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Sample records for acetone planar laser

  1. Acetone

    Integrated Risk Information System (IRIS)

    EPA / 635 / R - 03 / 004 www.epa.gov / iris TOXICOLOGICAL REVIEW OF ACETONE ( CAS No . 67 - 64 - 1 ) In Support of Summary Information on the Integrated Risk Information System ( IRIS ) May 2003 U.S . Environmental Protection Agency Washington , DC DISCLAIMER This document has been reviewed in accor

  2. Laser direct write of planar alkaline microbatteries

    NASA Astrophysics Data System (ADS)

    Arnold, C. B.; Kim, H.; Piqué, A.

    We are developing a laser engineering approach to fabricate and optimize alkaline microbatteries in planar geometries. The laser direct-write technique enables multicapability for adding, removing and processing material and provides the ability to pattern complicated structures needed for fabricating complete microbattery assemblies. In this paper, we demonstrate the production of planar zinc-silver oxide alkaline cells under ambient conditions. The microbattery cells exhibit 1.55-V open-circuit potentials, as expected for the battery chemistry, and show a flat discharge behavior under constant-current loads. High capacities of over 450 μAhcm-2 are obtained for 5-mm2 microbatteries.

  3. Planar fluoride waveguides for amplifiers and lasers

    SciTech Connect

    Grishutkina, T E; Doroshenko, M E; Karasik, A Ya; Konyushkin, V A; Konyushkin, D V; Nakladov, A N; Osiko, V V; Tsvetkov, V B

    2015-08-31

    We have produced planar optical waveguides having a crystalline CaF{sub 2} – YF{sub 3} – NdF{sub 3} mixed yttrofluorite core and two reflective claddings in order to improve waveguide excitation efficiency. Under diode pumping, lasing has been achieved at a wavelength of 1064 nm with a slope efficiency near 15%. (lasers)

  4. Application of LaserBreath-001 for breath acetone measurement in subjects with diabetes mellitus

    NASA Astrophysics Data System (ADS)

    Wang, Zhennan; Sun, Meixiu; Chen, Zhuying; Zhao, Xiaomeng; Li, Yingxin; Wang, Chuji

    2016-11-01

    Breath acetone is a promising biomarker of diabetes mellitus. With an integrated standalone, on-site cavity ringdown breath acetone analyzer, LaserBreath-001, we tested breath samples from 23 type 1 diabetic (T1D) patients, 312 type 2 diabetic (T2D) patients, 52 healthy subjects. In the cross-sectional studies, the obtained breath acetone concentrations were higher in the diabetic subjects compared with those in the control group. No correlation between breath acetone and simultaneous BG was observed in the T1D, T2D, and healthy subjects. A moderate positive correlation between the mean individual breath acetone concentrations and the mean individual BG levels was observed in the 20 T1D patients without ketoacidosis. In a longitudinal study, the breath acetone concentrations in a T1D patient with ketoacidosis decreased significantly and remained stable during the 5-day hospitalization. The results from a relatively large number of subjects tested indicate that an elevated mean breath acetone concentration exists in diabetic patients in general. Although many physiological parameters affect breath acetone concentrations, fast (<1 min) and on site breath acetone measurement can be used for diabetic screening and management under a specifically controlled condition.

  5. Ignition study of acetone/air mixtures by using laser-induced spark.

    PubMed

    Tihay, Virginie; Gillard, Philippe; Blanc, Denis

    2012-03-30

    The breakdown and the laser-induced spark ignition of acetone-air mixtures were experimentally studied using a nanosecond pulse at 1064 nm from a Q-switched Nd:YAG laser. The breakdown was first characterized for different mixtures with acetone and air. This part of the work highlighted the wide variation in the energy absorbed by the plasma during a breakdown. We also demonstrated that the presence of acetone in air tends to reduce the energy required to obtain a breakdown. Next, the ignition of acetone-air mixtures in the equivalence ratio range 0.9-2.4 was investigated. The probabilities of ignition were calculated in function to the laser energy. However, according to the variability of energy absorption by the plasma, we preferred to present the result according to the energy absorbed by the plasma. The minimum ignition energies were also provided. The minimum ignition energy was obtained for an equivalence ratio of 1.6 and an absorbed energy of 1.15 mJ. Finally the characteristics of the plasma (absorption coefficient and kernel temperature) were calculated for the experiments corresponding to minimum ignition energies.

  6. Composition measurement of bicomponent droplets using laser-induced fluorescence of acetone

    NASA Astrophysics Data System (ADS)

    Maqua, C.; Depredurand, V.; Castanet, G.; Wolff, M.; Lemoine, F.

    2007-12-01

    Commercial fuels are complex mixtures, the evaporation of which remains particularly difficult to model. Experimental characterization of the differential vaporization of the components is a problem that is seldom addressed. In this paper, the evaporation of binary droplets made of ethyl-alcohol and acetone is investigated using a technique of measurement of the droplet composition developed in purpose. This technique exploits the laser induced fluorescence of acetone which acts as a fluorescent tracer as well as the more volatile component of the fuel associated with an accurate measurement of the droplet diameter by forward scattering interferometry. A model of the fluorescence intensity of the binary mixture, taking into account the absorption of the acetone molecules, is proposed and validated. The sensitivity of the technique is discussed. Finally, the reliability of the technique is demonstrated on binary combusting droplets in linear stream.

  7. Boron nitride nano-structures produced by pulsed laser ablation in acetone

    NASA Astrophysics Data System (ADS)

    Nistor, L. C.; Epurescu, G.; Dinescu, M.; Dinescu, G.

    2010-11-01

    Different phases of boron nitride (BN) nano-structures are synthesized from an hBN ceramic target immersed in acetone, by ablation with a high power pulsed Nd: YAG laser. Transmission electron microscopy (TEM) and electron diffraction (ED) are used to identify the morphology and structure of the prepared colloidal suspensions. It is revealed that by varying solely a single experimental parameter, i.e. the laser pulse fluency, a large variety of BN nano-structures can be produced: nanotubes, very thin graphene-like foils, nano-curls and nano-particles, all with the hexagonal graphite-like hBN structure, as well as high pressure BN phases: orthorhombic explosion E-BN nano-rods, or cubic diamond-like cBN nano-particles.

  8. Laser-driven planar Rayleigh-Taylor instability experiments

    NASA Astrophysics Data System (ADS)

    Glendinning, S. G.; Weber, S. V.; Bell, P.; Dasilva, L. B.; Dixit, S. N.; Henesian, M. A.; Kania, D. R.; Kilkenny, J. D.; Powell, H. T.; Wallace, R. J.; Wegner, P. J.; Knauer, J. P.; Verdon, C. P.

    1992-08-01

    We have performed a series of experiments on the Nova Laser Facility to examine the hydrodynamic behavior of directly driven planar foils with initial perturbations of varying wavelength. The foils were accelerated with a single, frequency doubled, smoothed and temporally shaped laser beam at 0.8×1014 W/cm2. The experiments are in good agreement with numerical simulations using the computer codes LASNEX and ORCHID which show growth rates reduced to about 70% of classical for this nonlinear regime.

  9. Planar laser-driven ablation model for nonlocalized absorption

    SciTech Connect

    Dahmani, F.; Kerdja, T. )

    1991-05-01

    A model for planar laser-driven ablation is presented. Nonlocalized inverse bremsstrahlung absorption of laser energy at a density {ital n}{sub 1}{lt}{ital n}{sub {ital c}} is assumed. A steady-state solution in the conduction zone is joined to a rarefaction wave in the underdense plasma. The calculations relate all steady-state fluid quantities to only the material, absorbed intensity, and laser wavelength. The theory agrees well with results from a computer hydrodynamics code MEDUSA (Comput. Phys. Commun. {bold 7}, 271 (1974)) and experiments.

  10. Laser-driven planar Rayleigh-Taylor instability experiments

    SciTech Connect

    Glendinning, S.G.; Weber, S.V.; Bell, P.; DaSilva, L.B.; Dixit, S.N.; Henesian, M.A.; Kania, D.R.; Kilkenny, J.D.; Powell, H.T.; Wallace, R.J.; Wegner, P.J. ); Knauer, J.P.; Verdon, C.P. )

    1992-08-24

    We have performed a series of experiments on the Nova Laser Facility to examine the hydrodynamic behavior of directly driven planar foils with initial perturbations of varying wavelength. The foils were accelerated with a single, frequency doubled, smoothed and temporally shaped laser beam at 0.8{times}10{sup 14} W/cm{sup 2}. The experiments are in good agreement with numerical simulations using the computer codes LASNEX and ORCHID which show growth rates reduced to about 70% of classical for this nonlinear regime.

  11. Ion-implanted planar-buried-heterostructure diode laser

    DOEpatents

    Brennan, Thomas M.; Hammons, Burrell E.; Myers, David R.; Vawter, Gregory A.

    1991-01-01

    A Planar-Buried-Heterostructure, Graded-Index, Separate-Confinement-Heterostructure semiconductor diode laser 10 includes a single quantum well or multi-quantum well active stripe 12 disposed between a p-type compositionally graded Group III-V cladding layer 14 and an n-type compositionally graded Group III-V cladding layer 16. The laser 10 includes an ion implanted n-type region 28 within the p-type cladding layer 14 and further includes an ion implanted p-type region 26 within the n-type cladding layer 16. The ion implanted regions are disposed for defining a lateral extent of the active stripe.

  12. Cr:ZnSe planar waveguide mid-IR laser

    NASA Astrophysics Data System (ADS)

    Willimas, J. E.; Martyshkin, D. V.; Fedorov, V. V.; Moskalev, I. S.; Camata, R. P.; Mirov, S. B.

    2011-02-01

    Middle infrared (mid-IR) chromium-doped zinc selenide (Cr:ZnSe) bulk lasers have attracted a lot of attention due to their unique combination of optical and laser properties facilitating a wide range of potential scientific, industrial, and medical applications. Utilization of thin film waveguide geometry enabling good thermal management and control of beam quality is a viable pathway for compact chip-integrated optical laser design. Cr:ZnSe thin films are also promising as saturable absorbers and mode-lockers of the cavities of solid state lasers operating over 1.3-2.1 μm. We recently reported the first successful demonstration of mid-IR Cr:ZnSe planar waveguide lasing at 2.6 μm under gain-switched short-pulse (5 ns) 1.56 μm excitation as well as the passive Q-switching of the cavity of a fiber-pumped Er:YAG laser operating at 1645 nm using a highly doped Cr:ZnSe thin film. PLD grown Cr:ZnSe waveguide were fabricated on sapphire substrates (Cr:ZnSe/sapphire) with chromium concentration of 1018-1019 cm-3. Further development of mid-IR lasing in the Cr:ZnSe planar waveguide under continuous wave excitation were investigated. In addition, deposition of Cr:ZnSe-based thin film structures on n-type GaAs substrates were also investigated for possible mid-IR electroluminescence.

  13. A Direct Diode Laser System Using a Planar Lightwave Circuit

    NASA Astrophysics Data System (ADS)

    Hasegawa, Kazuo; Matsubara, Hiroyuki; Ichikawa, Tadashi; Maeda, Mitsutoshi; Ito, Hiroshi

    2008-08-01

    In this paper we propose a direct diode laser (DDL) system consisting of laser diode (LD) bars, a planar lightwave circuit (PLC), and an optical fiber. We have developed a PLC as an optical power combiner and an LD mounting technology that is suitable for coupling to the PLC. A DDL system is presented that consists of six LD-PLC optical modules for the laser-welding of highly heat-resistant plastics. The total output power is in the 200 W class, with a spot diameter of 5.52 mm for the major axis and 5.00 mm for the minor axis at a focal length of 50 mm. The total output efficiency is 60.9% from the laser diode to the welding torch.

  14. Graphene Q-switched Yb:KYW planar waveguide laser

    SciTech Connect

    Kim, Jun Wan; Young Choi, Sun; Jun Ahn, Kwang; Yeom, Dong-Il E-mail: rotermun@ajou.ac.kr; Rotermund, Fabian E-mail: rotermun@ajou.ac.kr; Aravazhi, Shanmugam; Pollnau, Markus; Griebner, Uwe; Petrov, Valentin; Bae, Sukang

    2015-01-15

    A diode-pumped Yb:KYW planar waveguide laser, single-mode Q-switched by evanescent-field interaction with graphene, is demonstrated for the first time. Few-layer graphene grown by chemical vapor deposition is transferred onto the top of a guiding layer, which initiates stable Q-switched operation in a 2.4-cm-long waveguide laser operating near 1027 nm. Average output powers up to 34 mW and pulse durations as short as 349 ns are achieved. The measured output beam profile, clearly exhibiting a single mode, agrees well with the theoretically calculated mode intensity distribution inside the waveguide. As the pump power is increased, the repetition rate and pulse energy increase from 191 to 607 kHz and from 7.4 to 58.6 nJ, respectively, whereas the pulse duration decreases from 2.09 μs to 349 ns.

  15. Pulsed laser deposition of ZnO thin films decorated with Au and Pd nanoparticles with enhanced acetone sensing performance

    NASA Astrophysics Data System (ADS)

    Alexiadou, M.; Kandyla, M.; Mousdis, G.; Kompitsas, M.

    2017-04-01

    We fabricate and compare nanocomposite thin-film ZnO chemoresistive acetone sensors with gold or palladium nanoparticles on the surface, at low operating temperatures. The sensors are fabricated by pulsed laser deposition and operate in the temperature range 159-200 °C. The ZnO films are polycrystalline, crystallizing mainly at the (002) and (101) orientations of the hexagonal phase. The nanocomposite ZnO:Au and ZnO:Pd sensors have a lower detection limit and show a response enhancement factor between 2 and 7, compared with pure ZnO sensors. The ZnO:Pd sensor performs better than the ZnO:Au sensor. The ZnO:Pd sensor sensitivity increases with the amount of palladium on the surface, while it remains roughly unchanged with the ZnO thickness. The lowest acetone concentration we detect is 26 ppm for the operating temperature of 200 °C.

  16. Fabrication of Planar Laser Targets with Sub-Micrometer Thickness Uniformity

    SciTech Connect

    Bono, M J; Castro, C; Hibbard, R L

    2005-07-21

    Lawrence Livermore National Laboratory routinely manufactures planar laser targets that consist of stacked and bonded foils for physics experiments on high-energy lasers. One recent planar laser target, the Equation of State target, had extremely tight specifications. The target required four bonded layers with thickness uniformities of several hundred nm, and the adhesive bonds between the layers could not exceed a few {micro}m. This paper describes the manufacturing process that was developed to meet these specifications.

  17. Planarization of metal films for multilevel interconnects by pulsed laser heating

    DOEpatents

    Tuckerman, David B.

    1987-01-01

    In the fabrication of multilevel integrated circuits, each metal layer is planarized by heating to momentarily melt the layer. The layer is melted by sweeping laser pulses of suitable width, typically about 1 microsecond duration, over the layer in small increments. The planarization of each metal layer eliminates irregular and discontinuous conditions between successive layers. The planarization method is particularly applicable to circuits having ground or power planes and allows for multilevel interconnects. Dielectric layers can also be planarized to produce a fully planar multilevel interconnect structure. The method is useful for the fabrication of VLSI circuits, particularly for wafer-scale integration.

  18. Pure colloidal metal and ceramic nanoparticles from high-power picosecond laser ablation in water and acetone.

    PubMed

    Bärsch, Niko; Jakobi, Jurij; Weiler, Sascha; Barcikowski, Stephan

    2009-11-04

    The generation of colloids by laser ablation of solids in a liquid offers a nearly unlimited material variety and a high purity as no chemical precursors are required. The use of novel high-power ultra-short-pulsed laser systems significantly increases the production rates even in inflammable organic solvents. By applying an average laser power of 50 W and pulse durations below 10 ps, up to 5 mg min(-1) of nanoparticles have been generated directly in acetone, marking a breakthrough in productivity of ultra-short-pulsed laser ablation in liquids. The produced colloids remain stable for more than six months. In the case of yttria-stabilized zirconia ceramic, the nanoparticles retain the tetragonal crystal structure of the ablated target. Laser beam self-focusing plays an important role, as a beam radius change of 2% on the liquid surface can lead to a decrease of nanoparticle production rates of 90% if the target position is not re-adjusted.

  19. High-power AlGaAs channeled substrate planar diode lasers for spaceborne communications

    NASA Technical Reports Server (NTRS)

    Connolly, J. C.; Goldstein, B.; Pultz, G. N.; Slavin, S. E.; Carlin, D. B.; Ettenberg, M.

    1988-01-01

    A high power channeled substrate planar AlGaAs diode laser with an emission wavelength of 8600 to 8800 A was developed. The optoelectronic behavior (power current, single spatial and spectral behavior, far field characteristics, modulation, and astigmatism properties) and results of computer modeling studies on the performance of the laser are discussed. Lifetest data on these devices at high output power levels is also included. In addition, a new type of channeled substrate planar laser utilizing a Bragg grating to stabilize the longitudinal mode was demonstrated. The fabrication procedures and optoelectronic properties of this new diode laser are described.

  20. Low noise planar external cavity laser for interferometric fiber optic sensors

    NASA Astrophysics Data System (ADS)

    Alalusi, Mazin; Brasil, Paul; Lee, Sanggeon; Mols, Peter; Stolpner, Lew; Mehnert, Axel; Li, Steve

    2009-05-01

    A 1550 nm DWDM planar external cavity laser (ECL) is demonstrated to provide low phase/frequency noise, narrow linewidth, and low RIN. The cavity includes a semiconductor gain chip and a planar lightwave circuit waveguide with Bragg grating, packaged in a 14-pin butterfly package. This planar ECL laser is designed to operate under vibration and in harsh environmental conditions. The laser shows linewidth <= 2.6 kHz, phase/frequency noise comparable with that of long cavity fiber lasers, RIN <= -147dB/Hz at 1kHz, and power >= 10mW. Performance is suitable for various high performance fiber optic sensing systems, including interferometric sensing in Oil and Gas, military/security and other applications, currently served mostly by costly and less reliable laser sources.

  1. Thin planar package for cooling an array of edge-emitting laser diodes

    DOEpatents

    Mundinger, David C.; Benett, William J.

    1992-01-01

    A laser diode array is disclosed that includes a plurality of planar assemblies and active cooling of each assembly. The laser diode array may be operated in a long duty cycle, or in continuous operation. A laser diode bar and a microchannel heat sink are thermally coupled in a compact, thin planar assembly having the laser diode bar located proximate to one edge. In an array, a number of such thin planar assemblies are secured together in a stacked configuration, in close proximity so that the laser diodes are spaced closely. The cooling means includes a microchannel heat sink proximate to the laser diode bar to absorb heat generated by laser operation. To provide the coolant to the microchannels, each thin planar assembly comprises passageways that connect the microchannels to inlet and outlet corridors. Each inlet passageway may comprise a narrow slot that directs coolant into the microchannels and increases the velocity of flow therethrough. The corridors comprises holes extending through each of the assemblies in the array. The inlet and outlet corridors are connected to a conventional coolant circulation system. The laser diode array with active cooling has applications as an optical pump for high power solid state lasers, or by mating the diodes with fiber optic lenses. Further, the arrays can be useful in applications having space constraints and energy limitations, and in military and space applications. The arrays can be incorporated in equipment such as communications devices and active sensors.

  2. Laser operation of a Tm:Y2O3 planar waveguide.

    PubMed

    Szela, Jakub W; Sloyan, Katherine A; Parsonage, Tina L; Mackenzie, Jacob I; Eason, Robert W

    2013-05-20

    We demonstrate the first Tm-doped yttria planar waveguide laser to our knowledge, grown by pulsed laser deposition. A maximum output power of 35 mW at 1.95 μm with 9% slope efficiency was achieved from a 12 μm-thick film grown on a Y(3)Al(5)O(12) substrate.

  3. Initiation precursors and initiators in laser-induced copolymerization of styrene and maleic anhydride in acetone

    NASA Technical Reports Server (NTRS)

    Miner, Gilda A.; Meador, Willard E.; Chang, C. Ken

    1990-01-01

    The initiation step of photopolymerized styrene/maleic anhydride copolymer was investigated at 365 nm. UV absorption measurements provide decisive evidence that the styrene/maleic anhydride charge transfer complex is the sole absorbing species; however, key laser experiments suggest intermediate reactions lead to a monoradical initiating species. A mechanism for the photoinitiation step of the copolymer is proposed.

  4. Frequency and Intensity Stabilization of Planar Waveguide-External Cavity Lasers

    NASA Astrophysics Data System (ADS)

    Tellez, Gregorio; Shoen, Steven; Quetschke, Volker

    2012-02-01

    Planar Waveguide External Cavity Lasers (PW-ECL) show an immense potential for use in precision measurement tasks and space missions because of its compactness and simple design. We show the techniques used to frequency and intensity stabilize a PW-ECL 1550nm laser system with the goal of achieving a frequency stability of 30 Hz/sqrt(Hz) and a RIN of less than 10-6. These PW-ECL systems are a potential replacement for Non-Planar Ring Oscillator (NPRO) laser systems, which have become a standard for low-noise interferometric applications, if the PW-ECL can meet the required stability. We present the initial experimental results of the intensity and frequency stabilization setup and we show a comparison between PW-ECL lasers and NPRO lasers with respect to measurements and applications requiring a high frequency and intensity stability.

  5. A comparison of planar, laser-induced fluorescence, and high-sensitivity interferometry techniques for gas-puff nozzle density measurements

    SciTech Connect

    Jackson, S. L.; Weber, B. V.; Mosher, D.; Phipps, D. G.; Stephanakis, S. J.; Commisso, R. J.; Qi, N.; Failor, B. H.; Coleman, P. L.

    2008-10-15

    The distribution of argon gas injected by a 12-cm-diameter triple-shell nozzle was characterized using both planar, laser-induced fluorescence (PLIF) and high-sensitivity interferometry. PLIF is used to measure the density distribution at a given time by detecting fluorescence from an acetone tracer added to the gas. Interferometry involves making time-dependent, line-integrated gas density measurements at a series of chordal locations that are then Abel inverted to obtain the gas density distribution. Measurements were made on nominally identical nozzles later used for gas-puff Z-pinch experiments on the Saturn pulsed-power generator. Significant differences in the mass distributions obtained by the two techniques are presented and discussed, along with the strengths and weaknesses of each method.

  6. Laser-assisted direct ink writing of planar and 3D metal architectures

    NASA Astrophysics Data System (ADS)

    Skylar-Scott, Mark A.; Gunasekaran, Suman; Lewis, Jennifer A.

    2016-05-01

    The ability to pattern planar and freestanding 3D metallic architectures at the microscale would enable myriad applications, including flexible electronics, displays, sensors, and electrically small antennas. A 3D printing method is introduced that combines direct ink writing with a focused laser that locally anneals printed metallic features “on-the-fly.” To optimize the nozzle-to-laser separation distance, the heat transfer along the printed silver wire is modeled as a function of printing speed, laser intensity, and pulse duration. Laser-assisted direct ink writing is used to pattern highly conductive, ductile metallic interconnects, springs, and freestanding spiral architectures on flexible and rigid substrates.

  7. Laser-assisted direct ink writing of planar and 3D metal architectures.

    PubMed

    Skylar-Scott, Mark A; Gunasekaran, Suman; Lewis, Jennifer A

    2016-05-31

    The ability to pattern planar and freestanding 3D metallic architectures at the microscale would enable myriad applications, including flexible electronics, displays, sensors, and electrically small antennas. A 3D printing method is introduced that combines direct ink writing with a focused laser that locally anneals printed metallic features "on-the-fly." To optimize the nozzle-to-laser separation distance, the heat transfer along the printed silver wire is modeled as a function of printing speed, laser intensity, and pulse duration. Laser-assisted direct ink writing is used to pattern highly conductive, ductile metallic interconnects, springs, and freestanding spiral architectures on flexible and rigid substrates.

  8. Laser-assisted direct ink writing of planar and 3D metal architectures

    PubMed Central

    Skylar-Scott, Mark A.; Gunasekaran, Suman; Lewis, Jennifer A.

    2016-01-01

    The ability to pattern planar and freestanding 3D metallic architectures at the microscale would enable myriad applications, including flexible electronics, displays, sensors, and electrically small antennas. A 3D printing method is introduced that combines direct ink writing with a focused laser that locally anneals printed metallic features “on-the-fly.” To optimize the nozzle-to-laser separation distance, the heat transfer along the printed silver wire is modeled as a function of printing speed, laser intensity, and pulse duration. Laser-assisted direct ink writing is used to pattern highly conductive, ductile metallic interconnects, springs, and freestanding spiral architectures on flexible and rigid substrates. PMID:27185932

  9. A unified planar measurement technique for compressible flows using laser-induced iodine fluorescence

    NASA Technical Reports Server (NTRS)

    Hartfield, Roy J., Jr.; Hollo, Steven D.; Mcdaniel, James C.

    1992-01-01

    A unified laser-induced fluorescence technique for conducting planar measurements of temperature, pressure and velocity in nonreacting, highly compressible flows has been developed, validated and demonstrated. Planar fluorescence from iodine, seeded into air, was induced by an argon-ion laser and collected using a liquid-nitrogen cooled CCD camera. In the measurement technique, temperature is determined from the fluorescence induced with the laser operated broad band. Pressure and velocity are determined from the shape and position of the fluorescence excitation spectrum which is measured with the laser operated narrow band. The measurement approach described herein provides a means of obtaining accurate, spatially-complete maps of the primary flow field parameters in a wide variety of cold supersonic and transonic flows.

  10. High-power 0.87-micron channel substrate planar lasers for spaceborne communications

    NASA Technical Reports Server (NTRS)

    Connolly, J. C.; Stewart, T. R.; Gilbert, D. B.; Slavin, S. E.; Carlin, D. B.

    1988-01-01

    High-power single-mode channeled-substrate planar AlGaAs diode lasers are being developed for reliable high-power operation for use as sources in spaceborne optical communication systems. The CSP laser structure has been optimized for operation at an emission wavelength of 870 nm. Such devices have exhibited output powers in excess of 80 mW CW at an operating temperature of 80 C.

  11. OH Planar Laser-Induced Fluorescence from Microgravity Droplet Combustion

    NASA Technical Reports Server (NTRS)

    Winter, Michael; Wegge, Jason; Kang, Kyung-Tae

    1997-01-01

    Droplet combustion under microgravity conditions has been extensively studied, but laser diagnostics have just begun to be employed in microgravity droplet experiments. This is due in part to the level of difficulty associated with laser system size, power and economic availability. Hydroxyl radical (OH) is an important product of combustion, and laser-induced fluorescence (LIF) has proved to be an adequate and sensitive tool to measure OH. In this study, a frequency doubled Nd:YAG laser and a doubled dye laser, compact and reliable enough to perform OH PLIF experiments aboard a parabolic flight-path aircraft, has been developed and successfully demonstrated in a methanol droplet flame experiment. Application to microgravity conditions is planned aboard parabolic flight-path aircraft.

  12. High-Reliability Pump Module for Non-Planar Ring Oscillator Laser

    NASA Technical Reports Server (NTRS)

    Liu, Duncan T.; Qiu, Yueming; Wilson, Daniel W.; Dubovitsky, Serge; Forouhar, Siamak

    2007-01-01

    We propose and have demonstrated a prototype high-reliability pump module for pumping a Non-Planar Ring Oscillator (NPRO) laser suitable for space missions. The pump module consists of multiple fiber-coupled single-mode laser diodes and a fiber array micro-lens array based fiber combiner. The reported Single-Mode laser diode combiner laser pump module (LPM) provides a higher normalized brightness at the combined beam than multimode laser diode based LPMs. A higher brightness from the pump source is essential for efficient NPRO laser pumping and leads to higher reliability because higher efficiency requires a lower operating power for the laser diodes, which in turn increases the reliability and lifetime of the laser diodes. Single-mode laser diodes with Fiber Bragg Grating (FBG) stabilized wavelength permit the pump module to be operated without a thermal electric cooler (TEC) and this further improves the overall reliability of the pump module. The single-mode laser diode LPM is scalable in terms of the number of pump diodes and is capable of combining hundreds of fiber-coupled laser diodes. In the proof-of-concept demonstration, an e-beam written diffractive micro lens array, a custom fiber array, commercial 808nm single mode laser diodes, and a custom NPRO laser head are used. The reliability of the proposed LPM is discussed.

  13. Acetone PLIF concentration measurements in a submerged round turbulent jet

    NASA Astrophysics Data System (ADS)

    Kravtsov, Z. D.; Chikishev, L. M.; Dulin, V. M.

    2016-10-01

    Transport of passive scalar in near-field of a submerged turbulent jet, was studied experimentally by using the planar laser-induced fluorescence technique. The jet issued from a round pipe with the inner diameter and length of 21 mm and 700 mm, respectively. Three cases of Reynolds numbers were studied: Re=3000, 6000, and 9000. Vapor of acetone, mixed to the jet flow, served as a passive fluorescent tracer. The paper describes data processing utilized to convert intensity of fluorescence images to the instantaneous concentration.

  14. Spatiospectral and picosecond spatiotemporal properties of a broad area operating channeled-substrate-planar laser array

    NASA Technical Reports Server (NTRS)

    Yu, NU; Defreez, Richard K.; Bossert, David J.; Wilson, Geoffrey A.; Elliott, Richard A.

    1991-01-01

    Spatiospectral and spatiotemporal properties of an eight-element channeled-substrate-planar laser array are investigated in both CW and pulsed operating conditions. The closely spaced CSP array with strong optical coupling between array elements is characterized by a broad area laserlike operation determined by its spatial mode spectra. The spatiotemporal evolution of the near and far field exhibits complex dynamic behavior in the picosecond to nanosecond domain. Operating parameters for the laser device have been experimentally determined. These results provide important information for the evaluation of the dynamic behavior of coherent semiconductor laser arrays.

  15. Compensation method for attenuated planar laser images of optically dense sprays

    NASA Astrophysics Data System (ADS)

    Abu-Gharbieh, Rafeef; Persson, John L.; Försth, Michael; Rosén, Arne; Karlström, Anders; Gustavsson, Tomas

    2000-03-01

    We present a method for compensating laser attenuation in optically dense sprays, in particular for use in combustion engine research. Images of the fuel sprays are produced by planar laser imaging, where Mie scattered light from a cross section of the spray is imaged onto a CCD camera. The compensation scheme is based on the Beer Lambert law, which is used here to sum up the loss of light along the path of the laser in the image, and to compensate iteratively, pixel by pixel, for this loss.

  16. High-average-power Nd:YAG planar waveguide laser that is face pumped by 10 laser diode bars.

    PubMed

    Lee, J R; Baker, H J; Friel, G J; Hilton, G J; Hall, D R

    2002-04-01

    A planar waveguide Nd:YAG laser is pumped with 430 W of power from 10 laser diode bars to produce a multimode output power of 150 W at an optical efficiency of 35%. Use of a hybrid resonator of the positive-branch confocal unstable type for the lateral axis and of one of the near-case I waveguide type for the transverse axis increased the laser brightness by a factor of ~26 with only 12% less power than in the multimode case.

  17. Laser-based excitation and diagnostics of planar fractures

    NASA Astrophysics Data System (ADS)

    Blum, T. E.; Van Wijk, K.; Snieder, R.; Willis, M. E.

    2011-12-01

    Faults are of interest not only to earth science, but also at different scales in the non-destructive testing (NDT) community. Remote sensing of faults is of interest to both communities, with the idea of inverting for the fracture properties in a non-invasive way. Alternatively, the wave field directly excited at the fracture is of interest to both communities because the waves thus radiated are equivalent to those emitted by acoustic emissions or micro-earthquakes. Much can be learned from recording of elastic waves excited at the the fracture. Based on technology developed for NDT, we use laser ultrasonics in the laboratory to excite and detect elastic waves, in order to determine the properties of fractures or faults in laboratory rock and synthetic samples. We show examples of wave propagation in a clear Poly(methyl methacrylate) cylinder. By focusing a high power infrared (IR) laser inside the cylinder we create a visible single disk-shaped fracture near the center of the sample. The laser generates a short pulse (~20 ns) of infrared light that is absorbed by the sample material at the focal point and is converted into heat. The sudden thermal expansion generates stress and forms a fracture parallel to the cylindrical axis. We excite elastic waves at the surface of the sample using the same high-power pulsed laser, but at a much lower energy setting, and with an unfocused beam. We measure the direct and scattered wave field from the fracture with a laser interferometer, and also excite the fracture directly with a fraction of the source laser energy impinging directly on the fracture. A comparison of the direct excitation and the elastic scattered wavefields, including studies of the tip diffractions from the fracture, shows strong agreement. The measured tip diffractions carry information about the stress concentration near the crack tips, which is crucial for understanding rupture processes. This novel laboratory technique allows us to measure the source

  18. Realization of autofocusing system for laser direct writing on non-planar surfaces.

    PubMed

    Luo, Jianbo; Liang, Yiyong; Yang, Guoguang

    2012-05-01

    This paper presents an autofocusing system for laser direct writing on non-planar surfaces, including focus error signal detection and focusing control. The focus error signal detection is based on modified confocal techniques, which features easy implementation, independence of the tilt angles of non-planar surfaces, and excellent suppression of common-mode noise or variable system factors. We also present a macro/micro dual-drive mechanism and its synchronous operation for focusing control on non-planar surfaces. Finally, a performance evaluation of the autofocusing system is presented. The uniform line width of 2.1 μm for a pattern on a convex spherical substrate with a curvature radius of 100 mm shows the autofocusing system performs well.

  19. Impacts of SiO2 planarization on optical thin film properties and laser damage resistance

    NASA Astrophysics Data System (ADS)

    Day, T.; Wang, H.; Jankowska, E.; Reagan, B. A.; Rocca, J. J.; Stolz, C. J.; Mirkarimi, P.; Folta, J.; Roehling, J.; Markosyan, A.; Route, R. R.; Fejer, M. M.; Menoni, C. S.

    2016-12-01

    Lawrence Livermore National Laboratory (LLNL) and Colorado State University (CSU) have co-developed a planarization process to smooth nodular defects. This process consists of individually depositing then etching tens of nanometers of SiO2 with a ratio of 2:1, respectively. Previous work shows incorporating the angular dependent ion surface etching and unidirectional deposition reduces substrate defect cross-sectional area by 90%. This work investigates the micro-structural and optical modifications of planarized SiO2 films deposited by ion beam sputtering (IBS). It is shown the planarized SiO2 thin films have 3x increase in absorption and 18% reduction in thin film stress as compared to control (as deposited) SiO2. Planarized SiO2 films exhibit 13% increase in RMS surface roughness with respect to the control and super polished fused silica substrates. Laser-induced damage threshold (LIDT) results indicate the planarization process has no effect on the onset fluence but alters the shape of the probability vs fluence trace.

  20. Performance of Planar-Waveguide External Cavity Laser for Precision Measurements

    NASA Technical Reports Server (NTRS)

    Numata, Kenji; Camp, Jordan; Krainak, Michael A.; Stolpner, Lew

    2010-01-01

    A 1542-nm planar-waveguide external cavity laser (PW-ECL) is shown to have a sufficiently low level of frequency and intensity noise to be suitable for precision measurement applications. The frequency noise and intensity noise of the PW-ECL was comparable or better than the nonplanar ring oscillator (NPRO) and fiber laser between 0.1 mHz to 100 kHz. Controllability of the PW-ECL was demonstrated by stabilizing its frequency to acetylene (13C2H2) at 10(exp -13) level of Allan deviation. The PW-ECL also has the advantage of the compactness of a standard butterfly package, low cost, and a simple design consisting of a semiconductor gain media coupled to a planar-waveguide Bragg reflector. These features would make the PW-ECL suitable for precision measurements, including compact optical frequency standards, space lidar, and space interferometry

  1. Nonlinear spectrum of the ablative Rayleigh-Taylor instability in laser-accelerated planar plasmas

    SciTech Connect

    Keskinen, M. J.; Schmitt, A.

    2007-01-15

    A model for the nonlinear spectrum of the ablative Rayleigh-Taylor instability in laser-accelerated planar plasmas has been developed for a wide range of Froude numbers and scale sizes. It is found that the spectrum can be characterized by an inverse power law with spectral index of approximately 2 in the limit of small-wavenumber spectrum cutoffs and small-scale density gradient scale lengths. Comparison of the model spectrum with recent experimental observations is made with good agreement.

  2. Planar Laser Imaging of Scattering and Fluorescence of Zooplankton Feeding in Layers of Phytoplankton in situ

    DTIC Science & Technology

    2007-09-30

    Planar Laser Imaging of Scattering and Fluorescence of Zooplankton Feeding in Layers of Phytoplankton in situ Peter J.S. Franks Scripps...herbivorous copepod feeding in the laboratory, and 2) to apply these methods in the field to observe the dynamics of copepod feeding in situ. In...particular we intend to test the “ feeding sorties” hypothesis vs. the “in situ feeding ” hypothesis regarding the location and timing of copepod feeding

  3. Injectant mole-fraction imaging in compressible mixing flows using planar laser-induced iodine fluorescence

    NASA Technical Reports Server (NTRS)

    Hartfield, Roy J., Jr.; Abbitt, John D., III; Mcdaniel, James C.

    1989-01-01

    A technique is described for imaging the injectant mole-fraction distribution in nonreacting compressible mixing flow fields. Planar fluorescence from iodine, seeded into air, is induced by a broadband argon-ion laser and collected using an intensified charge-injection-device array camera. The technique eliminates the thermodynamic dependence of the iodine fluorescence in the compressible flow field by taking the ratio of two images collected with identical thermodynamic flow conditions but different iodine seeding conditions.

  4. Planar laser-induced fluorescence measurements of high-enthalpy free jet flow with nitric oxide

    NASA Technical Reports Server (NTRS)

    Palmer, Jennifer L.; Mcmillin, Brian K.; Hanson, Ronald K.

    1992-01-01

    Planar laser-induced fluorescence (PLIF) measurements of property fields in a high-enthalpy, supersonic, underexpanded free jet generated in a reflection-type shock tunnel are reported. PLIF images showing velocity and temperature sensitivity are presented. The inferred radial velocity and relative rotational temperature fields are found to be in agreement with those predicted by a numerical simulation of the flowfield using the method of characteristics.

  5. Planar Laser-Induced Fluorescence fuel concentration measurements in isothermal Diesel sprays.

    PubMed

    Pastor, José; López, José; Juliá, J; Benajes, Jesús

    2002-04-08

    This paper presents a complete methodology to perform fuel concentration measurements of Diesel sprays in isothermal conditions using the Planar Laser-Induced Fluorescence (PLIF) technique. The natural fluorescence of a commercial Diesel fuel is used with an excitation wavelength of 355 nm. The correction and calibration procedures to perform accurate measurements are studied. These procedures include the study of the fluorescence characteristics of the fuel as well as the correction of the laser sheet non-homogeneities and the losses due to Mie scattering, absorption and autoabsorption. The results obtained are compared with theoretical models and other experimental techniques.

  6. Intracavity Beam Behavior in Hybrid Resonator Planar-Waveguide CO(2) Lasers.

    PubMed

    Wasilewski, B; Baker, H J; Hall, D R

    2000-11-20

    We describe a combined computer simulation and experimental investigation of the intracavity spatial beam profile characteristics of a planar-waveguide rf-excited CO(2) laser that incorporates a hybrid waveguide confocal unstable negative-branch resonator. The study includes results for the intracavity lateral beam intensity profile and output power of the laser as a function of resonator mirror misalignment. In addition, the behavior of the unstable resonator, observed experimentally and predicted by the simulation, in generating localized high intensity hot-spots when it is subjected to relatively large misalignment angles is reported.

  7. Planar temperature measurement in compressible flows using laser-induced iodine fluorescence

    NASA Technical Reports Server (NTRS)

    Hartfield, Roy J., Jr.; Hollo, Steven D.; Mcdaniel, James C.

    1991-01-01

    A laser-induced iodine fluorescence technique that is suitable for the planar measurement of temperature in cold nonreacting compressible air flows is investigated analytically and demonstrated in a known flow field. The technique is based on the temperature dependence of the broadband fluorescence from iodine excited by the 514-nm line of an argon-ion laser. Temperatures ranging from 165 to 245 K were measured in the calibration flow field. This technique makes complete, spatially resolved surveys of temperature practical in highly three-dimensional, low-temperature compressible flows.

  8. Method of making an ion-implanted planar-buried-heterostructure diode laser

    DOEpatents

    Brennan, Thomas M.; Hammons, Burrell E.; Myers, David R.; Vawter, Gregory A.

    1992-01-01

    Planar-buried-heterostructure, graded-index, separate-confinement-heterostructure semiconductor diode laser 10 includes a single quantum well or multi-quantum well active stripe 12 disposed between a p-type compositionally graded Group III-V cladding lever 14 and an n-type compositionally graded Group III-V cladding layer 16. The laser 10 includes an iion implanted n-type region 28 within the p-type cladding layer 14 and further includes an ion implanted p-type region 26 within the n-type cladding layer 16. The ion implanted regions are disposed for defining a lateral extent of the active stripe.

  9. Ceramic planar waveguide structures for amplifiers and lasers

    SciTech Connect

    Konyushkin, V A; Nakladov, A N; Konyushkin, D V; Doroshenko, Maxim E; Osiko, Vyacheslav V; Karasik, Aleksandr Ya

    2013-01-31

    Ceramic and crystalline weakly guiding optical fibres with the core - cladding refractive index difference of 10{sup -2} - 10{sup -4} are fabricated by a hot pressing method. The waveguides with one or several cores for operation in the spectral range 0.2 - 5 {mu}m are produced. The waveguides are based on CaF{sub 2}, SrF{sub 2}, and BaF{sub 2} ceramics and crystals and their solid solutions doped with trivalent Pr, Nd, Tb, Dy, Yb, Ho, Er, and Tm ions, as well as on LiF ceramics and crystals with colour centres. The first results of investigation of the lasing properties of ceramic SrF{sub 2} : NdF waveguides under diode pumping are presented, and the prospects of further investigation are discussed. (lasers)

  10. Influence of saturation of diode pump radiation absorption in YAG:Yb+3 crystal on parameters of planar waveguide lasers

    NASA Astrophysics Data System (ADS)

    Galushkin, M. G.; Yakunin, V. P.; Dyachkov, R. G.

    2017-01-01

    A method has been devised for calculating the energy parameters of generation of planar YAG:Yb3+ lasers, with regard to saturation of the absorption of pump diode laser radiation with a wavelength λ  =  940 nm. It has been shown that nonlinearity of the pump absorption coefficient can substantially reduce the small-signal gain at the transition with a wavelength λ  =  1030 nm. It has been found that pump saturation influence on the energy efficiency of planar lasers and power amplifiers is considerably weakened in the field of intense laser radiation.

  11. Stereoscopic Planar Laser-Induced Fluorescence Imaging at 500 kHz

    NASA Technical Reports Server (NTRS)

    Medford, Taylor L.; Danehy, Paul M.; Jones, Stephen B.; Jiang, N.; Webster, M.; Lempert, Walter; Miller, J.; Meyer, T.

    2011-01-01

    A new measurement technique for obtaining time- and spatially-resolved image sequences in hypersonic flows is developed. Nitric-oxide planar laser-induced fluorescence (NO PLIF) has previously been used to investigate transition from laminar to turbulent flow in hypersonic boundary layers using both planar and volumetric imaging capabilities. Low flow rates of NO were typically seeded into the flow, minimally perturbing the flow. The volumetric imaging was performed at a measurement rate of 10 Hz using a thick planar laser sheet that excited NO fluorescence. The fluorescence was captured by a pair of cameras having slightly different views of the flow. Subsequent stereoscopic reconstruction of these images allowed the three-dimensional flow structures to be viewed. In the current paper, this approach has been extended to 50,000 times higher repetition rates. A laser operating at 500 kHz excites the seeded NO molecules, and a camera, synchronized with the laser and fitted with a beam-splitting assembly, acquires two separate images of the flow. The resulting stereoscopic images provide three-dimensional flow visualizations at 500 kHz for the first time. The 200 ns exposure time in each frame is fast enough to freeze the flow while the 500 kHz repetition rate is fast enough to time-resolve changes in the flow being studied. This method is applied to visualize the evolving hypersonic flow structures that propagate downstream of a discrete protuberance attached to a flat plate. The technique was demonstrated in the NASA Langley Research Center s 31-Inch Mach 10 Air Tunnel facility. Different tunnel Reynolds number conditions, NO flow rates and two different cylindrical protuberance heights were investigated. The location of the onset of flow unsteadiness, an indicator of transition, was observed to move downstream during the tunnel runs, coinciding with an increase in the model temperature.

  12. Cellular dye lasers: lasing thresholds and sensing in a planar resonator

    PubMed Central

    Humar, Matjaž; Gather, Malte C.; Yun, Seok-Hyun

    2015-01-01

    Biological cell lasers are promising novel building blocks of future biocompatible optical systems and offer new approaches to cellular sensing and cytometry in a microfluidic setting. Here, we demonstrate a simple method for providing optical gain by using a variety of standard fluorescent dyes. The dye gain medium can be located inside or outside a cell, or in both, which gives flexibility in experimental design and makes the method applicable to all cell types. Due to the higher refractive index of the cytoplasm compared to the surrounding medium, a cell acts as a convex lens in a planar Fabry-Perot cavity. Its effect on the stability of the laser cavity is analyzed and utilized to suppress lasing outside cells. The resonance modes depend on the shape and internal structure of the cell. As proof of concept, we show how the laser output modes are affected by the osmotic pressure. PMID:26480446

  13. Ceramic planar waveguide laser of non-aqueous tape casting fabricated YAG/Yb:YAG/YAG

    PubMed Central

    Wang, Chao; Li, Wenxue; Yang, Chao; Bai, Dongbi; Li, Jiang; Ge, Lin; Pan, Yubai; Zeng, Heping

    2016-01-01

    Ceramic YAG/Yb:YAG/YAG planar waveguide lasers were realized on continuous-wave and mode-locked operations. The straight waveguide, fabricated by non-aqueous tape casting and solid state reactive sintering, enabled highly efficient diode-pumped waveguide continuous-wave laser with the slope efficiency of 66% and average output power of more than 3 W. The influence of the waveguide structure on the wavelength tunability was also experimentally investiccgated with a dispersive prism. Passively mode-locked operation of the ceramic waveguide laser was achieved by using a semiconductor saturable absorber mirror (SESAM), output 2.95 ps pulses with maximum power of 385 mW at the central wavelength of 1030 nm. PMID:27535577

  14. Thermal lensing characterization of a high-radiance 946nm planar waveguide laser

    NASA Astrophysics Data System (ADS)

    Ng, S. P.; Mackenzie, J. I.

    2012-06-01

    We present the characterization of the in-plane thermal lens in a quasi-four-level Nd:YAG planar waveguide (PW) laser configured for high-radiance operation with an external stable-cavity. Our approach utilises the measurement of the laser's output irradiance distribution at the near- and far-field positions concurrently in order to obtain the "real time" beam propagation parameter and thus beam quality factor, M2. Coupled with the knowledge of the intra-cavity-thermal-lens- dependent beam sizes at an intra-cavity beam waist, the power dependent effective thermal lens focal length was characterized. A thermal lens focal length of >450 mm was obtained at all incident pump powers up to the maximum level of 87 W. This characterization enabled the build of a 29 W 946 nm PW laser with a record output radiance of 4.3 TWm-2sr-1.

  15. Quasi-continuous burst-mode laser for high-speed planar imaging.

    PubMed

    Slipchenko, Mikhail N; Miller, Joseph D; Roy, Sukesh; Gord, James R; Danczyk, Stephen A; Meyer, Terrence R

    2012-04-15

    The pulse-burst duration of a compact burst-mode Nd:YAG laser is extended by one order of magnitude compared to previous flashlamp-pumped designs by incorporating a fiber oscillator and diode-pumped solid-state amplifiers. The laser has a linewidth of <2 GHz at 1064.3 nm with 150 mJ per individual pulse at 10 kHz. The performance of the system is evaluated by using the third-harmonic output at 354.8 nm for high-speed planar laser-induced fluorescence of formaldehyde in a lifted methane-air diffusion flame. A total of 100 and 200 sequential images of unsteady fluid-flame interactions are acquired at repetition rates of 10 kHz and 20 kHz, respectively.

  16. Planar waveguide Michelson interferometer fabricated by using 157nm mask laser micromachining

    NASA Astrophysics Data System (ADS)

    Bao, Haihong; Ran, Zengling; Wu, Xuezhong; Yang, Ke; Jiang, Yuan; Rao, Yunjiang

    2015-07-01

    A Michelson interferometer is fabricated on silica planar waveguide by using the one-step technology based on 157nm mask laser micromachining. The fabrication time for one device is ~10s. Experimental results show that such an interferometer has an excellent fringe contrast of >20dB. Its temperature and refractive index (RI) responses are tested by observing the wavelength shift of the interferometric fringes, which shows linear characteristics with a thermo-coefficient of ~9.5pm/°C and a RI-coefficient of ~36.7nm/RIU, respectively. The fabrication technology may pave a new way for direct writing of planar silica waveguide devices for sensing applications with high efficiency and quality.

  17. Characteristics of the Single-Longitudinal-Mode Planar-Waveguide External Cavity Diode Laser at 1064 nm

    NASA Technical Reports Server (NTRS)

    Numata, Kenji; Alalusi, Mazin; Stolpner, Lew; Margaritis, Georgios; Camp, Jordan B.; Krainak, Michael A.

    2014-01-01

    We describe the characteristics of the planar-waveguide external cavity diode laser (PW-ECL). To the best of our knowledge, it is the first butterfly-packaged 1064-nm semiconductor laser that is stable enough to be locked to an external frequency reference. We evaluated its performance from the viewpoint of precision experiments. Especially, using a hyperfine absorption line of iodine, we suppressed its frequency noise by a factor of up to104 at 10 mHz. The PW-ECLs compactness and low cost make it a candidate to replace traditional Nd:YAGnon-planar ring oscillators and fiber lasers in applications which require a single longitudinal-mode.

  18. Computer-controlled multi-parameter mapping of 3D compressible flowfields using planar laser-induced iodine fluorescence

    NASA Technical Reports Server (NTRS)

    Donohue, James M.; Victor, Kenneth G.; Mcdaniel, James C., Jr.

    1993-01-01

    A computer-controlled technique, using planar laser-induced iodine fluorescence, for measuring complex compressible flowfields is presented. A new laser permits the use of a planar two-line temperature technique so that all parameters can be measured with the laser operated narrowband. Pressure and temperature measurements in a step flowfield show agreement within 10 percent of a CFD model except in regions close to walls. Deviation of near wall temperature measurements from the model was decreased from 21 percent to 12 percent compared to broadband planar temperature measurements. Computer-control of the experiment has been implemented, except for the frequency tuning of the laser. Image data storage and processing has been improved by integrating a workstation into the experimental setup reducing the data reduction time by a factor of 50.

  19. Non-planar electron motion during direct laser acceleration by a linearly/circularly polarized laser pulse

    NASA Astrophysics Data System (ADS)

    Khudik, Vladimir; Arefiev, Alexey; Zhang, Xi; Shvets, Gennady

    2016-10-01

    Direct Laser Acceleration (DLA) of electrons in plasma bubbles or ion channels is investigated in the general case of arbitrary polarization of laser pulse. When the laser pulse is linearly polarized, the laser electromagnetic field drives electron oscillations in the polarization plane, intuitively suggesting that the electron trajectory lies in the same plane. We show that strong modulations of the relativistic gamma-factor cause the free oscillations perpendicular to the plane of the driven motion to become unstable. As a consequence, out of plane displacements grow and the electron trajectory becomes strongly three-dimensional, even if it starts out planar during the early stage of the acceleration. For a circularly polarized laser pulse, electron end up moving along a helical trajectory with slowly changing helix radius. By deriving a set of dimensionless equations for paraxial ultra-relativistic electron motion, we have found an estimate for the maximum attainable electron energy for arbitrary laser and plasma parameters. This work was supported by DOE Grants DESC0007889 and DE-SC0010622, and by an AFOSR Grant FA9550-14-1-0045.

  20. Investigation of the chemical stability of the laser-induced fluorescence tracers acetone, diethylketone, and toluene under IC engine conditions using Raman spectroscopy.

    PubMed

    Trost, Johannes; Zigan, Lars; Eichmann, Simone C; Seeger, Thomas; Leipertz, Alfred

    2013-09-01

    This paper reports on an investigation of the chemical stability of the common laser-induced fluorescence (LIF) tracers acetone, diethylketone, and toluene. Stability is analyzed using linear Raman spectroscopy inside a heated pressure cell with optical access, which is used for the LIF calibration of these tracers. The measurements examine the influence of temperature, pressure, and residence time on tracer oxidation, which occurs without a rise in temperature or pressure inside the cell, highlighting the need for optical detection. A comparison between the three different tracers shows large differences, with diethylketone having the lowest and toluene by far the highest stability. An analysis of the sensitivity of the measurement shows that the detection limit of the oxidized tracer is well below 3% molar fraction, which is typical for LIF applications in combustion devices such as internal combustion (IC) engines. Furthermore, the effect on the LIF signal intensity is examined in an isothermal turbulent mixing study.

  1. Planar integrated metasurfaces for highly-collimated terahertz quantum cascade lasers

    PubMed Central

    Liang, Guozhen; Dupont, Emmanuel; Fathololoumi, Saeed; Wasilewski, Zbigniew R.; Ban, Dayan; Liang, Hou Kun; Zhang, Ying; Yu, Siu Fung; Li, Lianhe H.; Davies, Alexander Giles; Linfield, Edmund H.; Liu, Hui Chun; Wang, Qi Jie

    2014-01-01

    We report planar integration of tapered terahertz (THz) frequency quantum cascade lasers (QCLs) with metasurface waveguides that are designed to be spoof surface plasmon (SSP) out-couplers by introducing periodically arranged SSP scatterers. The resulting surface-emitting THz beam profile is highly collimated with a divergence as narrow as ~4° × 10°, which indicates a good waveguiding property of the metasurface waveguide. In addition, the low background THz power implies a high coupling efficiency for the THz radiation from the laser cavity to the metasurface structure. Furthermore, since all the structures are in-plane, this scheme provides a promising platform where well-established surface plasmon/metasurface techniques can be employed to engineer the emitted beam of THz QCLs controllably and flexibly. More importantly, an integrated active THz photonic circuit for sensing and communication applications could be constructed by incorporating other optoelectronic devices such as Schottky diode THz mixers, and graphene modulators and photodetectors. PMID:25403796

  2. Femtosecond, two-photon, planar laser-induced fluorescence of carbon monoxide in flames.

    PubMed

    Richardson, Daniel R; Roy, Sukesh; Gord, James R

    2017-02-15

    Two-photon, planar laser-induced fluorescence (TP-PLIF) of carbon monoxide was performed in steady and driven flames using femtosecond (fs) laser pulses at 1 kHz. Excitation radiation at 230.1 nm (full-width at half-maximum bandwidth of 270  cm-1) was used to pump many rovibrational two-photon transitions in the B1+←X1+ system. Visible fluorescence in the range 362-516 nm was captured using an image intensifier and high-speed camera. The signal dependence on excitation energy and wavelength is presented. Photolytic interferences from the ultraviolet laser were explored in a sooting diffusion flame. Using an excitation laser intensity of 1010  W/cm2, negligible photolytic interferences were observed, and PLIF imaging of dynamic flame events was performed at 1 kHz.

  3. High-power single spatial mode AlGaAs channeled-substrate-planar semiconductor diode lasers for spaceborne communications

    NASA Technical Reports Server (NTRS)

    Connolly, J. C.; Carlin, D. B.; Ettenberg, M.

    1989-01-01

    A high power single spatial mode channeled substrate planar AlGaAs semiconductor diode laser was developed. The emission wavelength was optimized at 860 to 880 nm. The operating characteristics (power current, single spatial mode behavior, far field radiation patterns, and spectral behavior) and results of computer modeling studies on the performance of the laser are discussed. Reliability assessment at high output levels is included. Performance results on a new type of channeled substrate planar diode laser incorporating current blocking layers, grown by metalorganic chemical vapor deposition, to more effectively focus the operational current to the lasing region was demonstrated. The optoelectronic behavior and fabrication procedures for this new diode laser are discussed. The highlights include single spatial mode devices with up to 160 mW output at 8600 A, and quantum efficiencies of 70 percent (1 W/amp) with demonstrated operating lifetimes of 10,000 h at 50 mW.

  4. Hot electron generation and energy coupling in planar experiments with shock ignition high intensity lasers

    NASA Astrophysics Data System (ADS)

    Wei, M. S.; Krauland, C.; Alexander, N.; Zhang, S.; Peebles, J.; Beg, F. N.; Theobald, W.; Borwick, E.; Ren, C.; Yan, R.; Haberberger, D.; Betti, R.; Campbell, E. M.

    2016-10-01

    Hot electrons produced in nonlinear laser plasma interactions are critical issues for shock ignition (SI) laser fusion. We conducted planar target experiments to characterize hot electron and energy coupling using the high energy OMEGA EP laser system at SI high intensities. Targets were multilayered foils consisting of an ablator (either plastic or lithium) and a Cu layer to facilitate hot electron detection via fluorescence and bremsstrahlung measurements. The target was first irradiated by multi-kJ, low-intensity UV beams to produce a SI-relevant mm-scale hot ( 1 keV) preformed plasma. The main interaction pulse, either a kJ 1-ns UV pulse with intensity 1.6x1016 Wcm-2 or a kJ 0.1-ns IR pulse with intensity up to 2x1017 Wcm-2was injected at varied timing delays. The high intensity IR beam was found to strongly interact with underdense plasmas breaking into many filaments near the quarter critical density region followed by propagation of those filaments to critical density, producing hot electrons with Thot 70 keV in a well-contained beam. While the high intensity UV beam showed poor energy coupling. Details of the experiments and the complementary PIC modeling results will be presented. Work supported by U.S. DOE under contracts DE-NA0002730 (NLUF) and DE-SC0014666 (HEDLP).

  5. Experimental study of angular and frequency spectra of laser pulse diffraction on a planar periodic nanostructure of gold V antennas

    SciTech Connect

    Balabas, M V; Efremova, E A; Ivanov, A Yu; Kantserov, A I; Krylov, I R; Pelyukhova, E B; Petrov, Yu V; Prokhorova, U V; Silaev, R V; Tretiak, O Yu; Shimko, A A

    2015-10-31

    Irradiation of a planar structure made of periodically spaced gold V antennas by a femtosecond pulsed laser has revealed several anomalously reflected and refracted waves, interpreted as diffraction maxima. Compression of the pulse spectrum in scattered light is observed. The degree of compression and wave polarisation are found to be determined by the scattering direction. (nanophotonics)

  6. Power and radiance scaling of a 946 nm Nd:YAG planar waveguide laser

    NASA Astrophysics Data System (ADS)

    Ng, S. P.; Mackenzie, J. I.

    2012-03-01

    We present a diode-end-pumped Nd:YAG planar waveguide laser operating on neodymium's quasi-four-level transition at a wavelength of 946 nm. Two modes of operation are described: a high-power multi-mode monolithic cavity generating 105 for 210 W of incident pump power with a slope efficiency of ˜54%, and secondly, a high-radiance configuration employing an external stable resonator producing a maximum output power of 29.2 for 86.5 W of incident pump-power, with a slope efficiency of 33%. The output beam quality values of the external cavity were M2 of 3.2 by 2.4, leading to a maximum radiance of 0.43 GW cm-2 sr-1.

  7. High power YAG/Nd:YAG/YAG ceramic planar waveguide laser

    NASA Astrophysics Data System (ADS)

    Rao, Han; Liu, Zhaojun; Cong, Zhenhua; Huang, Qingjie; Liu, Yang; Zhang, Sasa; Zhang, Xingyu; Feng, Chao; Wang, Qingpu; Ge, Lin; Li, Jiang

    2017-04-01

    A high power YAG/Nd:YAG/YAG ceramic planar waveguide laser was demonstrated. For continuous wave regime, a maximum output power of 10.4 W at a center wavelength of 1064.6 nm was obtained under an absorbed pump power of 17.4 W, corresponding to an optical-to-optical conversion efficiency of 59.8%. For acousto-optically Q-switched operation, we obtained 2.5 W of output power at a pulse repetition frequency of 10 kHz. The pulse duration was 6.5 ns with peak power and pulse energy of 38.5 kW and 0.25 mJ, respectively.

  8. Spatially and temporally resolved gas distributions around heterogeneous catalysts using infrared planar laser-induced fluorescence

    PubMed Central

    Zetterberg, Johan; Blomberg, Sara; Gustafson, Johan; Evertsson, Jonas; Zhou, Jianfeng; Adams, Emma C.; Carlsson, Per-Anders; Aldén, Marcus; Lundgren, Edvin

    2015-01-01

    Visualizing and measuring the gas distribution in close proximity to a working catalyst is crucial for understanding how the catalytic activity depends on the structure of the catalyst. However, existing methods are not able to fully determine the gas distribution during a catalytic process. Here we report on how the distribution of a gas during a catalytic reaction can be imaged in situ with high spatial (400 μm) and temporal (15 μs) resolution using infrared planar laser-induced fluorescence. The technique is demonstrated by monitoring, in real-time, the distribution of carbon dioxide during catalytic oxidation of carbon monoxide above powder catalysts. Furthermore, we demonstrate the versatility and potential of the technique in catalysis research by providing a proof-of-principle demonstration of how the activity of several catalysts can be measured simultaneously, either in the same reactor chamber, or in parallel, in different reactor tubes. PMID:25953006

  9. Fabrication of organic-inorganic perovskite thin films for planar solar cells via pulsed laser deposition

    SciTech Connect

    Liang, Yangang; Zhang, Xiaohang; Gong, Yunhui; Shin, Jongmoon; Wachsman, Eric D.; Takeuchi, Ichiro; Yao, Yangyi; Hsu, Wei-Lun; Dagenais, Mario

    2016-01-15

    We report on fabrication of organic-inorganic perovskite thin films using a hybrid method consisting of pulsed laser deposition (PLD) of lead iodide and spin-coating of methylammonium iodide. Smooth and highly crystalline CH{sub 3}NH{sub 3}PbI{sub 3} thin films have been fabricated on silicon and glass coated substrates with fluorine doped tin oxide using this PLD-based hybrid method. Planar perovskite solar cells with an inverted structure have been successfully fabricated using the perovskite films. Because of its versatility, the PLD-based hybrid fabrication method not only provides an easy and precise control of the thickness of the perovskite thin films, but also offers a straightforward platform for studying the potential feasibility in using other metal halides and organic salts for formation of the organic-inorganic perovskite structure.

  10. Robust statistical approaches for local planar surface fitting in 3D laser scanning data

    NASA Astrophysics Data System (ADS)

    Nurunnabi, Abdul; Belton, David; West, Geoff

    2014-10-01

    This paper proposes robust methods for local planar surface fitting in 3D laser scanning data. Searching through the literature revealed that many authors frequently used Least Squares (LS) and Principal Component Analysis (PCA) for point cloud processing without any treatment of outliers. It is known that LS and PCA are sensitive to outliers and can give inconsistent and misleading estimates. RANdom SAmple Consensus (RANSAC) is one of the most well-known robust methods used for model fitting when noise and/or outliers are present. We concentrate on the recently introduced Deterministic Minimum Covariance Determinant estimator and robust PCA, and propose two variants of statistically robust algorithms for fitting planar surfaces to 3D laser scanning point cloud data. The performance of the proposed robust methods is demonstrated by qualitative and quantitative analysis through several synthetic and mobile laser scanning 3D data sets for different applications. Using simulated data, and comparisons with LS, PCA, RANSAC, variants of RANSAC and other robust statistical methods, we demonstrate that the new algorithms are significantly more efficient, faster, and produce more accurate fits and robust local statistics (e.g. surface normals), necessary for many point cloud processing tasks. Consider one example data set used consisting of 100 points with 20% outliers representing a plane. The proposed methods called DetRD-PCA and DetRPCA, produce bias angles (angle between the fitted planes with and without outliers) of 0.20° and 0.24° respectively, whereas LS, PCA and RANSAC produce worse bias angles of 52.49°, 39.55° and 0.79° respectively. In terms of speed, DetRD-PCA takes 0.033 s on average for fitting a plane, which is approximately 6.5, 25.4 and 25.8 times faster than RANSAC, and two other robust statistical methods, respectively. The estimated robust surface normals and curvatures from the new methods have been used for plane fitting, sharp feature

  11. Quantitative imaging of a non-combusting diesel spray using structured laser illumination planar imaging

    NASA Astrophysics Data System (ADS)

    Berrocal, E.; Kristensson, E.; Hottenbach, P.; Aldén, M.; Grünefeld, G.

    2012-12-01

    Due to its transient nature, high atomization process, and rapid generation of fine evaporating droplets, diesel sprays have been, and still remain, one of the most challenging sprays to be fully analyzed and understood by means of non-intrusive diagnostics. The main limitation of laser techniques for quantitative measurements of diesel sprays concerns the detection of the multiple light scattering resulting from the high optical density of such a scattering medium. A second limitation is the extinction of the incident laser radiation as it crosses the spray, as well as the attenuation of the signal which is to be detected. All these issues have strongly motivated, during the past decade, the use of X-ray instead of visible light for dense spray diagnostics. However, we demonstrate in this paper that based on an affordable Nd:YAG laser system, structured laser illumination planar imaging (SLIPI) can provide accurate quantitative description of a non-reacting diesel spray injected at 1,100 bar within a room temperature vessel pressurized at 18.6 bar. The technique is used at λ = 355 nm excitation wavelength with 1.0 mol% TMPD dye concentration, for simultaneous LIF/Mie imaging. Furthermore, a novel dual-SLIPI configuration is tested with Mie scattering detection only. The results confirm that a mapping of both the droplet Sauter mean diameter and extinction coefficient can be obtained by such complementary approaches. These new insights are provided in this article at late times after injection start. It is demonstrated that the application of SLIPI to diesel sprays provides valuable quantitative information which was not previously accessible.

  12. The interaction of intense ultrashort laser pulses with cryogenic He planar jets

    NASA Astrophysics Data System (ADS)

    Shihab, M.; Bornath, Th; Redmer, R.

