... Accession Number : ADD419473. Title : Photoacoustic Spectroscopy: A Measurement Technique for Low Absorption Coefficients,. ...
DTIC Science & Technology
... The two analytical techniques atomic absorption spectroscopy and inductively coupled plasma atomic emission spectroscopy are used for the ...
... IN BOTH CASES RF SUBSTITUTION TECHNIQUES ARE APPLIED TO DETERMINE THE ATTENUATION OF PULSED SIGNALS TRANSMITTED ...
... Accession Number : AD0824907. Title : LASER FLASH HEATING TECHNIQUES FOR ATOMIC ABSORPTION SPECTROSCOPY. ...
... augmented photography, holography, fringe techniques (laser anemometry and particle sizing), mass spectroscopy, and resonance absorption. ...
A multiline absorption spectroscopy technique was investigated based on the single-line absorption spectroscopy technique. An open-path methane-detecting system was designed. An LED was used as a broadband source, and a Fabry-Perot interferometer whose transmission peaks ...
PubMed
... The three techniques, in order of suitability are: furnace atomic absorption spectroscopy, rotating disc electrode atomic emission spectroscopy, and ...
Intracavity selective absorption spectroscopy has been studied as an analytical technique for measuring ultralow concentrations of airborne iodine radioisotopes. Data are presented which show the sensitivity, linearity, and selectivity of this technique in detecting iodine isotopes.
Energy Citations Database
A method for determining high concentrations of sodium by Atomic Absorption Spectroscopy (AAS) was developed. Parameter values were set and an interfering ion study completed. This technique utilizing sodium atomic absorption of zinc ion emission from zin...
National Technical Information Service (NTIS)
The high sensitivity technique of laser photoacoustic spectroscopy and optical absorption spectroscopy were utilized to investigate the hydrolysis of Pu(VI) in perchlorate media. Absorption bands attributed to the hydrolysis of Pu(VI) were characterized i...
The application of the Zeeman effect to atomic absorption spectroscopy has been studied over the past several years. This technique has a larger area of application than conventional AAS because of its high degree of selectivity. The ZAA technique can be ...
X-ray absorption spectroscopy is a powerful technique for determination of valency and coordination. Measurements can be made in air or in situ under electrochemical control. The technique will be described and its application to the analysis of passive oxide films, corrosion products, and inhibitors will be ...
DOE Information Bridge
... of spectrochemical and electrochemical techniques such as epi, ir, Raman and solution electronic absorption spectroscopy and cyclic voltametry. ...
... The techniques studied were based on laser spectroscopy, with emphasis on spectrally-resolved absorption and laser-induced fluorescence (LIF). ...
... and X-ray diffraction techniques, and selectively by scanning electron microscopy, X-ray fluorescence, and atomic absorption spectroscopy. ...
cylinder axis was determined using atomic absorption spectroscopy. These experimental techniques will be further elaborated upon ...
NASA Website
... Ultraviolet absorption spectroscopy and mass spectrometry have been applied to the low temperature matrix technique using model systems; they ...
An x-ray absorption spectrometric technique is described. A preliminary experiment to observe emission lines from a wide range of targets was attempted. (DLC)
An x-ray absorption spectrometric technique is described. A preliminary experiment to observe emission lines from a wide range of targets was attempted. (ERA citation 11:016775)
ellipsometry, electroanalytical techniques, impedance spectroscopy, scanning electron microscopy, surface area and porosimetry, X-ray absorption spectroscopy, X-ray...
Science.gov Websites
An accurate analysis of aluminum alloys is required for quality control and characterization purposes. The two analytical techniques atomic absorption spectroscopy and inductively coupled plasma atomic emission spectroscopy are used for the the determinat...
The status of current techniques and methods of atomic absorption (AA) spectroscopy (flame, hybrid, and furnace AA) is discussed, including limitations. Technological opportunities and how they may be used in AA are also discussed, focusing on automation, microprocessors, continuum AA, hybrid analyses, and others. (Author/JN)
ERIC Educational Resources Information Center
X-ray absorption spectroscopy and electron energy loss spectroscopy are complementary analytical techniques on energy and spatial resolution. These techniques are based on the same fundamental physical process of core excitation with either an incident ph...
A laser technique was developed for obtaining photographic absorption spectra of transient chemical species with lifetimes in the nanosecond time range. The lowest excited singlet states of several aromatic hydrocarbons were observed in absorption for the...
The potential of the radiofrequency resonance absorption spectroscopy (RRAS) techniques for detecting specified quantities of specific explosives in checked airline luggage was investigated. The RRAS techniques considered in this study included nuclear ma...
