Applied Spectroscopy最新文献

{"title":"High-Purity Strontium Carbonate Shows the Narrowest Peak Width of Raman Scattered Light.","authors":"Nobuyasu Itoh","doi":"10.1177/00037028251318757","DOIUrl":"https://doi.org/10.1177/00037028251318757","url":null,"abstract":"<p><p>Raman microscopes are widely used in various fields and their spectral resolutions differ greatly depending on the system and optical components. Thus, it is important to evaluate the spectral resolution of Raman systems under measurement conditions. Although calcite is a crystal with a trigonal structure and its narrow peak at ∼1086 cm^-1 has been used to evaluate the spectral resolution of Raman spectrometers, the peak width of calcite itself (∼1.3 cm^-1 at full width half-maximum [FWHM]) is not negligible under high spectral resolution conditions. Because the calcite peak at ∼1086 cm^-1 originates from symmetric stretching, which is a common vibration mode for carbonate salts, we examined strontium carbonate (SrCO₃), barium carbonate (BaCO₃), and lead carbonate (PbCO₃) reagents to find a material having a narrower peak width than calcite. SrCO₃, BaCO₃, and PbCO₃ peaks originating from symmetric stretching were observed at 1072, 1059, and 1054 cm^-1, respectively, and their peak widths at FWHM (0.67, 0.92, and 1.09 cm^-1, respectively) were narrower than that of calcite (1.36 cm^-1). The narrow peak width of SrCO₃ was strongly dependent on its purity, probably due to its high structural regularity, and the change in the peak width (FWHM) was only 0.12 cm^-1 between 5 °C and 45 °C. Thus, we concluded that the high-purity SrCO₃ peak at 1072 cm^-1 was the narrowest peak of Raman scattering light under ambient conditions and is suitable for evaluating high spectral resolution for Raman spectrometers.</p>","PeriodicalId":8253,"journal":{"name":"Applied Spectroscopy","volume":" ","pages":"37028251318757"},"PeriodicalIF":2.2,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143646992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prominent Composition-Dependent Dynamics Decoupling in the Choline Chloride-Glycerol Deep Eutectic Solvent System.","authors":"Allison Stettler, Piyuni Ishtaweera, Gary A Baker, Gary J Blanchard","doi":"10.1177/00037028251326101","DOIUrl":"https://doi.org/10.1177/00037028251326101","url":null,"abstract":"<p><p>Deep eutectic solvents (DESs) exhibit dynamic heterogeneity, where the intricate and dynamic hydrogen bonding within the DES mediates dynamic spatial variation in the DES local environment. The Type III DES composed of choline chloride and glycerol (ChCl:Gly) exhibits this effect prominently, and we report on the observed local organization and its dependence on system composition using the time-resolved reorientation dynamics of three illustrative chromophores of different polarities: perylene (neutral, nonpolar), oxazine 725 (cation, polar) and rose bengal (dianion, polar). Our findings demonstrate that the environments sensed by all three chromophores are markedly different than that predicted by the bulk viscosity of the DES, and that these local environments exhibit remarkably little change as the mole ratio of the DES constituents is varied. Taken collectively, these data provide clear evidence of short-range organization that bears very little resemblance to the longer-range structural organization that determines DES bulk properties.</p>","PeriodicalId":8253,"journal":{"name":"Applied Spectroscopy","volume":" ","pages":"37028251326101"},"PeriodicalIF":2.2,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143623336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Real-Time Mapping of Polymer Film Thickness Using Near-Infrared Hyperspectral Imaging.","authors":"Xiaoyun Chen, Jin Wang, Christopher Thurber, Matthew Benedict, Kurt Olson, Eric Marchbanks, Hyunwoo Kim, Michael Bishop","doi":"10.1177/00037028251323634","DOIUrl":"https://doi.org/10.1177/00037028251323634","url":null,"abstract":"<p><p>A new method based on near-infrared (NIR) hyperspectral imaging (HSI) has been developed for online polymer film thickness mapping. Traditional online methods, including X-ray, capacitance, and physical gauging (micrometers), can only determine film thickness for a point with each measurement. The NIR-HIS method allows the determination of film thickness for a line based on each image, thus enabling true real-time two-dimensional (2D) mapping of film thickness as the film translates in front of the instrument. A Specim NIR camera, 1000-2500 nm, 384 (spatial) × 288 (spatial) pixels, was used in this study for various low-density polyethylene (LDPE), and high-density polyethylene (HDPE) films. Sample thickness between μm to mm can be mapped based on the myriad NIR absorbance bands with various molar absorptivity. The 2310 nm NIR peak was found to be the most effective feature for determining film thickness over the range of polyethylene film studied in this project: 10∼100 μm. A good correlation was found between the 2310 nm absorbance and the incumbent X-ray thickness scanner results. Interference fringes were found to be a potential source of error for quantitative analysis of thin films, and a classical least squares (CLS) analysis was found to be effective in removing fringes. This method was implemented to map out film thickness in real-time in an industrial blown film process.