• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.146-149
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• 2004

Porous silicon(PS) as an excellent light diffuser can be used as an antireflection layer without other antireflection coating(ARC) materials. PS layers were obtained by electrochemical etching(ECE) anodization of silicon wafers in hydrofluoric acid/ethanol/de-ionized(DI) water solution($HF/EtOH/H_2O$). This technique is based on the selective removal of Si atoms from the sample surface forming a layer of PS with adjustable optical, electrical, and mechanical properties. A PS layer with optimal ARC characteristics was obtained in charge density (Q) of 5.2 $C/cm^2$. The weighted reflectance is reduced from 33 % to 4 % in the wavelength between 400 and 1000 nm. The weighted reflectance with optimized PS layers is much less than that obtained with a commercial SiNx ARC on a potassium hydroxide(KOH) pre-textured multi-crystalline silicon(mc-Si) surface.

• Journal of the Korean Vacuum Society
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• v.12 no.4
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• pp.257-262
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• 2003

The structure and optical properties of n-type and p-type porous silicon (PS) prepared by the chemical etching in the light and the dark, respectively, are reported in this paper. Microstructural features of the samples are mainly investigated by SEM, AFM XRDGI techniques. Also, their optical properties are investigated by photoluminescence (PL) and Fourier transform infrared absorption measurements. In the n-type PS, the room temperature photoluminescence is observed in a visible range from 500 nm to 650 nm in contrast to that in the blue region (400∼650 nm) in p-type PS. Further, semi-transparent Cu films in thickness range of ∼40 nm are deposited by rf-magnetron sputtering on PS to investigate the I-V characteristics of the samples.

• Journal of The Korean Society of Grassland and Forage Science
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• v.25 no.2
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• pp.105-112
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• 2005

This study was conducted on paddy-land at Kimje, ChunBuk in Korea from Nov. 1999 to Nov. 2002. The aim of this study was to investigate the effect of pig slurry (PS) on dry matter (DM) yield, N yield and nutritive value of rye, and soil total nitrogen (TN), Phosphorus (P) and organic matter (OM) content. This experiment was consisted of 4 plot (chemical fertilizer; N: 100/100, $P_2O_5: 150,\;K_2O: 150$ kg/ha; PS $100\%$ treatment, PS $200\%$ treatment and PS $100\%$ treatment with half of CF). 1. DM yields of rye revealed that there was an increase in order; PS $100\%$ treatment with half of chemical fertilizer (CF) > PS $200\%$ treatment > full of CF treatment > PS $100\%$ treatment. 2. Crude protein (CP) content was the highest with PS $200\%$ treatment ($10.53\%$) and followed by PS $100\%$ treatment with half of CF and full of CF treatment and the lowest with PS $100\%$ treatment. 3. The contents of NDF and TDN were hardly influenced by PS and CF 4. N yields of rye revealed that there was an increase in order; PS $200\%$ treatment > PS $100\%$ treatment with half of CF > full of CF treatment > PS $100\%$ treatment. 5. The contents of TN and OM were not influenced by the application levels of PS. however, The TN content increased by the application of PS, as increasing the application period 6. P content of the soil was not affected by the application levels of PS during the experimental period.

• Digital Contents
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• no.4 s.119
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• pp.146-151
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• 2003

PS2 기반 게임 SOE(State Of Emergency)가 성공을 거두자 이 게임의 개발업체인 미국 VIS엔터테이먼트사는 이를 X-box에서도 게임이 가능하도록 변환시키기로 결정했다. 이는 SOE의 성공을 보다 오랫동안 누리기 위한 방안이었다. 시간은 충분했다. PS2와의 계약기간이 8개월이나 남아 있었기에 그 이전에 SOE의 X-box버전을 개발해야할 필요성은 없었다. 문제는 수작업으로 조정된 모든 코드를 수정해야 한다는 점이었다. SOE의 사례를 바탕으로 새로운 미션에 대한 해결법을 찾아보자.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.301-301
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• 2013

전도성 고분자인 PEDOT은 PSS와 활용도를 높게 하기 위해 PSS와 함께 쓰이며, 다양한 분야에서 넓게 활용되고 있다. 하지만 박막 형성시 전도성이 작은 문제점이 있기 때문에 이를 개선할 필요성이 있다. 이에 본 연구에서는 용매를 사용한 PEDOT:PSS 박막의 처리 과정을 통하여 물성의 변화를 관찰하였으며, 전도성 향상을 관찰 하였다. 이를 위해 4-point probe장비를 이용하여 면저항을 측정하였으며, 동시에 Fe-SEM을 사용하여 박막의 무께를 알아 보았다. 또한 분자 수준의 관찰을 위해 Raman spectroscopy를 이용하였으며 동시에 FT-IR과 XPS장비를 사용하였다.

