... Title : The Development of an Integrating Cavity Absorption Meter to Measure Optical Absorption of Pure Waters and Suspended Particulates. ...
DTIC Science & Technology
... an integrating cavity absorption meter ... m rew instrument, the integrating cavity absorption meter , solves these two prob1ems in a unique manner. ...
The Integrating Cavity Absorption Meter (ICAM) provides an instrument capable of measuring optical absorption independent of scattering effects. The measurement of optical absorption has always been complicated by scattering effects. The most common and p...
National Technical Information Service (NTIS)
Calculation was made of the line profiles to be expected when a Fabry-Perot interferometer is used to measure absorption lines. It is shown that large errors may be introduced in the measurement of the integrated absorption, even when an interferometer of...
... scattering errors in the spectrophotometric measure- ment ... reflectivity 0.99, and absorption coefficient a ... Sensitivity Analysis The determination of the ...
We present measurements of the integrated radio continuum flux density of M33 at frequencies between
NASA Technical Reports Server (NTRS)
The equipment and experimental techniques used to observe the temperature dependence of absorptance in a small region of the 950/cm band of ammonia are described. The integrated absorptance of two spectral lines was measured at 214K and 300K for samples o...
Line-integrated refractivity is isolated as the basic parameter required for correcting atmosphere-induced radar ranging data errors. A basis for the determination of integrated refractivity from measurements of the absorption or emission of infrared and ...
Aug 2, 2011 ... COBALT makes measurements using off-axis integrated output spectroscopy. Instrument Type: Laser absorption. Measurements: ...
NASA Website
The development of highly transparent solids for fiber optics, integrated optics, and high-power lasers requires improved methods to measure very low absorption coefficients. A photoacoustic theory, which includes viscosity, has been developed for the cas...
The thermal neutron absorption cross-section of Th/sup 233/ and the resonance absorption integrals of Th/sup 232/, Th/sup 233/, and Co/sup 59/ were measured as 1450, 85, 400, and 75 barns, respectively, by neutron activation measurements using cadmium filters with reactor spectrum ...
Energy Citations Database
A method for measuring the optical extinction coefficient for absorption, the Integrating Plate Method (IPM), was validated in laboratory and field tests. The absorption cross sections for single sized particles of methylene blue, large enough to the opaque, were compared with calculated cross sections for ...
NASA Astrophysics Data System (ADS)
Measurements of effective resonance integrals of spherical HTGR fuel assemblies were performed. These measurements were carried out to test calculations models taking into account the influence of the grain structure on the effective resonance integral ca...
Integrated band intensities of the 620/cm absorption in (C2H2)2 are measured by FTIR spectroscopy at
Calculations are presented for the reflected and transmitted intensities and polarizations for the C wavelength pair used for Umkehr measurements. The present calculations utilize a numerical integration of the transfer equation which includes all orders ...
CW lasers were applied to path-integrated absorption measurements of transient shock-tube flows and spatially resolved laser-induced fluorescence ...
... However, a line-of-sight (LOS) integral of the absorption coefficient can be extracted from the transmittance measurements utilizing Beer's law: ...
... under Project 7.84, "Man-Machine Integration Technology ... and attempts to measure the characteristics of the ... from scattering and absorption that are ...
V.G.Kastrov. (Bibl.2]+) in- vestigated the integral absorption ...... Kastrov, V.G. : Measurement of Absorption of Solar Radiation in the Free. Atmosphere ...
Fourteen bands of ozone between 500 and 3300 per cm have been identified and values of the vibrational anharmonic constants determined. The integrated band absorptances of many of these bands have been measured from spectra of a 32 m path of ozone-oxygen ...
A prototype airborne downlooking infrared differential absorption system using CO2 TEA (transverse excited atmospheric) lasers is described. The system uses two wavelengths and topographic reflection to measure the integrated column concentration of ozone between the laser source...
EPA Science Inventory
Current ASTM standards concerned with the durability and reliability of absorptive coatings rely on integrated solar absorptance and emittance as the primary methods for assessing changes in absorber optical performance resulting from environmental exposu...
A new method is presented for analyzing the effects of self-absorption on photoluminescence integrating sphere quantum yield measurements. Both the observed quantum yield and luminescence spectrum are used to determine the self-absorption probability, taking into account both the initial emission and subsequent ...
The experimental measurement of the solar integrated coefficients of absorption, reflection, and transmission involves significant difficulties and cannot always be performed. This paper describes a method for calculating the absorption and transmission of solar radiation by thin semiconductor films as a function ...
The absorption of x rays from a continuous source is studied using the k alpha lines of chlorine ions originally belonging to the laser target. The spectra are solved and integrated to determine the electron temperatures and the absorption lengths in the ...
In order to study the change of temperature on the effects of carbon monoxide absorption spectral lines, first of all proceed from the principle of absorption spectra, using theoretical analysis method, and the transmission and absorption database of the high-resolution molecular educed the carbon monoxide ...
The optical characterization of solar absorbers for thermal solar collectors is usually performed by measurement of the spectral reflectance at near-normal angle of incidence and calculation of the solar absorptance from the measured reflectance. The solar absorptance is, however, a function of the angle of ...
