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Raman Spectroscopy: A Key Technique in Investigating Carbon-Based MaterialsThis article explains the key steps of using Raman technology to investigate carbon and carbon-based materials—such as carbon nanotubes, graphene, and carbon fibers and composites—as well as the process of analyzing the spectra.
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A Comprehensive Study of WSe2 Crystals Using Correlated Raman, Photoluminescence (PL), Second Harmonic Generation (SHG), and Atomic Force Microscopy (AFM) ImagingUsing confocal Raman imaging and other advanced measurement techniques, we study the localized strain characteristics of tungsten diselenide (WSe2), an important nanomaterial used for optoelectronic device applications.
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Detection of Trace Tin(II) by Salicylfluoroketone Complex Fluorescence MethodA complex fluorescence method utilizing the Sn(II)-salicylfluorescein (SAF)-cetyltrimethylammonium bromide (CTMAB) system demonstrated effective detection of Sn(II) with a linear relationship between its concentration and fluorescence intensity, along with successful application in various sample matrices with high recovery rates.
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Rapid Identification of Wood Species Based on Portable Near-Infrared Spectrometry and Chemometrics MethodsClassification and identification of different wood species are demonstrated using a portable near-infrared spectrometer, combined with four spectral pretreatment methods and three pattern recognition methods. Additional chemometric tools were used for comprehensive evaluation of classification model accuracy and complexity.
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Optimization of a Soil Particle Content Prediction Model Based on a Combined Spectral Index and Successive Projections Algorithm Using Vis-NIR SpectroscopyA rapid vis-NIR spectroscopy method for determining soil particle size and quality.
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Characterization of GeSbSe Thin Films Synthesized by the Conventional Melt-Quenching MethodSpectroscopic ellipsometry, correlated with UV-vis-NIR spectroscopy, is used to determine the optical constants of thin films, such as in GexSb40-xSe60 chalcogenide glass.
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Comprehensive Gas Chromatography Coupled to Simultaneous Dual Detection (TOF-MS/FID) as a Confirmatory Method for MOSH and MOAH Determination in FoodFood contamination from mineral oil saturated hydrocarbons (MOSHs) and mineral oil aromatic hydrocarbons (MOAHs) is problematic and requires a sensitive analytical technique. These contaminants were analyzed using GC×GC with flame ionization detection (FID) and time-of-flight–MS (TOF–MS) parallel dual detection. The method provides enhanced chromatographic separation, along with the full mass spectra information, and overcomes difficult interferences, resulting in reduction of false positives over conventional GC–MS methods.
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Identifying Freshness of Shrimp Following Refrigeration Using Near-Infrared Hyperspectral ImagingVarious chemometric approaches, including four discriminant models (ELM, TLBO–ELM, KELM, and TLBO–KELM), were used to detect shrimp freshness based on near-infrared hyperspectral imaging.
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Preparation and Spectral Properties of MgAl2O4: Tb3+ PhosphorA look at how the spectral properties single-phase green emission phosphor make it suitable for near-UV light-emitting diode (NUV-LED) applications.
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Optimized Explosives Analysis Using Portable Gas Chromatography–Mass Spectrometry for Battlefield ForensicsWhen explosives are encountered on the battlefield, the use of portable GC–MS is valuable for the detection and confirmatory identification of pre- and post-detonation threats. In addition, this technique provides information about the source of explosives based on the detection and identification of trace-level chemicals in the sample. The data presented here confirm this capability.
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Polychromatic and Microfocused X-ray Radiation for Traceable Quantitative X-ray Fluorescence AnalysisIn X-ray fluorescence (XRF) analysis, physical traceability chains are used to quantify the absolute elemental content in a sample. The physical traceability chain relies on absolute knowledge of the X-ray spectral distribution used for the excitation of the instrument and is currently used at synchrotron radiation facilities. Here, we discuss the transfer of the physical traceability chain to laboratory-based X-ray sources, which are often polychromatic, with the view to generate wider application of quantitative XRF analysis.
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Simulation of an Algorithm for Space Target Materials Identification Based on vis-NIR Hyperspectral DataA model based on similarity regularized nonnegative matrix factorization (SRNMF) can be used in space exploration and national security applications to exploit the spatial information in an image of a space target.
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A Brief Look at Optical Diffuse Reflection (ODR) SpectroscopyIn this short overview, we consider cases for diffuse reflection spectroscopy and introduce the Kubelka-Munk diffuse reflectance formula. We conclude by comparing diffuse transmittance, diffuse reflectance, logarithmic transforms of both, and the Kubelka-Munk transform for mid-infrared spectroscopy of the same sample.
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Detection of Trace Tin(II) by Salicylfluoroketone Complex Fluorescence MethodA complex fluorescence method utilizing the Sn(II)-salicylfluorescein (SAF)-cetyltrimethylammonium bromide (CTMAB) system demonstrated effective detection of Sn(II) with a linear relationship between its concentration and fluorescence intensity, along with successful application in various sample matrices with high recovery rates.
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Growth and Temperature-Dependent Spectral Properties of Yb3+, Tm3+ Co-Doped NaY(MoO4)2 CrystalThe possible energy transfer modes between Yb3+ and Tm3+ ions were analyzed.
