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    3087 results match your criteria Applied spectroscopy[Journal]

    1 OF 62

    Fault Detection Based on Near-Infrared Spectra for the Oil Desalting Process.
    Appl Spectrosc 2018 Jan 1:3702818776022. Epub 2018 Jan 1.
    Key Laboratory of Advanced Process Control for Light Industry (Ministry of Education), Institute of Automation, Jiangnan University, Wuxi, China.
    The fault detection problem of the oil desalting process is investigated in this paper. Different from the traditional fault detection approaches based on measurable process variables, near-infrared (NIR) spectroscopy is applied to acquire the process fault information from the molecular vibrational signal. With the molecular spectra data, principal component analysis was explored to calculate the Hotelling T and squared prediction error, which act as fault indicators. Read More

    Sensitive Hg Ion Detection Using Metal Enhanced Fluorescence of Novel Polyvinyl Pyrrolidone (PVP)-Templated Gold Nanoparticles.
    Appl Spectrosc 2018 Jan 1:3702818775704. Epub 2018 Jan 1.
    1 State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China.
    In this study, we report a straightforward strategy for Hg ion detection. Fluorescent Au nanoparticles (NPs) were one-pot synthesized using a polymer (polyvinyl pyrrolidone [PVP]) as both capping and fluorescence agent. The as-synthesized PVP-Au NPs showed a remarkably rapid response selectively for Hg ions compared to 14 other metal ions. Read More

    Simultaneous In Situ Monitoring of Trimethoxysilane Hydrolysis Reactions Using Raman, Infrared, and Nuclear Magnetic Resonance (NMR) Spectroscopy Aided by Chemometrics and Ab Initio Calculations.
    Appl Spectrosc 2018 Jan 1:3702818774570. Epub 2018 Jan 1.
    5 Dow Performance Silicones Process R&D, The Dow Chemical Company, Midland, MI, USA.
    Sol-gels are found in many different scientific fields and have very broad applications. They are often prepared by the hydrolysis and condensation of alkoxysilanes such as trimethoxysilanes, which are commonly used as precursors in the preparation of silsequioxanes via the sol-gel process. The reaction rates of such reactions are influenced by a wide range of experimental factors such as temperature, pH, catalyst, etc. Read More

    Imaging the Surface of a Hand-Colored 19th Century Daguerreotype.
    Appl Spectrosc 2018 Jan 1:3702818773760. Epub 2018 Jan 1.
    The University of Western Ontario (Western University), Department of Chemistry, London, ON, Canada.
    Daguerreotypes are valued artifacts that constitute a unique historical photographic memory of the 19th century. Understanding their surface chemistry is important in order to conserve and, when necessary, to restore them. Colored highlights were often added by hand to emphasize different features on the daguerreotype's subjects. Read More

    Evaluation of the Chemical Composition of Synthetic Leather Using Spectroscopy Techniques.
    Appl Spectrosc 2018 Jan 1:3702818764922. Epub 2018 Jan 1.
    Grupo de Análise Instrumental Aplicada (GAIA), Departamento de Química, Universidade Federal de São Carlos, Brazil.
    Synthetic leather samples from Brazil and Paraguay were evaluated in this study using three spectroscopy techniques: inductively coupled plasma optical emission spectrometry (ICP-OES), laser-induced breakdown spectroscopy (LIBS), and wavelength dispersive X-ray fluorescence (WDXRF). The obtained information from each technique was separately inspected with principal component analysis (PCA). The concentrations of the elements determined in the synthetic leathers using ICP-OES decreased in the following order: Ca > Cr > Mg > Ba > Pb > Al > Fe > Zn > Sb > Ni with a concentration range below the limit of quantification (Read More