PubMed
A large discrepancy is found between the value for the integrated total photonuclear cross section for /sup 16/O determined from the sum of the partial cross sections and that obtained from a total photon absorption measurement.
Absorption imaging was used to measure the chemical product formed in a nonpremixed reacting turbulent water-jet. A collimated light-beam was absorbed by red phenolphthalein formed through a chemical reaction between neutral (pH 7) jet fluid and alkaline tank fluid. The integrated absorption was imaged on a CCD ...
We present a design for a flow-through integrating cavity absorption meter. This instrument, in principle, is capable of measuring the spectral optical absorption coefficient of natural waters in situ independently of scattering effects. Monte Carlo simulations are used to determine the design parameters and ...
The signal-to-noise ratio (SNR) in off-axis integrated cavity output spectroscopy (OA-ICOS) is investigated and compared to direct absorption spectroscopy using multipass absorption cells [tunable diode laser absorption spectroscopy (TDLAS)]. Applying measured noise characteristics of a near-IR ...
... AIAA-2003-3259 Acoustic Absorption Measurements for ... AIAA 2003 - 3259 Acoustic Absorption Measurements for Characterization of Gas Mixing ...
We have modeled the path-length distribution in an integrating sphere used as a multipass optical cell for absorption measurements. The measured radiant flux as a function of analyte concentration is nonlinear as a result, deviating from that expected for a single path length. We have developed a full numerical ...
An active phase-controlling scheme based on a proportional-integral-derivative-controlled piezoelectric transducer is presented with the purpose of stabilizing a quasi-zero-background absorption spectrometer. A fiber-based balanced Michelson interferometer is used, and absorption due to a gas sample in one of its arms results in an ...
Airborne Lidar Measurements of Atmospheric Pressure Made Using the Oxygen A-Band ... nm and the integrated path differential absorption measurement technique. .... the ability to obtain spectral information in transient solar events. ...
integrating all angular measurements and is compared with the measured nadir. reectance. .... which is a ratio of two derivatives: F,' is the collimated irradi- ... reecting surface (e.g., leaf orientation. wetness), the bidirec- ...
An analytical solution is presented for the reconstruction of spatially resolved species number densities from spatially resolved laser-induced fluorescence measurements when the integrated absorption of the laser light is known. The stability of the solu...
Quantitative measurements of real-time variations of the chemical composition of a jet engine exhaust plume is demonstrated using a 4.86 ?mn intra-pulse quantum cascade laser spectrometer. The measurements of the gas turbine exhaust were carried out in collaboration with John Black and Mark Johnson at Rolls Royce. The recording of five sets of averaged ...
measurements are useful to determine the ionospheric absorption in the lower ... noise and to calculate ionospheric absorption it is developed a software at ...
Direct measurement of the aerosol absorption and extinction cross section for a variety of chemical and biological ... Extinction = scatter + absorption ...
Simultaneous measurements of bext (teleradiometer), b(sup sp) (integrating nephelometer) and b(sup ag) (NO/sub 2/ monitor) were used to obtain particle absorption-extinction coefficients b(sup sp) for the Denver atmosphere during January 1982. The average of the ratio bap/b(sup sp) was measured to be 0.185 + or - ...
An integrating sphere is used to measure spectral distribution, calculate total luminous flux and calculate chromaticity coordinates of LEDs. It usually has to consider self-absorption when light source is radiating in the integrating sphere. The LED with coloured parts, such as printed circuit board, heat sink and ...
Light absorption by particulate impurities in snow and ice can affect the surface albedo and is important for the climate. The absorption properties of these particles can be determined by collecting and melting snow samples and extracting the particulate material by filtration of the meltwater. This paper describes the optical design and testing of a new ...
... Accession Number : AD0468330. Title : MEASURED ATMOSPHERIC ABSORPTION AT RUBY OPTICAL MASER WAVELENGTHS,. ...
... Accession Number : AD0634830. Title : ABSORPTION MEASUREMENTS AT MORNING TWILIGHT,. Corporate Author : RAND ...
... Title : ABSORPTION COEFFICIENT MEASUREMENTS OF NITROUS OXIDE AND METHANE AT DF LASER WAVELENGTHS, IN: APPLIED ...
... Title : PHASE INTEGRAL CORRECTIONS TO RADIO ABSORPTION AND VIRTUAL HEIGHT FOR MODEL IONOSPHERIC LAYERS-JOURNAL OF ...
... Accession Number : ADA471353. Title : Microfluidic Integration on Detector Array for Absorption and Fluorescence Micro-Spectrometers. ...
The authors examine the measurements of the cross section for the absorption of thermal neutrons and the resonance integral of /sup 109/Cd, carried out in the heavy-water reactor at the Institute of Theoretical and Experimental Physics. The /sup 109/Cd sample, separated without the carrier from a silver target irradiated in a cyclotron ...
A pulsed, 2-?m coherent Differential Absorption Lidar (DIAL) / Integrated Path Differential Absorption (IPDA) transceiver, developed under the Laser Risk Reduction Program (LRRP) at NASA, is integrated into a fully functional lidar instrument. This instrument measures atmospheric CO2 profiles ...
