Applied Spectroscopy最新文献

{"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":"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":"1518-1526"},"PeriodicalIF":2.2,"publicationDate":"2025-10-01","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":"Application of Laser Spectroscopy and Machine Learning for Diagnostics of Uncontrolled Type 2 Diabetes.","authors":"Imran Rehan, Kamran Rehan, Sabiha Sultana, Mujeeb Ur Rehman","doi":"10.1177/00037028251334383","DOIUrl":"10.1177/00037028251334383","url":null,"abstract":"<p><p>Diabetes, a chronic metabolic disorder affecting millions worldwide, presents a persistent need for reliable and non-invasive diagnostic techniques. Here, we suggest a highly effective approach for differentiating between fingernails from diabetic individuals and those from healthy controls using laser-induced breakdown spectroscopy (LIBS). The excitation source employed was a Q-switched neodymium-doped yttrium aluminum garnet (Nd:YAG) laser emitting light with a wavelength of 1064  nm. The initial differentiation between individuals with and without diabetes was achieved by applying principal component analysis (PCA) to LIBS spectral data, which was then incorporated into a novel machine-learning model. The classification model designed for a non-invasive system included random forest (RF), an extreme learning machine (ELM) classifier, and a hybrid classification model incorporating cross-validation techniques to evaluate the outcomes. The algorithm analyses the complete spectrum of both healthy and diseased samples, categorizing them according to differences in LIBS spectral intensity. The classification performance of the model was assessed using a <i>k</i>-fold cross-validation method. Seven parameters, i.e., specificity, sensitivity, area under curve (AUC), accuracy, precision, recall, and F-score, were used to evaluate the model's overall performance. The findings affirmed that the suggested non-invasive model could predict diabetic diseases with an accuracy of 95%.</p>","PeriodicalId":8253,"journal":{"name":"Applied Spectroscopy","volume":" ","pages":"1478-1486"},"PeriodicalIF":2.2,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143960554","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":"Investigation of Thin Silicone Films on Opaque Solid Surfaces Using Coherent Raman Scattering Imaging.","authors":"Julian Naser, George Sarau, Jan Wrege, Silke Christiansen","doi":"10.1177/00037028251339495","DOIUrl":"10.1177/00037028251339495","url":null,"abstract":"<p><p>The measurement of thin films with a thickness in the nanometer range is challenging because it requires extensive sample preparation, vacuum condition, long measurement times or using test inks that additionally contaminate the surface. The detection of those films is crucial for production processes that rely on a boundary layer to create a proper interface like adhesive bonding, coating, or lithography in various industries like automotive, solar, energy storage and semiconductor manufacturing. Consequently, there is a need for quick, reliable measurement techniques with high sensitivity to ensure the technical cleanliness of the opaque surface. In this paper the feasibility of epi-detection with coherent Raman scattering (CRS) Imaging is investigated on different substrate materials and demonstrated to be a method for fast scanning of large nontransparent surfaces including chemical fingerprinting of the substances atop. Therefore, various samples with low surface energy filmic contaminations from polysiloxanes are produced and investigated with CRS Imaging, a technique mostly applied to biological samples with the novel use demonstrated here for surface contamination monitoring in material sciences.