• Food Science of Animal Resources
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• v.29 no.1
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• pp.62-67
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• 2009

This study was undertaken to develope a semi-cooked pork using oven to provide a more convenient recipe for food service systems. Pork sliced 2 or 4 mm thick prepared with a Korean traditional kochujang sauce was broiled in an oven, steam oven or on a pan. 4 mm-thick meat that was broiled in oven for 4 min at $170^{\circ}C$, obtained higher scores in sensory and color evaluations. In labor-concentrated food service kitchens, the inner temperature of the pork at $85^{\circ}C$ provoked the highest satisfaction. The assessments of color L was ordered as steam oven, oven and pan broiling. And a- and b-values of oven broiling were higher than those of the steam oven or pan broiling. The color values of the steam oven-broiled pork sliced 4 mm-thick were significantly higher than those of the pan-broiled (p<0.05). In sensory evaluation, the taste score of steam oven was better than other broiling with significant differences. Furthermore pork broiling in oven was tender with low score in cohesiveness and chewiness. Overall acceptability was ordered as pan, steam oven, and oven broiling. Thus it was expectable that international Korean traditional food can be made using oven for food service system. For the diversity of the menu in food service, however it need to develope the more convenient and simpler recipes with semi-cooked Korean food.

• Korean Journal of Food Science and Technology
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• v.30 no.6
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• pp.1362-1366
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• 1998

The sterilizing effect of electron beam was compared with that of gamma irradiation for commercial ginseng powders. White and red ginseng powders were contaminated by about $10^5\;CFU/g$ of total bacteria and by $10^3\;CFU$ of coliforms only in white ginseng powder. Data of microbial population for the sterilizing effect of electron beam irradiation showed that no microorganisms were detected in the samples irradiated up to 7.5 kGy for total aerobic bacteria and 2.5 kGy for molds and coliforms. Such doses were effective for controlling the microbial growth in the samples during 4 months of storage at room temperature. Decimal reduction doses $(D_{10}$ value) on the initial bacterial populations were $2.85{\sim}3.75\;kGy$ in electron beam and $2.33{\sim}2.44\;kGy$ in gamma irradiation, which were influenced by the initial microbial loads and the energy applied. Compared with gamma irradiation, electron beam showed a similar result in its sterilizing effect on ginseng powders, suggesting its potential utilization in due time.

• Korean Journal of Food Science and Technology
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• v.30 no.6
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• pp.1432-1438
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• 1998

The gamma-radiation sensitivity of eight kinds of pathogenic bacteria related to beef was investigated in frozen cells $(-18^{\circ}C)$ with 0.1 M phosphate buffer and inoculated cells in beef. In frozen cells, D10 values of pathogenic bacteria related to beef were $0.07{\sim}0.69$ kGy, and inactivation factors were $2.90{\sim}42.86$ at the radiation doses of $2{\sim}3$ kGy. Beef was inoculated with Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium, Enterobacter aerogenes, Vibrio parahaemolyticus, Staphylococcus aureus, Listeria monocytogenes, and Aeromonas hydrophila. Inoculated beef samples were packaged in air and irradiated at 0.005 to 3.0 kGy. Ninety percent of the viable pathogenic bacteria in beef was eliminated by doses of $0.1{\sim}0.61$ kGy at room temperature, and the inactivation factors were $3.28{\sim}30.0$ kGy at the radiation doses of $2{\sim}3$ kGy. Therefore, irradiation is considered to be an effective method to control pathogenic bacteria in beef.

• Korean Journal of Food Science and Technology
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• v.30 no.6
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• pp.1426-1431
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• 1998

The research was undertaken to characterize enzymatic properties of Streptomyces albus amylase expressed in recombinant Bacillus subtilis. Molecular weight and pI of the purified enzyme were estimated to be 50 kD by SDS-PAGE and 4.3 by isoelectric focusing. The optimum temperature and optimum pH were $45^{\circ}C$ and 6.0, respectively. D-and Z-value were estimated to measure thermostability of the purified enzyme. The Z-value was estimated $17.7^{\circ}C$, which is lower than typical amylase. Maltotetraose was produced as a major component from soluble starch in the early state of reaction but gradually degraded to maltose. Thin layer chromatography was also performed to analyze the reaction products. The parameters involved in Michaelis-Menten enzyme kinetics were found to be the maximum velocity of 0.37 mM/min and the Michaelis constant of 0.13%, respectively.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.1
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• pp.40.1-40.1
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• 2010

