• Korean Journal of Materials Research
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• v.5 no.6
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• pp.627-632
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• 1995

W-Cu composites utilize the high electrical conductivity of copper and arc erosion resistance of tungsten to provide properties better suited to electrical contact applications than either tungsten or copper alone. W-Cu composite materials were milled in an attritor with an impeller speed of 300rpm for various milling times. The milled powders were compacted at 300MPa into cylinders, 16m in diameter, and approximately 4m high. Sintering was performed in dry H$_2$at temperature ranging from 1200$^{\circ}C$ to 1400$^{\circ}C$. Samples were sectioned and were polished for scanning electron microscopy (SEM) of microstructures. Homogeneous W-Cu composites were formed after 10 hours mechanical alloying and could be attained 99% density at 1330$^{\circ}C$. As mechanical alloying time increased, Fe-concentration was increased linearly. Intermetallic compound formation interupted the growth of W particles Increased hardness.

• KSBB Journal
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• v.15 no.1
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• pp.80-83
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• 2000

Polyacetylenes were extracted from Korean ginseng using supercritical $CO_2$ Yield of extraction of panaxydol and panaxynol was increased as the pressure of supercritical $CO_2$ increased at the range from 200 to 300 bar. The optimal yields of panaxydol and panaxynol was achieved at 65 and $55^{\circ}C$, respectively. Methanol was applied as a modifier. The highest yield of panaxydol and panaxynol were 0.230 and 0.054 mg/g-dry weight at modifier concentration of 10%(w/w), 300 bar, and $65^{\circ}C$. When these results were compared to that of methanol-extraction, the recoveries of panaxydol and panaxynol by supercritical $CO_2$ extraction in SFE were 37.8 and 55.1%, respectively.

• Proceedings of the Korea Contents Association Conference
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• 2005.05a
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• pp.289-294
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• 2005

The international lighting market's growth about technologies and Methodologies to develop the products. but, domestic lighting fixtures are doing to price competition. Wish to accomplish process establishment for the effective Method to develop about the lighting technology and the new product design, through the development of PLS lighting technology and designs of 300W class lighting fixtures.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2047-2050
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• 1999

This paper presents some of the results of current research on 300 kN Suspension Insulator Design. In this paper, authors first used 2-dimensional field calculation to solve the electric field distribution of an insulator unit and insulator strings, and then 3-dimensional field calculation in order to overcome the shortcomings of 2-dimensional field calculation in which an axis-symmetrical coordinate has been used. And, it was found that the environmental configuration of 300 kN Suspension Insulator String gives great roles to the field distribution of the insulators.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2011.05a
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• pp.155-155
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• 2011

Dual coil을 사용하는 상용 AMAT DPS II 300 mm Centura 장비의 antenna의 전류비를 조절하여 $SiO_2$의 식각 균일도를 평가하였다. Inner turn과 outer turn의 흐르는 전류비를 분배 capacitor로 조절하여 16.9 %의 이온 전류 밀도 분포를 확인하였고, 투입 전력에 따라 200 W에서 12 %, 800 W에서 9 %로 점차 감소하는 경향을 확인하였다. 이때 300 mm wafer의 반지름 방향으로의 식각 균일도는 3 %로 측정되었고, FRC (flow ratio control)는 0.5에서 가장 균일한 결과를 얻었다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.5
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• pp.496-501
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• 2009

The thruster head unit of a 300 W cylindrical Hall thruster was developed for the propulsion system of small satellites. The magnetic topology in the thruster channel is a key parameter to achieve high performances. Two types of magnetic circuit structures were designed and manufactured to compare the thrust levels and efficiencies. Also the endurance test was conducted to measure the stable operation duration of the thruster head and to find degree of erosion after extended operation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.12
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• pp.3600-3607
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• 2009

This paper describes the development of a power sensor for wireless signal over the ultra wideband range of 300~3800MHz with the detecting range of 150mW~150W. The proposed power sensor fundamentally has the function of not only detecting wireless power, but recognizing frequency and measuring VSWR. The development of the power sensor is completed through the design of dual directional coupler, design of power detector block which produces DC data using the corresponding RF input power level, and establishment of collecting the exact calibration data. The dual directional coupler has the operating frequency of 300~3800MHz with the 0.085dB of insertion loss, and directivity of 30dB at least at 3800MHz. The developed power sensor has the capability of power sensing with less than 0.25dB of resolution as well as measuring VSWR of 1.17~1.96 under the practical operating situation of very high power up to 150W at 300~3800MHz.

• Journal of the Microelectronics and Packaging Society
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• v.25 no.4
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• pp.67-74
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• 2018

Thermoelectric thin film modules were fabricated by electroplating p-type $Sb_2Te_3$and n-type $Bi_2Te_3$ thin film legs with the same thickness of $20{\mu}m$ and different diameters of $100{\mu}m$, $300{\mu}m$, and $500{\mu}m$, respectively. The output voltage and output power of thin film modules were measured and compared as a function of the leg diameter. The modules processed with thin film legs of $100{\mu}m$, $300{\mu}m$, and $500{\mu}m$-diameter exhibited open circuit voltages of 365 mV at ${\Delta}T=36.7K$, 142 mV at ${\Delta}T=37.5K$, and 53 mV at ${\Delta}T=36.1K$, respectively. Maximum output powers of $845{\mu}W$ at ${\Delta}T=36.7K$, $631{\mu}W$ at ${\Delta}T=37.5K$, and $276{\mu}W$ at ${\Delta}T=36.1K$ were obtained for the modules fabricated with the thin film legs of $100{\mu}m$, $300{\mu}m$, and $500{\mu}m$-diameter, respectively.

• Journal of the Microelectronics and Packaging Society
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• v.12 no.4 s.37
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• pp.345-349
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• 2005

Low resistive ($300{\mu}{\Omega}$-cm) W-C-N films have been deposited on tetraethylorthosilicate (TEOS) interlayer dielectric by atomic layer deposition (ALD) with $WF_6-N_2-CH_4$ gas. The exposure cycles of $N_2$ and $CH_4$ are synchronized with pulse plasma. The W-C-N films on TEOS layer follow the ALD mechanism and keep constant deposition rate of 0.2 nm/cycle from 10 to 100 cycles. As a diffusion barrier for Cu interconnection the W-C-N films maintain amorphous phase and Cu inter-diffusion is not occurred even at $800^{\circ}C$ for 30 min.

• Journal of Plant Biology
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• v.36 no.3
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• pp.297-300
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• 1993

Six flavonoid compounds from the ethyl acetate fraction of Machilus thunbergii leaves were identified by HPLC. Separation by reversed phase chromatography on u-Bondapak C18 column was achieved by isocratic elution. The contents of the major flavonoids, guaijaverin and quercitrin were about 0.48% (w/w) and 0.98% (w/w) for the methanol extract, respectively.