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Diffuse reflectance FTIR of stains on grit blasted metals

Description: Diffuse reflectance mid-infrared Fourier transform (DRIFT) spectroscopy has been applied to the detection of oil contamination on grit-blasted metals. The object of this application is to detect and discriminate between silicone and hydrocarbon oil contamination at levels approaching 10 mg/m{sup 2}. A portable FTIR spectrometer with dedicated diffuse reflectance optics was developed for this purpose. Using translation devices positioned by instructions from the spectrometer operating system, images of macroscopic substrates were produced with millimeter spatial resolution. The pixels that comprise an image are each a full mid-infrared spectrum with excellent signal-to-noise, each determined as individual files and uniquely saved to disc. Reduced spectra amplitudes, based on peak height, area, or other chemometric techniques, mapped as a function of the spatial coordinates of the pixel are used to display the image. This paper demonstrates the application of the technique to the analysis of stains on grit-blasted metals, including the calibration of the method, the inspection of substrates, and the migration of oil contamination.
Date: August 9, 1997
Creator: Powell, G.L.; Hallman, R.L. Jr. & Cox, R.L.
Partner: UNT Libraries Government Documents Department

Evaluating open-path FTIR spectrometer data using different quantification methods, libraries, and background spectra obtained under varying environmental conditions

Description: Studies were performed to evaluate the accuracy of open-path Fourier Transform Infrared (OP-FTIR) spectrometers using a 35 foot outdoor exposure chamber in Pittsboro, North Carolina. Results obtained with the OP-FTIR spectrometer were compared to results obtained with a reference method (a gas chromatograph equipped with a flame ionization detector, GC-FID). Concentration results were evaluated in terms of the mathematical methods and spectral libraries used for quantification. In addition, the research investigated the effect on quantification of using different backgrounds obtained at various times during the day. The chemicals used in this study were toluene, cyclohexane, and methanol; and these were evaluated over the concentration range of 5-30 ppm.
Date: December 31, 1995
Creator: Tomasko, M.S.
Partner: UNT Libraries Government Documents Department

A linear motion machine for soft x-ray interferometry

Description: A Fourier Transform X-ray Spectrometer has been designed and built for use at the Advanced light source at Lawrence Berkeley National Laboratory. The design requires a total rectilinear motion of 15 mm with a maximum pitch error of the stage below {+-}0.4 {mu}radians, to achieve this the authors chose to build the entire machine as a single monolithic flexure. A hydraulic driver with sliding O-ring seals was developed with the intention to provide motion with a stick-slip position error of less than 0.8 nm at a uniform velocity of 20 {mu}m/sec. The machine is comprised of two pairs of nested linear motion flexures, all explained by means of a theory published earlier by Hathaway. Certain manufacturing errors were successfully corrected by an extra weak-link feature in the monolith frame. The engineering details of all the subsystems of the linear motion machine are described and measured performance reported.
Date: July 1, 1997
Creator: Duarte, R.; Howells, M.R.; Hussain, Z.; Lauritzen, T. & McGill, R.
Partner: UNT Libraries Government Documents Department

The first synchrotron infrared beamlines at the Advanced Light Source: Microspectroscopy and fast timing

Description: A set of new infrared (IR) beamlines on the 1.4 bending magnet port at the Advanced Light Source, LBNL, are described. Using a synchrotron as an IR source provides considerable brightness advantages, which manifests itself most beneficially when performing spectroscopy on a microscopic length scale. Beamline (BL) 1.4.3 is a dedicated microspectroscopy beamline, where the much smaller focused spot size using the synchrotron source is utilized. This enables an entirely new set of experiments to be performed where spectroscopy on a truly microscopic scale is now possible. BL 1.4.2 consists of a vacuum FTIR bench with a wide spectral range and step-scan capabilities. The fast timing is demonstrated by observing the synchrotron electron storage pattern at the ALS.
Date: May 1, 1998
Creator: Martin, M.C. & McKinney, W.R.
Partner: UNT Libraries Government Documents Department