</p>","PeriodicalId":8253,"journal":{"name":"Applied Spectroscopy","volume":" ","pages":"37028251323634"},"PeriodicalIF":2.2,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143623337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Visualizing Molybdenum Pentachloride Flow During Vapor Deposition Processes Using Absorption Imaging.","authors":"James E Maslar, Berc Kalanyan","doi":"10.1177/00037028251325565","DOIUrl":"https://doi.org/10.1177/00037028251325565","url":null,"abstract":"<p><p>An absorption imaging technique was described for visualizing molybdenum pentachloride (MoCl₅) flow during an atomic layer deposition/pulsed chemical vapor deposition process. The imaging system was composed of a telecentric lens and a commercial 7.1 megapixels (MP) complementary metal oxide semiconductor (CMOS) camera. The light source was a fiber-coupled light emitting diode operating at a peak emission wavelength of 443  nm. Flow images of MoCl₅ vapor entrained in a carrier gas were recorded at approximately 93 frames per second in a research-grade vapor deposition chamber. The utility of this technique was illustrated by comparing the MoCl₅ flow patterns for two precursor injection conditions, conditions consisting of different argon carrier gas flow rate and chamber pressure. For a low flow rate and chamber pressure, the flow images showed a gradual expansion of the MoCl₅ concentration front through the field of view with a relatively short MoCl₅ residence time. These flow patterns result in a relatively uniform precursor concentration front impinging on the wafer surface with the precursor being efficiently exhausted from the chamber, making these conditions desirable for thin film deposition in this chamber. For a high carrier gas flow rate and elevated chamber pressure, the flow images showed a high gas velocity jet impinging on the wafer chuck surface and the formation of gas recirculation zones, resulting in a relatively long residence time. These flow conditions would make it difficult to reproducibly deposit uniform thin films in this chamber. This comparison demonstrated the utility of this technique for qualitative characterization of precursor flow fields with minimal data processing. However, the two-dimensional data obtained from this technique can also provide the basis for training and validating computational fluid dynamics models. Furthermore, the addition of duplicate optical systems would provide the basis for determining the three-dimensional precursor distribution through tomographic analysis.</p>","PeriodicalId":8253,"journal":{"name":"Applied Spectroscopy","volume":" ","pages":"37028251325565"},"PeriodicalIF":2.2,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143623346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of the Fossilization Processes of <i>Vicarya callosa japonica</i> Shells Using Raman Micro-Mapping Combined with Principal Component Analysis and Partial Least Squares Regression.","authors":"Yuki Tanaka, Kosuke Hashimoto, Toshiya Ichiki, Hidetoshi Sato, Yukihiro Ozaki, Motohiro Tsuboi","doi":"10.1177/00037028251322807","DOIUrl":"https://doi.org/10.1177/00037028251322807","url":null,"abstract":"<p><p>Micro-Raman spectroscopic analysis of a fossil sample of <i>Vicarya callosa japonica</i> was performed to investigate the chemical process of fossilization. The <i>Vicarya</i> sample, originating from the Miocene Katsuta Group, Okayama prefecture, southwestern Japan, had a conical shell body with multiple protuberances on the outer layer. The interior of the shell was filled with a carbonate sediment. Raman mapping combined with principal component analysis (PCA) and partial least squares regression (PLSR) analysis were performed on the sample. Well-preserved, in vivo aragonite was found to be distributed on the shell and near the boundary between the internal carbonate precipitates and the shell. The internal precipitates were composed of pure calcite and black carbonates. The black-colored precipitates contained pyrite, suggesting that the carbonates were derived from the same biogenic tissue as the carbonate concretions and were the starting point for their crystallization. The rapid formation of the precipitates, also similar to that of carbonate concretions, and the suppression of the demineralization effect of the shell from pore water in the sediment may have contributed to the preservation of the aragonite. The reaction of the transition from aragonite to calcite in the shell progressed to some extent and crystallization was completed before the transition to calcite was complete.