The Experts below are selected from a list of 261 Experts worldwide ranked by ideXlab platform

Michael A Krainak - One of the best experts on this subject based on the ideXlab platform.

  • Laser Sounding Instrument using Oxygen A-Band for Atmospheric Pressure Sensing
    2015
    Co-Authors: Mark A Stephen, James B Abshire, Randy S Kawa, Jianping Mao, Xiaoli Sun, Michael A Krainak
    Abstract:

    Abstract—We report on the progress of an Oxygen spectroscopy laser sounding instrument designed as a calibration channel for a carbon dioxide (CO2) laser sounding instrument. We have developed a pulsed, frequency-doubled, fiber laser transmitter for use in an Oxygen instrument. The instrument concept uses the pressure broadening of spectroscopic lines of the Diatomic Oxygen A-band to deduce atmospheric pressure. There are many uses for this measurement but we are developing it primarily to make a measurement of the dry mixing ratio of CO2. The CO2 measurement can be affected by changes in atmospheric properties such as humidity, temperature and pressure. To remove these error sources requires measuring a stable, well-mixed gas like Oxygen. We will report on the basic theory behind the instrument, measurements made at a test site at Goddard, review the current state of the instrument technologies and the necessary steps to bring them to space readiness, and review the current state of the instrument development. 1

  • Oxygen spectroscopy laser sounding instrument for remote sensing of atmospheric pressure
    IEEE Transactions on Biomedical Engineering, 2008
    Co-Authors: Mark A Stephen, James B Abshire, Randy S Kawa, Michael A Krainak
    Abstract:

    We report on progress of a laser sounding instrument using the pressure broadening of spectroscopic absorption lines of the Diatomic Oxygen A-band to deduce atmospheric pressure and a pulsed, frequency-doubled, fiber laser transmitter.

  • Oxygen spectroscopy laser sounding instrument for remote sensing of atmospheric pressure
    IEEE Aerospace Conference, 2008
    Co-Authors: Mark A Stephen, James B Abshire, S R Kawa, Michael A Krainak
    Abstract:

    We report on the progress of an Oxygen spectroscopy laser sounding instrument designed as a calibration channel for a carbon dioxide (CO2) laser sounding instrument. We have developed a pulsed, frequency-doubled, fiber laser transmitter for use in an Oxygen instrument. The instrument concept uses the pressure broadening of spectroscopic lines of the Diatomic Oxygen A-band to deduce atmospheric pressure. There are many uses for this measurement but we are developing it primarily to make a measurement of the dry mixing ratio of CO2. The CO2 measurement can be affected by changes in atmospheric properties such as humidity, temperature and pressure. To remove these variances requires measuring a stable, well-mixed gas like Oxygen. We will report on the basic theory behind the instrument, measurements made at a test site at Goddard, review the current state of the instrument technologies and the necessary steps to bring them to space readiness, and review the current state of the instrument development.

  • Narrowband, tunable, frequency-doubled, erbium-doped fiber-amplifed transmitter.
    Optics letters, 2007
    Co-Authors: Mark A Stephen, Michael A Krainak, Haris Riris, Graham R. Allan
    Abstract:

    We report on the development of a fiber-based laser transmitter designed for active remote sensing spectroscopy. The transmitter uses a master oscillator power amplifier (MOPA) configuration with a distributed feedback diode-laser master oscillator and an erbium-doped fiber amplifier. The output from the MOPA is frequency-doubled with a periodically poled potassium titanium oxide phosphate crystal. With 35 W of single-frequency peak optical pump power, 8 W of frequency-doubled peak power was achieved. The utility of this single-frequency, wavelength tunable, power scalable laser was then demonstrated in a spectroscopic measurement of Diatomic Oxygen A band.

Mark A Stephen - One of the best experts on this subject based on the ideXlab platform.