Effect of jitter on an imaging FTIR spectrometer

Description: Line of sight (LOS) jitter produces temporal modulations of the signals which are detected in the focal plane of a temporally modulated imaging Fourier Transform Spectrometer. A theoretical treatment of LOS jitter effects is given, and is compared with the results of measurements with LIFTIRS1 (the Livermore Imaging Fourier Transform InfraRed Spectrometer). The identification, isolation, quantification and removal of jitter artifacts in hyperspectral imaging data by means of principal components analysis is discussed. The theoretical distribution of eigenvalues expected from principal components analysis is used to determine the level of significance of spatially coherent instrumental artifacts in general, including jitter as a representative example. It is concluded that an imaging FTIR spectrometer is much less seriously impacted by a given LOS jitter level than a non imaging FTIR spectrometer.
Date: April 1, 1997
Creator: Bennett, C. L., LLNL
Partner: UNT Libraries Government Documents Department

Real Time Air Monitoring Using Open-Path FTIR

Description: Over the last several years there has been renewed interest in the use of open-path Fourier Transform Infrared (FTIR) spectroscopy for a variety of air monitoring applications. The intersect has been motivated by the need for new technology to address the regulator requirements of the Clean Air Act Amendment of 1990. Interest has been expressed in exploring the applications of this technology to locate fugitive-source emissions and measuring total emissions from industrial facilities.
Date: September 23, 1998
Creator: Gamiles, D.S
Partner: UNT Libraries Government Documents Department

Use of step scan FT-IR and multivariate curve resolution to understand aging of propellant binder as a function of depth into the polymer material.

Description: A sample of polymeric propellant binder was aged from 0 to 60 days at 95 C and analyzed using FT-IR step scan photoacoustic spectroscopy. This technique has the ability of to obtain spectra of the polymer as a function of depth into the polymer material. Multivariate curve resolution was applied to the spectra data obtained to extract the contributions of the aged and un-aged spectral components from the spectra. It was found that multivariate curve resolution could efficiently separate highly overlapped spectra and yielded insights into the aging process.
Date: January 1, 2003
Creator: Rivera, Dion Arledge & Alam, Mary Kathleen
Partner: UNT Libraries Government Documents Department

On-chip IR spectral sensors by superconducting detector arrays. Semiannual report {number_sign} 2, 18 January 1995--18 July 1995

Description: The overall objective of Phase 2 is to bring this new spectrometer-on-a-chip technology concept to a sufficiently mature stage of development that it can attract commercial support and be carried to market. The specific technical missions of the Phase 2 program are those for the Project Tasks listed below. These mission objectives are: (1) to establish and prove-out the fabrication processing of silicon wafers into arrays of interference-filter plates; (2) to demonstrate that the linear-array HTS detector technology can be scaled up into square arrays of sufficient size and performance to meet the design requirements developed in the Phase 1 effort; (3) to expand the view of the technology so as to see it in a full engineering-systems context, and thus ensure that at the earliest stage possible conflicts can be resolved, thus a systems design can be accomplished that will realistically encompass all the interacting components; (4) to demonstrate, by fabrication and testing, that the components in this systems design can be combined and will deliver the functionality (e.g., spectral region, bandwidth, and resolution) predicted by the design, and in the context of one or two simple emission-line-spectroscopy prototype applications; (5) to identify and resolve conflicts in the design and fabrication methods/processes such that the new spectrometer can meet the desired goal of multiple applications potential. A brief description of each of these 5 tasks is given along with the progress made on each.
Date: September 29, 1995
Creator: Fenner, D.B.; Carangelo, R.M. & Kung, P.J.
Partner: UNT Libraries Government Documents Department

