Visible-near infrared spectroscopy based citrus greening detection: Evaluation of spectral feature extraction techniques

2011 ◽  
Vol 30 (11) ◽  
pp. 1508-1513 ◽  
Author(s):  
Sindhuja Sankaran ◽  
Reza Ehsani
2007 ◽  
Vol 15 (2) ◽  
pp. 115-121 ◽  
Author(s):  
B. Jagannadha Reddy ◽  
Ray L. Frost

In this endeavour, near infrared spectroscopy studies show evidence of variable composition in aurichalcite minerals of zinc copper carbonate hydroxides. The observation of a broad feature in the electronic part of the spectrum around 11,500 cm−1 (870 nm) is a strong indication of Cu2+ substitution for Zn2+ in the mineral. Overtones of OH vibrations in the spectra from 7250 to 5400 cm−1 (1380–1850 nm) show strong hydrogen bonding in these carbonates. A band common to spectra of all carbonates appears near 5400 cm−1 (1850 nm) due to the combination of both OH-stretching and HOH-bending vibrations, which may be attributed to adsorbed water. Aurichalcite minerals display a spectral sequence of five absorption bands with variation of both band positions and intensities and this is the chief spectral feature observed in the range 5200–5100 cm−1 (1920–2380 nm) due to vibrational processes of the carbonate ion. The frequency shift of carbonate bands suggests the effect of divalent cations and/or variations of the Zn/Cu ratio in aurichalcite minerals.


2018 ◽  
Vol 39 (11) ◽  
pp. 1627-1632
Author(s):  
秦玉华 QIN Yu-hua ◽  
张海涛 ZHANG Hai-tao ◽  
高 锐 GAO Rui ◽  
张 磊 ZHANG Lei

2021 ◽  
Vol 11 (20) ◽  
pp. 9662
Author(s):  
Miia O. Hurskainen ◽  
Jaakko K. Sarin ◽  
Sami Myllymaa ◽  
Wilfredo A. González-Arriagada ◽  
Arja Kullaa ◽  
...  

Near-infrared spectroscopy (NIRS) is a non-ionizing optical technique that can be used to quantify proteins, carbohydrates, fats, and other organic and biological substances. The aim of this study was to determine the ability of NIRS to identify different concentrations of L-fucose and L-proline solutions by utilizing different NIR spectral regions. NIR spectra of solid L-fucose and L-proline, their aqueous solutions in different concentrations, and the spectra of saliva samples collected from two patients with oral squamous cell carcinoma (OSCC) were studied. Differences in spectra of the pure solid reference samples and water were most noticeable in spectral regions 800–1250 nm and 1418–1867 nm. The saliva sample with an atypically high concentration of oral cancer biomarkers showed a similar spectral feature between 1530–1650 nm as the liquid samples with cancer biomarkers. In addition, a fine k-nearest neighbors (kNN) classifier was trained to differentiate the aqueous solutions and achieved 75.97% validation accuracy. The preliminary study presents that NIRS can be utilized to detect differences in spectra between the different biomarker concentrations in aqueous solutions. However, the qualitative measures may have resulted in limited sensitivity, which could be enhanced by additional samples and using a measurement probe dedicated to fluid measurements.


Sign in / Sign up

Export Citation Format

Share Document