Discharage characteristics of AD PDP as a parameter of ambient temperature and MgO

류성남 부산대학교 2003 국내석사

중학생과 기술직 전문가들이 요구하는 기술적 교양 설문 조사 및 이에 기반한 2007 개정 교육과정 기술교과서 분석

류성남 경북대학교 교육대학원 2013 국내석사

The purpose of this study is to investigate demand of students and engineers about the technical literacy, and to analyze the technical textbook content. The technical literacy means technical knowledge, technical thinking, technical capability. The technical knowledge is composed of manufacturing, transportation, information communication, construction, and biotechnology. The technical capability is composed of intelligent ability, hands-on make ability, problem solving ability, evaluation ability. The results of this study are as follows. First, the students takes an interest to the invention class. They promote a creative thinking through invention class. They like a practice formula class most. Students want to get hands-on make ability among abilities of technical capability. The hands-on make ability is related with a mind-on ability. So the hands-on ability is very important to students learning methods. Second, the engineers want to get creative problem solving ability most. Because when they meet an issue in actual lives, problem solving ability is necessary to generate ideas. Third, it is intelligent ability to be composing most a lot of section among textbook contents. The intelligent ability holds 81%, the hands-on make ability holds 1.6%, the problem solving ability holds 15.9%, the evaluation ability holds 1.4% These components drops an interest of students, and it is not helpful to an actual life. The conclusion of this study is as follows. The textbooks contents should be composed uniformly every scope. The intelligent ability scope section should be reduced, the hands-on ability and problem solving ability scope section should be increased. There are very important, in order to raise an interest of students.

웹사이트 운영을 통한 오프라인 기업의 브랜드확장전략의 효과에 대한 연구

류성남 경희대학교 경영대학원 2003 국내석사

Facile Fabrication and Patterning Study of Superhydrophilic/phobic Surfaces

류성남 포항공과대학교 일반대학원 2016 국내박사

최근 극친수/ 극소수성 표면 제작 및 응용에 대한 다양한 연구가 이루어지고 있다. 연꽃잎의 표면 구조를 통해 표면의 계층구조 및 표면 성질이 극친수/극소수 표면 제작에 중요한 요소임을 알게 된 후 이를 모사하기 위한 많은 시도가 진행되었다. MEMS, 리쏘그래피, UV 조사, 증착 등 다양한 방법을 통해 극친수/극소수 표면이 제작되었지만 실제 산업 분야로의 응용을 위해 보다 쉽고 저가의 제작 공정에 대한 요구가 이어져왔다. 또한 표면의 특정한 부분이나 복잡한 형상의 내, 외부의 젖음성을 달리 구현하기 위한 패터닝 방법에 관한 연구또한 기존의 잉크젯 방식, 마스크 방식등의 단점을 보완할 필요성이 대두되었다. 이 논문에서는 한 번의 간단한 공정으로 손쉽게 계층구조를 갖는 극친수/극소수 표면의 제작 방법에 대해소개하고, 보다 대량생산에 적합하고 저가인 표면 젖음성 패터닝 기술에 대해 소개한다. 양극산화를 통한 나노 플레이크 구조의 극친수/극소수 표면 제작, 모세관 압을 이용한 복잡한형상의 내,외부 패터닝, 스탬프를 이용한 패터닝 공정에 관한 연구가 진행되었고 각 공정 결과에 대한 유체 저항, 액적 분사, 패터닝 정밀도 실험이 진행되었다. In dissertation, research about fabrication and patterning of the superhydrophilic/phobic surfaces was conducted. Applications of fabrication and patterning techniques such as surface drag reduction, nano dispensing, and mass production patterning were introduced with experimental results. Hydrophobic surfaces with micro- or nanoscale pillars have been attracting considerable interest from scientists. In nature, such surfaces can be found on lotus leaves or under the feet of pond skaters. One significant property of these surfaces is friction drag reduction (FDR). Many studies have been conducted to demonstrate this reduction in terms of laminar and turbulent flows. The slip-length hypothesis is often used to explain this phenomenon. In this study, processes with the advantages of simplicity and cost effectiveness were used to fabricate dual-scale structures. Durable super-hydrophilic and super-hydrophobic surfaces were easily obtained from these structures. FDR was measured on a super-hydrophobic surface and was compared to that on smooth and super-hydrophilic surfaces. The experimental results in a circulating water channel revealed the Reynolds number range within which substantial FDR can occur on a super-hydrophobic surface. The mechanism of FDR and the role of slip are discussed by comparing experimental results. Owing to the fact that liquid-dispensing devices are used in a wide variety of scientific fields, including chemistry, biology, pharmacology, and mechanics, droplet dispensing has come to be regarded as a key technology with respect to micro/nanoengineering. Positive-placement dispensing technology is being used widely because it allows for a high degree of controllability without requiring a complex dispensing system; however, adhesion and slip-related issues limit the performance of this technology. In this letter, we report a technique for the fabrication of selective superhydrophilic/phobic coatings in syringe-type positive-displacement dispensing nozzle tips. The superhydrophilic capillary in the nozzle tip was coated selectively with superhydrophobic materials by exploiting the difference in the capillary pressure. The surface of the front part of the capillary was made superhydrophobic; it thus allowed the liquid to flow without adhesion. In contrast, the back part was made superhydrophilic; it retarded the flow of the liquid, holding it in place. Together, the two surfaces minimized the volume of the dispensed droplets. High-speed images of the dispensed liquid were taken to compare the two droplet-dispensation processes. It was found that the volume of the water droplets dispensed from the selectively coated nozzle tip was as low as 27 nL and much smaller than that of the droplets dispensed from the superhydrophobic nozzle tip. Patterning techniques are essential to many research fields such as chemistry, biology, medicine, and micro-electromechanical systems (MEMS). In this Letter, we report a simple, fast, and low-cost superhydrophobic patterning method using a superhydrophilic template. The technique is based on the contact stamping of the surface during hydrophobic dip coating. Surface characteristics were measured using scanning electron microscopy and energy-dispersive X-ray spectroscopic analysis. The results showed that the hydrophilic template, which was contacted with the stamp, was not affected by the hydrophobic solution. The resolution study was conducted using a stripe shaped stamp. The patterned line was linearly proportional to the width of the stamp line with a constant narrowing effect. A surface with regions of four different types of wetting was fabricated to demonstrate the patterning performance.

