERY FACILITIES FOR MUNICIPAL SOLID WASTE.

    EPA Science Inventory

    The purpose of this document is to address the technical and economic aspects of material recovery facility (MRF) equipment and technology in such a manner that the document may be of assistance to solid waste planners and engineers at the local community level. This docum...

  8. Mass spectrometric detection of solid and vapor explosive materials

    NASA Astrophysics Data System (ADS)

    Stott, William R.; Green, D.; Mercado, Alvaro G.

    1994-10-01

    The detection by chemical sensors of explosive devices in a terrorist or contraband scenario usually involves the acquisition of material in the vapor or solid form. Whether in the vapor form in ambient air or in solid form in a matrix of innocuous material, the chemical compounds may be present at very low concentrations or may be present in concentrations higher by orders of magnitude. In this study, a characterization of a tandem mass spectrometer detection system has been made to evaluate a variety of parameters as it relates to explosive chemicals in both the vapor and solid phases. In particular, a range of concentrations of standard solutions of RDX, PETN and TNT have been injected in determine the sensitivity, dynamic range, and lower level of detection of the SCIEX contraband tandem quadrupole mass spectrometer. Techniques for the introduction of samples include heated nebulization and direct injection/thermal desorption from a real time sampler belt. As well, explosive vapors produced by a special generator were injected in a 1 l/min stream of room air and used to characterize instrumental performance. Solid material was presented in a form simulating fingerprint material and then transferred to the detector using a real time sampling system and then thermally desorbed into the mass spectrometer ionization chamber.

  9. Introduction of Materials Science Through Solid State Chemistry.

    ERIC Educational Resources Information Center

    Mueller, William M.

    Presented is a report of a program of the American Society for Metals, designed to introduce materials science principles via solid state chemistry into high school chemistry courses. At the time of the inception of this program in the mid-sixties, it was felt that high school students were not being adequately exposed to career opportunities in…

  10. Development of Ceramic Solid-State Laser Host Material

    NASA Technical Reports Server (NTRS)

    Prasad, Narasimha S.; Trivedi, Sudhir; Kutcher, Susan; Wang, Chen-Chia; Kim, Joo-Soo; Hommerich, Uwe; Shukla, Vijay; Sadangi, Rajendra

    2009-01-01

    Polycrystalline ceramic laser materials are gaining importance in the development of novel diode-pumped solid-state lasers. Compared to single-crystals, ceramic laser materials offer advantages in terms of ease of fabrication, shape, size, and control of dopant concentrations. Recently, we have developed Neodymium doped Yttria (Nd:Y2O3) as a solid-state ceramic laser material. A scalable production method was utilized to make spherical non agglomerated and monodisperse metastable ceramic powders of compositions that were used to fabricate polycrystalline ceramic material components. This processing technique allowed for higher doping concentrations without the segregation problems that are normally encountered in single crystalline growth. We have successfully fabricated undoped and Neodymium doped Yttria material up to 2" in diameter, Ytterbium doped Yttria, and erbium doped Yttria. We are also in the process of developing other sesquioxides such as scandium Oxide (Sc2O3) and Lutesium Oxide (Lu2O3) doped with Ytterbium, erbium and thulium dopants. In this paper, we present our initial results on the material, optical, and spectroscopic properties of the doped and undoped sesquioxide materials. Polycrystalline ceramic lasers have enormous potential applications including remote sensing, chem.-bio detection, and space exploration research. It is also potentially much less expensive to produce ceramic laser materials compared to their single crystalline counterparts because of the shorter fabrication time and the potential for mass production in large sizes.

  11. Stardust interstellar preliminary examination (ISPE).

    SciTech Connect

    Westphal, A.J.; Allen, C.; Bajt, S.; Basset, R.; Flynn, G.L.; Sutton, S.

    2009-03-23

    The Stardust Interstellar Preliminary Examination (ISPE) is a three-year effort to characterize the Stardust interstellar dust collection and collector using non-destructive techniques. We summarize the status of the ISPE. In January 2006 the Stardust sample return capsule returned to Earth bearing the first solid samples from a primitive solar system body, Comet 81P/Wild2, and a collector dedicated to the capture and return of contemporary interstellar dust. Both collectors were {approx}0.1 m{sup 2} in area and were composed of aerogel tiles (85% of the collecting area) and aluminum foils. The Stardust Interstellar Dust Collector (SIDC) was exposed to the interstellar dust stream for a total exposure factor of 20 m{sup 2}-day during two periods before the cometary encounter. The Stardust Interstellar Preliminary Examination (ISPE) is a three-year effort to characterize the collection using nondestructive techniques. The goals and restrictions of the ISPE are described in Westphal et al. The ISPE consists of six interdependent projects: (1) Candidate identification through automated digital microscopy and a massively distributed, calibrated search; (2) Candidate extraction and photodocumentation; (3) Characterization of candidates through synchrotron-based Fourier-Tranform Infrared Spectroscopy (FTIR), Scanning X-Ray Fluoresence Microscopy (SXRF), and Scanning Transmission X-ray Microscopy (STXM); (4) Search for and analysis of craters in foils through FESEM scanning, Auger Spectroscopy and synchrotron-based Photoemission Electron Microscopy (PEEM); (5) Modeling of interstellar dust transport in the solar system; and (6) Laboratory simulations of hypervelocity dust impacts into the collecting media.

  12. Laboratory Astrochemistry: Interstellar PAH Analogs

    NASA Technical Reports Server (NTRS)

    Salama, Farid; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are now considered to be an important and ubiquitous component of the organic material in space. PAHs are found in a large variety of extraterrestrial materials such as interplanetary dust particles (IDPs) and meteoritic materials. PAHs are also good candidates to account for the infrared emission bands (UIRs) and the diffuse interstellar optical absorption bands (DIBs) detected in various regions of the interstellar medium. The recent observations made with the Infrared Space Observatory (ISO) have confirmed the ubiquitous nature of the UIR bands and their carriers. PAHs are though to form through chemical reactions in the outflow from carbon-rich stars in a process similar to soot formation. Once injected in the interstellar medium, PAHs are further processed by the interstellar radiation field, interstellar shocks and energetic particles. A major, dedicated, laboratory effort has been undertaken over the past years to measure the physical and chemical characteristics of these complex molecules and their ions under experimental conditions that mimic the interstellar conditions. These measurements require collision-free conditions where the molecules and ions are cold and chemically isolated. The spectroscopy of PAHs under controlled conditions represents an essential diagnostic tool to study the evolution of extraterrestrial PAHs. The Astrochemistry Laboratory program will be discussed through its multiple aspects: objectives, approach and techniques adopted, adaptability to the nature of the problem(s), results and implications for astronomy as well as for molecular spectroscopy. A review of the data generated through laboratory simulations of space environments and the role these data have played in our current understanding of the properties of interstellar PAHs will be presented. The discussion will also introduce the newest generation of laboratory experiments that are currently being developed in order to provide a

  13. Solid material evaporation into an ECR source by laser ablation

    SciTech Connect

    Harkewicz, R.; Stacy, J.; Greene, J.; Pardo, R.C.

    1993-09-01

    In an effort to explore new methods of producing ion beams from solid materials, we are attempting to develop a laser-ablation technique for evaporating materials directly into an ECR ion source plasma. A pulsed NdYaG laser with approximately 25 watts average power and peak power density on the order of 10{sup 7} W/cm{sup 2} has been used off-line to measure ablation rates of various materials as a function of peak laser power. The benefits anticipated from the successful demonstration of this technique include the ability to use very small quantities of materials efficiently, improved material efficiency of incorporation into the ECR plasma, and decoupling of the material evaporation process from the ECR source tuning operation. Here we report on the results of these tests and describe the design for incorporating such a system directly with the ATLAS PII-ECR ion source.

  14. The Local Interstellar Medium

    NASA Astrophysics Data System (ADS)

    Redfield, S.

    2006-09-01

    The Local Interstellar Medium (LISM) is a unique environment that presents an opportunity to study general interstellar phenomena in great detail and in three dimensions. In particular, high resolution optical and ultraviolet spectroscopy have proven to be powerful tools for addressing fundamental questions concerning the physical conditions and three-dimensional (3D) morphology of this local material. After reviewing our current understanding of the structure of gas in the solar neighborhood, I will discuss the influence that the LISM can have on stellar and planetary systems, including LISM dust deposition onto planetary atmospheres and the modulation of galactic cosmic rays through the astrosphere --- the balancing interface between the outward pressure of the magnetized stellar wind and the inward pressure of the surrounding interstellar medium. On Earth, galactic cosmic rays may play a role as contributors to ozone layer chemistry, planetary electrical discharge frequency, biological mutation rates, and climate. Since the LISM shares the same volume as practically all known extrasolar planets, the prototypical debris disks systems, and nearby low-mass star-formation sites, it will be important to understand the structures of the LISM and how they may influence planetary atmospheres.

  15. Innovative interstellar explorer

    NASA Astrophysics Data System (ADS)

    McNutt, R.; Innovative Interstellar Explorer Team

    Fundamental scientific questions about the interaction of the Sun with the interstellar medium can only be answered with in situ measurements. The problem is the development of a probe that can provide the required measurements and can reach a heliocentric distance of at least 200 astronomical units (AU) in 15 years or less, an average speed almost four times the 3.6 AU/yr speed of Voyager 1. The Innovative Interstellar Explorer (IIE) and its use of Radioisotope Electric Propulsion (REP) is now being studied under a NASA Vision Mission grant to enable such a mission. Speed is provided by a high-energy launch using current launch vehicle technology followed by long-term, low-thrust, continuous acceleration. The latter is provided by a kilowatt-class ion thruster running off of electricity provided by advanced Stirling radioisotope generators (SRGs) powered by Pu-238. While subject to mass and power limitations for the instruments on board, such an approach relies on known General Purpose Heat Source (GPHS) Pu-238 technology and current launch vehicles for speed, both of which require little new development and have well-known regulatory requirements for launch. In addition, this approach avoids the intrinsically large masses associated with nuclear fission reactors and incorporates launch of all nuclear material directly into an Earth-escape trajectory. We discuss the ongoing trade studies and development of this approach to an Interstellar Probe

  16. Review on anode material development in solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Siong @ Mahmud, Lily; Muchtar, Andanastuti; Somalu, Mahendra Rao

    2015-05-01

    New developments in technology require highly efficient, affordable, and green electrical energy. The materials to be used must also be reusable and environment friendly. These characteristics are among the major factors that may lead to the production of new and highly efficient power generation systems. Solid oxide fuel cells (SOFCs) have become major devices in producing electricity that emphasize the advance usage of material science and technological development. As part of the key elements of SOFCs, anodes have the primary function of stimulating the electrochemical oxidation of fuel. In this review, the progress in developing anode materials for SOFCs is briefly discussed.

  17. Isotopic Fractionation in Interstellar Chemistry

    NASA Technical Reports Server (NTRS)

    Charnley, Steven

    2009-01-01

    Isotopically fractionated material is found in many solar system objects, including meteorites and comets. It is thought, in some cases, to trace interstellar material that was incorporated into the solar sys tem without undergoing significant processing. In this poster, we sho w the results of several models of the nitrogen, oxygen, and carbon f ractionation in proto-stellar cores.

  18. Main-sequence stars with circumstellar solid material - The Vega phenomenon

    NASA Technical Reports Server (NTRS)

    Backman, Dana E.; Paresce, Francesco

    1993-01-01

    The detection of solid grains with temperatures of 50 to 125 K and fractional bolometric luminosities in the range 10 exp -5 to 10 exp -3 early in the IRAS mission around three nearby A main-sequence stars, Alpha Lyrae (Vega), Alpha Piscis Austrinus (Fomalhaut), and Beta Pictoris, is discussed. Spatial resolution of the emission indicates that: the grains are larger than interstellar grains, the material probably lies in disks in the stellar equatorial planes, the disks extend to distances of 100 to 1000 AU from the stars, and zones a few tens of AU in radius around the central stars are relatively empty. Subsequent surveys of IRAS data reveal more than 100 main-sequence stars of all spectral classes having unresolved excesses with similar temperatures and fractional luminosities to the three prototypes. Some stars with excesses have estimated ages of 1 to 5 Gyr. Thus, main-sequence FIR excesses appear to be widespread and are present in systems old enough to be probably past the stage of active planet formation.

  19. Constitutive modeling of solid propellant materials with evolving microstructural damage

    NASA Astrophysics Data System (ADS)

    Xu, F.; Aravas, N.; Sofronis, P.

    Solid propellants are composite materials with complex microstructure. In a generic form, the material consists of polymeric binder, crystal oxidizer (e.g., ammonium perchlorate), and fuel particles (e.g., aluminum). Severe stressing and extreme temperatures induce damage which is manifested in particle cracking, dewetting along particle/polymer interfaces, void nucleation and growth. Damage complicates the overall constitutive response of a solid propellant over and above the complexities associated with the differing constitutive properties of the particle and binder phases. Using rigorous homogenization theory for composite materials, we propose a general 3-D nonlinear macroscopic constitutive law that models microstructural damage evolution upon straining through continuous void formation and growth. The law addresses the viscous deformation rate within the framework of additive decomposition of the deformation rate and the concept of back stress is used to improve the model performance in stress relaxation. No restriction is placed on the magnitude of the strains. Experimental data from the standard relaxation and uniaxial tension tests are used to calibrate the model parameters in the case of a high elongation solid propellant. It is emphasized that the model parameters are descriptors of individual phase constitutive response and criticality conditions for particle decohesion which can systematically be determined through experiment. The model is used to predict the response of the material under more complex loading paths and to investigate the effect of crack tip damage on the mechanical behavior of a compact tension fracture specimen.

  20. Stardust Interstellar Preliminary Examination

    NASA Astrophysics Data System (ADS)

    Westphal, A.; Stardust Interstellar Preliminary Examation Team: http://www. ssl. berkeley. edu/~westphal/ISPE/

    2011-12-01

    A. J. Westphal, C. Allen, A. Ansari, S. Bajt, R. S. Bastien, H. A. Bechtel, J. Borg, F. E. Brenker, J. Bridges, D. E. Brownlee, M. Burchell, M. Burghammer, A. L. Butterworth, A. M. Davis, P. Cloetens, C. Floss, G. Flynn, D. Frank, Z. Gainsforth, E. Grün, P. R. Heck, J. K. Hillier, P. Hoppe, G. Huss, J. Huth, B. Hvide, A. Kearsley, A. J. King, B. Lai, J. Leitner, L. Lemelle, H. Leroux, R. Lettieri, W. Marchant, L. R. Nittler, R. Ogliore, F. Postberg, M. C. Price, S. A. Sandford, J.-A. Sans Tresseras, T. Schoonjans, S. Schmitz, G. Silversmit, A. Simionovici, V. A. Solé, R. Srama, T. Stephan, V. Sterken, J. Stodolna, R. M. Stroud, S. Sutton, M. Trieloff, P. Tsou, A. Tsuchiyama, T. Tyliszczak, B. Vekemans, L. Vincze, D. Zevin, M. E. Zolensky, >29,000 Stardust@home dusters ISPE author affiliations are at http://www.ssl.berkeley.edu/~westphal/ISPE/. In 2000 and 2002, a ~0.1m2 array of aerogel tiles and alumi-num foils onboard the Stardust spacecraft was exposed to the interstellar dust (ISD) stream for an integrated time of 200 days. The exposure took place in interplanetary space, beyond the orbit of Mars, and thus was free of the ubiquitous orbital debris in low-earth orbit that precludes effective searches for interstellar dust there. Despite the long exposure of the Stardust collector, <<100 ISD particles are expected to have been captured. The particles are thought to be ~1μm or less in size, and the total ISD collection is probably <10-6 by mass of the collection of cometary dust parti-cles captured in the Stardust cometary dust collector from the coma of the Jupiter-family comet Wild 2. Thus, although the first solid sample from the local interstellar medium is clearly of high interest, the diminutive size of the particles and the low numbers of particles present daunting challenges. Nevertheless, six recent developments have made a Preliminary Examination (PE) of this sample practical: (1) rapid automated digital optical scanning microscopy for three

  1. Accretion of solid materials onto circumplanetary disks from protoplanetary disks

    SciTech Connect

    Tanigawa, Takayuki; Maruta, Akito; Machida, Masahiro N.

    2014-04-01

    We investigate the accretion of solid materials onto circumplanetary disks from heliocentric orbits rotating in protoplanetary disks, which is a key process for the formation of regular satellite systems. In the late stage of the gas-capturing phase of giant planet formation, the accreting gas from protoplanetary disks forms circumplanetary disks. Since the accretion flow toward the circumplanetary disks affects the particle motion through gas drag force, we use hydrodynamic simulation data for the gas drag term to calculate the motion of solid materials. We consider a wide range of size for the solid particles (10{sup –2}-10{sup 6} m), and find that the accretion efficiency of the solid particles peaks around 10 m sized particles because energy dissipation of drag with circum-planetary disk gas in this size regime is most effective. The efficiency for particles larger than 10 m becomes lower because gas drag becomes less effective. For particles smaller than 10 m, the efficiency is lower because the particles are strongly coupled with the background gas flow, which prevents particles from accretion. We also find that the distance from the planet where the particles are captured by the circumplanetary disks is in a narrow range and well described as a function of the particle size.

  2. Interstellar isomers

    NASA Technical Reports Server (NTRS)

    Defrees, D.; Mclean, D.; Herbst, E.

    1986-01-01

    Both observational and theoretical studies of molecular clouds are hindered by many difficulties. One way to partially circumvent the difficulties of characterizing the chemistry within these objects is to study the relative abundances of isomers which are synthesized from a common set of precursors. Unfortunately, only one such system has been confirmed, the HCN/HNC pair of isomers. While the basic outlines of its chemistry have been known for some years, there are still many aspects of the chemistry which are unclear. Another potential pair of isomers is HCO+/HOC+; HCO+ is an abundant instellar molecule and a tentative identification of HOC+ has been made in Sgr B2. This identification is being challenged, however, based on theoretical and laboratory evidence that HOC+ reacts with H2. Another potential pair of interstellar isomers is methyl cyanide (CH3CN, acetonitrile) and methyl isocyanide (CH3NC). The cyanide is well known, however the isocyanide has yet to be observed despite theoretical predictions that appreciable quantities should be present.

  3. Method of encapsulating solid radioactive waste material for storage

    DOEpatents

    Bunnell, Lee Roy; Bates, J. Lambert

    1976-01-01

    High-level radioactive wastes are encapsulated in vitreous carbon for long-term storage by mixing the wastes as finely divided solids with a suitable resin, formed into an appropriate shape and cured. The cured resin is carbonized by heating under a vacuum to form vitreous carbon. The vitreous carbon shapes may be further protected for storage by encasement in a canister containing a low melting temperature matrix material such as aluminum to increase impact resistance and improve heat dissipation.

  4. Mass, energy and material balances of SRF production process. Part 3: solid recovered fuel produced from municipal solid waste.

    PubMed

    Nasrullah, Muhammad; Vainikka, Pasi; Hannula, Janne; Hurme, Markku; Kärki, Janne

    2015-02-01

    This is the third and final part of the three-part article written to describe the mass, energy and material balances of the solid recovered fuel production process produced from various types of waste streams through mechanical treatment. This article focused the production of solid recovered fuel from municipal solid waste. The stream of municipal solid waste used here as an input waste material to produce solid recovered fuel is energy waste collected from households of municipality. This article presents the mass, energy and material balances of the solid recovered fuel production process. These balances are based on the proximate as well as the ultimate analysis and the composition determination of various streams of material produced in a solid recovered fuel production plant. All the process streams are sampled and treated according to CEN standard methods for solid recovered fuel. The results of the mass balance of the solid recovered fuel production process showed that 72% of the input waste material was recovered in the form of solid recovered fuel; 2.6% as ferrous metal, 0.4% as non-ferrous metal, 11% was sorted as rejects material, 12% as fine faction and 2% as heavy fraction. The energy balance of the solid recovered fuel production process showed that 86% of the total input energy content of input waste material was recovered in the form of solid recovered fuel. The remaining percentage (14%) of the input energy was split into the streams of reject material, fine fraction and heavy fraction. The material balances of this process showed that mass fraction of paper and cardboard, plastic (soft) and wood recovered in the solid recovered fuel stream was 88%, 85% and 90%, respectively, of their input mass. A high mass fraction of rubber material, plastic (PVC-plastic) and inert (stone/rock and glass particles) was found in the reject material stream. PMID:25568089

  5. Heating of solid earthen material, measuring moisture and resistivity

    DOEpatents

    Heath, William O.; Gauglitz, Phillip A.; Pillay, Gautam; Bergsman, Theresa M.; Eschbach, Eugene A.; Goheen, Steven C.; Richardson, Richard L.; Roberts, Janet S.; Schalla, Ronald

    1996-01-01

    The present invention includes a method of treating solid earthen material having volatile, semi-volatile, and non-volatile contaminants that utilizes electrical energy. A plurality of electrodes are inserted into a region of earthen material to be treated in a selected geometric pattern. Varying phase and voltages configurations are applied to corresponding electrodes to achieve heating, physical phase changes, and the placement of substances within the treatment region. Additionally, treatment mediums can be added to either treat the contamination within the soil or to restrict their mobility.

  6. Heating of solid earthen material, measuring moisture and resistivity

    DOEpatents

    Heath, W.O.; Gauglitz, P.A.; Pillay, G.; Bergsman, T.M.; Eschbach, E.A.; Goheen, S.C.; Richardson, R.L.; Roberts, J.S.; Schalla, R.

    1996-08-13

    The present invention includes a method of treating solid earthen material having volatile, semi-volatile, and non-volatile contaminants that utilizes electrical energy. A plurality of electrodes are inserted into a region of earthen material to be treated in a selected geometric pattern. Varying phase and voltages configurations are applied to corresponding electrodes to achieve heating, physical phase changes, and the placement of substances within the treatment region. Additionally, treatment mediums can be added to either treat the contamination within the soil or to restrict their mobility. 29 figs.

  7. Cosmic Carbon Chemistry: From the Interstellar Medium to the Early Earth

    PubMed Central

    Ehrenfreund, Pascale; Cami, Jan

    2010-01-01

    Astronomical observations have shown that carbonaceous compounds in the gas and solid state, refractory and icy are ubiquitous in our and distant galaxies. Interstellar molecular clouds and circumstellar envelopes are factories of complex molecular synthesis. A surprisingly large number of molecules that are used in contemporary biochemistry on Earth are found in the interstellar medium, planetary atmospheres and surfaces, comets, asteroids and meteorites, and interplanetary dust particles. In this article we review the current knowledge of abundant organic material in different space environments and investigate the connection between presolar and solar system material, based on observations of interstellar dust and gas, cometary volatiles, simulation experiments, and the analysis of extraterrestrial matter. Current challenges in astrochemistry are discussed and future research directions are proposed. PMID:20554702

  8. Heating of solid earthen material, measuring moisture and resistivity

    DOEpatents

    Heath, William O.; Richardson, Richard L.; Goheen, Steven C.

    1994-01-01

    The present invention includes a method of treating solid earthen material having volatile, semi-volatile, and non-volatile contaminants. Six electrodes are inserted into a region of earthen material to be treated in a substantially equilateral hexagonal arrangement. Six phases of voltages are applied to corresponding electrodes. The voltages are adjusted within a first range of voltages to create multiple current paths between pairs of the electrodes. The current paths are evenly distributed throughout the region defined by the electrodes and therefore uniformly heat the region. The region of earthen material is heated to a temperature sufficient to substantially remove volatile and semi-volatile contaminants by promoting microbial action. This temperature is less than a melting temperature of the earthen material.

  9. Heating of solid earthen material, measuring moisture and resistivity

    DOEpatents

    Heath, W.O.; Richardson, R.L.; Goheen, S.C.

    1994-07-19

    The present invention includes a method of treating solid earthen material having volatile, semi-volatile, and non-volatile contaminants. Six electrodes are inserted into a region of earthen material to be treated in a substantially equilateral hexagonal arrangement. Six phases of voltages are applied to corresponding electrodes. The voltages are adjusted within a first range of voltages to create multiple current paths between pairs of the electrodes. The current paths are evenly distributed throughout the region defined by the electrodes and therefore uniformly heat the region. The region of earthen material is heated to a temperature sufficient to substantially remove volatile and semi-volatile contaminants by promoting microbial action. This temperature is less than a melting temperature of the earthen material. 13 figs.

  10. 40 CFR 227.32 - Liquid, suspended particulate, and solid phases of a material.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... solid phases of a material. 227.32 Section 227.32 Protection of Environment ENVIRONMENTAL PROTECTION... MATERIALS Definitions § 227.32 Liquid, suspended particulate, and solid phases of a material. (a) For the... obtained above prior to centrifugation and filtration. The solid phase includes all material settling...

  11. 40 CFR 227.32 - Liquid, suspended particulate, and solid phases of a material.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... solid phases of a material. 227.32 Section 227.32 Protection of Environment ENVIRONMENTAL PROTECTION... MATERIALS Definitions § 227.32 Liquid, suspended particulate, and solid phases of a material. (a) For the... obtained above prior to centrifugation and filtration. The solid phase includes all material settling...

  12. 40 CFR 227.32 - Liquid, suspended particulate, and solid phases of a material.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... solid phases of a material. 227.32 Section 227.32 Protection of Environment ENVIRONMENTAL PROTECTION... MATERIALS Definitions § 227.32 Liquid, suspended particulate, and solid phases of a material. (a) For the... obtained above prior to centrifugation and filtration. The solid phase includes all material settling...

  13. 40 CFR 227.32 - Liquid, suspended particulate, and solid phases of a material.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... solid phases of a material. 227.32 Section 227.32 Protection of Environment ENVIRONMENTAL PROTECTION... MATERIALS Definitions § 227.32 Liquid, suspended particulate, and solid phases of a material. (a) For the... obtained above prior to centrifugation and filtration. The solid phase includes all material settling...

  14. Calorimetry study of microwave absorption of some solid materials.

    PubMed

    He, Chun Lin; Ma, Shao Jian; Su, Xiu Juan; Chen, Yan Qing; Liang, Yu Shi

    2013-01-01

    In practice, the dielectric constant of a material varies the applied frequency the material composition, particle size, purity, temperature, physical state (solid or liquid), and moisture content. All of these parameters might change during processing, therefore, it is difficult to predict how well a material will absorb microwave energy in a given process. When the temperature is measured by a digital thermometer, it could not accurately reflect the true temperature of the bulk materials, especially for mixed materials. Thus, in this paper we measured the microwave absorption characteristics of different materials by calorimetry. The microwave power levels, irradiation times, and masses of the materials were varied. It was difficult to predict the microwave energy absorption characteristics of reagent-grade inorganic compounds based on their color, metallic cation, or water stoichiometry. CuO, MnO2, Fe3O4, and MnSO4 x H2O (Taishan) strongly absorbed microwave energy. Most of the remaining inorganic compounds were poor absorbers, with silica hardly absorbing any microwave energy. Carbon-based materials had significantly different microwave absorption characteristics. Activated carbon and coke were especially sensitive to microwaves, but different types of coal were poor absorbers. The jamesonite concentrate absorbed microwave energy strongly, while the zinc concentrate was a poor absorber. PMID:24779227

  15. Advanced materials for high-temperature solid electrolyte applications

    SciTech Connect

    Bates, J.L.; Chick, L.A.; Weber, W.J.; Youngblood, G.E.

    1990-05-01

    Advanced materials for use as electrodes, interconnections, and electrolytes in high-temperature electrochemical applications are under investigation. The air sinterability of La{sub 1-x}Sr{sub x}CrO{sub 3} is highly dependent upon a synergistic relationship between the (La + Sr)/Cr ratio, cation volatility, and second phase formation and transformation. Electrical conductivity in the ZrO{sub 2}--Y{sub 2}O{sub 3}--CeO{sub 2} and ZrO{sub 2}--Y{sub 2}O{sub 3}--TiO{sub 2} systems is highly dependent on composition and atmosphere. The electrochemical processes that occur at the solid-solid-gas interfaces in La(Sr)MnO{sub 3}/ZrO{sub 2}(Y{sub 2}O{sub 3}) have been studied using an unbonded interface cell and impedance spectroscopy. 6 refs., 7 figs.

  16. Elements of informatics for combinatorial solid-state materials science

    NASA Astrophysics Data System (ADS)

    Meguro, S.; Ohnishi, T.; Lippmaa, M.; Koinuma, H.

    2005-01-01

    The main purpose of using combinatorial techniques for materials science studies is to achieve higher experimental throughput than what is possible when samples are synthesized and characterized one at a time. The instrumentation needed for performing high-throughput synthesis and characterization has seen rapid development in recent years. The software tools needed to connect all parts of the materials development process are still largely lacking. In this paper we discuss the requirements of a combinatorial informatics system for materials science experiments. Specifically, we focus on solid-state thin film synthesis. We also describe an implementation of such a system that is based on widely-available open-source software. The system offers features such as remote access via a Web browser, an electronic notebook-style Web interface, automatic upload of new measurement or processing results and rapid preview of experimental data.

  17. Outgassing of solid material into vacuum thermal insulation spaces

    NASA Technical Reports Server (NTRS)

    Wang, Pao-Lien

    1994-01-01

    Many cryogenic storage tanks use vacuum between inner and outer tank for thermal insulation. These cryogenic tanks also use a radiation shield barrier in the vacuum space to prevent radiation heat transfer. This shield is usually constructed by using multiple wraps of aluminized mylar and glass paper as inserts. For obtaining maximum thermal performance, a good vacuum level must be maintained with the insulation system. It has been found that over a period of time solid insulation materials will vaporize into the vacuum space and the vacuum will degrade. In order to determine the degradation of vacuum, the rate of outgassing of the insulation materials must be determined. Outgassing rate of several insulation materials obtained from literature search were listed in tabular form.

  18. Interstellar Isotopes: Prospects with ALMA

    NASA Technical Reports Server (NTRS)

    Charnley Steven B.

    2010-01-01

    Cold molecular clouds are natural environments for the enrichment of interstellar molecules in the heavy isotopes of H, C, N and O. Anomalously fractionated isotopic material is found in many primitive Solar System objects, such as meteorites and comets, that may trace interstellar matter that was incorporated into the Solar Nebula without undergoing significant processing. Models of the fractionation chemistry of H, C, N and O in dense molecular clouds, particularly in cores where substantial freeze-out of molecules on to dust has occurred, make several predictions that can be tested in the near future by molecular line observations. The range of fractionation ratios expected in different interstellar molecules will be discussed and the capabilities of ALMA for testing these models (e.g. in observing doubly-substituted isotopologues) will be outlined.

  19. Concurrent Ultrasonic Tomography and Acoustic Emission in Solid Materials

    NASA Astrophysics Data System (ADS)

    Chow, Thomas M.

    A series of experiments were performed to detect stress induced changes in the elastic properties of various solid materials. A technique was developed where these changes were monitored concurrently by two methods, ultrasonic tomography and acoustic emission monitoring. This thesis discusses some experiments in which acoustic emission (AE) and ultrasonic tomography were performed on various samples of solid materials including rocks, concrete, metals, and fibre reinforced composites. Three separate techniques were used to induce stress in these samples. Disk shaped samples were subject to stress via diametral loading using an indirect tensile test geometry. Cylindrical samples of rocks and concrete were subject to hydraulic fracture tests, and rectangular samples of fibre reinforced composite were subject to direct tensile loading. The majority of the samples were elastically anisotropic. Full waveform acoustic emission and tomographic data were collected while these samples were under load to give information concerning changes in the structure of the material as it was undergoing stress change and/or failure. Analysis of this data indicates that AE and tomographic techniques mutually compliment each other to give a view of the stress induced elastic changes in the tested samples.

  20. Processing of solid mixed waste containing radioactive and hazardous materials

    DOEpatents

    Gotovchikov, V.T.; Ivanov, A.V.; Filippov, E.A.

    1998-05-12

    Apparatus for the continuous heating and melting of a solid mixed waste bearing radioactive and hazardous materials to form separate metallic, slag and gaseous phases for producing compact forms of the waste material to facilitate disposal includes a copper split water-cooled (cold) crucible as a reaction vessel for receiving the waste material. The waste material is heated by means of the combination of a plasma torch directed into the open upper portion of the cold crucible and an electromagnetic flux produced by induction coils disposed about the crucible which is transparent to electromagnetic fields. A metallic phase of the waste material is formed in a lower portion of the crucible and is removed in the form of a compact ingot suitable for recycling and further processing. A glass-like, non-metallic slag phase containing radioactive elements is also formed in the crucible and flows out of the open upper portion of the crucible into a slag ingot mold for disposal. The decomposition products of the organic and toxic materials are incinerated and converted to environmentally safe gases in the melter. 6 figs.

  1. Processing of solid mixed waste containing radioactive and hazardous materials

    DOEpatents

    Gotovchikov, Vitaly T.; Ivanov, Alexander V.; Filippov, Eugene A.

    1998-05-12

    Apparatus for the continuous heating and melting of a solid mixed waste bearing radioactive and hazardous materials to form separate metallic, slag and gaseous phases for producing compact forms of the waste material to facilitate disposal includes a copper split water-cooled (cold) crucible as a reaction vessel for receiving the waste material. The waste material is heated by means of the combination of a plasma torch directed into the open upper portion of the cold crucible and an electromagnetic flux produced by induction coils disposed about the crucible which is transparent to electromagnetic fields. A metallic phase of the waste material is formed in a lower portion of the crucible and is removed in the form of a compact ingot suitable for recycling and further processing. A glass-like, non-metallic slag phase containing radioactive elements is also formed in the crucible and flows out of the open upper portion of the crucible into a slag ingot mold for disposal. The decomposition products of the organic and toxic materials are incinerated and converted to environmentally safe gases in the melter.

  2. Interstellar Dust Instrumentation

    NASA Astrophysics Data System (ADS)

    Sternovsky, Zoltan; Gruen, E.; Horanyi, M.; Drake, K.; Collette, A.; Kempf, S.; Srama, R.; Postberg, F.; Krueger, H.; Auer, S.

    2010-10-01

    Interstellar grains traversing the inner planetary system have been identified by the Ulysses dust detector. Space dust detectors on other missions confirmed this finding. Analysis of the Stardust collectors is under way to search for and analyze such exotic grains. Interstellar dust particles can be detected and analyzed in the near-Earth space environment. New instrumentation has been developed to determine the origin of dust particles and their elemental composition. A Dust Telescope is a combination of a Dust Trajectory Sensor (DTS, Rev. Sci. Instrum. 79, 084501, 2008) together with a high mass resolution mass analyzer for the chemical composition of dust particles in space. Dust particles' trajectories are determined by the measurement of induced electric signals when a charged grain flies through a position sensitive electrode system. A modern DTS can measure dust particles as small as 0.2 micron in radius and dust speeds up to 100 km/s. Large area chemical analyzers of 0.1 m2 sensitive area have been tested at a dust accelerator and it was demonstrated that they have sufficient mass resolution to resolve ions with atomic mass number up to >100 (Earth, Moon and Planets, DOI: 10.1007/s11038-005-9040-z, 2005; Rev. Sci. Instrum. 78, 014501, 2007). The advanced Dust Telescope is capable of identifying interstellar and interplanetary grains, and measuring their mass, velocity vector, charge, elemental and isotopic compositions. An Active Dust Collector combines a DTS with an aerogel or other dust collector materials, e.g. like the ones used on the Stardust mission. The combination of a DTS with a dust collector provides not only individual trajectories of the collected particles but also their impact time and position on the collector which proves essential in finding collected sub-micron sized grains on the collector.

  3. Interstellar and Circumstellar Fullerenes

    NASA Astrophysics Data System (ADS)

    Bernard-Salas, J.; Cami, J.; Jones, A.; Peeters, E.; Micelotta, E.; Otsuka, M.; Sloan, G. C.; Kemper, F.; Groenewegen, M.

    Fullerenes are a particularly stable class of carbon molecules in the shape of a hollow sphere or ellipsoid that might be formed in the outflows of carbon stars. Once injected into the interstellar medium (ISM), these stable species survive and are thus likely to be widespread in the Galaxy where they contribute to interstellar extinction, heating processes, and complex chemical reactions. In recent years, the fullerene species C60 (and to a lesser extent C70 ) have been detected in a wide variety of circumstellar and interstellar environments showing that when conditions are favourable, fullerenes are formed efficiently. Fullerenes are the first and only large aromatics firmly identified in space. The detection of fullerenes is thus crucial to provide clues as to the key chemical pathways leading to the formation of large complex organic molecules in space, and offers a great diagnostic tool to describe the environment in which they reside. Since fullerenes share many physical properties with PAHs, understanding how fullerenes form, evolve and respond to their physical environment will yield important insights into one of the largest reservoirs of organic material in space. In spite of all these detections, many questions remain about precisely which members of the fullerene family are present in space, how they form and evolve, and what their excitation mechanism is. We present here an overview of what we know from astronomical observations of fullerenes in these different environments, and discuss current thinking about the excitation process. We highlight the various formation mechanisms that have been proposed, discuss the physical conditions conducive to the formation and/or detection of fullerenes in carbon stars, and their possible connection to PAHs, HACs and other dust features.

  4. Stardust Interstellar Preliminary Examination (ISPE)

    NASA Technical Reports Server (NTRS)

    Westphal, A. J.; Allen, C.; Bajt, S.; Basset, R.; Bastien, R.; Bechtel, H.; Bleuet, P.; Borg, J.; Brenker F.; Bridges, J.

    2009-01-01

    In January 2006 the Stardust sample return capsule returned to Earth bearing the first solid samples from a primitive solar system body, C omet 81P/Wild2, and a collector dedicated to the capture and return o f contemporary interstellar dust. Both collectors were approximately 0.1m(exp 2) in area and were composed of aerogel tiles (85% of the co llecting area) and aluminum foils. The Stardust Interstellar Dust Col lector (SIDC) was exposed to the interstellar dust stream for a total exposure factor of 20 m(exp 2-) day during two periods before the co metary encounter. The Stardust Interstellar Preliminary Examination ( ISPE) is a three-year effort to characterize the collection using no ndestructive techniques. The ISPE consists of six interdependent proj ects: (1) Candidate identification through automated digital microsco py and a massively distributed, calibrated search (2) Candidate extr action and photodocumentation (3) Characterization of candidates thro ugh synchrotronbased FourierTranform Infrared Spectroscopy (FTIR), S canning XRay Fluoresence Microscopy (SXRF), and Scanning Transmission Xray Microscopy (STXM) (4) Search for and analysis of craters in f oils through FESEM scanning, Auger Spectroscopy and synchrotronbased Photoemission Electron Microscopy (PEEM) (5) Modeling of interstell ar dust transport in the solar system (6) Laboratory simulations of h ypervelocity dust impacts into the collecting media

  5. Mid-infrared solid-state lasers and laser materials

    NASA Technical Reports Server (NTRS)

    Barnes, Norman P.; Byvik, Charles E.

    1988-01-01

    An account is given of NASA-Langley's objectives for the development of advanced lasers and laser materials systems applicable to remote sensing in the mid-IR range. Prominent among current concerns are fiber-optic spectroscopy, eye-safe solid-state lasers for both Doppler sensing and mid-IR wavelength-generation laser pumping, and nonlinear optics generating tunable mid-IR radiation. Ho:YAG lasers are noted to exhibit intrinsic advantages for the desired applications, and are pumpable by GaAlAs laser diodes with a quantum efficiency approaching 2.

  6. Interstellar Dust: Contributed Papers

    NASA Technical Reports Server (NTRS)

    Tielens, Alexander G. G. M. (Editor); Allamandola, Louis J. (Editor)

    1989-01-01

    A coherent picture of the dust composition and its physical characteristics in the various phases of the interstellar medium was the central theme. Topics addressed included: dust in diffuse interstellar medium; overidentified infrared emission features; dust in dense clouds; dust in galaxies; optical properties of dust grains; interstellar dust models; interstellar dust and the solar system; dust formation and destruction; UV, visible, and IR observations of interstellar extinction; and quantum-statistical calculations of IR emission from highly vibrationally excited polycyclic aromatic hydrocarbon (PAH) molecules.

  7. Characterization of the physical properties for solid granular materials

    SciTech Connect

    Tucker, Jonathan R.; Shadle, Lawrence J.; Guenther, Chris; Benyahia, Sofiane; Mei, Joseph S.; Banta, Larry

    2012-01-01

    Accurate prediction of the behavior of a system is strongly governed by the components within that system. For multiphase systems incorporating solid powder-like particles, there are many different physical properties which need to be known to some level of accuracy for proper design, modeling, or data analysis. In the past, the material properties were determined initially as a secondary part of the study or design. In an attempt to provide results with the least level of uncertainty, a procedure was developed and implemented to provide consistent analysis of several different types of materials. The properties that were characterized included particle sizing and size distributions, shape analysis, density (particle, skeletal and bulk), minimum fluidization velocities, void fractions, particle porosity, and assignment within the Geldart Classification. In the methods used for this experiment, a novel form of the Ergun equation was used to determine the bulk void fractions and particle density. Materials of known properties were initially characterized to validate the accuracy and methodology, prior to testing materials of unknown properties. The procedures used yielded valid and accurate results, with a high level of repeatability. A database of these materials has been developed to assist in model validation efforts and future designs. It is also anticipated that further development of these procedures wil be expanded increasing the properties included in the database.

  8. Process for the superatmospheric gasification of solid carbonaceous materials

    SciTech Connect

    Kamody, J.F.

    1982-03-30

    A process is disclosed for gasifying solid carbonaceous material at elevated temperature and pressure to produce a gas consisting of carbon monoxide and hydrogen, which comprises forming a slurry at atmospheric pressure of the carbonaceous material with a liquid having a specific gravity of from 1.1 to 1.9, a boiling temperature of at least 700 F, a latent heat of vaporization less than about 200 btu per pound, a critical temperature which is less than the incipient coking temperature of the carbonaceous material, a stability at temperatures up to 6000 F, an essentially inert chemical reaction with the carbonaceous material at temperatures less than about 6000 F, an immiscibility with water or solubility in water at no more than 5%, and a dissolving ability for hydrogen sulfide at temperature of from -40 to 2500 F, and raising the formed slurry to a pressure of at least the gasification pressure and vaporizing said liquid and gasifying said carbonaceous material, either in the same or in separate steps. Examples of suitable slurrying liquids are: carbon tetrachloride, carbon disulfide, trichloroethylene, bromoethane, chlorobenzene, methane dichloride , chloroform, or mixtures thereof.

  9. Solid Freeform Fabrication of Composite-Material Objects

    NASA Technical Reports Server (NTRS)

    Wang, C. Jeff; Yang, Jason; Jang, Bor Z.

    2005-01-01

    Composite solid freeform fabrication (C-SFF) or composite layer manufacturing (CLM) is an automated process in which an advanced composite material (a matrix reinforced with continuous fibers) is formed into a freestanding, possibly complex, three-dimensional object. In CLM, there is no need for molds, dies, or other expensive tooling, and there is usually no need for machining to ensure that the object is formed to the desired net size and shape. CLM is a variant of extrusion-type rapid prototyping, in which a model or prototype of a solid object is built up by controlled extrusion of a polymeric or other material through an orifice that is translated to form patterned layers. The second layer is deposited on top of the first layer, the third layer is deposited on top of the second layer, and so forth, until the stack of layers reaches the desired final thickness and shape. The elements of CLM include (1) preparing a matrix resin in a form in which it will solidify subsequently, (2) mixing the fibers and matrix material to form a continuous pre-impregnated tow (also called "towpreg"), and (3) dispensing the pre-impregnated tow from a nozzle onto a base while moving the nozzle to form the dispensed material into a patterned layer of controlled thickness. When the material deposited into a given layer has solidified, the material for the next layer is deposited and patterned similarly, and so forth, until the desired overall object has been built up as a stack of patterned layers. Preferably, the deposition apparatus is controlled by a computer-aided design (CAD) system. The basic CLM concept can be adapted to the fabrication of parts from a variety of matrix materials. It is conceivable that a CLM apparatus could be placed at a remote location on Earth or in outer space where (1) spare parts are expected to be needed but (2) it would be uneconomical or impractical to store a full inventory of spare parts. A wide variety of towpregs could be prepared and stored on

  10. Resilient Sealing Materials for Solid Oxide Fuel Cells

    SciTech Connect

    Signo T. Reis; Richard K. Brow

    2006-09-30

    This report describes the development of ''invert'' glass compositions designed for hermetic seals in solid oxide fuel cells (SOFC). Upon sealing at temperatures compatible with other SOFC materials (generally {le}900 C), these glasses transform to glass-ceramics with desirable thermo-mechanical properties, including coefficients of thermal expansion (CTE) over 11 x 10{sup -6}/C. The long-term (>four months) stability of CTE under SOFC operational conditions (e.g., 800 C in wet forming gas or in air) has been evaluated, as have weight losses under similar conditions. The dependence of sealant properties on glass composition are described in this report, as are experiments to develop glass-matrix composites by adding second phases, including Ni and YSZ. This information provides design-guidance to produce desirable sealing materials.

  11. Treating of solid earthen material and a method for measuring moisture content and resistivity of solid earthen material

    DOEpatents

    Heath, William; Richardson, Richard; Goheen, Steven

    1994-01-01

    The present invention includes a method of treating solid earthen material having volatile, semi-volatile and non-volatile contaminants. Six electrodes are inserted into a region of earthen material to be treated in a substantially equilateral hexagonal arrangement. Six phases of voltages are applied to corresponding electrodes. The voltages are adjusted within a first range of voltages to create multiple current paths between pairs of the electrodes. The current paths are evenly distributed throughout the region defined by the electrodes and therefore uniformly heat the region. The region of earthen material is heated to a temperature sufficient to substantially remove volatile and semi-volatile contaminants. This temperature is less than a melting temperature of the earthen material. The voltages are then increased to a second range of voltages effective to create dry regions around the electrodes. The dry regions have a perimeter which define a boundary between the dry regions and the earthen material exterior to the dry regions. Corona discharge occurs at the boundaries of the dry regions. As voltages are increased further, the dry regions move radially outward from the electrodes through the entire region. The corona boundaries decompose the non-volatilized contaminants remaining in the region. The hexagonal arrangement of electrodes is also preferable for measuring resistivity and moisture content of the earthen material. The electric field created between the electrodes is readily discernable and therefore facilitates accurate measurements.

  12. Materials System for Intermediate Temperature Solid Oxide Fuel Cell

    SciTech Connect

    Uday B. Pal; Srikanth Gopalan

    2006-01-12

    The objective of this work was to obtain a stable materials system for intermediate temperature solid oxide fuel cell (SOFC) capable of operating between 600-800 C with a power density greater than 0.2 W/cm{sup 2}. The solid electrolyte chosen for this system was La{sub 0.9}Sr{sub 0.1}Ga{sub 0.8}Mg{sub 0.2}O{sub 3}, (LSGM). To select the right electrode materials from a group of possible candidate materials, AC complex impedance spectroscopy studies were conducted between 600-800 C on symmetrical cells that employed the LSGM electrolyte. Based on the results of the investigation, LSGM electrolyte supported SOFCs were fabricated with La{sub 0.6}Sr{sub 0.4}Co{sub 0.8}Fe{sub 0.2}O{sub 3}-La{sub 0.9}Sr{sub 0.1}Ga{sub 0.8}Mg{sub 0.2}O{sub 3} (LSCF-LSGM) composite cathode and Nickel-Ce{sub 0.6}La{sub 0.4}O{sub 3} (Ni-LDC) composite anode having a barrier layer of Ce{sub 0.6}La{sub 0.4}O{sub 3} (LDC) between the LSGM electrolyte and the Ni-LDC anode. Electrical performance and stability of these cells were determined and the electrode polarization behavior as a function of cell current was modeled between 600-800 C. The electrical performance of the anode-supported SOFC was simulated assuming an electrode polarization behavior identical to the LSGM-electrolyte-supported SOFC. The simulated electrical performance indicated that the selected material system would provide a stable cell capable of operating between 600-800 C with a power density between 0.2 to 1 W/cm{sup 2}.

  13. Solid state dye lasers: rhodamines in silica-zirconia materials.

    PubMed

    Schultheiss, Silke; Yariv, Eli; Reisfeld, Renata; Breuer, Hans Dieter

    2002-05-01

    Silica-zirconia materials as well as silica-zirconia ormosils prepared by the sol-gel technique were doped with the laser dyes Rhodamine B and Rhodamine 6G and used as solid state dye lasers. The photostability and efficiency of the solid state laser samples were measured in a transverse pumping configuration by either a nitrogen laser or the second harmonic of a Nd-YAG laser. Under the excitation of a nitrogen laser the photostability of Rhodamine B in silica-zirconia materials was low and decreased with a growing amount of zirconia. The photophysical properties of the incorporated dyes were studied by time-resolved fluorescence spectroscopy. The fluorescence lifetimes of both dyes increased when the matrix was modified by organic compounds Furthermore, the threshold energy of Rhodamine 6G in two ormosils containing 3 and 50% methylsilica was measured. The results revealed that the threshold energy was lower for the matrix with a higher amount of ormosil while the slope efficiency was higher in the matrix containing 30% ormosil. PMID:12653469

  14. Chaotic Exchange of Solid Material Between Planetary Systems: Implications for Lithopanspermia

    PubMed Central

    Belbruno, Edward; Malhotra, Renu; Savransky, Dmitry

    2012-01-01

    Abstract We examined a low-energy mechanism for the transfer of meteoroids between two planetary systems embedded in a star cluster using quasi-parabolic orbits of minimal energy. Using Monte Carlo simulations, we found that the exchange of meteoroids could have been significantly more efficient than previously estimated. Our study is relevant to astrobiology, as it addresses whether life on Earth could have been transferred to other planetary systems in the Solar System's birth cluster and whether life on Earth could have been transferred from beyond the Solar System. In the Solar System, the timescale over which solid material was delivered to the region from where it could be transferred via this mechanism likely extended to several hundred million years (as indicated by the 3.8–4.0 Ga epoch of the Late Heavy Bombardment). This timescale could have overlapped with the lifetime of the Solar birth cluster (∼100–500 Myr). Therefore, we conclude that lithopanspermia is an open possibility if life had an early start. Adopting parameters from the minimum mass solar nebula, considering a range of planetesimal size distributions derived from observations of asteroids and Kuiper Belt objects and theoretical coagulation models, and taking into account Oort Cloud formation models, we discerned that the expected number of bodies with mass>10 kg that could have been transferred between the Sun and its nearest cluster neighbor could be of the order of 1014 to 3·1016, with transfer timescales of tens of millions of years. We estimate that of the order of 3·108·l (km) could potentially be life-bearing, where l is the depth of Earth's crust in kilometers that was ejected as the result of the early bombardment. Key Words: Extrasolar planets—Interplanetary dust—Interstellar meteorites—Lithopanspermia. Astrobiology 12, 754–774. PMID:22897115

  15. Solid State Ionic Materials - Proceedings of the 4th Asian Conference on Solid State Ionics

    NASA Astrophysics Data System (ADS)

    Chowdari, B. V. R.; Yahaya, M.; Talib, I. A.; Salleh, M. M.

