• Title/Summary/Keyword: Phase orientation

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The Study on the Phase Transition of Langmuir Film by Brewster-Angle Microscope (BAM(Brewster-Angle Microscope)으로 관측한 Langmuir막의 상전이에 관한 연구)

  • Cho, Wan-Je;Song, Kyung-Ho;Park, Tae-Gone;Park, Keun-Ho
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.05b
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    • pp.323-326
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    • 2000
  • In this study, we used Brewster-Angle Microscope(BAM) to study on the molecular orientation of monolayer on the water surface. The behaviors of molecules on three different subphase have been observed. Reproducible $\pi$-A isotherm have been obtained only on information about phase transition by molecular area. BAM facilitates the observation of morphology by optical anisotropy and thickness in monolayer and multilayers as BAM is shown to be sensitive to anisotropy of film. Every transition was found by BAM technique, either as a dramatic change in degree of contrast or as a sudden alteration of molecular action and $\pi$-A isotherm.

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Effect of Flow Inlet or Outlet Direction on Air-Water Two-Phase Distribution in a Parallel Flow Heat Exchanger Header

  • Kim, Nae-Hyun;Kim, Do-Young;Cho, Jin-Pyo;Kim, Jung-Oh;Park, Tae-Kyun
    • International Journal of Air-Conditioning and Refrigeration
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    • v.16 no.2
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    • pp.37-43
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    • 2008
  • The air and water flow distributions are experimentally studied for a round header - ten flat tube configuration. Three different inlet orientation modes (parallel, normal, vertical) were investigated. Tests were conducted with downward flow configuration for the mass flux from 70 to $130kg/m^2s$, quality from 0.2 to 0.6, non-dimensional protrusion depth (h/D) from 0,0 to 0.5. It is shown that, for almost all the test conditions, vertical inlet yielded the best flow distribution, followed by normal and parallel inlet. Possible explanation is provided using flow visualization results.

The Effect of Marketing Characteristic on Business Performance (창업마케팅특성이 기업성과에 미치는 영향)

  • Jeon, In-oh;An, Un-Seok
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.11 no.3
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    • pp.97-109
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    • 2016
  • In Korea, the survival rate of start-up of 5-year after foundation is as low as 29.6% of the country. This low survival rate is from because of insufficient resources in start-ups compared to those of mid-sized companies. Therefore, the marketing characteristics of entrepreneurship has emerged as a major cause. Therefore, In this study, because learning orientation, marketing experience, competition orientation and etc are differently owned in start-ups, marketing impact to marketing strategy in start-up companies are differently investigated. Therefore, the relationship of learning orientation, marketing experience, competition Orientation with marketing strategies was examined. Based on this, Business performance was examined to suggest contents related to eco-system of start-up companies to representative of start-up companies. For this study, Survey was conducted for 250 start-up entrepreneurs within 3 and half year since foundation from Nov. 20 to Dec. 20, 2015. In result of data-cleaning, 207 meaningful samples were gathered. Based on these, conclusion was obtained. Using SPSS 20.0 statistical program, frequency analysis, reliability analysis, correlation analysis and regression analysis were conducted. the following conclusions were drawn. First, in the impact of marketing environment of Phase 1 start-up companies on marketing strategy, product strategy, distribution strategy and promotion strategy were positively affected by learning orientation, marketing experience and competition orientation. Second, in the effect of 2nd phase marketing strategy to business performance, the financial performance and the non-financial performance. Were positively affected by product strategy, distribution strategy and promotion strategies. Third, The effect of learning orientation, marketing experience and competition orientation to financial performance was positively mediated by product strategy and distribution strategy among 3rd phase meditation strategies. the effect of learning orientation, marketing experience and competition orientation to non-financial performance was positively mediated by products strategy. In comprehensive summary, in order to increase business performance in start-up companies, marketing strategy should be applied in. Especially, the role of learning orientation and marketing experience is vital. In increasement of business performance to characteristics of star up marketing, financial performance can be increased by product strategy and distribution strategy. And, both of financial and non-financial performance can be increased by product strategy. Therefore, in conducting of marketing characteristics of start-up, to increase business performance, the apply of marketing strategy to marketing characteristics of start-up should be required.

