Non-destructive evaluation of puncture region in polyethylene composite by terahertz and X-ray radiation

Pałka, Norbert; Panowicz, R.; Chalimoniuk, Marek; Beigang, R.

doi:10.1016/j.compositesb.2016.02.030

Cited by 40 publications

(15 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…THz spectroscopy and imaging were actively used for this purpose during the past twenty years in the wide area of security applications [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. At the same time, this technique starts to be widely used for the non-destructive testing, for quality inspection of pharmaceuticals and food products as well as for medical applications [20][21][22][23][24][25][26][27].…”

Section: Introductionmentioning

confidence: 99%

High effective THz-TDS method for the detection and identification of substances in real conditions

et al. 2016

View full text Add to dashboard Cite

Low efficiency of the standard THz-TDS method for the detection and identification of substances is demonstrated. For this purpose, we use a few examples. In the first example, we model the noisy THz signals transmitted through the amphetamine-type stimulant in real conditions. Namely, with a temperature 18° C, the relative humidity of about 50 % and the distance between the parabolic mirror and the object about of 3.5 meters. We show that the standard THz-TDS method reveals the spectral features of many neutral substances and explosives in the noisy THz signals from the illicit stimulant MA, at the same time this method is not able to detect the presence of this stimulant in the noisy signals. The second example is the detection and identification of plastids with inhomogeneous surface in reflection mode. We show that inhomogeneous surface distorts spectral characteristics of the reflected THz signal main pulse, which cannot be used for the detection and identification of the plastids by means of the THz TDS method. In the last example we show that even under laboratory conditions (at short distance from the receiver), THz TDS detects in the semiconductors the absorption frequencies, which belong to both hazardous and neutral substances. To overcome this disadvantage, we propose to use the time-dependent spectrum of the THz pulse, transmitted through or reflected from a substance. For quality assessment of the presence of the standard substance absorption frequency in the signal under analysis, we use time-dependent integral correlation criteria. The influence of aperture placed in front of the sample on spectral properties of silicon wafers with different resistivity is demonstrated as well.Keywords: reflected and transmitted THz pulse, noisy THz pulse, method of spectral dynamics analysis, integral correlation criteria, identification of explosives and drugs. *vatro@cs.msu.ru; phone 7 495 939-5255; fax 7 495 939-2597

show abstract

Section: Introductionmentioning

confidence: 99%

High effective THz-TDS method for the detection and identification of substances in real conditions

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Terahertz time-domain spectroscopy (THz-TDS) is a powerful tool for characterizing the internal optical responses of optically opaque polymer-based materials11121314151617181920212223242526. Because the photon energy of terahertz waves is relatively small in comparison to that of visible light, they possess high transmittance, which enables us to access the internal states of opaque polymeric materials.…”

mentioning

confidence: 99%

Anisotropic optical response of optically opaque elastomers with conductive fillers as revealed by terahertz polarization spectroscopy

Okano

Watanabe

2016

Sci Rep

View full text Add to dashboard Cite

Elastomers are one of the most important materials in modern society because of the inherent viscoelastic properties due to their cross-linked polymer chains. Their vibration-absorbing and adhesive properties are especially useful and thus utilized in various applications, for example, tires in automobiles and bicycles, seismic dampers in buildings, and seals in a space shuttle. Thus, the nondestructive inspection of their internal states such as the internal deformation is essential in safety. Generally, industrial elastomers include various kinds of additives, such as carbon blacks for reinforcing them. The additives make most of them opaque in a wide spectral range from visible to mid-infrared, resulting in that the nondestructive inspection of the internal deformation is quite difficult. Here, we demonstrate transmission terahertz polarization spectroscopy as a powerful technique for investigating the internal optical anisotropy in optically opaque elastomers with conductive additives, which are transparent only in the terahertz frequency region. The internal deformation can be probed through the polarization changes inside the material due to the anisotropic dielectric response of the conductive additives. Our study about the polarization-dependent terahertz response of elastomers with conductive additives provides novel knowledge for in situ, nondestructive evaluation of their internal deformation.

show abstract

“…Most of the systems for detection of concealed objects operate in MMW or THz spectra using various processing methods to automatically detect the object. Other related methods to reveal concealed items are based on THz spectroscopy [4][5][6] but their practical application in real-life is limited.…”

Section: Related Workmentioning

confidence: 99%

Hidden Object Detection and Recognition in Passive Terahertz and Mid-wavelength Infrared

Kowalski

2019

J Infrared Milli Terahz Waves

View full text Add to dashboard Cite

The study presents the comparison of detection and recognition of concealed objects covered with various types of clothing by using passive imagers operating in a terahertz (THz) range at 1.2 mm (250 GHz) and a mid-wavelength infrared (MWIR) at 3-6 μm (50-100 THz). During this study, large dataset of images presenting various items covered with various types of clothing has been collected. The detection and classification algorithms aimed to operate robustly at high processing speed across these two spectrums. Properties of both spectrums, theoretical limitations, performance of imagers and physical properties of fabrics in both spectral domains are described. The paper presents a comparison of two deep learningbased processing methods. The comparison of the original results of various experiments for the two spectrums is presented.

show abstract

Non-destructive evaluation of puncture region in polyethylene composite by terahertz and X-ray radiation

Cited by 40 publications

References 21 publications

High effective THz-TDS method for the detection and identification of substances in real conditions

High effective THz-TDS method for the detection and identification of substances in real conditions

Anisotropic optical response of optically opaque elastomers with conductive fillers as revealed by terahertz polarization spectroscopy

Hidden Object Detection and Recognition in Passive Terahertz and Mid-wavelength Infrared

Contact Info

Product

Resources

About