• The Korean Journal of Ceramics
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• v.1 no.3
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• pp.152-154
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• 1995

A non-hydrolytic sol-gel process was developed to fabricate low-hydroxyl hard gels. The reaction of tert-butyl alcohol with silicon halides provided transparent low-hydroxyl hard gels. Some properties such as transparency, density, and refractive index was successfully doped into the hard gel matrices. The absorption spectrum of an erbium-doped methylsilsesquioxane was investigated to decide the pumping wavelength of an argon laser. The luminescence of the erbium-doped gel at 664 nm seems to be due to $4^F{9/2}\to 4^I_{15/2}$ transition.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.7 s.94
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• pp.1751-1760
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• 1993

The squeeze casting process is considered as an attractive way to form the primary product of near net shape metal matrix composites for wide use in automobile industry. To understand for infiltration limit in squeeze casting processes, the SAFFIL short fiber preform of volume fraction $10%{\sim}23%$ were fabricated by vaccum pumping and speed control press, and the optimal condition for fiber preform fabrication had been experimentally obtained. The composite materials were fabricated by forced infiltration of molten metals such as Al6061, Al7075, pure Al, AC8A, and Al2024. The infiltration distance and deformation of fiber preform are observed, and tensile strength were measured from at the room temperature.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.117-120
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• 2005

The SONOS devices have been fabricated by the conventional $0.35{\mu}m$ complementary metal-oxide-semiconductor (CMOS) process with NOR array. Two-bit operation using conventional process achieve the high density memory compare with other two-bit memory. Lateral diffusion phenomenon in the two-bit operation cause soft error in the memory. In this study, the programming conditions arc investigated in order to reduce lateral diffusion for two-bit operation of CSL-NOR type SONOS flash cell.

• Laser Solutions
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• v.5 no.3
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• pp.15-20
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• 2002

The principal obstacle to selection of a laser processing method in production is its relatively high equipment cost and the natural unwillingness of production supervision to try something new until it is thoroughly proven. The major objective of this work is focused on the combined features of gas tungsten arc and a low-power cold laser beam. In this work, the laser beam from a 7 watts carbon monoxide laser was combined with electrical discharges from a short-pulsed capacitive discharge GTA welding power supply. When the low power CO laser beam passes through a special composition shielding gas, the CO molecules in the gas absorbs the radiation, and ionizes through a process blown as non-equilibrium, vibration-vibration pumping. The resulting laser-induced plasma(LIP) was positioned between various configurations of electrodes. The high-voltage impulse applied to the electrodes forced rapid electrical breakdown between the electrodes. Electrical discharges between tungsten electrodes and aluminum sheet specimens followed the ionized path provided by LIP. The result was well-focused melted spots.

• Proceedings of the Membrane Society of Korea Conference
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• 1995.10a
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• pp.5-9
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• 1995

In the dry-jet-wet-spinning process of a hollow fiber membrane, the polymer solution is pumped into a coaxial tube, jet spinneret. The threadline emerging from the spinneret is stabilized by an internal coagulating medium(liquid or gas) as it emerges from the jet orifice. The nascent hollow thread is further stabilized in a quench bath as shown in Fig. 1. In this scheme, three mechanism of formatiota(temperature gradient, solvent evaporation, and solvent-nonsotvent exchange) can be combined. The changes which promote stabilization often play a dominant role in determining the ultimate fiber wall structure as well. Hence, in pratice, hollow fiber stabilization and development of membrane structure are commonly inseparable. However, fiber dimension(the inside diameter and wall thickness of the hollow fiber) is mainly a rheological problem and is determined by dope pumping rate, spinneret diatance from the coagulation bath, inner coagulant flow rate, and fiber draw-rate. Besides rheological phenomena play a prominent part in the final properties of the hollow fiber.