    Detection of Ozone and Nitric Oxide in Decomposition Products of Air-Insulated Switchgear Using Ultraviolet Differential Optical Absorption Spectroscopy (UV-DOAS).
    Appl Spectrosc 2018 Jan 1:3702818773091. Epub 2018 Jan 1.
    3 Department of Electrical and Computer Engineering, Center for Optical Material Science and Engineering Technologies (COMSET), Clemson University, Clemson, SC, USA.
    Air-insulated switchgear cabinets play a role in the protection and control of the modern power grid, and partial discharge (PD) switchgear is a long-term process in the non-normal operation of one of the situations; thus, condition monitoring of the switchgear is important. The air-insulated switchgear during PD enables the decomposition of air components, namely, O and NO. A set of experimental platforms was designed on the basis of the principle of ultraviolet differential optical absorption spectroscopy (UV-DOAS) to detect O and NO concentrations in air-insulated switchgear. Read More

    Determination of Elemental Content in Solder Mask Samples Used in Printed Circuit Boards Using Different Spectroanalytical Techniques.
    Appl Spectrosc 2018 Jan 1:3702818774580. Epub 2018 Jan 1.
    Grupo de Análise Instrumental Aplicada (GAIA), Departamento de Química, Universidade Federal de São Carlos (UFSCar), Brazil.
    Solder masks are essential materials used in the manufacture of printed circuit boards (PCB). This material protects PCBs against several types of damage and performance failure. In this study, the capabilities of laser-induced breakdown spectroscopy (LIBS) were investigated for the direct analysis of solder masks typically commercialized for homemade PCB production, and inductively coupled plasma-optical emission spectrometry (ICP-OES) was used to obtain a chemical profile for the target analytes Al, As, Ba, Cd, Co, Cr, Cu, Fe, Hg, Mg, Mn, Ni, Pb, Sb, Sn, and Zn. Read More

    Analysis of Rare Earth Elements in Uranium Using Handheld Laser-Induced Breakdown Spectroscopy (HH LIBS).
    Appl Spectrosc 2018 Jan 1:3702818775431. Epub 2018 Jan 1.
    Chemistry Division - Actinide Analytical Chemistry, Los Alamos National Laboratory, Los Alamos, NM, USA.
    A portable handheld laser-induced breakdown spectroscopy (HH LIBS) instrument was evaluated as a rapid method to qualitatively analyze rare earth elements in a uranium oxide matrix. This research is motivated by the need for development of a method to perform rapid, at-line chemical analysis in a nuclear facility, particularly to provide a rapid first pass analysis to determine if additional actions or measurements are warranted. This will result in the minimization of handling and transport of radiological and nuclear material and subsequent exposure to their associated hazards. Read More

    Evolution of Frying Oil Quality Using Fourier Transform Near-Infrared (FT-NIR) Spectroscopy.
    Appl Spectrosc 2018 Jan 1:3702818764125. Epub 2018 Jan 1.
    2 83178 Faculty of Agriculture and Forestry Engineering, University of Cordoba, Córdoba, Spain.
    This study assesses the capacity of a Fourier transform near-infrared (FT-NIR) spectrometer operating in the range 4500-12 000 cm (833.33-2222.22 nm) to provide quantitative predictions for the parameters of acidity (AV), p-anisidine (pAV), total polar materials (TPM), peroxide value (PV), and oxidative stability index (OSI). Read More

    Study of Higher Diffraction Order Contribution in a Flat Field Grating Spectrograph Using a High-Order Harmonic Source.
    Appl Spectrosc 2018 Jan 1:3702818772564. Epub 2018 Jan 1.
    1 62392 Laser Plasma Section, Raja Ramanna Centre for Advanced Technology, Indore, India.
    An experimental study has been carried out to characterize and investigate the performance of a flat-field grating spectrograph (FFGS) for higher diffraction order in the wavelength range of 80-170 Å. An aberration-corrected, mechanically ruled spherical grating with variable line spacing was used as a dispersive element in the spectrograph. The study was carried out using high-order harmonic radiation generated by an interaction of Ti:sapphire laser pulses with inert gas-filled cells. Read More

