• 제목/요약/키워드: Mixing Pattern

검색결과 298건 처리시간 0.028초

유도 결합 플라즈마를 이용한 백금 박막의 식각시 $O_2$ 가스 첨가 효과 (Effects of $O_2$ Gas Addition to Etching of Platinum Thin Film by Inductively Coupled Plasmas)

  • 김남훈;김창일;권광호;장의구
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 추계학술대회 논문집 학회본부 C
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    • pp.770-772
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    • 1998
  • The highest etch rate of Pt film was obtained at 10% $Cl_2$/90% Ar gas mixing ratio in our previous investigation. However, the problems such as the etch residues(fence) remained on the pattern sidewall, low selectivity to oxide as mask and low etch slope were presented. In this paper, the etching by additive $O_2$ gas to 10% $Cl_2$/90% Ar gas base was examined. As a result, the fence-free pattern and high etch slope was observed and the selectivity to oxide increased without decreasing of the etch rate. And the reasons for this phenomenon was investigated by XPS(x-ray photoelectron spectroscopy) surface analysis and plasma characteristic.

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원심 다익홴의 유동에 대한 컷 오프 각도의 영향 (Effect of Cut-off Angle on Flow Pattern of Centrifugal Multi-blade Fan)

  • 강경준;신유환;이윤표;김광호
    • 한국유체기계학회 논문집
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    • 제13권3호
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    • pp.37-42
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    • 2010
  • This study investigated on details of flow characteristics of a multi-blade fan for domestic ventilation. Experiments and analysis were carried out to describe on flow pattern with variations of cut-off angle near the scroll housing throat, which were performed by PIV measurement for the flow field and by total pressure probes. The stagnation point at cut-off region of the fan moves to the exit of the scroll housing as the cut-off angle increases. The movement of stagnation point and the variation of throat area of the scroll housing influence to the distribution of velocity magnitude at the exit of the fan. Furthermore, a large distortion of the velocity distribution at the scroll exit causes to increase mixing loss along the flow path.

디젤기관의 실린더내 유동 및 분무액적 거동의 수치적 연구(I) (A Study on the Numerical Analysis of Behavior of Spray Droplets and Internal Flow Field of Cylinder in Diesel Engine)

  • 장영준;박호준;전충환;김진원
    • Journal of Advanced Marine Engineering and Technology
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    • 제16권1호
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    • pp.35-46
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    • 1992
  • In this study, we calculated gas flow fields and distribution of fuel droplet and mass fraction using the CONCHAS-SPRAY code which modified to execute in IBM PC and changed three important factors, injection rate pattern (BASIC, I, II, III), different bowl shape and spray type. Especially vortices which be influenced by fuel-air mixing process, evaporation and flame propagation are generated more strongly in the bowl-piston type combustion chamber than in the flat-piston type. As the spray type changes, it is found that conical type produced large and strong vortices and fuel droplets are effictively diffused into the entire combustion chamber. As the injection rate pattern changes I, II, III based on BASIC type, we confirmed that End-of-Injection Effect strongly influence on droplets life time.

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Air-Water 모델에서 액상의 유동특성에 관한 연구 (A Study on the Flow Characteristics of Liquid Phase in Air-Water Model)

  • 오율권;서동표;박설현
    • 한국안전학회지
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    • 제19권1호
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    • pp.1-5
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    • 2004
  • In the present study, the gas injection system based on air-water model was designed to investigate the flow characteristics of liquid phase. A PIV system was applied to analyze the flow pattern in a ladle which gas stated to rise upward from the bottom. Gas flow is one of most important factors which could feature a flow pattern in a gas injection system. As the gas injected into the liquid, the kinetic energy of bubble transfer to liquid phase and a strong circulation flow develops in the liquid phase. Such a flow in the liquid develops vortex and improve the mixing process. Due to the centrifugal force, circulation flow was well developed near both wall sides and upper region respectively. Increasing gas flow was helpful to remove dead zone but, weak flow zone still exists in spite of the increasement of gas flow rate.

