• Journal of the Korean Chemical Society
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• v.44 no.5
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• pp.453-459
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• 2000

FED has deserved an intensive attentioD as a new flat panel display. The present investigationaims at undemtanding the photoluminescence and cathodoluminescent properties of hGaO$_3$: $Eu^{3+}$ phosphor bytaking into account the possibility that this phosphor could be applied for FED. In onler to investigate on.sucha detailed behavior; 8everM experimental skil18 Je conducted to the LaGaO$_3$:$Eu^{3+}$ phosphoL The excimtion srectrum artd emission spectmn were rnezsured in the UV range and then decay curve of $^5D_0$+$^7F_j$transitions\vas examined. The decay behavior of $^5D_0$ emission was anMyzed by a newly Iuoposed cross-relaxation mech-ani8In in asswiation with inteFwnter di1ffision (or migration). The cross-mlaxation from $^5D_0$ to CTB (Cha'geTransfer Band) wuld be a quite retsonable by considering the excitation spectrum. It could be also found thatthe quenching type was changed from ditfrsion controlled process to the direct quenching process -s inJeasing $Eu^{3+}$ oncntration.

• Korean Journal of Optics and Photonics
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• v.28 no.4
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• pp.166-171
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• 2017

Hydrogen gas is a green energy sources because it features no emission of pollutants during combustion. But hydrogen gas is very dangerous, being flammable and very explosive. Hydrogen gas detection is very important for the safety of a nuclear power plant. Hydrogen gas is generated by oxidation of nuclear fuel cladding during a critical accident, and leads to serious secondary damage in the containment building. This paper discusses the development of a Raman lidar system for remote detection and measurement of hydrogen gas. A small, portable Raman lidar system was designed, and a measurement algorithm was developed to quantitatively measure hydrogen gas concentration. To verify the capability of measuring hydrogen gas with the developed Raman lidar system, experiments were carried out under daytime outdoor conditions by using a gas chamber that can adjust the hydrogen gas density. As results, our Raman lidar system is able to measure a minimum density of 0.67 vol. % hydrogen gas at a distance of 20 m.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2000.04a
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• pp.12-13
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• 2000

최근 플라스틱제 식품 포장재에 대한 환경학적 문제가 제기됨으로 인하여 다양한 곡류 단백질의 필름 형성능력에 많은 관심이 모아지고 있다. 단백질 필름으로서 soy protein, wheat gluten, rice bran, corn zein, glatin 및 colloagen 등의 소재들이 많은 관심을 모으고 있으며, 비교적 필름 형성력이 뛰어나고, 저렴한 가격으로 구입할 수 있는 대두 단백질에 커다란 관심이 모아지고 있는 실정이다. 이들 물질로부터 제조된 가식성 필름 및 코팅제들은 식품의 보존기간을 연장시킬 뿐만 아니라 수분 및 용질의 이동을 방지하여 식품의 품질을 개선시킬 수 있다. 또한 이들 필름 및 코팅제들은 산소 및 이산화탄소의 이동, 이로 인한 지방 산화 그리고 휘발성 향기성분들의 감소 등을 조절할 수 있다. 대두 단백질 필름의 사과 코팅제로서의 이용은 개별적 포장이 용이하지 않는 제품들의 코팅제로서 활용하여 대두 단백질 필름 및 코팅제의 잠재적 시장성을 확인하는 하나의 응용분야이다. 본 실험의 목적은 대두 단백질 코팅제를 후지와 golden delicious 사과에 코팅하여 상온 (22$^{\circ}C$)과 냉장온도(2-4$^{\circ}C$)에서 60일동안 보관하여 색도, 경도 및 산도 변화 등을 측정하여 저장 중 사과의 품질에 미치는 영향을 조사하였다. 대두 단백질 코팅제는 대두 단백 용액들 (5g, 8g, 10g/100mL water)에 glycerin (50% w/w의 단백질)을 가소재로 첨가한 후 알칼리 용액으로 pH 9.0에 맞추었다. 그런후 85$^{\circ}C$에서 30분간 가열하여 코팅제를 준비하였다. 후지 사과(붉은색)와 golden delicious 사과 (초록색)를 dipping 방법으로 코팅하여 60일도안 실온과 냉장온도에 저자하여 보존기간의 연장을 확인하였다. 사과품질의 결정인자는 Hunter L, a, b 색도값과 사과의 조직의 강도 (외부 및 내부) 그리고 산도 등을 측정하였다. 코팅된 후지 및 golden delicious 사과의 표피 및 내부 경도는 control과 비교하여 높은 경도를 유지하였다. 또한 냉장온도에서 30일 동안 보관하였을 때, control 사과와 거의 비슷한 경도를 유지하였다. 식품의 색도를 소비자의 기호를 결정하는 중요한 인자이다. 대두 단백질로 코팅된 후지 사과는 상온에서 20일 동안은 control에 비하여 약간의 색도의 증가를 보였으나, 그 후 60일 동안은 색도의 증가를 보이지 않았다. 그러나 냉장 보관한 control 후지 사과에 비하여 색도의 증가가 관찰되었다. 대두 단백질 코팅제가 사과의 색도 변화를 방지하는 효과를 가졌으나, 저장 온도가 색도의 변화에 더욱 큰 영향을 미침을 알 수 있었다. 대두 단백질로 코팅된 golden delicious는 상온에서60일 동안 보관하였을 경우, 사과표피의 색도 변화를 현저히 지연시킴을 확인하였다. 또한 control과 비교하여 성공적으로 사과에 코팅하였으며, 상온에서 보관하여을 때 사과의 품질을 30일 이상 연장하는 효과를 관찰하였다. 이들 결과로부터 대두단백질 필름이 과일 등의 포장제로서 이용할 가능성을 확인하였다.

