• 대한기계학회논문집B
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• 제23권5호
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• pp.637-645
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• 1999

Horizontal two-phase flow pressure drop within rectangular channels with small gap heights have been examined experimentally. The gap heights range from 0.4mm to 4mm corresponding to aspect ratios(the channel height divided by the width) from 0.02 to 0.2. Water and air were used as the test fluids with the superficial velocity ranges being 0.03-2.39m/s and 0.05-18.7m/s, respectively. The experimental results In rectangular channels were compared with the Lockhart-Martinelli correlation, which are widely used for conventional round tube. The Lockhart-Martinelli correlation turned out to be Inappropriate to represent the present experimental data. In this respect, considering the aspect ratio and gap-height effects, an empirical correlation on two-phase flow pressure drop was proposed. The proposed correlation successfully covers the bubbly, plug, slug and annular flow regimes.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.370-370
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• 2012

Feature size of Cu interconnects keep shrinking into several tens of nanometer level. For this reason, the Cu interconnects face challenging issues such as increase of electro-migration, line-width dependent electrical resistivity increase, and gap-filling difficulty in high aspect ratio structures. As the thickness of the Cu film decreases below 30 nm, the electrical resistivity is not any more constant, but rather exponential. Research on alloying with other elements have been started to inhibit such escalation in the electrical resistivity. A faint trace of Al added in Cu film by sputtering was reported to contribute to suppression of the increase of the electrical resistivity. From an industrial point of view, we introduced cyclic metal organic chemical vapor deposition (MOCVD) in order to control Al concentration in the Cu film more easily by controlling the delivery time ratio of Cu and Al precursors. The amount of alloying element could be lowered at level of below 1 at%. Process of the alloy formation was applied into gap-filling to evaluate the performance of the gap-filling. Voidless gap-filling even into high aspect ratio trenches was achieved. In-depth analysis will be discussed in detail.

• 마이크로전자및패키징학회지
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• 제8권3호
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• pp.69-75
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• 2001

후막광식각 기술은 스크린 인쇄 등의 일반적 후막공정에 노광 및 현상등의 리소그라피 공정 을 접목시킨 새로운 기술이다. 그린시트를 적층한 후 감광성 Ag 페이스트를 도포하고, 패턴을 노광, 현상, 동시소성하여 스크린 인쇄법으로는 어려운 25 $\mu\textrm{m}$ 선폭과 25 $\mu\textrm{m}$ 선간공백을 구현하였다. 알루미나 기판을 사용하였을 경우에도 유사한 방법으로 20 $\mu\textrm{m}$에 가까운 선폭이 구현 가능하였으며, 노광량과 현상시간이 미세라인 형성에 있어서 가장 중요한 공정변수임을 확인하였다. 또한, 광식각 기술을 이용하여 정밀도가 높고 고주파 대역에서 전송특성이 우수한 microstrip 전송선로와 series gap 공진기를 제작하여, 이로부터 기판의 유전률 및 유전손실을 계산하였다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제55권5호
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• pp.239-244
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• 2006

To drive the high-image quality plasma displays of XGA and/or full-HD, we must effectively improve the driving waveform, which get the reset period for the stabilized control of wall charges, the address period to select discharge or non-discharge, and sustain period for luminance in 1 TV-frame, and also the display quality. To accomplish them, the development of the technology for the fast address discharge is required. In this paper, the correlation between the sustain-electrode gap and address discharge characteristics for the high-speed addressing was analyzed using the measurements of dynamic voltage margins. Results showed that the narrower the gap between the sustain electrodes, the narrower the with of the scan pulse became and a dynamic margin of data voltage of 29.2 V was obtained at scan pulse width of $1.0{\mu}s\;and\;V_{ramp}$ of 240 V for driving 4-inch test penal, which the gap between sustain electrodes was $65{\mu}m$.

• 대한토목학회논문집
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• 제35권5호
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• pp.1015-1024
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• 2015

본 연구에서는 유리섬유강화폴리머 판을 영구거푸집 및 인장 보강재로 활용한 현장타설 고강도콘크리트 합성보를 대상으로 판 하부의 잔골재 부착여부, 웨브의 천공유무 및 간격, 상부플랜지 폭을 변수로 하여 휨 파괴실험을 수행하였다. GFRP 판 웨브를 천공하지 않은 경우 잔골재 부착효과 여부를 위한 실험 결과, 잔골재를 부착한 경우 미부착의 경우 보다 약 43% 높은 극한하중 값을 보여주었으며, 웨브의 천공유무 및 간격효과는 잔골재를 부착하지 않은 경우 천공간격이 3배인 경우가 약 23% 정도 높은 극한하중 값을 보여주었으며, 잔골재를 부착한 경우 천공 간격이 5배인 경우가 약 11% 정도 높은 극한하중 값을 보여주었다. 상부플랜지 영향을 살펴보면, 폭 20mm 경우가 40mm에 비해 약 12% 정도 큰 극한하중 값을 보여주었다.

