On-Line Monitoring of Melt-Extrusion Transesterification of Ethylene Vinylacetate Copolymers by near Infrared Spectroscopy and Chemometrics

2002 ◽  
Vol 10 (3) ◽  
pp. 195-202 ◽  
Author(s):  
Tsuyoshi Furukawa ◽  
Yasuo Kita ◽  
Shigehiro Sasao ◽  
Kimihiro Matsukawa ◽  
Masahiro Watari ◽  
...  
Keyword(s):  
Near Infrared ◽  
Nir Spectroscopy ◽  
Principal Component ◽  
Intensity Change ◽  
Melt Extrusion ◽  
Peak Intensity ◽  
Fibre Optic Probe ◽  
On Line ◽  
Significant Intensity ◽  
Optic Probe

The melt-extrusion transesterification of ethylene/vinylacetate (EVA) copolymer to ethylene/vinylalcohol (EVAL) copolymers has been monitored by on-line near infrared (NIR) spectroscopy. A total of 60 NIR spectra were measured within 37 minutes after the initial addition of octanol (reagent) and catalyst (sodium methoxide) at the exit of the extruder by use of a fibre-optic probe. The most significant intensity change is observed for a band at 7089 cm−1 due to the first overtone of an OH stretching mode of the EVAL copolymers. We can monitor the progress of the reaction by plotting the peak intensity at 7089 cm−1 only. A principal component analysis (PCA) was carried out for the series of NIR spectra in the 7300–6900 cm−1 region. A score plot of PCA factor 1 is almost identical with the plot of the peak intensity at 7089 cm−1. Calibration models for predicting the vinyl acetate content in EVA copolymers have been developed by use of partial least squares (PLS) regression. The correlation coefficient and standard error of prediction are 0.96 and 0.85%, respectively, indicating that the described technique can be used to monitor the transesterification reaction.

Qualitative Analysis of Oil Sand Slurries Using On-Line NIR Spectroscopy

1996 ◽  
Vol 50 (12) ◽  
pp. 1535-1540 ◽  
Author(s):  
Waldemar I. Friesen
Keyword(s):  
Steady State ◽  
Water Content ◽  
Near Infrared ◽  
Nir Spectroscopy ◽  
Principal Component ◽  
Fiber Optic Probe ◽  
Oil Sand ◽  
Plant Environment ◽  
On Line ◽  
Optic Probe

The development of a reliable on-line method to monitor process streams is important for improved process control in oil sand extraction plants. The suitability of diffuse reflectance near-infrared (NIR) spectroscopy for this purpose has been tested in a pilot plant environment. Spectra of a feed slurry flowing through a pipe were measured with the use of an on-line fiber-optic probe. Data were collected throughout a nine-hour period during which ore type and slurry water content were varied. The feasibility of monitoring feed stream conditions is demonstrated by principal component analysis of the measured spectra. Clustering of these spectra according to ore type and water content enables the detection of deviations from and transitions between steady-state conditions of the process. Estimates are given of characteristic times for the process to reach a steady state after a change in condition has been initiated. The use of artificial neural networks for classifying spectra on the basis of ore type is also illustrated.

On-line non-destructive determination of proteins and infiltrated fat in Iberian pork loin by near infrared spectrometry with a remote reflectance fibre optic probe

2002 ◽  
Vol 453 (2) ◽  
pp. 281-288 ◽  
Author(s):  
Inmaculada González-Martı́n ◽  
Claudio González-Pérez ◽  
Jesús Hernández-Méndez ◽  
Noelia Alvarez-Garcı́a ◽  
José-Luis Hernández Andaluz
Keyword(s):  
Near Infrared ◽  
Infrared Spectrometry ◽  
Fibre Optic ◽  
Fibre Optic Probe ◽  
On Line ◽  
Near Infrared Spectrometry ◽  
Pork Loin ◽  
Optic Probe ◽  
Non Destructive