• Korean Journal of Microbiology
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• v.46 no.2
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• pp.134-139
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• 2010

Mycobacterium tuberculosis (Mtb) is one of the most successful pathogens to infect one third of world population. Th1-mediated immunity against Mtb infection is known as critical to express mycobacteriostatic function but it is not sufficient to resolve the infection. In this study, to verify the possibility Mtb itself change the gene expression to survive against host immune response, expression pattern of selected H37Rv genes, 16S rRNA, acr, fbpA, aceA, and ahpC, during the course of infection was measured with absolute quantitation method using real-time RT-PCR. The total number of transcripts of 16S rRNA increased during the course of infection, which was coincide with the increasing CFU. The total number of fbpA transcripts per CFU, which encode typical secreted Mtb antigen, Ag85A, increased for 10 days of infection before decreasing. The number of transcripts of acr per CFU, which encode heat shock protein, ${\alpha}$-crystallin, increased during the infection, and ahpC and aceA, they both are enzymes produced in oxidative stressful condition, increased for 20 days and then slightly decreased on day 30. These findings are one of survival strategy of pathogen evading host immune response lead to persistent infection inside host cells.

• Korean Journal of Microbiology
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• v.46 no.2
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• pp.219-222
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• 2010

In this study, we evaluated Vi-passive hemagglutination (Vi-PHA), SD Salmonella Typhi IgG/IgM ($SD^{(R)}$ kit) and Widal test for the rapid laboratory diagnosis of typhoid fever patients. A total of 36 serum samples from febrile patients in Korea from 2005 to 2006 were used. Among 36 patients, 27 were fever patients without typhoid, 9 were typhoid fever. Vi-PHA showed 8 positive results out of 9 typhoid fever patients (sensitivity 88.9%) and 1 positive and 26 negative results out of 27 febrile patients without typhoid (specificity 96.3%). The sensitivity and the specificity of $SD^{(R)}$ kit were 100% and 92.6%, respectively. However, the sensitivity and the specificity of Widal O & H tests were 88.9%, 100%, and 77.8%, 70.4%, respectively. Consequently, Widal H and $SD^{(R)}$ kit showed higher sensitivity and Vi-PHA showed higher specificity. To efficient diagnosis, Vi-PHA may be sufficient diagnosis method in acute cases and $SD^{(R)}$ kit and Widal test may be sufficient in sporadic area and high risk group.

• Polymer(Korea)
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• v.32 no.1
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• pp.26-30
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• 2008

This study was designed to investigate the effect of hybridization of synthetic/natural materials for annulus fibrosus (AF) tissue regeneration in vitro and in vivo. The synthetic/natural hybrid scaffolds were prepared using PLGA (poly (lactic-co-glycolic) acid), SIS (small intestinal submucosa) and DBP (demineralized bone particles). PLGA, PLGA/SIS(20%), PLGA/DBP(20%) and PLGA/SIS (10%)/DBP (10%) scaffold were manufactured by solvent casting/salt leaching method. Compressive strength was measured. Rabbit AF cells were isolated, cultured and seeded into experimental groups. Hydroxyproline production and DNA quantity of AP cells on each scaffold was measured at 2, 4 and 6 weeks after in vitro culture. Cell-scaffold composites were implanted subcutaneously into athymic mice. After 1,4 and 6 weeks postoperatively, specimens were taken and H&E, Safranin-O and type I collagen staining were carried out concerning formation of cartilagenous tissue. In vitro PLGA/SIS scaffold was evaluated for total collagen content (bydroryproline/DNA content) and PLGA scaffold was evaluated for compressive strength.