    2017-04-01

    We study the interaction of intense ultrashort laser pulses with cryogenic He planar jets, i.e., slabs, using 2D3V relativistic particle-in-cell simulations. Of particular interest are laser intensities ({10}15{--}{10}20) W cm‑2, pulse lengths ≤100 fs, and the wave length regime ∼800 nm for which the slabs are initially transparent and subsequently inhomogeneously ionized. Pulses ≥slant {10}16 W cm‑2 are found to drive ionization along the slab and outside the laser spot, the ionization front propagates along the slab at a considerable fraction of the speed of light. Within the ionized region, there is a highly transient field which is a result of the charge-neutralizing disturbance at the slab-vacuum interface and which may be interpreted in terms of a two-surface-wave decay. The ionized region is predicted to reach solid-like densities and temperatures of few to hundreds of eV, i.e., it belongs to warm and hot dense matter regimes. Such extreme conditions are relevant for high-energy densities as found, e.g., in shock-wave experiments and inertial confinement fusion studies. The temporal evolution of the ionization is studied considering theoretically a pump–probe x-ray Thomson scattering scheme. We observe plasmon and non-collective modes that are generated in the slab, and their amplitude is proportional to the ionized volume. Our theoretical findings could be tested at free-electron laser facilities such as FLASH and the European XFEL (Hamburg) and the LCLS (Stanford).

  13. Comparisons of Laser-Saturated, Laser-Induced, and Planar Laser-Induced Fluorescence Measurements of Nitric Oxide in a Lean Direct-Injection Spray Flame

    NASA Astrophysics Data System (ADS)

    Cooper, Clayton S.; Ravikrishna, Rayavarapu V.; Laurendeau, Normand M.

    1998-07-01

    We report quantitative, spatially resolved laser-saturated fluorescence (LSF), linear laser-induced fluorescence (LIF), and planar laser-induced fluorescence (PLIF) measurements of nitric oxide (NO) concentration in a preheated, lean direct-injection spray flame at atmospheric pressure. The spray is produced by a hollow-cone, pressure-atomized nozzle supplied with liquid heptane, and the overall equivalence ratio is unity. NO is excited by means of the Q 2 ( 26 . 5 ) transition of the (0, 0) band. LSF and LIF detection are performed in a 2-nm region centered on the (0, 1) band. PLIF detection is performed in a broad 70-nm region with a peak transmission at 270 nm. Quantitative radial NO profiles obtained by LSF are presented and analyzed so as to correct similar LIF and PLIF profiles. Excellent agreement is achieved among the three fluorescence methodologies.

  14. Effects of repetitive pulsing on multi-kHz planar laser-induced incandescence imaging in laminar and turbulent flames

    DOE PAGES

    Michael, James B.; Venkateswaran, Prabhakar; Shaddix, Christopher R.; ...

    2015-04-08

    Planar laser-induced incandescence (LII) imaging is reported at repetition rates up to 100 kHz using a burst-mode laser system to enable studies of soot formation dynamics in highly turbulent flames. Furthermore, to quantify the accuracy and uncertainty of relative soot volume fraction measurements, the temporal evolution of the LII field in laminar and turbulent flames is examined at various laser operating conditions. Under high-speed repetitive probing, it is found that LII signals are sensitive to changes in soot physical characteristics when operating at high laser fluences within the soot vaporization regime. For these laser conditions, strong planar LII signals aremore » observed at measurement rates up to 100 kHz but are primarily useful for qualitative tracking of soot structure dynamics. However, LII signals collected at lower fluences allow sequential planar measurements of the relative soot volume fraction with a sufficient signal-to-noise ratio at repetition rates of 10–50 kHz. Finally, guidelines for identifying and avoiding the onset of repetitive probe effects in the LII signals are discussed, along with other potential sources of measurement error and uncertainty.« less

  15. Effects of repetitive pulsing on multi-kHz planar laser-induced incandescence imaging in laminar and turbulent flames

    SciTech Connect

    Michael, James B.; Venkateswaran, Prabhakar; Shaddix, Christopher R.; Meyer, Terrence R.

    2015-04-08

    Planar laser-induced incandescence (LII) imaging is reported at repetition rates up to 100 kHz using a burst-mode laser system to enable studies of soot formation dynamics in highly turbulent flames. Furthermore, to quantify the accuracy and uncertainty of relative soot volume fraction measurements, the temporal evolution of the LII field in laminar and turbulent flames is examined at various laser operating conditions. Under high-speed repetitive probing, it is found that LII signals are sensitive to changes in soot physical characteristics when operating at high laser fluences within the soot vaporization regime. For these laser conditions, strong planar LII signals are observed at measurement rates up to 100 kHz but are primarily useful for qualitative tracking of soot structure dynamics. However, LII signals collected at lower fluences allow sequential planar measurements of the relative soot volume fraction with a sufficient signal-to-noise ratio at repetition rates of 10–50 kHz. Finally, guidelines for identifying and avoiding the onset of repetitive probe effects in the LII signals are discussed, along with other potential sources of measurement error and uncertainty.

  16. Effects of repetitive pulsing on multi-kHz planar laser-induced incandescence imaging in laminar and turbulent flames.

    PubMed

    Michael, James B; Venkateswaran, Prabhakar; Shaddix, Christopher R; Meyer, Terrence R

    2015-04-10

    Planar laser-induced incandescence (LII) imaging is reported at repetition rates up to 100 kHz using a burst-mode laser system to enable studies of soot formation dynamics in highly turbulent flames. To quantify the accuracy and uncertainty of relative soot volume fraction measurements, the temporal evolution of the LII field in laminar and turbulent flames is examined at various laser operating conditions. Under high-speed repetitive probing, it is found that LII signals are sensitive to changes in soot physical characteristics when operating at high laser fluences within the soot vaporization regime. For these laser conditions, strong planar LII signals are observed at measurement rates up to 100 kHz but are primarily useful for qualitative tracking of soot structure dynamics. However, LII signals collected at lower fluences allow sequential planar measurements of the relative soot volume fraction with a sufficient signal-to-noise ratio at repetition rates of 10-50 kHz. Guidelines for identifying and avoiding the onset of repetitive probe effects in the LII signals are discussed, along with other potential sources of measurement error and uncertainty.

  17. Characteristics of the Single-Longitudinal-Mode Planar-Waveguide External Cavity Diode Laser at 1064 nm

    NASA Technical Reports Server (NTRS)

    Numata, Kenji; Alalusi, Mazin; Stolpner, Lew; Margaritis, Georgios; Camp, Jordan; Krainak, Michael

    2014-01-01

    We describe the characteristics of the planar-waveguide external cavity diode laser (PW-ECL). To the best of our knowledge, it is the first butterfly-packaged 1064 nm semiconductor laser that is stable enough to be locked to an external frequency reference. We evaluated its performance from the viewpoint of precision experiments. Using a hyperfine absorption line of iodine, we suppressed its frequency noise by a factor of up to 104 at 10 mHz. The PWECL's compactness and low cost make it a candidate to replace traditional Nd:YAG nonplanar ring oscillators and fiber lasers in applications that require a single longitudinal mode.

  18. Characteristics of the single-longitudinal-mode planar-waveguide external cavity diode laser at 1064 nm.

    PubMed

    Numata, Kenji; Alalusi, Mazin; Stolpner, Lew; Margaritis, Georgios; Camp, Jordan; Krainak, Michael

    2014-04-01

    We describe the characteristics of the planar-waveguide external cavity diode laser (PW-ECL). To the best of our knowledge, it is the first butterfly-packaged 1064 nm semiconductor laser that is stable enough to be locked to an external frequency reference. We evaluated its performance from the viewpoint of precision experiments. Using a hyperfine absorption line of iodine, we suppressed its frequency noise by a factor of up to 10(4) at 10 mHz. The PW-ECL's compactness and low cost make it a candidate to replace traditional Nd:YAG nonplanar ring oscillators and fiber lasers in applications that require a single longitudinal mode.

  19. Planar laser-induced fluorescence (PLIF) investigation of hypersonic flowfields in a Mach 10 wind tunnel

    NASA Technical Reports Server (NTRS)

    Danehy, Paul M.; Wilkes, Jennifer A.; Aderfer, David W.; Jones, Stephen B.; Robbins, Anthony W.; Pantry, Danny P.; Schwartz, Richard J.

    2006-01-01

    Planar laser-induced fluorescence (PLIF) of nitric oxide (NO) was used to visualize four different hypersonic flowfields in the NASA Langley Research Center 31-Inch Mach 10 Air wind tunnel. The four configurations were: (1) the wake flowfield of a fuselage-only X-33 lifting body, (2) flow over a flat plate containing a rectangular cavity, (3) flow over a 70deg blunted cone with a cylindrical afterbody, formerly studied by an AGARD working group, and (4) an Apollo-geometry entry capsule - relevant to the Crew Exploration Vehicle currently being developed by NASA. In all cases, NO was seeded into the flowfield through tubes inside or attached to the model sting and strut. PLIF was used to visualize the NO in the flowfield. In some cases pure NO was seeded into the flow while in other cases a 5% NO, 95% N2 mix was injected. Several parameters were varied including seeding method and location, seeding mass flow rate, model angle of attack and tunnel stagnation pressure, which varies the unit Reynolds number. The location of the laser sheet was as also varied to provide three dimensional flow information. Virtual Diagnostics Interface (ViDI) technology developed at NASA Langley was used to visualize the data sets in post processing. The measurements demonstrate some of the capabilities of the PLIF method for studying hypersonic flows.

  20. Assessment of relative accuracy of AHN-2 laser scanning data using planar features.

    PubMed

    van der Sande, Corné; Soudarissanane, Sylvie; Khoshelham, Kourosh

    2010-01-01

    AHN-2 is the second part of the Actueel Hoogtebestand Nederland project, which concerns the acquisition of high-resolution altimetry data over the entire Netherlands using airborne laser scanning. The accuracy assessment of laser altimetry data usually relies on comparing corresponding tie elements, often points or lines, in the overlapping strips. This paper proposes a new approach to strip adjustment and accuracy assessment of AHN-2 data by using planar features. In the proposed approach a transformation is estimated between two overlapping strips by minimizing the distances between points in one strip and their corresponding planes in the other. The planes and the corresponding points are extracted in an automated segmentation process. The point-to-plane distances are used as observables in an estimation model, whereby the parameters of a transformation between the two strips and their associated quality measures are estimated. We demonstrate the performance of the method for the accuracy assessment of the AHN-2 dataset over Zeeland province of The Netherlands. The results show vertical offsets of up to 4 cm between the overlapping strips, and horizontal offsets ranging from 2 cm to 34 cm.

  1. Stereoscopic Imaging in Hypersonics Boundary Layers using Planar Laser-Induced Fluorescence

    NASA Technical Reports Server (NTRS)

    Danehy, Paul M.; Bathel, Brett; Inman, Jennifer A.; Alderfer, David W.; Jones, Stephen B.

    2008-01-01

    Stereoscopic time-resolved visualization of three-dimensional structures in a hypersonic flow has been performed for the first time. Nitric Oxide (NO) was seeded into hypersonic boundary layer flows that were designed to transition from laminar to turbulent. A thick laser sheet illuminated and excited the NO, causing spatially-varying fluorescence. Two cameras in a stereoscopic configuration were used to image the fluorescence. The images were processed in a computer visualization environment to provide stereoscopic image pairs. Two methods were used to display these image pairs: a cross-eyed viewing method which can be viewed by naked eyes, and red/blue anaglyphs, which require viewing through red/blue glasses. The images visualized three-dimensional information that would be lost if conventional planar laser-induced fluorescence imaging had been used. Two model configurations were studied in NASA Langley Research Center's 31-Inch Mach 10 Air Wind tunnel. One model was a 10 degree half-angle wedge containing a small protuberance to force the flow to transition. The other model was a 1/3-scale, truncated Hyper-X forebody model with blowing through a series of holes to force the boundary layer flow to transition to turbulence. In the former case, low flowrates of pure NO seeded and marked the boundary layer fluid. In the latter, a trace concentration of NO was seeded into the injected N2 gas. The three-dimensional visualizations have an effective time resolution of about 500 ns, which is fast enough to freeze this hypersonic flow. The 512x512 resolution of the resulting images is much higher than high-speed laser-sheet scanning systems with similar time response, which typically measure 10-20 planes.

  2. Planar Laser-Induced Fluorescence Imaging of OH in a Supersonic Combustor Fueled with Ethylene and Methane (Postprint)

    DTIC Science & Technology

    2010-02-01

    the facility is instrumented with multiple pressure taps and thermocouples for evaluating combustor performance. Combustor run times are typically 30...AFRL-RZ-WP-TP-2010-2056 PLANAR LASER-INDUCED FLUORESCENCE IMAGING OF OH IN A SUPERSONIC COMBUSTOR FUELED WITH ETHYLENE AND METHANE...FLUORESCENCE IMAGING OF OH IN A SUPERSONIC COMBUSTOR FUELED WITH ETHYLENE AND METHANE (POSTPRINT) 5a. CONTRACT NUMBER In-house 5b. GRANT NUMBER 5c

  3. Revisiting argon cluster formation in a planar gas jet for high-intensity laser matter interaction

    NASA Astrophysics Data System (ADS)

    Tao, Y.; Hagmeijer, R.; van der Weide, E. T. A.; Bastiaens, H. M. J.; Boller, K.-J.

    2016-04-01

    We determine the size of argon clusters generated with a planar nozzle, based on the optical measurements in conjunction with theoretical modelling. Using a quasi-one dimensional model for the moments of the cluster size distribution, we determine the influence of critical physical assumptions. These refer to the surface tension depending on the presence of thermal equilibrium, the mass density of clusters, and different methods to model the growth rate of the cluster radius. We show that, despite strong variation in the predicted cluster size, , the liquid mass ratio, g, can be determined with high trustworthiness, because g is predicted as being almost independent of the specific model assumptions. Exploiting this observation, we use the calculated value for g to retrieve the cluster size from optical measurements, i.e., calibrated Rayleigh scattering and interferometry. Based on the measurements of the cluster size vs. the nozzle stagnation pressure, we provide a new power law for the prediction of the cluster size in experiments with higher values of the Hagena parameter (Γ*>104 ) . This range is of relevance for experiments on high-intensity laser matter interactions.

  4. Investigation of Gas Seeding for Planar Laser-Induced Fluorescence in Hypersonic Boundary Layers

    NASA Technical Reports Server (NTRS)

    Arisman, C. J.; Johansen, C. T.; Bathel, B. F.; Danehy, P. M.

    2015-01-01

    Numerical simulations of the gas-seeding strategies required for planar laser-induced fluorescence in a Mach 10 (approximately Mach 8.2 postshock) airflow were performed. The work was performed to understand and quantify the adverse effects associated with gas seeding and to assess various types of seed gas that could potentially be used in future experiments. In prior experiments, NO and NO2 were injected through a slot near the leading edge of a flatplate wedge model used in NASA Langley Research Center's 31 in. Mach 10 air tunnel facility. In this paper, nitric oxide, krypton, and iodine gases were simulated at various injection rates. Simulations showing the deflection of the velocity boundary layer for each of the cases are presented. Streamwise distributions of velocity and concentration boundary-layer thicknesses, as well as vertical distributions of velocity, temperature, and mass distributions, are presented for each of the cases. A comparison between simulated streamwise velocity profiles and experimentally obtained molecular tagging velocimetry profiles using a nitric oxide seeding strategy is performed to verify the influence of such a strategy on the boundary layer. The relative merits of the different seeding strategies are discussed. The results from a custom solver based on OpenFOAM version 2.2.1 are compared against results obtained from ANSYS® Fluent version 6.3.

  5. Planar Laser-Induced Iodine Fluorescence Measurements in Rarefied Hypersonic Flow

    NASA Astrophysics Data System (ADS)

    Cecil, Eric; McDaniel, James C.

    2005-05-01

    A planar laser-induced fluorescence (PLIF) technique is discussed and applied to measurement of time-averaged values of velocity and temperature in an I2-seeded N2 hypersonic free jet facility. Using this technique, a low temperature, non-reacting, hypersonic flow over a simplified model of a reaction control system (RCS) was investigated. Data are presented of rarefied Mach 12 flow over a sharp leading edge flat plate at zero incidence, both with and without an interacting jet issuing from a nozzle built into the plate. The velocity profile in the boundary layer on the plate was resolved. The slip velocity along the plate, extrapolated from the velocity profile data, varied from nearly 100% down to 10% of the freestream value. These measurements are compared with results of a DSMC solution. The velocity variation along the centerline of a jet issuing from the plate was measured and found to match closely with the correlation of Ashkenas and Sherman. The velocity variation in the oblique shock terminating the jet was resolved sufficiently to measure the shock wave thickness.

  6. Planar Laser-Induced Iodine Fluorescence Measurements in Rarefied Hypersonic Flow

    NASA Technical Reports Server (NTRS)

    Cecil, Eric; McDaniel, James C.

    2005-01-01

    A planar laser-induced fluorescence (PLIF) technique is discussed and applied to measurement of time-averaged values of velocity and temperature in an I(sub 2)-seeded N(sub 2) hypersonic free jet facility. Using this technique, a low temperature, non-reacting, hypersonic flow over a simplified model of a reaction control system (RCS) was investigated. Data are presented of rarefied Mach 12 flow over a sharp leading edge flat plate at zero incidence, both with and without an interacting jet issuing from a nozzle built into the plate. The velocity profile in the boundary layer on the plate was resolved. The slip velocity along the plate, extrapolated from the velocity profile data, varied from nearly 100% down to 10% of the freestream value. These measurements are compared with results of a DSMC solution. The velocity variation along the centerline of a jet issuing from the plate was measured and found to match closely with the correlation of Ashkenas and Sherman. The velocity variation in the oblique shock terminating the jet was resolved sufficiently to measure the shock wave thickness.

  7. Planar laser-induced fluorescence imaging of flame heat release rate

    SciTech Connect

    Paul, P.H.; Najm, H.N.

    1997-12-12

    Local heat release rate represents one of the most interesting experimental observables in the study of unsteady reacting flows. The direct measure of burning or heat release rate as a field variable is not possible. Numerous experimental investigations have relied on inferring this type of information as well as flame front topology from indirect measures which are presumed to be correlated. A recent study has brought into question many of the commonly used flame front marker and burning rate diagnostics. This same study found that the concentration of formyl radical offers the best possibility for measuring flame burning rate. However, primarily due to low concentrations, the fluorescence signal level from formyl is too weak to employ this diagnostic for single-pulse measurements of turbulent reacting flows. In this paper the authors describe and demonstrate a new fluorescence-based reaction front imaging diagnostic suitable for single-shot applications. The measurement is based on taking the pixel-by-pixel product of OH and CH{sub 2}O planar laser-induced fluorescence images to yield an image closely related to a reaction rate. The spectroscopic and collisional processes affecting the measured signals are discussed and the foundation of the diagnostic, as based on laminar and unsteady flame calculations, is presented. The authors report the results of applying this diagnostic to the study of a laminar premixed flame subject to an interaction with an isolated line-vortex pair.

  8. Refractive Index Matching for Planar Laser-Induced Fluorescence Imaging of Fluid Mixing in Porous Media

    NASA Astrophysics Data System (ADS)

    Roth, E. J.; Tigera, R. G.; Crimaldi, J. P.; Mays, D. C.

    2015-12-01

    Research in porous media is often hampered by the difficulty in making pore-scale observations. By selecting porous media that is refractive index matched (RIM) to the pore fluid, the media becomes transparent. This allows optical imaging techniques such as static light scattering (SLS), dynamic light scattering (DLS), confocal microscopy, and planar laser-induced fluorescence (PLIF) to be employed. RIM is particularly useful for research concerning contaminant remediation in the subsurface, permitting visual observation of plume dynamics at the pore scale. The goal of this research is to explore and assess candidate combinations of porous media, fluid, and fluorescent dye. The strengths and weaknesses of each combination will then be evaluated in terms of safety, cost, and optical quality in order to select the best combination for use with PLIF. Within this framework, top-ranked RIM combinations include Pyrex glass beads, water beads, or granular Nafion saturated in vegetable glycerin, deionized water, and an aqueous solution of 48% isopropanol, respectively. This research lays the groundwork for future efforts to build a flow chamber in which the selected RIM porous media, solution, and dye will be used in evaluating subsurface pumping strategies designed to impose chaotic plume spreading in porous media. Though the RIM porous media explored in this research are selected based on the specifications of a particular experiment, the methods developed for working with and evaluating RIM porous media should be of utility to a wide variety of research interests.

  9. Analysis of multiple scattering suppression using structured laser illumination planar imaging in scattering and fluorescing media.

    PubMed

    Kristensson, E; Araneo, L; Berrocal, E; Manin, J; Richter, M; Aldén, M; Linne, M

    2011-07-04

    The accuracy, precision and limitations of the imaging technique named Structured Laser Illumination Planar Imaging (SLIPI) have been investigated. SLIPI, which allows multiply scattered light to be diminished, has previously demonstrated improvements in image quality and contrast for spray imaging. In the current study the method is applied to a controlled confined environment consisting of a mixture of water and monodisperse polystyrene microspheres. Elastic scattering and fluorescence are studied and the results obtained when probing different particle concentrations and diameters conclusively show the advantages of SLIPI for imaging within moderately turbid media. Although the technique presents both good repeatability and agreement with the Beer-Lambert law, discrepancies in its performance were, however, discovered. Photons undergoing scattering without changing their incident trajectory cannot be discriminated and, owing to differences in scattering phase functions, probing larger particles reduces the suppression of multiply scattered light. However, in terms of visibility such behavior is beneficial as it allows denser media to be probed. It is further demonstrated that the suppression of diffuse light performs equally well regardless of whether photons propagate along the incident direction or towards the camera. In addition, this filtering process acts independently on the spatial distribution of the multiply scattered light but is limited by the finite dynamic range and unavoidable signal noise of the camera.

  10. Planar Rayleigh scattering and laser-induced fluorescence for visualization of a hot, Mach 2 annular air jet

    NASA Technical Reports Server (NTRS)

    Balla, R. Jeffrey

    1994-01-01

    Planar Rayleigh scattering (PRS) and planar laser-induced fluorescence (PLIF) were used to investigate the vitiated air component of a coaxial hydrogen/vitiated air nonpremixed turbulent jet flame that is ejected at a Mach number of 2. All experiments were performed with a xenon chloride tunable excimer laser. Planar information for both techniques was obtained using laser sheets 6 cm high, 5 cm wide, and 300 micron thick. In this flow field, the effective Rayleigh cross section of the components in the vitiated air was assumed to be independent of composition. Therefore, the PRS technique produced signals which were proportional to total density. When the flow field was assumed to be at a known and uniform pressure, the PRS signal data for the vitiated air could be converted to temperature information. Also, PLIF images were generated by probing the OH molecule. These images contain striation patterns attributed to small localized instantaneous temperature nonuniformities. The results from the PLIF and PRS techniques were used to show that this flow field contains a nongaseous component, most likely liquid water that can be reduced by increasing the settling chamber wall temperature.

  11. Efficient gamma-ray generation by ultra-intense laser pulses obliquely incident on a planar plasma layer

    NASA Astrophysics Data System (ADS)

    Serebryakov, D. A.; Nerush, E. N.

    2016-04-01

    We have carried out numerical simulations of oblique incidence of a laser pulse with an intensity of I = 1.33 × 1023 W cm-2 on a planar plasma layer and found the plasma density and the angle of incidence of p-polarised laser pulses that correspond to the highest gamma-ray generation efficiency and high gamma-ray directivity. The shape of the plasma surface has been determined by simulation and conditions have been considered that lead to an increase in generation efficiency.

  12. Planar-waveguide external cavity laser stabilization for an optical link with 10(-19) frequency stability.

    PubMed

    Clivati, Cecilia; Mura, Alberto; Calonico, Davide; Levi, Filippo; Costanzo, Giovanni A; Calosso, Claudio E; Godone, Aldo

    2011-12-01

    We stabilized the frequency of a compact planar-waveguide external cavity laser (ECL) on a Fabry-Perot cavity (FPC) through a Pound-Drever-Hall scheme. The residual frequency stability of the ECL is 10(-14), comparable to the stability achievable with a fiber laser (FL) locked to an FPC through the same scheme. We set up an optical link of 100 km, based on fiber spools, that reaches 10(-19) relative stability, and we show that its performances using the ECL or FL are comparable. Thus ECLs could serve as an excellent replacement for FLs in optical links where cost-effectiveness and robustness are important considerations.

  13. Fourier-Space Nonlinear Rayleigh-Taylor Growth Measurements of 3D Laser-Imprinted Modulations in Planar Targets

    SciTech Connect

    Smalyuk, V.A.; Sadot, O.; Delettrez, J.A.; Meyerhofer, D.D.; Regan, S.P.; Sangster, T.C.

    2005-12-05

    Nonlinear growth of 3-D broadband nonuniformities was measured near saturation levels using x-ray radiography in planar foils accelerated by laser light. The initial target modulations were seeded by laser nonuniformities and later amplified during acceleration by Rayleigh-Taylor instability. The nonlinear saturation velocities are measured for the first time and are found to be in excellent agreement with Haan predictions. The measured growth of long-wavelength modes is consistent with enhanced, nonlinear, long-wavelength generation in ablatively driven targets.

  14. Planarized process for resonant leaky-wave coupled phase-locked arrays of mid-IR quantum cascade lasers

    NASA Astrophysics Data System (ADS)

    Chang, C.-C.; Kirch, J. D.; Boyle, C.; Sigler, C.; Mawst, L. J.; Botez, D.; Zutter, B.; Buelow, P.; Schulte, K.; Kuech, T.; Earles, T.

    2015-03-01

    On-chip resonant leaky-wave coupling of quantum cascade lasers (QCLs) emitting at 8.36 μm has been realized by selective regrowth of interelement layers in curved trenches, defined by dry and wet etching. The fabricated structure provides large index steps (Δn = 0.10) between antiguided-array element and interelement regions. In-phase-mode operation to 5.5 W front-facet emitted power in a near-diffraction-limited far-field beam pattern, with 4.5 W in the main lobe, is demonstrated. A refined fabrication process has been developed to produce phased-locked antiguided arrays of QCLs with planar geometry. The main fabrication steps in this process include non-selective regrowth of Fe:InP in interelement trenches, defined by inductive-coupled plasma (ICP) etching, a chemical polishing (CP) step to planarize the surface, non-selective regrowth of interelement layers, ICP selective etching of interelement layers, and non-selective regrowth of InP cladding layer followed by another CP step to form the element regions. This new process results in planar InGaAs/InP interelement regions, which allows for significantly improved control over the array geometry and the dimensions of element and interelement regions. Such a planar process is highly desirable to realize shorter emitting wavelength (4.6 μm) arrays, where fabrication tolerance for single-mode operation are tighter compared to 8 μm-emitting devices.

  15. The development of kilohertz planar laser diagnostics for applications in high power turbulent flames

    NASA Astrophysics Data System (ADS)

    Slabaugh, Carson Daniel

    In modern gas-turbine combustors, flame stabilization is achieved by inducing exhaust gas circulation within the flame zone through swirl-induced vortex breakdown. Swirling flows exhibit strong shear regions resulting in high turbulence and effective mixing. In combustion, these flows are characterized by complex unsteady interactions between turbulent flow structures and chemical reactions. Developments in high-resolution, quantitative, experimental measurement techniques must continue to improve fundamental understanding and support modeling efforts. This work describes the development of a gas turbine combustion experiment to support the application of advanced optical measurement techniques in flames operating at realistic engine conditions. Facility requirements are addressed, including instrumentation and control needs for remote operation when working with high energy flows. The methodology employed in the design of the optically-accessible combustion chamber is elucidated, including window considerations and thermal management of the experimental hardware under extremely high heat loads. Experimental uncertainties are also quantified. The stable operation of the experiment is validated using multiple techniques and the boundary conditions are verified. The successful prediction of operating conditions by the design analysis is documented and preliminary data is shown to demonstrate the capability of the experiment to produce high-fidelity datasets for advanced combustion research. Building on this experimental infrastructure, simultaneous measurements of velocity and scalar fields were performed in turbulent nonpremixed flames at gas turbine engine operating conditions using 5 kHz Particle-Image Velocimetry (PIV) and OH Planar Laser Induced Fluorescence (OH-PLIF). The experimental systems and the challenges associated with acquiring useful data at high pressures and high thermal powers are discussed. The quality of the particle scattering images used in the

  16. Automatic Registration of Terrestrial Laser Scanner Point Clouds Using Natural Planar Surfaces

    NASA Astrophysics Data System (ADS)

    Theiler, P. W.; Schindler, K.

    2012-07-01

    Terrestrial laser scanners have become a standard piece of surveying equipment, used in diverse fields like geomatics, manufacturing and medicine. However, the processing of today's large point clouds is time-consuming, cumbersome and not automated enough. A basic step of post-processing is the registration of scans from different viewpoints. At present this is still done using artificial targets or tie points, mostly by manual clicking. The aim of this registration step is a coarse alignment, which can then be improved with the existing algorithm for fine registration. The focus of this paper is to provide such a coarse registration in a fully automatic fashion, and without placing any target objects in the scene. The basic idea is to use virtual tie points generated by intersecting planar surfaces in the scene. Such planes are detected in the data with RANSAC and optimally fitted using least squares estimation. Due to the huge amount of recorded points, planes can be determined very accurately, resulting in well-defined tie points. Given two sets of potential tie points recovered in two different scans, registration is performed by searching for the assignment which preserves the geometric configuration of the largest possible subset of all tie points. Since exhaustive search over all possible assignments is intractable even for moderate numbers of points, the search is guided by matching individual pairs of tie points with the help of a novel descriptor based on the properties of a point's parent planes. Experiments show that the proposed method is able to successfully coarse register TLS point clouds without the need for artificial targets.

  17. Recombination emissions and spectral blueshift of pump radiation from ultrafast laser induced plasma in a planar water microjet

    NASA Astrophysics Data System (ADS)

    Anija, M.; Philip, Reji

    2009-09-01

    We report spectroscopic investigations of an ultrafast laser induced plasma generated in a planar water microjet. Plasma recombination emissions along with the spectral blueshift and broadening of the pump laser pulse contribute to the total emission. The laser pulses are of 100 fs duration, and the incident intensity is around 10 15 W/cm 2. The dominant mechanisms leading to plasma formation are optical tunnel ionization and collisional ionization. Spectrally resolved polarization measurements show that the high frequency region of the emission is unpolarized whereas the low frequency region is polarized. Results indicate that at lower input intensities the emission arises mainly from plasma recombinations, which is accompanied by a weak blueshift of the incident laser pulse. At higher input intensities strong recombination emissions are seen, along with a broadening and asymmetric spectral blueshift of the pump laser pulse. From the nature of the blueshifted laser pulse it is possible to deduce whether the rate of change of free electron density is a constant or variable within the pulse lifetime. Two input laser intensity regimes, in which collisional and tunnel ionizations are dominant respectively, have been thus identified.

  18. All-diode-pumped quasi-continuous burst-mode laser for extended high-speed planar imaging.

    PubMed

    Slipchenko, Mikhail N; Miller, Joseph D; Roy, Sukesh; Gord, James R; Meyer, Terrence R

    2013-01-14

    An all-diode-pumped, multistage Nd:YAG amplifier is investigated as a means of extending the duration of high-power, burst-mode laser pulse sequences to an unprecedented 30 ms or more. The laser generates 120 mJ per pulse at 1064.3 nm with a repetition rate of 10 kHz, which is sufficient for a wide range of planar laser diagnostics based on fluorescence, Raman scattering, and Rayleigh scattering, among others. The utility of the technique is evaluated for image sequences of formaldehyde fluorescence in a lifted methane-air diffusion flame. The advantages and limitations of diode pumping are discussed, along with long-pulse diode-bar performance characteristics to guide future designs.

  19. Planar measurement of flow field parameters in a nonreacting supersonic combustor using laser-induced iodine fluorescence

    NASA Technical Reports Server (NTRS)

    Hartfield, Roy J., Jr.; Hollo, Steven D.; Mcdaniel, James C.

    1990-01-01

    A nonintrusive optical technique, laser-induced iodine fluorescence, has been used to obtain planar measurements of flow field parameters in the supersonic mixing flow field of a nonreacting supersonic combustor. The combustor design used in this work was configured with staged transverse sonic injection behind a rearward-facing step into a Mach 2.07 free stream. A set of spatially resolved measurements of temperature and injectant mole fraction has been generated. These measurements provide an extensive and accurate experimental data set required for the validation of computational fluid dynamic codes developed for the calculation of highly three-dimensional combustor flow fields.

  20. Oxygen-implanted optical planar waveguides in Er/Yb-codoped silicate glasses for integrated laser generation

    NASA Astrophysics Data System (ADS)

    Liu, Chun-Xiao; Xu, Jun; Xu, Xiao-Li; Wu, Shu; Wei, Wei; Guo, Hai-Tao; Li, Wei-Nan; Peng, Bo

    2014-03-01

    Er3+/Yb3+-codoped silicate glasses are good candidates for the application of laser actions and signal amplification. Optical planar waveguides in Er/Yb-codoped silicate glasses are fabricated by 6.0-MeV oxygen-ion implantation with a dose of 6.0×1014 ions/cm2 at room temperature. The SRIM 2010 code is carried out to simulate the energy losses during the implantation process in order to obtain a better understanding of the waveguide formation. The guiding modes and near-field intensity distributions of the waveguide are characterized by the prism-coupling and end-face coupling methods. The refractive index profile and light propagation mode of the planar waveguide are numerically calculated by the reflectivity calculation method and finite difference beam propagation method. The waveguide has a "well+barrier" refractive index distribution and its optical loss is ˜1.02 dB/cm. The microluminescence and absorption investigation reveal that fluorescent and transmission properties in the waveguide are well preserved with respect to the bulk, suggesting promising potential for waveguide amplifiers and lasers.

  1. Three-dimensional and nonlinear analysis of efficiency enhancement in the E × B drifting electron laser with a prebunched electron beam and a planar wiggler

    NASA Astrophysics Data System (ADS)

    Maraghechi, B.; Jokar, M.; Bahman, F. Jafari; Naeimabadi, A.; Naeimabadi

    2013-10-01

    A nonlinear simulation of the E × B drifting electron laser (DEL) and the free-electron laser (FEL), in three dimensions, is presented for a prebunched electron beam to study efficiency enhancement. For the planar wiggler with flat pole faces, prebunching considerably shortens the saturation length, which favors the DEL compared to the FEL. Operation of the DEL with the planar wiggler with parabolic pole faces was not found to be possible due to the modulation of the E × B drift by the wiggler. However, simulation results of the FEL with this type of wiggler are reported.

  2. Planar waveguide solar concentrator with couplers fabricated by laser-induced backside wet etching

    NASA Astrophysics Data System (ADS)

    Zhang, Nikai

    Solar radiation can be converted directly into electricity by using the photovoltaic effect, which represents the principle of operation of solar cells. Currently, most solar cells are made of crystalline silicon and have a conversion efficiency of about 20% or less. Multi-junction solar cells, made of III-V compound semiconductors, can have efficiencies in excess of 40%. The main factor that prohibits such high-efficiency technologies from wider acceptance is the cost. An alternative approach to using large-area expensive solar cells is to employ lower cost optics and concentrate the solar radiation to smaller cell area, which is the basic principle of solar concentrators. In this thesis, we consider a solar concentrator module that consists of a combination of a lens array and a slab waveguide with etched conical holes on one side of the waveguide, which are aligned with the lenslets. Sunlight coming through each of these lenslets is focused on the backside of the waveguide, where a coupling structure (an etched cone) is fabricated. This coupler changes the propagation direction of the incident light in such a way that light is guided through total internal reflection (TIR) within the glass slab and eventually reaches a solar cell, which is properly mounted on the side of the slab. The concept of this concentrated photovoltaic (CPV) system is based on a planar light guide solar concentrator module, proposed earlier by another group. This project builds on the original idea by including the following substantial modifications. The lens array is to be made of solid glass by a mold technology and provided to us by our industrial partner, Libbey, Inc., as opposed to silicone on glass technology, in which the lenses are made out of silicone and sit on a glass substrate. The coupling structures are cone-shaped holes etched directly into the solid glass waveguide, as opposed to coupling structures that are formed by addition of polymeric layer and consequent patterning

  3. Planar Laser-Plasma Interaction Experiments at Direct-Drive Ignition-Relevant Scale Lengths at the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Rosenberg, M. J.; Solodov, A. A.; Seka, W.; Myatt, J. F.; Regan, S. P.; Hohenberger, M.; Epstein, R.; Froula, D. H.; Radha, P. B.; Michel, P. A.; Moody, J. D.; Masse, L.; Goyon, C.; Turnbull, D. P.; Barrios, M. A.; Bates, J. W.; Schmitt, A. J.

    2016-10-01

    The first experiments at the National Ignition Facility to probe laser-plasma interactions and the hot electron production at scale lengths relevant to direct-drive ignition are reported. The irradiation on one side of planar CH foils generated a plasma at the quarter-critical surface with predicted density scale lengths of Ln 600 μm, measured electron temperatures of Te 3.5 to 4.0 keV, and overlapped laser intensities of I 6 to 15 ×1014W/cm2. Optical emission from stimulated Raman scattering (SRS) and at ω/2 are correlated with the time-dependent hard x-ray signal. The fraction of laser energy converted to hot electrons increased from 0.5 % to 2.3 % as the laser intensity increased from 6 to 15 ×1014W/cm2, while the hot electron temperature was nearly constant around 40 to 50 keV. Only a sharp red-shifted feature is observed around ω/2, and both refracted and sidescattered SRS are detected, suggesting that multibeam SRS contributes to, and may even dominate, hot-electron production. These results imply a diminished presence of two-plasmon decay relative to SRS at these conditions, which has implications for hot-electron preheat mitigation strategies for direct-drive ignition. This work is supported by the DOE NNSA under Award Number DE-NA0001944.

  4. Assessment of planar liquid-laser-induced fluorescence measurements for spray mass distributions of like-doublet injectors

    NASA Astrophysics Data System (ADS)

    Jung, Kihoon; Koh, Hyeonseok; Yoon, Youngbin

    2003-08-01

    The planar liquid-laser-induced fluorescence (PLLIF) technique has been known to be a useful tool for the measurement of the spray mass distributions for various spray injectors because it can obtain two-dimensional images with high spatial resolutions without any intrusion on the spray field. In the cases of dense sprays, however, it has been known that the extinctions of the incident laser beam or fluorescence signal and the secondary emission can cause errors in quantifying the spray mass distributions. Since a like-doublet injector, which is commonly used in liquid rocket engines, has a locally concentrated spray zone at the spray centre, we investigated the applicability of the PLLIF technique for this injector. From the experimental results, we found out that the extinctions of the incident laser beam and fluorescence signal are not significant because the concentrated spray zone is narrow. Also, we found out an optimal incident laser power which can avoid a nonlinear increase of fluorescence signal at the spray centre as well as obtain a high signal-to-noise ratio, and we measured the spray mass concentration of the like-doublet injector spray using the optimal laser power. In order to assess the accuracy of the PLLIF data, we converted the spray mass concentration into the mass flux distribution and compared it with the data obtained by a mechanical patternator and phase Doppler particle analyser. From the result that the PLLIF data showed good agreement with those of the mechanical patternator, we concluded that the PLLIF technique can be successfully applied to measuring the mass distributions of the like-doublet injectors.

  5. 20 kHz toluene planar laser-induced fluorescence imaging of a jet in nearly sonic crossflow

    NASA Astrophysics Data System (ADS)

    Miller, V. A.; Troutman, V. A.; Mungal, M. G.; Hanson, R. K.

    2014-10-01

    This manuscript describes continuous, high-repetition-rate (20 kHz) toluene planar laser-induced fluorescence (PLIF) imaging in an expansion tube impulse flow facility. Cinematographic image sequences are acquired that visualize an underexpanded jet of hydrogen in Mach 0.9 crossflow, a practical flow configuration relevant to aerospace propulsion systems. The freestream gas is nitrogen seeded with toluene; toluene broadly absorbs and fluoresces in the ultraviolet, and the relatively high quantum yield of toluene produces large signals and high signal-to-noise ratios. Toluene is excited using a commercially available, frequency-quadrupled (266 nm), high-repetition-rate (20 kHz), pulsed (0.8-0.9 mJ per pulse), diode-pumped solid-state Nd:YAG laser, and fluorescence is imaged with a high-repetition-rate intensifier and CMOS camera. The resulting PLIF movie and image sequences are presented, visualizing the jet start-up process and the dynamics of the jet in crossflow; the freestream duration and a measure of freestream momentum flux steadiness are also inferred. This work demonstrates progress toward continuous PLIF imaging of practical flow systems in impulse facilities at kHz acquisition rates using practical, turn-key, high-speed laser and imaging systems.

  6. Planar laser-induced fluorescence imaging of OH in the exhaust of a bi-propellant thruster

    NASA Technical Reports Server (NTRS)

    Paul, Phillip H.; Clemens, N. T.; Makel, D. B.

    1992-01-01

    Planar laser-induced fluorescence imaging of the hydroxyl radical has been performed on the flow produced by the exhaust of a subscale H2/O2 fueled bi-propellant rocket engine. Measurements were made to test the feasibility of OH (0,0) and (3,0) excitation strategies by using injection seeded XeCl and KrF excimer lasers, respectively. The flow is produced with hydrogen and oxygen reacting at a combustor chamber pressure of 5 atm which then exhausts to the ambient. The hydroxyl concentration in the exhaust flow is approximately 8 percent. Fluorescence images obtained by pumping the Q1(3) transition in the (0,0) band exhibited very high signals but also showed the effect of laser beam absorption. To obtain images when pumping the P1(8) transition in the (3,0) band it was necessary to use exceptionally fast imaging optics and unacceptably high intensifier gains. The result was single-shot images which displayed a signal-to-noise ratio of order unity or less when measured on a per pixel basis.

  7. Measurements and modeling of mid- and high-Z coronal plasmas from laser-irradiated planar foils

    NASA Astrophysics Data System (ADS)

    Fein, Jeffrey; Trantham, Matt; Frank, Yechiel; Raicher, Erez; Fraenkel, Moshe; Holloway, James P.; Keiter, Paul; Shvarts, Dov; Drake, R. Paul

    2016-10-01

    Plasmas generated from mid- to high-Z elements with intense (1015 W/cm2) lasers have applications as x-ray drive for indirect-drive fusion, as means to mitigate laser-plasma instabilities in direct-drive fusion, and as bright sources of x-rays for imaging dense plasmas. However, modeling of these plasmas is difficult due to the wide range of densities and temperatures present, and the resulting wide range of physical processes that determine their energetics. Measurements of electron density profiles from irradiated planar foils show a shortening gradient length scale when increasing the foil material Z. We present analytical models and Rad-Hydro simulations to assess the role of Z-dependent processes, such as distributed laser absorption and nLTE atomic physics in determining the observed profiles. Supported through the NNSA-DS and SC-OFES Joint Program in HED Laboratory Plasmas, by Grant Number DE-NA0002956, the NLUF Grant Number DE-NA0002719, by the DTRA, Grant Number DTRA-1-10-0077 and by the NSF Graduate Research Fellowship.

  8. Fiber-Coupled Planar Light-Wave Circuit for Seed Laser Control in High Spectral Resolution Lidar Systems

    NASA Technical Reports Server (NTRS)

    Cook, Anthony; McNeil, Shirley; Switzer, Gregg; Battle, Philip

    2010-01-01

    Precise laser remote sensing of aerosol extinction and backscatter in the atmosphere requires a high-power, pulsed, frequency doubled Nd:YAG laser that is wavelength- stabilized to a narrow absorption line such as found in iodine vapor. One method for precise wavelength control is to injection seed the Nd:YAG laser with a low-power CW laser that is stabilized by frequency converting a fraction of the beam to 532 nm, and to actively frequency-lock it to an iodine vapor absorption line. While the feasibility of this approach has been demonstrated using bulk optics in NASA Langley s Airborne High Spectral Resolution Lidar (HSRL) program, an ideal, lower cost solution is to develop an all-waveguide, frequency-locked seed laser in a compact, robust package that will withstand the temperature, shock, and vibration levels associated with airborne and space-based remote sensing platforms. A key technology leading to this miniaturization is the integration of an efficient waveguide frequency doubling element, and a low-voltage phase modulation element into a single, monolithic, planar light-wave circuit (PLC). The PLC concept advances NASA's future lidar systems due to its compact, efficient and reliable design, thus enabling use on small aircraft and satellites. The immediate application for this technology is targeted for NASA Langley's HSRL system for aerosol and cloud characterization. This Phase I effort proposes the development of a potassium titanyl phosphate (KTP) waveguide phase modulator for future integration into a PLC. For this innovation, the proposed device is the integration of a waveguide-based frequency doubler and phase modulator in a single, fiber pigtail device that will be capable of efficient second harmonic generation of 1,064-nm light and subsequent phase modulation of the 532 nm light at 250 MHz, providing a properly spectrally formatted beam for HSRL s seed laser locking system. Fabrication of the integrated PLC chip for NASA Langley, planned for

  9. MHz-rate nitric oxide planar laser-induced fluorescence imaging in a Mach 10 hypersonic wind tunnel.

    PubMed

    Jiang, Naibo; Webster, Matthew; Lempert, Walter R; Miller, Joseph D; Meyer, Terrence R; Ivey, Christopher B; Danehy, Paul M

    2011-02-01

    Nitric oxide planar laser-induced fluorescence (NO PLIF) imaging at repetition rates as high as 1 MHz is demonstrated in the NASA Langley 31 in. Mach 10 hypersonic wind tunnel. Approximately 200 time-correlated image sequences of between 10 and 20 individual frames were obtained over eight days of wind tunnel testing spanning two entries in March and September of 2009. The image sequences presented were obtained from the boundary layer of a 20° flat plate model, in which transition was induced using a variety of different shaped protuberances, including a cylinder and a triangle. The high-speed image sequences captured a variety of laminar and transitional flow phenomena, ranging from mostly laminar flow, typically at a lower Reynolds number and/or in the near wall region of the model, to highly transitional flow in which the temporal evolution and progression of characteristic streak instabilities and/or corkscrew-shaped vortices could be clearly identified.

  10. Advanced optical diagnostics of multiphase combustion flow field using OH planar laser-induced fluorescence

    NASA Astrophysics Data System (ADS)

    Cho, Kevin Young-jin

    High-repetition-rate (5 kHz, 10 kHz) OH planar laser induced fluorescence (PLIF) was used to investigate the combustion of liquid, gelled, and solid propellants. For the liquid monomethyl hydrazine (MMH) droplet combustion experiment in N2O/N2 using 5 kHz OH PLIF and visible imaging system, the OH profile and the droplet diameter were measured. The N2O partial pressure was varied by 20% and 40%, and the total pressure was varied by 103, 172, 276, 414, 552 kPa. The OH location indicated that the oxidation flame front is between the visible dual flame fronts. The results showed thicker flame sheet and higher burning rate for increased N2O concentration for a given pressure. The burning rate increased with increased pressure at 20% partial pressure N2O, and the burning rate decreased with increased pressure at 40% partial pressure N2O. This work provides experimental data for validating chemical kinetics models. For the gelled droplet combustion experiment using a 5 kHz OH PLIF system, speeds and locations of fuel jets emanating from the burning gelled droplets were quantified for the first time. MMH was gelled with organic gellant HPC at 3 wt.% and 6 wt.%, and burned in air at 35, 103, 172, 276, and 414 kPa. Different types of interaction of vapor jets and flame front were distinguished for the first time. For high jet speed, local extinction of the flame was observed. By analyzing the jet speed statistics, it was concluded that pressure and jet speed had an inverse relationship and gellant concentration and jet speed had a direct relationship. This work provides more fundamental insight into the physics of gelled fuel droplet combustion. A 3D OH PLIF system was assembled and demonstrated using a 10 kHz OH PLIF system and a galvanometric scanning mirror. This is the first time that a reacting flow field was imaged with a 3D optical technique using OH PLIF. A 3D scan time of 1 ms was achieved, with ten slices generated per sweep with 1000 Hz scan rate. Alternatively

  11. OH Planar Laser Induced Fluorescence (PLIF) Measurements for the Study of High Pressure Flames: An Evaluation of a New Laser and a New Camera System

    NASA Technical Reports Server (NTRS)

    Tedder, Sarah; Hicks, Yolanda

    2012-01-01

    Planar laser induced fluorescence (PLIF) is used by the Combustion Branch at the NASA Glenn Research Center (NASA Glenn) to assess the characteristics of the flowfield produced by aircraft fuel injectors. To improve and expand the capabilities of the PLIF system new equipment was installed. The new capabilities of the modified PLIF system are assessed by collecting OH PLIF in a methane/air flame produced by a flat flame burner. Specifically, the modifications characterized are the addition of an injection seeder to a Nd:YAG laser pumping an optical parametric oscillator (OPO) and the use of a new camera with an interline CCD. OH fluorescence results using the injection seeded OPO laser are compared to results using a Nd:YAG pumped dye laser with ultraviolet extender (UVX). Best settings of the new camera for maximum detection of PLIF signal are reported for the controller gain and microchannel plate (MCP) bracket pulsing. Results are also reported from tests of the Dual Image Feature (DIF) mode of the new camera which allows image pairs to be acquired in rapid succession. This allows acquisition of a PLIF image and a background signal almost simultaneously. Saturation effects in the new camera were also investigated and are reported.

  12. Densification behavior, doping profile and planar waveguide laser performance of the tape casting YAG/Nd:YAG/YAG ceramics

    NASA Astrophysics Data System (ADS)

    Ge, Lin; Li, Jiang; Qu, Haiyun; Wang, Juntao; Liu, Jiao; Dai, Jiawei; Zhou, Zhiwei; Liu, Binglong; Kou, Huamin; Shi, Yun; Wang, Zheng; Pan, Yubai; Gao, Qingsong; Guo, Jingkun

    2016-10-01

    The sintering behavior and doping concentration profile of the planar waveguide YAG/Nd:YAG/YAG ceramics by the tape casting and solid-state reaction method were investigated on the basis of densification trajectory, microstructure evolution, and Nd3+ ions diffusion. The porosity of the green body by tape casting and cold isostatic pressing is about 38.6%. And the green bodies were consolidated from 1100 °C to 1800 °C for 0.5-20 h to study the densification and the doping diffusion behaviors. At the temperature higher than 1500 °C, pure YAG phase is formed, followed by the densification and grain growth process. With the increase of temperature, two sintering stages occur, corresponding to remarkable densification and significant grain growth, respectively. The mechanism controlling densification at 1550 °C is grain boundary diffusion. The diffusion of Nd3+ ions is more sensitive to temperature than the sintering time, and the minimum temperature required for the obvious diffusion of Nd3+ ions is higher than 1700 °C. Finally, planar waveguide YAG/1.5 at.%Nd:YAG/YAG transparent ceramics with in-line transmittance of 84.8% at 1064 nm were obtained by vacuum-sintering at 1780 °C for 30 h. The fluorescence lifetime of 4F3/2 state of Nd3+ in the specimen is about 259 μs. The prepared ceramic waveguide was tested in a laser amplifier and the laser pulse was amplificated from 87 mJ to 238 mJ, with the pump energy of 680 mJ.

  13. Planarization of Isolated Defects on ICF Target Capsule Surfaces by Pulsed Laser Ablation

    SciTech Connect

    Alfonso, Noel; Carlson, Lane C.; Bunn, Thomas L.

    2016-08-09

    Demanding surface quality requirements for inertial confinement fusion (ICF) capsules motivated the development of a pulsed laser ablation method to reduce or eliminate undesirable surface defects. The pulsed laser ablation technique takes advantage of a full surface (4π) capsule manipulation system working in combination with an optical profiling (confocal) microscope. Based on the defect topography, the material removal rate, the laser pulse energy and its beam profile, a customized laser raster pattern is derived to remove the defect. The pattern is a table of coordinates and number of pulses that dictate how the defect will be vaporized until its height is level with the capsule surface. This paper explains how the raster patterns are optimized to minimize surface roughness and how surface roughness after laser ablation is simulated. The simulated surfaces are compared with actual ablated surfaces. Large defects are reduced to a size regime where a tumble finishing process produces very high quality surfaces devoid of high mode defects. The combined polishing processes of laser ablation and tumble finishing have become routine fabrication steps for National Ignition Facility capsule production.

  14. Planarization of Isolated Defects on ICF Target Capsule Surfaces by Pulsed Laser Ablation

    DOE PAGES

    Alfonso, Noel; Carlson, Lane C.; Bunn, Thomas L.

    2016-08-09

    Demanding surface quality requirements for inertial confinement fusion (ICF) capsules motivated the development of a pulsed laser ablation method to reduce or eliminate undesirable surface defects. The pulsed laser ablation technique takes advantage of a full surface (4π) capsule manipulation system working in combination with an optical profiling (confocal) microscope. Based on the defect topography, the material removal rate, the laser pulse energy and its beam profile, a customized laser raster pattern is derived to remove the defect. The pattern is a table of coordinates and number of pulses that dictate how the defect will be vaporized until its heightmore » is level with the capsule surface. This paper explains how the raster patterns are optimized to minimize surface roughness and how surface roughness after laser ablation is simulated. The simulated surfaces are compared with actual ablated surfaces. Large defects are reduced to a size regime where a tumble finishing process produces very high quality surfaces devoid of high mode defects. The combined polishing processes of laser ablation and tumble finishing have become routine fabrication steps for National Ignition Facility capsule production.« less

  15. Experimental Assessment and Enhancement of Planar Laser-Induced Fluorescence Measurements of Nitric Oxide in an Inverse Diffusion Flame

    NASA Technical Reports Server (NTRS)

    Partridge, William P.; Laurendeau, Normand M.

    1997-01-01

    We have experimentally assessed the quantitative nature of planar laser-induced fluorescence (PLIF) measurements of NO concentration in a unique atmospheric pressure, laminar, axial inverse diffusion flame (IDF). The PLIF measurements were assessed relative to a two-dimensional array of separate laser saturated fluorescence (LSF) measurements. We demonstrated and evaluated several experimentally-based procedures for enhancing the quantitative nature of PLIF concentration images. Because these experimentally-based PLIF correction schemes require only the ability to make PLIF and LSF measurements, they produce a more broadly applicable PLIF diagnostic compared to numerically-based correction schemes. We experimentally assessed the influence of interferences on both narrow-band and broad-band fluorescence measurements at atmospheric and high pressures. Optimum excitation and detection schemes were determined for the LSF and PLIF measurements. Single-input and multiple-input, experimentally-based PLIF enhancement procedures were developed for application in test environments with both negligible and significant quench-dependent error gradients. Each experimentally-based procedure provides an enhancement of approximately 50% in the quantitative nature of the PLIF measurements, and results in concentration images nominally as quantitative as LSF point measurements. These correction procedures can be applied to other species, including radicals, for which no experimental data are available from which to implement numerically-based PLIF enhancement procedures.

  16. Fiber-coupled, 10 kHz simultaneous OH planar laser-induced fluorescence/particle-image velocimetry.

    PubMed

    Hsu, Paul S; Jiang, Naibo; Gord, James R; Roy, Sukesh

    2013-01-15

    Planar laser-induced fluorescence (PLIF) and particle-image velocimetry (PIV) techniques that employ free-standing optics face severe challenges when implemented in harsh environments associated with practical combustion facilities because of limited optical access and restrictions on operation of sensitive laser systems. To circumvent this problem, we have developed and implemented a fiber-coupled, high-speed ultraviolet (UV) PLIF/PIV system for measuring hydroxyl radical (OH) concentration and velocity in a realistic 4 MW combustion rig. This system permits delivery of high-power, 10 kHz, nanosecond-duration OH-PLIF excitation pulses (283 nm) and PIV pulses (532 nm) through a common 6 m long, 600 μm core, deep-UV-enhanced multimode fiber. Simultaneous OH-PLIF and PIV imaging at a data-acquisition rate of 10 kHz is demonstrated in turbulent premixed flames behind a bluff body. The effects of delivering high-repetition-rate, intense UV and visible beams through a long optical fiber are investigated, and potential system improvements are discussed.

  17. Infrared planar laser-induced fluorescence imaging and applications to imaging of carbon monoxide and carbon dioxide

    NASA Astrophysics Data System (ADS)

    Kirby, Brian James

    This dissertation introduces infrared planar laser- induced fluorescence (IR PLIF) techniques for visualization of species that lack convenient electronic transitions and are therefore unsuitable for more traditional electronic PLIF measurements. IR PLIF measurements can generate high signal levels that scale linearly with both laser energy and species concentration, thereby demonstrating advantages over Raman and multiphoton PLIF techniques. IR PLIF is shown to be a straightforward and effective tool for visualization of CO and CO2 in reactive flows. The slow characteristic times of vibrational relaxation and the large mole fractions of CO and CO2 in typical flows lead to high IR PLIF signal levels, despite the low emission rates typical of vibrational transitions. Analyses of rotational energy transfer (RET) and vibrational energy transfer (VET) show that excitation schemes in either linear (weak) or saturated (strong) limits may be developed, with the fluorescence collected directly from the laser-excited species or indirectly from bath gases in vibrational resonance with the laser-excited species. Use of short (~1 μs) exposures (for CO) or short exposures combined with long-pulse, high-pulse-energy excitation (for CO2) minimizes unwanted signal variation due to spatially-dependent VET rates. Results are presented for flows ranging from room- temperature mixing to a benchmark CH4 laminar diffusion flame. Linear excitation is appropriate for CO due to its slow vibrational relaxation. However, linear excitation is not well-suited for CO2 imaging due to fast H 2O-enhanced VET processes and the attendant difficulty in interpreting the resulting signal. Saturated excitation using a CO2 laser (or combined CO2 laser-OPO) technique is most appropriate for CO 2, as it generates high signal and minimizes spatial variations in fluorescence quantum yield. Since IR PLIF is applicable to most IR-active species, it has a high potential for expanding the diagnostic

  18. Diode laser bonding of planar microfluidic devices, MOEMS, bioMEMS, diagnostic chips, and microarrays

    NASA Astrophysics Data System (ADS)

    Chen, Jie-Wei; Zybko, Jerry M.

    2005-01-01

    The assembly of plastic microfluidic devices, MOEMS and microarrays requiring high positioning and welding accuracy in the micrometer range, has been successfully achieved using a new technology based on laser transmission welding combined with a photolithographic mask technique. This paper reviews a laser assembly platform for the joining of microfluidic plastic parts with its main related process characteristics and its potential for low-cost and high volume manufacturing. The system consists of a of diode laser with a mask and an automated alignment function to generate micro welding seams with freely definable geometries. A fully automated mask alignment system with a resolution of < 2 &mum and a precise, noncontact energy input allows a fast welding of micro structured plastic parts with high reproducibility and excellent welding quality.

  19. Development of the megahertz planar laser-induced fluorescence diagnostic for plasma turbulence visualization

    SciTech Connect

    Kuritsyn, Aleksey; Levinton, Fred M.

    2004-10-01

    A megahertz laser-induced fluorescence-based diagnostic system for measuring ion density fluctuations in two spatial dimensions is described. Well resolved spatial and temporal two-dimensional (2D) images of turbulent structures will be useful in understanding ion turbulence in magnetically confined plasmas which is a key factor in the performance of fusion experimental devices. A sheet beam of a megahertz repetition rate tunable Alexandrite laser is used to excite ion emission from argon plasma. The fluorescence emitted from the plane of the laser beam is detected with a narrow band interference filter and intensified ultrafast charge coupled device camera providing 2D images of relative ion density fluctuations every microsecond. It is expected that the edge plasma on fusion devices will be accessible to this technique.

  20. Fate of acetone in water

    USGS Publications Warehouse

    Rathbun, R.E.; Stephens, D.W.; Shultz, D.J.

    1982-01-01

    The physical, chemical, and biological processes that might affect the concentration of acetone in water were investigated in laboratory studies. Processes considered included volatilization, adsorption by sediments, photodecomposition, bacterial degradation, and absorption by algae and molds. It was concluded that volatilization and bacterial degradation were the dominant processes determining the fate of acetone in streams and rivers. ?? 1982.

  1. Laser-induced fluorescence measurement of the dynamics of a pulsed planar sheath

    SciTech Connect

    Goeckner, M.J.; Malik, S.M. ); Conrad, J.R. ); Breun, R.A. )

    1994-04-01

    Using laser-induced fluorescence (LIF) the ion density near the edge of an expanding plasma sheath has been measured. These measurements utilized a transition of N[sup +][sub 2] [the P12 component of the [ital X] [sup 2][Sigma][sup +][sub [ital g

  2. Recycling of acetone by distillation

    SciTech Connect

    Brennan, D.L.; Campbell, B.A.; Phelan, J.E.; Harper, M.

    1992-09-01

    The Resource Conservation Recovery Act (RCRA) identifies spent acetone solvent as a listed hazardous waste. At Fernald, acetone has been spent that has been contaminated with radionuclides and therefore is identified as a mixed hazardous waste. At the time of this publication there is no available approved method of recycling or disposal of radioactively contaminated spent acetone solvent. The Consent Decree with the Ohio EPA and the Consent Agreement with the United States EPA was agreed upon for the long-term compliant storage of hazardous waste materials. The purpose of this project was to demonstrate the feasibility for safely decontaminating spent acetone to background levels of radioactivity for reuse. It was postulated that through heat distillation, radionuclides could be isolated from the spent acetone.

  3. Laser patterning and preferential orientation of two-dimensional planar {beta}-BaB{sub 2}O{sub 4} crystals on the glass surface

    SciTech Connect

    Suzuki, F.; Ogawa, K.; Honma, T.; Komatsu, T.

    2012-01-15

    The laser-induced crystallization method is applied to pattern two-dimensional planar {beta}-BaB{sub 2}O{sub 4} crystals on the surface of Sm{sub 2}O{sub 3}-BaO-B{sub 2}O{sub 3} glass. By scanning Yb:YVO{sub 4} fiber lasers (wavelength: 1080 nm) continuously with a small step (0.5 {mu}m) between laser irradiated areas, homogeneous planar {beta}-BaB{sub 2}O{sub 4} crystals are patterned successfully, and a preferential growth orientation of {beta}-BaB{sub 2}O{sub 4} crystals is confirmed from linearly polarized micro-Raman scattering spectrum and second harmonic intensity measurements. It is found that the crystal growth direction is perpendicular to the laser scanning direction. This relation, i.e., the perpendicular relation, is different from the behavior in discrete crystal line patterning, where the crystal growth direction is consistent with the laser scanning direction. The present study proposes the possibility of the control of crystal growth direction in laser-induced crystallization in glasses. - Graphical abstract: This figure shows confocal scanning laser microscope and polarized optical microscope photographs for {beta}-BaB{sub 2}O{sub 4} crystals obtained by laser irradiations. The laser scanning was repeated with a step of 0.5 {mu}m between the lines using the condition of the power of P=0.8 W and a laser scanning speed of S=8 {mu}m/s. It is suggested that {beta}-BaB{sub 2}O{sub 4} crystals in the overlapped laser-irradiated region are highly oriented and the c-axis direction of {beta}-BaB{sub 2}O{sub 4} crystals is perpendicular to the laser scanning direction. Highlights: Black-Right-Pointing-Pointer Laser-induced crystallization method is applied to pattern {beta}-BaB{sub 2}O{sub 4} crystals. Black-Right-Pointing-Pointer Two-dimensional planar crystals are patterned on the glass surface. Black-Right-Pointing-Pointer Preferential growth orientation of {beta}-BaB{sub 2}O{sub 4} crystals is confirmed. Black-Right-Pointing-Pointer Crystal growth

  4. Development of the Megahertz Planar Laser-induced Fluorescence Diagnostic for Plasma Turbulence Visualization

    SciTech Connect

    Aleksey Kuritsyn; Fred M. Levinton

    2004-04-27

    A megahertz LIF-based diagnostic system for measuring ion density fluctuations in two spatial dimensions is described. Well resolved spatial and temporal 2D images of turbulent structures will be useful in understanding ion turbulence in magnetically confined plasmas which is a key factor in the performance of fusion experimental devices. A sheet beam of a megahertz repetition rate tunable Alexandrite laser is used to excite ion emission from argon plasma. The fluorescence emitted from the plane of the laser beam is detected with a narrow band interference filter and intensified ultra-fast CCD camera providing 2D images of relative ion density fluctuations every microsecond. It is expected that the edge plasma on fusion devices will be accessible to this technique.

  5. Detailed energy distributions in laser-produced plasmas of solid gold and foam gold planar targets

    SciTech Connect

    Dong, Yunsong; Zhang, Lu; Yang, Jiamin; Shang, Wanli

    2013-12-15

    Foam gold was proposed to increase the laser to x-ray conversion efficiency due to its important applications. To understand the mechanism of x-ray enhancement, the detailed energy distributions and plasma profiles for laser-irradiated solid gold and foam gold targets were studied comparatively by hydrodynamic simulations using the code Multi-1D. It is confirmed that the radiation heat wave is subsonic for the normal solid gold target, while supersonic for the foam gold target. The shock wave, which is behind the supersonic radiation heat wave for the foam gold target, generates a plasma temperature gradient with high temperature near the shock wave front to produce an additional net outward radiation for enhancement of the x-ray emission. Much larger inward plasma velocity is also driven by the shock wave as an initial plasma velocity for the laser deposition and electron thermal conduct zone, which decreases the expanding plasma kinetic energy loss and helps to increase the x-ray radiation.

  6. Continuous-wave and Q-switched operation of a compact, diode-pumped Yb3+:KY(WO4)2 planar waveguide laser.

    PubMed

    Bain, F M; Lagatsky, A A; Kurilchick, S V; Kisel, V E; Guretsky, S A; Luginets, A M; Kalanda, N A; Kolesova, I M; Kuleshov, N V; Sibbett, W; Brown, C T A

    2009-02-02

    A diode-pumped LPE-grown Yb:KYW planar waveguide laser is demonstrated in a microchip monolithic cavity configuration. Output powers as high as 148 mW and thresholds as low as 40 mW were demonstrated during continuous-wave operation. Pulses of 170 ns duration with maximum pulse energy of 44 nJ at a 722 kHz repetition rate were generated when Q-switched using a semiconductor saturable absorber mirror.

  7. Theoretical computation of the polarization characteristics of an X-ray Free-Electron Laser with planar undulator

    NASA Astrophysics Data System (ADS)

    Geloni, Gianluca; Kocharyan, Vitali; Saldin, Evgeni

    2015-12-01

    We show that radiation pulses from an X-ray Free-Electron Laser (XFEL) with a planar undulator, which are mainly polarized in the horizontal direction, exhibit a suppression of the vertical polarization component of the power at least by a factor λw2/(4 πLg) 2, where λw is the length of the undulator period and Lg is the FEL field gain length. We illustrate this fact by examining the XFEL operation under the steady state assumption. In our calculations we considered only resonance terms: in fact, non-resonance terms are suppressed by a factor λw3/(4 πLg) 3 and can be neglected. While finding a situation for making quantitative comparison between analytical and experimental results may not be straightforward, the qualitative aspects of the suppression of the vertical polarization rate at XFELs should be easy to observe. We remark that our exact results can potentially be useful to developers of new generation FEL codes for cross-checking their results.