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Structure Variation of Polypropylene Hollow Fiber Membrane with Operation Parameters in Stretching Process (연신 공정 조업변수에 따른 폴리프로필렌 중공사막의 구조 변화)

  • Lee Gyu-Ho;Kim Jin-Ho;Song Ki-Gook;Kim Sung-Soo
    • Polymer(Korea)
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    • v.30 no.2
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    • pp.175-181
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    • 2006
  • Hybrid process of thermally-induced phase separation and stretching was developed for the preparation of microporous polypropylene hollow fiber membranes. Precursor for stretching was prepared by using soybean oil as a diluent and benzoic acid as a nucleating agent far the sphenlite control and it was stretched far the micrporous hollow fiber membrane. The effects of stretching ratio and deformation rate for stretching process were investigated. Increase of stretching ratio resulted in the greater pore size with nonuniform size distribution. Higher deformation rate also increaser the pore size with uniform size distribution. Stretching ratio was closely related with the orientation of polymer chain and increased the mechanical strength of the fiber. Increase of deformation rate had little effects on the orientation of crystalline phase, and decreased the orientation of amorphous phase which caused the decrease of tensile strength of the fiber and broke the micro-fibrils connecting spherulites to form a circular pore shape.

A Metallurgical Study on Sputtered thin Film Magnet of high $_{i}\textrm{H}_{c}$ Nd-(Fe, Co)-B alloy and Magnetic

  • Kang, Ki-Won;Kim, Jin-Ku;Song, Jin-Tae
    • Korean Journal of Materials Research
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    • v.4 no.5
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    • pp.535-540
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    • 1994
  • Thin film magnet was fabricated by radio frequency magnetron sputtering using $Nd_13/(Fe.Co)_{70}B_{17}$ alloy target and magnetic properties were investigated according to sputtering conditions from the metallurgical point of view. we could obtain the best preferred orientation of $Nd_2Fe_{14}B$ phase at substrate temperatures between $450^{\circ}C$ and $460^{\circ}C$ with the input power 150W, and thin films had the anisotropic magnetic properties. But, as the thickness of thin film increased, the c-axis orientation gradually tended to be disordered and magnetic properties also become isotropic. Just like Nd-Fe-B meltspun ribbon, the microstructure of thin film magnet was consisted of very find cell shaped $Nd_2Fe_{14}B$ phase and the second phase along grain boundary. While, domain structure showed maze patterns whose magnetic easy axis was was perpendicular to film plane of thin film. It was concluded from these results that the perpendicualr anisotropy in magnetization was attributed to the perpendicular alignment of very find $Nd_2Fe_{14}B$ grains in thin film.

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Effect of Bonding Misfit on Single Crystallization of Transient Liquid Phase Bonded Joints of Ni Base Single Crystal Superalloy (단결정 Ni기 초내열합금 액상확산접합부 단결정화에 미치는 접합방위차의 영향)

  • 김대업
    • Journal of Welding and Joining
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    • v.20 no.5
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    • pp.93-98
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    • 2002
  • The effect of bonding misfit on single crystallization of transient liquid phase (TLP) bonded joints of single crystal superalloy CMSX-2 was investigated using MBF-80 insert metal. The bonding misfit was defined by (100) twist angle (rotating angle) at bonded interface. TLP bonding of specimens was carried out at 1523K for 1.8ks in vacuum. The post-bond heat treatment consisted of the solution and sequential two step aging treatment was conducted in the Ar atmosphere. The crystallographic orientation analysis across the TLP bonded joints was conducted three dimensionally using the electron back scattering pattern (EBSP) method. EBSP analyses f3r the bonded and post bonded heat treated specimens were conducted. All bonded joints had misorientation centering around the bonded interface for as-bonded and post-bond heat treated specimens with rotating angle. The average misorientation angle between both solid phases in bonded interlayer was almost identical to the rotating angle at bonded interface. HRTEM observation revealed that the atom arrangement of both solid phases in bonded interlayer was quite different across the bonded interface. It followed that grain boundary was formed in bonded interface. It was confirmed that epitaxial growth of the solid phase occurred from the base metal substrates during TLP bonding and single crystallization could not be achieved in joints with rotating angle.

