• Journal of Welding and Joining
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• 제19권5호
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• pp.512-519
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• 2001

Sink roll has been used in molten Zn-0.2%Al alloy bath of continuous galvanizing line in sinking and stabilizing process of the steel strip in molten metal bath. In this process, although the scraper scraps off the sink roll surface, the dross compounds is builded up on the sink roll surface and the life time of the sink roll is shorten by the dross compounds. The present study was investigated the application of the spray coating layer on sink roll body for improving durability In molten Zn-0.2%Al alloy. Through the durability tests in molten Zn-0.2%Al alloy with various ceramic and cermet coating layer, the optimum bond and top coating material was obtained. As the results, the system of STS430F base metal, WC-l7Co bond and $ZrO_2-SiO_2$ top coating was clarified to be the best quality of durability in molten Zn-0.2%Al alloy.

• 한국분무공학회지
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• 제12권1호
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• pp.45-57
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• 2007

This paper presents both experimental and numerical studies regarding nozzles used for the SI engine application, particularly for the intake-port fuel injection type. The atomization mechanism of the multi-hole plate nozzle was investigated experimentally. It was found that the nozzle design added turbulence into the liquid-film jet and the jet disintegrated rapidly. Based on the results, various plate types for the nozzle were developed and tested; six hole nozzle for liquid jet interaction, plate-type nozzle with flat duct channel, and the simpler structured nozzle. The spray characteristics of the prototype nozzles were examined experimentally while the internal flow of the nozzle was investigated computationally. It was shown that turbulent liquid-film was injected and atomization quality was improved by controlling the internal flow condition of the plate-type nozzle.

• 소성∙가공
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• 제13권1호
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• pp.45-52
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• 2004

This research conducted milling tests to study effects of cutting environment conditions of ball end mills on the characteristics of hard milling process. KP4 steels and STD11 heat treated steels were used as the workpiece and WC-Co ball end mill tools with TiAlN coated were utilized in the cutting tests. Dry cutting without coolant and semi-dry cutting using botanical oil coolant were conducted and MQL(Minimum Quantity Lubricant) device was used to spray coolant. Cutting forces, tool wear and surface roughness were measured in the cutting tests. Results showed that dry cutting of KP4 and hardened STD11 specimens produced better surface quality and wear performance than MQL spray cutting did.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1755-1760
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• 2004

The holographic velocimetry system has a significant potential for the measurements of three dimensional velocities of particles. In this study, orthogonal two-side holography system was developed to obtain three dimensional velocities and sizes of spray droplets. To get high quality of reconstructed images, singe-exposure holography at two time moments and two orthogonal sides was adopted instead of multi-exposure, single-side holography. From three dimensional positions of droplets determined by reconstruction and image processing system, the three dimensional velocities and sizes of each droplet was extracted using the PTV algorithm. To determine the position of particles in the optical axis, a new focusing parameter was introduced based on the correlation between two droplet images at the same distance. The measured results by holography system were compared with those by the PDPA.

• 플랜트 저널
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• 제6권4호
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• pp.63-71
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• 2010

The best way to prevent the corrosion of piston rod is a selection of quality of the material and method of construction which minimize the porosity. The high velocity oxy fuel(HVOF) method, which generates lower porosity than existing plasma spray, was applied to ceramic laminated bond layer. Porosity percentage fell to bellow 2%, lower than that of plasma spray at 7%. Coating material of ceramic-coated main layer was selected as the $Cr_2O_3$ affiliation material, which is more dense than $Al_2O_3$ affiliation. To fill up the pores formed after the coating process, we sealed the bond layer and main layer. Sealing process was performed twice, once after the coating and once after the grinding. Upon the anti-corrosion test on the sealed sample and on the non-sealed sample, it is confirmed that the sealed sample was not corroded for 1,000 hours while the non-sealed sample was corroded within 48 hours.

• 한국건축시공학회지
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• 제1권2호
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• pp.165-173
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• 2001

This study examinated the application in construction field and the development of waterproofing material system by the spray water-soluble rubber asphalt to solve the problems of synthetic polymer sheet and gio membrane(A mat sheet of Bentonite) that had been used domestic waterproofing material in advance. As the result of study, characters of study water-soluble rudder asphalt are the follows: 1) The amount of water absorption was '0.06'g and the seepage quality was '0'g in result. 2) The tensile strength was about 30.7kgf/$\textrm{cm}^2 and the elongation was about 72.4% in result. 3) After reliance of temperature test had been ended, the tensile strength was about 72.4kgf/$\textrm{cm}^2 in low temperature and about 30.7kgf/$\textrm{cm}^2 in normal temperature. 4) After acid and alkaline treatment had been ended, the tensile strength was about 19.7kgf/$\textrm{cm}^2$ and about 21.9kgf/$\textrm{cm}^2 in result. 5) After chlorine ion treatment had been ended, the tensile strength was 28.5kgf/$\textrm{cm}^2$ and the elongation was 250% in result. 6) The impact performance was subsided at 1.5m height. 7) After promotion weathering had been ended, the tensile and elongation was about 26.0kgf/$\textrm{cm}^2, 214% in result. So, this study can propose the spray water-soluble rubber asphalt to satisfy the and durability of waste filled land.

