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    3005 results match your criteria Applied spectroscopy[Journal]

    1 OF 61

    Characterization of Heat Diffusion Properties of Rubberized Two-Layer Systems Using Open Photoacoustic Cell Spectroscopy.
    Appl Spectrosc 2017 Jan 1:3702817727729. Epub 2017 Jan 1.
    1 42487 Departamento de Física, Universidade Estadual de Maringá, Maringá, PR, Brazil.
    We applied the open photoacoustic cell method operating at high frequency as an efficient and highly precise tool for the measurement of thermal properties of rubberized two-layer systems. The heat-coupling between the two layers is treated using the analogy between thermal and electrical resistances widely used in heat transfer problems. The thermal resistance between the two layers is considered effective and the problem is decoupled for each layer. Read More

    The Effect of Chain Length on Mid-Infrared and Near-Infrared Spectra of Aliphatic 1-Alcohols.
    Appl Spectrosc 2017 Jan 1:3702817732253. Epub 2017 Jan 1.
    49572 Faculty of Chemistry, University of Wrocław, Wrocław, Poland.
    Effect of the chain length on mid-infrared (MIR) and near-infrared (NIR) spectra of aliphatic 1-alcohols from methanol to 1-decanol was examined in detail. Of particular interest were the spectra-structure correlations in the NIR region and the correlation between MIR and NIR spectra of 1-alcohols. An application of two-dimensional correlation analysis (2D-COS) and chemometric methods provided comprehensive information on spectral changes in the data set. Read More

    Binary Complementary Filters for Compressive Raman Spectroscopy.
    Appl Spectrosc 2017 Jan 1:3702817732324. Epub 2017 Jan 1.
    1 8522 Department of Chemistry, Purdue University, West Lafayette, IN, USA.
    The previously described optimized binary compressive detection (OB-CD) strategy enables fast hyperspectral Raman (and fluorescence) spectroscopic analysis of systems containing two or more chemical components. However, each OB-CD filter collects only a fraction of the scattered photons and the remainder of the photons are lost. Here, we present a refinement of OB-CD, the OB-CD2 strategy, in which all of the collected Raman photons are detected using a pair of complementary binary optical filters that direct photons of different colors to two photon counting detectors. Read More

    Nanoscale Ex-Situ Thermal Impulse Sensors for Structural Fire Forensics.
    Appl Spectrosc 2017 Jan 1:3702817734292. Epub 2017 Jan 1.
    Applied Sciences Laboratory, Institute for Shock Physics, Washington State University, Spokane, WA, USA.
    We develop nanoscale ex situ thermal impulse (i.e., the temperature and duration of a heating event) sensors for structural fire forensics using a mixture of two lanthanide-doped oxide precursors (precursor Eu:ZrO2 and precursor Dy:Y2O3) that undergo irreversible phase changes when heated. Read More

    Quantitative Detection of Ethanol/Acetone in Complex Solutions Using Raman Spectroscopy Based on Headspace Gas Analysis.
    Appl Spectrosc 2017 Jan 1:3702817738010. Epub 2017 Jan 1.
    1 Institute of Photonics & Bio-medicine, Graduate School of Science, East China University of Science and Technology, Shanghai, China.
    This paper demonstrated the quantitative detection of ethanol and acetone mixtures in complex solutions with Raman spectroscopy based on headspace gas analysis. By analyzing the volatile components in the headspace, their concentrations in liquid solutions were determined. We constructed our own Raman spectroscopy system to detect the headspace gas quantitatively over a solution in a sealed vial. Read More

    A Newly Designed Infrared Reflection Absorption Spectroscopy System for In Situ Characterization from Ultrahigh Vacuum to Ambient Pressure.
    Appl Spectrosc 2017 Jan 1:3702817742053. Epub 2017 Jan 1.
    1 Laboratory of Environmental Science and Technology, Xinjiang Technical Institute of Physics & Chemistry; Key Laboratory of Functional Materials and Devices for Special Environments, 74610 Chinese Academy of Sciences, Urumqi , China.
    We present a novel ultrahigh vacuum (UHV) compatible polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS) system that is designed for in situ surface spectroscopic characterization on a transferable single crystalline sample. The innovative design of manipulator rod and high-pressure cell (HPC) ensures free movement of the sample between the preparation chamber and the HPC, and perfect separation of them during high pressure experiments. The pressure in the HPC can be varied from UHV (10(-9) mbar) to ambient pressure (1000 mbar) while keeping the preparation chamber under UHV conditions. Read More

