scholarly journals Fusion of Near-Infrared and Raman Spectroscopy for In-Line Measurement of Component Content of Molten Polymer Blends

Sensors ◽  
2019 ◽  
Vol 19 (16) ◽  
pp. 3463 ◽  
Author(s):  
Shichao Zhu ◽  
Zhuoming Song ◽  
Shengyu Shi ◽  
Mengmeng Wang ◽  
Gang Jin
Keyword(s):  
Raman Spectroscopy ◽  
Data Fusion ◽  
Polymer Blends ◽  
Raman Spectra ◽  
Near Infrared ◽  
Molten Polymer ◽  
Low Level ◽  
Line Measurement ◽  
Component Content ◽  
Level Fusion

Spectral measurement techniques, such as the near-infrared (NIR) and Raman spectroscopy, have been intensively researched. Nevertheless, even today, these techniques are still sparsely applied in industry due to their unpredictable and unstable measurements. This paper put forward two data fusion strategies (low-level and mid-level fusion) for combining the NIR and Raman spectra to generate fusion spectra or fusion characteristics in order to improve the in-line measurement precision of component content of molten polymer blends. Subsequently, the fusion value was applied to modeling. For evaluating the response of different models to data fusion strategy, partial least squares (PLS) regression, artificial neural network (ANN), and extreme learning machine (ELM) were applied to the modeling of four kinds of spectral data (NIR, Raman, low-level fused data, and mid-level fused data). A system simultaneously acquiring in-line NIR and Raman spectra was built, and the polypropylene/polystyrene (PP/PS) blends, which had different grades and covered different compounding percentages of PP, were prepared for use as a case study. The results show that data fusion strategies improve the ANN and ELM model. In particular, mid-level fusion enables the in-line measurement of component content of molten polymer blends to become more accurate and robust.

Potential of Near-Infrared Fourier Transform Raman Spectroscopy in Food Analysis

1992 ◽  
Vol 46 (10) ◽  
pp. 1503-1507 ◽  
Author(s):  
Y. Ozaki ◽  
R. Cho ◽  
K. Ikegaya ◽  
S. Muraishi ◽  
K. Kawauchi
Keyword(s):  
Raman Spectroscopy ◽  
Fourier Transform ◽  
Fatty Acid ◽  
Raman Spectra ◽  
Food Analysis ◽  
Near Infrared ◽  
Egg White ◽  
Ft Raman Spectroscopy ◽  
Ft Raman

The 1064-nm excited Fourier transform (FT) Raman spectra have been measured in situ for various foods in order to investigate the potential of near-infrared (NIR) FT-Raman spectroscopy in food analysis. It is demonstrated here that NIR FT-Raman spectroscopy is a very powerful technique for (1) detecting selectively the trace components in foodstuffs, (2) estimating the degree of unsaturation of fatty acids included in foods, (3) investigating the structure of food components, and (4) monitoring changes in the quality of foods. Carotenoids included in foods give two intense bands near 1530 and 1160 cm−1 via the pre-resonance Raman effect in the NIR FT-Raman spectra, and therefore, the NIR FT-Raman technique can be employed to detect them nondestructively. Foods consisting largely of lipids such as oils, tallow, and butter show bands near 1658 and 1443 cm−1 due to C=C stretching modes of cis unsaturated fatty acid parts and CH2 scissoring modes of saturated fatty acid parts, respectively. It has been found that there is a linear correlation for various kinds of lipid-containing foods between the iodine value (number) and the intensity ratio of two bands at 1658 and 1443 cm−1 ( I1658/ I1443), indicating that the ratio can be used as a practical indicator for estimating the unsaturation level of a wide range of lipid-containing foods. A comparison of the Raman spectra of raw and boiled egg white shows that the amide I band shifts from 1666 to 1677 cm−1 and the intensity of the amide III band at 1275 cm−1 decreases upon boiling. These observations indicate that most α-helix structure changes into unordered structure in the proteins constituting egg white upon boiling. The NIR FT-Raman spectrum of old-leaf (about one year old) Japanese tea has been compared with that of its new leaf. The intensity ratio of two bands at 1529 and 1446 cm−1 ( I1529/ I1446), assignable to carotenoid and proteins, respectively, is considerably smaller in the former than in the latter, indicating that the ratio is useful for monitoring the changes in the quality of Japanese tea.

