• Title/Summary/Keyword: spectroscopic methods

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Spectroscopic Techniques for Nondestructive Detection of Fungi and Mycotoxins in Agricultural Materials: A Review

  • Min, Hyunjung;Cho, Byoung-Kwan
    • Journal of Biosystems Engineering
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    • v.40 no.1
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    • pp.67-77
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    • 2015
  • Purpose: Fungal secondary metabolite (mycotoxin) contamination in foods can pose a serious threat to humans and animals. Spectroscopic techniques have proven to be potential alternative tools for early detection of mycotoxins. Thus, the aim of this review is to provide an overview of the current developments in nondestructive food safety testing techniques, particularly regarding fungal contamination testing in grains, focusing on the application of spectroscopic techniques to this problem. Methods: This review focuses on the use of spectroscopic techniques for the detection of fungi and mycotoxins in agricultural products as reported in the literature. It provides an overview of the characteristics of the main spectroscopic methods and reviews their applications in grain analysis. Results: It was found that spectroscopy has advantages over conventional methods used for fungal contamination detection, particularly when combined with chemometrics. These advantages include the rapidness and nondestructive nature of this approach. Conclusions: While spectroscopy offers many benefits for the detection of mycotoxins in agricultural products, a number of limitations exist, which must be overcome prior to widespread adoption of these techniques.

NEW ORBITAL PARAMETERS AND RADIAL VELOCITY CURVE ANALYSIS OF SPECTROSCOPIC BINARY STARS

  • Ghaderi, Kamal;Pirkhedri, Ali;Rostami, Touba;Khodamoradi, Salem;Fatahi, Hedayat
    • Journal of The Korean Astronomical Society
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    • v.45 no.1
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    • pp.1-6
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    • 2012
  • We use a Probabilistic Neural Network (PNN) technique to derive the orbital parameters of spectroscopic binary stars. Using measured radial velocity data of five double-lined spectroscopic binary systems (i.e., EQ Tau, V376 And, V776 Cas, V2377 Oph and EE Cet), we find the corresponding orbital and spectroscopic elements. Our numerical results are in good agreement with those obtained by other groups via more traditional methods.

Calibrations in rotating compensator spectroscopic ellipsometry (회전보상기를 이용한 분광타원기술에 있어서의 캘리브레이션)

  • An, Ilsin
    • Proceedings of the Optical Society of Korea Conference
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    • 2001.02a
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    • pp.256-259
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    • 2001
  • Rotating-compensator type ellipsometer was developed for spectroscopic measurements. For accurate data reduction, the azimuths of transmission axises of polarizer and analyzer, and the angular position of the fast axis of compensator should be determined through calibration process. In this paper, we present various calibration methods.

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Spectroscopic methods for the analysis of tandem fabry-perot interferometer (이중 패브리-페로 간섭계에 대한 분광학적 분석방법)

  • 이석목
    • Korean Journal of Optics and Photonics
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    • v.5 no.2
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    • pp.231-237
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    • 1994
  • We present spectroscopic methods to analyze the structural parameters of tandem Fabry-Perot interferometers. By using laser beams of two different frequencies by several tens of GHz, we investigated the cavity spacings of the two interferometers and ways to measure and to find the limitation of the neccesary conditions between the two interferometers. All of the theoretical results has been also confirmed experimentally.ntally.

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Study of Stray-light Analysis and Suppression Methods for the Spectroscopic System of a Solar-radiation Observer Instrument

  • Zheng, Ru;Liu, Bo;Wang, Lingyun;Gao, Yue;Li, Guangxi;Li, Changyu
    • Current Optics and Photonics
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    • v.5 no.3
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    • pp.220-228
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    • 2021
  • To improve the measurement accuracy of a solar-radiation observer instrument, aiming at the problem of multiorder-stray-light interference caused by the diffraction of the flat-field concave grating in the spectroscopic system, straylight suppression methods for different forms of optical traps are studied. According to the grating surface-scattering distribution-function model, the bidirectional scattering distribution function (BSDF) of a dust-polluted surface and the flat-field concave grating's transition area of the spectroscopic system is calculated, and a Lyot stop with blade baffle is designed to suppress this kind of stray light. For diffraction multiorder stray light, based on the theory of light-energy transmission, a design for precise positioning of the trench optical trap is proposed. The superiority of the method is verified through simulation and actual measurement. The simulation results show that in a spectroscopic system approximately 160 mm × 140 mm × 80 mm in size, the energy of the stray light is reduced by one order of magnitude by means of the trench optical trap and Lyot stop, and the number of beams is reduced from 5664 to 1040. The actual measurements show that the stray-light-suppression efficiency is about 69.4%, which is effective reduction of the amount of stray light.