    1994-07-01

    The Table of Contents for the full book PDF is as follows: * Preface * I. INVITED PAPERS * Diffusion of Cations and Anions in Solid Electrolytes * Silver Ion Conductors in the Crystalline State * NMR Studies of Superionic Conductors * Hall Effect and Thermoelectric Power in High Tc Hg-Ba-Ca-Cu-O Ceramics * Solid Electrolyte Materials Prepared by Sol-Gel Chemistry * Preparation of Proton-Conducting Gel Films and their Application to Electrochromic Devices * Thin Film Fuel Cells * Zirconia based Solid Oxide Ion Conductors in Solid Oxide Fuel Cells * The Influence of Anion Substitution on Some Phosphate-based Ion Conducting Glasses * Lithium Intercalation in Carbon Electrodes and its Relevance in Rocking Chair Batteries * Chemical Sensors using Proton Conducting Ceramics * NMR/NQR Studies of Y-Ba-Cu-O Superconductors * Silver Molybdate Glasses and Battery Systems * New Highly Conducting Polymer Ionics and their Application in Electrochemical Devices * Study of Li Electrokinetics on Oligomeric Electrolytes using Microelectrodes * Calculation of Conductivity for Mixed-Phase Electrolytes PEO-MX-Immiscible Additive by Means of Effective Medium Theory * II. CONTRIBUTED PAPERS * Phase Relationship and Electrical Conductivity of Sr-V-O System with Vanadium Suboxide * Amorphous Li+ Ionic Conductors in Li2SO4-Li2O-P2O5 System * Fast Ion Transport in KCl-Al2O3 Composites * The Effect of the Second Phase Precipitation on the Ionic Conductivity of Zr0.85Mg0.15O1.85 * Conductivity Measurements and Phase Relationships in CaCl2-CaHCl Solid Electrolyte * Relationships Between Crystal Structure and Sodium Ion Conductivity in Na7Fe4(AsO4)6 and Na3Al2(AsO4)3 * Electrical Conductivity and Solubility Limit of Ti4+ Ion in Na1+x TiyZr2-ySixP3-xO12 System * Study on Sodium Fast Ion Conductors of Na1+3xAlxTi2-xSi2xP3-2xO12 System * Influences of Zirconia on the Properties of β''-Alumina Ceramics * Decay of Luminescence from Cr3+ Ions in β-Alumina * Lithium Ion Conductivity in the Li4XO4-Li2

  16. Method of altering the effective bulk density of solid material and the resulting product

    DOEpatents

    Kool, Lawrence B.; Nolen, Robert L.; Solomon, David E.

    1983-01-01

    A method of adjustably tailoring the effective bulk density of a solid material in which a mixture comprising the solid material, a film-forming polymer and a volatile solvent are sprayed into a drying chamber such that the solvent evaporates and the polymer dries into hollow shells having the solid material captured within the shell walls. Shell density may be varied as a function of solid/polymer concentration, droplet size and drying temperature.

  17. Effects of mechanical interaction between the interstellar medium and comets

    SciTech Connect

    Stern, S.A.

    1986-11-01

    The present treatment of the mechanical interaction of Oort Cloud comets with the interstellar medium gives attention to the importance of the accretion of interstellar material onto comets, as well as to the erosion of cometary surfaces by impacting interstellar grains and the consequences of these interactions. Scaling analyses indicate that collisions with interstellar grains can furnish a potent evolutionary mechanism in the modification of cometary surfaces; this factor may also contribute a substantial number of low mass particulated to the interstellar medium. 48 references.

  18. Modelling interstellar organics: relevance for the identification of unidentified interstellar features

    NASA Astrophysics Data System (ADS)

    Malloci, Giuliano

    2003-02-01

    This thesis is part of the research activity of the Astrochemistry Group of the Cagliari Astronomical Observatory and the Physics Department at the University of Cagliari. The subjects of this work are two specific astrophysical problems concerning the Interstellar Medium (ISM) analysis: 1) the identification of Diffuse Interstellar Bands (DIBs) - Unidentified Infrared Bands (UIBs); 2) the identification of the Extended Red Emission (ERE). A new theoretical approach to the spectroscopic identification of these specific Unidentified Interstellar Features is presented.Concerning the DIBs-UIBs, this work is an extension of a computational Monte-Carlo model developed in the past few years by our group (Mulas G. A&A 1998,338,243) with the aim to integrate quantum-chemical ab initio tecnhiques in it and thus produce a self-contained molecular simulator. Concerning ERE, a general recipe is developed in order to extrapolate the expected photoluminescence of small particles starting from available laboratory results obtained on bulk samples. All the numerical results were obtained for interstellar carbonaceous compounds, hence the title ``Modelling interstellar organics'' given to the thesis. In particular, a specific molecule belonging to the class of polycyclic aromatic hydrocarbons (PAHs) is chosen as a test case to discuss the PAHs-DIBs-UIBs proposal, while the optical properties of laboratory samples of hydrogenated amorphous carbon (HAC) are used to obtain numerical results to be compared with luminescence phenomena such as ERE originating from some solid component of the ISM. The introductive chapter is intended to introduce the unfamiliar reader to the specific topic under study, and a short overview of the scientific scenario involved is given. Then, Part I and II discuss separately the two models above and represent the body of the work; each chapter follows a standard article format: introduction, theoretical method, numerical results, discussion and

  19. MATRIICES - Mass Analytical Tool for Reactions in Interstellar ICES

    NASA Astrophysics Data System (ADS)

    Isokoski, K.; Bossa, J. B.; Linnartz, H.

    2011-05-01

    The formation of complex organic molecules (COMs) observed in the inter- and circumstellar medium (ISCM) is driven by a complex chemical network yet to be fully characterized. Interstellar dust grains and the surrounding ice mantles, subject to atom bombardment, UV irradiation, and thermal processing, are believed to provide catalytic sites for such chemistry. However, the solid state chemical processes and the level of complexity reachable under astronomical conditions remain poorly understood. The conventional laboratory techniques used to characterize the solid state reaction pathways - RAIRS (Reflection Absorption IR Spectroscopy) and TPD (Temperature-Programmed Desorption) - are suitable for the analysis of reactions in ices made of relatively small molecules. For more complex ices comprising a series of different components as relevant to the interstellar medium, spectral overlapping prohibits unambiguous identification of reaction schemes, and these techniques start to fail. Therefore, we have constructed a new and innovative experimental set up for the study of complex interstellar ices featuring a highly sensitive and unambiguous detection method. MATRIICES (Mass Analytical Tool for Reactions in Interstellar ICES) combines Laser Ablation technique with a molecular beam experiment and Time-Of-Flight Mass Spectrometry (LA-TOF-MS) to sample and analyze the ice analogues in situ, at native temperatures, under clean ultra-high vacuum conditions. The method allows direct sampling and analysis of the ice constituents in real time, by using a pulsed UV ablation laser (355-nm Nd:YAG) to vaporize the products in a MALDI-TOF like detection scheme. The ablated material is caught in a synchronously pulsed molecular beam of inert carrier gas (He) from a supersonic valve, and analysed in a Reflectron Time-of-Flight Mass Spectrometer. The detection limit of the method is expected to exceed that of the regular surface techniques substantially. The ultimate goal is to fully

  20. Observations of Carbon Isotopic Fractionation in Interstellar Formaldehyde

    NASA Technical Reports Server (NTRS)

    Wirstrom, E. S.; Charnley, S. B.; Geppert, W. D.; Persson, C. M.

    2012-01-01

    Primitive Solar System materials (e.g. chondrites. IDPs, the Stardust sample) show large variations in isotopic composition of the major volatiles (H, C, N, and O ) even within samples, witnessing to various degrees of processing in the protosolar nebula. For ex ample. the very pronounced D enhancements observed in IDPs [I] . are only generated in the cold. dense component of the interstellar medium (ISM), or protoplanetary disks, through ion-molecule reactions in the presence of interstellar dust. If this isotopic anomaly has an interstellar origin, this leaves open the possibility for preservation of other isotopic signatures throughout the form ation of the Solar System. The most common form of carbon in the ISM is CO molecules, and there are two potential sources of C-13 fractionation in this reservoir: low temperature chemistry and selective photodissociation. While gas-phase chemistry in cold interstellar clouds preferentially incorporates C-13 into CO [2], the effect of self-shielding in the presence of UV radiation instead leads to a relative enhancement of the more abundant isotopologue, 12CO. Solar System organic material exhibit rather small fluctuations in delta C-13 as compared to delta N-15 and delta D [3][1], the reason for which is still unclear. However, the fact that both C-13 depleted and enhanced material exists could indicate an interstellar origin where the two fractionation processes have both played a part. Formaldehyde (H2CO) is observed in the gas-phase in a wide range of interstellar environments, as well as in cometary comae. It is proposed as an important reactant in the formation of more complex organic molecules in the heated environments around young stars, and formaldehyde polymers have been suggested as the common origin of chondritic insoluable organic matter (IOM) and cometary refractory organic solids [4]. The relatively high gas-phase abundance of H2CO observed in molecular clouds (10(exp- 9) - 10(exp- 8) relative to H2) makes

  1. Solid state nuclear magnetic resonance investigations of advanced energy materials

    NASA Astrophysics Data System (ADS)

    Bennett, George D.

    In order to better understand the physical electrochemical changes that take place in lithium ion batteries and asymmetric hybrid supercapacitors solid state nuclear magnetic resonance (NMR) spectroscopy has been useful to probe and identify changes on the atomic and molecular level. NMR is used to characterize the local environment and investigate the dynamical properties of materials used in electrochemical storage devices (ESD). NMR investigations was used to better understand the chemical composition of the solid electrolyte interphase which form on the negative and positive electrodes of lithium batteries as well as identify the breakdown products that occur in the operation of the asymmetric hybrid supercapacitors. The use of nano-structured particles in the development of new materials causes changes in the electrical, structural and other material properties. NMR was used to investigate the affects of fluorinated and non fluorinated single wall nanotubes (SWNT). In this thesis three experiments were performed using solid state NMR samples to better characterize them. The electrochemical reactions of a lithium ion battery determine its operational profile. Numerous means have been employed to enhance battery cycle life and operating temperature range. One primary means is the choice and makeup of the electrolyte. This study focuses on the characteristics of the solid electrolyte interphase (SEI) that is formed on the electrodes surface during the charge discharge cycle. The electrolyte in this study was altered with several additives in order to determine the influence of the additives on SEI formation as well as the intercalation and de-intercalation of lithium ions in the electrodes. 7Li NMR studies where used to characterize the SEI and its composition. Solid state NMR studies of the carbon enriched acetonitrile electrolyte in a nonaqueous asymmetric hybrid supercapacitor were performed. Magic angle spinning (MAS) coupled with cross polarization NMR

  2. Solid State Ionics Advanced Materials for Emerging Technologies

    NASA Astrophysics Data System (ADS)

    Chowdari, B. V. R.; Careem, M. A.; Dissanayake, M. A. K. L.; Rajapakse, R. M. G.; Seneviratne, V. A.

    2006-06-01

    Keynote lecture. Challenges and opportunities of solid state ionic devices / W. Weppner -- pt. I. Ionically conducting inorganic solids. Invited papers. Multinuclear NMR studies of mass transport of phosphoric acid in water / J. R. P. Jayakody ... [et al.]. Crystalline glassy and polymeric electrolytes: similarities and differences in ionic transport mechanisms / J.-L. Souquet. 30 years of NMR/NQR experiments in solid electrolytes / D. Brinkmann. Analysis of conductivity and NMR measurements in Li[symbol]La[symbol]TiO[symbol] fast Li[symbol] ionic conductor: evidence for correlated Li[symbol] motion / O. Bohnké ... [et al.]. Transport pathways for ions in disordered solids from bond valence mismatch landscapes / S. Adams. Proton conductivity in condensed phases of water: implications on linear and ball lightning / K. Tennakone -- Contributed papers. Proton transport in nanocrystalline bioceramic materials: an investigative study of synthetic bone with that of natural bone / H. Jena, B. Rambabu. Synthesis and properties of the nanostructured fast ionic conductor Li[symbol]La[symbol]TiO[symbol] / Q. N. Pham ... [et al.]. Hydrogen production: ceramic materials for high temperature water electrolysis / A. Hammou. Influence of the sintering temperature on pH sensor ability of Li[symbol]La[symbol]TiO[symbol]. Relationship between potentiometric and impedance spectroscopy measurements / Q. N. Pham ... [et al.]. Microstructure chracterization and ionic conductivity of nano-sized CeO[symbol]-Sm[symbol]O[symbol] system (x=0.05 - 0.2) prepared by combustion route / K. Singh, S. A. Acharya, S. S. Bhoga. Red soil in Northern Sri Lanka is a natural magnetic ceramic / K. Ahilan ... [et al.]. Neutron scattering of LiNiO[symbol] / K. Basar ... [et al.]. Preparation and properties of LiFePO[symbol] nanorods / L. Q. Mai ... [et al.]. Structural and electrochemical properties of monoclinic and othorhombic MoO[symbol] phases / O. M. Hussain ... [et al.]. Preparation of Zircon (Zr

  3. New Cathode Materials for Intermediate Temperature Solid Oxide Fuel Cells

    SciTech Connect

    Allan J. Jacobson

    2005-11-17

    Operation of SOFCs at intermediate temperatures (500-800 C) requires new combinations of electrolyte and electrode materials that will provide both rapid ion transport across the electrolyte and electrode--electrolyte interfaces and efficient electrocatalysis of the oxygen reduction and fuel oxidation reactions. This project concentrates on materials and issues associated with cathode performance that are known to become limiting factors as the operating temperature is reduced. The specific objectives of the proposed research are to develop cathode materials that meet the electrode performance targets of 1.0 W/cm{sup 2} at 0.7 V in combination with YSZ at 700 C and with GDC, LSGM or bismuth oxide based electrolytes at 600 C. The performance targets imply an area specific resistance of {approx}0.5 {Omega}cm{sup 2} for the total cell. The research strategy is to investigate both established classes of materials and new candidates as cathodes, to determine fundamental performance parameters such as bulk diffusion, surface reactivity and interfacial transfer, and to couple these parameters to performance in single cell tests. In this report, the oxygen exchange kinetics of a P2 composition are described in detail. The oxygen exchange kinetics of the oxygen deficient double perovskite LnBaCo{sub 2}O{sub 5.5+{delta}} (Ln=Pr and Nd) have been determined by electrical conductivity relaxation. The high electronic conductivity and rapid diffusion and surface exchange kinetics of PBCO suggest its application as cathode material in intermediate temperature solid oxide fuel cells.

  4. Materials System for Intermediate Temperature Solid Oxide Fuel Cell

    SciTech Connect

    Uday B. Pal; Srikanth Gopalan

    2005-01-24

    AC complex impedance spectroscopy studies were conducted between 600-800 C on symmetrical cells that employed strontium-and-magnesium-doped lanthanum gallate electrolyte, La{sub 0.9}Sr{sub 0.1}Ga{sub 0.8}Mg{sub 0.2}O{sub 3} (LSGM). The objective of the study was to identify the materials system for fabrication and evaluation of intermediate temperature (600-800 C) solid oxide fuel cells (SOFCs). The slurry-coated electrode materials had fine porosity to enhance catalytic activity. Cathode materials investigated include La{sub 1-x}Sr{sub x}MnO{sub 3} (LSM), LSCF (La{sub 1-x}Sr{sub x}Co{sub y}Fe{sub 1-y}O{sub 3}), a two-phase particulate composite consisting of LSM-doped-lanthanum gallate (LSGM), and LSCF-LSGM. The anode materials were Ni-Ce{sub 0.85}Gd{sub 0.15}O{sub 2} (Ni-GDC) and Ni-Ce{sub 0.6}La{sub 0.4}O{sub 2} (Ni-LDC) composites. Experiments conducted with the anode materials investigated the effect of having a barrier layer of GDC or LDC in between the LSGM electrolyte and the Ni-composite anode to prevent adverse reaction of the Ni with lanthanum in LSGM. For proper interpretation of the beneficial effects of the barrier layer, similar measurements were performed without the barrier layer. The ohmic and the polarization resistances of the system were obtained over time as a function of temperature (600-800 C), firing temperature, thickness, and the composition of the electrodes. The study revealed important details pertaining to the ohmic and the polarization resistances of the electrode as they relate to stability and the charge-transfer reactions that occur in such electrode structures.

  5. Novel Materials and Devices for Solid-State Neutron Detection

    SciTech Connect

    Manginell, Ronald P.; Pfeifer, Kent B.

    2015-11-01

    There is a need in many fields, such as nuclear medicine, non-proliferation, energy exploration, national security, homeland security, nuclear energy, etc, for miniature, thermal neutron detectors. Until recently, thermal neutron detection has required physically large devices to provide sufficient neutron interaction and transduction signal. Miniaturization would allow broader use in the fields just mentioned and open up other applications potentially. Recent research shows promise in creating smaller neutron detectors through the combination of high-neutron-cross-section converter materials and solid-state devices. Yet, till recently it is difficult to measure low neutron fluxes by solidstate means given the need for optimized converter materials (purity, chemical composition and thickness) and a lack of designs capable of efficient transduction of the neutron conversion products (x-rays, electrons, gamma rays). Gadolinium-based semiconductor heterojunctions have detected electrons produced by Gd-neutron reactions but only at high neutron fluxes. One of the main limitations to this type of approach is the use of thin converter layers and the inability to utilize all the conversion products. In this LDRD we have optimized the converter material thickness and chemical composition to improve capture of conversion electrons and have detected thermal neutrons with high fidelity at low flux. We are also examining different semiconductor materials and converter materials to attempt to capture a greater percentage of the conversion electrons, both low and higher energy varieties. We have studied detector size and bias scaling, and cross-sensitivity to xrays and shown that we can detect low fluxes of thermal neutrons in less than 30 minutes with high selectivity by our approach. We are currently studying improvements in performance with direct placement of the Gd converter on the detector. The advancement of sensitive, miniature neutron detectors will have benefits in

  6. 40 CFR 262.215 - Unwanted material that is not solid or hazardous waste.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 26 2011-07-01 2011-07-01 false Unwanted material that is not solid or... (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS APPLICABLE TO GENERATORS OF HAZARDOUS WASTE Alternative... Eligible Academic Entities § 262.215 Unwanted material that is not solid or hazardous waste. (a) If...

  7. 40 CFR 262.215 - Unwanted material that is not solid or hazardous waste.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 27 2012-07-01 2012-07-01 false Unwanted material that is not solid or... (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS APPLICABLE TO GENERATORS OF HAZARDOUS WASTE Alternative... Eligible Academic Entities § 262.215 Unwanted material that is not solid or hazardous waste. (a) If...

  8. 40 CFR 262.215 - Unwanted material that is not solid or hazardous waste.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 27 2013-07-01 2013-07-01 false Unwanted material that is not solid or... (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS APPLICABLE TO GENERATORS OF HAZARDOUS WASTE Alternative... Eligible Academic Entities § 262.215 Unwanted material that is not solid or hazardous waste. (a) If...

  9. 40 CFR 262.215 - Unwanted material that is not solid or hazardous waste.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 26 2014-07-01 2014-07-01 false Unwanted material that is not solid or... (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS APPLICABLE TO GENERATORS OF HAZARDOUS WASTE Alternative... Eligible Academic Entities § 262.215 Unwanted material that is not solid or hazardous waste. (a) If...

  10. 40 CFR 262.215 - Unwanted material that is not solid or hazardous waste.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS APPLICABLE TO GENERATORS OF HAZARDOUS WASTE Alternative... Eligible Academic Entities § 262.215 Unwanted material that is not solid or hazardous waste. (a) If an unwanted material does not meet the definition of solid waste in § 261.2, it is no longer subject to...

  11. Speckles in interstellar radio-wave scattering

    NASA Technical Reports Server (NTRS)

    Desai, K. M.; Gwinn, C. R.; Reynolds, J.; King, E. A.; Jauncey, D.; Nicholson, G.; Flanagan, C.; Preston, R. A.; Jones, D. L.

    1991-01-01

    Observations of speckles in the scattering disk of the Vela pulsar are presented and speckle techniques for studying and circumventing scattering of radio waves by the turbulent interstellar plasma are discussed. The speckle pattern contains, in a hologrammatic fashion, complete information on the structure of the radio source as well as the distribution of the scattering material. Speckle observations of interstellar scattering of radio waves are difficult because of their characteristically short timescales and narrow bandwidths. Here, first observations are presented, taken at 13 cm wavelength with elements of the SHEVE VLBI network, of speckles in interstellar scattering.

  12. Modeling of Material Removal by Solid State Heat Capacity Lasers

    SciTech Connect

    Boley, C D; Rubenchik, A M

    2002-04-17

    Pulsed lasers offer the capability of rapid material removal. Here we present simulations of steel coupon tests by two solid state heat capacity lasers built at LLNL. Operating at 1.05 pm, these deliver pulse energies of about 80 J at 10 Hz, and about 500 J at 20 Hz. Each is flashlamp-pumped. The first laser was tested at LLNL, while the second laser has been delivered to HELSTF, White Sands Missile Range. Liquid ejection appears to be an important removal mechanism. We have modeled these experiments via a time-dependent code called THALES, which describes heat transport, melting, vaporization, and the hydrodynamics of liquid, vapor, and air. It was previously used, in a less advanced form, to model drilling by copper vapor lasers [1] . It was also used to model vaporization in beam dumps for a high-power laser [2]. The basic model is in 1D, while the liquid hydrodynamics is handled in 2D.

  13. Interstellar and Cometary Dust

    NASA Technical Reports Server (NTRS)

    Mathis, John S.

    1997-01-01

    'Interstellar dust' forms a continuum of materials with differing properties which I divide into three classes on the basis of observations: (a) diffuse dust, in the low-density interstellar medium; (b) outer-cloud dust, observed in stars close enough to the outer edges of molecular clouds to be observed in the optical and ultraviolet regions of the spectrum, and (c) inner-cloud dust, deep within the cores of molecular clouds, and observed only in the infrared by means of absorption bands of C-H, C=O, 0-H, C(triple bond)N, etc. There is a surprising regularity of the extinction laws between diffuse- and outer-cloud dust. The entire mean extinction law from infrared through the observable ultraviolet spectrum can be characterized by a single parameter. There are real deviations from this mean law, larger than observational uncertainties, but they are much smaller than differences of the mean laws in diffuse- and outer-cloud dust. This fact shows that there are processes which operate over the entire distribution of grain sizes, and which change size distributions extremely efficiently. There is no evidence for mantles on grains in local diffuse and outer-cloud dust. The only published spectra of the star VI Cyg 12, the best candidate for showing mantles, does not show the 3.4 micro-m band which appreciable mantles would produce. Grains are larger in outer-cloud dust than diffuse dust because of coagulation, not accretion of extensive mantles. Core-mantle grains favored by J. M. Greenberg and collaborators, and composite grains of Mathis and Whiffen (1989), are discussed more extensively (naturally, I prefer the latter). The composite grains are fluffy and consist of silicates, amorphous carbon, and some graphite in the same grain. Grains deep within molecular clouds but before any processing within the solar system are presumably formed from the accretion of icy mantles on and within the coagulated outer-cloud grains. They should contain a mineral

  14. Boundary Conditions for the Paleoenvironment: Chemical and Physical Processes in Dense Interstellar Clouds: Summary of Research

    NASA Technical Reports Server (NTRS)

    Irvine, William M.

    1999-01-01

    The basic theme of this program was the study of molecular complexity and evolution for the biogenic elements and compounds in interstellar clouds and in primitive solar system objects. Research included the detection and study of new interstellar and cometary molecules and investigation of reaction pathways for astrochemistry from a comparison of theory and observed molecular abundances. The latter includes studies of cold, dark clouds in which ion-molecule chemistry should predominate, searches for the effects of interchange of material between the gas and solid phases in interstellar clouds, unbiased spectral surveys of particular sources, and systematic investigation of the interlinked chemistry and physics of dense interstellar clouds. In addition, the study of comets has allowed a comparison between the chemistry of such minimally thermally processed objects and that of interstellar clouds, shedding light on the evolution of the biogenic elements during the process of solar system formation. One PhD dissertation on this research was completed by a graduate student at the University of Massachusetts. An additional 4 graduate students at the University of Massachusetts and 5 graduate students from other institutions participated in research supported by this grant, with 6 of these thus far receiving PhD degrees from the University of Massachusetts or their home institutions. Four postdoctoral research associates at the University of Massachusetts also participated in research supported by this grant, receiving valuable training.

  15. Ultra-thin solid oxide fuel cells: Materials and devices

    NASA Astrophysics Data System (ADS)

    Kerman, Kian

    alloys and nanoscale compositionally graded membranes that are thermomechanically robust and provide added interfacial functionality. The work in this thesis advances experimental state-of-the-art with respect to solid oxide fuel cell operation temperature, provides fundamental boundaries expected for ultrathin electrolytes, develops the ability to integrate highly dissimilar material (such as oxide-polymer) heterostructures, and introduces nanoscale compositionally graded electrolyte membranes that can lead to monolithic materials having multiple functionalities.

  16. The violent interstellar medium

    NASA Technical Reports Server (NTRS)

    Mccray, R.; Snow, T. P., Jr.

    1979-01-01

    Observational evidence for high-velocity and high-temperature interstellar gas is reviewed. The physical processes that characterize this gas are described, including the ionization and emissivity of coronal gas, the behavior and appearance of high-velocity shocks, and interfaces between coronal gas and cooler interstellar gas. Hydrodynamical models for the action of supernova explosions and stellar winds on the interstellar medium are examined, and recent attempts to synthesize all the processes considered into a global model for the interstellar medium are discussed.

  17. Observations of interstellar zinc

    NASA Technical Reports Server (NTRS)

    Jura, M.; York, D.

    1981-01-01

    The International Ultraviolet Explorer observations of interstellar zinc toward 10 stars are examined. It is found that zinc is at most only slightly depleted in the interstellar medium; its abundance may serve as a tracer of the true metallicity in the gas. The local interstellar medium has abundances that apparently are homogeneous to within a factor of two, when integrated over paths of about 500 pc, and this result is important for understanding the history of nucleosynthesis in the solar neighborhood. The intrinsic errors in detecting weak interstellar lines are analyzed and suggestions are made as to how this error limit may be lowered to 5 mA per target observation.

  18. Solid State Ionic Materials - Proceedings of the 4th Asian Conference on Solid State Ionics

    NASA Astrophysics Data System (ADS)

    Chowdari, B. V. R.; Yahaya, M.; Talib, I. A.; Salleh, M. M.

    1994-07-01

    The Table of Contents for the full book PDF is as follows: * Preface * I. INVITED PAPERS * Diffusion of Cations and Anions in Solid Electrolytes * Silver Ion Conductors in the Crystalline State * NMR Studies of Superionic Conductors * Hall Effect and Thermoelectric Power in High Tc Hg-Ba-Ca-Cu-O Ceramics * Solid Electrolyte Materials Prepared by Sol-Gel Chemistry * Preparation of Proton-Conducting Gel Films and their Application to Electrochromic Devices * Thin Film Fuel Cells * Zirconia based Solid Oxide Ion Conductors in Solid Oxide Fuel Cells * The Influence of Anion Substitution on Some Phosphate-based Ion Conducting Glasses * Lithium Intercalation in Carbon Electrodes and its Relevance in Rocking Chair Batteries * Chemical Sensors using Proton Conducting Ceramics * NMR/NQR Studies of Y-Ba-Cu-O Superconductors * Silver Molybdate Glasses and Battery Systems * New Highly Conducting Polymer Ionics and their Application in Electrochemical Devices * Study of Li Electrokinetics on Oligomeric Electrolytes using Microelectrodes * Calculation of Conductivity for Mixed-Phase Electrolytes PEO-MX-Immiscible Additive by Means of Effective Medium Theory * II. CONTRIBUTED PAPERS * Phase Relationship and Electrical Conductivity of Sr-V-O System with Vanadium Suboxide * Amorphous Li+ Ionic Conductors in Li2SO4-Li2O-P2O5 System * Fast Ion Transport in KCl-Al2O3 Composites * The Effect of the Second Phase Precipitation on the Ionic Conductivity of Zr0.85Mg0.15O1.85 * Conductivity Measurements and Phase Relationships in CaCl2-CaHCl Solid Electrolyte * Relationships Between Crystal Structure and Sodium Ion Conductivity in Na7Fe4(AsO4)6 and Na3Al2(AsO4)3 * Electrical Conductivity and Solubility Limit of Ti4+ Ion in Na1+x TiyZr2-ySixP3-xO12 System * Study on Sodium Fast Ion Conductors of Na1+3xAlxTi2-xSi2xP3-2xO12 System * Influences of Zirconia on the Properties of β''-Alumina Ceramics * Decay of Luminescence from Cr3+ Ions in β-Alumina * Lithium Ion Conductivity in the Li4XO4-Li2

  19. Analysis of "Midnight" Tracks in the Stardust Interstellar Dust Collector: Possible Discovery of a Contemporary Interstellar Dust Grain

    NASA Technical Reports Server (NTRS)

    Westphal, A. J.; Allen, C.; Bajit, S.; Bastien, R.; Bechtel, H.; Bleuet, P.; Borg, J.; Brenker, F.; Bridges, J.; Brownlee, D. E.; Burchell, M.; Burghammer, M.; Butterworth, A. L.; Cloetens, P.; Cody, G.; Ferrior, T.; Floss, C.; Flynn, G. J.; Frank, D.; Gainsforth, Z.; Grun, E.; Hoppe, P.; Hudson, B.; Kearsley, A.; Lai, B.

    2010-01-01

    In January 2006, the Stardust sample return capsule returned to Earth bearing the first solid samples from a primitive solar system body, Comet 81P/Wild2, and a collector dedicated to the capture and return of contemporary interstellar dust. Both collectors were approximately 0.1m(exp 2) in area and were composed of aerogel tiles (85% of the collecting area) and aluminum foils. The Stardust Interstellar Dust Collector (SIDC) was exposed to the interstellar dust stream for a total exposure factor of 20 m(exp 2) day. The Stardust Interstellar Preliminary Examination (ISPE) is a three-year effort to characterize the collection using nondestructive techniques.

  20. Characterization of Thermal Transport in One-dimensional Solid Materials

    PubMed Central

    Liu, Guoqing; Lin, Huan; Tang, Xiaoduan; Bergler, Kevin; Wang, Xinwei

    2014-01-01

    The TET (transient electro-thermal) technique is an effective approach developed to measure the thermal diffusivity of solid materials, including conductive, semi-conductive or nonconductive one-dimensional structures. This technique broadens the measurement scope of materials (conductive and nonconductive) and improves the accuracy and stability. If the sample (especially biomaterials, such as human head hair, spider silk, and silkworm silk) is not conductive, it will be coated with a gold layer to make it electronically conductive. The effect of parasitic conduction and radiative losses on the thermal diffusivity can be subtracted during data processing. Then the real thermal conductivity can be calculated with the given value of volume-based specific heat (ρcp), which can be obtained from calibration, noncontact photo-thermal technique or measuring the density and specific heat separately. In this work, human head hair samples are used to show how to set up the experiment, process the experimental data, and subtract the effect of parasitic conduction and radiative losses. PMID:24514072

  1. The nature of interstellar/pre-cometary dust

    NASA Technical Reports Server (NTRS)

    Allamandola, Louis

    1990-01-01

    During the past 15 years considerable progress in observational techniques has been achieved in the middle-infrared region (5000-500/cm, 2-20 microns), the region where most diagnostic molecular vibrations occur. Spectra of many different astronomical infrared sources, some deeply embedded in dark molecular clouds and others obscured only by dust in the diffuse interstellar medium are now available. These spectra provide a powerful probe, not only for the identification of interstellar molecules in both the gas and solid phases, but also of the physical and chemical conditions which prevail in these two very different domains. By comparing these spectra with laboratory spectra one can determine the composition and abundance of the icy material frozen on the cold (- 10K) dust in the dark interior of molecular clouds and of the hydrocarbon component of dust in the diffuse interstellar medium. As these are the building blocks of comets, the work described here also gives insight into the nature of comets.

  2. Solid residues from Italian municipal solid waste incinerators: A source for "critical" raw materials.

    PubMed

    Funari, Valerio; Braga, Roberto; Bokhari, Syed Nadeem Hussain; Dinelli, Enrico; Meisel, Thomas

    2015-11-01

    The incineration of municipal solid wastes is an important part of the waste management system along with recycling and waste disposal, and the solid residues produced after the thermal process have received attention for environmental concerns and the recovery of valuable metals. This study focuses on the Critical Raw Materials (CRM) content in solid residues from two Italian municipal waste incinerator (MSWI) plants. We sampled untreated bottom ash and fly ash residues, i.e. the two main outputs of common grate-furnace incinerators, and determined their total elemental composition with sensitive analytical techniques such as XRF and ICP-MS. After the removal of a few coarse metallic objects from bottom ashes, the corresponding ICP solutions were obtained using strong digestion methods, to ensure the dissolution of the most refractory components that could host significant amounts of precious metals and CRM. The integration of accurate chemical data with a substance flow analysis, which takes into account the mass balance and uncertainties assessment, indicates that bottom and fly ashes can be considered as a low concentration stream of precious and high-tech metals. The magnesium, copper, antimony and zinc contents are close to the corresponding values of a low-grade ore. The distribution of the elements flow between bottom and fly ash, and within different grain size fractions of bottom ash, is appraised. Most elements are enriched in the bottom ash flow, especially in the fine grained fractions. However, the calculated transfer coefficients indicate that Sb and Zn strongly partition into the fly ashes. The comparison with available studies indicates that the CRM concentrations in the untreated solid residues are comparable with those residues that undergo post-treatment beneficiations, e.g. separation between ferrous and non-ferrous fractions. The suggested separate collection of "fresh" bottom ash, which could be processed for further mineral upgrading, can

  3. Solid State Ionics Advanced Materials for Emerging Technologies

    NASA Astrophysics Data System (ADS)

    Chowdari, B. V. R.; Careem, M. A.; Dissanayake, M. A. K. L.; Rajapakse, R. M. G.; Seneviratne, V. A.

    2006-06-01

    Keynote lecture. Challenges and opportunities of solid state ionic devices / W. Weppner -- pt. I. Ionically conducting inorganic solids. Invited papers. Multinuclear NMR studies of mass transport of phosphoric acid in water / J. R. P. Jayakody ... [et al.]. Crystalline glassy and polymeric electrolytes: similarities and differences in ionic transport mechanisms / J.-L. Souquet. 30 years of NMR/NQR experiments in solid electrolytes / D. Brinkmann. Analysis of conductivity and NMR measurements in Li[symbol]La[symbol]TiO[symbol] fast Li[symbol] ionic conductor: evidence for correlated Li[symbol] motion / O. Bohnké ... [et al.]. Transport pathways for ions in disordered solids from bond valence mismatch landscapes / S. Adams. Proton conductivity in condensed phases of water: implications on linear and ball lightning / K. Tennakone -- Contributed papers. Proton transport in nanocrystalline bioceramic materials: an investigative study of synthetic bone with that of natural bone / H. Jena, B. Rambabu. Synthesis and properties of the nanostructured fast ionic conductor Li[symbol]La[symbol]TiO[symbol] / Q. N. Pham ... [et al.]. Hydrogen production: ceramic materials for high temperature water electrolysis / A. Hammou. Influence of the sintering temperature on pH sensor ability of Li[symbol]La[symbol]TiO[symbol]. Relationship between potentiometric and impedance spectroscopy measurements / Q. N. Pham ... [et al.]. Microstructure chracterization and ionic conductivity of nano-sized CeO[symbol]-Sm[symbol]O[symbol] system (x=0.05 - 0.2) prepared by combustion route / K. Singh, S. A. Acharya, S. S. Bhoga. Red soil in Northern Sri Lanka is a natural magnetic ceramic / K. Ahilan ... [et al.]. Neutron scattering of LiNiO[symbol] / K. Basar ... [et al.]. Preparation and properties of LiFePO[symbol] nanorods / L. Q. Mai ... [et al.]. Structural and electrochemical properties of monoclinic and othorhombic MoO[symbol] phases / O. M. Hussain ... [et al.]. Preparation of Zircon (Zr

  4. Very Small Interstellar Spacecraft

    NASA Astrophysics Data System (ADS)

    Peck, Mason A.

    2007-02-01

    This paper considers lower limits of length scale in spacecraft: interstellar vehicles consisting of little more material than found in a typical integrated-circuit chip. Some fundamental scaling principles are introduced to show how the dynamics of the very small can be used to realize interstellar travel with minimal advancements in technology. Our recent study for the NASA Institute for Advanced Concepts provides an example: the use of the Lorentz force that acts on electrically charged spacecraft traveling through planetary and stellar magnetospheres. Schaffer and Burns, among others, have used Cassini and Voyager imagery to show that this interaction is responsible for some of the resonances in the orbital dynamics of dust in Jupiter's and Saturn's rings. The Lorentz force turns out to vary in inverse proportion to the square of this characteristic length scale, making it a more effective means of propelling tiny spacecraft than solar sailing. Performance estimates, some insight into plasma interactions, and some hardware concepts are offered. The mission architectures considered here involve the use of these propellantless propulsion techniques for acceleration within our solar system and deceleration near the destination. Performance estimates, some insight into plasma interactions, and some hardware concepts are offered. The mission architectures considered here involve the use of these propellantless propulsion techniques for acceleration within our solar system and deceleration near the destination. We might envision a large number of such satellites with intermittent, bursty communications set up as a one-dimensional network to relay signals across great distances using only the power likely from such small spacecraft. Conveying imagery in this fashion may require a long time because of limited power, but the prospect of imaging another star system close-up ought to be worth the wait.

  5. The Search for Interstellar Sulfide Grains

    NASA Technical Reports Server (NTRS)

    Keller, Lindsay P.; Messenger, Scott

    2010-01-01

    The lifecycle of sulfur in the galaxy is poorly understood. Fe-sulfide grains are abundant in early solar system materials (e.g. meteorites and comets) and S is highly depleted from the gas phase in cold, dense molecular cloud environments. In stark contrast, sulfur is essentially undepleted from the gas phase in the diffuse interstellar medium, indicating that little sulfur is incorporated into solid grains in this environment. It is widely believed that sulfur is not a component of interstellar dust grains. This is a rather puzzling observation unless Fe-sulfides are not produced in significant quantities in stellar outflows, or their lifetime in the ISM is very short due to rapid destruction. Fe sulfide grains are ubiquitous in cometary samples where they are the dominant host of sulfur. The Fe-sulfides (primarily pyrrhotite; Fe(1-x)S) are common, both as discrete 0.5-10 micron-sized grains and as fine (5-10 nm) nanophase inclusions within amorphous silicate grains. Cometary dust particles contain high abundances of well-preserved presolar silicates and organic matter and we have suggested that they should contain presolar sulfides as well. This hypothesis is supported by the observation of abundant Fe-sulfides grains in dust around pre- and post-main sequence stars inferred from astronomical spectra showing a broad 23 micron IR feature due to FeS. Fe-sulfide grains also occur as inclusions in bona fide circumstellar amorphous silicate grains and as inclusions within deuterium-rich organic matter in cometary dust samples. Our irradiation experiments show that FeS is far more resistant to radiation damage than silicates. Consequently, we expect that Fe sulfide stardust should be as abundant as silicate stardust in solar system materials.

  6. Is interstellar archeology possible?

    NASA Astrophysics Data System (ADS)

    Carrigan, Richard A.

    2012-09-01

    Searching for signatures of cosmic-scale archeological artifacts such as Dyson spheres is an interesting alternative to conventional radio SETI. Uncovering such an artifact does not require the intentional transmission of a signal on the part of the original civilization. This type of search is called interstellar archeology or sometimes cosmic archeology. A variety of interstellar archeology signatures is discussed including non-natural planetary atmospheric constituents, stellar doping, Dyson spheres, as well as signatures of stellar, and galactic-scale engineering. The concept of a Fermi bubble due to interstellar migration is reviewed in the discussion of galactic signatures. These potential interstellar archeological signatures are classified using the Kardashev scale. A modified Drake equation is introduced. With few exceptions interstellar archeological signatures are clouded and beyond current technological capabilities. However SETI for so-called cultural transmissions and planetary atmosphere signatures are within reach.

  7. Solid and liquid residues as raw materials for biotechnology.

    PubMed

    Gallert, C; Winter, J

    2002-11-01

    In the past few decades huge amounts of solid and paste-like wastes of domestic and industrial origin have been deposited on sanitary landfills worldwide. Only a small proportion was incinerated, where incineration plants were available. Since primary resources, such as ores for metal production or crude oil for the production of gasoline, diesel, solvents and plastics, or coal and natural gas as sources for energy or chemicals are not available in unlimited quantities, and because the deposition of residues, wastes and worn-out commodities on sanitary landfills causes pollution of the atmosphere, the soil and the groundwater due to hazardous gaseous emissions and toxic leachates, wastes from households and from industry must be avoided or minimized at an early stage. Whenever waste material can be recycled it must be re-introduced into production processes and the non-recyclable fractions should be used as a fuel for energy recovery. After incineration, the highly toxic dust fractions of ashes and slags resulting from burning the wastes should be deposited on sanitary landfills, while the granulated mineral slag fractions could be used as a substitute for the sand in cement as a construction material. Here we review various processes for the treatment of organic fractions of differently composed wastes to upgrade them to more valuable, re-usable products or at least to recover their energy content. Upgrading processes of organic wastes include composting, biogas fermentation, production of organic acids and solvents, and biopolymer or biosurfactants production. We also include biological purification procedures for the most important components of wastes, such as chitin from the shells of Crustaceae. Typical examples from pilot-scale or full-scale studies are discussed for each process. PMID:12451450

  8. Interstellar grain chemistry and organic molecules

    NASA Technical Reports Server (NTRS)

    Allamandola, L. J.; Sandford, S. A.

    1990-01-01

    The detection of prominant infrared absorption bands at 3250, 2170, 2138, 1670 and 1470 cm(-1) (3.08, 4.61, 4.677, 5.99 and 6.80 micron m) associated with molecular clouds show that mixed molecular (icy) grain mantles are an important component of the interstellar dust in the dense interstellar medium. These ices, which contain many organic molecules, may also be the production site of the more complex organic grain mantles detected in the diffuse interstellar medium. Theoretical calculations employing gas phase as well as grain surface reactions predict that the ices should be dominated only by the simple molecules H2O, H2CO, N2, CO, O2, NH3, CH4, possibly CH3OH, and their deuterated counterparts. However, spectroscopic observations in the 2500 to 1250 cm(-1)(4 to 8 micron m) range show substantial variation from source reactions alone. By comparing these astronomical spectra with the spectra of laboratory-produced analogs of interstellar ices, one can determine the composition and abundance of the materials frozen on the grains in dense clouds. Experiments are described in which the chemical evolution of an interstellar ice analog is determined during irradiation and subsequent warm-up. Particular attention is paid to the types of moderately complex organic materials produced during these experiments which are likely to be present in interstellar grains and cometary ices.

  9. Interstellar grain chemistry and organic molecules

    NASA Astrophysics Data System (ADS)

    Allamandola, L. J.; Sandford, S. A.

    1990-04-01

    The detection of prominant infrared absorption bands at 3250, 2170, 2138, 1670 and 1470 cm(-1) (3.08, 4.61, 4.677, 5.99 and 6.80 micron m) associated with molecular clouds show that mixed molecular (icy) grain mantles are an important component of the interstellar dust in the dense interstellar medium. These ices, which contain many organic molecules, may also be the production site of the more complex organic grain mantles detected in the diffuse interstellar medium. Theoretical calculations employing gas phase as well as grain surface reactions predict that the ices should be dominated only by the simple molecules H2O, H2CO, N2, CO, O2, NH3, CH4, possibly CH3OH, and their deuterated counterparts. However, spectroscopic observations in the 2500 to 1250 cm(-1)(4 to 8 micron m) range show substantial variation from source reactions alone. By comparing these astronomical spectra with the spectra of laboratory-produced analogs of interstellar ices, one can determine the composition and abundance of the materials frozen on the grains in dense clouds. Experiments are described in which the chemical evolution of an interstellar ice analog is determined during irradiation and subsequent warm-up. Particular attention is paid to the types of moderately complex organic materials produced during these experiments which are likely to be present in interstellar grains and cometary ices.

  10. O VI IN THE LOCAL INTERSTELLAR MEDIUM

    SciTech Connect

    Barstow, M. A.; Boyce, D. D.; Barstow, J. K.; Forbes, A. E.; Preval, S.; Welsh, B. Y.; Lallement, R.

    2010-11-10

    We report the results of a search for O VI absorption in the spectra of 80 hot DA white dwarfs observed by the FUSE satellite. We have carried out a detailed analysis of the radial velocities of interstellar and (where present) stellar absorption lines for the entire sample of stars. In approximately 35% of cases (where photospheric material is detected), the velocity differences between the interstellar and photospheric components were beneath the resolution of the FUSE spectrographs. Therefore, in 65% of these stars the interstellar and photospheric contributions could be separated and the nature of the O VI component unambiguously determined. Furthermore, in other examples, where the spectra were of a high signal-to-noise, no photospheric material was found and any O VI detected was assumed to be interstellar. Building on the earlier work of Oegerle et al. and Savage and Lehner, we have increased the number of detections of interstellar O VI and, for the first time, compared their locations with both the soft X-ray background emission and new detailed maps of the distribution of neutral gas within the local interstellar medium. We find no strong evidence to support a spatial correlation between O VI and SXRB emission. In all but a few cases, the interstellar O VI was located at or beyond the boundaries of the local cavity. Hence, any T {approx} 300,000 K gas responsible for the O VI absorption may reside at the interface between the cavity and surrounding medium or in that medium itself. Consequently, it appears that there is much less O VI-bearing gas than previously stated within the inner rarefied regions of the local interstellar cavity.

  11. Interstellar organic matter in meteorites

    NASA Technical Reports Server (NTRS)

    Yang, J.; Epstein, S.

    1983-01-01

    Deuterium-enriched hydrogen is present in organic matter in such meteorites as noncarbonaceous chondrites. The majority of the unequilibrated primitive meteorites contain hydrogen whose D/H ratios are greater than 0.0003, requiring enrichment (relative to cosmic hydrogen) by isotope exchange reactions taking place below 150 K. The D/H values presented are the lower limits for the organic compounds derived from interstellar molecules, since all processes subsequent to their formation, including terrestrial contamination, decrease their D/H ratios. In contrast, the D/H ratios of hydrogen associated with hydrated silicates are relatively uniform for the meteorites analyzed. The C-13/C-12 ratios of organic matter, irrespective of D/H ratio, lie well within those observed for the earth. Present findings suggest that other interstellar material, in addition to organic matter, is preserved and is present in high D/H ratio meteorites.

  12. INTERSTELLAR ANALOGS FROM DEFECTIVE CARBON NANOSTRUCTURES ACCOUNT FOR INTERSTELLAR EXTINCTION

    SciTech Connect

    Tan, Zhenquan; Abe, Hiroya; Sato, Kazuyoshi; Ohara, Satoshi; Chihara, Hiroki; Koike, Chiyoe; Kaneko, Kenji

    2010-11-15

    Because interstellar dust is closely related to the evolution of matter in the galactic environment and many other astrophysical phenomena, the laboratory synthesis of interstellar dust analogs has received significant attention over the past decade. To simulate the ultraviolet (UV) interstellar extinction feature at 217.5 nm originating from carbonaceous interstellar dust, many reports focused on the UV absorption properties of laboratory-synthesized interstellar dust analogs. However, no general relation has been established between UV interstellar extinction and artificial interstellar dust analogs. Here, we show that defective carbon nanostructures prepared by high-energy collisions exhibit a UV absorption feature at 220 nm which we suggest accounts for the UV interstellar extinction at 217.5 nm. The morphology of some carbon nanostructures is similar to that of nanocarbons discovered in the Allende meteorite. The similarity between the absorption feature of the defective carbon nanostructures and UV interstellar extinction indicates a strong correlation between the defective carbon nanostructures and interstellar dust.

  13. Process and material that encapsulates solid hazardous waste

    DOEpatents

    O'Brien, Michael H.; Erickson, Arnold W.

    1999-01-01

    A method of encapsulating mixed waste in which a thermoplastic polymer having a melting temperature less than about 150.degree. C. and sulfur and mixed waste are mixed at an elevated temperature not greater than about 200.degree. C. and mixed for a time sufficient to intimately mix the constituents, and then cooled to a solid. The resulting solid is also disclosed.

