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Applied Spectroscopy

Sabrina Stocker, Florian Foschum, Alwin Kienle
A new setup is described to characterize the scattering coefficient and the scattering phase function of liquid media. The setup utilizes the basic idea of a spatially resolved reflectance measurement combined with a sophisticated illumination geometry. The sample is illuminated parallel and close to the interface of the sample and a glass window to get information from single scattered and multiple scattered light. By illuminating the sample with a fiber orientated with the axis parallel to the glass surface, small distances to the source can be examined unimpeded by the illumination beam...
May 2018: Applied Spectroscopy
Cornelia Reitböck, Eric Głowacki, David Stifter
Self-assembled monolayers of alkyl phosphonic acids on anodic aluminum oxide (AlOx) surfaces are important as dielectric layers in thin film electronic devices. Assessing the properties and quality of these monolayers on amorphous AlOx is limited to a few surface-sensitive methods. In this work, we study using nonlinear optical measurements the molecular ordering in n-alkyl phosphonic acids with various alkyl chain lengths (6 to 18 carbons) deposited on AlOx and show the influence of temperature on stability and conformational order...
May 2018: Applied Spectroscopy
Otto Scheibelhofer, Patrick R Wahl, Boris Larchevêque, Fabien Chauchard, Johannes G Khinast
Understanding the behavior of light in granular media is necessary for determining the sample size, shape, and weight when probing using fiber optic setups. This is required for a correct estimate of the active pharmaceutical ingredient content in a pharmaceutical blend via near-infrared spectroscopy. Several strategies to describe the behavior of light in granular and turbid media exist. A common approach is the Monte-Carlo simulation of individual photons and their description using mean free path lengths for scattering and absorption...
April 2018: Applied Spectroscopy
Jianchu Lin, Lina Yu, Weijun Li, Hong Qin
The identification for haploid seeds is an important process in maize haploid breeding. Thanks to the diffuse transmission (DT) technology of near-infrared (NIR) spectroscopy, maize haploid seeds can be selected automatically using NIR spectrum features. However, the NIR spectra of maize seeds contain a large number of redundant features and noise that will degrade the identification performance. We resolved this problem by designing a low dimension and uniform space of seed spectrum features to improve the collected spectra...
April 2018: Applied Spectroscopy
Tanya L Myers, Russell G Tonkyn, Tyler O Danby, Matthew S Taubman, Bruce E Bernacki, Jerome C Birnbaum, Steven W Sharpe, Timothy J Johnson
For optical modeling and other purposes, we have created a library of 57 liquids for which we have measured the complex optical constants n and k. These liquids vary in their nature, ranging in properties that include chemical structure, optical band strength, volatility, and viscosity. By obtaining the optical constants, one can model most optical phenomena in media and at interfaces including reflection, refraction, and dispersion. Based on the works of others, we have developed improved protocols using multiple path lengths to determine the optical constants n/k for dozens of liquids, including inorganic, organic, and organophosphorus compounds...
April 2018: Applied Spectroscopy
Kodai Murayama, Daitaro Ishikawa, Takuma Genkawa, Yukihiro Ozaki
We present a rapid switching system between a newly developed near-infrared (NIR) spectrometer and its imaging system to select the spot size of a diffuse reflectance (DR) probe. In a previous study, we developed a portable NIR imaging system, known as D-NIRs, which has significant advantages over other systems. Its high speed, high spectral resolution, and portability are particularly useful in the process of monitoring pharmaceutical tablets. However, the spectral accuracies relating to the changes in the formulation of the pharmaceutical tablets have not been fully discussed...
April 2018: Applied Spectroscopy
Diana Gómora-Herrera, Juan Navarrete Bolaños, Irina V Lijanova, Octavio Olivares-Xometl, Natalya V Likhanova
The effects exerted by the adsorption of vapors of a non-polar compound (deuterated benzene) and a polar compound (water) on the surface of Ottawa sand and a sample of reservoir sand (Channel), which was previously impregnated with silicon oil or two kinds of surfactants, (2-hydroxyethyl) trimethylammonium oleate (HETAO) and (2-hydroxyethyl)trimethylammonium azelate (HETAA), were studied by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and thermogravimetric analysis (TGA). The surface chemistry of the sandstone rocks was elucidated by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX)...