  8. Local phase control for a planar array of fiber laser amplifiers

    NASA Astrophysics Data System (ADS)

    Steffanic, Patrick; Johannes, Benjamin T.; Sison, Claudia A.; Hughes, Gary B.; Lubin, Philip; Meinhold, Peter; Suen, Jonathan; O'Neill, Hugh; Kangas, Miikka; Brashears, Travis; Zhang, Qicheng; Griswold, Janelle; Riley, Jordan; Motta, Caio

    2015-09-01

    Arrays of phase-locked lasers have been developed for numerous directed-energy applications. Phased-array designs are capable of producing higher beam intensity than similar sized multi-beam emitters, and also allow beam steering and beam profile manipulation. In phased-array designs, individual emitter phases must be controllable, based on suitable feedback. Most current control schemes sample individual emitter phases, such as with an array-wide beam splitter, and compare to a master phase reference. Reliance on a global beam splitter limits scalability to larger array sizes due to lack of design modularity. This paper describes a conceptual design and control scheme that relies only on feedback from the array structure itself. A modular and scalable geometry is based on individual hexagonal frames for each emitter; each frame cell consists of a conventional lens mounted in front of the fiber tip. A rigid phase tap structure physically connects two adjacent emitter frame cells. A target sensor is mounted on top of the phase tap, representing the local alignment datum. Optical sensors measure the relative position of the phase tap and target sensor. The tap senses the exit phase of both emitters relative to the target normal plane, providing information to the phase controller for each emitter. As elements are added to the array, relative local position data between adjacent phase taps allows accurate prediction of the relative global position of emitters across the array, providing additional constraints to the phase controllers. The approach is scalable for target distance and number of emitters without loss of control.

  9. Three-dimensional, time-dependent simulation of free-electron lasers with planar, helical, and elliptical undulators

    NASA Astrophysics Data System (ADS)

    Freund, H. P.; van der Slot, P. J. M.; Grimminck, D. L. A. G.; Setija, I. D.; Falgari, P.

    2017-02-01

    Free-electron lasers (FELs) have been built ranging in wavelength from long-wavelength oscillators using partial wave guiding through ultraviolet through hard x-ray that are either seeded or start from noise. In addition, FELs that produce different polarizations of the output radiation ranging from linear through elliptic to circular polarization are currently under study. In this paper, we develop a three-dimensional, time-dependent formulation that is capable of modeling this large variety of FEL configurations including different polarizations. We employ a modal expansion for the optical field, i.e., a Gaussian expansion with variable polarization for free-space propagation. This formulation uses the full Newton–Lorentz force equations to track the particles through the optical and magnetostatic fields. As a result, arbitrary three-dimensional representations for different undulator configurations are implemented, including planar, helical, and elliptical undulators. In particular, we present an analytic model of an APPLE-II undulator to treat arbitrary elliptical polarizations, which is used to treat general elliptical polarizations. To model oscillator configurations, and allow propagation of the optical field outside the undulator and interact with optical elements, we link the FEL simulation with the optical propagation code OPC. We present simulations using the APPLE-II undulator model to produce elliptically polarized output radiation, and present a detailed comparison with recent experiments using a tapered undulator configuration at the Linac Coherent Light Source. Validation of the nonlinear formation is also shown by comparison with experimental results obtained in the Sorgente Pulsata Auto-amplificata di Radiazione Coerente SASE FEL experiment at ENEA Frascati, a seeded tapered amplifier experiment at Brookhaven National Laboratory, and the 10 kW upgrade oscillator experiment at the Thomas Jefferson National Accelerator Facility.

  10. Optical smoothing of laser imprinting in planar-target experiments on OMEGA EP using multi-FM 1-D smoothing by spectral dispersion

    NASA Astrophysics Data System (ADS)

    Hohenberger, M.; Shvydky, A.; Marozas, J. A.; Fiksel, G.; Bonino, M. J.; Canning, D.; Collins, T. J. B.; Dorrer, C.; Kessler, T. J.; Kruschwitz, B. E.; McKenty, P. W.; Meyerhofer, D. D.; Regan, S. P.; Sangster, T. C.; Zuegel, J. D.

    2016-09-01

    Direct-drive ignition on the National Ignition Facility (NIF) requires single-beam smoothing to minimize imprinting of laser nonuniformities that can negatively affect implosion performance. One-dimensional, multi-FM smoothing by spectral dispersion (SSD) has been proposed to provide the required smoothing [Marozas et al., Bull. Am. Phys. Soc. 55, 294 (2010)]. A prototype multi-FM SSD system has been integrated into the NIF-like beamline of the OMEGA EP Laser System. Experiments have been performed to verify the smoothing performance by measuring Rayleigh-Taylor growth rates in planar targets of laser-imprinted and preimposed surface modulations. Multi-FM 1-D SSD has been observed to reduce imprint levels by ˜50% compared to the nominal OMEGA EP SSD system. The experimental results are in agreement with 2-D DRACO simulations using realistic, time-dependent far-field spot-intensity calculations that emulate the effect of SSD.

  11. Electrochemical planarization

    DOEpatents

    Bernhardt, A.F.; Contolini, R.J.

    1993-10-26

    In a process for fabricating planarized thin film metal interconnects for integrated circuit structures, a planarized metal layer is etched back to the underlying dielectric layer by electropolishing, ion milling or other procedure. Electropolishing reduces processing time from hours to minutes and allows batch processing of multiple wafers. The etched back planarized thin film interconnect is flush with the dielectric layer. 12 figures.

  12. Electrochemical planarization

    DOEpatents

    Bernhardt, Anthony F.; Contolini, Robert J.

    1993-01-01

    In a process for fabricating planarized thin film metal interconnects for integrated circuit structures, a planarized metal layer is etched back to the underlying dielectric layer by electropolishing, ion milling or other procedure. Electropolishing reduces processing time from hours to minutes and allows batch processing of multiple wafers. The etched back planarized thin film interconnect is flush with the dielectric layer.

  13. Self-focusing property of a laser beam interacting with a lattice of nanoparticles in the presence of a planar magnetostatic wiggler

    NASA Astrophysics Data System (ADS)

    Esmaeildoost, N.; Zolghadr, S. H.; Jafari, S.

    2017-03-01

    In this paper, we study the nonlinear interaction of a laser beam with a periodic lattice of nanoparticles in the presence of a planar magnetostatic wiggler. The static magnetic field of the wiggler can couple with the electric field of the laser wave and change the electric field intensity of the pumped wave, leading to the formation of a nonlinear force. In consequence, the nonlinear force enhances plasmonic oscillations of the electronic cloud of each nanoparticle causing electron density modulation, which improves self-focusing property of the laser beam propagating through a periodic lattice of nanoparticles. By manipulating a classical microscopic approach into plasmonic oscillations of electronic clouds of the nanoparticles and the well-known perturbative method, a nonlinear dispersion relation describing the evolution of the laser amplitude propagating through the nanoparticle lattice has been obtained. The effect of the wiggler magnetic strength on the evolution of the laser transverse profile has been discussed. It was found that by increasing the wiggler strength, the transverse profile bandwidth shrinks and laser focusing is enhanced. In addition, further numerical results indicated that by increasing the wiggler field strength, the cut-off frequency of the body waves increases.

  14. Self-Associating Behavior of Acetone in Liquid Krypton.

    PubMed

    De Beuckeleer, Liene I; Herrebout, Wouter A

    2016-02-18

    Acetone molecules are inclined to self-associate through dipole-dipole interactions because of their large dipole moment. Infrared spectroscopy of compounds dissolved in liquid noble gases supported by high level ab initio calculations allows investigating the self-associating behavior and determining the thermodynamical properties. In this study, infrared spectra of various concentrations of acetone dissolved in liquid krypton are recorded at constant temperature. Overlapping monomer and dimer spectra are separated by analyzing the obtained data sets with numerical methods based on least-squares fitting. Although acetone is known to self-associate, only a few spectral features have been presented in literature before. In this study, the application of new numerical approaches succeeds in resolving overlapping spectra and allows observing isolated acetone dimer absorption bands for the complete mid infrared spectrum. By use of data sets of spectra recorded at temperatures between 134 and 142 K, the experimental standard dimerization enthalpy was determined to be -10.8 kJ mol(-1). MP2/aug-cc-pVDZ calculations predicted a stacked and planar dimer geometry of which the stacked geometry is more stable. Combining MP2 energies and single point corrections involving CCSD(T) calculations and complete basis set extrapolations based on the MP2/aug-cc-pVDZ equilibrium geometry lead to complexation energy of -28.4 kJ mol(-1) for the stacked geometry and -15.1 kJ mol(-1) for the planar geometry. The corresponding values for the complexation enthalpies in solution, obtained by combining these values with corrections for thermal and solvent influences are -13.7 and -5.8 kJ mol(-1).

  15. 300-MHz-repetition-rate, all-fiber, femtosecond laser mode-locked by planar lightwave circuit-based saturable absorber.

    PubMed

    Kim, Chur; Kim, Dohyun; Cheong, YeonJoon; Kwon, Dohyeon; Choi, Sun Young; Jeong, Hwanseong; Cha, Sang Jun; Lee, Jeong-Woo; Yeom, Dong-Il; Rotermund, Fabian; Kim, Jungwon

    2015-10-05

    We show the implementation of fiber-pigtailed, evanescent-field-interacting, single-walled carbon nanotube (CNT)-based saturable absorbers (SAs) using standard planar lightwave circuit (PLC) fabrication processes. The implemented PLC-CNT-SA device is employed to realize self-starting, high-repetition-rate, all-fiber ring oscillators at telecommunication wavelength. We demonstrate all-fiber Er ring lasers operating at 303-MHz (soliton regime) and 274-MHz (stretched-pulse regime) repetition-rates. The 303-MHz (274-MHz) laser centered at 1555 nm (1550 nm) provides 7.5 nm (19 nm) spectral bandwidth. After extra-cavity amplilfication, the amplified pulse train of the 303-MHz (274-MHz) laser delivers 209 fs (178 fs) pulses. To our knowledge, this corresponds to the highest repetition-rates achieved for femtosecond lasers employing evanescent-field-interacting SAs. The demonstrated SA fabrication method, which is based on well-established PLC processes, also shows a potential way for mass-producible and lower-cost waveguide-type SA devices suitable for all-fiber and waveguide lasers.

  16. Excitation/Detection Strategies for OH Planar Laser-Induced Fluorescence Measurements in the Presence of Interfering Fuel Signal and Absorption Effects

    NASA Technical Reports Server (NTRS)

    Heath, Christopher M.; Anderson, Robert C.; Hicks, Yolanda R.

    2011-01-01

    Planar laser-induced fluorescence (PLIF) excitation/detection methods have been applied to obtain spatial distributions of the hydroxyl [OH] reacting intermediary and hydrocarbon [HC] primary species in laminar and turbulent combustion reactions. In this report, broadband and narrowband excitation/filtering techniques are explored to identify an optimal experimental configuration yielding significant fluorescent signal with low absorption losses. The combustion environments analyzed include 1) a laminar non-premixed methane/air flame and 2) a turbulent, non-premixed Jet-A/air fueled flame within a lean flame tube combustor. Hydrocarbon-based fuel and OH were excited via the R1 (1), R1(10) and R2(7) transitions of the A(sup 2)Epsilon(+) X(sup 2)pi(1,0) band using a broadband Nd:YAG pumped optical parametric oscillator (OPO) and narrowband Nd:YAG/dye laser with ultraviolet frequency extension (UVX) package. Variables tested for influence on fluorescent signal and absorption characteristics were excitation line, laser energy, exciting linewidth, combustion reactants, and test flow conditions. Results are intended to guide the transition from a dye/UVX laser to an OPO system for performing advanced diagnostics of low-emission combustion concepts.

  17. Unified planar process for fabricating heterojunction bipolar transistors and buried-heterostructure lasers utilizing impurity-induced disordering

    NASA Astrophysics Data System (ADS)

    Thornton, R. L.; Mosby, W. J.; Chung, H. F.

    1988-12-01

    We describe results on a novel geometry of heterojunction bipolar transistor that has been realized by impurity-induced disordering. This structure is fabricated by a method that is compatible with techniques for the fabrication of low threshold current buried-heterostructure lasers. We have demonstrated this compatibility by fabricating a hybrid laser/transistor structure that operates as a laser with a threshold current of 6 mA at room temperature, and as a transistor with a current gain of 5.

  18. Ionization energy of acetone by vacuum ultraviolet mass-analyzed threshold ionization spectrometry

    NASA Astrophysics Data System (ADS)

    Kim, Jae Han; Kang, Do Won; Hong, Yong Jun; Hwang, Hyonseok; Kim, Hong Lae; Kwon, Chan Ho

    2013-04-01

    Mass-analyzed threshold ionization (MATI) time-of-flight mass spectrometer using coherent vacuum ultraviolet (VUV) laser generated by four-wave difference frequency mixing (FWDFM) in Kr has been constructed and utilized to obtain the accurate ionization energy of acetone. From the MATI onsets measured from various applied pulsed fields, the ionization energy to the ionic ground state of acetone has been determined to be 9.7074 ± 0.0019 eV.

  19. Optical smoothing of laser imprinting in planar-target experiments on OMEGA EP using multi-FM 1-D smoothing by spectral dispersion

    SciTech Connect

    Hohenberger, M.; Shvydky, A.; Marozas, J. A.; Fiksel, G.; Bonino, M. J.; Canning, D.; Collins, T. J. B.; Dorrer, C.; Kessler, T. J.; Kruschwitz, B. E.; McKenty, P. W.; Meyerhofer, D. D.; Regan, S. P.; Sangster, T. C.; Zuegel, J. D.

    2016-09-07

    Direct-drive ignition on the National Ignition Facility (NIF) requires single-beam smoothing to minimize imprinting of laser nonuniformities that can negatively affect implosion performance. One-dimensional, multi-FM smoothing by spectral dispersion (SSD) has been proposed to provide the required smoothing [J. A. Marozas, J. D. Zuegel, and T. J. B. Collins, Bull. Am. Phys. Soc. 55, 294 (2010)]. A prototype multi-FM SSD system has been integrated into the NIF-like beamline of the OMEGA EP Laser System. Experiments have been performed to verify the smoothing performance by measuring Rayleigh–Taylor growth rates in planar targets of laser-imprinted and preimposed surface modulations. Multi-FM 1-D SSD has been observed to reduce imprint levels by ~50% compared to the nominal OMEGA EP SSD system. In conclusion, the experimental results are in agreement with 2-D DRACO simulations using realistic, time-dependent far-field spot-intensity calculations that emulate the effect of SSD.

  20. Optical smoothing of laser imprinting in planar-target experiments on OMEGA EP using multi-FM 1-D smoothing by spectral dispersion

    DOE PAGES

    Hohenberger, M.; Shvydky, A.; Marozas, J. A.; ...

    2016-09-07

    Direct-drive ignition on the National Ignition Facility (NIF) requires single-beam smoothing to minimize imprinting of laser nonuniformities that can negatively affect implosion performance. One-dimensional, multi-FM smoothing by spectral dispersion (SSD) has been proposed to provide the required smoothing [J. A. Marozas, J. D. Zuegel, and T. J. B. Collins, Bull. Am. Phys. Soc. 55, 294 (2010)]. A prototype multi-FM SSD system has been integrated into the NIF-like beamline of the OMEGA EP Laser System. Experiments have been performed to verify the smoothing performance by measuring Rayleigh–Taylor growth rates in planar targets of laser-imprinted and preimposed surface modulations. Multi-FM 1-D SSDmore » has been observed to reduce imprint levels by ~50% compared to the nominal OMEGA EP SSD system. In conclusion, the experimental results are in agreement with 2-D DRACO simulations using realistic, time-dependent far-field spot-intensity calculations that emulate the effect of SSD.« less

  1. Planar micromixer

    DOEpatents

    Fiechtner, Gregory J.; Singh, Anup K.; Wiedenman, Boyd J.

    2008-03-18

    The present embodiment describes a laminar-mixing embodiment that utilizes simple, three-dimensional injection. Also described is the use of the embodiment in combination with wide and shallow sections of channel to affect rapid mixing in microanalytical systems. The shallow channel sections are constructed using all planar micromachining techniques, including those based on isotropic etching. The planar construction enables design using minimum dispersion concepts that, in turn, enable simultaneous mixing and injection into subsequent chromatography channels.

  2. Nitric-oxide planar laser-induced fluorescence at 10 kHz in a seeded flow, a plasma discharge, and a flame.

    PubMed

    Hammack, Stephen D; Carter, Campbell D; Gord, James R; Lee, Tonghun

    2012-12-20

    This study demonstrates high-repetition-rate planar laser-induced fluorescence (PLIF) imaging of both cold (~300 K) and hot (~2400 K) nitric oxide (NO) at a framing rate of 10 kHz. The laser system is composed of a frequency-doubled dye laser pumped by the third harmonic of a 10 kHz Nd:YAG laser to generate continuously pulsed laser radiation at 226 nm for excitation of NO. The laser-induced fluorescence signal is detected using a high-frame rate, intensified CMOS camera, yielding a continuous cinematographic propagation of the NO plume where data acquisition duration is limited only by camera memory. The pulse energy of the beam is ~20 μJ with a spectral width ~0.15 cm(-1), though energies as high as 40 μJ were generated. Hot NO is generated by passing air through a DC transient-arc plasma torch that dissociates air. The plasma torch is also used to ignite and sustain a CH(4)/air premixed flame. Cold NO is imaged from a 1% NO flow (buffered by nitrogen). The estimated signal-to-noise ratio (SNR) for the cold seeded flow and air plasma exceeds 50 with expected NO concentrations of 6000-8000 parts per million (ppm, volume basis). Images show distinct, high-contrast boundaries. The plasma-assisted flame images have an SNR of less than 10 for concentrations reaching 1000 ppm. For many combustion applications, the pulse energy is insufficient for PLIF measurements. However, the equipment and strategies herein could be applied to high-frequency line imaging of NO at concentrations of 10-100 ppm. Generation of 226 nm radiation was also performed using sum-frequency mixing of the 532 nm pumped dye laser and 355 nm Nd:YAG third harmonic but was limited in energy to 14 μJ. Frequency tripling a 532 nm pumped dye laser produced 226 nm radiation at energies comparable to the 355 nm pumping scheme.

  3. Design Features of a Planar Hybrid/Permanent Magnet Strong Focusing Undulator for Free Electron Laser (FEL) And Synchrotron Radiation (SR) Applications

    SciTech Connect

    Tatchyn, Roman; /SLAC

    2011-09-09

    Insertion devices for Angstrom-wavelength Free Electron Laser (FEL) amplifiers driven by multi-GeV electron beams generally require distributed focusing substantially stronger than their own natural focusing fields. Over the last several years a wide variety of focusing schemes and configurations have been proposed for undulators of this class, ranging from conventional current-driven quadrupoles external to the undulator magnets to permanent magnet (PM) lattices inserted into the insertion device gap. In this paper we present design studies of a flexible high-field hybrid/PM undulator with strong superimposed planar PM focusing proposed for a 1.5 Angstrom Linac Coherent Light Source (LCLS) driven by an electron beam with a 1 mm-mr normalized emittance. Attainable field parameters, tuning modes, and potential applications of the proposed structure are discussed.

  4. A fully integrated standalone portable cavity ringdown breath acetone analyzer

    NASA Astrophysics Data System (ADS)

    Sun, Meixiu; Jiang, Chenyu; Gong, Zhiyong; Zhao, Xiaomeng; Chen, Zhuying; Wang, Zhennan; Kang, Meiling; Li, Yingxin; Wang, Chuji

    2015-09-01

    Breath analysis is a promising new technique for nonintrusive disease diagnosis and metabolic status monitoring. One challenging issue in using a breath biomarker for potential particular disease screening is to find a quantitative relationship between the concentration of the breath biomarker and clinical diagnostic parameters of the specific disease. In order to address this issue, we need a new instrument that is capable of conducting real-time, online breath analysis with high data throughput, so that a large scale of clinical test (more subjects) can be achieved in a short period of time. In this work, we report a fully integrated, standalone, portable analyzer based on the cavity ringdown spectroscopy technique for near-real time, online breath acetone measurements. The performance of the portable analyzer in measurements of breath acetone was interrogated and validated by using the certificated gas chromatography-mass spectrometry. The results show that this new analyzer is useful for reliable online (online introduction of a breath sample without pre-treatment) breath acetone analysis with high sensitivity (57 ppb) and high data throughput (one data per second). Subsequently, the validated breath analyzer was employed for acetone measurements in 119 human subjects under various situations. The instrument design, packaging, specifications, and future improvements were also described. From an optical ringdown cavity operated by the lab-set electronics reported previously to this fully integrated standalone new instrument, we have enabled a new scientific tool suited for large scales of breath acetone analysis and created an instrument platform that can even be adopted for study of other breath biomarkers by using different lasers and ringdown mirrors covering corresponding spectral fingerprints.

  5. Magnetic Field Generation by the Nonlinear Rayleigh--Taylor Instability in Laser-Driven Planar Plastic Targets

    NASA Astrophysics Data System (ADS)

    Gao, L.; Igumenshchev, I. V.; Hu, S. X.; Stoeckl, C.; Froula, D. H.; Nilson, P. M.; Davies, J. R.; Betti, R.; Meyerhofer, D. D.; Haines, M. G.

    2012-10-01

    Magnetic field generation during the nonlinear phase of the Rayleigh--Taylor (RT) instability in an ablatively driven plasma using ultrafast laser-driven proton radiography has been measured. Thin plastic foils were irradiated with ˜4-kJ, 2.5-ns laser pulses focused to an intensity of ˜10^14 W/cm^2 on the OMEGA EP Laser System. Target modulations were seeded by laser nonuniformities and amplified during target acceleration by the RT instability. The experimental data show the hydrodynamic evolution of the target and MG-level magnetic fields generated in the broken foil. The experimental data are in good agreement with predictions from 2-D magnetohydrodynamic simulations. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC52-08NA28302.

  6. An MRI guided system for prostate laser ablation with treatment planning and multi-planar temperature monitoring

    NASA Astrophysics Data System (ADS)

    Xu, Sheng; Agarwal, Harsh; Bernardo, Marcelino; Seifabadi, Reza; Turkbey, Baris; Partanen, Ari; Negussie, Ayele; Glossop, Neil; Choyke, Peter; Pinto, Peter; Wood, Bradford J.

    2016-03-01

    Prostate cancer is often over treated with standard treatment options which impact the patients' quality of life. Laser ablation has emerged as a new approach to treat prostate cancer while sparing the healthy tissue around the tumor. Since laser ablation has a small treatment zone with high temperature, it is necessary to use accurate image guidance and treatment planning to enable full ablation of the tumor. Intraoperative temperature monitoring is also desirable to protect critical structures from being damaged in laser ablation. In response to these problems, we developed a navigation platform and integrated it with a clinical MRI scanner and a side firing laser ablation device. The system allows imaging, image guidance, treatment planning and temperature monitoring to be carried out on the same platform. Temperature sensing phantoms were developed to demonstrate the concept of iterative treatment planning and intraoperative temperature monitoring. Retrospective patient studies were also conducted to show the clinical feasibility of the system.

  7. Flat panel planar optic display

    SciTech Connect

    Veligdan, J.T.

    1994-11-01

    A prototype 10 inch flat panel Planar Optic Display, (POD), screen has been constructed and tested. This display screen is comprised of hundreds of planar optic class sheets bonded together with a cladding layer between each sheet where each glass sheet represents a vertical line of resolution. The display is 9 inches wide by 5 inches high and approximately 1 inch thick. A 3 milliwatt HeNe laser is used as the illumination source and a vector scanning technique is employed.

  8. Segmentation of Planar Surfaces from Laser Scanning Data Using the Magnitude of Normal Position Vector for Adaptive Neighborhoods.

    PubMed

    Kim, Changjae; Habib, Ayman; Pyeon, Muwook; Kwon, Goo-rak; Jung, Jaehoon; Heo, Joon

    2016-01-22

    Diverse approaches to laser point segmentation have been proposed since the emergence of the laser scanning system. Most of these segmentation techniques, however, suffer from limitations such as sensitivity to the choice of seed points, lack of consideration of the spatial relationships among points, and inefficient performance. In an effort to overcome these drawbacks, this paper proposes a segmentation methodology that: (1) reduces the dimensions of the attribute space; (2) considers the attribute similarity and the proximity of the laser point simultaneously; and (3) works well with both airborne and terrestrial laser scanning data. A neighborhood definition based on the shape of the surface increases the homogeneity of the laser point attributes. The magnitude of the normal position vector is used as an attribute for reducing the dimension of the accumulator array. The experimental results demonstrate, through both qualitative and quantitative evaluations, the outcomes' high level of reliability. The proposed segmentation algorithm provided 96.89% overall correctness, 95.84% completeness, a 0.25 m overall mean value of centroid difference, and less than 1° of angle difference. The performance of the proposed approach was also verified with a large dataset and compared with other approaches. Additionally, the evaluation of the sensitivity of the thresholds was carried out. In summary, this paper proposes a robust and efficient segmentation methodology for abstraction of an enormous number of laser points into plane information.

  9. Segmentation of Planar Surfaces from Laser Scanning Data Using the Magnitude of Normal Position Vector for Adaptive Neighborhoods

    PubMed Central

    Kim, Changjae; Habib, Ayman; Pyeon, Muwook; Kwon, Goo-rak; Jung, Jaehoon; Heo, Joon

    2016-01-01

    Diverse approaches to laser point segmentation have been proposed since the emergence of the laser scanning system. Most of these segmentation techniques, however, suffer from limitations such as sensitivity to the choice of seed points, lack of consideration of the spatial relationships among points, and inefficient performance. In an effort to overcome these drawbacks, this paper proposes a segmentation methodology that: (1) reduces the dimensions of the attribute space; (2) considers the attribute similarity and the proximity of the laser point simultaneously; and (3) works well with both airborne and terrestrial laser scanning data. A neighborhood definition based on the shape of the surface increases the homogeneity of the laser point attributes. The magnitude of the normal position vector is used as an attribute for reducing the dimension of the accumulator array. The experimental results demonstrate, through both qualitative and quantitative evaluations, the outcomes’ high level of reliability. The proposed segmentation algorithm provided 96.89% overall correctness, 95.84% completeness, a 0.25 m overall mean value of centroid difference, and less than 1° of angle difference. The performance of the proposed approach was also verified with a large dataset and compared with other approaches. Additionally, the evaluation of the sensitivity of the thresholds was carried out. In summary, this paper proposes a robust and efficient segmentation methodology for abstraction of an enormous number of laser points into plane information. PMID:26805849

  10. Planarization of metal films for multilevel interconnects

    DOEpatents

    Tuckerman, D.B.

    1989-03-21

    In the fabrication of multilevel integrated circuits, each metal layer is planarized by heating to momentarily melt the layer. The layer is melted by sweeping laser pulses of suitable width, typically about 1 microsecond duration, over the layer in small increments. The planarization of each metal layer eliminates irregular and discontinuous conditions between successive layers. The planarization method is particularly applicable to circuits having ground or power planes and allows for multilevel interconnects. Dielectric layers can also be planarized to produce a fully planar multilevel interconnect structure. The method is useful for the fabrication of VLSI circuits, particularly for wafer-scale integration. 6 figs.

  11. Planarization of metal films for multilevel interconnects

    DOEpatents

    Tuckerman, D.B.

    1985-08-23

    In the fabrication of multilevel integrated circuits, each metal layer is planarized by heating to momentarily melt the layer. The layer is melted by sweeping laser pulses of suitable width, typically about 1 microsecond duration, over the layer in small increments. The planarization of each metal layer eliminates irregular and discontinuous conditions between successive layers. The planarization method is particularly applicable to circuits having ground or power planes and allows for multilevel interconnects. Dielectric layers can also be planarized to produce a fully planar multilevel interconnect structure. The method is useful for the fabrication of VLSI circuits, particularly for wafer-scale integration.

  12. Simultaneous imaging of fuel vapor mass fraction and gas-phase temperature inside gasoline sprays using two-line excitation tracer planar laser-induced fluorescence.

    PubMed

    Zigan, Lars; Trost, Johannes; Leipertz, Alfred

    2016-02-20

    This paper reports for the first time, to the best of our knowledge, on the simultaneous imaging of the gas-phase temperature and fuel vapor mass fraction distribution in a direct-injection spark-ignition (DISI) spray under engine-relevant conditions using tracer planar laser-induced fluorescence (TPLIF). For measurements in the spray, the fluorescence tracer 3-pentanone is added to the nonfluorescent surrogate fuel iso-octane, which is excited quasi-simultaneously by two different excimer lasers for two-line excitation LIF. The gas-phase temperature of the mixture of fuel vapor and surrounding gas and the fuel vapor mass fraction can be calculated from the two LIF signals. The measurements are conducted in a high-temperature, high-pressure injection chamber. The fluorescence calibration of the tracer was executed in a flow cell and extended significantly compared to the existing database. A detailed error analysis for both calibration and measurement is provided. Simultaneous single-shot gas-phase temperature and fuel vapor mass fraction fields are processed for the assessment of cyclic spray fluctuations.

  13. 21 CFR 173.210 - Acetone.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Acetone. 173.210 Section 173.210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... established for acetone in spice oleoresins when present therein as a residue from the extraction of spice....

  14. 21 CFR 173.210 - Acetone.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acetone. 173.210 Section 173.210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... established for acetone in spice oleoresins when present therein as a residue from the extraction of spice....

  15. A Portable Real-Time Ringdown Breath Acetone Analyzer: Toward Potential Diabetic Screening and Management

    PubMed Central

    Jiang, Chenyu; Sun, Meixiu; Wang, Zhennan; Chen, Zhuying; Zhao, Xiaomeng; Yuan, Yuan; Li, Yingxin; Wang, Chuji

    2016-01-01

    Breath analysis has been considered a suitable tool to evaluate diseases of the respiratory system and those that involve metabolic changes, such as diabetes. Breath acetone has long been known as a biomarker for diabetes. However, the results from published data by far have been inconclusive regarding whether breath acetone is a reliable index of diabetic screening. Large variations exist among the results of different studies because there has been no “best-practice method” for breath-acetone measurements as a result of technical problems of sampling and analysis. In this mini-review, we update the current status of our development of a laser-based breath acetone analyzer toward real-time, one-line diabetic screening and a point-of-care instrument for diabetic management. An integrated standalone breath acetone analyzer based on the cavity ringdown spectroscopy technique has been developed. The instrument was validated by using the certificated gas chromatography-mass spectrometry. The linear fittings suggest that the obtained acetone concentrations via both methods are consistent. Breath samples from each individual subject under various conditions in total, 1257 breath samples were taken from 22 Type 1 diabetic (T1D) patients, 312 Type 2 diabetic (T2D) patients, which is one of the largest numbers of T2D subjects ever used in a single study, and 52 non-diabetic healthy subjects. Simultaneous blood glucose (BG) levels were also tested using a standard diabetic management BG meter. The mean breath acetone concentrations were determined to be 4.9 ± 16 ppm (22 T1D), and 1.5 ± 1.3 ppm (312 T2D), which are about 4.5 and 1.4 times of the one in the 42 non-diabetic healthy subjects, 1.1 ± 0.5 ppm, respectively. A preliminary quantitative correlation (R = 0.56, p < 0.05) between the mean individual breath acetone concentration and the mean individual BG levels does exist in 20 T1D subjects with no ketoacidosis. No direct correlation is observed in T1D subjects, T

  16. Time-resolved soft-x-ray studies of energy transport in layered and planar laser-driven targets

    SciTech Connect

    Stradling, G.L.

    1982-04-19

    New low-energy x-ray diagnostic techniques are used to explore energy-transport processes in laser heated plasmas. Streak cameras are used to provide 15-psec time-resolution measurements of subkeV x-ray emission. A very thin (50 ..mu..g/cm/sup 2/) carbon substrate provides a low-energy x-ray transparent window to the transmission photocathode of this soft x-ray streak camera. Active differential vacuum pumping of the instrument is required. The use of high-sensitivity, low secondary-electron energy-spread CsI photocathodes in x-ray streak cameras is also described. Significant increases in sensitivity with only a small and intermittant decrease in dynamic range were observed. These coherent, complementary advances in subkeV, time-resolved x-ray diagnostic capability are applied to energy-transport investigations of 1.06-..mu..m laser plasmas. Both solid disk targets of a variety of Z's as well as Be-on-Al layered-disk targets were irradiated with 700-psec laser pulses of selected intensity between 3 x 10/sup 14/ W/cm/sup 2/ and 1 x 10/sup 15/ W/cm/sup 2/.

  17. Picosecond planar laser-induced fluorescence measurements of OH A 2 ( 2) lifetime and energy transfer in atmospheric pressure flames

    NASA Astrophysics Data System (ADS)

    Bormann, Frank C.; Nielsen, Tim; Burrows, Michael; Andresen, Peter

    1997-08-01

    A picosecond, excimer-Raman laser (268 nm, 400 ps FWHM) was used for laser sheet excitation of OH in the (2, 0) band. The fluorescence was detected with a fast-gated, intensified camera (400-ps gate width). The effective collisional lifetime of the spectrally integrated fluorescence was measured in two dimensions by shifting the intensifier gate across the decay curve. The average lifetime is 2.0 ns for a stoichiometric methane air flame with spatial variations of 10 . Shorter collisional lifetimes were measured for rich flame conditions that are due to a higher number density of the quenchers. Vibrational energy transfer (VET) was observed in premixed methane air and methane oxygen flames by putting the fast-gated camera behind a spectrometer. The spectrum of the methane air flame shows strong VET in contrast with the methane oxygen flame. This is because N 2 is a weak electronic quencher but a strong VET agent. By fitting the measured time dependence of the different vibrational populations ( 2, 1, 0) to a four-level model, rate constants for quenching and VET were determined. For the lower states ( 0, 1) our results are in good agreement with literature values. For a prediction of a spectrally integrated, collisional lifetime in a known collisional environment it is important to consider not only the quenching but also the amount of energy transfer in the excited state as well as the spectral detection sensitivity.

  18. An investigation of liquid secondary ion and laser desorption mass spectroscopy for the analysis of planar chromatograms

    SciTech Connect

    Dunphy, J.C.

    1990-11-01

    In the work described in this dissertation, interfaces between two mass spectrometric methods, liquid secondary ion mass spectrometry (LSIMS) and laser desorption/ionization Fourier transform mass spectrometry (LD/FTMS), and thin-layer chromatography (TLC) and slab gel electrophoresis were developed for bioanalytical applications. In an investigation of direct LSIMS for TLC analysis (TLC/LSIMS), mass spectra of bile acids and bile salts were characterized directly from high-performance TLC plates. The scanning ability of the LSIMS instrument was used to generate spatial profiles of the characteristic bile acid ions in the mass spectra. A procedure for the analysis of bile salts in dog bile was developed involving an extraction step, followed by TLC separation and direct TLC/LSIMS detection and semi-quantitation. For peptides, an experiment called ``selected-sequence monitoring`` was developed to locate target peptides related in structure in complex mixtures developed on TLC plates. Ions characteristic of the bradykinin and enkephalin peptides were used to generate spatial profiles of members of those peptide families on TLC plates. Using a Fourier transform mass spectrometer (FTMS), a fundamental investigation was conducted into the factors affecting the quality of analytical data obtained using direct laser desorption/ionization to produce mass spectra from TLC plates.

  19. An investigation of liquid secondary ion and laser desorption mass spectroscopy for the analysis of planar chromatograms

    SciTech Connect

    Dunphy, J.C.

    1990-11-01

    In the work described in this dissertation, interfaces between two mass spectrometric methods, liquid secondary ion mass spectrometry (LSIMS) and laser desorption/ionization Fourier transform mass spectrometry (LD/FTMS), and thin-layer chromatography (TLC) and slab gel electrophoresis were developed for bioanalytical applications. In an investigation of direct LSIMS for TLC analysis (TLC/LSIMS), mass spectra of bile acids and bile salts were characterized directly from high-performance TLC plates. The scanning ability of the LSIMS instrument was used to generate spatial profiles of the characteristic bile acid ions in the mass spectra. A procedure for the analysis of bile salts in dog bile was developed involving an extraction step, followed by TLC separation and direct TLC/LSIMS detection and semi-quantitation. For peptides, an experiment called selected-sequence monitoring'' was developed to locate target peptides related in structure in complex mixtures developed on TLC plates. Ions characteristic of the bradykinin and enkephalin peptides were used to generate spatial profiles of members of those peptide families on TLC plates. Using a Fourier transform mass spectrometer (FTMS), a fundamental investigation was conducted into the factors affecting the quality of analytical data obtained using direct laser desorption/ionization to produce mass spectra from TLC plates.

  20. Immiscible experiments on the Rayleigh-Taylor instability using simultaneous particle image velocimetry and planar laser induced fluorescence concentration measurements

    NASA Astrophysics Data System (ADS)

    Mokler, Matthew; Jacobs, Jeffrey

    2014-11-01

    Incompressible Rayleigh-Taylor instability experiments are presented in which two stratified liquids having Atwood number of 0.2 are accelerated in a vertical linear induction motor driven drop tower. A test sled having only vertical freedom of motion contains the experiment tank and visualization equipment. The sled is positioned at the top of the tower within the linear induction motors and accelerated downward causing the initially stable interface to be unstable and allowing the Rayleigh-Taylor instability to develop. Forced and unforced experiments are conducted using an immiscible liquid combination. Forced initial perturbations are produced by vertically oscillating the test sled prior to the start of acceleration. The interface is visualized using a 445 nm laser light source that illuminates a fluorescent dye mixed in one of the fluids and aluminum oxide particles dispersed in both fluids. The laser beam is synchronously swept across the fluorescent fluid, at the frame rate of the camera, exposing a single plane of the interface. The resulting images are recorded using a monochromatic high speed video camera. Time dependent velocity and density fields are obtained from the recorded images allowing for 2D full field measurements of turbulent kinetic energy and turbulent mass transport.

  1. Characterization of a two-dimensional temperature field within a rapid compression machine using a toluene planar laser-induced fluorescence imaging technique

    NASA Astrophysics Data System (ADS)

    Strozzi, Camille; Sotton, Julien; Mura, Arnaud; Bellenoue, Marc

    2009-12-01

    The homogeneous charge compression ignition (HCCI) combustion process is an advanced operating mode for automotive engines. The self-ignition mechanisms that occur within the combustion chamber exhibit extreme temperature dependence. Therefore, the thorough understanding of corresponding phenomena requires the use of diagnostic methods featuring a sufficient thermal sensitivity, applicable in severe conditions similar to those encountered within engines. In this respect, toluene planar laser-induced fluorescence (PLIF) is applied to the inert compression flow generated within an optical rapid compression machine (RCM). A relatively simple diagnostic system is retained: a single wavelength excitation device (266 nm) and a single (filtered) collection system. This diagnostic system is associated with an image processing strategy specifically adapted to RCM devices. Despite the severe conditions under consideration (40 bar, 700-950 K), the method allows us to obtain relatively large two-dimensional temperature fields that display a level of description seldom achieved in such devices. In particular the temperature gradients, which play a crucial role in HCCI combustion processes, can be estimated. The present experimental results confirm the good reliability and accuracy of the method. The information gathered with this toluene PLIF method puts in evidence its high potentialities for the study of aero-thermal-reactive processes as they take place in real engine conditions. The retained strategy also brings new possibilities of non-intrusive analysis for flows practically encountered within industrial devices.

  2. Non-planar interconnects in double-sided flexible Cu-PET substrates using a laser-assisted maskless microdeposition process: 3D finite element modeling and experimental analysis

    NASA Astrophysics Data System (ADS)

    Jabari, Elahe; Tong, Steven; Azhari, Amir; Toyserkani, Ehsan

    2014-03-01

    Non-planar (3D) interconnects have an important role in the electronic packaging industry these days. These unconventional interconnects allow manufacturers to save materials and space while connecting circuit components on flexible and non-planar substrates. Among a variety of flexible boards, double-sided flexible substrates have attracted the electronic industry to effectively and compactly develop miniaturized flexible devices such as sensors-on-chips. This study reports our developmental procedure for the creation of non-planar silver interconnects on the edge of double-sided copper substrates separated by a layer of polyethylene terephthalate (PET) using laser-assisted maskless microdeposition (LAMM). The article consists of the characterization of the LAMM process to effectively deposit Ag nanoparticles for production of conductive interconnects. Several parameters, including the deposition and laser processing parameters, are optimized to achieve interconnects free of pores, cracks and delamination. For investigating the topography and microstructure of interconnects, various analytical tools, such as SEM, XRD, Profilometery, and EDS were used. Furthermore, a 3D finite element numerical model was developed to predict the laser processing of silver nanoparticles on the substrate. The model includes a coupled thermal and structural governing physics to derive the temperature history throughout the simulation as well as strain/displacement within the substrate, which is identified the major source of cark formation in Ag tracks. The SEM micrographs of the laser processed nanoparticles suggest that a minimum of 1.24 W laser power was needed for an effective nanoparticles sintering to obtain conductive 3D interconnects with minimum amount of cracks whereas a 1.7 W laser power caused PET to decompose.

  3. Planarization of metal films for multilevel interconnects

    DOEpatents

    Tuckerman, David B.

    1989-01-01

    In the fabrication of multilevel integrated circuits, each metal layer is anarized by heating to momentarily melt the layer. The layer is melted by sweeping laser pulses of suitable width, typically about 1 microsecond duration, over the layer in small increments. The planarization of each metal layer eliminates irregular and discontinuous conditions between successive layers. The planarization method is particularly applicable to circuits having ground or power planes and allows for multilevel interconnects. Dielectric layers can also be planarized to produce a fully planar multilevel interconnect structure. The method is useful for the fabrication of VLSI circuits, particularly for wafer-scale integration.

  4. Planarization of metal films for multilevel interconnects

    DOEpatents

    Tuckerman, David B.

    1987-01-01

    In the fabrication of multilevel integrated circuits, each metal layer is anarized by heating to momentarily melt the layer. The layer is melted by sweeping laser pulses of suitable width, typically about 1 microsecond duration, over the layer in small increments. The planarization of each metal layer eliminates irregular and discontinuous conditions between successive layers. The planarization method is particularly applicable to circuits having ground or power planes and allows for multilevel interconnects. Dielectric layers can also be planarized to produce a fully planar multilevel interconnect structure. The method is useful for the fabrication of VLSI circuits, particularly for wafer-scale integration.

  5. The interaction of polarized microwaves with planar arrays of femtosecond laser-produced plasma filaments in air

    SciTech Connect

    Marian, Anca; El Morsli, Mbark; Vidal, Francois; Payeur, Stephane; Kieffer, Jean-Claude; Chateauneuf, Marc; Theberge, Francis; Dubois, Jacques

    2013-02-15

    The interaction of polarized microwaves with subwavelength arrays of parallel plasma filaments, such as those produced by the propagation of high-power femtosecond laser pulses in ambient air, was investigated by calculating the reflection and transmission coefficients as a function of the incidence angles using the finite-difference time-domain (FDTD) method. The time evolution of these coefficients was calculated and compared with experiments. It is found that the plasma filaments array becomes transparent when the polarization of the microwave radiation is perpendicular to the filaments axis, regardless the incidence angle of the microwave with respect to the filaments, except near grazing incidence. Increasing the filaments electron density or diameter, or decreasing the electron collision frequency or filaments spacing, decreases the transmission and increases the reflection. Transmission decreases when increasing the number of filament layers while reflection remains unchanged as the number of filament layers exceeds a given number ({approx}3 in our case). Transmission slightly increases when disorder is introduced in the filament arrays. The detailed calculation results are compared with those obtained from the simple birefringent slab model, which provides a convenient framework to calculate approximately the properties of filament arrays.

  6. 2D and 3D imaging of the gas phase close to an operating model catalyst by planar laser induced fluorescence

    NASA Astrophysics Data System (ADS)

    Blomberg, Sara; Zhou, Jianfeng; Gustafson, Johan; Zetterberg, Johan; Lundgren, Edvin

    2016-11-01

    In recent years, efforts have been made in catalysis related surface science studies to explore the possibilities to perform experiments at conditions closer to those of a technical catalyst, in particular at increased pressures. Techniques such as high pressure scanning tunneling/atomic force microscopy (HPSTM/AFM), near ambient pressure x-ray photoemission spectroscopy (NAPXPS), surface x-ray diffraction (SXRD) and polarization-modulation infrared reflection absorption spectroscopy (PM-IRAS) at semi-realistic conditions have been used to study the surface structure of model catalysts under reaction conditions, combined with simultaneous mass spectrometry (MS). These studies have provided an increased understanding of the surface dynamics and the structure of the active phase of surfaces and nano particles as a reaction occurs, providing novel information on the structure/activity relationship. However, the surface structure detected during the reaction is sensitive to the composition of the gas phase close to the catalyst surface. Therefore, the catalytic activity of the sample itself will act as a gas-source or gas-sink, and will affect the surface structure, which in turn may complicate the assignment of the active phase. For this reason, we have applied planar laser induced fluorescence (PLIF) to the gas phase in the vicinity of an active model catalysts. Our measurements demonstrate that the gas composition differs significantly close to the catalyst and at the position of the MS, which indeed should have a profound effect on the surface structure. However, PLIF applied to catalytic reactions presents several beneficial properties in addition to investigate the effect of the catalyst on the effective gas composition close to the model catalyst. The high spatial and temporal resolution of PLIF provides a unique tool to visualize the on-set of catalytic reactions and to compare different model catalysts in the same reactive environment. The technique can be

  7. 2D and 3D imaging of the gas phase close to an operating model catalyst by planar laser induced fluorescence.

    PubMed

    Blomberg, Sara; Zhou, Jianfeng; Gustafson, Johan; Zetterberg, Johan; Lundgren, Edvin

    2016-11-16

    In recent years, efforts have been made in catalysis related surface science studies to explore the possibilities to perform experiments at conditions closer to those of a technical catalyst, in particular at increased pressures. Techniques such as high pressure scanning tunneling/atomic force microscopy (HPSTM/AFM), near ambient pressure x-ray photoemission spectroscopy (NAPXPS), surface x-ray diffraction (SXRD) and polarization-modulation infrared reflection absorption spectroscopy (PM-IRAS) at semi-realistic conditions have been used to study the surface structure of model catalysts under reaction conditions, combined with simultaneous mass spectrometry (MS). These studies have provided an increased understanding of the surface dynamics and the structure of the active phase of surfaces and nano particles as a reaction occurs, providing novel information on the structure/activity relationship. However, the surface structure detected during the reaction is sensitive to the composition of the gas phase close to the catalyst surface. Therefore, the catalytic activity of the sample itself will act as a gas-source or gas-sink, and will affect the surface structure, which in turn may complicate the assignment of the active phase. For this reason, we have applied planar laser induced fluorescence (PLIF) to the gas phase in the vicinity of an active model catalysts. Our measurements demonstrate that the gas composition differs significantly close to the catalyst and at the position of the MS, which indeed should have a profound effect on the surface structure. However, PLIF applied to catalytic reactions presents several beneficial properties in addition to investigate the effect of the catalyst on the effective gas composition close to the model catalyst. The high spatial and temporal resolution of PLIF provides a unique tool to visualize the on-set of catalytic reactions and to compare different model catalysts in the same reactive environment. The technique can be

  8. Photochemistry of Acetone in Simulated Atmosphere

    NASA Astrophysics Data System (ADS)

    Chakraborty, T.; Ghosh, A. K.; Chattopadhyay, A.

    2013-06-01

    Acetone has been identified to be one of the dominant non-methane organic species present in our atmosphere with an annual budget of ˜40-60; Tg; (10^{12} ;g). It has been proposed that the major fraction of atmospheric acetone (˜65%) is removed via photodissociation channel. Numerous laboratory investigations were devoted in the past to understand how the reactions are evolved in presence of oxygen and water vapour. Our recent study, wherein the photo products are probed using a tandem methodology of quadrupole mass spectrometry and gas-phase infrared spectroscopy reveals that a significant fraction of acetone is converted to formic acid in presence of oxygen when exposed to ultraviolet light of wavelengths available in troposphere. The measurement has been repeated with other linear and cyclic ketones and some of their deuterated analogues. The details of our findings will be presented in the talk.

  9. Acetone transport in poly(ethylene terephthalate)

    NASA Astrophysics Data System (ADS)

    Ouyang, Hao; Chen, Che-Chen

    1997-05-01

    Organic solvents like acetone can penetrate into poly(ethylene terephthalate) (PET). The model of case I (Fickian) and case II (swelling) is employed to study the phenomenon of mass transport. This model is successful in explaining the behavior of mass transport in an amorphous polymer, for example, poly(methyl methacrylate) (PMMA). The characteristic parameters, diffusivity D and velocity v, can be obtained from the analysis of experimental data. The mass transport in PET is different from that in PMMA. It is accompanied by a large-scale structural rearrangement, which leads to induced crystallization of the original amorphous state. This is the so-called "solvent-induced crystallization." Acetone-induced crystallization was confirmed by x-ray diffraction. The differential scanning calorimetry thermograms of acetone-treated PET show that the crystallization peak disappears and the glass transition temperature decreases.

  10. Preliminary toxicological study of ferric acetyl acetonate

    SciTech Connect

    London, J.E.; Smith, D.M.

    1983-01-01

    The calculated acute oral LD/sub 50//sup 30/ (lethal does for 50% of the animals occuring with 30 days after compound administration) values for ferric acetyl acetonate were 584 mg/kg in mice and 995 mg/kg in rats. According to classical guidelines, this compound would be considered slightly toxic in both species. Skin application studies in the rabbit demonstrated the compound to be irritating. The eye irritation study disclosed the compound to be a severe irritant causing permanent damage to the cornea (inflammation and scarring resulting in blindness). The sensitization study in the guinea pig did not show ferric acetyl acetonate to be deleterious in this regard.

  11. Bacterial degradation of acetone in an outdoor model stream

    USGS Publications Warehouse

    Rathbun, R.E.; Stephens, D.W.; Tai, D.Y.

    1993-01-01

    Diurnal variations of the acetone concentration in an outdoor model stream were measured with and without a nitrate supplement to determine if the nitrate supplement would stimulate bacterial degradation of the acetone. Acetone loss coefficients were computed from the diurnal data using a fitting procedure based on a Lagrangian particle model. The coefficients indicated that bacterial degradation of the acetone was occurring in the downstream part of the stream during the nitrate addition. However, the acetone concentrations stabilized at values considerably above the limit of detection for acetone determination, in contrast to laboratory respirometer studies where the acetone concentration decreased rapidly to less than the detection limit, once bacterial acclimation to the acetone had occurred. One possible explanation for the difference in behavior was the limited 6-hour residence time of the acetone in the model stream.

  12. High-sensitivity detection of triacetone triperoxide (TATP) and its precursor acetone

    NASA Astrophysics Data System (ADS)

    Dunayevskiy, Ilya; Tsekoun, Alexei; Prasanna, Manu; Go, Rowel; Patel, C. Kumar N.

    2007-09-01

    Triacetone triperoxide (C9H18O6, molecular mass of 222.24 g/mol) (TATP) is a powerful explosive that is easy to synthesize using commonly available household chemicals, acetone, and hydrogen peroxide 1 2. Because of the simplicity of its synthesis, TATP is often the explosive of choice for terrorists, including suicide bombers. For providing safety to the population, early detection of TATP and isolation of such individuals are essential. We report unambiguous, high-sensitivity detection of TATP and its precursor, acetone, using room-temperature quantum cascade laser photoacoustic spectroscopy (QCL-PAS). The available sensitivity is such that TATP, carried on a person (at a nominal body temperature of 37 °C), should be detectable at some distance. The combination of demonstrated detection of TATP and acetone should be ideal for screening at airports and other public places for providing increased public safety.

  13. Exploration of detection sensitivity of biomarker acetone in aqueous samples using cavity ringdown spectroscopy

    NASA Astrophysics Data System (ADS)

    Mbi, Armstrong; Wang, Chuji

    2007-03-01

    Breath acetone is a biomarker for diabetes (Type 1). Currently, high sensitivity breath gas analysis is mainly performed by gas chromatography-mass spectrometry (GC-MC). We are developing a potable ringdown spectrometer for diabetes diagnostics using non-invasive breath gas analysis. The ringdown spectrometer consists of a compact Nd: YAG laser source operating at 266 nm, a atmospheric gas cell of 43 cm in length, a miniature detector, and a data processing section. In this work, the exploration of detection sensitivity of acetone in aqueous samples using cavity ringdown spectroscopy is presented. Pure acetone is diluted in distilled water in different concentrations ranging from 0.5 drop/liter to 8 drops/liter, or 730 ppbv - 12 ppmv in gas phase. The instrument performance using two sampling methods is evaluated. With the mirror reflectivity of 99.98%, the spectrometer demonstrates a detection limit of acetone of 450 ppbv (based on 1-σ), which is slightly lower than the threshold number of acetone concentration in normal human breath. Preliminary results from actual breath gases are also presented.

  14. 21 CFR 173.210 - Acetone.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Acetone. 173.210 Section 173.210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Solvents, Lubricants, Release Agents and...

  15. 21 CFR 172.802 - Acetone peroxides.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.802... proportions of higher polymers, manufactured by reaction of hydrogen peroxide and acetone. (b) The additive... additive container and any intermediate premix thereof shall bear, in addition to the other...

  16. Development and application of a high-speed planar laser-induced fluorescence imaging system to evaluate liquid and vapor phases of sprays from a multi-hole diesel fuel injector

    NASA Astrophysics Data System (ADS)

    Parrish, S. E.; Zink, R. J.

    2013-02-01

    A high-speed imaging system capable of acquiring elastic scattering images and planar laser-induced fluorescence (PLIF) images in a near-simultaneous fashion has been developed. Acquiring both elastic scattering and PLIF images enables the liquid phase to be discriminated from the vapor phase. High-speed imaging allows the temporal evolution of flow structures to be evaluated. Images of sprays from a multi-hole diesel fuel injector operating under engine-like conditions were acquired. The vapor phase images reveal intricate fluid dynamic structures that exhibit a high degree of variability, indicative of a turbulent gas jet.

  17. Acetone excretion into urine of workers exposed to acetone in acetate fiber plants.

    PubMed

    Satoh, T; Omae, K; Takebayashi, T; Nakashima, H; Higashi, T; Sakurai, H

    1995-01-01

    To develop a proper protocol for biological exposure monitoring of acetone, we evaluated whether exposure to acetone on the previous day affects the biological monitoring value at the end of a work day. One hundred and ten male workers exposed to acetone in three acetate fiber manufacturing plants were monitored using a liquid passive sampler on two consecutive working days after 2 days without exposure. Urine samples were collected at the start of the workshift and the end of the shift on both days for each subject. For ten exposed workers urine samples were collected approximately every 2 h during and after the first working day until the following morning. Acetone concentrations in urine (Cu) at the start of the first working day were 1.3 +/- 2.4 (range: ND-14.1) mg/l in nonexposed workers and 2.4 +/- 5.6 (range: ND-40.3) mg/l in exposed workers. The urinary acetone concentration at the beginning of the second working day indicated that urinary levels of acetone do not decline to background level by the following morning when exposure concentration exceeds 300 ppm. However, linear regression analysis demonstrated that the relationship between environmental exposure level and urine level was similar on the 1st day and the 2nd day. Thus, although urine acetone levels did not return completely to baseline after high exposures, under the present exposure levels the exposure on the previous day did not significantly affect urinary acetone at the end of the workshift of the next day.

  18. Insights on Clusters Formation Mechanism by Time of Flight Mass Spectrometry. 2. The Case of Acetone-Water Clusters

    NASA Astrophysics Data System (ADS)

    Apicella, B.; Li, X.; Passaro, M.; Russo, C.

    2016-11-01

    This paper is the second of a series dealing with clusters formation mechanism. In part 1, water clusters with the addition of an electrophilic molecule such as ethanol were studied by Time Of Flight Mass Spectrometry (TOFMS). Mass distributions of molecular clusters of ethanol, water and ethanol-water mixed clusters, were obtained by means of two different ionization methods: Electron Ionization (EI) and picosecond laser Photo-Ionization (PI) at a wavelength of 355 nm. In part 2, the same experimental approach was employed to obtain mass spectra of clusters generated by acetone-water binary mixtures with a different composition. Strong dependence of the mass spectra of clusters with EI and PI on the acetone-water mixing ratio was observed. It was shown that the spectral pattern changes gradually and water-rich cluster signals become fainter while acetone-rich cluster signals become more intensive with increasing acetone concentrations from 0.3% to 40%. Owing to the hydrogen bond acceptor character of acetone, its self-association is discouraged with respect to ethanol. The autocorrelation function (AF) was used to analyze the variation of the water clusters composition with the increase of the acetone concentration in terms of fundamental periodicities. However, although acetone and ethanol present a very different hydrogen-bonding ability, similarly to ethanol-water system, in acetone-water system the formation of water-rich clusters and subsequent metastable fragmentation are the dominant process that determine the clusters distribution, irrespective of the ionization process, while the ionization process significantly affects the acetone-rich clusters distribution.

  19. 46 CFR 153.1035 - Acetone cyanohydrin or lactonitrile solutions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Acetone cyanohydrin or lactonitrile solutions. 153.1035... Special Cargo Procedures § 153.1035 Acetone cyanohydrin or lactonitrile solutions. No person may operate a tankship carrying a cargo of acetone cyanohydrin or lactonitrile solutions, unless that cargo is...

  20. 46 CFR 153.1035 - Acetone cyanohydrin or lactonitrile solutions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Acetone cyanohydrin or lactonitrile solutions. 153.1035... Special Cargo Procedures § 153.1035 Acetone cyanohydrin or lactonitrile solutions. No person may operate a tankship carrying a cargo of acetone cyanohydrin or lactonitrile solutions, unless that cargo is...

  1. 46 CFR 153.1035 - Acetone cyanohydrin or lactonitrile solutions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Acetone cyanohydrin or lactonitrile solutions. 153.1035... Special Cargo Procedures § 153.1035 Acetone cyanohydrin or lactonitrile solutions. No person may operate a tankship carrying a cargo of acetone cyanohydrin or lactonitrile solutions, unless that cargo is...

  2. 46 CFR 153.1035 - Acetone cyanohydrin or lactonitrile solutions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Acetone cyanohydrin or lactonitrile solutions. 153.1035... Special Cargo Procedures § 153.1035 Acetone cyanohydrin or lactonitrile solutions. No person may operate a tankship carrying a cargo of acetone cyanohydrin or lactonitrile solutions, unless that cargo is...

  3. 46 CFR 153.1035 - Acetone cyanohydrin or lactonitrile solutions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Acetone cyanohydrin or lactonitrile solutions. 153.1035... Special Cargo Procedures § 153.1035 Acetone cyanohydrin or lactonitrile solutions. No person may operate a tankship carrying a cargo of acetone cyanohydrin or lactonitrile solutions, unless that cargo is...

  4. Acetone potentiation of acute acetonitrile toxicity in rats

    SciTech Connect

    Freeman, J.J.; Hayes, E.P.

    1985-01-01

    The purpose of these studies was to investigate the nature and mechanism of a toxicologic interaction between acetonitrile and acetone. Results of oral doe-response studies utilizing 1:1 (w/w) mixture of acetonitrile and acetone, or varying doses of acetonitrile administered together with a constant dose of acetone, indicated that acetone potentiated acute acetonitrile toxicity three- to fourfold in rats. The onset of severe toxicity (manifested by tremors and convulsions) was delayed in the groups dosed with both solvents compared to the groups that received acetonitrile or acetone alone. Blood cyanide (a metabolite of acetonitrile) and serum acetonitrile and acetone concentrations were measured after oral administration of 25% aqueous solutions of acetonitrile, acetone, or acetonitrile plus acetone. Concentrations of cyanide in the blood of rats given acetonitrile plus acetone remained near baseline, in contrast to the high concentrations found in rats dosed with acetonitrile alone. At 34-36 h, high blood cyanide concentrations were found in rats dosed with both of the solvents. This delayed onset of elevation of blood cyanide coincided with the occurrence of clinical signs and with the disappearance of serum acetone. In further pharmacokinetic studies, blood cyanide concentrations were measured after similar dosage regimens of acetone and acetonitrile. Peak cyanide concentrations were found to be significantly greater in rats dosed with both solvents than in rats given only acetonitrile. Administration of either sodium thiosulfate or a second dose of acetone prevented the toxicity associated with exposure to both solvents.

  5. Lasers.

    ERIC Educational Resources Information Center

    Schewe, Phillip F.

    1981-01-01

    Examines the nature of laser light. Topics include: (1) production and characteristics of laser light; (2) nine types of lasers; (3) five laser techniques including holography; (4) laser spectroscopy; and (5) laser fusion and other applications. (SK)

  6. Multinuclear NMR spectroscopy for differentiation of molecular configurations and solvent properties between acetone and dimethyl sulfoxide

    NASA Astrophysics Data System (ADS)

    Wen, Yuan-Chun; Kuo, Hsiao-Ching; Jia, Hsi-Wei

    2016-04-01

    The differences in molecular configuration and solvent properties between acetone and dimethyl sulfoxide (DMSO) were investigated using the developed technique of 1H, 13C, 17O, and 1H self-diffusion liquid state nuclear magnetic resonance (NMR) spectroscopy. Acetone and DMSO samples in the forms of pure solution, ionic salt-added solution were used to deduce their active sites, relative dipole moments, dielectric constants, and charge separations. The NMR results suggest that acetone is a trigonal planar molecule with a polarized carbonyl double bond, whereas DMSO is a trigonal pyramidal-like molecule with a highly polarized S-O single bond. Both molecules use their oxygen atoms as the active sites to interact other molecules. These different molecular models explain the differences their physical and chemical properties between the two molecules and explain why DMSO is classified as an aprotic but highly dipolar solvent. The results are also in agreement with data obtained using X-ray diffraction, neutron diffraction, and theoretical calculations.

  7. Dynamics of S 1 acetone studied with single rotorvibronic level resolution

    NASA Astrophysics Data System (ADS)

    Bitto, H.

    1994-08-01

    The spectroscopy and dynamics of selected vibronic bands of the S 1(nπ *) ← S 0 transition of acetone and acetone- d6 were studied with single rotational-torsional-vibronic (rotorvibronic) level resolution in a jet up to an S 1 excess energy of 1300 cm -1. Using clean coherent excitation with Fourier transform-limited nanosecond laser pulses quantum beats were observed in the time-resolved fluorescence and were attributed to coherently excited siglet-triplet eigenstates as identified by their magnetic properties. In the 8 123 0- and the 8 1 23 0+I(2,1) state of acetone, and the 7 1I(1,0) state of aceton- d6, lifetimes increase with the rotational quantum number of the excited state N due to a breakdown of K selection rules for the spin-orbit interaction in this very asymmetric rotor. In the 8 123 0- state, the rotorvibronic levels of the methyl torsion tunnelling component with G symmetry exhibit the longest lifetimes among the tunnelling components. Vibrational coupling of G torsional levels in the triplet manifold favoured by symmetry is proposed to selectively increase the density of coupling triplet states and, hence, the lifetime of the eigenstates.

  8. Antimutagenicity of an acetone extract of yogurt.

    PubMed

    Nadathur, S R; Gould, S J; Bakalinsky, A T

    1995-04-01

    Reconstituted non-fat dry milk powder, fermented by a mixture of Streptococcus thermophilus CH3 and Lactobacillus bulgaricus 191R to produce yogurt, was freeze-dried and extracted in acetone. After evaporation of the acetone, the extract was dissolved in dimethyl sulfoxide (DMSO) and tested for antimutagenicity. In the Ames test, significant dose-dependent activity was observed against N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), 4-nitro-quinoline-N-oxide (4NQO), 3,2'-dimethyl-4-aminobiphenyl (DMAB), 9,10-dimethyl-1,2-benz[a]anthracene (DMBA), and 3-amino-1-methyl-5H-pyrido[4,3-b]indole acetate (Trp-P-2). Weak activity was observed against 1,2,7,8-diepoxyoctane (DEO), and no activity was observed against methyl methanesulfonate (MMS), ethyl methanesulfonate (EMS), or aflatoxin B1 (AFB1). In a related assay (Saccharomyces cerevisiae D7), significant antimutagenic activity was detected against MNNG and 4NQO. Activity against the experimental colon carcinogens MNNG and DMAB was examined further, as assayed in the Ames test (Salmonella typhimurium TA100). Compounds responsible for both activities were less soluble in aqueous solutions than in DMSO. Adjustment of yogurt pH to 3, 7.6, or 13 prior to freeze-drying and acetone extraction did not significantly alter the amount of anti-MNNG activity recovered. In contrast, extractability of anti-DMAB activity was significantly greater at acidic pH. Conjugated linoleic acid, a known dairy anticarcinogen, failed to inhibit mutagenesis caused by either mutagen, suggesting that other yogurt-derived compound(s) are responsible. Unfermented milk was treated with lactic acid, yogurt bacteria without subsequent growth, or both, to determine if formation of antimutagenic activity required bacterial growth. Extracts of the milk treatments exhibited the same weak antimutagenicity observed in unfermented milk, approximately 2.5-fold less than in the yogurt extracts, suggesting that antimutagenic activity is associated with bacterial

  9. Enzymology of acetone-butanol-isopropanol formation

    SciTech Connect

    Chen, Jiann-Shin.

    1992-01-01

    The long-term goal of the project is to understand the fundamental properties of biological solvent production. Our approach is to elucidate first the molecular properties of solvent-producing enzymes and then to apply to information gained from the enzymological study to investigate control mechanisms for the solvent-producing pathways and the expression of solvent-production genes. Our research primarily involves two strains of Clostridium beijerinckii: C. Beijerinckii NRRL B593 which produces isopropanol in addition to acetone, butanol, and ethanol, and C. beijerinckii NRRL B592 which produces acetone, butanol and ethanol, but not isopropanol. In more recent studies, we also included another solvent-producing organism, Bacillus macerans. Objectives for the reporting period were: to characterize the distinct types of alcohol dehydrogenase; to purify and characterize acetoacetyl-CoA-reacting enzymes; and to clone and sequence the gene encoding the primary/secondary alcohol dehydrogenase of C beijerinckii NRRL B593 and to search for the promoter region for solvent-production genes.

  10. Economic evaluation of the acetone - butanol fermentation

    SciTech Connect

    Lenz, T.G.; Morevra, A.R.

    1980-12-01

    The economics of producing acetone and 1-butanol via fermentation have been examined for a 45 X 10 to the power of 6 kg of solvents/year plant. For a molasses substrate, the total annual production costs were about $24.4 million vs. a total annual income of $36 million, with about $20 million total required capital. Molasses cost of about $24.4 million/year was critical to these economics. Liquid whey was next evaluated as an alternative feed. Whey feed saved about $11 million annually in feed costs and yielded about $7 million net additional annual revenues from protein sale. These primary differences gave an annual gross profit of about $15 million for the whey case and resulted in a discounted cash flow rate of return of 29%. It is concluded that waste based acetone-butanol production via fermentation deserves further attention in view of the attractive whey-based economics and the excellent potential of butanol as a fuel extender, especially for diesohol blending.