The Effects of Perceived Service Quality and Relational Benefits on Relationship Development Process between Fashion Retail Stores and Customers (지각된 서비스 품질과 관계효익이 패션점포와 고객간의 관계발달 과정에 미치는 영향)

  • Ju, Seong-Rae;Chung, Myung-Sun
    • Journal of the Korean Society of Clothing and Textiles
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    • v.29 no.2
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    • pp.328-339
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    • 2005
  • The purpose of this study were to extract and empirically examine the effect variables on phase performance of relationship development process by identifying relationship development process between apparel store and customer. The questionnaires was asministered to 333 women frequency use of a department store, big shopping mall, discount store in Gwang-ju city during March 4-11, 2003. The data was analyzed by factor analysis, correlation analysis, and Structural Equation Model using LISREL 8.30 program. As the results, the perceived service quality with attractive factor of relationship explration phase direct positively influenced customer satisfaction among relationship expansion phases. However, relational benefit directly influenced customer satisfaction with the primary phase of relationship maintain as well as trust, customer commiment and long-term orientation. Also, customer satisfaction direct positively influenced trust, and customer' trust direct positively influenced customer commitment. Finally, the customer commitment direct positively influenced long-term orientation.

The Effect of $\beta$-Heat Treatment on the Microstructure and Mechanical Characteristics of Zircaloy-4 for Nuclear Fuel Cladding (핵연료 피복관용 지르칼로이-4의 미세조직과 기계적 특성에 미치는 $\beta$-열처리의 영향)

  • Koh, Jin-Hyun;Oh, Young-Kun;Kim, Gwang-Soo
    • Korean Journal of Materials Research
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    • v.9 no.6
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    • pp.589-594
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    • 1999
  • The effect of $\beta$-heat treatment on th microstructure, mechanical properties and texture in the nuclear fuel cladding of Zircaloy-4 tubes was chosen at 1000, 1100 and 120$0^{\circ}C$, and the tubes were heat-treated by a high frequency vacuum induction furnace. Morphology of the second phase particles and $\alpha$-grain of as-received tubes were markedly changed by heat treatment. The average sizes of second phase particles of as-received and $\beta$-heat treated tubes were 0.1$\mu\textrm{m}$ and 0.076$\mu\textrm{m}$, respectively. However, the average sizes of second phase particles were not much changed in the $\beta$-heated temperatures. With increasing heat treatment temperatures, the 0.2% yield strength and the hoop strength were decreased because of changes in preferred orientation as will as $\alpha$-plate width. Heat treated Zircaloy-4 tubes exhibited texture changes but the preferred orientation of grains still remained.

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Crystal Structure and Morphology of Nitride Precipitates in TiAl (TiAl에 석출한 질화물의 결정구조와 형태)

  • Han, Chang-Suk;Koo, Kyung-Wan
    • Korean Journal of Materials Research
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    • v.18 no.1
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    • pp.51-56
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    • 2008
  • The crystal structures and morphologies of precipitates in $L1_0$-ordered TiAl intermetallics containing nitrogen were investigated by transmission electron microscopy (TEM). Under aging at an approximate temperature of 1073 K after quenching from 1423 K, TiAl hardens appreciably due to the nitride precipitation. TEM observations revealed that needle-like precipitates, which lie only in one direction parallel to the [001] axis of the $L1_0$-TiAl matrix, appear in the matrix preferentially at the dislocations. Selected area electron diffraction (SAED) pattern analyses showed that the needle-shaped precipitate is perovskite-type $Ti_3AlN$ (P-phase). The orientation relationship between the P-phase and the $L1_0$-TiAl matrix was found to be $(001)_P//(001)_{TiAl}\;and\;[010]_P//[010]_{TiAl}$. By aging at higher temperatures or for longer periods at 1073 K, plate-like precipitates of $Ti_2AlN$ (H-phase) with a hexagonal structure formed on the {111} planes of the $L1_0$-TiAl matrix. The orientation relationship between the $Ti_2AlN$ and the $L1_0$-TiAl matrix is $(0001)_H//(111)_{TiAl}\;and\;_H//_{TiAl}$.

Thermo-Recording for The Composite System of (Disk-Like Molecules and Liquid Crystals)

  • Jeong, Hwan-Kyeong
    • Journal of the Korean Applied Science and Technology
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    • v.19 no.3
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    • pp.245-249
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    • 2002
  • A (disk-like liquid crystal (DLC) monomer/liquid crystals(LCs)/chiral dopant/dichroic dye) composite was irradiated with ultraviolet (UV) light. The (DLC network/LCs/chiral dopant/dichroic dye) was formed in the homeotropically oriented smectic A(SA) phase by the surface orientation treatment and the electric field. A focal-conic texture exhibiting strong light scattering appeared in the heat-induced chiral nematic phase(N${\ast}$) of the composite upon heating. Thermo-recording in the composite system has been realized by using a He-Ne laser. The laser irradiation was induced the phase transitions from SA phase to chiral nematic(N${\ast}$) phase in the composite system.