    A Direct Quantitative Raman Method for the Measurement of Dissolved Bisulfate in Acid-Sulfate Fluids.
    Appl Spectrosc 2018 Jan 1:3702818773117. Epub 2018 Jan 1.
    1 CAS Key Laboratory of Marine Geology and Environment & Center of Deep Sea Research, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.
    Raman spectroscopy has been applied to the quantitative analysis of the concentration of bisulfate in acid-sulfate fluids at different temperatures. The quantitative analysis method is based on the peak area ratios of [Formula: see text](ν) and HO (ν), where PA([Formula: see text]/HO) = [[Formula: see text]] × (0.0066 × T + 1. Read More

    Validation of Fluorescence Spectroscopy to Detect Adulteration of Edible Oil in Extra Virgin Olive Oil (EVOO) by Applying Chemometrics.
    Appl Spectrosc 2018 Jan 1:3702818768485. Epub 2018 Jan 1.
    1 National Institute of Lasers and Optronics (NILOP), Islamabad, Pakistan.
    Due to high price and nutritional values of extra virgin olive oil (EVOO), it is vulnerable to adulteration internationally. Refined oil or other vegetable oils are commonly blended with EVOO and to unmask such fraud, quick, and reliable technique needs to be standardized and developed. Therefore, in this study, adulteration of edible oil (sunflower oil) is made with pure EVOO and analyzed using fluorescence spectroscopy (excitation wavelength at 350 nm) in conjunction with principal component analysis (PCA) and partial least squares (PLS) regression. Read More

    On the Widths of Bands in the Infrared Spectra of Oxyanions.
    Appl Spectrosc 2018 Jan 1:3702818764446. Epub 2018 Jan 1.
    3 Air Quality Research Center, University of California Davis, Davis, CA, USA.
    It is well known that the antisymmetric stretching (ν) band in the mid-infrared spectra of oxyanion salts is usually very broad, whereas all the other fundamental bands are narrow. In this paper, we propose that the underlying cause of the increased width is the effect of the very high absorption index of this band for samples prepared with a range of particle sizes. When oxyanion salts are ground, the diameter of the resulting particles usually varies from less than 100 nm to about 2 µm. Read More

    Simultaneous Measurements of CO and CO Employing Wavelength Modulation Spectroscopy Using a Signal Averaging Technique at 1.578 μm.
    Appl Spectrosc 2018 Jan 1:3702818766904. Epub 2018 Jan 1.
    2 State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan, China.
    A resolved line pair was selected for simultaneous measurement of carbon monoxide (CO) and carbon dioxide (CO) in the near-infrared (NIR) region. The spectral lines of CO and CO at 1.578 µm were measured by wavelength modulation spectroscopy (WMS)-2 f and the absorption was enhanced with a multipass absorption cell. Read More

    Infrared Evaluation of Enantiometric Amount and Application to Racemization at the Interface Between L- and D-Alanine.
    Appl Spectrosc 2018 Jan 1:3702818770575. Epub 2018 Jan 1.
    Graduate School of Frontier Biosciences, Osaka University, Suita, Japan.
    Amino acids, except for glycine, have two types of molecular structures, L- and D-forms, which are enantiomers. As the L- and D-form molecules have identical chemical and physical properties, they cannot be easily identified by conventional methods. In this study, we found that the amount and the spatial distribution of D-enantiomers in an L-alanine (CHCH(COOH)NH) matrix in evaporated thin films, which is one of amino acid molecules, can be evaluated quantitatively using an infrared micro spectroscopy with synchrotron radiation. Read More

    Standard Reference Line Combined with One-Point Calibration-Free Laser-Induced Breakdown Spectroscopy (CF-LIBS) to Quantitatively Analyze Stainless and Heat Resistant Steel.
    Appl Spectrosc 2018 Jan 1:3702818770572. Epub 2018 Jan 1.
    1 Anhui Provincial Key Laboratory of Photonic Devices and Materials, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei, China.
    Due to the influence of major elements' self-absorption, scarce observable spectral lines of trace elements, and relative efficiency correction of experimental system, accurate quantitative analysis with calibration-free laser-induced breakdown spectroscopy (CF-LIBS) is in fact not easy. In order to overcome these difficulties, standard reference line (SRL) combined with one-point calibration (OPC) is used to analyze six elements in three stainless-steel and five heat-resistant steel samples. The Stark broadening and Saha - Boltzmann plot of Fe are used to calculate the electron density and the plasma temperature, respectively. Read More