  11. Acetone-butanol Fermentation of Marine Macroalgae

    SciTech Connect

    Huesemann, Michael H.; Kuo, Li-Jung; Urquhart, Lindsay A.; Gill, Gary A.; Roesijadi, Guritno

    2012-03-01

    Mannitol and laminarin, which are present at high concentrations in the brown macroalga Saccharina spp., a type of kelp, are potential biochemical feedstocks for butanol production. To test their bioconversion potential, aqueous extracts of the kelp Saccharina spp., mannitol, and glucose (a product of laminarin hydrolysis) were subjected to acetone-butanol fermentation by Clostridium acetobutylicum (ATCC 824). Both mannitol and glucose were readily fermented. Mixed substrate fermentations with glucose and mannitol resulted in diauxic growth of C. acetobutylicum with glucose depletion preceding mannitol utilization. Fermentation of kelp extract exhibited triauxic growth, with an order of utilization of free glucose, mannitol, and bound glucose, presumably laminarin. The lag in laminarin utilization reflected the need for enzymatic hydrolysis of this polysaccharide into fermentable sugars. The butanol and total solvent yields were 0.12 g/g and 0.16 g/g, respectively, indicating that significant improvements are still needed to make industrial-scale acetone-butanol fermentations of seaweed economically feasible.

  12. Apparatus and method for monitoring breath acetone and diabetic diagnostics

    DOEpatents

    Duan, Yixiang; Cao, Wenqing

    2008-08-26

    An apparatus and method for monitoring diabetes through breath acetone detection and quantitation employs a microplasma source in combination with a spectrometer. The microplasma source provides sufficient energy to produce excited acetone fragments from the breath gas that emit light. The emitted light is sent to the spectrometer, which generates an emission spectrum that is used to detect and quantify acetone in the breath gas.

  13. Determination of equilibrium constants for the reaction between acetone and HO2 using infrared kinetic spectroscopy.

    PubMed

    Grieman, Fred J; Noell, Aaron C; Davis-Van Atta, Casey; Okumura, Mitchio; Sander, Stanley P

    2011-09-29

    The reaction between the hydroperoxy radical, HO(2), and acetone may play an important role in acetone removal and the budget of HO(x) radicals in the upper troposphere. We measured the equilibrium constants of this reaction over the temperature range of 215-272 K at an overall pressure of 100 Torr using a flow tube apparatus and laser flash photolysis to produce HO(2). The HO(2) concentration was monitored as a function of time by near-IR diode laser wavelength modulation spectroscopy. The resulting [HO(2)] decay curves in the presence of acetone are characterized by an immediate decrease in initial [HO(2)] followed by subsequent decay. These curves are interpreted as a rapid (<100 μs) equilibrium reaction between acetone and the HO(2) radical that occurs on time scales faster than the time resolution of the apparatus, followed by subsequent reactions. This separation of time scales between the initial equilibrium and ensuing reactions enabled the determination of the equilibrium constant with values ranging from 4.0 × 10(-16) to 7.7 × 10(-18) cm(3) molecule(-1) for T = 215-272 K. Thermodynamic parameters for the reaction determined from a second-law fit of our van't Hoff plot were Δ(r)H°(245) = -35.4 ± 2.0 kJ mol(-1) and Δ(r)S°(245) = -88.2 ± 8.5 J mol(-1) K(-1). Recent ab initio calculations predict that the reaction proceeds through a prereactive hydrogen-bonded molecular complex (HO(2)-acetone) with subsequent isomerization to a hydroxy-peroxy radical, 2-hydroxyisopropylperoxy (2-HIPP). The calculations differ greatly in the energetics of the complex and the peroxy radical, as well as the transition state for isomerization, leading to significant differences in their predictions of the extent of this reaction at tropospheric temperatures. The current results are consistent with equilibrium formation of the hydrogen-bonded molecular complex on a short time scale (100 μs). Formation of the hydrogen-bonded complex will have a negligible impact on the

  14. Determination of induction period and crystal growth mechanism of dexamethasone sodium phosphate in methanol-acetone system

    NASA Astrophysics Data System (ADS)

    Hao, Hongxun; Wang, Jingkang; Wang, Yongli

    2005-02-01

    The induction period of dexamethasone sodium phosphate at different supersaturation was experimentally determined in a methanol-acetone system. The laser monitoring observation technique was used to determine the appearance of the first nucleus in solution. The effect of solution composition on induction period was discussed. Based on classical homogeneous nucleation theory, the solid-liquid interfacial tension and surface entropy factor were calculated from the induction period data. The experimentally determined values of interfacial tension are in agreement with the theoretical values predicted by the Mersmann equation. It was found that the nucleus of dexamethasone sodium phosphate grows continuously in pure methanol and turns from continuous growth to birth and spread growth with increasing acetone content in a methanol-acetone mixture.

  15. Reduction of acetone to isopropanol using producer gas fermenting microbes.

    PubMed

    Ramachandriya, Karthikeyan D; Wilkins, Mark R; Delorme, Marthah J M; Zhu, Xiaoguang; Kundiyana, Dimple K; Atiyeh, Hasan K; Huhnke, Raymond L

    2011-10-01

    Gasification-fermentation is an emerging technology for the conversion of lignocellulosic materials into biofuels and specialty chemicals. For effective utilization of producer gas by fermenting bacteria, tar compounds produced in the gasification process are often removed by wet scrubbing techniques using acetone. In a preliminary study using biomass generated producer gas scrubbed with acetone, an accumulation of acetone and subsequent isopropanol production was observed. The effect of 2 g/L acetone concentrations in the fermentation media on growth and product distributions was studied with "Clostridium ragsdalei," also known as Clostridium strain P11 or P11, and Clostridium carboxidivorans P7 or P7. The reduction of acetone to isopropanol was possible with "C. ragsdalei," but not with P7. In P11 this reaction occurred rapidly when acetone was added in the acidogenic phase, but was 2.5 times slower when added in the solventogenic phase. Acetone at concentrations of 2 g/L did not affect the growth of P7, but ethanol increased by 41% and acetic acid concentrations decreased by 79%. In the fermentations using P11, growth was unaffected and ethanol concentrations increased by 55% when acetone was added in the acidogenic phase. Acetic acid concentrations increased by 19% in both the treatments where acetone was added. Our observations indicate that P11 has a secondary alcohol dehydrogenase that enables it to reduce acetone to isopropanol, while P7 lacks this enzyme. P11 offers an opportunity for biological production of isopropanol from acetone reduction in the presence of gaseous substrates (CO, CO₂, and H₂).

  16. Dissociative electron attachment studies on acetone

    NASA Astrophysics Data System (ADS)

    Prabhudesai, Vaibhav S.; Tadsare, Vishvesh; Ghosh, Sanat; Gope, Krishnendu; Davis, Daly; Krishnakumar, E.

    2014-10-01

    Dissociative electron attachment (DEA) to acetone is studied in terms of the absolute cross section for various fragment channels in the electron energy range of 0-20 eV. H- is found to be the most dominant fragment followed by O- and OH- with only one resonance peak between 8 and 9 eV. The DEA dynamics is studied by measuring the angular distribution and kinetic energy distribution of fragment anions using Velocity Slice Imaging technique. The kinetic energy and angular distribution of H- and O- fragments suggest a many body break-up for the lone resonance observed. The ab initio calculations show that electron is captured in the multi-centered anti-bonding molecular orbital which would lead to a many body break-up of the resonance.

  17. Dissociative electron attachment studies on acetone

    SciTech Connect

    Prabhudesai, Vaibhav S. Tadsare, Vishvesh; Ghosh, Sanat; Gope, Krishnendu; Davis, Daly; Krishnakumar, E.

    2014-10-28

    Dissociative electron attachment (DEA) to acetone is studied in terms of the absolute cross section for various fragment channels in the electron energy range of 0–20 eV. H{sup −} is found to be the most dominant fragment followed by O{sup −} and OH{sup −} with only one resonance peak between 8 and 9 eV. The DEA dynamics is studied by measuring the angular distribution and kinetic energy distribution of fragment anions using Velocity Slice Imaging technique. The kinetic energy and angular distribution of H{sup −} and O{sup −} fragments suggest a many body break-up for the lone resonance observed. The ab initio calculations show that electron is captured in the multi-centered anti-bonding molecular orbital which would lead to a many body break-up of the resonance.

  18. Hydrogen in ferromagnetic semiconductors for planar spintronics

    NASA Astrophysics Data System (ADS)

    Farshchi, Rouin

    This dissertation documents the use of hydrogen for controlling electrical and magnetic properties of ferromagnetic semiconductors, particularly GaMnAs. With minimal structural perturbation, hydrogen forms complexes with Mn acceptors and renders them neutral, thereby substantially increasing electrical resistivity and removing ferromagnetism. A major finding presented herein is that laser annealing can be used to controllably dissociate the Mn-H complexes and restore ferromagnetism. Structural, electrical, and magnetic effects of the laser activation process are thoroughly explored through experiments and numerical modeling. Local laser activation with tightly-focused ultra-short laser pulses allows for high-resolution direct-writing of ferromagnetic patterns in semiconductors, introducing a new paradigm for device design. Prospects for laser formation of high-temperature phases in ferromagnetic semiconductors are investigated. Finally, several device concepts incorporating the laser activation process are discussed as building blocks towards planar all-semiconductor spintronics.

  19. Effect of Cobalt Particle Size on Acetone Steam Reforming

    SciTech Connect

    Sun, Junming; Zhang, He; Yu, Ning; Davidson, Stephen; Wang, Yong

    2015-06-11

    Carbon-supported cobalt nanoparticles with different particle sizes were synthesized and characterized by complementary characterization techniques such as X-ray diffraction, N-2 sorption, acetone temperature-programmed desorption, transmission electron microscopy, and CO chemisorption. Using acetone steam reforming reaction as a probe reaction, we revealed a volcano-shape curve of the intrinsic activity (turnover frequency of acetone) and the CO2 selectivity as a function of the cobalt particle size with the highest activity and selectivity observed at a particle size of approximately 12.8nm. Our results indicate that the overall performance of acetone steam reforming is related to a combination of particle-size-dependent acetone decomposition, water dissociation, and the oxidation state of the cobalt nanoparticles.

  20. Characterization of sputtered iridium oxide thin films on planar and laser micro-structured platinum thin film surfaces for neural stimulation applications

    NASA Astrophysics Data System (ADS)

    Thanawala, Sachin

    Electrical stimulation of neurons provides promising results for treatment of a number of diseases and for restoration of lost function. Clinical examples include retinal stimulation for treatment of blindness and cochlear implants for deafness and deep brain stimulation for treatment of Parkinsons disease. A wide variety of materials have been tested for fabrication of electrodes for neural stimulation applications, some of which are platinum and its alloys, titanium nitride, and iridium oxide. In this study iridium oxide thin films were sputtered onto laser micro-structured platinum thin films by pulsed-DC reactive sputtering of iridium metal in oxygen-containing atmosphere, to obtain high charge capacity coatings for neural stimulation applications. The micro-structuring of platinum films was achieved by a pulsed-laser-based technique (KrF excimer laser emitting at lambda=248nm). The surface morphology of the micro-structured films was studied using different surface characterization techniques. In-vitro biocompatibility of these laser micro-structured films coated with iridium oxide thin films was evaluated using cortical neurons isolated from rat embryo brain. Characterization of these laser micro-structured films coated with iridium oxide, by cyclic voltammetry and impedance spectroscopy has revealed a considerable decrease in impedance and increase in charge capacity. A comparison between amorphous and crystalline iridium oxide thin films as electrode materials indicated that amorphous iridium oxide has significantly higher charge capacity and lower impedance making it preferable material for neural stimulation application. Our biocompatibility studies show that neural cells can grow and differentiate successfully on our laser micro-structured films coated with iridium oxide. This indicates that reactively sputtered iridium oxide (SIROF) is biocompatible.

  1. Large-scale planar lightwave circuits

    NASA Astrophysics Data System (ADS)

    Bidnyk, Serge; Zhang, Hua; Pearson, Matt; Balakrishnan, Ashok

    2011-01-01

    By leveraging advanced wafer processing and flip-chip bonding techniques, we have succeeded in hybrid integrating a myriad of active optical components, including photodetectors and laser diodes, with our planar lightwave circuit (PLC) platform. We have combined hybrid integration of active components with monolithic integration of other critical functions, such as diffraction gratings, on-chip mirrors, mode-converters, and thermo-optic elements. Further process development has led to the integration of polarization controlling functionality. Most recently, all these technological advancements have been combined to create large-scale planar lightwave circuits that comprise hundreds of optical elements integrated on chips less than a square inch in size.

  2. Carbon dioxide slab laser

    SciTech Connect

    Tulip, J.

    1988-01-12

    A gas slab laser is described comprising: first and second elongated electrodes each including a planar light reflecting surface disposed so as to form a light guide only in a plane perpendicular to the planar surface and to define a gas discharge gap therebetween; a laser gas disposed in the gap; and means for applying a radio frequency current between the first and second electrodes to establish a laser-exciting discharge in the laser gas.

  3. Simultaneous Burst Imaging of Dual Species Using Planar Laser-Induced Fluorescence at 50 kHz in Turbulent Premixed Flames.

    PubMed

    Li, Zheming; Rosell, Joakim; Aldén, Marcus; Richter, Mattias

    2016-11-18

    Spatially and temporally resolved measurements are of great importance in turbulent premixed flame studies, especially when investigating rapid processes such as when flame local extinction, re-ignition, or flashback occur in a reacting flow. Here, an experimental approach for simultaneously probing two different species at high frame rates (50 kHz) is presented by employing a multi-YAG laser system. The laser radiation at 355 nm generated by a multi-YAG laser system was split into two beam paths: one beam for exciting formaldehyde and the other for pumping an optical parametric oscillator (OPO). To be able to capture the resulting fluorescence at such a high frame rate without significant loss in spatial resolution, two framing cameras, containing a total of 16 intensified charge-coupled devices (CCDs), were employed. In principle, the proposed setup provides the possibility of probing formaldehyde and simultaneously accessing the distribution of one other relevant species at this high frame rate. In this demonstration, the laser wavelength was tuned to 283 nm and, in conjunction with the 355 nm beam path, simultaneously high speed two-dimensional (2D) visualization of OH-radicals and formaldehyde was achieved. A modified flat flame, McKenna-type burner was used to provide a turbulent premixed jet-flame supported by a surrounding pilot flame. Local flame extinction and re-ignition processes were recorded for fuel/air jet speeds of 120 m/s.

  4. Measuring breath acetone for monitoring fat loss: Review

    PubMed Central

    2015-01-01

    Objective Endogenous acetone production is a by‐product of the fat metabolism process. Because of its small size, acetone appears in exhaled breath. Historically, endogenous acetone has been measured in exhaled breath to monitor ketosis in healthy and diabetic subjects. Recently, breath acetone concentration (BrAce) has been shown to correlate with the rate of fat loss in healthy individuals. In this review, the measurement of breath acetone in healthy subjects is evaluated for its utility in predicting fat loss and its sensitivity to changes in physiologic parameters. Results BrAce can range from 1 ppm in healthy non‐dieting subjects to 1,250 ppm in diabetic ketoacidosis. A strong correlation exists between increased BrAce and the rate of fat loss. Multiple metabolic and respiratory factors affect the measurement of BrAce. BrAce is most affected by changes in the following factors (in descending order): dietary macronutrient composition, caloric restriction, exercise, pulmonary factors, and other assorted factors that increase fat metabolism or inhibit acetone metabolism. Pulmonary factors affecting acetone exchange in the lung should be controlled to optimize the breath sample for measurement. Conclusions When biologic factors are controlled, BrAce measurement provides a non‐invasive tool for monitoring the rate of fat loss in healthy subjects. PMID:26524104

  5. Multiple Optical Traps with a Single-Beam Optical Tweezer Utilizing Surface Micromachined Planar Curved Grating

    NASA Astrophysics Data System (ADS)

    Kuo, Ju-Nan; Chen, Kuan-Yu

    2010-11-01

    In this paper, we present a single-beam optical tweezer integrated with a planar curved diffraction grating for microbead manipulation. Various curvatures of the surface micromachined planar curved grating are systematically investigated. The planar curved grating was fabricated using multiuser micro-electro-mechanical-system (MEMS) processes (MUMPs). The angular separation and the number of diffracted orders were determined. Experimental results indicate that the diffraction patterns and curvature of the planar curved grating are closely related. As the curvature of the planar curved grating increases, the vertical diffraction angle increases, resulting in the strip patterns of the planar curved grating. A single-beam optical tweezer integrated with a planar curved diffraction grating was developed. We demonstrate a technique for creating multiple optical traps from a single laser beam using the developed planar curved grating. The strip patterns of the planar curved grating that resulted from diffraction were used to trap one row of polystyrene beads.

  6. Design of reconfigurable GRIN planar optical interconnects

    NASA Astrophysics Data System (ADS)

    Gomez-Reino, C.; Flores-Arias, M. T.; Perez, M. V.; Bao, C.; Castelo, A.; Nieto, D.

    2008-04-01

    Design of all-optics reconfigurable GRIN (Gradient-Index) planar structure for crossover and parallel interconnects will be presented. Design represents a unique combination of GRIN materials, simple geometry optics and waveguide technology for both parallel and distributed processing and communication networks. The optical analysis is based on-axis and off-axis multiple imaging property of GRIN components. The analysis includes the study of the Point Spread Function (PSF) for describing the performance of the GRIN planar structure and the evaluation of the Space Bandwidth Product (SBP) for estimating the number of channels which can be handled. The dependence of the number of channels on the wavelength of the light and the aperture of the planar interconnect is shown. The results are given for five working wavelengths of Laser Diode (LD) and for four transverse aperture of reconfigurable optical interconnect.

  7. Analysis of the light-current relationships in the optimized planar buried mesa ridge (PBMR) InGaAsP laser

    NASA Astrophysics Data System (ADS)

    Procházková, O.; Novotný, J.; Šrobár, F.

    1992-05-01

    Inclusion of the optimized composite waveguide concept in the InGaAsP/InP PBMR laser construction resulted in an improvement of the differential quantum efficiency value by more than ten per cent. Analysis of the kinetic equations for the carrier and photon populations was used to evaluate various contributions (radiative recombination, Auger processes, electron drift and parasitic leakage currents) to the threshold current in the optimized PBMR geometry.

  8. An Acetone Nanosensor For Non-invasive Diabetes Detection

    NASA Astrophysics Data System (ADS)

    Wang, L.; Yun, X.; Stanacevic, M.; Gouma, P. I.

    2009-05-01

    Diabetes is a most common disease worldwide. Acetone in exhaled breath is a known biomarker of Type- 1 diabetes. An exhaled breath analyzer has been developed with the potential to diagnose diabetes as a non-invasive alternative of the currently used blood-based diagnostics. This device utilizes a chemiresistor based on ferroelectric tungsten oxide nanoparticles and detects acetone selectively in breath-simulated media. Real-time monitoring of the acetone concentration is feasible, potentially making this detector a revolutionary, non- invasive, diabetes diagnostic tool.

  9. Planar gradient metamaterials

    NASA Astrophysics Data System (ADS)

    Xu, Yadong; Fu, Yangyang; Chen, Huanyang

    2016-12-01

    Metamaterials possess exotic properties that do not exist in nature. Gradient metamaterials, which are characterized by a continuous spatial variation of their properties, provide a promising approach to the development of both bulk and planar optics. In particular, planar gradient metamaterials can be classified into three categories: gradient metasurfaces, gradient index metamaterials and gradient metallic gratings. In this Review, we summarize the progress made in the theoretical modelling of these materials, in their experimental implementation and in the design of functional devices. We discuss the use of planar gradient metamaterials for wave bending and focusing in free space, for supporting surface plasmon polaritons and for the realization of trapped rainbows. We also focus on the implementation of these materials in waveguide systems, which can enable electromagnetic cloaking, Fano resonances, asymmetric transmission and guided mode conversion. Finally, we discuss promising trends, such as the use of dielectric rather than metallic unit elements and the use of planar gradient metamaterials in 3D systems.

  10. Toward Portable Breath Acetone Analysis for Diabetes Detection

    PubMed Central

    Righettoni, Marco; Tricoli, Antonio

    2013-01-01

    Diabetes is a lifelong condition that may cause death and seriously affects the quality of life of a rapidly growing number of individuals. Acetone is a selective breath marker for diabetes that may contribute to the monitoring of related metabolic disorder and thus simplify the management of this illness. Here, the overall performance of Si-doped WO3 nanoparticles made by flame spray pyrolysis as portable acetone detectors is critically reviewed focusing on the requirements for medical diagnostic. The effect of flow rate, chamber volume and acetone dissociation within the measuring chamber are discussed with respect to the calibration of the sensor response. The challenges for the fabrication of portable breath acetone sensors based on chemo-resistive detectors are underlined indicating possible solutions and novel research directions. PMID:21828897

  11. Learning planar Ising models

    SciTech Connect

    Johnson, Jason K.; Oyen, Diane Adele; Chertkov, Michael; Netrapalli, Praneeth

    2016-12-01

    Inference and learning of graphical models are both well-studied problems in statistics and machine learning that have found many applications in science and engineering. However, exact inference is intractable in general graphical models, which suggests the problem of seeking the best approximation to a collection of random variables within some tractable family of graphical models. In this paper, we focus on the class of planar Ising models, for which exact inference is tractable using techniques of statistical physics. Based on these techniques and recent methods for planarity testing and planar embedding, we propose a greedy algorithm for learning the best planar Ising model to approximate an arbitrary collection of binary random variables (possibly from sample data). Given the set of all pairwise correlations among variables, we select a planar graph and optimal planar Ising model defined on this graph to best approximate that set of correlations. Finally, we demonstrate our method in simulations and for two applications: modeling senate voting records and identifying geo-chemical depth trends from Mars rover data.

  12. Learning planar Ising models

    DOE PAGES

    Johnson, Jason K.; Oyen, Diane Adele; Chertkov, Michael; ...

    2016-12-01

    Inference and learning of graphical models are both well-studied problems in statistics and machine learning that have found many applications in science and engineering. However, exact inference is intractable in general graphical models, which suggests the problem of seeking the best approximation to a collection of random variables within some tractable family of graphical models. In this paper, we focus on the class of planar Ising models, for which exact inference is tractable using techniques of statistical physics. Based on these techniques and recent methods for planarity testing and planar embedding, we propose a greedy algorithm for learning the bestmore » planar Ising model to approximate an arbitrary collection of binary random variables (possibly from sample data). Given the set of all pairwise correlations among variables, we select a planar graph and optimal planar Ising model defined on this graph to best approximate that set of correlations. Finally, we demonstrate our method in simulations and for two applications: modeling senate voting records and identifying geo-chemical depth trends from Mars rover data.« less

  13. Learning planar ising models

    SciTech Connect

    Johnson, Jason K; Chertkov, Michael; Netrapalli, Praneeth

    2010-11-12

    Inference and learning of graphical models are both well-studied problems in statistics and machine learning that have found many applications in science and engineering. However, exact inference is intractable in general graphical models, which suggests the problem of seeking the best approximation to a collection of random variables within some tractable family of graphical models. In this paper, we focus our attention on the class of planar Ising models, for which inference is tractable using techniques of statistical physics [Kac and Ward; Kasteleyn]. Based on these techniques and recent methods for planarity testing and planar embedding [Chrobak and Payne], we propose a simple greedy algorithm for learning the best planar Ising model to approximate an arbitrary collection of binary random variables (possibly from sample data). Given the set of all pairwise correlations among variables, we select a planar graph and optimal planar Ising model defined on this graph to best approximate that set of correlations. We present the results of numerical experiments evaluating the performance of our algorithm.

  14. Acetone sensor based on zinc oxide hexagonal tubes

    SciTech Connect

    Hastir, Anita Singh, Onkar Anand, Kanika Singh, Ravi Chand

    2014-04-24

    In this work hexagonal tubes of zinc oxide have been synthesized by co-precipitation method. For structural, morphological, elemental and optical analysis synthesized powders were characterized by using x-ray diffraction, field emission scanning microscope, EDX, UV-visible and FTIR techniques. For acetone sensing thick films of zinc oxide have been deposited on alumina substrate. The fabricated sensors exhibited maximum sensing response towards acetone vapour at an optimum operating temperature of 400°C.

  15. Activation of Acetone and Other Simple Ketones in Anaerobic Bacteria.

    PubMed

    Heider, Johann; Schühle, Karola; Frey, Jasmin; Schink, Bernhard

    2016-01-01

    Acetone and other ketones are activated for subsequent degradation through carboxylation by many nitrate-reducing, phototrophic, and obligately aerobic bacteria. Acetone carboxylation leads to acetoacetate, which is subsequently activated to a thioester and degraded via thiolysis. Two different types of acetone carboxylases have been described, which require either 2 or 4 ATP equivalents as an energy supply for the carboxylation reaction. Both enzymes appear to combine acetone enolphosphate with carbonic phosphate to form acetoacetate. A similar but more complex enzyme is known to carboxylate the aromatic ketone acetophenone, a metabolic intermediate in anaerobic ethylbenzene metabolism in denitrifying bacteria, with simultaneous hydrolysis of 2 ATP to 2 ADP. Obligately anaerobic sulfate-reducing bacteria activate acetone to a four-carbon compound as well, but via a different process than bicarbonate- or CO2-dependent carboxylation. The present evidence indicates that either carbon monoxide or a formyl residue is used as a cosubstrate, and that the overall ATP expenditure of this pathway is substantially lower than in the known acetone carboxylase reactions.

  16. Ten inch Planar Optic Display

    SciTech Connect

    Beiser, L.; Veligdan, J.

    1996-04-01

    A Planar Optic Display (POD) is being built and tested for suitability as a high brightness replacement for the cathode ray tube, (CRT). The POD display technology utilizes a laminated optical waveguide structure which allows a projection type of display to be constructed in a thin (I to 2 inch) housing. Inherent in the optical waveguide is a black cladding matrix which gives the display a black appearance leading to very high contrast. A Digital Micromirror Device, (DMD) from Texas Instruments is used to create video images in conjunction with a 100 milliwatt green solid state laser. An anamorphic optical system is used to inject light into the POD to form a stigmatic image. In addition to the design of the POD screen, we discuss: image formation, image projection, and optical design constraints.

  17. Quantitative Clinical Diagnostic Analysis of Acetone in Human Blood by HPLC: A Metabolomic Search for Acetone as Indicator

    PubMed Central

    Akgul Kalkan, Esin; Sahiner, Mehtap; Ulker Cakir, Dilek; Alpaslan, Duygu; Yilmaz, Selehattin

    2016-01-01

    Using high-performance liquid chromatography (HPLC) and 2,4-dinitrophenylhydrazine (2,4-DNPH) as a derivatizing reagent, an analytical method was developed for the quantitative determination of acetone in human blood. The determination was carried out at 365 nm using an ultraviolet-visible (UV-Vis) diode array detector (DAD). For acetone as its 2,4-dinitrophenylhydrazone derivative, a good separation was achieved with a ThermoAcclaim C18 column (15 cm × 4.6 mm × 3 μm) at retention time (tR) 12.10 min and flowrate of 1 mL min−1 using a (methanol/acetonitrile) water elution gradient. The methodology is simple, rapid, sensitive, and of low cost, exhibits good reproducibility, and allows the analysis of acetone in biological fluids. A calibration curve was obtained for acetone using its standard solutions in acetonitrile. Quantitative analysis of acetone in human blood was successfully carried out using this calibration graph. The applied method was validated in parameters of linearity, limit of detection and quantification, accuracy, and precision. We also present acetone as a useful tool for the HPLC-based metabolomic investigation of endogenous metabolism and quantitative clinical diagnostic analysis. PMID:27298750

  18. Flat panel planar optic display. Revision 4/95

    SciTech Connect

    Veligdan, J.T.

    1995-05-01

    A prototype 10 inch flat panel Planar Optic display, (POD), screen has been constructed and tested. This display screen is comprised of hundreds of planar optic glass sheets bonded together with a cladding layer between each sheet where each glass sheet represents a vertical line of resolution. The display is 9 inches wide by 5 inches high and approximately 1 inch thick. A 3 milliwatt HeNe laser is used as the illumination source and a vector scanning technique is employed.

  19. Acetone production with metabolically engineered strains of Acetobacterium woodii.

    PubMed

    Hoffmeister, Sabrina; Gerdom, Marzena; Bengelsdorf, Frank R; Linder, Sonja; Flüchter, Sebastian; Öztürk, Hatice; Blümke, Wilfried; May, Antje; Fischer, Ralf-Jörg; Bahl, Hubert; Dürre, Peter

    2016-07-01

    Expected depletion of oil and fossil resources urges the development of new alternative routes for the production of bulk chemicals and fuels beyond petroleum resources. In this study, the clostridial acetone pathway was used for the formation of acetone in the acetogenic bacterium Acetobacterium woodii. The acetone production operon (APO) containing the genes thlA (encoding thiolase A), ctfA/ctfB (encoding CoA transferase), and adc (encoding acetoacetate decarboxylase) from Clostridium acetobutylicum were cloned under the control of the thlA promoter into four vectors having different replicons for Gram-positives (pIP404, pBP1, pCB102, and pCD6). Stable replication was observed for all constructs. A. woodii [pJIR_actthlA] achieved the maximal acetone concentration under autotrophic conditions (15.2±3.4mM). Promoter sequences of the genes ackA from A. woodii and pta-ack from C. ljungdahlii were determined by primer extension (PEX) and cloned upstream of the APO. The highest acetone production in recombinant A. woodii cells was achieved using the promoters PthlA and Ppta-ack. Batch fermentations using A. woodii [pMTL84151_actthlA] in a bioreactor revealed that acetate concentration had an effect on the acetone production, due to the high Km value of the CoA transferase. In order to establish consistent acetate concentration within the bioreactor and to increase biomass, a continuous fermentation process for A. woodii was developed. Thus, acetone productivity of the strain A. woodii [pMTL84151_actthlA] was increased from 1.2mgL(-1)h(-1) in bottle fermentation to 26.4mgL(-1)h(-1) in continuous gas fermentation.

  20. Communication: two-dimensional gas-phase coherent anti-Stokes Raman spectroscopy (2D-CARS): simultaneous planar imaging and multiplex spectroscopy in a single laser shot.

    PubMed

    Bohlin, Alexis; Kliewer, Christopher J

    2013-06-14

    Coherent anti-Stokes Raman spectroscopy (CARS) has been widely used as a powerful tool for chemical sensing, molecular dynamics measurements, and rovibrational spectroscopy since its development over 30 years ago, finding use in fields of study as diverse as combustion diagnostics, cell biology, plasma physics, and the standoff detection of explosives. The capability for acquiring resolved CARS spectra in multiple spatial dimensions within a single laser shot has been a long-standing goal for the study of dynamical processes, but has proven elusive because of both phase-matching and detection considerations. Here, by combining new phase matching and detection schemes with the high efficiency of femtosecond excitation of Raman coherences, we introduce a technique for single-shot two-dimensional (2D) spatial measurements of gas phase CARS spectra. We demonstrate a spectrometer enabling both 2D plane imaging and spectroscopy simultaneously, and present the instantaneous measurement of 15,000 spatially correlated rotational CARS spectra in N2 and air over a 2D field of 40 mm(2).

  1. Communication: Two-dimensional gas-phase coherent anti-Stokes Raman spectroscopy (2D-CARS): Simultaneous planar imaging and multiplex spectroscopy in a single laser shot

    NASA Astrophysics Data System (ADS)

    Bohlin, Alexis; Kliewer, Christopher J.

    2013-06-01

    Coherent anti-Stokes Raman spectroscopy (CARS) has been widely used as a powerful tool for chemical sensing, molecular dynamics measurements, and rovibrational spectroscopy since its development over 30 years ago, finding use in fields of study as diverse as combustion diagnostics, cell biology, plasma physics, and the standoff detection of explosives. The capability for acquiring resolved CARS spectra in multiple spatial dimensions within a single laser shot has been a long-standing goal for the study of dynamical processes, but has proven elusive because of both phase-matching and detection considerations. Here, by combining new phase matching and detection schemes with the high efficiency of femtosecond excitation of Raman coherences, we introduce a technique for single-shot two-dimensional (2D) spatial measurements of gas phase CARS spectra. We demonstrate a spectrometer enabling both 2D plane imaging and spectroscopy simultaneously, and present the instantaneous measurement of 15 000 spatially correlated rotational CARS spectra in N2 and air over a 2D field of 40 mm2.

  2. Communication: Two-dimensional gas-phase coherent anti-Stokes Raman spectroscopy (2D-CARS): Simultaneous planar imaging and multiplex spectroscopy in a single laser shot

    SciTech Connect

    Bohlin, Alexis; Kliewer, Christopher J.

    2013-01-01

    Coherent anti-Stokes Raman spectroscopy (CARS) has been widely used as a powerful tool for chemical sensing, molecular dynamics measurements, and rovibrational spectroscopy since its development over 30 years ago, finding use in fields of study as diverse as combustion diagnostics, cell biology, plasma physics, and the standoff detection of explosives. The capability for acquiring resolved CARS spectra in multiple spatial dimensions within a single laser shot has been a long-standing goal for the study of dynamical processes, but has proven elusive because of both phase-matching and detection considerations. Here, by combining new phase matching and detection schemes with the high efficiency of femtosecond excitation of Raman coherences, we introduce a technique for single-shot two-dimensional (2D) spatial measurements of gas phase CARS spectra. We demonstrate a spectrometer enabling both 2D plane imaging and spectroscopy simultaneously, and present the instantaneous measurement of 15, 000 spatially correlated rotational CARS spectra in N2 and air over a 2D field of 40 mm2.

  3. 1.3-μm InGaAsP planar buried heterostructure laser diodes with AlInAs electron stopper layer

    NASA Astrophysics Data System (ADS)

    Tsai, Chia-Lung; Yen, Chih-Ta; Chou, Cheng-Yi; Chang, S. J.; Wu, Meng-Chyi

    2012-06-01

    This study reports on the realization of 1.3-μm InGaAsP buried-heterostructure (BH) laser diodes (LDs) via an Fe-doped semi-insulating InP layer and an AlInAs electron stopper layer (ESL). Experimentally, the as-cleaved BH LD with an AlInAs ESL exhibited improved characteristics in terms of threshold current, slope efficiency, and maximum light output power at 90 °C as compared to those of the normal BH LD without an AlInAs ESL. In addition, high internal quantum efficiency or reduced threshold current density was observed, indicating increased modal gain in BH LDs fabricated with an AlInAs epilayer on top of the active region. It was also found that the temperature sensitivity of the BH LDs with an AlInAs ESL is more stable than that of the normal BH LDs. These results could be attributed to the suppression of thermal carrier leakage out of strain-compensated multiple-quantum-well by a large conduction-band offset of the AlInAs/InGaAsP heterojunction. Otherwise, without consideration of damping factor or coupling loss, the 3-dB bandwidth of the proposed BH LDs reaches a high value of 15.3 GHz. Finally, this TO-can packaged BH LD shows an eye-opening feature with the extinction ratio of 7.49 dB while operating at 10 Gbit/s at 50 mA.

  4. Microbiological production of acetone-butanol by Clostridium acetobutylicum.

    PubMed

    Abou-Zeid, A A; Fouad, M; Yassein, M

    1978-01-01

    Trials succeeded in raising the efficiencies of the fermentation medium, used in the fermentative production of acetone-butanol by Clostridium acetobutylicum. Egyptian black strap molasses (50.0% sugars) was suitable as carbon source in the fermentation medium, and (NH4)2SO4 was utilized with great success as inorganic nitrogen source. 140.0 g/l black strap molasses (about 7.0% sugars) and 3.0 g/l (NH4)2SO4 were the optimum concentrations for obtaining good yields of acetone and butanol. Molasses and (NH4)2SO4 were preferred because they are cheaper than the other carbon and organic nitrogen sources, used in the fermentative production of acetone-butanol. The percentage increase of the total solvents produced in the fermentation (production medium) was increased by 64.0. The slop (by-product of the acetone-butanol fermentation after distillation) was re-used in the fermentation medium as organic nitrogen source and supported the microorganisms for a good production of acetone and butanol, while when stillage was used in the production medium, the total solvents output was less than that produced in the medium containing slop.

  5. Biogenic and biomass burning sources of acetone to the troposphere

    SciTech Connect

    Atherton, C.S.

    1997-04-01

    Acetone may be an important source of reactive odd hydrogen in the upper troposphere and lower stratosphere. This source of odd hydrogen may affect the concentration of a number of species, including ozone, nitrogen oxides, methane, and others. Traditional, acetone had been considered a by-product of the photochemical oxidation of other species, and had not entered models as a primary emission. However, recent work estimates a global source term of 40-60 Tg acetone/year. Of this, 25% is directly emitted during biomass burning, and 20% is directly emitted by evergreens and other plants. Only 3% is due to anthropogenic/industrial emissions. The bulk of the remainder, 51% of the acetone source, is a secondary product from the oxidation of propane, isobutane, and isobutene. Also, while it is speculated that the oxidation of pinene (a biogenic emission) may also contribute about 6 Tg/year, this term is highly uncertain. Thus, the two largest primary sources of acetone are biogenic emission and biomass burning, with industrial/anthropogenic emissions very small in comparison.

  6. Sensor gas analyzer for acetone determination in expired air

    NASA Astrophysics Data System (ADS)

    Baranov, Vitaly V.

    2001-05-01

    Diseases and changes in the way of life change the concentration and composition of the expired air. Our adaptable gas analyzer is intended for the selective analysis of expired air and can be adapted for the solution of current diagnostic and analytical tasks by the user (a physician or a patient). Having analyzed the existing trends in the development of noninvasive diagnostics we have chosen the method of noninvasive acetone detection in expired air, where the acetone concentration correlates with blood and urine glucose concentrations. The appearance of acetone in expired air is indicative of disorders that may be caused not only by diabetes but also be wrong diet, incorrect sportsmen training etc. To control the disorders one should know the acetone concentration in the human body. This knowledge allows one to judge upon the state of the patient, choose a correct diet that will not cause damage to the patient's health, determine sportsmen training efficiency and results and solve the artificial pancreas problem. Our device provide highly accurate analysis, rapid diagnostics and authentic acetone quantification in the patient's body at any time aimed at prediction of the patient's state and assessing the efficiency of the therapy used. Clinical implementation of the device will improve the health and save lives of many thousands of diabetes sufferers.

  7. Nitrate-Dependent Degradation of Acetone by Alicycliphilus and Paracoccus Strains and Comparison of Acetone Carboxylase Enzymes ▿

    PubMed Central

    Dullius, Carlos Henrique; Chen, Ching-Yuan; Schink, Bernhard

    2011-01-01

    A novel acetone-degrading, nitrate-reducing bacterium, strain KN Bun08, was isolated from an enrichment culture with butanone and nitrate as the sole sources of carbon and energy. The cells were motile short rods, 0.5 to 1 by 1 to 2 μm in size, which gave Gram-positive staining results in the exponential growth phase and Gram-negative staining results in the stationary-growth phase. Based on 16S rRNA gene sequence analysis, the isolate was assigned to the genus Alicycliphilus. Besides butanone and acetone, the strain used numerous fatty acids as substrates. An ATP-dependent acetone-carboxylating enzyme was enriched from cell extracts of this bacterium and of Alicycliphilus denitrificans K601T by two subsequent DEAE Sepharose column procedures. For comparison, acetone carboxylases were enriched from two additional nitrate-reducing bacterial species, Paracoccus denitrificans and P. pantotrophus. The products of the carboxylase reaction were acetoacetate and AMP rather than ADP. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of cell extracts and of the various enzyme preparations revealed bands corresponding to molecular masses of 85, 78, and 20 kDa, suggesting similarities to the acetone carboxylase enzymes described in detail for the aerobic bacterium Xanthobacter autotrophicus strain Py2 (85.3, 78.3, and 19.6 kDa) and the phototrophic bacterium Rhodobacter capsulatus. Protein bands were excised and compared by mass spectrometry with those of acetone carboxylases of aerobic bacteria. The results document the finding that the nitrate-reducing bacteria studied here use acetone-carboxylating enzymes similar to those of aerobic and phototrophic bacteria. PMID:21841031

  8. Complex Planar Splines.

    DTIC Science & Technology

    1981-05-01

    try todefine a complex planar spline by holomorphic elements like polynomials, then by the well known identity theorem (e.g. Diederich- Remmert [9, p...R. Remmert : Funktionentheorie I, Springer, Berlin, Heidelberg, New York, 1972, 246 p. 10 0. Lehto - K.I. Virtanen: Quasikonforme AbbildunQen, Springer

  9. Acetone Powder From Dormant Seeds of Ricinus communis L

    NASA Astrophysics Data System (ADS)

    Cavalcanti, Elisa D. C.; Maciel, Fábio M.; Villeneuve, Pierre; Lago, Regina C. A.; Machado, Olga L. T.; Freire, Denise M. G.

    The influence of several factors on the hydrolytic activity of lipase, present in the acetone powder from dormant castor seeds (Ricinus communis) was evaluated. The enzyme showed a marked specificity for short-chain substrates. The best reaction conditions were an acid medium, Triton X-100 as the emulsifying agent and a temperature of 30°C. The lipase activity of the acetone powder of different castor oil genotypes showed great variability and storage stability of up to 90%. The toxicology analysis of the acetone powder from genotype Nordestina BRS 149 showed a higher ricin (toxic component) content, a lower 2S albumin (allergenic compound) content, and similar allergenic potential compared with untreated seeds.

  10. Enjoyment of Euclidean Planar Triangles

    ERIC Educational Resources Information Center

    Srinivasan, V. K.

    2013-01-01

    This article adopts the following classification for a Euclidean planar [triangle]ABC, purely based on angles alone. A Euclidean planar triangle is said to be acute angled if all the three angles of the Euclidean planar [triangle]ABC are acute angles. It is said to be right angled at a specific vertex, say B, if the angle ?ABC is a right angle…

  11. Dielectric Covered Planar Antennas

    NASA Technical Reports Server (NTRS)

    Llombart Juan, Nuria (Inventor); Lee, Choonsup (Inventor); Chattopadhyay, Goutam (Inventor); Gill, John J. (Inventor); Skalare, Anders J. (Inventor); Siegel, Peter H. (Inventor)

    2014-01-01

    An antenna element suitable for integrated arrays at terahertz frequencies is disclosed. The antenna element comprises an extended spherical (e.g. hemispherical) semiconductor lens, e.g. silicon, antenna fed by a leaky wave waveguide feed. The extended spherical lens comprises a substantially spherical lens adjacent a substantially planar lens extension. A couple of TE/TM leaky wave modes are excited in a resonant cavity formed between a ground plane and the substantially planar lens extension by a waveguide block coupled to the ground plane. Due to these modes, the primary feed radiates inside the lens with a directive pattern that illuminates a small sector of the lens. The antenna structure is compatible with known semiconductor fabrication technology and enables production of large format imaging arrays.

  12. Planar electrochemical device assembly

    DOEpatents

    Jacobson; Craig P. , Visco; Steven J. , De Jonghe; Lutgard C.

    2010-11-09

    A pre-fabricated electrochemical device having a dense electrolyte disposed between an anode and a cathode preferably deposited as thin films is bonded to a porous electrically conductive support. A second porous electrically conductive support may be bonded to a counter electrode of the electrochemical device. Multiple electrochemical devices may be bonded in parallel to a single porous support, such as a perforated sheet to provide a planar array. Planar arrays may be arranged in a stacked interconnected array. A method of making a supported electrochemical device is disclosed wherein the method includes a step of bonding a pre-fabricated electrochemical device layer to an existing porous metal or porous metal alloy layer.

  13. Planar electrochemical device assembly

    DOEpatents

    Jacobson, Craig P.; Visco, Steven J.; De Jonghe, Lutgard C.

    2007-06-19

    A pre-fabricated electrochemical device having a dense electrolyte disposed between an anode and a cathode preferably deposited as thin films is bonded to a porous electrically conductive support. A second porous electrically conductive support may be bonded to a counter electrode of the electrochemical device. Multiple electrochemical devices may be bonded in parallel to a single porous support, such as a perforated sheet to provide a planar array. Planar arrays may be arranged in a stacked interconnected array. A method of making a supported electrochemical device is disclosed wherein the method includes a step of bonding a pre-fabricated electrochemical device layer to an existing porous metal or porous metal alloy layer.

  14. NASOPHARYNGEAL CONCENTRATIONS IN THE HUMAN VOLUNTEER BREATHING ACETONE

    EPA Science Inventory

    In an effort to examine the absorption of a common chemical into the nasopharyngeal region in humans, a 57 year old male volunteer inhaled uniformly labeled 13C-acetone at 1.4 ppm for 30 min while performing different breathing maneuvers; nose inhale, nose exhale (NINE); mouth ...

  15. Controlling tunnelling in methane loss from acetone ions by deuteration.

    PubMed

    Bodi, Andras; Baer, Tomas; Wells, Nancy K; Fakhoury, Daniel; Klecyngier, David; Kercher, James P

    2015-11-21

    Energetic acetone cations decay by methane or methyl radical loss. Although the methane-loss barrier to form the ketene cation is higher and the activation entropy is lower, it has a significant branching ratio at low energies thanks to quantum tunnelling. H-atom tunnelling can be selectively quenched and the methane-loss channel suppressed quantitatively by deuteration.

  16. Planar plasmonic chiral nanostructures

    NASA Astrophysics Data System (ADS)

    Zu, Shuai; Bao, Yanjun; Fang, Zheyu

    2016-02-01

    A strong chiral optical response induced at a plasmonic Fano resonance in a planar Au heptamer nanostructure was experimentally and theoretically demonstrated. The scattering spectra show the characteristic narrow-band feature of Fano resonances for both left and right circular polarized lights, with a chiral response reaching 30% at the Fano resonance. Specifically, we systematically investigate the chiral response of planar heptamers with gradually changing the inter-particle rotation angles and separation distance. The chiral spectral characteristics clearly depend on the strength of Fano resonances and the associated near-field optical distributions. Finite element method simulations together with a multipole expansion method demonstrate that the enhanced chirality is caused by the excitation of magnetic quadrupolar and electric toroidal dipolar modes. Our work provides an effective method for the design of 2D nanostructures with a strong chiral response.A strong chiral optical response induced at a plasmonic Fano resonance in a planar Au heptamer nanostructure was experimentally and theoretically demonstrated. The scattering spectra show the characteristic narrow-band feature of Fano resonances for both left and right circular polarized lights, with a chiral response reaching 30% at the Fano resonance. Specifically, we systematically investigate the chiral response of planar heptamers with gradually changing the inter-particle rotation angles and separation distance. The chiral spectral characteristics clearly depend on the strength of Fano resonances and the associated near-field optical distributions. Finite element method simulations together with a multipole expansion method demonstrate that the enhanced chirality is caused by the excitation of magnetic quadrupolar and electric toroidal dipolar modes. Our work provides an effective method for the design of 2D nanostructures with a strong chiral response. Electronic supplementary information (ESI) available

  17. Planar triode pulser socket

    DOEpatents

    Booth, Rex

    1994-01-01

    A planar triode is mounted in a PC board orifice by means of a U-shaped capacitor housing and anode contact yoke removably attached to cathode leg extensions passing through and soldered to the cathode side of the PC board by means of a PC cathode pad. A pliant/flexible contact attached to the orifice make triode grid contact with a grid pad on the grid side of the PC board, permitting quick and easy replacement of bad triodes.

  18. Planar triode pulser socket

    DOEpatents

    Booth, R.

    1994-10-25

    A planar triode is mounted in a PC board orifice by means of a U-shaped capacitor housing and anode contact yoke removably attached to cathode leg extensions passing through and soldered to the cathode side of the PC board by means of a PC cathode pad. A pliant/flexible contact attached to the orifice make triode grid contact with a grid pad on the grid side of the PC board, permitting quick and easy replacement of bad triodes. 14 figs.

  19. Scalable Designs for Planar Ion Trap Arrays

    NASA Astrophysics Data System (ADS)

    Slusher, R. E.

    2007-03-01

    Recent progress in quantum operations with trapped ion qubits has been spectacular for qubit counts up to approximately ten ions. Two qubit quantum gates, quantum error correction, simple quantum algorithms and entanglement of up to 8 qubits have been demonstrated by groups including those at NIST, University of Michigan, University of Innsbruck and Oxford. Interesting problems in quantum information processing including quantum simulations of condensed matter systems and quantum repeaters for long distance quantum communication systems require hundreds or thousands of qubits. Initial designs for an ion trap ``Quantum CCD'' using spatially multiplexed planar ion traps as well as initial experiments using planar ion traps are promising routes to scaling up the number of trapped ions to more interesting levels. We describe designs for planar ion traps fabricated using silicon VLSI techniques. This approach allows the control voltages required for the moving and positioning the ions in the array to be connected vertically through the silicon substrate to underlying CMOS electronics. We have developed techniques that allow the ion trap structures to be fabricated monolithically on top of the CMOS electronics. The planar traps have much weaker trapping depths than the more conventional multi-level traps. However, the trap depths are still adequate for trapping hot ions from many ion sources. The planar traps also involve more complex configurations for laser cooling and micromotion control. Initial solutions to these problems will be presented. Laser access to the ions can be provided by laser beams grazing the trap surface or by using vertical slots through the trap chip. We will also discuss limits imposed by power dissipation and ion transport through trap junctions (e.g. crosses and Ys). We have fabricated these VLSI based traps in a number of configurations. Initial fabrication and packaging challenges will be discussed. D. Kielpinski, C. Monroe, and D.J. Wineland

  20. Quantitative planar laser-induced fluorescence imaging of multi-component fuel/air mixing in a firing gasoline-direct-injection engine: Effects of residual exhaust gas on quantitative PLIF

    SciTech Connect

    Williams, Ben; Ewart, Paul; Wang, Xiaowei; Stone, Richard; Ma, Hongrui; Walmsley, Harold; Cracknell, Roger; Stevens, Robert; Richardson, David; Fu, Huiyu; Wallace, Stan

    2010-10-15

    A study of in-cylinder fuel-air mixing distributions in a firing gasoline-direct-injection engine is reported using planar laser-induced fluorescence (PLIF) imaging. A multi-component fuel synthesised from three pairs of components chosen to simulate light, medium and heavy fractions was seeded with one of three tracers, each chosen to co-evaporate with and thus follow one of the fractions, in order to account for differential volatility of such components in typical gasoline fuels. In order to make quantitative measurements of fuel-air ratio from PLIF images, initial calibration was by recording PLIF images of homogeneous fuel-air mixtures under similar conditions of in-cylinder temperature and pressure using a re-circulation loop and a motored engine. This calibration method was found to be affected by two significant factors. Firstly, calibration was affected by variation of signal collection efficiency arising from build-up of absorbing deposits on the windows during firing cycles, which are not present under motored conditions. Secondly, the effects of residual exhaust gas present in the firing engine were not accounted for using a calibration loop with a motored engine. In order to account for these factors a novel method of PLIF calibration is presented whereby 'bookend' calibration measurements for each tracer separately are performed under firing conditions, utilising injection into a large upstream heated plenum to promote the formation of homogeneous in-cylinder mixtures. These calibration datasets contain sufficient information to not only characterise the quantum efficiency of each tracer during a typical engine cycle, but also monitor imaging efficiency, and, importantly, account for the impact of exhaust gas residuals (EGR). By use of this method EGR is identified as a significant factor in quantitative PLIF for fuel mixing diagnostics in firing engines. The effects of cyclic variation in fuel concentration on burn rate are analysed for different

  1. High slope efficiency and low threshold in a laser-diode-pumped passively Q-switched ion-implanted Nd:YVO4 planar waveguide laser with GaAs saturable absorber

    NASA Astrophysics Data System (ADS)

    Du, G. L.; Li, G. Q.; Zhao, S. Z.; Li, T.; Yang, K. J.; Li, X.

    2011-11-01

    A passively Q-switched waveguide laser, to our knowledge, has been firstly demonstrated in Nd: YVO4 crystal formed by 3 MeV Si+ ion implantation at a dose of 1 × 1015 ions/cm2 at room temperature, in which GaAs was used as saturable absorber. The dependences of the average output power, pulse width, pulse repetition rate on absorbed pump power have been measured at different output plane mirror transmissions. At an absorbed pump power of 78.8 mW and output transmission of 20%, the shortest pulse width of 3.88 ns was obtained, corresponding to the peak power and single pulse energy of 212 W and 0.82 μJ, respectively. The threshold pump power was as low as 40 mW, and the slope efficiency was about 64.5% when the absorbed pump power was lower than 70 mW.

  2. Optical planar waveguide for cell counting

    NASA Astrophysics Data System (ADS)

    LeBlanc, John; Mueller, Andrew J.; Prinz, Adrian; Butte, Manish J.

    2012-01-01

    Low cost counting of cells has medical applications in screening, military medicine, disaster medicine, and rural healthcare. In this report, we present a shallow, buried, planar waveguide fabricated by potassium ion exchange in glass that enables low-cost and rapid counting of metal-tagged objects that lie in the evanescent field of the waveguide. Laser light transmitted through the waveguide was attenuated proportionately to the presence of metal-coated microstructures fabricated from photoresist. This technology enables the low-cost enumeration of cells from blood, urine, or other biofluids.

  3. Theoretical analysis of planar pulse microwiggler

    SciTech Connect

    Qing-Xiang Liu |; Yong Xu

    1995-12-31

    The Magnetic field distributions of a planar pulse microwiggler are studied analytically and numerically. Exact solutions of two-dimensional magnetic fields are derived, which show that along the electron axis the fields have a variation close enough to a sine wave. We also investigate wiggler field errors due to machining tolerance and effects of the field errors on trajectories of electron with the help numerical simulations. The results are critical for successful operation of CAEP compact free-electron laser experiment under preparation.

  4. Measurement of the diffusion coefficient of acetone in succinonitrile at its melting point

    NASA Technical Reports Server (NTRS)

    Chopra, M. A.; Glicksman, M. E.; Singh, N. B.

    1988-01-01

    The diffusion coefficient of acetone in liquid succinonitrile at 331.1 K was determined using the method of McBain and Dawson (1935). Only dilute mixtures of SCN-acetone were studied. The interdiffusion constant was determined to be 0.0000127 sq cm/s and was essentially independent of the acetone concentration over the range investigated (0.5 to 18 mol pct acetone).

  5. Does acetone react with HO2 in the upper-troposphere?

    NASA Astrophysics Data System (ADS)

    Dillon, T. J.; Pozzer, A.; Crowley, J. N.; Lelieveld, J.

    2010-07-01

    Recent theoretical calculations showed that reaction of HO2 with acetone (CH3C(O)CH3) could be a potentially important sink for acetone and source for acetic acid in cold parts of the atmosphere (e.g. the tropopause region). The reaction HO2+CH3C(O)CH3⇌(CH3)2C(OH)OO (R1, R-1) was therefore studied experimentally at low-temperatures for the first time. HO2 was generated by pulsed laser photolysis, and converted by reaction with NO to OH for detection by laser induced fluorescence. Reduced yields of OH at T<220 K provided evidence for stabilisation of (CH3)2C(OH)OO at such temperatures. In contrast, no evidence for (R1) was observed at T>230 K, probably due to rapid thermal dissociation of the peroxy radical product back to reactants (R-1). The experimental data indicate that the rate coefficient for the forward reaction, k1(207 K), is larger than 1.6×10-12 cm3 molecule-1 s-1, in line with recent quantum mechanical calculations. In contrast, an upper limit for the equilibrium constant K1(T)=k1(T)/k-1(T) of 7.8×1028exp(50.6 kJ mol-1/RT) was obtained, considerably smaller than calculated from theory. Incorporation of these results into a global 3-D chemical model demonstrated that (R1) is neither a significant loss process for CH3C(O)CH3 nor a significant source of acetic acid in the atmosphere.

  6. Lasers.

    PubMed

    Passeron, T

    2012-12-01

    Lasers are a very effective approach for treating many hyperpigmented lesions. They are the gold standard treatment for actinic lentigos and dermal hypermelanocytosis, such as Ota nevus. Becker nevus, hyperpigmented mosaicisms, and lentigines can also be successfully treated with lasers, but they could be less effective and relapses can be observed. However, lasers cannot be proposed for all types of hyperpigmentation. Thus, freckles and café-au-lait macules should not be treated as the relapses are nearly constant. Due to its complex pathophysiology, melasma has a special place in hyperpigmented dermatoses. Q-switched lasers (using standard parameters or low fluency) should not be used because of consistent relapses and the high risk of post-inflammatory hyperpigmentation. Paradoxically, targeting the vascular component of the melasma lesion with lasers could have a beneficial effect. However, these results have yet to be confirmed. In all cases, a precise diagnosis of the type of hyperpigmentation is mandatory before any laser treatment, and the limits and the potential side effects of the treatment must be clearly explained to patients.

  7. [Lasers].

    PubMed

    Passeron, T

    2012-11-01

    Lasers are a very effective approach for treating many hyperpigmented lesions. They are the gold standard treatment for actinic lentigos and dermal hypermelanocytosis, such as Ota nevus. Becker nevus, hyperpigmented mosaicisms, and lentigines can also be successfully treated with lasers, but they could be less effective and relapses can be observed. However, lasers cannot be proposed for all types of hyperpigmentation. Thus, freckles and café-au-lait macules should not be treated as the relapses are nearly constant. Due to its complex pathophysiology, melasma has a special place in hyperpigmented dermatoses. Q-switched lasers (using standard parameters or low fluency) should not be used because of consistent relapses and the high risk of post-inflammatory hyperpigmentation. Paradoxically, targeting the vascular component of the melasma lesion with lasers could have a beneficial effect. However, these results have yet to be confirmed. In all cases, a precise diagnosis of the type of hyperpigmentation is mandatory before any laser treatment, and the limits and the potential side effects of the treatment must be clearly explained to patients.

  8. The influence of small additions of diethylenetriamine on the detonation waves stability for nitromethane/acetone solution

    NASA Astrophysics Data System (ADS)

    Mochalova, V.; Utkin, A.

    2014-05-01

    Instability of detonation front in the nitromethane/acetone (NM/A) solution was observed in our previous work: at 10% of acetone the amplitude of heterogeneities was about 20 microns and at 20% of acetone this size was 50 microns. It is known that small additions of diethylenetriamine (DETA) considerably increase the initial rate of chemical reaction in detonation waves for NM. It was expected that DETA would influence the stability of detonation waves in the NM/A solution too. To investigate this phenomenon the laser interferometer VISAR was used for the recording of particle velocity profiles in detonation waves for NM/A. It was found that at the addition of 0.5% DETA to NM/A 90/10 the oscillations in the velocity profile decreased several times over. At the addition of 1% DETA the profile is smooth, i.e. the heterogeneities disappear and detonation wave becomes steady-state. In NM/A 80/20 at the addition of 5% DETA the heterogeneities size is reduced by the order. The increase of detonation wave velocity of NM/A grater than 1% was observed at small concentrations of DETA. Thus it was found that small additions of DETA to the NM/A solution with an unstable detonation front resulted not only in the decrease of heterogeneities size but in their disappearance and stabilization of detonation waves.

  9. Acetone photolysis at 248 nm revisited: pressure dependence of the CO and CO2 quantum yields.

    PubMed

    Somnitz, H; Ufer, T; Zellner, R

    2009-10-14

    Pressure dependent CO and CO2 quantum yields in the laser pulse photolysis of acetone at 248 nm and T = 298 K have been measured directly using quantitative infrared diode laser absorption. The experiments cover the pressure range from 50 to 900 mbar. It is found that the quantum yields show a significant dependence on total pressure, with Phi(CO) decreasing from around 0.5 at 20 mbar to approximately 0.3 at 900 mbar. The corresponding CO2 yields as observed when O2 exists in the reaction mixture, exhibit exactly the opposite behaviour. For the sum of both a value of 1.05(-0.05)(+0.02) independent of pressure is obtained, showing that the sum of (Phi(CO) + Phi(CO2)) is a measure for the primary quantum yield in the photolysis of acetone. In addition, CO quantum yields and corresponding pressure dependences were measured in experiments using different bath gases including He, Ar, Kr, SF6, and O2 as third body colliders. The theoretical framework in which we discuss these data is based on our previous findings that the pressure dependence of the CO yield is a consequence of a stepwise fragmentation mechanism during which acetone decomposes initially into methyl and a vibrationally 'hot' acetyl radical, with the latter being able to decompose promptly into methyl plus CO. The pressure dependence of the CO yield then originates from the second step and is modelled quantitatively via statistical dynamical calculations using a combination of RRKM theory with a time-dependent master equation (ME) approach. From a comparison of experiment with theory the amount of excess energy in the vibrationally hot acetyl radicals (E* approximately 65 kJ mol(-1)) as well as the characteristic collision parameters for interaction of acetyl with the different bath gases were derived. Values of 90, 280, 310, 545, 550 and 1800 cm(-1) for the average energy transferred per downward collision for the bath gases He, Ar, Kr, O2, N2, and SF6, respectively, are obtained. The calculations also

  10. Evaluation of unbound free heme in plant cells by differential acetone extraction.

    PubMed

    Espinas, Nino A; Kobayashi, Koichi; Takahashi, Shigekazu; Mochizuki, Nobuyoshi; Masuda, Tatsuru

    2012-07-01

    Heme functions not only as a prosthetic group of hemoproteins but also as a regulatory molecule, suggesting the presence of 'free' heme. Classically, total non-covalently bound heme is extracted from plant samples with acidic acetone after removal of pigments with basic and neutral acetone. Earlier work proposed that free heme can be selectively extracted into basic acetone. Using authentic hemoproteins, we confirmed that acidic acetone can quantitatively extract heme, while no heme was extracted into neutral acetone. Meanwhile, a certain amount of heme was extracted into basic acetone from hemoglobin and myoglobin. Moreover, basic acetone extracted loosely bound heme from bovine serum albumin, implying that the nature of hemoproteins largely influences heme extraction into basic acetone. Using a highly sensitive heme assay, we found that basic and neutral acetone can extract low levels of heme from plant samples. In addition, neutral acetone quantitatively extracted free heme when it was externally added to plant homogenates. Furthermore, the level of neutral acetone-extractable heme remained unchanged by precursor (5-aminolevulinic acid) feeding, while increased by norflurazon treatment which abolishes chloroplast biogenesis. However, changes in these heme levels did not correlate to genomes uncoupled phenotypes, suggesting that the level of unbound free heme would not affect retrograde signaling from plastids to the nucleus. The present data demonstrate that the combination of single-step acetone extraction following a sensitive heme assay is the ideal method for determining total and free heme in plants.

  11. trans-Dichloridobis[tris-(4-meth-oxy-lphen-yl)phosphane-κP]platinum(II) acetone disolvate.

    PubMed

    Muller, Alfred

    2012-12-01

    In the title compound, [PtCl2(C21H21O3P)2]·2C3H6O, the asymmetric unit contains a Pt(II) ion situated on an inversion center, one chloride anion, one tris-(4-meth-oxy-lphen-yl)phosphane (L) ligand and one acetone solvent mol-ecule. The Pt(II) ion is coordinated by two P atoms [Pt-P = 2.3196 (5) Å] from two L ligands and two chloride anions [Pt-Cl = 2.3075 (5) Å] in a distorted square-planar geometry with P-Pt-Cl angles of 88.016 (16) and 91.984 (16)°. The effective cone angle of the phosphane ligand was calculated to be 156°. Weak C-H⋯O and C-H⋯Cl hydrogen bonds hold mol-ecules together.

  12. Planar oscillatory stirring apparatus

    NASA Technical Reports Server (NTRS)

    Wolf, Martin F. (Inventor)

    1987-01-01

    Apparatus (11) for applying planar oscillations to a container (13). Pressurized air (99) is supplied to a moveable slide plate (27) which employs arms (19) having an air bearing vent structure (29, 31) which allows the slide plate to float and to translate. The container (13) to be oscillated is secured to the upper surface of the slide plate (27). A motor (39) driven rotating eccentric shaft (59) loosely extends into a center hole bearing (37) of the slide plate (27) to cause the oscillations.

  13. Enhanced Acetone Sensing Characteristics of ZnO/Graphene Composites.

    PubMed

    Zhang, Hao; Cen, Yuan; Du, Yu; Ruan, Shuangchen

    2016-11-09

    ZnO/graphene (ZnO-G) hybrid composites are prepared via hydrothermal synthesis with graphite, N-methyl-pyrrolidone (NMP), and Zn(NO₃)₂·6H₂O as the precursors. The characterizations, including X-ray diffraction (XRD), thermogravimetric analyses (TGA), Raman spectroscopy, and transmission electron microscopy (TEM) indicate the formation of ZnO-G. Gas sensors were fabricated with ZnO-G composites and ZnO as sensing material, indicating that the response of the ZnO towards acetone was significantly enhanced by graphene doping. It was found that the ZnO-G sensor exhibits remarkably enhanced response of 13.3 at the optimal operating temperature of 280 °C to 100 ppm acetone, an improvement from 7.7 with pure ZnO.

  14. Economic evaluation of the acetone-butane fermentation

    SciTech Connect

    Lenz, T.G.; Moreira, A.R.

    1980-01-01

    The economics of producing acetone as 1-butanol via fermentation have been examined for a 45 x 1 kg of solvents/year plant. For a molasses substrate the total annual production costs were approximately $39 million vs. a total annual income of $36 million, with approximatley $20 million total required capital. Molasses cost of approximately $24.4 million/year was critical to these economics. Liquid whey was next evaluated as an alternative feed. Whey feed saved approximately 11 million dollars annually in feed costs and yielded approximately 8 million net additional annual revenues from protein sale. The primary differences gave an annual gross profit of approximately $15 million for the whey case and resulted in a discounted cash flow rate return of 29%. Waste-based acetone-butanol production via fermentation deserves further attention in view of the attractive whey-based economics and the excellent potential of butanol as a fuel extender, especially for diesohol blending.

  15. Enhanced Acetone Sensing Characteristics of ZnO/Graphene Composites

    PubMed Central

    Zhang, Hao; Cen, Yuan; Du, Yu; Ruan, Shuangchen

    2016-01-01

    ZnO/graphene (ZnO-G) hybrid composites are prepared via hydrothermal synthesis with graphite, N-methyl-pyrrolidone (NMP), and Zn(NO3)2·6H2O as the precursors. The characterizations, including X-ray diffraction (XRD), thermogravimetric analyses (TGA), Raman spectroscopy, and transmission electron microscopy (TEM) indicate the formation of ZnO-G. Gas sensors were fabricated with ZnO-G composites and ZnO as sensing material, indicating that the response of the ZnO towards acetone was significantly enhanced by graphene doping. It was found that the ZnO-G sensor exhibits remarkably enhanced response of 13.3 at the optimal operating temperature of 280 °C to 100 ppm acetone, an improvement from 7.7 with pure ZnO. PMID:27834870

  16. Effect of Coadsorbed Water on the Photodecomposition of Acetone on TiO2(110)

    SciTech Connect

    Henderson, Michael A.