DATA REDUCTION OF AKARI/IRC SPECTROSCOPIC OBSERVATIONS

  • Usui, Fumihiko;Onaka, Takashi;AKARI/IRC team
    • Publications of The Korean Astronomical Society
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    • v.32 no.1
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    • pp.41-43
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    • 2017
  • AKARI performed about 10,000 spectroscopic observations with the Infrared Camera (IRC) during its mission phase. These IRC observations provide unique spectroscopic data at near- and mid-infrared wavelengths for studies of the next few decades because of its high sensitivity and unique wavelength coverage. In this paper, we present the current status of the activity for improving the IRC spectroscopic data reduction process, including the toolkit and related data packages, and also discuss the goal of this project.

Spectroscopic Techniques for Nondestructive Quality Inspection of Pharmaceutical Products: A Review

  • Kandpal, Lalit Mohan;Park, Eunsoo;Tewari, Jagdish;Cho, Byoung-Kwan
    • Journal of Biosystems Engineering
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    • v.40 no.4
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    • pp.394-408
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    • 2015
  • Spectroscopy is an emerging technology for the quality assessment of pharmaceutical samples, from tablet manufacturing to final quality assurance. The traditional methods for the quality management of pharmaceutical tablets are time consuming and destructive, while spectroscopic techniques allow rapid analysis in a non-destructive manner. The advantage of spectroscopy is that it collects both spatial and spectral information (called hyperspectral imaging), which is useful for the chemical imaging of pharmaceutical samples. These chemical images provide both qualitative and quantitative information on tablet samples. In the pharmaceutics, spectroscopic techniques are used for a variety of applications, such as analysis of the homogeneity of powder samples as well as determination of particle size, product composition, and the concentration, uniformity, and distribution of the active pharmaceutical ingredient in solid tablets. This review paper presents an introduction to the applications of various spectroscopic techniques such as hyperspectroscopy and vibrational spectroscopies (Raman spectroscopy, FT-NIR, and IR spectroscopy) for the quality and safety assessment of pharmaceutical solid dosage forms. In addition, various chemometric techniques that are highly essential for analyzing the spectroscopic data of pharmaceutical samples are also reviewed.

Synthesis and spectroscopic characterization of zinc ferrite nanoparticles

  • Arora, Shefali;Nandy, Subhajit;Latwal, Mamta;Pandey, Ganesh;Singh, Jitendra P.;Chae, Keun H.
    • Advances in nano research
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    • v.13 no.5
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    • pp.437-451
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    • 2022
  • Synthesis approaches usually affect the physical and chemical properties of ferrites. This helps ferrite materials to design them for desired applications. Some of these methods are mechanical milling, ultrasonic method, micro-emulsion, co-precipitation, thermal decomposition, hydrothermal, microwave-assisted, sol-gel, etc. These methods are extensively reviewed by taking example of ZnFe2O4. These methods also affect the microstructure and local structure of ferrite which ultimately affect the physical and chemical properties of ferrites. Various spectroscopic techniques such as Raman spectroscopy, Fourier Transform Infrared spectroscopy, Ultra Violet-Visible spectroscopy, Mossbauer spectroscopy, extended x-ray absorption fine structure, and electron paramagnetic resonance are found helpful to reveal this information. Hence, the basic principle and the usefulness of these techniques to find out appropriate information in ZnFe2O4 nanoparticles is elaborated in this review.

Quantum Mechanical Calculation of Spectroscopic Constants of ClO and $CIO^+$

  • Hae-Sun Song;Eun-Mo Sung
    • Bulletin of the Korean Chemical Society
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    • v.14 no.4
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    • pp.476-480
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    • 1993
  • The ab initio calculations were performed on ClO and $ClO^+$ using the configuration interaction and M${\phi}$ller-Plesset methods of several different levels of approximation. Three different basis sets, 66 contracted Gaussian-type orbitals,6-31$G^*$ and 6-311$G^*$, were employed in this calculation. The results of calculation were compared with the experimental values of ClO. The values from the calculation with 66cGTO basis set gave excellent agreement with the experimental values. The spectroscopic constants of $ClO^+$ were also predicted.