Four different techniques for sample preparation were evaluated for determining vanadium and nickel in crude oils by atomic absorption (AA) spectroscopy: (1) The flame-analyzed dilution method which consists of direct-flame AA analysis after diluting the ...
A functioning optical component absorption measurement facility has been assembled to (1) develop technical competency in evaluating the effectiveness of the technique, and (2) implement the technique as a routine measurement procedure for optical compone...
The research was primarily concerned with the energy levels of ions in crystals. In particular, the use of techniques involving absorption from excited states were explored. These techniques are useful in two ways. First, due to selection rules many excit...
... high resolution IR absorption spectroscopy in ... Descriptors : *HYDROGEN, *ABSORPTION, *SOLID ... PROPERTIES, INFRARED SPECTROSCOPY ...
Jan 10, 2003 ... Using proven techniques of laser absorption spectroscopy, which are simple in concept and easily calibrated, high sensitivities are readily ...
The theory of IRAS and the experimental techniques used are described in some detail and illustrated with experimental results. (Atomindex citation 11:532868)
... rates of HCl on aluminum oxide (alumina) particles were measured by a new technique involving real-time ultraviolet absorption spectroscopy in a ...
This Level-2G global total column ozone product is derived from OMDOAO3 which is based on the Differential Absorption Spectroscopy (DOAS) fitting technique ...
An optical diagnostic technique for electric field measurement in plasma is presented which is based on observing the Doppler shift in absorption lines due to ion drift.
... spectroscopy techniques used to characterize these materials included four-wave mixing, two photon absorption and fluorescence line narrowing. ...
to a variety of techniques including x-ray diffraction (XRD), scanning-transmission electron microscopy (STEM), and x-ray absorption spectroscopy (XAS). The combination of...
... establishment of absorber sample preparation techniques; measurement of initial calibration spectra using several copper compounds; study of ...
This is done by using a novel diode laser absorption spectroscopy technique to measure the spatial distribution of acetylene, CO, CO2, O2, or other species ...
Six hundred and thirty references are cited in this review. The information in the review is divided into 12 major areas: books, reviews, and bibliographies; fundamental studies in flames; developments in instrumentation; measurement techniques and procedure; flame emission spectrometry; flame atomic absorption spectrometry; flame molecular ...
Several spectroscopic methods based on mid-infrared quantum cascade lasers for the ultrasensitive detection of nitric oxide have been developed with detection limit in ppbv and sub-ppbv range. We will describe here a selection of the most effective techniques, i.e., laser absorption spectroscopy, cavity-enhanced ...
The results of a literature survey of several analytical techniques and their applicability toward measuring fluorine atom concentrations in laser systems are reported. These techniques include: electron paramagnetic resonance, absorption spectroscopy, ma...
A powerful, yet often underutilized tool available to probe the structure of macromolecules is absorption spectroscopy. The first of the various spectroscopic techniques to be widely developed, data from absorption spectroscopy is commonly viewed as low in overall information content compared ...
The overall purpose of the program was to study the emission and absorption characteristics of organic compounds containing nitrogen or phosphorus. The excitation methods included the use of rf plasma and hollow cathode discharge lamps. Results showed tha...
Like other analytical techniques, flameless atomic absorption is subject to matrix or interference effects. Upon heating, nitrate and sulfate salts decompose to generate oxidizing species such as nitrogen dioxide or sulfur trioxide. These concomitant oxid...
Operational factors in the use of atomic absorption spectroscopy have been studied on a collaborative basis for use with steelworks materials. Sensitivity, limit of detection and noise level, instrument drift, and calibration procedures have each been exa...
Methods based on atomic-absorption spectrophotometry, and involving various techniques for dissolution and measurement of the sample, have been developed for the determination of trace elements in coal. Non-volatile elements are determined by flame atomic...
This letter describes the extension of saturated absorption spectroscopy to spatially resolved (point) absorption measurements for diagnostic applications. The technique modifies the standard configuration of Doppler-free saturation spectroscopy by using crossed, rather than counterpropagating, ...
IR absorption spectroscopy is a suitable technique to study degradation and damaging effects, induced by gamma radiation, on polymeric materials. The most important effects, crosslinking and oxidative degradation, influence IR spectra which are very sensi...
The recently developed techniques of solid state photoacoustic spectroscopy have been applied to the study of absorption processes in dielectric and semiconducting solids which are of interest in high power laser or electronic applications. The photoacous...
