The amorphous polymorphism of the classic network-forming tetrahedral-oxide glasses such as GeO2 and SiO2, is fundamentally important in the theories of glass structure. Our recent density measurements show that GeO2 glass exhibits a complicated compression process from tetrahedral to the octahedral forms. In this work, we report in situ x-ray absorption fine structure (XAFS) ...
NASA Astrophysics Data System (ADS)
... Title : Absorption Air Conditioning. ... Abstract : NOS, Indian Head has proposed a study of steam absorption air conditioning. ...
DTIC Science & Technology
Raman and visible absorption spectra of AlH3 were measured at high pressures in order to clarify the structural and electronic phase transitions. For the Raman results, abrupt decrease in Raman intensity was found at 30 GPa, implying that there exists a structural transition from the ? phase to higher pressure phase. Correspondingly, the spectral change in ...
.5 GPa 2.7 GPa 2 GPa 0 GPa Optical Density Photon Energy (eV) (b) YbS Energy (eV) Pressure (GPa) Fig. 3Vol. 34 (2003) ACTA PHYSICA POLONICA B No 2 DIRECT OBSERVATION OF THE PRESSURE measured infrared absorption spectra under pressure and re- #29;ectivity spectra of YbS in ...
E-print Network
... Title : INVESTIGATIONS OF ABSORPTION AS A FUNCTION OF AIR PRESSURE AT THE WAVELENGTHS OF 029, 036 AND 045 MILLIMETERS ...
The magnetism and structure of compressed Co has been studied up to 120 GPa using K-edge x-ray magnetic circular dichroism (XMCD) and x-ray absorption near edge spectroscopy (XANES). The XMCD signal decreases linearly with pressure and is totally suppressed around 120 GPa at ambient temperature. We detect local fcc-like atomic ...
We have compressed xenon in a diamond-anvil cell to approximately 200 GPa. The metallization of xenon by band-gap closure was investigated by obtaining optical data for xenon in both the metallic and insulating states. In the metallic state, we determined the pressure dependence of the plasma frequency from absorption-data fit with a free-electron model. ...
Energy Citations Database
Raman and infrared absorption spectra of solid carbon dioxide (CO2) have been measured at high pressures up to 80 GPa and room temperature. The broadening and weakening of lattice vibrational signals and the disappearance of molecular vibration were detected at 65 GPa by means of the Raman and infrared absorption ...
... CRDEC-TR-88027 0r) ('v) ION CONTENT AND INFRARED ABSORPTION OF MOIST ATMOSPHERIC AIR ... 04 02 Infrared Absorption Mnist Air Ions ...
... MEASUREMENT OF AIR POLLUTANTS BY ABSORPTIONS OF INFRARED RADIATION-AIR POLLUTION CONTROL ASSOCIATION JOURNAL ...
... Absorption by ground and ground cover Absorption by the atmosphere Classical absorption ... suspended particles, turbulence, or ground cover). ...
Sep 18, 2007 ... PROPOSAL TITLE: Multispectral Particle Absorption Monitor ... of the average aerosol absorption coefficient in the parcel of sample air. ...
NASA Website
... Accession Number : AD0445686. Title : INFRARED ABSORPTION OF MAGNESIUM STANNIDE,. Corporate Author : AIR ...
Decaborane, a molecular boron hydride, was compressed to 131 GPa at room temperature to explore possible non-molecular phases in this system and their physical properties. Decaborane changed its colour from transparent yellow to orange/red above 50 GPa and then to black above 100 GPa, suggesting some transformations. Raman scattering ...
... Accession Number : ADA222044. Title : Plasma Cloaking: Air Chemistry, Broadband Absorption, and Plasma Generation. ...
Sound absorption in air at 1/3-octave frequency intervals as function of humidity and temperature at
NASA Technical Reports Server (NTRS)
An absorption filter for the purification of gas or air streams, especially gas or air streams which contain toxic or radioactive contaminants is described.
... Accession Number : AD0622797. Title : ABSORPTION COEFFICIENTS OF HEATED AIR: A COMPILATION TO 24,000 K. VOLUME I. ...
X-ray absorption measurements have been performed on BaTiO3 and SrTiO3 at the Ti K edge under pressure. For BaTiO3, the phase transformation to the cubic phase is observed at 2 GPa. In this structure the Ti atoms remain off centre with respect to the oxygen octahedron up to 10 GPa. Above this pressure the Ti atoms are at the centre of ...
Density-driven polyamorphism of GeO{sub 2} glass under high pressure has been studied by density, x-ray scattering, and optical Raman measurements. Density data obtained by an x-ray absorption method display distinct compression behavior in different pressure regions, with rapid density increases at 5 and 10 GPa and a plateau at 6-9 ...
