Quantitative Characterization of Arnicae flos by RP-HPLC-UV and NIR Spectroscopy

The possibility of applying near-infrared (NIR) spectroscopy to monitor 13 active components (phenolic acids, flavonoids, and sesquiterpene lactones) in Arnicae flos was studied. The preprocessing of the spectra were performed by using the conventional Golay-Savitzky procedure and the newly developed step-by-step filter. The results obtained show that the step-by-step filter derivatives provide a better signal-to-noise ratio at a lower convolution window. Better calibration for the content of protocatechuic acid, chlorogenic acid, caffeic acid, p-cumaric acid, ferulic acid, isoquercitrin, and quercetin were obtained by step-by-step filter derivatives, compared to the direct raw spectra processing and the Golay-Savitzky approach. Although the step-by-step filter substantially reduces the spectral distortion, the convolution procedure leads to loss of spectral points in the red end of the spectral curve. Probably for this reason this approach shows better calibration only in seven of the monitored 13 active components.

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Optical Absorption Spectroscopy of DNA-Wrapped HiPco Carbon Nanotubes

Materials Science Forum ◽

10.4028/www.scientific.net/msf.943.95 ◽

2019 ◽

Vol 943 ◽

pp. 95-99

Author(s):

Li Jun Wang ◽

Kazuo Umemura

Keyword(s):

Carbon Nanotubes ◽

Aqueous Solution ◽

Optical Absorption ◽

Absorption Spectroscopy ◽

Near Infrared ◽

Nir Spectroscopy ◽

Optical Characterization ◽

Optical Absorption Spectroscopy ◽

Double Stranded Dna

Optical absorption spectroscopy provides evidence for individually dispersed carbon nanotubes. A common method to disperse SWCNTs into aqueous solution is to sonicate the mixture in the presence of a double-stranded DNA (dsDNA). In this paper, optical characterization of dsDNA-wrapped HiPco carbon nanotubes (dsDNA-SWCNT) was carried out using near infrared (NIR) spectroscopy and photoluminescence (PL) experiments. The findings suggest that SWCNT dispersion is very good in the environment of DNA existing. Additionally, its dispersion depends on dsDNA concentration.

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Near Infrared Spectroscopy for Rapid Determination of Mankin Score Components: A Potential Tool for Quantitative Characterization of Articular Cartilage at Surgery

Arthroscopy The Journal of Arthroscopic and Related Surgery ◽

10.1016/j.arthro.2014.04.097 ◽

2014 ◽

Vol 30 (9) ◽

pp. 1146-1155 ◽

Cited By ~ 21

Author(s):

Isaac Oluwaseun Afara ◽

Indira Prasadam ◽

Hayley Moody ◽

Ross Crawford ◽

Yin Xiao ◽

...

Keyword(s):

Infrared Spectroscopy ◽

Articular Cartilage ◽

Near Infrared Spectroscopy ◽

Near Infrared ◽

Rapid Determination ◽

Mankin Score ◽

Quantitative Characterization ◽

Potential Tool

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QUANTITATIVE CHARACTERIZATION OF SUSTAINED RELEASE TABLETS WITH DICLOFENAC SODIUM BY MEANS OF NEAR-INFRARED SPECTROSCOPY AND CHEMOMETRY

FARMACIA ◽

10.31925/farmacia.2020.4.20 ◽

2020 ◽

Vol 68 (4) ◽

pp. 728-739

Author(s):

LUCA-LIVIU RUS

Keyword(s):

Infrared Spectroscopy ◽

Sustained Release ◽

Near Infrared Spectroscopy ◽

Near Infrared ◽

Diclofenac Sodium ◽

Quantitative Characterization ◽

Sustained Release Tablets

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Searching for the near-infrared counterpart of Proxima c using multi-epoch high-contrast SPHERE data at VLT

Astronomy and Astrophysics ◽

10.1051/0004-6361/202037594 ◽

2020 ◽

Vol 638 ◽

pp. A120 ◽

Cited By ~ 2

Author(s):

R. Gratton ◽

A. Zurlo ◽

H. Le Coroller ◽

M. Damasso ◽

F. Del Sordo ◽

...

Keyword(s):