    Fluorescence Excitation Spectroscopy for Phytoplankton Species Classification Using an All-Pairs Method: Characterization of a System with Unexpectedly Low Rank.
    Appl Spectrosc 2017 Jan 1:3702817741278. Epub 2017 Jan 1.
    1 Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, USA.
    An all-pairs method is used to analyze phytoplankton fluorescence excitation spectra. An initial set of nine phytoplankton species is analyzed in pairwise fashion to select two optical filter sets, and then the two filter sets are used to explore variations among a total of 31 species in a single-cell fluorescence imaging photometer. Results are presented in terms of pair analyses; we report that 411 of the 465 possible pairings of the larger group of 31 species can be distinguished using the initial nine-species-based selection of optical filters. Read More

    Photothermal Determination of Absorption and Scattering Spectra of Silver Nanoparticles.
    Appl Spectrosc 2017 Jan 1:3702817738056. Epub 2017 Jan 1.
    3007 Department of Physics and Engineering, Delaware State University, Dover, DE, USA.
    This work reports on photothermal lens spectra of silver nanoparticles of different dimensions in the spectral region of 370-730 nm performed using an arc-lamp-based photothermal spectrophotometer. We show that the photothermal and extinction cross-section spectra of the samples are similar for nanoparticles of reduced dimensions where scattering effects are small. The results differ substantially for nanoparticles of a diameter larger than 30 nm for which scattering becomes relevant. Read More

    Measurement of Wavelength and Temperature-Dependent Optical Properties of Thermochromic Pigments.
    Appl Spectrosc 2017 Jan 1:3702817740586. Epub 2017 Jan 1.
    142683 Department of Civil Engineering, Case Western Reserve University, Bingham, Cleveland, OH, USA.
    Thermochromic material is a substance that is capable of changing reversibly the color as the temperature rises. Therefore, the optical spectrum of thermochromic material is responsive to the environmental temperature. In this study, the temperature-dependent optical constants of thermochromic pigments over the wavelength of 350-1800 nm were investigated. Read More

    Study on the Characteristic Spectral Properties for Species Identification of Animal-Derived Feedstuff Using Fourier Transform Infrared Spectroscopy.
    Appl Spectrosc 2017 Nov 2;71(11):2446-2456. Epub 2017 Oct 2.
    Biomass and Bioresource Utilization Laboratory, College of Engineering, China Agricultural University, Beijing, China.
    The objective of the present study was to explore the effective spectral bands related to lipid characteristics in spectra of raw animal-derived feedstuff and figure out which marked spectral regions (single or combined) contributed more to species discrimination. A total of 82 meat and bone meals, including porcine, poultry, bovine, ovine, and fish, were studied. Raw materials, extracted lipid, and defatted samples were simultaneously analyzed and calculated using Fourier transform infrared (FT-IR) spectroscopy in combination with chemometric methods. Read More

    Design and Characterization of a Singly Labeled Fluorescent Smart Probe for In Vitro Detection of miR-21.
    Appl Spectrosc 2017 Jan 1:3702817736527. Epub 2017 Jan 1.
    108765 Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran 31261, Kingdom of Saudi Arabia.
    A sensitive hairpin smart probe (SP) has been developed and tested for its sequence-specificity and sensitivity for detecting microRNAs (miRNAs). The loop sequence of this SP is perfectly complementary to microRNA-21 (miR-21) sequence. This miRNA regulates certain biological processes and has been implicated in certain forms of cancer. Read More