Hyperspectral imaging in the infrared using LIFTIRS. Revision 1

Description: In this article the ideal performance for various possible designs for imaging spectrometers is discussed. Recent characterization measurements made with LIFTIRS, the Livermore Imaging Fourier Transform InfraRed Spectrometer are also presented. Hyperspectral imagers, characterized by having a large number of spectral channels, enable definitive identification and quantitative measurement of the composition of objects in the field of view. Infrared hyperspectral imagers are particularly useful for remote chemical analysis, since almost all molecules have characteristic rotation-vibration spectra in the infrared, and a broad portion of the so-called fingerprint region of the infrared spectrum lies where the atmosphere is relatively transparent, between 8 and 13 {micro}m.
Date: October 1, 1995
Creator: Bennett, C.L.; Carter, M.R. & Fields, D.J.
Partner: UNT Libraries Government Documents Department

Detection of emission sources using passive-remote Fourier transform infrared spectroscopy

Description: The detection and identification of toxic chemicals released in the environment is important for public safety. Passive-remote Fourier transform infrared (FTIR) spectrometers can be used to detect these releases. Their primary advantages are their small size and ease of setup and use. Open-path FTIR spectrometers are used to detect concentrations of pollutants from a fixed frame of reference. These instruments detect plumes, but they are too large and difficult to aim to be used to track a plume to its source. Passive remote FTIR spectrometers contain an interferometer, optics, and a detector. They can be used on tripods and in some cases can be hand-held. A telescope can be added to most units. We will discuss the capability of passive-remote FTIR spectrometers to detect the origin of plumes. Low concentration plumes were released using a custom-constructed vaporizer. These plumes were detected with different spectrometers from different distances. Passive-remote spectrometers were able to detect small 10 cm on a side chemical releases at concentration-pathlengths at the low parts per million-meter (ppm-m) level.
Date: April 1, 1995
Creator: Demirgian, J.C.; Macha, S.M.; Darby, S.M. & Ditillo, J.
Partner: UNT Libraries Government Documents Department

Design considerations for the development of a space qualification Short Wavelength Imaging Fourier Transform Spectrometer (SWIFTS)

Description: This document is the final report on work performed at Sandia National Laboratories during FY 1992 and 1993 for a Laboratory Directed Research and Development (LDRD) program to look at problems associated with the design and long term operation of a short wavelength imaging Fourier Transform (FT) spectrometer for use in space. In attempts to answer two fundamental questions: is a FT spectrometer with a resolution of 1 cm{sup {minus}1} covering the silicon detector wavelength range of 0.4 to 1.1 microns feasible in a long life space instrument and, if so, is it the best method of obtaining the desired information? Emphasis has been on identifying methods which minimize reliance on precision mechanical alignment and precise velocity control. An important consideration has also been to develop methods which will be compatible with a variety of self-scanning solid state imaging devices. A breadboard instrument was constructed using cube corner retroreflectors and a laser diode position reference. Some preliminary results are reported. This work is primarily intended to act as an aid to engineers at Sandia who wish to pursue the fabrication of a flight qualified instrument. The theoretical parts are intended to be somewhat tutorial in nature to aid the engineer who is not familiar with FT spectroscopy.
Date: June 1, 1997
Creator: Abbink, R. E.
Partner: UNT Libraries Government Documents Department

Rapid characterization of mixed waste by FTIR-fiber optic method

Description: Tank waste characterization requires various analytical systems to identify and quantify the chemical composition and water content of Hanford Site high-level waste. Safe long-term storage of the waste depends on its chemical and physical data. An analytical database is also the key to the design and implementation of pre-treatment and disposal processes. To provide a faster, cheaper, and safer technique to monitor the moisture content of tank waste, two types of near-infrared (NIR) diffuse reflectance fiber optic probes interfaced to a Fouiier transform infrared (FTIR) spectrometry system were studied. Lower absorptivities in the NIR region enable longer pathlengths to be used leading to easier nondestructive sampling. Both overtone and combination bands Of Water can be used for moisture measurements. While a previous report` provides evidence for the feasibility of using fiber optic probes, the results were strictly qualitative. In this study, the fiber optic probe is installed in a hot cell making it possible to characterize highly radioactive mixed waste rapidly and quantitatively. In seeking a strategy to identify individual species in the waste with minimal sample preparation, a modular transfer optic system equipped with a mid-infrared diffuse reflectance sampler was assessed. Light pipes were used to present the sample to the FTIR spectrometer. Its performance for obtaining rapid, high quality mid-infrared (MIR) spectra of mixed waste is compared with FTIR- photoacoustic spectroscopy.
Date: July 26, 1996
Creator: Rebagay, T. V.
Partner: UNT Libraries Government Documents Department

