• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.4
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• pp.321-329
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• 1999

The effect of water deficits on soybean [Glycine max (L.) Merr.] could appear on seed quality through changes of morphological plant characteristics. Two Korean genotypes, Hwangkeum (determinate growth habit) and Muhan (indeterminate growth habit), were used to examine the influences of treatment stage and method of water deficit during reproductive growth period on yield and seed quality of soybean. Water deficit at R5 or R6 stages was as damaging to seed quality as double water-deficit treatments at R2+R5 or R2+R6. However, seed from double water-deficit treatment tended to have lower oxidation-reduction potential compare to the corresponding single water-deficit treatment. In comparison with Muhan, Hwangkeum had significantly greater oxidation-reduction potential value. Seed yield per plant in both genotypes depended greatly on seed yield of branches. However, the proportion of number of branch seed to total seed umber in Hwangkeum was increased as the water deficit was applied during later reproductive stage, whereas, in Muhan the proportion was lower. Water-deficit treatments including the single and double water-deficit treatments and non-stressed treatment were able to be classified into five groups for Hwangkeum and four groups for Muhan based on the influences on yield components, number of pod, number of seed, and single seed weight, using principal component analysis. In both genotypes, R2+R5 water-deficit treatment decreased number of pod and seed, but increased single seed weight. On the contrary, R6 or R2+R6 stress increased the pod and seed number, but decreased single seed weight.

• Resources Recycling
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• v.12 no.6
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• pp.57-63
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• 2003

In this study, the separation of neodymium was investigated from NdFeB permanent magnet scrap. Decomposition and leach-ing process of NdFeB permanent magnet scrap by oxidation roasting and sulfuric arid leaching were examined. Neodymium could be separated from iron by double salt precipitation using sodium sulfate. The optimum conditions established for decom-position and leaching are as follows: oxidation roasting temperature is $500^{\circ}C$ for sintered scrap and $700^{\circ}C$ for bonded scrap, concentration of sulfuric acid in leaching solution is 2.0 M, leaching temperature and time is $50^{\circ}C$ and 2 hrs, and pulp density is 15%. The leaching yield of neodymium and iron was 99.4% and 95.7% respectively. The optimum condition for separation of neodymium by double-salt precipitation was 2 equivalents of sodium sulfate and $50^{\circ}C$ The yield of neodymium was above 99.9%.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.287.2-287.2
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• 2013

We synthesized a new composite of poly sodium 4-styrenesulfonate intercalated graphene oxide for energy storage devices by controlling oxidation time in the synthesis of graphite oxide. Specific capacitance was improved from 20 F/g of the previous composites to 88 F/g of the new composite at the current density of 0.3 A/g. The capacitance retention was 94% after 3000 cycles, indicating that the new composites of high cyclic stability, prominent performance as electric double layer capacitor, and even low resistance could be an excellent carbon based electrode for further energy storage devices.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.340-340
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• 2012

최근 MOS 소자들이 게이트 산화막을 Mono-layer가 아닌 Multi-Layer을 사용하는 추세이다. Bulk와 High-k물질간의 Dangling Bond를 줄이기 위해 Passivation 층을 만드는 것을 예로 들 수 있다. 이러한 Double Layer의 쓰임이 많아지면서 계면에서의 Interface State Density의 영향도 커지게 되면서 이를 측정하는 방법에 대한 연구가 활발히 진행되고 있다. 본 연구에서는 $SiO_2$ Double Layer의 Interface State Density를 Conductance Method를 사용하여 구하는 연구를 진행하였다. Wet Oxidation과 Chemical Vapor Deposition (CVD) 공정을 이용하여 $SiO_2$ Double-layer로 증착한 후 Aluminium을 전극으로 하는 MOS-Cap 구조를 만들었다. 마지막 공정은 $450^{\circ}C$에서 30분 동안 Forming-Gas Annealing (FGA) 공정을 진행하였다. LCR meter를 이용하여 high frequency C-V를 측정한 후 North Carolina State University California Virtual Campus (NCSU CVC) 프로그램을 이용하여 Flatband Voltage를 구한 후에 Conductance Method를 측정하여 Dit를 측정하였다. 본 연구 결과 Double layer (Wet/CVD $SiO_2$)에 대해서 Conductance Method를 방법을 이용하여 Dit를 측정하는 것이 유효하다는 것을 확인 할 수 있었다. 본 실험은 앞으로 많이 쓰이고 측정될 Double layer (Wet/CVD $SiO_2$)에 대한 Interface State Density의 측정과 분석에 대한 방향을 제시하는데 도움이 될 것이라 판단된다.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.2
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• pp.134-139
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• 2003

This study was carried out to investigate the aging and conversion characteristics of oxidation catalysts for a natural gas vehicle with lean-bum system. The conversion of $CH_4$ was observed over the various composition ratio of PMs(Precious metals) and washcoating methods. On the fresh catalysts, Pd affected on the activity of $CH_4$ at low temperature more than other PMs in Pd-only and Rh/Pd/Pt catalysts. The activity at low temperature increased as a mount of Pd increases. On the aged catalysts, the $CH_4$ conversion efficiency of Pd-only catalyst with mono-layer washcoat decreased more than that of the other catalysts of $CH_4$ conversion. It was observed that the thermal durability of Rh/Pd/Pt catalysts with double-layer washcoat was better than the single washcoat catalyst.