보조동력장치용 환형 역류형 연소기 (TS2) 성능 시험 (Performance Test of A Reverse-Annular Type Combustor (TS2) for APU)

  • 고영성;한영민;이강엽;양수석;이대성
    • 대한기계학회논문집B
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    • 제26권6호
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    • pp.805-810
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    • 2002
  • Development of a small gas-turbine combustor for 100㎾ class APU(Auxiliary Power Unit) has been performed. This combustor is a reverse-annular type and has a tangential swiller in the liner head to improve the fuel/air mixing and flame stability. Three main and three pilot fuel injectors of the simplex pressure-swirl type are used. The performance target at the design condition includes a turbine inlet temperature of l170k, a combustion efficiency of 99%, a pattern factor of 30%, and an engine durability of 3000 hours. Under developing the combustor, we conducted the performance test of our first prototype(TS1) with some variants. As a result of the test, the performance targets of the combustor are satisfied except that the pattern factor is about 4% higher than the target value. Therefore, the second prototype(TS2) was redesigned and the performance test was conducted with the critical focus on the pattern factor and the exit mean temperature. We adopted TS2 four variants to check the improvement of the pattern factor. As a result, the pattern factors of several variants were satisfied with the performance target. Finally, the TS2A variant was chosen as a final combustor fur our APU model.

서울 근교 농촌주택에 있어서 식사 및 취사공간에 관한 사례 연구 -경기도 용인군 용인읍 삼가 3리 마을을 중심으로- (A Casestudy on the Eating and the Cooking Spaces of Farmhouse in Suburban Area)

  • 윤정숙
    • 대한가정학회지
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    • 제26권4호
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    • pp.87-100
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    • 1988
  • The purpose of this study was to investigate the dweller's housing needs through the connection between dwellers' living pattern and space usage. The objectives were (1) to examine how to eat and cook in the eating and cooking spaces, (2) to examine how to alter the original housing, (3) to research the dwellers' housing needs for the eating and cooking spaces, and the changing process of dwellers' housing needs, and (4) to classify the type of eating and cooking spcaces. The results of this study were (1) there were changed in eating pattern of space usage according to the season. The eating activities were a Korean living pattern : sitting on the floor and eating at the BAB SANG. (2) There was a difference in the pattern of space usage and the activity for main cooking and KIM CHI. (3) AN BANG (eating space for winter) as well as MARU (eating space for summer) has changed to a larger space. (4) By the changing of living patterns, BU AUK (a main cooking space ) has showed a various alternations: function, dimension of space, facilities, floor materials and floor level. (5) The dwellers' housing needs for eating space were a multipurpose room, and a dining kitchen of western living pattern (using a dining table and chairs) with the present changing life styles. (6) The dwellers' housing needs for cooking space were a multipurpose room of working area, a seperation of heating area, a western living pattern, a plan of flat fllor level and a dining kitchen. (7) BU AUK of eating and cooking spaces was classified into 4 types: a traditional type, a mixing type, a modernized type, and a western type.

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Highly Tunable Block Copolymer Self-assembly for Nanopatterning

  • 정연식;정재원
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 2011년도 춘계학술발표대회
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    • pp.6.1-6.1
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    • 2011
  • Nanoscale block copolymer (BCP) patterns have been pursued for applications in sub-30 nm nanolithography. BCP self-assembly processing is scalable and low cost, and is well-suited for integration with existing semiconductor fabrication techniques. However, one of the major technical challenges for BCP self-assembly is limited tunability in pattern geometry, dimension, and functionality. We suggest methods for extending the degree of tunability by choosing highly incompatible polymer blocks and utilizing solvent vapor treatment techniques. Siloxane BCPs have been developed as self-assembling resists due to many advantages such as high etch-selectivity, good etch-resistance, long-range ordering, and reduced line-edge roughness. The large incompatibility leads to extensive degree of pattern tunability since the effective volume fraction can be easily manipulated by solvent-based treatment techniques. Thus, control of the microdomain size, periodicity, and morphology is possible by changing the vapor pressure and the mixing ratio of selective solvents. This allows a range of different pattern geometry such as dots, lines and holes and critical dimension simply by changing the processing conditions of a given block copolymer without changing a polymer chain length. We demonstrate highly extensive tunability (critical dimension ~6~30 nm) of self-assembled patterns prepared by a siloxane BCP with extreme incompatibility.

