• Journal of the Korean institute of surface engineering
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• v.31 no.6
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• pp.379-388
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• 1998

The iron-zinc interfacial reaction and corrosin properties in galvanizing bath containning Ni have been intestigated. The substrate steel plates were galvanized in Zn or Zn-0.018Al baths with various Ni contents. The corrosion resistance of galvanized specimens was also evaluated by $60^{\circ}$bending test for galvannealing speaaimens. The corrosion resistance was improved with Ni addition in pure Zn bath, while deteriorated with Ni addition in Zn-0.18Al bath. The anti-powdering property, on thhe otherhand, was improved with Ni addition in Zn-0.18Al bath, while deteriorated with Ni addition in pure Zn. It was found that the anti-powdering property was improved with increasing $\xi$ phase ratio in reaction layer.

• Journal of the Korean institute of surface engineering
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• v.22 no.2
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• pp.101-108
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• 1989

Effects of Na+ ion on zeta potential of SiC and Al2O3 particles suspended in nikel sufate and nickel chloride solutions were investigated. various complexing agents for Ni2+ ion were added to electroless Ni composite bath and the effects of the complexing agents on zeta potential and codeposition of the particles from the baths were studied. It was confirmed that Na+ ion was absorbed on the particles bringing about the positive surface charge and thus they promoted the entrapment of the particles into the nickel deposit. On the basis of these results it was possible to deposit SiCc particle in nickel chloride electrolyte containing complex agent such as trisodium citrate+sodium succinate.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.176-176
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• 2016

마이크로 블레이드 제조를 위한 기초 연구로서, 전기도금 방법을 이용하여 Ni 및 다이아몬드 분말을 복합도금을 시켰다. $15{\sim}25{\mu}m$ 크기 분포를 갖는 다이아몬드 분말 농도 변화에 따라 전착되는 다이아몬드 분포 및 전기도금 용액 내 Ni 농도 변화에 따라 전착되는 다이아몬드 분포를 관찰하였다. 이를 위하여 광학현미경, 전자현미경(SEM), EDS 및 XED를 이용하였다. Ni 농도 변화보다는 다이아몬드 분말 농도 변화가 전착되는 다이아몬드 분포에 더 큰 영향을 미침을 알 수 있었다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.124.2-124.2
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• 2016

Corrosion resistance and adhesion of electro-paint (E-paint) with fluoride conversion coating (FCC) on AZ31 Mg alloy were studied. Corrosion resistance and adhesion were studied as a function of FCC-treatment time and concentration of FCC-bath. Aqueous hydrogen fluoride (HF) solutions, with concentrations ranging from 0.5 M to 5 M, were used to form FCC on chemically polished AZ31 Mg alloy samples for six different times; 10, 30, 60, 90, 120, and 180s. The results from salt spray test (SST) showed that corrosion resistance of E-paint appeared to decrease with increasing FCC treatment times in low concentration FCC baths. The number of blisters formed on the FCC-treated samples increased with increasing FCC treatment time of more than 1 min in low concentration (0.5 M to 1 M) solutions. On the other hand, samples treated in the 5 M HF solution for 120s showed no delamination or blistering even after 1200h of SST.

• Journal of the Korean housing association
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• v.14 no.3
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• pp.67-76
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• 2003

This study was to investigate the needs for the community in the elderly institution and the related factors. The raw data, collected in 2000, from the Study for the Silver Industry in Ulsan were used for the analysis. The sample consisted of 292 elderly aged 65 and over living in Ulsan, and the purpose was accomplished using frequencies, percentages, and chi-squared test with cross-tabulations. The results indicated that the elderly tends to have negative responses to the discriminations by health conditions and sharing the public spaces with neighbors. However it was more likely that the elderly wants to have separate public spaces and facilities by gender. They prefer private residential units rather than public spaces for the meals, baths, and receptions. It was also found that gender, with or without spouse, education level, and economic condition of the elderly have significant effects on the needs for the community in the elderly housing.