    Variability in the Raman Spectrum of Unpolished Growth and Fracture Surfaces of Pyrite Due to Laser Heating and Crystal Orientation.
    Appl Spectrosc 2017 Jan 1:3702817736516. Epub 2017 Jan 1.
    1 Department of Earth & 7548 Planetary Sciences, Washington University in St. Louis, St. Louis, MO, USA.
    Two probable causes of variability in the Raman spectrum of unpolished pyrite are well recognized, in principle, but not always in practice, namely: (1) downshifting of band positions due to laser heating; and (2) variations in the ratios of band intensities due to crystallographic orientation of the sample with respect to the laser's dominant polarization plane. The aims of this paper are to determine whether these variations can be used to acquire additional information about pyrites. Here, using laser Raman microprobe analysis of natural, unpolished pyrite samples, we investigate the magnitude of downshifting of band positions associated with laser heating of different sizes of pyrite grains. Read More

    Empirical Factors Affecting the Quality of Non-Negative Matrix Factorization of Mammalian Cell Raman Spectra.
    Appl Spectrosc 2017 Jan 1:3702817732117. Epub 2017 Jan 1.
    1 Michael Smith Laboratories, The University of British Columbia, Vancouver, BC, Canada.
    Mammalian cells contain various macromolecules that can be investigated non-invasively with Raman spectroscopy. The particular mixture of major macromolecules present in a cell being probed are reflected in the measured Raman spectra. Determining macromolecular identities and estimating their concentrations from these mixture Raman spectra can distinguish cell types and otherwise enable biological research. Read More

    Infrared Extinction Performance of Randomly Oriented Microbial-Clustered Agglomerate Materials.
    Appl Spectrosc 2017 Nov 21;71(11):2555-2562. Epub 2017 Sep 21.
    3 Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences and Anhui Province, Hefei, Anhui, China.
    In this study, the spatial structure of randomly distributed clusters of fungi An0429 spores was simulated using a cluster aggregation (CCA) model, and the single scattering parameters of fungi An0429 spores were calculated using the discrete dipole approximation (DDA) method. The transmittance of 10.6 µm infrared (IR) light in the aggregated fungi An0429 spores swarm is simulated by using the Monte Carlo method. Read More

    A Review of Calibration Transfer Practices and Instrument Differences in Spectroscopy.
    Appl Spectrosc 2017 Jan 1:3702817736064. Epub 2017 Jan 1.
    1 316964 Unity Scientific, Milford, MA, USA.
    Calibration transfer for use with spectroscopic instruments, particularly for near-infrared, infrared, and Raman analysis, has been the subject of multiple articles, research papers, book chapters, and technical reviews. There has been a myriad of approaches published and claims made for resolving the problems associated with transferring calibrations; however, the capability of attaining identical results over time from two or more instruments using an identical calibration still eludes technologists. Calibration transfer, in a precise definition, refers to a series of analytical approaches or chemometric techniques used to attempt to apply a single spectral database, and the calibration model developed using that database, for two or more instruments, with statistically retained accuracy and precision. Read More

    A Study of the Effect of a Protein on the Structure of Water in Solution Using Terahertz Time-Domain Spectroscopy.
    Appl Spectrosc 2017 Jan 1:3702817735551. Epub 2017 Jan 1.
    104705 Institute of Cell Biophysics of Russian Academy of Sciences, Moscow, Russia.
    Terahertz time-domain spectroscopy (THz-TDS) was used to determine the spectra (range = 1.2-120 cm(-1)) of aqueous solutions of bovine serum albumin (BSA) at pH range 2.5-10. Read More

    Edge-Preserving Image Smoothing Constraint in Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) of Hyperspectral Data.
    Appl Spectrosc 2017 Jan 1:3702817735598. Epub 2017 Jan 1.
    1 27022 Université de Lille, Sciences et Technologies, LASIR, CNRS, Lille, France.
    This article explores smoothing with edge-preserving properties as a spatial constraint for the resolution of hyperspectral images with multivariate curve resolution-alternating least squares (MCR-ALS). For each constrained component image (distribution map), irrelevant spatial details and noise are smoothed applying an L1- or L0-norm penalized least squares regression, highlighting in this way big changes in intensity of adjacent pixels. The feasibility of the constraint is demonstrated on three different case studies, in which the objects under investigation are spatially clearly defined, but have significant spectral overlap. Read More

