• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.172-174
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• 2004

본 논문은 광산산성배수(AMD)에서 철 및 알루미늄 제거 효과가 입증되고 ARD(Acid Rock Drainage)에서의 비소제거 효과가 확인된 인회석을 침전제로 사용하여 철, 알루미늄 및 비소가 아닌 다른 중긍속의 제거효율을 알아보기 위해 도금폐수를 이용하여 실내실험을 실시하였다. 실험결과, 도금폐수의 수질분석결과에 의하면 '수질환경보존법 오염물질 배출허용기준' <가>지역 방출수 기준을 초과하는 것은 pH, Zn, Fe, Cu, Cr 및 P였다. 실험 결과 인회석 40번체 통과분-100번체 잔류분을 사용하는 것이 가장 적절할 것으로 생각되며 유속은 1kg의 인회석에 11의 도금폐수를 3시간 동안 반응시키면 경제적, 시간적 측면에서 가장 적절한 것으로 사료된다. 이 경우 pH는 1.98에서 5.30으로 증가하고 Cr, Fe, Cu 및 Zn은 각각 77.10%, 99.58%, 99.39% 및 40.77% 제거되는 것으로 나타났다. 용해율은 0.3619 g/min/kg으로 계산되었다. 그러나 3시간의 반응시간으로는 크롬 및 아연을 기준치 이하로 제거하지 못하므로 인회석 반응조를 다단계로 하는 실험을 수행해 그 결과를 평가해야 할 것이다.

• Journal of the Microelectronics and Packaging Society
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• v.26 no.2
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• pp.51-54
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• 2019

The electrodeposition of rhodium (Rh) on silicon substrate at different current conditions were investigated. The cracks were found at high current density during the direct current (DC) plating. The pulse current (PC) plating were applied to avoid the formation of cracks on the deposits. Off time in the pulse plating relieved the residual stress of the Rh deposits and consequently the current conditions for the crack-free Rh deposits were obtained. Optimum pulse current (PC) condition is 5:5 (on:off) for the crack-free Rh electroplating.

• Conservation Science in Museum
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• v.23
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• pp.91-108
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• 2020

This study conducted non-destructive analyses of the material features of seven gilt-bronze crowns of Baekje Kingdom that were excavated in the Cheonan, Gongju, Seosan, Iksan, Naju, and Hapcheon areas. A typical Baekje gilt-bronze crown has a conical inner crown and an outer crown embellished with vertical ornaments on the front and the back, a tube topped with a hemispherical ornament, and other ornamentation. Diverse designs (e.g., dragon, bonghwang, flowers, and plants) were applied using a range of techniques, including repoussé, chasing, openwork, and engraving. Formal features differ among the crowns according to their period of production and site of excavation. The substrate metal of the crowns is either pure copper or mixed copper with a small amount of lead. The crowns were amalgam-plated on the surface with pure gold or gold with a small amount of silver. The crown from Okjeon Tomb No. 23 in Hapcheon in the ancient Gaya region has a high silver content, which appears to be a regional feature. In addition, this crown from Okjeon Tomb No. 23, which can be categorized as Baekje-style gilt-bronze crown, seems to be plated at most three times, while the gilt-bronze crowns found within Baekje Kingdom territory were plated once or twice.

• Journal of Conservation Science
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• v.27 no.1
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• pp.41-47
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• 2011

If the nondestructive analysis is carried out by using an X-ray Fluorescence Analyzer(XRF) for ingredient analysis with the target of gold plated silverware that plates gold on a silver basis, a singular point showing big difference at the value of weight percent(wt.%) according to the electron orbit of the principal ingredient can be confirmed. The present research made reproduced samples and carried out comparative analysis in order to suggest a basis that can judge whether the technique of gold plated silverware was used in case of remains uneasy to understand with eyes by using this singular point. As a result, the same result as analysis results of actual remains could be seen in specimens manufactured by a mercury amalgam plating method. However, in case of gold and silver alloy specimens, it could be confirmed that the difference according to the electron orbit of the principal ingredients is slight unlike plated specimens. The reason appearing at plated specimens seems to be generated while absorbing XRF beam at plated layers by double structure due to plating instead of single material. Accordingly, if this result appearing at nondestructive analysis is used, it was confirmed that the application of the technique of gold plated silverware can be judged without observing its section.