  • Laser Sounding Instrument using Oxygen A-Band for Atmospheric Pressure Sensing
    2015
    Co-Authors: Mark A Stephen, James B Abshire, Randy S Kawa, Jianping Mao, Xiaoli Sun, Michael A Krainak
    Abstract:

    Abstract—We report on the progress of an Oxygen spectroscopy laser sounding instrument designed as a calibration channel for a carbon dioxide (CO2) laser sounding instrument. We have developed a pulsed, frequency-doubled, fiber laser transmitter for use in an Oxygen instrument. The instrument concept uses the pressure broadening of spectroscopic lines of the Diatomic Oxygen A-band to deduce atmospheric pressure. There are many uses for this measurement but we are developing it primarily to make a measurement of the dry mixing ratio of CO2. The CO2 measurement can be affected by changes in atmospheric properties such as humidity, temperature and pressure. To remove these error sources requires measuring a stable, well-mixed gas like Oxygen. We will report on the basic theory behind the instrument, measurements made at a test site at Goddard, review the current state of the instrument technologies and the necessary steps to bring them to space readiness, and review the current state of the instrument development. 1

  • Fiber-Based Laser Transmitter for Oxygen A-Band Spectroscopy and Remote Sensing
    2010
    Co-Authors: Mark A Stephen, James B Abshire
    Abstract:

    A fiber-based laser transmitter has been designed for active remote-sensing spectroscopy. The transmitter uses a master-oscillator-power-amplifier (MOPA) configuration with a distributed feedback diode-laser master oscillator and an erbium-doped fiber amplifier. The output from the MOPA is frequency-doubled with a periodically poled nonlinear crystal. The utility of this single-frequency, wavelength-tunable, power-scalable laser has been demonstrated in a spectroscopic measurement of the Diatomic Oxygen A-band.

  • Oxygen spectroscopy laser sounding instrument for remote sensing of atmospheric pressure
    IEEE Transactions on Biomedical Engineering, 2008
    Co-Authors: Mark A Stephen, James B Abshire, Randy S Kawa, Michael A Krainak
    Abstract:

    We report on progress of a laser sounding instrument using the pressure broadening of spectroscopic absorption lines of the Diatomic Oxygen A-band to deduce atmospheric pressure and a pulsed, frequency-doubled, fiber laser transmitter.

  • Oxygen spectroscopy laser sounding instrument for remote sensing of atmospheric pressure
    IEEE Aerospace Conference, 2008
    Co-Authors: Mark A Stephen, James B Abshire, S R Kawa, Michael A Krainak
    Abstract:

    We report on the progress of an Oxygen spectroscopy laser sounding instrument designed as a calibration channel for a carbon dioxide (CO2) laser sounding instrument. We have developed a pulsed, frequency-doubled, fiber laser transmitter for use in an Oxygen instrument. The instrument concept uses the pressure broadening of spectroscopic lines of the Diatomic Oxygen A-band to deduce atmospheric pressure. There are many uses for this measurement but we are developing it primarily to make a measurement of the dry mixing ratio of CO2. The CO2 measurement can be affected by changes in atmospheric properties such as humidity, temperature and pressure. To remove these variances requires measuring a stable, well-mixed gas like Oxygen. We will report on the basic theory behind the instrument, measurements made at a test site at Goddard, review the current state of the instrument technologies and the necessary steps to bring them to space readiness, and review the current state of the instrument development.

  • Narrowband, tunable, frequency-doubled, erbium-doped fiber-amplifed transmitter.
    Optics letters, 2007
    Co-Authors: Mark A Stephen, Michael A Krainak, Haris Riris, Graham R. Allan
    Abstract:

    We report on the development of a fiber-based laser transmitter designed for active remote sensing spectroscopy. The transmitter uses a master oscillator power amplifier (MOPA) configuration with a distributed feedback diode-laser master oscillator and an erbium-doped fiber amplifier. The output from the MOPA is frequency-doubled with a periodically poled potassium titanium oxide phosphate crystal. With 35 W of single-frequency peak optical pump power, 8 W of frequency-doubled peak power was achieved. The utility of this single-frequency, wavelength tunable, power scalable laser was then demonstrated in a spectroscopic measurement of Diatomic Oxygen A band.

