• Title/Summary/Keyword: heating elements

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Fabrication of $\textrm{MoSi}_2$ Heating Elements (이규화몰리브덴 고온발열체의 제조에 관한 연구)

  • Kim, Won-Baek;Sim, Geon-Ju;Jang, Dae-Gyu;Seo, Chang-Yeol
    • Korean Journal of Materials Research
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    • v.7 no.9
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    • pp.763-771
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    • 1997
  • 이규화몰리브덴 고온발열체의 제조공정을 개발하였다. 원료분말은 상용 MoSi$_{2}$분말이었으며 Bentonite, Si$_{3}$N$_{4}$, B, ThO$_{2}$를 각각 가소제와 첨가제로 사용하였다. 이들은 진공압출, 소결, 단자부 기계가공, U자형 성형, 용접 등의 과정을 거쳐 U자형 발열체로 제조되었다. 사용제품의 분석결과 최근 사용온도가 크게 증가된 것으로 알려진 190$0^{\circ}C$용 발열체는 다량(33wt%)의 W이 Mo을 치환하고 있는 것으로 나타났다. 발열체의 전기비저항은 겉보기 밀도가 증가함에 따라 급격하게 감소하는 경향을 보였으며 첨가물들의 영향은 미미하였다. 1400-1$600^{\circ}C$에서 용접한 경우 용접면에서의 전기비저항은 비용접부보다 낮았으며 용접온도가 증사함에 따라 감소하였다. 발열시험결과 제조된 발열체는 표면온도가 1$700^{\circ}C$이하에서는 문제가 없었으며 175$0^{\circ}C$ 이상의 온도에서는 원형의 융기가 표면에 발생하면서 급속하게 파괴되었다. 이 융기는 X-선 회절분석결과 SiO로 밝혀졌으며 따라서 발열체의 파괴는 MoSi$_{2}$/SiO$_{2}$계면에서의 Si(in MoSi$_{2}$) + SiO$_{2}$=2SiO(g)반응에 으해 일어나는 것으로 판단된다.

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A study on the Changes of the Korean-chinese's Rural Houses for the Modernization Process - Focused on the Longshan Village, a County of Korean-Chinese in JiLinSheng, China- (조선족 농촌주거의 근대화 과정에 따른 변화 연구 - 중국 길림성 조선족자치주 용정시 용산촌을 중심으로 -)

  • Kim, June-Bong;Lee, Hea-Dae;Kim, Jeong Tai
    • KIEAE Journal
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    • v.12 no.1
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    • pp.55-63
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    • 2012
  • Ever since China declared its economic reform and opening up policies in the late 1970s, it has been under rapid change. The modernization process of China's history and society was in progress at a pace far too fast in the middle of the 20th century, and housing sector was no exception. This study is based on the houses showing enough changes of modernization process in the rural area, and with a comparative analysis based on the field survey data conducted respectively in the present decade, considered the architectural elements and changing aspects of housing lifestyle. This paper will explore (1) The changes and the status of the members of the village, (2) The changes and the status of the structures, (3) The changes and the status of the main areas of housing, (4) The changes and the status of the heating system and the kitchen that crucially affects the space size among the housing facilities, and (5) The changes and the status of the bathroom. Through this analysis, this paper will firstly look at how traditional rural houses has been changed under the modernization process, and will objectively evaluate the modernization process of the traditional rural houses so that it will help find a way of improving China's rural houses in the future.

Effects of Sintering Conditions and Additives on the Properties of Sintered MoSi$_2$Powders Prepared by Self-propagating High-Temperature Synthesies (자전고온합성법으로 제조한 이규화몰리브덴 발열체의 소결특성에 미치는 소결조건 및 첨가물의 영향)

  • Sim, Geon-Ju;Jang, Dae-Gyu;Seo, Chang-Yeol;Kim, Un-Baek
    • Korean Journal of Materials Research
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    • v.5 no.8
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    • pp.921-928
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    • 1995
  • MoSi$_2$heating elements were fabricated using MoSi$_2$, powder prepared by SHS. Their apparent density, electrical resistivity, bending strength and victors hardness were measured as a function of sintering temperature, time and the amount of ceramic additives. The additives were A1$_2$O$_3$, SiO$_2$and bentonite which were added as a plastisizer. The electrical resistivity of MoSi$_2$decreased with the increase in the apparent density as expected. It decreased when the additives were added and the increase was the largest for the case of SiO$_2$. The bending strength and hardness decreased when the grain size becomes larger which is opposite to the expectation from the Hall-Petch type relation. Instead, they showed inverse proportionality with the volume fraction of pores probably in an exponential manner. The strength and hardness also decreased with the additives.