A Multivariate NIR Study of Skin Alterations in Diabetic Patients as Compared to Control Subjects

2000 ◽  
Vol 8 (4) ◽  
pp. 217-227 ◽  
Author(s):  
Paul Geladi ◽  
Josefina Nyström ◽  
Jan W. Eriksson ◽  
Anders Nilsson ◽  
Folke Lithner ◽  
...  
Keyword(s):  
Diabetes Complications ◽  
Near Infrared ◽  
Nir Spectroscopy ◽  
Diabetic Patients ◽  
Healthy Controls ◽  
Skin Changes ◽  
Skin Reflectance ◽  
Fibre Optic Probe ◽  
Optic Probe ◽  
Skin Conditions

A group of 15 diabetic persons with different degrees of diabetes complications, including skin changes, was studied by Fourier Transform Near Infrared (FT-NIR) spectroscopy. Skin reflectance spectra were measured with a fibre-optic probe in four locations (sites): hand, arm, leg and foot. For reference, a group of 28 healthy controls was also measured. Multivariate analysis of the NIR spectra obtained shows a high potential for classification and discrimination of the skin conditions. Valuable indications for future experiments can be observed.

Potential of near Infrared Spectroscopy for On-Line Analysis at the Milking Parlour Using a Fibre-Optic Probe Presentation

NIR news ◽  
2011 ◽  
Vol 22 (7) ◽  
pp. 11-13 ◽  
Author(s):  
Hoang Nam Nguyen ◽  
Frédéric Dehareng ◽  
Mohamed Hammida ◽  
Vincent Baeten ◽  
Eric Froidmont ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Fibre Optic ◽  
Fibre Optic Probe ◽  
On Line ◽  
Optic Probe ◽  
Line Analysis

On-line NIR monitoring during anaerobic treatment of municipal solid waste

2003 ◽  
Vol 48 (4) ◽  
pp. 9-13 ◽  
Author(s):  
M. Hansson ◽  
Å Nordberg ◽  
B. Mathisen
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Near Infrared ◽  
C:N Ratio ◽  
Nir Spectroscopy ◽  
Principal Component ◽  
Anaerobic Treatment ◽  
Operating Conditions ◽  
On Line ◽  
Process Disturbances

An anaerobic digester (8 l) was fed with the organic fraction of municipal solid waste and monitored intermittently for two years with on-line near-infrared (NIR) spectroscopy and traditional chemical parameters analysed off-line. The dynamics that occurred due to changes in substrate composition (changed C:N ratio) and changes in operating conditions (overloading) could be followed using principal component analysis of the obtained NIR-spectra. In addition, process disturbances such as failed stirring and increased foaming were readily detected by the NIR-spectra. Using PLS regression the propionate concentration could be predicted in the range 0.1-3.6 g/l, RMSEP 0.53 g/l with slope 0.74 and correlation coefficient 0.85. The response on changes in the digester fluid was reproducible and could be detected within 2.5 minutes, which can be considered as real-time monitoring.

Composition and Particle Diameter for Styrene/Methyl Methacrylate Copolymer Latex Using UV and NIR Spectroscopy

1993 ◽  
Vol 47 (11) ◽  
pp. 1852-1870 ◽  
Author(s):  
Paul D. Gossen ◽  
John F. Macgregor ◽  
Robert H. Pelton
Keyword(s):  
Methyl Methacrylate ◽  
Standard Error ◽  
Near Infrared ◽  
Particle Diameter ◽  
Nir Spectroscopy ◽  
Principal Component ◽  
Uv Spectra ◽  
Fiber Optic Probe ◽  
Linear Calibration ◽  
Optic Probe

