• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.38-41
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• 2001

The combustion characteristics of the disilicides molybdenum system have been studied experimentally. The pertinent reaction parameters that control self-propagating high temperature synthesis reactions have been examined. These include reactant particle size, powder mixing and compaction, reaction stoichiometry, diluents. The influence of experimental variables on integrity, uniformity, structure, and related material properties will be discussed. Formation mechanism of $MoSi_2$ during SHS might be different and depending on experimental conditions.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.38-41
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• 2001

The combustion characteristics of the disilicides molybdenum system have been studied experimentally. The pertinent reaction parameters that control self-propagating high temperature synthesis reactions have been examined. These include reactant particle size, powder mixing and compaction, reaction stoichiometry, diluents. The inf1uence of experimental variables on integrity, uniformity, structure, and related material properties will be discussed. Formation mechanism of MoSi$_2$ during SHS might be different and depending on experimental conditions.

• Journal of Magnetics
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• 제14권2호
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• pp.53-61
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• 2009

Herein, different concepts for domain wall propagation based on currents and fields that could potentially be used in magnetic data storage devices based on domains and domain walls are reviewed. By direct imaging, we show that vortex and transverse walls can be displaced using currents due to the spin transfer torque effect. For the case of field-induced wall motion, particular attention is paid to the influence of localized fields and local heating on the depinning and propagation of domain walls. Using an Au nanowire adjacent to a permalloy structure with a domain wall, the depinning field of the wall, when current pulses are injected into the Au nanowire, was studied. The current pulse drastically modified the depinning field, which depended on the interplay between the externally applied field direction and polarity of the current, leading subsequently to an Oersted field and heating of the permalloy at the interface with the Au wire. Placing the domain wall at various distances from the Au wire and studying different wall propagation directions, the range of Joule heating and Oersted field was determined; both effects could be separated. Approaches beyond conventional field- and current-induced wall displacement are briefly discussed.

• KIEE International Transactions on Electrophysics and Applications
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• 제4C권4호
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• pp.137-141
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• 2004

In this paper, a thermopneumatic PMDS (polydimethlysiloxane) micropump with nozzle/diffuser elements is presented. The micropump is composed of nozzle/diffuser elements as dynamic valves, an actuator consisting of a circular PDMS diaphragm and a Cr/Au heater on a glass substrate. Four PDMS layers are used for fabrication of an actuator chamber, actuator diaphragm by a spin coating process, spacer layer, and nozzle/diffuser by the SU-8 molding process. The radius and thickness of the actuator diaphragm is 2 mm and 30 ${\mu}{\textrm}{m}$, respectively. The length and the conical angle of the nozzle/diffuser elements are 3.5 mm and 20$^{\circ}$, respectively. The actuator diaphragm is driven by the air cavity pressure variation caused by ohmic heating and natural cooling. The flow rate of the micropump in the frequency domain is measured for various duty cycles of the square wave input voltage. When the square wave input voltage of 5 V DC is applied to the heater, the maximum flow rate of the micropump is 44.6 ${mu}ell$/min at 100 Hz with a duty ratio of 80% under the zero pressure difference.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 춘계학술발표대회 논문집
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• pp.43-48
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• 2009

In this study, through case studies, solar energy systems were coordinated with architectural plan elements and the others in apartment complex, and the energy performance was evaluated quantitatively through computer simulation PVSYST and RETScreen. As a results, in plan process of the application of solar energy systems in apartment complex, solar energy system should be considered as not only energy reducing technical element but also part of architectural plan element. And it must be considered with architectural plan elements, composition methods, energy storage methods, technical elements from the early basic plan stage. Photovoltaic system was installed on the wall facing the south and rooftop. The energy ratio of electric load was shown to be 5.5%. The result showed 7.2% when adding it to shading device additionally, and 6.4% in case of putting extra translucent module on windows. Active solar collecting system was applied on roof with the angle of 45. Maximum number of solar collector was 10 in a row, and the total solar collecting area was $915.00m^2$. The energy ratio of domestic water heating load by active solar hot water system is shown to be 11.4%.

• 한국주거학회논문집
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• 제21권3호
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• pp.1-9
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• 2010

The purposes of this study were to determine the actual state of indoor environments of solitary elderly houses in the rural district during winter and to analyze the relationship between the influencing factors and indoor physical elements. Field surveys consisted of measurements of physical elements, observations of living factors, and resident's responses in interviews. Field surveys were carried out in 4 houses from $28^{th}$ of February to $2^{nd}$ of March 2008. The elements measured were air temperature, relative humidity, floor temperature, seating-place temperature, CO2 concentration, CO concentration, and illumination. The results showed that the average indoor temperature for houses was $13.5{\sim}22.5^{\circ}C$, relative humidity was 30.6~55.4%, floor temperature was $13.9{\sim}24.0^{\circ}C$, temperature when seated was $27.6{\sim}51.1^{\circ}C$, $CO_2$ concentration was 1434.6~3305.5 ppm, CO concentration was 2.8~8.4 ppm, and illumination was 31.0~96.7 lux. The residents' clothing values were 1.10~1.78 clo. The environment was evaluated as being in an unsuitable state, and it was revealed that the main reason was the lack of heating and ventilation.