    Determination of Rare Earth Elements in Geological Samples Using Laser-Induced Breakdown Spectroscopy (LIBS).
    Appl Spectrosc 2017 Jan 1:3702817734854. Epub 2017 Jan 1.
    2 Department of Physics and Astronomy, Mississippi State University, MS, USA.
    Laser-induced breakdown spectroscopy (LIBS) was used to detect rare earth elements (REEs) in natural geological samples. Low and high intensity emission lines of Ce, La, Nd, Y, Pr, Sm, Eu, Gd, and Dy were identified in the spectra recorded from the samples to claim the presence of these REEs. Multivariate analysis was executed by developing partial least squares regression (PLS-R) models for the quantification of Ce, La, and Nd. Read More

    Fourier Transform Infrared (FT-IR) and Laser Ablation Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) Imaging of Cerebral Ischemia: Combined Analysis of Rat Brain Thin Cuts Toward Improved Tissue Classification.
    Appl Spectrosc 2017 Jan 1:3702817734618. Epub 2017 Jan 1.
    1 Institute of Chemical Technologies and Analytics, TU Wien, Vienna, Austria.
    Microspectroscopic techniques are widely used to complement histological studies. Due to recent developments in the field of chemical imaging, combined chemical analysis has become attractive. This technique facilitates a deepened analysis compared to single techniques or side-by-side analysis. Read More

    Thermal Breakdown Kinetics of 1-Ethyl-3-Methylimidazolium Ethylsulfate Measured Using Quantitative Infrared Spectroscopy.
    Appl Spectrosc 2017 Jan 1:3702817727293. Epub 2017 Jan 1.
    1 Department of Mechanical Engineering, Colorado School of Mines, Golden, CO, USA.
    In this work, the thermal stability of the room temperature ionic liquid (RTIL) 1-ethyl-3-methylimidazolium ethylsulfate ([EMIM][EtSO4]) is investigated using infrared (IR) spectroscopy. Quantitative IR absorption spectral data are measured for heated [EMIM][EtSO4]. Spectra have been collected between 25 ℃ and 100 ℃ using a heated optical cell. Read More

    A Calibration-Free Laser-Induced Breakdown Spectroscopy (CF-LIBS) Quantitative Analysis Method Based on the Auto-Selection of an Internal Reference Line and Optimized Estimation of Plasma Temperature.
    Appl Spectrosc 2017 Jan 1:3702817734293. Epub 2017 Jan 1.
    2 School of Engineering & Applied Science, Aston University, Birmingham, UK.
    The quantitative analysis accuracy of calibration-free laser-induced breakdown spectroscopy (CF-LIBS) is severely affected by the self-absorption effect and estimation of plasma temperature. Herein, a CF-LIBS quantitative analysis method based on the auto-selection of internal reference line and the optimized estimation of plasma temperature is proposed. The internal reference line of each species is automatically selected from analytical lines by a programmable procedure through easily accessible parameters. Read More

    A Piecewise Local Partial Least Squares (PLS) Method for the Quantitative Analysis of Plutonium Nitrate Solutions.
    Appl Spectrosc 2017 Jan 1:3702817734000. Epub 2017 Jan 1.
    2 Environmental Stewardship Directorate, Savannah River National Laboratory, Aiken, SC, United States.
    We have developed a piecewise local (PL) partial least squares (PLS) analysis method for total plutonium measurements by absorption spectroscopy in nitric acid-based nuclear material processing streams. Instead of using a single PLS model that covers all expected solution conditions, the method selects one of several local models based on an assessment of solution absorbance, acidity, and Pu oxidation state distribution. The local models match the global model for accuracy against the calibration set, but were observed in several instances to be more robust to variations associated with measurements in the process. Read More