  14. Interstellar fullerene compounds and diffuse interstellar bands

    NASA Astrophysics Data System (ADS)

    Omont, Alain

    2016-05-01

    Recently, the presence of fullerenes in the interstellar medium (ISM) has been confirmed and new findings suggest that these fullerenes may possibly form from polycyclic aromatic hydrocarbons (PAHs) in the ISM. Moreover, the first confirmed identification of two strong diffuse interstellar bands (DIBs) with the fullerene, C60+, connects the long standing suggestion that various fullerenes could be DIB carriers. These new discoveries justify reassessing the overall importance of interstellar fullerene compounds, including fullerenes of various sizes with endohedral or exohedral inclusions and heterofullerenes (EEHFs). The phenomenology of fullerene compounds is complex. In addition to fullerene formation in grain shattering, fullerene formation from fully dehydrogenated PAHs in diffuse interstellar clouds could perhaps transform a significant percentage of the tail of low-mass PAH distribution into fullerenes including EEHFs. But many uncertain processes make it extremely difficult to assess their expected abundance, composition and size distribution, except for the substantial abundance measured for C60+. EEHFs share many properties with pure fullerenes, such as C60, as regards stability, formation/destruction and chemical processes, as well as many basic spectral features. Because DIBs are ubiquitous in all lines of sight in the ISM, we address several questions about the interstellar importance of various EEHFs, especially as possible carriers of diffuse interstellar bands. Specifically, we discuss basic interstellar properties and the likely contributions of fullerenes of various sizes and their charged counterparts such as C60+, and then in turn: 1) metallofullerenes; 2) heterofullerenes; 3) fulleranes; 4) fullerene-PAH compounds; 5) H2@C60. From this reassessment of the literature and from combining it with known DIB line identifications, we conclude that the general landscape of interstellar fullerene compounds is probably much richer than heretofore realized

  15. New Cathode Materials for Intermediate Temperature Solid Oxide Fuel Cells

    SciTech Connect

    Allan J. Jacobson

    2006-09-30

    the perovskite compositions that were being investigated at PNNL, in order to assess the relative importance of the intrinsic properties such as oxygen ion diffusion and surface exchange rates as predictors of performance in cell tests. We then used these measurements to select new materials for scaled up synthesis and performance evaluation in single cell tests. The results of the single cell tests than provided feedback to the materials synthesis and selection steps. In this summary, the following studies are reported: (1) Synthesis, characterization, and DC conductivity measurements of the P1 compositions La{sub 0.8}Sr{sub 0.2}FeO{sub 3-x} and La{sub 0.7}Sr{sub 0.3}FeO{sub 3-x} were completed. A combinational approach for preparing a range P1 (La,Sr)FeO{sub 3} compositions as thin films was investigated. Synthesis and heat treatment of amorphous SrFeO{sub 3-x} and LaFeO{sub 3-x} films prepared by pulsed laser deposition are described. (2) Oxygen transport properties of K1 compositions La{sub x}Pr{sub 2-x}NiO{sub 4+d} (x =2.0, 1.9, 1.2, 1.0 and 0) measured by electrical conductivity relaxation are presented in this report. Area specific resistances determined by ac impedance measurements for La{sub 2}NiO{sub 4+{delta}} and Pr{sub 2}NiO{sub 4+{delta}} on CGO are encouraging and suggest that further optimization of the electrode microstructure will enable the target to be reached. (3) The oxygen exchange kinetics of the oxygen deficient double perovskite LnBaCo{sub 2}O{sub 5.5+{delta}} (Ln=Pr and Nd) were determined by electrical conductivity relaxation. The high electronic conductivity and rapid diffusion and surface exchange kinetics of PBCO suggest its application as cathode material in intermediate temperature solid oxide fuel cells. The first complete cell measurements were performed on Ni/CGO/CGO/PBCO/CGO cells. (4) The oxygen exchange kinetics of highly epitaxial thin films of PrBaCo{sub 2}O{sub 5.5+{delta}} (PBCO) has been determined by electrical conductivity

  16. The Organic Component of Interstellar Dust

    NASA Technical Reports Server (NTRS)

    Pendleton, Yvonne

    2003-01-01

    The distribution, chemical structure, and formation of organic matter in the interstellar medium are important to our understanding of the overall evolution of dust. The exchange of dust between the dense and diffuse interstellar medium, and the effects of processing on dust within dense clouds will affect the inventory of material available for incorporation into newly forming star and planetary systems. Observational ground-based studies have confirmed the widespread distribution of the 3.4 pm absorption band attributed to aliphatic hydrocarbons in the diffuse interstellar medium of our own galaxy, and in the dusty spectra of a few nearby galaxies, while space based observations from IS0 probed the signatures of corresponding mid-infrared features. Laboratory experiments which utilize both thermal processes and energetic processing by high energy photons and cosmic rays, produce candidate materials which offer close matches to the observed diffuse interstellar medium and extragalactic hydrocarbon absorption features. Through an analysis of the 4000 to 1000 cm (2.5 to 10 micrometers) region of the spectrum of diffuse interstellar medium (DISM) dust compared with the spectra of thirteen chemical entities produced in the laboratory which serve as analogs to the interstellar material, significant constraints have been placed on the applicability of proposed candidate materials to explain the interstellar features. The results indicate that the organic refractory material in the diffuse interstellar medium is predominantly hydrocarbon in nature, possessing little nitrogen or oxygen, with the carbon distributed between the aromatic and aliphatic forms. Long alkane chains H3C-(CH2),- with n much greater than 4 or 5 are not major constituents of this material. Comparisons to laboratory analogs indicate the DISM organic material resembles plasma processed pure hydrocarbon residues much more so than energetically processed ice residues. This result is consistent with a

  17. Instrumentation for interstellar exploration

    NASA Astrophysics Data System (ADS)

    Gruntman, M.

    The time has arrived for designing, building, and instrumenting a spacecraft for a dedicated foray into interstellar space surrounding our star, the Sun. This region was probed in the past by remote techniques and it will be explored in situ by the Interstellar Probe mission. The mission will significantly advance our understanding of the nature of the local interstellar medium and explore the distant frontier of the solar system by revealing the details of the interaction between the Sun and Galaxy. This mission will also be an important practical step toward interstellar flight of the future. Reaching interstellar space in reasonable time requires high escape velocities and will likely be enabled by non-chemical propulsion such as nuclear-powered electric propulsion or solar sailing. Unusually high spacecraft velocities, enormous distances from the Sun, and non-chemical propulsion will significantly influence the design of the mission, spacecraft and scientific instrumentation. We will review measurement objectives of the first mission into interstellar space and outline constrains on the instrumentation. Measurement of particles, fields, and dust in the interstellar medium will be complemented by search for complex molecules and remote sensing capabilities in various spectral bands. A "look" back at our solar system will also be a glimpse of wh at a flyby mission of the distant future would encounter in approaching another star. The instrumentation for interstellar exploration presents numerous challenges. Mass, telemetry, and power constraints would place a premium on miniaturization and autonom . There are, however,y physical limits on how small the sensors could be. New instrument concepts may be required to achieve the desired measurement capabilities under the stringent constraints of a realistic interstellar mission.

  18. Instrumentation for interstellar exploration

    NASA Astrophysics Data System (ADS)

    Gruntman, Mike

    2004-01-01

    The time has arrived for designing, building, and instrumenting a spacecraft for a dedicated foray into the galactic environment surrounding our star, the sun. This region was probed in the past by remote techniques and it will be explored in situ by the NASA's planned Interstellar Probe mission. The mission will significantly advance our understanding of the nature of the local interstellar medium and explore the distant frontier of the solar system by revealing the details of the interaction between the sun and the Galaxy. This mission will also be an important practical step toward interstellar flight of the future. Reaching interstellar space in reasonable time requires high escape velocities and will likely be enabled by non-chemical propulsion such as nuclear-powered electric propulsion or solar sailing. Unusually high spacecraft velocities, enormous distances from the Sun, and non-chemical propulsion will significantly influence design of the mission, spacecraft, and scientific instrumentation. We will review measurement objectives of the first dedicated mission into interstellar space and outline constraints on the instrumentation. Measurement of particles, fields, and dust in the interstellar medium will be complemented by search for complex organic molecules and remote sensing capabilities in various spectral bands. A "look" back at our solar system will also be a glimpse of what a truly-interstellar mission of the distant future would encounter in approaching a target star. The instrumentation for interstellar exploration presents numerous challenges. Mass, telemetry, and power constraints would place a premium on miniaturization and autonomy. There are, however, physical limits on how small the sensors could be. New instrument concepts may be required to achieve the desired measurement capabilities under the stringent constraints of a realistic interstellar mission.

  19. Computational Interstellar Chemistry

    NASA Astrophysics Data System (ADS)

    Hirata, So; Fan, Peng-Dong; Head-Gordon, Martin; Kamiya, Muneaki; Keçeli, Murat; Lee, Timothy J.; Shiozaki, Toru; Szczepanski, Jan; Vala, Martin; Valeev, Edward F.; Yagi, Kiyoshi

    Computational applications of electronic and vibrational many-body theories are increasingly indispensable in interpreting and, in some instances, predicting the spectra of gas-phase molecular species of importance in interstellar chemistry as well as in atmospheric and combustion chemistry. This chapter briefly reviews our methodological developments of electronic and vibrational many-body theories that are particularly useful for these gas-phase molecular problems. Their applications to anharmonic vibrational frequencies of triatomic and tetratomic interstellar molecules and to electronic absorption spectra of the radical ions of polycyclic aromatic hydrocarbons, which are ubiquitous in the interstellar medium, are also discussed.

  20. A model for electrical tree growth in solid insulating materials using cellular automata

    SciTech Connect

    Danikas, M.G.; Karafyllidis, I.; Thanailakis, A.; Bruning, A.M.

    1996-12-31

    Models proposed to explain the breakdown mechanisms of the solid insulating materials are based, among others, on electromagnetic theory, avalanche theory and fractals. In this paper the breakdown of insulating materials is simulated using von Neumann`s Cellular Automata (CAs). An algorithm for solid dielectric breakdown simulation based on CAs is presented with a point/plane electrode arrangement. The algorithm is also used to simulate breakdown in a solid dielectric having a spherical void.

  1. Laboratory Studies of Interstellar PAH Analogs

    NASA Technical Reports Server (NTRS)

    Salama, Farid; DeVincenzi, Donald (Technical Monitor)

    2000-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are now considered to be an important and ubiquitous component of the organic material in space. PAHs are found in a large variety of extraterrestrial materials such as interplanetary dust particles (IDPs) and meteoritic materials. PAHs are also good candidates to account for the infrared emission bands (UIRs) and the diffuse interstellar optical absorption bands (DIBs) detected in various regions of the interstellar medium. The recent observations made with the Infrared Space Observatory (ISO) have confirmed the ubiquitous nature of the UIR bands and their carriers. PAHs are though to form through chemical reactions in the outflow from carbon-rich stars in a process similar to soot formation. Once injected in the interstellar medium, PAHs are further processed by the interstellar radiation field, interstellar shocks and energetic particles. A major, dedicated, laboratory effort has been undertaken over the past years to measure the physical and chemical characteristics of these complex molecules and their ions under experimental conditions that mimic the interstellar conditions. These measurements require collision-free conditions where the molecules and ions are cold and chemically isolated. The spectroscopy of PAHs under controlled conditions represents an essential diagnostic tool to study the evolution of extraterrestrial PAHs. The Astrochemistry Laboratory program will be discussed through its multiple aspects: objectives, approach and techniques adopted, adaptability to the nature of the problem(s), results and implications for astronomy as well as for molecular spectroscopy. A review of the data generated through laboratory simulations of space environments and the role these data have played in our current understanding of the properties of interstellar PAHs will be presented. The discussion will also introduce the newest generation of laboratory experiments that are currently being developed in order to provide a

  2. Molecular Spectroscopy in Astrophysics: Interstellar PAHs

    NASA Technical Reports Server (NTRS)

    Salama, Farid; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are now considered to be an important and ubiquitous component of the organic material in space. PAHs are found in a large variety of extraterrestrial materials such as interplanetary dust particles (IDPs) and meteoritic materials. PAHs are also good candidates to account for the infrared emission bands (UIRs) and the diffuse interstellar optical absorption bands (DIBs) detected in various regions of the interstellar medium. The recent observations made with the Infrared Space Observatory (ISO) have confirmed the ubiquitous nature of the UIR bands and their carriers. PAHs are thought to form through chemical reactions in the outflow from carbon-rich stars in a process similar to soot formation. Once injected in the interstellar medium, PAHs are further processed by the interstellar radiation field, interstellar shocks and energetic particles. A long-term laboratory effort has been undertaken to measure the physical and chemical characteristics of these carbon molecules and their ions under experimental conditions that mimic the interstellar conditions. These measurements require collision-free conditions where the molecules and ions are cold and chemically isolated. The spectroscopy of PAHs under controlled conditions represents an essential diagnostic tool to study the evolution of extraterrestrial PAHs. The laboratory results will be discussed as well as the implications for astronomy and for molecular spectroscopy. A review of the data generated through laboratory simulations of space environments and the role these data have played in our current understanding of the properties of interstellar PAHs will be presented. We will also present the new generation of laboratory experiments that are currently being developed in order to provide a closer simulation of space environments and a better support to space missions.

  3. 75 FR 64585 - Bulk Solid Hazardous Materials: Harmonization With the International Maritime Solid Bulk Cargoes...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-19

    ...The Coast Guard is harmonizing its regulations with amendments to Chapter VI and Chapter VII of the International Maritime Organization (IMO) International Convention for the Safety of Life at Sea, 1974, as amended, (SOLAS) that make the International Maritime Solid Bulk Cargoes (IMSBC) Code mandatory. The amendments require that all vessels subject to SOLAS, and carrying bulk solid cargoes......

  4. Status of the Stardust ISPE and the Origin of Four Interstellar Dust Candidates

    NASA Technical Reports Server (NTRS)

    Westphal, A. J.; Allen, C.; Ansari, A.; Bajt, S.; Bastien, R. S.; Bassim, N.; Bechtel, H. A.; Borg, J.; Brenker, F. E.; Bridges, J.; Brownlee, D. E.; Burchell, M.; Burghammer, M.; Butterworth, A. L.; Changela, H.; Cloetens, P.; Davis, A. M.; Floss, C.; Flynn, G.; Fougeray, P.; Frank, D.; Gainsforth, Z.; Gruen, E.; Sandford, S. A.; Zolensky, M. E.

    2012-01-01

    Some bulk properties of interstellar dust are known through infrared and X-ray observations of the interstellar medium. However, the properties of individual interstellar dust particles are largely unconstrained, so it is not known whether individual interstellar dust particles can be definitively distinguished from interplanetary dust particles in the Stardust Interstellar Dust Collector (SIDC) based only on chemical, mineralogical or isotopic analyses. It was therefore understood from the beginning of the Stardust Interstellar Preliminary Examination (ISPE) that identification of interstellar dust candidates would rest on three criteria - broad consistency with known extraterrestrial materials, inconsistency with an origin as secondary ejecta from impacts on the spacecraft, and consistency, in a statistical sense, of observed dynamical properties - that is, trajectory and capture speed - with an origin in the interstellar dust stream. Here we quantitatively test four interstellar dust candidates, reported previously [1], against these criteria.

  5. Photochemistry of interstellar molecules

    NASA Technical Reports Server (NTRS)

    Stief, L. J.

    1971-01-01

    The photochemistry of two diatomic and eight polyatomic molecules is discussed quantitatively. For an interstellar molecule, the lifetime against photodecomposition depends upon the absorption cross section, the quantum yield or probability of dissociation following photon absorption, and the interstellar radiation field. The constant energy density of Habing is used for the unobserved regions of interstellar radiation field, and the field in obscuring clouds is estimated by combining the constant flux with the observed interstellar extinction curve covering the visible and ultraviolet regions. Lifetimes against photodecomposition in the unobscured regions and as a function of increasing optical thickness in obscuring clouds are calculated for the ten species. The results show that, except for CO, all the molecules have comparable lifetimes of less than one hundred years. Thus they can exist only in dense clouds and can never have been exposed to the unobscured radiation. The calculations further show that the lifetimes in clouds of moderate opacity are of the order of one million years.

  6. Interstellar shock waves

    NASA Technical Reports Server (NTRS)

    Mckee, C. F.; Hollenbach, D. J.

    1980-01-01

    The structure of interstellar shocks driven by supernova remnants and by expanding H II regions around early-type stars is discussed. Jump conditions are examined, along with shock fronts, post-shock relaxation layers, collisional shocks, collisionless shocks, nonradiative shocks, radiative atomic shocks, and shock models of observed nebulae. Effects of shock waves on interstellar molecules are examined, with reference to the chemistry behind shock fronts, infrared and vibrational-rotational cooling by molecules, and observations of shocked molecules. Some current problems and applications of the study of interstellar shocks are summarized, including the initiation of star formation by radiative shock waves, interstellar masers, the stability of shocks, particle acceleration in shocks, and shocks in galactic nuclei.

  7. Interstellar magnesium abundances

    NASA Technical Reports Server (NTRS)

    Murray, M. J.; Dufton, P. L.; Hibbert, A.; York, D. G.

    1984-01-01

    An improved evaluation of the Mg II 1240 A doublet oscillator strength is used in conjunction with recently published Copernicus observations to derive accurate Mg II column densities toward 74 stars. These imply an average of 40 percent of interstellar magnesium is in the gaseous phase. Magnesium depletion is examined as a function of various interstellar extinction and density parameters, and the results are briefly discussed in terms of current depletion theories.

  8. Interstellar Propulsion Concepts Assessment

    NASA Technical Reports Server (NTRS)

    Forward, Robert L.

    2000-01-01

    NASA is investigating the feasibility of conducting extra-solar and interstellar missions over the next 10 to 50 years. An assessment of technologies supporting these near and far term objectives is required. To help meet these objectives the Principal Investigator assessed the feasibility of candidate propulsion systems for the proposed 'Interstellar Probe', a mission to send a spacecraft to the Heliopause at 250 AU and beyond.

  9. Interstellar organic chemistry.

    NASA Technical Reports Server (NTRS)

    Sagan, C.

    1972-01-01

    Most of the interstellar organic molecules have been found in the large radio source Sagittarius B2 toward the galactic center, and in such regions as W51 and the IR source in the Orion nebula. Questions of the reliability of molecular identifications are discussed together with aspects of organic synthesis in condensing clouds, degradational origin, synthesis on grains, UV natural selection, interstellar biology, and contributions to planetary biology.

  10. Observations of interstellar zinc

    NASA Technical Reports Server (NTRS)

    York, D. G.; Jura, M.

    1982-01-01

    IUE observations toward 10 stars have shown that zinc is not depleted in the interstellar medium by more than a factor of two, suggesting that its abundance may serve as a tracer of the true metallicity in the gas. A result pertinent to the history of nucleosynthesis in the solar neighborhood is that the local interstellar medium has abundances that appear to be homogeneous to within a factor of two, when integrated over paths of about 500 pc.

  11. Interstellar chemistry - Polycyanoacetylene formation

    NASA Technical Reports Server (NTRS)

    Langer, W. D.; Schloerb, F. P.; Snell, R. L.; Young, J. S.

    1981-01-01

    It is argued that interstellar polycyanoacetylenes are formed not on dust grains by catalytic buildup or by dissociation of longer molecules, but rather by gas phase ion-molecule reactions. The primary evidence for this view is the detection of deuterated cyanoacetylene in an interstellar cloud. It is also argued that the relative abundance of successive homologs of polycyanoacetylenes rules out the grain catalysis theory.

  12. Discovery of interstellar rubidium

    NASA Technical Reports Server (NTRS)

    Jura, M.; Smith, W. H.

    1981-01-01

    Interstellar rubidium is detected through observations of the resonance line of Rb I at 7800 A towards zeta Oph. The abundance ratio of rubidium to potassium is estimated to be approximately solar, and if rubidium is generally found to have an abundance similar to potassium, it is indicated that the local interstellar medium is well mixed with a wide variety of the products of nucleosynthesis.

  13. The Interstellar Conspiracy

    NASA Technical Reports Server (NTRS)

    Johnson, Les; Matloff, Gregory L.

    2005-01-01

    If we were designing a human-carrying starship that could be launched in the not-too-distant future, it would almost certainly not use a warp drive to instantaneously bounce around the universe, as is done in Isaac Asimov's classic Foundation series or in episodes of Star Trek or Star Wars. Sadly, those starships that seem to be within technological reach could not even travel at high relativistic speeds, as does the interstellar ramjet in Poul Anderson's Tau Zero. Warp-speeds seem to be well outside the realm of currently understood physical law; proton-fusing ramjets may never be technologically feasible. Perhaps fortunately in our terrorist-plagued world, the economics of antimatter may never be attractive for large-scale starship propulsion. But interstellar travel will be possible within a few centuries, although it will certainly not be as fast as we might prefer. If humans learn how to hibernate, perhaps we will sleep our way to the stars, as do the crew in A. E. van Vogt's Far Centaurus. However, as discussed in a landmark paper in The Journal of the British Interplanetary Society, the most feasible approach to transporting a small human population to the planets (if any) of Alpha Centauri is the worldship. Such craft have often been featured in science fiction. See for example Arthur C. Clarke's Rendezvous with Rama, and Robert A. Heinlein's Orphans of the Sky. Worldships are essentially mobile versions of the O Neill free-space habitats. Constructed mostly from lunar and/or asteroidal materials, these solar-powered, multi-kilometer-dimension structures could house 10,000 to 100,000 humans in Earth-approximating environments. Artificial gravity would be provided by habitat rotation, and cosmic ray shielding would be provided by passive methods, such as habitat atmosphere and mass shielding, or magnetic fields. A late 21st century space-habitat venture might support itself economically by constructing large solar-powered satellites to beam energy back to

  14. Desorption from interstellar grains

    NASA Technical Reports Server (NTRS)

    Leger, A.; Jura, M.; Omont, A.

    1985-01-01

    Different desorption mechanisms from interstellar grains are considered to resolve the conflict between the observed presence of gaseous species in molecular clouds and their expected depletion onto grains. The physics of desorption is discussed with particular reference to the process of grain heating and the specific heat of the dust material. Impulsive heating by X-rays and cosmic rays is addressed. Spot heating of the grains by cosmic rays and how this can lead to desorption of mantles from very large grains is considered. It is concluded that CO depletion on grains will be small in regions with A(V) less than five from the cloud surface and n(H) less than 10,000, in agreement with observations and in contrast to expectations from pure thermal equilibrium. Even in very dense and obscured regions and in the absence of internal ultraviolet sources, the classical evaporation of CO or N2 and O2-rich mantles by cosmic rays is important.

  15. Processing Mechanisms for Interstellar Ices: Connections to the Solar System

    NASA Technical Reports Server (NTRS)

    Pendleton, Y. J.; Cuzzi, Jeffrey N. (Technical Monitor)

    1995-01-01

    The organic component of the interstellar medium, which has revealed itself through the ubiquitous 3.4 micrometers hydrocarbon absorption feature, is widespread throughout the disk of our galaxy and has been attributed to dust grains residing in the diffuse interstellar medium. The absorption band positions near 3.4 micrometers are characteristic of C-H stretching vibrations in the -CH3 and -CH2- groups of saturated aliphatic hydrocarbons associated with perturbing chemical groups. The production of complex molecules is thought to occur within dense molecular clouds when ice-mantled grains are processed by various energetic mechanisms. Studies of the processing of interstellar ices and the subsequent production of organic residues have relevance to studies of ices in the solar system, because primitive, icy solar system bodies such as those in the Kuiper belt are likely reservoirs of organic material, either preserved from the interstellar medium or produced in situ. Connections between the interstellar medium and the early solar nebula have long been a source of interest. A comparison of the interstellar organics and the Murchison meteorite illustrates the importance of probing the interstellar connection to the solar system, because although the carbonaceous meteorites are undoubtedly highly processed, they do retain specific interstellar signatures (such as diamonds, SiC grains, graphite and enriched D/H). The organic component, while not proven interstellar, has a remarkable similarity to the interstellar organics observed in over a dozen sightlines through our galaxy. This paper compares spectra from laboratory organics produced through the processing of interstellar ice analog materials with the high resolution infrared observations of the interstellar medium in order to investigate the mechanisms (such as ion bombardment, plasma processing, and UV photolysis) that may be producing the organics in the ISM.

  16. Nonaqueous composition for slip casting or cold forming refractory material into solid shapes

    SciTech Connect

    Montgomery, L.C.

    1993-08-24

    A composition is described for slip casting or cold forming non-oxide refractory material(s) into solid shape comprising finely divided solid refractory materials selected from the group consisting of metal boride, refractory carbide, nitride, silicide and a refractory metal of tungsten, molybdenum, tantalum and chromium suspended in a nonaqueous liquid slip composition consisting essentially of a deflocculent composed of a vinyl chloride-vinyl acetate resin dissolved in an organic solvent.

  17. Solid-phase materials for chelating metal ions and methods of making and using same

    DOEpatents

    Harrup, Mason K.; Wey, John E.; Peterson, Eric S.

    2003-06-10

    A solid material for recovering metal ions from aqueous streams, and methods of making and using the solid material, are disclosed. The solid material is made by covalently bonding a chelating agent to a silica-based solid, or in-situ condensing ceramic precursors along with the chelating agent to accomplish the covalent bonding. The chelating agent preferably comprises a oxime type chelating head, preferably a salicylaldoxime-type molecule, with an organic tail covalently bonded to the head. The hydrocarbon tail includes a carbon-carbon double bond, which is instrumental in the step of covalently bonding the tail to the silica-based solid or the in-situ condensation. The invented solid material may be contacted directly with aqueous streams containing metal ions, and is selective to ions such as copper (II) even in the presence of such ions as iron (III) and other materials that are present in earthen materials. The solid material with high selectivity to copper may be used to recover copper from mining and plating industry streams, to replace the costly and toxic solvent extraction steps of conventional copper processing.

  18. Composition, structure and chemistry of interstellar dust

    NASA Technical Reports Server (NTRS)

    Tielens, Alexander G. G. M.; Allamandola, Louis J.

    1986-01-01

    The observational constraints on the composition of the interstellar dust are analyzed. The dust in the diffuse interstellar medium consists of a mixture of stardust (amorphous silicates, amorphous carbon, polycyclic aromatic hydrocarbons, and graphite) and interstellar medium dust (organic refractory material). Stardust seems to dominate in the local diffuse interstellar medium. Inside molecular clouds, however, icy grain mantles are also important. The structural differences between crystalline and amorphous materials, which lead to differences in the optical properties, are discussed. The astrophysical consequences are briefly examined. The physical principles of grain surface chemistry are discussed and applied to the formation of molecular hydrogen and icy grain mantles inside dense molecular clouds. Transformation of these icy grain mantles into the organic refractory dust component observed in the diffuse interstellar medium requires ultraviolet sources inside molecular clouds as well as radical diffusion promoted by transient heating of the mantle. The latter process also returns a considerable fraction of the molecules in the grain mantle to the gas phase.

  19. Solid Suspension Flow Batteries Using Earth Abundant Materials.

    PubMed

    Mubeen, Syed; Jun, Young-Si; Lee, Joun; McFarland, Eric W

    2016-01-27

    The technical features of solid-electrode batteries (e.g., high energy density, relatively low capital cost ($/kWh)) and flow batteries (e.g., long cycle life, design flexibility) are highly complementary. It is therefore extremely desirable to integrate their advantages into a single storage device for large-scale energy storage applications where lifetime cost ($/kW-h/cycle) is an extremely important parameter. Here, we demonstrate a non-Li-based-flow battery concept that replaces the aqueous solution of redox-active molecules found in typical redox flow batteries with suspensions of hydrophilic carbon particles ("solid suspension electrodes") coated with earth-abundant redox-active metals. The solid suspension electrodes charge by depositing earth-abundant redox-active metals onto the carbon particle suspension, which are then stripped during discharge operation. The electrical contact to the solid suspension electrodes is fed through fixed redox-inert hydrophobic carbon current collectors through "contact charge transfer" mechanism. The hydrophobicity of the current collectors prevents direct plating of redox-active metals onto their surfaces. The above concept was successfully used to demonstrate several non-Li-based battery chemistries including zinc-copper, zinc-manganese oxide, zinc-bromine, and zinc-sulfur, providing a pathway for potential applications in medium and large-scale electrical energy storage. PMID:26727225

  20. Complex Organics from Laboratory Simulated Interstellar Ices

    NASA Technical Reports Server (NTRS)

    Dworkin, J. P.

    2003-01-01

    -enriched provides evidence for a connection between intact organic material in the interstellar medium and in meteorites. Thus, some of the oxidized aromatics, amphiphiles, amino acids, hydroxy acids, and other compounds found in meteorites may have had an interstellar ancestry and not solely a product of parent body aqueous alteration. Such compounds should also be targeted for searches of organics in cometary dust.

  1. Liquefaction process for solid carbonaceous materials containing alkaline earth metal humates

    DOEpatents

    Epperly, William R.; Deane, Barry C.; Brunson, Roy J.

    1982-01-01

    An improved liquefaction process wherein wall scale and particulate agglomeration during the liquefaction of solid carbonaceous materials containing alkaline earth metal humates is reduced and/or eliminated by subjecting the solid carbonaceous materials to controlled cyclic cavitation during liquefaction. It is important that the solid carbonaceous material be slurried in a suitable solvent or diluent during liquefaction. The cyclic cavitation may be imparted via pressure cycling, cyclic agitation and the like. When pressure cycling or the like is employed an amplitude equivalent to at least 25 psia is required to effectively remove scale from the liquefaction vessel walls.

  2. Liquefaction process for solid carbonaceous materials containing alkaline earth metal humates

    SciTech Connect

    Brunson, R.J.; Deane, B.C.; Epperly, W.R.

    1982-06-01

    An improved liquefaction process wherein wall scale and particulate agglomeration during the liquefaction of solid carbonaceous materials containing alkaline earth metal humates is reduced and/or eliminated by subjecting the solid carbonaceous materials to controlled cyclic cavitation during liquefaction. It is important that the solid carbonaceous material be slurried in a suitable solvent or diluent during liquefaction. The cyclic cavitation may be imparted via pressure cycling, cyclic agitation and the like. When pressure cycling or the like is employed an amplitude equivalent to at least 25 psia is required to effectively remove scale from the liquefaction vessel walls.

  3. Solid state ionics 3. Materials Research Society Symposium Proceedings, volume 293

    NASA Astrophysics Data System (ADS)

    Nazri, Gholam A.; Tarascon, Jean M.; Armand, Michel

    This proceedings volume includes most of the invited and contributed papers presented as Symposium U, Solid State Ionics, at the 1992 MRS Fall meeting in Boston, Massachusetts, U.S.A. The Symposium covered material aspects of solid state ionics, theory of ion transfer in solids, ionically and electronically conductive polymers and their application in solid state devices, and various in-situ and ex-situ techniques for materials characterization. The first part of this proceedings volume deals with physics and chemistry of insertion compounds and application of these in advanced solid state batteries. The optical and electrochemical properties of insertion compounds are also presented. The second part of the proceedings deals with ionic and electronic conductive polymers. A new class of rubbery phase polymer electrolytes and their structure-conductivity relationship are presented. Physical and chemical properties of polymer electrolytes and electrodes and their application in solid state devices are presented.

  4. A review on synthesis and characterization of solid acid materials for fuel cell applications

    NASA Astrophysics Data System (ADS)

    Mohammad, Norsyahida; Mohamad, Abu Bakar; Kadhum, Abdul Amir H.; Loh, Kee Shyuan

    2016-08-01

    Solid acids emerged as an electrolyte material for application in fuel cells due to their high protonic conductivity and stability at high temperatures between 100 °C and 250 °C. This paper gives an overview of the different solid acid materials and their properties, such as high protonic conductivity and thermal stability, in relation to phase transitions and mechanisms of proton transport. Various solid acid synthesis methods including aqueous and dry mixing, electrospinning, sol-gel, impregnation and thin-film casting will be discussed, and the impact of synthesis methods on the properties of solid acids will be highlighted. The properties of solid acids synthesized as either single crystals and or polycrystalline powders were identified via X-ray diffraction, nuclear magnetic resonance, thermal analyses, optical microscopy and infrared spectroscopy. A selection of electrolyte-electrode assembly methods and the performance of solid acid fuel cell prototypes are also reviewed.

  5. 40 CFR 241.3 - Standards and procedures for identification of non-hazardous secondary materials that are solid...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... identification of non-hazardous secondary materials that are solid wastes when used as fuels or ingredients in...) SOLID WASTES SOLID WASTES USED AS FUELS OR INGREDIENTS IN COMBUSTION UNITS Identification of Non-Hazardous Secondary Materials That Are Solid Wastes When Used as Fuels or Ingredients in Combustion...

  6. 40 CFR 241.3 - Standards and procedures for identification of non-hazardous secondary materials that are solid...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... identification of non-hazardous secondary materials that are solid wastes when used as fuels or ingredients in...) SOLID WASTES SOLID WASTES USED AS FUELS OR INGREDIENTS IN COMBUSTION UNITS Identification of Non-Hazardous Secondary Materials That Are Solid Wastes When Used as Fuels or Ingredients in Combustion...

  7. 40 CFR 241.3 - Standards and procedures for identification of non-hazardous secondary materials that are solid...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... identification of non-hazardous secondary materials that are solid wastes when used as fuels or ingredients in...) SOLID WASTES SOLID WASTES USED AS FUELS OR INGREDIENTS IN COMBUSTION UNITS Identification of Non-Hazardous Secondary Materials That Are Solid Wastes When Used as Fuels or Ingredients in Combustion...

  8. Waves in Interstellar Medium

    NASA Astrophysics Data System (ADS)

    Kamaya, H.

    1998-03-01

    Many hydrodynamical researches have been developed. Especially, analysis of the compressible flow is significantly improved by interstellar physicists. To obtain sufficient appreciation, we should not analyze only the effect of self-gravity of the system but also consider the property of inhomogeneity of the interstellar medium. I stress that another hydrodynamical approach is appreciated. That is the multi-phase-flow method. In the astrophysical context, there are few preliminary works of it. I intend to develop it in more suitable method for the interstellar physics. This dissertation is only the first step for me. But, fundamental properties of the multi-phase-flow are presented, considering the effect of compressibility, self-(and/or mutual) gravity, and friction between two phases. All of these properties are generally important to examine the origin, destruction and the global distribution of interstellar medium. My motivation is trying to delve into the global properties of the interstellar medium. The method of multi-phase-flow has great advantage for my aim, and its usefulness has been shown in this thesis.

  9. From Interstellar PAHs and Ices to the Origin of Life

    NASA Technical Reports Server (NTRS)

    Allamandola, Louis J.; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    Tremendous strides have been made in our understanding of interstellar material over the past twenty years thanks to significant, parallel developments in observational astronomy and laboratory astrophysics. Twenty years ago the composition of interstellar dust was largely guessed at, the concept of ices in dense molecular clouds ignored, and the notion of large, abundant, gas phase, carbon rich molecules widespread throughout the interstellar medium (ISM) considered impossible. Today the composition of dust in the diffuse ISM is reasonably well constrained to micron-sized cold refractory materials comprised of amorphous and crystalline silicates mixed with an amorphous carbonaceous material containing aromatic structural units and short, branched aliphatic chains. In dense molecular clouds, the birthplace of stars and planets, these cold dust particles are coated with mixed molecular ices whose composition is very well constrained. Lastly, the signature of carbon-rich polycyclic aromatic hydrocarbons (PAHs), shockingly large molecules by earlier interstellar chemistry standards, is widespread throughout the Universe. The first part of this lecture will describe how infrared studies of interstellar space, combined with laboratory simulations, have revealed the composition of interstellar ices (the building blocks of comets) and the high abundance and nature of interstellar PAHs. The laboratory database has now enabled us to gain insight into the identities, concentrations, and physical state of many interstellar materials. Within a dense molecular cloud, and especially in the solar nebula during the star and planet formation stage, the materials frozen into interstellar/precometary ices are photoprocessed by ultraviolet light, producing more complex molecules. The remainder of the presentation will focus on the photochemical evolution of these materials and the possible role of these compounds on the early Earth. As these materials are thought to be the building

  10. Solid oxide fuel cell with single material for electrodes and interconnect

    DOEpatents

    McPheeters, C.C.; Nelson, P.A.; Dees, D.W.

    1994-07-19

    A solid oxide fuel cell is described having a plurality of individual cells. A solid oxide fuel cell has an anode and a cathode with electrolyte disposed there between, and the anode, cathode and interconnect elements are comprised of substantially one material. 9 figs.

  11. 46 CFR 194.05-11 - Flammable solids and oxidizing materials-Detail requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 CFR parts 172, 173, and 176. ... 46 Shipping 7 2014-10-01 2014-10-01 false Flammable solids and oxidizing materials-Detail... and Marking § 194.05-11 Flammable solids and oxidizing materials—Detail requirements. (a)...

  12. 49 CFR 173.240 - Bulk packaging for certain low hazard solid materials.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... portable tanks; UN portable tanks; marine portable tanks conforming to 46 CFR part 64; and sift-proof non... 49 Transportation 2 2013-10-01 2013-10-01 false Bulk packaging for certain low hazard solid... Than Class 1 and Class 7 § 173.240 Bulk packaging for certain low hazard solid materials. When §...

  13. 46 CFR 194.05-11 - Flammable solids and oxidizing materials-Detail requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 CFR parts 172, 173, and 176. ... 46 Shipping 7 2013-10-01 2013-10-01 false Flammable solids and oxidizing materials-Detail... and Marking § 194.05-11 Flammable solids and oxidizing materials—Detail requirements. (a)...

  14. 49 CFR 173.240 - Bulk packaging for certain low hazard solid materials.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... portable tanks; UN portable tanks; marine portable tanks conforming to 46 CFR part 64; and sift-proof non... 49 Transportation 2 2014-10-01 2014-10-01 false Bulk packaging for certain low hazard solid... Than Class 1 and Class 7 § 173.240 Bulk packaging for certain low hazard solid materials. When §...

  15. 46 CFR 194.05-11 - Flammable solids and oxidizing materials-Detail requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 CFR parts 172, 173, and 176. ... 46 Shipping 7 2011-10-01 2011-10-01 false Flammable solids and oxidizing materials-Detail... and Marking § 194.05-11 Flammable solids and oxidizing materials—Detail requirements. (a)...

  16. 46 CFR 194.05-11 - Flammable solids and oxidizing materials-Detail requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 CFR parts 172, 173, and 176. ... 46 Shipping 7 2010-10-01 2010-10-01 false Flammable solids and oxidizing materials-Detail... and Marking § 194.05-11 Flammable solids and oxidizing materials—Detail requirements. (a)...

  17. 46 CFR 194.05-11 - Flammable solids and oxidizing materials-Detail requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 CFR parts 172, 173, and 176. ... 46 Shipping 7 2012-10-01 2012-10-01 false Flammable solids and oxidizing materials-Detail... and Marking § 194.05-11 Flammable solids and oxidizing materials—Detail requirements. (a)...

  18. 49 CFR 173.240 - Bulk packaging for certain low hazard solid materials.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... portable tanks; UN portable tanks; marine portable tanks conforming to 46 CFR part 64; and sift-proof non... 49 Transportation 2 2012-10-01 2012-10-01 false Bulk packaging for certain low hazard solid... Than Class 1 and Class 7 § 173.240 Bulk packaging for certain low hazard solid materials. When §...

  19. Alternative materials for solid oxide fuel cells: Processing and interactions of materials

    SciTech Connect

    Bates, J.L.; Armstrong, T.R.; Chick, L.A.

    1993-11-01

    The purpose of this research is to develop alternative materials for solid oxide fuel cell (SOFC) interconnections and electrodes with improved electrical, thermal, and electrochemical properties. The overall approach for this research and development is to: minimize the number of cations in the electrode, electrolyte, and interconnection by developing yttrium compounds, such as Y(Ca)CrO{sub 3} as the interconnection, and Y(M{prime})MnO{sub 3} as the air electrode; develop advanced synthesis and fabrication processes for air sintering, below 1,500 C, of chromite interconnections through (1) the use of sintering aids; and (2) the synthesis of submicrometer powders; establish methods for the simultaneous processing and consolidation of air-sinterable powders; electrochemically evaluate interface reactions (in reproducible and controlled laboratory tests) for both the alternate and state-of-the-art materials and cell components developed under this program; and evaluate the chemical reactivity and interdiffusion effects that take place between the various fuel cell components: electrolyte/cathode, interconnect/cathode, and interconnect/anode. This paper describes a comprehensive study that assessed the processing of air-sinterable chromites, the sintering mechanism of chromites, and the chemical reactivity and interdiffusional effects between the interconnect, air, and fuel electrodes. Materials evaluated were La{sub 0.7}Ca{sub 0.31}CrO{sub 3}, La{sub 0.7}Ca{sub 0.29}CrO{sub 3}, (Y{sub 0.6}Ca{sub 0.4}){sub 1.05}Cr{sub 0.95}O{sub 3}, La{sub 1{minus}x}Sr{sub x}MnO{sub 3}, La{sub 1{minus}x}Ca{sub x}MnO{sub 3}, Y{sub 1{minus}x}Ca{sub x}MnO{sub 3}, and Y{sub 1{minus}x}Sr{sub x}MnO{sub 3}.

  20. GAS PHASE EXPOSURE HISTORY DERIVED FROM MATERIAL PHASE CONCENTRATION PROFILES USING SOLID PHASE MICRO-EXTRACTION

    EPA Science Inventory

    EPA Identifier: F8P31059
    Title: Gas Phase Exposure History Derived from Material Phase Concentration Profiles Using Solid Phase Micro-Extraction
    Fellow (Principal Investigator): Jonathan Lewis McKinney
    Institution: University of Missouri - ...

  1. Laser Ablation/Ionisation Mass Spectrometry: Sensitive and Quantitative Chemical Depth Profiling of Solid Materials.

    PubMed

    Riedo, Andreas; Grimaudo, Valentine; Moreno-García, Pavel; Neuland, Maike B; Tulej, Marek; Broekmann, Peter; Wurz, Peter

    2016-01-01

    Direct quantitative and sensitive chemical analysis of solid materials with high spatial resolution, both in lateral and vertical direction is of high importance in various fields of analytical research, ranging from in situ space research to the semiconductor industry. Accurate knowledge of the chemical composition of solid materials allows a better understanding of physical and chemical processes that formed/altered the material and allows e.g. to further improve these processes. So far, state-of-the-art techniques such as SIMS, LA-ICP-MS or GD-MS have been applied for chemical analyses in these fields of research. In this report we review the current measurement capability and the applicability of our Laser Ablation/Ionisation Mass Spectrometer (instrument name LMS) for the chemical analysis of solids with high spatial resolution. The most recent chemical analyses conducted on various solid materials, including e.g. alloys, fossils and meteorites are discussed. PMID:27131112

  2. Interstellar H3+

    PubMed Central

    Oka, Takeshi

    2006-01-01

    Protonated molecular hydrogen, H3+, is the simplest polyatomic molecule. It is the most abundantly produced interstellar molecule, next only to H2, although its steady state concentration is low because of its extremely high chemical reactivity. H3+ is a strong acid (proton donor) and initiates chains of ion-molecule reactions in interstellar space thus leading to formation of complex molecules. Here, I summarize the understandings on this fundamental species in interstellar space obtained from our infrared observations since its discovery in 1996 and discuss the recent observations and analyses of H3+ in the Central Molecular Zone near the Galatic center that led to a revelation of a vast amount of warm and diffuse gas existing in the region. PMID:16894171

  3. The interstellar gas experiment

    NASA Technical Reports Server (NTRS)

    Lind, D. L.; Geiss, J.; Buehler, F.; Eugster, O.

    1992-01-01

    The Interstellar Gas Experiment (IGE) exposed thin metallic foils to collect neutral interstellar gas particles. These particles penetrate the solar system due to their motion relative to the sun. Thus, it is possible to entrap them in the collecting foils along with precipitating magnetospheric and perhaps some ambient atmospheric particles. For the entire duration of the Long Duration Exposure Facility (LDEF) mission, seven of these foils collected particles arriving from seven different directions as seen from the spacecraft. In the mass spectroscopic analysis of the noble gas component of these particles, we have detected the isotopes of He-3, He-4, Ne-20, and Ne-22. In the foil analyses carried out so far, we find a distribution of particle arrival directions which shows that a significant part of the trapped particles are indeed interstellar atoms. The analysis needed to subtract the competing fluxes of magnetospheric and atmospheric particles is still in progress.

  4. Interstellar Sweat Equity

    NASA Astrophysics Data System (ADS)

    Cohen, M. H.; Becker, R. E.; O'Donnell, D. J.; Brody, A. R.

    So, you have just launched aboard the Starship, headed to an exoplanet light years from Earth. You will spend the rest of your natural life on this journey in the expectation and hope that your grandchildren will arrive safely, land, and build a new settlement. You will need to govern the community onboard the Starship. This system of governance must meet unique requirements for participation, representation, and decision-making. On a spaceship that can fly and operate by itself, what will the crewmembers do for their generations in transit? Certainly, they will train and train again to practice the skills they will need upon arrival at a new world. However, this vicarious practice neither suffices to prepare the future pioneers for their destiny at a new star nor will it provide them with the satisfaction in their own work. To hone the crewmembers' inventive and technical skills, to challenge and prepare them for pioneering, the crew would build and expand the interstellar ship in transit. This transstellar ``sweat equity'' gives a stake in the enterprise to all the people, providing meaningful and useful activity to the new generations of crewmembers. They build all the new segments of the vessel from raw materials - including atmosphere - stored on board. Construction of new pressure shell modules would be one option, but they also reconstruct or fill-in existing pressurized volumes. The crew makes new life support system components and develops new agricultural modules in anticipation of their future needs. Upon arrival at the new star or planet, the crew shall apply these robustly developed skills and self-sufficient spirit to their new home.

  5. The Interstellar Medium Surrounding the Sun

    NASA Astrophysics Data System (ADS)

    Frisch, Priscilla C.; Redfield, Seth; Slavin, Jonathan D.

    2011-09-01

    The Solar System is embedded in a flow of low-density, warm, and partially ionized interstellar material that has been sampled directly by in situ measurements of interstellar neutral gas and dust in the heliosphere. Absorption line data reveal that this interstellar gas is part of a larger cluster of local interstellar clouds, which is spatially and kinematically divided into additional small-scale structures indicating ongoing interactions. An origin for the clouds that is related to star formation in the Scorpius-Centaurus OB association is suggested by the dynamic characteristics of the flow. Variable depletions observed within the local interstellar medium (ISM) suggest an inhomogeneous Galactic environment, with shocks that destroy grains in some regions. Although photoionization models of the circumheliospheric ISM do an excellent job of reproducing the observed properties of the surrounding ISM, the unknown characteristics of the very low-density hot plasma filling the Local Bubble introduces uncertainty about the source of ionization and nature of cloud boundaries. Recent observations of small cold clouds provide new insight into the processes affecting the local ISM. A fuller understanding of the local ISM can provide insights into the past and future Galactic environment of the Sun, and deeper knowledge of the astrospheres of nearby stars.

  6. Solid spherical glass particle impingement studies of plastic materials

    NASA Technical Reports Server (NTRS)

    Rao, P. V.; Young, S. G.; Buckley, D. H.

    1983-01-01

    Erosion experiments on polymethyl methacrylate (PMMA), polycarbonate, and polytetrafluoroethylene (PTFE) were conducted with spherical glass beads impacting at normal incidence. Optical and scanning electron microscopic studies and surface profile measurements were made on specimens at predetermined test intervals. During the initial stage of damage to PMMA and polycarbonate, material expands or builds up above the original surface. However, this buildup disappears as testing progresses. Little or no buildup was observed on PTFE. PTFE is observed to be the most resistant material to erosion and PMMA the least. At low impact pressures, material removal mechanisms are believed to be similar to those for metallic materials. However, at higher pressures, surface melting is indicated at the center of impact. Deformation and fatigue appear to play major roles in the material removal process with possible melting or softening.

  7. PAH in the laboratory and interstellar space

    NASA Technical Reports Server (NTRS)

    Wdowiak, Thomas J.; Flickinger, Gregory C.; Boyd, David A.

    1989-01-01

    The theory that polycyclic aromatic hydrocarbons (PAHs) are a constituent of the interstellar medium, and a source of the IR emission bands at 3.3, 6.2, 7.7, 8.6, and 11.3 microns is being studied using PAH containing acid insoluble residue of the Orgueil CI meteorite and coal tar. FTIR spectra of Orgueil PAH material that has undergone thermal treatment, and a solvent insoluble fraction of coal tar that has been exposed to hydrogen plasma are presented. The UV excided luminescence spectrum of a solvent soluble coal tar film is also shown. Comparison of the lab measurements with observations appears to support the interstellar PAH theory, and shows the process of dehydrogenation expected to take place in the interstellar medium.

  8. Liquefaction of solid carbonaceous material with catalyst recycle

    DOEpatents

    Gupta, Avinash; Greene, Marvin I.

    1992-01-01

    In the two stage liquefaction of a carbonaceous solid such as coal wherein coal is liquefied in a first stage in the presence of a liquefaction solvent and the first stage effluent is hydrogenated in the presence of a supported hydrogenation catalyst in a second stage, catalyst which has been previously employed in the second stage and comminuted to a particle size distribution equivalent to 100% passing through U.S. 100 Mesh, is passed to the first stage to improve the overall operation.

  9. Time-dependent interstellar chemistry

    NASA Technical Reports Server (NTRS)

    Glassgold, A. E.

    1985-01-01

    Some current problems in interstellar chemistry are considered in the context of time-dependent calculations. The limitations of steady-state models of interstellar gas-phase chemistry are discussed, and attempts to chemically date interstellar clouds are reviewed. The importance of studying the physical and chemical properties of interstellar dust is emphasized. Finally, the results of a series of studies of collapsing clouds are described.

  10. Stardust Interstellar Preliminary Examination III: Infrared spectroscopic analysis of interstellar dust candidates

    NASA Astrophysics Data System (ADS)

    Bechtel, Hans A.; Flynn, George J.; Allen, Carlton; Anderson, David; Ansari, Asna; Bajt, SašA.; Bastien, Ron K.; Bassim, Nabil; Borg, Janet; Brenker, Frank E.; Bridges, John; Brownlee, Donald E.; Burchell, Mark; Burghammer, Manfred; Butterworth, Anna L.; Changela, Hitesh; Cloetens, Peter; Davis, Andrew M.; Doll, Ryan; Floss, Christine; Frank, David R.; Gainsforth, Zack; Grün, Eberhard; Heck, Philipp R.; Hillier, Jon K.; Hoppe, Peter; Hudson, Bruce; Huth, Joachim; Hvide, Brit; Kearsley, Anton; King, Ashley J.; Lai, Barry; Leitner, Jan; Lemelle, Laurence; Leroux, Hugues; Leonard, Ariel; Lettieri, Robert; Marchant, William; Nittler, Larry R.; Ogliore, Ryan; Ong, Wei Ja; Postberg, Frank; Price, Mark C.; Sandford, Scott A.; Tresseras, Juan-Angel Sans; Schmitz, Sylvia; Schoonjans, Tom; Silversmit, Geert; Simionovici, Alexandre S.; Solé, Vicente A.; Srama, Ralf; Stadermann, Frank J.; Stephan, Thomas; Sterken, Veerle J.; Stodolna, Julien; Stroud, Rhonda M.; Sutton, Steven; Trieloff, Mario; Tsou, Peter; Tsuchiyama, Akira; Tyliszczak, Tolek; Vekemans, Bart; Vincze, Laszlo; von Korff, Joshua; Westphal, Andrew J.; Wordsworth, Naomi; Zevin, Daniel; Zolensky, Michael E.

    2014-09-01

    Under the auspices of the Stardust Interstellar Preliminary Examination, picokeystones extracted from the Stardust Interstellar Dust Collector were examined with synchrotron Fourier transform infrared (FTIR) microscopy to establish whether they contained extraterrestrial organic material. The picokeystones were found to be contaminated with varying concentrations and speciation of organics in the native aerogel, which hindered the search for organics in the interstellar dust candidates. Furthermore, examination of the picokeystones prior to and post X-ray microprobe analyses yielded evidence of beam damage in the form of organic deposition or modification, particularly with hard X-ray synchrotron X-ray fluorescence. From these results, it is clear that considerable care must be taken to interpret any organics that might be in interstellar dust particles. For the interstellar candidates examined thus far, however, there is no clear evidence of extraterrestrial organics associated with the track and/or terminal particles. However, we detected organic matter associated with the terminal particle in Track 37, likely a secondary impact from the Al-deck of the sample return capsule, demonstrating the ability of synchrotron FTIR to detect organic matter in small particles within picokeystones from the Stardust interstellar dust collector.

  11. Fabrication, properties, and tritium recovery from solid breeder materials

    SciTech Connect

    Johnson, C.E. ); Kondo, T. ); Roux, N. ); Tanaka, S. ); Vollath, D. )

    1991-01-01

    The breeding blanket is a key component of the fusion reactor because it directly involves tritium breeding and energy extraction, both of which are critical to development of fusion power. The lithium ceramics continue to show promise as candidate breeder materials. This promise was recognized by the International Thermonuclear Experimental Reactor (ITER) design team in its selection of ceramics as the first option for the ITER breeder material. Blanket design studies have indicated properties in the candidate materials data base that need further investigation. Current studies are focusing on tritium release behavior at high burnup, changes in thermophysical properties with burnup, compatibility between the ceramic breeder and beryllium multiplier, and phase changes with burnup. Laboratory and in-reactor tests, some as part of an international collaboration for development of ceramic breeder materials, are underway. 133 refs., 1 fig.