• 한국환경보건학회지
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• 제16권2호
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• pp.31-39
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• 1990

An analytical method for particulate carbon and other elements by using elemental analyzer was investigated. Carbon, hydrogen, and nitrogen was determined as CO$_{2}$, H$_{2}$, and N$_{2}$, respectively. Organic was determined after scparation from elemental carbon(Cae) by volatilization and thermal decomposition in a heated helium flow. With organic materials examined in this reprot, more than 90% of carbon was detected as above 600$^{\circ}$C. But it is considered that a few percents of some compounds were charred above 550$^{\circ}$C. A small amount of Cae was oxidized in the inert atmosphere above 850$^{\circ}$C, but the reason was not explained clearly. Based on the thermal chracteristics of Cao it was found that the optimum temperature of heating in the helium flow of an elemental analyzer for Cao analysis is 630$^{\circ}$C. Carbon in a sample after removing Cao was assumed as Cae and the gramatom ratio of hydrogen to carbon in the sample was 0.4 and less. Rescovery of nitrogen derived from some ammonium salts and nitrates was 100% by two-step measurement with elemental analyzer. By the analytical method investigated in this report, carbon and other elements in suspended particulates(S.P) collected at an urban area in Seoul were measured. There was a good correlation between total nitrogen in SP measured by elemental analyzer and nitrogen estimated form ammonium ions and nitrate ions in SP. The nitrogen from these ions accounts for 80% of the total nitrogen. It is further suggested that the residue(20%) of the total nitrogen is attributed to the other nitrogeneous compounds.

• 한국태양에너지학회 논문집
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• 제30권6호
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• pp.89-94
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• 2010

A large portion of the energy cost of a building is cooling and heating to maintain a comfortable indoor environment. Air conditioning is now one of the important parts in the building design, as increase in energy consumption and pollutant emission in energy conversion process. In this study, elements that affects the energy consumption of model building are identified and the perfomance analysis of the alternative a Low Energy Cooling Systems considering characteristics of model building and energy saving performance is analyzed. In this study, elements that affect the energy consumption of office building are identified and energy saving performance of the alternative air conditioning system is analyzed. As a result, applied to earn and suggest basic data for energy saving measures. In this study, EnergyPlus simulation program was used to evaluate the energy load when alternative Low Energy Cooling Systems are applied to the model building. The reliability of simulation program is verified by comparing actual energy load from operation data of building management office and predicted energy load using simulation program. For Low Energy Cooling System application which considers the purpose and characteristics of the building, reasonable and energy-saving air conditioning method obtained by analyzing energy consumption elements for each expected air conditioning methods is used to deduct result of this study.

• 한국전자통신학회논문지
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• 제5권6호
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• pp.645-650
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• 2010

본 연구에서 울산 현대중공업 및 사천 유니슨에 설치사용 중인 공업용로의 연소문제 및 시스템을 분석하고 열효율 개선방안을 제시하여 연료절감 및 생산성 향상에 도움이 되고자 한다. 단조산업에 사용 중인 공업용로는 원소재의 가열 및 재료의 특성향상을 위한 설비로 운전조건 및 연소시스템에 따라 연료의 사용량 및 재료의 특성에 지대한 영향을 줄 수 있다. 따라서 현대중공업에 설치운전 중인 100톤 가열로 및 열처리로의 연소시스템의 특성을 분석하였다. 통상적으로 각 가열장치에 설치된 버너(Burner)는 용량에 맞는 공연비를 가지며 버너가 작동할 수 있는 Turndown ratio를 가지고 있다. 이는 각각의 공업용로 특성을 정하는 것으로서 가열성능 및 온도정밀도에 지대한 영향을 미친다. 용량이 큰 버너를 설치한 열처리로는 가열성능은 향상시킬 수 있어도 유지구간에서의 온도정밀도를 얻기 힘들다. 이에 버너의 성능을 최대한 발휘할 수 있도록 연소시스템을 개선하여 각 가열구간에 맞는 연소특성을 적용 분석한 현대중공업의 가열로 및 열처리로를 예시로 연료의 절감 및 온도정밀도를 향상시키도록 본 연구에서 방안을 제시하였다.

• 한국CDE학회논문집
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• 제18권1호
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• pp.58-70
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• 2013

This study for establishing specific standards of atrium design aims to discuss design of atrium to consider energy performance atrium in office buildings. In order to evaluate a type and a scale of atrium at the early design stage, modeling details of mass design were set as standards of conceptual design. In the experiment, Project Vasari was used to analyze modeling and energy consumption, based on the LOD 100-step suggested by AIA, because there is no guideline to specify a level of modeling details at each design process. From this analysis, the correlation among a simple-typed atrium and scale and energy load was considered. The result of this research is as follows: First, the single-sided atrium reduced energy the most, and it was followed by three-sided, two-sided, four-sided and continuous-typed ones. On the whole, they could decrease energy by up to about 15%. Also, the atrium with a wide facade facing in the south was more favorable to reduce energy. Second, planning the atrium within 10~30% of the whole building area was more energy efficient. Third, rather than the depth, adjusting the length in designing an atrium could reduce cooling and heating loads by 1.5% per 1m. As explained above, energy performance evaluation considering types and planning elements of atrium helps to assess alternatives in a reasonable way. In particular, considering the use of building needs to be preceded to select a type of atrium, although it is also important to consider its planning elements.