• Electrical & Electronic Materials
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• v.10 no.2
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• pp.141-149
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• 1997

L $a_{0.7}$S $r_{0.3}$Mn $O_{3}$ powders were prepared by both GNP(Glycine-Nitrate Process) and solid state reaction method in various of calcination temperature(800-1000.deg. C) and time in air. Also, L $a_{0.7}$S $r_{0.3}$Mn $O_{3}$ cathode contacts on YSZ(Yttria-Stabilized Zirconia) substrate were prepared by screen printing and sintering method as a function of sintering temperature(1100-1450.deg. C) in air. Sintering behaviors have been investigated by SEM(Scanning Electron Microscope) and porosity measurement. Compositional and structural characterization were carried out by X-ray diffractometer and ICP AES(Inductively Coupled Plasma-Atomic Emission Spectrometry) analysis. Electrical characterization was carried out by the electrical conductivity with linear 4 point probe method. As the calcination period increased in solid state reaction method, L $a_{0.7}$S $r_{0.3}$Mn $O_{3}$ phase increased. Although L $a_{0.7}$S $r_{0.3}$Mn $O_{3}$ single phase was obtained only for 48hrs at 1000.deg. C, in GNP method it was easy to get single and ultra-fine L $a_{0.7}$S $r_{0.3}$Mn $O_{3}$ powders with submicron particle size at 650.deg. C for 30min. The particle size and thickness of L $a_{0.7}$S $r_{0.3}$Mn $O_{3}$ cathode contact by solid state reaction method did not change during the heat treatment, while those by GNP method showed good sintering characteristics because initial powder size fabricated from GNP method is smaller than that fabricated from solid state reaction method. Based on enthalpy change from thermodynamic data and ICP-AES analysis, it was suggested to make cathode contact in composition of (L $a_{0.7}$S $r_{0.3}$)$_{0.91}$ Mn $O_{3}$ which have little second phase (L $a_{2}$Z $r_{2}$ $O_{7}$) for high efficient solid oxide fuel cells applications. As (L $a_{0.7}$S $r_{0.3}$)$_{0.91}$Mn $O_{3}$ cathode contact on YSZ substrate was sintering at 1250.deg. C the temperature that liquid phase sintering did not occur. It was possible to obtain proper cathode contacts with electrical conductivity of 150(S/cm) and porosity content of 30-40%.m) and porosity content of 30-40%.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.1
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• pp.175-180
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• 2016

Waste bumpers from out-of-service vehicles are recycled in the manufacturing process of plastic parts by incorporating pristine materials after removing the coated paint on a bumper. This study examined the chemical properties and mechanical properties of a mixture of recycled bumper and pristine materials as a function of the mixing ratio. When the pristine materials and the recycled bumper pieces were mixed, the stiffness (tensile strength and the flexural modulus) was provided by their composition averages. On the other hand, the toughness (Izod impact strength and the elongation-at-break) was lower than their composition averages (i.e., negative deviation). FTIR analysis showed that these results were due to the absence of the compatibility between the pristine materials and recycled bumper pieces. When the recycled bumper pieces were loaded at more than 30 wt. %, the toughness decreased drastically. A previous study showed that a paint removal efficiency up to 80 wt.% was easily attainable. The other 20 wt.% of paint on the bumper is very difficult to remove. Therefore, this study examined the mechanical properties of a mixture of recycled bumper pieces containing the unremoved paint and recycled bumper pieces without paint. When the recycled bumper pieces containing the unremoved paint were incorporated in only small quantities, the mechanical properties were decreased to a great extent. These results show that the paint removal efficiency is very important in the recycled bumper industry.

• Journal of Embryo Transfer
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• v.18 no.1
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• pp.15-25
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• 2003

