• Korean Journal of Medicinal Crop Science
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• v.21 no.1
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• pp.54-60
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• 2013

According to previous reports, antioxidant activities of Codonopsis lanceolata could be increased by a steaming process. This study was performed to improve its antioxidant activity and skin whitening activities of C. lanceolata by high pressure and stepwise steaming complex process. The complex processed C. lanceolata showed highest free radical scavenging acitivity as 45.21%, and for phenol and flavonoid contents, complex processed C. lanceolata contained higher than those from conventional extraction process or steaming process alone. The Cytotoxicity of all C. lanceolata extracts also showed low cytotoxicity against human fibroblast cell (CCD-986sk) as 4.49 ~ 10.40%. In whitening activity, high inhibition of tyrosinase activity was estimated as 25.08% by adding the extracts from complex process. We found that whitening and antioxidant activity of complex processed C. lancolata extract was higher than those obtained from conventional extraction and a steaming process because various kinds of antioxidant compounds could be easily released by combined process, compared to one of each process.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.3 s.333
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• pp.15-18
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• 2005

Multiple space-time codes (M-STTC) is composed of several space-time codes. That provides high transmission rate as well as diversity and coding gain without bandwidth expansion. In this paper, the layered receiver structures employing whitening process for M-STTC is proposed. The proposed receiver is composed of the decoding order decision block and the layered detection block. The whitening process in the latter is utilized to maximize the receive diversity gain in the layered detection. The layered receiver employing whitening process has more diversity gain and advantage of the required number of receive antenna over the layered detection with MMSE nulling. The proposed scheme achieves a 5dB gain compared to the coded layered space-time processing at the FER of $10^{-2}$.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.3
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• pp.167-167
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• 2004

The system combined layered space-time processing and space-time trellis codes (STTC) provide high transmission rate as well as diversity and coding gain without bandwidth expansion. In this paper, two layered receiver structures are proposed. One is the LSTT-MMSE in which received bit streams are decoupled by interference nulling and then decoded by separate STTC decoders. The decoded outputs are cancelled from the received signal before advancing to the next layer detection. The other is LSTT-Whitening employing whitening rather than nulling. The receiver employing whitening process shows several advantages on diversity gain and the required number of receive antennas compare to the convolutional coded space-time processing. The proposed receivers use different decoding order scheme according to each interference suwression. The (4, 3) LSTT-Whitening receiver still achieves 1㏈ gain over the (4, 4) LSTT-MMSE and the (4, 4) coded layered space-time processing.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.3
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• pp.9-14
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• 2004

The system combined layered space-time processing and space-time trellis codes (STTC) provide high transmission rate as well as diversity and coding gain without bandwidth expansion. In this paper, two layered receiver structures are proposed. One is the LSTT-MMSE in which received bit streams are decoupled by interference nulling and then decoded by separate STTC decoders. The decoded outputs are cancelled from the received signal before advancing to the next layer detection. The other is LSTT-Whitening employing whitening rather than nulling. The receiver employing whitening process shows several advantages on diversity gain and the required number of receive antennas compare to the convolutional coded space-time processing. The proposed receivers use different decoding order scheme according to each interference suwression. The (4, 3) LSTT-Whitening receiver still achieves 1㏈ gain over the (4, 4) LSTT-MMSE and the (4, 4) coded layered space-time processing.

• Textile Coloration and Finishing
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• v.29 no.1
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• pp.11-17
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• 2017

In this study, ozone oxidation experiment was carried out for the removal of fluorescent whitening agent which is widely used in textile dyeing and paper industry. The stilbene fluorescent whitening agent has been industrialized since the earliest, and the amount of current production is the highest. Due to the characteristics of the fluorescent whitening agent that can not be removed by conventional wastewater treatment methods, the fluorescent whitening agent in wastewater treatment has difficulty in using as recycled water in the process. Pre-treatment ozone oxidation experiment was conducted prior to the introduction of Membrane Bio Reactor(MBR) treatment process by converting biodegradable materials into biodegradable materials. The removal efficiencies of fluorescent whitening agents, a diaminostilbenedisulfonic acid derivative by ozone oxidation were evaluated by $UV_{254}$ Scan, $COD_{Mn}$, T-N and color using a synthetic wastewater sample ($COD_{Mn}=433.0mg/{\ell}$) and paper and paper mill wastewater ($COD_{Mn}=157.2mg/{\ell}$).

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.6
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• pp.63-68
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• 2017

The purpose of this study is to improve the whitening phenomenon around the PET preform gate for blow molding. CAE analysis of plastic injection molding has been applied to design of preform shape and select the injection molding conditions. A ceramic insulation gate with lower thermal conductivity than metal is applied to improve the whitening phenomenon created around the gate in the injection molding process. According to the results of CAE analysis, the warpage deformation at the square corner was estimated to be about 0.34 mm at the bottom. From the results of the temperature history analysis, it was confirmed that the resin near the gate cooled more rapidly than the cavity. Ceramic insulated gates were fabricated to reduce the cooling rate and experiments were conducted to confirm the effectiveness of the whitening phenomenon improvement. As a result of the ceramic insulation gate experiment, it was confirmed that the whitening phenomenon was significantly reduced around the gate.