James B Abshire - One of the best experts on this subject based on the ideXlab platform.

  • Laser Sounding Instrument using Oxygen A-Band for Atmospheric Pressure Sensing
    2015
    Co-Authors: Mark A Stephen, James B Abshire, Randy S Kawa, Jianping Mao, Xiaoli Sun, Michael A Krainak
    Abstract:

    Abstract—We report on the progress of an Oxygen spectroscopy laser sounding instrument designed as a calibration channel for a carbon dioxide (CO2) laser sounding instrument. We have developed a pulsed, frequency-doubled, fiber laser transmitter for use in an Oxygen instrument. The instrument concept uses the pressure broadening of spectroscopic lines of the Diatomic Oxygen A-band to deduce atmospheric pressure. There are many uses for this measurement but we are developing it primarily to make a measurement of the dry mixing ratio of CO2. The CO2 measurement can be affected by changes in atmospheric properties such as humidity, temperature and pressure. To remove these error sources requires measuring a stable, well-mixed gas like Oxygen. We will report on the basic theory behind the instrument, measurements made at a test site at Goddard, review the current state of the instrument technologies and the necessary steps to bring them to space readiness, and review the current state of the instrument development. 1

  • Fiber-Based Laser Transmitter for Oxygen A-Band Spectroscopy and Remote Sensing
    2010
    Co-Authors: Mark A Stephen, James B Abshire
    Abstract:

    A fiber-based laser transmitter has been designed for active remote-sensing spectroscopy. The transmitter uses a master-oscillator-power-amplifier (MOPA) configuration with a distributed feedback diode-laser master oscillator and an erbium-doped fiber amplifier. The output from the MOPA is frequency-doubled with a periodically poled nonlinear crystal. The utility of this single-frequency, wavelength-tunable, power-scalable laser has been demonstrated in a spectroscopic measurement of the Diatomic Oxygen A-band.

  • Oxygen spectroscopy laser sounding instrument for remote sensing of atmospheric pressure
    IEEE Transactions on Biomedical Engineering, 2008
    Co-Authors: Mark A Stephen, James B Abshire, Randy S Kawa, Michael A Krainak
    Abstract:

    We report on progress of a laser sounding instrument using the pressure broadening of spectroscopic absorption lines of the Diatomic Oxygen A-band to deduce atmospheric pressure and a pulsed, frequency-doubled, fiber laser transmitter.

  • Oxygen spectroscopy laser sounding instrument for remote sensing of atmospheric pressure
    IEEE Aerospace Conference, 2008
    Co-Authors: Mark A Stephen, James B Abshire, S R Kawa, Michael A Krainak
    Abstract:

    We report on the progress of an Oxygen spectroscopy laser sounding instrument designed as a calibration channel for a carbon dioxide (CO2) laser sounding instrument. We have developed a pulsed, frequency-doubled, fiber laser transmitter for use in an Oxygen instrument. The instrument concept uses the pressure broadening of spectroscopic lines of the Diatomic Oxygen A-band to deduce atmospheric pressure. There are many uses for this measurement but we are developing it primarily to make a measurement of the dry mixing ratio of CO2. The CO2 measurement can be affected by changes in atmospheric properties such as humidity, temperature and pressure. To remove these variances requires measuring a stable, well-mixed gas like Oxygen. We will report on the basic theory behind the instrument, measurements made at a test site at Goddard, review the current state of the instrument technologies and the necessary steps to bring them to space readiness, and review the current state of the instrument development.

Gerald Gourdin - One of the best experts on this subject based on the ideXlab platform.