    Qualitative Analysis of Dairy and Powder Milk Using Laser-Induced Breakdown Spectroscopy (LIBS).
    Appl Spectrosc 2017 Jan 1:3702817733264. Epub 2017 Jan 1.
    1 Institute for Clean Energy Technology and Department of Physics and Astronomy, Mississippi State University, MS, USA.
    Laser-induced breakdown spectroscopy (LIBS) technique was used to compare various types of commercial milk products. Laser-induced breakdown spectroscopy spectra were investigated for the determination of the elemental composition of soy and rice milk powder, dairy milk, and lactose-free dairy milk. The analysis was performed using radiative transitions. Read More

    Origin of Analyte-Induced Porous Silicon Photoluminescence Quenching.
    Appl Spectrosc 2017 Sep 20;71(9):2136-2145. Epub 2017 Mar 20.
    2 Department of Chemistry, Natural Sciences Complex, SUNY-Buffalo, Buffalo, NY, USA.
    We report on gaseous analyte-induced photoluminescence (PL) quenching of porous silicon, as-prepared (ap-pSi) and oxidized (ox-pSi). By using steady-state and emission wavelength-dependent time-resolved intensity luminescence measurements in concert with a global analysis scheme, we find that the analyte-induced quenching is best described by a three-component static quenching model. In the model, there are blue, green, and red emitters (associated with the nanocrystallite core and surface trap states) that each exhibit unique analyte-emitter association constants and these association constants are a consequence of differences in the pSi surface chemistries. Read More

    The Effect of Moderate Temperatures on Latent Fingerprint Chemistry.
    Appl Spectrosc 2017 Sep 14;71(9):2102-2110. Epub 2017 Mar 14.
    Cranfield University, The Defence Academy of the United Kingdom, Shrivenham, UK.
    The effect of moderate temperatures (25-75 ℃) on latent fingerprints over a five-hour period was examined using Fourier transform infrared (FT-IR) microspectroscopy. The aim of the study was to detect changes in IR spectra due to any changes in fingerprint chemistry; these results were then compared to pure compounds found in sebum that was subjected to 75 ℃ for 5 h. Latent fingerprints deposited on CaF2 microscope slides and placed on a Peltier pump heating stage showed that higher temperatures significantly reduced the quantity of sebaceous compounds after 5 h, whereas temperatures below 45 ℃ had little effect on the quantity of these compounds over the same time period. Read More

    Random Forest-Based Evaluation of Raman Spectroscopy for Dengue Fever Analysis.
    Appl Spectrosc 2017 Sep 17;71(9):2111-2117. Epub 2017 Mar 17.
    1 Agri-biophotonics Laboratory, National Institute for Lasers & Optronics, Islamabad, Pakistan.
    This work presents the evaluation of Raman spectroscopy using random forest (RF) for the analysis of dengue fever in the infected human sera. A total of 100 dengue suspected blood samples, collected from Holy Family Hospital, Rawalpindi, Pakistan, have been used in this study. Out of these samples, 45 were dengue-positive based on immunoglobulin M (IgM) capture enzyme-linked immunosorbent assay (ELISA) tests. Read More

    Data Processing Algorithm for Diagnostics of Combustion Using Diode Laser Absorption Spectrometry.
    Appl Spectrosc 2017 Jan 1:3702817732252. Epub 2017 Jan 1.
    Institute for Spectroscopy, Russian Academy of Sciences, Moscow, Russian Federation.
    A new algorithm for the evaluation of the integral line intensity for inferring the correct value for the temperature of a hot zone in the diagnostic of combustion by absorption spectroscopy with diode lasers is proposed. The algorithm is based not on the fitting of the baseline (BL) but on the expansion of the experimental and simulated spectra in a series of orthogonal polynomials, subtracting of the first three components of the expansion from both the experimental and simulated spectra, and fitting the spectra thus modified. The algorithm is tested in the numerical experiment by the simulation of the absorption spectra using a spectroscopic database, the addition of white noise, and the parabolic BL. Read More