• Proceedings of the Materials Research Society of Korea Conference
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• 1997.10a
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• pp.147-147
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• 1997

• Journal of Microbiology and Biotechnology
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• v.17 no.6
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• pp.1031-1035
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• 2007

Prostate specific $antigen-{\alpha}_1-antichymotrypsin$ was detected by a double-enhancement strategy involving the exploitation of both colloidal gold nanoparticles (AuNPs) and precipitation of an insoluble product formed by HRP-biocatalyzed oxidation. The AuNPs were synthesized and conjugated with horse-radish peroxidase-PSA polyclonal antibody by physisorption. Using the protein-colloid for SPR-based detection of the PSPJACT complex showed their enhancement as being consistent with other previous studies with regard to AuNPs enhancement, while the enzyme precipitation using DAB substrate was applied for the first time and greatly amplified the signal. The limit of detection was found at as low as 0.027 ng/ml of the PSA/ACT complex (or 300 fM), which is much higher than that of previous reports. This study indicates another way to enhance SPR measurement, and it is generally applicable to other SPR-based immunoassays.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.05a
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• pp.90-93
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• 2004

In this work, we have used different techniques for the surface passivation: conventional thermal oxidation (CTO), rapid thermal oxidation (RTO), and plasma-enhanced chemical vapour deposition (PECVD). The surface passivation qualities of eight different single and combined double layer have been investigated both on the phosphorus non-diffused p-type FZ silicon and on phosphorus diffused emitter of 100 ${\Omega}/Sq$ and 40 ${\Omega}/Sq$. In the single layer, silicon dioxide $(SiO_2)$ passivates good on the emitter while silicon nitride (SiN) passivates better than on the non-diffused surface. In the double layers, CTO/SiN1 passivates very well both on non-diffused surface on the emitter. However, RTO/SiN1 and RTO/SiN2 stacks are more suitable for surface passivation in solar cells caused by a relatively good passivation qualities and the low optical reflection. Applying these stacks in solar cells we achieved 18.5 % and 18.8 % on 0.5 ${\Omega}$ cm FZ-Si with planar and textured front surface, respectively. The excellent open circuit voltage $(V_{oc})$ of 675.6 mV is obtained the planar cell with RTO/SiN stack.

• Transactions on Electrical and Electronic Materials
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• v.1 no.3
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• pp.23-28
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• 2000

A block-oxide layer was formed on the surface of Cu-based leadframe by chamical oxidation method in order to enhance the adhesion strength between Cu-based leadframe and epoxy molding compound (EMC) Using sandwiched double cantilever beam (SDCB) specimens, the adesion strength was measured in terms of interfacial fracture toughness, G$\sub$IC//Results showed that the black-oxide layer was composed of two kinds of layers: pebble-like Cu$_2$O layer and acicular CuO layer, At the initial stage of oxidation the Cu$_2$O layer was preferentially formed and thickened up to around 200 nm whithin 1 minute of the oxidation time. Then the CuO layer started to from atop of the Cu$_2$O layer and thickened up to around 1300 nm until 20 minutes. As soon as the CuO layer formed, the thickness of Cu$_2$O layer began to reduce and finally reached to around 150 nm. The pre-cleaned and the Cu$_2$O coated leadframes showed almost no adhesion of EMC, however, as the CuO precipitates appeared and became continuous, G$\sub$IC/ increased up to around 80 J/㎡. Further oxidation raised G$\sub$IC/ up. to around 100 J/㎡.

• Journal of the Korean Applied Science and Technology
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• v.40 no.5
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• pp.1163-1175
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• 2023

Cholesterol is prone to oxidation, which results in the formation of cholesterol oxidation products (COPs). This occurs because it is a monounsaturated lipid with a double bond on C-5 position. Cholesterol in foods is mostly non-enzymatically oxidized by reactive oxygen species (ROS)-mediated auto-oxidative reaction. The COPs are found in many common foods of animal-origin and are formed during their manufacture process. The formation of COPs is mainly related to the temperature and the heating time the food is processed, storage condition, light exposure and level of activator present such as free radical. The level of COPs in processed foods could reach up to 1-10 % of the total cholesterol depending on the foods. The most predominant COPs in foods including meat, eggs, dairy products as well as other foods of animal origin were 7-ketocholesterol, 7 α-hydroxycholesterol (7α-OH), 7β-hydroxycholesterol (7β-OH), 5,6α-epoxycholesterol (5,6α-EP), 5,6β-epoxycholesterol (5,6β-EP), 25-hydoxycholesterol (25-OH), 20-hydroxycholesterol (20-OH) and cholestanetriol (triol). They are mainly formed non-enzymatically by cholesterol autoxidation. The COPs are known to be potentially more hazardous to human health than pure cholesterol. The procedure to block cholesterol oxidation in foods should be similar to that of lipid oxidation inhibition since both cholesterol and lipid oxidation go through the same free radical mechanism. The formation of COPs in foods can be stopped by decreasing heating time and temperature, controlling storage condition as well as adding antioxidants into food products. This review aims to present, discuss and respond to articles and studies published on the topics of the formation and inhibition of COPs in foods and key factors that might affect cholesterol oxidation. This review may be used as a basic guide to control the formation of COPs in the food industry.