    2008-06-10

    The influence of coadsorbed water on the photodecomposition of acetone on TiO2 was examined using temperature programmed desorption (TPD) and the rutile TiO2(110) surface as a model photocatalyst. Of the two major influences ascribed to water in the heterogeneous photocatalysis literature (promotion via OH radical supply and inhibition due to site blocking), only the negative influence of water was observed. As long as the total water and acetone coverage was maintained well below the first layer saturation coverage (‘1 ML’), little inhibition of acetone photodecomposition was observed. However, as the total water+acetone coverage exceeded 1 ML, acetone was preferentially displaced from the first layer to physisorbed states by water and the extent of acetone photodecomposition attenuated. The displacement originated from water compressing acetone into high coverage regions where increased acetone-acetone repulsions caused displacement from the first layer. The immediate product of acetone photodecomposition was adsorbed acetate, which occupies twice as many surface sites per molecule as compared to acetone. Since the acetate intermediate was more stable on the TiO2(110) surface than either water or acetone (as gauged by TPD) and since its photodecomposition rate was less than that of acetone, additional surface sites were not opened up during acetone photodecomposition for previously displaced acetone molecules to re-enter the first layer. Results in this study suggest that increased molecular-level repulsions between organic molecules brought about by increased water coverage are as influential in the inhibiting effect of water on photooxidation rates as are water-organic repulsions.

  17. Pervaporation of ethanol and acetone above normal boiling temperatures

    SciTech Connect

    Windmoeller, D.; Galembeck, F. )

    1992-08-01

    Pervaporation experiments were performed at higher than normal feed liquid boiling temperatures by applying pressure to the feed compartment. Ethanol, acetone, and aqueous ethanol solutions were pervaporated through silicone rubber dense membranes. Large increases were observed in the permeate flow as the temperature rose above the liquid boiling temperature. Separation factors in aqueous ethanol pervaporation are not affected by these increases in permeate output, and they are in the same range as those obtained in conventional pervaporation.

  18. Reverse osmosis application for butanol-acetone fermentation

    SciTech Connect

    Garcia, A.; Iannotti, E.L.; Fischer, J.R.

    1984-01-01

    The problems of dilute solvent concentration in butanol-acetone fermentation can be solved by using reverse osmosis to dewater the fermentation liquor. Polyamide membranes exhibited butanol rejection rates as high as 85%. Optimum rejection of butanol occurs at a pressure of approximately 5.5 to 6.5 MPa and hydraulic recoveries of 50-70%. Flux ranged from 0.5 to 1.8 l.

  19. Mixing and stabilization study of a partially premixed swirling flame using laser induced fluorescence

    SciTech Connect

    Galley, D.; Ducruix, S.; Lacas, F.; Veynante, D.

    2011-01-15

    A laboratory-scale swirling burner, presenting many similarities with gas turbines combustors, has been studied experimentally using planar laser induced fluorescence (PLIF) on OH radical and acetone vapor in order to characterize the flame stabilization process. These diagnostics show that the stabilization point rotates in the combustion chamber and that air and fuel mixing is not complete at the end of the mixing tube. Fuel mass fraction decays exponentially along the mixing tube axis and transverse profiles show a gaussian shape. However, radial pressure gradients tend to trap the fuel in the core of the vortex that propagates axially in the mixing tube. As the mixing tube vortex enters the combustion chamber, vortex breakdown occurs through a precessing vortex core (PVC). The axially propagating vortex shows a helicoidal trajectory in the combustion chamber which trace is observed with transverse acetone PLIF. As a consequence, the stabilizing point of the flame in the combustion chamber rotates with the PVC structure. This phenomenon has been observed in the present study with a high speed camera recording spontaneous emission of the flame. The stabilization point rotation frequency tends to increase with mass flow rates. It was also shown that the coupling between the PVC and the flame stabilization occurs via mixing, explaining one possible coupling mechanism between acoustic waves in the flow and the reaction rate. This path may also be envisaged for flashback, an issue that will be more completely treated in a near future. (author)

  20. Molecular interaction forces in acetone + ethanol binary liquid solutions: FTIR and theoretical studies

    NASA Astrophysics Data System (ADS)

    Jadhav, Deepali L.; Karthick, N. K.; Kannan, P. P.; Shanmugam, R.; Elangovan, A.; Arivazhagan, G.

    2017-02-01

    FTIR spectra of neat acetone, ethanol and their binary solutions at the molar ratios 0.2:0.8 (ethanol: acetone), 0.4:0.6, 0.6:0.4 and 0.8:0.2 have been recorded at room temperature. Theoretical calculations have also been made on acetone (monomer and dimer), ethanol monomer, dimer, trimer, tetramer, pentamer, hexamer and ethanol - acetone complex molecules. 4:1 (ethanol:acetone), 5:1 and 6:2 complexation through the classical Cdbnd O⋯Hsbnd O and (acetone) Csbnd H⋯Osbnd C(ethanol) hydrogen bonds has been identified. Ethanol rich solutions may consist of ethanol multimers such as tetramer, pentamer and hexamer along with 4:1, 5:1 and 6:2 complex molecules depending upon ethanol concentration. Acetone seems to exist as a mixture of monomer and dimer.

  1. Improvement of 2,4-dinitrophenylhydrazine derivatization method for carbon isotope analysis of atmospheric acetone.

    PubMed

    Wen, Sheng; Yu, Yingxin; Guo, Songjun; Feng, Yanli; Sheng, Guoying; Wang, Xinming; Bi, Xinhui; Fu, Jiamo; Jia, Wanglu

    2006-01-01

    Through simulation experiments of atmospheric sampling, a method via 2,4-dinitrophenylhydrazine (DNPH) derivatization was developed to measure the carbon isotopic composition of atmospheric acetone. Using acetone and a DNPH reagent of known carbon isotopic compositions, the simulation experiments were performed to show that no carbon isotope fractionation occurred during the processes: the differences between the predicted and measured data of acetone-DNPH derivatives were all less than 0.5 per thousand. The results permitted the calculation of the carbon isotopic compositions of atmospheric acetone using a mass balance equation. In this method, the atmospheric acetone was collected by a DNPH-coated silica cartridge, washed out as acetone-DNPH derivatives, and then analyzed by gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS). Using this method, the first available delta13C data of atmospheric acetone are presented.

  2. Planar Rowland spectrometer for fiber-optic wavelength demultiplexing

    NASA Technical Reports Server (NTRS)

    Yen, H. W.; Friedrich, H. R.; Morrison, R. J.; Tangonan, G. L.

    1981-01-01

    A planar Rowland spectrometer was fabricated and characterized as a wavelength demultiplexer for multimode fiber-optic applications. The spectrometer consisted of a planar multimode glass waveguide with two curved end faces and a cylindrical concave attached to one of the end faces. Semiconductor lasers with wavelengths between 0.825 and 0.845 micron were used for the measurements. Cross-talk isolation between two adjacent fibers with center-to-center separation of 175 microns (100 A in wavelength difference) was measured to be 18 dB. The device's performance was limited by grating diffraction efficiency, optical aberration, waveguide dispersion, and waveguide losses.

  3. Acetone and Acetaldehyde Exchange Above a Managed Temperate Mountain Grassland

    NASA Astrophysics Data System (ADS)

    Hörtnagl, L. J.; Bamberger, I.; Graus, M.; Ruuskanen, T.; Schnitzhofer, R.; Hansel, A.; Wohlfahrt, G.

    2011-12-01

    The exchange of acetone and acetaldehyde was measured above an intensively managed hay meadow in the Stubai Valley (Tyrol, Austria) during the growing seasons in 2008 and 2009. Half-hourly fluxes of both compounds were calculated by means of the virtual disjunct eddy covariance (vDEC) method by combining the 3-dimensional wind data from a sonic anemometer with the compound specific volume mixing ratios quantified with a proton-transfer-reaction mass spectrometer (PTR-MS). The cutting of the meadow resulted in the largest perturbation of the VOC exchange rates. Peak emissions for both VOC species were observed during and right after the cutting of the meadow, with rates of up to 12.1 and 10.1 nmol m-2 s-1 for acetaldehyde and acetone, respectively, reflecting the drying of the wounded plant material. During certain time periods, undisturbed by management events, both compounds exhibited a clear diurnal cycle. Emission rates of up to 3.7 nmol m-2 s-1 for acetaldehyde and 3.2 nmol m-2 s-1 for acetone were measured in October 2008, while a uptake of both compounds with rates of up to 1.8 and 2.1 nmol m-2 s-1, respectively, could be observed in May 2009, when also clear compensation points of 0.3 ppb for acetaldehyde and 1.0 ppb for acetone were observed. In an effort to explore the controls on observed exchange patterns, a simple and multiple linear regression analysis was conducted. A clear interconnection between VOC concentrations and VOC exchange could be seen only in May 2009, when concentration values alone explained 30.6% and 11.7% of the acetaldehyde and acetone flux variance, respectively. However, when trying to predict the observed exchange patterns of both VOC species in a multiple linear regression based on supporting environmental measurements - including air and soil temperature, soil water content and PAR among others - the analysis yielded unsatisfactory results, accounting for 10% and 4% of the observed acetaldehyde and acetone flux variance over both

  4. Planar oscillatory stirring apparatus

    NASA Astrophysics Data System (ADS)

    Wolf, M. F.

    1985-08-01

    The present invention is directed to an apparatus for stirring materials using planar orthogonal axes oscillations. The apparatus has a movable slide plate sandwiched between two fixed parallel support plates. Pressurized air is supplied to the movable slide plate which employs a tri-arm air bearing vent structure which allows the slide plate to float and to translate between the parallel support plates. The container having a material to be stirred is secured to the upper surface of the slide plate through an aperture in the upper support plate. A motor driven eccentric shaft loosely extends into a center hole bearing of the slide plate to cause the horizontal oscillations. Novelty lies in the combination of elements which exploits the discovery that low frequency, orthogonal oscillations applied horizontally to a Bridgman crucible provides a very rigorous stirring action, comparable with and more effective by an order of magnitude than the accelerated crucible rotation technique.

  5. Planar oscillatory stirring apparatus

    NASA Technical Reports Server (NTRS)

    Wolf, M. F. (Inventor)

    1985-01-01

    The present invention is directed to an apparatus for stirring materials using planar orthogonal axes oscillations. The apparatus has a movable slide plate sandwiched between two fixed parallel support plates. Pressurized air is supplied to the movable slide plate which employs a tri-arm air bearing vent structure which allows the slide plate to float and to translate between the parallel support plates. The container having a material to be stirred is secured to the upper surface of the slide plate through an aperture in the upper support plate. A motor driven eccentric shaft loosely extends into a center hole bearing of the slide plate to cause the horizontal oscillations. Novelty lies in the combination of elements which exploits the discovery that low frequency, orthogonal oscillations applied horizontally to a Bridgman crucible provides a very rigorous stirring action, comparable with and more effective by an order of magnitude than the accelerated crucible rotation technique.

  6. Planar elliptic growth

    SciTech Connect

    Mineev, Mark

    2008-01-01

    The planar elliptic extension of the Laplacian growth is, after a proper parametrization, given in a form of a solution to the equation for areapreserving diffeomorphisms. The infinite set of conservation laws associated with such elliptic growth is interpreted in terms of potential theory, and the relations between two major forms of the elliptic growth are analyzed. The constants of integration for closed form solutions are identified as the singularities of the Schwarz function, which are located both inside and outside the moving contour. Well-posedness of the recovery of the elliptic operator governing the process from the continuum of interfaces parametrized by time is addressed and two examples of exact solutions of elliptic growth are presented.

  7. Insights into Acetone Photochemistry on Rutile TiO2(110). 1. Off-Normal CH3 Ejection from Acetone Diolate.

    SciTech Connect

    Petrik, Nikolay G.; Henderson, Michael A.; Kimmel, Gregory A.

    2015-06-04

    Thermal- and photon-stimulated reactions of acetone co-adsorbed with oxygen on rutile TiO2(110) surface are studied with infrared reflection-adsorption spectroscopy (IRAS) combined with temperature programmed desorption and angle-resolved photon stimulated desorption. IRAS results show that n2-acetone diolate ((CH3)2COO) is produced via thermally-activated reactions between the chemisorbed oxygen with co-adsorbed acetone. Formation of acetone diolate is also consistent with 18O / 16O isotopic exchange experiments. During UV irradiation at 30 K, CH3 radicals are ejected from the acetone diolate with a distribution that is peaked at .-. +- 66 degrees from the surface normal along the azimuth (i.e. perpendicular to the rows of bridging oxygen and Ti5c ions). This distribution is also consistent with the orientation of the C–CH3 bonds in the n2-acetone diolate on TiO2(110). The acetone diolate peaks disappear from the IRAS spectra after UV irradiation and new peaks are observed and associated with n2-acetate. The data presented here demonstrate direct signatures of the proposed earlier 2-step mechanism for acetone photooxidation on TiO2(110)

  8. Enhancing acetone biosynthesis and acetone-butanol-ethanol fermentation performance by co-culturing Clostridium acetobutylicum/Saccharomyces cerevisiae integrated with exogenous acetate addition.

    PubMed

    Luo, Hongzhen; Ge, Laibing; Zhang, Jingshu; Ding, Jian; Chen, Rui; Shi, Zhongping

    2016-01-01

    Acetone is the major by-product in ABE fermentations, most researches focused on increasing butanol/acetone ratio by decreasing acetone biosynthesis. However, economics of ABE fermentation industry strongly relies on evaluating acetone as a valuable platform chemical. Therefore, a novel ABE fermentation strategy focusing on bio-acetone production by co-culturing Clostridium acetobutylicum/Saccharomyces cerevisiae with exogenous acetate addition was proposed. Experimental and theoretical analysis revealed the strategy could, enhance C. acetobutylicum survival oriented amino acids assimilation in the cells; control NADH regeneration rate at moderately lower level to enhance acetone synthesis but without sacrificing butanol production; enhance the utilization ability of C. acetobutylicum on glucose and direct most of extra consumed glucose into acetone/butanol synthesis routes. By implementing the strategy using synthetic or acetate fermentative supernatant, acetone concentrations increased to 8.27-8.55g/L from 5.86g/L of the control, while butanol concentrations also elevated to the higher levels of 13.91-14.23g/L from 11.63g/L simultaneously.

  9. Direct measurement of Criegee intermediate (CH2OO) reactions with acetone, acetaldehyde, and hexafluoroacetone.

    PubMed

    Taatjes, Craig A; Welz, Oliver; Eskola, Arkke J; Savee, John D; Osborn, David L; Lee, Edmond P F; Dyke, John M; Mok, Daniel W K; Shallcross, Dudley E; Percival, Carl J

    2012-08-14

    Criegee biradicals, i.e., carbonyl oxides, are critical intermediates in ozonolysis and have been implicated in autoignition chemistry and other hydrocarbon oxidation systems, but until recently the direct measurement of their gas-phase kinetics has not been feasible. Indirect determinations of Criegee intermediate kinetics often rely on the introduction of a scavenger molecule into an ozonolysis system and analysis of the effects of the scavenger on yields of products associated with Criegee intermediate reactions. Carbonyl species, in particular hexafluoroacetone (CF(3)COCF(3)), have often been used as scavengers. In this work, the reactions of the simplest Criegee intermediate, CH(2)OO (formaldehyde oxide), with three carbonyl species have been measured by laser photolysis/tunable synchrotron photoionization mass spectrometry. Diiodomethane photolysis produces CH(2)I radicals, which react with O(2) to yield CH(2)OO + I. The formaldehyde oxide is reacted with a large excess of a carbonyl reactant and both the disappearance of CH(2)OO and the formation of reaction products are monitored. The rate coefficient for CH(2)OO + hexafluoroacetone is k(1) = (3.0 ± 0.3) × 10(-11) cm(3) molecule(-1) s(-1), supporting the use of hexafluoroacetone as a Criegee-intermediate scavenger. The reactions with acetaldehyde, k(2) = (9.5 ± 0.7) × 10(-13) cm(3) molecule(-1) s(-1), and with acetone, k(3) = (2.3 ± 0.3) × 10(-13) cm(3) molecule(-1) s(-1), are substantially slower. Secondary ozonides and products of ozonide isomerization are observed from the reactions of CH(2)OO with acetone and hexafluoroacetone. Their photoionization spectra are interpreted with the aid of quantum-chemical and Franck-Condon-factor calculations. No secondary ozonide was observable in the reaction of CH(2)OO with acetaldehyde, but acetic acid was identified as a product under the conditions used (4 Torr and 293 K).

  10. A sensitivity analysis of key natural factors in the modeled global acetone budget

    NASA Astrophysics Data System (ADS)

    Brewer, J. F.; Bishop, M.; Kelp, M.; Keller, C. A.; Ravishankara, A. R.; Fischer, E. V.

    2017-02-01

    Acetone is one of the most abundant carbonyl compounds in the atmosphere, and it serves as an important source of HOx (OH + HO2) radicals in the upper troposphere and a precursor for peroxyacetyl nitrate. We present a global sensitivity analysis targeted at several major natural source and sink terms in the global acetone budget to find the input factor or factors to which the simulated acetone mixing ratio was most sensitive. The ranges of input factors were taken from literature. We calculated the influence of these factors in terms of their elementary effects on model output. Of the six factors tested here, the four factors with the highest contribution to total global annual model sensitivity are direct emissions of acetone from the terrestrial biosphere, acetone loss to photolysis, the concentration of acetone in the ocean mixed layer, and the dry deposition of acetone to ice-free land. The direct emissions of acetone from the terrestrial biosphere are globally important in determining acetone mixing ratios, but their importance varies seasonally outside the tropics. Photolysis is most influential in the upper troposphere. Additionally, the influence of the oceanic mixed layer concentrations are relatively invariant between seasons, compared to the other factors tested. Monoterpene oxidation in the troposphere, despite the significant uncertainties in acetone yield in this process, is responsible for only a small amount of model uncertainty in the budget analysis.

  11. Molybdenum disulfide catalyzed tungsten oxide for on-chip acetone sensing

    NASA Astrophysics Data System (ADS)

    Li, Hong; Ahn, Sung Hoon; Park, Sangwook; Cai, Lili; Zhao, Jiheng; He, Jiajun; Zhou, Minjie; Park, Joonsuk; Zheng, Xiaolin

    2016-09-01

    Acetone sensing is critical for acetone leak detection and holds a great promise for the noninvasive diagnosis of diabetes. It is thus highly desirable to develop a wearable acetone sensor that has low cost, miniature size, sub-ppm detection limit, great selectivity, as well as low operating temperature. In this work, we demonstrate a cost-effective on-chip acetone sensor with excellent sensing performances at 200 °C using molybdenum disulfide (MoS2) catalyzed tungsten oxide (WO3). The WO3 based acetone sensors are first optimized via combined mesoscopic nanostructuring and silicon doping. Under the same testing conditions, our optimized mesoporous silicon doped WO3 [Si:WO3(meso)] sensor shows 2.5 times better sensitivity with ˜1000 times smaller active device area than the state-of-art WO3 based acetone sensor. Next, MoS2 is introduced to catalyze the acetone sensing reactions for Si:WO3(meso), which reduces the operating temperature by 100 °C while retaining its high sensing performances. Our miniaturized acetone sensor may serve as a wearable acetone detector for noninvasive diabetes monitoring or acetone leakage detection. Moreover, our work demonstrates that MoS2 can be a promising nonprecious catalyst for catalytic sensing applications.

  12. Phase transitions of amorphous solid acetone in confined geometry investigated by reflection absorption infrared spectroscopy.

    PubMed

    Shin, Sunghwan; Kang, Hani; Kim, Jun Soo; Kang, Heon

    2014-11-26

    We investigated the phase transformations of amorphous solid acetone under confined geometry by preparing acetone films trapped in amorphous solid water (ASW) or CCl4. Reflection absorption infrared spectroscopy (RAIRS) and temperature-programmed desorption (TPD) were used to monitor the phase changes of the acetone sample with increasing temperature. An acetone film trapped in ASW shows an abrupt change in the RAIRS features of the acetone vibrational bands during heating from 80 to 100 K, which indicates the transformation of amorphous solid acetone to a molecularly aligned crystalline phase. Further heating of the sample to 140 K produces an isotropic solid phase, and eventually a fluid phase near 157 K, at which the acetone sample is probably trapped in a pressurized, superheated condition inside the ASW matrix. Inside a CCl4 matrix, amorphous solid acetone crystallizes into a different, isotropic structure at ca. 90 K. We propose that the molecularly aligned crystalline phase formed in ASW is created by heterogeneous nucleation at the acetone-water interface, with resultant crystal growth, whereas the isotropic crystalline phase in CCl4 is formed by homogeneous crystal growth starting from the bulk region of the acetone sample.

  13. Non-planar chemical preconcentrator

    DOEpatents

    Manginell, Ronald P.; Adkins, Douglas R.; Sokolowski, Sara S.; Lewis, Patrick R.

    2006-10-10

    A non-planar chemical preconcentrator comprises a high-surface area, low mass, three-dimensional, flow-through sorption support structure that can be coated or packed with a sorptive material. The sorptive material can collect and concentrate a chemical analyte from a fluid stream and rapidly release it as a very narrow temporal plug for improved separations in a microanalytical system. The non-planar chemical preconcentrator retains most of the thermal and fabrication benefits of a planar preconcentrator, but has improved ruggedness and uptake, while reducing sorptive coating concerns and extending the range of collectible analytes.

  14. Fate of acetone in an outdoor model stream in southern Mississippi, U.S.A.

    USGS Publications Warehouse

    Rathbun, R.E.; Stephens, D.W.; Shultz, D.J.; Tai, D.Y.

    1988-01-01

    The fate of acetone in water was investigated in an outdoor model stream located in southern Mississippi, U.S.A. Acetone was injected continuously for 32 days resulting in small milligram-perliter concentrations in the stream. Rhodamine-WT dye was injected at the beginning and at the end of the study to determine the time-of-travel and dispersion characteristics of the stream. A 12-h injection of t-butyl alcohol (TBA) was used to determine the volatilization characteristics of the stream. Volatilization controlled the acetone concentration in the stream. Significant bacterial degradation of acetone did not occur, contrary to expectations based on previous laboratory studies. Attempts to induce degradation of the acetone by injecting glucose and a nutrient solution containing bacteria acclimated to acetone were unsuccessful. Possible explanations for the lack of bacterial degradation included a nitrate limitation and a limited residence time in the stream system. ?? 1988.

  15. Object Classification via Planar Abstraction

    NASA Astrophysics Data System (ADS)

    Oesau, Sven; Lafarge, Florent; Alliez, Pierre

    2016-06-01

    We present a supervised machine learning approach for classification of objects from sampled point data. The main idea consists in first abstracting the input object into planar parts at several scales, then discriminate between the different classes of objects solely through features derived from these planar shapes. Abstracting into planar shapes provides a means to both reduce the computational complexity and improve robustness to defects inherent to the acquisition process. Measuring statistical properties and relationships between planar shapes offers invariance to scale and orientation. A random forest is then used for solving the multiclass classification problem. We demonstrate the potential of our approach on a set of indoor objects from the Princeton shape benchmark and on objects acquired from indoor scenes and compare the performance of our method with other point-based shape descriptors.

  16. The Effect of Fluorocarbon Surfactant Additives on the Effective Viscosity of Acetone Solutions of Cellulose Diacetate,

    DTIC Science & Technology

    2014-09-26

    34 FOREIGN TECHNOLOGY DIVISION i00 Lfl .. THE EFFECT OF FLUOROCARBON SURFACTANT ADDITIVES ON THE EFFECTIVE VISCOSITY OF ACETONE SOLUTIONS OF CELLULOSE...ADDITIVES ON TH~ .. t- ’_ ition EFFECTIVE VISCOSITY OF ACETONE SOLUTIONS OF CELLULOSE DIACETATE D~rbt~l By: L.A. Shits, N. Yu. Kal’nova Codesuton English...VISCOSITY OF ACETONE SOLUTIONS OF CELLULOSE DIACETATE L. A. Shits, N. Yu. Kal’nova (Institute of Physical Chemistry of the AS USSR, Moscow) ! - The

  17. Fluorometric biosniffer (biochemical gas sensor) for breath acetone as a volatile indicator of lipid metabolism

    NASA Astrophysics Data System (ADS)

    Mitsubayashi, Kohji; Chien, Po-Jen; Ye, Ming; Suzuki, Takuma; Toma, Koji; Arakawa, Takahiro

    2016-11-01

    A fluorometric acetone biosniffer (biochemical gas sensor) for assessment of lipid metabolism utilizing reverse reaction of secondary alcohol dehydrogenase was constructed and evaluated. The biosniffer showed highly sensitivity and selectivity for continuous monitoring of gaseous acetone. The measurement of breath acetone concentration during fasting and aerobic exercise were also investigated. The acetone biosniffer provides a novel analytical tool for noninvasive evaluation of human lipid metabolism and it is also expected to use for the clinical and physiological applications such as monitoring the progression of diabetes.

  18. Capabilities of DLW for fabrication of planar waveguides in PDMS

    NASA Astrophysics Data System (ADS)

    Jandura, D.; Pudiš, D.; Gašo, P.

    2014-12-01

    In this paper, capabilities of the fabrication technology for planar waveguide structures and devices in polydimethylsiloxane (PDMS) are presented. Direct laser writing in combination with imprinting technique was used to pattern photoresist layer as a master for imprinting process. In the next step, PDMS waveguide structures as channel waveguide, Y-branch waveguide splitter and ring resonator were imprinted. Finally, optical and morphological properties of prepared devices were investigated by confocal microscopy and atomic force microscopy.

  19. Electrodynamics of planar Archimedean spiral resonator

    NASA Astrophysics Data System (ADS)

    Maleeva, N.; Averkin, A.; Abramov, N. N.; Fistul, M. V.; Karpov, A.; Zhuravel, A. P.; Ustinov, A. V.

    2015-07-01

    We present a theoretical and experimental study of electrodynamics of a planar spiral superconducting resonator of a finite length. The resonator is made in the form of a monofilar Archimedean spiral. By making use of a general model of inhomogeneous alternating current flowing along the resonator and specific boundary conditions on the surface of the strip, we obtain analytically the frequencies fn of resonances which can be excited in such system. We also calculate corresponding inhomogeneous RF current distributions ψ n ( r ) , where r is the coordinate across a spiral. We show that the resonant frequencies and current distributions are well described by simple relationships f n = f 1 n and ψ n ( r ) ≃ sin [ π n ( r / R e ) 2 ] , where n = 1 , 2... and Re is the external radius of the spiral. Our analysis of electrodynamic properties of spiral resonators' is in good agreement with direct numerical simulations and measurements made using specifically designed magnetic probe and laser scanning microscope.

  20. Optical properties of a planar turbulent jet.

    PubMed

    Joia, I A; Perkins, R J; Uscinski, B J; Balmer, G; Jordan, D; Jakeman, E

    1995-10-20

    A planar heated air jet was constructed. Its flow properties were characterized and shown to be both reproducible and in good agreement with the results of turbulence theory. The optical properties of the jet were studied with the help of a 632.8-nm He-Ne laser beam. The random phase modulations imposed on the wave front of the beam traversing the jet were measured by interferometric means, and their spectra and variance were determined. The one-dimensional phase fluctuation spectrum obeyed a -8/3 power law as predicted by theory, whereas the phase variance (?(2)) depended on the jet temperature and was studied for values to as high as 0.4 (rad)(2)).

  1. Integral planar supercapacitor with CNT-based composite electrodes for heat-sensitive MEMS and NEMS

    NASA Astrophysics Data System (ADS)

    Lebedev, E.; Alekseyev, A.; Gavrilin, I.; Sysa, A.; Kitsyuk, E.; Ryazanov, R.; Gromov, D.

    2016-12-01

    A method based on electrophoretic deposition (EPD) has been developed to produce uniform and local deposits of multiwalled carbon nanotubes (CNT) on interdigital structures of planar supercapacitor (SC) at room temperatures. Alcohol/acetone suspensions were used under constant voltage conditions in the range of 6 to 100 V, with deposition times ranging from 2 to 60 minutes and electrodes space from 2 to 15 mm. It was shown that for dense layers deposition with good adhesion on the narrow lines of the planar SC electrodes it is necessary to use average values of the electric field and multi-stage method in which the deposition and drying processes are alternated. Electrochemical tests of the sandwich-like supercapacitors with electrodes obtained by the described method were carried out. The specific capacity of experimental samples increased from 0.24 to 1.07 mF/cm2 with an increase in the number of EPD cycles from 3 to 9.

  2. Instantaneous planar visualization of reacting supersonic flows using silane seeding

    NASA Technical Reports Server (NTRS)

    Smith, Michael W.; Northam, G. B.

    1991-01-01

    A new visualization technique for reacting flows has been developed. This technique, which is suitable for supersonic combustion flows, has been demonstrated on a scramjet combustor model. In this application, gaseous silane (SiH4) was added to the primary hydrogen fuel. When the fuel reacted, so did the (SiH4), producing silica (SiO2) particles in situ. The particles were illuminated with a laser sheet formed from a frequency-doubled Nd:YAG laser (532 nm) beam and the Mie scattering signal was imaged. These planar images of the silica Mie scattering provided instantaneous 'maps' of combustion progress within the turbulent reacting flowfield.

  3. Hybrid and monolithic integration of planar lightwave circuits (PLCs)

    NASA Astrophysics Data System (ADS)

    Chen, Ray T.

    2008-02-01

    In this paper, we review the status of monolithic and hybrid integration of planar lightwave circuits (PLCs). Building blocks needed for system integration based on polymeric materials, III-V semiconductor materials, LiNbO 3 and SOI on Silicon are summarized with pros and cons. Due to the maturity of silicon CMOS technology, silicon becomes the platform of choice for optical application specific integrated circuits (OASICs). However, the indirect bandgap of silicon makes the formation of electrically pumped silicon laser a remote plausibility which requires hybrid integration of laser sources made out of III-V compound semicouductor.

  4. Expression of Clostridium acetobutylicum ATCC 824 Genes in Escherichia coli for Acetone Production and Acetate Detoxification

    PubMed Central

    Bermejo, Lourdes L.; Welker, Neil E.; Papoutsakis, Eleftherios T.

    1998-01-01

    A synthetic acetone operon (ace4) composed of four Clostridium acetobutylicum ATCC 824 genes (adc, ctfAB, and thl, coding for the acetoacetate decarboxylase, coenzyme A transferase, and thiolase, respectively) under the control of the thl promoter was constructed and was introduced into Escherichia coli on vector pACT. Acetone production demonstrated that ace4 is expressed in E. coli and resulted in the reduction of acetic acid levels in the fermentation broth. Since different E. coli strains vary significantly in their growth characteristics and acetate metabolism, ace4 was expressed in three E. coli strains: ER2275, ATCC 11303, and MC1060. Shake flask cultures of MC1060(pACT) produced ca. 2 mM acetone, while both strains ER2275(pACT) and ATCC 11303(pACT) produced ca. 40 mM acetone. Glucose-fed cultures of strain ATCC 11303(pACT) resulted in a 150% increase in acetone titers compared to those of batch shake flask cultures. External addition of sodium acetate to glucose-fed cultures of ATCC 11303(pACT) resulted in further increased acetone titers. In bioreactor studies, acidic conditions (pH 5.5 versus 6.5) improved acetone production. Despite the substantial acetone evaporation due to aeration and agitation in the bioreactor, 125 to 154 mM acetone accumulated in ATCC 11303(pACT) fermentations. These acetone titers are equal to or higher than those produced by wild-type C. acetobutylicum. This is the first study to demonstrate the ability to use clostridial genes in nonclostridial hosts for solvent production. In addition, acetone-producing E. coli strains may be useful hosts for recombinant protein production in that detrimental acetate accumulation can be avoided. PMID:9501448

  5. Evaluating the Potential Importance of Monoterpene Degradation for Global Acetone Production

    NASA Astrophysics Data System (ADS)

    Kelp, M. M.; Brewer, J.; Keller, C. A.; Fischer, E. V.

    2015-12-01

    Acetone is one of the most abundant volatile organic compounds (VOCs) in the atmosphere, but estimates of the global source of acetone vary widely. A better understanding of acetone sources is essential because acetone serves as a source of HOx in the upper troposphere and as a precursor to the NOx reservoir species peroxyacetyl nitrate (PAN). Although there are primary anthropogenic and pyrogenic sources of acetone, the dominant acetone sources are thought to be from direct biogenic emissions and photochemical production, particularly from the oxidation of iso-alkanes. Recent work suggests that the photochemical degradation of monoterpenes may also represent a significant contribution to global acetone production. We investigate that hypothesis using the GEOS-Chem chemical transport model. In this work, we calculate the emissions of eight terpene species (α-pinene, β-pinene, limonene, Δ3-carene, myrcene, sabinene, trans-β-ocimene, and an 'other monoterpenes' category which contains 34 other trace species) and couple these with upper and lower bound literature yields from species-specific chamber studies. We compare the simulated acetone distributions against in situ acetone measurements from a global suite of NASA aircraft campaigns. When simulating an upper bound on yields, the model-to-measurement comparison improves for North America at both the surface and in the upper troposphere. The inclusion of acetone production from monoterpene degradation also improves the ability of the model to reproduce observations of acetone in East Asian outflow. However, in general the addition of monoterpenes degrades the model comparison for the Southern Hemisphere.

  6. Acetone-CO enhancement ratios in the upper troposphere based on 7 years of CARIBIC data: new insights and estimates of regional acetone fluxes

    NASA Astrophysics Data System (ADS)

    Fischbeck, Garlich; Bönisch, Harald; Neumaier, Marco; Brenninkmeijer, Carl A. M.; Orphal, Johannes; Brito, Joel; Becker, Julia; Sprung, Detlev; van Velthoven, Peter F. J.; Zahn, Andreas

    2017-02-01

    Acetone and carbon monoxide (CO) are two important trace gases controlling the oxidation capacity of the troposphere; enhancement ratios (EnRs) are useful in assessing their sources and fate between emission and sampling, especially in pollution plumes. In this study, we focus on in situ data from the upper troposphere recorded by the passenger-aircraft-based IAGOS-CARIBIC (In-service Aircraft for a Global Observing System-Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container) observatory over the periods 2006-2008 and 2012-2015. This dataset is used to investigate the seasonal and spatial variation of acetone-CO EnRs. Furthermore, we utilize a box model accounting for dilution, chemical degradation and secondary production of acetone from precursors. In former studies, increasing acetone-CO EnRs in a plume were associated with secondary production of acetone. Results of our box model question this common presumption and show increases of acetone-CO EnR over time without taking secondary production of acetone into account. The temporal evolution of EnRs in the upper troposphere, especially in summer, is not negligible and impedes the interpretation of EnRs as a means for partitioning of acetone and CO sources in the boundary layer. In order to ensure that CARIBIC EnRs represent signatures of source regions with only small influences by dilution and chemistry, we limit our analysis to temporal and spatial coherent events of high-CO enhancement. We mainly focus on North America and Southeast Asia because of their different mix of pollutant sources and the good data coverage. For both regions, we find the expected seasonal variation in acetone-CO EnRs with maxima in summer, but with higher amplitude over North America. We derive mean (± standard deviation) annual acetone fluxes of (53 ± 27) 10-13 kg m-2 s-1 and (185 ± 80) 10-13 kg m-2 s-1 for North America and Southeast Asia, respectively. The derived flux for North America

  7. Planar photovoltaic solar concentrator module

    DOEpatents

    Chiang, C.J.

    1992-12-01

    A planar photovoltaic concentrator module for producing an electrical signal from incident solar radiation includes an electrically insulating housing having a front wall, an opposing back wall and a hollow interior. A solar cell having electrical terminals is positioned within the interior of the housing. A planar conductor is connected with a terminal of the solar cell of the same polarity. A lens forming the front wall of the housing is operable to direct solar radiation incident to the lens into the interior of the housing. A refractive optical element in contact with the solar cell and facing the lens receives the solar radiation directed into the interior of the housing by the lens and directs the solar radiation to the solar cell to cause the solar cell to generate an electrical signal. An electrically conductive planar member is positioned in the housing to rest on the housing back wall in supporting relation with the solar cell terminal of opposite polarity. The planar member is operable to dissipate heat radiated by the solar cell as the solar cell generates an electrical signal and further forms a solar cell conductor connected with the solar cell terminal to permit the electrical signal generated by the solar cell to be measured between the planar member and the conductor. 5 figs.

  8. Planar photovoltaic solar concentrator module

    DOEpatents

    Chiang, Clement J.

    1992-01-01

    A planar photovoltaic concentrator module for producing an electrical signal from incident solar radiation includes an electrically insulating housing having a front wall, an opposing back wall and a hollow interior. A solar cell having electrical terminals is positioned within the interior of the housing. A planar conductor is connected with a terminal of the solar cell of the same polarity. A lens forming the front wall of the housing is operable to direct solar radiation incident to the lens into the interior of the housing. A refractive optical element in contact with the solar cell and facing the lens receives the solar radiation directed into the interior of the housing by the lens and directs the solar radiation to the solar cell to cause the solar cell to generate an electrical signal. An electrically conductive planar member is positioned in the housing to rest on the housing back wall in supporting relation with the solar cell terminal of opposite polarity. The planar member is operable to dissipate heat radiated by the solar cell as the solar cell generates an electrical signal and further forms a solar cell conductor connected with the solar cell terminal to permit the electrical signal generated by the solar cell to be measured between the planar member and the conductor.

  9. Influence of dynamic hand-grip exercise on acetone in gas emanating from human skin.

    PubMed

    Mori, Kenji; Funada, Toshiaki; Kikuchi, Maasa; Ohkuwa, Tetsuo; Itoh, Hiroshi; Yamazaki, Yoshihiko; Tsuda, Takao

    2008-01-01

    This study investigated the effects of dynamic hand-grip exercise on skin-gas acetone concentration. The subjects for this experiment were seven healthy males. In the first experiment, to ascertain the reproducibility of the results for the skin-gas acetone concentration test, the skin gas was collected four times from one subject. In the second experiment, all subjects performed three different types of exercise (Exercises I-III) for a duration of 60 s. Exercise I was performed at 10 kg with one contraction every 3 s. Exercise II was 30 kg with one contraction every 3 s. Exercise III was 10 kg with one contraction per second. Acetone concentration was analyzed by gas chromatography. In the first experiment, reasonable reproducibility was obtained in measurements of skin-gas acetone concentration during the hand-grip exercise. In the second experiment, acetone concentration in skin gas during hand-grip exercise II was significantly higher than the basal level. Although skin-gas acetone levels increased in all subjects during exercises I and III, a significant difference was not found. No significant difference was found in skin-gas acetone concentration during dynamic hand-grip exercise among exercises I, II, and III. This study confirmed that skin-gas acetone levels increase during dynamic hand-grip exercise.

  10. Influence of cycle exercise on acetone in expired air and skin gas.

    PubMed

    Yamai, Kazuaki; Ohkuwa, Tetsuo; Itoh, Hiroshi; Yamazaki, Yoshihiko; Tsuda, Takao

    2009-01-01

    This study investigated the influence of cycle exercise on acetone concentration in expired air and skin gas. The subjects for this experiment were eight healthy males. Subjects performed a continuous graded exercise test on a cycle ergometer. The workloads were 360 (1.0 kg), 720 (2.0 kg), 990 (2.75 kg) kgm/min, and each stage was 5 min in duration. A pedaling frequency of 60 rpm was maintained. Acetone concentration was analyzed by gas chromatography. The acetone concentration in expired air and skin gas during exercise at 990 kgm/min intensity was significantly increased compared with the basal level. The skin-gas acetone concentration at 990 kgm/min significantly increased compared with the 360 kgm/min (P < 0.05). The acetone excretion of expired air at 720 kgm/min and 990 kgm/min significantly increased compared with the basal level (P < 0.05). Acetone concentration in expired air was 4-fold greater than skin gas at rest and 3-fold greater during exercise (P < 0.01). Skin gas acetone concentration significantly related with expired air (r = 0.752; P < 0.01). This study confirmed that the skin-gas acetone concentration reflected that of expired air.

  11. Infrared spectroscopy of acetone-methanol liquid mixtures: Hydrogen bond network

    NASA Astrophysics Data System (ADS)

    Max, Jean-Joseph; Chapados, Camille

    2005-01-01

    Acetone and methanol mixtures covering the whole solubility range are studied by Fourier transform infrared attenuated total reflectance spectroscopy. The strong bathochromic shifts observed on methanol OH and acetone CO stretch IR bands are related to hydrogen bonds between these groups. Factor analysis separates the spectra into four acetone and four methanol principal factors. A random molecular model developed for the acetone-water system [Max and Chapados, J. Chem. Phys. 119, 5632 (2003); 120, 6625 (2004)] was modified for the acetone-methanol system. This model, which takes into account H bonds accepted by methanol and acetone, is made up of 12 methanol and 11 acetone species. The 23 species abundances are regrouped according to evolving patterns or spectral similarities to compare them to the eight experimental factors. Methanol acetone mixtures are almost but not exactly random: the methanol oxygen atoms have stronger capacities than acetone to accept H bonds from methanol in the proportion 1.5 to 1. Since oxygen atoms are in excess, all labile hydrogen atoms will form H bonds. As acetone is added to methanol, its OH stretch band blueshifts as the number of accepted H bonds decreases. When methanol gives one H bond and accepts one, an H-bonding network is formed that was coined "chained organization." However, the acetone molecules do not sequester any methanol molecules by breaking or increasing the H-bond methanol network. Similarly, the methanol molecules do not sequester any acetone molecules. Consequently no acetone-methanol complex is formed in the mixtures. Gaussian simulation of the four principal factors in the methanol OH stretch region gave three distinct absorption regimes consisting of the OH stretch bands and their satellites that are identified as MeOH1, MeOH2, and MeOH3 (subscript indicates the number of H, covalent and H bond, which surround the oxygen). These regimes are related to those identified in the water-acetone system as OH2, OH3

  12. Planar Submillimeter-Wave Mixer Technology with Integrated Antenna

    NASA Technical Reports Server (NTRS)

    Chattopadhyay, Gautam; Mehdi, Imran; Gill, John J.; Lee, Choonsup; lombart, Muria L.; Thomas, Betrand

    2010-01-01

    High-performance mixers at terahertz frequencies require good matching between the coupling circuits such as antennas and local oscillators and the diode embedding impedance. With the availability of amplifiers at submillimeter wavelengths and the need to have multi-pixel imagers and cameras, planar mixer architecture is required to have an integrated system. An integrated mixer with planar antenna provides a compact and optimized design at terahertz frequencies. Moreover, it leads to a planar architecture that enables efficient interconnect with submillimeter-wave amplifiers. In this architecture, a planar slot antenna is designed on a thin gallium arsenide (GaAs) membrane in such a way that the beam on either side of the membrane is symmetric and has good beam profile with high coupling efficiency. A coplanar waveguide (CPW) coupled Schottky diode mixer is designed and integrated with the antenna. In this architecture, the local oscillator (LO) is coupled through one side of the antenna and the RF from the other side, without requiring any beam sp litters or diplexers. The intermediate frequency (IF) comes out on a 50-ohm CPW line at the edge of the mixer chip, which can be wire-bonded to external circuits. This unique terahertz mixer has an integrated single planar antenna for coupling both the radio frequency (RF) input and LO injection without any diplexer or beamsplitters. The design utilizes novel planar slot antenna architecture on a 3- mthick GaAs membrane. This work is required to enable future multi-pixel terahertz receivers for astrophysics missions, and lightweight and compact receivers for planetary missions to the outer planets in our solar system. Also, this technology can be used in tera hertz radar imaging applications as well as for testing of quantum cascade lasers (QCLs).

  13. Integration of stable isotope and trace contaminant concentration for enhanced forensic acetone discrimination

    SciTech Connect

    Moran, James J.; Ehrhardt, Christopher J.; Wahl, Jon H.; Kreuzer, Helen W.; Wahl, Karen L.

    2013-07-18

    We analyzed 21 neat acetone samples from 15 different suppliers to demonstrate the utility of a coupled stable isotope and trace contaminant strategy for distinguishing forensically-relevant samples. By combining these two pieces of orthogonal data we could discriminate all of the acetones that were produced by the 15 different suppliers. Using stable isotope ratios alone, we were able to distinguish 9 acetone samples, while the remaining 12 fell into four clusters with highly similar signatures. Adding trace chemical contaminant information enhanced discrimination to 13 individual acetones with three residual clusters. The acetones within each cluster shared a common manufacturer and might, therefore, not be expected to be resolved. The data presented here demonstrates the power of combining orthogonal data sets to enhance sample fingerprinting and highlights the role disparate data could play in future forensic investigations.

  14. Detection of acetone processing of castor bean mash for forensic investigation of ricin preparation methods.

    PubMed

    Kreuzer, Helen W; Wahl, Jon H; Metoyer, Candace N; Colburn, Heather A; Wahl, Karen L

    2010-07-01

    Samples containing the toxic castor bean protein ricin have been recently seized in connection with biocriminal activity. Analytical methods that enable investigators to determine how the samples were prepared and to match seized samples to potential source materials are needed. One commonly described crude ricin preparation method is acetone extraction of crushed castor beans. Here, we describe the use of solid-phase microextraction and headspace analysis to determine whether castor beans were processed by acetone extraction. We prepared acetone-extracted castor bean mash, along with controls of unextracted mash and mash extracted with nonacetone organic solvents. Samples of acetone-extracted mash and unextracted mash were stored in closed containers for up to 109 days at both room temperature and -20 degrees C, and in open containers at room temperature for up to 94 days. Acetone-extracted bean mash could consistently be statistically distinguished from controls, even after storage in open containers for 94 days.

  15. Boron nitride nanotube based nanosensor for acetone adsorption: a DFT simulation.

    PubMed

    Ganji, Masoud Darvish; Rezvani, Mahyar

    2013-03-01

    We have investigated the adsorption properties of acetone on zigzag single-walled BNNTs using density functional theory (DFT) calculations. The results obtained show that acetone is strongly bound to the outer surface of a (5,0) BNNT on the top site directly above the boron atom, with a binding energy of -96.16 kJ mol(-1) and a B-O binding distance of 1.654 Å. Our first-principles calculations also predict that the ability of zigzag BNNTs to adsorb acetone is significantly stronger than the corresponding ability of zigzag CNTs. A comparative investigation of BNNTs with different diameters indicated that the ability of the side walls of the tubes to adsorb acetone decreases significantly for nanotubes with larger diameters. Furthermore, the stability of the most stable acetone/BNNT complex was tested using ab initio molecular dynamics simulation at room temperature.

  16. Heat transfer performance of a pulsating heat pipe charged with acetone-based mixtures

    NASA Astrophysics Data System (ADS)

    Wang, Wenqing; Cui, Xiaoyu; Zhu, Yue

    2016-12-01

    Pulsating heat pipes (PHPs) are used as high efficiency heat exchangers, and the selection of working fluids in PHPs has a great impact on the heat transfer performance. This study investigates the thermal resistance characteristics of the PHP charged with acetone-based binary mixtures, where deionized water, methanol and ethanol were added to and mixed with acetone, respectively. The volume mixing ratios were 2:1, 4:1 and 7:1, and the heating power ranged from 10 to 100 W with filling ratios of 45, 55, 62 and 70%. At a low filling ratio (45%), the zeotropic characteristics of the binary mixtures have an influence on the heat transfer performance of the PHP. Adding water, which has a substantially different boiling point compared with that of acetone, can significantly improve the anti-dry-out ability inside the PHP. At a medium filling ratio (55%), the heat transfer performance of the PHP is affected by both phase transition characteristics and physical properties of working fluids. At high heating power, the thermal resistance of the PHP with acetone-water mixture is between that with pure acetone and pure water, whereas the thermal resistance of the PHP with acetone-methanol and acetone-ethanol mixtures at mixing ratios of 2:1 and 4:1 is less than that with the corresponding pure fluids. At high filling ratios (62 and 70%), the heat transfer performance of the PHP is mainly determined by the properties of working fluids that affects the flow resistance. Thus, the PHP with acetone-methanol and acetone-ethanol mixtures that have a lower flow resistance shows better heat transfer performance than that with acetone-water mixture.

  17. Structure and internal rotation dynamics of the acetone-neon complex studied by microwave spectroscopy

    NASA Astrophysics Data System (ADS)

    Gao, Jiao; Seifert, Nathan A.; Thomas, Javix; Xu, Yunjie; Jäger, Wolfgang

    2016-12-01

    The microwave spectra of the van der Waals complexes acetone-20Ne and acetone-22Ne were measured using a cavity-based supersonic jet Fourier-transform microwave spectrometer in the region from 5 to 18 GHz. For these two isotopologues, both c- and weaker a-type transitions were observed. The transitions are split into multiplets due to the internal rotation of the two methyl groups in acetone. Initial electronic structure calculations were performed at the MP2/6-311++g (2d, p) level of theory and the internal rotation barrier height of the methyl groups was calculated to be ∼2.8 kJ/mol. The ab initio rotational constants were the basis for the spectroscopic searches, but the multiplet structures and floppiness of the complex made the quantum number assignment very difficult. The assignment was finally achieved with the aid of constructing closed frequency loops and predicting internal rotation splittings using the XIAM internal rotation program. The acetone methyl group tunneling barrier height was determined experimentally to be 3.10(6) kJ mol-1 [259(5) cm-1] in the acetone-Ne complex, which is lower than in the acetone monomer but comparable to the acetone-Ar complex (Kang et al., 2002). Experimental data and high-level CCSD(T)/aug-cc-pVTZ calculations suggest that the Ne atom lies directly above the plane formed by the carbonyl group and the two carbon-carbon bonds, which is different than the slightly offset position found previously in the acetone-Ar complex. Additionally, ab initio calculations and Quantum Theory of Atoms in Molecules analyses were used to analyze the methyl internal rotation motions in acetone and acetone-Ne.

  18. Conditioned Place Preference to Acetone Inhalation and the Effects on Locomotor Behavior and 18FDG Uptake

    SciTech Connect

    Pai, J.C.; Dewey, S.L.; Schiffer, W.; Lee, D.

    2006-01-01

    Acetone is a component in many inhalants that have been widely abused. While other solvents have addictive potential, such as toluene, it is unclear whether acetone alone contains addictive properties. The locomotor, relative glucose metabolism and abusive effects of acetone inhalation were studied in animals using the conditioned place preference (CPP) paradigm and [18F]2-fluorodeoxy-D-glucose (18FDG) imaging. The CPP apparatus contains two distinct conditioning chambers and a middle adaptation chamber, each lined with photocells to monitor locomotor activity. Adolescent Sprague-Dawley rats (n=16; 90-110 g) were paired with acetone in least preferred conditioning chamber, determined on the pretest day. The animals were exposed to a 10,000 ppm dose for an hour, alternating days with air. A CPP test was conducted after the 3rd, 6th and 12th pairing. In these same animals, the relative glucose metabolism effects were determined using positron emission tomography (PET) imaging with 18FDG. Following the 3rd pairing, there was a significant aversion to the acetone paired chamber (190.9 ± 13.7 sec and 241.7 ± 16.9 sec, acetone and air, respectively). After the 6th pairing, there was no significant preference observed with equal time spent in each chamber (222 ± 21 sec and 207 ± 20 sec, acetone and air-paired, respectively). A similar trend was observed after the 12th pairing (213 ± 21 sec and 221 ± 22 sec, acetone and air-paired, respectively). Locomotor analysis indicated a significant decrease (p<0.05) from air pairings to acetone pairings on the first and sixth pairings. The observed locomotor activity was characteristic of central nervous system (CNS) depressants, without showing clear abusive effects in this CPP model. In these studies, acetone vapors were not as reinforcing as other solvents, shown by overall lack of preference for the acetone paired side of the chamber. PET imaging indicated a regionally specific distribution of 18FDG uptake following

  19. Formation of halogenated acetones in the lower troposphere

    NASA Astrophysics Data System (ADS)

    Sattler, Tobias; Wittmer, Julian; Krause, Torsten; Schöler, Heinz Friedrich; Kamilli, Katharina; Held, Andreas; Zetzsch, Cornelius; Ofner, Johannes; Atlas, Elliot

    2015-04-01

    Western Australia is a semi-/arid region that is heavily influenced by climate change and agricultural land use. The area is known for its saline lakes with a wide range of hydrogeochemical parameters and consists of ephemeral saline and saline groundwater fed lakes with a pH range from 2.5 to 7.1. In 2012 a novel PTFE-chamber was setup directly on the lakes. The 1.5 m³ cubic chamber was made of UV transparent PTFE foil to permit photochemistry while preventing dilution of the air due to lateral wind transport. This experimental setup allows linking measured data directly to the chemistry of and above the salt lakes. Air samples were taken using stainless steel canisters and measured by GC-MS/ECD. Sediment, crust and water samples were taken for investigation of potential VOC and VOX emissions in the laboratory using GC-MS. Several lakes were investigated and canister samples were taken over the day to see diurnal variations. The first samples were collected at 6 a.m. and from this time every 2 hours a canister was filled with chamber air. Concentrations of chloroacetone up to 15 ppb and of bromoacetone up to 40 ppb in the air samples were detected. The concentrations vary over the day and display their highest values around noon. Soil and water samples showed a variety of highly volatile and semi-volatile VOC/VOX but no halogenated acetones. An abiotic formation of these VOC/VOX seems conclusive due to iron-catalysed reactions below the salt crust [1]. The salt crust is the interface through which VOC/VOX pass from soil/groundwater to the atmosphere where they were photochemically altered. This explains the finding of halo acetones only in the air samples and not in water and soil samples measured in the laboratory. The main forming pathway for these haloacetones is the direct halogenation due to atomic chlorine and bromine above the salt lakes [2]. A minor pathway is the atmospheric degradation of chloropropane and bromopropane [3]. These halopropanes were found

  20. Eckart frames for planar molecules

    NASA Astrophysics Data System (ADS)

    Wei, Hua

    2003-04-01

    Explicit analytic expressions of Eckart frames for planar molecules in Radau, Jacobi and bond coordinates have been presented. The orientation of the frame axis system with respect to the molecular plane at equilibrium is specified by an angle θ1e.

  1. The planar dynamics of airships

    NASA Technical Reports Server (NTRS)

    Regan, F. J.

    1975-01-01

    The forces and moments acting upon a LTA vehicle are considered in order to develop parameters describing planar motion. Similar expressions for HTA vehicles will be given to emphasize the greater complexity of aerodynamic effects when buoyancy effects cannot be neglected. A brief summary is also given of the use of virtual mass coefficients to calculate loads on airships.

  2. Investigation of acetone, butanol and carbon dioxide as new breath biomarkers for convenient and noninvasive diagnosis of obstructive sleep apnea syndrome.

    PubMed

    Bayrakli, Ismail; Öztürk, Önder; Akman, Hatice

    2016-12-01

    The objective of the present study was to investigate whether analysis of carbon dioxide, acetone and/or butanol present in human breath can be used as a simple and noninvasive diagnosis method for obstructive sleep apnea syndrome (OSAS). For this purpose, overnight changes in the concentrations of these breath molecules were measured before and after sleep in 10 patients who underwent polysomnography and were diagnosed with OSAS, and were compared with the levels of these biomarkers determined after sleep in 10 healthy subjects. The concentrations of exhaled carbon dioxide were measured using external cavity laser-based off-axis cavity enhanced absorption spectroscopy, whereas the levels of exhaled acetone and butanol were determined using thermal desorption gas chromatography mass spectrometry. We observed no significant changes in the levels of exhaled acetone and carbon dioxide in OSAS patients after sleep compared with pre-sleep values and compared with those in healthy control subjects. However, for the first time, to our knowledge, analyses of expired air showed an increased concentration of butanol after sleep compared with that before sleep and compared with that in healthy subjects. These results suggest that butanol can be established as a potential biomarker to enable the convenient and noninvasive diagnosis of OSAS in the future.

  3. Measurements of the Weak UV Absorptions of Isoprene and Acetone at 261–275 nm Using Cavity Ringdown Spectroscopy for Evaluation of a Potential Portable Ringdown Breath Analyzer

    PubMed Central

    Sahay, Peeyush; Scherrer, Susan T.; Wang, Chuji

    2013-01-01

    The weak absorption spectra of isoprene and acetone have been measured in the wavelength range of 261–275 nm using cavity ringdown spectroscopy. The measured absorption cross-sections of isoprene in the wavelength region of 261–266 nm range from 3.65 × 10−21 cm2·molecule−1 at 261 nm to 1.42 × 10−21 cm2·molecule−1 at 266 nm; these numbers are in good agreement with the values reported in the literature. In the longer wavelength range of 270–275 nm, however, where attractive applications using a single wavelength compact diode laser operating at 274 nm is located, isoprene has been reported in the literature to have no absorption (too weak to be detected). Small absorption cross-sections of isoprene in this longer wavelength region are measured using cavity ringdown spectroscopy for the first time in this work, i.e., 6.20 × 10−23 cm2·molecule−1 at 275 nm. With the same experimental system, wavelength-dependent absorption cross-sections of acetone have also been measured. Theoretical detection limits of isoprene and comparisons of absorbance of isoprene, acetone, and healthy breath gas in this wavelength region are also discussed. PMID:23803787

  4. 40 CFR 721.10238 - Formaldehyde, polymers with acetone-phenol reaction products and phenol, potassium sodium salts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Formaldehyde, polymers with acetone..., polymers with acetone-phenol reaction products and phenol, potassium sodium salts. (a) Chemical substance..., polymers with acetone-phenol reaction products and phenol, potassium sodium salts (PMN P-09-147; CAS...

  5. Heterogeneous photocatalytic oxidation of acetone for airpurification by near UV-irradiated titanium dioxide.

    PubMed

    Chang, Chiu-Ping; Chen, Jong-Nan; Lu, Ming-Chun

    2003-06-01

    This work presents a photocatalysis-based method to treat and purify air because of its broad applicability to common, oxidizable air contaminants. The effect of oxygen content, temperature, water vapor, and acetone concentration on the photooxidation of acetone on TiO2 surface was investigated. The photocatalytic decomposition reaction of acetone obeyed the first-order equation. The decomposition rate increased with increasing the oxygen content. The rate of acetone oxidation increased when water vapor increased from 18.7 to 417 microM and decreased at higher than 417 microM. The conversion and mineralization of acetone decreased at higher than 138 degrees C. The initial rate of acetone degradation can be well described by the Langmuir-Hinshelwood rate form. The specific reaction rate constant and the equilibrium adsorption are 15.8 microM/min and 0.0671 L/microM, respectively. The difference between observed and estimated half-lives became larger when the initial concentration of acetone was increased. It is assumed that the intermediates competed with parent compound so that delayed the half-life. The detection of CO2 production can support this assumption.

  6. Measurement of breath acetone concentrations by selected ion flow tube mass spectrometry in type 2 diabetes.

    PubMed

    Storer, Malina; Dummer, Jack; Lunt, Helen; Scotter, Jenny; McCartin, Fiona; Cook, Julie; Swanney, Maureen; Kendall, Deborah; Logan, Florence; Epton, Michael

    2011-12-01

    Selected ion flow tube-mass spectrometry (SIFT-MS) can measure volatile compounds in breath on-line in real time and has the potential to provide accurate breath tests for a number of inflammatory, infectious and metabolic diseases, including diabetes. Breath concentrations of acetone in type 2 diabetic subjects undertaking a long-term dietary modification programme were studied. Acetone concentrations in the breath of 38 subjects with type 2 diabetes were determined by SIFT-MS. Anthropomorphic measurements, dietary intake and medication use were recorded. Blood was analysed for beta hydroxybutyrate (a ketone body), HbA1c (glycated haemoglobin) and glucose using point-of-care capillary (fingerprick) testing. All subjects were able to undertake breath manoeuvres suitable for analysis. Breath acetone varied between 160 and 862 ppb (median 337 ppb) and was significantly higher in men (median 480 ppb versus 296 ppb, p = 0.01). In this cross-sectional study, no association was observed between breath acetone and either dietary macronutrients or point-of-care capillary blood tests. Breath analysis by SIFT-MS offers a rapid, reproducible and easily performed measurement of acetone concentration in ambulatory patients with type 2 diabetes. The high inter-individual variability in breath acetone concentration may limit its usefulness in cross-sectional studies. Breath acetone may nevertheless be useful for monitoring metabolic changes in longitudinal metabolic studies, in a variety of clinical and research settings.

  7. Synthesis of the first chiral bidendate bis(trifluoromethyl)phosphane ligand through stabilization of the bis(trifluoromethyl)phosphanide anion in the presence of acetone.

    PubMed

    Hoge, Berthold; Thösen, Christoph; Pantenburg, Ingo

    2006-12-04

    Lewis acid/Lewis base adduct formation of the P(CF3)2- ion and acetone leads to a reduced negative hyperconjugation and, therefore, limits the C--F bond activation. The resulting increased thermal stability of the P(CF3)2- ion in the presence of acetone allows selective substitutions and enables the synthesis of the first example of a chiral, bidentate bis(trifluoromethyl)phosphane ligand: a DIOP derivative, [(2,2-dimethyl-1,3-dioxolane-4,5-diyl)bis(methylene)]bis(diphenylphosphane), in which the phenyl groups at the phosphorus atoms are replaced by strong electron-withdrawing trifluoromethyl groups. The resulting high electron-acceptor strength of the synthesized bidentate (CF3)2P ligand is demonstrated by a structural and vibrational study of the corresponding tetracarbonyl-molybdenum complex. The stabilization of the P(CF3)2- ion in the presence of acetone is based on the formation of a dynamic Lewis acid/Lewis base couple, (CF3)2PC(CH3)2O-. Although there is no spectroscopic evidence for the formation of the formulated alcoholate ion, the intermediate formation of (CF3)2PC(CH3)2O- could be proved through the reaction with (CF3)2PP(CF3)2, which yields the novel phosphane-phosphinite ligand (CF3)2PC(CH3)2OP(CF3)2. This ligand readily forms square-planar Pt(II) complexes upon treatment with solid PtCl2.

  8. Concentration of dilute acetone-water solutions using pervaporation

    SciTech Connect

    Hollein, M.E.; Hammond, M.; Slater, C.S. )

    1993-03-01

    The separation of acetone-water mixtures by pervaporation has been studied. Four membranes were evaluated: a silicone composite (SC) membrane, a polydimethylsiloxane (PDMS) membrane, a polymethoxysiloxane (PMS), and a poly-ether-block-polyamide copolymer (PEBA) membrane. The silicone composite membrane exhibited a higher flux and selectivity than any of the other membranes studies. At a feed temperature of 50[degrees]C, a permeate-side pressure of 1 torr, and a feed concentration of 5.0%, the silicone composite membrane had a flux of 1.1 kg/m[sup 2][center dot]h and a selectivity of 50. The effects of temperature and permeate-side pressure on membrane transport were studied using the SC membrane. An increase in temperature increased the flux exponentially, but had little effect on selectivity. An analysis of the data shows that the trend agrees quite well with an Arrhenius-type relationship. As the permeate-side pressure increased, the flux decreased in a sigmoidal fashion over the range evaluated. Selectivity did not change significantly over the lower portion of the pressure range studied. The effect of feed concentration on flux and selectivity was also investigated. 30 refs., 11 figs.

  9. Mathematical modelling of clostridial acetone-butanol-ethanol fermentation.

    PubMed

    Millat, Thomas; Winzer, Klaus

    2017-03-01

    Clostridial acetone-butanol-ethanol (ABE) fermentation features a remarkable shift in the cellular metabolic activity from acid formation, acidogenesis, to the production of industrial-relevant solvents, solventogensis. In recent decades, mathematical models have been employed to elucidate the complex interlinked regulation and conditions that determine these two distinct metabolic states and govern the transition between them. In this review, we discuss these models with a focus on the mechanisms controlling intra- and extracellular changes between acidogenesis and solventogenesis. In particular, we critically evaluate underlying model assumptions and predictions in the light of current experimental knowledge. Towards this end, we briefly introduce key ideas and assumptions applied in the discussed modelling approaches, but waive a comprehensive mathematical presentation. We distinguish between structural and dynamical models, which will be discussed in their chronological order to illustrate how new biological information facilitates the 'evolution' of mathematical models. Mathematical models and their analysis have significantly contributed to our knowledge of ABE fermentation and the underlying regulatory network which spans all levels of biological organization. However, the ties between the different levels of cellular regulation are not well understood. Furthermore, contradictory experimental and theoretical results challenge our current notion of ABE metabolic network structure. Thus, clostridial ABE fermentation still poses theoretical as well as experimental challenges which are best approached in close collaboration between modellers and experimentalists.

  10. Determination of acetone and methyl ethyl ketone in water

    USGS Publications Warehouse

    Tai, D.Y.

    1978-01-01

    Analytical procedures for the determination of acetone and methyl ethyl ketone in water samples were developed. Concentrations in the milligram-per-liter range were determined by injecting an aqueous sample into the analysis system through an injection port, trapping the organics on Tenax-GC at room temperature, and thermally desorbing the organics into a gas chromatograph with a flame ionization detector for analysis. Concentrations in the microgram-per-liter range were determined by sweeping the headspace vapors over a water sample at 50C, trapping on Tenax-GC, and thermally desorbing the organics into the gas chromatograph. The precision for two operators of the milligram-per-liter concentration procedure, expressed as the coefficient of variation, was generally less than 2 percent for concentrations ranging from 16 to 160 milligrams per liter. The precision from two operators of the microgram-per-liter concentration procedure was between 2 and 4 percent for concentrations of 20 and 60 micrograms per liter. (Woodard-USGS)

  11. Acetone, butanol, and ethanol production from wastewater algae.

    PubMed

    Ellis, Joshua T; Hengge, Neal N; Sims, Ronald C; Miller, Charles D

    2012-05-01

    Acetone, butanol, and ethanol (ABE) fermentation by Clostridium saccharoperbutylacetonicum N1-4 using wastewater algae biomass as a carbon source was demonstrated. Algae from the Logan City Wastewater Lagoon system grow naturally at high rates providing an abundant source of renewable algal biomass. Batch fermentations were performed with 10% algae as feedstock. Fermentation of acid/base pretreated algae produced 2.74 g/L of total ABE, as compared with 7.27 g/L from pretreated algae supplemented with 1% glucose. Additionally, 9.74 g/L of total ABE was produced when xylanase and cellulase enzymes were supplemented to the pretreated algae media. The 1% glucose supplement increased total ABE production approximately 160%, while supplementing with enzymes resulted in a 250% increase in total ABE production when compared to production from pretreated algae with no supplementation of extraneous sugar and enzymes. Additionally, supplementation of enzymes produced the highest total ABE production yield of 0.311 g/g and volumetric productivity of 0.102 g/Lh. The use of non-pretreated algae produced 0.73 g/L of total ABE. The ability to engineer novel methods to produce these high value products from an abundant and renewable feedstock such as algae could have significant implications in stimulating domestic energy economies.

