• Laser Solutions
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• v.11 no.1
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• pp.12-18
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• 2008

Laser micromachining is a promising technique to fabricate the micro-scale devices. However, there remains important challenges to reducethe redeposition of ablated materials around the laser irradiated zone and to get a smooth surface, especially for metal and semiconductor materials. To achieve the high-quality micromachined devices, various methods have been developed. Liquid-assisted micromachining can be a good solution to overcome the previously mentioned problems. During the laser ablation process, the liquid around the solid sample dramatically changes the ablation characteristics, such as ablation rate, surface profile, formation of debris, and so on. In this investigation, we conducted the laser micromachining of Si in various liquid environmental conditions, such as liquid types, liquid thickness. In addition, using nanoscale time-resolved shadowgraphy technique, we observed the ablation process in liquid environments to understand the mechanism of liquid-assisted laser micromachining.

• Journal of the Optical Society of Korea
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• v.20 no.3
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• pp.427-430
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• 2016

The effect of the liquid density difference on interface shape of a double-liquid lens is analyzed in detail. The expressions of interface shape of two liquids with liquid density difference are analyzed and fitted with “even asphere”. The imaging analysis of the aspheric interface shape of a double-liquid lens is presented. The results show that the density difference of two liquids can cause the interface to be an aspheric surface, which can improve the image quality of a double-liquid lens. The result provides a new selection for the related further research and a wider application field for liquid lenses.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.163-165
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• 2009

It is commonly found that liquid crystals stored in a common environment degrade with time, trapping more and more ion impurity in the materials. In this paper, we demonstrate how the electrical property of an old batch of liquid crystal can be effectively restored by a novel regenerative agent.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.29B no.9
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• pp.27-36
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• 1992

A design of scanning electrode driving IC chip has been implemented aiming at the application to liquid crystal color television displays. The chip reflects the design characteristics of high quality liquid crystal panels and satisfies specifications of NTSC type color television displays. The design was verified using logic and circuit simulation, and fabricated using a high voltage CMOS process. A fully working die has been obtained that can be readily applicable to commercial color liquid crystal panels.

• Journal of The Korean Society of Grassland and Forage Science
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• v.7 no.2
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• pp.103-108
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• 1987

The experiment was carried out to determine the optimum application rate of liquid waste from methane fermentation (LW) and its effect on botanical composition, dry matter yields and nutrient quality of pasture mixtures. Experimental fields was designed as a randomized block treated with NPK chemical fertilizer (NPK = 28-20-24 kg/lOa), NPK + Water 28 ton, 112 NPK + LW 28 ton, 112 NPK + LW 42 ton, LW 28 ton, LW 42 ton and LW 56 ton/lOa at Livestock Experiment Station in Suweon, 1985. The results obtained are summarized as follows: 1. Vegetation of introduced pastures, both in grasses and legumes, was markedly increased in the plots treated with methane-liquid waste. However, heavy application of liquid waste tended to increase of native weeds such as Polygronum spp., Rumex spp. and Lactuca spp. 2. Crude protein contents was increased in the plants applied with liquid waste, but NFE was decreased compared with those of chemical fertilizer applied. The concentrations of crude fat and crude fibre were, however less affected by the fertilizer resource. Among cell-wall constituents, cellulose content was decreased as the liquid waste application rate increased, while hemicellulose showed a negative association. 3. Productivity of the pasture was increased as the liquid waste application rate increased. The highest dry matter yields was obtained in the plot treated with LW 42 ton/lOa by 71 1 kg/lOa, which shows about 71% increments compared with those of chemical fertilizer treated. Net energy yields, both in starch value and NEL, were also markedly increased under liquid waste application. As a results, the optimum application rate of methane-liquid waste was found to be 42 ton in 10 a.

• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.2
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• pp.121-126
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• 1999

Manure management is a top priority on both dairy and swine farrns at present. This experiment was carried out to determine the effect of different types and N rates of liquid manure on forage yield and quality of oats(Avena sativa L.) in Suweon, 1997. Seven treatments consisting of chemical fertilizer $120kg\;N\;ha^{-1}$, liquid cattle manure 120, 240 and $360kg\;N\;ha^{-1}$, and liquid swine manure 120, 240 and $360kg\;N\;ha^{-1}$ were arranged in a randomized complete block design with three replications. As increasing N rate of the liquid manure, the plant height was increased, but dry matter content of oats was decreased as increasing liquid manure N rate. There were significant differences in dry matter yield of oats among the liquid manure N rates(P<0.05). Crude protein(CP) content of oats ranged from 14.7 to 24.1% (P<0.05), and CP yield was orderly ranked as liquid swine manure $360kg\;N\;ha^{-1}$>liquid cattle manure $360kg\;N\;ha^{-1}$>liquid swine manure $240kg\;N\;ha^{-1}$(P<0.05). Acid detergent fiber(ADF) content of the liquid cattle manure treatment showed a slightly higher than that of the liquid swine manure treatment(P<0.05). Neutral detergent fiber(NDF) content of the liquid cattle manure treatment was lower than that of the liquid swine manure treatment(P<0.05). Relative feed value(RFV) of the liquid cattle manure treatment decreased with increasing liquid manure N rates compared with that of the liquid swine manure treatment. Based on the results of this experiment, it is indicates that to increase the N rates from liquid manure application could be obtained from the increase of forage yield.