As the simplest stable boron hydride in its condensed phase, diborane exhibits an interesting structural chemistry with uniquely bridged hydrogen bonds. Here we report the first room-temperature infrared (IR) absorption spectra of solid diborane compressed to pressures as high as 50 GPa using a diamond anvil cell. At room temperature and 3.5 ...
PubMed
Raman, IR, and visible absorption spectra of scandium trihydride (ScH3) have been measured at high pressures up to 50 GPa, to investigate the structural and electronic phase transitions. Successive hcp-intermediate-fcc phase transitions were observed at 25 and 46 GPa by Raman and IR measurements. It was suggested that the intermediate ...
celsian showed room temperature flexural strength of 131 MPa, elastic modulus of 96 GPa ..... hot pressed celsian is stable in air up to 1500?C. Replacement ...
Ga K-edge energy dispersive x-ray absorption spectroscopy and Raman spectroscopy measurements were employed to follow the pressure-induced semiconductor-metal phase transition of nanocrystalline GaSb produced by mechanical alloying up to 26 GPa. The results showed a slight increase of the phase transition pressures for both as-milled (8 ...
We report Raman scattering and visible to near-infrared absorption spectra of solid hydrogen under static pressure up to 285 GPa between 20 and 140 K. We obtain pressure dependences of vibron and phonon modes consistent with results previously determined to lower pressures. The results indicate the stability of the ordered molecular phase III to the ...
PubMed Central
A biography of the dimensions, frequency, and character of fog and the meteorological conditions that produce and sustain it was assembled for all fogs responsible for visibilities of one mile or less and unaccompanied by precipitation at Greater Pittsburgh Airport (GPA) during a five year period. A thorough diagnosis of each fog situation resulted in the following breakdown ...
Absorption in Air and (II) Detection of Infrasound Generated by Clear Air. Turbulence. I. MEASUREMENT OF SOUND ABSORPTION IN AIR ...
We have determined the melting temperature of formic acid (HCOOH) to 8.5 GPa using infrared absorption spectroscopy, Raman spectroscopy and visual observation of samples in a resistively heated diamond-anvil cell. The experimentally determined melting curve compares favorably with a two-phase thermodynamic model. Decomposition reactions were observed above ...
... (Author). Descriptors : *GAS ANALYSIS, *ABSORPTION COEFFICIENTS, *SPECTROPHONES, AIR POLLUTION, MONITORING, AIR, SAMPLING ...
... to predict threshold power in clean air which is in reasonable agreement with the experimental results. The laser absorption coefficient by the air ...
Transient absorption spectra from 390-890 nm of laser shocked RDX, PETN, sapphire, and polyvinylnitrate (PVN) at sub-nanosecond time scales are reported. RDX shows a nearly linear increase in absorption with time after shock at {approx}23 GPa. PETN is similar, but with smaller total absorption. A broad visible ...
A chemical absorptive separation of air in multiple stage of absorption and desorption is performed with partial recycle of absorbent between stages of desorption necessary to match equilibrium conditions in the various stages of absorption. This allows reduced absorbent flow, reduced energy demand and reduced ...
DOEpatents
An experimental technique to obtain time-resolved absorption spectra and kinetics in shocked pentaerythritol tetranitrate (PETN) single crystals was developed. Absorption spectra, with 50 ns resolution, and photodiode transmission records, with 0.5 ns resolution, have been obtained for shock compression along the [110] and [100] directions. Results for ...
... The optical absorption of several air-bridge structures was modeled, and optimized dimensions and electrode conductivity are presented which ...
... self absorption, air and window absorption, window scatter, and shield and holder scatter corrections were determined for weightless point sources ...
In this study, we have validated the CRTM modules (gaseous absorption model, cloud absorption and scattering model, and surface emissivity models over ...
... K G. Mueller - Provided the absorption coefficients for NO Z , 0- photodetachment, and free-free processes. (Z. Taulbee ...
... ionized air vs. photon energy. The absorption edge is at the energy of the K absorption edge of nitrogen. effective mass ...
A model is derived for the resonance absorption of molecular bands composed of Lorentzian lines is suitable for calculating fluorescence from irradiated air. The model is based on an explicit functional form derived for the resonance absorption of a singl...
National Technical Information Service (NTIS)
Oct 23, 2008 ... PROPOSAL TITLE: Multispectral Particle Absorption Monitor ... of the average aerosol absorption coefficient in a parcel of sample air. ...