Detection of Surface Contaminant Residue by Tunable Infrared Laser Imaging

Description: We report the development of a new, real-time non-contacting monitor for cleaning verification based on tunable infrared-laser methods. New analytical capabilities are required to maximize the efficiency of cleaning operations at a variety of federal (Department of Defense [DoD] and Department of Energy [DOE]) and industrial facilities. These methods will lead to a reduction in the generation of waste streams while improving the quality of subsequent processes and the long-term reliability of manufactured, repaired or refurbished parts. We have demonstrated the feasibility of tunable infrared-laser imaging for the detection of contaminant residues common to DoD and DOE components. The approach relies on the technique of infrared reflection spectroscopy for the detection of residues. An optical interface for the laser-imaging method was constructed, and a series of test surfaces was prepared with known amounts of contaminants. Independent calibration of the laser reflectance images was performed with Fourier transform infrared (FTIR) spectroscopy. The performance of both optical techniques was evaluated as a function of several variables, including the amount of contaminant, surface roughness of the panel, and the presence of possible interfering species (such as water). Finally, detection limits for generic hydrocarbon contaminants were evaluated as a function of system noise level.
Date: June 1, 2001
Creator: Ottesen, David; Johnsen, Howard; Allendorf, Sarah; Kulp, Tom; Armstrong, Karla; Robinson, Scott et al.
Partner: UNT Libraries Government Documents Department

Material characterization using a hyperspectral infrared imaging spectrometer

Description: Fourier transform spectroscopy has found application in many areas including chemometrics, biomedical and biochemical studies, and atmospheric chemistry. This paper describes an investigation into the application of the LLNL Hyperspectral Infrared Imaging Spectrometer (HIRIS) to the non-destructive evaluation of man-made and natural materials. We begin by describing the HIRIS system and the objects studied in the investigation. Next, we describe the technique used to collect the hyperspec- tral imagery, and discuss the processing required to transform the data into usable form. We then describe a technique to analyze the data, and provide some preliminary results.
Date: October 30, 1998
Creator: Aimonetti, W D; Bixler, J V & Roberts, R S
Partner: UNT Libraries Government Documents Department


Description: Fourier transform spectrometers developed in three distinct spectral regions in the early 1960s. Pierre Connes and his coworkers in France developed remarkably sophisticated step-scan interferometers that permitted near-infrared spectra to be measured with a resolution of better than 0.0 1 cm{sup {minus}1}. These instruments may be considered the forerunners of the step-scan interferometers made by Bruker, Bio-Rad (Cambridge, MA, USA) and Nicolet although their principal application was in the field of astronomy. Low-resolution rapid-scanning interferometers were developed by Larry Mertz and his colleagues at Block Engineering (Cambridge, MA, USA) for remote sensing. Nonetheless, the FT-IR spectrometers that are so prevalent in chemical laboratories today are direct descendants of these instruments. The interferometers that were developed for far-infrared spectrometry in Gebbie's laboratory ,have had no commercial counterparts for at least 15 years. However, it could be argued that these instruments did as much to demonstrate the power of Fourier transform spectroscopy to the chemical community as any of the instruments developed for mid- and near-infrared spectrometry. Their performance was every bit as good as today's rapid-scanning interferometers. However, the market for these instruments is so small today that it has proved more lucrative to modify rapid-scanning interferometers that were originally designed for mid-infrared spectrometry than to compete with these instruments with slow continuous scan or step-scan interferometers.
Date: May 4, 2001
Creator: Griffiths, P. R. & Homes, C.
Partner: UNT Libraries Government Documents Department


