• 한국표면공학회지
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• 제17권4호
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• pp.106-119
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• 1984

Brass was electrodeposited over the range of the current densities from 2 to 8 A/$dm^2$ in cyanide bath at 20 and 40$^{\circ}C$. The cathode overpotential increased and the cathode efficiency was decreased respectively with decreasing temperature, increasing current density and addition of organic substance. The perferred orientation of the deposits were associated with the cathode overpotential and the nucleation energy of lattice planes. The (111) preferred orientation developed at the low current density and low cathode overpotential (440-520mV). On the other hand, the (111)+(100) preferred orientation developed at higher cathode overpotential (528-680mV). The (111)+(100) preferred orientation developed over the whole range of overpotential in the cyanide solution with organic additive. The copper content of deposit decreased with increasing current density and decreasing temperature. The morphology of the deposits with no additive was the polygonal body type of structure and the structure of the cross section was columnar structure. The morphology of the deposits with additive, on the other hand, was fine crystallite type of structure. And the structure of the cross section of them was the finer granular structure.

• Corrosion Science and Technology
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• 제3권1호
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• pp.26-29
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• 2004

Metal plated plastics are becoming more prevalent in materials of communication parts. A new technique MmSH is a process of injecting plastics to produce innovated physical properties compared to the conventional injection process. This study involves two ways of coating plastics Ni by electroless plating and varying bath and plasma treatment for improved adhesion strength between plating layer and surface. MmSH injection processed ASS with plasma treated after neutralization showed a superior adhesion force and a gloss and rate of deposition when it was in pH 7.5. On the other hand, conventional injection processed ASS was in pH 6.5.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2016년도 추계학술대회 논문집
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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.

• 한국세라믹학회지
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• 제30권5호
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• pp.411-419
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• 1993

A process for the preparation of cobalt oxide powders was developed by the evaporaton of emulsion containing cobalt. The characteristics of powders were examined by means of DTA, X-ray diffracton, SEM, PSA. Cobalt oxide powders were produced by evaporating the emulsion prepared by mixing cobalt sulfate solution and organic phase consisted of kerosene, Span 80 and D2EHPA in the kerosene bath at 16$0^{\circ}C$, then the precursor obtained was calcined at 100$0^{\circ}C$. As the concentration of cobalt ions in the aqueous solution, Span 80 and the stirring speed increased, the mean size of cobalt oxide powders decreased and the size distribution was improved. At the volume ratio of one of the aqueous to organic phase, the finest mean size and the optimum size distribution was obtained. On the other hand the concentration of D2EHPA and liquid paraffin had little effect on the mean size as well as on the size distribution of powders.

• 한국염색가공학회지
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• 제12권3호
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• pp.174-182
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• 2000

We prepared natural indigo/calcium hydroxide complex powder from tinctoria's leaf, according to the demand of developing new dyeing technique of natural fibre with natural indigo. FT- IR and UV/Visible spectra were operated to find the dyeing properties of synthetic indigo and natural indigo powder. Cotton, flax and silk fabrics were dyed with different pH, dye concentration and dyeing time. The colour yield of indigo dye was quite sensitive to dye bath pH and fabric. In synthetic indigo, the highest K/S value of dyed silk fabric was shown at near pH 9.0, and which of flax and cotton fabric were shown at pH 11.0. In other hand, in the case of natural indigo complex powder, the highest K/S value of dyed silk fabric was shown at near pH 8.0, and which of flax and cotton fabric were shown at pH 9.5∼pH 10. Mercerized cotton fabric dyed with natural indigo powder has a little antimicrobial activity.

• 한국잠사곤충학회지
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• 제18권1호
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• pp.27-39
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• 1976

복합견방사 및 복합견직물을 시작하여 다음의 결과를 얻었다. 1 정연제별 처리효과는 규산소다, 가성소다, 탄산소 및 비누의 순이다. 2. 가성소다 3% 액으로 정연할 경우는 견담백질의 과잉 용해로 진면제조가 불가하다. 3. 견의 정연효과는 처리시간보다 농도가 크다. 4. 정연제의 단독사용보다는 이중이상을 혼용하는 것이 진면품질을 향상시킬 수 있다. 5. 견수방사의 명주소리와 광택향상을 위하여서는 유기산의 혼용이 요구된다. 6. 심사에 의하여 복합수방사의 강도는 증가한다. 7. 복합수방사의 성도변동율은 8∼l2%이다. 8. 견과 데도롱직의 염색은 이욕법으로 처리하여야 한다. 9. 복합수방사 견직물의 수축율은 23%이다. 10. 복합수방사직물은 여자용 동복지로 복합생사 직물은 부라우스지로 사용 가능하다.

• 한국주거학회논문집
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• 제19권3호
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• pp.39-48
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• 2008

The purpose of this study was to investigate the attitude of the middle and old age about the elderly housing and the planning elements according to the types of silver town. For this study, a pre-interview and a survey method were used for data collection. A questionnaire survey of 372 women over 45 years old was carried out. Among the data, 321 cases were analyzed by SPSS for Windows V12.0. The major findings were as follows: 1) Regarding the elderly housing, While the couple cohabitation type preferred the existing housing and the general housing, the single habitation type preferred the apartment and silver town. Some people wanted silver town occupancy due to the decrease of children support burden, the other did not want it due to economical burden and the absence of homelike affection. When they move into silver town, they wanted to take money, clothes, and photo album. 2) In silver town development, while the couple cohabitation type preferred the apartment, independent house, the single type preferred the apartment, housing complex and group-home. The unit housing sizes of them were around 82.6 and 49.6 square meters respectively. In the space composition of unit housing, while the couple cohabitation type preferred bath room, kitchen, living room and two of bed room, the single type preferred one of bed room and bath room at least. On the other hand, this study found out that it was possible to plan the space for eating and washing as the common space. 3) According to single or couple, and ages, there were significant differences in preferred spatial planning elements, which needs to be reflected in the silver town development. These results can provide improvement guidelines for the development of the silver town with the differentiation of design factors for the silver town planners.