鐵鋼슬래그로부터 磁力選別法에 의한 有價金屬(Fe分)의 回收

柳成南 순천대학교 2001 국내석사

In recent years, the recovery of valuable resources from industrial waste is attracting our concern as they can minimize the problem of pollution and can reutilize resources. Therefore, this study aims to analyze the properties of slag, to understand the manipulation of the magnetic separator which is effective in recycling slag, to figure out the amount of iron recovered according to the intensity of the magnetic field, to the revolving speed of the drum, and to the input speed of the slag, and thus to find out the optimum condition of the separator and the amount of iron recovered and the total iron content at each particle size. The conclusion of this experiment is as follows. 1. Since moist slag of minute powder has great influence on the separating by magnetic force, possibly the use of 100% dried slag is recommended to block the infusion of impurities and to obtain accurate results. 2. As for low iron-content in BF-slag, the fewer the feeder vibration is and the slower the drum revolves, the higher the rate of recovery goes. However, it is not without shortcomings. It causes more infusion of impurities and requires more time. It recorded the highest recovery rate, approximately 42%, with the particle size of 1.2~2.4mm, and it gathered the highest quality iron when separated by magnetic force with the particle size of 0.5mm and over. 3. As for as water-cooled converter slag with much minute powder, the more the feeder vibration is and the slower the drum rotates, the higher the rate of recovery goes. It marked the highest recovery rate, over 55% with the particle size of 0.5mm and less. The smaller the magnitude of particle size, the higher the recovery rate goes at each particle size. Under the size of 0.5mm, 98% metallic iron is recovered. 4. As for air-cooled spherical converter slag, when the feeder rate is as low as 30Hz or 40Hz, the higher the revolution per minute is, the lower the recovery rate goes. When the feeder rate is as high as 60Hz or 70Hz, the higher the revolution is, the higher the recovery rate goes. It marked the highest recovery rate, approximately 37% with the particle size of 1.2~2.4mm. 5. Stable sorting rates for each slag have been recorded, with vibration 40Hz, revolution 50 rpm for BF-slag, with vibration 60Hz, revolution 30 rpm for water-cooled converter slag, and with vibration 50Hz, revolution 40 rpm for air-cooled converter slag. These results suggest that the setting of the separator should be manipulated according to the shape and the ingredients of each stuff. 6. While sorting by magnetic force, the stronger the magnetic field is, the higher the recovery rate goes. However, the quality becomes worse since the infusion of iron compound other than metallic iron increases.