Description: The thickness and high absorptivity of single hairs typically result in the saturation of major infrared bands and their distortion. Single human hairs longitudinally microtomed and mounted on mirror slides were scanned routinely in the past with a 20 {micro}m x 100 {micro}m aperture that limited spatial resolution for localized probing and detailed mapping. Use of the nondivergent, bright, and low-noise synchrotron source for FT-IR microspectroscopy enables good S/N even at apertures as small as 5--6 {micro}m. Functional group mapping as well as localized probing for extraneous materials illustrates the utility of this powerful probe.
Date: August 10, 1997
Creator: Williams, G. P. & Wetzel, D. L.
Partner: UNT Libraries Government Documents Department

Step-scan Fourier transform infrared (FTIR) spectrometer for investigating chemical reactions of energy-related materials. Final report, April 1, 1995--March 31, 1997

Description: Two step-scan Fourier transform infrared (FTIR) spectrometers were purchased with URI-DOE funds by the University of Utah. These infrared spectrometers have been used to carry out the following investigations: the determination of strength of adsorption of organic molecules at the liquid-solid interface of coated attenuated total reflectance (ATR) elements, the kinetic study of the photoinitiated polymerization of a dental resin, the exploration of the kinetics of photochemical reactions of organic molecules in solution, and the development of a stopped-flow FTIR interface for measuring rates and mechanisms of reactions in solution that are not photoinitiated and do not have convenient ultraviolet-visible spectral features.
Date: November 4, 1997
Creator: Eyring, E.M.
Partner: UNT Libraries Government Documents Department

Operational Comparison of the ARM SGP AERI and BN AERI Instruments

Description: The U.S. Department of Energy's Atmospheric Radiation Measurement program Southern Great Plain Atmospheric Emitted Radiance Interferometer has been in operation since May 1995. This instrument has collected a vast amount of atmospheric-emitted radiance data during its decade-long operation. In early 2003, the U.S. Department of Energy's Remote Sensing Laboratory operated by Bechtel Nevada acquired a more advanced spectrometer, the BOMEM MR300 Fourier Transform Infrared. The Bechtel Nevada spectrometer and Southern Great Plain Atmospheric Emitted Radiance Interferometer were built by the same company on the same concept. During the period of 10-13 June 2003, both instruments were installed side-by-side at the Atmospheric Radiation Measurement Southern Great Plain site for data comparison. Analysis of the data suggests that the sky radiance data collected by both instruments are comparable and consistent. The relative differences of both data sets are in the range of 0.05 with the exception of the water vapor bands. Empirical relationships between the radiance data collected by both instruments were established line-by-line using a regression technique.
Date: September 2004
Creator: Yuan, Ding & Williams, Gustavious
Partner: UNT Libraries Government Documents Department

Reducing System Artifacts in Hyperspectral Image Data Analysis with the Use of Estimates of the Error Covariance in the Data

Description: Hyperspectral Fourier transform infrared images have been obtained from a neoprene sample aged in air at elevated temperatures. The massive amount of spectra available from this heterogeneous sample provides the opportunity to perform quantitative analysis of the spectral data without the need for calibration standards. Multivariate curve resolution (MCR) methods with non-negativity constraints applied to the iterative alternating least squares analysis of the spectral data has been shown to achieve the goal of quantitative image analysis without the use of standards. However, the pure-component spectra and the relative concentration maps were heavily contaminated by the presence of system artifacts in the spectral data. We have demonstrated that the detrimental effects of these artifacts can be minimized by adding an estimate of the error covariance structure of the spectral image data to the MCR algorithm. The estimate is added by augmenting the concentration and pure-component spectra matrices with scores and eigenvectors obtained from the mean-centered repeat image differences of the sample. The implementation of augmentation is accomplished by employing efficient equality constraints on the MCR analysis. Augmentation with the scores from the repeat images is found to primarily improve the pure-component spectral estimates while augmentation with the corresponding eigenvectors primarily improves the concentration maps. Augmentation with both scores and eigenvectors yielded the best result by generating less noisy pure-component spectral estimates and relative concentration maps that were largely free from a striping artifact that is present due to system errors in the FT-IR images. The MCR methods presented are general and can also be applied productively to non-image spectral data.
Date: January 1, 2002
Partner: UNT Libraries Government Documents Department