  12. Infrared spectroscopy of acetone-water liquid mixtures. I. Factor analysis

    NASA Astrophysics Data System (ADS)

    Max, Jean-Joseph; Chapados, Camille

    2003-09-01

    Acetone and water mixtures covering the whole solubility range were measured by Fourier transform infrared attenuated total reflectance spectroscopy. In this system, only water can supply the hydrogen atoms necessary for hydrogen bonding. Using spectral windowing with factor analysis (FA), 10 principal factors were retrieved, five water and five acetone. Hydrogen bonding is observed on the carbonyl stretch band as water is introduced in the solution, redshifting the band further from its gas position than that observed in pure liquid acetone. This indicates that the hydrogen bonding is stronger than the acetone dipole-dipole interactions because it overrides them. A water molecule isolated in acetone is twice H bonded through its two H atoms; although both OH groups are H-bond donors, the OH stretch band is less redshifted (˜138 cm-1) than that of pure liquid water (˜401 cm-1). This is attributable to the two lone electron pairs remaining on the oxygen atom that sustain a large part of the OH valence bond strength. Hydrogen bonds on the water oxygen weaken both its OH valence bonds and modify the OH stretch band when water is added to the solution. The oxygen atoms of both water and acetone can accept 0, 1, and 2 H bonds given by water to yield three water and three acetone situations. Since these six situations are far less than the 10 principal factors retrieved by FA, other perturbations must be present to account for the difference. Although acetone and water are intermingled through H bonds, hydrates in the sense of an acetone molecule sequestering a number of water molecules or altering the H-bonding water network are not present because the principal factors evolve independently.

  13. Mid-IR acoustooptic interaction in planar waveguides

    NASA Astrophysics Data System (ADS)

    Deriugin, L. N.; Anikin, V. I.; Gudzenko, A. I.; Dneprovskii, V. G.; Terichev, V. F.

    1980-04-01

    The interaction of surface acoustic waves (SAW) and surface optical waves in planar infrared waveguides has been studied experimentally at a wavelength of 10.6 microns, corresponding to the output wavelength of a CO2 laser. In the planar waveguide used, the supporting layer was a film of As-Se chalcogenide glass deposited by thermal evaporation on a substrate of a high-resistivity cadmium sulfide single crystal. Diffraction efficiency vs acoustic power and diffraction efficiency vs SAW frequency plots are presented. The maximum intensity of the diffracted light was observed when the infrared light was incident on the acoustic column at an angle of 1 deg 59 min, which is in good agreement with the calculated value.

  14. Modified reverse tapering method to prevent frequency shift of the radiation in the planar undulator

    NASA Astrophysics Data System (ADS)

    Shim, Chi Hyun; Ko, In Soo; Parc, Yong Woon

    2017-03-01

    This paper presents a modified reverse tapering method to generate a polarized soft x ray in x-ray free-electron lasers (XFELs) with a higher photon power and a shorter undulator length than the simple linear reverse tapering method. In the proposed method, a few untapered planar undulators are added before the simple linear reverse tapering section of the undulator line. This simple modification prevents the frequency shift of the radiation that occurs when the simple linear reverse tapering method is applied to planar undulators. In the proposed method, the total length of planar undulators decreased in spite of the additional untapered undulators. When the modified reverse tapering method is used with four untapered planar undulators, the total length of the planar undulators is 64.6 m. On the other hand, the required length of the planar undulators is 94.6 m when the simple linear reverse tapering method is used. The proposed method gives us a way to generate a soft x-ray pulse (1.24 keV) with a high degree of polarization (>0.99 ) and radiation power (>30 GW ) at the new undulator line with a 10-GeV electron beam in the Pohang Accelerator Laboratory X-ray Free-Electron Laser. This method can be applied in the existing XFELs in the world without any change in the undulator lines.

  15. Comparison studies of surface cleaning methods for PAN-based carbon fibers with acetone, supercritical acetone and subcritical alkali aqueous solutions

    NASA Astrophysics Data System (ADS)

    Meng, Linghui; Fan, Dapeng; Huang, Yudong; Jiang, Zaixing; Zhang, Chunhua

    2012-11-01

    Four kinds of polyacrylonitrile-based carbon fibers were cleaned by three methods and were characterized by X-ray photoelectron spectroscopy, monofilament tensile strength test and atomic force microscopy (AFM). Experimental results of these tests reveal that the method using supercritical acetone or subcritical potassium hydroxide aqueous solution act as the processing medium shows a better cleaning effect compared to the traditional method, Soxhlet extraction with acetone. The method using supercritical acetone is more appropriate to wipe off the oxygenated contaminants on carbon fibers' surfaces and causes a relatively smaller damage to the bulk strength of each carbon fiber. As far as treating method using the subcritical alkali aqueous solution, it can thoroughly remove silicious contaminants on the surfaces of treated fibers.

  16. Planarization of metal films for multilevel interconnects

    DOEpatents

    Tuckerman, D.B.

    1985-06-24

    In the fabrication of multilevel integrated circuits, each metal layer is planarized by heating to momentarily melt the layer. The layer is melted by sweeping lase pulses of suitable width, typically about 1 microsecond duration, over the layer in small increments. The planarization of each metal layer eliminates irregular and discontinuous conditions between successive layers. The planarization method is particularly applicable to circuits having ground or power planes and allows for multilevel interconnects. Dielectric layers can also be planarized to produce a fully planar multilevel interconnect structure. The method is useful for the fabrication of VLSI circuits, particularly for wafer-scale integration.

  17. Principles of planar polarity in animal development

    PubMed Central

    Goodrich, Lisa V.; Strutt, David

    2011-01-01

    Planar polarity describes the coordinated polarisation of cells or structures in the plane of a tissue. The patterning mechanisms that underlie planar polarity are well characterised in Drosophila, where many events are regulated by two pathways: the ‘core’ planar polarity complex and the Fat/Dachsous system. Components of both pathways also function in vertebrates and are implicated in diverse morphogenetic processes, some of which self-evidently involve planar polarisation and some of which do not. Here, we review the molecular mechanisms and cellular consequences of planar polarisation in diverse contexts, seeking to identify the common principles across the animal kingdom. PMID:21521735

  18. Biological activity of palladium(II) and platinum(II) complexes of the acetone Schiff bases of S-methyl- and S-benzyldithiocarbazate and the X-ray crystal structure of the [Pd(asme)2] (asme=anionic form of the acetone Schiff base of S-methyldithiocarbazate) complex.

    PubMed

    Akbar Ali, Mohammad; Mirza, Aminul Huq; Butcher, Raymond J; Tarafder, M T H; Keat, Tan Boon; Ali, A Manaf

    2002-11-25

    Palladium(II) and platinum(II) complexes of general empirical formula, [M(NS)(2)] (NS=uninegatively charged acetone Schiff bases of S-methyl- and S-benzyldithiocarbazate; M=Pt(II) and Pd(II)) have been prepared and characterized by a variety of physicochemical techniques. Based on conductance, IR and electronic spectral evidence, a square-planar structure is assigned to these complexes. The crystal and molecular structure of the [Pd(asme)(2)] complex (asme=anionic form of the acetone Schiff base of S-methyldithiocarbazate) has been determined by X-ray diffraction. The complex has a distorted cis-square planar structure with the ligands coordinated to the palladium(II) ions as uninegatively charged bidentate NS chelating agents via the azomethine nitrogen and the mercaptide sulfur atoms. The distortion from a regular square-planar geometry is attributed to the restricted bite angles of the ligands. Antimicrobial tests indicate that the Schiff bases exhibit strong activities against the pathogenic bacteria, Bacillus subtilis (mutant defective DNA repair), methicillin-resistant Staphylococcus aureus, B. subtilis (wild type) and Pseudomonas aeruginosa and the fungi, Candida albicans (CA), Candida lypotica (2075), Saccharomyces cerevisiae (20341) and Aspergillus ochraceous (398)-the activities exhibited by these compounds being greater than that of the standard antibacterial and antifungal drugs, streptomycin and nystatin, respectively. The palladium(II) and platinum(II) complexes are inactive against most of these organisms but, the microbe, Pseudomonas aeruginosa shows strong sensitivity to the platinum(II) complexes. Screening of the compounds for their cytotoxicities against T-lymphoblastic leukemia cancer cells has shown that the acetone Schiff base of S-methyldithiocarbazate (Hasme) exhibits a very weak activity, whereas the S-benzyl derivative (Hasbz) is inactive. However, the palladium(II) complexes exhibit strong cytotoxicities against this cancer; their

  19. Window defect planar mapping technique

    NASA Technical Reports Server (NTRS)

    Minton, F. R.; Minton, U. O. (Inventor)

    1976-01-01

    A method of planar mapping defects in a window having an edge surface and a planar surface. The method is comprised of steps for mounting the window on a support surface. Then a light sensitive paper is placed adjacent to the window surface. A light source is positioned adjacent to the window edge. The window is then illuminated with the source of light for a predetermined interval of time. Defects on the surface of the glass, as well as in the interior of the glass are detected by analyzing the developed light sensitive paper. The light source must be in the form of optical fibers or a light tube whose light transmitting ends are placed near the edge surface of the window.

  20. Manufacturing of planar ceramic interconnects

    SciTech Connect

    Armstrong, B.L.; Coffey, G.W.; Meinhardt, K.D.; Armstrong, T.R.

    1996-12-31

    The fabrication of ceramic interconnects for solid oxide fuel cells (SOFC) and separator plates for electrochemical separation devices has been a perennial challenge facing developers. Electrochemical vapor deposition (EVD), plasma spraying, pressing, tape casting and tape calendering are processes that are typically utilized to fabricate separator plates or interconnects for the various SOFC designs and electrochemical separation devices. For sake of brevity and the selection of a planar fuel cell or gas separation device design, pressing will be the only fabrication technique discussed here. This paper reports on the effect of the characteristics of two doped lanthanum manganite powders used in the initial studies as a planar porous separator for a fuel cell cathode and as a dense interconnect for an oxygen generator.

  1. Planar polarity of ependymal cilia.

    PubMed

    Kishimoto, Norihito; Sawamoto, Kazunobu

    2012-02-01

    Ependymal cells, epithelial cells that line the cerebral ventricles of the adult brain in various animals, extend multiple motile cilia from their apical surface into the ventricles. These cilia move rapidly, beating in a direction determined by the ependymal planar cell polarity (PCP). Ciliary dysfunction interferes with cerebrospinal fluid circulation and alters neuronal migration. In this review, we summarize recent studies on the cellular and molecular mechanisms underlying two distinct types of ependymal PCP. Ciliary beating in the direction of fluid flow is established by a combination of hydrodynamic forces and intracellular planar polarity signaling. The ciliary basal bodies' anterior position on the apical surface of the cell is determined in the embryonic radial glial cells, inherited by ependymal cells, and established by non-muscle myosin II in early postnatal development.

  2. Summing Planar Bosonic Open Strings

    SciTech Connect

    Bardakci, Korkut

    2006-02-16

    In earlier work, planar graphs of massless {phi}{sup 3} theory were summed with the help of the light cone world sheet picture and the mean field approximation. In the present article, the same methods are applied to the problem of summing planar bosonic open strings. They find that in the ground state of the system, string boundaries form a condensate on the world sheet, and a new string emerges from this summation. Its slope is always greater than the initial slope, and it remains non-zero even when the initial slope is set equal to zero. If they assume the initial string tends to a field a theory in the zero slope limit, this result provides evidence for string formation in field theory.

  3. Ozonolysis at vegetation surfaces. a source of acetone, 4-oxopentanal, 6-methyl-5-hepten-2-one, and geranyl acetone in the troposphere

    NASA Astrophysics Data System (ADS)

    Fruekilde, P.; Hjorth, J.; Jensen, N. R.; Kotzias, D.; Larsen, B.

    The present study gives a possible explanation for the ubiquitous occurrence of 6-methyl-5-hepten-2-one and acetone in ambient air and reports for the first time on a widespread occurrence of geranyl acetone and 4-oxopentanal. We have conducted a series of laboratory experiments in which it is demonstrated that significant amounts of geranyl acetone, 6-methyl-5-hepten-2-one (6-MHO), 4-oxopentanal (4-OPA), and acetone are formed by the reaction of ozone with foliage of common vegetation in the Mediterranean area ( Quercus ilex>Citrus sinensis>Quercus suber>Quercus freinetto>Pinus pinea). In order to rule out biological formation, epicuticular waxes were extracted from the leaves, dispersed on glass wool and allowed to react with a flow of artificial air. Significant amounts of 6-MHO and 4-OPA were formed at ozone concentrations of 50-100 ppbv, but not at zero ozone. A number of terpenoids common in vegetation contain the structural element necessary for ozonolytic formation of 6-MHO. Two sesquiterpenes (nerolidol; farnesol), and a triterpene (squalene) selected as representative test compounds were demonstrated to be strong precursors for acetone, 4-OPA, and 6-MHO. Squalene was also a strong precursor for geranyl acetone. The atmospheric lifetime of geranyl acetone and 6-MHO is less than 1 h under typical conditions. For the present study, we have synthesized 4-OPA and investigated the kinetics of its gas-phase reaction with OH, NO 3, and O 3. A tropospheric lifetime longer than 17 h under typical conditions was calculated from the measured reaction rate constants, which explains the tropospheric occurrence of 4-OPA. It is concluded that future atmospheric chemistry investigations should included geranyl acetone, 6-MHO, and 4-OPA. In a separate experiment it was demonstrated that human skin lipid which contains squalene as a major component is a strong precursor for the four above-mentioned compounds plus nonanal and decanal. The accidental touching of material

  4. Enjoyment of Euclidean planar triangles

    NASA Astrophysics Data System (ADS)

    Srinivasan, V. K.

    2013-09-01

    This article adopts the following classification for a Euclidean planar ?, purely based on angles alone. A Euclidean planar triangle is said to be acute angled if all the three angles of the Euclidean planar ? are acute angles. It is said to be right angled at a specific vertex, say B, if the angle ? is a right angle with the two remaining angles as acute angles. It is said to be obtuse angled at the vertex B if ? is an obtuse angle, with the two remaining angles as acute angles. In spite of the availability of numerous text books that contain our human knowledge of Euclidean plane geometry, softwares can offer newer insights about the characterizations of planar geometrical objects. The author's characterizations of triangles involve points like the centroid G, the orthocentre H of the ?, the circumcentre S of the ?, the centre N of the nine-point circle of the ?. Also the radical centre rc of three involved diameter circles of the sides BC, AC and AB of the ? provides a reformulation of the orthocentre, resulting in an interesting theorem, dubbed by the author as 'Three Circles Theorem'. This provides a special result for a right-angled ?, again dubbed by the author as 'The Four Circles Theorem'. Apart from providing various inter connections between the geometrical points, the relationships between shapes of the triangle and the behaviour of the points are reasonably explored in this article. Most of these results will be useful to students that take courses in Euclidean Geometry at the college level and the high school level. This article will be useful to teachers in mathematics at the high school level and the college level.

  5. Compact planar microwave blocking filters

    NASA Technical Reports Server (NTRS)

    U-Yen, Kongpop (Inventor); Wollack, Edward J. (Inventor)

    2012-01-01

    A compact planar microwave blocking filter includes a dielectric substrate and a plurality of filter unit elements disposed on the substrate. The filter unit elements are interconnected in a symmetrical series cascade with filter unit elements being organized in the series based on physical size. In the filter, a first filter unit element of the plurality of filter unit elements includes a low impedance open-ended line configured to reduce the shunt capacitance of the filter.

  6. Planar and nonplanar ion acoustic shock waves in relativistic degenerate astrophysical electron-positron-ion plasmas

    SciTech Connect

    Ata-ur-Rahman,; Qamar, A.; Ali, S.; Mirza, Arshad M.

    2013-04-15

    We have studied the propagation of ion acoustic shock waves involving planar and non-planar geometries in an unmagnetized plasma, whose constituents are non-degenerate ultra-cold ions, relativistically degenerate electrons, and positrons. By using the reductive perturbation technique, Korteweg-deVries Burger and modified Korteweg-deVries Burger equations are derived. It is shown that only compressive shock waves can propagate in such a plasma system. The effects of geometry, the ion kinematic viscosity, and the positron concentration are examined on the ion acoustic shock potential and electric field profiles. It is found that the properties of ion acoustic shock waves in a non-planar geometry significantly differ from those in planar geometry. The present study has relevance to the dense plasmas, produced in laboratory (e.g., super-intense laser-dense matter experiments) and in dense astrophysical objects.

  7. Site Competition During Coadsorption of Acetone with Methanol and Water on TiO2(110)

    SciTech Connect

    Shen, Mingmin; Henderson, Michael A.

    2011-08-02

    The competitive interaction between acetone and two solvent molecules (methanol and water) for surface sites on rutile TiO2(110) was studied using temperature programmed desorption (TPD). On a vacuum reduced TiO2(110) surface, which possessed ~5% oxygen vacancy sites, excess methanol displaced preadsorbed acetone molecules to weakly bound and physisorbed desorption states below 200 K, whereas acetone was stabilized to 250 K against displacement by methanol on an oxidized surface through formation of an acetone-diolate species. These behaviors of acetone differ from the competitive interactions between acetone and water in that acetone is less susceptible to displacement by water. Examination of acetone+methanol and acetone+water multilayer combinations shows that acetone is more compatible in water-ice films than in methanol-ice films, presumably because water has greater potential as a hydrogen-bond donor than does methanol. Acetone molecules displaced from the TiO2(110) surface by water are more likely to be retained in the near-surface region, having a greater opportunity to revisit the surface, than when methanol is used as a coadsorbate. This work was supported by the US Department of Energy Basic Energy Sciences' Chemical Sciences, Geosciences & Biosciences Division. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

  8. Concentration dependences of the physicochemical properties of a water-acetone system

    NASA Astrophysics Data System (ADS)

    Fedyaeva, O. A.; Poshelyuzhnaya, E. G.

    2017-01-01

    Concentration dependences of the UV spectrum, refractive index, specific electrical conductivity, boiling point, pH, surface tension, and heats of dissolution of a water-acetone system on the amount of acetone in the water are studied. It is found that the reversible protolytic interaction of the components occurs in all such solutions, resulting in the formation of hydroxyl and acetonium ions. It is shown that shifts of the equilibrium between the molecules and ions in the solution leads to extreme changes in their electrical properties. It is concluded that the formation of acetone solutions of water is accompanied by heat absorption, while the formation of aqueous solutions of acetone is accompanied by heat release.

  9. Cilia organize ependymal planar polarity

    PubMed Central

    Mirzadeh, Zaman; Han, Young-Goo; Soriano-Navarro, Mario; García-Verdugo, Jose Manuel; Alvarez-Buylla, Arturo

    2010-01-01

    Multi-ciliated epithelial cells, called ependymal cells, line the ventricles in the adult brain. Most ependymal cells are born prenatally and are derived from radial glia. Ependymal cells have a remarkable planar polarization that determines orientation of ciliary beating and propulsion of cerebrospinal fluid (CSF). Disruption of ependymal ciliary beating, by injury or disease, results in aberrant CSF circulation and hydrocephalus, a common disorder of the central nervous system. Very little is known about the mechanisms guiding ependymal planar polarity and whether this organization is acquired during ependymal cell development or is already present in radial glia. Here we show that basal bodies in ependymal cells in the lateral ventricle walls of adult mice are polarized in two ways: i) rotational; angle of individual basal bodies with respect to their long axis and ii) translational; the position of basal bodies on the apical surface of the cell. Conditional ablation of motile cilia disrupted rotational orientation, but translational polarity was largely preserved. In contrast, translational polarity was dramatically affected when radial glial primary cilia were ablated earlier in development. Remarkably, radial glia in the embryo have a translational polarity that predicts the orientation of mature ependymal cells. These results suggest that ependymal planar cell polarity is a multi-step process initially organized by primary cilia in radial glia and then refined by motile cilia in ependymal cells. PMID:20164345

  10. NMR planar microcoil for microanalysis

    NASA Astrophysics Data System (ADS)

    Sorli, B.; Chateaux, J. F.; Quiquerez, L.; Bouchet-Fakri, L.; Briguet, A.; Morin, P.

    2006-11-01

    This article deals with the analysis of small sample volume by using a planar microcoil and a micromachined cavity. This microcoil is used as a nuclear magnetic resonance (NMR) radio frequency detection coil in order to perform in vitro NMR analysis of the sample introduced into the microcavity. It is a real challenging task to develop microsystem for NMR spectrum extraction for smaller and smaller sample volume. Moreover, it is advantageous that these microsystems could be integrated in a Micro Total Analysing System (μ -TAS) as an analysing tool. In this paper, NMR theory, description, fabrication process and electrical characterization of planar microcoils receiver are described. Results obtained on NMR microspectroscopy experiments have been performed on water and ethanol, using a 1 mm diameter planar coil. This microcoil is tuned and matched at 85.13 MHz which is the Larmor frequency of proton in a 2 T magnetic field. This paper has been presented at “3e colloque interdisciplinaire en instrumentation (C2I 2004)”, École Normale Supérieure de Cachan, 29 30 janvier 2004.

  11. The planar shape of drumlins

    NASA Astrophysics Data System (ADS)

    Spagnolo, Matteo; Clark, Chris D.; Hughes, Anna L. C.; Dunlop, Paul; Stokes, Chris R.

    2010-12-01

    The asymmetry of the planar shape of drumlins is an established paradigm in the literature and characterizes drumlins as resembling tear drops with a blunt (bullet-shaped) stoss end and a tapering (pointed) lee end. It is widely cited and never been seriously questioned. In this paper, the planar shape of 44,500 drumlins mapped in various regional settings from drumlin fields in North America and Northern Europe were objectively analysed by means of Geographic Information System tools. Two parameters were considered. The first (denoted here as Aspl) focuses on the relative position of the point of intersection between the axes of the maximum length and the maximum width. It is defined as the distance between the upstream (i.e. beginning of the drumlin) and the intersection point (measured along the longitudinal axis) divided by the entire length of the long axis. Results indicate that the intersection point of the majority of drumlins (64%) is very close to the longitudinal midpoint (0.33 < Aspl < 0.66). The second parameter ( Aspl _A) is defined as the ratio between the area of the upstream half of the drumlin to that of the entire drumlin. Results show that for most drumlins (81%), the upper half area is almost as large as the down-half (0.45 < Aspl _A < 0.55). Taken together, these results concordantly indicate that drumlin planar shape has a strong tendency to be longitudinally symmetric and that the long-established paradigm of their plan form is false.

  12. Cilia organize ependymal planar polarity.

    PubMed

    Mirzadeh, Zaman; Han, Young-Goo; Soriano-Navarro, Mario; García-Verdugo, Jose Manuel; Alvarez-Buylla, Arturo

    2010-02-17

    Multiciliated epithelial cells, called ependymal cells, line the ventricles in the adult brain. Most ependymal cells are born prenatally and are derived from radial glia. Ependymal cells have a remarkable planar polarization that determines orientation of ciliary beating and propulsion of CSF. Disruption of ependymal ciliary beating, by injury or disease, results in aberrant CSF circulation and hydrocephalus, a common disorder of the CNS. Very little is known about the mechanisms guiding ependymal planar polarity and whether this organization is acquired during ependymal cell development or is already present in radial glia. Here we show that basal bodies in ependymal cells in the lateral ventricle walls of adult mice are polarized in two ways: (1) rotational; angle of individual basal bodies with respect to their long axis and (2) translational; the position of basal bodies on the apical surface of the cell. Conditional ablation of motile cilia disrupted rotational orientation, but translational polarity was largely preserved. In contrast, translational polarity was dramatically affected when radial glial primary cilia were ablated earlier in development. Remarkably, radial glia in the embryo have a translational polarity that predicts the orientation of mature ependymal cells. These results suggest that ependymal planar cell polarity is a multistep process initially organized by primary cilia in radial glia and then refined by motile cilia in ependymal cells.

  13. Electrocatalytic reduction of acetone in a proton-exchange-membrane reactor: a model reaction for the electrocatalytic reduction of biomass.

    PubMed

    Green, Sara K; Tompsett, Geoffrey A; Kim, Hyung Ju; Bae Kim, Won; Huber, George W

    2012-12-01

    Acetone was electrocatalytically reduced to isopropanol in a proton-exchange-membrane (PEM) reactor on an unsupported platinum cathode. Protons needed for the reduction were produced on the unsupported Pt-Ru anode from either hydrogen gas or electrolysis of water. The current efficiency (the ratio of current contributing to the desired chemical reaction to the overall current) and reaction rate for acetone conversion increased with increasing temperature or applied voltage for the electrocatalytic acetone/water system. The reaction rate and current efficiency went through a maximum with respect to acetone concentration. The reaction rate for acetone conversion increased with increasing temperature for the electrocatalytic acetone/hydrogen system. Increasing the applied voltage for the electrocatalytic acetone/hydrogen system decreased the current efficiency due to production of hydrogen gas. Results from this study demonstrate the commercial feasibility of using PEM reactors to electrocatalytically reduce biomass-derived oxygenates into renewable fuels and chemicals.

  14. A study of global atmospheric budget and distribution of acetone using global atmospheric model STOCHEM-CRI

    NASA Astrophysics Data System (ADS)

    Khan, M. A. H.; Cooke, M. C.; Utembe, S. R.; Archibald, A. T.; Maxwell, P.; Morris, W. C.; Xiao, P.; Derwent, R. G.; Jenkin, M. E.; Percival, C. J.; Walsh, R. C.; Young, T. D. S.; Simmonds, P. G.; Nickless, G.; O'Doherty, S.; Shallcross, D. E.

    2015-07-01

    The impact of including a more detailed VOC oxidation scheme (CRI v2-R5) with a multi-generational approach for simulating tropospheric acetone is investigated using a 3-D global model, STOCHEM-CRI. The CRI v2-R5 mechanism contains photochemical production of acetone from monoterpenes which account for 64% (46.8 Tg/yr) of the global acetone sources in STOCHEM-CRI. Both photolysis and oxidation by OH in the troposphere contributes equally (42%, each) and dry deposition contributes 16% of the atmospheric sinks of acetone. The tropospheric life-time and the global burden of acetone are found to be 18 days and 3.5 Tg, respectively, these values being close to those reported in the study of Jacob et al. (2002). A dataset of aircraft campaign measurements are used to evaluate the inclusion of acetone formation from monoterpenes in the CRI v2-R5 mechanism used in STOCHEM-CRI. The overall comparison between measurements and models show that the parameterised approach in STOCHEM-NAM (no acetone formation from monoterpenes) underpredicts the mixing ratios of acetone in the atmosphere. However, using a detailed monoterpene oxidation mechanism forming acetone has brought the STOCHEM-CRI into closer agreement with measurements with an improvement in the vertical simulation of acetone. The annual mean surface distribution of acetone simulated by the STOCHEM-CRI shows a peak over forested regions where there are large biogenic emissions and high levels of photochemical activity. Year-long observations of acetone and methanol at the Mace Head research station in Ireland are compared with the simulated acetone and methanol produced by the STOCHEM-CRI and found to produce good overall agreement between model and measurements. The seasonal variation of model and measured acetone levels at Mace Head, California, New Hampshire and Minnesota show peaks in summer and dips in winter, suggesting that photochemical production may have the strongest effect on its seasonal trend.

  15. Acetone vapor fiber sensor based on side polished fiber coated with cholesteric liquid crystal

    NASA Astrophysics Data System (ADS)

    Tang, Jieyuan; Chen, Zhe; Luo, Yunhan; Yu, Jianhui; Lu, Huihui; Zhang, Jun; Hsiao, Vincent K. S.

    2015-09-01

    The organic acetone vapor sensing characteristics of side-polished fiber coating with cholesteric liquid crystal film were investigated. The cholesteric liquid crystal used in our experiments is a mixture compound, which contains 30% cholesteryl oleyl carbonate, 60% cholesteryl pelargonat, and 25% cholesteryl chloride. When cholesteric liquid crystal film was coated on the surface of side-polished fiber, an interference transmission spectrum of fiber could be observed. When the fiber is exposing in acetone vapor, a blue shift of the interference spectrum was found. The higher concentration of acetone vapor is, the larger blue shift of spectrum is found. The shift of transmission spectrum is linear to the concentration of acetone vapor. The sensitivity is 1.356nm/vol% when the concentration of acetone vapor ranges from 3vol% to 16vol%. This study demonstrates a new all-fiber low-cost and portable acetone vapor sensor. It can be also used to investigate the helical structure and molecular orientation of cholesteric liquid crystal.

  16. Stability and interface properties of thin cellulose ester films adsorbed from acetone and ethyl acetate solutions.

    PubMed

    Amim, Jorge; Kosaka, Priscila M; Petri, Denise F S; Maia, Francisco C B; Miranda, Paulo B

    2009-04-15

    Stability and interface properties of cellulose acetate propionate (CAP) and cellulose acetate butyrate (CAB) films adsorbed from acetone or ethyl acetate onto Si wafers have been investigated by means of contact angle measurements and atomic force microscopy (AFM). Surface energy (gamma(S)(total)) values determined for CAP adsorbed from acetone are larger than those from ethyl acetate. In the case of CAB films adsorbed from ethyl acetate and acetone were similar. Dewetting was observed by AFM only for CAP films prepared from ethyl acetate. Positive values of effective Hamaker constant (A(eff)) were found only for CAP prepared from ethyl acetate, corroborating with dewetting phenomena observed by AFM. On the contrary, negative values of A(eff) were determined for CAP and CAB prepared from acetone and for CAB prepared from ethyl acetate, corroborating with experimental observations. Sum frequency generation (SFG) vibrational spectra indicated that CAP and CAB films prepared from ethyl acetate present more alkyl groups oriented perpendicularly to the polymer-air interface than those films prepared from acetone. Such preferential orientation corroborates with macroscopic contact angle measurements. Moreover, SFG spectra showed that acetone binds strongly to Si wafers, creating a new surface for CAP and CAB films.

  17. The photochemistry of acetone in the upper troposphere: A source of odd-hydrogen radicals

    NASA Astrophysics Data System (ADS)

    McKeen, S. A.; Gierczak, T.; Burkholder, J. B.; Wennberg, P. O.; Hanisco, T. F.; Keim, E. R.; Gao, R.-S.; Liu, S. C.; Ravishankara, A. R.; Fahey, D. W.

    This paper summarizes measured photodissociation quantum yields for acetone in the 290-320 nm wavelength region for pressures and temperatures characteristic of the upper troposphere. Calculations combine this laboratory data with trace gas concentrations obtained during the NASA and NOAA sponsored Stratospheric Tracers of Atmospheric Transport (STRAT) field campaign, in which measurements of OH, HO2, odd-nitrogen, and other compounds were collected over Hawaii, and west of California during fall and winter of 1995/1996. OH and HO2 concentrations within 2 to 5 km layers just below the tropopause are ∼50% larger than expected from O3, CH4, and H2O chemistry alone. Although not measured during STRAT, acetone is inferred from CO measurements and acetone-CO correlations from a previous field study. These inferred acetone levels are a significant source of odd-hydrogen radicals that can explain a large part of the discrepancy in the upper troposphere. For lower altitudes, the inferred acetone makes a negligible contribution to HOx (HO+HO2), but influences NOy partitioning. A major fraction of HOx production by acetone is through CH2O formation, and the HOx discrepancy can also be explained by CH2O levels in the 20 to 50 pptv range, regardless of the source.

  18. Acetone and monoterpene emissions from the boreal forest in northern Europe

    NASA Astrophysics Data System (ADS)

    Janson, Robert; de Serves, Claes

    Acetone is a ubiquitous component of the atmosphere which, by its photolysis, can play an important role in photochemical reactions in the free troposphere. This paper investigates the biogenic source of acetone from Scots pine ( Pinus sylvestris) and Norway spruce ( Picea abies) in the Scandinavian boreal zone. Branch emission measurements of acetone, monoterpenes, and isoprene were made with an all-Teflon flow-through branch chamber from five specimens of Scots pine at three sites in Sweden and Finland, and from one specimen of Norway spruce at one site in Sweden. Acetone samples were taken with SepPak™ DNPH cartridges, monoterpenes with Tenax TA, and isoprene with 3 l electropolished canisters. Acetone was found to dominate the carbonyl emission of both Scots pine and Norway spruce, as large as the monoterpene emissions and for Norway spruce, as the isoprene emission. The average standard emission rate (30°C) and average β-coefficient for the temperature correlation for 5 specimens of Scots pine were 870 ng C gdw -1 h -1 (gdw=gram dry weight) and 0.12, respectively. For the monoterpenes the values were 900 ng C gdw -1 h -1 and 0.12, respectively. The standard emission rate (30°C) for acetone from Norway spruce was 265 ng C gdw -1 h -1, but the sparsity of data, along with the unusual weather conditions at the time of the measurements, precludes the establishment of a summertime best estimate emission factor.

  19. Acetone and isopropanol in ruminal fluid and feces of lactating dairy cows.

    PubMed

    Sato, Hiroshi; Shiogama, Yumiko

    2010-03-01

    Acetone and its metabolite isopropanol are produced by gut microbes as well as by the host's metabolism. To evaluate the production of acetone and isopropanol in alimentary tracts, a total of 80 pair-samples of feces and ruminal fluid were taken in lactating dairy cows that had been fed silage-containing diets. Acetone and isopropanol were analyzed, together with ethanol and volatile fatty acids (VFAs). Isopropanol was detected in 57 fecal and all the ruminal samples; however, the ruminal isopropanol and ethanol concentrations were distinctly lower than those in the feces. Acetone was detected in 13 fecal and 53 ruminal samples; however, there was no significant difference in acetone concentrations between the feces and the ruminal fluid. The group with higher fecal isopropanol concentration showed higher fecal proportions of acetate accompanied by low proportion of minor VFA, which consisted of isobutyrate and iso- and n-valerate. In the group with higher ruminal isopropanol concentration, ethanol concentration was higher; the ruminal VFA profiles showed only a negligible difference. Fecal and ruminal ethanol concentrations were not affected by feed ethanol. Thus, the colon showed an accelerated alcoholic fermentation compared with the rumen of dairy cows; however, acetone was present at higher frequency in the rumen than in the feces.

  20. Lipid peroxidation and antioxidant system in rats acutely treated with acetone.

    PubMed

    Mathias, M G; Almeida, B B de; Bueno, J E; Portari, G V; Jordao, A A

    2010-06-01

    Cascades of metabolic changes leading to acetone production are induced in states of energy catabolism such as starvation or the use of a ketogenic diet. The reduced capacity for cell detoxification or the increased generation of free radicals is responsible for the toxic effect of acetone. The objective of the present study was to determine the effects of acute treatment (AT) with acetone on the oxidative and metabolic status of rats. The AT group (n=16) was treated by gavage with a single administration of 7.0 g acetone/kg body weight at a concentration of 25% (m/v). Eight rats were euthanized 6 h later (AT6) and eight 24 h later (AT24). Acetone levels were determined in blood and urine and oxidative parameters were analyzed by determining thiobarbituric acid reactive species (TBARS, indicators of lipid peroxidation) and reduced glutathione (GSH) and vitamin E as antioxidant parameters. Serum glucose, blood cholesterol and triglycerieds and hepatic fat were also determined. The results indicated a significant difference in the hepatic oxidative parameters, serum glucose and in plasma triglycerides between the groups. Thus, we conclude that the administration of acute acetone doses can promote changes in some biochemical parameters and in the hepatic oxidative profile.

  1. Fermentation and genomic analysis of acetone-uncoupled butanol production by Clostridium tetanomorphum.

    PubMed

    Gong, Fuyu; Bao, Guanhui; Zhao, Chunhua; Zhang, Yanping; Li, Yin; Dong, Hongjun

    2016-02-01

    In typical acetone-butanol-ethanol (ABE) fermentation, acetone is the main by-product (50 % of butanol mass) of butanol production, resulting in a low yield of butanol. It is known that some Clostridium tetanomorphum strains are able to produce butanol without acetone in nature. Here, we described that C. tetanomorphum strain DSM665 can produce 4.16 g/L butanol and 4.98 g/L ethanol at pH 6.0, and 9.81 g/L butanol and 1.01 g/L ethanol when adding 1 mM methyl viologen. Butyrate and acetate could be reassimilated and no acetone was produced. Further analysis indicated that the activity of the acetate/butyrate:acetoacetyl-CoA transferase responsible for acetone production is lost in C. tetanomorphum DSM665. The genome of C. tetanomorphum DSM665 was sequenced and deposited in DDBJ, EMBL, and GenBank under the accession no. APJS00000000. Sequence analysis indicated that there are no typical genes (ctfA/B and adc) that are typically parts of an acetone synthesis pathway in C. tetanomorphum DSM665. This work provides new insights in the mechanism of clostridial butanol production and should prove useful for the design of a high-butanol-producing strain.

  2. Acetone production in solventogenic Clostridium species: new insights from non-enzymatic decarboxylation of acetoacetate.

    PubMed

    Han, Bei; Gopalan, Venkat; Ezeji, Thaddeus Chukwuemeka

    2011-08-01

    Development of a butanologenic strain with high selectivity for butanol production is often proposed as a possible route for improving the economics of biobutanol production by solventogenic Clostridium species. The acetoacetate decarboxylase (aadc) gene encoding acetoacetate decarboxylase (AADC), which catalyzes the decarboxylation of acetoacetate into acetone and CO(2), was successfully disrupted by homologous recombination in solventogenic Clostridium beijerinckii NCIMB 8052 to generate an aadc ( - ) mutant. Our fermentation studies revealed that this mutant produces a maximum acetone concentration of 3 g/L (in P2 medium), a value comparable to that produced by wild-type C. beijerinckii 8052. Therefore, we postulated that AADC-catalyzed decarboxylation of acetoacetate is not the sole means for acetone generation. Our subsequent finding that non-enzymatic decarboxylation of acetoacetate in vitro, under conditions similar to in vivo acetone-butanol-ethanol (ABE) fermentation, produces 1.3 to 5.2 g/L acetone between pH 6.5 and 4 helps rationalize why various knock-out and knock-down strategies designed to disrupt aadc in solventogenic Clostridium species did not eliminate acetone production during ABE fermentation. Based on these results, we discuss alternatives to enhance selectivity for butanol production.

  3. A modified pathway for the production of acetone in Escherichia coli.

    PubMed

    May, Antje; Fischer, Ralf-Jörg; Maria Thum, Simone; Schaffer, Steffen; Verseck, Stefan; Dürre, Peter; Bahl, Hubert

    2013-01-01

    A modified synthetic acetone operon was constructed. It consists of two genes from Clostridium acetobutylicum (thlA coding for thiolase and adc coding for acetoacetate decarboxylase) and one from Bacillus subtilis or Haemophilus influenzae (teII(srf) or ybgC, respectively, for thioesterase). Expression of this operon in Escherichia coli resulted in the production of acetone starting from the common metabolite acetyl-CoA via acetoacetyl-CoA and acetoacetate. The thioesterases do not need a CoA acceptor for acetoacetyl-CoA hydrolysis. Thus, in contrast to the classic acetone pathway of Clostridium acetobutylicum and related microorganisms which employ a CoA transferase, the new pathway is acetate independent. The genetic background of the host strains was crucial. Only E. coli strains HB101 and WL3 were able to produce acetone via the modified plasmid based pathway, up to 64mM and 42mM in 5-ml cultures, respectively. Using glucose fed-batch cultures the concentration could be increased up to 122mM acetone with HB101 carrying the recombinant plasmid pUC19ayt (thioesterase from H. influenzae). The formation of acetone led to a decreased acetate production by E. coli.

  4. Does acetone react with HO2 in the upper-troposphere?

    NASA Astrophysics Data System (ADS)

    Dillon, T. J.; Pozzer, A.; Vereecken, L.; Crowley, J. N.; Lelieveld, J.

    2012-02-01

    Recent theoretical calculations showed that reaction with HO2 could be an important sink for acetone (CH3C(O)CH3) and source of acetic acid (CH3C(O)OH) in cold parts of the atmosphere (e.g. the tropopause region). This work details studies of HO2 + CH3C(O)CH3 (CH3)2C(OH)OO (R1) in laboratory-based and theoretical chemistry experiments; the atmospheric significance of Reaction (R1) was assessed in a global 3-D chemical model. Pulsed laser-kinetic experiments were conducted, for the first time, at the low-temperatures representative of the tropopause. Reaction with NO converted HO2 to OH for detection by laser induced fluorescence. Reduced yields of OH at T < 220 K provided indirect evidence for the sequestration of HO2 by CH3C(O)CH3 with a forward rate coefficient greater than 2 × 10-12 cm3 molecule-1 s-1. No evidence for Reaction (R1) was observed at T > 230 K, probably due to rapid thermal dissociation back to HO2 + CH3C(O)CH3. Numerical simulations of the data indicate that these experiments were sensitive to only (R1a) HO2-CH3C(O)CH3 complex formation, the first step in (R1). Rearrangement (R1b) of the complex to form peroxy radicals, and hence the atmospheric significance of (R1) has yet to be rigorously verified by experiment. Results from new quantum chemical calculations indicate that K1 is characterised by large uncertainties of at least an order of magnitude at T < 220 K. The large predicted values from Hermans et al. lie at the top end of the range of values obtained from calculations at different (higher) levels of theory. Atmospheric modelling studies demonstrated that whilst (R1) chemistry may be a significant loss process for CH3C(O)CH3 near the tropopause, it cannot explain observations of CH3C(O)OH throughout the troposphere.

  5. Determination of residual acetone and acetone related impurities in drug product intermediates prepared as Spray Dried Dispersions (SDD) using gas chromatography with headspace autosampling (GCHS).

    PubMed

    Quirk, Emma; Doggett, Adrian; Bretnall, Alison

    2014-08-05

    Spray Dried Dispersions (SDD) are uniform mixtures of a specific ratio of amorphous active pharmaceutical ingredient (API) and polymer prepared via a spray drying process. Volatile solvents are employed during spray drying to facilitate the formation of the SDD material. Following manufacture, analytical methodology is required to determine residual levels of the spray drying solvent and its associated impurities. Due to the high level of polymer in the SDD samples, direct liquid injection with Gas Chromatography (GC) is not a viable option for analysis. This work describes the development and validation of an analytical approach to determine residual levels of acetone and acetone related impurities, mesityl oxide (MO) and diacetone alcohol (DAA), in drug product intermediates prepared as SDDs using GC with headspace (HS) autosampling. The method development for these analytes presented a number of analytical challenges which had to be overcome before the levels of the volatiles of interest could be accurately quantified. GCHS could be used after two critical factors were implemented; (1) calculation and application of conversion factors to 'correct' for the reactions occurring between acetone, MO and DAA during generation of the headspace volume for analysis, and the addition of an equivalent amount of polymer into all reference solutions used for quantitation to ensure comparability between the headspace volumes generated for both samples and external standards. This work describes the method development and optimisation of the standard preparation, the headspace autosampler operating parameters and the chromatographic conditions, together with a summary of the validation of the methodology. The approach has been demonstrated to be robust and suitable to accurately determine levels of acetone, MO and DAA in SDD materials over the linear concentration range 0.008-0.4μL/mL, with minimum quantitation limits of 20ppm for acetone and MO, and 80ppm for DAA.

  6. Fluorescent immunosensors using planar waveguides

    NASA Astrophysics Data System (ADS)

    Herron, James N.; Caldwell, Karin D.; Christensen, Douglas A.; Dyer, Shellee; Hlady, Vladimir; Huang, P.; Janatova, V.; Wang, Hiabo K.; Wei, A. P.

    1993-05-01

    The goal of our research program is to develop competitive and sandwich fluoroimmunoassays with high sensitivity and fast response time, that do not require external reagents. Our approach to this problem is to employ an optical immunoassay based on total internal reflection fluorescence (TIRF). Specifically, monoclonal antibodies are immobilized on a planar waveguide. Total internal reflection of light in the planar waveguide sets up an evanescent field which extends about 2000 angstroms from the interface. In the competitive immunoassay, a fluorescent label is coupled to a small synthetic antigen which is packaged with the antibody. In the absence of analyte, the fluorescently labeled antigen binds to the antibody and is excited by the evanescent field. Upon the addition of analyte, the fluorescently labeled antigen molecules are displaced by unlabeled antigen molecules and diffuse out of the evanescent field. In the sandwich assay, a primary or `capture' antibody is immobilized on the planar waveguide, and a secondary or `tracer' antibody (which is labeled with a fluorescent dye) is added to the bulk solution. In the absence of analyte, the tracer antibody remains in solution and very little fluorescence is observed. However, upon addition of analyte, a `molecular sandwich' is formed on the waveguide, composed of: (1) the capture antibody; (2) the analyte; and (3) the tracer antibody. Once this sandwich forms, the tracer antibody is within the evanescent field and fluoresces. Fluorescence emission is detected by a charged- coupled device (CCD). Using this approach, we have developed a prototype immunosensor for the detection of human chorionic gonadotropin (hCG). This device meets our design goals and exhibits a sensitivity of 0.1 - 1 pmolar.

  7. Fluorescence particle detection using microfluidics and planar optoelectronic elements

    NASA Astrophysics Data System (ADS)

    Kettlitz, Siegfried W.; Moosmann, Carola; Valouch, Sebastian; Lemmer, Uli

    2014-05-01

    Detection of fluorescent particles is an integral part of flow cytometry for analysis of selectively stained cells. Established flow cytometer designs achieve great sensitivity and throughput but require bulky and expensive components which prohibit mass production of small single-use point-of-care devices. The use of a combination of innovative technologies such as roll-to-roll printed microuidics with integrated optoelectronic components such as printed organic light emitting diodes and printed organic photodiodes enables tremendous opportunities in cost reduction, miniaturization and new application areas. In order to harvest these benefits, the optical setup requires a redesign to eliminate the need for lenses, dichroic mirrors and lasers. We investigate the influence of geometric parameters on the performance of a thin planar design which uses a high power LED as planar light source and a PIN-photodiode as planar detector. Due to the lack of focusing optics and inferior optical filters, the device sensitivity is not yet on par with commercial state of the art flow cytometer setups. From noise measurements, electronic and optical considerations we deduce possible pathways of improving the device performance. We identify that the sensitivity is either limited by dark noise for very short apertures or by noise from background light for long apertures. We calculate the corresponding crossover length. For the device design we conclude that a low device thickness, low particle velocity and short aperture length are necessary to obtain optimal sensitivity.

  8. Preliminary comparison of laser and solar space power systems

    NASA Technical Reports Server (NTRS)

    Deyoung, R. J.; Tepper, W. D.; Conway, E. J.; Humes, D. H.

    1983-01-01

    Four laser receiver systems are compared to onboard solar photovoltaic power generation for spacecraft electrical requirements. The laser photovoltaic and laser MHD receivers were found to be lighter than a comparable planar solar photovoltaic system. The laser receiver also shows less drag at lower altitudes. Panel area is also reduced for the laser receiver allowing fewer Shuttle trips for construction. Finally, it is shown that a 1 megawatt laser and receiver system might be constructed with less weight than a comparable planar solar photovoltaic system.

  9. Covalent binding of acetone to aminophospholipids in vitro and in vivo.

    PubMed

    Kuksis, Arnis; Ravandi, Amir; Schneider, Michael

    2005-06-01

    We have determined the ions characteristic of acetone adducts of reference aminophospholipids and have used them as markers for identification of acetone adducts of aminophospholipids in commercial lecithin, acetone extracts of tissue lipids, and in plasma and red blood cells of diabetic subjects. The acetonation products were determined by normal-phase high-performance liquid chromatography (HPLC) with on-line electrospray-mass spectrometry, and electrospray/collision-induced dissociation in the negative ion mode. The major acetone complexes of PtdEtn and PtdSer were identified as the diacetone derivatives [PtdEtn+116-H2O]- and [PtdSer+116-H2O]-, respectively, although ions corresponding to monoacetone [PtdEtn+58-H2O]- and doubly dehydrated diacetone adducts [PtdSer+116-2 x 18]- were also observed. Upon increase of the capillary exit voltage (CapEx) from -160 to -300 V, new ions appeared with the original retention time but with 58 masses (one acetone molecule) lower than the mass of the parent compounds, along with fragment ions corresponding to lysoGPE+40 and free fatty acids. Scanning of chloroform/methanol extracts of red blood cell lipids of two of five diabetic subjects examined yielded elevated levels (in relation to nondiabetic subjects) for ions corresponding to the diacetone adducts [M+98]- of the major molecular species of PtdEtn and PtdSer. Because of possible overlap with major molecular species of PtdIns, the identification of the acetonated PtdSer in diabetic blood requires further confirmation.

  10. Method for laser welding a fin and a tube

    DOEpatents

    Fuerschbach, Phillip W.; Mahoney, A. Roderick; Milewski, John O

    2001-01-01

    A method of laser welding a planar metal surface to a cylindrical metal surface is provided, first placing a planar metal surface into approximate contact with a cylindrical metal surface to form a juncture area to be welded, the planar metal surface and cylindrical metal surface thereby forming an acute angle of contact. A laser beam, produced, for example, by a Nd:YAG pulsed laser, is focused through the acute angle of contact at the juncture area to be welded, with the laser beam heating the juncture area to a welding temperature to cause welding to occur between the planar metal surface and the cylindrical metal surface. Both the planar metal surface and cylindrical metal surface are made from a reflective metal, including copper, copper alloys, stainless steel alloys, aluminum, and aluminum alloys.

  11. A simulation study of planar swaging deformation

    NASA Astrophysics Data System (ADS)

    Zhang, Cheng-Gen; Jen, Gwang-Shen; Su, Gwang-Huei

    1992-08-01

    Planar swaging deformation was studied with a photoplastic method. The domestic polycarbonate was used as a simulation material. The full-field strain distribution for planar swaging deformation was obtained. The average error of the calculated strain was less than 7 percent. The deformation area and the effect of friction on deformation area were studied with the characteristics of photoplasticity. This paper points out the special features of planar swaging deformation and the effect of lubrication on deformation flow.

  12. Liftings and stresses for planar periodic frameworks

    PubMed Central

    Borcea, Ciprian; Streinu, Ileana

    2015-01-01

    We formulate and prove a periodic analog of Maxwell’s theorem relating stressed planar frameworks and their liftings to polyhedral surfaces with spherical topology. We use our lifting theorem to prove deformation and rigidity-theoretic properties for planar periodic pseudo-triangulations, generalizing features known for their finite counterparts. These properties are then applied to questions originating in mathematical crystallography and materials science, concerning planar periodic auxetic structures and ultrarigid periodic frameworks. PMID:26973370

  13. Liftings and stresses for planar periodic frameworks.

    PubMed

    Borcea, Ciprian; Streinu, Ileana

    2015-06-01

    We formulate and prove a periodic analog of Maxwell's theorem relating stressed planar frameworks and their liftings to polyhedral surfaces with spherical topology. We use our lifting theorem to prove deformation and rigidity-theoretic properties for planar periodic pseudo-triangulations, generalizing features known for their finite counterparts. These properties are then applied to questions originating in mathematical crystallography and materials science, concerning planar periodic auxetic structures and ultrarigid periodic frameworks.

  14. Planar Hall effect bridge magnetic field sensors

    SciTech Connect

    Henriksen, A. D.; Dalslet, B. T.; Skieller, D. H.; Lee, K. H.; Okkels, F.; Hansen, M. F.

    2010-07-05

    Until now, the planar Hall effect has been studied in samples with cross-shaped Hall geometry. We demonstrate theoretically and experimentally that the planar Hall effect can be observed for an exchange-biased ferromagnetic material in a Wheatstone bridge topology and that the sensor signal can be significantly enhanced by a geometric factor. For the samples in the present study, we demonstrate an enhancement of the sensor output by a factor of about 100 compared to cross-shaped sensors. The presented construction opens a new design and application area of the planar Hall effect, which we term planar Hall effect bridge sensors.

  15. Planarized fiber-FHD optical composite

    NASA Astrophysics Data System (ADS)

    Holmes, C.; Carpenter, L. G.; Gates, J. C.; Gawith, C. B. E.; Smith, P. G. R.

    2015-03-01

    We demonstrate the fabrication of a mechanically robust planarised fibre-FHD optical composite. Fabrication is achieved through deposition and consolidation of optical grade silica soot on to both an optical fibre and planar substrate. The consolidated silica acts in joining the fibre and planar substrate both mechanically and optically. The concept lends itself to applications where long interaction lengths (order of tens of centimetres) and optical interaction via a planar waveguide are required, such as pump schemes, precision layup of fibre optics and hybrid fibre-planar devices. This paper considers the developments in fabrication process that enable component development.

  16. Helical axis stellarator with noninterlocking planar coils

    DOEpatents

    Reiman, Allan; Boozer, Allen H.

    1987-01-01

    A helical axis stellarator using only noninterlocking planar, non-circular coils, generates magnetic fields having a magnetic well and large rotational transform with resultant large equilibrium beta.

  17. The simulation model of planar electrochemical transducer

    NASA Astrophysics Data System (ADS)

    Zhevnenko, D. A.; Vergeles, S. S.; Krishtop, T. V.; Tereshonok, D. V.; Gornev, E. S.; Krishtop, V. G.

    2016-12-01

    Planar electrochemical systems are very perspective to build modern motion and pressure sensors. Planar microelectronic technology is successfully used for electrochemical transducer of motion parameters. These systems are characterized by an exceptionally high sensitivity towards mechanic exposure due to high rate of conversion of the mechanic signal to electric current. In this work, we have developed a mathematical model of this planar electrochemical system, which detects the mechanical signals. We simulate the processes of mass and charge transfer in planar electrochemical transducer and calculated its transfer function with different geometrical parameters of the system.

  18. Planar waveguide sensor of ammonia

    NASA Astrophysics Data System (ADS)

    Rogoziński, Roman; Tyszkiewicz, Cuma; Karasiński, Paweł; Izydorczyk, Weronika

    2015-12-01

    The paper presents the concept of forming ammonia sensor based on a planar waveguide structure. It is an amplitude sensor produced on the basis of the multimode waveguide. The technological base for this kind of structure is the ion exchange method and the sol-gel method. The planar multimode waveguide of channel type is produced in glass substrate (soda-lime glass of Menzel-Glaser company) by the selective Ag+↔Na+ ion exchange. On the surface of the glass substrate a porous (~40%) silica layer is produced by the sol-gel method. This layer is sensitized to the presence of ammonia in the surrounding atmosphere by impregnation with Bromocresol Purple (BCP) dye. Therefore it constitutes a sensor layer. Spectrophotometric tests carried out showed about 50% reduction of cross-transmission changes of such sensor layer for a wave λ=593 nm caused by the presence of 25% ammonia water vapor in its ambience. The radiation source used in this type of sensor structure is a light emitting diode LED. The gradient channel waveguide is designed for frontal connection (optical glue) with a standard multimode telecommunications waveguide 62.5/125μm.

  19. Detection of Acetone Processing of Castor Bean Mash for Forensic Investigation of Ricin Preparation Methods

    SciTech Connect

    Kreuzer-Martin, Helen W.; Wahl, Jon H.; Metoyer, Candace N.; Colburn, Heather A.; Wahl, Karen L.

    2010-07-01

    The toxic protein ricin is of concern as a potential biological threat agent (BTA) Recently, several samples of ricin have been seized in connection with biocriminal activity. Analytical methods are needed that enable federal investigators to determine how the samples were prepared, to match seized samples to potential source materials, and to identify samples that may have been prepared by the same method using the same source materials. One commonly described crude ricin preparation method is acetone extraction of crushed castor beans. Here we describe the use of solid-phase microextraction and headspace analysis of crude ricin preparation samples to determine whether they were processed by acetone extraction. In all cases, acetone-extracted bean mash could be distinguished from un-extracted mash or mash extracted with other organic solvents. Statistical analysis showed that storage in closed containers for up to 109 days had no effect on acetone signal intensity. Signal intensity in acetone-extracted mash decreased during storage in open containers, but extracted mash could still be distinguished from un-extracted mash after 94 days.

  20. Two-stage bile preparation with acetone for recovery of fluorescent aromatic compounds (FACs).

    PubMed

    Karami, Ali; Syed, Mohd A; Christianus, Annie; Willett, Kristine L; Mazzeo, Jeffrey R; Courtenay, Simon C

    2012-07-15

    In this study we sought to optimize recovery of fluorescent aromatic compounds (FACs) from the bile of African catfish (Clarias gariepinus) injected with 10mg/kg benzo[a]pyrene (BaP). Fractions of pooled bile were hydrolyzed, combined with ten volumes of methanol, ethanol, acetonitrile, or acetone, centrifuged and supernatants were analyzed by high-performance liquid chromatography with fluorescent detection (HPLC/FL). As well, to test whether FACs were being lost in solids from the centrifugation, pellets were resuspended, hydrolyzed and mixed with six volumes of the organic solvent that produced best FAC recovery from the supernatant, and subjected to HPLC/FL. Highest FAC concentrations were obtained with 2000μl and 1250μl acetone for supernatants and resuspended pellets respectively. FACs concentrations were negatively correlated with biliary protein content but were unaffected by addition of bovine serum albumin (BSA) followed by no incubation indicating that the presence of proteins in the biliary mixture does not simply interfere with detection of FACs. In another experiment, efficiency of acetone addition was compared to two different liquid-liquid extractions (L-LEs). Acetone additions provided significantly higher biliary FACs than the L-LE methods. The new two-stage bile preparation with acetone is an efficient, inexpensive and easily performed method.

  1. Application of finite inverse gas chromatography in hypromellose acetate succinate-water-acetone systems.

    PubMed

    Chiu, Sheng-Wei; Sturm, Derek R; Moser, Justin D; Danner, Ronald P

    2016-09-30

    A modification of a GC was developed to investigate both infinitely dilute and finite concentrations of solvents in polymers. Thermodynamic properties of hypromellose acetate succinate (HPMCAS-L)-acetone-water systems are important for the optimization of spray-drying processes used in pharmaceutical manufacturing of solid dispersion formulations. These properties, at temperatures below the glass transition temperature, were investigated using capillary column inverse gas chromatography (CCIGC). Water was much less soluble in the HPMCAS-L than acetone. Experiments were also conducted at infinitely dilute concentrations of one of the solvents in HPMCAS-L that was already saturated with the other solvent. Overall the partitioning of the water was not significantly affected by the presence of either water or acetone in the polymer. The acetone partition coefficient decreased as either acetone or water was added to the HPMCAS-L. A representation of the HPMCAS-L structure in terms of UNIFAC groups has been developed. With these groups, the UNIFAC-vdw-FV model did a reasonable job of predicting the phase equilibria in the binary and ternary systems. The Flory-Huggins correlation with fitted interaction parameters represented the data well.

  2. Field Demonstration of Acetone Pretreatment and Composting of Particulate-TNT-Contaminated Soil

    SciTech Connect

    Radtke, Corey William; Smith, D.; Owen, S.; Roberto, Francisco Figueroa

    2002-02-01

    Solid fragments of explosives in soil are common in explosives testing and training areas. In this study we initially sieved the upper 6 in of contaminated soil through a 3-mm mesh, and found 2, 4, 6-trinitrotoluene (TNT) fragments. These contributed to an estimated concentration of 1.7 kg per cubic yard soil, or for 2000 ppm TNT in the soil. Most of the fragments ranged 4 mm to 10 mm diameter in size, but explosives particles weighing up to 56 g (about 4 cm diameter) were frequently observed. An acetone pretreatment/composting system was then demonstrated at field scale. The amount of acetone required for a TNT-dissolving slurry process was controlled by the viscosity of the soil/acetone mix rather than the TNT dissolution rate. The amount needed was estimated at about 55 gallons acetone per cubic yard soil. Smaller, 5- to 10-mm-diameter fragments went into solution in less than 15 min at a mixer speed of 36 rpm, with a minimum of 2 g TNT going into solution per 30 min for the larger chunks. The slurries were than mixed with compost starting materials and composted in a vented 1 yd3 container. After 34 days incubation time TNT was below the site-specific regulatory threshold of 44 ppm. TNT metabolites and acetone were also below their regulatory thresholds established for the site.

  3. Vibrational Excitation of Both Products of the Reaction of CN Radicals with Acetone in Solution

    PubMed Central

    2015-01-01

    Transient electronic and vibrational absorption spectroscopy unravel the mechanisms and dynamics of bimolecular reactions of CN radicals with acetone in deuterated chloroform solutions. The CN radicals are produced by ultrafast ultraviolet photolysis of dissolved ICN. Two reactive forms of CN radicals are distinguished by their electronic absorption bands: “free” (uncomplexed) CN radicals, and “solvated” CN radicals that are complexed with solvent molecules. The lifetimes of the free CN radicals are limited to a few picoseconds following their photolytic production because of geminate recombination to ICN and INC, complexation with CDCl3 molecules, and reaction with acetone. The acetone reaction occurs with a rate coefficient of (8.0 ± 0.5) × 1010 M–1 s–1 and transient vibrational spectra in the C=N and C=O stretching regions reveal that both the nascent HCN and 2-oxopropyl (CH3C(O)CH2) radical products are vibrationally excited. The rate coefficient for the reaction of solvated CN with acetone is 40 times slower than for free CN, with a rate coefficient of (2.0 ± 0.9) × 109 M–1 s–1 obtained from the rise in the HCN product v1(C=N stretch) IR absorption band. Evidence is also presented for CN complexes with acetone that are more strongly bound than the CN–CDCl3 complexes because of CN interactions with the carbonyl group. The rates of reactions of these more strongly associated radicals are slower still. PMID:26192334

  4. Recovery and reuse of spent acetone via a mobile solvent recovery unit

    SciTech Connect

    Townsend, M.W.

    1996-11-01

    The Monsanto Chemical Company operates a plastics and resins plant located in Addyston, Ohio. The process equipment requires routine rinsing with technical grade acetone between batches. Due to the volumes of spent acetone generated and the associated RCRA hazardous waste regulations, the plant sought to recycle and reuse the acetone to reduce the purchase cost of virgin acetone and the cost of spent acetone disposal. One of the first options explored was package unit distillation units. The cost of these units was in the $20--$30,000 range in 1989 dollars. Even though the cost of a package unit was not deemed unreasonable, there were additional costs and concerns that led to elimination of this option. The unit would have required additional manpower to operate and maintain, i.e., at least a fraction of an operator and mechanic. For plant safety reasons, it was desired to operate this package unit outside the production building, thus construction of an outbuilding would have added to the expense of the project. Additionally, there were concerns of package unit reliability. During this evaluation, tractor-trailer mounted distillation units were discovered. The portable units were equipped with either thin-film evaporator technology capable of processing 240 to 480 gallons per hour, or pot still (batch) distillation technology capable of rates from 120 to 240 gallons per hour. Both units were constructed of stainless steel.

  5. Photochemical degradation of citrate buffers leads to covalent acetonation of recombinant protein therapeutics

    PubMed Central

    Valliere-Douglass, John F; Connell-Crowley, Lisa; Jensen, Randy; Schnier, Paul D; Trilisky, Egor; Leith, Matt; Follstad, Brian D; Kerr, Jennifer; Lewis, Nathan; Vunnum, Suresh; Treuheit, Michael J; Balland, Alain; Wallace, Alison

    2010-01-01

    Novel acetone and aldimine covalent adducts were identified on the N-termini and lysine side chains of recombinant monoclonal antibodies. Photochemical degradation of citrate buffers, in the presence of trace levels of iron, is demonstrated as the source of these modifications. The link between degradation of citrate and the observed protein modifications was conclusively established by tracking the citrate decomposition products and protein adducts resulting from photochemical degradation of isotope labeled 13C citrate by mass spectrometry. The structure of the acetone modification was determined by nuclear magnetic resonance (NMR) spectroscopy on modified–free glycine and found to correspond to acetone linked to the N-terminus of the amino acid through a methyl carbon. Results from mass spectrometric fragmentation of glycine modified with an acetone adduct derived from 13C labeled citrate indicated that the three central carbons of citrate are incorporated onto protein amines in the presence of iron and light. While citrate is known to stoichiometrically decompose to acetone and CO2 through various intermediates in photochemical systems, it has never been shown to be a causative agent in protein carbonylation. Our results point to a previously unknown source for the generation of reactive carbonyl species. This work also highlights the potential deleterious impact of trace metals on recombinant protein therapeutics formulated in citrate buffers. PMID:20836085

  6. Efficient acetone-butanol-ethanol production by Clostridium beijerinckii from sugar beet pulp.

    PubMed

    Bellido, Carolina; Infante, Celia; Coca, Mónica; González-Benito, Gerardo; Lucas, Susana; García-Cubero, María Teresa

    2015-08-01

    Sugar beet pulp (SBP) has been investigated as a promising feedstock for ABE fermentation by Clostridium beijerinckii. Although lignin content in SBP is low, a pretreatment is needed to enhance enzymatic hydrolysis and fermentation yields. Autohydrolysis at pH 4 has been selected as the best pretreatment for SBP in terms of sugars release and acetone and butanol production. The best overall sugars release yields from raw SBP ranged from 66.2% to 70.6% for this pretreatment. The highest ABE yield achieved was 0.4g/g (5.1g/L of acetone and 6.6g/L butanol) and 143.2g ABE/kg SBP (62.3g acetone and 80.9g butanol) were obtained when pretreated SBP was enzymatically hydrolyzed at 7.5% (w/w) solid loading. Higher solid loadings (10%) offered higher acetone and butanol titers (5.8g/L of acetone and 7.8g/L butanol). All the experiments were carried out under not-controlling pH conditions reaching about 5.3 in the final samples.

  7. Versatile fs laser-written glass chip lasers

    NASA Astrophysics Data System (ADS)

    Lancaster, D. G.; Gross, S.; Fuerbach, A.; Ebendorff Heidepriem, H.; Monro, T. M.; Withford, M. J.

    2013-03-01

    We report laser-written chip lasers with potential to be a platform planar technology versatile enough to cover the visible through to the mid-infrared spectral region. By femtosecond laser direct-writing a thulium doped fluoride based glass host (ZBLAN), we have demonstrated a 151% quantum efficiency λ=1.9 μm laser with a close to diffraction limited beam quality (M2~ 1.12 +/- 0.08) with 225 nm of continuous tunability in a device that can be rapidly fabricated by singlestep optical processing. The 9 mm long planar chip developed for concept demonstration contains fifteen large modearea waveguides that can operate in semi-monolithic or external cavity laser configurations. This chip laser has achieved the highest quantum efficiency from a planar glass waveguide laser. The depressed cladding geometry supports the largest fundamental modes reported for a rare-earth doped waveguide laser thereby favouring high peak-power operation which is demonstrated by achieving 1.9 kW peak-power pulses when Q-switched.

  8. High energy efficient solid state laser sources

    NASA Technical Reports Server (NTRS)

    Byer, Robert L.