  12. MATERIALS SYSTEM FOR INTERMEDIATE TEMPERATURE SOLID OXIDE FUEL CELL

    SciTech Connect

    Uday B. Pal; Srikanth Gopalan

    2004-02-15

    AC complex impedance spectroscopy studies were conducted on symmetrical cells of the type [gas, electrode/LSGM electrolyte/electrode, gas]. The electrode materials were slurry-coated on both sides of the LSGM electrolyte support. The electrodes selected for this investigation are candidate materials for SOFC electrodes. Cathode materials include La{sub 1-x}Sr{sub x}MnO{sub 3} (LSM), LSCF (La{sub 1-x}Sr{sub x}Co{sub y}Fe{sub 1-y}O{sub 3}), a two-phase particulate composite consisting of LSM + doped-lanthanum gallate (LSGM), and LSCF + LSGM. Pt metal electrodes were also used for the purpose of comparison. Anode material investigated was the Ni + GDC composite. The study revealed important details pertaining to the charge-transfer reactions that occur in such electrodes. The information obtained can be used to design electrodes for intermediate temperature SOFCs based on LSGM electrolyte.

  13. Kinetic extruder - a dry pulverized solid material pump

    DOEpatents

    Meyer, John W [Palo Alto, CA; Bonin, John H [Sunnyvale, CA; Daniel, Jr., Arnold D.

    1983-01-01

    Method and apparatus are shown for the continuous feeding of pulverized material to a high pressure container. A rotor is located within the high pressure container. The pulverized material is fed from a feed hopper through a stationary feed pipe to a vented spin-up chamber to a plurality of two-stage sprues mounted in the rotor. Control nozzles downstream from the sprues meter the flow of coal through the sprues.

  14. Kinetic extruder - a dry pulverized solid material pump

    DOEpatents

    Meyer, J. W.; Bonin, J. H.; Daniel, A. D. Jr.

    1983-03-15

    Method and apparatus are shown for the continuous feeding of pulverized material to a high pressure container. A rotor is located within the high pressure container. The pulverized material is fed from a feed hopper through a stationary feed pipe to a vented spin-up chamber to a plurality of two-stage sprues mounted in the rotor. Control nozzles downstream from the sprues meter the flow of coal through the sprues. 19 figs.

  15. Subscale solid motor nozzle tests, phase 4 and nozzle materials screening and thermal characterization, phase 5

    NASA Technical Reports Server (NTRS)

    Arnold, J.; Dodson, J.; Laub, B.

    1979-01-01

    Subscale solid motor nozzles containing a baseline material or low cost materials to be considered as potential replacements for the baseline material are designed and tested. Data are presented from tests of four identically designed 2.5 inch throat diameter nozzles and one 7 inch throat diameter nozzle. The screening of new candidate low cost materials, as well as their thermophysical and thermochemical characterization is also discussed.

  16. Application of hybrid materials in solid-state electrochromic devices

    NASA Astrophysics Data System (ADS)

    Rodrigues, L. C.; Barbosa, P. C.; Silva, M. M.; Smith, M. J.; Gonçalves, A.; Fortunato, E.

    2009-08-01

    Sol-gel derived cross-linked PEO/siloxane xerogels (designated as di-ureasils) were prepared using lithium trifluoromethanesulfonyl imide (LiTFSI) as a guest salt. In this paper we describe the assembly of a prototype solid-state electrochromic device (ECD) based on a four-layer sandwich structure, with the following configuration: glass/IZO/WO 3/polymer electrolyte/IZO/glass. The electrochromic switching performance of these devices was characterized as a function of salt concentration. The average transmittance in the visible region of the spectrum was above 69% for all the bleached samples characterized. After coloration the structures assembled with d-U(900) nLiTFSI presented an average transmittance in the visible wavelength region above 22% and an optical density above 0.49.

  17. Molecules in interstellar clouds

    NASA Astrophysics Data System (ADS)

    Irvine, W. M.; Hjalmarson, A.; Rydbeck, O. E. H.

    The physical conditions and chemical compositions of the gas in interstellar clouds are reviewed in light of the importance of interstellar clouds for star formation and the origin of life. The Orion A region is discussed as an example of a giant molecular cloud where massive stars are being formed, and it is pointed out that conditions in the core of the cloud, with a kinetic temperature of about 75 K and a density of 100,000-1,000,000 molecules/cu cm, may support gas phase ion-molecule chemistry. The Taurus Molecular Clouds are then considered as examples of cold, dark, relatively dense interstellar clouds which may be the birthplaces of solar-type stars and which have been found to contain the heaviest interstellar molecules yet discovered. The molecular species identified in each of these regions are tabulated, including such building blocks of biological monomers as H2O, NH3, H2CO, CO, H2S, CH3CN and H2, and more complex species such as HCOOCH3 and CH3CH2CN.

  18. The Voyager Interstellar Mission.

    PubMed

    Rudd, R P; Hall, J C; Spradlin, G L

    1997-01-01

    The Voyager Interstellar Mission began on January 1, 1990, with the primary objective being to characterize the interplanetary medium beyond Neptune and to search for the transition region between the interplanetary medium and the interstellar medium. At the start of this mission, the two Voyager spacecraft had already been in flight for over twelve years, having successfully returned a wealth of scientific information about the planetary systems of Jupiter, Saturn, Uranus, and Neptune, and the interplanetary medium between Earth and Neptune. The two spacecraft have the potential to continue returning science data until around the year 2020. With this extended operating lifetime, there is a high likelihood of one of the two spacecraft penetrating the termination shock and possibly the heliopause boundary, and entering interstellar space before that time. This paper describes the Voyager Interstellar Mission--the mission objectives, the spacecraft and science payload, the mission operations system used to support operations, and the mission operations strategy being used to maximize science data return even in the event of certain potential spacecraft subsystem failures. The implementation of automated analysis tools to offset and enable reduced flight team staffing levels is also discussed. PMID:11540770

  19. Compatibility tests between Jarytherm DBT synthetic oil and solid materials from wastes

    NASA Astrophysics Data System (ADS)

    Fasquelle, Thomas; Falcoz, Quentin; Neveu, Pierre; Flamant, Gilles; Walker, Jérémie

    2016-05-01

    Direct thermocline thermal energy storage is the cheapest sensible thermal energy storage configuration. Indeed, a thermocline tank consists in one tank instead of two and reduces costs. Thermocline thermal energy storages are often filled with cheap solid materials which could react with the heat transfer fluid in the case of incompatibility. PROMES laboratory is building a pilot-scale parabolic trough solar loop including a direct thermocline thermal energy storage system. The working fluid will be a synthetic oil, the Jarytherm® DBT, and the thermal energy storage tank will be filled with stabilized solid materials elaborated from vitrified wastes. Compatibility tests have been conducted in order to check on one hand if the thermo-mechanical properties and life time of the energy storage medium are not affected by the contact with oil and, on the other hand, if the thermal oil performances are not degraded by the solid filler. These experiments consisted in putting in contact the oil and the solid materials in small tanks. In order to discriminate the solid materials tested in the shortest time, accelerating aging conditions at 330 °C for 500 hours were used. The measurements consisted in X-Ray Diffraction and Scanning Electron Microscopy for the solids, and thermo-physical and chemical properties measurements for the oil. Regarding the solid samples, their crystalline structure did not change during the test, but it is difficult to conclude about their elementary composition and they seem to absorb oil. While thermal properties still makes Jarytherm® DBT a good heat transfer fluid after the accelerated aging tests, this study results in differentiating most compatible materials. Thus according to our study, Jarytherm® DBT can be used in direct thermocline thermal energy storage applications when compatibility of the solid material has been demonstrated.

  20. Search for interstellar adenine

    NASA Astrophysics Data System (ADS)

    Chakrabarti, Sandip K.; Majumdar, Liton; Das, Ankan; Chakrabarti, Sonali

    2015-05-01

    It is long debated if pre-biotic molecules are indeed present in the interstellar medium. Despite substantial works pointing to their existence, pre-biotic molecules are yet to be discovered with a complete confidence. In this paper, our main aim is to study the chemical evolution of interstellar adenine under various circumstances. We prepare a large gas-grain chemical network by considering various pathways for the formation of adenine. Majumdar et al. (New Astron. 20:15, 2013) proposed that in the absence of adenine detection, one could try to trace two precursors of adenine, namely, HCCN and NH2CN. Recently Merz et al. (J. Phys. Chem. A 118:3637-3644, 2014), proposed another route for the formation of adenine in interstellar condition. They proposed two more precursor molecules. But it was not verified by any accurate gas-grain chemical model. Neither was it known if the production rate would be high or low. Our paper fills this important gap. We include this new pathways to find that the contribution through this pathways for the formation of Adenine is the most dominant one in the context of interstellar medium. We propose that observers may look for the two precursors (C3NH and HNCNH) in the interstellar media which are equally important for predicting abundances of adenine. We perform quantum chemical calculations to find out spectral properties of adenine and its two new precursor molecules in infrared, ultraviolet and sub-millimeter region. Our present study would be useful for predicting abundance of adenine.

  1. A novel shielding material prepared from solid waste containing lead for gamma ray

    NASA Astrophysics Data System (ADS)

    Erdem, Mehmet; Baykara, Oktay; Doğru, Mahmut; Kuluöztürk, Fatih

    2010-09-01

    Human beings are continuously exposed to cosmogenic radiation and its products in the atmosphere from naturally occurring radioactive materials (NORM) within Earth, their bodies, houses and foods. Especially, for the radiation protection environments where high ionizing radiation levels appear should be shielded. Generally, different materials are used for the radiation shielding in different areas and for different situations. In this study, a novel shielding material produced by a metallurgical solid waste containing lead was analyzed as shielding material for gamma radiation. The photon total mass attenuation coefficients ( μ/ ρ) were measured and calculated using WinXCom computer code for the novel shielding material, concrete and lead. Theoretical and experimental values of total mass attenuation coefficient of the each studied sample were compared. Consequently, a new shielding material prepared from the solid waste containing lead could be preferred for buildings as shielding materials against gamma radiation.

  2. Development of high temperature materials for solid propellant rocket nozzle applications

    NASA Technical Reports Server (NTRS)

    Manning, C. R., Jr.; Lineback, L. D.

    1974-01-01

    Aspects of the development and characteristics of thermal shock resistant hafnia ceramic material for use in solid propellant rocket nozzles are presented. The investigation of thermal shock resistance factors for hafnia based composites, and the preparation and analysis of a model of elastic materials containing more than one crack are reported.

  3. Cathode and electrolyte materials for solid oxide fuel cells and ion transport membranes

    DOEpatents

    Jacobson, Allan J; Wang, Shuangyan; Kim, Gun Tae

    2014-01-28

    Novel cathode, electrolyte and oxygen separation materials are disclosed that operate at intermediate temperatures for use in solid oxide fuel cells and ion transport membranes based on oxides with perovskite related structures and an ordered arrangement of A site cations. The materials have significantly faster oxygen kinetics than in corresponding disordered perovskites.

  4. An extended Foerster-Dexter model for correlated donor-acceptor placement in solid state materials

    NASA Astrophysics Data System (ADS)

    Rotman, S. R.; Hartmann, F. X.

    1987-09-01

    The current theory of donor-acceptor interactions in solid-state materials is based on a random distribution of donors and acceptors through the crystal. In this paper, we present a model to calculate the observable transfer rates for the correlated positioning of donors and acceptors in laser materials. Chemical effects leading to such correlations are discussed.

  5. Method of producing carbon monoxide and hydrogen by gasification of solid carbonaceous material involving microwave irradiation

    SciTech Connect

    Helm, J.L. Jr.

    1984-03-06

    A process is claimed for the gasification of carbon of solid carbonaceous material to form carbon monoxide and hydrogen by contacting the material with superheated steam and irradiating the product of said contacting with an amount of microwave energy sufficient to gasify said carbon, and apparatus therefor.

  6. Environmental management of solid waste: Dredged material and mine tailings

    SciTech Connect

    Salomons, W.; Forstner, U.

    1988-01-01

    The problems and questions mine tailings and dredged materials pose with regard to safe environmental deposition are similar: aquatic versus terrestrial disposal, revegetation, leaching of contaminants. Larger projects in the fields of both mine tailings reclamation and dredged material disposal are increasingly requiring a multidisciplinary team approach. A major part of mineral reserves are in less-developed countries with limited environmental controls. Such experience implies far-going demands from the host countries: (1) reclamation should be carried out, as far as possible, during the life of the mine; (2) technology to ameliorate long-term effects should be as self-supporting as possible; (3) simple, reliable, low-energy techniques for minimizing deleterious effects of mining should be developed. Separate abstracts are processed for 14 chapters in this book for inclusion in the appropriate data bases.

  7. Determining mechanical behavior of solid materials using miniature specimens

    DOEpatents

    Manahan, M.P.; Argon, A.S.; Harling, O.K.

    1986-02-04

    A Miniaturized Bend Test (MBT) capable of extracting and determining mechanical behavior information from specimens only so large as to have at least a volume or smallest dimension sufficient to satisfy continuum behavior in all directions is disclosed. The mechanical behavior of the material is determined from the measurements taken during the bending of the specimen and is processed according to the principles of linear or nonlinear material mechanics or both. In a preferred embodiment the determination is carried out by a code which is constructed according to the finite element method, and the specimen used for the determinations is a miniature disk simply supported for central loading at the axis on the center of the disk. 51 figs.

  8. Determining mechanical behavior of solid materials using miniature specimens

    DOEpatents

    Manahan, Michael P.; Argon, Ali S.; Harling, Otto K.

    1986-01-01

    A Miniaturized Bend Test (MBT) capable of extracting and determining mechanical behavior information from specimens only so large as to have at least a volume or smallest dimension sufficient to satisfy continuum behavior in all directions. The mechanical behavior of the material is determined from the measurements taken during the bending of the specimen and is processed according to the principles of linear or nonlinear material mechanics or both. In a preferred embodiment the determination is carried out by a code which is constructed according to the finite element method, and the specimen used for the determinations is a miniature disk simply supported for central loading at the axis on the center of the disk.

  9. Development and evaluation of an ablative closeout material for solid rocket booster thermal protection system

    NASA Technical Reports Server (NTRS)

    Patterson, W. J.

    1979-01-01

    A trowellable closeout/repair material designated as MTA-2 was developed and evaluated for use on the Solid Rocket Booster. This material is composed of an epoxy-polysulfide binder and is highly filled with phenolic microballoons for density control and ablative performance. Mechanical property testing and thermal testing were performed in a wind tunnel to simulate the combined Solid Rocket Booster trajectory aeroshear and heating environments. The material is characterized by excellent thermal performance and was used extensively on the Space Shuttle STS-1 and STS-2 flight hardware.

  10. LCSR Method to Verify the Attachment of Temperature Sensors and Strain Gauges to Solid Material

    NASA Astrophysics Data System (ADS)

    Hashemian, H. M.

    2003-09-01

    Resistance Temperature Detectors (RTDs) and thermocouples in some applications are attached to solid surfaces or imbedded in solid material for measurement of temperature of the solid material or the material within the solid boundary. For example, thermocouples are imbedded in the nozzle of Solid Rocket Motors (SRMs) to measure the temperature of the lining material of the nozzle. These thermocouples must remain intact during SRM firing tests to provide an accurate temperature profile especially under transient temperature conditions. This paper describes the Loop Current Step Response (LCSR) method that was developed for this and a number of other applications. This method is based on heating the thermocouple with an electric current to characterize the heat transfer condition around the measuring tip of the thermocouple. The same principle can also be used to verify the attachment of RTDs and strain gauges to solid surfaces. This is important in such applications as fuel leak detection in space shuttle engines, measurement of fluid temperatures within pressure sensing lines in nuclear power plants, and diagnostics of problems in instrumentation which involve strain gauges.

  11. Some Open Questions in the Physics of Interstellar Dust

    NASA Astrophysics Data System (ADS)

    Draine, Bruce T.

    2014-06-01

    Our efforts to understand interstellar dust proceed by trying to develop models that are consistent with the laws of physics as well as with the many observational constraints provided by astronomical observations, the meteoritic record, and observations of interstellar dust grains entering the solar system today.I will review some open questions in physics and surface chemistry that are important for current modeling of dust.Nature has provided us with hundreds of spectroscopic clues -- the diffuse interstellar bands -- and it is an embarrasment that we haven't yet been able to decipher them.Interstellar grains contain iron, which could be in ferromagnetic or ferrimagnetic materials. If so, does magnetic dissipation contribute significantly to emission from dust at microwave and submm frequencies? This can be addressed in the laboratory.We do know that interstellar grains are not spherical, but we don't know whether they are compact, or whether they are have extended "fluffy" structures. To find out, we will have to compare observed optical properties of interstellar dust with theoretical models. How can we calculate the optical properties of fluffy grains at wavelengths ranging from X-rays to far-infrared? Theoretical methods will be described.It seems very likely that interstellar grains are often destroyed in the ISM; if so, then the observed abundance of grains requires that new grain material be formed in interstellar space. How can grain materials "grow" in the ISM? In particular, is it possible to grow amorphous silicates in cold interstellar clouds? What about carbonaceous material, in particular the nanoparticles that are thought to be responsible for the strong "PAH" emission bands? The possibilities and limitations of laboratory studies will be discussed.

  12. Novel functionalized polymeric fabric and fiber material as solid support for solid-phase synthesis and biomedical applications

    NASA Astrophysics Data System (ADS)

    Xiang, Bei

    The aim of the research is to develop novel polymer solid support by modifying or fabricating polymeric fibrous materials for peptide synthesis and biomedical applications. Originally chemical inert isotactic polypropylene (iPP) fabric was utilized and modified to serve as a functional flexible planar solid support for solid phase peptide synthesis. The modification was achieved through thermal initiated radical grafting polymerization using acrylic acid, poly (ethylene glycol) diacrylate as monomers, and benzoyl peroxide as radical initiator. The iPP fabric was successfully functionalized and possessing as high as 0.7mmol/g carboxylic acid groups. Peptide ligand LHPQF was successfully synthesized on the new functional planar support. Specific enzyme immobilization was fulfilled on the functional iPP fabric support. A commercially available ethylene-acrylic acid copolymer was made into ultrafine copolymer fiber bundles which are composed of nanofibers with diameters ranging from 200nm to 800nm. Various mixing ratios of copolymer/matrix materials were utilized to explore the effect on the final nanofiber physical properties including morphology and stability in solvents. The surface carboxylic acid groups were further converted to amino groups before the functional nanofibers can be applied in solid phase peptide synthesis. Two peptide ligands, LHPQF and HWRGWV, were also successfully synthesized on the nanofiber bundles. Streptavidin and human immunoglobulin G specific binding with the corresponding ligand which was anchored on the nanofibers was conducted successfully to illustrate the potential applications of the nanofiber materials in biomedical field. Further study on the dispersion of the ethylene-acrylic acid nanofiber bundles was pursued to take advantage of the super high active surface area of functional nanofibers. To manipulate the polymer nanofibers during synthesis and bio-assays, a technique was developed to controllably assemble and disperse the

  13. Process for hydroliquefying coal or like carbonaceous solid materials

    DOEpatents

    Malek, John Michael

    1977-01-01

    In this process the products of the dissolution-hydrogenation of coal or the like material in a hydrocarbon rich solvent are subjected in their slurryform fraction to an asphaltenes decomposing action of an alkali, like caustic soda or, being admixed after the gasiform fraction of the hydrogenation products has been taken off the slurryform fraction of the hydrogenation products now including the admixed alkali is subjected to a rehydrogenation by a hydrogen rich gas which after its rehydrogenating use is preferably applied, as source of hydrogen, to said dissolution-hydrogenation of coal. Optionally the admixed alkali includes minor amounts of a carboxylic acid salt of calcium.

  14. Interstellar and Planetary Analogs in the Laboratory

    NASA Technical Reports Server (NTRS)

    Salama, Farid

    2013-01-01

    We present and discuss the unique capabilities of the laboratory facility, COSmIC, that was developed at NASA Ames to investigate the interaction of ionizing radiation (UV, charged particles) with molecular species (neutral molecules, radicals and ions) and carbonaceous grains in the Solar System and in the Interstellar Medium (ISM). COSmIC stands for Cosmic Simulation Chamber, a laboratory chamber where interstellar and planetary analogs are generated, processed and analyzed. It is composed of a pulsed discharge nozzle (PDN) expansion that generates a free jet supersonic expansion in a plasma cavity coupled to two ultrahigh-sensitivity, complementary in situ diagnostics: a cavity ring down spectroscopy (CRDS) system for photonic detection and a Reflectron time-of-flight mass spectrometer (ReTOF-MS) for mass detection. This setup allows the study of molecules, ions and solids under the low temperature and high vacuum conditions that are required to simulate some interstellar, circumstellar and planetary physical environments providing new fundamental insights on the molecular level into the processes that are critical to the chemistry in the ISM, circumstellar and planet forming regions, and on icy objects in the Solar System. Recent laboratory results that were obtained using COSmIC will be discussed, in particular the progress that have been achieved in monitoring in the laboratory the formation of solid particles from their gas-phase molecular precursors in environments as varied as circumstellar outflow and planetary atmospheres.

  15. System Design and New Materials for Reversible, Solid-Oxide, High Temperature Steam Electrolysis

    SciTech Connect

    Ruud, J.A.

    2007-12-20

    High temperature solid oxide electrolysis cells (SOECs) offer high electrical efficiency and a potential path to large scale hydrogen production. Solid oxide technology is capable of both power generation and hydrogen production. That makes it possible for the development of a reversible solid-oxide system that can respond to market conditions to produce electricity or hydrogen on demand. New high-temperature electrolyzer cell materials are needed to enable cost-effective hydrogen production system designs based on reversible steam electrolysis. Two test methods were established for the eventual development of the reversible, durable electrode materials: the button cell test and the oxygen electrode test. The button cell test is capable of evaluating the performance and degradation of full solid oxide cells with dual atmosphere of air and hydrogen-steam. The oxygen electrode test is capable of isolating the performance and degradation of the oxygen electrode. It has higher throughput and sensitivity than the button cell test.

  16. Alternative materials for solid oxide fuel cells: Factors affecting air-sintering of chromite interconnections

    SciTech Connect

    Chick, L.A.; Bates, J.L.

    1992-07-01

    The purpose of this research is to develop alternative materials for solid oxide fuel cell (SOFC) interconnections and electrodes with improved electrical, thermal and electrochemical properties. Another objective is to develop synthesis and fabrication processes for these materials whereby they can be consolidated in air into SOFCs. The approach is to (1) develop modifications of the current, state-of-the-art materials used in SOFCs, (2) minimize the number of cations used in the SOFC materials to reduce potential deleterious interactions, (3) improve thermal, electrical, and electrochemical properties, (4) develop methods to synthesize both state-of-the-art and alternative materials for the simultaneous fabrication and consolidation in air of the interconnections and electrodes with the solid electrolyte, and (5) understand electrochemical reactions at materials interfaces and the effects of component compositions and processing on those reactions.

  17. 75 FR 34573 - Bulk Solid Hazardous Materials: Harmonization With the International Maritime Solid Bulk Cargoes...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-17

    ... FR 3316). D. Public Meeting We do not now plan to hold a public meeting. You may submit a request for... Environmental Protection Agency FR Federal Register HMR Hazardous Materials Regulations, 49 CFR Parts 171-180... transported without special permit from the Coast Guard; the list was last revised in 1984 (49 FR 16794)....

  18. Cr/sup 3+/-doped colquiriite solid state laser material

    SciTech Connect

    Payne, S.A.; Chase, L.L.; Newkirk, H.W.; Krupke, W.F.

    1989-03-07

    Chromium doped colquiriite, LiCaAlF/sub 6/:Cr/sup 3+/, is useful as a tunable laser crystal that has a high intrinsic slope efficiency, comparable to or exceeding that of alexandrite, the current leading performer of vibronic sideband Cr/sup 3+/ lasers. The laser output is tunable from at least 720 nm to 840 nm with a measured slope efficiency of about 60% in a Kr laser pumped laser configuration. The intrinsic slope efficiency (in the limit of large output coupling) may approach the quantum defect limited value of 83%. The high-slope efficiency implies that excited state absorption (ESA) is negligible. The potential for efficiency and the tuning range of this material satisfy the requirements for a pump laser for a high density storage medium incorporating Nd/sup 3+/ or Tm/sup 3+/ for use in a multimegajoule single shot fusion research facility.

  19. Cr/sup 3 +/-doped colquiriite solid state laser material

    SciTech Connect

    Payne, S.A.; Chase, L.L.; Newkirk, H.W.; Krupke, W.F.

    1988-03-31

    Chromium doped colquiriite, LiCaAlF/sub 6/:Cr/sup 3 +/, is useful as a tunable laser crystal that has a high intrinsic slope efficiency, comparable to or exceeding that of alexandrite, the current leading performer of vibronic sideband Cr/sup 3 +/ lasers. The laser output is tunable from at least 720 nm to 840 nm with a measured slope efficiency of about 60% in a Kr laser pumped laser configuration. The intrinsic slope efficiency (in the limit of large output coupling) may approach the quantum defect limited value of 83%. The high slope efficiency implies that excited state absorption (ESA) is negligible. The potential for efficiency and the tuning range of this material satisfy the requirements for a pump laser for a high density storage medium incorporating Nd/sup 3 +/ or Tm/sup 3 +/ for use in a multimegajoule single shot fusion research facility. 4 figs.

  20. Cr.sup.3+ -doped colquiriite solid state laser material

    SciTech Connect

    Payne, Stephen A.; Chase, Lloyd L.; Newkirk, Herbert W.; Krupke, William F.

    1989-01-01

    Chromium doped colquiriite, LiCaAlF.sub.6 :Cr.sup.3+, is useful as a tunable laser crystal that has a high intrinsic slope efficiency, comparable to or exceeding that of alexandrite, the current leading performer of vibronic sideband Cr.sup.3+ lasers. The laser output is tunable from at least 720 nm to 840 nm with a measured slop efficiency of about 60% in a Kr laser pumped laser configuration. The intrinsic slope efficiency (in the limit of large output coupling) may approach the quantum defect limited value of 83%. The high slope efficiency implies that excited state absorption (ESA) is negligible. The potential for efficiency and the tuning range of this material satisfy the requirements for a pump laser for a high density storage medium incorporating Nd.sup.3+ or Tm.sup.3+ for use in a multimegajoule single shot fusion research facility.

  1. Determination of Material Properties in the Semi-Solid State Using Gleeble Simulator

    SciTech Connect

    Solek, Krzysztof; Kuziak, Roman; Kapranos, Plato

    2007-04-07

    This work shows that the Gleeble thermomechanical simulator can be used to carry out controlled material tests. Although originally the simulator was not designed for testing materials in the semi-solid state, it could be adapted to such tests with only minor changes based on the construction of a special chamber for material heating and moulds for material shaping. To achieve this, a special resistance heating system was developed and installed in the Gleeble simulator. The design of a heating chamber that allows uniform heating of the material was achieved by computer simulations. The numerical model of the resistance heating developed and the results of calculations are described in detail.

  2. The Interstellar Medium

    NASA Technical Reports Server (NTRS)

    Tielens, Alexander G. G. M.

    1995-01-01

    The Interstellar Medium (ISM) forms an integral part of the lifecycle of stars and the galaxy. Stars are formed by gravitational contraction of interstellar clouds. Over their life, stars return much of their mass to the ISM through winds and supernova explosions, resulting in a slow enrichment in heavy elements. Understanding the origin and evolution of the ISM is a key problem within astrophysics. The KAO has made many important contributions to studies of the interstellar medium both on the macro and on the micro scale. In this overview, I will concentrate on two breakthroughs in the last decade in which KAO observations have played a major role: (1) the importance of large Polycyclic Aromatic Hydrocarbon (PAH) molecules for the ISM (section 3) and (2) the study of Photodissociation Regions (PDRs) as an analog for the diffuse ISM at large (section 4). Appropriately, the micro and macro problem are intricately interwoven in these problems. Finally, section 5 reviews the origin of the (CII) emission observed by COBE.

  3. Interstellar Grain Surface Chemistry

    NASA Technical Reports Server (NTRS)

    Tielens, Alexander G. G. M.; Cuzzi, Jeffrey N. (Technical Monitor)

    1995-01-01

    Chemistry on grain surfaces plays an Important role in the formation of interstellar Ices, It can also influence the composition of the gas phase through outgassing near luminous, newly formed stars. This paper reviews the chemical processes taking place on Interstellar grain surfaces with the emphasis on those transforming CO into other hydrocarbons. At low, molecular cloud temperatures (approximately equal to 10K), physisorption processes dominate interstellar grain surface chemistry and GO is largely hydrogenated through reactions with atomic H and oxidized through reactions with atomic O. The former will lead to the formation of H2CO and CH3OH ices, while the latter results in CO2 ice. The observational evidence for these ices in molecular clouds will be discussed. Very close to protostars, the gas and grain temperatures are much higher (approximately equal to 500K) and chemisorption processes, including catalytic surface reactions, becomes important. This will be illustrated based upon our studies of the Fischer-Tropsch Synthesis of CH4 from CO on metallic surfaces. Likely, this process has played an important role in the early solar nebula. Observational consequences will be pointed out.

  4. Material growth and characterization for solid state devices

    NASA Technical Reports Server (NTRS)

    Collis, Ward J.; Abul-Fadl, A.; Iyer, S.

    1987-01-01

    During this period InGaAs and InGaAsP were grown on (100)InP by liquid phase electroepitaxy (LPEE). Results of the epitaxial growth of InGaAs on sputtered quartz masked substrates are presented. The resulting surface morphology can be related to the current density distribution near the edges of a masked pattern. The quaternary InGaAs was grown with compositions corresponding to 1.3 micron and 1.5 micron emission wavelengths. Growth rates were found to be linearly dependent upon current density, and a strong dependence upon composition was noted. These compositions lie in the miscibility gap region of the alloy phase diagram at the 645 C growth temperature. Growths were performed at 685 C to avoid the miscibility gap. Epilayers were characterized by photoluminescence, X-ray diffraction, secondary ion mass spectrometry, and Hall effect measurements. Aluminum oxide was deposited on silicon and InGaAs substrates for the characterization of this material as an insulator in a field effect transistor structure. It was determined that the results did not warrant further work with the deposition from an aluminum isopropoxide source. A metallographic vapor phase epitaxy system installation is nearing completion for use in hybrid III-V semiconductor epilayer growths.

  5. Materials modeling by design: applications to amorphous solids

    NASA Astrophysics Data System (ADS)

    Biswas, Parthapratim; Tafen, D. N.; Inam, F.; Cai, Bin; Drabold, D. A.

    2009-02-01

    In this paper, we review a host of methods used to model amorphous materials. We particularly describe methods which impose constraints on the models to ensure that the final model meets a priori requirements (on structure, topology, chemical order, etc). In particular, we review work based on quench from the melt simulations, the 'decorate and relax' method, which is shown to be a reliable scheme for forming models of certain binary glasses. A 'building block' approach is also suggested and yields a pleading model for GeSe1.5. We also report on the nature of vulcanization in an Se network cross-linked by As, and indicate how introducing H into an a-Si network develops into a-Si:H. We also discuss explicitly constrained methods including reverse Monte Carlo (RMC) and a novel method called 'Experimentally Constrained Molecular Relaxation'. The latter merges the power of ab initio simulation with the ability to impose external information associated with RMC.

  6. Materials modeling by design: applications to amorphous solids.

    PubMed

    Biswas, Parthapratim; Tafen, D N; Inam, F; Cai, Bin; Drabold, D A

    2009-02-25

    In this paper, we review a host of methods used to model amorphous materials. We particularly describe methods which impose constraints on the models to ensure that the final model meets a priori requirements (on structure, topology, chemical order, etc). In particular, we review work based on quench from the melt simulations, the 'decorate and relax' method, which is shown to be a reliable scheme for forming models of certain binary glasses. A 'building block' approach is also suggested and yields a pleading model for GeSe(1.5). We also report on the nature of vulcanization in an Se network cross-linked by As, and indicate how introducing H into an a-Si network develops into a-Si:H. We also discuss explicitly constrained methods including reverse Monte Carlo (RMC) and a novel method called 'Experimentally Constrained Molecular Relaxation'. The latter merges the power of ab initio simulation with the ability to impose external information associated with RMC. PMID:21817359

  7. Coupling phase transition kinetics and hydrodynamics: Models for solid-solid and liquid-solid transformation in dynamically driven materials

    NASA Astrophysics Data System (ADS)

    Belof, Jonathan; Benedict, Lorin; Chernov, Alexander; Hall, Burl; Hamel, Sebastien; Haxhimali, Tomorr; Sadigh, Babak; Zepeda-Ruiz, Luis

    High pressure and high strain-rate experiments are opening a new frontier toward the study of material science under extreme conditions. As the energy density of experimental platforms is increased, the timescale for observation is typically decreased to the point where the time dependence of phase transitions is now a subject of direct study. We will present new phase transition kinetics models that have been developed with unique considerations that arise in shock-wave driven phase transformation, highlighting applications of the methodology to the simulation of recent experiments of iron and water. This work is performed under the auspices of the U. S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  8. From interstellar dust to comets

    NASA Technical Reports Server (NTRS)

    Greenberg, J. M.

    1989-01-01

    The bulk and microstructure of comet nuclei are derived from the morphological structure and chemical composition of submicron sized interstellar dust grains which have undergone cold aggregation in the pre-solar nebula. The evolutionary picture of dust which is emerging is a cyclic one in which the particles, before being destroyed or going into solar system bodies, find themselves during their 5 billion year lifetime alternately in diffuse clouds and in molecular clouds. A small silicate core captured within a molecular cloud accretes various ices and gradually builds up an inner mantle of organic refractory material which has been produced by photoprocessing of the volatile ices. Clumps of grains form, and then clumps of clumps, and so on, until finally we reach the size of the comet nucleus.

  9. Detection of solid C(triple bond)N bearing materials on solar system bodies

    NASA Technical Reports Server (NTRS)

    Cruikshank, Dale P.; Hartmann, W. K.; Tholen, David J.; Allamandola, L. J.; Brown, R. H.; Matthews, C. N.; Bell, J. F.

    1991-01-01

    We found observational evidence for the presence of C(triple bond)N-bearing solid materials on four classes of Solar System bodies: comets, asteroids, the rings of Uranus, and Saturn's satellite Iapetus. Gaseous CN was known in comet spectra, and the IR spectra of Comet P/Halley show emission of the CN fundamental at 4.5 microns interpreted as solids containing CN- group in the grains of the inner coma. The presented data offer the first evidence for chemically related material on the other objects.

  10. Detection of solid C(triple bond)N bearing materials on solar system bodies

    NASA Astrophysics Data System (ADS)

    Cruikshank, Dale P.; Hartmann, W. K.; Tholen, David J.; Allamandola, L. J.; Brown, R. H.; Matthews, C. N.; Bell, J. F.

    1991-10-01

    We found observational evidence for the presence of C(triple bond)N-bearing solid materials on four classes of Solar System bodies: comets, asteroids, the rings of Uranus, and Saturn's satellite Iapetus. Gaseous CN was known in comet spectra, and the IR spectra of Comet P/Halley show emission of the CN fundamental at 4.5 microns interpreted as solids containing CN- group in the grains of the inner coma. The presented data offer the first evidence for chemically related material on the other objects.

  11. Remote photoacoustic imaging on solid material using a two-wave mixing interferometer.

    PubMed

    Berer, Thomas; Hochreiner, Armin; Zamiri, Saeid; Burgholzer, Peter

    2010-12-15

    We report on remote and contactless photoacoustic imaging (PAI) for the inspection of solid materials using a two-wave mixing interferometer. In this Letter, a semitransparent sample was excited with picosecond laser pulses. The local absorption of the electromagnetic radiation led to generation of broadband ultrasonic waves inside the sample. Ultrasonic waves arriving at the sample surface were detected utilizing a two-wave mixing interferometer. After data acquisition, the initial pressure distribution was reconstructed using a Fourier space synthetic aperture technique algorithm. We show the potential of PAI for the inspection of semitransparent solid materials. PMID:21165120

  12. Data summary of municipal solid waste management alternatives. Volume 7, Appendix E -- Material recovery/material recycling technologies

    SciTech Connect

    1992-10-01

    The enthusiasm for and commitment to recycling of municipal solid wastes is based on several intuitive benefits: Conservation of landfill capacity; Conservation of non-renewable natural resources and energy sources; Minimization of the perceived potential environmental impacts of MSW combustion and landfilling; Minimization of disposal costs, both directly and through material resale credits. In this discussion, ``recycling`` refers to materials recovered from the waste stream. It excludes scrap materials that are recovered and reused during industrial manufacturing processes and prompt industrial scrap. Materials recycling is an integral part of several solid waste management options. For example, in the preparation of refuse-derived fuel (RDF), ferrous metals are typically removed from the waste stream both before and after shredding. Similarly, composting facilities, often include processes for recovering inert recyclable materials such as ferrous and nonferrous metals, glass, Plastics, and paper. While these two technologies have as their primary objectives the production of RDF and compost, respectively, the demonstrated recovery of recyclables emphasizes the inherent compatibility of recycling with these MSW management strategies. This appendix discusses several technology options with regard to separating recyclables at the source of generation, the methods available for collecting and transporting these materials to a MRF, the market requirements for post-consumer recycled materials, and the process unit operations. Mixed waste MRFs associated with mass bum plants are also presented.

  13. Aluminum Foils of the Stardust Interstellar Collector: The Challenge of Recognizing Micrometer-sized Impact Craters made by Interstellar Grains

    NASA Technical Reports Server (NTRS)

    Kearsley, A. T.; Westphal, A. J.; Burchell, M. J.; Zolensky, Michael E.

    2008-01-01

    Preliminary Examination (PE) of the Stardust cometary collector revealed material embedded in aerogel and on aluminium (Al) foil. Large numbers of sub-micrometer impact craters gave size, structural and compositional information. With experience of finding and analyzing the picogram to nanogram mass remains of cometary particles, are we now ready for PE of the Interstellar (IS) collector? Possible interstellar particle (ISP) tracks in the aerogel are being identified by the stardust@home team. We are now assessing challenges facing PE of Al foils from the interstellar collector.

  14. The Nature of Interstellar Dust

    NASA Technical Reports Server (NTRS)

    Huss, G. R.

    2003-01-01

    The STARDUST mission is designed to collect dust the coma of comet Wild 2 and to collect interstellar dust on a second set of collectors. We have a reasonable idea of what to expect from the comet dust collection because the research community has been studying interplanetary dust particles for many years. It is less clear what we should expect from the interstellar dust. This presentation discusses what we might expect to find on the STARDUST interstellar dust collector.

  15. Collection-efficient, axisymmetric vacuum sublimation module for the purification of solid materials

    NASA Astrophysics Data System (ADS)

    May, Michael; Paul, Elizabeth; Katovic, Vladimir

    2015-11-01

    A vacuum sublimation module of axisymmetric geometry was developed and employed to purify solid-phase materials. The module provides certain practical advantages and it comprises: a metering valve, glass collector, glass lower body, main seal, threaded bushing, and glass internal cartridge (the latter to contain starting material). A complementary process was developed to de-solvate, sublime, weigh, and collect solid chemical materials exemplified by oxalic acid, ferrocene, pentachlorobenzene, chrysene, and urea. The oxalic acid sublimate was analyzed by titration, melting range, Fourier Transform Infrared (FT-IR) Spectroscopy, cyclic voltammetry, and its (aqueous phase) electrolytically generated gas. The analytical data were consistent with a high-purity, anhydrous oxalic acid sublimate. Cyclic voltammograms of 0.11 mol. % oxalic acid in water displayed a 2.1 V window on glassy carbon electrode beyond which electrolytic decomposition occurs. During module testing, fifteen relatively pure materials were sublimed with (energy efficient) passive cooling and the solid-phase recovery averaged 95 mass %. Key module design features include: compact vertical geometry, low-angle conical collector, uniformly compressed main seal, modest power consumption, transparency, glovebox compatibility, cooling options, and preferential conductive heat transfer. To help evaluate the structural (module) heat transfer, vertical temperature profiles along the dynamically evacuated lower body were measured versus electric heater power: for example, an input of 18.6 W generated a temperature 443-K at the bottom. Experimental results and engineering calculations indicate that during sublimation, solid conduction is the primary mode of heat transfer to the starting material.

  16. Research on ignition and flame spread of solid materials in Japan

    NASA Technical Reports Server (NTRS)

    Ito, Kenichi; Fujita, Osamu

    1995-01-01

    Fire safety is one of the main concerns for crewed missions such as the space station. Materials used in spacecraft may burn even if metalic. There are severe restrictions on the materials used in spacecraft from the view of fire safety. However, such restrictions or safety standards are usually determined based on experimental results under normal gravity, despite large differences between the phenomena under normal and microgravity. To evaluate the appropriateness of materials for use in space, large amount of microgravity fire-safety combustion data is urgently needed. Solid material combustion under microgravity, such as ignition and flame spread, is a relatively new research field in Japan. As the other reports in this workshop describe, most of microgravity combustion research in Japan is droplet combustion as well as some research on gas phase combustion. Since JAMIC, the Japan Microgravity Center, (which offers 10 seconds microgravity time) opened in 1992, microgravity combustion research is robust, and many drop tests relating to solid combustion (paper combustion, cotton string combustion, metal combustion with Aluminium or Magnesium) have been performed. These tests proved that the 10 seconds of microgravity time at JAMIC is useful for solid combustion research. Some experiments were performed before JAMIC opened. For example, latticed paper was burned under microgravity by using a 50 m drop tower to simulate porous material combustion under microgravity. A 50 m tower provides only 2 seconds microgravity time however, and it was not long enough to investigate the solid combustion phenomena.

  17. Solid State Ionics 4. Proceedings of Materials Research Society Symposium, volume 369

    NASA Astrophysics Data System (ADS)

    Nazri, Gholam-Abbas; Tarascon, Jean-Marie; Schreiber, Martha

    The proceeding of the 4th Solid State Ionics symposium is presented. This first part of the proceeding deals with the chemistry and physics of insertion materials, mostly from the viewpoint of applications as cathode materials for rechargeable lithium batteries, Ni/Cd, and Ni/metal hydride systems. Crystal chemistry and electrochemistry properties of potential oxides cathodes are discussed. The second part of the proceeding deals with sol-gel process for preparation of cathode materials for lithium batteries and other applications. Novel synthetic methods of preparation of high surface area transition metal oxides are presented. The third part deals with theory of ion conduction in solids, as well as mechanisms of ion conduction in glassy and polymeric materials. Part four deals with defect chemistry in solid electrolytes and the role of defect on ionic conductivity of ceramic electrolytes. The fifth part of the proceedings deals with polymer electrolytes and electrodes. Synthesis, characterization and performance of various polymer electrolytes and electrodes are discussed. The last part of the proceedings deals with characteristics and materials aspect of ionic devices. this includes advance solid state batteries, sensors, electrochromic devices, fuel cells, and the dynamic of ion exchange in high T(c) superconductors.

  18. Interstellar clouds and molecular hydrogen

    NASA Technical Reports Server (NTRS)

    Jura, M.

    1977-01-01

    Data obtained from the Copernicus Orbiting Astronomical Observatory, launched in 1972 and still obtaining information, are used in a discussion of the interstellar medium. The Copernicus instruments have facilitated direct estimates for the density and temperature of individual interstellar clouds, and improved the ability to determine where along the line of sight a cloud lies with respect to background stars. The physical characteristics of hydrogen molecules are considered, with attention to the formation and destruction of interstellar hydrogen. The differences between 'thin' clouds, in which molecular hydrogen is optically thin, and 'thick' clouds are examined. Several features of the interstellar medium are described.

  19. Review of comparative energy use in materials potentially recoverable from municipal solid waste

    NASA Astrophysics Data System (ADS)

    Renard, M. L.

    1982-03-01

    Published literature on the energy savings that might be realized from manufacturing four materials present in municipal solid waste (MSW), using recycled rather than virgin materials is reviewed. The four materials examined are glass, paper, steel, and aluminum. An attempt is made to assess this energy savings, reported by diverse sources, on a consistent basis or at least by pointing out the conceptual bases on which the results were obtained. Significant savings in manufacturing energy are achievable for aluminum, steel, glass, and certain grades of paper. These materials are all potentially recoverable from the municipal solid waste stream, but must be of a purity and in a form acceptable to the respective industries for reuse in manufacturing.

  20. Isotope Fractionation in the Interstellar Medium

    NASA Technical Reports Server (NTRS)

    Charnley, Steven

    2011-01-01

    Anomalously fractionated isotopic material is found in many primitive Solar System objects, such as meteorites and comets. It is thought, in some cases, to trace interstellar matter that was incorporated into the Solar Nebula without undergoing significant processing. We will present the results of models of the nitrogen, oxygen, and carbon fractionation chemistry in dense molecular clouds, particularly in cores where substantial freeze-out of molecules on to dust has occurred. The range of fractionation ratios expected in different interstellar molecules will be discussed and compared to the ratios measured in molecular clouds, comets and meteoritic material. These models make several predictions that can be tested in the near future by molecular line observations, particularly with ALMA.

  1. An automatic granular structure generation and finite element analysis of heterogeneous semi-solid materials

    NASA Astrophysics Data System (ADS)

    Sharifi, Hamid; Larouche, Daniel

    2015-09-01

    The quality of cast metal products depends on the capacity of the semi-solid metal to sustain the stresses generated during the casting. Predicting the evolution of these stresses with accuracy in the solidification interval should be highly helpful to avoid the formation of defects like hot tearing. This task is however very difficult because of the heterogeneous nature of the material. In this paper, we propose to evaluate the mechanical behaviour of a metal during solidification using a mesh generation technique of the heterogeneous semi-solid material for a finite element analysis at the microscopic level. This task is done on a two-dimensional (2D) domain in which the granular structure of the solid phase is generated surrounded by an intergranular and interdendritc liquid phase. Some basic solid grains are first constructed and projected in the 2D domain with random orientations and scale factors. Depending on their orientation, the basic grains are combined to produce larger grains or separated by a liquid film. Different basic grain shapes can produce different granular structures of the mushy zone. As a result, using this automatic grain generation procedure, we can investigate the effect of grain shapes and sizes on the thermo-mechanical behaviour of the semi-solid material. The granular models are automatically converted to the finite element meshes. The solid grains and the liquid phase are meshed properly using quadrilateral elements. This method has been used to simulate the microstructure of a binary aluminium-copper alloy (Al-5.8 wt% Cu) when the fraction solid is 0.92. Using the finite element method and the Mie-Grüneisen equation of state for the liquid phase, the transient mechanical behaviour of the mushy zone under tensile loading has been investigated. The stress distribution and the bridges, which are formed during the tensile loading, have been detected.

  2. Solid oxide fuel cells, and air electrode and electrical interconnection materials therefor

    DOEpatents

    Bates, J.L.

    1992-09-01

    In one aspect of the invention, an air electrode material for a solid oxide fuel cell comprises Y[sub 1[minus]a]Q[sub a]MnO[sub 3], where Q is selected from the group consisting of Ca and Sr or mixtures thereof and a' is from 0.1 to 0.8. Preferably, a' is from 0.4 to 0.7. In another aspect of the invention, an electrical interconnection material for a solid oxide fuel cell comprises Y[sub 1[minus]b]Ca[sub b]Cr[sub 1[minus]c]Al[sub c]O[sub 3], where b' is from 0.1 to 0.6 and c' is from 0 to 9.3. Preferably, b' is from 0.3 to 0.5 and c' is from 0.05 to 0.1. A composite solid oxide electrochemical fuel cell incorporating these materials comprises: a solid oxide air electrode and an adjacent solid oxide electrical interconnection which commonly include the cation Y, the air electrode comprising Y[sub 1[minus]a]Q[sub a]MnO[sub 3], where Q is selected from the group consisting of Ca and Sr or mixtures thereof and a' is from 0.1 to 0.8, the electrical interconnection comprising Y[sub 1[minus]b]Ca[sub b]Cr[sub 1[minus]c]Al[sub c]O[sub 3], where b' is from 0.1 to 0.6 and c' is from 0.0 to 0.3; a yttrium stabilized solid electrolyte comprising (1[minus]d)ZrO[sub 2]-(d)Y[sub 2]O[sub 3] where d' is from 0.06 to 0.5; and a solid fuel electrode comprising X-ZrO[sub 2], where X' is an elemental metal. 5 figs.

  3. Solid oxide fuel cells, and air electrode and electrical interconnection materials therefor

    DOEpatents

    Bates, J. Lambert

    1992-01-01

    In one aspect of the invention, an air electrode material for a solid oxide fuel cell comprises Y.sub.1-a Q.sub.a MnO.sub.3, where "Q" is selected from the group consisting of Ca and Sr or mixtures thereof and "a" is from 0.1 to 0.8. Preferably, "a" is from 0.4 to 0.7. In another aspect of the invention, an electrical interconnection material for a solid oxide fuel cell comprises Y.sub.1-b Ca.sub.b Cr.sub.1-c Al.sub.c O.sub.3, where "b" is from 0.1 to 0.6 and "c" is from 0 to 9.3. Preferably, "b" is from 0.3 to 0.5 and "c" is from 0.05 to 0.1. A composite solid oxide electrochemical fuel cell incorporating these materials comprises: a solid oxide air electrode and an adjacent solid oxide electrical interconnection which commonly include the cation Y, the air electrode comprising Y.sub.1-a Q.sub.a MnO.sub.3, where "Q" is selected from the group consisting of Ca and Sr or mixtures thereof and "a" is from 0.1 to 0.8, the electrical interconnection comprising Y.sub.1-b Ca.sub.b Cr.sub.1-c Al.sub.c O.sub.3, where "b" is from 0.1 to 0.6 and "c" is from 0.0 to 0.3; a yttrium stabilized solid electrolyte comprising (1-d)ZrO.sub.2 -(d)Y.sub.2 O.sub.3 where "d" is from 0.06 to 0.5; and a solid fuel electrode comprising X-ZrO.sub.2, where "X" is an elemental metal.

  4. New instrumentation technologies for testing the bonding of sensors to solid materials

    NASA Technical Reports Server (NTRS)

    Hashemian, H. M.; Shell, C. S.; Jones, C. N.

    1996-01-01

    This report presents the results of a comprehensive research and development project that was conducted over a three-year period to develop new technologies for testing the attachment of sensors to solid materials for the following NASA applications: (1) testing the performance of composites that are used for the lining of solid rocket motor nozzles, (2) testing the bonding of surface-mounted platinum resistance thermometers that are used on fuel and oxidizer lines of the space shuttle to detect valve leaks by monitoring temperature, (3) testing the attachment of strain gages that are used in testing the performance of space shuttle main engines, and (4) testing the thermocouples that are used for determining the performance of blast tube liner material in solid rocket boosters.

  5. Short time proton dynamics in bulk ice and in porous anode solid oxide fuel cell materials

    SciTech Connect

    Basoli, Francesco; Senesi, Roberto; Kolesnikov, Alexander I; Licoccia, Silvia

    2014-01-01

    Oxygen reduction and incorporation into solid electrolytes and the reverse reaction of oxygen evolution play a cru-cial role in Solid Oxide Fuel Cell (SOFC) applications. However a detailed un derstanding of the kinetics of the cor-responding reactions, i.e. on reaction mechanisms, rate limiting steps, reaction paths, electrocatalytic role of materials, is still missing. These include a thorough characterization of the binding potentials experienced by protons in the lattice. We report results of Inelastic Neutron Scattering (INS) measurements of the vibrational state of the protons in Ni- YSZ highly porous composites (75% to 90% ), a ceramic-metal material showing a high electrical conductivity and ther mal stability, which is known to be most effectively used as anodes for solid ox ide fuel cells. The results are compared with INS and Deep Inelastic Neutron Scattering (DINS) experiments on the proton binding states in bulk ice.