The Main payload of the STSAT-3 (Korea Science & Technology Satellite-3), MIRIS (Multipurpose Infra-Red Imaging System) has been developed for last 3 years by KASI, and its Flight Model (FM) is now being developed as the final stage. All optical lenses and the opto-mechanical components of the FM have been completely fabricated with slight modifications that have been made to some components based on the Engineering Qualification Model (EQM) performances. The components of the telescope have been assembled and the test results show its optical performances are acceptable for required specifications in visual wavelength (@633 nm) at room temperature. The ensuing focal plane integration and focus test will be made soon using the vacuum chamber. The MIRIS mechanical structure of the EQM has been modified to develop FM according to the performance and environment test results. The filter-wheel module in the cryostat was newly designed with Finite Element Analysis (FEM) in order to compensate for the vibration stress in the launching conditions. Surface finishing of all components were also modified to implement the thermal model for the passive cooling technique. The FM electronics design has been completed for final fabrication process. Some minor modifications of the electronics boards were made based on EQM test performances. The ground calibration tests of MIRIS FM will be made with the science grade Teledyne PICNIC IR-array.

• Journal of the Microelectronics and Packaging Society
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• v.10 no.2
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• pp.7-12
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• 2003

The $Bi_{3.3}La_{0.7}O_{12}$(BLT) capacitors with Metal-Ferroelectric-Insulator-Silicon structure were prepared on $SiO_2/Si$ substrates by using sol-gel method. The BLT thin films annealed at $650^{\circ}C$ and $700^{\circ}C$ showed randomly oriented perovskite crystalline structures. The full with at half maximum (FWHM) of the (117) main peak was decreased from $0.65^{\circ}$ to $0.53^{\circ}$ with increasing the annealing temperature from $650^{\circ}C$ to $700^{\circ}C$, indicating the improvement in the crystalline quality of the film. In addition, the grain size and $R_rms$ , values were increased with increasing the annealing temperatures, showing the rough film surface at higher annealing temperatures. From the capacitance-voltage (C-V) measurements, the memory window voltage of the BLT film annealed at $700^{\circ}C$ was found to be about 0.7 V at an applied voltage of 5 V. The leakage current density of the BLT film annealed at $700^{\circ}C$ was about $3.1{\times}10^{-8}A/cm^2$.

• Journal of the Microelectronics and Packaging Society
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• v.10 no.2
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• pp.13-17
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• 2003

In this study, new LTCC materials of $ZnWO_4$-LiF system were developed for the application to RF Module fabrication. Pure $ZnWO_4$ must be sintered above $1050^{\circ}C$ in order to obtain up to 98% of full density. The measured dielectric constant ($\epsilon_r$)quality factor ($Q{\times}f0$), and temperature coefficient of resonant frequency ($\tau_f$ were 15.5, 74000 GHz, and $-70ppm^{\circ}C$, respectively. LiF addition resulted in a liquid phase formation at 81$0^{\circ}C$ due to interaction between ZnWO$_4$ and LiF. Therefore, ZnWO$_4$ with 0.5∼1.5 wt% LiF could be densified at $850^{\circ}C$. In the given LiF addition range, the sintering shrinkage increased with increasing LiF content. Addition of LiF slightly lowered the dielectric constant from 15.5 to 14.2∼15 due to lower dielectric constant of LiF. Qxfo value decreased with increasing LiF content. This can be explained in terms of the interaction between LiF and $ZnWO_4$, and inhomogeneity of grain structure.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2000.11a
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• pp.11-11
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• 2000