... Laboratory), Hanscom Air Force Base, MA ... Wallser, 1975, "Absorption Coefficient Measurements of ... Laser Absorption Coefficients for Determining ...
Cesium thiomolybdate, Cs{sub 2}MoS{sub 4}, has been investigated at pressures up to 12 GPa. Two phase transitions have been detected by absorption measurements, Raman spectroscopy, and energy dispersive x-ray diffraction. The first phase transition to a monoclinic phase II [a=14.061(9) {Angstrom}, b=11.552(7) {Angstrom}, c=9.852(6) {Angstrom}, ...
Two experiments were conducted to investigate the use of the co-sorption effect of a desiccant wheel for improving indoor air quality. One experiment was conducted in a climate chamber to investigate the co-sorption effect of a desiccant wheel on the chemical removal of indoor air pollutants; another experiment was conducted in an office room to ...
NOS, Indian Head has proposed a study of steam absorption air conditioning. The utilization of waste steam for absorption air conditioning of Navy facilities is discussed and absorption and compression systems compared. Accordingly, the specific study and costs for the singular application at ...
... INFRARED ABSORPTION IN HEATED AIR FROM VIBRATION-ROTATION BANDS OF NITRIC OXIDE by ... 52 vibration-rotation bands of nitric oxide. ...
... Accession Number : AD0751016. Title : CO2 Laser Radiation Absorption in SF6-Air Boundary Layers,. Corporate Author ...
... AN ATLAS OY AIR ABSORPTIONS IN THE INFRARED by DJ Lovell June 1969 Department of Physics and Astronomy ... "Ii D. J. Lovell i int roduct ion ...
to the rate of decay of sound in a chamber or room caused by air absorption, may be converted to the attenuation coefficient m per meter as ...
... Title : ABSORPTION COEFFICIENTS OF HEATED AIR: A COMPILATION TO 24,000 deg K, VOLUME 2. Descriptive Note : Final rept. ...
... Accession Number : AD0087813. Title : ABSORPTION COEFFICIENTS OF AIR FROM 6000 K TO 18,000 K. Descriptive Note : Research memo.,. ...
Absorption and emission spectra of initiating crystals are obtained at two times during initiation, and a time-resolved record of integrated light is obtained during plane-wave shock initiation of single crystals of PETN at 4 GPa. Time-resolved photodiode...
The ability to remotely control the creation of mechanical work, rapidly, with high spatial precision, and over long distances, offers many intriguing possibilities. Whether driving direct conformational changes, initiating reversible chemical reactions to release stored strain, or converting the photon to a local temperature increase, combinations of photoactive units, nanoparticles, ordered ...
Alicyclic polyimides were prepared from polyalicyclic monomers using a two-step method. Light absorption of polyimides was elucidated from quantum chemistry. The alicyclic polyimide films were colorless, and the transparencies in the visible region were over 85%. The semi-aromatic polyimide films had an average refractive index range of 1.599 to 1.617, and that of a ...
The local environment of manganese atoms in LaMnO{sub 3} under pressure up to 15.3 GPa has been studied by x-ray absorption spectroscopy. For pressures below 8 GPa, no change is detected within the MnO{sub 6} octahedra. Above this pressure a continuous reduction of the long Mn-O distance takes place, however, the octahedral distortion ...
The density of hydrous peridotite magma containing 5 wt.% H2O was measured at pressures and temperatures up to 4.3 GPa and 2073 K, respectively, using the X-ray absorption method. A fit of pressure-density-temperature data to the high-temperature Birch-Murnaghan equation of state yields isothermal bulk modulus KT = 8.8 � 1.9 GPa, its ...
The impact of multiple ionization of air plasma on the inverse Bremsstrahlung absorption of laser radiation is investigated for air breathing laser propulsion. Thermochemical properties of multiply ionized air plasma species are computed for temperatures ...
Nanometric orthorhombic ZnSb was prepared by mechanical alloying and its structural stability was studied as a function of pressure. The changes were followed by Raman and x-ray absorption spectroscopy. Between 11.0 and 14.6 GPa, we observed an irreversible phase transformation from the orthorhombic phase to a hexagonal hP1 phase. A similar transformation ...
High-pressure infrared (IR) absorption study of phase transition in pentaerythritol (PET) is reported. The changes in the IR spectra with increasing and decreasing pressure have been followed up to a maximum pressure of ?11GPa. We observe several changes in the spectra including splitting of modes and sudden change in the slope of the frequency vs. ...