발생학에서 키메라(chimera)는 2개 이상의 다른 유전자형의 세포, 또는 다른 종의 세포로부터 만들어진 1개의 생물개체를 뜻하는 말로, 이는 초기 수정란의 발달과 포유류의 분화를 연구하는데 이용되고 있다. 키메라를 만드는 방법에는 할구와 내세포괴를 응집시키는 방법과 배반포 내에 여러 종류의 세포를 주입하는 방법이 있다 본 실험에서는 서로 다른 두 가지 방법의 활성화 처리법, 즉, ionomycin 처리 후 Cycloheximide (CHX) 또는 6-Dimetylaminopurine (6-DMAP)에 따른 단위 발생란의 분할과 단계적인 발달율을 살펴 보고자 하였으며, 서로 다른 방법에 의해 생산된 단위발생란 유래의 할구와 체외수정란 유래 할구를 응집하여 키메라 수정란(chimeric embryo)를 만든 후 체외수정란과 발달율을 비교해 보았다. 도축장 유래의 난소에서 난자를 채취하여 체외에서 22~24시간 성숙시킨 후 난구세포를 제거하고 metaphase II 단계의 난자를 5 $\mu$M ionomycin에 4분간 처리한 후, 10 $\mu$g/ml CHX/5 $\mu$g/ml cytochalasin B (CCB)에 5시간 또는 1.9 mM 6-DMAP에 4시간 처리하여 분할율과 배반포기 발달율을 비교 조사하였다. 난자 분할율에서는 체외수정란과 6-DMAP처리 단위 발생란에서 각각가 83.7 와 85.5%로 CHX/CCB 처리 단위발생란의 57.9%보다 유의적으로 높게(P<0.05) 나타났으며, 배반포기 발달율에 있어서는 체외수정란의 발달율이 27.8%로 6-DMAP처리 활성란 12.3%와 CHX/CCB 처리 활성란 5.3%보다 유의적으로 높게 (P<0.05) 나타났다. 키메라 수정란(chimeric embryo)은 서로 다른 두 가지 처리에 의해 생산된 단위발생란의 할구 2개와 체외수정란 유래의 할구 2개를 빈 투명대 내에서 응집시켜 제조하였다 빈 투명대 내에 키메라 수정란(chimeric embryos)의 8 세포기까지의 발달율은, 체외 수정란 할구 2개와 CHX/CCB 처리에 의한 할구 2개를 응집한 그룹은 46.1%, 체외 수정란 할구와 6-DMAP 유래 할구 2개를 응집한 그룹은 52.8% 였으며, handled control은 54.7%로 체외 수정란 77.7%에 비해 유의적으로 낮게(P<0.05) 나타났다. 배반포기까지의 발달율은 체외 수정란과 CHX/CCB에 의해 생산된 키메라 수정란(chimeric embryo)은 12.8%, 체외 수정란과 6-DMAP에 의한 키메라 수정란(chimeric embryo)은 18.8%로 handled control의 21.4%에 비해 유의적으로 낮았으며(P<0.05), 이들 키메라 수정란(chimeric embryos)은 체외 수정란의 34.9%에 비해 유의적으로 낮게(P<0.05)나타났다. 6-DMAP 처리 단위발생이 유기된 수정란 할구 2개와 체외수정란의 할구 2개의 응집에 의한 키메라 수정란(chimeric embryos)의 발달율이 CHX/CCB와 체외수정란의 응집에 의한 키메라 수정란(chimeric embryos)에 비해 다소 높게 나타났으나, 유의적인 차이는 없었다. 본 실험의 결과 서로 다른 방법에 의한 단위 발생란 유래의 할구와 체외 수정란 유래의 할구가 응집에 의한 재조합이 가능하였고 이들을 체외에서 배양하여 배반포기의 수정란까지 발달시켰다.

• Korean Journal of Optics and Photonics
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• v.11 no.2
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• pp.73-79
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• 2000

We measure a beam diameter of scan and sub-scan direction of LSD (Laser Scanning Urnt) which uses $fheta$ lens produced by injecLion molding method as a scanning lens. While the measured beam diameter in scan direction, which is $62muextrm{m}$ to $68\mu\textrm{m}$, shows similar size comparing to the design beam diameter, the sub-scan beam diameter shows sIzable beam diameter deviation as much as 37 11m ranging from $78\mu\textrm{m}$ to $115\mu\textrm{m}$. Injection molding lens has the surface figure error due to the shrinkage III the cooling time and the internal distortion (birefringence) due to the uneven cooling conditIOn so that these bring about wavefront aberration (i.e., the enlargement of beam size), and are eventually expre~sed as the deterioration of the pdnting image. In this paper. we first measure and analyze beam diameter, birefringence (polanzation ratio), and asphedcal figure error of mIens in order to know the principle cause of the beam diameter deviation in sub-scan directIOn. And Lhen. through the analysis of a designed depth of focus and a calculated field curvature (imaging position of the optical axis directIon) using the above figure elTor data, we know Lhat the birefringence IS the main factor of sizable beam diameter deVIation in sub-scan direction. ction.

• The Korean Journal of Mycology
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• v.40 no.4
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• pp.235-243
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• 2012

We studied the effect of fermented Rhus verniciflua stem bark (FRVSB) extract (used in herbal med-icine by Koreans) on the microbial growth and enzyme activity of 12 soybean-fermenting microorganisms, including Bacillus spp., lactic acid bacteria, yeast, and other harmful bacteria. The ethanol and methanol extracts of FRVSB inhibited the growth of Bacillus subtilis, Bacillus licheniformis, Bacillus cereus, and Zygosaccharomyces rouxii, and in the disk diffusion assay, their inhibition zone diameters were 11.06-12.23, 12.32-18.38, 11.47-11.84, and 13.59-14.21 mm, respectively. The water extract did not show any inhibitory effect. In fact, the water extract addition enhanced the growth of B. subtilis and B. licheniformis by 1.3-4.5 fold and that of B. cereus by 1.2-1.4 fold. However, the water extract did not affect the growth of Lactobacillus plantarum, Lactobacillus mesenteroides, Saccharomyces cer-evisiae, and Escherichia coli. The addition of water extract increased the amylase and protease activity of B. subtilis and B. licheniformis.

