• Korean Journal of Materials Research
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• v.12 no.1
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• pp.16-20
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• 2002

In this study, the 95W heavy alloys of 3/7, 5/5 and 7/3 of Ni/Fe ratio were sintered at the temperature range between 1420 and $1480^{\circ}C$ for 1h and their microstructures were discussed for an effect of the ${\mu}$-phase $(Fe_7W_6)$ on the microstructure. The ${\mu}$-phase was observed in the only 95W-1.5Ni-3.5Fe alloy of 3/7 and it is thought to be formed and grown from the surface of the W particle. The W particle was surrounded with the ${\mu}$-phase and there were only the W particles and this phase without Ni-Fe-W matrix at the most part. The ${\mu}$-phase changed the interphase structure in the alloy and the grain growth of the W was suppressed because of interrupting the solution-reprecipitation of the W. The W content in the matrix was considered to be lowered due to the interruption of the solution-reprecipitation and the formation of the ${\mu}$-phase in the .

• Journal of Powder Materials
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• v.6 no.1
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• pp.36-41
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• 1999

The present work has attempted to investigate the dependence of Cu infiltration kinetics on in-situ structure modification of W powder skeleton in W-Cu system. In-situ structure modification of W skeleton by addition of 0.3wt%Ni-P eutectic alloy was designed to proceed during heat-up of the W compact for Cu infiltration process. It was found that the Ni-P added W skeleton underwent remarkable stucture change only during heating-up. its structure was composed of large necks of W particles above 0.5 in the ratio of neck to particle size and smooth pore channels. The infiltration experiment showed that the infiltration kinetics for the W-Ni-P followed well the linear relationship of h vs. $t^{1/2}$ the rate constant K of which was in good agreement with the theoretical value. On the other hand, in case of the pure W skeleton a lower K value by 20% than the theoretical one was obatined. Such discrepancy is discussed in terms of skeleton structure induced infiltration mechanics.

• Fire Science and Engineering
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• v.26 no.2
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• pp.105-111
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• 2012

In this research, aluminum composite panels of the general materials and fire retardant materials as building claddings make researches about fire performance comparison analysis. Test methods of the small and medium cone calorimeter experiments and SBI (Single Burning Item) experiments was applied to the determination. As a result, in the experiments peak heat release rate cone calorimeter the general aluminum composite panel $1,293kW/m^2$ ($75kW/m^2$), flame-retardant aluminum composite panel $70kW/m^2$ ($75kW/m^2$) was measured. In the SBI experiments fire growth rate the general fire aluminum composite panel is approximately 743 W/s and the flame-retardant aluminum composite panel is approximately 97 W/s of the value were measured. Thus, a standards enactment are urgently required in this case it is used as building claddings of the aluminum composite panel by fire risk assessment.

• The Plant Pathology Journal
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• v.16 no.4
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• pp.211-215
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• 2000

Symptoms on 4 varieties of watermelons inoculated with watermelon mosaic potyvirus II isolated from watermelon (WMV-W) were severe mosaic and leaf malformation while those inoculated with cucumber green mottle mosaic tobamovirus from watermelon (CGMMV-W) were mild mosaic and chlorotic spots. Inoculation of the mixture of WMV-W and CGMMV-W produced extremely severe mosaic along with necrotic spots and general necrosis. Doubly infected plants were also stunted. Cells infected with WMV-W or CGMMV-W alone exhibited the intrinsically ultra-structural properties of each virus infection. WMV-W induced potyvirus-characteristic cylindrical inclusions in the cytosol. Virus particles were orderly aligned along the tonoplasts. CGMMV-W induced tobamovirus-characteristic stacked crystalline arrays of virus particles in the cytosol. Cells infected doubly with WMV-W and CGMMV-W contained striking cytopathic effects that were not present in single infection of each virus. The unique ring structure, nonagon, was that a single potyvirus particle was surrounded by 9 CGMMV-W tobamovirus particles.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.5
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• pp.426-429
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• 2017

For the W-band remote sensing radiometer, direct detection type radiometer receiver is designed. The receiver should be low noise and high gain of 60 dB unlike communication and radar receiver. The W-band radiometer consist of 4-stage low noise, high gain amplifier, band pass filter and square law detector. The developed direct detection receiver show 4 GHz bandwidth, 56 dB gain, and 4,500 mV/mW voltage sensitivity at integrator output port for -20 dBm input power at 94 GHz.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.12
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• pp.949-954
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• 2012

The K-PCS and W-CDMA dual band dielectric duplexer and bandpass filters have been designed and fabricated. The dual band duplexer consists of the separate monoblock K-PCS and W-CDMA duplexers using common antenna port. The coupling capacitance and I/O impedance matching have been designed to minimize the cross interference between the bands. Isolations of crosspoint between Tx and Rx in K-PCS and W-CDMA dualband were about 47 dB and 100 dB, respectively. On the other hand, isolations of Tx and Rx in K-PCS and W-CDMA were about 66 dB and 65 dB, respectively. The difference between 47 dB and 100 dB originated from the different center frequencies in Tx and Rx of K-PCS and W-CDMA bands. The coupling capacitance of the bandwidth, I/O capacitance of I/O matching and impedance matching, and various capacitances were important role to fabricate the dielectric duplexer and bandpass filters.

• Korean Journal of Materials Research
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• v.13 no.1
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• pp.6-10
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• 2003

Electroplated Ni and Ni-W micro-molds using LIGA-like process for replication of micro-components such as microfluidic parts and micro optical parts have been investigated. In general, it is hard to produce micro-parts using conventional mechanical processes. Micro-mold formed by LIGA-like process could fabricate micro-parts with high aspect ratio. In this paper, fabrication and properties of electroplated Ni molds with varying applied current types as well as those of Ni-W molds were investigated. Ni molds fabricated under pulse-reverse current showed the highest hardness value of about 160 Hv. Ni-W molds showed the hardness of about 500 Hv which was much harder than that of Ni electroplated molds. The above results suggested that high quality micro-molds could be fabricated by using Ni electroplating of pulse-reverse type for core molds and sequential Ni-W alloys coating.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.11c
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• pp.1625-1628
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• 2003

컴포넌트 기반 시스템의 개발 생산성과 유지 보수성을 향상시키기 위해 기존에 생성된 소프트웨어 컴포넌트를 재사용할 수 있는 컴포넌트 기반 시스템 개발 방법론을 제시하고 종합적이고 체계적인 형태로 재사용 프로세스를 구성하고 각 단계별로 필요한 작업과 핵심 산출물을 살펴보도록 한다.

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.230.2-230.2
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• 2008

• Food Science and Preservation
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• v.14 no.4
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• pp.394-399
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• 2007

In this study, the characteristic qualities of whole soymilk were examined based on differing hydrolysis condition. The results showed that as the concentration of enzyme preparation(KMF-G) increase, $^{\circ}Brix$, calcium-binding capacity, and the content of free amino acid components also increased. Additionally SDS-PAGE analysis revealed a similar pattern of in the molecular weight of proteins at enzyme preparation concentration 0.20 and 0.35%(w/w). The quality of whole soymilk hydrolysate was shown to be best at a enzyme preparation(KMF-G) concentration of 0.20%(w/w) and hydrolysis time of 60 min. When sterilized at 115, 130 and $145\;^{\circ}C$ for 15 sec each the change in whole soymilk quality was not substantial. Based on the above results, a 0.20%(w/w) enzyme preparation(KMF-G) concentration and 60 mim hydrolysis time was determined to be the optimal hydrolysis condition for whole soymilk. It is anticipated that soymilk hydrolysis will a food material that is diverse in its application and uses.