• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.8
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• pp.1747-1752
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• 2012

The SiOC film of carbon centered system was prepared using bistrimethylsilylmethane (BTMSM) and oxygen mixed precursor by the chemical vapor deposition. The dielectric constant is measured by MIS(metal/insulator/Si) structure, but it could decrease the reliability because the uniformity is not assured. To research the dielectric constant of SiOC film, the range of low polarization was researched in SiOC film using the optical analysis and hardness, and then calculated the dielectric constant of SiOC film with amorphous structure of high degree. After annealing, the dielectric constant of SiOC film was decreased owing to the lowering of polarization, and FTIR spectra of the main bond was shifted to higher wave number. The main bond of 950~1200 cm-1 was composed of the Si-C and Si-O bonds. The intensity increases in Si-O bond infers the bonding strength became stronger than that of deposited film. Annealed SiOC film showed 2.06 in dielectric constant.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.13 no.6
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• pp.297-303
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• 2003

Mn-Ni-Co type thin films were prepared at various conditions by a rf magnetron sputtering system. At the condition. or substrate temperature of $300^{\circ}C$ and $Ar/O_2$= 10/0, a cubic spinel phase was obtained. When oxygen was included in process gas, a cubic spinel phase was not formed even after the thermal annealing at $900^{\circ}C$. The thermistor thin film had no other elements except Mn, Ni and Co. The infrared reflection spectra of the thermistor thin films showed that the films had somewhat high reflectance for incoming infrared ray with some angle. The etch rate of the thermistor thin films was about 63nm/min at a condition of DI water : $HNO_3$: HCl = 60 : 30 : 10 vol%. The B constant and temperature coefficient of resistance of the thermistor thin films were 3500 K and -3.95 %/K, respectively. The voltage responsivity of the thermistor thin film infrared sensor was 108.5 V/W and its noise equivalent power and specific detectivity were $5.1\times 10^{-7}$ W/$Hz^{-1/2}$ and $0.2\times 10^6$cm $Hz^{1/2}$/W, respectively.

• Fashion & Textile Research Journal
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• v.13 no.5
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• pp.797-805
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• 2011

This study was carried out to investigate dyeing characteristics of CDP(cation dyeable polyester)/silk knitted fabrics with disperse type cation dyes/acid dyes by one bath dyeing method in comparison with two bath dyeing method in the interests for rationalization of the dyeing process. The apparent color depth(K/S) of the disperse type cation dyes with CDP and that of acid dyes with silk decreased slowly with increasing pH values of dyebath with the exception of sharp decrease at alkali region for CDP. The contamination behavior of CDP by the acid dyes and that of silk by the disperse type cation dyes decreased with progressing of dyeing. The migration ratio(%) of the disperse type cation dyes with CDP is low compared with that of acid dyes with silk. The sediment in mixed dying solution of disperse type cation dyes and acid dyes remarkably less compared with that of regular type cation dyes and acid dyes at $100^{\circ}C$ regardless applying of preventer agent of precipitation. When CDP/silk knitted fabrics was dyed with by with mixtures of disperse type cation dyes/acid dyes one bath or two bath dyeing method, the characteristic of reflectance spectra of CDP components were greatly influenced by disperse type cation dyes and that of silk components by acid dyes. It was confirmed that K/S values of each components of CDP/silk knitted fabrics dyed by one bath dyeing method decreased slightly compared with two bath dyeing method.

• Korean Journal of Materials Research
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• v.28 no.1
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• pp.68-74
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• 2018

Cobalt-incorporated zeolitic imidazolate framework ZIF-8 was synthesized by a simple one-pot synthesis method at room temperature. Powder X-ray diffraction patterns and energy dispersive X-ray spectrum confirmed the formation of the bimetallic Co/Zn-ZIF structure. UV-Vis diffuse reflectance spectra revealed that the bimetallic ZIF had a lower HOMO-LUMO gap compared with ZIF-8 due to the charge transfer process from organic ligands to cobalt centers. A hydrolytic stability test showed that Co/Zn-ZIF is very robust in aqueous solution - the most important criterion for any material to be applied in photodegradation. The photocatalytic efficiency of the synthesized samples was investigated over the Indigo Carmine (IC) dye degradation under solar simulated irradiation. Cobalt incorporated ZIF-8 exhibited high efficiency over a wide range of pH and initial concentration. The degradation followed through three distinct stages: a slow initial stage, followed by an accelerated stage and completed with a decelerated stage. Moreover, the photocatalytic performance of the synthesized samples was highly improved in alkaline environment rather than in acidic or neutral environments, which may have been because in high pH medium, the increased concentration of hydroxyl ion facilitated the formation of hydroxyl radicals, a reactive species responsible for the breaking of the Indigo Carmine structure. Thus, Co/Zn-ZIF is a promising and green material for solving the environmental pollution caused by textile industries.

• Journal of Biosystems Engineering
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• v.39 no.3
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• pp.184-193
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• 2014

Purpose: The aim of this study was to develop a technique for the non-destructive and rapid prediction of the moisture content in red pepper powder using near-infrared (NIR) spectroscopy and a partial least squares regression (PLSR) model. Methods: Three red pepper powder products were separated into three groups based on their particle sizes using a standard sieve. Each product was prepared, and the expected moisture content range was divided into six or seven levels from 3 to 21% wb with 3% wb intervals. The NIR reflectance spectra acquired in the wavelength range from 1,100 to 2,300 nm were used for the development of prediction models of the moisture content in red pepper powder. Results: The values of $R{_V}{^2}$, SEP, and RPD for the best PLSR model to predict the moisture content in red pepper powders of varying particle sizes below 1.4 mm were 0.990, ${\pm}0.487%$ wb, and 10.00, respectively. Conclusions: These results demonstrated that NIR spectroscopy and a PLSR model could be useful techniques for measuring rapidly and non-destructively the moisture content in red pepper powder.

