• Journal of the Semiconductor & Display Technology
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• v.20 no.2
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• pp.87-91
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• 2021

Various Cu ions are discharged into water from various industries, which results in a severe trouble for groundwater, soil, air, and eventually animals and humans. In this work, graphene oxide (GO) is introduced as a Cu removal absorber and the real-time monitoring method is demonstrated. The results show that GO is a very effective material to absorb Cu ions in the solution. In addition, the residual Cu ions in the solution is monitored via optical transmittance method, which well match with Inductively Coupled Plasma Mass Spectrometer (ICP-MS) analysis.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11c
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• pp.525-532
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• 2000

A new spectroscopic method for pesticide residues detection on agricultural products was developed. The general determination methods are high performance liquid chromatography (HPLC), gas chromatography (GC) or GC-mass spectrometry. They have provided relatively good detection limit and accuracy with complicated and time-consuming (5hrs above) procedures. In addition freshness is very important for evaluating qualities of agricultural products. This requires a simple and fast method for detection of pesticides. Reflectance, transmittance and fluorescence spectrometry of pesticides were tested using UV range because most of pesticides contain conjugation band in the molecular structures. Fluorescence spectrometry showed better sensitive to detect pesticide residues than did reflectance and transmittance spectrometry. Intensity and shape of fluorescence spectra showed different patterns with different structures of pesticides. Detection limit for fluorescence spectrometry was 0.1 ppm to 10 ppm depending on the structures of pesticides. Application of fluorescence spectrometry appears to be an easy method for detection of pesticide residues on agricultural products.

• Clean Technology
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• v.17 no.3
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• pp.215-224
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• 2011

It is an important issue to develop quality assessing system for biofuel for the purpose of accelerating the mass production of biofuel. It is particularly challenging to conduct testing method in the mass production of bioethanol while meeting quality specifications such as ASTM (American Society for Testing & Materials) D4806-10. In order to address this challenge, this paper proposes on-line spectroscopic quality assesment system based on Near Infrared spectrum and Partial Least Squares method in Chemometrics. As a result of testing a number of preprocessing methods and Partial Least Squares, it was found out that Savitzky-Golay method showed the best performance in terms of spectrum correction, noise reduction, and model maintenance. The proposed system allows us to assess multiple quality components continuously using spectroscopic facilities with the cheap cost. Since the value of R2 is more than 0.99, it is possible to replace the laboratory analysis.

• Korean Journal of Materials Research
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• v.8 no.10
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• pp.961-968
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• 1998

In order to investigate the effects of substrate bias voltage on the formation of$ZnS-SiO_2$ protective film in phase change optical disk by R.F. magnetron sputtering method, thin dielectric film was formed on Si wafer and Corning glass by using ZnS(80mol%)-$SiO_2$(20mol%)t arget under argon gas. In this study, the Taguchi experimental method was applied in order to obtain optimum conditions with reduced number of experiments and to control numerous variables effectively. At the same time this method can assure the reproducibility of experiments. Optimum conditions for film formation obtained by above method were target RF power of 200 W. substrate RF power of 20 W, Ar pressure of 5 mTorr. sputtering time of 20 min.. respectively. The phase of specimen was determined by using XRD and TEM. The compositional analysis of specimen was performed by XPS test. In order to measure the thermal resistivity of deposited specimen, annealing test was carried out at $300^{\circ}C$ and $600^{\circ}C$. For the account of void fraction in thin film, the Bruggeman EMA(Effective Medium Approximation) method was applied using the optical data obtained by Spectroscopic Ellipsometry. According to the results of this work, the existence of strong interaction between bias voltage and sputtering time was confirmed for refractive index value. According to XRD and TEM analysis of specimen, the film structure formed in bias voltage resulted in more refined structures than that formed without bias voltage. But excess bias voltage resulted in grain growth in thin film. It was confirmed that the application of optimum bias voltage increased film density by reduction of void fraction of about 3.7%.

• Proceedings of the KIEE Conference
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• 2001.11a
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• pp.12-15
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• 2001

Polycrystalline diamond films are deposited by cyclic method. modulating the $H_2$ Plasma and $CH_4+H_2$ plasma during the growth step. Diamond quality is evaluated by FWHM and $I_D/I_G$ ratio obtained from Raman spectroscopic analysis. Structural defects and impurities generated during the growth step are characterized by cathodoluminescence, and the variations between band-A(430 nm) line and nitrogen-related(578 nm) line are investigated as a function of $T_E/T_G$. Furthermore, the correlations between preferential orientation. film morphologies and CL characteristics are also investigated.

• Korean Journal of Pharmacognosy
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• v.32 no.1 s.124
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• pp.43-48
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• 2001

Epimedii Herba has been used for tonic, cardiotonic, impotency, amnestic and diuretic. Icariin, a main component was isolated from the Epimedii Herba and identified by the spectroscopic methods. In order to evaluate the quality of Epimedii Herba purchased from various regions of Korea, quantitative determination of icariin in Epimedii Herba using HPLC method has been conducted. Quantitative analysis showed the average amount of icariin in commercial 42 samples was 0.34% on the dry weight basis.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2011.04a
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• pp.93-99
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• 2011

Proton-NMR spectroscopic method was applied to kinetics study of concentrated sulfuric acid hydrolysis reaction. Xylan was used as model compounds. Without neutralization steps in proton-NMR methods, this analysis method is valid for analysis of xylose, furfural and formic acid in acid hydrolyzates.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.2
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• pp.292-298
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• 1998

${\alpha}-Fe_2O_3$films were prepared by a dip-coating method using the mixed solution of ferric nitrate, ethylene glycol and acethyl acetone. The polymerization effect of the mixed solution was studied by FT-IR spectroscopic analysis, and the decomposition of organic parts and crystallization of the dip-coated film were investigated by FT-IR, XRD and DSC. In addition, AFM and SEM were employed to analyze the surface roughness and the thickness of ${\alpha}-Fe_2O_3$films.

• Korean Journal of Pharmacognosy
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• v.33 no.2 s.129
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• pp.96-99
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• 2002

20-Hydroxyecdysone was isolated from Melandrii Herba and identified by the spectroscopic methods. In order to evaluate the quality of it, quantitative determination of 20-hydroxyecdysone in Melandrii Herba using HPLC method has been conducted. Content of 20-hydroxyecdysone in Melandrii Herba showed average 0.0138% in 42 samples collected throughout the regions of Korea.

• Korean Journal of Pharmacognosy
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• v.33 no.2 s.129
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• pp.100-104
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• 2002

Sanguisorbae Radix has hemostatic, analgesic and astrigent properties and it has been used for the treatment of burns, scalds and internal hemorrhage. Ziyuglycoside I was isolated from Sanguisorbae Radix and identified by the spectroscopic methods. In order to evaluate the quality of it, quantitative determination of Ziyuglycoside I in Sanguisorbae Radix using HPLC method has been conducted. Quantitative analysis of Ziyuglycoside I showed average 3.005% in 30 samples collected throughout the regions of Korea.