    1987-01-01

    Investigations continue of diode-laser-pumped solid-state laser oscillators and nonlinear processes using them as sources. Diode laser array pumped Nd:YAG and Nd:glass lasers have been demonstrated. Theoretical studies of non-planar oscillators have been advanced, producing new designs which should be more resistant to feedback and offer better frequency stability. A monolithic, singly resonant Optical Parametric Oscillator in MgO:LiNbO3 has been operated.

  9. Using acetone as solvent to study removal of anthracene in soil inhibits microbial activity and alters nitrogen dynamics.

    PubMed

    Núñez, Edgar Vázquez; Rodríguez, Viviana; Gaytán, Alejandro García; Luna-Guido, Marco; Betancur-Galvis, Liliana A; Marsch, Rodolfo; Dendooven, Luc

    2009-08-01

    Acetone is often used as a carrier to contaminate soil with polycyclic aromatic hydrocarbons (PAHs) and then to study the factors that control their removal. Acetone is an organic solvent that might affect soil processes. An alkaline saline (Texcoco soil) and an agricultural soil (Acolman soil) were amended with or without acetone, nitrogen + phosphorus (NP), and contaminated with anthracene at 520 mg/kg soil while emissions of CO2 and N2O and concentrations of NH4+, NO2(-) and NO3(-) were monitored. The CO2 emission rate decreased greater than 10 times in the soils amended with acetone. Emission of N2O decreased 70 times in the Acolman soil amended with acetone and NP and 5 times in the Texcoco soil. The concentration of NH4+ decreased in the unamended Acolman and Texcoco soil but increased when acetone was added in the first and remained constant in the latter. Acetone inhibited the increase in the amount of NO3(-) in the Acolman soil but not in the Texcoco soil. It was found that microbial activity as evidenced by the emission of CO2, nitrification, and production of N2O were inhibited by acetone. The amount of acetone used as solvent should thus be kept to a minimum, but it can be assumed that its effect on soil processes will be temporary, as microorganisms are known to repopulate soil quickly.

  10. Designing and creating a modularized synthetic pathway in cyanobacterium Synechocystis enables production of acetone from carbon dioxide.

    PubMed

    Zhou, Jie; Zhang, Haifeng; Zhang, Yanping; Li, Yin; Ma, Yanhe

    2012-07-01

    Ketones are a class of important organic compounds. As the simplest ketone, acetone is widely used as solvents or precursors for industrial chemicals. Presently, million tonnes of acetone is produced worldwide annually, from petrochemical processes. Here we report a biotechnological process that can produce acetone from CO(2), by designing and creating a modularized synthetic pathway in engineered cyanobacterium Synechocystis sp. PCC 6803. The engineered Synechocystis cells are able to produce acetone (36.0 mgl(-1) culture medium) using CO(2) as the sole carbon source, thus opens the gateway for biosynthesis of ketones from CO(2).

  11. Increased blood concentration of isopropanol in ketotic dairy cows and isopropanol production from acetone in the rumen.

    PubMed

    Sato, Hiroshi

    2009-08-01

    To evaluate acetone and isopropanol metabolism in bovine ketosis, the blood concentrations of isopropanol, acetone, plasma 3-hydroxybutyrate (3-HB) and other metabolites were analyzed in 12 healthy controls and 15 ketotic dairy cows including fatty liver and inferior prognosis after laparotomy for displaced abomasum. In ruminal fluid taken from 6 ketotic cows, ruminal isopropanol and acetone were also analyzed. Ketotic cows showed higher concentrations of isopropanol, acetone, 3-HB and nonesterified fatty acid, and higher activities of aspartate transaminase and gamma-glutamyl transferase than control cows. Blood samples had higher concentration of isopropanol accompanied by increased acetone. In the ketotic cows, acetone was detected not only in blood but also in ruminal fluid, while higher ruminal isopropanol did not necessarily accompany its elevation in the blood. Using 2 steers with rumen cannula, all ruminal content was emptied and then substituted with artificial saliva to evaluate the importance of ruminal microbes in isopropanol production. Under each condition of intact and emptied rumen, acetone was infused into the rumen and blood isopropanol was analyzed. The elevation in the blood isopropanol concentration after acetone infusion was markedly inhibited by the emptying. Here, increased blood concentrations of isopropanol and acetone were observed in ketotic cows, and the importance of ruminal microbes in isopropanol production was confirmed.

  12. Sine-squared potential of planar channeled particles and Kumakhov radiation of charged particles

    SciTech Connect

    Luo Shiyu; Shao Mingzhu

    1984-07-01

    A new planar-continuum potential, the sine-squared potential, is introduced to analyze the behavior of particle motion in a planar channel, and the equation of particle motion is reduced to the well-known pendulum equation. Particle motion equation and oscillation period are solved exactly by Jacobi elliptic functions and the first kind of complete elliptic integral. Radiation intensity and spectral characteristics of Kumakhov radiation are analyzed. The results show that Kumakhov radiation is a promising new source for the ..gamma..-ray laser.

  13. Superimposed grating wavelength division multiplexing in Ge-doped SiO2/Si planar waveguides

    NASA Astrophysics Data System (ADS)

    Othonos, Andreas; Bismuth, J.; Sweeny, M.; Kevorkian, Antoine P.; Xu, Jing Ming M.

    1998-02-01

    An improved model of wavelength division multiplexing (WDM) by superimposed gratings in planar waveguides has been developed. Based on this theory, principal design rules of N- channel WDM are established and a fanout capacity of 100 is estimated. Finally, four-channel WDM at 840 nm has been demonstrated on a Ge:SiO(subscript 2)/SiO(subscript 2)/Si planar waveguide, which was hydrogenated to enhance its photosensitivity. The superimposed gratings were written using a narrow linewidth KrF excimer laser in an interferometric setup used in inscribing fiber Bragg gratings.

  14. Planar Rayleigh Scattering Results in Helium/Air Mixing Experiments in a Mach 6 Wind Tunnel

    NASA Technical Reports Server (NTRS)

    Shirinzadeh, B.; Balla, R. Jeffrey; Hillard, M. E.; Anders, J. B.; Exton, R. J.; Waitz, I. A.

    1991-01-01

    Planar Rayleigh scattering measurements using an ArF-excimer laser have been performed to investigate helium mixing into air at supersonic speeds. The capability of the Rayleigh scattering technique for flow visualization of a turbulent environment is demonstrated in a large-scale, Mach 6facility. The detection limit obtained with the present setup indicates that planar, quantitative measurements of density can be made over a large cross sectional area (5 cm by 10 cm) of the flow field in the absence of clusters.

  15. Acetone Sensing Properties of a Gas Sensor Composed of Carbon Nanotubes Doped With Iron Oxide Nanopowder

    PubMed Central

    Tan, Qiulin; Fang, Jiahua; Liu, Wenyi; Xiong, Jijun; Zhang, Wendong

    2015-01-01

    Iron oxide (Fe2O3) nanopowder was prepared by a precipitation method and then mixed with different proportions of carbon nanotubes. The composite materials were characterized by X-ray powder diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy. A fabricated heater-type gas sensor was compared with a pure Fe2O3 gas sensor under the influence of acetone. The effects of the amount of doping, the sintering temperature, and the operating temperature on the response of the sensor and the response recovery time were analyzed. Experiments show that doping of carbon nanotubes with iron oxide effectively improves the response of the resulting gas sensors to acetone gas. It also reduces the operating temperature and shortens the response recovery time of the sensor. The response of the sensor in an acetone gas concentration of 80 ppm was enhanced, with good repeatability. PMID:26569253

  16. Thiamine pyrophosphate stimulates acetone activation by Desulfococcus biacutus as monitored by a fluorogenic ATP analogue.

    PubMed

    Gutiérrez Acosta, Olga B; Hardt, Norman; Hacker, Stephan M; Strittmatter, Tobias; Schink, Bernhard; Marx, Andreas

    2014-06-20

    Acetone can be degraded by aerobic and anaerobic microorganisms. Studies with the strictly anaerobic sulfate-reducing bacterium Desulfococcus biacutus indicate that acetone degradation by these bacteria starts with an ATP-dependent carbonylation reaction leading to acetoacetaldehyde as the first reaction product. The reaction represents the second example of a carbonylation reaction in the biochemistry of strictly anaerobic bacteria, but the exact mechanism and dependence on cofactors are still unclear. Here, we use a novel fluorogenic ATP analogue to investigate its mechanism. We find that thiamine pyrophosphate is a cofactor of this ATP-dependent reaction. The products of ATP cleavage are AMP and pyrophosphate, providing first insights into the reaction mechanism by indicating that the reaction proceeds without intermediate formation of acetone enol phosphate.

  17. Flow-injection determination of acetone with diazotized anthranilic acid through a fluorescent reaction intermediate.

    PubMed

    García de María, C; Hueso Domínguez, K B; Martín Garrido, N

    2007-09-26

    Acetone and diazotized anthranilic acid react in alkaline solution, giving a fluorescent intermediate that can be measured at excitation and emission wavelengths of 305 and 395 nm, respectively. Based on this, a fluorimetric flow-injection method is proposed for the determination of acetone in aqueous solution. Under the proposed conditions, acetone can be detected at concentrations higher than 8 x 10(-7)M, with a linear application range from 1 x 10(-6) to 2 x 10(-4)M and an R.S.D. of 2.7% (1.0 x 10(-5)M, n=10). A sampling frequency of 24h(-1) is achieved. Some potentially interfering species are investigated.

  18. Acetone gas sensing mechanism on zinc oxide surfaces: A first principles calculation

    NASA Astrophysics Data System (ADS)

    Sadeghian Lemraski, M.; Nadimi, E.

    2017-03-01

    Semiconducting metal oxide gas sensors have attracted growing interest as a result of their outstanding performance in the bio and industrial applications. Nevertheless, the sensing mechanism is yet not totally understood. In this study, we extensively investigate the adsorption mechanism of acetone molecule on ZnO-based thin film sensors by performing ab initio density functional theory calculations and employing quantum molecular dynamic simulations. Since the sensitivity of a metal oxide sensor is exceedingly depends on molecular oxygen exposure and operating temperature, we explore the competitive adsorption of acetone and oxygen molecule on the most stable orientation of ZnO surface (10 1 ̅ 0) at different temperatures. Results indicate that at elevated temperatures acetone gains required thermal energy to remove preadsorbed oxygen molecule from the surface in a competitive process. We will show that this competition is responsible for the resistive switching behavior in the ZnO-based gas sensors.

  19. Preparation of CuO nanoparticles by laser ablation in liquid

    NASA Astrophysics Data System (ADS)

    Abdulateef, Sinan A.; MatJafri, M. Z.; Omar, A. F.; Ahmed, Naser M.; Azzez, Shrook A.; Ibrahim, Issam M.; Al-Jumaili, Batool E. B.

    2016-07-01

    Colloidal Cu nanoparticles (NPs) were synthesized by pulsed Nd:YAG laser ablation in acetone. Cu NPs were converted into CuO. The size and optical properties of these NPs were characterized using an UV/Vis spectrophotometer, transmission electron microscopy, and X-ray diffraction. Cu NPs were spherical, and their mean diameter in acetone was 8 nm-10 nm. Optical extinction immediately after the ablation showed surface Plasmon resonance peaks at 602 nm. The color of Cu NPs in acetone was green and stable even after a long time.

  20. The simplicity of planar networks

    NASA Astrophysics Data System (ADS)

    Viana, Matheus P.; Strano, Emanuele; Bordin, Patricia; Barthelemy, Marc

    2013-12-01

    Shortest paths are not always simple. In planar networks, they can be very different from those with the smallest number of turns - the simplest paths. The statistical comparison of the lengths of the shortest and simplest paths provides a non trivial and non local information about the spatial organization of these graphs. We define the simplicity index as the average ratio of these lengths and the simplicity profile characterizes the simplicity at different scales. We measure these metrics on artificial (roads, highways, railways) and natural networks (leaves, slime mould, insect wings) and show that there are fundamental differences in the organization of urban and biological systems, related to their function, navigation or distribution: straight lines are organized hierarchically in biological cases, and have random lengths and locations in urban systems. In the case of time evolving networks, the simplicity is able to reveal important structural changes during their evolution.

  1. The planar parabolic optical antenna.

    PubMed

    Schoen, David T; Coenen, Toon; García de Abajo, F Javier; Brongersma, Mark L; Polman, Albert

    2013-01-09

    One of the simplest and most common structures used for directing light in macroscale applications is the parabolic reflector. Parabolic reflectors are ubiquitous in many technologies, from satellite dishes to hand-held flashlights. Today, there is a growing interest in the use of ultracompact metallic structures for manipulating light on the wavelength scale. Significant progress has been made in scaling radiowave antennas to the nanoscale for operation in the visible range, but similar scaling of parabolic reflectors employing ray-optics concepts has not yet been accomplished because of the difficulty in fabricating nanoscale three-dimensional surfaces. Here, we demonstrate that plasmon physics can be employed to realize a resonant elliptical cavity functioning as an essentially planar nanometallic structure that serves as a broadband unidirectional parabolic antenna at optical frequencies.

  2. Planar cell polarity in Drosophila

    PubMed Central

    Maung, Saw Myat Thanda W

    2011-01-01

    In all multicellular organisms, epithelial cells are not only polarized along the apical-basal axis, but also within the epithelial plane, giving cells a sense of direction. Planar cell polarity (PCP) signaling regulates establishment of polarity within the plane of an epithelium. The outcomes of PCP signaling are diverse and include the determination of cell fates, the generation of asymmetric but highly aligned structures, such as the stereocilia in the human inner ear or the hairs on a fly wing, or the directional migration of cells during convergence and extension during vertebrate gastrulation. In humans, aberrant PCP signaling can result in severe developmental defects, such as open neural tubes (spina bifida), and can cause cystic kidneys. In this review, we discuss the basic mechanism and more recent findings of PCP signaling focusing on Drosophila melanogaster, the model organism in which most key PCP components were initially identified. PMID:21983142

  3. Acetone reactions over the surfaces of polycrystalline UO2: a kinetic and spectroscopic study.

    PubMed

    King, Richard; Idriss, Hicham

    2009-04-21

    The reaction of acetone is studied on the surfaces of polycrystalline UO2, prepared by hydrogen reduction of U3O8 at 770 K. The study is conducted by in situ Fourier transform infrared (FTIR) and temperature-programmed desorption (TPD). Acetone adsorption does not fit the simple Langmuir model, and adsorbate-adsorbate interactions are found to be significant. Acetone adsorbs molecularly on UO2 as evidenced by the nuCO of the eta1(O) mode at 1686 cm(-1). Part of acetone is reduced to the isopropoxide species ((CH3)2HC-O-U4+) upon heating (nu(CC), rho(CH3) at 1167 cm(-1) and nu(CO), rho(CH3) at 980 cm(-1)), and upon further heating, acetates (CH3COO(a), (a) for adsorbed) are observed. Detailed TPD studies indicated that the main reaction of acetone on UO2 is the deoxygenation to propene, driven by the oxophilic nature of UO2. Other reactions were also observed to a lesser extent, and these included reductive coupling to 2,3-dimethylbutene and condensation to mesityl oxide. An attempt to extract kinetic parameters from TPD data was conducted. Three models were studied: variation of heating rate, leading edge analysis (Habenschaden-Kuppers method), and complete analysis. The complete analysis provided the most plausible results, in particular, at low coverage. With this method, at nearly zero coverage the activation energy, Ed, for desorption was found to be close to 140 kJ/mol with a prefactor of 10(13) s(-1). Ed dropped sharply with increasing coverage, theta, to ca. 35 kJ/mol at theta=0.15 with a prefactor of 10(11) s(-1). The activation energy for the desorption of acetone on UO2(111) single crystals, at saturation coverage, was previously found to be equal to 65 kJ/mol using the leading edge analysis.

  4. Ultrafast α -CC bond cleavage of acetone upon excitation to 3p and 3d Rydberg states by femtosecond time-resolved photoelectron imaging

    NASA Astrophysics Data System (ADS)

    Hüter, O.; Temps, F.

    2016-12-01

    The radiationless electronic relaxation and α -CC bond fission dynamics of jet-cooled acetone in the S1 (n π* ) state and in high-lying 3p and 3d Rydberg states have been investigated by femtosecond time-resolved mass spectrometry and photoelectron imaging. The S1 state was accessed by absorption of a UV pump photon at selected wavelengths between λ = 320 and 250 nm. The observed acetone mass signals and the S1 photoelectron band decayed on sub-picosecond time scales, consistent with a recently proposed ultrafast structural relaxation of the molecules in the S1 state away from the Franck-Condon probe window. No direct signatures could be observed by the experiments for CC dissociation on the S1 potential energy hypersurface in up to 1 ns. The observed acetyl mass signals at all pump wavelengths turned out to be associated with absorption by the molecules of one or more additional pump and/or probe photons. In particular, absorption of a second UV pump photon by the S1 (n π* ) state was found to populate a series of high-lying states belonging to the n = 3 Rydberg manifold. The respective transitions are favored by much larger cross sections compared to the S1 ← S0 transition. The characteristic energies revealed by the photoelectron images allowed for assignments to the 3p and 3dyz states. At two-photon excitation energies higher than 8.1 eV, an ultrafast reaction pathway for breaking the α -CC bond in 50-90 fs via the 3dyz Rydberg state and the elusive π π* state was observed, explaining the formation of acetyl radicals after femtosecond laser excitation of acetone at these wavelengths.

  5. Fractionation of Organosolv Lignin Using Acetone:Water and Properties of the Obtained Fractions

    SciTech Connect

    Sadeghifar, Hasan; Wells, Tyrone; Le, Rosemary Khuu; Sadeghifar, Fatemeh; Yuan, Joshua S.; Jonas Ragauskas, Arthur

    2016-11-07

    In this study, lignin fractions with different molecular weight were prepared using a simple and almost green method from switchgrass and pine organosolv lignin. Different proportions of acetone in water, ranging from 30 to 60%, were used for lignin fractionation. A higher concentration of acetone dissolved higher molecular weight fractions of the lignin. Fractionated organosolv lignin showed different molecular weight and functional groups. Higher molecular weight fractions exhibited more aliphatic and less phenolic OH than lower molecular weight fractions. Lower molecular weight fractions lead to more homogeneous structure compared to samples with a higher molecular weight. In conclusion, all fractions showed strong antioxidant activity.

  6. Fractionation of Organosolv Lignin Using Acetone:Water and Properties of the Obtained Fractions

    DOE PAGES

    Sadeghifar, Hasan; Wells, Tyrone; Le, Rosemary Khuu; ...

    2016-11-07

    In this study, lignin fractions with different molecular weight were prepared using a simple and almost green method from switchgrass and pine organosolv lignin. Different proportions of acetone in water, ranging from 30 to 60%, were used for lignin fractionation. A higher concentration of acetone dissolved higher molecular weight fractions of the lignin. Fractionated organosolv lignin showed different molecular weight and functional groups. Higher molecular weight fractions exhibited more aliphatic and less phenolic OH than lower molecular weight fractions. Lower molecular weight fractions lead to more homogeneous structure compared to samples with a higher molecular weight. In conclusion, all fractionsmore » showed strong antioxidant activity.« less

  7. Gum rosin-acetone system as an analogue to the degassing behaviour of hydrated magmas

    NASA Astrophysics Data System (ADS)

    Phillips, J. C.; Lane, S. J.; Lejeune, A.-M.; Hilton, M.

    1995-08-01

    Solutions of gum rosin and acetone reproduce the volatile- and temperature-dependent viscosity, together with the phase behaviour, of hydrated magmas. A range of experimental exsolution conditions was investigated, including the variation of supersaturation, rate of decompression, solution temperature and volatile content. Degassing processese were controlled by the formation of an exsolution interface above a supersaturated liquid. The end-products ranged from a mildly degassed liquid to a solid foam, which preserved strained vesicles. Solutions of gum rosin and acetone are proposed as a suitable analogue system with which to study magma degassing processes.

  8. Scaling relationships in photoelectron-photoion coincidence studies: The aceton ion dissociation

    NASA Astrophysics Data System (ADS)

    Johnson, Kieth; Powis, I.; Danby, C. J.

    1981-12-01

    The distributions of internal energy released into translation in the fragmentation of energy-selected acetone ions (as determined by photoelectron-photoion coincidence studies) are shown to obey a scaling law, as do the calculated distributions derived from a statistical-dynamical phase space theory. A single function contains the dynamical history of the reaction system, at least at higher energies, in contrast to the predictions of the rigid rotor harmonic oscillator model. The scaling law provides an analysis of the bimodal form of the translational energy distributions which are found for the dissociation of the enol form of the acetone ion. This is shown to be consistent with the ergodic hypothesis.

  9. Optical coupling of bare optoelectronic components and flexographically printed polymer waveguides in planar optronic systems

    NASA Astrophysics Data System (ADS)

    Wang, Yixiao; Wolfer, Tim; Lange, Alex; Overmeyer, Ludger

    2016-05-01

    Large scale, planar optronic systems allowing spatially distributed functionalities can be well used in diverse sensor networks, such as for monitoring the environment by measuring various physical quantities in medicine or aeronautics. In these systems, mechanically flexible and optically transparent polymeric foils, e.g. polymethyl methacrylate (PMMA) and polyethylene terephthalate (PET), are employed as carrier materials. A benefit of using these materials is their low cost. The optical interconnections from light sources to light transmission structures in planar optronic systems occupy a pivotal position for the sensing functions. As light sources, we employ the optoelectronic components, such as edgeemitting laser diodes, in form of bare chips, since their extremely small structures facilitate a high integration compactness and ensure sufficient system flexibility. Flexographically printed polymer optical waveguides are deployed as light guiding structures for short-distance communication in planar optronic systems. Printing processes are utilized for this generation of waveguides to achieve a cost-efficient large scale and high-throughput production. In order to attain a high-functional optronic system for sensing applications, one of the most essential prerequisites is the high coupling efficiency between the light sources and the waveguides. Therefore, in this work, we focus on the multimode polymer waveguide with a parabolic cross-section and investigate its optical coupling with the bare laser diode. We establish the geometrical model of the alignment based on the previous works on the optodic bonding of bare laser diodes and the fabrication process of polymer waveguides with consideration of various parameters, such as the beam profile of the laser diode, the employed polymer properties of the waveguides as well as the carrier substrates etc. Accordingly, the optical coupling of the bare laser diodes and the polymer waveguides was simulated

  10. Electro-oxidation of 2-propanol and acetone over platinum, platinum-ruthenium, and ruthenium nanoparticles in alkaline electrolytes

    NASA Astrophysics Data System (ADS)

    Markiewicz, Matthew E. P.; Bergens, Steven H.

    The voltammetric and chronoamperometric electro-oxidations of 2-propanol and acetone were carried out in base over Pt, Pt-Ru, and Ru nanoparticle electro-catalysts. A low-potential current maximum occurs during chronoamperometric electro-oxidations attributed to a reversible 2-propanol/acetone redox couple. The potential of this current maximum becomes more negative with increasing Ru content.

  11. 40 CFR 721.10238 - Formaldehyde, polymers with acetone-phenol reaction products and phenol, potassium sodium salts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-phenol reaction products and phenol, potassium sodium salts. 721.10238 Section 721.10238 Protection of..., polymers with acetone-phenol reaction products and phenol, potassium sodium salts. (a) Chemical substance..., polymers with acetone-phenol reaction products and phenol, potassium sodium salts (PMN P-09-147; CAS...

  12. 40 CFR 721.10238 - Formaldehyde, polymers with acetone-phenol reaction products and phenol, potassium sodium salts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-phenol reaction products and phenol, potassium sodium salts. 721.10238 Section 721.10238 Protection of..., polymers with acetone-phenol reaction products and phenol, potassium sodium salts. (a) Chemical substance..., polymers with acetone-phenol reaction products and phenol, potassium sodium salts (PMN P-09-147; CAS...

  13. Effects of acetone and fasting on cytochrome P-450 and xenobiotic metabolism in intact and hypophysectomized rats

    SciTech Connect

    Williams, M.T.; Simonet, L.

    1987-05-01

    Hypophysectomized and intact male and female rats were fasted for 24-48 hrs or given acetone (5ml/kg body weight) in order to evaluate the effects of these treatments on hepatic microsomal cytochrome P-450 and xenobiotic metabolism. Fasting and acetone treatment resulted in a significant increase (p < 0.05) in total P-450 in intact female rats. However, there was no significant changes in P-450 in microsomes from fasted or acetone-treated hypophysectomized rats. Fasting and acetone treatment resulted in significant increases in nitrosamine metabolism in intact rats. This effect was markedly reduced in the hypophysectomized rat. When intact male rats were fasted or treated with acetone there was a significant increase in P-450 in microsomes from acetone treated rats. Aryl hydrocarbon hydroxylase activity was significantly increased in both intact and hypophysectomized male and female rats treated with acetone. These results suggest that the pituitary gland or some product markedly influences acetone-stimulated nitrosamine metabolism.

  14. Laser diagnostics for NTP fuel corrosion studies

    NASA Technical Reports Server (NTRS)

    Wantuck, Paul J.; Butt, D. P.; Sappey, A. D.

    1993-01-01

    Viewgraphs and explanations on laser diagnostics for nuclear thermal propulsion (NTP) fuel corrosion studies are presented. Topics covered include: NTP fuels; U-Zr-C system corrosion products; planar laser-induced fluorescence (PLIF); utilization of PLIF for corrosion product characterization of nuclear thermal rocket fuel elements under test; ZrC emission spectrum; and PLIF imaging of ZrC plume.

  15. A simple procedure for preparing chitin oligomers through acetone precipitation after hydrolysis in concentrated hydrochloric acid.

    PubMed

    Kazami, Nao; Sakaguchi, Masayoshi; Mizutani, Daisuke; Masuda, Tatsuhiko; Wakita, Satoshi; Oyama, Fumitaka; Kawakita, Masao; Sugahara, Yasusato

    2015-11-05

    Chitin oligomers are of interest because of their numerous biologically relevant properties. To prepare chitin oligomers containing 4-6 GlcNAc units [(GlcNAc)4-6], α- and β-chitin were hydrolyzed with concentrated hydrochloric acid at 40 °C. The reactant was mixed with acetone to recover the acetone-insoluble material, and (GlcNAc)4-6 was efficiently recovered after subsequent water extraction. Composition analysis using gel permeation chromatography and MALDI-TOF mass spectrometry indicated that (GlcNAc)4-6 could be isolated from the acetone-insoluble material with recoveries of approximately 17% and 21% from the starting α-chitin and β-chitin, respectively. The acetone precipitation method is highly useful for recovering chitin oligomers from the acid hydrolysate of chitin. The changes in the molecular size and higher-order structure of chitin during the course of hydrolysis were also analyzed, and a model that explains the process of oligomer accumulation is proposed.

  16. The recombination rate coefficient of a protonated acetone dimer with electrons: indication of a temperature dependence

    NASA Astrophysics Data System (ADS)

    Glosík, Juraj; Plasil, Radek

    2000-10-01

    The formation and recombination of a protonated acetone dimer with electrons was studied in the flowing afterglow. H3O+ ions were formed in the early post-discharge region. The subsequent addition of acetone leads to the formation of the protonated ions CH3COCH3H+. These ions further associate with acetone forming the cluster ions H+·(CH3COCH3)2 that react further with acetone, but very slowly. This facilitates the creation of an afterglow plasma with a dominant population of H+·(CH3COCH3)2. The evolution of electron number density (ne) and electron temperature (Te) is measured using the Langmuir probe. The recombination rate coefficients that are obtained indicate a negative temperature dependence: α = (3.4±1)×10-6 cm3 s-1 at Te = (580±150) K and α = (7±2.5)×10-6 cm3 s-1 at Te = (450±100) K.

  17. A DFT study of the role of water in the rhodium-catalyzed hydrogenation of acetone.

    PubMed

    Polo, Victor; Schrock, Richard R; Oro, Luis A

    2016-11-24

    The positive effect of the addition of water to acetone hydrogenation by [RhH2(PR3)2S2](+) catalysts has been studied by DFT calculations. The studied energetic profiles reveal that the more favourable mechanistic path involves a hydride migration to the ketone followed by a reductive elimination that is assisted by two water molecules.

  18. Photooxidation of Isopropanol and Acetone Using TiO(sub 2) Suspension and UV Light

    SciTech Connect

    El-Morsi, Taha; Nanny, Mark A.

    2004-03-31

    Small polar organic compounds such as alcohols, ketones and aldehydes are highly soluble and do not adsorb strongly to the TiO2 surface and, therefore, may be fairly resistant to photocatalytic degradation. Photodegradation of an aqueous solution of isopropanol and its resulting photodegradation product acetone was investigated as a function of TiO2 substrate concentrations and solution ionic strength and pH. In the presence of 2g/L TiO2, isopropanol completely disappeared within 3 hrs, resulting in the nearly complete transformation into acetone. Subsequent photodegradation of acetone occurred at a much slower rate and resulted in complete mineralization. Increasing the pH slightly decreased the photodegradation rate. Conversely, the degradation rate was enhanced slightly by increasing the ionic strength. The presence of tetranitromethane decreased the isopropanol degradation significantly. This result, combined with the minimal degree of adsorption of isopropanol and acetone onto the surface of the photocatalyst, suggests that the photodegradation pathway occurs via free OH radicals in bulk solution rather than on the catalyst surface.

  19. The post-mortem relationship between beta-hydroxybutyrate (BHB), acetone and ethanol in ketoacidosis.

    PubMed

    Elliott, Simon; Smith, Christopher; Cassidy, Diane

    2010-05-20

    A reduced blood pH (ketoacidosis) from the production of beta-oxidative ketone bodies as a result of alcoholism (alcoholic ketoacidosis, AKA) or diabetes (diabetic ketoacidosis, DKA) can feature in many fatalities and analytical evidence can be used to support a pathological diagnosis, or provide a possible cause of death in the absence of other pathologically significant findings. Existing beliefs concerning the relationship of BHB concentrations, acetone and ethanol have been re-examined by analysis of BHB, acetone and ethanol in over 350 fatalities grouped into alcoholics, diabetics, alcoholic diabetics, coupled with speculative cases and those with an alternative cause of death. Uniquely, the concentrations of BHB were measured in post-mortem blood, urine and vitreous humour using selective GC-MS. The results showed that existing beliefs need to be re-evaluated. Ethanol is not always low (<10mg/dL) or absent in cases of AKA. Also, the absence of acetone precludes [corrected] a high BHB (>250mg/L), therefore acetone can be used as an initial marker pathologically significant ketoacidosis. For blood and urine BHB concentrations the following interpretative ranges can be used (in mg/L); normal (<50mg/L), raised (51-249mg/L), high and pathologically significant (>250mg/L). Initial data suggest vitreous humour BHB could be a useful alternative in the absence of blood (same interpretative ranges may also apply). Analytical recommendation for investigation of post-mortem ketoacidosis is also presented.

  20. Chemical-specific adjustment factors for intraspecies variability of acetone toxicokinetics using a probabilistic approach.

    PubMed

    Mörk, Anna-Karin; Johanson, Gunnar

    2010-07-01

    Human health risk assessment has begun to depart from the traditional methods by replacement of the default assessment factors by more reasonable, data-driven, so-called chemical-specific adjustment factors (CSAFs). This study illustrates a scheme for deriving CSAFs in the general and occupationally exposed populations by quantifying the intraspecies toxicokinetic variability in surrogate dose using probabilistic methods. Acetone was used as a model substance. The CSAFs were derived by Monte Carlo simulation, combining a physiologically based pharmacokinetic model for acetone, probability distributions of the model parameters from a Bayesian analysis of male volunteer experimental data, and published distributions of physiological and anatomical parameters for females and children. The simulations covered how factors such as age, gender, endogenous acetone production, and fluctuations in workplace air concentration and workload influence peak and average acetone levels in blood, used as surrogate doses. According to the simulations, CSAFs of 2.1, 2.9, and 3.8 are sufficient to cover the differences in surrogate dose at the upper 90th, 95th, and 97.5th percentile, respectively, of the general population. However, higher factors were needed to cover the same percentiles of children. The corresponding CSAFs for the occupationally exposed population were 1.6, 1.8, and 1.9. The methodology presented herein allows for derivation of CSAFs not only for populations as a whole but also for subpopulations of interest. Moreover, various types of experimental data can readily be incorporated in the model.

  1. Assessment of in situ butanol recovery by vacuum during acetone butanol ethanol (ABE) fermentation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Butanol fermentation is product limiting due to butanol toxicity to microbial cells. Butanol (boiling point: 118 deg C) boils at a greater temperature than water (boiling point: 100 deg C) and application of vacuum technology to integrated acetone-butanol-ethanol (ABE) fermentation and recovery may ...

  2. Piezo Voltage Controlled Planar Hall Effect Devices.

    PubMed

    Zhang, Bao; Meng, Kang-Kang; Yang, Mei-Yin; Edmonds, K W; Zhang, Hao; Cai, Kai-Ming; Sheng, Yu; Zhang, Nan; Ji, Yang; Zhao, Jian-Hua; Zheng, Hou-Zhi; Wang, Kai-You

    2016-06-22

    The electrical control of the magnetization switching in ferromagnets is highly desired for future spintronic applications. Here we report on hybrid piezoelectric (PZT)/ferromagnetic (Co2FeAl) devices in which the planar Hall voltage in the ferromagnetic layer is tuned solely by piezo voltages. The change of planar Hall voltage is associated with magnetization switching through 90° in the plane under piezo voltages. Room temperature magnetic NOT and NOR gates are demonstrated based on the piezo voltage controlled Co2FeAl planar Hall effect devices without the external magnetic field. Our demonstration may lead to the realization of both information storage and processing using ferromagnetic materials.

  3. Piezo Voltage Controlled Planar Hall Effect Devices

    NASA Astrophysics Data System (ADS)

    Zhang, Bao; Meng, Kang-Kang; Yang, Mei-Yin; Edmonds, K. W.; Zhang, Hao; Cai, Kai-Ming; Sheng, Yu; Zhang, Nan; Ji, Yang; Zhao, Jian-Hua; Zheng, Hou-Zhi; Wang, Kai-You

    2016-06-01

    The electrical control of the magnetization switching in ferromagnets is highly desired for future spintronic applications. Here we report on hybrid piezoelectric (PZT)/ferromagnetic (Co2FeAl) devices in which the planar Hall voltage in the ferromagnetic layer is tuned solely by piezo voltages. The change of planar Hall voltage is associated with magnetization switching through 90° in the plane under piezo voltages. Room temperature magnetic NOT and NOR gates are demonstrated based on the piezo voltage controlled Co2FeAl planar Hall effect devices without the external magnetic field. Our demonstration may lead to the realization of both information storage and processing using ferromagnetic materials.

  4. Global asymptotic stabilisation for switched planar systems

    NASA Astrophysics Data System (ADS)

    Zhang, Junfeng; Han, Zhengzhi; Huang, Jun

    2015-04-01

    This paper studies the stabilisation problem of a class of switched planar systems. The present method is different from the existing one designing directly controllers for the underlying systems. The controllers are constructed through two steps. Firstly, by means of the backstepping approach, homogeneous controllers stabilising the nominal systems are obtained. Secondly, the controllers stabilising the planar subsystems are attained by modifying the obtained homogeneous controllers. The controllers depend on perturbations of the switched systems. Finally, by using the multiple Lyapunov functions approach, a sufficient condition of the stabilisation for switched planar systems is given. The conclusions are extended to multiple dimensional switched systems. An illustrative example verifies the validity of the design.

  5. An Acetone Microsensor with a Ring Oscillator Circuit Fabricated Using the Commercial 0.18 μm CMOS Process

    PubMed Central

    Yang, Ming-Zhi; Dai, Ching-Liang; Shih, Po-Jen

    2014-01-01

    This study investigates the fabrication and characterization of an acetone microsensor with a ring oscillator circuit using the commercial 0.18 μm complementary metal oxide semiconductor (CMOS) process. The acetone microsensor contains a sensitive material, interdigitated electrodes and a polysilicon heater. The sensitive material is α-Fe2O3 synthesized by the hydrothermal method. The sensor requires a post-process to remove the sacrificial oxide layer between the interdigitated electrodes and to coat the α-Fe2O3 on the electrodes. When the sensitive material adsorbs acetone vapor, the sensor produces a change in capacitance. The ring oscillator circuit converts the capacitance of the sensor into the oscillation frequency output. The experimental results show that the output frequency of the acetone sensor changes from 128 to 100 MHz as the acetone concentration increases 1 to 70 ppm. PMID:25036331

  6. The interaction between two planar and nonplanar quantum electron acoustic solitary waves in dense electron-ion plasmas

    SciTech Connect

    EL-Labany, S. K.; El-Mahgoub, M. G.; EL-Shamy, E. F.

    2012-06-15

    The interaction between two planar and nonplanar (cylindrical and spherical) quantum electron acoustic solitary waves (QEASWs) in quantum dense electron-ion plasmas has been studied. The extended Poincare-Lighthill-Kuo method is used to obtain planar and nonplanar phase shifts after the interaction of the two QEASWs. The change of phase shifts and trajectories for QEASWs due to the effect of the different geometries, the quantum corrections of diffraction, and the cold electron-to-hot electron number density ratio are discussed. It is shown that the interaction of the QEASWs in planar geometry, cylindrical geometry, and spherical geometry are different. The present investigation may be beneficial to understand the interaction between two planar and nonplanar QEASWs that may occur in the quantum plasmas found in laser-produced plasmas as well as in astrophysical plasmas.

  7. Planar cell polarity of the kidney.

    PubMed

    Schnell, Ulrike; Carroll, Thomas J

    2016-05-01

    Planar cell polarity (PCP) or tissue polarity refers to the polarization of tissues perpendicular to the apical-basal axis. Most epithelia, including the vertebrate kidney, show signs of planar polarity. In the kidney, defects in planar polarity are attributed to several disease states including multiple forms of cystic kidney disease. Indeed, planar cell polarity has been shown to be essential for several cellular processes that appear to be necessary for establishing and maintaining tubule diameter. However, uncovering the genetic mechanisms underlying PCP in the kidney has been complicated as the roles of many of the main players are not conserved in flies and vice versa. Here, we review a number of cellular and molecular processes that can affect PCP of the kidney with a particular emphasis on the mechanisms that do not appear to be conserved in flies or that are not part of canonical determinants.

  8. Non-planar microfabricated gas chromatography column

    DOEpatents

    Lewis, Patrick R.; Wheeler, David R.

    2007-09-25

    A non-planar microfabricated gas chromatography column comprises a planar substrate having a plurality of through holes, a top lid and a bottom lid bonded to opposite surfaces of the planar substrate, and inlet and outlet ports for injection of a sample gas and elution of separated analytes. A plurality of such planar substrates can be aligned and stacked to provide a longer column length having a small footprint. Furthermore, two or more separate channels can enable multi-channel or multi-dimensional gas chromatography. The through holes preferably have a circular cross section and can be coated with a stationary phase material or packed with a porous packing material. Importantly, uniform stationary phase coatings can be obtained and band broadening can be minimized with the circular channels. A heating or cooling element can be disposed on at least one of the lids to enable temperature programming of the column.

  9. Novel Planar and Integrated Microwave Antennas

    NASA Technical Reports Server (NTRS)

    Saed, Mohammad A.

    2000-01-01

    This project dealt with design, analysis, and testing of new types of planar and integrated antennas operating in the microwave frequency range. The following was accomplished during this project period:

  10. Forming a seal between planar sealing surfaces

    SciTech Connect

    Ezekoye, L.I.; Rusnica, E.J.; Sepp, H.A. Jr.

    1987-12-29

    A method of forming a seal between the confronting planar sealing surfaces on two annular structural members which are drawn together by axially extending bolts is described comprising the steps of: forming a seal assembly by locking a toroidal, crushable seal member within a substantially flat annular spacer member against an annular shoulder formed on the inner diameter thereof with an annular resilient member seated in a radially extending groove in the inner surface of the substantially flat annular member, the flat annular member being axially thinner than the toroidal, crushable seal member; placing the sealing assembly between the planar sealing surfaces and positively aligning the assembly relative to the axially extending bolts; and tightening the bolts to draw the planar sealing surfaces toward each other and into contact with the flat annular member while crushing the toroidal, crushable seal member to form a seal between the planar sealing surfaces.

  11. Recent progress in design and hybridization of planar grating-based transceivers

    NASA Astrophysics Data System (ADS)

    Bidnyk, S.; Pearson, M.; Balakrishnan, A.; Gao, M.

    2007-06-01

    We report on recent progress in simulations, physical layout, fabrication and hybridization of planar grating-based transceivers for passive optical networks (PONs). Until recently, PON transceivers have been manufactured using bulk micro-optical components. Today, advancements in modeling and simulation techniques has made it possible to design complex elements in the same silica-on silicon PLC platform and create an alternative platform for manufacturing of bi-directional transceivers. In our chips we simulated an integrated chip that monolithically combined planar reflective gratings and cascaded Mach-Zehnder interferometers. We used a combination of the finite element method and beam propagation method to model cascaded interferometers with enhanced coupling coefficients. Our simulations show that low-diffraction order planar reflective gratings, designed for small incidence and reflection angles, possess the required dispersion strength to meet the PON specifications. Subsequently, we created structures for passive alignment and hybridized photodetectors and lasers. We believe that advancements in simulation of planar lightwave circuits with embedded planar reflective gratings will result in displacement of the thin-film filters (TFFs) technology in many applications that require a high degree of monolithic and hybrid integration.

  12. Pfaffian Correlation Functions of Planar Dimer Covers

    NASA Astrophysics Data System (ADS)

    Aizenman, Michael; Valcázar, Manuel Laínz; Warzel, Simone

    2017-01-01

    The Pfaffian structure of the boundary monomer correlation functions in the dimer-covering planar graph models is rederived through a combinatorial/topological argument. These functions are then extended into a larger family of order-disorder correlation functions which are shown to exhibit Pfaffian structure throughout the bulk. Key tools involve combinatorial switching symmetries which are identified through the loop-gas representation of the double dimer model, and topological implications of planarity.

  13. Terahertz planar waveguide devices based on graphene

    NASA Astrophysics Data System (ADS)

    Yuan, Yizhe; Guo, Xiaoyong; An, Liqun; Xu, Wen

    2017-02-01

    We present a theoretical study on graphene-semiconductor planar structures. The frequency of the photonic modes in the structure, which can be efficiently tuned via varying the sample parameters, is within the terahertz (THz) bandwidth. Furthermore, it is found that a roughly linear dispersion relation can be obtained for photonic modes in the THz region. Hence, the proposed graphene-semiconductor planar structures can be served as THz waveguide with desirable transmission characteristics.

  14. Shift multiplexing by planar waveguide referencing

    NASA Astrophysics Data System (ADS)

    Yi, Tao; Zhang, Jiasen; Yan, Lifen; Gong, Qihuang

    2005-09-01

    We present a new method with which to implement shift multiplexing by planar waveguide referencing. In this method, a planar waveguide is used to steer the reference beam, and we implement shift multiplexing by shifting the recording medium. A spatial selectivity as high as 1.1 μm is obtained. By using waveguide referencing we can make a compact and simple holographic system.

  15. Single-shot hyperspectral coherent Raman planar imaging in the range 0-4200 cm-1

    NASA Astrophysics Data System (ADS)

    Bohlin, Alexis; Kliewer, Christopher J.

    2014-10-01

    We propose a technique for ultrabroadband planar coherent Raman spectroscopy that enables wideband chemically selective mapping of molecular partition functions in the gas-phase within a single-laser-shot. A spectral region spanning 0-4200 cm-1 is excited simultaneously, in principle allowing for coherent planar imaging of most all fundamental Raman-active modes. This unique instantaneous and spatially correlated assessment enables multiplexed studies of transient dynamical systems in a two-dimensional (2D) field. Here, we demonstrate single-laser-shot high temperature diagnostics of H2, with spatially resolved 2D measurement of transitions of both the pure-rotational H2 S-branch and the vibrational H2 Q-branch, analyzing the temperature contour of a reacting fuel-species as it evolves at a flame-front.

  16. Normal planar undulators doubling as transverse gradient undulators

    NASA Astrophysics Data System (ADS)

    Jia, Qika; Li, Heting

    2017-02-01

    The transverse gradient undulator (TGU) has important application in the short-wavelength high-gain free electron lasers (FELs) driven by laser-plasma accelerators. However, the usual transversely tapered TGUs need special design and manufacture, and the transverse gradient cannot be tuned arbitrarily. In this paper we explore a new and simple method of using the natural transverse gradient of a normal planar undulator to compensate the beam energy spread effect. In this method, a vertical dispersion on the electron beam is introduced, then the dispersed beam passes through a normal undulator with a vertical off-axis orbit where the vertical field gradient is selected properly related to the dispersion strength and the beam energy spread. Theoretical analysis and numerical simulations for self-amplified spontaneous emission FELs based on laser plasma accelerators are presented, and indicate that this method can greatly reduce the effect of the beam energy spread, leading to a similar enhancement on FEL performance as the usual transversely tapered TGU, but with the advantages of economy, tunable transverse gradient and no demand of extra field for correcting the orbit deflection induced by the field gradient.

  17. Self-imaging and high-beam-quality operation in multi-mode planar waveguide optical amplifiers.

    PubMed

    Baker, Howard; Lee, Jason; Hall, Denis

    2002-03-25

    Self-imaging in a multi-mode active waveguide is examined as a method to preserve beam quality when amplifying a fundamental gaussian beam. Misalignment tolerance, gain saturation and thermal lensing effects are evaluated for the use of self-imaging in high average power, diodepumped, planar waveguide lasers.

  18. Ultrasonic Imaging and Theoretical Prediction of Orthotropic Plate Stiffness in all Planar Directions

    SciTech Connect

    Telschow, Kenneth Louis; Deason, Vance Albert; Mukdadi, O.; Datta, S. K.

    2000-07-01

    Exact and approximate theoretical analysis of the wavelengths of plate wave mode propagation in all planar directions for the dispersive antisymmetric Lamb wave mode are compared with measurements from a laser ultrasonic imaging approach that records the out of plane ultrasonic motion over a large area in a single frame without scanning. Good agreement is demonstrated, based on independent determination of the elastic constants, for two different types of paper.

  19. Ceramic planar waveguide structures for amplifiers and lasers

    NASA Astrophysics Data System (ADS)

    Konyushkin, V. A.; Nakladov, A. N.; Konyushkin, D. V.; Doroshenko, Maxim E.; Osiko, Vyacheslav V.; Karasik, Aleksandr Ya

    2013-01-01

    Ceramic and crystalline weakly guiding optical fibres with the core - cladding refractive index difference of 10-2 - 10-4 are fabricated by a hot pressing method. The waveguides with one or several cores for operation in the spectral range 0.2 - 5 μm are produced. The waveguides are based on CaF2, SrF2, and BaF2 ceramics and crystals and their solid solutions doped with trivalent Pr, Nd, Tb, Dy, Yb, Ho, Er, and Tm ions, as well as on LiF ceramics and crystals with colour centres. The first results of investigation of the lasing properties of ceramic SrF2 : NdF waveguides under diode pumping are presented, and the prospects of further investigation are discussed.

  20. Experiments on planar plasma flow switches at Los Alamos

    SciTech Connect

    Benage, J.F. Jr.; Wysocki, F.J.; Bowers, R.; Oona, H.

    1997-12-01

    The authors have performed a series of experiments on the Colt facility at Los Alamos to study the performance of plasma flow switches and to understand the important physics issues which affect that performance. These experiments were done in planar geometry on a small machine to allow for better diagnostic access and a higher repetition rate. The Colt facility is a capacitor bank which stores 300 kJ at maximum charge and produced a peak current of 1.1 MA in 2.0 microseconds for these experiments. The diagnostics used for these experiments included an array of b-dot probes, visible framing pictures, visible spectroscopy, and laser interferometry. Characteristics of the switch are determined from spatial and temporal profiles of the magnetic field and the spatial profile and temperature of the switch plasma. Here the authors present results from experiments for a variety of switch conditions.

  1. Planar Particle Imaging and Doppler Velocimetry System and Method

    NASA Technical Reports Server (NTRS)

    Wernet, Mark P. (Inventor)

    2003-01-01

    A planar velocity measurement system (100) is operative to measure all three velocity components of a flowing fluid (106) across an illuminated plane (108) using only a single line of sight. The fluid flow is seeded with small particles which accurately follow the flow field fluctuations. The seeded flow field is illuminated with pulsed laser light source (102) and the positions of the particles in the flow are recorded on CCD cameras (122,124). The in-plane velocities are measured by determining the in-plane particle displacements. The out-of-plane velocity component is determined by measuring the Doppler shift of the light scattered by the particles. Both gas and liquid velocities can be measured, as well as two-phase flows.

  2. Infrared spectroscopy of acetone-water liquid mixtures. II. Molecular model

    NASA Astrophysics Data System (ADS)

    Max, Jean-Joseph; Chapados, Camille

    2004-04-01

    In aqueous acetone solutions, the strong bathochromic shifts observed on the OH and CO stretch infrared (IR) bands are due to hydrogen bonds between these groups. These shifts were evaluated by factor analysis (FA) that separated the band components from which five water and five acetone principal factors were retrieved [J. Chem. Phys. 119, 5632 (2003)]. However, these factors were abstract making them difficult to interpret. To render them real an organization model of molecules is here developed whose abundances are compared to the experimental ones. The model considers that the molecules are randomly organized limited by the hydrogen bond network formed between the water hydrogen atoms and the acetone or water oxygen atoms, indifferently. Because the oxygen of water has two covalent hydrogen atoms which are hydrogen-bonded and may receive up to two hydrogen atoms from neighbor molecules hydrogen-bonded to it, three types of water molecules are found: OH2, OH3, and OH4 (covalent and hydrogen bonds). In the OH stretch region these molecules generate three absorption regimes composed of ν3, ν1, and their satellites. The strength of the H-bond given increases with the number of H-bonds accepted by the oxygen atom of the water H-bond donor, producing nine water situations. Since FA cannot separate those species that evolve concomitantly the nine water situations are regrouped into five factors, the abundance of which compared exactly to that retrieved by FA. From the factors' real spectra the OH stretch absorption are simulated to, respectively, give for the ν3 and ν1 components the mean values for OH2, 3608, 3508; OH3, 3473, 3282 and OH4, 3391, 3223 cm-1. The mean separations from the gas-phase position which are respectively about 150, 330, and 400 cm-1 are related to the vacancy of the oxygen electron doublets: two, one, and zero, respectively. No acetone hydrate that sequesters water molecules is formed. Similarly, acetone produces ten species, two of which

  3. APPLICATION OF INFRARED SPECTROSCOPY TO THE ANALYSIS OF INORGANIC NITRATES. PHASE 1. SPECTRA OF INORGANIC NITRATES IN ACETONE AND THE USE OF SUCH SPECTRA IN ANALYTICAL CHEMISTRY

    DTIC Science & Technology

    A study was made of the spectra of soluble inorganic nitrates in acetone solution and the use of such spectra in analytical chemistry . The spectra of...solubilities of anhydrous inorganic nitrates in acetone. The applications of the spectra of inorganic nitrates in acetone to analytical chemistry is

  4. Variability of acetone in milk in a large low-production dairy herd: a longitudinal case study.

    PubMed

    Heuer, C; Wangler, A; Schukken, Y H; Noordhuizen, J P

    2001-05-01

    The objective of this study was to relate acetone in milk with cow and management factors in one low producing dairy herd (5260 kg milk per 305-day lactation). Milk acetone was measured in regular monthly milk samples one to three times within 100 days of lactation in 4433 lactations (2639 cows, 7800 measurements) from one herd over a period of 32 months (1988-91). Associations between milk acetone and cow factors and surrogate measures of management were evaluated by variance components of multiple fixed effect models. Lactation stage, calendar month of study, production groups and milk yield were strong, and percentage milk fat and parity were weak predictors of milk acetone. There was a trend of increasing body weight loss from the first to the second month of lactation with increasing milk acetone level. A substantial increase in milk production in 1991 was accompanied by an almost twofold rise in milk acetone. It was concluded that environmental parameters had strong relationships with milk acetone even in this low-producing herd.

  5. Hybrid planar lightwave circuits for defense and aerospace applications

    NASA Astrophysics Data System (ADS)

    Zhang, Hua; Bidnyk, Serge; Yang, Shiquan; Balakrishnan, Ashok; Pearson, Matt; O'Keefe, Sean

    2010-04-01

    We present innovations in Planar Lightwave Circuits (PLCs) that make them ideally suited for use in advanced defense and aerospace applications. We discuss PLCs that contain no micro-optic components, no moving parts, pose no spark or fire hazard, are extremely small and lightweight, and are capable of transporting and processing a range of optical signals with exceptionally high performance. This PLC platform is designed for on-chip integration of active components such as lasers and detectors, along with transimpedance amplifiers and other electronics. These active components are hybridly integrated with our silica-on-silicon PLCs using fully-automated robotics and image recognition technology. This PLC approach has been successfully applied to the design and fabrication of multi-channel transceivers for aerospace applications. The chips contain hybrid DFB lasers and high-efficiency detectors, each capable of running over 10 Gb/s, with mixed digital and analog traffic multiplexed to a single optical fiber. This highlyintegrated functionality is combined onto a silicon chip smaller than 4 x 10 mm, weighing < 5 grams. These chip-based transceivers have been measured to withstand harsh g-forces, including sinusoidal vibrations with amplitude of 20 g acceleration, followed by mechanical shock of 500 g acceleration. The components operate over a wide range of temperatures, with no device failures after extreme temperature cycling through a range of > 125 degC, and more than 2,000 hours operating at 95 degC ambient air temperature. We believe that these recent advancements in planar lightwave circuits are poised to revolutionize optical communications and interconnects in the aerospace and defense industries.

  6. New-type planar field emission display with superaligned carbon nanotube yarn emitter.

    PubMed

    Liu, Peng; Wei, Yang; Liu, Kai; Liu, Liang; Jiang, Kaili; Fan, Shoushan

    2012-05-09

    With the superaligned carbon nanotube yarn as emitter, we have fabricated a 16 × 16 pixel field emission display prototype by adopting screen printing and laser cutting technologies. A planar diode field emission structure has been adopted. A very sharp carbon nanotube yarn tip emitter can be formed by laser cutting. Low voltage phosphor was coated on the anode electrodes also by screen printing. With a specially designed circuit, we have demonstrated the dynamic character display with the field emission display prototype. The emitter material and fabrication technologies in this paper are both easy to scale up to large areas.

  7. trans-Dichloridobis[tris­(4-meth­oxy­lphen­yl)phosphane-κP]platinum(II) acetone disolvate

    PubMed Central

    Muller, Alfred

    2012-01-01

    In the title compound, [PtCl2(C21H21O3P)2]·2C3H6O, the asymmetric unit contains a PtII ion situated on an inversion center, one chloride anion, one tris­(4-meth­oxy­lphen­yl)phosphane (L) ligand and one acetone solvent mol­ecule. The PtII ion is coordinated by two P atoms [Pt—P = 2.3196 (5) Å] from two L ligands and two chloride anions [Pt—Cl = 2.3075 (5) Å] in a distorted square-planar geometry with P—Pt—Cl angles of 88.016 (16) and 91.984 (16)°. The effective cone angle of the phosphane ligand was calculated to be 156°. Weak C—H⋯O and C—H⋯Cl hydrogen bonds hold mol­ecules together. PMID:23468701

  8. Integration of planar transformer and/or planar inductor with power switches in power converter

    DOEpatents

    Chen, Kanghua; Ahmed, Sayeed; Zhu, Lizhi

    2007-10-30

    A power converter integrates at least one planar transformer comprising a multi-layer transformer substrate and/or at least one planar inductor comprising a multi-layer inductor substrate with a number of power semiconductor switches physically and thermally coupled to a heat sink via one or more multi-layer switch substrates.

  9. Roles of Acetone and Diacetone Alcohol in Coordination and Dissociation Reactions of Uranyl Complexes

    SciTech Connect

    Rios, Daniel; Schoendorff, George E.; Van Stipdonk, Michael J.; Gordon, Mark S.; Windus, Theresa L.; Gibson, John K.; De Jong, Wibe A.

    2012-12-03

    Combined collision-induced dissociation mass-spectrometry experiments and DFT calculations were employed to elucidate the molecular structure of "hypercoordinated" species and the energetics of water-elimination reactions of uranyl acetone complexes observed in earlier work (Rios, D.; Rutkowski, P. X.; Van Stipdonk, M. J.; Gibson, J. K. Inorg. Chem. 2011, 50, 4781). It is shown that the "hypercoordinated" species contain diacetone alcohol ligands bonded in either bidentate or monodentate fashion, which are indistinguishable from (acetone)2 in mass spectrometry. Calculations confirm that four diacetone ligands can form stable complexes, but that the effective number of atoms coordinating with uranium in the equatorial plane does not exceed five. Diacetone alcohol ligands are shown to form mesityl oxide ligands and alkoxide species through the elimination of water, providing an explanation for the observed water-elimination reactions.

  10. Detection of acetone in exhaled breath with the use of micropreconcentrator and a commercial gas sensor

    NASA Astrophysics Data System (ADS)

    Michoń, Dagmara; Rydosz, Artur; Domański, Krzysztof; Maziarz, Wojciech; Pisarkiewicz, Tadeusz

    2016-12-01

    This paper presents investigation results obtained with the measuring system enabling detection of acetone with concentrations lower than 1 ppm. In the experiment we used both conventional preconcentrators made from materials such as stainless steel and quartz tubes and a micropreconcentrator manufactured in MEMS technology. The active volume of all preconcentrators was equal to enable comparisons of their performance. As a gas detector at the output of the measurement system we used both commercial semiconductor gas sensor and a mass spectrometer for comparison purposes. The obtained results show that the measurement system with micropreconcentrator and a commercial gas sensor can be used for detection of low level acetone present in the air exhaled by diabetics.

  11. DSC and curing kinetics study of epoxy grouting diluted with furfural -acetone slurry

    NASA Astrophysics Data System (ADS)

    Yin, H.; Sun, D. W.; Li, B.; Liu, Y. T.; Ran, Q. P.; Liu, J. P.

    2016-07-01

    The use of furfural-acetone slurry as active diluents of Bisphenol-A epoxy resin (DGEBA) groutings has been studied by dynamic and non-isothermal DSC for the first time. Curing kinetics study was investigated by non-isothermal differential scanning calorimetries at different heating rates. Activation enery (Ea) was calculated based on Kissinger and Ozawa Methods, and the results showed that Ea increased from 58.87 to 71.13KJ/mol after the diluents were added. The furfural-acetone epoxy matrix could cure completely at the theoretical curing temperature of 365.8K and the curing time of 139mins, which were determined by the kinetic model parameters.

  12. Graphene oxide foams and their excellent adsorption ability for acetone gas

    SciTech Connect

    He, Yongqiang; Zhang, Nana; Wu, Fei; Xu, Fangqiang; Liu, Yu; Gao, Jianping

    2013-09-01

    Graphical abstract: - Highlights: • GO and RGO foams were prepared using a simple and green method, unidirectional freeze-drying. • The porous structure of the foams can be adjusted by changing GO concentrations. • GO and RGO foams show good adsorption efficiency for acetone gas. - Abstract: Graphene oxide (GO) and reduced graphene oxide (RGO) foams were prepared using a unidirectional freeze-drying method. These porous carbon materials were characterized by thermal gravimetric analysis, differential scanning calorimetry, X-ray photoelectron spectroscopy and scanning electron microscopy. The adsorption behavior of the two kinds of foams for acetone was studied. The result showed that the saturated adsorption efficiency of the GO foams was over 100%, and was higher than that of RGO foams and other carbon materials.

  13. Proton transfer reactions between nitric acid and acetone, hydroxyacetone, acetaldehyde and benzaldehyde in the solid phase.

    PubMed

    Lasne, Jérôme; Laffon, Carine; Parent, Philippe

    2012-12-05

    The heterogeneous and homogeneous reactions of acetone, hydroxyacetone, acetaldehyde and benzaldehyde with solid nitric acid (HNO(3)) films have been studied with Reflection-Absorption Infrared Spectroscopy (RAIRS) under Ultra-High Vacuum (UHV) conditions in the 90-170 K temperature range. In the bulk or at the surface of the films, nitric acid transfers its proton to the carbonyl function of the organic molecules, producing protonated acetone-H(+), hydroxyacetone-H(+), acetaldehyde-H(+) and benzaldehyde-H(+), and nitrate anions NO(3)(-), a reaction not observed when nitric acid is previously hydrated [J. Lasne, C. Laffon and Ph. Parent, Phys. Chem. Chem. Phys., 2012, 14, 697]. This provides a molecular-scale description of the carbonyl protonation reaction in an acid medium, the first step of the acid-catalyzed condensation of carbonyl compounds, fuelling the growth of secondary organic aerosols (SOA) in the atmosphere.

  14. Technical and economic assessment of processes for the production of butanol and acetone

    NASA Technical Reports Server (NTRS)

    1982-01-01

    This report represents a preliminary technical and economic evaluation of a process which produces mixed solvents (butaol/acetone/ethanol) via fermentation of sugars derived from renewable biomass resources. The objective is to assess the technology of producing butanol/acetone from biomass, and select a viable process capable of serving as a base case model for technical and economic analysis. It is anticipated that the base case process developed herein can then be used as the basis for subsequent studies concerning biomass conversion processes capable of producing a wide range of chemicals. The general criteria utilized in determining the design basis for the process are profit potential and non-renewable energy displacement potential. The feedstock chosen, aspen wood, was selected from a number of potential renewable biomass resources as the most readily available in the United States and for its relatively large potential for producing reducing sugars.

  15. Enhancement of seawater corrosion resistance in copper using acetone-derived graphene coating

    NASA Astrophysics Data System (ADS)

    Huh, Jae-Hoon; Kim, Seung Hyun; Chu, Jae Hwan; Kim, Sung Youb; Kim, Ji Hyun; Kwon, Soon-Yong

    2014-03-01

    We show that acetone-derived graphene coating can effectively enhance the corrosion efficiency of copper (Cu) in a seawater environment (0.5-0.6 M (~3.0-3.5%) sodium chloride). By applying a drop of acetone (~20 μl cm-2) on Cu surfaces, rapid thermal annealing allows the facile and rapid synthesis of graphene films on Cu surfaces with a monolayer coverage of almost close to ~100%. Under optimal growth conditions, acetone-derived graphene is found to have a relatively high crystallinity, comparable to common graphene grown by chemical vapor deposition. The resulting graphene-coated Cu surface exhibits 37.5 times higher corrosion resistance as compared to that of mechanically polished Cu. Further, investigation on the role of graphene coating on Cu surfaces suggests that the outstanding corrosion inhibition efficiency (IE) of 97.4% is obtained by protecting the underlying Cu against the penetration of both dissolved oxygen and chlorine ions, thanks to the closely spaced atomic structure of the graphene sheets. The increase of graphene coating thickness results in the enhancement of the overall corrosion IE up to ~99%, which can be attributed to the effective blocking of the ionic diffusion process via grain boundaries. Overall, our results suggest that the acetone-derived graphene film can effectively serve as a corrosion-inhibiting coating in the seawater level and that it may have a promising role to play for potential offshore coating.We show that acetone-derived graphene coating can effectively enhance the corrosion efficiency of copper (Cu) in a seawater environment (0.5-0.6 M (~3.0-3.5%) sodium chloride). By applying a drop of acetone (~20 μl cm-2) on Cu surfaces, rapid thermal annealing allows the facile and rapid synthesis of graphene films on Cu surfaces with a monolayer coverage of almost close to ~100%. Under optimal growth conditions, acetone-derived graphene is found to have a relatively high crystallinity, comparable to common graphene grown by

  16. Investigations on the structure of DMSO and acetone in aqueous solution

    SciTech Connect

    McLain, Sylvia E; Soper, Alan K

    2007-01-01

    Aqueous solutions of dimethyl sulfoxide (DMSO) and acetone have been investigated using neutron diffraction augmented with isotopic substitution and empirical potential structure refinement computer simulations. Each solute has been measured at two concentrations-1:20 and 1:2 solute:water mole ratios. At both concentrations for each solute, the tetrahedral hydrogen bonding network of water is largely unperturbed, though the total water molecule coordination number is reduced in the higher 1:2 concentrations. With higher concentrations of acetone, water tends to segregate into clusters, while in higher concentrations of DMSO the present study reconfirms that the structure of the liquid is dominated by DMSO-water interactions. This result may have implications for the highly nonideal behavior observed in the thermodynamic functions for 1:2 DMSO-water solutions.

  17. Production of acetone, butanol, and ethanol from biomass of the green seaweed Ulva lactuca.

    PubMed

    van der Wal, Hetty; Sperber, Bram L H M; Houweling-Tan, Bwee; Bakker, Robert R C; Brandenburg, Willem; López-Contreras, Ana M

    2013-01-01

    Green seaweed Ulva lactuca harvested from the North Sea near Zeeland (The Netherlands) was characterized as feedstock for acetone, ethanol and ethanol fermentation. Solubilization of over 90% of sugars was achieved by hot-water treatment followed by hydrolysis using commercial cellulases. A hydrolysate was used for the production of acetone, butanol and ethanol (ABE) by Clostridium acetobutylicum and Clostridium beijerinckii. Hydrolysate-based media were fermentable without nutrient supplementation. C. beijerinckii utilized all sugars in the hydrolysate and produced ABE at high yields (0.35 g ABE/g sugar consumed), while C. acetobutylicum produced mostly organic acids (acetic and butyric acids). These results demonstrate the great potential of U. lactuca as feedstock for fermentation. Interestingly, in control cultures of C. beijerinckii on rhamnose and glucose, 1,2 propanediol was the main fermentation product (9.7 g/L).

  18. 100 kHz thousand-frame burst-mode planar imaging in turbulent flames.

    PubMed

    Michael, James B; Venkateswaran, Prabhakar; Miller, Joseph D; Slipchenko, Mikhail N; Gord, James R; Roy, Sukesh; Meyer, Terrence R

    2014-02-15

    High-repetition-rate, burst-mode lasers can achieve higher energies per pulse compared with continuously pulsed systems, but the relatively few number of laser pulses in each burst has limited the temporal dynamic range of measurements in unsteady flames. A fivefold increase in the range of timescales that can be resolved by burst-mode laser-based imaging systems is reported in this work by extending a hybrid diode- and flashlamp-pumped Nd:YAG-based amplifier system to nearly 1000 pulses at 100 kHz during a 10 ms burst. This enables an unprecedented burst-mode temporal dynamic range to capture turbulent fluctuations from 0.1 to 50 kHz in flames of practical interest. High pulse intensity enables efficient conversion to the ultraviolet for planar laser-induced fluorescence imaging of nascent formaldehyde and other potential flame radicals.