    Quantitative Micro-Raman Spectroscopy for Partial Pressure Measurement in Small Volumes.
    Appl Spectrosc 2017 Jan 1:3702817724410. Epub 2017 Jan 1.
    122364 CSEM (Centre Suisse d'Électronique et de Microtechnique) SA, Neuchâtel, Switzerland.
    We demonstrate the quantitative capabilities of Raman confocal microscopy as a nondestructive method to measure the partial pressure of molecular gases in mm(3) range sealed volume having an optical access. Thanks to a calibration procedure, we apply this technique for the characterization of the absolute nitrogen partial pressure inside buffered micro electromechanical system (MEMS) atomic vapor cells developed for atomic clocks. Our results are compared with measurements obtained by rubidium hyperfine frequency spectroscopy and a good agreement is demonstrated between the two methods, with a three-sigma detection limit below 10 mbar for a 1 h integration time, using a 33 mW 532 nm excitation laser. Read More

    Label-Free Raman Hyperspectral Imaging of Single Cells Cultured on Polymer Substrates.
    Appl Spectrosc 2017 Jan 1:3702817715042. Epub 2017 Jan 1.
    1 School of Physics and Astronomy, University of Nottingham, Nottingham, UK.
    While Raman hyperspectral imaging has been widely used for label-free mapping of biomolecules in cells, these measurements require the cells to be cultured on weakly Raman scattering substrates. However, many applications in biological sciences and engineering require the cells to be cultured on polymer substrates that often generate large Raman scattering signals. Here, we discuss the theoretical limits of the signal-to-noise ratio in the Raman spectra of cells in the presence of polymer signals and how optical aberrations may affect these measurements. Read More

    Multivariate Analysis of Mixed Lipid Aggregate Phase Transitions Monitored Using Raman Spectroscopy.
    Appl Spectrosc 2017 Jan 1:3702817729347. Epub 2017 Jan 1.
    Department of Chemistry and Biochemistry, University of Delaware, Newark, DE, USA.
    The phase behavior of aqueous 1,2-dimyristoyl-sn-glycero-3-phosphorylcholine (DMPC)/1,2-dihexanoyl-sn-glycero-3-phosphocholine (DHPC) mixtures between 8.0 ℃ and 41.0 ℃ were monitored using Raman spectroscopy. Read More

    Vibrational Spectroscopy for the Determination of Ionizable Group Content in Ionomer Materials.
    Appl Spectrosc 2017 Jan 1:3702817728243. Epub 2017 Jan 1.
    2 Department of Chemistry, Clemson University, Hunter Laboratories, Clemson, SC, USA.
    An approach based on vibrational spectral measurements is described for determining the ionizable group content of ion conducting polymer membrane materials. Aimed at supporting the assessment of membrane stability and wear characteristics, performance is evaluated for attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopy, confocal Raman microscopy, and ATR FT-IR microscopy using perfluorinated ionomer membrane standards. One set of ionomer standards contained a sulfonic acid ionizable group and the other a sulfonyl imide group. Read More

    Modeling Microalgal Biosediment Formation based on Attenuated Total Reflection Fourier Transform Infrared (ATR FT-IR) Monitoring.
    Appl Spectrosc 2017 Jan 1:3702817728070. Epub 2017 Jan 1.
    Department of Chemistry, University of Tennessee, Knoxville, TN, USA.
    With increasing amounts of anthropogenic pollutants being released into ecosystems, it becomes ever more important to understand their fate and interactions with living organisms. Microalgae play an important ecological role as they are ubiquitous in marine environments and sequester inorganic pollutants which they transform into organic biomass. Of particular interest in this study is their role as a sink for atmospheric CO2, a greenhouse gas, and nitrate, one cause of harmful algal blooms. Read More

    Quantitative Analysis of Polyacrylamide Grafted on Polylactide Film Surfaces Employing Spectroscopic Techniques.
    Appl Spectrosc 2017 Nov 15;71(11):2457-2468. Epub 2017 Sep 15.
    School of Biochemical Engineering and Technology, Sirindhorn International Institute of Technology (SIIT), Thammasat University, Pathum Thani, 12121 Thailand.
    Standard techniques for quantitative measurement of polyacrylamide (PAm) contents grafted on polylactide (PLA) film substrates, P(LA- g-Am- co-MBAm), which are commonly used as cell culture substrates or scaffolds, and pH-sensitive absorbents have been developed with X-ray photoelectron (XPS), proton-nuclear magnetic resonance ((1)H-NMR), and Fourier transform infrared (FT-IR) spectroscopy. The techniques are then applied to examine P(LA- g-Am- co-MBAm) samples prepared from two separate photo-initiator/co-initiator systems. Efficiency and accuracy of the techniques are compared. Read More