    Vibrational Spectroscopy as a Promising Toolbox for Analyzing Functionalized Ceramic Membranes.
    Appl Spectrosc 2018 Jan 1:3702818769479. Epub 2018 Jan 1.
    2 Center for Materials and Processes (MAPEX), University of Bremen, Bremen, Germany.
    Ceramic materials find use in many fields including the life sciences and environmental engineering. For example, ceramic membranes have shown to be promising filters for water treatment and virus retention. The analysis of such materials, however, remains challenging. Read More

    Handheld Raman Spectrometer Instrumentation for Quantitative Tuberculosis Biomarker Detection: A Performance Assessment for Point-of-Need Infectious Disease Diagnostics.
    Appl Spectrosc 2018 Jan 1:3702818770666. Epub 2018 Jan 1.
    5 Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, USA.
    Techniques for the detection of disease biomarkers are key components in the protection of human health. While work over the last few decades has redefined the low-level measurement of disease biomarkers, the translation of these capabilities from the formal clinical setting to point-of-need (PON) usage has been much more limited. This paper presents the results of experiments designed to examine the potential utility of a handheld Raman spectrometer as a PON electronic reader for a sandwich immunoassay based on surface-enhanced Raman scattering (SERS). Read More

    Broadband and High-Resolution Static Fourier Transform Spectrometer with Bandpass Sampling.
    Appl Spectrosc 2018 Jan 1:3702818767431. Epub 2018 Jan 1.
    52991 Faculty of Engineering and Natural Sciences, Sabanci University, İstanbul, Turkey.
    In this study, experimental demonstration of a static Fourier transform spectrometer (static-FTS), based on division of the spectrum into multiple narrowband signals, is presented. The bandpass sampling technique used in this novel spectrometer solves the Nyquist sampling rate limitations and enables recording of wideband spectrum in high resolution. The proposed spectrometer not only has the potential of operating in a wide spectral range, but also has a resolution potential better than 2 cm. Read More

    Understanding the Interaction Between Oligopeptide and Water in Aqueous Solution Using Temperature-Dependent Near-Infrared Spectroscopy.
    Appl Spectrosc 2018 Jan 1:3702818769410. Epub 2018 Jan 1.
    1 12538 Research Center for Analytical Sciences, College of Chemistry, Nankai University, Tianjin, China.
    Investigating the interaction between oligopeptide and water is essential for understanding the structure, dynamics and function of proteins. Temperature-dependent near-infrared (NIR) spectroscopy and independent component analysis (ICA) were employed to study the interaction between oligopeptide and water in aqueous solution. The NIR spectra of two homo-oligopeptides, penta-aspartic acid (D) and penta-lysine (K), in aqueous solution of different concentration were measured at different temperature (30-90 ℃). Read More

    Polarization-Dependent Atomic Force Microscopy-Infrared Spectroscopy (AFM-IR): Infrared Nanopolarimetric Analysis of Structure and Anisotropy of Thin Films and Surfaces.
    Appl Spectrosc 2018 Jan 1:3702818763604. Epub 2018 Jan 1.
    Leibniz-Institut für Analytische Wissenschaften-ISAS e.V., Berlin, Germany.
    Infrared techniques enable nondestructive and label-free studies of thin films with high chemical and structural contrast. In this work, we review recent progress and perspectives in the nanoscale analysis of anisotropic materials using an extended version of the atomic force microscopy-infrared (AFM-IR) technique. This advanced photothermal technique, includes polarization control of the incoming light and bridges the gap in IR spectroscopic analysis of local anisotropic material properties. Read More