</p>","PeriodicalId":8253,"journal":{"name":"Applied Spectroscopy","volume":" ","pages":"37028251322807"},"PeriodicalIF":2.2,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143623334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Confocal Raman Microscopy as a Probe of Material Deconstruction in Processed Low-Density Polyethylene Particles.","authors":"Md Wahiduzzaman, Jeremy Lawrence, Ashley Moreno-Gongora, Jiahe Xu, Dominick J Casadonte, Gerardine G Botte, Carol Korzeniewski","doi":"10.1177/00037028251322142","DOIUrl":"https://doi.org/10.1177/00037028251322142","url":null,"abstract":"<p><p>Confocal Raman microscopy was applied to detect structural change within individual particles of low-density polyethylene (LDPE) following chemical and electrochemical processing steps that aimed to facilitate material decomposition. A high numerical aperture (NA) oil-immersion objective enabled depth-profiling through the near surface region (20 μm-40 μm) of irregularly shaped particles with an axial spatial resolution < 2 μm estimated from measurements of instrument detection efficiency profiles. Changes in vibrational bands sensitive to polyethylene crystallinity were evident following treatments and linked to the release of low molecular weight compounds present as additives and products of processing. Effects of processing were probed by monitoring the rise of Raman scattering intensity in vibrational modes associated with polyethylene chains in a zig-zag (trans) conformation near 1128 cm^-1, 1294 cm^-1, and 1418 cm^-1, signaling chain clustering and development of organized, crystalline-like assemblies. Pristine LDPE particles displayed a uniform structure across the near surface region, while particles treated initially with chemical extractant and then further processed displayed increasingly enhanced crystallinity up to the maximum depth probed (40 μm). As a step toward measurements on ensembles of particles, least squares modeling was adapted to derive pure component spectra reflecting crystallinity change within spectral datasets. The work demonstrates high spatial resolution Raman depth-profiling for the characterization of processed polymers using a high NA immersion objective to overcome the limitations of air-objectives often used for confocal Raman microscopy.</p>","PeriodicalId":8253,"journal":{"name":"Applied Spectroscopy","volume":" ","pages":"37028251322142"},"PeriodicalIF":2.2,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143623335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advertising and Front Matter.","authors":"","doi":"10.1177/00037028251325051","DOIUrl":"https://doi.org/10.1177/00037028251325051","url":null,"abstract":"","PeriodicalId":8253,"journal":{"name":"Applied Spectroscopy","volume":"79 3","pages":"349-352"},"PeriodicalIF":2.2,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143603614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Laser-Induced Breakdown Spectroscopy and a Convolutional Neural Network Model for Predicting Total Iron Content in Iron Ores.","authors":"Yue Jin, Shu Liu, Hong Min, Chenglin Yan, Piao Su, ZhuoMin Huang, Yarui An, Chen Li","doi":"10.1177/00037028241294088","DOIUrl":"10.1177/00037028241294088","url":null,"abstract":"<p><p>Laser-induced breakdown spectroscopy (LIBS) is a rapid method for detecting total iron (TFe) content in iron ores. However, accuracy and measurement error of univariate regression analysis in LIBS are limited due to factors such as laser energy fluctuations and spectral interference. To address this, multiple regression analysis and feature selection/extraction are needed to reduce redundant information, decrease the correlation between variables, and quantify the TFe content of iron ores accurately. Overall, 339 batches of iron ore samples from five countries were obtained from the ports of China during the discharging, and 2034 representative spectra were collected. A convolutional neural network (CNN) model for total iron content prediction in iron ores is established. The performance of variable importance random forest (VI-RF), variable importance back propagation artificial neural network (VI-BP-ANN), and CNN-assisted LIBS in predicting the TFe content of iron ores was compared. Coefficient of determination (<i>R</i>²), root mean square error (RMSE), mean relative error (MRE), and modeling time were selected for model evaluation. The result shows that variable importance significantly enhances the quantitative accuracy and reduces modeling time compared to traditional BP-ANN and RF models. Moreover, the CNN model outperformed manual feature selection methods (VI-BP-ANN and VI-RF), exhibiting the shortest modeling time, highest <i>R</i>², lowest RMSE, and MRE. CNN model's unique characteristics, such as weight sharing and local connection, make it well suited for analyzing high-dimensional LIBS data in multivariate regression analysis. Our approach demonstrates the effectiveness of machine learning and deep learning approaches in improving the accuracy of LIBS for TFe content prediction in iron ores. CNN-assisted LIBS method holds great potential for practical applications in the mining industry.