• 한국추진공학회지
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• 제18권6호
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• pp.88-95
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• 2014

액체로켓 엔진 재생냉각챔버의 무게 감량을 위하여 내피에 스피닝 공정을 적용하였다. 스피닝 도중 실린더부와 노즐목부의 블랭크에 파손이 발생하였다. 이 문제를 극복하기 위해 맨드럴 및 블랭크 형상을 수정하였으며 이러한 수정을 통해 스피닝을 사용하여 내피를 제작할 수 있었다. 제작된 노즐목부 스피닝 시제품은 균열이나 네킹없이 성공적으로 벌징이 되어 연소기 제작에 적용할 수 있는 충분한 성형성을 확보한 것을 확인하였다.

• 동력기계공학회지
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• 제21권3호
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• pp.12-18
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• 2017

Diesel and gasoline engines will be used as main power system of automobiles. Recently, engine downsizing is widely applied to both gasoline and diesel engines in order to improve fuel economy and exhaust emissions. Engine downsizing means small engine combustion chamber with higher combustion pressure. Therefore, spray and combustion process should be investigated under these high pressure and temperature conditions. In this study, constant volume combustion chamber which enables easy optical access from six directions was developed. Combustion chamber was designed to resist maximum pressure of 15 MPa and maximum temperature of 2,000 K. Combustible pre-mixed mixture was introduced into combustion chamber and ignited by spark plugs. High pressure and temperature were implemented by combustion of pre-mixed mixture. Three initial conditions of different pressure and density were tested. High repeatability of combustion process was implemented which was proven by low standard deviation of combustion pressure.

• 한국분무공학회지
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• 제8권4호
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• pp.39-45
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• 2003

The Objective of this study is to investigate the effect of internal swiller angle and swirl chamber aspect ratio of nozzle on spray characteristics for application of spray system in micro fabrication process. The macro-spray characterictics such as the spray angle and breakup process were obtained by photographs illustrating atomization. The micro-spray characteristics such as droplet size and axial velocity were measured by using PDA with swirler angle and swirl chamber aspect ratio. The swiller angles were $13.5^{\circ},\;27^{\circ},\;and\;40.5^{\circ}$. The swirl chamber aspect ratios were 1.2, 1.6, and 2.0. It was found that the smaller swirl chamber aspect ratio was, the larger axial velocity and drop size were.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.767-768
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• 2006

In this study, copper vapor chambers with built-in cooling fins, which eliminated the soldered or brazed joints in the conventional vapor chamber, were fabricated using the metal injection molding process. The results show that with optimized molding parameters, fins with an aspect ratio up to 18 could be produced. After sintering, the densities of the fin and chamber reached 96%. With only 32 cooling fins and a small fan installed, the thermal resistance of the heat sink was $1.156^{\circ}C/W$, and the power dissipation was 40W when the junction temperature was $70^{\circ}C$. When copper powder was sintered onto the chamber to make a vapor chamber, the thermal resistance decreased to $1.046^{\circ}C/W$.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.1026-1031
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• 2003

A vibration isolation system fur a large reverberation chamber (1,228㎥, 1,000ton) has been installed. The reverberation chamber generates loud noise and induces high level of vibration to perform spacecraft acoustic environmental tests. The isolation system prevents vibration transfer from the chamber to enclosure buildings. This paper describes logical design process and commissioning experiments of the system. Design criteria have been induced from rigid body model of the chamber. Finite element model has been employed to select the characteristics of rubber pads. A total of 21 rubber pads have been installed between the chamber and supporting pedestals. A sand bag of 800kg was dropped on the chamber floor to measure the natural frequency of the isolation system. Absolute transmissibility has been measured while generating 145㏈ in the chamber. The natural frequency of the chamber is 10.5㎐, which is 80% of estimated value. Overall transmissibility at working frequency range (25㎐-10,000㎐) is less than -6㏈.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.195-195
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• 2015

반도체 제조 시 ohmic contact을 형성하고, barrier metal layer형성을 위해 NH3 기체를 사용하는 rapid thermal nitridation (RTN)은 반도체 공정에 있어 매우 중요한 핵심 기술이다. 그러나 공정 진행 시 발생하는 공정 부산물에 의한 chamber오염으로 인해 매우 정확히 입사 되어야 할 thermal energy의 controllability가 저하되고 있어, 미세 공정능력 구현의 한계에 부닥치고 있다. 본 연구에서는 quartz plate liner를 적용하여 RTN 공정에서 발생하는 공정 부산물인 ammonium chloride (NH4Cl)의 chamber 표면 증착을 최소화하였고, 공정 진행 온도의 controllability를 확보하였다.

• 전자공학회논문지B
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• 제31B권1호
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• pp.34-40
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• 1994

The design and implementation of a fuzzy self-organizing controller for an environmental temperature chamber is discussed. The chamber is a non-linear, time-variant system with delay-time and dead-time. And the parameter tuning is required in PI control when the performance degraded. However the proposed fuzzy-SOC monitors the performance of the process. modifies the data base, and performs the delay-time compensation based on the idealized process model. A series of experiments was performed for the conventional PI and the fuzzy-SOC. These experimental results show the usefulness of the fuzzy-SOC.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.407-410
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• 2003

We will introduce our new concept deposition system for SMOLED manufacturing in this conference. This system is designed to deposit organic and metal material to downward to overcome the limit of substrate size and process tact time hurdle for OLED mass production, and is organized with organic deposition chamber, substrate pre-cleaning chamber, metal deposition chamber and encapsulation system. These entire process chambers are integrated with linear type substrate transfer system. We also compare our new SMOLED manufacturing system with conventional vacuum deposition systems, and show basic organic thin film property data, organic material deposition property data, and basic device property.

• Membrane and Water Treatment
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• 제4권1호
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• pp.1-9
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• 2013

The process of electromembrane transformation of L-lysine monohydrochlorides into their zwitterionic form in four- and two-chamber electrodialysis apparatus was investigated. The process of transformation at various concentrations of lysine monohydrochloride (0.1-0.6 mol.L-1) was studied and it was established that at the optimum density of current optimal concentrations of lysine hydrochloride during electrodyalisis was in the range of 0.2-0.4 mol.L-1. It was determined that the process of total transformation was accomplished when pH of the lysine solution achieved 10. Changes of concentrations of $Cl^-$ ions and lysine diffused into the neighboring chamber were determined depending on the time. The method developed by us allows adjusting the removal coefficient of $Cl^-$ ions during transformation to a maximal value, the losses of lysine diffused into the next chamber after its return to the technological cycle being less than 1.0 %. The specific energy consumption during the process of transformation in two- and four-chamber electrodialyzers was 0.19 and 0.205 A.h.kg-1 and the current efficiency was 75.9 and 73.1 %, correspondingly. Study of the process of electromembrane transformation allowed obtaining zwitterionic form of L-lysine from L-lysine monohydrochloride with minimal reagent and energy consumption.

• 동굴
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• 제78호
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• pp.29-31
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• 2007

This paper is devoted to a study of the characterization of the plasma state. For the purpose of monitoring plasma condition, we experiment on reactive ion etching (RIE) process. Without actual etch process, generated oxygen plasma, measurement of plasma emission intensity. Changing plasma process parameters, oxygen flow, RF power and chamber pressure have controlled. Using the optical emission spectroscopy (OES), we conform to the unique oxygen wavelength (777nm), the most powerful intensity region of the designated range. Increase of RF power and chamber pressure, emission intensity is increased. oxygen flow is not affect to emission intensity.