The continuous absorption spectra of small molecules have been examined using Laser Induced Photodissociation Spectroscopy (LIPS). In this technique, molecules are photolyzed using a flashlamp-pumped tunable dye laser; the atomic products of the dissociat...
A tunable diode laser infrared spectrometer has been constructed which uses the general techniques of infrared reflection and absorption spectroscopy to measure in situ molecular vibrational spectra of liquids and their interactions with metal oxide surfa...
The chemical speciation of arsenic in sulfidic waters is complicated by the existence of thioarsenic species. The purpose of this research was to use advanced spectroscopy techniques along with speciation modeling and chromatography to elucidate the chemical speciation of As in ...
EPA Science Inventory
New techniques for spectroscopy in supersonic expansions have been developed since the initiation of the research program. Examples include: The Construction of a Pulsed, Planar, Supersonic, Slit Nozzle; Absorption Spectroscopy in Supersonic Expansions; D...
Near-infrared spectroscopy is a powerful technique to study the composition of planetary surfaces, as the main minerals exhibit absorption bands in this spectral range. It gave important information on the mineralogy and petrology of Mars in the past twen...
The techniques of deep level derivative absorption spectroscopy (DLDAS), photoinduced-transients-spectroscopy (P.I.T.S.) were employed to study deep levels and interfaces in GaAs. Optical transitions due to impurities and structural imperfections where ob...
The kinetics of acetylene absorption on clean Fe(110) have been investigated using a combination of molecular beam relaxation spectroscopy (MBRS) and Auger electron spectroscopy (AES) techniques. AES studies indicated significant beam-surface interaction,...
Abstracts from experimental studies on analytical chemistry are presented. Several techniques have been used, such as: neutron activation analysis, potentiometry, optical emission spectroscopy, alpha and gamma spectroscopy, atomic absorption spectrophotom...
A method for determining high concentrations of sodium by Atomic Absorption Spectroscopy (AAS) was developed. Parameter values were set and an interfering ion study completed. This technique utilizing sodium atomic absorption of zinc ion emission from zinc hollow cathode lamp allows analyses of solutions with ...
... Title : ULTRASONIC ABSORPTION SPECTROSCOPY IN FLUIDS BY OPTICAL DETECTION OF PHOTOACOUSTIC PULSE PROFILES. ...
TUNABLE DIODE LASER ABSORPTION SPECTROSCOPY VERIFICATION ANALYSIS FOR USE IN THE COMBUSTION OPTIMIZATION AND ...
... Accession Number : AD0422032. Title : THE USE OF INFRARED ABSORPTION SPECTROSCOPY IN RESEARCH ON HAFNIA AND ZIRCONIA. ...
... Accession Number : AD0606049. Title : ATOMIC ABSORPTION SPECTROSCOPY. Descriptive Note : Final rept. Corporate ...
... Accession Number : ADD752978. Title : AEROSOL ABSORPTION SPECTROSCOPY. Descriptive Note : CONFERENCE PAPER. ...
... Title : A STUDY OF OPTICAL ABSORPTION SPECTROSCOPY FROM METASTABLE EXCITED STATES OF TRANSITION METALS IONS IN ...
The high sensitivity technique of laser photoacoustic spectroscopy and visible absorption spectroscopy were utilized to investigate the hydrolysis of Pu(VI) in perchlorate media. Pu(VI) absorption bands in the 600 to 700 nm were characterized as a functio...
In x-ray absorption spectroscopy, the accurate determination of the incident intensity (I sub 0) has long been a difficult problem. Several techniques have been used to collect I sub 0 data, but none have simultaneously obtained both I sub 0 and I (transm...
-transformInfra-redReflection AbsorptionSpectroscopy Infra-red reflection absorption spectroscopy (IRRAS) is a technique for studying a technique for polarization-modulated Fourier-transform IRRAS (PM-FTIRRAS) using a rapid-scanning FourierPM-IRRASMethods Most IRRAS experiments utilize a high ...
E-print Network
A new technique, vacuum-ultraviolet laser absorption spectroscopy, has been developed to quantitatively determine the absolute density of H and H sub 2 within a plasma. The technique is particularly well suited to measurement in a plasma, where high charg...
The paper describes a technique for measuring the average energy: and its temporal changes: of intense electron beams on time scales down to a few nanoseconds using 3-channel absorption spectroscopy of the bremsstrahlung from a thin target. The technique appears useful for reasonably monoenergetic electron beams ...
The technique of using two laser-produced plasmas for absorption spectroscopy of ionic species has been greatly improved. A new signal detection system and a new data processing technique have been implemented in the experiment. This experimental technique has been applied to the ...
