Non-destructive Detection for Foreign Bodies of Tea Stalks in Finished Tea Products Using Terahertz Spectroscopy and Imaging

2022 ◽  
pp. 104018
Author(s):  
Xudong Sun ◽  
Dongdong Cui ◽  
Yun Shen ◽  
Wenping Li ◽  
Jiahua Wang
Keyword(s):  
Foreign Bodies ◽  
Terahertz Spectroscopy ◽  
Non Destructive

scholarly journals Terahertz characterization of two-dimensional low-conductive layers enabled by metal gratings

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Prashanth Gopalan ◽  
Yunshan Wang ◽  
Berardi Sensale-Rodriguez
Keyword(s):  
Optical Transmission ◽  
Terahertz Spectroscopy ◽  
Design Guidelines ◽  
Two Dimensional ◽  
Highly Sensitive ◽  
Transmission Measurements ◽  
Metal Gratings ◽  
Low Sensitivity ◽  
Non Destructive

AbstractWhile terahertz spectroscopy can provide valuable information regarding the charge transport properties in semiconductors, its application for the characterization of low-conductive two-dimensional layers, i.e., σs <  < 1 mS, remains elusive. This is primarily due to the low sensitivity of direct transmission measurements to such small sheet conductivity levels. In this work, we discuss harnessing the extraordinary optical transmission through gratings consisting of metallic stripes to characterize such low-conductive two-dimensional layers. We analyze the geometric tradeoffs in these structures and provide physical insights, ultimately leading to general design guidelines for experiments enabling non-contact, non-destructive, highly sensitive characterization of such layers.

Terahertz Spectroscopy Imaging Technique: Non-Destructive Tool For Evaluation Of Quality And Safety Of Food Products

2021 ◽  
pp. 141-157
Author(s):  
Amreena Jan ◽  
R. Pandiselvam ◽  
Anjineyulu Kothakota ◽  
N. U. Sruthi ◽  
S. V. Ramesh
Keyword(s):  
Terahertz Spectroscopy ◽  
Imaging Technique ◽  
Food Products ◽  
Quality And Safety ◽  
Non Destructive

scholarly journals Non-destructive Detection of Insect Foreign Bodies in Finishing Tea Product Based on Terahertz Spectrum and Image

2021 ◽  
Vol 8 ◽  
Author(s):  
Xudong Sun ◽  
Jiajun Li ◽  
Yun Shen ◽  
Wenping Li
Keyword(s):  
Least Squares ◽  
Time Domain ◽  
Foreign Bodies ◽  
Nearest Neighbor ◽  
K Nearest Neighbor ◽  
Terahertz Time Domain Spectroscopy ◽  
Destructive Testing ◽  
Safety Control ◽  
Main Challenge ◽  
Non Destructive

Non-destructive testing of low-density and organic foreign bodies is the main challenge for food safety control. Terahertz time-domain spectroscopy (THz-TDS) and imaging technologies were applied to explore the feasibility of detection for insect foreign bodies in the finishing tea products. THz-TDS of tea leaves and foreign bodies of insects demonstrated significant differences in terms of time domain and frequency signals in the range of 0.3–1.0 THz. These signals were corrected by the use of adaptive iteratively reweighted penalized least squares (AirPLS), asymmetric least squares (AsLS), and baseline estimation and de-noising using sparsity (BEADS) for reducing baseline drift and enhancing effective spectral information. The K-nearest neighbor (KNN) and partial least squares discrimination analysis (PLS-DA) models showed the best performance after AirPLS correction with the prediction accuracy of 98 and 100%, respectively. In addition, the locations and outlines of insect bodies could be clearly presented via the THz-TDS image. These results suggested that THz-TDS spectroscopy and imaging provide an alternative tool for the detection of insect foreign bodies in finishing tea products.

scholarly journals Non-destructive inspection of food and technical oils by terahertz spectroscopy

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Mindaugas Karaliūnas ◽  
Kinan E. Nasser ◽  
Andrzej Urbanowicz ◽  
Irmantas Kašalynas ◽  
Dalia Bražinskienė ◽  
...  
Keyword(s):  
Terahertz Spectroscopy ◽  
Non Destructive

Novel nondestructive investigations of rubber products by terahertz spectroscopy & electrical measurement

Impact ◽  
2020 ◽  
Vol 2020 (1) ◽  
pp. 24-26
Author(s):  
Yasuyuki Hirakawa
Keyword(s):  
Terahertz Spectroscopy ◽  
Electrical Current ◽  
Electrical Measurement ◽  
Thz Radiation ◽  
Electronic Engineering ◽  
Filler Dispersion ◽  
Institute Of Technology ◽  
And Performance ◽  
Non Destructive

Vulcanisation is a chemical process that is used to reinforce rubber, and the process makes it suitable for use in a number of products and industries. Both good mixing conditions and filler dispersion are essential to keep high-quality of rubber products; however, they are quite difficult to be evaluated by conventional techniques. Prof Yasuyuki Hirakawa is based at the Department of Electrical and Electronic Engineering, National Institute of Technology (KOSEN), Kurume College. He is working to further evaluate ways to enhance rubber's productivity and performance. This is being done using terahertz (THz) radiation and electrical current, which can evaluate and inspect materials in a non-destructive way.

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