</p>","PeriodicalId":8253,"journal":{"name":"Applied Spectroscopy","volume":" ","pages":"1508-1517"},"PeriodicalIF":2.2,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12504782/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144109601","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":"EXPRESS: Raman Spectroscopy for Monitoring Polymerization, Quality Control, and Additive Distribution in Styrene-Divinylbenzene Based Proppants.","authors":"Marcelo Sosa Morales, C J Pérez, María Alvarez, Lucas Fabian, José M Carella, J Pablo Tomba","doi":"10.1177/00037028251386484","DOIUrl":"https://doi.org/10.1177/00037028251386484","url":null,"abstract":"<p><p>Raman spectroscopy was applied to monitor polymerization, verify quality control, and analyze additive distribution in styrene-divinylbenzene (Sty-DVB) based proppants. The method relies on C=C vibrational markers to follow monomer consumption, crosslinking, and additive incorporation. Quality control included quantifying vinyl, cis, and trans C=C in polybutadiene (PB) modifiers and the ethyl-vinyl benzene (EVB) content in DVB crosslinkers. EVB content by Raman showed excellent agreement with independent carbon-13 nuclear magnetic resonance (¹³C-NMR) measurements. Styrene copolymerization with DVB was tracked in real time using a fiber-optic Raman probe in a temperature-controlled microreactor. DVB accelerates styrene consumption due to its higher reactivity and radical stabilization. PB additives do not affect overall polymerization kinetics. In terms of additives, Raman calibration confirms that PB double bonds remain largely unreacted, consistent with limited copolymerization and phase separation. Polyphenylene oxide (PPO) slows down Sty polymerization while Raman mapping demonstrates its homogeneous dispersion within the matrix, validating its incorporation and expected impact on material properties. Overall, Raman spectroscopy provides a direct, non-invasive, and scalable approach to monitor polymerization and verify additive distribution, establishing it as a practical tool for process optimization in Sty-DVB proppant formulations.</p>","PeriodicalId":8253,"journal":{"name":"Applied Spectroscopy","volume":" ","pages":"37028251386484"},"PeriodicalIF":2.2,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145147463","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":"Prediction of Soil pH in Ash-Enriched Laboratory Columns Using Portable Near-Infrared Spectroscopy: A Comparison of Analytical Strategies.","authors":"Edouard J Acuña, Francisco J Calderon, Carlos A Bonilla","doi":"10.1177/00037028251385574","DOIUrl":"10.1177/00037028251385574","url":null,"abstract":"<p><p>In the post-fire stage, precipitation and superficial incorporation of ashes alter the chemical properties of the soil. This study evaluated the combined effects of spectral preprocessing methods, data partitioning strategies, and modeling approaches on soil pH prediction using a portable near-infrared (NIR) spectrometer in wildfire ash-enriched soil. A laboratory column experiment was conducted using disturbed sandy loam soil, in which wildfire ashes were incorporated. The experimental design considered five treatments (<i>n</i> = 3) of <i>Eucalyptus globulus</i> and <i>Quillaja saponaria</i> ash incorporations (C: no ash; T1: 2% ash at 2.5  cm; T2: 2% ash at 5  cm; T3: 4% ash at 2.5  cm; T4: 4% ash at 5  cm). After simulating a precipitation of 20  mm h^-1 for 6 hours, the soil columns were sampled at 5 depths (D1: 2-3  cm, D2: 7-8  cm, D3: 12-13  cm, D4: 16-17  cm, D5: 20-21  cm). The samples were analyzed using a NIR spectrometer (range: 1350-2550  nm), and the levels of pH (1:2.5) were determined in the laboratory. Eight preprocessing techniques (P0 to P7) were tested, including absorbance conversion, mean centering, trimming, smoothing, standard normal variate (SNV), moving window average (MWA), Savitzky-Golay filtering, and first derivative transformation. Using the Kennard-Stone method, 70% of the data was used for calibration (CAL) and 30% for validation (VAL), considering two partitioning approaches, the same partition by pseudo absorbance values (Scenario A) and different partitions by preprocessing method (Scenario B). Partial least square (PLS) and random forest (RF) models were applied, and performance was assessed using root mean square error (RMSE), coefficient of determination (<i>r</i>²), and ratio of performance to interquartile distance (RPIQ) analyses. The most accurate pH predictions were achieved with RF under Scenario B using trimming + standard normal variate (SNV) + moving weighted average (MWA) preprocessing, yielding <i>r</i>² values of 0.95 (CAL) and 0.91 (VAL), with RMSEs of 0.23 (CAL) and 0.57 (VAL), and RPIQs of 4.33 (CAL) and 4.61 (VAL). Overall, portable NIR spectroscopy demonstrated strong potential for soil pH prediction in ash-enriched soil, emphasizing the critical role of appropriate spectral preprocessing to avoid overfitting. These findings provide insights into applying portable NIR spectroscopy as a cost-effective tool for monitoring soil pH following wildfires.