  • Potassium Superoxide: A Unique Alternative for Metal–Air Batteries
    Accounts of chemical research, 2018
    Co-Authors: Neng Xiao, Xiaodi Ren, William D. Mcculloch, Gerald Gourdin
    Abstract:

    ConspectusLithium–Oxygen (Li–O2) batteries have been envisaged and pursued as the long-term successor to Li-ion batteries, due to the highest theoretical energy density among all known battery chemistries. However, their practical application is hindered by low energy efficiency, sluggish kinetics, and a reliance on catalysts for the Oxygen reduction and evolution reactions (ORR/OER). In a superoxide battery, Oxygen is also used as the cathodic active medium but is reduced only to superoxide (O2•–), the anion formed by adding an electron to a Diatomic Oxygen molecule. Therefore, O2/O2•– is a unique single-electron ORR/OER process. Since the introduction of K–O2 batteries by our group in 2013, superoxide batteries based on potassium superoxide (KO2) have attracted increasing interest as promising energy storage devices due to their significantly lower overpotentials and costs.We have selected potassium for building the superoxide battery because it is the lightest alkali metal cation to form the thermodyna...

  • potassium superoxide a unique alternative for metal air batteries
    Accounts of Chemical Research, 2018
    Co-Authors: Neng Xiao, Xiaodi Ren, William D. Mcculloch, Gerald Gourdin
    Abstract:

    ConspectusLithium–Oxygen (Li–O2) batteries have been envisaged and pursued as the long-term successor to Li-ion batteries, due to the highest theoretical energy density among all known battery chemistries. However, their practical application is hindered by low energy efficiency, sluggish kinetics, and a reliance on catalysts for the Oxygen reduction and evolution reactions (ORR/OER). In a superoxide battery, Oxygen is also used as the cathodic active medium but is reduced only to superoxide (O2•–), the anion formed by adding an electron to a Diatomic Oxygen molecule. Therefore, O2/O2•– is a unique single-electron ORR/OER process. Since the introduction of K–O2 batteries by our group in 2013, superoxide batteries based on potassium superoxide (KO2) have attracted increasing interest as promising energy storage devices due to their significantly lower overpotentials and costs.We have selected potassium for building the superoxide battery because it is the lightest alkali metal cation to form the thermodyna...

A.g. Voropayev - One of the best experts on this subject based on the ideXlab platform.

  • Enhanced Oxidation of Nickel in Atomic Oxygen.
    ChemInform, 2010
    Co-Authors: Sergei A. Raspopov, A.g. Gusakov, A.g. Voropayev, A.a. Vecher, V. K. Grishin
    Abstract:

    Abstract The oxidation of nickel in atomic Oxygen has been investigated at the conditions close to those of a low Earth orbit (at an atomic Oxygen incident flux of 10 16 −6 × 10 16 atoms cm −2 s −1 ) and in the temperature range 773–1373 K. The rate constant of nickel oxidation in atomic Oxygen at low pressures was found to be higher by orders of magnitude than that in Diatomic Oxygen having the same pressure even at these rather high temperatures. As regards the dependence of oxidation rate on Oxygen pressure, while in Diatomic Oxygen the parabolic rate constant of nickel oxidation is proportional to P | staggered | o 2 0.35 , in atomic Oxygen it is proportional to P O 0.72 (the power is twice that in O 2 ). Also, the activation energy of oxidation decreases from 182 kJ mol −1 for molecular Oxygen to 76 kJ mol −1 for atomic Oxygen. A model is proposed explaining these observations, which is based on the assumption that atomic Oxygen in the gas phase and the Oxygen chemisorbed on the NiO surface are close to equilibrium.

  • INTERACTION OF TITANIUM WITH ATOMIC AND MOLECULAR Oxygen
    Journal of the Chemical Society Faraday Transactions, 1996
    Co-Authors: Sergei A. Raspopov, A.g. Voropayev, A.a. Vecher, Anatoli G. Gusakov, Alexander A. Savitski, Vasili K. Grishin
    Abstract:

    Oxidation of α-titanium has been studied under conditions simulating low Earth orbits i.e. in atomic Oxygen at an incident flux of 1016–1017 particles cm–2 s–1. The temperature range was 873–1123 K, in which α-modification of Ti exists. The kinetics of oxidation in atomic Oxygen and in low-pressure (0.01–0.1 Pa) Diatomic Oxygen have been investigated in the initial stages of the process (i.e. before oxide scale formation) in relation to Oxygen flux and temperature. The flux of Oxygen dissolving in the metal across and metal/gas interface was determined by electrical resistance measurements. Linear rate law was observed at the initial stages of oxidation. For the dependence of reaction rate on Diatomic Oxygen pressure (or incident flux), the order with respect to pressure was found to be below unity (0.65 at 973 K and 0.82 at 1073 K). A high value of activation energy was obtained, 183 kJ mol–1. A kinetic explanation of these observations has been proposed. Strong acceleration of oxidation in dissociated Oxygen was found only at temperatures below 973 K. The reaction rate increase four-fold with a degree of Oxygen dissociation of 28.7% at 923 K and two-fold at 973 K. This increase in oxidation rate was confirmed by gravimetry and measurements of the titanium lattice parameter.

  • Oxidation of vanadium in atomic and molecular Oxygen at low pressures
    Journal of Alloys and Compounds, 1994
    Co-Authors: Sergei A. Raspopov, A.g. Gusakov, A.g. Voropayev, A.a. Vecher
    Abstract:

    Abstract The vanadium oxidation in atomic and molecular Oxygen is investigated in the temperature range 873–1373 K at Oxygen pressures of 9 × 10−3−7 × 10−2 Pa. At the initial stage of oxidation, when the dissolution of Oxygen in vanadium takes place, both the Diatomic and atomic Oxygen absorption probabilities are independent on the incident flux. The absorption probability of atomic Oxygen is not much higher than that of Diatomic Oxygen (approximately three fold). The rate of reaction at the Oxygen dissolution stage is determined by the chemisorption of atomic or Diatomic Oxygen on the vanadium surface.

  • Studies of the reaction of atomic and molecular Oxygen with niobium and niobium-(1 at.% zirconium)-(0.7 at.% carbon) (PWC-11) alloy at low pressures
    Journal of Alloys and Compounds, 1994
    Co-Authors: Sergei A. Raspopov, A.g. Gusakov, A.g. Voropayev, A.a. Vecher
    Abstract:

    Abstract The interaction of atomic and Diatomic Oxygen with niobium and niobium-(1 at.% zirconium)-(0.7 at.% carbon) alloy has been studied between 773 and 1373 K at an Oxygen pressure in the range 9×10 −3 –7×10 −2 Pa. At the initial stage of oxidation, when the dissolution of Oxygen in niobium or alloy takes place, both the Diatomic and atomic Oxygen absorption probabilities are independent of the incident flux, apparently the rate of reaction is determined by the Oxygen chemisorption on the metal surface. Atomic and molecular Oxygen absorption probability at rather high temperatures are also almost independent of temperature, whereas at lower temperatures molecular Oxygen absorption probability demonstrates a strong temperature dependence. Oversaturation of the metal surface with dissolved Oxygen is observed if oxidation occurs in dissociated Oxygen at a temperature below 973 K. At the oxide film growth stage, oxidation occurs according to a parabolic law, consequently the reaction rate is determined by diffusion through the oxide film. Nevertheless dissociation of Oxygen increases the reaction rate.

  • Interaction of tantalum with Diatomic and atomic Oxygen at low pressures
    Journal of Alloys and Compounds, 1993
    Co-Authors: A.g. Gusakov, A.a. Vecher, Sergei A. Raspopov, A.g. Voropayev
    Abstract:

    Abstract Oxidation of tantalum in atomic (O( 3 P)) and Diatomic Oxygen has been investigated in the temperature range 773–1573 K at an Oxygen pressure in the range 9 × 10 −3 −7×10 −2 Pa. When the dissolution of Oxygen in tantalum takes place, the absorption probability of atoms is considerably higher than that of molecules (14-fold higher at 1073 K). The Ta 2 O 5 film growth rate is apparently determined by the reaction of chemisorbed Oxygen atoms with tantalum according to a Langmuir-Hinshelwood mechanism and, in the case of Diatomic Oxygen, is proportional to the square root of the Oxygen pressure.