이동통신기술의 급격한 발달로 고주파회로의 packaging과 interconnect 기술의 고성능화 와 저가격화에 대한 새로운 도전이 요구되고 있다‘ 대부분 기존의 무선통신 부품은 P PCB(Printed Wiring Board)기술을 활용하고 있으나 이러한 기술이 점차로 고주파화되는 경 향을 만족시킬수 없어 새로운 고주파 부품기술이 요구되고 있는 실정이다 .. RF 회로를 구성 하기 위하여 PCB소재의 환경적, 치수안정성 문제를 극복하기 위하여 L TCC(Low T Temperature Cofired Ceramics)기술이 최근 주목을 받고 있다. 차세대 이동통신 기술은 수십 GHz 이상의 고주파특성이 우수하고, 고성능의 초소형의 부품을 저가격으로 제조할수 있으며, 시장의 변화에 기민하게 대처할수 있는 기술이 요구되 고 있으며, 이러한 기술적 필요성에 부합할수 있도록 LTCC 기술이 제안되었다. 이러한 C Ceramic Interconnect 기술은 높은 신뢰성을 바탕으로 fine patterning 기술과 저가의 m metallizing 기술로 가능하게 되었다. 초고주파 통신부품기술은 미국과 유럽 등을 중심으로 G GHz 대역또는 mm wave 대역의 기술에 대하여 치열한 기술개발 경쟁을 벌이고 있으며, 이 러한 고주파 패키징 기술을 바탕으로 미래의 군사, 항공, 우주 및 이동통신 기술에 지대한 영향을 미칠수 있는 기반기술로 자리잡을 전망이다. L LTCC 기술은 기존의 후막혼성기술에 비하여 공정이 단순하고 대량생산이 가능하고 가 격이 비교적 저렴하다. 또한 다층구조로 제작할수 있고, 수동소자를 내장할수 있어 회로의 소형화와 고밀도화가 가능하다. 특히 무선으로 초고속 정보를 처리하기 위하여 이동통신기 기의 고주파화가 빠르게 진행됨에 따라서 고분자재료에 비하여 고주파특성이 우수할뿐아니 라 환경적, 치수안정성이 우수한 세라믹소재플 사용함으로써 고주파 손실율을 저감할 수 있 다 .. LTCC 기술은 후막회로 기술과 tape dielectric 기술이 결합된 기술이다. 표준화된 소재 와 공정기술을 활용하여 저가격으로 고성능소자플 제작할 수 있으며, 전극재료로서 높은 전 도도를 갖고 있는 Ag, Cu, Au 및 Pd! Ag릎 사용함으로써 고주파 손실을 저감시킬 수 있다. L LTCC 기술이 최종적으로 소형화, 고기능 고주파 부품기술로 지속적으로 발전하기 위하여 무수축(Zero shrinkage) 소성기술, 광식각 후막기술 등이 원천기술로서 확립될 수 있어야 하 며, 특히 국내의 이동통신 기술에 대한 막대한 투자에도 불구하고 차세대 이동통신 부품기 술에 대한 개발은 상대적으로 미흡한 실정이므로 국내에 LTCC 관련 소재공정 및 부품소자 기술에 대한 개발투자가 시급히 이루워져야 할 것으로 판단된다. 본 발표에서는 지금까지 국내외 LTCC 기술의 발전과정을 정리하였고, 현재 이 기술의 응용과 소재와 공정을 중심으로한 개발현황에 대하여 조사하였으며, 앞으로 LTCC가 발전 해야할 방향을 제시하고자 한다.

• Journal of the Microelectronics and Packaging Society
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• v.13 no.3 s.40
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• pp.1-8
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• 2006

Higher density integration and adoption of new materials in advanced electronic package systems result in severe electrochemical reliability issues in microelectronic packaging due to higher electric field under high temperature and humidity conditions. Under these harsh conditions, metal interconnects respond to applied voltages by electrochemical ionization and conductive filament formation, which leads to short-circuit failure of the electronic package. In this work, in-situ water drop test and evaluation of corrosion characteristics for SnPb solder alloys in D.I. water and NaCl solutions were carried out to understand the fundamental electrochemical migration characteristics and to correlate each other. It was revealed that electrochemical migration behavior of SnPb solder alloys was closely related to the corrosion characteristics, and Pb was primarily ionized in both D.I. water and $Cl^{-}$ solutions. The quality of passive film formed at film surface seems to be critical not only for corrosion resistance but also for ECM resistance of solder alloys.

• Journal of the Microelectronics and Packaging Society
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• v.15 no.4
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• pp.51-57
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• 2008

In this paper, wetting and interfacial reaction properties for low Ag containing Sn-Ag-Cu Pb-free solder alloy, i.e., Sn-0.3Ag-0.7Cu were investigated and compared with those of Sn-1.0Ag-0.5Cu and Sn-3.0Ag-0.5Cu. Melting behavior and stress-strain curves of some Sn-xAg-xCu alloys were also measured using a differential scanning calorimeter(DSC) and a tensile test machine, respectively. In order to enhance insufficient wetting properties of Sn-0.3Ag-0.7Cu alloy, the improvement of wetting properties were analyzed by applying fluxes containing higher content of halide or indium adding of 0.2wt.% into the solder alloy. It was concluded that the small addition of indium is more effective for the improvement of wettability in low temperature range of $230{\sim}240^{\circ}C$ than applying flux containing higher content of halide.