• Solar Energy
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• v.10 no.1
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• pp.92-97
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• 1990

The electrochemical approach to the characteristics of black chrome solar selective coatings has been reviewed. Based on the formula of the ChromOnyx bath solution manufactured by Harshaw Company, the chromic acid-propionic acid bath solutions have been prepared by KIER. Comprehensive review of the black chrome electrodeposition mechanism also has been performed on the role played by constituents in the bath solution during electrodeposition. The optical properties such as absorption and emittance of electrodeposited black chrome coatings obtained from the new formula and their surface analysis will be reported in detail.

• Journal of Conservation Science
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• v.22
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• pp.87-98
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• 2008

Microstructures and chemical compositions of 24 bronze mirrors recovered from the Korean peninsula were examined using the scanning electron microscope equipped with the energy dispersive spectrometer in an effort to characterize the treatments applied on their surface. Their provenance and chronology are mostly unspecified except for two objects from a Koryo burial site. In antiquity the surface of bronze mirrors was frequently finished by mere polishing when their tin content was high enough to guarantee the required reflectivity. In many cases, however, their surface was given a special treatment. The most typical treatment was to coat the surface with tin in two different processes referred to as wipe-tinning and amalgam-tinning. In wipe-tinning only tin was used, but in amalgam-tinning tin and mercury were used together. The surface was often coated with mercury in a process known as mercury-polishing. The present mirrors showed that all these techniques were in fact practiced, not only on the reflective surface but, in some cases, on the decorative surface. The detection of mercury played a crucial role in the assessment of a specific technique applied in each mirror. Mercury often remained in the substrate in the form of sulfide and thereby allowed the method of surface treatment to be estimated even when the coated layer was completely lost. The future study is expected to uncover the regional and temporal variation of the surface treatments to the better understanding of bronze mirrors with respect to provenance and chronology.

• Applied Chemistry for Engineering
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• v.24 no.4
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• pp.438-442
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• 2013

In the present work, electroless plating was used for coating thin films consisting mainly of Ni and P on carbon fiber. Structural changes appeared upon the post-annealing at various temperatures of the Ni-P film on carbon fiber was studied using various analysis methods. Scanning, a flat surface structure of Ni-P film on carbon fiber was found after electroless plating of Ni-P film on carbon fiber without post-annealing, whereas annealing at $350^{\circ}C$ resulted the formation of porous structures. With increasing the annealing temperature to $650^{\circ}C$ with an interval of $50^{\circ}C$, the pore size increased, but the density decreased. X-ray diffraction (XRD) showed the existence of metallic Ni, and Ni-P compounds before post-annealing, whereas the post-annealing resulted in the appearance of NiO peaks, and the decrease in the intensity of the peak of metallic Ni. Using X-ray photoelectron spectroscopy (XPS), phosphorous oxides were detected on the surface upon annealing at $650^{\circ}C$, and $700^{\circ}C$, which can be attributed to the phosphorous compounds originally existing in the deeper layers of the Ni films, which undergo sublimation and escape from the film upon annealing. Escape of phosphorous species from the bulk of Ni-P film upon annealing could leave a porous structure in the Ni films. Porous materials can be of potential applications in diverse fields due to their interesting physical properties such as high surface area, and methods for fabricating porous Ni films introduced here could be easily applied to a large-scale production, and therefore applicable in diverse fields such as environmental filters.

• Proceedings of the Korean Magnestics Society Conference
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• 2006.06a
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• pp.172-173
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• 2006

• Proceedings of the Materials Research Society of Korea Conference
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• 2007.11a
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• pp.55.2-55.2
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• 2007

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2005.11a
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• pp.82-83
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• 2005