• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.87-87
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• 2010

We report a new patterning technique of inorganic materials by using thin-film transfer printing (TFTP) with atomic layer deposition. This method consists of the atomic layer deposition (ALD) of inorganic thin film and a nanotransfer printing (nTP) that is based on a water-mediated transfer process. In the TFTP method, the Al2O3 ALD growth occurs on FTS-coated PDMS stamp without specific chemical species, such as hydroxyl group. The CF3-terminated alkylsiloxane monolayer, which is coated on PDMS stamp, provides a weak adhesion between the deposited Al2O3 and stamp, and promotes the easy and complete release of Al2O3 film from the stamp. And also, the water layer serves as an adhesion layer to provide good conformal contact and form strong covalent bonding between the Al2O3 layer and Si substrate. Thus, the TFTP technique is potentially useful for making nanochannels of various inorganic materials.

• 한국재료학회지
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• 제29권11호
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• pp.670-676
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• 2019

We study substrate support structures and materials to improve uptime and shorten preventive maintenance cycles for chemical vapor deposition equipment. In order to improve the rolling of the substrate support, the bushing device adopts a ball transfer method in which a large ball and a small ball are mixed. When the main transfer ball of the bushing part of the substrate support contacts the substrate support, the small ball also rotates simultaneously with the rotation of the main ball, minimizing the resistance that can be generated during the vertical movement of the substrate support. As a result of the improvement, the glass substrate breakage rate is reduced by more than 90 ~ 95 %, and the equipment preventive maintenance and board support replacement cycles are extended four times or more, from once a month to more than four months, and the equipment uptime is at least 15 % improved. This study proposes an optimization method for substrate support structure and material improvement of chemical vapor deposition equipment.

• 대한기계학회논문집
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• 제18권11호
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• pp.3057-3065
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• 1994

An experimental study has been made for heat transfer and particle deposition during the Modified Chemical Vapor Deposition process which is currently utilized to manufacture high quality optical waveguides. The distributions of tube wall temperatures, rates and efficiencies of particle deposition were measured. Results indicate that the temperature distributions of the tube wall in the axial direction yield the quasi-steady form in which temperature distributions fit in one curve if the relative distance from the moving torch is used as an axial coordinate. Due to the repeated heatings from the traversing torch, the wall temperatures are shown to reach the minimum ahead of torch and it is shown that the two torch formulation suggested by Park and Choi is valid to predict this minimum temperature. Measured wall temperatures, particle deposition efficiencies and tapered entry length are compared with the previous modelling results and shown to be in agreement.

• Reproductive and Developmental Biology
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• 제28권3호
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• pp.141-145
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• 2004

Mucin coat is deposited on the embryos during passage through the oviduct in rabbit. When in vitro cultured blastocysts were transferred to the recipients, the lack of mucin coat might account in part for failure of pregnancy after transfer. The present study were carried out to investigate whether deposition of mucin coat were induced when in vitro cultured blastocysts were transferred to recipients. At 19 ～20 hours post-coitus one-cell embryos were collected by flushing oviducts. These embryos cultured for 72 hours were reached to blastocyst stage. And these blastocysts were transferred to the oviduct of asynchronized (one day later than the donors) and synchronized recipient. To confirm deposition of the mucin coat, blastocysts transferred to the oviduct were recovered at 24 and 48 hours after the transfer. Fifty eight percent of blastocysts recovered from uterus of asynchronous recipient at 24 hours after transfer and 92.9% of blastocysts recovered from uterus of synchronous recipient were 0～10 ㎛ of mucin coat thickness. And 11.8% of blastocysts of asynchronized recipients and 7.1% of blastocysts from asynchronized recipients were in 11～20 ㎛ of mucin coat thickness. When blastocysts were recovered from uterus at 48 hours after transfer, 87.0% of blastocysts from asynchronized recipients and 5.9% of blastocyst from synchronized recipients were in 0～10 ㎛ of mucin coat thickness. And 76.5% of blastocysts of synchronized recipients and 4.4% of blastocysts from asynchronized recipients were in 11～20 ㎛ of mucin coat thickness. From these results it is speculated that the low implantation rate of in vitro cultured rabbit blastocysts transferred to oviduct of recipient was caused by high degeneration of the embryo after transfer and inappropriate deposition of mucin coat.