• Membrane Journal
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• v.19 no.3
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• pp.228-236
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• 2009

ABA type triblock copolymer of poly(hydroxyl ethyl acrylate )-b-polystyrene-b-poly(hydroxyl ethyl acrylate), i.e. PHEA-b-PS-b-PHEA, was synthesized throughatom transfer radical polymerization (ATRP). This block copolymer was thermally crosslinked with 4,5-imidazole dicarboxylic acid (IDA) via the esterification between the -OH groups of PHEA in block copolymer and the -COOH groups of IDA. Upon doping with ${H_3}{PO_4}$ to form imidazole-${H_3}{PO_4}$ complexes, the proton conductivity of membranes continuously increased with increasing ${H_3}{PO_4}$ content. The PHEA-b-PS-b-PHEA/IDA/${H_3}{PO_4}$ polymer membrane with [HEA]:[IDA]:[${H_3}{PO_4}$]=3:4:4 exhibited a maximum proton conductivity of 0.01 S/cm at $100^{\circ}C$ under anhydrous conditions. Thermal gravimetric analysis (TGA) shows that the PHEA-b-PS-b-PHEA/IDA/${H_3}{PO_4}$ complex membranes were thermally stable up to $350^{\circ}C$, indicating their applicability in fuel cells.

• Korean journal of food and cookery science
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• v.12 no.4
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• pp.499-505
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• 1996

The facillities for Kimchi preservation were investigated in order to develop the taste, flavor and commercial quality of Kimchi during fermentation. Four kinds of facillities used for this experiment were PP(Polypropylene). PSC(Polypropylene+ceramic)and PPP was selected newly and laminated of three layers with PETG (Polyester G), PS (Polystyrene) and PETG. The change of total number of lactic acid Bacteria, pH, acidity, color, gas contents and free internal volume of package were measured for the Kimchi packaged by 4 facillities during 6 days fermentation at 15$^{\circ}C$. The total No. of lactic acid Bacteria within the Kimchi in the PPP facillity was more and remained longer time (120 hrs.) than other Kimchi in the PP, PS and PPC facillities. Also the pH of all Kimchi were decreased to pH 4 within 72 hrs. and the pH of Kimchi in the PPP facillity was kept as pH 4 for 120 hrs., so that was shown to be decreased more dully than others. In case of fimchi in the PPP facillity, the color was retained better, CO$_2$ contents was lower similar to PPC facillity, and swelling degree of free internal volume was higher than others. By the sensory evaluation, the Kimchi in the PPP facillity represented as better than others for color, flavor, texture and total preferences until 48 hrs. fermentation. And the PPP facillity is transparent, so these will be selected and confirmed more easily, also PPP facillity is so hard to endure the swelling pressure of internal gas. Therefore it is thought that the PPP facillity used as Kimchi package will be desirable for better taste, flavor, and commercial quality.

• Microbiology and Biotechnology Letters
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• v.36 no.1
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• pp.61-66
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• 2008

The proteins in whey are separated and used as food additives. The remains (mainly lactose) are spray-dried to produce sweet whey powder, which is widely used as an additive for animal feed. Sweet whey powder is also used as a carbon source for the production of valuable products such as polysaccharides. Glucose, fructose, galactose, and sucrose as asupplemental carbon source were evaluated for the production of PS-7 from Azotobacter indicus var. myxogenes L3 grown on whey based MSM media. Productions of PS-7 with 2% (w/v) fructose and sucrose were 2.05 and 2.31g/L, respectively. The highest production of PS-7 was 2.82g/L when 2% (w/v) glucose was used as the carbon source. Galactose showed low production of PS-7 among the carbon sources tested. The effects of various carbon sources addition to whey based MSM medium showed that glucose could be the best candidate for the enhancement of PS-7 production using whey based MSM medium. To evaluate the effect of glucose addition to whey based media on PS-7 production, fermentations with whey and glucose mixture (whey 1, 2, 3%; whey 1% + glucose 1%, whey 1% + glucose 2% and glucose 2%, w/v) were carried out. Significant enhancement of PS-7 production with addition of 1% (w/v) and 2% (w/v) glucose in 1% (w/v) whey media was observed. The PS-7 concentration of 2% glucose added whey lactose based medium was higher than that of 1% glucose addition, however, the product yield $Y_{p/s}$ was higher in 1% glucose added whey lactose based MSM medium. Therefore, the optimal condition for the PS-7 production from the Azotobacter indicus var.myxogenes L3, was 1% glucose addition to 1% whey lactose MSM medium.