Near Infrared ◽

Planetary System ◽

Orbital Motion ◽

Signal To Noise Ratio ◽

Orbital Plane ◽

Radial Velocities ◽

Random Fluctuation ◽

Direct Imaging ◽

Imaging Detection

Context. Proxima Centauri is the closest star to the Sun and it is known to host an Earth-like planet in its habitable zone; very recently a second candidate planet was proposed based on radial velocities. At quadrature, the expected projected separation of this new candidate is larger than 1 arcsec, making it a potentially interesting target for direct imaging. Aims. While identification of the optical counterpart of this planet is expected to be very difficult, successful identification would allow for a detailed characterization of the closest planetary system. Methods. We searched for a counterpart in SPHERE images acquired over four years through the SHINE survey. In order to account for the expected large orbital motion of the planet, we used a method that assumes the circular orbit obtained from radial velocities and exploits the sequence of observations acquired close to quadrature in the orbit. We checked this with a more general approach that considers Keplerian motion, called K-stacker. Results. We did not obtain a clear detection. The best candidate has signal-to-noise ratio (S∕N) = 6.1 in the combined image. A statistical test suggests that the probability that this detection is due to random fluctuation of noise is <1%, but this result depends on the assumption that the distribution of noise is uniform over the image, a fact that is likely not true. The position of this candidate and the orientation of its orbital plane fit well with observations in the ALMA 12 m array image. However, the astrometric signal expected from the orbit of the candidate we detected is 3σ away from the astrometric motion of Proxima as measured from early Gaia data. This, together with the unexpectedly high flux associated with our direct imaging detection, means we cannot confirm that our candidate is indeed Proxima c. Conclusions. On the other hand, if confirmed, this would be the first observation in imaging of a planet discovered from radial velocities and the second planet (after Fomalhaut b) of reflecting circumplanetary material. Further confirmation observations should be done as soon as possible.

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Some Applications of Vibrational Spectroscopy for the Analysis of Polymers and Polymer Composites

Polymers ◽

10.3390/polym11071159 ◽

2019 ◽

Vol 11 (7) ◽

pp. 1159 ◽

Cited By ~ 4

Author(s):

Liliane Bokobza

Keyword(s):

Polymer Composites ◽

Vibrational Spectroscopy ◽

Near Infrared ◽

Nir Spectroscopy ◽

Polymeric Materials ◽

Molecular Structures ◽

Hydroxyl Groups ◽

Inorganic Particles ◽

Reinforcing Fillers

Vibrational spectroscopies, including infrared and Raman techniques, are important tools for the characterization of chemical composition, molecular structures, and chain orientation under mechanical deformation of polymeric materials. The development of fiber-optic-based spectrometers has broadened the use of vibrational spectroscopy for process monitoring in various fields including polymerization, curing, and manufacturing processes. Combined with chemometrics, near-infrared (NIR) spectroscopy is now recognized as one of the most important techniques for polymer analyses. Infrared and Raman studies also offer invaluable means for the analysis of inorganic particles used as reinforcing fillers for polymers. The characterization of surface species and the nature of interfacial bonding between the organic and inorganic phases are important issues for the understanding of composite properties. Infrared spectroscopy is particularly convenient for the detection and analysis of hydroxyl groups on filler surfaces, and Raman spectroscopy is particularly well suited for the study of carbon-based materials. In both techniques, polymer-filler interactions can be evidenced through frequency shifts or width changes of bands associated with vibrational modes of functional groups of either macromolecular chains or filler particles. Selected examples of application of infrared and Raman spectroscopies illustrate their potential for monitoring polymer processes, measuring polymer orientation, and characterizing polymer composites.

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Non Destructive Characterization of Wooden Members Using near Infrared Spectroscopy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.778.328 ◽

2013 ◽

Vol 778 ◽

pp. 328-334 ◽

Cited By ~ 6

Author(s):

Anna Sandak ◽

Mariapaola Riggio ◽

Jakub Sandak

Keyword(s):

Near Infrared ◽

Species Recognition ◽

Nir Spectroscopy ◽

Visual Assessment ◽

Additional Information ◽

Drilling Resistance ◽

Non Destructive ◽

Non Destructive Characterization ◽

Routine Assessment

On site characterization of wood members is a very challenging task, after considering all the variables affecting the whole structure itself and material used for construction. The up-to-data procedures are limited to few characterizations, and in general based on visual assessment supported by local drilling resistance analysis, stress-wave time of flight measurement and/or moisture content estimation. The goal of this work was to promote near infrared (NIR) spectroscopy as a supplementary tool providing additional information for the expert assessing timber structures. The paper presents several examples of successful NIR application in species recognition, physical properties prediction, evaluation of wood weathering and/or fungal degradation level. However, it must be stated that implementation of NIR in routine assessment protocols requires prior preparation of a dedicated databases of high precision reference values to build reliable, flexible and sufficiently generalized models.

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Comparison of Near-Infrared, Infrared, and Raman Spectroscopy for the Analysis of Heavy Petroleum Products

Applied Spectroscopy ◽

10.1366/0003702001949168 ◽

2000 ◽

Vol 54 (2) ◽

pp. 239-245 ◽

Cited By ~ 36

Author(s):

Hoeil Chung ◽

Min-Sik Ku

Keyword(s):