• Polymer(Korea)
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• v.31 no.3
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• pp.201-205
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• 2007

Biodegradable polymers such as polylactide, polyglycolide and poly (lactide- co-glycolide) (PLGA) have been extensively investigated because of easily controlled drug release rate, completely degradable materials without the toxic by-product, and good biocompatibility. But, according to the bulk erosion property of PLGA in vitro test, it had the disadvantage that first-order release reduced releasing amount slowly after excessive initial burst. In this study we used PLGA powder obtained through recrystallization to revise bulk erosion property of PLGA. The PLGA used in this study was prepared by vacuum drying method and to estimate release profiles of BCNU loaded PLGA wafer. We also evaluated the release profile of drug with the water soluble additive. It was found that the drug loaded PLGA recrystallized by vacuum drying method exhibited the initial burst and the constant rate of drug release compared to that prepared by a conventional method.

• Journal of Korean Medicine for Obesity Research
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• v.4 no.1
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• pp.45-54
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• 2004

Objective: To evaluate the effect of Ephedra Sinica and Evodia Rutaecarpa on resting metabolic rate(RMR), weight and body composition in obese women during low-calorie diet. Methods: We recruited 90 healthy premenopausal women$(body\;mass\;index{\geq}25kg/m^2)$ and randomly assigned to three groups(ephedra group, evodia group and placebo group). Subjects were administered Ephedra Sinica(6g twice a day) or Evodia Rutaecarpa(6g twice a day) or placebo in a double-blind fashion and participated in low-calorie diet for 8 weeks. Resting metabolic rate and body composition were measured at baseline, 4 and 8 weeks. Results: RMR change for 4 weeks was significantly higher in the ephedra group compared with the placebo group(p<.05). But the change for 8 weeks was not significant and the Evodia group showed no significant RMR change. Weight and percent body fat changes for 4 weeks and 8 weeks were significantly higher than the placebo group in the ephedra group(p<.05), but the Evodia group didn't show significant level. Conclusions: This study supports and emphasizes the benefits of herbal medicine in maintaining or increasing RMR during low-calorie diet. Especially Ephedra treatment was effective on significant maintainment of RMR, loss of weight and percent body fat(P<.05).

• Solar Energy
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• v.15 no.3
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• pp.105-117
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• 1995

Heat transfer coefficients on a single spiral coil tube in the furan foundry sand fluidized bed have been investigated. Heat transfer coefficients(ho) to an immersed single spiral coil tube were measured in the bed. The bed diameter was 0.21 m. The following quantities were varied: (l)bed temperature, (2)mean particle diameter, (3) fluidization rate, (4)the ratio of heated coil tube pitch to diameter(p/Do), and (5)the ratio of heated coil tube pitch to mean particle diameter(p/dp). In addition, the experimental values of maximum Nusselts number were compared with the values of maximum Nusselts number predicted by the existing correlations. The values of heat transfer coefficient increase with the increase in bed temperature and fluidization rate, but decrease with increase in particle diameter. An empirical formulus of maximum Nusselts number which is applicable in the furan foundry sand fluidization bed is as follows: $$Nu_{max}=1.01\;Re^{0.48}Prg^{0.4}(p/dp)^{0.28}(p/Do)^{0.05}$$.

• Journal of the Korean Magnetics Society
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• v.10 no.5
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• pp.225-231
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• 2000

The crystallographic and magnetic properties of the sample F $e_{0.8}$ $Co_{0.18}$(BN)$_{0.02}$ synthesized by microwave arc-melting with the maximum power of 3.5 kW have been studied by the methods of an X-ray diffraction and the measurement of the magnetic hysteresis using the vibrating sample magnetometer at room temperature. The samples were prepared in a form of pellet pressed under the pressure of 9,000 N/c $m^2$, rolled coldly, and treated with the different temperatures. The X-ray diffraction pattern of pelleted sample shows that the crystal structure of the sample is bcc as same as that of Fe with a good uniformity. The X-ray diffraction pattern shows that a residual stress, which exists in the sample, is eliminated by final 90$0^{\circ}C$ annealing. As rolling rate and heat treatment temperature increases, the saturation magnetization and the remanence of the samples increase whereas the coercivity of the samples shows decrease. Also the saturation magnetization and the remanence of the samples were affected by rolling rate and rolling direction than heat treatment temperature, but the coercivity of the samples was affected by rolling rate and direction as well as heat treatment temperature. This means that a domain wall motion is easy due to elimination of a residual stress and an inclusion which exists in the sample by rolling and heat treatment and a local induced-magnetization easy axis was also formed to parallel to the rolling direction due to creation of the like-atom pairs across the slip plane by rolling......