    Toward a Noninvasive, Label-Free Screening Method for Determining Spore Inoculum Quality of Penicillium chrysogenum Using Raman Spectroscopy.
    Appl Spectrosc 2017 Jan 1:3702817727728. Epub 2017 Jan 1.
    1 Institute of Chemical Technologies and Analytics, TU Wien, Vienna, Austria.
    We report on a label-free, noninvasive method for determination of spore inoculum quality of Penicillium chrysogenum prior to cultivation/germination. Raman microspectroscopy providing direct, molecule-specific information was used to extract information on the viability state of spores sampled directly from the spore inoculum. Based on the recorded Raman spectra, a supervised classification method was established for classification between living and dead spores and thus determining spore inoculum quality for optimized process control. Read More

    Determination of Magnesium Oxide Content in Mineral Medicine Talcum Using Near-Infrared Spectroscopy Integrated with Support Vector Machine.
    Appl Spectrosc 2017 Nov 21;71(11):2427-2436. Epub 2017 Sep 21.
    1 Key Laboratory of Ministry of Education on Traditional Chinese Medicine Resource and Compound Prescription & Hubei University of Chinese Medicine, Wuhan, China.
    In this research paper, a fast, quantitative, analytical model for magnesium oxide (MgO) content in medicinal mineral talcum was explored based on near-infrared (NIR) spectroscopy. MgO content in each sample was determined by ethylenediaminetetraacetic acid (EDTA) titration and taken as reference value of NIR spectroscopy, and then a variety of processing methods of spectra data were compared to establish a good NIR spectroscopy model. To start, 50 batches of talcum samples were categorized into training set and test set using the Kennard-Stone (K-S) algorithm. Read More

    Determination of Depth in Transmission Raman Spectroscopy in Turbid Media Using a Beam Enhancing Element.
    Appl Spectrosc 2017 Aug 24;71(8):1849-1855. Epub 2017 Feb 24.
    3 Central Laser Facility, Research Complex at Harwell, STFC Rutherford Appleton Laboratory, Harwell Oxford, UK.
    This study demonstrates experimentally a method to enable prediction of depth of a chemical species buried in a turbid medium by using transmission Raman spectroscopy alone. The method allows the prediction of the depth of a single, chemically distinct layer within a turbid matrix by performing two measurements, with and without a beam enhancing element, or "photon diode." The samples employed consisted of two different polymers, of total thickness 3. Read More

    Raman Microspectroscopic Mapping with Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) Applied to the High-Pressure Polymorph of Titanium Dioxide, TiO2-II.
    Appl Spectrosc 2017 Aug 7;71(8):1816-1833. Epub 2017 Mar 7.
    1 Department of Chemistry & Biochemistry, University of Delaware, USA.
    The high-pressure, α-PbO2-structured polymorph of titanium dioxide (TiO2-II) was recently identified in micrometer-sized grains recovered from four Neoarchean spherule layers deposited between ∼2.65 and ∼2.54 billion years ago. Read More

    Implementation of Resonance Tracking for Assuring Reliability in Resonance Enhanced Photothermal Infrared Spectroscopy and Imaging.
    Appl Spectrosc 2017 Aug 14;71(8):2013-2020. Epub 2017 Mar 14.
    1 Institute for Chemical Technologies and Analytics, Technical University of Vienna, Vienna, Austria.
    Photothermal-induced resonance (PTIR) is a method for optical spectroscopy that allows for infrared (IR) chemical imaging at spatial resolution below the limit of diffraction. By using the mechanical resonance of the cantilever for amplification the technique has been shown to allow sensitivity down to single monolayers. In this work, we discuss the challenges that must be overcome for performing stable resonant PTIR measurements and how imprecise experimental procedures can lead to irreproducible or even erroneous results. Read More

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