• Title/Summary/Keyword: micro-duty

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Thermal Spray Coating Layer for Improvement of Erosion and Corrosion Resistance Applicable to Large Sized High Speed Ship's Rudder (대형 고속 선박용 러더의 내침식, 부식 특성 향상을 위한 용사 코팅막)

  • Lee, Yu-Song;Heo, Seong-Hyeon;Kim, Jin-Hong;Kim, Yeo-Jung;Bae, Il-Yong;Lee, Myeong-Hun
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2011.05a
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    • pp.196-197
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    • 2011
  • Rudder, one of the most important component in the marine vessel, is now being decreased life time to serve due to cavitation erosion, vortex current, high flow speed suffer from ship speed going up dramatically. In this study, 10 kinds of thermal spray coating materials(2 of Zn alloy series, 3 of Al alloy series, 3 of Cu alloy series, 2 of STS alloy series) are chosen to apply on specimens and analyze micro structure, metallic composition, properties(porosity, oxidation) by using visual observation, XRD, EDX etc.. Additionally, to refine the characteristic of corrosion endurance for thermal spray coating layer, compared with thermal spray process and 5 kinds of heavy duty painting and AC paint (Anti-Corrosion Paint). Based on above mentioned experimental results, a priority of all coated specimens on corrosion-erosion endurances finalized and summarized there by desirable composition and process of thermal sprayed material properly.

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New Space of Citizenship : From National Citizenship To Cultural Citizenship (새로운 시민성의 공간 등장 : 국가 시민성에서 문화적 시민성으로)

  • Cho, Chul-Ki
    • Journal of the Korean association of regional geographers
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    • v.22 no.3
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    • pp.714-729
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    • 2016
  • National citizenship has been empathized by nation-state since modern times. But with recent wave of globalization, the force of national citizenship is gradually reducing. Globalization requires citizens of global citizenship needed in the global village on the one hand, and of cultural citizenship suited in multicultural society on the other hand. The trend shows that the geographical focus of citizenship is shifted or expanded from the political domain to the social and cultural domain. Moreover, with concerns of personal everyday life citizenship is extended from standard personality by Western view to inclusion and exclusion in micro everyday space, non-Western view based on social difference of gender, class, ethnicity etc. New spaces of citizenship, cultural citizenship and everyday citizenship which empathizes personal right and difference is emerging instead of national citizenship based on personal allegiance and duty of the state. This means that the state has not only a task of establishment of common national citizenship, but also a challenge to recognize of diversity of citizens.

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Nucleation and growth mechanism of nitride films deposited on glass by unbalanced magnetron sputtering

  • Jung, Min J.;Nam, Kyung H.;Han, Jeon G.
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2001.06a
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    • pp.14-14
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    • 2001
  • Nitride films such as TiN, CrN etc. deposited on glass by PVD processes have been developed for many industrial applications. These nitride films deposited on glass were widely used for not only decorative and optical coatings but also wear and corrosion resistance coatings employed as dies and molds made of glass for the example of lens forming molds. However, the major problem of nitride coatings on glass by PVD process is non-uniform film owing to pin-hole and micro crack. It is estimated that nonuniform coating is influenced by a different surface energy between metal nitrides and glass due to binding states. In this work, therefore, for the evaluation of nucleation and growth mechanism of nitride films on glass TiN and CrN film were synthesized on glass with various nitrogen partial pressure by unbalanced magnetron sputtering. Prior to deposition, for the examination of relationship between surface energy and film microstructure plasma pre-treatment process was carried out with various argon to hydrogen flow rate and substrate bias voltage, duty cycle and frequency by using pulsed DC power supply. Surface energy owing to the different plasma pre-treatment was calculated by the measurement of wetting angle and surface conditions of glass were investigated by X-ray Photoelectron Spectroscopy(XPS) and Atomic Force Microscope(AFM). The microstructure change of nitride films on glass with increase of film thickness were analyzed by X-Ray Diffraction(XRD) and Scanning Electron Microscopy(SEM).

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The Ecological Variables Research on the Effect of Teacher's Happiness in Child Care Center (보육교사의 행복에 영향을 미치는 생태체계변인 연구)

  • Lee, Soon-Mi
    • Journal of the Korea Convergence Society
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    • v.8 no.11
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    • pp.423-430
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    • 2017
  • The purpose of research is analyzing the ecological variables on the effect of child care teacher's happiness. The data was collected by the survey of the happiness factors and ecological variables of child care teachers. The results are listed below. First, of organismic variable, the age and the educational background of child care teacher showed discrimination one's happiness. Second, of micro system variable, the marital status is the only thing that affect the happiness. Third, of meso system variable, the teachers who are highly interact on each other such as, child to teacher and parents to teacher are much happier than others. Finally, of the outside system variable, the teachers who are working at the better working environment and good quality of duty are much happier than others.