The properties of a polymer latex were measured over the course of a semi-batch polymerization with the use of ultraviolet (UV) and near-infrared (NIR) spectroscopy. The spectra were very complex, and their characteristics changed dramatically throughout the course of a batch, so linear calibration models were constructed for groups of similar spectra using Partial Least-Squares (PLS). Principal Component Analysis (PCA) was used as a pattern recognition tool to group spectra before calibration or prediction. UV spectra from 190 to 800 nm were taken of diluted latex. The weight fractions of styrene monomer and poly(styrene) were predicted with a standard error less than 0.5 wt%. NIR spectra from 900 to 1800 nm were taken of undiluted latex with a transflectance fiber-optic probe. Calibrations could predict the concentrations of all the major components [water, poly(styrene), poly(methyl methacrylate), styrene, methyl methacrylate] with a standard error of less than 0.5 wt%. Mean particle size was also well predicted for some of the calibration sets.

Simultaneous Determination of Physical and Chemical Properties of Sodium Chloride Solutions by near Infrared Spectroscopy

1993 ◽  
Vol 1 (2) ◽  
pp. 109-120 ◽  
Author(s):  
Jie Lin ◽  
Chris W. Brown
Keyword(s):  
Simultaneous Determination ◽  
Near Infrared ◽  
Chemical Properties ◽  
Nir Spectroscopy ◽  
Physical And Chemical Properties ◽  
Fibre Optic Probe ◽  
Optic Probe ◽  
Physical And Chemical ◽  
And Chemical Properties

Near infrared (NIR) spectroscopy has been investigated as a new technique for the simultaneous determination of physical and chemical properties of NaCl solutions. The spectra of NaCl solutions (0 to 5 M) were measured with cuvettes in the 1100–2500 nm and 680–1230 nm regions at temperatures between 23.0 and 28.5°C, and with a fibre-optic probe in the 1100–1870 nm region at room temperature (23.0 ± 0.5°C). These spectra were correlated with various properties of NaCl solutions by principal component regression (PCR) and multilinear regression (MLR) models. The properties studied include water concentration, density, refractive index, relative viscosity, freezing point depression, osmolality, electrical conductance and activity coefficient of NaCl. Very good correlations were found between the NIR predicted values and literature values. The results of this study demonstrate that several properties of NaCl solutions can be determined simultaneously with NIR spectroscopy. Remote sensing of the properties can be performed with the use of a fibre-optic probe.

Evaluation of Standardisation Methods of near Infrared Calibration Models

2002 ◽  
Vol 10 (4) ◽  
pp. 269-278 ◽  
Author(s):  
F.S.G. Lima ◽  
L.E.P. Borges
Keyword(s):  
Fourier Transform ◽  
Least Squares ◽  
Near Infrared ◽  
Diesel Oil ◽  
Tunable Filter ◽  
Calibration Models ◽  
Fibre Optic Probe ◽  
On Line ◽  
Optic Probe ◽  
Direct Standardisation

The standardisation of eight partial least squares calibration models for the prediction of diesel oil properties was studied. The models were developed using spectra acquired on a laboratory accousto-optic tunable filter (AOTF) near infrared (NIR) spectrophotometer (with a quartz cuvette) and transferred to another AOTF-NIR spectrophotometer (with a fibre-optic probe) and to an Fourier transform NIR spectrometer, both designed for on-line application. Thirteen standardisation methods, using different approaches, were studied: standardisation by the pretreatment of spectra, (piecewise) direct standardisation and (piecewise) reverse standardisation. The reverse approach proved to be the best strategy to transfer the models.

scholarly journals Influence of environmental factors on the detection of blood in sheep faeces using visible–near-infrared spectroscopy as a measure of Haemonchus contortus infection

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Elise A. Kho ◽  
Jill N. Fernandes ◽  
Andrew C. Kotze ◽  
Glen P. Fox ◽  
Maggy T. Sikulu-Lord ◽  
...  
Keyword(s):  
Principal Component Analysis ◽  
Haemonchus Contortus ◽  
Prediction Accuracy ◽  
Near Infrared ◽  
Nir Spectroscopy ◽  
Principal Component ◽  
Component Analysis ◽  
Diagnostic Methods ◽  
Calibration Models ◽  
Good Prediction Accuracy