</p>","PeriodicalId":8253,"journal":{"name":"Applied Spectroscopy","volume":" ","pages":"37028251385574"},"PeriodicalIF":2.2,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145129785","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":"Morphology-Enhanced Rolling Ball Algorithm for Baseline Removal.","authors":"Xiaoyang Li, Hanjun Zhang, Zhong Wang, Yuee Li","doi":"10.1177/00037028251384654","DOIUrl":"10.1177/00037028251384654","url":null,"abstract":"<p><p>As a preprocessing step of spectroscopic techniques such as Raman spectroscopy, infrared spectroscopy, electrophoresis, etc., the baseline correction is very important for improving the signal quality, thereby ensuring the reliability and accuracy of the data analysis. Methods such as polynomial fitting, wavelet transforms, and frequency-domain filtering are widely used for baseline correction, effectively reducing interference and enhancing the reliability of signal analysis. However, these methods have certain limitations: (i) Polynomial fitting faces challenges in determining the optimal order, which may affect the fitting quality, (ii) wavelet transforms are complex and require fine adjustments, and (iii) frequency-domain filtering may cause signal distortion. These shortcomings affect the implementation of the algorithm in spectral related industries. Therefore, finding an appropriate algorithm to optimize baseline removal is crucial for the development of automated spectral analysis equipment. Here, we propose a rolling ball baseline removal algorithm based on morphological operations. With its simple implementation and excellent baseline removal performance, this method effectively avoids the overfitting problems. It is suitable for baseline correction in not only Raman spectroscopy, but also various other types of spectral data. In all, this approach offers a convenient and efficient general solution for the processing of various spectral data.</p>","PeriodicalId":8253,"journal":{"name":"Applied Spectroscopy","volume":" ","pages":"37028251384654"},"PeriodicalIF":2.2,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145084897","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":"Re-Examining Tip-Enhanced Raman Signals at High Spatial Resolution Under Ambient Conditions Using Graphene Nanobubbles.","authors":"Yuto Fujita, Norihiko Hayazawa, Maria Vanessa Balois-Oguchi, Satoshi Yasuda, Takuo Tanaka, Tomoko K Shimizu","doi":"10.1177/00037028251382936","DOIUrl":"10.1177/00037028251382936","url":null,"abstract":"<p><p>High spatial resolution tip-enhanced Raman spectroscopy (TERS) measurements were carried out under ambient conditions on graphene nanobubbles with various associated structural features. The resulting signals were analyzed with consideration of the characteristic features inherent to high resolution TERS. Compared to flat graphene regions, nanobubbles and their associated nanoconvex pinning sites demonstrated enhanced TERS signals, attributed to the efficient coupling between the strong tip-enhanced electric field and out-of-plane deformations in graphene. Strong coupling with highly confined near-field light activates the D bands even in the absence of defects, with intensity depending on the degree of deformations. While the D band is observed across the nanobubbles, some local regions exhibit a weaker D band intensity compared to the surrounding areas. Given the finite number of hexagonal lattices within the area of highly confined near-field, this reduction in intensity is likely to result from defects that cause missing hexagonal lattices. These findings highlight the capability of near-field induced Raman signals in probing high resolution features of nanomaterials even under ambient conditions, providing deeper insights into their characteristics in situ.