The near-UV spectrum of benzene is used to illustrate the effects of variations in instrument spectral bandwidth on absorbance and molar absorptivity measurements and on the independence of values of quantities such as the oscillator strength that are based on integrated absorptivity. Excel-based computer ...
ERIC Educational Resources Information Center
The free-atom fractions, beta, of five elements in pre-mixed laminar H2/O2/Ar flames produced with a shielded Meker-type burner were measured as a function of flame composition and height using a relative integrated absorption method. The flame temperatur...
Simultaneous measurements of bext (teleradiometer), b(sup sp) (integrating nephelometer) and b(sup ag) (N02 monitor) were used to obtain particle absorption extinction coefficients b(sup sp) for the Denver atmosphere during January 1982. The average of the ratio bap/b(sup sp) was...
The relationships between differential and integral cross sections are considered together with their application to the calculation of reaction rates in reactor spectra. A brief review of the measurement of these quantities is given in order to show the importance of chemical analysis in all methods. Particular attention is devoted to the ...
The estimate of tissue optical properties is an important challenge in biomedical science. In the research of precancerous diagnosis and glucose concentration detection, the accuracy of chromospheres concentrations measurement depends on the measurement of absorption coefficient. So determining the absorption ...
The measurement of cloud absorption from aircraft has been a controversial subject largely because broadband measurements provide little insight into the physical mechanisms underlying the absorption. To partition and quantify the various mechanisms of cloud absorption, spectrally resolved ...
Current ASTM standards concerned with the durability and reliability of absorptive coatings rely on integrated solar absorptance and emittance as the primary methods for assessing changes in absorber optical performance resulting from environmental exposure. This study was undertaken to determine if infrared reflectance ...
Along with X{sup (3)}, the magnitude of the optical absorption in the transparent window below the principal absorption edge is an important parameter which will ultimately determine the utility of conjugated polymers in active integrated optical devices. With an absorptance sensitivity of < 10{sup {minus}5}, ...
We report on a lidar approach to measure atmospheric CO2 column concentration being developed as a candidate for NASA's ASCENDS mission. It uses a pulsed dual-wavelength lidar measurement based on the integrated path differential absorption (IPDA) technique. We demonstrated the approach using the CO2 ...
An innovative fiber optic setup for the scattering-free absorption spectroscopy of liquids is presented. It makes use of an integrating sphere that contains the sample under test, coupled to a fiber optic supercontinuum source and to a fiber optic spectrometer. The highly-bright broadband light shining on the sphere's surface is diffusely reflected and ...
We analyze optical soliton propagation in the presence of weak absorption lines with much narrower linewidths as compared to the soliton spectrum width by using a perturbation analysis technique based on an integral representation in the spectral domain. The stable soliton acquires a spectral modulation that follows the associated index of refraction of ...
We analyze optical soliton propagation in the presence of weak absorption lines with much narrower linewidths as compared to the soliton spectrum width using the novel perturbation analysis technique based on an integral representation in the spectral domain. The stable soliton acquires spectral modulation that follows the associated index of refraction of ...
E-print Network
The infrared absorption coefficient of H2SO4 vapor has been measured for the first time. The vapor was obtained from liquid acid held at the azeotrope. The temperature dependence of the absorption confirmed that the azeotrope concentration was accurate to better than 1%. The P, Q, and R branches of the measured ...
Welding laser modelling requires knowledge about relative changes of many thermo-physical parameters involved in the interaction. The absorptivity of the material is one of the most important. In this study, experimental measurements of absorptivity with an integrating sphere on two alloys (aluminium and magnesium) ...
PubMed Central
of total RNA preparations, denaturing agarose gel electrophoresis fol- lowed by ethidium bromide stain- ing denaturing agarose gels and the quantitation was comparable to UV absorption measurements. #12;integrates % agarose gel with formaldehyde and stained with ethidium bromide (figure 5-B). The total RNA separation
This report discusses the theory of modulation and coding detection schemes. Applications of these techniques in active radiation dosimetry measurements would appear to be particularly promising. Modern integrated circuits provide ready made modulation an...
Synoptic maps of a normalized function of fmin are used to obtain the integrated absorption along a 10,000 km propagation path for comparison with the lowest observed frequency (LOF) measured by oblique incidence ionosonde over the same path in the month ...
This report describes the design and operation of a diagnostic instrument used for light balance measurements in inertial fusion experiments. The instrument is a light-integrating cylinder that uses the integrating principles of the Ulbricht sphere, but which was designed to operate in a reflective illumination environment. The ...
The absorption coefficients of stratospheric aerosols are measured using a variation on the integrating plate method. The technique is based on the decrease in the transparency of a substrate when an absorbing aerosol is deposited on it. A Lambert scatterer is placed behind the substrate to integrate forward ...
Methods of measuring the concentration of atmospheric pollutants by laser absorption spectroscopy, such as differential absorption lidar (DIAL) and integrated long-path techniques, all rely on the validity of Beer's exponential absorption law. It is shown here that departures from this ...