scholarly journals 785 nm Raman Spectroscopy of CVD Diamond Films

2007 ◽  
Vol 1039 ◽  
Author(s):  
Paul William May ◽  
James A Smith ◽  
Keith N Rosser
Keyword(s):  
Raman Spectroscopy ◽  
Film Thickness ◽  
Raman Spectra ◽  
Relative Intensity ◽  
Near Infrared ◽  
Diamond Films ◽  
Polycrystalline Diamond ◽  
Cvd Diamond ◽  
Raman Study ◽  
Thin Polycrystalline

AbstractRaman spectroscopy is a powerful technique often used to study CVD diamond films, however, very little work has been reported for the Raman study of CVD diamond films using near infrared (785 nm) excitation. Here, we report that when using 785 nm excitation, the Raman spectra from thin polycrystalline diamond films exhibit a multitude of peaks (over 30) ranging from 400-3000 cm−1. These features are too sharp to be photoluminescence, and are a function of film thickness. For films >30 μm thick, freestanding films, and for films grown in diamond substrates the Raman peaks disappear, suggesting that the laser is probing the disordered small-grained interface between the diamond and substrate. Some of the peaks change in relative intensity with time (‘blinking’), and the spectra are very sensitive to position on the substrate – this is reminiscent of the behaviour seen in SERS spectra.

scholarly journals Determination of the Geographical Origin of Hazelnuts (Corylus avellana L.) by Near-Infrared Spectroscopy (NIR) and a Low-Level Fusion with Nuclear Magnetic Resonance (NMR)

2021 ◽  
Author(s):  
Navid Shakiba ◽  
Annika Gerdes ◽  
Nathalie Holz ◽  
Sören Wenck ◽  
René Bachmann ◽  
...  
Keyword(s):  
Data Fusion ◽  
Near Infrared ◽  
Geographical Origin ◽  
Nir Spectroscopy ◽  
Test Accuracy ◽  
Classification Models ◽  
Food Fraud ◽  
Low Level ◽  
The Individual

Fourier-transform near-infrared (FT-NIR) spectroscopy was used to determine the geographical origin of 233 hazelnut samples of various varieties from five different countries (Germany, France, Georgia, Italy, Turkey). The experimental determination of the geographical origin of hazelnuts is important, because there are usually large price differences between the producer countries and thus a risk of food fraud that should not be underestimated. The present work is a feasibility study using a low-cost method, as high-field NMR and UPLC-QTOF-MS have already been used for this question. Sample sets were split with repeated nested cross validation and an ensemble of discriminant classifiers with random subspaces was used to build the classification models. By using a preprocessing strategy consisting of multiplicative scatter correction, bucketing and the mean averaging of five measured spectra per sample, a test accuracy of 90.6 ± 3.9% was achieved, which rivals results obtained with much more expensive infrastructure. The application of the feature selection approach surrogate minimal depth showed that the successful classification is mainly caused by protein signals. In addition, a low-level data fusion of the NIR and NMR data was performed to assess how well the two methods complement each other. The data fusion was compared to a complementary approach, where the classification results based on the individual NIR and NMR models were jointly examined. The data fusion performed better than the individual methods with a test accuracy of 96.6 ± 2.8%. A comparison of the outliers in all classification models shows conspicuities in always the same samples, indicating that robust classification models are obtained.

scholarly journals Original plant traceability of Dendrobium species using multi-spectroscopy fusion and mathematical models

2019 ◽  
Vol 6 (5) ◽  
pp. 190399 ◽  
Author(s):  
Ye Wang ◽  
Zhi-Tian Zuo ◽  
Heng-Yu Huang ◽  
Yuan-Zhong Wang
Keyword(s):  
Mathematical Models ◽  
Near Infrared ◽  
Scatter Correction ◽  
Support Vector ◽  
Discrimination Analysis ◽  
Fusion Strategy ◽  
Low Level ◽  
Original Plant ◽  
Mir Spectra ◽  
Level Fusion