April 2018: Applied Spectroscopy
Fabien Pottier, Anne Michelin, Christine Andraud, Fabrice Goubard, Bertrand Lavédrine
Ultraviolet visible (UV-Vis) fluorescence spectroscopy is widely used to study polychrome objects and can help to identify the nature of certain materials when they present specific fluorescent properties. However, given the complexity of the stratified and heterogeneous materials under study, the characterization of an intrinsic fluorescence related to a given constituent (a pigment or a binder composing a paint layer for example) is not straightforward, and the recorded raw data need to be corrected for a number of effects that can influence the detected spectral distribution...
April 2018: Applied Spectroscopy
Jafar Gharavi-Naeini, Kyung W Yoo, Nathan A Stump
Systematic micro-Raman scattering investigations have been carried out on Sm+2 doped 2(BaO)-n(B2 O3 ) matrices for n = 4, 5, 8, and 2(BaO)-(Na2 O)-9(B2 O3 ) using the 364 nm excitation of an Ar+ laser. The Raman results have been compared with the known structures of barium tetraborate, barium pentaborate, barium octaborate, and barium sodium nonaborate. An excellent correlation has been found between the BO4 /BO3 composition ratios for each product and intensity ratios of the designated BO4 and BO3 Raman peaks...
April 2018: Applied Spectroscopy
Jakob Kilgus, Kristina Duswald, Gregor Langer, Markus Brandstetter
Mid-infrared (MIR) supercontinuum (SC) lasers are an attractive new option in the field of IR spectroscopy, especially for standoff detection. Supercontinuum radiation unites high brightness, high spatial coherence, and broadband spectral coverage, thereby surpassing thermal IR sources and challenging quantum cascade lasers. The employed SC source operates in the spectral region of 1.2-4.6 µm, filling the spectral gap where quantum cascade lasers lack broader availability. In this work, the SC radiation was recorded by compact Fabry-Pérot filter spectrometers ideally suited for sensitive standoff detection with real-time capability...
April 2018: Applied Spectroscopy
Jason Hartwig, Gaurav Mittal, Kamal Kumar, Chih-Jen Sung
This paper presents a set of system validation experiments that can be used to qualify either static or flow experimental systems for gathering tracer photophysical data or conducting laser diagnostics at high pressure and temperature in order to establish design and operation limits and reduce uncertainty in data interpretation. Tests demonstrated here quantify the effect of tracer absorption at the test cell walls, stratification, photolysis, pyrolysis, adequacy of mixing and seeding, and reabsorption of laser light using acetone as the tracer and 282 nm excitation...
April 2018: Applied Spectroscopy
Ran Pelta, Amihai Granot, Eyal Ben-Dor
Reflection spectroscopy, in the visible-near-infrared-shortwave infrared region (Vis-NIR-SWIR, 350-2500 nm), is a useful technology to extract chemical and physical properties of materials, but might be useless in identifying the spectral features of transparent or dark opaque liquids. Low reflectance values of a liquid reduce the ability to identify characteristic absorption features at specific wavelengths in the reflectance spectrum. In this study, we present a rapid and easy-to-use method to increase the measured reflectance spectrum and expose characteristic absorption features of a liquid...
April 2018: Applied Spectroscopy
Nathan B J Traynor, Christopher McLauchlin, Kenneth Dodge, James E McGarrah, Stephen J Padalino, Michelle McCluskey, T C Sangster, James G McLean
The spectral reflection (specular and diffuse) and transmission of Columbia Resin 39 (CR-39) were measured for incoherent light with wavelengths in the range of 200-2500 nm. These results will be of use for the optical characterization of CR-39, as well as in investigations of the chemical modifications of the polymer caused by ultraviolet (UV) exposure. A Varian Cary 5000 was used to perform spectroscopy on several different thicknesses of CR-39. With proper analysis for the interdependence of reflectance and transmittance, results are consistent across all samples...