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A Study on the Korean traditional interior space and major elements in contemporary apartment (아파트 내부에 나타난 한국전통 실내 공간의 특성 및 구성 요소에 관한 연구)

  • 오혜경
    • Archives of design research
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    • v.11
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    • pp.72-81
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    • 1995
  • The purpose of this study was investigate the consistency of Korean traditional space in apartment. Fifty-two apartments and its dwellers were selected for field survey research and questionnaire. The major findings were summarized as follows: First, the space layout which has its origin in Korean traditional house was found in contemporary apartment and favored than that of western apartment. Second, among the Korean traditional space characteristics, the openness and closeness were found between the living room and room, living room and dining room, dining room and kitchen. Third, the heating system has been being changed from radiator to on-dol. Also favored finishing materials were revealed on-dol wood flooring and picture window for the living room, jang-pan flooring and Korean lattice window for the master room, wall covering for every wall and ceiling.

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Development of Air Cleaning System for Railroad Vehicles (차세대 객차용 청정시스템 개발)

  • Park, Duck-Shin;Cho, Young-Min;Kwon, Soon-Bark;Park, Eun-Young;Kim, Se-Young;Jung, Mi-Young
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.2109-2113
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    • 2008
  • As the standard of living is higher, the passengers using public transportations desire better qualities of environment as well as more comfortable indoor environment. In case of train, the passengers' comfort in passenger cabin is one of the most important elements to be competitive with other transport systems. The indoor air quality of the cabin should be managed properly, because many passengers travel for a long time in the small space of $144\;m^3$. For proper management of the air quality, the heating, ventilation and air conditioning (HVAC) system is required for the ventilation of the compartment. To maintain comfortable environment in the compartment, the automatic ventilation system is needed to exchange the indoor air with fresh air or clean indoor air. In this study, we investigated the indoor air quality (PM-10, $CO_2$, and VOCs) in the compartment of train. In addition, type and pattern of PM-10 has been analyzed through the clustering analysis. Based on the analysis, we could found that the fine particulate matters in the compartment can be a serious hazard to human. To control the concentration of PM-10 and $CO_2$ air cleaners were developed. Through this study, it is expected that people who take a train will be in a more comfortable environment.

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A Monitoring System of Energy Usage for Apartment Houses Using Smart TV (스마트TV를 이용한 공동주택의 에너지 사용 모니터링 시스템)

  • Park, Sungsoo;Jin, Younghoon;Nam, Sanghun;Chai, Youngho
    • Korean Journal of Computational Design and Engineering
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    • v.18 no.6
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    • pp.451-460
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    • 2013
  • This paper presents the necessary elements and data flow in developing a monitoring system of energy usage for apartment houses with a Smart TV. Energy consumption data in each home are collected and analyzed in the HUB station by way of measuring instruments. And the amount of energy usage, such as electricity, gas, hot water, heating, water and other utilities are displayed through the Smart TV application. Energy consumption Database in the HUB station are processed and displayed in the browser of a Smart TV through XML, JAVASCRIPT and Flash. Smart TV users can get the energy consumption status through the energy consumption analysis display of the Smart TV application and improve the energy efficiency by comparing the usage patterns with neighboring houses. And the application display energy usage information, consumption ranking, rates to user as well. Furthermore, usage of last month or year can be compared to help to reduce the energy usage. The proposed system can provide the information about the amount of energy use to be reduced and the warning on the waste of energy.

Daily Variation of Heat Budget Balance in the Gangjeong-Goryung Reservoir for Summertime - Concerning around the Rate of Heat Storage - (낙동강 강정고령보의 여름철 열수지 일변화 - 열 저장량 변동을 중심으로 -)

  • Kim, Seong-Rak;Cho, Chang-Bum;Kim, Hae-Dong
    • Journal of Environmental Science International
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    • v.24 no.6
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    • pp.721-729
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    • 2015
  • Surface heat balance of the Gangjeong-Goryung Reservoir is analyzed for 12-17 August 2013. Each flux elements at the water surface is derived from the special field observations with application of an aerodynamical bulk method for the turbulent heat fluxes and empirical formulae for the radiation heat fluxes. The rate of heat storage in the reservoir is estimated by using estimated by surface heating rate and the vertical water temperature data. The flux divergence of heat transport is estimated as a residual. The features of the surface heat balance are almost decided by the latent heat flux and the solar radiation flux. On average for 12-17 August 2014 in the Gangjeong- Goryung Reservoir, if one defines the insolation at the water surface as 100 %, 94 % is absorbed in the reservoir; thereafter the reservoir loses about 30~50% by sensible heat, latent heat and net long-wave radiation. The residue of 50~80 % raises the water temperature in the reservoir or transported away by the river flow during the daytime.