  6. Investigation of Carbonaceous Interstellar Dust Analogues by Infrared Spectroscopy: Effects of Energetic Processing

    NASA Astrophysics Data System (ADS)

    Maté, Belén; Jiménez-Redondo, Miguel; Tanarro, Isabel; Herrero, Victor Jose

    2015-06-01

    Carbonaceous compounds, both solids and gas-phase molecules, are found in very diverse astronomical media. A significant amount of the elemental carbon is found in small dust grains. This carbonaceous dust, mostly formed in the last stages of evolution of C-rich stars, is the carrier of characteristic IR absorption bands revealing the presence of aliphatic, aromatic and olefinic functional groups in variable proportions. Among the various candidate materials investigated as possible carriers of these bands, hydrogenated amorphous carbon (a-C:H) has led to the best agreement with the observations. Carbonaceous grains are processed by H atoms, UV radiation, cosmic rays and interstellar shocks in their passage from asymptotic giant branch stars to planetary nebulae and to the diffuse interstellar medium. The mechanisms of a-C:H production and evolution in astronomical media are presently a subject of intensive investigation. In this work we present a study of the stability of carbonaceous dust analogues generated in He+CH_4 radiofrequency discharges. In order to simulate the processing of dust in the interstellar environments, the samples have been subjected to electron bombardment, UV irradiation, and both He and H_2 plasma processing. IR spectroscopy is employed to monitor the changes in the structure and composition of the carbonaceous films. A.G.G.M. Tielens. Rev. Mod. Phys., 85, 1021 (2013) J.E. Chiar, A.G.G.M. Tielens, A.J. Adamson and A. Ricca. Astrophys. J., 770, 78 (2013)

  7. An Italian process for materials separation and recovery of municipal solid waste

    SciTech Connect

    Sim, W.J. ); Carrera, P. )

    1988-01-01

    This paper explains an Italian system for processing municipal solid wastes which recovers plastic, ferrous material, paper, aluminum, glass (if economic) and produces high quality refuse derived fuel if required. A system for composting the organic fraction and processes for improving the quality of the recovered materials is explained. The RDF from the system can be burned in a mass burn grate, traveling grate or fluidized bed boiler or alternatively can be reduced in volume and landfilled.

  8. X-ray diffraction from shocked materials: investigating solid-solid phase transitions

    NASA Astrophysics Data System (ADS)

    Wark, Justin

    2008-04-01

    X-ray diffraction on nanosecond and sub-nanosecond time-scales has proven to be a useful tool in investigating the transient response of shocked crystals. Perhaps the most notable success in this area has been the direct observation of the α- ɛ transition in laser-shocked single crystals of [001] iron. [1,2] The information extracted from the diffraction patterns has been shown to be in remarkable agreement with multi-million atom molecular dynamics calculations. [3] Having successfully observed the transition in single crystals shocked along the principal axis, several further challenges remain. Amongst these are the exploration of the response of single crystals to shocks propagating along other crystallographic directions (where significantly different response is predicted [4]) the role of pre-existing defects in the time-scale of the elastic/plastic response of the material, and any differences that may occur in polycrystalline compared with single crystal samples.[5] A further challenge will be the development of rapid compression techniques that take samples to off-Hugoniot states (for example so-called quasi-isentropic compression). If such states can be produced in a controlled way, much could potentially be learnt about the state of certain planetary cores, including our own. [1] D.H. Kalantar, J.F. Belak, G.W. Collins, J.D. Colvin, H.M. Davies, J.H. Eggert, T.C. Germann, J. Hawreliak, B.L. Holian, K. Kadau, P.S. Lomdahl, H.E. Lorenzana, M.A. Meyers, K. Rosolankova, M.S. Schneider, J. Sheppard, J.S. Stolken and J.S. Wark, Phys. Rev. Lett., 95 075502, 2005 [2] J. Hawreliak, J.D. Colvin, J.H.Eggert, D. Kalantar, H.E. Lorenzana, J.S. Stölken, H.M. Davies, T.C. Germann, B.L. Holian, K. Kadau, P.S. Lomdahl, A. Higginbotham, K. Rosolankova, J. Sheppard, and J.S. Wark, Phys. Rev. B, 74, 184107, 2006 [3] K. Kadau, Timothy C. Germann, Peter S. Lomdahl, and Brad Lee Holian, Science, 296, 1681, 2002 [4] Kai Kadau, Timothy C. Germann, Peter S. Lomdahl, and Brad

  9. Method for separating liquid and solid products of liquefaction of coal or like carbonaceous materials

    DOEpatents

    Malek, John M.

    1978-04-18

    A method of improving the quality of slurry products taken from coal liquefaction reactors comprising subjecting the slurry to treatment with an alkaline compound such as caustic soda in the presence of steam in order to decompose the phenolic and acidic materials present in the slurry, and to also lower the slurry viscosity to allow separation of solid particles by sedimentation.

  10. VOLATILE ORGANO-METALLOIDS IN BIO-SOLID MATERIALS: ANALYSIS BY VACUUM DISTILLATION-GC/MS

    EPA Science Inventory

    An analytical method based on vacuum distillation-gas chromatography-mass spectrometry (VD-GC-MS)

    was developed for determining volatile organo-metalloid contaminants in bio-solid materials. Method

    performance was evaluated for dimethylselenide (DMSe), dimethyldisel...

  11. 40 CFR 227.32 - Liquid, suspended particulate, and solid phases of a material.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Liquid, suspended particulate, and solid phases of a material. 227.32 Section 227.32 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING CRITERIA FOR THE EVALUATION OF PERMIT APPLICATIONS FOR OCEAN DUMPING...

  12. 49 CFR 173.241 - Bulk packagings for certain low hazard liquid and solid materials.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... portable tanks; marine portable tanks conforming to 46 CFR part 64; and non-DOT Specification portable... solid materials. 173.241 Section 173.241 Transportation Other Regulations Relating to Transportation... Other Than Class 1 and Class 7 § 173.241 Bulk packagings for certain low hazard liquid and...

  13. 49 CFR 173.241 - Bulk packagings for certain low hazard liquid and solid materials.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... portable tanks; marine portable tanks conforming to 46 CFR part 64; and non-DOT Specification portable... solid materials. 173.241 Section 173.241 Transportation Other Regulations Relating to Transportation... Other Than Class 1 and Class 7 § 173.241 Bulk packagings for certain low hazard liquid and...

  14. 49 CFR 173.241 - Bulk packagings for certain low hazard liquid and solid materials.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... portable tanks; marine portable tanks conforming to 46 CFR part 64; and non-DOT Specification portable... solid materials. 173.241 Section 173.241 Transportation Other Regulations Relating to Transportation... Other Than Class 1 and Class 7 § 173.241 Bulk packagings for certain low hazard liquid and...

  15. EUROPEAN DEVELOPMENTS IN THE RECOVERY OF ENERGY AND MATERIALS FROM MUNICIPAL SOLID WASTE

    EPA Science Inventory

    This is the report of a study which set out to determine whether priorities in Western Europe with respect to energy and materials recovery from municipal solid waste are the same as those in the United States, which include (a) the use of refuse as a supplementary fuel, (b) pyro...

  16. 76 FR 53897 - EPA Seeking Input Materials Measurement; Municipal Solid Waste (MSW), Recycling, and Source...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-30

    ... period established in the Federal Register of August 2, 2011 (76 FR 46290?) (FRL-9446-9). In that... AGENCY EPA Seeking Input Materials Measurement; Municipal Solid Waste (MSW), Recycling, and Source... management, recycling, measurement, data, data collection, construction and demolition (C&D)...

  17. 76 FR 46290 - EPA Seeking Input Materials Measurement; Municipal Solid Waste (MSW), Recycling, and Source...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-02

    ... AGENCY EPA Seeking Input Materials Measurement; Municipal Solid Waste (MSW), Recycling, and Source... INFORMATION: Background For decades, EPA has been providing information on the recycling, reuse and generation... safe recycling and source reduction. The Agency will consider the information gathered from this...

  18. Solid rocket booster thermal protection system materials development. [space shuttle boosters

    NASA Technical Reports Server (NTRS)

    Dean, W. G.

    1978-01-01

    A complete run log of all tests conducted in the NASA-MSFC hot gas test facility during the development of materials for the space shuttle solid rocket booster thermal protection system are presented. Lists of technical reports and drawings generated under the contract are included.

  19. ELIMINATION OF TOXIC MATERIALS AND SOLVENTS FROM SOLID PROPELLANT COMPONENTS (PP1058)

    EPA Science Inventory

    Solid rocket motor (srm) propellant used in military tactical and strategic missile weapon systems contain hazardous and toxic materials. Lead is used as a ballistic catalyst in minimum signature propellants. It's use results in approximately 161,000 pounds of lead compound usag...

  20. 75 FR 31843 - Identification of Non-Hazardous Secondary Materials That Are Solid Waste

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-04

    ... Petroleum Refineries 324110 Automotive Repair and Replacement 811111 Shops. Recyclable Material Wholesalers...''). See 70 FR 55568. In the CISWI Definitions Rule, EPA defined ``commercial and industrial solid waste... recycling. That discussion is relevant to this proposal and is incorporated into this rulemaking. We...

  1. Innovative interstellar explorer

    NASA Astrophysics Data System (ADS)

    McNutt, Ralph L.; Gold, Robert E.; Krimigis, Tom; Roelof, Edmond C.; Gruntman, Mike; Gloeckler, George; Koehn, Patrick L.; Kurth, William S.; Oleson, Steven R.; Fiehler, Douglas I.; Horanyi, Mihaly; Mewaldt, Richard A.; Leary, James C.; Anderson, Brian J.

    2006-09-01

    An interstellar ``precursor'' mission has been under discussion in the scientific community for at least 30 years. Fundamental scientific questions about the interaction of the Sun with the interstellar medium can only be answered with in situ measurements that such a mission can provide. The Innovative Interstellar Explorer (IIE) and its use of Radioisotope Electric Propulsion (REP) is being studied under a NASA ``Vision Mission'' grant. Speed is provided by a combination of a high-energy launch, using current launch vehicle technology, a Jupiter gravity assist, and long-term, low-thrust, continuous acceleration provided by an ion thruster running off electricity provided by advanced radioisotope electric generators. A payload of ten instruments with an aggregate mass of ~35 kg and requiring ~30 W has been carefully chosen to address the compelling science questions. The nominal 20-day launch window opens on 22 October 2014 followed by a Jupiter gravity assist on 5 February 2016. The REP system accelerates the spacecraft to a ``burnout'' speed of 7.8 AU per year at 104 AU on 13 October 2032 (Voyager 1's current speed is ~3.6 AU/yr). The spacecraft will return at least 500 bits per second from at least 200 AU ~30 years after launch. Additional (backup) launch opportunities occur every 13 months to early 2018. In addition to addressing basic heliospheric science, the mission will ensure continued information on the far-heliospheric galactic cosmic ray population after the Voyagers have fallen silent and as the era of human Mars exploration begins.

  2. Interstellar Probe: The Next Step To Flight

    NASA Astrophysics Data System (ADS)

    McNutt, Ralph; Zurbuchen, Thomas H.

    2016-07-01

    In the years following the discovery of the solar wind, the term "heliosphere" was coined and defined as "the region of interplanetary space where the solar wind is flowing supersonically." In June 1971, with the development of the Pioneer probes to Jupiter and beyond well underway, a session of the American Astronautical Society meeting considered scientific exploration reaching beyond the solar system and into the interstellar medium. Despite many discussions, studies, and meetings since, the most recent held under the auspices of the Keck Institute for Space Studies (8-11 September 2014 and 13-15 January 2015), such missions have been relegated to the '"future" due to the large distances and solar system escape speeds contemplated for their execution. In the meantime, the Voyager Interstellar Mission (VIM), consisting of the twin Voyager spacecraft almost 40 years since their respective launches, are making inroads into this region beyond the termination shock of the solar wind, a new region of the solid bodies of the solar system has been opened by the New Horizons flyby of the Pluto system, and the Cassini Ion and Neutral CAmera (INCA) and Interstellar Boundary Explorer (IBEX) have remotely sensed neutral atoms that have provided significant clues to the global structure of the interaction of the solar wind and interstellar medium. It is now time for a dedicated mission to the regime beyond the solar system to explore our galactic environment. A first, near-term implementation can be carried out with the near-current flight system technology. What is also clear is that the high speeds required will limit the spacecraft to a relatively small mass of no more than ~500 kg, regardless of the propulsion details. The recent success of the New Horizons mission at the Pluto system illustrates that with modern technologies, such spacecraft sizes can still accommodate the means to produce paradigm-shifting science, providing for a compelling scientific mission. The

  3. The Interstellar Heliopause Probe

    NASA Astrophysics Data System (ADS)

    Lyngvi, A.; Falkner, P.; Peacock, A.

    The Interstellar Heliopause Probe (IHP) is one of four Technology Reference Missions (TRM) introduced by the Planetary Exploration Studies Section of the Science Payload & Advanced Concepts Office (SCI-A) at ESA. The overall purpose of the TRMs is to focus the development of strategically important technologies of likely relevance to future science missions. This is accomplished through the study of several technologically demanding and scientifically interesting missions, which are currently not part of the ESA science programme. The TRM baseline uses small satellites (< 200kg), with highly miniaturized and highly integrated payload suites. The motivation for this is to use low resource spacecraft in a phased approach, which will reduce the risk and cost, compared to a single, high resource mission. Equipped with a Highly Integrated Payload Suite (HIPS) the IHP will answer scientific questions concerning the nature of the interstellar medium, how the interstellar medium affects our solar system and how the solar system impacts the interstellar medium. The HIPS, which is a standard element in all TRMs miniaturize through resource reduction, by using miniaturized components and sensors, and by sharing common structures and payload functionality. To achieve the scientific requirements of the mission the spacecraft is to leave the solar system as close to the heliosphere nose as possible and reach a distance of 200 AU from the Sun within 25 years. The requirement of all TRMs is to use a Souyz-Fregat version 2B or equivalent low cost launch vehicle. With this constraint no current propulsion system is capable of delivering the necessary mass to the final destination. Technologies are therefore needed to enable this mission. The current alternatives are using nuclear propulsion, either with radioisotope or reactor power system or solar sailing. All these alternatives are currently being investigated. Other challenges exist as well such as designing a communication link

  4. Abundant Solar Nebula Solids in Comets

    NASA Technical Reports Server (NTRS)

    Messenger, S.; Keller, L. P.; Nakamura-Messenger, K.; Nguyen, A. N.; Clemett, S.

    2016-01-01

    Comets have been proposed to consist of unprocessed interstellar materials together with a variable amount of thermally annealed interstellar grains. Recent studies of cometary solids in the laboratory have shown that comets instead consist of a wide range of materials from across the protoplanetary disk, in addition to a minor complement of interstellar materials. These advances were made possible by the return of direct samples of comet 81P/Wild 2 coma dust by the NASA Stardust mission and recent advances in microscale analytical techniques. Isotopic studies of 'cometary' chondritic porous interplanetary dust particles (CP-IDPs) and comet 81P/Wild 2 Stardust samples show that preserved interstellar materials are more abundant in comets than in any class of meteorite. Identified interstellar materials include sub-micron-sized presolar silicates, oxides, and SiC dust grains and some fraction of the organic material that binds the samples together. Presolar grain abundances reach 1 weight percentage in the most stardust-rich CP-IDPs, 50 times greater than in meteorites. Yet, order of magnitude variations in presolar grain abundances among CP-IDPs suggest cometary solids experienced significant variations in the degree of processing in the solar nebula. Comets contain a surprisingly high abundance of nebular solids formed or altered at high temperatures. Comet 81P/Wild 2 samples include 10-40 micron-sized, refractory Ca- Al-rich inclusion (CAI)-, chondrule-, and ameboid olivine aggregate (AOA)-like materials. The O isotopic compositions of these refractory materials are remarkably similar to their meteoritic counterparts, ranging from 5 percent enrichments in (sup 16) O to near-terrestrial values. Comet 81P/Wild 2 and CP-IDPs also contain abundant Mg-Fe crystalline and amorphous silicates whose O isotopic compositions are also consistent with Solar System origins. Unlike meteorites, that are dominated by locally-produced materials, comets appear to be composed of

  5. Solid waste initiative Macro Material Flow Modeling conceptual description and requirements

    SciTech Connect

    Holter, G.M.; Stapp, D.C.

    1993-01-01

    This report describes a Macro Material Flow Modeling (MMFM) concept and approach that are being adopted to develop a predictive modeling capability that can be used as the basis for evaluating potential impacts from various solid waste management system configurations and operating scenarios, as well as the impacts of various policies on solid waste quantities and compositions. This capability, as part of a broader Solid Waste Initiative at Pacific Northwest Laboratory, is intended to provide an increased understanding of solid waste as a disposal, energy, and resource problem on a national and global scale, particularly over the long term. The results of this increased understanding will eventually have an impact on a variety of US federal government activities, as well as on the activities of other entities. This increased understanding will also help provide the basis for subsequent activities under the Solid Waste Initiative. The report describes current solid waste management practices and their context, defines questions of interest relating to these practices, and proposes an approach that could be employed to analyze these practices and possible alternatives to them. A preliminary review, analysis, and summary of available data to support this approach are also provided.

  6. Stardust@home: A Massively Distributed Public Search for Interstellar Dust in the Stardust Interstellar Dust Collector

    NASA Technical Reports Server (NTRS)

    Westphal, Andrew J.; Butterworth, Anna L.; Snead, Christopher J.; Craig, Nahide; Anderson, David; Jones, Steven M.; Brownlee, Donald E.; Farnsworth, Richard; Zolensky, Michael E.

    2005-01-01

    In January 2006, the Stardust mission will return the first samples from a solid solar system body beyond the Moon. Stardust was in the news in January 2004, when it encountered comet Wild2 and captured a sample of cometary dust. But Stardust carries an equally important payload: the first samples of contemporary interstellar dust ever collected. Although it is known that interstellar (IS) dust penetrates into the inner solar system [2, 3], to date not even a single contemporary interstellar dust particle has been captured and analyzed in the laboratory. Stardust uses aerogel collectors to capture dust samples. Identification of interstellar dust impacts in the Stardust Interstellar Dust Collector probably cannot be automated, but will require the expertise of the human eye. However, the labor required for visual scanning of the entire collector would exceed the resources of any reasonably-sized research group. We are developing a project to recruit the public in the search for interstellar dust, based in part on the wildly popular SETI@home project, which has five million subscribers. We call the project Stardust@home. Using sophisticated chemical separation techniques, certain types of refractory ancient IS particles (so-called presolar grains) have been isolated from primitive meteorites (e.g., [4] ). Recently, presolar grains have been identified in Interplanetary Dust Particles[6]. Because these grains are not isolated chemically, but are recognized only by their unusual isotopic compositions, they are probably less biased than presolar grains isolated from meteorites. However, it is entirely possible that the typical interstellar dust particle is isotopically solar in composition. The Stardust collection of interstellar dust will be the first truly unbiased one.

  7. Visualizing Interstellar's Wormhole

    NASA Astrophysics Data System (ADS)

    James, Oliver; von Tunzelmann, Eugénie; Franklin, Paul; Thorne, Kip S.

    2015-06-01

    Christopher Nolan's science fiction movie Interstellar offers a variety of opportunities for students in elementary courses on general relativity theory. This paper describes such opportunities, including: (i) At the motivational level, the manner in which elementary relativity concepts underlie the wormhole visualizations seen in the movie; (ii) At the briefest computational level, instructive calculations with simple but intriguing wormhole metrics, including, e.g., constructing embedding diagrams for the three-parameter wormhole that was used by our visual effects team and Christopher Nolan in scoping out possible wormhole geometries for the movie; (iii) Combining the proper reference frame of a camera with solutions of the geodesic equation, to construct a light-ray-tracing map backward in time from a camera's local sky to a wormhole's two celestial spheres; (iv) Implementing this map, for example, in Mathematica, Maple or Matlab, and using that implementation to construct images of what a camera sees when near or inside a wormhole; (v) With the student's implementation, exploring how the wormhole's three parameters influence what the camera sees—which is precisely how Christopher Nolan, using our implementation, chose the parameters for Interstellar's wormhole; (vi) Using the student's implementation, exploring the wormhole's Einstein ring and particularly the peculiar motions of star images near the ring, and exploring what it looks like to travel through a wormhole.

  8. Interstellar Travel without 'Magic'

    NASA Astrophysics Data System (ADS)

    Woodcock, G.

    The possibility of interstellar space travel has become a popular subject. Distances of light years are an entirely new realm for human space travel. New means of propulsion are needed. Speculation about propulsion has included "magic", space warps, faster-than-light travel, known physics such as antimatter for which no practical implementation is known and also physics for which current research offers at least a hint of implementation, i.e. fusion. Performance estimates are presented for the latter and used to create vehicle concepts. Fusion propulsion will mean travel times of hundreds of years, so we adopt the "space colony" concepts of O'Neill as a ship design that could support a small civilization indefinitely; this provides the technical means. Economic reasoning is presented, arguing that development and production of "space colony" habitats for relief of Earth's population, with addition of fusion engines, will lead to vessels that can go interstellar. Scenarios are presented and a speculative estimate of a timetable is given.

  9. Interstellar Cloud Collisions

    NASA Astrophysics Data System (ADS)

    Lattanzio, J. C.; Monaghan, J. J.; Pongracic, H.; Schwarz, M. P.

    1985-07-01

    We describe the results of a three-dimensional numerical simulation of isothermal interstellar clouds in the absence of magnetic fields. A wide variety of high and low Mach number, head-on and off-centre collisions of clouds with mass ratios 1, 2.5, 5.0 and 10.1 have been studied. The results show that a necessary, but not sufficient, condition for the gravitational instability of a substantial fraction of the matter is that the initial clouds should be either marginally stable or unstable according to the usual Jeans criterion. The collisions, in general, do not result in one or more clouds. Instead we find, in most cases, that the matter disperses in an irregular way. The calculations therefore suggest that if the initial state of the interstellar medium is one of cool dense clouds in a hotter more tenuous background, collisions will rapidly mix the medium rather than produce a steady-state spectrum of cool clouds.

  10. An interstellar precursor mission

    NASA Technical Reports Server (NTRS)

    Jaffe, L. D.; Ivie, C.; Lewis, J. C.; Lipes, R.; Norton, H. N.; Stearns, J. W.; Stimpson, L. D.; Weissman, P.

    1980-01-01

    A mission out of the planetary system, launched about the year 2000, could provide valuable scientific data as well as test some of the technology for a later mission to another star. Primary scientific objectives for the precursor mission concern characteristics of the heliopause, the interstellar medium, stellar distances (by parallax measurements), low-energy cosmic rays, interplanetary gas distribution, and the mass of the solar system. Secondary objectives include investigation of Pluto. The mission should extend to 400-1000 AU from the sun. A heliocentric hyperbolic escape velocity of 50-100 km/sec or more is needed to attain this distance within a reasonable mission duration (20-50 years). The trajectory should be toward the incoming interstellar gas. For a year 2000 launch, a Pluto encounter and orbiter can be included. A second mission targeted parallel to the solar axis would also be worthwhile. The mission duration is 20 years, with an extended mission to a total of 50 years. A system using one or two stages of nuclear electric propulsion (NEP) was selected as a possible baseline. The most promising alternatives are ultralight solar sails or laser sailing, with the lasers in earth orbit, for example. The NEP baseline design allows the option of carrying a Pluto orbiter as a daughter spacecraft.

  11. Solid-State Thermal Reaction of a Molecular Material and Solventless Synthesis of Iron Oxide

    NASA Astrophysics Data System (ADS)

    Roy, Debasis; Roy, Madhusudan; Zubko, Maciej; Kusz, Joachim; Bhattacharjee, Ashis

    2016-09-01

    Solid-state thermal decomposition reaction of a molecular material {As}({C}6{H}5)4[{Fe}^{II}{Fe}^{III} ({C}2{O}4)3]}n has been studied using non-isothermal thermogravimetry (TG) in an inert atmosphere. By analyzing the TG data collected at multiple heating rates in 300 K-1300 K range, the kinetic parameters (activation energy, most probable reaction mechanism function and frequency factor) are determined using different multi-heating rate analysis programs. Activation energy and the frequency factor are found to be strongly dependent on the extent of decomposition. The decomposed material has been characterized to be hematite using physical techniques (FT-IR and powder XRD). Particle morphology has been checked by TEM. A solid-state reaction pathway leading the molecular precursor to hematite has been proposed illustrating an example of solventless synthesis of iron oxides utilizing thermal decomposition as a technique using innocuous materials.

  12. Mesoscale modeling of strain induced solid state amorphization in crystalline materials

    NASA Astrophysics Data System (ADS)

    Lei, Lei

    Solid state amorphization, and in particular crystalline to amorphous transformation, can be observed in metallic alloys, semiconductors, intermetallics, minerals, and also molecular crystals when they undergo irradiation, hydrogen gas dissolution, thermal interdiffusion, mechanical alloying, or mechanical milling. Although the amorphization mechanisms may be different, the transformation occurs due to the high level of disorder introduced into the material. Milling induced solid state amorphization is proposed to be the result of accumulation of crystal defects, specifically dislocations, as the material is subjected to large deformations during the high energy process. Thus, understanding the deformation mechanisms of crystalline materials will be the first step in studying solid state amorphization in crystalline materials, which not only has scientific contributions, but also technical consequences. A phase field dislocation dynamics (PFDD) approach is employed in this work to simulate plastic deformation of molecular crystals. This PFDD model has the advantage of tracking all of the dislocations in a material simultaneously. The model takes into account the elastic interaction between dislocations, the lattice resistance to dislocation motion, and the elastic interaction of dislocations with an external stress field. The PFDD model is employed to describe the deformation of molecular crystals with pharmaceutical applications, namely, single crystal sucrose, acetaminophen, gamma-indomethacin, and aspirin. Stress-strain curves are produced that result in expected anisotropic material response due to the activation of different slip systems and yield stresses that agree well with those from experiments. The PFDD model is coupled to a phase transformation model to study the relation between plastic deformation and the solid state amorphization of crystals that undergo milling. This model predicts the amorphous volume fraction in excellent agreement with

  13. Electrical, optical, and magnetic properties of organic solid-state materials IV. Materials Research Society, symposium proceedings Volume 488

    SciTech Connect

    Reynolds, J.R.; Jen, A.K.Y.; Rubner, M.F.; Chiang, L.Y.; Dalton, L.R.

    1998-07-01

    The symposium, Electrical, Optical, and Magnetic Properties of Organic Solid-State Materials IV, was sponsored by the Materials Research Society and held December 1--5, 1997, in Boston, Massachusetts. Early studies of charge transport in conducting polymers have evolved from the elucidation of fundamental structure/function relationships to applications as batteries, simple electrical devices such as diodes, chemical sensors, antistatic coatings, microwave and millimeter wave-absorbing materials, and photochromic devices. A particularly exciting evolution has been the discovery and development of organic light-emitting diodes (OLEDs) which appear to be nearing commercialization in an amazingly short period of time. This application is of particular interest because both electrical and optical properties must be considered, and these have been important parallel themes of the conference. Moreover, nanostructure control is important for OLEDs, and nanoscale architectural engineering has been an increasingly important theme of the conference. Indeed, not only has the study of conjugated (quasidelocalized) electrons in organic solid-state materials resulted in interesting physical properties and device applications, but the desire to exploit these properties has promoted the development of new synthesis and processing methodologies to achieve special nanoscale and microscale structures. One hundred five papers have been processed separately for inclusion on the data base.

  14. Discharge characteristics of lithium/molten nitrate thermal battery cells using silver salts as solid cathode materials

    NASA Astrophysics Data System (ADS)

    McManis, G. E.; Miles, M. H.; Fletcher, A. N.

    1985-12-01

    Thermal battery cells using molten nitrate electrolytes and liquid lithium anodes have been evaluated using several silver salts with low solubility in molten nitrates as solid cathode materials. These cathode materials do not readily diffuse into the anolyte and, thus, do not have parasitic reactions with the lithium anode. Furthermore, the solid cathode materials have voltammetric characteristics as favorable as many soluble silver salt cathodes. This paper presents the effects of temperature, current density, and cathode material on cell discharge characteristics.

  15. O VI absorption in interstellar cloud surfaces

    NASA Technical Reports Server (NTRS)

    Cowie, L. L.; Jenkins, E. B.; Songaila, A.; York, D. G.

    1979-01-01

    The velocity profiles of O VI absorption lines of 24 stars, observed in early Copernicus surveys, have been compared with the line profiles of Si III (1206.51 A) and N II (1083.99 A). The velocity structures of the O VI lines appear to be correlated with those of the material in the lower ionization stages. It is argued that the O VI absorption arises in the coronal gas of the conductive interface between hot gas, responsible for extended, soft X-ray emission, and cooler interstellar clouds. The velocity broadening of both sets of lines is attributed to motions of the cloud surfaces induced by pressure fluctuations in the interstellar medium.

  16. Collection-efficient, axisymmetric vacuum sublimation module for the purification of solid materials.

    PubMed

    May, Michael; Paul, Elizabeth; Katovic, Vladimir

    2015-11-01

    A vacuum sublimation module of axisymmetric geometry was developed and employed to purify solid-phase materials. The module provides certain practical advantages and it comprises: a metering valve, glass collector, glass lower body, main seal, threaded bushing, and glass internal cartridge (the latter to contain starting material). A complementary process was developed to de-solvate, sublime, weigh, and collect solid chemical materials exemplified by oxalic acid, ferrocene, pentachlorobenzene, chrysene, and urea. The oxalic acid sublimate was analyzed by titration, melting range, Fourier Transform Infrared (FT-IR) Spectroscopy, cyclic voltammetry, and its (aqueous phase) electrolytically generated gas. The analytical data were consistent with a high-purity, anhydrous oxalic acid sublimate. Cyclic voltammograms of 0.11 mol. % oxalic acid in water displayed a 2.1 V window on glassy carbon electrode beyond which electrolytic decomposition occurs. During module testing, fifteen relatively pure materials were sublimed with (energy efficient) passive cooling and the solid-phase recovery averaged 95 mass %. Key module design features include: compact vertical geometry, low-angle conical collector, uniformly compressed main seal, modest power consumption, transparency, glovebox compatibility, cooling options, and preferential conductive heat transfer. To help evaluate the structural (module) heat transfer, vertical temperature profiles along the dynamically evacuated lower body were measured versus electric heater power: for example, an input of 18.6 W generated a temperature 443-K at the bottom. Experimental results and engineering calculations indicate that during sublimation, solid conduction is the primary mode of heat transfer to the starting material. PMID:26628150

  17. Utilization of sepiolite materials as a bottom liner material in solid waste landfills.

    PubMed

    Guney, Yucel; Cetin, Bora; Aydilek, Ahmet H; Tanyu, Burak F; Koparal, Savas

    2014-01-01

    Landfill bottom liners are generally constructed with natural clay soils due to their high strength and low hydraulic conductivity characteristics. However, in recent years it is increasingly difficult to find locally available clay soils that satisfy the required engineering properties. Fine grained soils such as sepiolite and zeolite may be used as alternative materials in the constructions of landfill bottom liners. A study was conducted to investigate the feasibility of using natural clay rich in kaolinite, sepiolite, zeolite, and their mixtures as a bottom liner material. Unconfined compression tests, swell tests, hydraulic conductivity tests, batch and column adsorption tests were performed on each type of soil and sepiolite-zeolite mixtures. The results of the current study indicate that sepiolite is the dominant material that affects both the geomechanical and geoenvironmental properties of these alternative liners. An increase in sepiolite content in the sepiolite-zeolite mixtures increased the strength, swelling potential and metal adsorption capacities of the soil mixtures. Moreover, hydraulic conductivity of the mixtures decreased significantly with the addition of sepiolite. The utilization of sepiolite-zeolite materials as a bottom liner material allowed for thinner liners with some reduction in construction costs compared to use of a kaolinite-rich clay. PMID:24220149

  18. Electron spin resonance and its implication on the maximum nuclear polarization of deuterated solid target materials

    SciTech Connect

    Heckmann, J.; Meyer, W.; Radtke, E.; Reicherz, G.; Goertz, S.

    2006-10-01

    ESR spectroscopy is an important tool in polarized solid target material research, since it allows us to study the paramagnetic centers, which are used for the dynamic nuclear polarization (DNP). The polarization behavior of the different target materials is strongly affected by the properties of these centers, which are added to the diamagnetic materials by chemical doping or irradiation. In particular, the ESR linewidth of the paramagnetic centers is a very important parameter, especially concerning the deuterated target materials. In this paper, the results of the first precise ESR measurements of the deuterated target materials at a DNP-relevant magnetic field of 2.5 T are presented. Moreover, these results allowed us to experimentally study the correlation between ESR linewidth and maximum deuteron polarization, as given by the spin-temperature theory.

  19. Ionic liquid-modified materials for solid-phase extraction and separation: a review.

    PubMed

    Vidal, Lorena; Riekkola, Marja-Liisa; Canals, Antonio

    2012-02-17

    In recent years, materials science has propelled to the research forefront. Ionic liquids with unique and fascinating properties have also left their footprints to the developments of materials science during the last years. In this review we highlight some of their recent advances and provide an overview at the current status of ionic liquid-modified materials applied in solid-phase extraction, liquid and gas chromatography and capillary electrochromatography with reference to recent applications. In addition, the potential of ionic liquids in the modification of capillary inner wall in capillary electrophoresis is demonstrated. The main target material modified with ionic liquids is silica, but polymers and monoliths have recently joined the studies. Although imidazolium is still clearly the most commonly used ionic liquid for the covalently modification of materials, the exploitation of pyridinium and phosphonium will most probably increase in the future. PMID:22244164

  20. General introduction: Liquid and solid (materials, main properties and applications …)

    NASA Astrophysics Data System (ADS)

    Zabler, Simon

    2014-10-01

    A general introduction about the diversity of foam structures is given with focus onto the structural, mechanical and dynamical properties at hand. Two classes of materials are addressed: liquid and semi-solid foams, on the one hand, solid foams, on the other hand. The latter can be subdivided into metallic, ceramic and organic foams, depending on the nature of the solid skeleton that supports the overall cell structure. Solid foams generally stem from the concept of mechanical light-weight structures, but they can just as well be employed for their large surface area as well as for their acoustic and thermal properties. Modern biomaterials use tailored ceramic or organo-ceramic foams as bone scaffolds, whereas hierarchically micro- and nanoporous structures are being used by chemistry to control catalytic reactions. Future materials design and development is going to rely increasingly on natural and synthetic foam structures and properties, be it food, thermal insulators or car frames, thus giving a promising outlook onto the foam research and development that is about to come. xml:lang="fr"

  1. Solid-phase reaction synthesis of mesostructured tungsten disulfide material with a high specific surface area

    SciTech Connect

    An, Gaojun; Lu, Changbo; Xiong, Chunhua

    2011-09-15

    Highlights: {yields} WS{sub 2} material was synthesized through solid-phase reaction. {yields} (NH{sub 4}){sub 2}WS{sub 4} as precursor and n-octadecylamine as template. {yields} WS{sub 2} material has high specific surface area (145.9 m{sup 2}/g). {yields} The whole preparation process is simple, convenient, green and clean. -- Abstract: A mesostructured tungsten disulfide (WS{sub 2}) material was prepared through a solid-phase reaction utilizing ammonium tetrathiotungstate as the precursor and n-octadecylamine as the template. The as-synthesized WS{sub 2} material was characterized by X-ray powder Diffraction (XRD), Low-temperature N{sub 2} Adsorption (BET method), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM). The characterization results indicate that the WS{sub 2} material has the typical mesopore structure (3.7 nm) with a high specific surface area (145.9 m{sup 2}/g), and large pore volume (0.18 cm{sup 3}/g). This approach is novel, green and convenient. The plausible mechanism for the formation of the mesostructured WS{sub 2} material is discussed herein.

  2. An interstellar precursor mission

    NASA Technical Reports Server (NTRS)

    Jaffe, L. D.; Ivie, C.; Lewis, J. C.; Lipes, R. G.; Norton, H. N.; Stearns, J. W.; Stimpson, L.; Weissman, P.

    1977-01-01

    A mission out of the planetary system, with launch about the year 2000, could provide valuable scientific data as well as test some of the technology for a later mission to another star. Primary scientific objectives for the precursor mission concern characteristics of the heliopause, the interstellar medium, stellar distances (by parallax measurements), low energy cosmic rays, interplanetary gas distribution, and mass of the solar system. Secondary objectives include investigation of Pluto. Candidate science instruments are suggested. Individual spacecraft systems for the mission were considered, technology requirements and problem areas noted, and a number of recommendations made for technology study and advanced development. The most critical technology needs include attainment of 50-yr spacecraft lifetime and development of a long-life NEP system.

  3. Interstellar sulfur chemistry

    NASA Technical Reports Server (NTRS)

    Prasad, S. S.; Huntress, W. T., Jr.

    1980-01-01

    The results of a chemical model of SO, CS, and OCS chemistry in dense clouds are summarized. The results are obtained from a theoretical study of sulfur chemistry in dense interstellar clouds using a large-scale time-dependent model of gas-phase chemistry. Among the results are the following: (1) owing to activation energy, the reaction of CS with O atoms is efficient as a loss mechanism of CS during the early phases of cloud evolution or in hot and oxygen-rich sources such as the KL nebula; (2) if sulfur is not abnormally depleted in dense clouds, then the observed abundances of SO, SO2, H2S, CS, OCS, H2CS, and SiS indicate that sulfur is mostly atomic in dense clouds; and (3) OCS is stable against reactions with neutral atoms and radicals in dense clouds.

  4. Interstellar carbon in meteorites

    NASA Technical Reports Server (NTRS)

    Swart, P. K.; Grady, M. M.; Pillinger, C. T.; Lewis, R. S.; Anders, E.

    1983-01-01

    The Murchison and Allende chondrites contain up to 5 parts per million carbon that is enriched in carbon-13 by up to +1100 per mil (the ratio of carbon-12 to carbon-13 is approximately 42, compared to 88 to 93 for terrestrial carbon). This 'heavy' carbon is associated with neon-22 and with anomalous krypton and xenon showing the signature of the s-process (neutron capture on a slow time scale). It apparently represents interstellar grains ejected from late-type stars. A second anomalous xenon component ('CCFXe') is associated with a distinctive, light carbon (depleted in carbon-13 by 38 per mil), which, however, falls within the terrestrial range and hence may be of either local or exotic origin.

  5. Advanced materials and electrochemical processes in high-temperature solid electrolytes

    SciTech Connect

    Bates, J.L.; Chick, L.A.; Youngblood, G.E.; Weber, W.J.

    1990-10-01

    Fuel cells for the direct conversion of fossil fuels to electric energy necessitates the use of high-temperature solid electrodes. This study has included: (1) determination of electrical transport, thermal and electrical properties to illucidate the effects of microstructure, phase equilibria, oxygen partial pressure, additives, synthesis and fabrication on these properties; (2) investigation of synthesis and fabrication of advanced oxide materials, such as La{sub 0.9}Sn{sub 0.1}MnO{sub 3}; and (3) application of new analytical techniques using complex impedance coupled with conventional electrochemical methods to study the electrochemical processes and behavior of materials for solid oxide fuel cells and other high-temperature electrolyte electrochemical process. 15 refs., 10 figs., 2 tabs. (BM)

  6. Designing room-temperature multiferroic materials in a single-phase solid-solution film

    NASA Astrophysics Data System (ADS)

    Mao, H. J.; Song, C.; Cui, B.; Peng, J. J.; Li, F.; Xiao, L. R.; Pan, F.

    2016-09-01

    The search for multiferroic materials with simultaneous ferroelectric and ferromagnetic properties in a single phase at room temperature continues to be fuelled from the perspective of developing multifunctional devices. Here we design a single-phase multiferroic La0.67Sr0.33MnO3-BaTiO3 film, which possesses epitaxial single-crystal and solid-solution structure, high magnetic Curie temperature (~640 K) as well as switchable ferroelectric polarization. Moreover, a notable strain-mediated magnetoelectric coupling at room temperature in the way of modulating the magnetism with an external applied voltage is also observed. The synthetic solid-solution multiferroic film may open an extraordinary avenue for exploring a series of room-temperature multiferroic materials.

  7. Non-contact measurement of linear thermal expansion coefficients of solid materials by infrared image correlation

    NASA Astrophysics Data System (ADS)

    Montanini, R.; Freni, F.

    2014-01-01

    A new non-contact optical method (IIC, infrared image correlation) for the determination of the coefficients of thermal expansion of solid materials is presented. The proposed method is based on performing a digital image correlation between thermal images recorded at different temperatures by means of an infrared camera. It allows the coefficient of thermal expansion of both isotropic and anisotropic solid materials to be determined by measuring simultaneously the fractional increase in length and the actual thermal field over a small region of interest in which a dual-emissivity stochastic speckle pattern has been created. The results reported in this paper prove the effectiveness of the proposed method that can be applied either to carry out reference measurements in laboratory or to evaluate thermal stresses and strains on structural components in-field.

  8. Probing model interstellar grain surfaces with small molecules

    NASA Astrophysics Data System (ADS)

    Collings, M. P.; Frankland, V. L.; Lasne, J.; Marchione, D.; Rosu-Finsen, A.; McCoustra, M. R. S.

    2015-05-01

    Temperature-programmed desorption and reflection-absorption infrared spectroscopy have been used to explore the interaction of oxygen (O2), nitrogen (N2), carbon monoxide (CO) and water (H2O) with an amorphous silica film as a demonstration of the detailed characterization of the silicate surfaces that might be present in the interstellar medium. The simple diatomic adsorbates are found to wet the silica surface and exhibit first-order desorption kinetics in the regime up to monolayer coverage. Beyond that, they exhibit zero-order kinetics as might be expected for sublimation of bulk solids. Water, in contrast, does not wet the silica surface and exhibits zero-order desorption kinetics at all coverages consistent with the formation of an islanded structure. Kinetic parameters for use in astrophysical modelling were obtained by inversion of the experimental data at sub-monolayer coverages and by comparison with models in the multilayer regime. Spectroscopic studies in the sub-monolayer regime show that the C-O stretching mode is at around 2137 cm-1 (5.43 μm), a position consistent with a linear surface-CO interaction, and is inhomogenously broadened as resulting from the heterogeneity of the surface. These studies also reveal, for the first time, direct evidence for the thermal activation of diffusion, and hence de-wetting, of H2O on the silica surface. Astrophysical implications of these findings could account for a part of the missing oxygen budget in dense interstellar clouds, and suggest that studies of the sub-monolayer adsorption of these simple molecules might be a useful probe of surface chemistry on more complex silicate materials.

  9. Palynological Investigation of Post-Flight Solid Rocket Booster Foreign Material

    NASA Technical Reports Server (NTRS)

    Nelson, Linda; Jarzen, David

    2008-01-01

    Investigations of foreign material in a drain tube, from the Solid Rocket Booster (SRB) of a recent Space Shuttle mission, was identified as pollen. The source of the pollen is from deposits made by bees, collecting pollen from plants found at the Kennedy Space Center, Cape Canaveral, Florida. The pollen is determined to have been present in the frustum drain tubes before the shuttle flight. During the flight the pollen did not undergo thermal maturation.

  10. Analysis of stress singularities at singular points of elastic solids made of functionally graded materials

    NASA Astrophysics Data System (ADS)

    Matveenko, V. P.; Fedorov, A. Yu.; Shardakov, I. N.

    2016-01-01

    The results of analytical and numerical investigations on estimating the character of the singularity of stresses in a vicinity of different variants of special points of the 2D elastic solids made of functionally graded materials (FGMs) are presented. The variant of construction by analytical methods in the polar system of coordinates is considered for eigensolutions in the flat wedges made of the FGM, the elastic properties of which are represented as power series in terms of the radial coordinate.

  11. Evaluation of dry-solids-blend material source for grouts containing 106-AN waste: Final report

    SciTech Connect

    Spence, R.D.; Gilliam, T.M.; Osborne, S.C.; Francis, C.L.; Trotter, D.R.

    1993-09-01

    Stabilization/solidification technology is one of the most widely used techniques for the treatment and ultimate disposal of both radioactive and chemically hazardous wastes. Cement-based products, commonly referred to as grouts, are the predominant materials of choice because of their low associated processing costs, compatibility with a wide variety of disposal scenarios, and ability to meet stringent processing and performance requirements. Such technology is being utilized in a Grout Treatment Facility (GTF) by the Westinghouse Hanford Company (WHC) for the disposal of various wastes, including 106-AN wastes, located on the Hanford Reservation. The WHC personnel have developed a grout formula for 106-AN disposal that is designed to meet stringent performance requirements. This formula consists of a dry-solids blend containing 40 wt % limestone, 28 wt % granulated blast furnace slag (BFS), 28 wt % American Society for Testing and Materials (ASTM) Class F fly ash, and 4 wt % Type I-II-LA Portland cement. This blend is mixed with 106-AN at a mix ratio of 9 lb of dry-solids blend per gallon of waste. This report documents the final results of efforts at Oak Ridge National Laboratory in support of WHC`s Grout Technology Program to assess the effects of the source of the dry-solids-blend materials on the resulting grout formula.

  12. Matrix isolation as a tool for studying interstellar chemical reactions

    NASA Technical Reports Server (NTRS)

    Ball, David W.; Ortman, Bryan J.; Hauge, Robert H.; Margrave, John L.

    1989-01-01

    Since the identification of the OH radical as an interstellar species, over 50 molecular species were identified as interstellar denizens. While identification of new species appears straightforward, an explanation for their mechanisms of formation is not. Most astronomers concede that large bodies like interstellar dust grains are necessary for adsorption of molecules and their energies of reactions, but many of the mechanistic steps are unknown and speculative. It is proposed that data from matrix isolation experiments involving the reactions of refractory materials (especially C, Si, and Fe atoms and clusters) with small molecules (mainly H2, H2O, CO, CO2) are particularly applicable to explaining mechanistic details of likely interstellar chemical reactions. In many cases, matrix isolation techniques are the sole method of studying such reactions; also in many cases, complexations and bond rearrangements yield molecules never before observed. The study of these reactions thus provides a logical basis for the mechanisms of interstellar reactions. A list of reactions is presented that would simulate interstellar chemical reactions. These reactions were studied using FTIR-matrix isolation techniques.

  13. PAH Clusters and the Interstellar Infrared Emission Bands

    NASA Astrophysics Data System (ADS)

    Ricca, Alessandra; Roser, Joseph

    2016-06-01

    Polycyclic aromatic hydrocarbons (or PAHs) are the leading candidate for the emitters of the interstellar aromatic infrared emission bands. Some aspects of these emission bands indicate a contribution from PAH clusters. To better assess this contribution, we measured infrared absorption spectra of a series of homogeneous and heterogeneous PAH clusters using matrix isolation spectroscopy in solid argon and we performed theoretical calculations. The spectral shifts observed in the absorption spectra as a function of the PAH concentration can be related to preferred cluster structures forming in the argon matrix. Based upon our results, we predict that the large PAHs present in the interstellar medium are likely to have clusters with redshifted absorption bands in the C–H out-of-plane bending region. These clusters could contribute to a well-known red-shading observed in the profile of the interstellar 11.2 micron emission band.

  14. Repulsive Casimir forces between solid materials with high-refractive-index intervening liquids

    SciTech Connect

    Zwol, P. J. van; Palasantzas, G.

    2010-06-15

    In order to explore repulsive Casimir or van der Waals forces between solid materials with liquid as the intervening medium, we analyze dielectric data for a wide range of materials as, for example, (p)olytetrafluoroethylene, polystyrene, silica, and more than 20 liquids. Although significant variation in the dielectric data from different sources exists, we provide a scheme based on measured static dielectric constants, refractive indices, and applying Kramers-Kronig consistency to dielectric data to create accurate dielectric functions at imaginary frequencies. The latter is necessary for more accurate force calculations via the Lifshitz theory, thereby allowing reliable predictions of repulsive Casimir forces.

  15. From Brittle to Pliant Viscoelastic Materials with Solid State Linear Polyphosphonium - Carboxylate Assemblies

    PubMed Central

    Godeau, Guilhem; Navailles, Laurence; Nallet, Frédéric; Lin, Xinrong; McIntosh, Thomas J.; Grinstaff, Mark W.

    2013-01-01

    A polystyrenylphosphonium polymer was synthesized and complexed with various carboxylic acid derivatives to form new solid-state polyelectrolyte-surfactant assemblies. The properties of these ionic materials were highly dependent on the nature of the anion and included a brittle material, a rubbery ball that bounces, or a sticky fiber. The values for the equilibrium modulus, storage modulus, and loss modulus were dependent on the composition of the carboxylic acid and the number of electrostatic interactions. Small-angle X-ray scattering studies on the supramolecular assemblies confirmed a bilayer structure for two of the assemblies. PMID:24511156

  16. Large-Spot Material Interactions with a High-Power Solid-State Laser Beam

    SciTech Connect

    Boley, C D; Fochs, S N; Rubenchik, A M

    2008-08-06

    We study the material interactions produced by the beam of a 25-kW solid-state laser, in experiments characterized by relatively large spot sizes ({approx}3 cm) and the presence of airflow. The targets are iron or aluminum slabs, of thickness 1 cm. In the experiments with iron, we show that combustion plays an important role in heating the material. In the experiments with aluminum, we observe a sharp transition from no melting to complete melt-through as the intensity on target increases. A layer of paint greatly reduces the requirements for melt-through. We explain these effects and incorporate them into an overall computational model.

  17. Review of Physics Related Research and Development Activities in Nondestructive Characterization of Solid Rocket Motor Materials

    NASA Astrophysics Data System (ADS)

    Pearson, Lee H.

    1998-10-01

    The perception that solid rocket motors (srm) are of relatively simple mechanical construction with a long history in private, military, and NASA applications may lead some to believe that little is left to be done in terms of basic and applied research and development in support of this technology. The fact is that srm?s are very complicated primarily because of the complexity of the materials from which they are built. The reliability and performance of srm?s are determined by the ballistic and mechanical properties of each individual material component, and by the manufacturing processes that conjoin these materials. In order to insure reliability and good performance, there are on-going materials research and development activities in the srm community. Included are activities involving the development of nondestructive evaluation (NDE) methods used for materials and processes characterization. Typical applications include: detection and characterization of defects in fiber reinforced composite materials, detection of weak bonds and debonds, verification of surface cleanliness prior to bonding, characterization of aging materials and bondlines, measurement of elastic properties in filled polymeric materials, monitoring of cure in polymeric materials, and measurement of film or coating thicknesses. NDE methods and physics principles upon which they are based will be described. Challenges and future research and development directions will be identified.