• International Journal of Fluid Machinery and Systems
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• 제8권1호
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• pp.46-54
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• 2015

Thrust-ring-pump is a kind of extreme-low specific speed centrifugal pump with special structure as numerous restrictions from thrust bearing and operation conditions of hydro-generator units. Because the oil circulatory and cooling system with thrust-ring-pump has a lot of advantages in maintenance and compactness in structure, it has widely been used in large and medium-sized hydro-generator units. Since the diameter and the speed of the thrust ring is limited by the generator set, the matching relationship between the flow passage inside the thrust ring (equivalent to impeller) and oil bath (equivalent to volute) has great influence on hydrodynamic performance of thrust-ring-pump. On another hand, the head and flow rate are varying with the operation conditions of hydro-generator units and the oil circulatory and cooling system. As so far, the empirical calculation method is employed during the actual engineering design, in order to guarantee the operating performance of the oil circulatory and cooling system with thrust-ring-pump at different conditions, a collaborative hydrodynamic design and optimization is purposed in this paper. Firstly, the head and flow rate at different conditions are decided by 1D flow numerical simulation of the oil circulatory and cooling system. Secondly, the flow passages of thrust-ring-pump are empirically designed under the restrictions of diameter and the speed of the thrust ring according to the head and flow rate from the simulation. Thirdly, the flow passage geometry matching optimization between thrust ring and oil bath is implemented by means of 3D flow simulation and performance prediction. Then, the pumps and the oil circulatory and cooling system are collaborative hydrodynamic optimized with predicted head-flow rate curve and the efficiency-flow rate curve of thrust-ring-pump. The presented methodology has been adopted by DFEM in design process of thrust-ring-pump and it shown can effectively improve the performance of whole system.

• 폴리머
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• 제25권2호
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• pp.151-160
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• 2001

결정성 약제가 함침된 생분해성 고분자학이 고분자(poly(d,1-lactide)), 약제(progesterone) 및 용매(dimethylformamide)로 이루어진 고분자용액을 고형화시켜 제조되었다. 용매에 약제 및 고분자를 용해시켜 준비된 제막용액을 유리판 위에 도포한 후, 이로부터 용매를 증발시켜 고형화시키거나, 또는 고분자 및 함침 약제 모두에 비용매로 작용하는 물과 용액 필름에 존재하는 용매를 교환시켜 용액 필름이 응고되도록 하였다. 제조된 고분자막들은 용액 필름의 응고화 경로에 따라 뚜렷하게 다른 형상을 보여주었다. 진공 상태에서 용매의 증발을 통해 응고화되었을 때, 함침 약제인 프로제스테론은 구의 형상을 보여주며 고형화된 고분자 구조에 둘러싸여 막의 내부에 균일하게 분포되었다. 이에 비해, 비용매인 물에 침지시켜 용매와 비용매의 급속한 확산에 의해 응고화시키거나, 대기에 방치시켜 대기에 존재하는 수증기의 흡수에 의해 고분자 희박 지역의 핵 형성을 통한 용액 필름의 액체-액체 상분리를 유도하며 응고화시킨 경우, 함침된 약제는 고분자막 내부에 편상의 결정 구조를 지니며 막 내부에 불균일하게 분포되었다.

• 대한화장품학회지
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• 제40권4호
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• pp.331-339
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• 2014

2010년 1월에서 2012년 12월까지 서울특별시 보건환경연구원에 품질검사가 의뢰된 화장품 9,879건에 대해, 국산과 수입화장품에 대한 집계자료를 바탕으로 제조국가별, 연도별, 적용부위별로 검사의뢰 유형을 비교하여 품질 및 안전성관리에 대한 기초자료를 제공하고자 본 조사를 시행하였다. 전체 화장품 중 국산은 645건(6.5%), 수입산은 9,234건(93.5%)이며, 제조국가별로는 프랑스 4,342건(44.0%), 독일 1,637건(16.6%), 미국 1,476건(14.9%), 한국 645건(6.5%), 이태리 557건(5.6%), 기타 1,222건(12.4%)이었다. 또한 연도별 위수탁 화장품 검사의뢰건수는 2010년 3,784건, 2011년 3,394건, 2012년 2,701건으로 나타나 일반 화장품은 감소하고 기능성 화장품이나 염모제에 대한 품질 검사가 증가되었다. 화장품 유형별로는 기초제품 5,470건(55.4%), 색조 1,908건(19.3%), 손발관리 1,026건(10.4%), 두발관리 616건(6.2%), 목욕용이 361건(3.7%), 기타 498건(5.0%)이며 국산화장품의 유형별 분포는 기초 > 두발관리 > 색조 > 손발관리 > 목욕용 순이나 수입화장품에서는 기초 > 색조 > 손발관리 > 두발관리 > 목욕용 제품의 순서로 나타났다. 국제적 품질관리기준의 우선순위를 설정하기 위해 국내 소비자들의 경향부터 직간접적으로 파악하는 일이 필요하다. 위수탁검사의뢰된 국산 및 수입화장품의 제품 유형과 인체 적용 부위별 비율 등을 비교 활용하여 미래지향적인 화장품 안전관리의 기초자료로 활용하고자 한다.