• Korean Journal of Medicinal Crop Science
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• v.23 no.2
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• pp.155-160
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• 2015

This research evaluate antioxidant and skin-whitening effect of Abeliophyllum distichum Nakai by extraction processes. First, antioxidant effects were follows: EE (70% ethanol extract) showed higher DPPH scavenging activity of 69.66% than WE (hot water exract) 59.13% at $0.3mg/m{\ell}$, also UE's (70% ethanol extract by sonication process) higher than EE. Reducing power was that also EE showed higher than WE, and it was the highest value with UE's because of ultrasonic pretreatment. Next, the whitening effect tyrosinase inhibition activity was measured that EE was 23.88%, WE's was 16.69%, and UE was 23.34%. Ultrasonic pretreatment did not influence to tyrosinase inhibition activity. Cell viability showed low cell toxicity in all groups. UE's inhibited melanin synthesis, 55.1%, that is higher than EE and WE, 52.7% and 39.5%, respectively. As a result, we confirmed that antioxidant activities and skin-whitening effect by extraction process. Also, this results confirmed that the Abeliophyllum distichum Nakai extracts worth as cosmetic materials.

• Textile Coloration and Finishing
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• v.30 no.1
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• pp.51-61
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• 2018

In this study, effluent water was produced through Submerged Membrane Bio-Reactor(SMBR) process, which is a simple system and decomposes organic matter contained in wastewater with biological treatment process and performs solid-liquid separation, Especially, ozone oxidation treatment process is applied to effluent water containing fluorescent whitening agent, which is a trace pollutant which is not removed by biological treatment, and influences the quality of reused water. The concentration of $COD_{Cr}$ in the SMBR was $449.3mg/{\ell}-COD_{Cr}$, and the concentration of permeate water was $100.3mg/{\ell}-COD_{Cr}$. The removal efficiency was about 70.1%. The amount of ozone required for the removal of the fluorescent whitening agent in the permeated water in SMBR was $6.67g-O_3/min$, and the amount of ozone required to remove $COD_{Mn}$ relative to the permeate water was calculated to remove $0.997mg-COD_{Mn}$ for 1mg of $O_3$.

• Journal of Biosystems Engineering
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• v.12 no.1
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• pp.20-30
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• 1987

Major rice grain losses both in quality and in quantity are incurred in the whitening process which is indispensable in the milling process. Rice whitening it performed by two different whitening actions known as abrasive and frictional. In Korea, abrasive-type whiteners equipped with a emery-stone roller have been adopted in the whitening system in large scale milling plants, but not in customary small scale. However, researches on this type whitener have rarely been conducted in Korea. This study was attempted to establish design criteria or a modified abrasive-type whitener which is aerated with blower. The factors considered in this study were three levels of feedscrew pitch (20, 27, 34 mm) and three levels of clearance(11, 13, 15 mm) between surfaces or emery-stone roller and screen and two levels of moisture content (14.5%, 15.7%, w.b.) of brown rice. Also, the effect of aeration on whitening performance was examined, and a system performance consisting of one pass in the aerated abrasive-type and two passes in the existing friction type was compared with the performance of the existing whitening system consisting of three passes in friction type only. The latter system is prevailed in customery small milling plants. The results of this study are summarized as follows. 1. The interactions between feed-screw pitch and chamber clearance of the aerated abrasive-type whitener had great effect on the performance of the machine. When the value of a nondimensional parameter, $C^2/(P{\cdot}d_p)$, expressing the relations between feed-screw pitch, P, and chamber clearance, C, ranged from 0.40 to 0.45, the performance of the aerated abrasive-type whitener was the best. 2. Aeration to the abrasive-type whitener gave positive effect on milled and head rice recoveries. 3. The whitening system involving the aerated abrasive-type whitener, which has appropriate feed-screw pitch and chamber clearance as described in item 1 above, produced more milled and head rice recoveries by about 1.5% and 2.0%, respectively, than the existing frictional whitening system. The former also consumed less electricity by about 10% (0.9KwH/1000kg).

• Restorative Dentistry and Endodontics
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• v.44 no.1
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• pp.6.1-6.11
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• 2019

Objectives: The aim of the present study was to evaluate the effect of whitening mouth rinses alone and in combination with conventional whitening treatments on color, microhardness, and surface roughness changes in enamel specimens. Materials and Methods: A total of 108 enamel specimens were collected from human third molars and divided into 9 groups (n = 12): 38% hydrogen peroxide (HP), 10% carbamide peroxide (CP), 38% HP + Listerine Whitening (LW), 10% CP + LW, 38% HP + Colgate Plax Whitening (CPW), 10% CP + CPW, LW, CPW, and the control group (CG). The initial color of the specimens was measured, followed by microhardness and roughness tests. Next, the samples were bleached, and their color, microhardness, and roughness were assessed. Data were analyzed through 2-way analysis of variance (ANOVA; microhardness and roughness) and 1-way ANOVA (color change), followed by the Tukey post hoc test. The Dunnett test was used to compare the roughness and microhardness data of the CG to those of the treated groups. Results: Statistically significant color change was observed in all groups compared to the CG. All groups, except the LW group, showed statistically significant decreases in microhardness. Roughness showed a statistically significant increase after the treatments, except for the 38% HP group. Conclusions: Whitening mouth rinses led to a whitening effect when they were used after conventional treatments; however, this process caused major changes on the surface of the enamel specimens.