Abstract Background Existing diagnostic methods for the parasitic gastrointestinal nematode, Haemonchus contortus, are time consuming and require specialised expertise, limiting their utility in the field. A practical, on-farm diagnostic tool could facilitate timely treatment decisions, thereby preventing losses in production and flock welfare. We previously demonstrated the ability of visible–near-infrared (Vis–NIR) spectroscopy to detect and quantify blood in sheep faeces with high accuracy. Here we report our investigation of whether variation in sheep type and environment affect the prediction accuracy of Vis–NIR spectroscopy in quantifying blood in faeces. Methods Visible–NIR spectra were obtained from worm-free sheep faeces collected from different environments and sheep types in South Australia (SA) and New South Wales, Australia and spiked with various sheep blood concentrations. Spectra were analysed using principal component analysis (PCA), and calibration models were built around the haemoglobin (Hb) wavelength region (387–609 nm) using partial least squares regression. Models were used to predict Hb concentrations in spiked faeces from SA and naturally infected sheep faeces from Queensland (QLD). Samples from QLD were quantified using Hemastix® test strip and FAMACHA© diagnostic test scores. Results Principal component analysis showed that location, class of sheep and pooled versus individual samples were factors affecting the Hb predictions. The models successfully differentiated ‘healthy’ SA samples from those requiring anthelmintic treatment with moderate to good prediction accuracy (sensitivity 57–94%, specificity 44–79%). The models were not predictive for blood in the naturally infected QLD samples, which may be due in part to variability of faecal background and blood chemistry between samples, or the difference in validation methods used for blood quantification. PCA of the QLD samples, however, identified a difference between samples containing high and low quantities of blood. Conclusion This study demonstrates the potential of Vis–NIR spectroscopy for estimating blood concentration in faeces from various types of sheep and environmental backgrounds. However, the calibration models developed here did not capture sufficient environmental variation to accurately predict Hb in faeces collected from environments different to those used in the calibration model. Consequently, it will be necessary to establish models that incorporate samples that are more representative of areas where H. contortus is endemic.

scholarly journals Cancer Discrimination Using Fourier Transform Near-Infrared Spectroscopy with Chemometric Models

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Hui Chen ◽  
Zan Lin ◽  
Chao Tan
Keyword(s):  
Cancer Diagnosis ◽  
Near Infrared ◽  
Nir Spectroscopy ◽  
Principal Component ◽  
Classification Model ◽  
Support Vector ◽  
Biomedical Analysis ◽  
First Derivative ◽  
Svm Model ◽  
High Prediction

Near-infrared (NIR) spectroscopy technique offers many potential advantages as tool for biomedical analysis since it enables the subtle biochemical signatures related to pathology to be detected and extracted. In conjunction with advanced chemometrics, NIR spectroscopy opens the possibility of their use in cancer diagnosis. The study focuses on the application of near-infrared (NIR) spectroscopy and classification models for discriminating colorectal cancer. A total of 107 surgical specimens and a corresponding NIR diffuse reflection spectral dataset were prepared. Three preprocessing methods were attempted and least-squares support vector machine (LS-SVM) was used to build a classification model. The hybrid preprocessing of first derivative and principal component analysis (PCA) resulted in the best LS-SVM model with the sensitivity and specificity of 0.96 and 0.96 for the training and 0.94 and 0.96 for test sets, respectively. The similarity performance on both subsets indicated that overfitting did not occur, assuring the robustness and reliability of the developed LS-SVM model. The area of receiver operating characteristic (ROC) curve was 0.99, demonstrating once again the high prediction power of the model. The result confirms the applicability of the combination of NIR spectroscopy, LS-SVM, PCA, and first derivative preprocessing for cancer diagnosis.

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