Dendrobium is the largest genus of orchids most of which have excellent medicinal properties. Fresh stems of some species have been consumed in daily life by Asians for thousands of years. However, there are differences in flavour and clinical efficacy among different species. Therefore, it is necessary for a detector to establish an effective and rapid method controlling botanical origins of these crude materials. In our study, three spectroscopies including mid-infrared (MIR) (transmission and reflection mode) and near-infrared (NIR) spectra were investigated for authentication of 12 Dendrobium species. Generally, two fusion strategies, reflection MIR and NIR spectra, were combined with three mathematical models (random forest, support vector machine with grid search (SVM-GS) and partial least-squares discrimination analysis (PLS-DA)) for discrimination analysis. In conclusion, a low-level fusion strategy comprising two spectra after pretreated by the second derivative and multiplicative scatter correction was recommended for discrimination analysis because of its excellent performance in three models. Compared with MIR spectra, NIR spectra were more responsible for the discrimination according to a bi-plot analysis of PLS-DA. Moreover, SVM-GS and PLS-DA were suitable for accurate discrimination (100% accuracy rates) of calibration and validation sets. The protocol combined with low-level fusion strategy and chemometrics provides a rapid and effective reference for control of botanical origins in crude Dendrobium materials.

scholarly journals Quantitative Evaluation of Acetaminophen in Oral Solutions by Dispersive Raman Spectroscopy for Quality Control

2012 ◽  
Vol 27 ◽  
pp. 215-228 ◽  
Author(s):  
Viviane G. Borio ◽  
Rubens Vinha ◽  
Renata A. Nicolau ◽  
Hueder Paulo M. de Oliveira ◽  
Carlos J. de Lima ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Quality Control ◽  
Pharmaceutical Industry ◽  
Raman Spectra ◽  
Near Infrared ◽  
Calibration Model ◽  
Fiber Optic Probe ◽  
Analytical Methodology ◽  
Gold Standard Method ◽  
Optic Probe

This work used dispersive Raman spectroscopy to evaluate acetaminophen in commercially available formulations as an analytical methodology for quality control in the pharmaceutical industry. Raman spectra were collected using a near-infrared dispersive Raman spectrometer (830 nm, 50 mW, 20 s exposure time) coupled to a fiber optic probe. Solutions of acetaminophen diluted in excipient (70 to 120% of the commercial concentration of 200 mg/mL) were used to develop a calibration model based on partial least squares (PLSs) applied to Raman spectra of solutions and, subsequently, obtain linearity, accuracy, precision (repeatability), and sensitivity of the method using the near-infrared spectroscopy (NIRS) as a gold standard method. This model was used to predict the acetaminophen concentration in commercial samples from different lots of acetaminophen formulations (200 mg/mL) with a PLS-prediction error of about 0.6%. Commercial medicines had PLS predicted concentrations errors below 2.5%, whereas NIRS had an error of about 3.7% compared to the label concentration. It has been demonstrated the applicability of Raman spectroscopy with fiber probe for quality control in pharmaceutical industry of commercial formulations.

Characterization of Raman Spectra Measured in Vivo for the Detection of Cervical Dysplasia

2007 ◽  
Vol 61 (9) ◽  
pp. 986-993 ◽  
Author(s):  
Amy Robichaux-Viehoever ◽  
Elizabeth Kanter ◽  
Heidi Shappell ◽  
Dean Billheimer ◽  
Howard Jones ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Sensitivity And Specificity ◽  
Near Infrared ◽  
Squamous Metaplasia ◽  
Cervical Dysplasia ◽  
High Grade Dysplasia ◽  
Measured Signal ◽  
High Grade

Raman spectroscopy has been shown to have the potential for providing differential diagnosis in the cervix with high sensitivity and specificity in previous studies. The research presented here further evaluates the potential of near-infrared Raman spectroscopy to detect cervical dysplasia in a clinical setting. Using a portable system, Raman spectra were collected from the cervix of 79 patients using clinically feasible integration times (5 seconds on most patients). Multiple Raman measurements were taken from colposcopically normal and abnormal areas prior to the excision of tissue. Data were processed to extract Raman spectra from measured signal, which includes fluorescence and noise. The resulting spectra were correlated with the corresponding histopathologic diagnosis to determine empirical differences between different diagnostic categories. Using histology as the gold standard, logistic regression discrimination algorithms were developed to distinguish between normal ectocervix, squamous metaplasia, and high-grade dysplasia using independent training and validation sets of data. An unbiased estimate of the accuracy of the model indicates that Raman spectroscopy can distinguish between high-grade dysplasia and benign tissue with sensitivity of 89% and specificity of 81%, while colposcopy in expert hands was able to discriminate with a sensitivity and specificity of 87% and 72%.