• Coupled systems mechanics
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• v.4 no.2
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• pp.157-172
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• 2015

Control of potable water treatment plant (PWTP) is nowadays based on experience. The aim of this article is to show that model based control of treatment process is more efficient than process operation based on experience. Stimela environment is used for modeling of processes of potable water treatment. Application of the model was conducted on PWTP "Crkvice" in Zenica (BiH). This plant has used conventional rapid sand filters. By effective application of the model it is determined the optimal filter run time for different input turbidity of raw water. This results in the possibility of reducing the consumption of backwashing water, lower costs for its pumping and reducing the amount of coagulants. In the existing practice, based on experience, these benefits are not used.

• Journal of the Semiconductor & Display Technology
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• v.16 no.2
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• pp.75-78
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• 2017

We reports improved monitoring performance of Self plasma-optical emission spectroscopy (SP-OES) by augmenting a by-pass tube to a conventional straight (or single) tube type self plasma reactor. SP-OES has been used as a tool for the monitoring of plasma chemistry indirectly in plasma process system. The benefits of SP-OES are low cost and easy installation, but some semiconductor industries who adopted commercialized SP-OES product experiencing less sensitivity and slow sensor response. OH out-gas chemistry monitoring was performed to have a direct comparison of a conventional single type tube and a by-pass type tube, and fluid dynamic simulation on the improved hardware design was also followed. It is observed faster pumping out of OH from the chamber in the by-pass type SP-OES.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.7
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• pp.176-184
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• 1996

To overcome the drawbacks of conventional LDMOSFETs, we propose RESURF EDMOSFETs which can be adapted in varous circuit applications, be driven without charge pumping circuity and thowe threshold voltage can be adjusted. The devices have the diffused drift region formed by a high tmperature process before the gate oxidaton. After the polysilicon gate electrode formation, a fraction of the drift region around the gate edge is opened for supplemental self-aligned ion implantation to obtain self-aligned drift region. This leads to a shorter gate length and desirable drift region junction contour under the gate edge for minimum specific-on-resistance. In additon, a and maximize the breakdown voltage. Also, by biasing the metal field plate, we can reduce the specific-on-resistance further. The devices are optimized by using the TSUPREM-4 process simulator and the MEDICI device simulator. The optimized devices have the breakdwon voltage and the specific-on-resistance of 101.5V and 1.14m${\Omega}{\cdot}cm^{2}$, respectively for n-channel RESURF EDMOSFET, and 98V and 2.75m.ohm..cm$^{2}$ respectively for p-channel RESURF EDMOSFET. To check the validity of the simulations, we fabricated n-channel EDMOSFETs and confirmed the measured breakdown voltage of 97V and the specific-on-resistance of 1.28m${\Omega}{\cdot}cm^{2}$. These results are superior to those of any other reported power devices for smart power IC applications.

• Nuclear Engineering and Technology
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• v.49 no.8
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• pp.1727-1732
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• 2017

Pyroprocessing is an alternative method of reprocessing spent fuel, usually involving the dissolving spent fuel in a molten salt media. The National Nuclear Laboratory designed, built, and commissioned a molten salt dynamics rig to investigate the transfer characteristics of molten lithium chloride-potassium chloride eutectic salt. The efficacy and flow characteristics of a high-temperature centrifugal pump and argon gas lift were obtained for pumping the molten salt at temperatures up to $500^{\circ}C$. The rig design proved suitable on an industrial scale and transfer methods appropriate for use in future molten salt systems. Corrosion within the rig was managed, and melting techniques were optimized to reduce stresses on the rig. The results obtained improve the understanding of molten salt transport dynamics, materials, and engineering design issues and support the industrialization of molten salts pyroprocessing.

• Journal of Information Display
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• v.2 no.4
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• pp.34-38
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• 2001

We suggested new PDP packaging technology using the direct joint method, which does not need an exhausting hole and tube. The advantages of this method are simple process, short process time and time panel package. To packaging, we drew the seal line of glass frit by dispenser followed by forming the lump, which provide pumping-out path during the packaging process. And, we have performed a pretreatment of glass frit to reduce the out-gases. After which, both front and rear glass plates were aligned and loaded into vacuum packaging chamber. The 4-inch monochrome AC-PDP was successfully packaged and fully emitted with brightness of 1000 $cd/m^2$. Also, glass frit properties for pretreatment condition was investigated by AES and SEM analyses.