• Journal of Environmental Health Sciences
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• v.25 no.3
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• pp.103-107
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• 1999

Even if odorous compounds remain very low concentration in water, it cause strong odor. Because Geosmin and most of odorous compound had very low vaporization, those were difficult to analyze with GC/MSD and Purge & Trap. So, we needed pre-treatment method for decreasing amounts of extracting solvents, improving recovery efficiencies and increasing analytical efficiencies. This study developed efficient technology for analyzing odorous compounds, using various adsorbents and extracting solvents. The optimum adsorbent was XAD resins. Especially, XAD-2, XAD-7 and XAD-2010 were superior, but XAD-2 of these and the optimum extraction solvent is MTBE. Other extraction solvents' efficiency is in order of MTBE>Dichloromethane>n-Hexane>Diethylether. The optimum NaCl dosage for increasing efficiency is 5 g in liquid-liquid extraction method. The shaking time(0~24hr) has no concern with adsorption efficiency. The optimum adsorbent is XAD-2 resin and extraction solvent is MTBE. Dosing NaCl, adsorption efficiency is increased in liquid-liquid extraction method, but NaCl has no effect on liquid-solid extraction method. In this experimental results, this algae toxins(Mycrocystin, Anatoxin etc.).

• Journal of the Korean Applied Science and Technology
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• v.23 no.4
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• pp.307-318
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• 2006

The pyrolysis of high density polyethylene(HDPE) and low density polyethylene(LDPE) was carried out at temperature between 425 and $500^{\circ}C$ from 35 to 80 minutes. The liquid products formed during pyrolysis were classified into gasoline, kerosene, gas oil and wax according to the petroleum product quality standard of Korea Petroleum Quality Inspection Institute. The conversion and yield of liquid products for HDPE pyrolysis increased continuously according to pyrolysis temperature and pyrolysis time. The influence of pyrolysis temperature was more severe than pyrolysis time for the conversion of HDPE. For example, the liquid products of HDPE pyrolysis at $450^{\circ}C$ for 65 minutes were ca. 30wt.% gas oil, 15wt.% wax, 14wt.% kerosene and 11wt.% gasoline. The increase of pyrolysis temperature up to $500^{\circ}C$ showed the increase of wax product and the decrease of kerosene. The conversion and yield of liquid products for LDPE pyrolysis continuously increased according to pyrolysis temperature and pyrolysis time, similar to HDPE pyrolysis. The liquid products of LDPE pyrolysis at $450^{\circ}C$ for 65 minutes were ca. 27wt.% gas oil, 18wt.% wax, 16wt.% kerosene and 13wt.% gasoline.

• Journal of the Korean Ceramic Society
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• v.25 no.1
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• pp.78-82
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• 1988

Good quality LiNbO3 single crystals which can be applied to SAW devices, were grown by Czochralski method. It was observed that the gas-bubbles were concentrated in ring shape at the outer part of grown crystals, and this anomaly was illustrated by modeling the mechanism of gas-bubble entrapment according to the melt flow pattern in the crucible. And this mechanism was also encertained by observation of solid-liquid interface shape of grown crystals. The optimal condition for good quality crystals was known that the solid-liquid interface shape was slightly concave.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.3
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• pp.136-143
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• 2006

The study was carried out to evaluate odor emission during storage time and quality of liquid slurry fertilizer along with three storage container types installed at farmer's fields in Cheorwon. Liquid slurry manure stored in the liquid-circulated or the air-injected tank was very homogeneous in concentration of nutritional elements because of well mixing operation, while nutritional concentration of the manure stored in the non-treated tank was significantly different from top to bottom in the tank, which may bring about partially irregular growth of plant after its application. The potential capacity of offensive odor emitted from liquid slurry manure stored in the liquid-circulated or the air-injected tank was much lower than that emitted from manure stored in the non-treated tank. Low potential capacity may less emit offensive odor after application of piggery liquid slurry on the field. The efficiency in oder to reduce odor emission from liquid manure was slightly higher in the liquid-circulated tank than the air-injected tank