    The Spectrum of the Universe.
    Appl Spectrosc 2018 May 4;72(5):663-688. Epub 2018 Apr 4.
    Department of Physics & Astronomy, University of British Columbia, Vancouver, BC, Canada.
    Cosmic background (CB) radiation, encompassing the sum of emission from all sources outside our own Milky Way galaxy across the entire electromagnetic spectrum, is a fundamental phenomenon in observational cosmology. Many experiments have been conceived to measure it (or its constituents) since the extragalactic Universe was first discovered; in addition to estimating the bulk (cosmic monopole) spectrum, directional variations have also been detected over a wide range of wavelengths. Here we gather the most recent of these measurements and discuss the current status of our understanding of the CB from radio to γ-ray energies. Read More

    Detection of Nitrogen Content in Rubber Leaves Using Near-Infrared (NIR) Spectroscopy with Correlation-Based Successive Projections Algorithm (SPA).
    Appl Spectrosc 2018 May 4;72(5):740-749. Epub 2018 Apr 4.
    School of Mechanical and Electrical Engineering, Hainan University, Haikou, China.
    Near-infrared spectroscopy is an efficient, low-cost technology that has potential as an accurate method in detecting the nitrogen content of natural rubber leaves. Successive projections algorithm (SPA) is a widely used variable selection method for multivariate calibration, which uses projection operations to select a variable subset with minimum multi-collinearity. However, due to the fluctuation of correlation between variables, high collinearity may still exist in non-adjacent variables of subset obtained by basic SPA. Read More

    Spectrally Resolved UV Absorption Cross-Sections of Alkali Hydroxides and Chlorides Measured in Hot Flue Gases.
    Appl Spectrosc 2018 Jan 1:3702818763819. Epub 2018 Jan 1.
    1 Division of Combustion Physics, 5193 Lund University , Sweden.
    Spectrally resolved ultraviolet (UV) absorption cross-sections of gas-phase sodium chloride (NaCl), potassium hydroxide (KOH), and sodium hydroxide (NaOH) were measured, for the first time, in hot flue gases at different temperatures. Homogenous gas-phase NaCl, KCl (potassium chloride), NaOH, and KOH at temperatures 1200 K, 1400 K, 1600 K, and 1850 K were prepared in the post-flame zone of laminar flames by seeding nebulized droplets out of aqueous solution of corresponding alkali species. The amount of droplets seeded into the flame was kept constant, so the relative concentration of different alkali species can be derived. Read More

    Surface-Enhanced Raman Scattering (SERS) in Microbiology: Illumination and Enhancement of the Microbial World.
    Appl Spectrosc 2018 Jan 1:3702818764672. Epub 2018 Jan 1.
    School of Chemistry, Manchester Institute of Biotechnology, University of Manchester, UK.
    The microbial world forms a huge family of organisms that exhibit the greatest phylogenetic diversity on Earth and thus colonize virtually our entire planet. Due to this diversity and subsequent complex interactions, the vast majority of microorganisms are involved in innumerable natural bioprocesses and contribute an absolutely vital role toward the maintenance of life on Earth, whilst a small minority cause various infectious diseases. The ever-increasing demand for environmental monitoring, sustainable ecosystems, food security, and improved healthcare systems drives the continuous search for inexpensive but reproducible, automated and portable techniques for detection of microbial isolates and understanding their interactions for clinical, environmental, and industrial applications and benefits. Read More

    Mach-Zehnder Stationary Two-Beam Spectroscopy Using Compound Prisms.
    Appl Spectrosc 2018 Jan 1:3702818763820. Epub 2018 Jan 1.
    42562 Centro de Investigaciones en Optica , León Guanajuato, México.
    An interferometric optical setup for diffraction-less spectroscopy is tested as an optical design for control of interference frequency. Its design is based on a Mach-Zehnder interferometer in which a pair of compound prisms is introduced in the interferometer path to obtain interference patterns, which avoids the diffraction phenomena and nonlinear dispersion found on spectrometers that use gratings. Computer simulations of the interference patterns generated by the proposed optical setup are presented, and confirmed by the experimental results of the optical implementation. Read More