A STUDY ON THE RELATIONSHIP BETWEEN PLASMA CHARACTERISTICS AND FILM PROPERTIES FOR MgO BY PULSED DC MAGNETRON SPUTTERING

  • Nam, Kyung H.;Chung, Yun M.;Han, Jeon G.
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2001.11a
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    • pp.35-35
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    • 2001
  • agnesium Oxide (MgO) with a NaCI structure is well known to exhibit high secondary electron emission, excellent high temperature chemical stability, high thermal conductance and electrical insulating properties. For these reason MgO films have been widely used for a buffer layer of high $T_c$ superconducting and a protective layer for AC-plasma display panels to improve discharge characteristics and panel lifetime. Up to now MgO films have been synthesized by lE-beam evaporation, Molecular Beam Epitaxy (MBE) and Metalorganic Chemical Vapor Deposition (MOCVD), however there have been some limitations such as low film density and micro-cracks in films. Therefore magnetron sputtering process were emerged as predominant method to synthesis high density MgO films. In previous works, we designed and manufactured unbalanced magnetron source with high power density for the deposition of high quality MgO films. The magnetron discharges were sustained at the pressure of O.lmtorr with power density of $110W/\textrm{cm}^2$ and the maximum deposition rate was measured at $2.8\mu\textrm{m}/min$ for Cu films. In this study, the syntheses of MgO films were carried out by unbalanced magnetron sputtering with various $O_2$ partial pressure and specially target power densities, duty cycles and frequency using pulsed DC power supply. And also we investigated the plasma states with various $O_2$ partial pressure and pulsed DC conditions by Optical Emission Spectroscopy (OES). In order to confirm the relationships between plasma states and film properties such as microstructure and secondary electron emission coefficient were analyzed by X-Ray Diffraction(XRD), Transmission Electron Microscopy(TEM) and ${\gamma}-Focused$ Ion Beam (${\gamma}-FIB$).

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PARTIAL REPLACEMENT OF GRASS SILAGE WITH WHOLE-CROP CEREAL SILAGE FOR GROWING BEEF CATTLE

  • Raza, S.H.;Rowlinson, P.
    • Asian-Australasian Journal of Animal Sciences
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    • v.8 no.3
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    • pp.281-287
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    • 1995
  • A study was conducted to investigate the effect of different inclusion levels of urea treated whole-crop wheat silage (UWCWS) in grass silage based rations on the performance of growing beef cattle. The winter wheat (variety, Riband) was harvested (in the summer of 1991) at a dry matter proportion of 520 g/kg and treated with feed grade urea at the rate of 37 kg/tonne crop dry matter and preserved in a heavy duty plastic bag using a silo press. The urea treated whole crop wheat silage (UWCWS) was mixed with grass silage to replace 0.00 (S100), 0.33 (S33) and 0.67 (S67) parts of the forage dry matter and fed ad libitum in a cross over design to 18 Simmental X Holstein Friesian growing beef animals. Two energy sources {one high in starch, rolled barley (RB) and one high in digestible fibre, sugar beet pulp (SBP)} were fed to supply sufficient energy for the efficient use of nitrogen by the rumen micro-organisms. The data on DMIF (dry matter intake of forage), TDMI (total dry matter intake), DLWG (daily live weight gain), FCR (feed conversion ratio) were recorded and faecal samples were collected to determine the digestibility coefficients. Results revealed that with the inclusion of UWCW in the animals' diets the DMI of the forage was significantly increased (p < 0.05). The highest DMIF was found in the treatment "S33" ($6.28{\pm}0.25kg$) where 67% of the silage dry matter was replaced with the UWCW and the lowest value for DMIF was observed in the control treatment ($5.03{\pm}0.23kg$). The DLWG did not differ significantly between the treatments. However, treatment "S100" showed a trend towards a superior DLWG. Feed conversion ratio in the control treatment differed significantly from "S67" and "S33". The addition of the UWCW in the animals' diet resulted in the lower FCR There was no effect of type of energy supplement on any aspect of performance either overall or in interaction with grass silage: UWCWS ratio. The regression and correlation coefficients for DMIF (r = 5.22 + 0.0184x*), DLWG (r = $1.04-0.00086x^{NS}$) and FCR (r = 4.78 = 0.022x*) on the inclusion of UWCW in the diet were calculated. The effect of the inclusion of UWCW on the overall digestibility coefficients was significant (p < 0.05). The addition of the UWCWS in the diet decreased the digestibility of the DM, OM, ADF and NFE but effect on the protein digestibility was non significant. The results of present study suggests that a DLWG slightly over 1 kg can be achieved with UWCW during the store period (period in which animal performance targets are low especially during winter) and the prediction of ME was overestimated as the high intake of DM did not reflect in improved animal performance.

Spatio-temporal Characteristics of the Daily Activities of economic-active married women (취업주부의 일상생활활동의 시 ${\cdot}$ 공간적 특성)

  • Park, Soon-Ho;Kim, Enn-Sook
    • Korea journal of population studies
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    • v.21 no.2
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    • pp.113-143
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    • 1998
  • Married women who follow occupations have remarkably increased. Economic-activies married women[EAMW] have experienced a great degree of role confilcts as the results of that they should play the role of wage workers and do duty as household affairs as well as raise children. To understand problems of EAMW and to make alterniative plans for EAMW, the daily life actives of EAMW should be examined. This study attempts to understand the daily life activites of EAMW. To obtain the goal this research generalizes the daily life actives of EAMW. classifies the patterns the activites, and analyzes the activites in the micro-level. The acivites of EAMW mainly consist of formal business and household affairs. The spatial bounds of activities are influenced by weekdays and holidays. During the weekday their activities are mainly found around residences and/or work places; while, during the weekend, they are discovered around residences and/or around residences or relatives who take care of their children. EAMW move longer distance rather than a full-time housewife; however, the activites of EAMW are residential orientation like those of full-time housewives. The role conflicts of EAMW are mainly from social cultural structure, the distance between workplace and residence, and the location of public service institutes.

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