Holographic Spectroscopy for Rapid Electron Bunch Analysis: Development of an Instrument with THZ Resolved Optical Gating

Description: The main thrust of our project was to apply the concepts of holographic spectroscopy, developed earlier in the visible and near IR spectral regions for satellite mapping, to the THz region in order to measure the spectral signature of the coherent radiation emanating from a relativistic electron bunch to obtain the bunch length itself. There were four major discoveries. (1) In the course of this ground-breaking work we developed and built the first static THz interferometer suitable for the realization of such a holographic Fourier transform spectrometer. Experimental tests and analysis of the observed results have provided the necessary foundation for future development of THz detector arrays optimized for spectroscopic applications. (2) Since such detectors do not exist at the present time our next effort was to find an alternative approach. We explored the electro-optic (EO) detection of the THz pulse using the short pulse of a visible diode laser synchronized to the bunch with the long-term goal aimed at single bunch measurement capability. The main hurdle was found to be the parasitic scattering of the diode radiation in the EO medium. By using the optical Fourier transform of the THz interference pattern the effects of this background were suppressed enough to obtain the spectrum using multiple shot acquisition. During our experiments at the FLASH facility at DESY we determined that for single bunch measurement capability the diode laser has to be able to produce sub 100 ps pulses with peak power of at least 1 W. Since these parameters are quite feasible at the current stage of diode laser science this combination of techniques can be used for single shot measurement of a short electron bunch. (3) In carrying out the above effort a simpler measurement possibility was uncovered involving the visible/nearIR pulse of incoherent radiation produced by the ...
Date: October 28, 2011
Creator: Sievers, Albert
Partner: UNT Libraries Government Documents Department

Characterization of Water and CO2 Adsorption by Stores 3A Desiccant Samples Using Thermal Gravimetric Analysis and Fourier Transform Infrared Spectroscopy

Description: Two lots of manufactured Type 3a zeolite samples were compared by TGA/IR analysis. The first lot, obtained from Davidson Chemical, a commercial vendor, was characterized during the previous study cycle for its water and water-plus-CO{sub 2} uptake in order to determine whether CO{sub 2} uptake prevented water adsorption by the zeolite. It was determined that CO{sub 2} did not hamper water adsorption using the Davidson zeolite. CO{sub 2} was found on the zeolite surface at dewpoints below -40 C, however it was found to be reversibly adsorbed. During the course of the previous studies, chemical analyses revealed that the Davidson 3a zeolite contained calcium in significant quantities, along with the traditional counterions potassium and sodium. Chemical analysis of a Type 3a zeolite sample retrieved from Kansas City (heretofore referred to as the ''Stores 3a'' sample) indicated that the Stores sample was a more traditional Type 3a zeolite, containing no calcium. TGA/IR studies this year focused on obtaining CO{sub 2} and water absorbance data from the Stores 3a zeolite. Within the Stores 3a sample, CO{sub 2} was found to be reversibly absorbed within the sample, but only at and below -60 C with 5% CO{sub 2} loading. The amount of CO{sub 2} observed eluting from the Stores zeolite at this condition was similar to what was observed from the Davidson zeolite sample but with a greater uncertainty in the measured value. The results of the Stores 3a studies are summarized within this report.
Date: February 1, 2003
Partner: UNT Libraries Government Documents Department

SigmaPlot 2000, Version 6.00, SPSS Inc. Computer Software Project Management, Requirements, and Design Document

Description: SigmaPlot is a vendor software product that will be used to convert the area under an absorbance curve generated by a Fourier transform infrared spectrometer (FTIR) to a relative area. SigmaPlot will be used in conjunction with procedure ZA-565-301, ''Determination of Moisture by Supercritical Fluid Extraction and Infrared Detection.''
Date: October 24, 2000
Creator: HURLBUT, S.T.
Partner: UNT Libraries Government Documents Department