• Journal of Biosystems Engineering
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• v.5 no.2
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• pp.26-39
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• 1980

A study was investigated to find out the mechanical optimum conditions of power tiller-plow system on both paddy field and upland. Mathematical model was developed for the theoretical analysis of this system and the experimentation on the field was carried out with two different sizes of 5PS and 8PS power tiller equipped with rubber tire. 1) The relationship between the plowing depth and draft resistance of the power tiller-plow system was a quadratic function. 2) The minimum point of the specific draft resistance of the 5 PS plow was found at the smaller plowing depth than that of 8 PS plow, therefore we can find that the curved surface of 5PS plow bottom should be improved for the effective plowing operation. 3) As the improvement of the mechanical balance by the desirable change of the curved surface of plow bottom, the relative position of hitch point and dimension of plow beam would be realized, the 5 PS power tiller could be used to plow deeply (about 16-17cm). 4) The virtual acting point of the total draft resistance on the plow bottom approached to the land side as the plowing depth increased. 5) The resultant of vertical reaction force $R_2$ on the landside was increased with the plowing depth, while the vertical reaction force $R_1$ on the wheel was decreased as the slope angle of the body of power tiller increased. 6) For the effective plowing operations ; a) The slope angle of the body should be as small as possible. b) The diameter of the wheel should be as small possible. c) The horizontal and vertical distances $l_2, h_1$ between the wheel axis and plow bottom should be as large as possible. 7) To use the 5PS power tiller as the major unit of agricultural machinery, the curved surface of the 5 PS plower bottom and the mechanism of attachment between the power tiller and the plow should be changed as the indications of this study, and in addition to these, the new operation method of the field work should be developed.

• Asian Journal of Turfgrass Science
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• v.6 no.1
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• pp.11-22
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• 1992

To determine the use of waste materials as root zone soil mixtures for turfgrass culture, the effects of paper mill sludge and briquet ash on physical and chemical properties of soil and growth of turfgrasses were examined. Three turfgrass species of zoysiagrass(Zoysia japonicaSteud.). kentycky bluegrass(Poa pratensis L. 'Ram I') and creeping bentgrass(Agrostis panistris Huds 'Persucross') were cultured in 32cm diameter plastic pots containing various soil mixtures. The basic ingredients used for mixtures included sand(SD), field soil(SL), paper mill sludge(PS), sphagnum peat moss(PM) and briquet ash(BA). Seven combinations using these ingreients were mixed in different percentage by volume as follows: SD+SL+PM(80:10.10), SH+SL+PS(80:10:10), SD-PM(80:20), SD+PS (80:20), SD+BA(80:20), SD+BA+PM(60:20:20) and SD+BA+PS(60:20:20). 1. Paper mill sludge showed pH of 6.6, more than 30% of organic matter content, and higher concentrations of total N, P, k, Ca, Mg and CEC. Bulk density, fild moisture capacity and electrical conductivity of soil mixtures were increased by the comimation of 10~20% PS by volume. 2. Briquet ash showed pH of 8.0, and higher levels of P, k, Ca and Mg than those of field soiks. Bulk density, field moisture capacity and hardenss of soil mixtures were increased but vertical water flow rate and electrical conductivity were decreased by the combination of 20% BA by volume. 3. Phytotoxic effects of PS and BA on growth of turfgrasses were not found. Shoot growth of all three species was higher in soil combination of SD+BA+PS than that of SD+SL+PM added with fertilizer. However, root growth was better in soil mixtures combined with PM. Soil mixtureomposed of 60% SD, 20% BA and 20% PS by volume was most effective on growth of all three species. 4. Paper mill sludge resulted in higher N level in the leaf tissue. The contents of heavy metals such as Cd and Ph did not vary significantly among soil mixtures and species. However, the Mn level was 2~3 times higher in plants growh in mixtures containing PM compared with others, and especially it was higher in creeping bentgrass than other species.