The behavior of CdSe nanocrystals shocked to stresses of 2-3.75 GPa has been studied. Above 3 GPa a near-complete disappearance of the first excitonic feature and broadening of the low-energy absorption edge were observed, consistent with a wurtzite to rocksalt structural transformation. The transformation pressure is reduced relative ...
We have studied for the first time the infrared reflectance and absorption spectra of ice and deuterated ice to 95 GPa (room and liquid nitrogen temperatures) with synchrotron radiation. We find that the frequencies of the high-frequency stretching and low-frequency rotational modes of ice VII (ice VIII at low temperatures) approach each other at 65-75 ...
... 15 micron sensitive free air thermometer was subjected ... RADIOMETERS, *SUPERSONIC FLIGHT, *THERMOMETERS, ABSORPTION, AIRBORNE ...
The collisional processes that influence the absorption of monochromatic light by iodine in air have
... require the application of air dry thermal control coatings. Instrumental methods for blending these coatings to desired solar absorptance to ...
... The analysis indicates that band systems of NO2 make an important contribution to the absorption coefficient of air below 6000 K, and the ...
It has recently been suggested that a significant amount of Xe can be absorbed in ?-quartz and that this might be a significant process in the recycling of Xe from the atmosphere to the interior of the Earth. This suggestion is tested by ab initio calculations of Xe in ?-quartz using DFT. Three distinct candidate sites for Xe absorption are identified�substitutional at the ...
We report Raman and infrared absorption spectroscopy along with x-ray diffraction for brucite-type{beta}-Cd(OH){sub 2} to 28 GPa at 300 K. The OH-stretching modes soften with pressure and disappear at 21 GPa with their widths increasing rapidly above 5 GPa, consistent with a gradual disordering of the H sublattice ...
We report Raman and infrared absorption spectroscopy alongwith X-ray diffraction for brucite-type beta-Cd(OH)2 to 28 GPa at 300 K.The OH-stretching modes soften with pressure and disappear at 21 GPa withtheir widths increasing rapidly above 5 GPa, consistent with a gradualdisordering of the H sublattice at 5 20 ...
DOE Information Bridge
Contents: Theory of radiation in hot gases (elementary radiative transfer, theory of radiation, theory of molecular absorption); Spectral and mean absorption coefficients of heated air (historical review: research on hot gas absorption coefficients since ...
This paper describes the variation of absorption produced by nuclear air bursts during the transition period from night to day. For air bursts occurring some 15 to 30 minutes before sunrise at 100 km, the transition absorption characteristics are found to...
... Abstract : Predictions are given for the Bremsstrahlung absorption cross section of atomic oxygen and atomic nitrogen. ...
... DIOXIDE, *AIRCRAFT CABINS, ABSORPTION, AIR CONDITIONING EQUIPMENT, CONTROLLED ATMOSPHERES, BREATHING APPARATUS ...
... Abstract : Experimental methods proposed for the measurement of the absorption coefficient of light in air are analyzed. ...
A study was performed on 8 healthy male subjects to investigate the effect of nonelastic resistance 6-40 GPa (the air flow velocity being 90 1/min) on the duration of proprioceptive reflexes of respiratory muscles, volume and velocity parameters of forced...
Geodynamic models of heat transport and the thermal evolution of Earth's interior require knowledge of thermal conductivity for high-pressure phases at relevant temperatures and pressures. Here we present new data on radiative and lattice heat transfer in mantle materials determined from optical spectroscopy and time-resolved optical radiometry. The pressure dependence of optical ...
Pressure-induced changes in the local structure about Rb atoms in RbCl are investigated by means of x-ray-absorption fine-structure spectroscopy. Rb K-edge data were taken in fine steps across the pressure-induced NaCl-structure (B1)-to-CsCl-structure(B2)transition at 0.55 GPa. Previous diffraction studies of this phase transition indicate several ...
We report an in situ high pressure investigation of the structural change in vitreous As2S3 up to 60 GPa using the diamond anvil cell and energy dispersive x-ray absorption spectroscopy. The main finding of the present study is a gradual elongation of the average As-S bond length, which takes place in the pressure range of 15-50 GPa. ...
We report an in situ high pressure investigation of the structural change in vitreous As(2)S(3) up to 60 GPa using the diamond anvil cell and energy dispersive x-ray absorption spectroscopy. The main finding of the present study is a gradual elongation of the average As-S bond length, which takes place in the pressure range of 15-50 ...
We present an extensive study of the optical, electronic, and structural properties of silane (SiH4) to 150 GPa through the use of Raman spectroscopy, optical microscopy, synchrotron infrared reflectivity, optical absorption, and synchrotron x-ray diffraction measurements. To mitigate possible contamination from previously reported metal hydride formation, ...