NASA Astrophysics Data System (ADS)
In this paper, we determined the ratio of C13/C12 of methane in slurry gas from oil wells by the method of laser frequency modulation absorption spectroscopy that has many advantages such as high precision, high spectroscopic resolution and rapidly and simply dealing with samples. This technique provided us with a subsidiary method for ...
The direct-atomization technique of flameless atomic absorption spectroscopy has shown to be a useful and accurate method when applied to determination of the concentration of lead in human lung tissue. The analytical results are highly reproducible and agree with those obtained by the conventional flame atomic ...
Having as an aim the utilization of atomic absorption method with flame's excitement, the limits of detection in water of six metals (Ag, Co, Cr, Cu, Ni, Zn) were determined in synthetic samples through atomic absorption spectroscopy. Techniques to optimi...
Method 1620 was developed by the Industrial Technology Division (ITD) within the United States Environmental Protection Agency's (USEPA) Office of Water Regulations and Standards (OWRS) to provide improved precision and accuracy of analysis of pollutants in aqueous and solid matrices. The ITD is responsible for development and promulgation of nationwide standards setting limits on ...
We have adapted our in-cylinder Fourier-transform spectroscopy technique to measure absorption spectra in a reciprocating engine. Previously, we had used the technique for emission spectroscopy; the upgrade to absorption spectroscopy mode is important ...
... ATOMIC EMISSION SPECTROSCOPY; ATOMIC ABSORPTION ... SPECTROSCOPY; MOLECULAR FLUORESCENCE SPECTROSCOPY; X- ...
... STRUCTURE, SPECTROSCOPY, INFRARED SPECTROSCOPY, ABSORPTION SPECTRA, ULTRAVIOLET SPECTROSCOPY, CHEMICAL ...
... MOLECULAR SPECTROSCOPY, LASER INDUCED FLUORESCENCE, MOLECULAR ... ABSORPTION, ATOMIC SPECTROSCOPY, DISSOCIATION ...
Advanced optical diagnostic techniques relevant to propulsion were investigated. The techniques studied were based on laser spectroscopy, with emphasis on spectrally-resolved absorption and laser-induced fluorescence (LIF). Laser sources included tunable ...
Advanced optical diagnostic techniques relevant to propulsion were investigated. The techniques studied were based on laser spectroscopy, with emphasis on spectrally-resolved absorption and laser-induced fluorescence (LIF) . Spectrally narrow, continuous ...
This report discusses work demonstrating that X-Ray Absorption Spectroscopy is a very powerful technique for the study of electrocatalysts. Results for a prototech catalyst, and platinum are presented. (JL)
A technique to measure the time-resolved coefficients of emission and absorption in a striated mercury-argon flow discharge is described. The measurement technique utilizes the Double Path method and photon counting in conjunction with a multichannel anal...
The technique of Fourier transform infrared reflection-absorption (FTIR-RA) spectroscopy has been successfully adapted to studying bulk and interfacially activated photodegradation of several types of polymers on various metallic substrates. The technique...
Discussions are presented for implementing photoacoustic spectroscopy as a technique for describing the photoacoustic effect. This technique makes it possible to study optical absorption in samples which are usually difficult to study. It is suggested that this approach makes understanding of the photoacoustic ...
Multiphoton ionization techniques provide a versatile means for studying highly excited states of atoms and molecules and provide a valuable complement to traditional techniques based on single-photon absorption and ionization studies. In this paper we pr...
This report comprises fundamental procedures and techniques employed to utilize a moderate power cw laser for vaporization of metallic alloys with subsequent spectrophotometric analysis. A substantial amount of data is presented for zinc, copper, lead, al...
Advanced optical diagnostic techniques relevant to propulsion were investigated The techniques studied were based on laser spectroscopy. with emphasis on spectrally-resolved absorption and laser-induced fluorescence (LIF). Laser sources included tunable c...
The contents of this book are: Semiclassical principles of atomic and molecular spectra; Lasers for spectroscopy; Resonance photoionization spectroscopy; Applications of laser absorption; Laser plasmas for chemical analysis; Laser-induced molecular dissociation; Laser Raman techniques; Laser remote sensing ...
The visible absorption spectrum of liquid ethylene at ? 108 K from 5500 � to 7200 � was measured by using a pulsed tunable dye laser, immersed-transducer, gated-detection opto-acoustic spectroscopy technique. The absorption features show the strongest band with an absorption coefficient of ...