  18. High reliability solid refractive index matching materials for field installable connections in FTTH network

    NASA Astrophysics Data System (ADS)

    Saito, Kotaro; Kihara, Mitsuru; Shimizu, Tomoya; Yoneda, Keisuke; Kurashima, Toshio

    2015-06-01

    We performed environmental and accelerated aging tests to ensure the long-term reliability of solid type refractive index matching material at a splice point. Stable optical characteristics were confirmed in environmental tests based on an IEC standard. In an accelerated aging test at 140 °C, which is very much higher than the specification test temperature, the index matching material itself and spliced fibers passing through it had steady optical characteristics. Then we performed an accelerated aging test on an index matching material attached to a built-in fiber before splicing it in the worst condition, which is different from the normal use configuration. As a result, we confirmed that the repeated insertion and removal of fiber for splicing resulted in failure. We consider that the repetition of adhesion between index matching material and fibers causes the splice to degrade. With this result, we used the Arrhenius model to estimate a median lifetime of about 68 years in a high temperature environment of 60 °C. Thus solid type index matching material at a splice point is highly reliable over long periods under normal conditions of use.

  19. 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.

  20. Detection of Interstellar Urea

    NASA Astrophysics Data System (ADS)

    Kuo, Hsin-Lun; Remijan, Anthony J.; Snyder, Lewis E.; Looney, Leslie W.; Friedel, Douglas N.; Lovas, Francis J.; McCall, Benjamin J.; Hollis, Jan M.

    2010-11-01

    Urea, a molecule discovered in human urine by H. M. Rouelle in 1773, has a significant role in prebiotic chemistry. Previous BIMA observations have suggested that interstellar urea [(NH2)2CO] is a compact hot core molecule such as other large molecules (e.g. methyl formate and acetic acid). We have conducted an extensive search for urea toward the high mass hot molecular core Sgr B2(N-LMH) using BIMA, CARMA and the IRAM 30 m. Because the spectral lines of heavy molecules like urea tend to be weak and hot cores display lines from a wide range of molecules, it is necessary to detect a number of urea lines and apply sophisticated statistical tests before having confidence in an identification. The 1 mm resolution of CARMA enables favorable coupling of the source size and synthesized beam size, which was found to be essential for the detection of weak signals. We have detected a total of 65 spectral lines (32 molecular transitions and 33 unidentified transitions), most of which are narrower than the SEST survey (Nummelin et al. 1998) due to the small synthesized beam (2.5" x 2") of CARMA. It significantly resolves out the contamination by extended emission and reveals the eight weak urea lines that were previously blended with nearby transitions. Our analysis indicates that these lines are likely to be urea since the resulting observed line frequencies are coincident with a set of overlapping connecting urea lines, and the observed line intensities are consistent with the expected line strengths of urea. In addition, we have developed a new statistical approach to examine the spatial correlation between the observed lines by applying the Student's t test to the high resolution channel maps obtained from CARMA. The t test shows consistent spatial distributions from all eight candidate lines, suggesting a common molecular origin, urea. Our t test method could have a broad impact on the next generation of arrays, such as ALMA, because the new arrays will require a method

  1. Photoluminescence by Interstellar Dust

    NASA Astrophysics Data System (ADS)

    Vijh, U. P.

    2005-12-01

    In this dissertation talk, I will report on our study of interstellar dust through the process of photoluminescence (PL). We present the discovery of a new band of dust PL, blue luminescence (BL) with λ peak ˜ 370 nm in the proto-planetary nebula known as the Red Rectangle (RR). We attribute this to fluorescence by small, 3-4-ringed polycyclic aromatic hydrocarbon (PAH) molecules. Further analysis reveals additional independent evidence for the presence of small PAHs in this nebula. Detection of BL using long-slit spectroscopic observations in other ordinary reflection nebulae suggests that the BL carrier is an ubiquitous component of the ISM and is not restricted to the particular environment of the RR. We present the spatial distribution of the BL in these nebulae and find that the BL is spatially correlated with IR emission structures attributed to aromatic emission features (AEFs), attributed to PAHs. The carrier of the dust-associated photoluminescence process causing the extended red emission (ERE), known now for over twenty five years, remains unidentified. We constrain the character of the ERE carrier by determining the wavelengths of the radiation that initiates the ERE -- λ < 118 nm. We note that under interstellar conditions most PAH molecules are ionized to the di-cation stage by photons with E > 10.5 eV and that the electronic energy level structure of PAH di-cations is consistent with fluorescence in the wavelength band of the ERE. I will also present first results from ongoing work: Using narrow-band imaging, we present the optical detection of the circum-binary disk of the RR in the light of the BL, and show that the morphology of the BL and ERE emissions in the RR nebula are almost mutually exclusive. It is very suggestive to attribute them to different ionization stages of the same family of carriers such as PAH molecules. Financial support for this study was provided through NSF Grant AST0307307 to The University of Toledo.

  2. Photoluminescence by Interstellar Dust

    NASA Astrophysics Data System (ADS)

    Vijh, U. P.

    2005-08-01

    In this dissertation, we report on our study of interstellar dust through the process of photoluminescence (PL). We present the discovery of a new band of dust PL, blue luminescence (BL) with λpeak˜370 nm in the proto-planetary nebula known as the Red Rectangle (RR). We attribute this to fluorescence by small, 3-4-ringed polycyclic aromatic hydrocarbon (PAH) molecules. Further analysis reveals additional independent evidence for the presence of small PAHs in this nebula. Detection of BL using long-slit spectroscopic observations in other ordinary reflection nebulae suggests that the BL carrier is an ubiquitous component of the ISM and is not restricted to the particular environment of the RR. We present the spatial distribution of the BL in these nebulae and find that the BL is spatially correlated with IR emission structures attributed to aromatic emission features (AEFs), attributed to PAHs. The carrier of the dust-associated photoluminescence process causing the extended red emission (ERE), known now for over twenty five years, remains unidentified. We constrain the character of the ERE carrier by determining the wavelengths of the radiation that initiates the ERE -- λ < 118 nm. We note that under interstellar conditions most PAH molecules are ionized to the di-cation stage by photons with E > 10.5 eV and that the electronic energy level structure of PAH di-cations is consistent with fluorescence in the wavelength band of the ERE. In the last few chapters of the dissertation we present first results from ongoing work: i) Using narrow-band imaging, we present the optical detection of the circum-binary disk of the RR in the light of the BL, and show that the morphology of the BL and ERE emissions in the RR nebula are almost mutually exclusive. It is very suggestive to attribute them to different ionization stages of the same family of carriers such as PAH molecules. ii) We also present a pure spectrum of the BL free of scattered light, resolved into seven

  3. Solid-state resistance upset welding: A process with unique advantages for advanced materials

    SciTech Connect

    Kanne, W.R. Jr.

    1993-12-31

    Solid-state resistance upset welding is suitable for joining many alloys that are difficult to weld using fusion processes. Since no melting takes place, the weld metal retains many of the characteristics of the base metal. Resulting welds have a hot worked structure, and thereby have higher strength than fusion welds in the same mate. Since the material being joined is not melted, compositional gradients are not introduced, second phase materials are minimally disrupted, and minor alloying elements, do not affect weldability. Solid-state upset welding has been adapted for fabrication of structures considered very large compared to typical resistance welding applications. The process has been used for closure of capsules, small vessels, and large containers. Welding emphasis has been on 304L stainless steel, the material for current applications. Other materials have, however, received enough attention to have demonstrated capability for joining alloys that are not readily weldable using fusion welding methods. A variety of other stainless steels (including A-286), superalloys (including TD nickel), refractory metals (including tungsten), and aluminum alloys (including 2024) have been successfully upset welded.

  4. Study of transport of laser-driven relativistic electrons in solid materials

    NASA Astrophysics Data System (ADS)

    Leblanc, Philippe

    With the ultra intense lasers available today, it is possible to generate very hot electron beams in solid density materials. These intense laser-matter interactions result in many applications which include the generation of ultrashort secondary sources of particles and radiation such as ions, neutrons, positrons, x-rays, or even laser-driven hadron therapy. For these applications to become reality, a comprehensive understanding of laser-driven energy transport including hot electron generation through the various mechanisms of ionization, and their subsequent transport in solid density media is required. This study will focus on the characterization of electron transport effects in solid density targets using the state-of- the-art particle-in-cell code PICLS. A number of simulation results will be presented on the topics of ionization propagation in insulator glass targets, non-equilibrium ionization modeling featuring electron impact ionization, and electron beam guiding by the self-generated resistive magnetic field. An empirically derived scaling relation for the resistive magnetic in terms of the laser parameters and material properties is presented and used to derive a guiding condition. This condition may prove useful for the design of future laser-matter interaction experiments.

  5. Crystallization of solid-state materials via decomplexation of soluble complexes

    SciTech Connect

    Doxsee, K.M.

    1998-10-01

    A variety of compounds which are at best sparingly soluble in aqueous media may be readily brought into solution through the formation of soluble coordination complexes. Modification of experimental conditions through, e.g., dilution or slow removal of the complexing agent, leads to supersaturation and, consequently, crystallization of the original solid-state phase. This technique of decomplexation crystallization, both of simple inorganic coordination complexes and of complexes with macrocyclic organic chelating agents, offers the opportunity both to effect the recrystallization of sparingly soluble species and to modify their crystal morphology. Similarly, precursors for solid-state materials may be solubilized in nonaqueous solvents through the formation of soluble complexes and then allowed to undergo reaction crystallization, allowing the examination of both solvent effects and chelation effects on the morphology and phase of the resulting solid-state materials. These effects are often dramatic, and such complexation-mediated crystallization approaches offer promise for the facile preparation of metastable phases from simple precursors under ambient conditions.

  6. Laser-solid interaction and dynamics of the laser-ablated materials

    SciTech Connect

    Chen, K.R.; Leboeuf, J.N.; Geohegan, D.B.; Wood, R.F.; Donato, J.M.; Liu, C.L.; Puretzky, A.A.

    1995-07-01

    Rapid transformations through the liquid and vapor phases induced by laser-solid interactions are described by the authors` thermal model with the Clausius-Clapeyron equation to determine the vaporization temperature under different surface pressure condition. Hydrodynamic behavior of the vapor during and after ablation is described by gas dynamic equations. These two models are coupled. Modeling results show that lower background pressure results lower laser energy density threshold for vaporization. The ablation rate and the amount of materials removed are proportional to the laser energy density above its threshold. The authors also demonstrate a dynamic source effect that accelerates the unsteady expansion of laser-ablated material in the direction perpendicular to the solid. A dynamic partial ionization effect is studied as well. A self-similar theory shows that the maximum expansion velocity is proportional to c{sub s}{alpha}, where 1 {minus} {alpha} is the slope of the velocity profile. Numerical hydrodynamic modeling is in good agreement with the theory. With these effects, {alpha} is reduced. Therefore, the expansion front velocity is significantly higher than that from conventional models. The results are consistent with experiments. They further study how the plume propagates in high background gas condition. Under appropriate conditions, the plume is slowed down, separates with the background, is backward moving, and hits the solid surface. Then, it splits into two parts when it rebounds from the surface. The results from the modeling will be compared with experimental observations where possible.

  7. Studies in new materials for intermediate temperature solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Skinner, Alex W.

    Ceramic materials have historically been of interest for their thermal and mechanical properties. However, certain ceramic materials can have very interesting electrical, magnetic and optical properties, leading to a new subclass, the electroceramics. Perovskites, in particular, have become the subject of intense research in this field. Specifically, doped barium zirconates have shown high proton conductivity in the intermediate temperature range (600--800°C), making them advantageous for use in solid oxide fuel cells. Solid oxide fuel cells (SOFCs) are electrochemical devices that convert chemical energy into electricity using ion-conducting oxide ceramics as electrolytes. The anode component of the cell is also of interest. Cermets or ceramic metals can serve a dual role as substrates for thin film electrolytes and anodes in the cell. Thin films of gadolinium and ytterbium doped barium zirconate were deposited using pulsed laser deposition (KrF; 1--3 J/cm2) on several substrates, including cermets developed in our lab, in a 10--400 mTorr oxygen environment with various substrate temperatures. Crystalline structure and chemical composition was determined by X-ray diffraction (XRD) and energy dispersive x-ray analysis, respectively. Preliminary electrical measurements of the electrolyte/cermet structure were taken using electrochemical impedance spectroscopy. Keywords: solid oxide fuel cells (SOFCs), perovskites, proton conductors, electroceramics, gadolinium-doped barium zirconate (BZG).

  8. Novel Energy Sources -Material Architecture and Charge Transport in Solid State Ionic Materials for Rechargeable Li ion Batteries

    SciTech Connect

    Katiyar, Ram S; Gómez, M; Majumder, S B; Morell, G; Tomar, M S; Smotkin, E; Bhattacharya, P; Ishikawa, Y

    2009-01-19

    Since its introduction in the consumer market at the beginning of 1990s by Sony Corporation ‘Li-ion rechargeable battery’ and ‘LiCoO2 cathode’ is an inseparable couple for highly reliable practical applications. However, a separation is inevitable as Li-ion rechargeable battery industry demand more and more from this well serving cathode. Spinel-type lithium manganate (e.g., LiMn2O4), lithium-based layered oxide materials (e.g., LiNiO2) and lithium-based olivine-type compounds (e.g., LiFePO4) are nowadays being extensively studied for application as alternate cathode materials in Li-ion rechargeable batteries. Primary goal of this project was the advancement of Li-ion rechargeable battery to meet the future demands of the energy sector. Major part of the research emphasized on the investigation of electrodes and solid electrolyte materials for improving the charge transport properties in Li-ion rechargeable batteries. Theoretical computational methods were used to select electrodes and electrolyte material with enhanced structural and physical properties. The effect of nano-particles on enhancing the battery performance was also examined. Satisfactory progress has been made in the bulk form and our efforts on realizing micro-battery based on thin films is close to give dividend and work is progressing well in this direction.

  9. Laser driven light sails: An examination of the possibilities for interstellar probes and other missions

    NASA Technical Reports Server (NTRS)

    Rather, J. D. G.; Zeiders, G. W.; Vogelsang, K. R.

    1976-01-01

    A theoretical discussion of high energy laser propelled light sails is presented. Selection of sail materials, interstellar drag forces, beam pointing, flight velocity, probe mass, and radiation shielding are among the factors discussed. Interstellar probe missions and colonization of the solar system via the light sail are considered.

  10. Synthesis of mesoporous silica materials from municipal solid waste incinerator bottom ash.

    PubMed

    Liu, Zhen-Shu; Li, Wen-Kai; Huang, Chun-Yi

    2014-05-01

    Incinerator bottom ash contains a large amount of silica and can hence be used as a silica source for the synthesis of mesoporous silica materials. In this study, the conditions for alkaline fusion to extract silica from incinerator bottom ash were investigated, and the resulting supernatant solution was used as the silica source for synthesizing mesoporous silica materials. The physical and chemical characteristics of the mesoporous silica materials were analyzed using BET, XRD, FTIR, SEM, and solid-state NMR. The results indicated that the BET surface area and pore size distribution of the synthesized silica materials were 992 m2/g and 2-3.8 nm, respectively. The XRD patterns showed that the synthesized materials exhibited a hexagonal pore structure with a smaller order. The NMR spectra of the synthesized materials exhibited three peaks, corresponding to Q(2) [Si(OSi)2(OH)2], Q(3) [Si(OSi)3(OH)], and Q(4) [Si(OSi)4]. The FTIR spectra confirmed the existence of a surface hydroxyl group and the occurrence of symmetric Si-O stretching. Thus, mesoporous silica was successfully synthesized from incinerator bottom ash. Finally, the effectiveness of the synthesized silica in removing heavy metals (Pb2+, Cu2+, Cd2+, and Cr2+) from aqueous solutions was also determined. The results showed that the silica materials synthesized from incinerator bottom ash have potential for use as an adsorbent for the removal of heavy metals from aqueous solutions. PMID:24656468

  11. Materials for suspension (semi-solid) electrodes for energy and water technologies.

    PubMed

    Hatzell, Kelsey B; Boota, Muhammad; Gogotsi, Yury

    2015-12-01

    Suspension or semi-solid electrodes have recently gained increased attention for large-scale applications such as grid energy storage, capacitive water deionization, and wastewater treatment. A suspension electrode is a multiphase material system comprised of an active (charge storing) material suspended in ionic solution (electrolyte). Gravimetrically, the electrolyte is the majority component and aids in physical transport of the active material. This principle enables, for the first time, scalability of electrochemical energy storage devices (supercapacitors and batteries) previously limited to small and medium scale applications. This critical review describes the ongoing material challenges encompassing suspension-based systems. The research described here combines classical aspects of electrochemistry, colloidal science, material science, fluid mechanics, and rheology to describe ion and charge percolation, adsorption of ions, and redox charge storage processes in suspension electrodes. This review summarizes the growing inventory of material systems, methods and practices used to characterize suspension electrodes, and describes universal material system properties (rheological, electrical, and electrochemical) that are pivotal in the design of high performing systems. A discussion of the primary challenges and future research directions is included. PMID:26412441

  12. FUNDAMENTAL STUDIES OF THE DURABILITY OF MATERIALS FOR INTERCONNECTS IN SOLID OXIDE FUEL CELLS

    SciTech Connect

    Frederick S. Pettit; Gerald H. Meier

    2003-06-30

    This report describes the result of the first eight months of effort on a project directed at improving metallic interconnect materials for solid oxide fuel cells (SOFCs). The results include cyclic oxidation studies of a group of ferritic alloys, which are candidate interconnect materials. The exposures have been carried out in simulated fuel cell atmospheres. The oxidation morphologies have been characterized and the ASR has been measured for the oxide scales. The effect of fuel cell electric current density on chromia growth rates has been considered The thermomechanical behavior of the scales has been investigated by stress measurements using x-ray diffraction and interfacial fracture toughness measurements using indentation. The ultimate goal of this thrust is to use knowledge of changes in oxide thickness, stress and adhesion to develop accelerated testing methods for evaluating SOFC interconnect alloys. Finally a theoretical assessment of the potential for use of ''new'' metallic materials as interconnect materials has been conducted and is presented in this report. Alloys being considered include materials based on pure nickel, materials based on the ''Invar'' concept, and coated materials to optimize properties in both the anode and cathode gases.

  13. Assessment of Bacterial Spores in Solid Materials: Curriculum Improvements Partnership Award for the Integration of Research (CIPAIR)

    NASA Technical Reports Server (NTRS)

    Lavallee, Richard J.

    2012-01-01

    This summer, we quantified the release, by cryogenic grinding at liquid nitrogen temperatures, of microbes present in 4 different spacecraft solids: epoxy 9309, epoxy 9394, epoxy 9396, and a silicone coating. Three different samples of each material were prepared: aseptically prepared solid material, powdered material inoculated with a known spore count of Bacillus atrophaeus, and solid material artificially embedded with a known spore count of Bacillus atrophaeus. Samples were cryogenically ground as needed, and the powders were directly cultured to determine the number of microbial survivors per gram of material. Recovery rates were found to be highly material-dependent, varying from 0.2 to 50% for inoculated material surfaces and 0.002 to 0.5% for embedded spores. A study of the spore survival rate versus total grinding time was also performed, with results indicating that longer grinding time decreases recovery rates of viable spores.

  14. Elaboration and Characterization of High Silica ZSM-5 and Mordenite Solid Microporous Materials

    NASA Astrophysics Data System (ADS)

    Khemaissia, Sihem; Nibou, Djamel; Amokrane, Samira; Lebaili, Nemcha

    In this study, we were interested to use a hydrothermally method of elaboration of ZSM-5 and Mordenite solid microporous materials. This method is based on crystallization of amorphous gels composed of silicon and aluminium solutions. The elaborations were carried out in stainless steel Teflon lined autoclave over different operation conditions: heating temperature, contact time, pH and agitation of the reactional medium. After crystallization, samples were characterized by several techniques as X ray diffraction, scanning microscopy, infrared spectroscopy. The used method was allowed the obtaining of pure phases of solids belonging to ZSM-5 and mordenite structures respectively. The crystal growth environment during nucleation and crystallization was occurred at the liquid-gel interface in the dispersed gel-solution mixtures. The composition of these structures was found as high silica zeolites.

  15. High temperature solid lubricant materials for heavy duty and advanced heat engines

    SciTech Connect

    DellaCorte, C.; Wood, J.C.

    1994-10-01

    Advanced engine designs incorporate higher mechanical and thermal loading to achieve efficiency improvements. This approach often leads to higher operating temperatures of critical sliding elements (e.g. piston ring/cylinder wall contacts and valve guides) which compromise the use of conventional and even advanced synthetic liquid lubricants. For these applications solid lubricants must be considered. Several novel solid lubricant composites and coatings designated PS/PM200 have been employed to dry and marginally oil lubricated contacts in advanced heat engines. These applications include cylinder kits of heavy duty diesels, and high temperature sterling engines, sidewall seals of rotary engines and various exhaust valve and exhaust component applications. The following paper describes the tribological and thermophysical properties of these tribomaterials and reviews the results of applying them to engine applications. Other potential tribological materials and applications are also discussed with particular emphasis to heavy duty and advanced heat engines.

  16. Method for removing solid particulate material from within liquid fuel injector assemblies

    DOEpatents

    Simandl, R.F.; Brown, J.D.; Andriulli, J.B.; Strain, P.D.

    1998-09-08

    A method is described for removing residual solid particulate material from the interior of liquid fuel injectors and other fluid flow control mechanisms having or being operatively associated with a flow-regulating fixed or variable orifice. The method comprises the sequential and alternate introduction of columns of a non-compressible liquid phase and columns of a compressed gas phase into the body of a fuel injector whereby the expansion of each column of the gas phase across the orifice accelerates the liquid phase in each trailing column of the liquid phase and thereby generates turbulence in each liquid phase for lifting and entraining the solid particulates for the subsequent removal thereof from the body of the fuel injector. 1 fig.

  17. Method for removing solid particulate material from within liquid fuel injector assemblies

    DOEpatents

    Simandl, Ronald F.; Brown, John D.; Andriulli, John B.; Strain, Paul D.

    1998-01-01

    A method for removing residual solid particulate material from the interior of liquid fuel injectors and other fluid flow control mechanisms having or being operatively associated with a flow-regulating fixed or variable orifice. The method comprises the sequential and alternate introduction of columns of a non-compressible liquid phase and columns of a compressed gas phase into the body of a fuel injector whereby the expansion of each column of the gas phase across the orifice accelerates the liquid phase in each trailing column of the liquid phase and thereby generates turbulence in each liquid phase for lifting and entraining the solid particulates for the subsequent removal thereof from the body of the fuel injector.

  18. High Temperature Solid Lubricant Materials for Heavy Duty and Advanced Heat Engines

    NASA Technical Reports Server (NTRS)

    Dellacorte, C.; Wood, J. C.

    1994-01-01

    Advanced engine designs incorporate higher mechanical and thermal loading to achieve efficiency improvements. This approach often leads to higher operating temperatures of critical sliding elements (e.g. piston ring/cylinder wall contacts and valve guides) which compromise the use of conventional and even advanced synthetic liquid lubricants. For these applications solid lubricants must be considered. Several novel solid lubricant composites and coatings designated PS/PM200 have been employed to dry and marginally oil lubricated contacts in advanced heat engines. These applications include cylinder kits of heavy duty diesels, and high temperature Stirling engines, sidewall seals of rotary engines, and various exhaust valve and exhaust component applications. This paper describes the tribological and thermophysical properties of these tribomaterials and reviews the results of applying them to engine applications. Other potential tribological materials and applications are also discussed with particular emphasis on heavy duty and advanced heat engines.

  19. Materials and processes for shuttle engine, external tank, and solid rocket booster

    NASA Technical Reports Server (NTRS)

    Schwinghamer, R. J.

    1977-01-01

    The Shuttle flight system is composed of the Orbiter, an External Tank (ET) that contains the ascent propellant to be used by the Space Shuttle Main Engines (SSME), and two Solid Rocket Boosters (SRB). The ET is expended on each launch; the Orbiter and SRB's are reusable. It is the requirement for reuse which poses the exciting new materials and processes challenges in the development of the Space Shuttle. A brief description of the Space Shuttle and the mission profile is given. The Shuttle configuration is then described with emphasis on the SSME, ET, and SRB. The materials selection, tracking, and control system used to assure reliability and to minimize cost are described, and salient features and challenges in materials and processes associated with the SSME, ET, and SRB are subsequently discussed.

  20. Separation of asphaltic materials from heptane soluble components in liquified solid hydrocarbonaceous extracts

    SciTech Connect

    Gleim, W.

    1980-07-08

    An improved method is described for maximizing the separation of the heat labile fraction of asphaltic materials in a liquified solid hydrocarbonaceous extract, which comprises the steps of: (A) adding a solvent having a boiling range of from about 50 to 200/sup 0/C for the heptane solubles of said extract, (B) effecting a mixing of said solvent and said extract and providing a pressurized centrifuging action of the combined stream in a confined pressure-tight powered centrifuging zone at a temperature in the range of 100/sup 0/C, to about 200/sup 0//c while at an elevated pressure at least sufficient to maintain the solvent material in a liquid state, whereby to separate the heavier heat labile asphaltic materials fraction from the mixture, and (C) effecting the withdrawal of the asphaltic fraction from the centrifuging zone substantially free of the resulting solution of the heptane soluble liquified fuel extract.

  1. Synthesis and solid state NMR characterization of novel peptide/silica hybrid materials.

    PubMed

    Werner, Mayke; Heil, Andreas; Rothermel, Niels; Breitzke, Hergen; Groszewicz, Pedro Braga; Thankamony, Aany Sofia; Gutmann, Torsten; Buntkowsky, Gerd

    2015-11-01

    The successful synthesis and solid state NMR characterization of silica-based organic-inorganic hybrid materials is presented. For this, collagen-like peptides are immobilized on carboxylate functionalized mesoporous silica (COOH/SiOx) materials. A pre-activation of the silica material with TSTU (O-(N-Succinimidyl)-N,N,N',N'-tetramethyluronium tetrafluoroborate) is performed to enable a covalent binding of the peptides to the linker. The success of the covalent immobilization is indicated by the decrease of the (13)C CP-MAS NMR signal of the TSTU moiety. A qualitative distinction between covalently bound and adsorbed peptide is feasible by (15)N CP-MAS Dynamic Nuclear Polarization (DNP). The low-field shift of the (15)N signal of the peptide's N-terminus clearly identifies it as the binding site. The DNP enhancement allows the probing of natural abundance (15)N nuclei, rendering expensive labeling of peptides unnecessary. PMID:26411982

  2. Charting the Interstellar Magnetic Field causing the Interstellar Boundary Explorer (IBEX) Ribbon of Energetic Neutral Atoms

    NASA Astrophysics Data System (ADS)

    Frisch, P. C.; Berdyugin, A.; Piirola, V.; Magalhaes, A. M.; Seriacopi, D. B.; Wiktorowicz, S. J.; Andersson, B.-G.; Funsten, H. O.; McComas, D. J.; Schwadron, N. A.; Slavin, J. D.; Hanson, A. J.; Fu, C.-W.

    2015-12-01

    The interstellar magnetic field (ISMF) near the heliosphere is a fundamental component of the solar galactic environment that can only be studied using polarized starlight. The results of an ongoing survey of the linear polarizations of local stars are analyzed with the goal of linking the ISMF that shapes the heliosphere to the nearby field in interstellar space. We present new results on the direction of the magnetic field within 40 pc obtained from analyzing polarization data using a merit function that determines the field direction that provides the best fit to the polarization data. Multiple magnetic components are identified, including a dominant interstellar field, {B}{POL}, that is aligned with the direction ℓ, b = 36.°2, 49.°0 (±16.°0). Stars tracing {B}{POL} have the same mean distance as stars that do not trace {B}{POL}, but show weaker average polarizations consistent with a smaller column density of polarizing material. {B}{POL} is aligned with the ISMF traced by the IBEX Ribbon to within {7.6}-7.6+14.9 degrees. The variations in the polarization position angle directions derived from the data that best match {B}{POL} indicate a low level of magnetic turbulence, ˜9° ± 1°. The direction of {B}{POL} is obtained after excluding polarization data tracing a separate magnetic structure that appears to be associated with interstellar dust deflected around the heliosphere. The velocities of local interstellar clouds relative to the Local Standard of Rest (LSR) increase with the angles between the LSR velocities and {B}{POL}, indicating that the kinematics of local interstellar material is ordered by the ISMF. The Loop I superbubble that extends close to the Sun contains dust that reddens starlight and whose distance is determined by the color excess E(B - V) of starlight. Polarizations caused by grains aligned with respect to {B}{POL} are consistent with the location of the Sun in the rim of the Loop I superbubble. An angle of {76

  3. Oxygen transport in perovskite-type solid oxide fuel cell materials: insights from quantum mechanics.

    PubMed

    Muñoz-García, Ana B; Ritzmann, Andrew M; Pavone, Michele; Keith, John A; Carter, Emily A

    2014-11-18

    CONSPECTUS: Global advances in industrialization are precipitating increasingly rapid consumption of fossil fuel resources and heightened levels of atmospheric CO2. World sustainability requires viable sources of renewable energy and its efficient use. First-principles quantum mechanics (QM) studies can help guide developments in energy technologies by characterizing complex material properties and predicting reaction mechanisms at the atomic scale. QM can provide unbiased, qualitative guidelines for experimentally tailoring materials for energy applications. This Account primarily reviews our recent QM studies of electrode materials for solid oxide fuel cells (SOFCs), a promising technology for clean, efficient power generation. SOFCs presently must operate at very high temperatures to allow transport of oxygen ions and electrons through solid-state electrolytes and electrodes. High temperatures, however, engender slow startup times and accelerate material degradation. SOFC technologies need cathode and anode materials that function well at lower temperatures, which have been realized with mixed ion-electron conductor (MIEC) materials. Unfortunately, the complexity of MIECs has inhibited the rational tailoring of improved SOFC materials. Here, we gather theoretically obtained insights into oxygen ion conductivity in two classes of perovskite-type materials for SOFC applications: the conventional La1-xSrxMO3 family (M = Cr, Mn, Fe, Co) and the new, promising class of Sr2Fe2-xMoxO6 materials. Using density functional theory + U (DFT+U) with U-J values obtained from ab initio theory, we have characterized the accompanying electronic structures for the two processes that govern ionic diffusion in these materials: (i) oxygen vacancy formation and (ii) vacancy-mediated oxygen migration. We show how the corresponding macroscopic oxygen diffusion coefficient can be accurately obtained in terms of microscopic quantities calculated with first-principles QM. We find that the

  4. A New View on Interstellar Dust - High Fidelity Studies of Interstellar Dust Analogue Tracks in Stardust Flight Spare Aerogel

    NASA Technical Reports Server (NTRS)

    Zolensky, Michael E.; Postberg F.; Allen, C.; Bajt, S.; Bechtel, H. A.; Borg, J.; Brenker, F.; Bridges, J.; Brownlee, D. E.; Bugiel, S.; Burchell, M.; Burghammer, M.; Butterworth, A. L.; Cloetens, P.; Davis, A. M.; Floss, C.; Flynn, G. J.; Frank, D.; Gainsforth, Z.

    2011-01-01

    In 2000 and 2002 the Stardust Mission exposed aerogel collector panels for a total of about 200 days to the stream of interstellar grains sweeping through the solar system. The material was brought back to Earth in 2006. The goal of this work is the laboratory calibration of the collection process by shooting high speed [5 - 30km/s] interstellar dust (ISD) analogues onto Stardust aerogel flight spares. This enables an investigation into both the morphology of impact tracks as well as any structural and chemical modification of projectile and collector material. First results indicate a different ISD flux than previously assumed for the Stardust collection period.

  5. The violent interstellar medium associated with the Carina Nebula

    NASA Astrophysics Data System (ADS)

    Laurent, C.; Paul, J. A.; Pettini, M.

    1982-06-01

    The physical conditions and chemical composition of the interstellar medium in line to HD 93205, an O3V star in the Great Carina Nebula, were studied, using UV spectra. The two main high velocity components show different relative abundance patterns. The red shifted component shows no depletion. For the blue shifted component, the relative abundance pattern seems difficult to explain in terms of elements locked into grains. Its composition is attributed to mixing with freshly synthetized material ejected by a recent supernova explosion. One low velocity component is identified with the normal interstellar gas in the disk of the Galaxy. In this component, column densities of interstellar CIV and SiIV, free from contamination by circumstellar material, were measured. The other low velocity component is identified with the approaching part of the expanding ionized nebula around the Carina OB associations. It consists of a dense HII region in which the two conspicuous OI fine structure lines originate.

  6. AN ANALYTICAL MODEL OF INTERSTELLAR GAS IN THE HELIOSPHERE TAILORED TO INTERSTELLAR BOUNDARY EXPLORER OBSERVATIONS

    SciTech Connect

    Lee, Martin A.; Kucharek, Harald; Moebius, Eberhard; Wu Xian; Bzowski, Maciej; McComas, David

    2012-02-01

    The stationary distribution of interstellar neutral gas in the heliosphere subject to solar gravity, solar radiation pressure, photoionization, and charge exchange is investigated analytically assuming ionization rates and radiation pressure that are proportional to R{sup -2}, where R is the heliocentric radius. The collisionless hyperbolic trajectories of the individual atoms including ionization losses are combined with Liouville's Theorem to construct the heliospheric phase-space distribution function of an interstellar gas species in the solar reference frame under the assumption that the distribution is a drifting Maxwellian at large distances from the Sun. The distribution is transformed to the Earth (essentially Interstellar Boundary Explorer (IBEX)) frame as a function of solar longitude. The expression is then tailored to the latitudinal scan of IBEX as a function of longitude using the fact that IBEX detects each atom close to perihelion in its hyperbolic orbit. The distribution is further adapted to IBEX by integrating the differential intensity over the entrance aperture solid angle of the IBEX-Lo collimator, and over energy to predict the IBEX count rate of helium. The major features of the predicted count rate are described, including a peak in longitude, a peak in latitude at each longitude, and the widths of the major peak in both latitude and longitude. Analytical formulae for these features are derived for comparison with IBEX observations in order to determine the temperature and bulk velocity of the gas in interstellar space. Based in part on these formulae, the results for helium are presented in the companion paper by Moebius et al.

  7. Dynamic Nuclear Polarization (DNP) solid-state NMR spectroscopy, a new approach to study humic material?

    NASA Astrophysics Data System (ADS)

    Knicker, Heike; Lange, Sascha; van Rossum, Barth; Oschkinat, Hartmut

    2016-04-01

    Compared to solution NMR spectroscopy, solid-state NMR spectra suffer from broad resonance lines and low resolution. This could be overcome by the use of 2-dimenstional solid-state NMR pulse sequences. Until recently, this approach has been unfeasible as a routine tool in soil chemistry, mainly because of the low NMR sensitivity of the respective samples. A possibility to circumvent those sensitivity problems represents high-field Dynamic Nuclear Polarization (DNP) solid-state NMR spectroscopy (Barnes et al., 2008), allowing considerable signal enhancements (Akbey et al., 2010). This is achieved by a microwave-driven transfer of polarization from a paramagnetic center to nuclear spins. Application of DNP to MAS spectra of biological systems (frozen solutions) showed enhancements of the factor 40 to 50 (Hall et al., 1997). Enhancements of this magnitude, thus may enable the use of at least some of the 2D solid-state NMR techniques that are presently already applied for pure proteins but are difficult to apply to soil peptides in their complex matrix. After adjusting the required acquisition parameters to the system "soil organic matter", lower but still promising enhancement factors were achieved. Additional optimization was performed and allowed the acquisition of 2D 13C and 15N solid-state NMR spectra of humified 13C and 15N enriched plant residues. Within the present contribution, the first solid-state DNP NMR spectra of humic material are presented. Those data demonstrate the great potential of this approach which certainly opens new doors for a better understanding of biochemical processes in soils, sediments and water. Akbey, Ü., Franks, W.T., Linden, A., Lange, S., Griffin, R.G., van Rossum, B.-J., Oschkinat, H., 2010. Dynamic nuclear polarization of deuterated proteins. Angewandte Chemie International Edition 49, 7803-7806. Barnes, A.B., De Paëpe, G., van der Wel, P.C.A., Hu, K.N., Joo, C.G., Bajaj, V.S., Mak-Jurkauskas, M.L., Sirigiri, J.R., Herzfeld, J

  8. Computational Investigations of a Possible New Class of Materials: A Superatom Ionic Solid

    NASA Astrophysics Data System (ADS)

    Sohlberg, Karl; Nasto, Violeta

    2013-03-01

    A ``superatom'' is a cluster of atoms that shows high stability. High stability can arise from the geometric arrangement of the atoms in the cluster. For example, when atoms are close packed, clusters containing an integer number of closed shells of atoms, (i.e. 13, 55, 137... atoms) exhibit enhanced stability and are termed ``magic clusters.'' High stability can also arise from the electronic structure. High symmetry metal clusters that have exactly 8, 20, 40..., valence electrons show enhanced stability. Superatoms can act chemically like a single atom of a different element. We have used electronic structure calculations to test the idea that a new class of materials may be formed based on the periodic arrangement of superatom ions, instead of the typical atomic or polyatomic ions of a conventional ionic solid. A solid is formed based on crystalline packing of anionic (Al@Cu54-)and cationic (Ce@C60+),nearly spherical superatom species that show exceptional stability. According to radius-ratio rules, these ions will favor a CsCl crystal structure with a body-centered (bcc) type of unit cell. Calculations on this material suggest that it is stable, semiconducting and less dense than common metal oxides, but that the metal anion clusters deform within the material.

  9. Torsional rheometer for granular materials slurries and gas-solid mixtures and related methods

    DOEpatents

    Rajagopal, Chandrika; Rajagopal, Kumbakonam R.; Yalamanchili, Rattaya C.

    1997-01-01

    A torsional rheometer apparatus for determining rheological properties of a specimen is provided. A stationary plate and a rotatable plate are in generally coaxial position and structured to receive a specimen therebetween. In one embodiment, at least one of the plates and preferably both have roughened specimen engaging surfaces to serve to reduce undesired slippage between the plate and the specimen. A motor is provided to rotate the rotatable plate and a transducer for monitoring forces applied to the stationary plate and generating output signals to a computer which determines the desired rheological properties are provided. In one embodiment, the roughened surfaces consist of projections extending toward the specimen. Where granular material is being evaluated, it is preferred that the roughness of the plate is generally equal to the average size of the granular material being processed. In another embodiment, an air-solid mixture is processed and the roughened portions are pore openings in the plates. Air flows through the region between the two pore containing plates to maintain the solid materials in suspension. In yet another embodiment, the base of the stationary plate is provided with a deformable capacitance sensor and associated electronic means.

  10. Torsional rheometer for granular materials slurries and gas-solid mixtures and related methods

    DOEpatents

    Rajagopal, C.; Rajagopal, K.R.; Yalamanchili, R.C.

    1997-03-11

    A torsional rheometer apparatus for determining rheological properties of a specimen is provided. A stationary plate and a rotatable plate are in generally coaxial position and structured to receive a specimen there between. In one embodiment, at least one of the plates and preferably both have roughened specimen engaging surfaces to serve to reduce undesired slippage between the plate and the specimen. A motor is provided to rotate the rotatable plate and a transducer for monitoring forces applied to the stationary plate and generating output signals to a computer which determines the desired rheological properties are provided. In one embodiment, the roughened surfaces consist of projections extending toward the specimen. Where granular material is being evaluated, it is preferred that the roughness of the plate is generally equal to the average size of the granular material being processed. In another embodiment, an air-solid mixture is processed and the roughened portions are pore openings in the plates. Air flows through the region between the two pore containing plates to maintain the solid materials in suspension. In yet another embodiment, the base of the stationary plate is provided with a deformable capacitance sensor and associated electronic means. 17 figs.

  11. Apparatus for the processing of solid mixed waste containing radioactive and hazardous materials

    DOEpatents

    Gotovchikov, Vitaly T.; Ivanov, Alexander V.; Filippov, Eugene A.

    1999-03-16

    Apparatus for the continuous heating and melting of a solid mixed waste bearing radioactive and hazardous materials to form separate metallic, slag and gaseous phases for producing compact forms of the waste material to facilitate disposal includes a copper split water-cooled (cold) crucible as a reaction vessel for receiving the waste material. The waste material is heated by means of the combination oaf plasma torch directed into the open upper portion of the cold crucible and an electromagnetic flux produced by induction coils disposed about the crucible which is transparent to electromagnetic fields. A metallic phase of the waste material is formed in a lower portion of the crucible and is removed in the form of a compact ingot suitable for recycling and further processing. A glass-like, non-metallic slag phase containing radioactive elements is also formed in the crucible and flows out of the open upper portion of the crucible into a slag ingot mold for disposal. The decomposition products of the organic and toxic materials are incinerated and converted to environmentally safe gases in the melter.

  12. Apparatus for the processing of solid mixed waste containing radioactive and hazardous materials

    DOEpatents

    Gotovchikov, V.T.; Ivanov, A.V.; Filippov, E.A.

    1999-03-16

    Apparatus for the continuous heating and melting of a solid mixed waste bearing radioactive and hazardous materials to form separate metallic, slag and gaseous phases for producing compact forms of the waste material to facilitate disposal includes a copper split water-cooled (cold) crucible as a reaction vessel for receiving the waste material. The waste material is heated by means of the combination of a plasma torch directed into the open upper portion of the cold crucible and an electromagnetic flux produced by induction coils disposed about the crucible which is transparent to electromagnetic fields. A metallic phase of the waste material is formed in a lower portion of the crucible and is removed in the form of a compact ingot suitable for recycling and further processing. A glass-like, non-metallic slag phase containing radioactive elements is also formed in the crucible and flows out of the open upper portion of the crucible into a slag ingot mold for disposal. The decomposition products of the organic and toxic materials are incinerated and converted to environmentally safe gases in the melter. 6 figs.

  13. Final reports of the Stardust Interstellar Preliminary Examination

    NASA Astrophysics Data System (ADS)

    Westphal, Andrew J.; Bechtel, Hans A.; Brenker, Frank E.; Butterworth, Anna L.; Flynn, George; Frank, David R.; Gainsforth, Zack; Hillier, Jon K.; Postberg, Frank; Simionovici, Alexandre S.; Sterken, Veerle J.; Stroud, Rhonda M.; Allen, Carlton; Anderson, David; Ansari, Asna; Bajt, SašA.; Bastien, Ron K.; Bassim, Nabil; Borg, Janet; Bridges, John; Brownlee, Donald E.; Burchell, Mark; Burghammer, Manfred; Changela, Hitesh; Cloetens, Peter; Davis, Andrew M.; Doll, Ryan; Floss, Christine; Grün, Eberhard; Heck, Philipp R.; Hoppe, Peter; Hudson, Bruce; Huth, Joachim; Hvide, Brit; Kearsley, Anton; King, Ashley J.; Lai, Barry; Leitner, Jan; Lemelle, Laurence; Leroux, Hugues; Leonard, Ariel; Lettieri, Robert; Marchant, William; Nittler, Larry R.; Ogliore, Ryan; Ong, Wei Ja; Price, Mark C.; Sandford, Scott A.; Tresseras, Juan-Angel Sans; Schmitz, Sylvia; Schoonjans, Tom; Silversmit, Geert; Solé, Vicente A.; Srama, Ralf; Stadermann, Frank; Stephan, Thomas; Stodolna, Julien; Sutton, Steven; Trieloff, Mario; Tsou, Peter; Tsuchiyama, Akira; Tyliszczak, Tolek; Vekemans, Bart; Vincze, Laszlo; Korff, Joshua; Wordsworth, Naomi; Zevin, Daniel; Zolensky, Michael E.

    2014-09-01

    With the discovery of bona fide extraterrestrial materials in the Stardust Interstellar Dust Collector, NASA now has a fundamentally new returned sample collection, after the Apollo, Antarctic meteorite, Cosmic Dust, Genesis, Stardust Cometary, Hayabusa, and Exposed Space Hardware samples. Here, and in companion papers in this volume, we present the results from the Preliminary Examination of this collection, the Stardust Interstellar Preliminary Examination (ISPE). We found extraterrestrial materials in two tracks in aerogel whose trajectories and morphology are consistent with an origin in the interstellar dust stream, and in residues in four impacts in the aluminum foil collectors. While the preponderance of evidence, described in detail in companion papers in this volume, points toward an interstellar origin for some of these particles, alternative origins have not yet been eliminated, and definitive tests through isotopic analyses were not allowed under the terms of the ISPE. In this summary, we answer the central questions of the ISPE: How many tracks in the collector are consistent in their morphology and trajectory with interstellar particles? How many of these potential tracks are consistent with real interstellar particles, based on chemical analysis? Conversely, what fraction of candidates are consistent with either a secondary or interplanetary origin? What is the mass distribution of these particles, and what is their state? Are they particulate or diffuse? Is there any crystalline material? How many detectable impact craters (>100 nm) are there in the foils, and what is their size distribution? How many of these craters have analyzable residue that is consistent with extraterrestrial material? And finally, can craters from secondaries be recognized through crater morphology (e.g., ellipticity)?

  14. Laser-material interactions: A study of laser energy coupling with solids

    SciTech Connect

    Shannon, M A

    1993-11-01

    This study of laser-light interactions with solid materials ranges from low-temperature heating to explosive, plasma-forming reactions. Contained are four works concerning laser-energy coupling: laser (i) heating and (ii) melting monitored using a mirage effect technique, (iii) the mechanical stress-power generated during high-powered laser ablation, and (iv) plasma-shielding. First, a photothermal deflection (PTD) technique is presented for monitoring heat transfer during modulated laser heating of opaque solids that have not undergone phase-change. Of main interest is the physical significance of the shape, magnitude, and phase for the temporal profile of the deflection signal. Considered are the effects that thermophysical properties, boundary conditions, and geometry of the target and optical probe-beam have on the deflection response. PTD is shown to monitor spatial and temporal changes in heat flux leaving the surface due to changes in laser energy coupling. The PTD technique is then extended to detect phase-change at the surface of a solid target. Experimental data shows the onset of melt for indium and tin targets. The conditions for which melt can be detected by PTD is analyzed in terms of geometry, incident power and pulse length, and thermophysical properties of the target and surroundings. Next, monitoring high-powered laser ablation of materials with stress-power is introduced. The motivation for considering stress-power is given, followed by a theoretical discussion of stress-power and how it is determined experimentally. Experiments are presented for the ablation of aluminum targets as a function of energy and intensity. The stress-power response is analyzed for its physical significance. Lastly, the influence of plasma-shielding during high-powered pulsed laser-material interactions is considered. Crater size, emission, and stress-power are measured to determine the role that the gas medium and laser pulse length have on plasma shielding.

  15. Composition, structure, and chemistry of interstellar dust

    NASA Technical Reports Server (NTRS)

    Tielens, A. G. G. M.; Allamandola, L. J.

    1987-01-01

    Different dust components present in the interstellar medium (IM) such as amorphous carbon, polycyclic aromatic hydrocarbons, and those IM components which are organic refractory grains and icy grain mantles are discussed as well as their relative importance. The physical properties of grain surface chemistry are discussed with attention given to the surface structure of materials, the adsorption energy and residence time of species on a grain surface, and the sticking probability. Consideration is also given to the contribution of grains to the gas-phase composition of molecular clouds.

  16. Identification of Possible Interstellar Dust Impact Craters on Stardust Foil I033N,1

    NASA Astrophysics Data System (ADS)

    Ansari, A.; ISPE Team; 29,000 Stardust@home Dusters

    2011-12-01

    The Interstellar Dust Collector onboard NASA's Stardust Mission - the first to return solid extraterrestrial material to Earth from beyond the Moon - was exposed to the interstellar dust stream for a total of 229 days prior to the spacecraft's return in 2006 [1]. Aluminum foils and aerogel tiles on the collector may have captured the first samples of contemporary interstellar dust. Interstellar Preliminary Examination (ISPE) focuses in part on crater identification and analysis of residue within the craters to determine the nature and origin of the impacting particles. Thus far, ISPE has focused on nine foils and found a total of 20 craters. The number density of impact craters on the foils exceeds by far estimates made from interstellar flux calculations [2]. To identify craters, foil I1033N,1 was scanned with the Field Museum's Evo 60 Scanning Electron Microscope (SEM) at a resolution of 52 nm/pixel with a 15 kV and 170-240 pA beam. Contamination was monitored according to the ISPE protocol: four 4 μm × 3 μm areas of C layers of different thicknesses on a Stardust-type Al foil were irradiated 20 times for 50 s each, while the C and Al signals were recorded with energy-dispersive X-ray spectroscopy (EDS). The C/Al ratio did not increase after 20 repetitions on each of the four areas. The same experiment repeated 7 months later yielded identical results. Thus, analysis with the SEM results in no detectable contamination. Crater candidates were manually selected from SEM images, then reimaged at higher resolution (17 nm/pixel) in order to eliminate false detections. The foil was then sent to Washington University for Auger Nanoprobe elemental analysis of crater 11_175 (diam. 1.1 μm), and to the Naval Research Laboratory for focused ion beam work and transmission electron microscopy and EDS. Twelve crater candidates (diam. 0.28 - 1.1 μm), both elliptical and circular, were identified. The number density of craters on foil 1033N is 15.8 cm^-2. Auger measurements

  17. Laser-Material Interaction Studies Utilizing the Solid-State Heat Capacity Laser

    SciTech Connect

    Yamamoto, R; Parker, J; Boley, C; Cutter, K; Fochs, S; Rubenchik, A

    2007-04-19

    A variety of laser-material interaction experiments have been conducted at Lawrence Livermore National Laboratory (LLNL) utilizing the solid-state heat capacity laser (SSHCL). For these series of experiments, laser output power is 25kW, on-target laser spot sizes of up to 16 cm by 16 cm square, with air speeds of approximately 100 meters per second flowing across the laser-target interaction surface as shown in Figure 1. The empirical results obtained are used to validate our simulation models.

  18. Solid C triple bond N bearing material on outer solar system bodies

    NASA Astrophysics Data System (ADS)

    Cruikshank, Dale P.; Allamandola, L. J.; Hartmann, William K.; Tholen, D. J.; Brown, R. H.; Matthews, C. N.; Bell, J. F.

    1991-12-01

    Recent telescopic observations have led to the identification of cyanogroup-containing molecules in the dark surface solids of several D-class asteroids, cometary dusts, and the rings of Uranus, as well as the low-albedo atmosphere of Iapetus. The occurrence of the 2.2-micron overtone of C triple-bond N's stretching fundamental mode in all four classes of small solar system bodies is presently suggested to serve as a diagnostic of both exposure duration and degree of modification of surface materials.

  19. Solid C triple bond N bearing material on outer solar system bodies

    NASA Technical Reports Server (NTRS)

    Cruikshank, Dale P.; Allamandola, L. J.; Hartmann, William K.; Tholen, D. J.; Brown, R. H.; Matthews, C. N.; Bell, J. F.

    1991-01-01

    Recent telescopic observations have led to the identification of cyanogroup-containing molecules in the dark surface solids of several D-class asteroids, cometary dusts, and the rings of Uranus, as well as the low-albedo atmosphere of Iapetus. The occurrence of the 2.2-micron overtone of C triple-bond N's stretching fundamental mode in all four classes of small solar system bodies is presently suggested to serve as a diagnostic of both exposure duration and degree of modification of surface materials.