    Heating Effects of Desi Ghee Using Raman Spectroscopy.
    Appl Spectrosc 2018 Jan 1:3702818763331. Epub 2018 Jan 1.
    2 Department of Physics, 236246 Mirpur University of Science and Technology (MUST) Mirpur, Azad Kashmir, Pakistan.
    Raman spectroscopy as a fast and nondestructive technique has been used to investigate heating effects on Desi ghee during frying/cooking of food for the first time. A temperature in the range of 140-180℃ has been investigated within which Desi ghee can be used safely for cooking/frying without much alteration of its natural molecular composition. In addition, heating effects in case of reuse, heating for different times, and cooking inside pressure cookers are also presented. Read More

    Forensic Discrimination of Latent Fingerprints Using Laser-Induced Breakdown Spectroscopy (LIBS) and Chemometric Approaches.
    Appl Spectrosc 2018 Jan 1:3702818765183. Epub 2018 Jan 1.
    Department of Aerospace Engineering, 26725 Seoul National University , Republic of Korea.
    A novel technique is reported for separating overlapping latent fingerprints using chemometric approaches that combine laser-induced breakdown spectroscopy (LIBS) and multivariate analysis. The LIBS technique provides the capability of real time analysis and high frequency scanning as well as the data regarding the chemical composition of overlapping latent fingerprints. These spectra offer valuable information for the classification and reconstruction of overlapping latent fingerprints by implementing appropriate statistical multivariate analysis. Read More

    Optical Characterization of Paper Aging Based on Laser-Induced Fluorescence (LIF) Spectroscopy.
    Appl Spectrosc 2018 Jan 1:3702818761669. Epub 2018 Jan 1.
    1 70573 College of Mechanical and Electrical Engineering, Henan Agricultural University, Zhengzhou, China.
    Paper aging and degradation are growing concerns for those who are responsible for the conservation of documents, archives, and libraries. In this study, the paper aging was investigated using laser-induced fluorescence spectroscopy (LIFS), where the fluorescence properties of 47 paper samples with different ages were explored. The paper exhibits fluorescence in the blue-green spectral region with two peaks at about 448 nm and 480 nm under the excitation of 405 nm laser. Read More

    Quantitative Identification of the Annealing Degree of Apatite Fission Tracks Using Terahertz Time Domain Spectroscopy (THz-TDS).
    Appl Spectrosc 2018 Jan 1:3702818761668. Epub 2018 Jan 1.
    1 State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing, China.
    Apatite fission-track (AFT) analysis, a widely used low-temperature thermochronology method, can provide details of the hydrocarbon generation history of source rocks for use in hydrocarbon exploration. The AFT method is based on the annealing behavior of fission tracks generated by U fission in apatite particles during geological history. Due to the cumbersome experimental steps and high expense, it is imperative to find an efficient and inexpensive technique to determinate the annealing degree of AFT. Read More

    Linear and Nonlinear Thermal Lens Signal of the (Δν = 6) C-H Vibrational Overtone of Naphthalene in Liquid Solutions of n-Hexane.
    Appl Spectrosc 2018 Jan 1:3702818761671. Epub 2018 Jan 1.
    Department of Chemistry & Biochemistry, Baylor University, Waco, TX, USA.
    The thermal lens technique is applied to vibrational overtone spectroscopy of solutions of naphthalene (CH) in liquid hexane. The C-H fifth vibrational (Δν = 6) overtone spectrum of CH is detected at room temperature for mole fractions from 0.08 to 19 × 10 using n-CH as solvent. Read More

    Spatially Resolved Lateral Transmission Measurements to Characterize Changes in the Scattering Coefficient and the Anisotropy Factor.
    Appl Spectrosc 2018 May 21;72(5):757-764. Epub 2018 Feb 21.
    Institut für Lasertechnologien in der Medizin und Meßtechnik, Ulm, Germany.
    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. Read More

    Sum-Frequency Generation Vibrational Spectroscopy Investigations of Phosphonic Acids on Anodic Aluminum Oxide Films.
    Appl Spectrosc 2018 May 13;72(5):725-730. Epub 2018 Feb 13.
    1 Center for Surface- and Nanoanalytics, Johannes Kepler University Linz, Linz, Austria.
    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. Read More

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