• Applied Chemistry for Engineering
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• v.23 no.6
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• pp.554-560
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• 2012

Recently, it has been increasing trend to use conductive materials as electronics and communication technology in electronics industry are developing. The noble metal such as Ag, Pt, Pd etc. are mostly used as conductive materials, To reduce production cost, alternative materials with similar characteristics of noble metals are needed. Copper has advantages, i.e its electronic properties are similar to noble metals and low cost than noble metal, but its use has been restricted because of oxidation in air. In this study, the tin film was coated on copper by electroless plating to protect copper from oxidation and to confirm the effects of temperature, pH, amount of $SnCl_2$, and feeding speed in plating conditions. Additionally, we apply $Cu_{core}Sn_{shell}$ powder as conductive filler with low-temperature densification and analysis by SEM, XRD, FIB and 4-Point Probe techniques. As result of the study, tin film was coated well on copper and was protected from oxidation. After low-temperature densification treatment, the meted tin made chemical interconnections with copper. Accordingly, conductivity was increased than before condition. We hope $Cu_{core}Sn_{shell}$ powder to replace noble metals and use in the electronic field.

• Korean Journal of Food Science and Technology
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• v.46 no.5
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• pp.616-621
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• 2014

This study was conducted to investigate the detoxification effect of extract from soy-sprout grown using high concentrated oxygen water extract (SE) against alcohol-induced hangover in male Sprague-Dawley (SD) rats. The rats were orally administered with different concentrations of SE beverage [26, 260 and 2,000 mg/kg body weight (b.w.)] and, after 30 min, with alcohol at a dose of 3 g/kg b.w. After 1 and 3 h of alcohol administration, blood was collected from the retro-orbital plexus, while after 5 h, blood was collected from the heart. In the 2,000 mg/kg b.w. SE group, the concentration of blood alcohol was significantly reduced after 1-5 h of alcohol loading as compared with that in the other groups. In addition, the blood acetaldehyde concentration was reduced by SE (2,000 mg/kg b.w.). These results suggest that SE beverage can alleviate alcohol hangover symptoms by stimulating the activities related to hepatic alcohol-metabolizing enzymes.

• Korean Journal of Food Science and Technology
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• v.46 no.5
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• pp.581-587
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• 2014

The antioxidant and alcohol-degrading enzyme activities of soybean sprout sugar solutions (oligosaccharide and sucrose, $50^{\circ}Bx$) were characterized under different soaking conditions. The ratio of sugar solution to sprout content was 25%, 50%, and 75% (w/w), and the soaking times studied were 1, 3, 6, 12, and 24 h. Higher 1,1-diphenyl-2-pycrylhydrazyl (DPPH) radical-scavenging activity was detected in case of the oligosaccharide solution, compared to the sucrose solution. A similar tendency was observed for alcohol-degrading enzyme activity. When the ratio of sugar solution to sprout content was 50% (w/w), the total phenol and flavonoid contents were found to be higher, compared to those observed at 20% (w/w). However, we did not observe a significant difference between 50% and 75% (w/w). Soaking time did not significantly affect the antioxidant and alcohol-degrading enzyme activities of the solutions. As a result, when oligosaccharide solution was used for soaking soy sprouts at a ratio of >50% (w/w), higher antioxidant and alcoholdegrading enzyme activities were observed.

• Fire Science and Engineering
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• v.26 no.4
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• pp.77-81
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• 2012

This study of aims to provide basic data for improve the performance of air respirators that generate by bad influencing elements in fire emergency field. With three types of conditions set up for these tests, the pressures of containers have been extracted; the ambient temperatures have been checked, and the generation of moisture inside and outside container have been checked and identified. Specifically, these tests have been conducted at temperatures ranging between $-20{\sim}40^{\circ}C$. The pressures of containers have been extracted to reach between 0.4~0.8 MPa, using a pressure regulating valve. These tests have resulted in no change in the temperature and moisture outside the containers and no generation of moisture inside the containers as well. Although moisture has been generated inside the pressure gauge, the amount of moisture has not exceeded 25 $mg/m^3$, i.e. the limit suggested by the Korean Government. Therefore, it is judged that the moisture generated inside air respirators, which can be the most critical issue in the equipment, is likely to be caused in the process of managing the equipment or replacing air in the equipment at places of end-users, rather than in the process of manufacturing and production of the equipment.

• Journal of agriculture & life science
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• v.44 no.6
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• pp.147-157
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• 2010

This study was carried out to develop the normal temperature-circulatable retort sterilized imitation crab leg (RSIC) with long shelf-life by retort sterilization. We have examined the optimum retort sterilization conditions and quality characteristics of the RSIC. Central composite design for response surface methodology (RSM) was adopted for optimization of retort sterilization, and experimental central composite design consisted of 11 samples such as 4 factorial points; 4 star points; 3 central points. Sterilization temperature and $F_0-value$ for retort sterilization were chosen for independent variables, and shearing force, whiteness and sensory score about texture were selected as a dependent variable. As a results of RSM analysis, multiple response optimization for the RSIC by Minitap statistical programing was $F_0-value$ 3.3 min. at $117.5{^{\circ}C}$. Also RSM analysis indicated such as sterilization temperature during retort sterilization was the most influential factor, while $F_0-value$ little affected on quality of the RSIC.