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Streamline Optical Control and Characterization with Software-Defined InstrumentationFPGA-based, software-defined equipment can help labs customize system applications and save on costly resources.
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An Archaeometric Investigation into the Former Cataract House Hotel via Elemental AnalysisPortable X-ray fluorescence was used to analyze the archaeological remains of an Underground Railroad station to gain a clearer understanding of the construction phases it underwent during the 19th century.
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Efficient Discrimination of Some Moss Species by Fourier Transform Infrared Spectroscopy and ChemometricsIn combination with attenuated total reflectance (ATR), Fourier transform infrared (FT-IR) spectroscopy can be used to classify different moss species.
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Raman Spectroscopy Analysis of Minerals Based on Feature VisualizationThe advantages of machine-learning methods have been widely explored in Raman spectroscopy analysis. In this study, a lightweight network model for mineral analysis based on Raman spectral feature visualization is proposed. The model, called the fire module convolutional neural network (FMCNN), was based on a convolutional neural network, and a fire-module was introduced to increase the width of the network, while also ensuring fewer trainable parameters in the network and reducing the model’s computational complexity. The visualization process is based on a deconvolution network, which maps the features of the middle layer back to the feature space. While fully exploring the features of the Raman spectral data, it also transparently displays the neural network feature extraction results. Experiments show that the classification accuracy of the model reaches 0.988. This method can accurately classify Raman spectra of minerals with less reliance on human participation. Combined with the analysis of the results of feature visualization, our method has high reliability and good application prospects in mineral classification.
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Novel LC–MS/MS Method with a Dual ESI and APCI Ion Source for Analysis of California-Regulated Pesticides and Mycotoxins in Medium-Chain Triglyceride (MCT) Oil Cannabis TincturesAnalysis of 66 pesticides and 5 mycotoxins regulated by the State of California in cannabis tinctures were analyzed using LC–MS/MS with an ESI source, and LC–MS/MS with an APCI source. A simple, fast, and cheap acetonitrile solvent extraction method was used for sample preparation for good recovery and high throughput, and internal standards were used to compensate for ion suppression effects from the hydrophobic matrix.
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Laser Induced Breakdown Spectroscopy Combined with a Tuned Back Propagation Algorithm for Oil Crop Straw Combustion Smoke Detection and TraceabilityIn this paper, a system based on laser induced breakdown spectroscopy (LIBS) and back propagation (BP) method was developed for the composition and traceability analysis of crop burning smoke.
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Identifying Doxycycline Hydrochloride and Tylosin in Chicken Using Surface-Enhanced Raman SpectroscopyAn increasing number of antibiotic residue problems in food have emerged around the world. We examine how SERS is used to identify antibiotic residues in chicken, focusing on doxycycline hydrochloride and tylosin.
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Raman Rxn4 Analyzer for LNG Truck LoadingThe Raman Rxn4 analyzer for LNG provides accurate measurement of the composition and calorific value of LNG, with 10 times lower uncertainty than GC-vaporizer system.
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Nondestructive Spectroscopic Techniques for Detection of Fungal and Mycotoxin Infections in Food Products: A ReviewFungal infections and mycotoxin contamination in food products pose a major threat to the world population. Mycotoxins contaminate approximately 25% of the world’s food products and cause severe health problems through the utilization of affected food products. The major mycotoxins in different foods are aflatoxins, ochratoxins, fumonisins, zearalenone, trichothecenes, and deoxynivalenol. Today, various conventional and nondestructive techniques are available for the detection of mycotoxins across multiple food products. Conventional methods are time-consuming, require chemical reagents, and include many laborious steps. Therefore, nondestructive techniques like near-infrared (NIR) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, hyperspectral imaging, and the electronic nose are a priority for online detection of fungal and mycotoxin problems in different food products. In this article, we discuss recent improvements and utilization of different nondestructive techniques for the early detection of fungal and mycotoxin infections in various food products.
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A Novel High Selectivity Fluorimetric and Colorimetric Probe Based on Rhodamine B Hydrazide Derivatives for Detecting Hg2+ in Aqueous MediaA simple colorimetric and fluorescent dual-channel chemosensor was designed and synthesized to identify Hg2+ in an aqueous solution with demonstrated high selectivity and sensitivity.
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Density Functional Model of Raman Spectra for the Seminiferous Tubules of Hindlimb Unloaded MiceThis study examines whether the computed spectrum can be used to accurately identify amino acids, by comparing the computer spectrum to the measured spectrum of a biological sample.
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Strategies for Analyzing Challenging Samples: Fusion for ICP & XRF Sample PrepWebinar Date/Time: Wed, Nov 20, 2024 2:00 PM EST
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Challenges of Spectrofluorometry, Part 1: Collect Data Right the First TimeAnalysts using fluorescence emission and fluorescence excitation spectroscopy may encounter several common problems in their measurements. This tutorial, the first of a three-part series, provides a procedure to help avoid them.
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Quantum Computer Helium Laboratory Oxygen Deficiency MonitorThis application note demonstrates the performance of the Oxigraf Safety Monitor to measure the concentration of oxygen molecules in gas samples at a helium laboratory.