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중국내 묘족의 직물에 나타난 기법과 문양 고찰 (The Study on Technique and Design Appeared in Textile of Miaos in China)

  • 부애진;홍정민
    • 복식
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    • 제37권
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    • pp.149-162
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    • 1998
  • This study is thed Embroidery, Cross-stitchery, Weaving, Wax-Printing of technique and design appeared in textile of Miaos dwells in south-west among the minority people of china. The study is as follows. First, the technique of textile1) satin stitch, couching stitch, french-knot stitch, etc. using anther silk thread or cotton thread color 2) cross-stitchery 3) hand-weaving technique which is shaped other warp or weft using simple loom 4) the technique of dyeing of pattern using effect with wax. These methods are singly used mixing together, therefore doubled beauty. Second, these technuque of ornament have other independence, specially ornament apron, sling, sleeve borders, slack borderss, edge of upper garment, take off and put on easily, heighten effect of various ornament, can preserve many years. Third, Maker, female born in this country fashion by need of herself, used liberal method shown in unique creativity of life. This texture make standards capable female proud of intelligent and skill of herself. Fourth, Design appeared in textile like as pattern flying bird in the sky, strolling beast in the field, lion rolling gem, laughing dragon winding snake at gem, birks, flowers, fish, butterfly is used as the wish of long life, a lucky sign. They expressed creativity and unique conception using formation : the technique transform other shape using by omitting or adding or overestimating. Geometric pattern of tartan, revealing, Fifth, composition structure having balance and symmetry or contradiction towards center and circumstance of the center harmonized repeatedly method, expressed unique artful attraction by full composition.

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TV 드라마 의상에 나타난 스타일에 관한 연구 - 드라마 ′Sex & The City′를 중심으로 - (A Study on the Fashion Style in TV Drama - Focused on ′Sex & The City′-)

  • 이지현;정은숙
    • 복식
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    • 제54권2호
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    • pp.25-38
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    • 2004
  • The purpose of this study is to analyze the fashion style in the drama 'sex and the city's character. Frist of all, mixing and matching style is one of Carrie's signiture styles, namely her ability to combine haute couture fashion with high street bargains and vintage buys to make ingenious ensambles. There are two main ways to go with this seperates look, the equal look, when tops are put with equally fabulous bottoms, and the unequal look, when fabulous tops go with less fabulous bottoms. Second, nowadays vintage style is one of fashion trend. The 'Sex and the city' has define trends when it comes to jewellery, it is the 'Carrie' nameplate and the Hermes's horseshoe necklaces, especially pearls were a big hit for vintage style. Also it takes a floral pattern and various hat makes a vintage style. Third, Sexual style shows a halter and sleeveless dress with long earing and splendid necklaces. And it takes a leopard pattern. Fourth, romantic style, one of the 'Sex and the city"s character's favourite garments is the dress. Its makes romantic moods a delicate with handbags, Manolo Blahnik's and Jimmy Choo's high hill shoes and corsages. The romantic pattern is floral and material is chiffon.ffon.

리소그래피 없이 제작된 그물망 구조의 은나노와이어-고분자화합물 복합소재 기반 유연 투명전극의 특성 (Characteristics of a Flexible Transparent Electrode based on a Silver Nanowire-polymer Composite Material with a Mesh Pattern Formed without Lithography)

  • 박태곤;박종설;박진석
    • 반도체디스플레이기술학회지
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    • 제19권4호
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    • pp.11-17
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    • 2020
  • In this study, a new method for fabricating flexible transparent electrodes based on silver nanowire-polymer (AgNW-PEDOT:PSS) composite materials having a mesh pattern formed by a solution-based process without lithography was proposed. By optimizing conditions such as the amount of ultraviolet (UV) photosensitizer injected into the suspension of AgNW and PEDOT:PSS, UV exposure time, and deionized (DI) washing time, a clear and uniform mesh pattern was obtained. For the fabricated AgNW-PEDOT:PSS-based mesh-type electrodes, characteristics such as electrical sheet resistance, light transmittance, haze, and bending flexibility were analyzed according to the mixing ratio of AgNW and PEDOT:PSS included in the suspension. The fabricated mesh electrodes typically exhibited a low electrical sheet resistance of less than 20 Ω/sq while maintaining a high transmittance of 80% or more. In addition, it was confirmed from the results of analyzing the effect of PEDOT:PSS on the characteristics of the mesh-type AgNW-PEDOT electrode that the optical visibility was greatly enhanced by reducing the surface roughness and haze, and the bending flexibility was remarkably improved.