• Membrane and Water Treatment
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• v.5 no.1
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• pp.41-56
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• 2014

A series of microporous PVDF membranes were prepared by isothermal immersionprecipitation of PVDF/TEP casting dopes in both soft and harsh coagulation baths. Morphologies of the membranes' top surfaces were found to depend strongly on the bath strength, which could be controlled by the TEP content in the bath. By changing the bath gradually from pure water to 70% TEP, the top surface evolved from a dense skin-like (asymmetric) to a totally open porous morphology (symmetric). The latter structure could similarly be obtained by precipitation of the same dope in an alcoholic bath, e.g., 1-butanol. Membrane distillation processes to desalt sodium chloride aqueous solutions were conducted using various prepared membranes and two commercial microporous membranes, PTFE (Toyo, Japan, code: J020A330R) and PVDF (GE, USA, code: YMJWSP3001). The permeation fluxes were compared and correlated with the morphologies of the tested membranes.

• Textile Coloration and Finishing
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• v.10 no.4
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• pp.7-14
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• 1998

Microwaves are high frequency radiation capable of generating very rapid, uniform and efficient heating of textile material. Microwave heated dyeing of polyester fabric was tried with different solvent systems, irradiation time and dye concentration. Microwave fixation methods were used with 100% water,30% urea, EG and DMF, respectively, pad-baths in which the padded fabrics were exposed over a heated or boiling water bath to maintain sufficient moisture content during irradiation. In order to ascertain the relation between the dyeing property of polyester fabric and the microwave irradiation condition caused by microwave heating, the K/S values and fastness properties of dyed fabrics such as light, washing and sublimation fastness were measured.

• Applied Chemistry for Engineering
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• v.5 no.1
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• pp.105-113
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• 1994

The amount of nitrogen gas adsorbed by Spherocarb and Sucrose Char was measured as a function of the relative pressure with temperature being kept constant at 77 to 184K. Isotherms at different temperatures were obtained by keeping the adsorbent at a constant temperature using liquid nitrogen, iso-pentane, n-pentane, ethyl alcohol, and iso-propyl alcohol slush baths. The objective for this study is to provide information on the specific surface area and pore volume by analyzing the experimental data using adsorption models such as the Brunauer-Emmett-Teller and Dubinin-Radushkevich models.

• Journal of Urban Science
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• v.9 no.1
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• pp.33-40
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• 2020

This research aims to analyze the determinants of apartment rents in the Seoul Metropolitan area using spatial econometrics approaches. Since spatial econometrics approaches have advantages to solve limitations of ordinary multiple regression such as spatial dependence and spatial heterogeneity. This research includes structural variables such as number of rooms and baths, neighborhood variables such as number of housing units in the apartment complex, and location variables including distances to subway stations, to traditional markets, to educational institutes, and to urban services such as parks, etc. The result shows that the accessibilities to the CBD, to subcenters, to subway station, to school, and to parks contribute to apartment rent uplift and also shows different spatial variations in rent premiums by accessibility variables. In particular, apartments located south of Han river along the Lines 2, 3, 7 and 9 have the highest rent premiums due to the accessibility to the subway.

• Journal of the Korean institute of surface engineering
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• v.27 no.6
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• pp.319-326
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• 1994

The effects of electrolysis conditions on the composition and preferred orientation of Ni-Fe alloy were studied using the sulfate-chloride baths paddle agitated. Cathode current efficiency is higher in the deposits from bath 2 than that of deposits from bath 1. The Fe content of alloy deposits from bath 2 is nearly constant(19∼21wt.%) in the wide range of current density, while it decreases noticeably with current density in the deposits from bath 1. The variation of Fe content at the edge of specimen is lower in deposits from bath 2 than those from bath 1. The alloy deposits show (111) & (200) preferred orientation for the deposits from bath 1 and bath 2 respectively.