Preparation of Carbon-Coated $TiO_2$ at Different Heat Treatment Temperatures and Their Photoactivity

  • Chen, Ming-Liang;Bae, Jang-Soon;Oh, Won-Chun
    • Carbon letters
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    • v.7 no.4
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    • pp.259-265
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    • 2006
  • Carbon-coated $TiO_2$ was prepared by $CCl_4$ solvent mixing method with the different heat treated temperatures (HTTs). Since the carbon layers derived from pitch on the $TiO_2$ particles were porous, the carbon-coated $TiO_2$ sample series showed a good adsorptivity. The values of BET surface areas measured were shown independently on the HTTs. The surface states by SEM present to the characterization of porous texture on the carbon-coated $TiO_2$ sample and carbon distributions on the surfaces. From XRD data, PT700 and PT750 were shown the X-ray diffraction patterns of the anatase $TiO_2$, but PT800 and PT850 were kept anatase-type structure even after heating at $800^{\circ}C$, though small amount of the rutile-type structure appears. The results of EDX microanalyses were observed for each sample show the spectra corresponding to almost all samples similar to C, O and Ti elements with an increase of HTTs. Finally, the excellent photoactivity of carbon-coated $TiO_2$ (especially, PT700 and PT750) could be attributed to the homogeneous coated carbon on the external surface and the structural anatase phase.

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A Study on the ecological design elements of elementary school interior - Focused on the elementary schools of Osaka, Japan and Busan, Korea - (초등학교 실내공간 디자인의 환경친화적 특성에 관한 연구 - 부산시와 오사카시 초등학교 사례를 중심으로 -)

  • Yun Ji-Young;Song Ju-Eun
    • Korean Institute of Interior Design Journal
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    • v.14 no.3 s.50
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    • pp.46-54
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    • 2005
  • This study explored how the elementary schools provided proper interior environments to the students in terms of ecological aspects. 14 cases-7 in Busan and 7 in Osaka which were newly built or remodelled since 2000 were selected. These schools were analyzed based on the eco-school guideline suggested In the former study. The guideline categorizes into three parts: 1) energy efficiency related with lighting, ventilation, heating and insulation, 2) greening, 3) sustainability including recycling water system and use of environmentally friendly materials. The results showed that Korean schools require more systematic planning for natural lighting, ventilation, Insulation, greening and new water system while Japanese schools need use of environmentally friendly materials and consideration for natural lighting, insulation and interior greening. Especially, natural lighting and natural ventilation through roof window, atrium, wind tower and use of natural insulation and blind window system should be basically considered at the Initial planning. Also, this study reveals that ecological approach including greening and natural lighting with various architectural form should be applied in future elementary school design to make the school environment more agreeable and economical.

Indoor Environmental Condition by Existing Front Balcony in Apartment House during Winter (아파트의 전면발코니 개조여부에 따른 겨울철 실내환경 측정비교)

  • Choi, Yoon-Jung
    • Proceedings of the Korean Institute of Interior Design Conference
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    • 2005.05a
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    • pp.267-270
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    • 2005
  • The purpose of this study was to make clear the indoor environmental efficiency of front balcony 'in apartment houses during winter. The field measurements of indoor environmental elements were carried out at an ordinary house with an existing front balcony and a house renovated the front balcony into the living room. The measurements in two-subject houses were taken on simultaneously the 20$^{th}$ ${\sim}$ 21$^{th}$ of January 2003. As results, the averages indoor temperature in the ordinary house and the renovated house were same as 23.6${\circ}$C, and the averages globe temperature in two houses were same as 23.7${\circ}$C. But, estimated heating time of the renovated house was longer than that of the ordinary house. The daily ranges of indoor temperature and globe temperature in the renovated house were wider than the ordinary house. The daily ranges of indoor temperature and globe temperature in the renovated house was longer than that of the ordinary house. The uniformity ratio range of daylight in the ordinary house were calculated at 1/3.4${\sim}$1/6.2, but those of the renovated house were 1/6${\sim}$1/16.2. Therefore. it was found that indoor temperature, globe temperature and uniformity ratio of daylight in the ordinary house maintained more constant than the renovated house by green house effect and earning effect of front balcony.

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