Nondestructive Discrimination of Biological Materials by Near-Infrared Fourier Transform Raman Spectroscopy and Chemometrics: Discrimination among Hard and Soft Ivories of African Elephants and Mammoth Tusks and Prediction of Specific Gravity of the Ivories

1997 ◽  
Vol 51 (8) ◽  
pp. 1154-1158 ◽  
Author(s):  
Masahiko Shimoyama ◽  
Hisashi Maeda ◽  
Hidetoshi Sato ◽  
Toshio Ninomiya ◽  
Yukihiro Ozaki
Keyword(s):  
Raman Spectroscopy ◽  
Fourier Transform ◽  
Specific Gravity ◽  
Raman Spectra ◽  
Near Infrared ◽  
Principal Component ◽  
Biological Materials ◽  
Calibration Model ◽  
Fourier Transform Raman Spectroscopy ◽  
Ft Raman

This paper demonstrates the usefulness of near-infrared (NIR) Fourier transform (FT) Raman spectroscopy and chemometrics in nondestructive discrimination of biological materials. The discrimination among three kinds of materials—hard ivories, soft ivories, and mammoth tusks—has been investigated as an example. NIR (1064-nm) excited FT-Raman spectra were measured in situ for these materials, and principal component analysis (PCA) of the obtained spectra was carried out over the 1800–400-cm−1 region. The two kinds of ivories are clearly discriminated from one another on the basis of a one-factor plot. It was found that treatment of the Raman data by multiplicative scatter correction (MSC) greatly improves the ability to discriminate. Principal component weight loadings show that the discrimination relies upon the ratio of collagen and hydroxyapatite included in two kinds of ivories. The discrimination among the hard and soft ivories and mammoth tusks was made by a three-factor plot for FT-Raman spectra after the MSC treatments. Partial least-squares regression (PLSR) enabled us to make a calibration model which predicts the specific gravity of the hard and soft ivories.

Near-Infrared Raman Spectroscopy Using CCD Detection and a Semiconductor Bandgap Filter for Rayleigh Line Rejection

1992 ◽  
Vol 46 (6) ◽  
pp. 891-893 ◽  
Author(s):  
Alfons Schulte
Keyword(s):  
Raman Spectroscopy ◽  
Fourier Transform ◽  
Raman Spectra ◽  
Near Infrared ◽  
Sapphire Laser ◽  
Laser Line ◽  
Rayleigh Line ◽  
Rejection Filter ◽  
Multichannel Detection ◽  
Fourier Transform Raman

A novel application of a tuneable Ti: sapphire laser and a CdTe Rayleigh line rejection filter for near-infrared Raman spectroscopy employing a single grating spectrograph and multichannel detection is demonstrated. Raman spectra of liquid, solid, and photobiological samples have been measured within 75 cm−1 of the exciting laser line. At excitation wavelengths between 790 and 850 nm, a significant improvement in sensitivity over that for present Fourier transform Raman techniques has been obtained.

Near-Infrared Raman Spectroscopy with High Resolution Using the Scanning Multichannel Technique

1994 ◽  
Vol 48 (4) ◽  
pp. 454-457 ◽  
Author(s):  
J.-C. Panitz ◽  
F. Zimmermann ◽  
F. Fischer ◽  
W. Häfner ◽  
A. Wokaun
Keyword(s):  
Raman Spectroscopy ◽  
High Resolution ◽  
Raman Spectra ◽  
Near Infrared ◽  
Experimental Setup ◽  
Good Resolution ◽  
Multichannel Detection ◽  
Ccd Detector ◽  
Definition Of ◽  
Double Monochromator

An experimental setup has been developed for the measurement of Raman spectra with NIR excitation, which combines high resolution with multichannel detection. The instrument is based on a Ti:sapphire laser for excitation, a double monochromator, and a CCD detector. The scanning multichannel technique is used for efficient acquisition of Raman spectra. Principal features of the software designed for control of the spectrometer are described, including definition of problem-adapted resolution elements and spike-removal routines. Raman spectra of several compounds are given, demonstrating the good resolution obtainable with this version of NIR Raman spectroscopy.

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