April 2018: Applied Spectroscopy
XueXian Yang, Yonghui Liu, Xin Juan Liu, Jin Zhang Peng, Heping Zhao, Chang Qing Sun
We formulated the composition and temperature dependence of the Si and Si1- x Ge x Raman shift from the perspectives of bond order-length-strength correlation and local bond average approach. It is verified that the Raman shift Δω varies in the form of Δω ∝ zE1/2 / d, with inclusion of bond length d and energy E changing with temperature and composition. Numerical reproduction of the thermally induced Si1- x Ge x phonon softening indicates that bond thermal expansion and energy loss dictate the frequency redshift, which resulted in quantitative information on the bond energy and the reference frequencies from which the Raman shifts proceed...
April 2018: Applied Spectroscopy
Paul S Hsu, Naibo Jiang, Anil K Patnaik, Vish Katta, Sukesh Roy, James R Gord
Two-color, planar laser-induced fluorescence (PLIF)-based two-dimensional (2D) thermometry techniques for reacting flows, which are typically developed in the laboratory conditions, face a stiff challenge in their practical implementation in harsh environments such as combustion rigs. In addition to limited optical access, the critical experimental conditions (i.e., uncontrolled humidity, vibration, and large thermal gradients) often restrict sensitive laser system operation and cause difficulties maintaining beam-overlap...
April 2018: Applied Spectroscopy
Daniele A Redoglio, Natascia Palazzo, Francesca Migliorini, Roberto Dondè, Silvana De Iuliis
In this work, laser-induced breakdown spectroscopy (LIBS) is applied for quantitative measurements of Pb in aerosols. In order to investigate the carrier gas role and, in particular, the effect of O2 addition to the gas itself, measurements are carried out in nitrogen and air atmosphere. Aerosol particles are produced by nebulizing Pb(CH3 COO)2 * 3H2 O aqueous solutions of known concentration and the atomic line of 405.8 nm is detected as Pb signature. The plasma generated with the laser pulse is characterized in terms of plasma temperature and electron density, showing no substantial differences with the two carrier gases used...
April 2018: Applied Spectroscopy
Barry K Lavine
No abstract text is available yet for this article.
March 2018: Applied Spectroscopy
Tyler D Stokes, Mellou Foteini, Brett Brownfield, John H Kalivas, George Mousdis, Aziz Amine, Constantinos Georgiou
Synchronous fluorescence spectroscopy (SFS) is used for quantitative analysis as well as for qualitative analysis, such as with classification methods. With SFS, determination of a useful wavelength interval between the excitation and emission wavelengths (Δλ) is required. There are a multitude of Δλ intervals that can be evaluated and optimization of the best one is complex. Presented here is a fusion approach for combining Δλ intervals, thereby negating the need to perform the selection by a skilled operator...
March 2018: Applied Spectroscopy
Timothy C Corcoran
In the chemometric context in which spectral loadings of the analytes are already known, spectral filter functions may be constructed which allow the scores of mixtures of analytes to be determined in on-the-fly fashion directly, by applying a compressive detection strategy. Rather than collecting the entire spectrum over the relevant region for the mixture, a filter function may be applied within the spectrometer itself so that only the scores are recorded. Consequently, compressive detection shrinks data sets tremendously...
March 2018: Applied Spectroscopy
Víctor Olmos, Carmen Bedia, Romà Tauler, Anna de Juan
The study of pollutant effects on living organisms provides information about the possible biological and environmental response to a contaminant. Progression of prostate cancer may be related to exposure to pesticides or other chemical substances. In this work, the effect of the pesticide aldrin on human prostate cancer cells (DU145) is studied using Raman spectroscopy and chemometric techniques. Prostate cancer cell line DU145 has been exposed acutely the pesticide aldrin. Individual Raman spectra coming from control and treated cell populations have been acquired...
March 2018: Applied Spectroscopy
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