</p>","PeriodicalId":8253,"journal":{"name":"Applied Spectroscopy","volume":" ","pages":"426-437"},"PeriodicalIF":2.2,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142666313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Raman Spectroscopy Detects Bone Mineral Changes with Aging in Archaeological Human Lumbar Vertebrae from Thornton Abbey.","authors":"Sheona Isobel Shankland, Hugh Willmott, Adam Michael Taylor, Jemma Gillian Kerns","doi":"10.1177/00037028241291601","DOIUrl":"10.1177/00037028241291601","url":null,"abstract":"<p><p>Archaeological human remains provide key insight into lifestyles, health, and diseases affecting past societies. However, only limited analyses can be conducted without causing damage due to the destructive nature of current technologies. The same problem exists with current clinical analyses of the skeleton, and the preferred advanced imaging techniques only provide macroscopic information. Raman spectroscopy could provide chemical information without detriment to archaeological bone samples and perhaps the need for invasive diagnostic procedures in the future. This study measured archaeological human vertebrae to investigate if chemical differences with aging were detectable with Raman spectroscopy and if differences in mineral chemistry could contribute to information on bone mineral diseases. The three lowest bones of the spine (lumbar vertebrae L3-L5), which are subject to the heaviest loading in life, of nine adults from three age groups (18-25, 25-45, and 45+ years) were provided by the Thornton Abbey Project. Three biomechanically important anatomical locations were selected for analysis; likely sites chosen to measure any chemical changes associated with aging, the vertebral body center and the zygapophyseal joints. Results detected chemical changes associated with aging. These changes relate to the minerals phosphate (∼960 cm^-1) and carbonate (∼1070 cm^-1), which are fundamental to bone function. Overall mineralization was found to increase with aging, but while carbonate increased with age, phosphate increased up to ∼45 years and then declined. These fluctuations were found in all three vertebrae, but were more distinct in L5, particularly in the vertebral body, indicating this is an optimal area for detecting bone mineral chemistry changes with aging. This is the first Raman analysis of bone samples from the historically significant site of Thornton Abbey. Results detected age-related changes, illustrating that ancient remains can be used to enhance understanding of modern diseases and provide information on the health and lifestyle of historic individuals.</p>","PeriodicalId":8253,"journal":{"name":"Applied Spectroscopy","volume":" ","pages":"413-425"},"PeriodicalIF":2.2,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11898377/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142602888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Real-Time In Vivo Human Skin Testing Using a Handheld Fourier Transform Infrared Spectrometer with a Three-Bounce Two-Pass Attenuated Total Reflection Interface.","authors":"Samuel F Williams, John Chittock, Kirsty Brown, Linda J Kay, Michael J Cork, Simon G Danby","doi":"10.1177/00037028241298714","DOIUrl":"10.1177/00037028241298714","url":null,"abstract":"<p><p>Attenuated total reflection (ATR) Fourier transform infrared spectroscopy (FT-IR) is used to characterize a vast array of materials at the molecular level in various industry types. Here we compare the performance of a portable spectrometer with a novel three-bounce-two-pass (3B2P) ATR scanning interface to the same device with a standard one-bounce (1B) ATR, and to a benchtop spectrometer with a 10-bounce (10B) ATR, in ideal sample-interface conditions and an applied dermatological study setting. In both application settings, the benchtop 10B ATR interface showed the highest signal-to-noise ratio (SNR), however, the novel 3B2P produced a six-fold increase in the sensitivity of the portable spectrometer when analyzing isopropanol and showed the greatest consistency of SNR of all devices when analyzing isopropanol and in vivo skin samples. Spectral data were sourced from a recently undertaken dermatological study involving a cohort of 180 healthy, full-term babies, using both 1B and 3B2P interfaces. Use of the 3B2P interface resulted in a 55% greater successful high-quality spectrum collection rate, compared to the 1B, and showed significantly superior SNR at both observed study time points, i.e., birth (1B: 68.37; 3B2P: 77.37), and at four weeks (1B: 74.53; 3B2P: 80.22). The utility of ATR FT-IR spectrometers as a dermatological clinical tool was also exemplified here, by quantifying the moisture level of newborn skin. By gathering rich spectroscopic data on the molecular structure of the skin, this technique holds great promise for the quantification of skin disease-specific biomarkers.</p>","PeriodicalId":8253,"journal":{"name":"Applied Spectroscopy","volume":" ","pages":"404-412"},"PeriodicalIF":2.2,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142778773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}