</p>","PeriodicalId":8253,"journal":{"name":"Applied Spectroscopy","volume":" ","pages":"37028251382936"},"PeriodicalIF":2.2,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145068907","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":"Determination of Provenance Soil Type Using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) Analyses of <i>Pinus ponderosa</i> Ash.","authors":"M Fernanda Delgado Cornelio, Michael E Ketterer, James A Jordan, Tyler B Coplen, Caelin P Celani, Helder V Carneiro, Karl S Booksh","doi":"10.1177/00037028251358899","DOIUrl":"10.1177/00037028251358899","url":null,"abstract":"<p><p>This study demonstrates the feasibility of determining soil provenance from tree ash composition using elemental analysis and chemometric techniques. To date, no published studies have applied chemometric approaches to classify ash for provenance determination following forest fires. In this work, <i>Pinus ponderosa</i> ash was analyzed to distinguish samples based on soil type and geographic location. <i>Pinus ponderosa</i>, a widely distributed pine species in the western United States where wildfires are prevalent, was selected as a model system. Needles were collected from trees grown in five distinct soil types across northern Arizona and Colorado, then dry-ashed under controlled conditions. Classification was performed using three preprocessing techniques and five machine learning algorithms, including hierarchical modeling structures to optimize separation. Partial least squares discriminant analysis (PLS-DA) following a Box-Cox transformation yielded the highest classification accuracy, achieving a prediction kappa value of 0.98 for soil type identification. However, classification performance decreased when distinguishing both soil type and geographic location, indicating that additional variability may influence predictive accuracy in broader applications. These findings highlight the potential of inductively coupled plasma mass spectrometry (ICP-MS) and machine learning for post-wildfire forensic analysis and environmental monitoring.</p>","PeriodicalId":8253,"journal":{"name":"Applied Spectroscopy","volume":" ","pages":"1398-1408"},"PeriodicalIF":2.2,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144820432","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":"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":"1325-1333"},"PeriodicalIF":2.2,"publicationDate":"2025-09-01","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":"Confocal Raman Microscopy for Measuring In-Situ Temperature-Dependent Structural Changes in Poly(Ethylene Oxide) Thin Films.","authors":"Miharu Koh, Jay P Kitt, Andrew D Pendergast, Joel M Harris, Shelley D Minteer, Carol Korzeniewski","doi":"10.1177/00037028241310904","DOIUrl":"10.1177/00037028241310904","url":null,"abstract":"<p><p>Crystallization from the melt is a critical process governing the properties of semi-crystalline polymeric materials. While structural analyses of melting and crystallization transitions in bulk polymers have been widely reported, in contrast, those in thin polymer films on solid supports have been underexplored. Herein, in situ Raman microscopy and self-modeling curve resolution (SMCR) analysis are applied to investigate the temperature-dependent structural changes in poly(ethylene oxide) (PEO) films during melting and crystallization phase transitions. By resolving complex overlapping sets of spectra, SMCR analysis reveals that the thermal transitions of 50 µm thick PEO films comprise two structural phases: an ordered crystalline phase and a disordered amorphous phase. The ordered structure of the crystalline PEO film entirely disappears as the polymer is heated; conversely, the disordered structure of the amorphous PEO film reverts to the ordered structure as the polymer is cooled. Broadening of the Raman bands was observed in PEO films above the melting temperature (67 °C), while sharpening of bands was observed below the crystallization temperature (45 °C). The temperatures at which these spectral changes occurred were in good agreement with differential scanning calorimetry (DSC) measurements, especially during the melting transition. The results illustrate that in situ Raman microscopy coupled with SMCR analysis is a powerful approach for unraveling complex structural changes in thin polymer films during melting and crystallization processes. Furthermore, we show that confocal Raman microscopy opens opportunities to apply the methodology to interrogate the structural features of PEO or other surface-supported polymer films as thin as 2 µm, a thickness regime beyond the reach of conventional thermal analysis techniques.</p>","PeriodicalId":8253,"journal":{"name":"Applied Spectroscopy","volume":" ","pages":"1334-1345"},"PeriodicalIF":2.2,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142998925","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}