• Journal of the Korean Physical Society
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• 제73권9호
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• pp.1279-1282
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• 2018

This paper reports the deposition of a metal line using a multilayer stack and laser-induced forward transfer (LIFT) using a low cost continuous wave blue laser with a wavelength of 450 nm. The donor structure was composed of a light-to-heat (LTH) layer, a release layer, and a transfer layer in series. Amorphous silicon as the LTH layer absorbs photon energy and converts it to heat. A release layer was melted so that a silver transfer layer would be transferred to the receiver substrate. The transferred silver layer showed reasonable physical and electrical characteristics. A low cost fine linewidth metal layer could be achieved using this modified LIFT technique and blue laser.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집B
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• pp.359-364
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• 2000

The fluid flow, heat transfer and the local mass fi-action of chemical species in the chemical vapor deposition(CVD) manufacturing process are numerically studied. The deposition of silicon from dilute silane is hydrogen carrier gas in a horizontal CVD reactor is investigated. The effect of inlet carrier gas velocity, mass fraction of silane, susceptor angle on the deposition thickness and uniformity was represented.

• 대한기계학회논문집
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• 제18권1호
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• pp.212-222
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• 1994

In the annular Modified Chemical Vapor Deposition process using two concentric tubes, the inner tube is heated to maintain high temperature gradients to have high thermophoretic force which can increase particle deposition efficiency. However, higher axial velocity in a narrow gap between inner and outer tubes can result in a longer tapered entry length. In the present paper, a new concept using an annular jet from the inner tube is presented and shown to significantly reduce the tapered entry length with maintaining high efficiency. Effects of a jet injection on heat transfer, fluid flow and particle deposition have been studied. Of particular interests are the effects of jet velocity, jet location and temperature on the deposition efficiency and tapered length . Torch heating effects from both the previous and present passes are included and the effect of surface radiation between inner and outer tubes is also considered.

• 대한기계학회논문집B
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• 제21권3호
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• pp.436-444
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• 1997

Three-dimensional conjugate heat transfer and particle deposition on a circular cylinder in the OVD process are numerically investigated. Flow and temperature fields are obtained by an iterative method, and thermophoretic particle deposition is simulated. Effects of the heat conduction in the cylinder, the rotation speed of the cylinder, and the traversing speed of torch on the deposition are studied. Effects of variable properties are also included. As the conductivity of the cylinder decreases, particle deposition rate and deposition efficiency greatly decrease due to the reduced temperature gradient. The rotation of the cylinder has no significant effect on the deposition due to the small diameter of the cylinder and low speed of rotation. Since the increase of the torch speed keeps the surface low temperature, the particle deposition increases with the traversing speed.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 1996년도 특별강연 및 춘계학술발표 개요집
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• pp.66-68
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• 1996

• Bulletin of the Korean Chemical Society
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• 제29권10호
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• pp.1983-1987
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• 2008

This study demonstrates the electrochemical conversion of the synthetic procedure of monolayer-protected clusters using a thin toluene layer over an edge plane pyrolytic graphite electrode. A thin toluene layer with a thickness of 0.31 mm was coated over the electrode and an immiscible liquid/liquid water/toluene interface was introduced. The transfer of the tetrachloroaurate ($AuCl_4^-$) ions into the toluene layer interposed between the aqueous solution and the electrode surface was electrochemically monitored. The $AuCl_4^-$ ions initially could not move through into the toluene layer, showing no reduction wave, but, in the presence of the phase transfer reagent, tetraoctylammonium bromide (TOABr), a cathodic wave at 0.23 V vs. Ag/AgCl was observed, indicating the reduction of the transferred $AuCl_4^-$ ions in the toluene layer. In the presence of dodecanethiol together with TOABr, a self-assembled monolayer was formed over the electro-deposited metallic gold surface. The E-SEM image of the surface indicates the formation of a highly porous metallic gold surface, rather than individual nanoparticles, over the EPG electrode.