• 한국의류학회지
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• 제29권11호
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• pp.1399-1409
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• 2005

The purpose of this study was to analyze the shape of gathered skirts using a three-dimensional measurement system. And in this experiment, I try to accumulate three-dimensional data of wearing model and to figure out analyzing method made by shape of clothes. The experimental design consists of two factorial designs. I set up three different kinds of fabrics, ratio of gathers. Therefore nine samples were made. The instrument and tools for three-dimensional measurement was whole body 3D scanner. Analysis program used in experiment is RapidForm 2004 PP1 and Pattern Design 2000. Data analysis utilizes SPSS WIN 10.0 Package. T-test to effect an inspection of evidence, there was difference about measurement times. One-way ANOVA to analysis effect of gather made by gathering conditions. The following results were obtained; 1. As a result of inspecting an error several times using a three-dimension measurement system, convinced data was obtained. 2. At front, distribution of gap amount was larger than back. And as ratio of gathers increased, distribution of gap amount showed regularly. 3. After analyzing horizontal sectional figure of skirts, as a height of skirt changed from waist to the bottom of skirts, the results showed as follows. While section width, section thickness, node width, node depth increased, node count decreased. 4. With the horizontal section levels of gather skirt, the silhouette on middle hip section was similar with the silhouette of body line. And as ratio of gathers around hip section increased, nodes showed regularly. At the bottom of skirts showed different nodes by different gathering condition.

• Steel and Composite Structures
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• 제30권2호
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• pp.81-96
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• 2019

The behavior of a new Three-Tube Buckling-Restrained Brace (TTBRB) with circumference pre-stress (${\sigma}_{{\theta},pre}$) in core tube are investigated through a verified finite element model. The TTBRB is composed of one core tube and two restraining tubes. The core tube is in the middle to provide the axial stiffness, to carry the axial load and to dissipate the earthquake energy. The two restraining tubes are at inside and outside of the core tube, respectively, to restrain the global and local buckling of the core tube. Based on the yield criteria of fringe fiber, a design method for restraining tubes is proposed. The applicability of the proposed design equations are verified by TTBRBs with different radius-thickness ratios, with different gap widths between core tube and restraining tubs, and with different levels of ${\sigma}_{{\theta},pre}$. The outer and inner tubes will restrain the deformation of the core tube in radius direction, which causes circumference stress (${\sigma}_{\theta}$) in the core tube. Together with the ${\sigma}_{{\theta},pre}$ in the core tube that is applied through interference fit of the three tubes, the yield strength of the core tube in the axial direction is improved from 160 MPa to 235 MPa. Effects of gap width between the core tube and restraining tubes, and ${\sigma}_{{\theta},pre}$ on hysteretic behavior of TTBRBs are presented. Analysis results showed that the gap width and the ${\sigma}_{{\theta},pre}$ can significantly affect the hysteretic behavior of a TTBRB.

• Journal of Advanced Marine Engineering and Technology
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• 제40권3호
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• pp.205-209
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• 2016

본 연구는 상류측에 작은 삼각주를 가진 정방형주의 유동장 특성을 정방형주 한 변의 길이에 대한 삼각주의 폭비 및 정방형주 전면에서부터 삼각주 후면까지의 간격을 변수로 하여 PIV를 이용한 가시화실험으로 파악한 것이다. 그 결과를 요약하면 다음과 같다. 정방형주 후류측 스트로할 수는 항력감소율과 같은 특성을 나타내었는데, 간격비가 증가할수록 증가한 후 감소하는 특성을 보였다. 삼각주를 설치한 경우 정방형주 상류측과 하류측에 정체영역이 나타났으며, 그 정체영역의 크기는 정방형주의 상류측은 삼각주의 폭비가 클수록 증가하는데 비해, 하류측은 오히려 감소했다.

• 대한기계학회논문집A
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• 제32권10호
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• pp.831-835
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• 2008

We present a continuous electrical cell lysis chip, using a DC bias voltage to generate the focused high electric field for cell lysis as well as the electroosmotic flow for cell transport. The previous cell lysis chips apply an AC voltage between micro-gap electrodes for cell lysis and use pumps or valves for cell transport. The present DC chip generates high electrical field by reducing the width of the channel between a DC electrode pair, while the previous AC chips reducing the gap between an AC electrode pair. The present chip performs continuous cell pumping without using additional flow source, while the previous chips need additional pumps or valves for the discontinuous cell loading and unloading in the lysis chambers. The experimental study features an orifice whose width and length is 20 times narrower and 175 times shorter than the width and length of a microchannel. With an operational voltage of 50 V, the present chip generates high electric field strength of 1.2 kV/cm at the orifice to disrupt cells with 100% lysis rate of Red Blood Cells and low electric field strength of 60 V/cm at the microchannel to generate an electroosmotic flow of $30{\mu}m/s{\pm}9{\mu}m/s$. In conclusion, the present chip is capable of continuous self-pumping cell lysis at a low voltage; thus, it is suitable for a sample pretreatment component of a micro total analysis system or lab-on-a-chip.

• 반도체디스플레이기술학회지
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• 제22권3호
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• pp.14-20
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• 2023

The electrostatic chuck is a technology that uses electroadhesion to attach objects and is widely used in semiconductor and display processes. This research conducted Maxwell by varying parameters to examine the distribution and variations of chucking force in a bipolar-type ESC. The parameters that were changed include the material properties of the dielectric layer and attachment substrate, applied voltage to the electrode, and the gap and width between the electrodes. The analysis results showed that as the relative permittivity of the dielectric layer and substrate increased, the chucking force also increased, with the relative permittivity of the substrate having a greater impact on the chucking force. And increasing the applied voltage led to an increase in both the chucking force and its rate of change. Lastly, as the gap between the electrodes increased, the chucking force rapidly decreased until a certain distance, after which the decrease became less significant. On the contrary, increasing the electrode width resulted in a rapid increase in the chucking force until a certain width, beyond which the increase became less pronounced, eventually converging to a chucking force of 1700 Pa. This paper is expected to have high potential for the development and research of ESC for OLED deposition.