  20. Process for the production of thermodynamically stable solid ion conductor materials

    SciTech Connect

    Hartwig, P.; Wepper, W.; Winfried, W.

    1985-07-02

    The present invention provides a process for the production of solid in conductor materials based on the following formula: A3 /SUB u/ /sub +/2 /SUB v/ /sub +/ /SUB w/ XuYuZw wherein A is lithium or sodium, X is nitrogen, phosphorus or arsenic, Y is nitrogen, sulphur, tellurium or selenium, Z is hydrogen or a halogen, and u, v, and w each represent a number from 0 to 1 inclusive, with the proviso that only one of u, v, and w can assume the value of 0.

  1. Laser ablation in liquids as a new technique of sampling in elemental analysis of solid materials

    NASA Astrophysics Data System (ADS)

    Muravitskaya, E. V.; Rosantsev, V. A.; Belkov, M. V.; Ershov-Pavlov, E. A.; Klyachkovskaya, E. V.

    2009-02-01

    Laser ablation in liquid media is considered as a new sample preparation technique in the elemental composition analysis of materials using optical emission spectroscopy of inductively coupled plasma (ICP-OES). Solid samples are transformed into uniform colloidal solutions of nanosized analyte particles using laser radiation focused onto the sample surface. High homogeneity of the resulting solution allows performing the ICP-OES quantitative analysis especially for the samples, which are poorly soluble in acids. The technique is compatible with the conventional solution-based standards.

  2. Review of high-throughput techniques for detecting solid phase Transformation from material libraries produced by combinatorial methods

    NASA Technical Reports Server (NTRS)

    Lee, Jonathan A.

    2005-01-01

    High-throughput measurement techniques are reviewed for solid phase transformation from materials produced by combinatorial methods, which are highly efficient concepts to fabricate large variety of material libraries with different compositional gradients on a single wafer. Combinatorial methods hold high potential for reducing the time and costs associated with the development of new materials, as compared to time-consuming and labor-intensive conventional methods that test large batches of material, one- composition at a time. These high-throughput techniques can be automated to rapidly capture and analyze data, using the entire material library on a single wafer, thereby accelerating the pace of materials discovery and knowledge generation for solid phase transformations. The review covers experimental techniques that are applicable to inorganic materials such as shape memory alloys, graded materials, metal hydrides, ferric materials, semiconductors and industrial alloys.

  3. Interstellar Electron Density Spectra

    NASA Astrophysics Data System (ADS)

    Lambert, Hendrick Clark

    This study concerns the investigation of the form of the wavenumber spectrum of the Galactic electron density fluctuations through an examination of the scattering of the radio pulses emitted by pulsars as they propagate through the diffuse ionized interstellar gas. A widely used model for the electron density spectrum is based on the simple power-law: Pne(q)∝ q-β, where β = 11/3 is usually assumed, corresponding to Kolmogorov's turbulence spectrum. The simple Kolmogorov model provides satisfactory agreement for observations along many lines of sight; however, major inconsistencies remain. The inconsistencies suggest that an increase in the ratio of the power between the high (10-8[ m]-1≤ q<=10-7[ m]-1) and low (10-13[ m]-1≤ q<=10-12[ m]-1) wavenumbers is needed. This enhancement in the ratio can in turn be achieved by either including an inner scale, corresponding to a dissipation scale for the turbulent cascade, in the Kolmogorov spectrum or by considering steeper spectra. Spectra with spectral exponents β > 4 have been in general rejected based on observations of pulsar refractive scintillations. The special case of β = 4 has been given little attention and is analyzed in detail. Physically, this 'β = 4' model corresponds to the random distribution, both in location and orientation, of discrete objects with relatively sharp boundaries across the line of sight. An outer scale is included in the model to account for the average size of such objects. We compare the predictions of the inner-scale and β = 4 models both with published observations and observations we made as part of this investigation. We conclude that the form of the wavenumber spectrum is dependent on the line of sight. We propose a composite spectrum featuring a uniform background turbulence in presence of randomly distributed discrete objects, as modeled by the β = model.

  4. SPUTTERING FROM A POROUS MATERIAL BY PENETRATING IONS

    SciTech Connect

    Rodriguez-Nieva, J. F.; Bringa, E. M.; Cassidy, T. A.; Caro, A.; Loeffler, M. J.; Farkas, D.

    2011-12-10

    Porous materials are ubiquitous in the universe and weathering of porous surfaces plays an important role in the evolution of planetary and interstellar materials. Sputtering of porous solids in particular can influence atmosphere formation, surface reflectivity, and the production of the ambient gas around materials in space. Several previous studies and models have shown a large reduction in the sputtering of a porous solid compared to the sputtering of the non-porous solid. Using molecular dynamics simulations we study the sputtering of a nanoporous solid with 55% of the solid density. We calculate the electronic sputtering induced by a fast, penetrating ion, using a thermal spike representation of the deposited energy. We find that sputtering for this porous solid is, surprisingly, the same as that for a full-density solid, even though the sticking coefficient is high.

  5. Sputtering from a Porous Material by Penetrating Ions

    NASA Technical Reports Server (NTRS)

    Rodriguez-Nieva, J. F.; Bringa, E. M.; Cassidy, T. A.; Johnson, R. E.; Caro, A.; Fama, M.; Loeffler, M.; Baragiola, R. A.; Farkas, D.

    2012-01-01

    Porous materials are ubiquitous in the universe and weathering of porous surfaces plays an important role in the evolution of planetary and interstellar materials. Sputtering of porous solids in particular can influence atmosphere formation, surface reflectivity, and the production of the ambient gas around materials in space, Several previous studies and models have shown a large reduction in the sputtering of a porous solid compared to the sputtering of the non-porous solid. Using molecular dynamics simulations we study the sputtering of a nanoporous solid with 55% of the solid density. We calculate the electronic sputtering induced by a fast, penetrating ion, using a thermal spike representation of the deposited energy. We find that sputtering for this porous solid is, surprisingly, the same as that for a full-density solid, even though the sticking coefficient is high.

  6. Advanced materials for solid oxide fuel cells: Hafnium-Praseodymium-Indium Oxide System

    SciTech Connect

    Bates, J.L.; Griffin, C.W.; Weber, W.J.

    1988-06-01

    The HfO/sub 2/-PrO/sub 1.83/-In/sub 2/O/sub 3/ system has been studied at the Pacific Northwest Laboratory to develop alternative, highly electrically conducting oxides as electrode and interconnection materials for solid oxide fuel cells. A coprecipitation process was developed for synthesizing single-phase, mixed oxide powders necessary to fabricate powders and dense oxides. A ternary phase diagram was developed, and the phases and structures were related to electrical transport properties. Two new phases, an orthorhombic PrInO/sub 3/ and a rhombohedral Hf/sub 2/In/sub 2/O/sub 7/ phase, were identified. The highest electronic conductivity is related to the presence of a bcc, In/sub 2/O/sub 3/ solid solution (ss) containing HfO/sub 2/ and PrO/sub 1.83/. Compositions containing more than 35 mol % of the In/sub 2/O/sub 3/ ss have electrical conductivities greater than 10/sup /minus/1/ (ohm-cm)/sup /minus/1/, and the two or three phase structures that contain this phase appear to exhibit mixed electronic-ionic conduction. The high electrical conductivities and structures similar to the Y/sub 2/O/sub 3/-stabilized ZrO/sub 2/(HfO/sub 2/) electrolyte give these oxides potential for use as cathodes in solid oxide fuel cells. 21 refs.

  7. Steps toward interstellar silicate dust mineralogy

    NASA Technical Reports Server (NTRS)

    Dorschner, J.; Guertler, J.; Henning, TH.

    1989-01-01

    One of the most certain facts on interstellar dust is that it contains grains with silicon oxygen tetrahedra (SOT), the internal vibrations of which cause the well known silicate bands at 10 and 18 microns. The broad and almost structureless appearance of them demonstrates lack of translation symmetry in these solids that must be considered amorphous or glassy silicates. There is no direct information on the cations in these interstellar silicates and on the number of bridging oxygens per tetrahedron (NBO). Comparing experimental results gained on amorphous silicates, e.g., silicate glasses, of cosmically most abundant metals (Mg, Fe, Ca, Al) with the observations is the only way to investigate interstellar silicate dust mineralogy (cf, Dorschner and Henning, 1986). At Jena University Observatory IR spectra of submicrometer-sized grains of pyroxene glasses (SSG) were studied. Pyroxenes are common minerals in asteroids, meteorites, interplanetary, and supposedly also cometary dust particles. Pyroxenes consist of linearly connected SOT (NBO=2). In the vitreous state reached by quenching melted minerals, the SOT remain nearly undistorted (Si-O bond length unchanged); the Si-O-Si angles at the bridging oxygens of pyroxenes, however, scatter statistically. Therefore, the original cation oxygen symmetry of the crystal (octahedral and hexahedral coordination by O) is completely lost. The blended bands at 10 and 18 microns lose their diagnostic differences and become broad and structureless. This illustrates best the basic problem of interstellar silicate mineral diagnostics. Optical data of glasses of enstatite, bronzite, hypersthene, diopside, salite, and hedenbergite have been derived. Results of enstatite (E), bronzite (B), and hypersthene (H) show very good agreement with the observed silicate features in the IR spectra of evolutionarily young objects that show P-type silicate signature according to the classification by Gurtler and Henning (1986). Compositional

  8. Materials Science Viewpoint for Recent Development of Solid Oxide Fuel Cells

    NASA Astrophysics Data System (ADS)

    Yokokawa, Harumi

    2013-07-01

    Historical aspects of research and development of solid oxide fuel cells have been discussed on three generation cells in terms of efficiency, durability and cost from the materials science point of view. The first generation (1G) cell can be categorized as the stable materials with high durability, whereas the second (2G) and the third generation (3G) cells can be regarded as high performance with rather low durability. Since these features are closely related with the materials characteristics used in respective cells, key issues of materials compatibility have been discussed with an emphasis on electrolyte and cathode materials. Characteristic features of electrolyte are the chemical volume expansion and the oxygen permeation; GDC as well as LSGM have to be carefully examined on these issues. Important features of cathodes are their interactions with electrolyte as well as impurities such as chromium containing vapors. A difference in strategy of developing cells is discussed between the 1G- and the 2G-cells and compared with recent progress in the respective cells. Interestingly enough, the common feature can be extracted for the durability; that is, use of doped ceria plays an essentially important role of achieving high durability.

  9. A new model of composite interstellar grains

    NASA Astrophysics Data System (ADS)

    Voshchinnikov, N. V.; Il'in, V. B.; Henning, Th.; Dubkova, D. N.

    The approach to model composite interstellar dust grains using the exact solution to the light scattering problem for multi-layered spheras suggested by Voshchinnikov & Mathis (1999) is further developed. Heterogeneous scatterers are represented by particles with very large numof shells each including a homogeneous layer per material considered (here amorphous carbon, astronomical silicate and vacuum). It is demonstrated that the scattering characteristics (cross-sections, albedo, asymmetry factor, etc.) well converge with the increase of the number of shells (layers) and each of the characteristics has the same limit independent of the layer order in the shells. The limit obviously corresponds to composite particles consisting of several well mixed materials. However, our results indicate that layered particles with even a few shells (layers) have the characteristics close enough to these limits. The applicability of the effective medium theory (EMT) mostly utilized earlier to approximate inhomogeneous interstellar grains is examined on the base of the model. It is shown that the used EMT rules generally have the accuracy of several percents in the whole range of particle sizes provided the porosity does not exceed about 50%. For larger porosity, the rules give wrong results. Using the model we reanalyze basics of interpretation of various manifestations of cosmic dust --- interstellar extinction, scattered radiation, infrared radiation, radiation pressure, etc. It is found that an increase of porosity typically leads to the increase of cross-sections, albedo and the sweeping efficiency of small grains as well as to the decrease of dust temperature and the strength of infrared bands (the EMT fails to produce these effects). We also conclude that pure iron even in negligible amount (<˜1 % by the volume fractis unlikely to form a layer on or inside a grain because of peculiar absorption of radiation by such particles. As an example of the potential of the model, it

  10. Analytical Electron Microscopy for Characterization of Fluid or Semi-Solid Multiphase Systems Containing Nanoparticulate Material

    PubMed Central

    Klang, Victoria; Valenta, Claudia; Matsko, Nadejda B.

    2013-01-01

    The analysis of nanomaterials in pharmaceutical or cosmetic preparations is an important aspect both in formulation development and quality control of marketed products. Despite the increased popularity of nanoparticulate compounds especially in dermal preparations such as emulsions, methods and protocols of analysis for the characterization of such systems are scarce. This work combines an original sample preparation procedure along with different methods of analytical electron microscopy for the comprehensive analysis of fluid or semi-solid dermal preparations containing nanoparticulate material. Energy-filtered transmission electron microscopy, energy-dispersive X-ray spectroscopy, electron energy loss spectroscopy and high resolution imaging were performed on model emulsions and a marketed product to reveal different structural aspects of both the emulsion bulk phase and incorporated nanosized material. An innovative analytical approach for the determination of the physical stability of the emulsion under investigation is presented. Advantages and limitations of the employed analytical imaging techniques are highlighted. PMID:24300401

  11. Testing and environmental exposure of parachute materials for the solid rocket booster decelerator subsystem

    NASA Technical Reports Server (NTRS)

    Tannehill, B. K.

    1978-01-01

    Static tests and evaluation of nonmetallic materials for use in parachutes for recovery of solid rocket boosters used in the space shuttle program are reported. Literature survey and manufacturer and vendor contacts led to the choice of nylon as the fabric most capable of withstanding the extreme loads and environmental conditions during repeated use. The material tests included rupture strength, elongation, abrasion resistance, shrinkage, environmental exposure, and degradation levels. Rinsing and drying procedures were also investigated and a salt-free level for nylon recommended in preparation for reuse. In all possible cases, worst-case conditions were used (e.g., inflation loads, seawater exposure for 3 days per drop-recovery, etc.).

  12. Editorial: Interstellar Boundary Explorer (IBEX): Direct Sampling of the Interstellar Medium

    NASA Astrophysics Data System (ADS)

    McComas, D. J.

    2012-02-01

    This special supplement issue of the Astrophysical Journal comprises six coordinated papers that provide the first detailed analyses of the direct sampling of interstellar neutral atoms by the Interstellar Boundary Explorer (IBEX). Interstellar atoms are the detritus of older stars—their stellar winds, novae, and supernovae—spread across the galaxy, which fill the vast interstellar space between the stars. The very local interstellar medium around the Sun is filled with both ionized and neutral atoms with approximately equal numbers, and occasional ionization, charge exchange, and recombination makes them a single interacting material over large distances. IBEX (McComas et al. 2009a) is a NASA Small Explorer mission with the sole, focused science objective to discover the global interaction between the solar wind and the interstellar medium; this objective has primarily been achieved by taking the first global energetic neutral atom (ENA) images, which provide detailed ENA fluxes and energy spectra over all look directions in space. IBEX was launched 2008 October 19 and subsequently maneuvered into a high-altitude, highly elliptical (~15,000 × 300,000 km), roughly week-long orbit. The payload comprises two very high sensitivity, single-pixel ENA cameras: IBEX-Hi (Funsten et al. 2009a), which measures ENAs from ~300 eV to 6 keV, and IBEX-Lo (Fuselier et al. 2009a), which measures ENAs from ~10 eV to 2 keV. The initial IBEX ENA results were published together in a special issue of Science magazine (McComas et al. 2009b; Funsten et al. 2009b; Fuselier et al. 2009b; Schwadron et al. 2009). Since then there have been numerous additional studies of the IBEX ENA observations of the heliosphere, as well as ENAs from the Moon and Earth's magnetosphere (see recent review by McComas et al. 2011 and references therein). Prior to IBEX, the only interstellar neutral atoms to be directly sampled were He, observed by the Ulysses spacecraft a decade ago (Witte et al. 1996

  13. Mesoscale Modeling of Heterogeneous Materials Systems: From Solid Oxide Fuel Cells to Bulk Metallic Glasses

    NASA Astrophysics Data System (ADS)

    Abdeljawad, Fadi F.

    Heterogeneous materials systems hold the key to the future development of a broad range of increasingly complex technological applications. For example, multi-phase and/or multi-component materials are at the forefront research on the development of efficient energy devices, and the future generation of structural materials with optimal mechanical properties. In this dissertation, we focus on two materials systems, namely, solid oxide fuel cells (SOFCs) and bulk metallic glasses (BMGs), where we investigate, through theoretical and mesoscale computational models, the role of microstructure on the properties of these heterogeneous systems. For the solid oxide fuel cell project, a computational framework is developed to investigate the topological evolution of Ni phase in SOFC porous anodes, and the accompanying changes to a wide range of microstructural attributes that affect electrochemical performance. Additionally, with the aid of this framework, we study the reduction-oxidation instability, mechanical deformation and damage accumulation in SOFC anodes. In particular, the SOFC project is focused on the role of anode microstructure, characterized by particle size and ratio, on the microstructural stability and mechanical durability of SOFC anodes. For the bulk metallic glass project, a mesoscale model is introduced that accounts for the structural heterogeneity of monolithic BMGs and BMG composites, and captures the fundamental aspects of plastic deformation in such systems. We examine the effect of internal structure, characterized by rigid/soft short range order (SRO), on the deformation behavior of monolithic BMGs, while for BMG composites, we study the role of ductile phase microstructure, particle size, morphology and area fraction, on the mechanical properties and overall ductility of these systems.

  14. 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.

  15. An Interstellar Sail before 2020?

    NASA Astrophysics Data System (ADS)

    Matloff, G. L.; Johnson, L.

    In 2017, NASA plans to launch the Near Earth Asteroid (NEA) Scout, a solar-photon-sail propelled probe to rendezvous with one or more near-Earth asteroids. According to a publication describing early design parameters, the spacecraft mass is 12 kg and the square sail has an area of 83 square meters. This craft, like many other NASA science missions, will likely remain functional after the completion of its primary mission. This paper investigates options for application of this spacecraft during its extended mission as an Interstellar Trailblazer. As well as kinematics, thermal aspects and the communications challenges are discussed. Although interstellar velocities for this craft will not be high and engineering the pre-perihelion trajectory will be challenging, an extended demonstration mission of this type would certainly spur interest in the development of true interstellar sails. As of December 2014, the design of this spacecraft continues to evolve. The performance estimates presented here may be overly conservative.

  16. The Interstellar Ethics of Self-Replicating Probes

    NASA Astrophysics Data System (ADS)

    Cooper, K.

    Robotic spacecraft have been our primary means of exploring the Universe for over 50 years. Should interstellar travel become reality it seems unlikely that humankind will stop using robotic probes. These probes will be able to replicate themselves ad infinitum by extracting raw materials from the space resources around them and reconfiguring them into replicas of themselves, using technology such as 3D printing. This will create a colonising wave of probes across the Galaxy. However, such probes could have negative as well as positive consequences and it is incumbent upon us to factor self-replicating probes into our interstellar philosophies and to take responsibility for their actions.

  17. The interstellar medium and the soft X-ray background

    NASA Technical Reports Server (NTRS)

    Snowden, S. L.

    1996-01-01

    The soft X-ray background (SXRB) surface brightness provides data to study the approximately 10(exp 6) K plasma of the local interstellar medium of our Galaxy. Various studies were carried out in order to search for negative correlation, or shadowing, of the SXRB, and were coupled with interstellar medium absorption line studies. The purpose was to determine whether the distances to the shadowing material will lead to a three dimensional mapping of the X-ray emitting, and X-ray absorbing components.

  18. Interstellar clouds - From a dynamical perspective on their chemistry

    NASA Technical Reports Server (NTRS)

    Prasad, S. S.

    1985-01-01

    The possibility is examined that in the course of its dynamical evolution, a single mass of interstellar gas would exhibit properties of diffuse clouds, dense clouds and finally also of clouds perturbed by shocks or intense UV or X-ray radiation generated by a star of its own creation. This concept provides a common thread through the bewildering diversity of physical and chemical compositional properties shown by interstellar clouds. From this perspective, instead of being static objects, interstellar clouds are possibly incessantly evolving from initially diffuse to later dense state and then to star formation which ultimately restructures or disperses the remaining cloud material to begin the whole evolutionary process once again. Based on a simplified study of interstellar chemistry from a dynamical perspective, the ideas are presented as an heuristic: to encourage thought on the future direction of molecular astrophysics and the need to consider the chemical behavior of interstellar clouds in conjunction with, rather than in isolation from, their dynamical behavior. A physical basis must be sought for the semiempirical temperature formula which has been given a critical role in the collapse of diffuse clouds. Self-shielding effects in the chemistry of CO were neglected and this drawback should be removed; the ability of the model to explain the fractional abundances of more complex molecules, such as cyanopolyynes, should be examined.

  19. Interstellar Organic Molecules: from Clouds to Solar Nebula

    NASA Astrophysics Data System (ADS)

    Kuan, Yi-Jehng; Huang, Hui-Chun; Charnley, Steven B.; Markwick, Andrew; Botta, Oliver; Ehrenfreund, Pascale; Kisiel, Zbigniew; Butner, Harold M.

    Although laboratory experiments involving energetic processing of simple molecules were able to reproduce many of the biomolecules that are the building blocks of living organisms impacts of comets and asteroids could have delivered large amounts of organic matter to the early Earth. Volatile cometary matter appears to retain a significant interstellar signature; observations of recent bright comets indicate that they have a molecular inventory consistent with their ices being largely unmodified interstellar material. Many simple organic molecules with biochemical significance observed in circumstellar envelopes and in molecular clouds similar to that from which the Solar System formed may have acted as the precursors of the more complex organics found in meteorites. Therefore there is potentially a strong link between interstellar organics and prebiotic chemical evolution. Radioastronomical observations particularly at millimeter wavelengths allow us to determine the chemical composition and characteristics of the molecular inventory in interstellar space. We have thus conducted an extensive astronomical search for complex organic molecules Quinoline Isoquinoline Pyridine and Pyrimidine. Some of our recent results for interstellar organics will be presented.

  20. Interrelationships between interstellar and interplanetary grains

    NASA Technical Reports Server (NTRS)

    Clayton, D. D.

    1986-01-01

    The relationship between solar system dust (SSD) and interstellar dust particles (ISMD) is being reconsidered because of the discovery of isotopic anomalies in meteorites. Meteoritic, circumstellar/meteoritic, interstellar/meteoritic, planetary, and cometary data are reviewed.

  1. Photochromic Solid Materials Based on Poly(decylviologen) Complexed with Alginate and Poly(sodium 4-styrenesulfonate).

    PubMed

    Sanhueza, Luis; Castro, Joaquín; Urzúa, Esteban; Barrientos, Lorena; Oyarzun-Ampuero, Felipe; Pesenti, Héctor; Shibue, Toshimichi; Sugimura, Natsuhiko; Tomita, Wataru; Nishide, Hiroyuki; Moreno-Villoslada, Ignacio

    2015-10-15

    Photochromic solid materials based on the cationic polymer poly(decylviologen) are reported. The solids were obtained by freeze-drying colloidal suspensions of nanocomplexes obtained by mixing aqueous solutions of the polycation with different solutions of polyanions such as poly(sodium 4-styrenesulfonate) or sodium alginate, at a cationic/anionic polymeric charge ratio of 0.7. The photochromic responses of the solid materials fabricated with alginate as complementary charged polyelectrolyte of the cationic polyviologen are faster than those of the solid materials fabricated with poly(sodium 4-styrenesulfonate), achieving coloration kinetics in the order of minutes, and discoloration kinetics in the order of hours for the former. Aromatic-aromatic interactions between the latter polyanion and the polyviologen may stabilize the dicationic form of the viologen derivative, increasing the necessary energy to undergo photoreduction, thus decreasing the reduction kinetics. PMID:26398329

  2. From Interstellar Polycyclic Aromatic Hydrocarbons and Ice to the Origin of Life

    NASA Technical Reports Server (NTRS)

    Allamandola, Louis

    2004-01-01

    Tremendous strides have been made in our understanding of interstellar material over the past twenty years thanks to significant, parallel developments in observational astronomy and laboratory astrophysics. Twenty years ago the composition of interstellar dust was largely guessed at, the concept of ices in dense molecular clouds ignored, and the notion of large, abundant, gas phase, carbon rich molecules widespread throughout the interstellar medium (ISM) considered impossible. Today the composition of dust in the diffuse ISM is reasonably well constrained to cold refractory materials comprised of amorphous and crystalline silicates mixed with an amorphous carbonaceous material containing aromatic structural units and short, branched aliphatic chains. In the dense ISM, the birthplace of stars and planets, these cold dust particles are coated with mixed molecular ices whose composition is very well constrained. Lastly, the signature of carbon-rich polycyclic aromatic hydrocarbons (PAHs), shockingly large molecules by early interstellar chemistry standards, is widespread throughout the Universe. The first part of this talk will describe how infrared studies of interstellar space, combined with laboratory simulations, have revealed the composition of interstellar ices (the building blocks of comets) and the high abundance and nature of interstellar PAHs. The laboratory database has now enabled us to gain insight into the identities, abundances, and physical state of many interstellar materials. Within a dense molecular cloud, and especially in the presolar nebula, the materials frozen into the interstellar/precometary ices are photoprocessed by ultraviolet light and produce more complex molecules. The remainder of the presentation will focus on the photochemical evolution of these materials and the possible role of these compounds on the to the carbonaceous components of micrometeorites, they are likely to have been important sources of complex materials on the early

  3. Interstellar Initiative Web Page Design

    NASA Technical Reports Server (NTRS)

    Mehta, Alkesh

    1999-01-01

    This summer at NASA/MSFC, I have contributed to two projects: Interstellar Initiative Web Page Design and Lenz's Law Relative Motion Demonstration. In the Web Design Project, I worked on an Outline. The Web Design Outline was developed to provide a foundation for a Hierarchy Tree Structure. The Outline would help design a Website information base for future and near-term missions. The Website would give in-depth information on Propulsion Systems and Interstellar Travel. The Lenz's Law Relative Motion Demonstrator is discussed in this volume by Russell Lee.

  4. A speckle hologram of the interstellar plasma

    NASA Technical Reports Server (NTRS)

    Desai, K. M.; Gwinn, C. R.; Reynolds, J.; King, E. A.; Jauncey, D.; Flanagan, C.; Nicolson, G.; Preston, R. A.; Jones, D. L.

    1992-01-01

    Observations of a speckle hologram of scattering material along the line of sight to the Vela pulsar indicate that this material is concentrated in the Vela supernova remnant, deep within the Gum Nebula. The speckle hologram is observed through the amplitude and phase variations of the interferometric cross-power spectrum with time and frequency. These variations describe the density fluctuations of the interstellar plasma, in a holographic fashion. The decorrelation due to the phase variations of the speckles yields the angular size of the scattering disk; comparison with the bandwidth of their amplitude variations yields a characteristic distance from earth to the scattering material of 0.81 +/- 0.03 of the distance from earth to the pulsar. This result is consistent with theories of irregularities associated with particle acceleration in shocks in supernova remnants.

  5. Rational design of novel cathode materials in solid oxide fuel cells using first-principles simulations

    NASA Astrophysics Data System (ADS)

    Choi, YongMan; Lin, M. C.; Liu, Meilin

    The search for clean and renewable sources of energy represents one of the most vital challenges facing us today. Solid oxide fuel cells (SOFCs) are among the most promising technologies for a clean and secure energy future due to their high energy efficiency and excellent fuel flexibility (e.g., direct utilization of hydrocarbons or renewable fuels). To make SOFCs economically competitive, however, development of new materials for low-temperature operation is essential. Here we report our results on a computational study to achieve rational design of SOFC cathodes with fast oxygen reduction kinetics and rapid ionic transport. Results suggest that surface catalytic properties are strongly correlated with the bulk transport properties in several material systems with the formula of La 0.5Sr 0.5BO 2.75 (where B = Cr, Mn, Fe, or Co). The predictions seem to agree qualitatively with available experimental results on these materials. This computational screening technique may guide us to search for high-efficiency cathode materials for a new generation of SOFCs.

  6. Food-processes wastewaters treatment using food solid-waste materials as adsorbents or absorbents

    NASA Astrophysics Data System (ADS)

    Rapti, Ilaira; Georgopoulos, Stavros; Antonopoulou, Maria; Konstantinou, Ioannis; Papadaki, Maria

    2016-04-01

    The wastewaters generated by olive-mills during the production of olive oil, wastewaters from a dairy and a cow-farm unit and wastewaters from a small food factory have been treated by means of selected materials, either by-products of the same units, or other solid waste, as absorbents or adsorbents in order to identify the capacity of those materials to remove organic load and toxicity from the aforementioned wastewaters. The potential of both the materials used as absorbents as well as the treated wastewaters to be further used either as fertilizers or for agricultural irrigation purposes are examined. Dry olive leaves, sheep wool, rice husks, etc. were used either in a fixed-bed or in a stirred batch arrangemen,t employing different initial concentrations of the aforementioned wastewaters. The efficiency of removal was assessed using scpectrophotometric methods and allium test phytotoxicity measurements. In this presentation the response of each material employed is shown as a function of absorbent/adsorbent quantity and kind, treatment time and wastewater kind and initial organic load. Preliminary results on the potential uses of the adsorbents/absorbents and the treated wastewaters are also shown. Keywords: Olive-mill wastewaters, dairy farm wastewaters, olive leaves, zeolite, sheep wool

  7. Identification and Mitigation of Generated Solid By-Products during Advanced Electrode Materials Processing.

    PubMed

    Tsai, Candace S J; Dysart, Arthur D; Beltz, Jay H; Pol, Vilas G

    2016-03-01

    A scalable, solid-state elevated-temperature process was developed to produce high-capacity carbonaceous electrode materials for energy storage devices via decomposition of a starch-based precursor in an inert atmosphere. In a separate study, it is shown that the fabricated carbonaceous architectures are useful as an excellent electrode material for lithium-ion, sodium-ion, and lithium-sulfur batteries. This article focuses on the study and analysis of the formed nanometer-sized by-products during the lab-scale synthesis of the carbon material. The material production process was studied in operando (that is, during the entire duration of heat treatment). The unknown downstream particles in the process exhaust were collected and characterized via aerosol and liquid suspensions, and they were quantified using direct-reading instruments for number and mass concentrations. The airborne emissions were collected using the Tsai diffusion sampler (TDS) for characterization and further analysis. Released by-product aerosols collected in a deionized (DI) water trap were analyzed, and the aerosols emitted from the post-water-suspension were collected and characterized. After long-term sampling, individual particles in the nanometer size range were observed in the exhaust aerosol with layer-structured aggregates formed on the sampling substrate. Upon the characterization of the released aerosol by-products, methods were identified to mitigate possible human and environmental exposures upon industrial implementation. PMID:26716402

  8. Materials Selection for Superheater Tubes in Municipal Solid Waste Incineration Plants

    NASA Astrophysics Data System (ADS)

    Morales, M.; Chimenos, J. M.; Fernández, A. I.; Segarra, M.

    2014-09-01

    Corrosion reduces the lifetime of municipal solid waste incineration (MSWI) superheater tubes more than any other cause. It can be minimized by the careful selection of those materials that are most resistant to corrosion under operating conditions. Since thousands of different materials are already known and many more are developed every year, here the selection methodology developed by Prof. Ashby of the University of Cambridge was used to evaluate the performance of different materials to be used as MSWI superheater tubes. The proposed materials can operate at steam pressures and temperatures over 40 bars and 400 °C, respectively. Two case studies are presented: one makes a balanced selection between mechanical properties and cost per thermal unit; and the other focuses on increasing tube lifetime. The balanced selection showed that AISI 410 martensitic stainless steel (wrought, hard tempered) is the best candidate with a good combination of corrosion resistance, a relatively low price (0.83-0.92 €/kg) and a good thermal conductivity (23-27 W/m K). Meanwhile, Nitronic 50/XM-19 stainless steel is the most promising candidate for long-term selection, as it presents high corrosion resistance with a relatively low price (4.86-5.14 €/kg) compared to Ni-alloys.

  9. Experimental interstellar organic chemistry - Preliminary findings

    NASA Technical Reports Server (NTRS)

    Khare, B. N.; Sagan, C.

    1973-01-01

    Review of the results of some explicit experimental simulation of interstellar organic chemistry consisting in low-temperature high-vacuum UV irradiation of condensed simple gases known or suspected to be present in the interstellar medium. The results include the finding that acetonitrile may be present in the interstellar medium. The implication of this and other findings are discussed.

  10. On the question of interstellar travel

    NASA Technical Reports Server (NTRS)

    Wolfe, J. H.

    1985-01-01

    Arguments are presented which show that motives for interstellar travel by advanced technological civilizations based on an extrapolation of earth's history may be quite invalid. In addition, it is proposed that interstellar travel is so enormously expensive and perhaps so hazardous, that advanced civilizations do not engage in such practices because of the ease of information transfer via interstellar communication.

  11. VUV spectroscopy of carbon dust analogs: contribution to interstellar extinction

    NASA Astrophysics Data System (ADS)

    Gavilan, L.; Alata, I.; Le, K. C.; Pino, T.; Giuliani, A.; Dartois, E.

    2016-02-01

    Context. A full spectral characterization of carbonaceous dust analogs is necessary to understand their potential as carriers of observed astronomical spectral signatures such as the ubiquitous UV bump at 217.5 nm and the far-ultraviolet (FUV) rise common to interstellar extinction curves. Aims: Our goal is to study the spectral properties of carbonaceous dust analogs from the FUV to the mid-infrared (MIR) domain. We seek in particular to understand the spectra of these materials in the FUV range, for which laboratory studies are scarce. Methods: We produced analogs to carbonaceous interstellar dust encountered in various phases of the interstellar medium: amorphous hydrogenated carbons (a-C:H), for carbonaceous dust observed in the diffuse interstellar medium, and soot particles, for the polyaromatic component. Analogs to a-C:H dust were produced using a radio-frequency plasma reactor at low pressures, and soot nanoparticles films were produced in an ethylene (C2H4) flame. We measured transmission spectra of these thin films (thickness <100 nm) in the far-ultraviolet (190-250 nm) and in the vacuum-ultraviolet (VUV; 50-190 nm) regions using the APEX chamber at the DISCO beam line of the SOLEIL synchrotron radiation facility. These were also characterized through infrared microscopy at the SMIS beam line. Results: We successfully measured the transmission spectra of these analogs from λ = 1 μm to 50 nm. From these, we extracted the laboratory optical constants via Kramers-Kronig inversion. We used these constants for comparison to existing interstellar extinction curves. Conclusions: We extend the spectral measurements of these types of carbonaceous analogs into the VUV and link the spectral features in this range to the 3.4 μm band. We suggest that these two materials might contribute to different classes of interstellar extinction curves.

  12. Interstellar dust in the Local Cloud surrounding the Sun

    NASA Astrophysics Data System (ADS)

    Kimura, Hiroshi

    2015-05-01

    On the basis of the most recent view on the local interstellar medium consisting of a single continuous cloud, termed the Local Cloud, we study the destruction of interstellar dust by the propagation of a shock wave in the Local Cloud. We survey gas-phase column densities of dust-forming elements in the literature to determine how the dust destruction fraction varies with the angle from the minor axis of the cloud. Our results indicate that the propagation of a shock wave destroyed approximately 20 per cent of interstellar dust towards the minor axis of the cloud pointing near the anti-apex of motion with a shock of <100 km s-1, weaker than previously expected. The gas-to-dust ratio of the Local Cloud is approximately 120 towards the apex of cloud motion and organic-forming elements occupy 40 per cent of the mass in the dust phase. We find that a correlation in the gas-phase abundances between silicon and magnesium is consistent with the destruction of silicate grains with enstatite stoichiometry. We also derive the most plausible composition of interstellar dust from the dust-phase elemental abundances and the correlations between the dust-forming elements. We suggest that the major constituents of interstellar dust are organic materials, magnesium silicates and iron alloys, while the minor ones are spinels and iron sulphides. Since no organic materials have been detected in the grains that penetrate into the Solar system, we claim that the composition of interstellar dust may not remain intact en route to the inner Solar system.

  13. Interstellar Aldehydes and their corresponding Reduced Alcohols: Interstellar Propanol?

    NASA Astrophysics Data System (ADS)

    Etim, Emmanuel; Chakrabarti, Sandip Kumar; Das, Ankan; Gorai, Prasanta; Arunan, Elangannan

    2016-07-01

    There is a well-defined trend of aldehydes and their corresponding reduced alcohols among the known interstellar molecules; methanal (CH_2O) and methanol (CH_3OH); ethenone (C_2H_2O) and vinyl alcohol (CH_2CHOH); ethanal (C_2H_4O) and ethanol(C_2H_5OH); glycolaldehyde (C_2H_4O_2) and ethylene glycol(C_2H_6O_2). The reduced alcohol of propanal (CH_3CH_2CHO) which is propanol (CH_3CH_2CH_2OH) has not yet been observed but its isomer; ethyl methyl ether (CH_3CH_2OCH_3) is a known interstellar molecule. In this article, different studies are carried out in investigating the trend between aldehydes and their corresponding reduced alcohols and the deviation from the trend. Kinetically and with respect to the formation route, alcohols could have been produced from their corresponding reduced aldehydes via two successive hydrogen additions. This is plausible because of (a) the unquestionable high abundance of hydrogen, (b) presence of energy sources within some of the molecular clouds and (c) the ease at which successive hydrogen addition reaction occurs. In terms of stability, the observed alcohols are thermodynamically favorable as compared to their isomers. Regarding the formation process, the hydrogen addition reactions are believed to proceed on the surface of the interstellar grains which leads to the effect of interstellar hydrogen bonding. From the studies, propanol and propan-2-ol are found to be more strongly attached to the surface of the interstellar dust grains which affects its overall gas phase abundance as compared to its isomer ethyl methyl ether which has been observed.

  14. Coordinated Microanalyses of Seven Particles of Probable Interstellar Origin from the Stardust Mission

    NASA Technical Reports Server (NTRS)

    Westphal, Andrew J.; Stroud, Rhonda M.; Bechtel, Hans A.; Brenker, Frank E.; Butterworth, Anna L.; Flynn, George J.; Frank, David R.; Gainsforth, Zack; Hillier, Jon K.; Postberg, Frank; Simionovici, Alexandre S.; Sterken, Veerle J.; Allen, Carlton; Anderson, David; Ansari, Asna; Bajt, Sasa; Bastien, Ron K.; Bassim, Nabil; Bridges, John; Brownlee, Donald E.; Burchell, Mark.; Burghammer, Manfred; Changela, Hitesh; Sandford, Scott A.; Zolensky, Michael

    2014-01-01

    Stardust, a NASA Discovery-class mission, was the first sample-return mission to return solid samples from beyond the Moon. Stardust was effectively two missions in one spacecraft: it returned the first materials from a known primitive solar system body, the Jupiter-family comet Wild 2; Stardust also returned a collector that was exposed to the contemporary interstellar dust stream for 200 days during the interplanetary cruise. Both collections present severe technical challenges in sample preparation and in analysis. By far the largest collection is the cometary one: approximately 300 micro g of material was returned from Wild 2, mostly consisting of approx. 1 ng particles embedded in aerogel or captured as residues in craters on aluminum foils. Because of their relatively large size, identification of the impacts of cometary particles in the collection media is straightforward. Reliable techniques have been developed for the extraction of these particles from aerogel. Coordinated analyses are also relatively straightforward, often beginning with synchrotron-based x-ray fluorescence (S-XRF), X-ray Absorption Near-Edge Spectoscopy (XANES) and x-ray diffraction (S-XRD) analyses of particles while still embedded in small extracted wedges of aerogel called ``keystones'', followed by ultramicrotomy and TEM, Scanning Transmission X-ray Microscopy (STXM) and ion microprobe analyses (e.g., Ogliore et al., 2010). Impacts in foils can be readily analyzed by SEM-EDX, and TEM analysis after FIB liftout sample preparation. In contrast, the interstellar dust collection is vastly more challenging. The sample size is approximately six orders of magnitude smaller in total mass. The largest particles are only a few pg in mass, of which there may be only approx.10 in the entire collection. The technical challenges, however, are matched by the scientific importance of the collection. We formed a consortium carry out the Stardust Interstellar Preliminary Examination (ISPE) to carry

  15. Methods for using novel cathode and electrolyte materials for solid oxide fuel cells and ion transport membranes

    DOEpatents

    Jacobson, Allan J.; Wang, Shuangyan; Kim, Gun Tae

    2016-01-12

    Methods using novel cathode, electrolyte and oxygen separation materials operating at intermediate temperatures for use in solid oxide fuel cells and ion transport membranes include oxides with perovskite related structures and an ordered arrangement of A site cations. The materials have significantly faster oxygen kinetics than in corresponding disordered perovskites.

  16. COMPARISONS OF THE INTERSTELLAR MAGNETIC FIELD DIRECTIONS OBTAINED FROM THE IBEX RIBBON AND INTERSTELLAR POLARIZATIONS

    SciTech Connect

    Frisch, Priscilla C.; Andersson, B-G; Berdyugin, Andrei; Piirola, Vilppu; Funsten, Herbert O.; Magalhaes, Antonio M.; McComas, David J.; Schwadron, Nathan A.; Slavin, Jonathan D.; Wiktorowicz, Sloane J. E-mail: bgandersson@sofia.usra.ed E-mail: piirola@utu.f E-mail: mario@astro.iag.usp.b E-mail: nschwadron@guero.sr.unh.ed E-mail: sloane@berkeley.ed

    2010-12-01

    Variations in the spatial configuration of the interstellar magnetic field (ISMF) near the Sun can be constrained by comparing the ISMF direction at the heliosphere found from the Interstellar Boundary Explorer (IBEX) spacecraft observations of a 'Ribbon' of energetic neutral atoms (ENAs), with the ISMF direction derived from optical polarization data for stars within {approx}40 pc. Using interstellar polarization observations toward {approx}30 nearby stars within {approx}90{sup 0} of the heliosphere nose, we find that the best fits to the polarization position angles are obtained for a magnetic pole directed toward ecliptic coordinates of {lambda}, {beta} {approx} 263{sup 0}, 37{sup 0} (or galactic coordinates of l, b {approx} 38{sup 0}, 23{sup 0}), with uncertainties of {+-}35{sup 0} based on the broad minimum of the best fits and the range of data quality. This magnetic pole is 33{sup 0} from the magnetic pole that is defined by the center of the arc of the ENA Ribbon. The IBEX ENA ribbon is seen in sight lines that are perpendicular to the ISMF as it drapes over the heliosphere. The similarity of the polarization and Ribbon directions for the local ISMF suggests that the local field is coherent over scale sizes of tens of parsecs. The ISMF vector direction is nearly perpendicular to the flow of local interstellar material (ISM) through the local standard of rest, supporting a possible local ISM origin related to an evolved expanding magnetized shell. The local ISMF direction is found to have a curious geometry with respect to the cosmic microwave background dipole moment.

  17. X-ray radiographic measurements of radiation-driven shock and interface motion in solid density material

    SciTech Connect

    Hammel, B.A.; Griswold, D.; Landen, O.L.; Perry, T.S.; Remington, B.A.; Miller, P.L.; Peyser, T.A.; Kilkenny, J.D. )

    1993-07-01

    Time resolved x-ray radiographic measurements at high photon energy ([similar to]7 keV) are used to observe radiation-driven shock propagation and interface motion in solid density plastic samples, produced by indirect drive on the Nova laser. Measurements of x-ray transmission through the shock compressed material are used to infer a density of approximately three times solid. In addition, by doping a section of a sample with high-[ital Z] material (Br) for radiographic contrast, the shocked particle velocity was measured by observing the motion of the interface between the doped and nondoped materials resulting from acceleration by a shock.

  18. Analysis of optimization processses for solid state fabrication of olivine cathode materials

    NASA Astrophysics Data System (ADS)

    Oladimeji, Charles

    Lithium ion battery discovered since the 1980s has become pivotal to our energy needs. With the need for a shift to renewable energy and increased use of portable devices, energy storage has become a very important aspect of modern day life and technology. In the thesis, optimization techniques for solid state calcination of lithium olivine batteries are characterized and analyzed. A brief introduction into lithium ion battery is discussed, the chemistry and physics of the materials is studied in details. Emphasis is placed on the olivine structure, industrially utilized synthesis method and the performance of olivine lithium ion batteries are also discussed in details. Olivine structure LiFePO4 (LFP) was synthesized via solid state processes, using Li2CO3, NH4H 2PO4 and FeC2O4˙H2O and C12H22O11 as precursor materials. The effects of calendaring in terms of charge/discharge capacity, cycle life performance, surface morphology, and ac impedance was analyzed. The resulting LFP electrode was divided in part, Part A was left as is and Part B was calendared. The calendared electrode exhibited lower impedance under electrochemical impedance test. The calendared electrode also exhibited a higher discharge capacity of about 130 mAh/g at 0.1C compared to the as-is electrode with discharge capacity of about 120mAh/g. Olivine structure LiMnPO4 (LMP) was also synthesized via solid state processes, using Li2CO3, NH4H 2PO4, MnCO3 and C12H22O 11 as precursor materials. Comparison of the carbon addition process was done by adding sucrose to the initial precursor mix and carbon black at the later stages of fabrication. The 3 step carbon addition exhibited the highest specific capacity of about 72mAh/g, 1 step carbon addition possessed the least capacity of about 45mAh/g, while the 2 step process had a capacity of about 65mA/g.

  19. Synthesis of mesoporous silica materials from municipal solid waste incinerator bottom ash

    SciTech Connect

    Liu, Zhen-Shu Li, Wen-Kai; Huang, Chun-Yi

    2014-05-01

    Highlights: • The optimal alkaline agent for the extraction of silica from bottom ash was Na{sub 2}CO{sub 3}. • The pore sizes for the mesoporous silica synthesized from bottom ash were 2–3.8 nm. • The synthesized materials exhibited a hexagonal pore structure with a smaller order. • The materials have potential for the removal of heavy metals from aqueous solutions. - Abstract: Incinerator bottom ash contains a large amount of silica and can hence be used as a silica source for the synthesis of mesoporous silica materials. In this study, the conditions for alkaline fusion to extract silica from incinerator bottom ash were investigated, and the resulting supernatant solution was used as the silica source for synthesizing mesoporous silica materials. The physical and chemical characteristics of the mesoporous silica materials were analyzed using BET, XRD, FTIR, SEM, and solid-state NMR. The results indicated that the BET surface area and pore size distribution of the synthesized silica materials were 992 m{sup 2}/g and 2–3.8 nm, respectively. The XRD patterns showed that the synthesized materials exhibited a hexagonal pore structure with a smaller order. The NMR spectra of the synthesized materials exhibited three peaks, corresponding to Q{sup 2} [Si(OSi){sub 2}(OH){sub 2}], Q{sup 3} [Si(OSi){sub 3}(OH)], and Q{sup 4} [Si(OSi){sub 4}]. The FTIR spectra confirmed the existence of a surface hydroxyl group and the occurrence of symmetric Si–O stretching. Thus, mesoporous silica was successfully synthesized from incinerator bottom ash. Finally, the effectiveness of the synthesized silica in removing heavy metals (Pb{sup 2+}, Cu{sup 2+}, Cd{sup 2+}, and Cr{sup 2+}) from aqueous solutions was also determined. The results showed that the silica materials synthesized from incinerator bottom ash have potential for use as an adsorbent for the removal of heavy metals from aqueous solutions.

  20. Torque measurements reveal large process differences between materials during high solid enzymatic hydrolysis of pretreated lignocellulose

    PubMed Central

    2012-01-01

    Background A common trend in the research on 2nd generation bioethanol is the focus on intensifying the process and increasing the concentration of water insoluble solids (WIS) throughout the process. However, increasing the WIS content is not without problems. For example, the viscosity of pretreated lignocellulosic materials is known to increase drastically with increasing WIS content. Further, at elevated viscosities, problems arise related to poor mixing of the material, such as poor distribution of the enzymes and/or difficulties with temperature and pH control, which results in possible yield reduction. Achieving good mixing is unfortunately not without cost, since the power requirements needed to operate the impeller at high viscosities can be substantial. This highly important scale-up problem can easily be overlooked. Results In this work, we monitor the impeller torque (and hence power input) in a stirred tank reactor throughout high solid enzymatic hydrolysis (< 20% WIS) of steam-pretreated Arundo donax and spruce. Two different process modes were evaluated, where either the impeller speed or the impeller power input was kept constant. Results from hydrolysis experiments at a fixed impeller speed of 10 rpm show that a very rapid decrease in impeller torque is experienced during hydrolysis of pretreated arundo (i.e. it loses its fiber network strength), whereas the fiber strength is retained for a longer time within the spruce material. This translates into a relatively low, rather WIS independent, energy input for arundo whereas the stirring power demand for spruce is substantially larger and quite WIS dependent. By operating the impeller at a constant power input (instead of a constant impeller speed) it is shown that power input greatly affects the glucose yield of pretreated spruce whereas the hydrolysis of arundo seems unaffected. Conclusions The results clearly highlight the large differences between the arundo and spruce materials, both in terms of

  1. Term Projects on Interstellar Comets

    ERIC Educational Resources Information Center

    Mack, John E.

    1975-01-01

    Presents two calculations of the probability of detection of an interstellar comet, under the hypothesis that such comets would escape from comet clouds similar to that believed to surround the sun. Proposes three problems, each of which would be a reasonable term project for a motivated undergraduate. (Author/MLH)

  2. Erratum: Interstellar Abundance Standards Revisited

    NASA Astrophysics Data System (ADS)

    Sofia, U. J.; Meyer, D. M.

    2001-09-01

    In the Letter ``Interstellar Abundance Standards Revisited'' by U. J. Sofia and D. M. Meyer (ApJ, 554, L221 [2001]), Table 2 and its footnotes contain several typographical errors. The corrected table is shown below. We note that the solar reference standard now implies a positive abundance of nitrogen in halo dust.

  3. The effect of catastrophic collisional fragmentation and diffuse medium accretion on a computational interstellar dust system

    NASA Technical Reports Server (NTRS)

    Liffman, Kurt

    1990-01-01

    The effects of catastrophic collisional fragmentation and diffuse medium accretion on a the interstellar dust system are computed using a Monte Carlo computer model. The Monte Carlo code has as its basis an analytic solution of the bulk chemical evolution of a two-phase interstellar medium, described by Liffman and Clayton (1989). The model is subjected to numerous different interstellar processes as it transfers from one interstellar phase to another. Collisional fragmentation was found to be the dominant physical process that shapes the size spectrum of interstellar dust. It was found that, in the diffuse cloud phase, 90 percent of the refractory material is locked up in the dust grains, primarily due to accretion in the molecular medium. This result is consistent with the observed depletions of silicon. Depletions were found to be affected only slightly by diffuse cloud accretion.