• Analytical Science and Technology
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• v.13 no.2
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• pp.250-257
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• 2000

Paint, fiber and dye which play a critcal role in proving the relationship between a suspect and a victim or a crime scene, are one of the most frequently encountered trace evidences at a forensic laboratory, however, in usual, because of infinitesimally small sizes of forensic samples, investigation of the spectroscopic characteristics of such samples is becomming more and more prevalent in forensic science as a non-destructive method. In this study, transmittance/reflectance profiles at ultraviolet-visible region (240-780nm), were investigated by UV/visible microspectro- photometer and used to analyze the spectral characteristics of different types of 14 microfibers, 12 inks of four colors and 44 automotive paints of two colors. Good results for discrimination were given from spectra of these samples due to the characteristic bands in uv/vis region, respectively.

• Journal of Biosystems Engineering
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• v.38 no.4
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• pp.312-317
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• 2013

Purpose: Conventional methods used to evaluate seeds viability are destructive, time consuming, and require the use of chemicals, which are not feasible to implement to process plant in seed industry. In this study, the effectiveness of Fourier transform near infrared (FT-NIR) spectroscopy to differentiate between viable and nonviable watermelon seeds was investigated. Methods: FT-NIR reflectance spectra of both viable and non-viable (aging) seeds were collected in the range of 4,000 - 10,000 $cm^{-1}$ (1,000 - 2,500 nm). To differentiate between viable and non-viable seeds, a multivariate classification model was developed with partial least square discrimination analysis (PLS-DA). Results: The calibration and validation set derived from the PLS-DA model classified viable and non-viable seeds with 100% accuracy. The beta coefficient of PLS-DA, which represented spectral difference between viable and non-viable seeds, showed that change in the chemical component of the seed membrane (such as lipids and proteins) might be responsible for the germination ability of the seeds. Conclusions: The results demonstrate the possibility of using FT-NIR spectroscopy to separate seeds based on viability, which could be used in the development of an online sorting technique.

• Bulletin of the Korean Chemical Society
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• v.35 no.2
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• pp.441-447
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• 2014

$AgI/AgCl/H_2WO_4$ double heterojunctions photocatalyst was prepared via deposition-precipitation followed by ion exchange method. The structure, crystallinity, morphology, chemical content and other physical-chemical properties of the samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive x-ray spectra (EDX), UV-vis diffuse reflectance spectroscopy (DRS), and photoluminescence (PL). The photocatalytic activity of the $AgI/AgCl/H_2WO_4$ was evaluated by degrading methyl orange (MO) under visible light irradiation (${\lambda}$ > 400 nm). The double heterojunctions photocatalyst displayed more efficient photocatalytic activity than pure AgI, AgCl, $H_2WO_4$ and AgCl/$H_2WO_4$. Based on the reactive species and energy band structure, the enhanced photocatalytic activity mechanism of $AgI/AgCl/H_2WO_4$ was discussed in detail. The improved photocatalytic performance of $AgI/AgCl/H_2WO_4$ double heterojunctions could be ascribed to the enhanced interfacial charge transfer and the inhibited recombination of electron-hole pairs, which was in close relation with the $AgI/AgCl/H_2WO_4$ heterojunctions formed between AgI, AgCl and $H_2WO_4$.

• Korean Journal of Materials Research
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• v.27 no.4
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• pp.206-210
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• 2017

In this study, an ${\alpha}-Fe_2O_3$ (hematite) coated porcelain plate was sintered in a temperature range from $1100^{\circ}C$ to $1250^{\circ}C$ using ferrous sulfate. The specimens were investigated by X-ray diffractometer (XRD), scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS), and UV-visible spectrophotometer. It was confirmed that ${\alpha}-Fe_2O_3$ (hematite) was densely fused to the surface at several tens of ${\mu}m$, the ${\alpha}-Fe_2O_3$ (hematite) was in the form of thin platelet and polyhedra, and no other compounds appeared in the sintering process. In the specimen coated with ${\alpha}-Fe_2O_3$ (hematite), the reflectance spectra show a red absorption band of 560-650 nm. The $L^*$ value decreased from 53.18 to 46.94 with the firing temperature. The values of $a^*$ and $b^*$ were at 19.03 and 15.25 at $1100^{\circ}C$ and gradually decreased with increasing temperature; these values decreased rapidly at $1250^{\circ}C$ to 11.54 and 7.98, respectively. It is considered that the new phases are formed by the phase transition of the porcelain plate (clay), and thus the $a^*$ and $b^*$ values are greatly influenced.

• Bulletin of the Korean Chemical Society
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• v.33 no.11
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• pp.3761-3766
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• 2012

$Ag_2Se$-Graphene/$TiO_2$ composite was synthesized by a facile sonochemical method. The as-prepared products were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis, transmission electron microscopy (TEM) and UV-vis diffuse reflectance spectrophotometer. During the reaction, both of the reduction of graphene oxide and loading of $Ag_2Se$ and $TiO_2$ particles were achieved. The as-prepared $Ag_2Se$-Graphene/$TiO_2$ composites possessed great adsorptivity of dyes, extended light absorption range, and efficient charge separation properties simultaneously. Hence, in the photodegradation of rhodamine B (Rh.B), a significant enhancement in the reaction rate was observed with $Ag_2Se$-Graphene/$TiO_2$ composites, compared to the pure $TiO_2$. The high activity can be attributed to the synergetic effects of high charge mobility, and red shift in absorption edge of $Ag_2Se$-Graphene/$TiO_2$ composites.