• Progress in Superconductivity
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• 제8권1호
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• pp.71-74
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• 2006

High $J_c$ over 1 $MA/cm^2$ YBCO film has been successfully prepared using nitrate precursors by spray pyrolysis method. Aerosol drolpets generated using a concentric spray nozzle were directly sprayed on a $LaAlO_3$(100) single crystal substrate. The cation ratio of precursor solution was Y:Ba:Cu=1:2.65:1.35. The distance between nozzle and substrate was 15 cm. Deposition temperature was ranging from $750^{\circ}C\;to\;800^{\circ}C$. Deposition pressure was 100 Torr, and oxygen partial pressure was varied from 10 Torr to 50 Torr. The microstructure, phase formation, texture development and superconducting properties of deposited films were largely changed with oxygen partial pressure. Deposited films showed a texture with(001) planes parallel to substrate plane. High quality film was obtained when film was deposited at $760^{\circ}C$ with an oxygen partial pressure of 30 Torr. The critical current density($J_c$) of the YBCO film was 1.75 $MA/cm^2$ at 77 K and self-field.

• 한국식품저장유통학회지
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• 제13권5호
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• pp.569-573
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• 2006

생리활성물질을 다량 함유하고 있는 노루궁뎅이 버섯을 효과적으로 섭취하기 위하여 분말, 과립, 타블렛, 캅셀 등 다양한 제형으로 가공하였으며 이들의 품질특성을 비교하였다. 수분함량은 분무건조 분말, 과립, 타블렛 순으로 그 값은 각각 4.37%, 3.78%, 3.43%으로 나타났으며 총당 함량은 분무건조 분말이 19.14 g%로 가장 낮은 함량을 보여주었고 단백질 함량은 분무건조 분말, 과립, 타블렛 순으로 그 값은 각각 4.39 g% 1.04g%, 0.75g% 임을 확인하였다. 제형별 수분결합지수는 과립 및 타블렛 제품이 분무건조분말 제품보다 수분결합지수가 낮은 것으로 나타났는데 이는 과립과 타블렛 제조시 가용성의 탄수화물 제제인 부형제가 많이 첨가되었기 때문인 것으로 판단된다. 전체적인 색상을 나타내는 hue angle은 분무건조 분말이 $85.50^{\circ}$, 과립이 $95.37^{\circ}$, 타블렛이 $94.67^{\circ}$로 나타났다. 저장안정성을 확인하기 위한 제형별 흡습특성은 분무건조 분말이 가장 높은 흡습성을 보였으며 과립, 타블렛 순으로 뚜렷한 차이를 나타내어 분무건조 분말보다는 타블렛 형태로 제조한다면 저장성 면에서 더 우수한 제품을 얻을 것으로 사료된다.

• 한국식품저장유통학회지
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• 제23권5호
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• pp.654-659
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• 2016

칡의 활용성 증대 및 식품 소재로 개발하기 위하여 칡을 열수추출 한 후 추출물을 분무 및 동결건조를 실시하여 칡 추출분말의 품질특성을 조사하였다. 건조방법을 달리한 칡 추출분말의 색도는 분무건조 분말에서 명도와 황색도는 낮고 적색도는 높았다. 수분흡수지수는 동결건조 분말이 1.40~1.41로 분무건조에 비해 높았고, 수분용해지수는 분무건조가 94.10%로 높았으나 안식각을 측정한 결과 분무건조 분말이 동결건조 분말에 비해 응집력 및 흐름성을 가지는 것을 확인하였다. 한편, 칡 추출분말의 총 폴리페놀 및 플라보노이드 함량은 분무건조가 각각 18.09 mg/g, 13.42 mg/g으로 동결건조 보다 높은 함량을 나타내었으며, DPPH 및 ABTS 라디칼 소거활성에서는 전체적으로 농도 의존적으로 증가하는 경향을 나타내었으며 모든 농도에서 분무건조 분말의 라디칼 소거활성이 높았고 특히 DPPH 라디칼 소거활성 경우 분무건조가 85.38%, 동결건조가 59.38%로 분무건조 분말이 높은 소거활성을 보였다. 이러한 결과를 종합해 볼 때, 칡 추출분말 제조 시 분무건조 분말이 동결건조 분말에 비하여 가공적성 및 항산화 활성이 우수하여 가공 산업의 활용도가 높을 것으로 판단된다.

• 생물환경조절학회지
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• 제14권1호
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• pp.1-6
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• 2005

본 연구에서는 주행경로의 설정 및 제어가 용이한 고정 경로 방식을 이용한 주행 시스템을 개발하여 온실의 형태, 고랑의 위치 등에 무관하게 자동관수 및 송풍장치에 따른 생육상태를 실험할 수 있는 다목적 자동작업시스템을 개발하였다. 이 시스템의 성능들을 알아보기 위해 과채류에 대하여 실험한 결과 다음과 같은 결과를 얻었다. 오이는 초장, 줄기 지름, 엽면적 및 줄기 한마디의 평균 길이에 있어서 고속송풍에 따른 억제효과가 나타났으나, 관수 회수에 따른 차이는 크지 않았다. 토마토는 송풍처리에 따라 송풍속도가 강할수록 초장이 억제되는 효과를 나타냈다. 줄기의 지름은 처리구간 큰 차이를 나타내지 않았다. 3회 관수처리구의 경우 송풍속도가 강할수록 줄기의 지름이 두꺼워지는 경향을 나타내었다. 엽면적은 대조구(Hand spray)에 비해 2회 관수처리구의 엽면적이 높게 나타났으며, 송풍속도에 따른 차이가 나타나지 않았다. 고추는 전체적으로 대조구에 비해 자동관수 처리구와 송풍처리구가 초장, 줄기의 지름, 엽면적 등이 낮게 나타났다.