  4. Decades-long changes of the interstellar wind through our solar system.

    PubMed

    Frisch, P C; Bzowski, M; Livadiotis, G; McComas, D J; Moebius, E; Mueller, H-R; Pryor, W R; Schwadron, N A; Sokół, J M; Vallerga, J V; Ajello, J M

    2013-09-01

    The journey of the Sun through the dynamically active local interstellar medium creates an evolving heliosphere environment. This motion drives a wind of interstellar material through the heliosphere that has been measured with Earth-orbiting and interplanetary spacecraft for 40 years. Recent results obtained by NASA's Interstellar Boundary Explorer mission during 2009-2010 suggest that neutral interstellar atoms flow into the solar system from a different direction than found previously. These prior measurements represent data collected from Ulysses and other spacecraft during 1992-2002 and a variety of older measurements acquired during 1972-1978. Consideration of all data types and their published results and uncertainties, over the three epochs of observations, indicates that the trend for the interstellar flow ecliptic longitude to increase linearly with time is statistically significant. PMID:24009386

  5. The interstellar oxygen crisis, or where have all the oxygen atoms gone?

    NASA Astrophysics Data System (ADS)

    Wang, Shu; Li, Aigen; Jiang, B. W.

    2015-11-01

    The interstellar medium (ISM) seems to have a significant surplus of oxygen which was dubbed as the `O crisis': independent of the adopted interstellar reference abundance, the total number of O atoms depleted from the gas phase far exceeds that tied up in solids by as much as ˜160 ppm of O/H. Recently, it has been hypothesized that the missing O could be hidden in μm-sized H2O ice grains. We examine this hypothesis by comparing the infrared (IR) extinction and far-IR emission arising from these grains with that observed in the Galactic diffuse ISM. We find that it is possible for the diffuse ISM to accommodate ˜160 ppm of O/H in μm-sized H2O ice grains without violating the observational constraints including the absence of the 3.1 μm O-H absorption feature. More specifically, H2O ice grains of radii ˜4 μm and O/H = 160 ppm are capable of accounting for the observed flat extinction at ˜3-8 μm and produce no excessive emission in the far-IR. These grains could be present in the diffuse ISM through rapid exchange of material between dense molecular clouds where they form and diffuse clouds where they are destroyed by photosputtering.

  6. Stardust Interstellar Preliminary Examination VII: Synchrotron X-ray fluorescence analysis of six Stardust interstellar candidates measured with the Advanced Photon Source 2-ID-D microprobe

    NASA Astrophysics Data System (ADS)

    Flynn, George J.; Sutton, Steven R.; Lai, Barry; Wirick, Sue; Allen, Carlton; Anderson, David; Ansari, Asna; Bajt, SašA.; Bastien, Ron K.; Bassim, Nabil; Bechtel, Hans A.; Borg, Janet; Brenker, Frank E.; Bridges, John; Brownlee, Donald E.; Burchell, Mark; Burghammer, Manfred; Butterworth, Anna L.; Changela, Hitesh; Cloetens, Peter; Davis, Andrew M.; Doll, Ryan; Floss, Christine; Frank, David; Gainsforth, Zack; Grün, Eberhard; Heck, Philipp R.; Hillier, Jon K.; Hoppe, Peter; Hudson, Bruce; Huth, Joachim; Hvide, Brit; Kearsley, Anton; King, Ashley J.; Leitner, Jan; Lemelle, Laurence; Leroux, Hugues; Leonard, Ariel; Lettieri, Robert; Marchant, William; Nittler, Larry R.; Ogliore, Ryan; Ong, Wei Ja; Postberg, Frank; Price, Mark C.; Sandford, Scott A.; Tresseras, Juan-Angel Sans; Schmitz, Sylvia; Schoonjans, Tom; Silversmit, Geert; Simionovici, Alexandre; Sol, Vicente A.; Srama, Ralf; Stadermann, Frank J.; Stephan, Thomas; Sterken, Veerle; Stodolna, Julien; Stroud, Rhonda M.; Trieloff, Mario; Tsou, Peter; Tsuchiyama, Akira; Tyliszczak, Tolek; Vekemans, Bart; Vincze, Laszlo; von Korff, Joshua; Westphal, Andrew J.; Wordsworth, Naomi; Zevin, Daniel; Zolensky, Michael E.

    2014-09-01

    The NASA Stardust spacecraft exposed an aerogel collector to the interstellar dust passing through the solar system. We performed X-ray fluorescence element mapping and abundance measurements, for elements 19 ≤ Z ≤ 30, on six "interstellar candidates," potential interstellar impacts identified by Stardust@Home and extracted for analyses in picokeystones. One, I1044,3,33, showed no element hot-spots within the designated search area. However, we identified a nearby surface feature, consistent with the impact of a weak, high-speed particle having an approximately chondritic (CI) element abundance pattern, except for factor-of-ten enrichments in K and Zn and an S depletion. This hot-spot, containing approximately 10 fg of Fe, corresponds to an approximately 350 nm chondritic particle, small enough to be missed by Stardust@Home, indicating that other techniques may be necessary to identify all interstellar candidates. Only one interstellar candidate, I1004,1,2, showed a track. The terminal particle has large enrichments in S, Ti, Cr, Mn, Ni, Cu, and Zn relative to Fe-normalized CI values. It has high Al/Fe, but does not match the Ni/Fe range measured for samples of Al-deck material from the Stardust sample return capsule, which was within the field-of-view of the interstellar collector. A third interstellar candidate, I1075,1,25, showed an Al-rich surface feature that has a composition generally consistent with the Al-deck material, suggesting that it is a secondary particle. The other three interstellar candidates, I1001,1,16, I1001,2,17, and I1044,2,32, showed no impact features or tracks, but allowed assessment of submicron contamination in this aerogel, including Fe hot-spots having CI-like Ni/Fe ratios, complicating the search for CI-like interstellar/interplanetary dust.

  7. Low cost stable air electrode material for high temperature solid oxide electrolyte electrochemical cells

    DOEpatents

    Kuo, L.J.H.; Singh, P.; Ruka, R.J.; Vasilow, T.R.; Bratton, R.J.

    1997-11-11

    A low cost, lanthanide-substituted, dimensionally and thermally stable, gas permeable, electrically conductive, porous ceramic air electrode composition of lanthanide-substituted doped lanthanum manganite is provided which is used as the cathode in high temperature, solid oxide electrolyte fuel cells and generators. The air electrode composition of this invention has a much lower fabrication cost as a result of using a lower cost lanthanide mixture, either a natural mixture or an unfinished lanthanide concentrate obtained from a natural mixture subjected to incomplete purification, as the raw material in place of part or all of the higher cost individual lanthanum. The mixed lanthanide primarily contains a mixture of at least La, Ce, Pr, and Nd, or at least La, Ce, Pr, Nd and Sm in its lanthanide content, but can also include minor amounts of other lanthanides and trace impurities. The use of lanthanides in place of some or all of the lanthanum also increases the dimensional stability of the air electrode. This low cost air electrode can be fabricated as a cathode for use in high temperature, solid oxide fuel cells and generators. 4 figs.

  8. Advanced concepts for high power RF generation using solid state materials

    SciTech Connect

    Fazio, M.V.; Erickson, G.A.

    1999-05-01

    Traditionally, high power radio frequency and microwave energy have been generated using electron beam driven hard-vacuum tubes such as klystrons and magnetrons. High-power solid-state sources of RF have not been available. It is well known that a non-linear, dispersive system can convert a pulse into an array of solitons. Although this effect has been exploited in the optical field, using non-linear optical materials, little work has been done in the field of high voltage electronics. It is the goal of this work, which is just beginning, to develop sources of RF in the few hundreds of megahertz to gigahertz range with power levels in the hundreds of megawatts to the gigawatt level. To generate solitons a high voltage pulse is fed onto a transmission line that is periodically loaded with a non-linear ceramic dielectric in the paraelectric phase. The combination of the non-linearity and dispersion causes the pulse to break up into an array of solitons. A soliton-based system has several components: the solid state, high voltage, high current switch to provide the initial high voltage pulse; a shock line to decrease the rise time of the initial pulse to less than a few nanoseconds; and the soliton generating transmission line where the high power RF is generated when driven by the fast rising pulse from the shock line. The approach and progress to date will be described. {copyright} {ital 1999 American Institute of Physics.}

  9. Low cost stable air electrode material for high temperature solid oxide electrolyte electrochemical cells

    DOEpatents

    Kuo, Lewis J. H.; Singh, Prabhakar; Ruka, Roswell J.; Vasilow, Theodore R.; Bratton, Raymond J.

    1997-01-01

    A low cost, lanthanide-substituted, dimensionally and thermally stable, gas permeable, electrically conductive, porous ceramic air electrode composition of lanthanide-substituted doped lanthanum manganite is provided which is used as the cathode in high temperature, solid oxide electrolyte fuel cells and generators. The air electrode composition of this invention has a much lower fabrication cost as a result of using a lower cost lanthanide mixture, either a natural mixture or an unfinished lanthanide concentrate obtained from a natural mixture subjected to incomplete purification, as the raw material in place of part or all of the higher cost individual lanthanum. The mixed lanthanide primarily contains a mixture of at least La, Ce, Pr, and Nd, or at least La, Ce, Pr, Nd and Sm in its lanthanide content, but can also include minor amounts of other lanthanides and trace impurities. The use of lanthanides in place of some or all of the lanthanum also increases the dimensional stability of the air electrode. This low cost air electrode can be fabricated as a cathode for use in high temperature, solid oxide fuel cells and generators.

  10. DEVELOPMENT AND VERIFICATION OF NEW SOLID DENTAL FILLING TEMPORARY MATERIALS CONTAINING ZINC. FORMULA DEVELOPMENT STAGE.

    PubMed

    Pytko-Polończyk, Jolanta; Antosik, Agata; Zajac, Magdalena; Szlósarczyk, Marek; Krywult, Agnieszka; Jachowicz, Renata; Opoka, Włodzimierz

    2016-01-01

    Caries is the most popular problem affecting teeth and this is the reason why so many temporary dental filling materials are being developed. An example of such filling is zinc oxide paste mixed with eugenol, Thymodentin and Coltosol F®. Zinc-oxide eugenol is used in dentistry because of its multiplied values: it improves heeling of the pulp by dentine bridge formation; has antiseptic properties; is hygroscopic. Because of these advantages compouds of zinc oxide are used as temporary fillings, especially in deep caries lesions when treatment is oriented on support of vital pulp. Temporary dental fillings based on zinc oxide are prepared ex tempone by simple mixing powder (Thymodentin) and eugenol liqiud together or a ready to use paste Coltosol F®. Quantitative composition depends mainly on experience of person who is preparing it, therefore, exact qualitative composition of dental fillings is not replicable. The main goal of the study was to develop appropriate dental fillings in solid form containing set amount of zinc oxide. Within the study, the influence of preparation method on solid dental fillings properties like mechanical properties and zinc ions release were examined. PMID:27476293

  11. Process for forming a homogeneous oxide solid phase of catalytically active material

    DOEpatents

    Perry, Dale L.; Russo, Richard E.; Mao, Xianglei

    1995-01-01

    A process is disclosed for forming a homogeneous oxide solid phase reaction product of catalytically active material comprising one or more alkali metals, one or more alkaline earth metals, and one or more Group VIII transition metals. The process comprises reacting together one or more alkali metal oxides and/or salts, one or more alkaline earth metal oxides and/or salts, one or more Group VIII transition metal oxides and/or salts, capable of forming a catalytically active reaction product, in the optional presence of an additional source of oxygen, using a laser beam to ablate from a target such metal compound reactants in the form of a vapor in a deposition chamber, resulting in the deposition, on a heated substrate in the chamber, of the desired oxide phase reaction product. The resulting product may be formed in variable, but reproducible, stoichiometric ratios. The homogeneous oxide solid phase product is useful as a catalyst, and can be produced in many physical forms, including thin films, particulate forms, coatings on catalyst support structures, and coatings on structures used in reaction apparatus in which the reaction product of the invention will serve as a catalyst.

  12. Development of advanced blanket materials for a solid breeder blanket of a fusion reactor

    NASA Astrophysics Data System (ADS)

    Kawamura, H.; Ishitsuka, E.; Tsuchiya, K.; Nakamichi, M.; Uchida, M.; Yamada, H.; Nakamura, K.; Ito, H.; Nakazawa, T.; Takahashi, H.; Tanaka, S.; Yoshida, N.; Kato, S.; Ito, Y.

    2003-08-01

    The design of an advanced solid breeding blanket in a DEMO reactor requires a tritium breeder and a neutron multiplier that can withstand high temperatures and high neutron fluences, and the development of such advanced blanket materials has been carried out by collaboration between JAERI, universities and industries in Japan. The Li2TiO3 pebble fabricated by a wet process is a reference material as a tritium breeder, but its stability at high temperatures has to be improved for its application in a DEMO blanket. One of these improved materials, TiO2-doped Li2TiO3 pebbles, was successfully fabricated and studied. For the advanced neutron multiplier, beryllides that have a high melting point and good chemical stability have been studied. Some characterization of Be12Ti was conducted, and it became clear that it had lower swelling and tritium inventory than beryllium metal. Pebble fabrication study for Be12Ti was also performed and Be12Ti pebbles were successfully fabricated. These activities have shown that there is a bright prospect in realizing a DEMO blanket by the application of TiO2-doped Li2TiO3 and beryllides.

  13. Construction material properties of slag from the high temperature arc gasification of municipal solid waste.

    PubMed

    Roessler, Justin G; Olivera, Fernando D; Wasman, Scott J; Townsend, Timothy G; McVay, Michael C; Ferraro, Christopher C; Blaisi, Nawaf I

    2016-06-01

    Slag from the high temperature arc gasification (HTAG) of municipal solid waste (MSW) was tested to evaluate its material properties with respect to use as a construction aggregate. These data were compared to previously compiled values for waste to energy bottom ash, the most commonly produced and beneficially used thermal treatment residue. The slag was tested using gradations representative of a base course and a course aggregate. Los Angeles (LA) abrasion testing demonstrated that the HTAG slag had a high resistance to fracture with a measured LA loss of 24%. Soundness testing indicated a low potential for reactivity and good weathering resistance with a mean soundness loss of 3.14%. The modified Proctor compaction testing found the slag to possess a maximum dry density (24.04kN/m(3)) greater than conventionally used aggregates and WTE BA. The LBR tests demonstrated a substantial bearing capacity (>200). Mineralogical analysis of the HTAG suggested the potential for self cementing character which supports the elevated LBR results. Preliminary material characterization of the HTAG slag establishes potential for beneficial use; larger and longer term studies focusing on the material's possibility for swelling and performance at the field scale level are needed. PMID:27020344

  14. Interstellar matter research with the Copernicus satellite

    NASA Technical Reports Server (NTRS)

    Spitzer, L., Jr.

    1976-01-01

    The use of the Copernicus satellite in an investigation of interstellar matter makes it possible to study absorption lines in the ultraviolet range which cannot be observed on the ground because of atmospheric absorption effects. A brief description is given of the satellite and the instrument used in the reported studies of interstellar matter. The results of the studies are discussed, giving attention to interstellar molecular hydrogen, the chemical composition of the interstellar gas, the coronal gas between the stars, and the interstellar abundance ratio of deuterium to hydrogen.

  15. Production of beams from solid materials at Center for Nuclear Study electron cyclotron resonance ion source

    NASA Astrophysics Data System (ADS)

    Ohshiro, Y.; Yamaka, S.; Watanabe, S.; Kobayashi, K.; Kotaka, Y.; Nishimura, M.; Kase, M.; Muto, H.; Yamaguchi, H.; Shimoura, S.

    2014-02-01

    Two methods for the feed of vapor from solid materials in the Center for Nuclear Study ECR ion source are described. A rod placed near the wall of the plasma chamber, operating up to a melting point of 2600 °C, has been used for CaO, SiO2, and FeO. An oven with a number of openings, operating up to 800 °C, has been used for P2O5, Li, and S. Typical ion beam intensities of 7Li2+, 6Li3+, 40Ca12+, and 56Fe15+ are achieved 280, 75, 28, and 7 eμA, respectively. High intensity heavy ion beams are stably supplied into the azimuthally varying field cyclotron.

  16. Atomistic modeling of the solid-state chemistry of actinide materials

    NASA Astrophysics Data System (ADS)

    Shuller, Lindsay C.

    Materials that incorporate actinides are critical to the nuclear fuel cycle, either as nuclear fuels or nuclear waste forms. In this thesis, I examine four materials: i) ThO2-UO2 solid solutions, ii) binary ThO2-CeO2-ZrO2 solid solutions, iii) Np-doped studtite, iv) Np-doped boltwoodite. Computational methods, particularly density functional theory (DFT) calculations and Monte-Carlo (MC) simulations, are used to determine the energetics and structures of these actinide-bearing materials. The solid-solution behavior of nuclear fuels and nuclear waste forms indicate the thermodynamic stability of the material, which is important for understanding the in-reactor fuel properties and long-term stability of used fuel. The ThxU1-xO2 and ThxCe 1-xO2 binaries are almost completely miscible; however, DeltaGmix reveals a small tendency for the systems to exsolve (e.g., DeltaEexsoln(Th xU1-xO2) = 0.13 kJ/(mol cations) at 750 K). Kinetic hindrances (e.g., interfacial energy) may inhibit exsolution, especially at the low temperatures necessary to stabilize the nanoscale exsolution lamellae observed in the ThxU1-xO2 and Ce xZr1-xO2 binaries. Miscibility in the Zr-bearing binaries is limited. At 1400 °C, only 3.6 and 0.09 mol% ZrO2 is miscible in CeO2 and ThO2, respectively. The incorporation of minor amounts of Np5+,6+ into uranium alteration phases, e.g., studtite [UO2O2 (H2O)4] or boltwoodite [K(UO2)(SiO 3OH)(H2O)1.5] , may limit the mobility of aqueous neptunyl complexes released from oxidized nuclear fuels. Np6+-incorporation into studtite requires less energy than Np5+-incorporation (e.g., with source/sink = Np2O5/UO 3 DeltaEincorp(Np6+) = 0.42 eV and DeltaEincorp(Np5+) = 1.12 eV). In addition, Np6+ is completely miscible in studtite at room temperature with respect to a hypothetical Np6+-studtite. Electronic structure calculations provide insight into Np-bonding in studtite. The Np 5f orbitals are within the band gap of studtite, resulting in the narrowing of the band gap

  17. Nanometer-sized materials for solid-phase extraction of trace elements.

    PubMed

    Hu, Bin; He, Man; Chen, Beibei

    2015-04-01

    This review presents a comprehensive update on the state-of-the-art of nanometer-sized materials in solid-phase extraction (SPE) of trace elements followed by atomic-spectrometry detection. Zero-dimensional nanomaterials (fullerene), one-dimensional nanomaterials (carbon nanotubes, inorganic nanotubes, and nanowires), two-dimensional nanomaterials (nanofibers), and three-dimensional nanomaterials (nanoparticles, mesoporous nanoparticles, magnetic nanoparticles, and dendrimers) for SPE are discussed, with their application for trace-element analysis and their speciation in different matrices. A variety of other novel SPE sorbents, including restricted-access sorbents, ion-imprinted polymers, and metal-organic frameworks, are also discussed, although their applications in trace-element analysis are relatively scarce so far. PMID:25577358

  18. High peak power solid-state laser for micromachining of hard materials

    NASA Astrophysics Data System (ADS)

    Herbst, Ludolf; Quitter, John P.; Ray, Gregory M.; Kuntze, Thomas; Wiessner, Alexander O.; Govorkov, Sergei V.; Heglin, Mike

    2003-06-01

    Laser micromachining has become a key enabling technology in the ever-continuing trend of miniaturization in microelectronics, micro-optics, and micromechanics. New applications have become commercially viable due to the emergence of innovative laser sources, such as diode pumped solid-state lasers (DPSSL), and the progress in processing technology. Examples of industrial applications are laser-drilled micro-injection nozzles for highly efficient automobile engines, or manufacturing of complex spinnerets for production of synthetic fibers. The unique advantages of laser-based techniques stem from their ability to produce high aspect ratio holes, while yielding low heat affected zones with exceptional surface quality, roundness and taper tolerances. Additionally, the ability to drill blind holes and slots in very hard materials such as diamond, silicon, sapphire, ceramics and steel is of great interest for many applications in microelectronics, semiconductor and automotive industry. This kind of high quality, high aspect ratio micromachining requires high peak power and short pulse durations.

  19. Experiments on sorption characteristics of solid desiccant materials for solar desiccant cooling systems

    SciTech Connect

    Pesaran, A.A.

    1984-11-01

    A test facility for measuring the sorption properties of candidate solid desiccant materials under dynamic conditions as well as equilibrium conditions, those experienced during desiccant dehumidifier operation, was constructed and tested. The theory of perturbation chromatography was initially used to measure the equilibrium properties of a desiccant/water-vapor system for the first time. Silica gel, molecular sieve, and gamma-manganese dioxide were tested. The equilibrium capacity estimated by the perturbation chromatography was lower than those available in literature, which suggests that perturbation chromatography may not be applicable to desiccant/water-vapor systems. The perturbation chromatography was replaced with a gravimetric technique, and satisfactory results were obtained for a water-vapor/molecular-sieve system.

  20. The Sun's dusty interstellar environment

    NASA Astrophysics Data System (ADS)

    Sterken, Veerle

    2016-07-01

    The Sun's dusty interstellar environment Interstellar dust from our immediate interstellar neighborhood travels through the solar system at speeds of ca. 26 km/s: the relative speed of the solar system with respect to the local interstellar cloud. On its way, its trajectories are altered by several forces like the solar radiation pressure force and Lorentz force. The latter is due to the charged dust particles that fly through the interplanetary magnetic field. These trajectories differ per particle type and size and lead to varying fluxes and directions of the flow inside of the solar system that depend on location but also on phase in the solar cycle. Hence, these fluxes and directions depend strongly on the configuration of the inner regions and outer regions of the heliosphere. Several missions have measured this dust in the solar system directly. The Ulysses dust detector data encompasses 16 years of intestellar dust fluxes and approximate directions, Stardust captured returned to Earth a few of these particles sucessfully, and finally the Cassini dust detector allowed for compositional information to be obtained from the impacts on the instrument. In this talk, we give an overview of the current status of interstellar dust research through the measurements made inside of the solar system, and we put them in perspective to the knowledge obtained from more classical astronomical means. In special, we focus on the interaction of the dust with the interplanetary magnetic field, and on what we learn about the dust (and the fields) by comparing the available dust data to computer simulations of dust trajectories. Finally, we synthesize the different methods of observation, their results, and give a preview on new research opportunities in the coming year(s).

  1. The Role of Polycyclic Aromatic Hydrocarbons in Dense Cloud Absorption Features: The Last Major Unanswered Question in Interstellar Ice Spectroscopy

    NASA Astrophysics Data System (ADS)

    Chiar, Jean

    Interstellar dust plays a vital role in the star formation process and the eventual formation of planetary systems including our own. Ice mantles are an important component of the dust: reactions involving simple ices can create more complex (and astrobiologically interesting) molecules, and ices sublimated back into the gas phase influence the gas- phase chemistry. Although polycyclic aromatic hydrocarbons (PAHs) are commonly thought to be very abundant interstellar species and, as such, are likely to be important components of interstellar ices, their contribution to the infrared spectra and chemistry of ices in dense molecular clouds is an open question. This program makes extensive use of three major NASA-funded databases: the Spitzer archive, the 2MASS archive, and the NASA Ames PAH database in order to answer the last major unanswered question in interstellar ice spectroscopy: what role do PAHs play in contributing to unidentified absorption features observed in dense cloud spectra. PAHs are observed to be present and abundant in nearly all phases of the galactic and extragalactic interstellar medium. The evidence for the ubiquity of interstellar PAHs is the widespread well-known family of prominent emission bands at 3.28, 6.2, 7.7, 8.6, and 11.2 micron. To date, these PAH bands have been most easily detected in regions where individual gas phase PAH molecules (neutrals and ions) become highly vibrationally excited by the ambient radiation field. While PAHs and closely related aromatic materials should be present throughout dense interstellar regions, PAH emission is quenched in cold dark dense clouds. Also, in these regions, most PAHs should efficiently condense out onto dust grains, either as "pure" solids or as "guest molecules" in icy grain mantles, much as is the case for most other interstellar molecules. Thus, in dense molecular clouds, condensed PAHs will give rise to IR absorption bands rather than emission features. While PAH absorption has been

  2. Extracting material response from simple mechanical tests on hardening-softening-hardening viscoplastic solids

    NASA Astrophysics Data System (ADS)

    Mohan, Nisha

    Compliant foams are usually characterized by a wide range of desirable mechanical properties. These properties include viscoelasticity at different temperatures, energy absorption, recoverability under cyclic loading, impact resistance, and thermal, electrical, acoustic and radiation-resistance. Some foams contain nano-sized features and are used in small-scale devices. This implies that the characteristic dimensions of foams span multiple length scales, rendering modeling their mechanical properties difficult. Continuum mechanics-based models capture some salient experimental features like the linear elastic regime, followed by non-linear plateau stress regime. However, they lack mesostructural physical details. This makes them incapable of accurately predicting local peaks in stress and strain distributions, which significantly affect the deformation paths. Atomistic methods are capable of capturing the physical origins of deformation at smaller scales, but suffer from impractical computational intensity. Capturing deformation at the so-called meso-scale, which is capable of describing the phenomenon at a continuum level, but with some physical insights, requires developing new theoretical approaches. A fundamental question that motivates the modeling of foams is `how to extract the intrinsic material response from simple mechanical test data, such as stress vs. strain response?' A 3D model was developed to simulate the mechanical response of foam-type materials. The novelty of this model includes unique features such as the hardening-softening-hardening material response, strain rate-dependence, and plastically compressible solids with plastic non-normality. Suggestive links from atomistic simulations of foams were borrowed to formulate a physically informed hardening material input function. Motivated by a model that qualitatively captured the response of foam-type vertically aligned carbon nanotube (VACNT) pillars under uniaxial compression [2011,"Analysis of

  3. Evaluation of shuttle solid rocket booster case materials. Corrosion and stress corrosion susceptibility of several high temperature materials

    NASA Technical Reports Server (NTRS)

    Pionke, L. J.; Garland, K. C.

    1973-01-01

    Candidate alloys for the Shuttle Solid Rocket Booster (SRB) case were tested under simulated service conditions to define subcritical flaw growth behavior under both sustained and cyclic loading conditions. The materials evaluated were D6AC and 18 Ni maraging steel, both heat treated to a nominal yield strength of 1380 MN/sq m (200 ksi). The sustained load tests were conducted by exposing precracked, stressed specimens of both alloys to alternate immersion in synthetic sea water. It was found that the corrosion and stress corrosion resistance of the 18 Ni maraging steel were superior to that of the D6AC steel under these test conditions. It was also found that austenitizing temperature had little influence on the threshold stress intensity of the D6AC. The cyclic tests were conducted by subjecting precracked surface-flawed specimens of both alloys to repeated load/thermal/environmental profiles which were selected to simulate the SRB missions. It was found that linear removal operations that involve heating to 589 K (600 F) cause a decrease in cyclic life of D6AC steel relative to those tests conducted with no thermal cycling.

  4. NOVEL ELECTRODE MATERIALS FOR LOW-TEMPERATURE SOLID-OXIDE FUEL CELLS

    SciTech Connect

    X. Lu; C. Xia; Y. Liu; W. Rauch; M. Liu

    2002-12-01

    Composite electrodes consisting of silver and bismuth vanadates exhibit remarkable catalytic activity for oxygen reduction at 500-550 C and greatly reduce the cathode-electrolyte (doped ceria) resistances of low temperature SOFCs, down to about 0.53 {Omega}cm{sup 2} at 500 C and 0.21 {Omega}cm{sup 2} at 550 C. The observed power densities of 231, 332, and 443 mWcm{sup -2} at 500, 525 and 550 C, respectively, make it possible to operate SOFCs at temperatures about 500 C. Using in situ potential dependent FTIR emission spectroscopy, we have found evidence for two, possibly three distinct di-oxygen species present on the electrode surface. We have successfully identified which surface oxygen species is present under a particular electrical or chemical condition and have been able to deduce the reaction mechanisms. This technique will be used to probe the gas-solid interactions at or near the TPB and on the surfaces of mixed-conducting electrodes in an effort to understand the molecular processes relevant to the intrinsic catalytic activity. Broad spectral features are assigned to the polarization-induced changes in the optical properties of the electrode surface layer. The ability of producing vastly different microstructures and morphologies of the very same material is critical to the fabrication of functionally graded electrodes for solid-state electrochemical devices, such as SOFCs and lithium batteries. By carefully adjusting deposition parameters of combustion CVD, we have successfully produced oxide nano-powders with the size of 30 {approx} 200 nm. Porous films with various microstructures and morphologies are also deposited on several substrates by systematic adjustment of deposition parameters. Symmetrical cells were fabricated by depositing cathode materials on both sides of GDC electrolytes.

  5. The Interstellar Production of Biologically Important Organics

    NASA Technical Reports Server (NTRS)

    Sandford, Scott A.; Bernstein, Max P.; Dworkin, Jason; Allamandola, Louis J.

    2000-01-01

    One of the primary tasks of the Astrochemistry Laboratory at Ames Research Center is to use laboratory simulations to study the chemical processes that occur in dense interstellar clouds. Since new stars are formed in these clouds, their materials may be responsible for the delivery of organics to new habitable planets and may play important roles in the origin of life. These clouds are extremely cold (less than 50 kelvin), and most of the volatiles in these clouds are condensed onto dust grains as thin ice mantles. These ices are exposed to cosmic rays and ultraviolet (UV) photons that break chemical bonds and result in the production of complex molecules when the ices are warmed (as they would be when incorporated into a star-forming region). Using cryovacuum systems and UV lamps, this study simulates the conditions of these clouds and studies the resulting chemistry. Some of the areas of progress made in 1999 are described below. It shows some of the types of molecules that may be formed in the interstellar medium. Laboratory simulations have already confirmed that many of these compounds are made under these conditions.

  6. Synthesis of novel solid materials from carbon dioxide and carbon monoxide

    NASA Astrophysics Data System (ADS)

    Huo, Yan

    The increase of atmospheric CO2 has been identified as the primary cause for the observed global warming over the past century. The geological and oceanic sequestration of CO2 has issues, such as cost and leakage as well as effects on sea biota. The ideal solution should be the conversion of CO2 into useful materials. However, most processes require high energy input. Therefore, it is necessary to explore novel processes with low energy demands to convert CO2 to useful solid materials. Amorphous carbon nitride and graphone received much attention due to their unusual structures and properties as well as their potential applications. However, to date there has been no attempt to synthesize those solid materials from CO2. Lithium nitride (Li3N) and lithium imide (Li2NH) are important hydrogen storage materials. However, their optical properties and reactivity has not yet studied. This dissertation research is aimed at the synthesis of carbon nitrides and graphone from CO2 and CO via their reaction with Li3N and Li2NH. The research was focused on (1) the evaluation of Li 3N and Li2NH properties, (2) thermodynamic analysis of conversion of carbon dioxide and carbon monoxide into carbon nitride and other solid materials, (3) synthesis of carbon nitride from carbon dioxide, and (4) synthesis of graphone from carbon monoxide. First, the properties of Li3N, Li2NH, and LiNH 2 were investigated. The X-ray diffraction measurements revealed that heat-treatment at 500°C introduce a phase transformation of β-Li3N to α-Li3N. Furthermore, the UV-visible absorption evaluation showed that the energy gaps of α-Li3N and β-Li 3N are 1.81 and 2.14 eV, respectively. The UV-visible absorption measurements also revealed that energy gaps are 3.92 eV for Li2NH and 3.93 eV for LiNH2. This thermodynamic analysis was performed to predict the reactions. It was demonstrated that the reaction between carbon dioxide and lithium nitride is thermodynamically favorable and exothermic, which can

  7. Study of metallic materials for solid oxide fuel cell interconnect applications.

    SciTech Connect

    Natesan, K.; Zeng, Z.; Nuclear Engineering Division

    2009-04-24

    Metallic interconnect acts as a gas separator and a gas distributor and therefore, it needs to function adequately in two widely different environments. The interconnect material will be exposed to air on one side and natural gas or coal-derived synthesis gas on the other side. The viable material for the interconnect application must be resistant not only to oxidation but also carburization in hydrocarbon containing low-oxygen environments. In addition, the scales that develop on the exposed surfaces must possess adequate electrical conductivity for them to function as current leads over long service life of the fuel cell. This report addresses five topics of interest for the development of metallic interconnects with adequate performance in fuel cells for long service life. The research conducted over the years and the conclusions reached were used to identify additional areas of research on materials for improved performance of components, especially metallic interconnects, in the complex fuel cell environments. This report details research conducted in the following areas: measurement of area specific electrical resistivity, corrosion performance in dual gas environments by experiments using alloy 446, long term corrosion performance of ferritic and austenitic alloys in hydrogen and methane-reformed synthesis fuel-gas environments, approaches to reduce the area resistance of metallic interconnect, and reduction of electrical resistivity of alumina scales on metallic interconnect. Based on the key requirements for metallic interconnects and the data developed on the corrosion behavior of candidate materials in meeting those requirements, several areas are recommended for further research to develop metallic interconnects with acceptable and reliable long-term performance in solid oxide fuel cells.

  8. Spectroscopic Evidence for Interstellar Ice in Comet Hyakutake

    NASA Technical Reports Server (NTRS)

    Irvine, W. M.; Bockelee-Morvan, D.; Lis, D. C.; Matthews, H. E.; Biver, N.; Crovisier, J.; Davies, J. K.; Dent, W. R. F.; Gautier, D.; Godfrey, P. D.; Keene, J.; Lovell, A. J.; Owen, T. C.; Phillips, T. G.; Rauer, H.; Schloerb, F. P.; Senay, M.; Young, K.

    1996-01-01

    Volatile compounds in comets are the most pristine materials surviving from the time of formation of the Solar System, and thus potentially provide information about conditions that prevailed in the primitive solar material. Moreover, comets may have supplied a substantial fraction of the volatiles on the terrestrial planets, perhaps including organic compounds that played a role in the origin of life on Earth. Here we report the detection of hydrogen isocyanide (HNC) in comet Hyakutake. The abundance of HNC relative to hydrogen cyanide (HCN) is very similar to that observed in quiescent interstellar molecular clouds, and quite different from the equilibrium ratio expected in the outermost solar nebula, where comets are thought to form. Such a departure from equilibrium has long been considered a hallmark of gas-phase chemical processing in the interstellar medium, suggesting that interstellar gases have been incorporated into the comet's nucleus, perhaps as ices frozen onto interstellar grains. If this interpretation is correct, our results should provide constraints on the temperature of the solar nebula, and the subsequent chemical processes that occurred in the region where comets formed.

  9. Monte Carlo modeling of 60Co HDR brachytherapy source in water and in different solid water phantom materials

    PubMed Central

    Sahoo, S.; Selvam, T. Palani; Vishwakarma, R. S.; Chourasiya, G.

    2010-01-01

    The reference medium for brachytherapy dose measurements is water. Accuracy of dose measurements of brachytherapy sources is critically dependent on precise measurement of the source–detector distance. A solid phantom can be precisely machined and hence source–detector distances can be accurately determined. In the present study, four different solid phantom materials such as polymethylmethacrylate (PMMA), polystyrene, Solid Water, and RW1 are modeled using the Monte Carlo methods to investigate the influence of phantom material on dose rate distributions of the new model of BEBIG 60Co brachytherapy source. The calculated dose rate constant is 1.086 ± 0.06% cGy h−1 U−1 for water, PMMA, polystyrene, Solid Water, and RW1. The investigation suggests that the phantom materials RW1 and Solid Water represent water-equivalent up to 20 cm from the source. PMMA and polystyrene are water-equivalent up to 10 cm and 15 cm from the source, respectively, as the differences in the dose data obtained in these phantom materials are not significantly different from the corresponding data obtained in liquid water phantom. At a radial distance of 20 cm from the source, polystyrene overestimates the dose by 3% and PMMA underestimates it by about 8% when compared to the corresponding data obtained in water phantom. PMID:20177566

  10. Hydrocarbons in interstellar ice analogues : UV-vis spectroscopy and VUV photochemistry

    NASA Astrophysics Data System (ADS)

    Cuylle, Steven Hendrik

    2015-01-01

    This thesis treats the chemical behaviour of carbonaceous molecules in water-dominated interstellar ices. VUV photons are considered as the chemical trigger to induce solid state chemistry as it is omnipresent. Lyman- radiation occurs even in dense molecular clouds as a result of cosmic ray excitation of H2 and subsequently emitting its excess energy at 122 nm (Mathis et al. 1983). It comprises the addition of new tools to laboratory astrochemistry, expanding knowledge on the behaviour of PAHs in interstellar ices and research into the role of C 2H2 and polyynes in interstellar ice VUV photochemistry. It provides with spectroscopic tools for observers to enable the identification of the hydrocarbons encountered in interstellar ices, and it provides modellers with reaction dynamic information that can be used as an input for their models.

  11. TOPICAL REVIEW The physics of solid-state neutron detector materials and geometries

    NASA Astrophysics Data System (ADS)

    Caruso, A. N.

    2010-10-01

    Detection of neutrons, at high total efficiency, with greater resolution in kinetic energy, time and/or real-space position, is fundamental to the advance of subfields within nuclear medicine, high-energy physics, non-proliferation of special nuclear materials, astrophysics, structural biology and chemistry, magnetism and nuclear energy. Clever indirect-conversion geometries, interaction/transport calculations and modern processing methods for silicon and gallium arsenide allow for the realization of moderate- to high-efficiency neutron detectors as a result of low defect concentrations, tuned reaction product ranges, enhanced effective omnidirectional cross sections and reduced electron-hole pair recombination from more physically abrupt and electronically engineered interfaces. Conversely, semiconductors with high neutron cross sections and unique transduction mechanisms capable of achieving very high total efficiency are gaining greater recognition despite the relative immaturity of their growth, lithographic processing and electronic structure understanding. This review focuses on advances and challenges in charged-particle-based device geometries, materials and associated mechanisms for direct and indirect transduction of thermal to fast neutrons within the context of application. Calorimetry- and radioluminescence-based intermediate processes in the solid state are not included.

  12. Coarsening in Solid-Liquid Mixtures-2: A Materials Science Experiment for the ISS

    NASA Technical Reports Server (NTRS)

    Hickman, J. Mark; Voorhees, Peter W.; Kwon, Yongwoo; Lorik, Tibor

    2004-01-01

    A materials science experiment has been developed and readied for operation aboard the International Space Station (ISS). Components of this experiment are onboard ISS and area awaiting the flight of science samples. The goal of the experiment is to understand the dynamics of Ostwald ripening, also known as coarsening, a process that occurs in nearly any two-phase mixture found in nature. Attempts to obtain experimental data in ground-based laboratories are hindered due to the presence of gravity, which introduces material transport modes other than that of the coarsening phenomenon. This introduces adjustable parameters in the formulation of theory. The original Coarsening in Solid-Liquid Mixtures (CSLM) mission, which flew on the Space Shuttle in 1997, produced data from a coarsened eutectic alloy. Unfortunately, both the science matrix and the hardware, while nominally functional, did not account adequately for operations in microgravity. A significantly redesigned follow-on experiment, CSLM-2 has been developed to redress the inadequacies of the original experiment. This paper reviews the CSLM-2 project: its history, science goals, flight hardware implementation, and planned operations and analysis

  13. Next Generation Electrocaloric and Pyroelectric Materials for Solid State Electrothermal Interconversion

    NASA Astrophysics Data System (ADS)

    Alpay, S. Pamir; Mantese, Joseph V.; Trolier-McKinstry, Susan; Zhang, Qiming; Whatmore, Roger W.

    2015-03-01

    Thin film electrocaloric (EC) and pyroelectric (PE) electrothermal interconversion energy sources have recently emerged as viable means for primary and auxiliary solid state cooling and power generation. This emergence is a result of two significant developments: (1) advancements in the formation of high quality polymeric and ceramic thin films with figures of merit that project system level performance as a large percentage of Carnot efficiency, and (2) the ability of these newer materials to support larger electric fields which permit operation at higher voltage; thus making the power electronic architectures more favorable for thermal to electric interconversion. Current research targets to adequately address commercial device needs, include reduction of parasitic losses, increases in mechanical robustness, and the ability to form nearly free-standing element in the range of 1 - 10 microns in thickness. This article will describe the current state-of-the-art materials, thermodynamic cycles and device losses; pointing to potential lines of research that would lead to substantially better figures of merit for electrothermal interconversion.

  14. The interstellar C3 chain molecule in different interstellar environments

    NASA Astrophysics Data System (ADS)

    Galazutdinov, G.; Pětlewski, A.; Musaev, F.; Moutou, C.; Lo Curto, G.; Krelowski, J.

    2002-12-01

    We present an analysis of spectra of six stars taken with high resolution (R=220 000). The stars are reddened by molecular clouds that differ by the relative strength of the 5797 and 5780 diffuse interstellar bands (DIBs). The high signal-to-noise ratio of the spectra (S/N ~ 700-1000) shows that the abundance of the linear molecule C3 with respect to EB-V varies considerably from one star to an other. There is no correlation with EB-V. The strong variations in the abundance of C3 must therefore be caused by another circumstance. We point out that this may be the case: from an analysis of the interstellar potassium lines in the same spectra we conclude large differences in the state of ionization produced by interstellar photons with energies below the ionization potential of hydrogen. The ratio of the abundances of C3 and C2 varies considerably in different directions, even when the ratio between the strengths of various DIBs remains approximately constant. Based on data collected at the ESO 3.6 m telescope operated on La Silla Observatory, Chile.

  15. Diamonds in dense molecular clouds - A challenge to the standard interstellar medium paradigm

    NASA Technical Reports Server (NTRS)

    Allamandola, L. J.; Sandford, S. A.; Tielens, A. G. G. M.; Herbst, T. M.

    1993-01-01

    Observations of a newly discovered infrared C-H stretching band indicate that interstellar diamond-like material appears to be characteristic of dense clouds. In sharp contrast, the spectral signature of dust in the diffuse interstellar medium is dominated by -CH2- and -CH3 groups. This dichotomy in the aliphatic organic component between the dense and diffuse media challenges standard assumptions about the processes occurring in, and interactions between, these two media. The ubiquity of this interstellar diamond-like material rules out models for meteoritic diamond formation in unusual circumstellar environments and implies that the formation of the diamond-like material is associated with common interstellar processes or stellar types.

  16. Interstellar dust. Evidence for interstellar origin of seven dust particles collected by the Stardust spacecraft.

    PubMed

    Westphal, Andrew J; Stroud, Rhonda M; Bechtel, Hans A; Brenker, Frank E; Butterworth, Anna L; Flynn, George J; Frank, David R; Gainsforth, Zack; Hillier, Jon K; Postberg, Frank; Simionovici, Alexandre S; Sterken, Veerle J; Nittler, Larry R; Allen, Carlton; Anderson, David; Ansari, Asna; Bajt, Saša; Bastien, Ron K; Bassim, Nabil; Bridges, John; Brownlee, Donald E; Burchell, Mark; Burghammer, Manfred; Changela, Hitesh; Cloetens, Peter; Davis, Andrew M; Doll, Ryan; Floss, Christine; Grün, Eberhard; Heck, Philipp R; Hoppe, Peter; Hudson, Bruce; Huth, Joachim; Kearsley, Anton; King, Ashley J; Lai, Barry; Leitner, Jan; Lemelle, Laurence; Leonard, Ariel; Leroux, Hugues; Lettieri, Robert; Marchant, William; Ogliore, Ryan; Ong, Wei Jia; Price, Mark C; Sandford, Scott A; Sans Tresseras, Juan-Angel; Schmitz, Sylvia; Schoonjans, Tom; Schreiber, Kate; Silversmit, Geert; Solé, Vicente A; Srama, Ralf; Stadermann, Frank; Stephan, Thomas; Stodolna, Julien; Sutton, Stephen; Trieloff, Mario; Tsou, Peter; Tyliszczak, Tolek; Vekemans, Bart; Vincze, Laszlo; Von Korff, Joshua; Wordsworth, Naomi; Zevin, Daniel; Zolensky, Michael E

    2014-08-15

    Seven particles captured by the Stardust Interstellar Dust Collector and returned to Earth for laboratory analysis have features consistent with an origin in the contemporary interstellar dust stream. More than 50 spacecraft debris particles were also identified. The interstellar dust candidates are readily distinguished from debris impacts on the basis of elemental composition and/or impact trajectory. The seven candidate interstellar particles are diverse in elemental composition, crystal structure, and size. The presence of crystalline grains and multiple iron-bearing phases, including sulfide, in some particles indicates that individual interstellar particles diverge from any one representative model of interstellar dust inferred from astronomical observations and theory. PMID:25124433

  17. Laboratory simulations of chemical reactions on dust grains in the interstellar medium

    NASA Astrophysics Data System (ADS)

    Roser, Joseph E.

    Dust grains exert a major influence upon the chemical composition of the interstellar medium: photoelectrons emitted from the dust grains are the primary energy source for heating interstellar gas, dust grains in dense molecular clouds can accumulate layers of frozen interstellar gases that participate in solid phase chemical reactions, and the most abundant molecule in the Universe, molecular hydrogen, primarily forms from hydrogen atoms adsorbed onto grain surfaces. Molecular hydrogen influences the evolution of molecular clouds by acting as a coolant during the gravitational collapse of the cloud and serving as a precursor for the formation of many molecular species. A complete description of molecular hydrogen formation in molecular clouds requires an understanding of the efficiency of hydrogen atom recombination on ice surfaces. Observations of interstellar carbon dioxide ice have the potential for serving as a diagnostic sign of the evolution of interstellar ice layers but require a satisfactory explanation of the formation mechanisms of interstellar CO 2 . This work describes a series of investigations that were designed to study the properties of interstellar dust grains and to obtain and analyze data for astrophysically important chemical reactions. We measured the recombination efficiency of H atoms on the surface of amorphous H 2 O ices and measured the kinetics of H 2 formation and desorption on different morphologies of ice substrate. We demonstrated that the hydrogen atom recombination kinetics depend upon the morphology of the ice layer and that the recombination efficiency is consistent with observations of molecular clouds. We also demonstrated that CO and O can be trapped within an amorphous H 2 O ice layer at temperatures greater than their sublimation temperatures and that the reaction CO (ads) + O (ads) [arrow right] CO 2,(ads) can produce appreciable amounts of CO2 within an interstellar ice layer in the absence of ultraviolet or cosmic

  18. Alternative comparison, analysis, and evaluation of solid waste and materials system alternatives

    SciTech Connect

    Brothers, A.J.

    1995-09-01

    This paper presents a comprehensive analysis of the impact of solid waste technical options on values and objectives that are important to the public. It is written in support of the Solid Waste and Materials Systems Alternatives Study (WHC, 1995). Described are the values that were identified, the major programmatic risks, how the impacts were measured, the performance of alternatives, the methodology used for the analysis, and the implications of the results. Decision analysis was used to guide the collection and analysis of data and the logic of the evaluation. Decision analysis is a structured process for the analysis and evaluation of alternatives. It is theoretically grounded in a set of axioms that capture the basic principles of decision making (von Neuman and Morgenstern 1947). Decision analysis objectively specifies what factors are to be considered, how they are to be measured and evaluated, and heir relative importance. The result is an analysis in which the underlying rationale or logic upon which the decision is based is made explicit. This makes possible open discussion of the decision basis in which facts and values are clearly distinguished, resulting in a well- documented decision that can be clearly explained and justified. The strategy of decision analysis is to analyze the various components relevant to the decision separately and then integrate the individual judgments to arrive at an overall decision. This assures that all the relevant factors are identified and their relative importance is considered. The procedure for obtaining the individual judgments, and the decision rules, for combining them and evaluating alternatives, have both theoretical and empirical foundation in mathematics, economics, and psychology.

  19. Strength and Fracture Toughness of Solid Oxide Fuel Cell Electrolyte Material Improved

    NASA Technical Reports Server (NTRS)

    Bansal, Narottam P.; Choi, Sung R.

    2002-01-01

    Solid oxide fuel cells (SOFC) are being developed for various applications in the automobile, power-generation, and aeronautics industries. Recently, the NASA Glenn Research Center has been exploring the possibility of using SOFC's for aeropropulsion under its Zero Carbon Dioxide Emission Technology (ZCET) Program. 10-mol% yttriastabilized zirconia (10YSZ) is a very good anionic conductor at high temperatures and is, therefore, used as an oxygen solid electrolyte in SOFC. However, it has a high thermal expansion coefficient, low thermal shock resistance, low fracture toughness, and poor mechanical strength. For aeronautic applications, the thin ceramic electrolyte membrane of the SOFC needs to be strong and tough. Therefore, we have been investigating the possibility of enhancing the strength and fracture toughness of the 10YSZ electrolyte without degrading its electrical conductivity to an appreciable extent. We recently demonstrated that the addition of alumina to zirconia electrolyte increases its strength as well as its fracture toughness. Zirconia-alumina composites containing 0 to 30 mol% of alumina were fabricated by hot pressing. The hot pressing procedure was developed and various hot pressing parameters were optimized, resulting in dense, crackfree panels of composite materials. Cubic zirconia and a-alumina were the only phases detected, indicating that there was no chemical reaction between the constituents during hot pressing at elevated temperatures. Flexure strength sf and fracture toughness K(sub IC) of the various zirconia-alumina composites were measured at room temperature as well as at 1000 C in air. Both properties showed systematic improvement with increased alumina addition at room temperature and at 1000 C. Use of these modified electrolytes with improved strength and fracture toughness should prolong the life and enhance the performance of SOFC in aeronautics and other applications.

  20. Codisposal of FBC by-products and coal slurry solids: Characterization of materials

    SciTech Connect

    Tungate, D.E.; Darmody, R.G.; Dreher, G.B.; Roy, W.R.; Steele, J.D.

    1997-12-31

    The preparation and combustion of high sulfur coal generates many waste products including cleaning and combustion wastes. Pyrite is associated with coal cleaning wastes and it makes them potentially acidic. Coal slurry solids (CSS), the finest textured cleaning wastes, are stored in large impoundments. After the impoundments are retired, they must be reclaimed with a 1.2 in soil cap. Reclamation of abandoned CSS impoundments by direct revegetation would avoid costs associated with the required soil cap. However, CSS have physical and chemical limitations for plant growth including undesirable pH, surface temperatures, and moisture holding capacity. Fluidized bed combustion is a coal combustion technique designed to reduce smoke stack emissions of SO{sub 2}. It results in a highly alkaline by-product (FBC). The combination of CSS and FBC may allow direct revegetation of CSS materials. This would possibly be a more cost effective method of reclaiming CSS materials than using a soil cap while creating an economic value for FBC by-products. This will also preclude the necessity of disturbing a borrow area for the soil cap. An experiment was designed to evaluate the potential for CSS/FBC mixtures to support direct revegetation. Three test blocks with 18 plots each were established on a temporarily inactive portion of an active coal slurry impoundment. The addition of FBC increased the pH of the potentially acidic CSS. Soil fertility analyses indicated Al, B, Ca, Mg, Zn, and soluble salts increased with additions of FBC, while Cu, Fe, K, P, and S remained relatively unchanged, and Mn and Na concentration decreased. Direct revegetation of CSS materials may be facilitated by the addition of FBC by-products. However, other treatments in addition to FBC amendments may be necessary to optimize conditions for plant growth.