宣敎 敎育論 理解 : 韓國敎會 敎育 更新을 爲한 硏究

류성남 韓國神學大學 宣敎神學大學院 1977 국내석사

固體高分子電解質과 金屬間의 電氣化學反應 및 그 應用

유성남 충남대학교 대학원 2002 국내박사

In this study, the electrochemical reaction of solid polymer electrolyte to metals and its applications have been researched. Specifically, the purposes of this study were to devise the new method for water electrolysis using metal plating (mainly Pt) on solid polymer electrolyte as an electrode, to produce O₂and H₂at low prices in a safer way by this new method, and to obtain O₃at low prices in a safer way by immediate transforming O₂which was produced in the process of electrolyzing water into O₃. The results obtained through this study which was on the electrochemical reaction of solid polymer electrolyte to metals and its applications were as following. 1) Pt(NH₃)₄Cl₂·H₂O and H₂O and H₂Pt(OH)_6 were synthesised by the following steps. After H₂PtCl_6 was made by melting Pt in aqua regia, H₂PtCl₄could be made from that. t-Pt(NH₃)₂Cl₂was prepared from H₂PtCl₄made like above-mentioned, and then Pt(NH₃)₄Cl₂·H₂O with high purity was prepared from t-Pt(NH₃)₂Cl₂. H₂PtCl_6 was made by melting Pt in aqua regia, and Na₂Pt(OH)_6 could be made from that. H₂Pt(OH)_6 was prepared by letting Na₂Pt(OH)_6 made like this react to HCl through cation exchange membrane. 2) The method of Pt plating on solid polymer electrolyte surface with electroless plating using Pt(NH₃)₄Cl₂·H₂O and N₂H₄was developed. The appropriate dipping time in Pt(NH₃)₄Cl₂·H₂O was about 20 minutes and reduction time in N₂H₄solution was about 1.5 hours. At more or less than that, the condition of plating layer on soild polymer electrolyte surface was worsened and the movement of H was decreased by the loss of ion exchange lines. 3) Electroplating was used in Pt plating on Ti mesh. H₂Pt(OH)_6 was used as Pt plating reagent. In plating, Pt wire was used as an anode and Ti mesh to be plated as a cathode. In this case, the temperature of plating solution at 75℃±3℃ and the amperage range of 2.5±0.002V, 0.5±0.1A were the optimum plating conditions. To increase Pt plating time on Ti mesh didn't have influence on the surface condition except for accompanying the thickness of Pt plating layer. 4) Electrodepositing was used in β-PbO₂depositing on Ti mesh. First of all, Pt plating on Ti mesh was performed because there was the difficulty in direct β-PbO₂depositing on Ti mesh. Pb(NO₃)₂was used as β- PbO₂depositing reagent. In this case, the temperature of 65℃±3℃ and the amperage range of 3.6±0.0002V, 0.7±0.1A were the optimum depositing conditions. In depositing, Pt plated Ti mesh was used as an anode and Ti mesh as a cathode. In β-PbO₂depositing on Ti mesh, Pt plating time of the base part was at least more than 10 minutes, and β-PbO₂depositing time was at least more than 2 minutes. 5) Solid polymer electrolyte water electrolysis cell consisted of Pt plated solid polymer electrolyte on both sides, β-PbO₂deposited Ti mesh as an anode, Pt plated Ti mesh as a cathode, and each electrode had three sheets of Ti mesh, In addition to these, rubber, polymer, and Ti plate gasket were devised and used. And the cell combined with these items was tied with Al plate to fix up. 6) With water electrolysis using solid polymer electrolyte water electrolysis cell, the generation of O₃was confirmed at the range of 3.2~3.6V, 1.0~1.5A/㎠, and the devised O₃and H₂generator with amperage of 6V, 100A was based on this.