Near Infrared ◽

Signal To Noise Ratio ◽

Reference Method ◽

Nir Spectroscopy ◽

Petroleum Products ◽

American Petroleum Institute ◽

Visible Range ◽

Pls Regression ◽

Absorption Bands ◽

Heavy Petroleum

Near-infrared (NIR) spectroscopy has been successfully applied to the determination of API (American Petroleum Institute) gravity of atmospheric residue (AR), which is the heaviest fraction in crude oil. This fraction is completely dark and very viscous. Preliminary studies involving Raman and infrared (IR) spectroscopies were also evaluated along with NIR spectroscopy. The Raman spectrum of AR was completely dominated by strong fluorescence from polycyclic aromatic hydrocarbons, called asphaltenes. IR spectroscopy provided reasonable spectral features; however, its spectral reproducibility was poorer and noisier than that of NIR. Although absorption bands in the NIR region were broad and less characterized, NIR provided better spectral reproducibility with higher signal-to-noise ratio (which is one of the most important parameters in quantitative calibration in comparison to Raman and IR spectroscopies). Partial least-squares (PLS) regression was utilized to develop calibration models. NIR spectra of AR samples were broad, and baselines were varying due to the strong absorption in the visible range. However, the necessary information was successfully extracted and correlated to the reference API gravity with the use of PLS regression. API gravities in the prediction set were accurately predicted with an SEP (standard error of prediction) of 0.22. Additionally NIR showed approximately three times better repeatability compared to the ASTM reference method, which directly influences the process control performance.

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Characterization of Biochar Properties Affected by Different Pyrolysis Temperatures Using Visible-Near-Infrared Spectroscopy

ISRN Spectroscopy ◽

10.5402/2012/712837 ◽

2012 ◽

Vol 2012 ◽

pp. 1-7 ◽

Cited By ~ 10

Author(s):

Haiqing Yang ◽

Kuichuan Sheng

Keyword(s):

Near Infrared ◽

Nir Spectroscopy ◽

Calorific Value ◽

Volatile Matter ◽

Coefficient Of Determination ◽

Single Type ◽

Good Prediction ◽

Cotton Stalk ◽

Fixed Carbon

Rapid characterization of biochar for energy and ecological purpose utilization is fundamental. In this work, visible and near-infrared (vis-NIR) spectroscopy was used to measure ash, volatile matter, fixed carbon contents, and calorific value of three types of biochar produced from pine wood, cedar wood, and cotton stalk, respectively. The vis-NIR spectroscopy was also used to discriminate biochar feedstock types and pyrolysis temperature. Prediction result shows that partial least squares (PLS) regression calibrating the spectra to the values of biochar properties achieved very good or excellent performance with coefficient of determination (R2) of 0.86~0.91 and residual prediction deviation (RPD) of 2.58~3.32 for ash, volatile matter, and fixed carbon, and good prediction with R2 of 0.81 and RPD of 2.30 for calorific value. Linear discrimination analysis (LDA) of the principal components (PCs) produced from PCA of wavelength matrix shows that three types of biochar can be successfully discriminated with 95.2% accuracy. The classification of biochar with different pyrolysis temperatures can be conducted with 69% accuracy for all three types and 100% accuracy for single type of cotton stalk. This experiment suggests that the vis-NIR spectroscopy is promising as an alternative of traditionally quantitative and qualitative analysis of biochar properties.

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Multi-Channel Optical Receiver for Ground-Based Topographic Hyperspectral Remote Sensing

Remote Sensing ◽

10.3390/rs11050578 ◽

2019 ◽

Vol 11 (5) ◽

pp. 578 ◽

Cited By ~ 1

Author(s):

Sean Salazar ◽

Richard Coffman

Keyword(s):

Near Infrared ◽

Signal To Noise Ratio ◽

Absorption Spectrometry ◽

Optical Receiver ◽

Infrared Range ◽

Receiver Design ◽

Remote Sensor ◽

Rapid Characterization ◽

Shortwave Infrared

Receiver design is integral to the development of a new remote sensor. An effective receiver delivers backscattered light to the detector while optimizing the signal-to-noise ratio at the desired wavelengths. Towards the goal of effective receiver design, a multi-channel optical receiver was developed to collect range-resolved, backscattered energy for simultaneous hyperspectral and differential absorption spectrometry (LAS) measurements. The receiver is part of a new, ground-based, multi-mode lidar instrument for remote characterization of soil properties. The instrument, referred to as the soil observation laser absorption spectrometer (SOLAS), was described previously in the literature. A detailed description of the multi-channel receiver of the SOLAS is presented herein. The hyperspectral channel receives light across the visible near-infrared (VNIR) to shortwave infrared (SWIR) spectrum (350–2500 nm), while the LAS channel was optimized for detection in a narrower portion of the near-infrared range (820–850 nm). The range-dependent field of view for each channel is presented and compared with the beam evolution of the SOLAS instrument transmitter. Laboratory-based testing of each of the receiver channels was performed to determine the effectiveness of the receiver. Based on reflectance spectra collected for four soil types, at distances of 20, 35, and 60 m from the receiver, reliable hyperspectral measurements were gathered, independent of the range to the target. Increased levels of noise were observed at the edges of the VNIR and SWIR detector ranges, which were attributed to the lack of sensitivity of the instrument in these regions. The suitability of the receiver design, for the collection of both hyperspectral and LAS measurements at close-ranges, is documented herein. Future development of the instrument will enable the combination of long-range, ground-based hyperspectral measurements with the LAS measurements to correct for absorption, due to atmospheric water vapor. The envisioned application for the instrument includes the rapid characterization of bare or vegetated soils and minerals, such as are present in mine faces and tailings, or unstable slopes.

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