PubMed Central
Results of experiments on the absorption of niobium in a hot, dense plasma are presented. These results represent a major step in the development of absorption techniques necessary for the quantitative characterization of hot, dense matter. A general discussion is presented of the requirements for performing quantitative analysis of ...
In this paper several detection techniques of laser spectroscopy are presented which are illustrated by some examples. They are either based on modified absorption spectroscopy with frequency- or wavelength modulation, on opto-acoustic and opto-thermal spectroscopy, on laser-induced ...
A simulative investigation of noise effects in wavelength modulation spectroscopy (WMS) and direct absorption diode laser absorption spectroscopy is presented. Special attention is paid to the impact of quantization noise of the analog-to-digital conversion (ADC) of the photodetector signal in the two detection ...
X-ray absorption spectroscopy at the C K edge has been performed on carbon nanotubes to demonstrate the capability of the technique to investigate the electronic structure of these systems. We compare and discuss the experimental results achieved on both graphite and nanotubes trying also to determine the relationship between multiple ...
Optical spectroscopy is used to study the laser ablation process of ZnO targets. It is demonstrated that even if Partial Local Thermal Equilibrium is present, self absorption process leads to a decrease of recorded lines emission intensities and have to be taken into account to obtain correct values of such parameters. It is presented a method that ...
We demonstrate a new all-optical, frequency-multiplexed and fast technique for gas-phase ultrasonic absorption spectroscopy. A pulsed laser produces a short-duration acoustic pulse in the gas sample, and the acoustic pulse profiles at two distances are mo...
Metal speciation in biological samples with the aid of atomic absorption spectroscopy has proved a basically feasible, new analytic-chemical technique. However, it requires further development, involves complex apparatus, and is therefore not likely to be...
Laser vaporization is being explored as a means to seed supersonic expansions of rare gases with species which are solid under normal conditions. The quantity of vaporized material must reach a level suitable for cavity ringdown laser absorption spectroscopy which we use to probe the expansions. The technique is applied to anthracene ...
A study was conducted of instrumentation used to determine metals in water. Several of the techniques most commonly used for analysis and routine determinations of metals in water are shown in Table 1. They are atomic absorption spectroscopy, both flame and flameless, atomic emission spectroscopy using conventional ...
Cavity Ring-Down Spectroscopy (CRDS) is a novel technique of measurement of the absorption coefficient based on determination of the Q-factor of an optical resonator which contains the investigated absorber. We present a modified CRDS method (so called CRD-Spectrography) in which the signal is simultaneously analysed within a broad ...
Protein crystallography and NMR spectroscopy took decades to emerge as routine techniques in structural biology. X-ray absorption spectroscopy now has reached a similar stage of maturity for obtaining complementary local structural information around metals in metalloproteins. However, the relatively recent ...
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 ...
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 ...
Optical absorption measurements have been performed on unmodified and on ion-implanted lead lanthanum zirconate titanate ceramics using the photothermal deflection spectroscopy technique. Bulk absorption coefficients depend on the average grain size of the material while the absorption ...
The sensitivity of x-ray absorption edge spectra and extended x-ray absorption fine structure (EXAFS) to the environment of metal atoms make x-ray absorption spectroscopy a useful probe of the environment of the molybdenum in nitrogenase. It is of particular interest to investigate any perturbations of the ...
Velocity-modulation spectroscopy is an established technique for performing laser absorption spectroscopy of molecular ions in a discharge. However, such experiments are often plagued by a coherent background signal arising from emission from the discharge or from electronic pickup. Fluctuations in the background ...
The techniques of extended x-ray absorption fine structure (EXAFS), and x-ray absorption edge spectroscopy (XAES) are used to obtain specific structural information about the manganese coordination environment in synthetic inorganic complexes, and in biol...
Optoacoustic techniques are used to systematically investigate the absorption of CH3OH (methanol) around each of the normal CO2 laser lines. A cylindrical single-pass sealed cell was used, and signal detection was by means of an electret microphone inside the cell. A graphic atlas of the 158 absorptions obtained is presented. These ...
Assemblies of porphyrins on DNA are of potential catalytic interest. Hence, the authors studied the interactions of metalloporphyrins and porphyrins with the monoclonal antibody for meso-tetrakis(carboxyphenyl)porphine (TCPP). UV-vis absorption spectroscopy, emission spectroscopy, and circular dichroism (CD) ...
In this paper the fundamentals of photothermal spectroscopy are presented, special emphasis is done in the obtention of the optical absorption spectra. It is shown that this spectroscopy can be used successfully for the monitoring of protozoans that could infect the human. The usefulness of the technique is ...