  19. Surface tension isotherms of the dioxane-acetone-water and glycerol-ethanol-water ternary systems

    NASA Astrophysics Data System (ADS)

    Dzhambulatov, R. S.; Dadashev, R. Kh.; Elimkhanov, D. Z.; Dadashev, I. N.

    2016-10-01

    The results of the experimental and theoretical studies of the concentration dependence of surface tension of aqueous solutions of the 1,4-dioxane-acetone-water and glycerol-ethanol-water ternary systems were given. The studies were performed by the hanging-drop method on a DSA100 tensiometer. The maximum error of surface tension was 1%. The theoretical models for calculating the surface tension of the ternary systems of organic solutions were analyzed.

  20. Planar factors of proper homogeneous Lorentz transformations

    SciTech Connect

    Fahnline, D.E.

    1985-02-01

    This article discusses two constructions factoring proper homogeneous Lorentz transformations H into the product of two planar transformations. A planar transformation is a proper homogeneous Lorentz transformation changing vectors in a two-flat through the origin, called the transformation two-flat, into new vectors in the same two-flat and which leaves unchanged vectors in the orthogonal two-flat, called the pointwise invariant two-flat. The first construction provides two planar factors such that a given timelike vector lies in the transformation two-flat of one and in the pointwise invariant two-flat of the other; it leads to several basic conditions on the trace of H and to necessary and sufficient conditions for H to be planar. The second construction yields explicit formulas for the orthogonal factors of H when they exist and are unique, where two planar transformations are orthogonal if the transformation two-flat of one is the pointwise invariant two-flat of the other.

  1. Acetone in theGlobal Troposphere: Its Possible Role as a Global Source of PAN

    NASA Technical Reports Server (NTRS)

    Singh, H. B.; Kanakidou, M.

    1994-01-01

    Oxygenated hydrocarbons are thought to be important components of the atmosphere but, with the exception of formaldehyde, very little about their distribution and fate is known. Aircraft measurements of acetone (CH3COCH3), PAN (CH3CO3NO2) and other organic species (e. g. acetaldehyde, methanol and ethanol) have been performed over the Pacific, the southern Atlantic, and the subarctic atmospheres. Sampled areas extended from 0 to 12 km altitude over latitudes of 70 deg N to 40 deg S. All measurements are based on real time in-situ analysis of cryogenically preconcentrated air samples. Substantial concentrations of these oxygenated species (10-2000 ppt) have been observed at all altitudes and geographical locations in the troposphere. Important sources include, emissions from biomass burning, plant and vegetation, secondary oxidation of primary non-methane hydrocarbons, and man-made emissions. Direct measurements within smoke plumes have been used to estimate the biomass burning source. Photochemistry studies are used to suggest that acetone could provide a major source of peroxyacetyl radicals in the atmosphere and play an important role in sequestering reactive nitrogen. Model calculations show that acetone photolysis contributes significantly to PAN formation in the middle and upper troposphere.

  2. Nesterenkonia sp. strain F, a halophilic bacterium producing acetone, butanol, and ethanol under aerobic conditions

    PubMed Central

    Amiri, Hamid; Azarbaijani, Reza; Parsa Yeganeh, Laleh; Shahzadeh Fazeli, Abolhassan; Tabatabaei, Meisam; Hosseini Salekdeh, Ghasem; Karimi, Keikhosro

    2016-01-01

    The moderately halophilic bacterium Nesterenkonia sp. strain F, which was isolated from Aran-Bidgol Lake (Iran), has the ability to produce acetone, butanol, and ethanol (ABE) as well as acetic and butyric acids under aerobic and anaerobic conditions. This result is the first report of ABE production with a wild microorganism from a family other than Clostridia and also the first halophilic species shown to produce butanol under aerobic cultivation. The cultivation of Nesterenkonia sp. strain F under anaerobic conditions with 50 g/l of glucose for 72 h resulted in the production of 105 mg/l of butanol, 122 mg/l of acetone, 0.2 g/l of acetic acid, and 2.5 g/l of butyric acid. Furthermore, the strain was cultivated on media with different glucose concentrations (20, 50, and 80 g/l) under aerobic and anaerobic conditions. Through fermentation with a 50 g/l initial glucose concentration under aerobic conditions, 66 mg/l of butanol, 125 mg/l of acetone, 291 mg/l of ethanol, 5.9 g/l of acetic acid, and 1.2 g/l of butyric acid were produced. The enzymes pertaining to the fermentation pathway in the strain were compared with the enzymes of Clostridium spp., and the metabolic pathway of fermentation used by Nesterenkonia sp. strain F was investigated. PMID:26725518

  3. Sources and sinks of acetone, methanol, and acetaldehyde in North Atlantic air

    NASA Astrophysics Data System (ADS)

    Lewis, A. C.; Hopkins, J. R.; Carpenter, L. J.; Stanton, J.; Read, K. A.; Pilling, M. J.

    2005-03-01

    Measurements of acetone, methanol, acetaldehyde and a range of non-methane hydrocarbons have been made in North Atlantic marine air at the Mace Head observatory. Under maritime conditions the combination of OVOCs (acetone, methanol and 5 acetaldehyde) contributed up to 85% of the total mass of measured non methane organics in air and up to 80% of the OH radical organic sink, when compared with the sum of all other organic compounds including non-methane hydrocarbons, DMS and OH-reactive halocarbons (trichloromethane and tetrachloroethylene). The observations showed anomalies in the variance and abundance of acetaldehyde and acetone 10 over that expected for species with a remote terrestrial emission source and OH controlled chemical lifetime. A detailed model incorporating an explicit chemical degradation mechanism indicated in situ formation during air mass transport was on timescales longer than the atmospheric lifetime of precursor hydrocarbons or primary emission. The period over which this process was significant was similar to that of airmass mo15 tion on intercontinental scales, and formation via this route may reproduce that of a widespread diffuse source. The model indicates that continued short chain OVOC formation occurs many days from the point of emission, via longer lived intermediates of oxidation such as organic peroxides and long chain alcohols.

  4. Sources and sinks of acetone, methanol, and acetaldehyde in North Atlantic marine air

    NASA Astrophysics Data System (ADS)

    Lewis, A. C.; Hopkins, J. R.; Carpenter, L. J.; Stanton, J.; Read, K. A.; Pilling, M. J.

    2005-08-01

    Measurements of acetone, methanol, acetaldehyde and a range of non-methane hydrocarbons have been made in North Atlantic marine air at the Mace Head observatory. Under maritime conditions the combination of OVOCs (acetone, methanol and acetaldehyde) contributed up to 85% of the total mass of measured non methane organics in air and up to 80% of the OH radical organic sink, when compared with the sum of all other organic compounds including non-methane hydrocarbons, DMS and OH-reactive halocarbons (trichloromethane and tetrachloroethylene). The observations showed anomalies in the variance and abundance of acetaldehyde and acetone over that expected for species with a remote terrestrial emission source and OH controlled chemical lifetime. A detailed model incorporating an explicit chemical degradation mechanism indicated in situ formation during air mass transport was on timescales longer than the atmospheric lifetime of precursor hydrocarbons or primary emission. The period over which this process was significant was similar to that of airmass motion on intercontinental scales, and formation via this route may reproduce that of a widespread diffuse source. The model indicates that continued short chain OVOC formation occurs many days from the point of emission, via longer lived intermediates of oxidation such as organic peroxides and long chain alcohols.

  5. Sensitivity of silica microspheres modified by xerogel layers to acetone and ethanol

    NASA Astrophysics Data System (ADS)

    Matějec, Vlastimil; Todorov, Filip; Jelinek, Michal; Fibrich, Martin; Chomát, Miroslav; Kubeček, Václav; Berková, Daniela

    2011-05-01

    The paper deals with the preparation and characterization of whispering-gallery-mode silica spherical microresonators and with effects of liquid acetone, ethanol, and xerogel layers applied onto these microresonators on their resonance spectra. Microrespheres with diameters ranging from 320 to 360 μm have been prepared by heating a tip of a silica fiber with a hydrogen-oxygen burner. The microspheres were excited by a fiber taper or a bulk prism and their resonance spectra were measured. Values of the Q factor from 104 to 106 have been determined from these spectra. In experiments, it has been found that short contact of microspheres with acetone causes a shift of resonance dips due to surface effects caused by acetone. A decrease of the Q factor has been observed with a microresonator onto which a xerogel silica layer was applied by the sol-gel method. A very high decrease of the Q factor has been observed when the silica microresonator was brought in contact with liquid ethanol.

  6. Acetone as a greener alternative to acetonitrile in liquid chromatographic fingerprinting.

    PubMed

    Funari, Cristiano Soleo; Carneiro, Renato Lajarim; Khandagale, Manish M; Cavalheiro, Alberto José; Hilder, Emily F

    2015-05-01

    A considerable amount of chemical waste from liquid chromatography analysis is generated worldwide. Acetonitrile is the most employed solvent in liquid chromatography analyses since it exhibits favorable physicochemical properties for separation and detection, but it is an unwelcome solvent from an environmental point of view. Acetone might be a much greener alternative to replace acetonitrile in reversed-phase liquid chromatography, since both share similar physicochemical properties, but its applicability with ultraviolet absorbance-based detectors is limited. In this work, a reference method using acetonitrile and high-performance liquid chromatography coupled to an ultraviolet photodiode array detector coupled to a corona charged aerosol detector system was developed to fingerprint a complex sample. The possibility of effectively substituting acetonitrile with acetone was investigated. Design of experiments was adopted to maximize the number of peaks acquired in both fingerprint developments. The methods with acetonitrile or acetone were successfully optimized and proved to be statistically similar when only the number of peaks or peak capacity was taken into consideration. However, the superiority of the latter was evidenced when parameters of separation and those related to greenness were heuristically combined. A green, comprehensive, time- and resource-saving approach is presented here, which is generic and applicable to other complex matrices. Furthermore, it is in line with environmental legislation and analytical trends.

  7. Acetone Sensing by Modified SnO2 Nanocrystalline Sensor Materials

    NASA Astrophysics Data System (ADS)

    Krivetsky, V. V.; Petukhov, D. V.; Eliseev, A. A.; Smirnov, A. V.; Rumyantseva, M. N.; Gaskov, Aleksandre M.

    A complementary gas sensor and gas chromatography/mass spectrometry study was performed to investigate the chemical basis of acetone vapor sensing via semiconductor metal oxide gas sensors. The effect of additives to nanocrystalline SnO2-based sensor materials was analyzed. The main process that contributes to the electrical yield of this interaction and thus to the sensor response is a complete acetone oxidation to CO2and H2O. At the same time it is clearly shown that this sensor response is severely limited by the rate of desorption of the reaction products. The main contributors to this negative influence on the sensor response are heavy organic compounds with molar masses larger than that of acetone. It is also shown that their negative effect could be mitigated by the incorporation of catalytic clusters of gold on the surface of SnO2based sensor materials. This kind of catalyst acts either as a preventor of the formation of heavy and complex organic molecules on the sensor surface or as a combustion catalyst, which facilitates their decomposition.

  8. Modulation of Acetone-Butanol-Ethanol Fermentation by Carbon Monoxide and Organic Acids

    PubMed Central

    Datta, Rathin; Zeikus, J. G.

    1985-01-01

    Metabolic modulation of acetone-butanol-ethanol fermentation by Clostridium acetobutylicum with carbon monoxide (CO) and organic acids is described. CO, which is a known inhibitor of hydrogenase, was found to be effective in the concentration range of dissolved CO corresponding to a CO partial pressure of 0.1 to 0.2 atm. Metabolic modulation by CO was particularly effective when organic acids such as acetic and butyric acids were added to the fermentation as electron sinks. The uptake of organic acids was enhanced, and increases in butyric acid uptake by 50 to 200% over control were observed. Hydrogen production could be reduced by 50% and the ratio of solvents could be controlled by CO modulation and organic acid addition. Acetone production could be eliminated if desired. Butanol yield could be increased by 10 to 15%. Total solvent yield could be increased 1 to 3% and the electron efficiency to acetone-butanol-ethanol solvents could be increased from 73 to 78% for controls to 80 to 85% for CO- and organic acid-modulated fermentations. Based on these results, the dynamic nature of electron flow in this fermentation has been elucidated and mechanisms for metabolic control have been hypothesized. PMID:16346746

  9. Inhalation developmental toxicology studies: Teratology study of acetone in mice and rats: Final report

    SciTech Connect

    Mast, T.J.; Evanoff, J.J.; Rommereim, R.L.; Stoney, K.H.; Weigel, R.J.; Westerberg, R.B.

    1988-11-01

    Acetone, an aliphatic ketone, is a ubiquitous industrial solvent and chemical intermediate; consequently, the opportunity for human exposure is high. The potential for acetone to cause developmental toxicity was assessed in Sprague-Dawley rats exposed to 0, 440, 2200, or 11000 ppm, and in Swiss (CD-1) mice exposed to 0, 440, 2200, and 6600 ppm acetone vapors, 6 h/day, 7 days/week. Each of the four treatment groups consisted of 10 virgin females (for comparison), and approx.32 positively mated rats or mice. Positively mated mice were exposed on days 6-17 of gestation (dg), and rats on 6-19 dg. The day of plug or sperm detection was designated as 0 dg. Body weights were obtained throughout the study period, and uterine and fetal body weights were obtained at sacrifice (rats, 20 dg; mice, 18 dg). Implants were enumerated and their status recorded. Live fetuses were sexed and examined for gross, visceral, skeletal, and soft-tissue craniofacial defects. 46 refs., 6 figs., 27 tabs.

  10. Fluorescence quenching of 7-Diethylamino-4-trifluoromethyl Coumarin in presence of acetone

    NASA Astrophysics Data System (ADS)

    Pattanaik, Amitansu; Nanda, Maitreyee; Sahare, P. D.

    2006-12-01

    The development of sensors based on immobilized fluorescent reagent is a matter of growing interest. Chemiluminescence seems to be attractive because light is generated through the chemical reactions. No light source is needed, which makes the experimental set up very simple. In present work, the sensor presented is an optical sensor based on fluorescence quenching. Fluorescence quenching refers to any process, which decreases the fluorescence intensity of a certain fluorophore. Acetone is a commercially used solvent of great importance as it has got wide chemical and biomedical applications. It is on the hazardous substance list as well as on the special health hazard substance list. Hence identification of acetone has an immense importance. Fluorescence quenching of 7-Diethylamino-4-trifluoro methyl Coumarin is reported here. It was found that the quenching observed was of dynamic in nature. It was also observed that quenching of the fluorescence of the indicator had a full reversibility. As it has a full reversibility, an optical sensor for acetone can be constructed on this quenching.

  11. Nesterenkonia sp. strain F, a halophilic bacterium producing acetone, butanol, and ethanol under aerobic conditions.

    PubMed

    Amiri, Hamid; Azarbaijani, Reza; Parsa Yeganeh, Laleh; Shahzadeh Fazeli, Abolhassan; Tabatabaei, Meisam; Salekdeh, Ghasem Hosseini; Karimi, Keikhosro

    2016-01-04

    The moderately halophilic bacterium Nesterenkonia sp. strain F, which was isolated from Aran-Bidgol Lake (Iran), has the ability to produce acetone, butanol, and ethanol (ABE) as well as acetic and butyric acids under aerobic and anaerobic conditions. This result is the first report of ABE production with a wild microorganism from a family other than Clostridia and also the first halophilic species shown to produce butanol under aerobic cultivation. The cultivation of Nesterenkonia sp. strain F under anaerobic conditions with 50 g/l of glucose for 72 h resulted in the production of 105 mg/l of butanol, 122 mg/l of acetone, 0.2 g/l of acetic acid, and 2.5 g/l of butyric acid. Furthermore, the strain was cultivated on media with different glucose concentrations (20, 50, and 80 g/l) under aerobic and anaerobic conditions. Through fermentation with a 50 g/l initial glucose concentration under aerobic conditions, 66 mg/l of butanol, 125 mg/l of acetone, 291 mg/l of ethanol, 5.9 g/l of acetic acid, and 1.2 g/l of butyric acid were produced. The enzymes pertaining to the fermentation pathway in the strain were compared with the enzymes of Clostridium spp., and the metabolic pathway of fermentation used by Nesterenkonia sp. strain F was investigated.

  12. Shock-Tube Measurement of Acetone Dissociation Using Cavity-Enhanced Absorption Spectroscopy of CO.

    PubMed

    Wang, Shengkai; Sun, Kai; Davidson, David F; Jeffries, Jay B; Hanson, Ronald K

    2015-07-16

    A direct measurement for the rate constant of the acetone dissociation reaction (CH3COCH3 = CH3CO + CH3) was conducted behind reflected shock wave, utilizing a sub-ppm sensitivity CO diagnostic achieved by cavity-enhanced absorption spectroscopy (CEAS). The current experiment eliminated the influence from secondary reactions and temperature change by investigating the clean pyrolysis of <20 ppm acetone in argon. For the first time, the acetone dissociation rate constant (k1) was directly measured over 5.5 orders of magnitude with a high degree of accuracy: k1 (1004-1494 K, 1.6 atm) = 4.39 × 10(55) T(-11.394) exp(-52 140K/T) ± 24% s(-1). This result was seen to agree with most previous studies and has bridged the gap between their temperature and pressure conditions. The current work also served as an example demonstration of the potential of using the CEAS technique in shock-tube kinetics studies.

  13. Research into acetone removal from air by biofiltration using a biofilter with straight structure plates

    PubMed Central

    Baltrėnas, Pranas; Zagorskis, Alvydas; Misevičius, Antonas

    2015-01-01

    The biological air treatment method is based on the biological destruction of organic compounds using certain cultures of microorganisms. This method is simple and may be applied in many branches of industry. The main element of biological air treatment devices is a filter charge. Tests were carried out using a new-generation laboratory air purifier with a plate structure. This purifier is called biofilter. The biofilter has a special system for packing material humidification which does not require additional energy inputs. In order to extend the packing material's durability, it was composed of thermally treated birch fibre. Pollutant (acetone) biodegradation occurred on thermally treated wood fibre in this research. According to the performed tests and the received results, the process of biodestruction was highly efficient. When acetone was passed through biofilter's packing material at 0.08 m s−1 rate, the efficiency of the biofiltration process was from 70% up to 90%. The species of bacteria capable of removing acetone vapour from the air, i.e. Bacillus (B. cereus, B. subtilis), Pseudomonas (P. aeruginosa, P. putida), Stapylococcus (S. aureus) and Rhodococcus sp., was identified in this study during the process of biofiltration. Their amount in the biological packing material changed from 1.6 × 107 to 3.7 × 1011 CFU g−1. PMID:26019659

  14. Ion-based materials comprising planar charged species.

    PubMed

    Dong, Bin; Maeda, Hiromitsu

    2013-05-14

    Materials comprising planar units have the propensity to form stacking assemblies with nanoscale architectures and intriguing properties. In this feature article, some recent examples of ion-based materials comprising positively and negatively charged planar species are described. Various ion-based solid and soft materials can be formed by planar charged species alone or with the aid of other components. It is more challenging to prepare planar anions than planar cations; however, the noncovalent association of electronically neutral planar anion receptors and anions is an efficient strategy for the preparation of planar anions. Suitable candidates include dipyrrolyldiketone boron complexes, which exhibit the formation of various receptor-anion complexes and can be used to fabricate advanced materials in combination with countercations. Ion-based materials consisting of planar charged components have potential as electrically conductive materials, resulting from the ordered arrangement of the planar charged species.

  15. Piezo Voltage Controlled Planar Hall Effect Devices

    PubMed Central

    Zhang, Bao; Meng, Kang-Kang; Yang, Mei-Yin; Edmonds, K. W.; Zhang, Hao; Cai, Kai-Ming; Sheng, Yu; Zhang, Nan; Ji, Yang; Zhao, Jian-Hua; Zheng, Hou-Zhi; Wang, Kai-You

    2016-01-01

    The electrical control of the magnetization switching in ferromagnets is highly desired for future spintronic applications. Here we report on hybrid piezoelectric (PZT)/ferromagnetic (Co2FeAl) devices in which the planar Hall voltage in the ferromagnetic layer is tuned solely by piezo voltages. The change of planar Hall voltage is associated with magnetization switching through 90° in the plane under piezo voltages. Room temperature magnetic NOT and NOR gates are demonstrated based on the piezo voltage controlled Co2FeAl planar Hall effect devices without the external magnetic field. Our demonstration may lead to the realization of both information storage and processing using ferromagnetic materials. PMID:27329068

  16. Planar zeros in gauge theories and gravity

    NASA Astrophysics Data System (ADS)

    Jiménez, Diego Medrano; Vera, Agustín Sabio; Vázquez-Mozo, Miguel Á.

    2016-09-01

    Planar zeros are studied in the context of the five-point scattering amplitude for gauge bosons and gravitons. In the case of gauge theories, it is found that planar zeros are determined by an algebraic curve in the projective plane spanned by the three stereographic coordinates labelling the direction of the outgoing momenta. This curve depends on the values of six independent color structures. Considering the gauge group SU( N) with N = 2 , 3 , 5 and fixed color indices, the class of curves obtained gets broader by increasing the rank of the group. For the five-graviton scattering, on the other hand, we show that the amplitude vanishes whenever the process is planar, without imposing further kinematic conditions. A rationale for this result is provided using color-kinematics duality.

  17. The Feynman Identity for Planar Graphs

    NASA Astrophysics Data System (ADS)

    da Costa, G. A. T. F.

    2016-08-01

    The Feynman identity (FI) of a planar graph relates the Euler polynomial of the graph to an infinite product over the equivalence classes of closed nonperiodic signed cycles in the graph. The main objectives of this paper are to compute the number of equivalence classes of nonperiodic cycles of given length and sign in a planar graph and to interpret the data encoded by the FI in the context of free Lie superalgebras. This solves in the case of planar graphs a problem first raised by Sherman and sets the FI as the denominator identity of a free Lie superalgebra generated from a graph. Other results are obtained. For instance, in connection with zeta functions of graphs.

  18. First Discovery of Acetone Extract from Cottonseed Oil Sludge as a Novel Antiviral Agent against Plant Viruses

    PubMed Central

    Zhao, Lei; Feng, Chaohong; Hou, Caiting; Hu, Lingyun; Wang, Qiaochun; Wu, Yunfeng

    2015-01-01

    A novel acetone extract from cottonseed oil sludge was firstly discovered against plant viruses including Tobacco mosaic virus (TMV), Rice stripe virus (RSV) and Southern rice black streaked dwarf virus (SRBSDV). Gossypol and β-sitosterol separated from the acetone extract were tested for their effects on anti-TMV and analysed by nuclear magnetic resonance (NMR) assay. In vivo and field trials in different geographic distributions and different host varieties declared that this extract mixture was more efficient than the commercial agent Ningnanmycin with a broad spectrum of anti-plant-viruses activity. No phytotoxic activity was observed in the treated plants and environmental toxicology showed that this new acetone extract was environmentally friendly, indicating that this acetone extract has potential application in the control of plant virus in the future. PMID:25705894

  19. Targeted mutagenesis of the Clostridium acetobutylicum acetone-butanol-ethanol fermentation pathway.

    PubMed

    Cooksley, Clare M; Zhang, Ying; Wang, Hengzheng; Redl, Stephanie; Winzer, Klaus; Minton, Nigel P

    2012-11-01

    The production of the chemical solvents acetone and butanol by the bacterium Clostridium acetobutylicum was one of the first large-scale industrial processes to be developed, and in the first part of the last century ranked second in importance only to ethanol production. After a steep decline in its industrial use, there has been a recent resurgence of interest in the acetone-butanol-ethanol (ABE) fermentation process, with a particular emphasis on butanol production. In order to generate strains suitable for efficient use on an industrial scale, metabolic engineering is required to alter the AB ratio in favour of butanol, and eradicate the production of unwanted products of fermentation. Using ClosTron technology, a large-scale targeted mutagenesis in C. acetobutylicum ATCC 824 was carried out, generating a set of 10 mutants, defective in alcohol/aldehyde dehydrogenases 1 and 2 (adhE1, adhE2), butanol dehydrogenases A and B (bdhA, bdhB), phosphotransbutyrylase (ptb), acetate kinase (ack), acetoacetate decarboxylase (adc), CoA transferase (ctfA/ctfB), and a previously uncharacterised putative alcohol dehydrogenase (CAP0059). However, inactivation of the main hydrogenase (hydA) and thiolase (thl) could not be achieved. Constructing such a series of mutants is paramount for the acquisition of information on the mechanism of solvent production in this organism, and the subsequent development of industrial solvent producing strains. Unexpectedly, bdhA and bdhB mutants did not affect solvent production, whereas inactivation of the previously uncharacterised gene CAP0059 resulted in increased acetone, butanol, and ethanol formation. Other mutants showed predicted phenotypes, including a lack of acetone formation (adc, ctfA, and ctfB mutants), an inability to take up acids (ctfA and ctfB mutants), and a much reduced acetate formation (ack mutant). The adhE1 mutant in particular produced very little solvents, demonstrating that this gene was indeed the main contributor to

  20. Recirculating planar magnetrons: simulations and experiment

    SciTech Connect

    Franzi, Matthew; Gilgenbach, Ronald; French, David; Lau, Y.Y.; Simon, David; Hoff, Brad; Luginsland, John W.

    2011-07-01

    The Recirculating Planar Magnetron (RPM) is a novel crossed-field device whose geometry is expected to reduce thermal load, enhance current yield as well as ease the geometric limitations in scaling to high RF frequencies as compared to the conventional cylindrical magnetrons. The RPM has two different adaptations: A. Axial B field and radial E field; B. Radial B field and axial E field. The preliminary configuration (A) to be used in experiments at the University of Michigan consists of two parallel planar sections which join on either end by cylindrical regions to form a concentric extruded ellipse. Similar to conventional magnetrons, a voltage across the AK gap in conjunction with an axial magnetic field provides the electrons with an ExB drift. The device is named RPM because the drifting electrons recirculate from one planar region to the other. The drifting electrons interact with the resonantly tuned slow wave structure on the anode causing spoke formation. These electron spokes drive a RF electric field in the cavities from which RF power may be extracted to Waveguides. The RPM may be designed in either a conventional configuration with the anode on the outside, for simplified extraction, or as an inverted magnetron with the anode at the inner conductor, for fast start-up. Currently, experiments at the Pulsed Power and Microwave Laboratory at the University of Michigan are in the setup and design phase. A conventional RPM with planar cavities is to be installed on the Michigan Electron Long Beam Accelerator (MELBA) and is anticipated to operate at -200kV, 0.2T with a beam current of 1-10 kA at 1GHz. The conventional RPM consists of 12 identical planar cavities, 6 on each planar side, with simulated quality factor of 20.

  1. Co-production of acetone and ethanol with molar ratio control enables production of improved gasoline or jet fuel blends.

    PubMed

    Baer, Zachary C; Bormann, Sebastian; Sreekumar, Sanil; Grippo, Adam; Toste, F Dean; Blanch, Harvey W; Clark, Douglas S

    2016-10-01

    The fermentation of simple sugars to ethanol has been the most successful biofuel process to displace fossil fuel consumption worldwide thus far. However, the physical properties of ethanol and automotive components limit its application in most cases to 10-15 vol% blends with conventional gasoline. Fermentative co-production of ethanol and acetone coupled with a catalytic alkylation reaction could enable the production of gasoline blendstocks enriched in higher-chain oxygenates. Here we demonstrate a synthetic pathway for the production of acetone through the mevalonate precursor hydroxymethylglutaryl-CoA. Expression of this pathway in various strains of Escherichia coli resulted in the co-production of acetone and ethanol. Metabolic engineering and control of the environmental conditions for microbial growth resulted in controllable acetone and ethanol production with ethanol:acetone molar ratios ranging from 0.7:1 to 10.0:1. Specifically, use of gluconic acid as a substrate increased production of acetone and balanced the redox state of the system, predictively reducing the molar ethanol:acetone ratio. Increases in ethanol production and the molar ethanol:acetone ratio were achieved by co-expression of the aldehyde/alcohol dehydrogenase (AdhE) from E. coli MG1655 and by co-expression of pyruvate decarboxylase (Pdc) and alcohol dehydrogenase (AdhB) from Z. mobilis. Controlling the fermentation aeration rate and pH in a bioreactor raised the acetone titer to 5.1 g L(-1) , similar to that obtained with wild-type Clostridium acetobutylicum. Optimizing the metabolic pathway, the selection of host strain, and the physiological conditions employed for host growth together improved acetone titers over 35-fold (0.14-5.1 g/L). Finally, chemical catalysis was used to upgrade the co-produced ethanol and acetone at both low and high molar ratios to higher-chain oxygenates for gasoline and jet fuel applications. Biotechnol. Bioeng. 2016;113: 2079-2087. © 2016 Wiley

  2. Optical Planar Discrete Fourier and Wavelet Transforms

    NASA Astrophysics Data System (ADS)

    Cincotti, Gabriella; Moreolo, Michela Svaluto; Neri, Alessandro

    2007-10-01

    We present all-optical architectures to perform discrete wavelet transform (DWT), wavelet packet (WP) decomposition and discrete Fourier transform (DFT) using planar lightwave circuits (PLC) technology. Any compact-support wavelet filter can be implemented as an optical planar two-port lattice-form device, and different subband filtering schemes are possible to denoise, or multiplex optical signals. We consider both parallel and serial input cases. We design a multiport decoder/decoder that is able to generate/process optical codes simultaneously and a flexible logarithmic wavelength multiplexer, with flat top profile and reduced crosstalk.

  3. Planar Inlet Design and Analysis Process (PINDAP)

    NASA Technical Reports Server (NTRS)

    Slater, John W.; Gruber, Christopher R.

    2005-01-01

    The Planar Inlet Design and Analysis Process (PINDAP) is a collection of software tools that allow the efficient aerodynamic design and analysis of planar (two-dimensional and axisymmetric) inlets. The aerodynamic analysis is performed using the Wind-US computational fluid dynamics (CFD) program. A major element in PINDAP is a Fortran 90 code named PINDAP that can establish the parametric design of the inlet and efficiently model the geometry and generate the grid for CFD analysis with design changes to those parameters. The use of PINDAP is demonstrated for subsonic, supersonic, and hypersonic inlets.

  4. Low temperature acetone detection by p-type nano-titania thin film: Equivalent circuit model and sensing mechanism

    NASA Astrophysics Data System (ADS)

    Bhowmik, B.; Dutta, K.; Hazra, A.; Bhattacharyya, P.

    2014-09-01

    Undoped nanocrystalline anatase p-type TiO2 thin film was deposited by sol-gel method on thermally oxidized p-Si (2-5 Ω cm, <1 0 0>) substrates. The thin film was characterized by X-ray Diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM) to confirm the formation of nanocrystalline anatase titania and to determine the crystallite size (∼7 nm). The resistive sensor structure was fabricated employing two lateral Pd electrodes on top of the TiO2 sensing layer. The developed sensor was tested in the temperature range of 50-200 °C for the detection of low ppm acetone (0.5-50 ppm). The maximum response of ∼115% was obtained at 150 °C with response/recovery time of 14 s/22 s at 50 ppm acetone (in air). Moreover, the sensors were capable of detecting acetone as low as 0.5 ppm with acceptable response magnitude. As titania acetone sensors are mostly n-TiO2 based, the acetone sensing mechanism for p-TiO2 is yet to be established authentically. To address the issue, an equivalent circuit model, based on the corresponding band diagram of nanocrystalline p-TiO2 with Pd electrode, was developed to describe the electron transfer mechanism through grain, grain boundary and Pd electrode under the influence of acetone vapor.

  5. Assessment of acetone as an alternative to acetonitrile in peptide analysis by liquid chromatography/mass spectrometry.

    PubMed

    Fritz, Ria; Ruth, Wolfgang; Kragl, Udo

    2009-07-01

    Acetonitrile as a solvent used in liquid chromatography/mass spectrometry (LC/MS) of peptides and proteins is a relatively toxic solvent (LD50 oral; rat; 2,460 mg/kg) compared to alternatives like methanol (LD50 oral; rat; 5,628 mg/kg) and acetone (LD50 oral; rat; 5,800 mg/kg). Strategies to minimize its consumption in LC are either to reduce the inner diameter of the column or replace acetonitrile with a suitable alternative. Methanol is often recommended to replace acetonitrile in peptide analysis. In this study however, the main focus lies on another alternative solvent for LC/MS of peptides; acetone. A number of model proteins were tryptically digested and the peptide solutions were analyzed on a linear trap quadrupole (LTQ) mass spectrometer. The performances of acetonitrile, methanol and acetone were compared according to the quality of the chromatograms obtained and identification of the peptides using the BioWorks software developed by Thermo Scientific. In accordance to the elutropic series, acetone was found to significantly reduce the retention times of peptides separated by C18 column material with regard to acetonitrile while methanol led to increased retention times. Acetone was the superior solvent to methanol for most of the tested model proteins reaching similar sequence coverage and numbers of identified peptides as acetonitrile. We therefore propose acetone as an alternative to acetonitrile in LC/MS of peptides.

  6. Selective Concentration of Ultra-trace Acetone in the Air by Cryogenic Temperature Programmed Desorption (cryo-TPD).

    PubMed

    Suzuki, Taku T; Sakaguchi, Isao

    2016-01-01

    A gas analytical technique with compact size, low cost, sufficient sensitivity, and excellent reproducibility is required in many fields including exhaled breath analysis for medical monitoring. In the present study, we examined selective acetone concentration by quench condensation at cryogenic temperature followed by temperature programmed desorption (cryogenic temperature programmed desorption (cryo-TPD)) for possible applications to breath analysis for medical monitoring. The essence of cryo-TPD is rough mass selection by thermal desorption followed by quantification of certain species using mass spectrometry. The performance of cryo-TPD was investigated in the acetone concentration range below 1 × 10(-6) volume fraction (1 ppmv). It was found that acetone is selectively quench-condensed on a tungsten substrate at 50 K without the major components of air, such as N2 and O2. The concentrated acetone gas was obtained by the following thermal desorption at around 151 K. Under conditions of condensation for 1 min and pressure of 1 × 10(-2) Pa, the lowest limit of detection reached well below 10 × 10(-9) volume fraction (10 ppbv). The relationship between the cetone intensity of cryo-TPD and the acetone concentration in the gas was almost linear in the ppbv range. The separation of acetone and propanal using the fragmentation pattern, which have almost the identical molecular mass, was also demonstrated in the present study.

  7. Acetone poisoning

    MedlinePlus

    ... in: Nail polish remover Some cleaning solutions Some glues, including rubber cement Some lacquers Other products may ... condition The name of the product (ingredients and strength, if known) The time it was swallowed The ...

  8. Modular package for cooling a laser diode array

    DOEpatents

    Mundinger, David C.; Benett, William J.; Beach, Raymond J.

    1992-01-01

    A laser diode array is disclosed that includes a plurality of planar packages and active cooling. The laser diode array may be operated in a long duty cycle, or in continuous operation. A laser diode bar and a microchannel heat sink are thermally coupled in a compact, thin planar package having the laser diode bar located proximate to one edge. In an array, a number of such thin planar packages are secured together in a stacked configuration, in close proximity so that the laser diodes are spaced closely. The cooling means includes a microchannel heat sink that is attached proximate to the laser bar so that it absorbs heat generated by laser operation. To provide the coolant to the microchannels, each thin planar package comprises a thin inlet manifold and a thin outlet manifold connected to an inlet corridor and an outlet corridor. The inlet corridor comprises a hole extending through each of the packages in the array, and the outlet corridor comprises a hole extending through each of the packages in the array. The inlet and outlet corridors are connected to a conventional coolant circulation system. The laser diode array with active cooling has application as an optical pump for high power solid state lasers. Further, it can be incorporated in equipment such as communications devices and active sensors, and in military and space applications, and it can be useful in applications having space constraints and energy limitations.

  9. Room-temperature near-infrared high-Q perovskite whispering-gallery planar nanolasers.

    PubMed

    Zhang, Qing; Ha, Son Tung; Liu, Xinfeng; Sum, Tze Chien; Xiong, Qihua

    2014-10-08

    Near-infrared (NIR) solid-state micro/nanolasers are important building blocks for true integration of optoelectronic circuitry. Although significant progress has been made in III-V nanowire lasers with achieving NIR lasing at room temperature, challenges remain including low quantum efficiencies and high Auger losses. Importantly, the obstacles toward integrating one-dimensional nanowires on the planar ubiquitous Si platform need to be effectively tackled. Here we demonstrate a new family of planar room-temperature NIR nanolasers based on organic-inorganic perovskite CH3NH3PbI(3-a)X(a) (X = I, Br, Cl) nanoplatelets. Their large exciton binding energies, long diffusion lengths, and naturally formed high-quality planar whispering-gallery mode cavities ensure adequate gain and efficient optical feedback for low-threshold optically pumped in-plane lasing. We show that these remarkable wavelength tunable whispering-gallery nanolasers can be easily integrated onto conductive platforms (Si, Au, indium tin oxide, and so forth). Our findings open up a new class of wavelength tunable planar nanomaterials potentially suitable for on-chip integration.

  10. COMPUTER ANALYSIS OF PLANAR GAMMA CAMERA IMAGES

    EPA Science Inventory



    COMPUTER ANALYSIS OF PLANAR GAMMA CAMERA IMAGES

    T Martonen1 and J Schroeter2

    1Experimental Toxicology Division, National Health and Environmental Effects Research Laboratory, U.S. EPA, Research Triangle Park, NC 27711 USA and 2Curriculum in Toxicology, Unive...

  11. Helical axis stellarator with noninterlocking planar coils

    DOEpatents

    Reiman, A.; Boozer, A.H.

    1984-03-06

    The present invention generates stellarator fields having favorable properties (magnetic well and large rotational transform) by a simple coil system consisting only of unlinked planar non-circular coils. At large rotational transform toroidal effects on magnetic well and rotational transform are small and can be ignored. We do so herein, specializing in straight helical systems.

  12. Planar tetracoordinate carbons in cyclic hydrocarbons.

    PubMed

    Perez, Nancy; Heine, Thomas; Barthel, Robert; Seifert, Gotthard; Vela, Alberto; Mendez-Rojas, Miguel Angel; Merino, Gabriel

    2005-04-14

    [structure: see text] A series of cyclic hydrocarbons containing a planar tetracoordinate carbon atom is proposed. To rationalize the electronic factors contributing to the stability of these molecules, an analysis of the molecular orbitals and the induced magnetic field is presented.

  13. Planar antenna system for direction finding

    NASA Astrophysics Data System (ADS)

    Mardale, Iulia-Cezara; Cocias, Gabriela; Dumitrascu, Ana; Tamas, Razvan; Berescu, Serban

    2015-02-01

    Applications of direction finding techniques include detection and localization of pulsed electromagnetic sources. This paper presents the design and analysis of a planar antenna system for direction finding. Our proposed system includes 4 hybrid couplers that generate 900 shifted signals, 2 crossover couplers also known as 0dB couplers, two 450 phase shifters, two 00 phase shifters and 4 patch antennas.

  14. Model for designing planar magnetron cathodes

    SciTech Connect

    Garcia, M.

    1997-09-30

    This report outlines an analytical model of the distribution of plasma in the cathode fall of a planar magnetron cathode. Here I continue commentary on previous work, and introduce an ion sheath model to describe the discharge dark space below the magnetron halo.

  15. Piecewise-Planar Parabolic Reflectarray Antenna

    NASA Technical Reports Server (NTRS)

    Hodges, Richard; Zawadzki, Mark

    2009-01-01

    The figure shows a dual-beam, dualpolarization Ku-band antenna, the reflector of which comprises an assembly of small reflectarrays arranged in a piecewise- planar approximation of a parabolic reflector surface. The specific antenna design is intended to satisfy requirements for a wide-swath spaceborne radar altimeter, but the general principle of piecewise-planar reflectarray approximation of a parabolic reflector also offers advantages for other applications in which there are requirements for wideswath antennas that can be stowed compactly and that perform equally in both horizontal and vertical polarizations. The main advantages of using flat (e.g., reflectarray) antenna surfaces instead of paraboloidal or parabolic surfaces is that the flat ones can be fabricated at lower cost and can be stowed and deployed more easily. Heretofore, reflectarray antennas have typically been designed to reside on single planar surfaces and to emulate the focusing properties of, variously, paraboloidal (dish) or parabolic antennas. In the present case, one approximates the nominal parabolic shape by concatenating several flat pieces, while still exploiting the principles of the planar reflectarray for each piece. Prior to the conception of the present design, the use of a single large reflectarray was considered, but then abandoned when it was found that the directional and gain properties of the antenna would be noticeably different for the horizontal and vertical polarizations.

  16. "Finite part" electric and magnetic stored energies for planar antennas

    NASA Technical Reports Server (NTRS)

    Cockrell, C. R.

    1981-01-01

    A pair of formulas representing the time-average "finite part" electric and magnetic stored energies for planar antennas are derived. It is also shown that the asymptotic reciprocal relationship between quality factor and relative bandwidth exists for planar antennas.

  17. Four Decades of the Chemistry of Planar Hypercoordinate Compounds.

    PubMed

    Yang, Li-Ming; Ganz, Eric; Chen, Zhongfang; Wang, Zhi-Xiang; Schleyer, Paul von Ragué

    2015-08-10

    The idea of planar tetracoordinate carbon (ptC) was considered implausible for a hundred years after 1874. Examples of ptC were then predicted computationally and realized experimentally. Both electronic and mechanical (e.g., small rings and cages) effects stabilize these unusual bonding arrangements. Concepts based on the bonding motifs of planar methane and the planar methane dication can be extended to give planar hypercoordinate structures of other chemical elements. Numerous planar configurations of various central atoms (main-group and transition-metal elements) with coordination numbers up to ten are discussed herein. The evolution of such planar configurations from small molecules to clusters, to nanospecies and to bulk solids is delineated. Some experimentally fabricated planar materials have been shown to possess unusual electrical and magnetic properties. A fundamental understanding of planar hypercoordinate chemistry and its potential will help guide its future development.

  18. Effect of zinc supplementation on acetone-butanol-ethanol fermentation by Clostridium acetobutylicum.

    PubMed

    Wu, You-Duo; Xue, Chuang; Chen, Li-Jie; Bai, Feng-Wu

    2013-05-10

    In this article, effect of zinc supplementation on acetone-butanol-ethanol (ABE) fermentation by Clostridium acetobutylicum was studied. It was found that when 0.001 g/L ZnSO4·7H2O was supplemented into the medium, solventogenesis was initiated earlier, with 21.0 g/L ABE (12.6 g/L butanol, 6.7 g/L acetone and 1.7 g/L ethanol) produced with a fermentation time of 40 h, compared to 19.4 g/L ABE (11.7 g/L butanol, 6.4 g/L acetone and 1.3g/L ethanol) produced with a fermentation time of 64 h in the control without zinc supplementation, and correspondingly ABE and butanol productivities were increased to 0.53 and 0.32 g/L/h from 0.30 and 0.18 g/L/h, increases of 76.7% and 77.8%, respectively, but their yields were not compromised. The reason for this phenomenon was attributed to rapid acids re-assimilation for more efficient ABE production, which was in accordance with relatively high pH and ORP levels maintained during the fermentation process. The maximum cell density increased by 23.8%, indicating that zinc supplementation stimulated cell growth, and consequently facilitated glucose utilization. However, more zinc supplementation exhibited an inhibitory effect, indicating that zinc supplementation at very low levels such as 0.001 g/L ZnSO4·7H2O will be an economically competitive strategy for improving butanol production.

  19. Global transcriptional changes of Clostridium acetobutylicum cultures with increased butanol:acetone ratios.

    PubMed

    Hönicke, Daniel; Janssen, Holger; Grimmler, Christina; Ehrenreich, Armin; Lütke-Eversloh, Tina

    2012-05-15

    Artificial electron carriers have been widely used to shift the solvent ratio toward butanol in acetone-butanol-ethanol (ABE) fermentation of solventogenic clostridia according to decreased hydrogen production. In this study, first insights on the molecular level were gained to explore the effect of methyl viologen addition to cultures of Clostridium acetobutylicum. Employing batch fermentation in mineral salts medium, the butanol:acetone ratio was successively increased from 2.3 to 12.4 on a 100-ml scale in serum bottles and from 1.4 to 16.5 on a 1300-ml scale in bioreactors, respectively. The latter cultures were used for DNA microarray analyses to provide new information on the transcriptional changes referring to methyl viologen exposure and thus, exhibit gene expression patterns according to the manipulation of the cellular redox balance. Methyl viologen-exposed cultures revealed lower expression levels of the sol operon (CAP0162-0164) and the adjacent adc gene (CAP0165) responsible for solvent formation as well as iron and sulfate transporters and the CAC0105-encoded ferredoxin. On the contrary, genes for riboflavin biosynthesis, for the butyrate/butanol metabolic pathway and genes coding for sugar transport systems were induced. Interestingly, the adhE2-encoded bifunctional NADH-dependent aldhehyde/alcohol-dehydrogenase (CAP0035) was upregulated up to more than 100-fold expression levels as compared to the control culture without methyl viologen addition. The data presented here indicate a transcriptional regulation for decreased acetone biosynthesis and the redox-dependent substitution of adhE1 (CAP0162) by adhE2.

  20. Laser synthesis and modification of composite nanoparticles in liquids

    SciTech Connect

    Tarasenko, N V; Butsen, A V

    2010-12-29

    The works devoted to the formation and modification of nanoparticles using laser ablation of solid targets in liquids are reviewed. Several approaches to implement laser ablation in liquids, aimed at synthesising nanoparticles of complex composition, are considered: direct laser ablation of a target of corresponding composition, laser ablation of a combined target composed of two different metals, laser irradiation of a mixture of two or more colloidal solutions, and laser ablation in reactive liquids. The properties of two-component bimetallic systems (Ag - Cu, Ag - Au), semiconductor nanocrystals (ZnO, CdSe), chalcopyrite nanoparticles, and doped oxide nanoparticles (ZnO:Ag, Gd{sub 2}O{sub 2}:Tb{sup 3+}) formed as a result of single- and double-pulse laser ablation in different liquids (water, ethanol, acetone, solutions of polysaccharides) are discussed. (photonics and nanotechnology)

  1. Infrared microscopy for the study of biological cell monolayers. I. Spectral effects of acetone and formalin fixation.

    PubMed

    Hastings, Gary; Wang, Ruili; Krug, Peter; Katz, David; Hilliard, Julia

    2008-11-01

    Infrared spectroscopy of biological cell monolayers grown on surfaces is a poorly developed field. This is unfortunate because these monolayers have potential as biological sensors. Here we have used infrared microscopy, in both transmission and transflection geometries, to study air-dried Vero cell monolayers. Using both methods allows one to distinguish sampling artefactual features from real sample spectral features. In transflection experiments, amide I/II absorption bands down-shift 9/4 cm(-1), respectively, relative to the corresponding bands in transmission experiments. In all other spectral regions no pronounced frequency differences in spectral bands in transmission and transflection experiments were observed. Transmission and transflection infrared microscopy were used to obtain infrared spectra for unfixed and acetone- or formalin-fixed Vero cell monolayers. Formalin-fixed monolayers display spectra that are very similar to that obtained using unfixed cells. However, acetone fixation leads to considerable spectral modifications. For unfixed and formalin-fixed monolayers, a distinct band is observed at 1740 cm(-1). This band is absent in spectra obtained using acetone-fixed monolayers. The 1740 cm(-1) band is associated with cellular ester lipids. In support of this hypothesis, two bands at 2925 and 2854 cm(-1) are also found to disappear upon acetone fixation. These bands are associated with C-H modes of the cellular lipids. Acetone fixation also leads to modification of protein amide I and II absorption bands. This may be expected as acetone causes coagulation of soluble cellular proteins. Other spectral changes associated with acetone or formalin fixation in the 1400-800 cm(-1) region are discussed.

  2. Sensitive gas chromatographic detection of acetaldehyde and acetone using a reduction gas detector

    NASA Technical Reports Server (NTRS)

    O'Hara, Dean; Singh, Hanwant B.

    1988-01-01

    The response of a newly available mercuric oxide Reduction Gas Detector (RGD-2) to subpicomole and larger quantities of acetaldehyde and acetone is tested. The RGD-2 is found to be capable of subpicomole detection for these carbonyls and is more sensitive than an FID (Flame Ionization Detector) by an order of magnitude. Operating parameters can be further optimized to make the RGD-2 some 20-40 times more sensitive than an FID. The detector is linear over a wide range and is easily adapted to a conventional gas chromatograph (GC). Such a GC-RGD-2 system should be suitable for atmospheric carbonyl measurements in clean as well as polluted environments.

  3. Density Functional Studies on the Complexation and Spectroscopy of Uranyl Ligated with Acetonitrile and Acetone Derivatives

    SciTech Connect

    Schoendorff, George E.; Windus, Theresa L.; De Jong, Wibe A.

    2009-12-12

    The coordination of nitrile (acetonitrile, propionitrile, and benzonitrile) and carbonyl (formaldehyde, ethanal, and acetone) ligands to the uranyl dication (UO22+) has been examined using density functional theory (DFT) utilizing relativistic effective core potentials (RECPs). Complexes containing up to six ligands have been modeled for all ligands except formaldehyde, for which no minimum could be found. A comparison of relative binding energies indicates that five coordinate complexes are predominant while a six coordinate complex involving propionitrile ligands might be possible. Additionally, the relative binding energy and the weakening of the uranyl bond is related to the size of the ligand and, in general, nitriles bind more strongly to uranyl than carbonyls.

  4. Pervaporation of model acetone-butanol-ethanol fermentation product solutions using polytetrafluoroethylene membranes

    SciTech Connect

    Vrana, D.L.; Meagher, M.M.; Hutkins, R.W.; Duffield, B. )

    1993-10-01

    A pervaporation apparatus was designed and tested in an effort to develop an integrated fermentation and product recovery process for acetone-butanol-ethanol(ABE) fermentation. A crossflow membrane module able to accommodate flat sheet hydrophobic membranes was used for the experiments. Permeate vapors were collected under vacuum and condensed in a dry ice/ethanol cold trap. The apparatus containing polytetrafluoroethylene membranes was tested using butanol-water and model solutions of ABE products. Parameters such as product concentration, component effect, temperature, and permeate side pressure were examined. 25 refs., 3 figs., 5 tabs.

  5. Marking planes of surgical excision on breast biopsy specimens: use of artists' pigments suspended in acetone.

    PubMed Central

    Paterson, D A; Davies, J D

    1988-01-01

    The performance of carbon and metallic inks, silver nitrate solution, and artists' pigments mounted in acetone was compared for marking the surface of surgical biopsy specimens. Using India ink is an unsatisfactory procedure because of slow drying, messiness, and spreading of the ink. It is concluded that use of artists' pigments has many advantages over other reagents, because of their rapid drying, resistance to tissue processing, and the ability to mark simultaneously many different planes of excision. Furthermore, the pigments are readily visible, are distinguishable from each other on microscopical examination, and the method entails little extra cost. Images Fig 1 Fig 2 PMID:3056982

  6. Experimental localization ability of planar gradiometer systems for biomagnetic measurements

    SciTech Connect

    Bruno, A.C.; Pizzella, V.; Torrioli, G.; Romani, G.L.

    1989-03-01

    The localization ability of SQUID planar gradiometers for biomagnetic applications has been investigated. A linear planar gradiometer of superconducting wire was constructed and tested. Localization tests were performed both on a current dipole model and on human subjects. The accuracy of localization results were not significantly affected by the use of the planar configuration.

  7. Fiber Laser Development for LISA

    NASA Technical Reports Server (NTRS)

    Numata, Kenji; Chen, Jeffrey R.

    2009-01-01

    We have developed a linearly-polarized Ytterbium-doped fiber ring laser with single longitudinal-mode output at 1064nm for LISA and other space applications. Single longitudinal-mode selection was achieved by using a fiber Bragg grating (FBG) and a fiber Fabry-Perot (FFP). The FFP also serves as a frequency-reference within our ring laser. Our laser exhibits comparable low frequency and intensity noise to Non-Planar Ring Oscillator (NPRO). By using a fiber-coupled phase modulator as a frequency actuator, the laser frequency can be electro-optically tuned at a rate of 100kHz. It appears that our fiber ring laser is promising for space applications where robustness of fiber optics is desirable.

  8. Generation of planar blast waves using carbon nanotubes-poly-dimethylsiloxane optoacoustic transducer

    NASA Astrophysics Data System (ADS)

    Moon, C.; Fan, X.; Ha, K.; Kim, D.

    2017-01-01

    We have generated planar blast waves over the large area using carbon nanotubes(CNT)-poly-dimethylsiloxane(PDMS) optoacoustic transducer. Pulse laser is absorbed by CNT and converted to heat, and the heat is transferred to PDMS inducing its thermal expansion and blast wave generation. To theoretically describe the planar blast wave generation, we build one-dimensional simulation model and find analytical solutions for temperature and pressure distributions. The analytical solution validated by the experimental data sheds light on how to improve the performance of the new transducer. Resonance of acoustic waves inside the transducer is also discussed. The new optoacoustic transducer optimized based on the fundamental understandings will be useful in generating high quality blast waves for research and industrial applications.

  9. CCCCC pentadentate chelates with planar Möbius aromaticity and unique properties

    PubMed Central

    Zhu, Congqing; Yang, Caixia; Wang, Yongheng; Lin, Gan; Yang, Yuhui; Wang, Xiaoyong; Zhu, Jun; Chen, Xiaoyuan; Lu, Xin; Liu, Gang; Xia, Haiping

    2016-01-01

    The coordinating atoms in polydentate chelates are primarily heteroatoms. We present the first examples of pentadentate chelates with all binding atoms of the chelating agent being carbon atoms, denoted as CCCCC chelates. Having up to five metal-carbon bonds in the equatorial plane has not been previously observed in transition metal chemistry. Density functional theory calculations showed that the planar metallacycle has extended Craig-Möbius aromaticity arising from 12-center–12-electron dπ-pπ π-conjugation. These planar chelates have broad absorption in the ultraviolet-visible–near-infrared region and, thus, notable photothermal performance upon irradiation by an 808-nm laser, indicating that these chelates have potential applications in photothermal therapy. The combination of facile synthesis, high stability, and broad absorption of these complexes could make the polydentate carbon chain a novel building block in coordination chemistry. PMID:27574707

  10. Circular polarization with crossed-planar undulators in high gain FELs.

    SciTech Connect

    Kim, K.-J.

    1999-08-31

    We propose a crossed undulator configuration for a high-gain free-electron laser to allow versatile polarization control. This configuration consists of a long (saturation length) planar undulator, a dispersive section, and a short (a few gain lengths) planar undulator oriented perpendicular to the first one. In the first undulator, a radiation component linearly polarized in the x-direction is amplified to saturation. In the second undulator, the x-polarized component propagates freely, while a new component, polarized in the y-direction, is generated and reaches saturation in a few gain lengths. By adjusting the strength of the dispersive section, the relative phase of two radiation components can be adjusted to obtain a suitable polarization for the total radiation field, including the circular polarization. The operating principle of the high-gain crossed undulator, which is quite different from that of the crossed undulator for spontaneous radiation, is illustrated in terms of 1-D FEL theory.

  11. Fabrication of Mesoscale Energy Storage Systems by Laser Direct-Write

    DTIC Science & Technology

    2003-04-01

    delivered by batteries, while high power is supplied by ultracapacitors, and solar cells could be used to harvest energy and recharge the...same interdigitated planar cell at a discharge current of 25 pA. The data shows that the planar alkaline microbattery made by laser direct-write has...temperature and atmospheric conditions, resulting in films with the desired morphological and electrochemical properties. Planar and stacked cell

  12. Ion-exchanged glass waveguide amplifiers and lasers

    NASA Astrophysics Data System (ADS)

    Kevorkian, Antoine P.

    1998-04-01

    Planar devices made by ion-exchange provide efficient active or active/passive functions. Compact amplifiers with 24 dB single pass gain for a single 980 nm laser diode pumping are presented, as well as 1535 nm lasers with 27% slope efficiency.

  13. Vortical and turbulent structure of planar and lobed mixer free-shear layers

    NASA Astrophysics Data System (ADS)

    McCormick, Duane Clark

    A comprehensive experimental investigation of the free-shear layer vortical and turbulent structure downstream of a lobed mixer has been conducted. Pulsed-laser flow visualization with smoke and three-dimensional velocity measurements with triple-sensor hot film anemometry were obtained for two lobed mixer configurations (symmetric and unsymmetric waveforms) and a baseline, planar configuration. Both laminar and turbulent initial boundary layer conditions were documented for each of the three configurations. The main result of this investigation is that a new vortex structure was found to exist for the lobed mixers in addition to the well-known streamwise vortex array. The normal vortex (due to the Kelvin-Helmholtz instability) sheds periodically from the convoluted trailing edge of the lobed mixer and plays a major part in the enhanced mixing process in combination with the streamwise vorticity. The streamwise vorticity deforms the normal vortex into a pinched-off structure that creates intense turbulence and mixing. The scale of the normal vortex was approximately one fourth that of the planar case, thereby introducing a small-scale turbulence over a large cross-stream area of the flow that dominates the near-field Reynolds shear stress distribution. Thus, the lobed mixer free-shear layer provides enhanced mixing down to the molecular scale. The shear layer growth rate for the first 5-6 lobe heights was substantially greater than the planar free-shear layer due to the normal and streamwise vortex interaction. Downstream of six lobe heights, the growth rate slowed considerably to a rate below that of the planar configuration due to the reduced turbulent kinetic energy of a double-layered shear layer structure. The streamwise and normal vorticity were completely dissipated by 5-6 lobe heights. Also, the lobe mixer development was found to be surprisingly insensitive to initial laminar and turbulent boundary layer conditions (unlike the planar case).

  14. Vortical and Turbulent Structure of Planar and Lobed Mixer Free-Shear Layers

    NASA Astrophysics Data System (ADS)

    McCormick, Duane Clark

    A comprehensive experimental investigation of the free-shear layer vortical and turbulent structure downstream of a lobed mixer has been conducted. Pulsed-laser flow visualization with smoke and three-dimensional velocity measurements with triple-sensor hot film anemometry were obtained for two lobed mixer configurations (symmetric and unsymmetric waveforms) and a baseline, planar configuration. Both laminar and turbulent initial boundary layer conditions were documented for each of the three configurations. The main result of this investigation is that a new vortex structure was found to exist for the lobed mixers in addition to the well-known streamwise vortex array. The normal vortex (due to the Kelvin-Helmholtz instability) sheds periodically from the convoluted trailing edge of the lobed mixer and plays a major part in the enhanced mixing process in combination with the streamwise vorticity. The streamwise vorticity deforms the normal vortex into a pinched -off structure that creates intense turbulence and mixing. The scale of the normal vortex was approximately one fourth that of the planar case, thereby introducing a small-scale turbulence over a large cross-stream area of the flow that dominates the near-field Reynolds shear stress distribution. Thus, the lobed mixer free-shear layer provides enhanced mixing down to the molecular scale. The shear layer growth rate for the first 5-6 lobe heights was substantially greater than the planar free-shear layer due to the normal and streamwise vortex interaction. Downstream of six lobe heights, the growth rate slowed considerably to a rate below that of the planar configuration due to the reduced turbulent kinetic energy of a double-layered shear layer structure. The streamwise and normal vorticity were completely dissipated by 5-6 lobe heights. Also, the lobed mixer development was found to be surprisingly insensitive to initial laminar and turbulent boundary layer conditions (unlike the planar case).

  15. Evaluation of the Acetone and Aqueous Extracts of Mature Stem Bark of Sclerocarya birrea for Antioxidant and Antimicrobial Properties

    PubMed Central

    Tanih, Nicoline F.; Ndip, Roland N.

    2012-01-01

    We assayed the antimicrobial activity of acetone and aqueous extracts of the stem bark of Sclerocarya birrea on some selected bacteria and fungi species including; Streptococcus pyogenes, Plesiomonas shigelloides, Aeromonas hydrophila, Salmonella typhimurium, Cryptococcus neoformans, Candida glabrata, Trichosporon mucoides, and Candida krusei using both agar well diffusion and minimum inhibitory concentration (MIC) assays. Based on the levels of activity, the acetone extract was examined for total polyphenolic content, radical scavenging and antioxidant activities. Total phenols of the extract were determined spectrophotometrically. The antioxidant activity was determined by the DPPH, ABTS and reducing power. All the bacteria and fungi species were susceptible to the plant extracts. The acetone extract was the most active for the bacterial species with MIC (0.156–0.625 mg/mL) while the aqueous extract was the most active for the fungi species with MIC (0.3125–1.25 mg/mL). The polyphenolic compounds were found as 27.2 mg/g tannic acid equivalent, 25.2 mg/g quercetin equivalent, 9.1 mg/g quercetin equivalent for phenols, flavonoid and flavonols respectively. The acetone extract exhibited a remarkable ability to scavenge radicals, strong reducing ability and a potential source of natural antioxidants. Both the acetone and aqueous extracts of S. birrea may provide a target for drug discovery. PMID:22675390

  16. Fate of acetone in an outdoor model stream with a nitrate supplement, southern Mississippi, U.S.A.

    USGS Publications Warehouse

    Rathbun, R.E.; Stephens, D.W.; Tai, D.Y.

    1991-01-01

    The fate of acetone in an outdoor model stream to which nitrate was added as a nutrient supplement was determined. The stream, in southern Mississippi, U.S.A. was 234 m long. Water was supplied to the stream by an artesian well at about 1.21 s-1, resulting in a mean water velocity of about 0.5 m min-1. Acetone was injected continuously for 26 days resulting in concentrations of 20-40 mg l-1. A nitrate solution was injected for 21 days resulting in an instream concentration of about 1.7 mg l-1 at the upstream end of the stream. Rhodamine-WT dye was used to determine the travel time and dispersion characteristics of the stream, and t-butyl alcohol was used to determine the volatilization characteristics. Volatilization controlled the fate of acetone in the model stream. The lack of substantial bacterial degradation of acetone was contrary to expectations based on the results of laboratory degradation studies using model stream water enriched with nitrate. A possible explanation for the lack of significant degradation in the model stream may be the limited 6-h residence time of the acetone in the stream. ?? 1991.

  17. An acetone breath analyzer using cavity ringdown spectroscopy: an initial test with human subjects under various situations

    NASA Astrophysics Data System (ADS)

    Wang, Chuji; Surampudi, Anand B.

    2008-10-01

    We have developed a portable breath acetone analyzer using cavity ringdown spectroscopy (CRDS). The instrument was initially tested by measuring the absorbance of breath gases at a single wavelength (266 nm) from 32 human subjects under various conditions. A background subtraction method, implemented to obtain absorbance differences, from which an upper limit of breath acetone concentration was obtained, is described. The upper limits of breath acetone concentration in the four Type 1 diabetes (T1D) subjects, tested after a 14 h overnight fast, range from 0.80 to 3.97 parts per million by volume (ppmv), higher than the mean acetone concentration (0.49 ppmv) in non-diabetic healthy breath reported in the literature. The preliminary results show that the instrument can tell distinctive differences between the breath from individuals who are healthy and those with T1D. On-line monitoring of breath gases in healthy people post-exercise, post-meals and post-alcohol-consumption was also conducted. This exploratory study demonstrates the first CRDS-based acetone breath analyzer and its potential application for point-of-care, non-invasive, diabetic monitoring.

  18. Enzymology of acetone-butanol-isopropanol formation. Progress report, January 1, 1991--December 31, 1991

    SciTech Connect

    Chen, Jiann-Shin

    1992-01-01

    The long-term goal of the project is to understand the fundamental properties of biological solvent production. Our approach is to elucidate first the molecular properties of solvent-producing enzymes and then to apply to information gained from the enzymological study to investigate control mechanisms for the solvent-producing pathways and the expression of solvent-production genes. Our research primarily involves two strains of Clostridium beijerinckii: C. Beijerinckii NRRL B593 which produces isopropanol in addition to acetone, butanol, and ethanol, and C. beijerinckii NRRL B592 which produces acetone, butanol and ethanol, but not isopropanol. In more recent studies, we also included another solvent-producing organism, Bacillus macerans. Objectives for the reporting period were: to characterize the distinct types of alcohol dehydrogenase; to purify and characterize acetoacetyl-CoA-reacting enzymes; and to clone and sequence the gene encoding the primary/secondary alcohol dehydrogenase of C beijerinckii NRRL B593 and to search for the promoter region for solvent-production genes.

  19. RABA (Reductive Alkylation By Acetone): A novel stable isotope labeling approach for quantitative proteomics

    PubMed Central

    Zhai, Jianjun; Liu, Xiaoyan; Huang, Zhenyu; Zhu, Haining

    2009-01-01

    Quantitative proteomics is challenging and various stable isotope based approaches have been developed to meet the challenge.. Hereby we describe a simple, efficient, reliable and inexpensive method named RABA (reductive alkylation by acetone) to introduce stable isotopes to peptides for quantitative analysis. The RABA method leads to alkylation of N-terminal and lysine amino groups with isopropyl moiety. Using unlabeled (d0) and deuterium labeled (d6) acetone, a 6 Da mass split is introduced to each isopropyl modification between the light and heavy isotope labeled peptides, which is ideally suited for quantitative analysis. The reaction specificity, stoichoimetry, labeling efficiency and linear range of the RABA method has been thoroughly evaluated in this study using standard peptides, tryptic digest of proteins as well as human cell lysate. Reliable quantitative results have been consistently obtained in all experiments. We also applied the RABA method to quantitative analysis of proteins in spinal cords of transgenic mouse models of amyotrophic lateral sclerosis. Highly homologous proteins (transgenic human SOD1 and endogenous mouse SOD1) were distinguished and quantified using the method developed in this study. In addition, the quantitative results using the RABA approach were independently validated by Western blot. PMID:19419886

  20. Acetone Extract of Almond Hulls Provides Protection against Oxidative Damage and Membrane Protein Degradation.

    PubMed

    Meshkini, Azadeh

    2016-06-01

    Several studies have revealed that among foods, the consumption of edible nuts has beneficial effects on health which are attributed to their high content of potent antioxidants. Among nuts, the whole seed of the almond (Prunus dulcis) has been demonstrated to possess potent free radical scavenging activity, which is related to the presence of phenolic compounds. The aim of the current study is to evaluate the polyphenol content and the antioxidant ability of almond hull, which is an agriculture solid waste. The present results revealed that among different extraction methods, the acetone extract of almond hulls has a high content of phenolic and flavonoid compounds and a high antioxidant ability, which were determined by using the phosphomolybdenum method and by measuring the potency of the antioxidant, respectively. Moreover, the experimental data disclosed that the acetone extract of almond hulls provides protection against the oxidative damage and the membrane protein degradation that are caused in human erythrocytes by hydrogen peroxide. These phenomena may likely be due to the recruitment of antioxidants by cell membranes and/or translocation to cytosol. Overall, almond hull extract could be considered as a natural source of antioxidants, and its consumption could have a positive effect on human health.