• Journal of Microbiology and Biotechnology
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• 제13권5호
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• pp.731-737
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• 2003

Mucinase complex from V. parahaemolyticus ATCC 17802 was purified 6-fold with 0.4% yield by two sequential steps of Q-Sepharose and Superdex 200HR column chromatographies. Partially purified mucinase complex showed at least 8 times higher mucin-degrading activity than the culture filtrates. The mucinase complex also showed gelatin-and-casein-hydrolyzing activities, which demonstrates that the protein is a complex compound containing several proteases. The optimum pH and temperature of partially purified mucinase complex for mucin degradation was 8.0 and $35^{\circ}C$, respectively. The partially purified mucinase complex showed high cytotoxic activity on vero cells when examined by MTT assay and microscopic observations. Cytotoxicity was significantly increased in proportion to the concentration of the mucinase complex. Mouse experiments revealed that the jejunum, ileum. and large intestinal tissues were damaged by the injection of the mucinase complex. In particular, the reduction of the goblet cells in the large intestine was remarkable. Collectively, these data suggest that the mucinase complex partially purified from V. parahaemolyticus ATCC 17802 contributes to the adhesion and invasion of V. parahaemolyticus into the host intestinal tract.

• 한국임상수의학회지
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• 제6권1호
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• pp.199-208
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• 1989

This study was carried out to Investigate the effects of detomidine and xylazine on physical sign, electrocardiogram, blood pressure, acid-base status and the antagonistic effect of yohimbine on detomidine in goats. Yohimbine was administered 10 minutes after detomidine injection. Maintenance time of sedation was remarkably decreased in yohimbine-treated group(59.5${\pm}$3.8min). compared with detomidine-treated group(99.8 ${\pm}$ 14.7min). Body temperature was slightly decreased, heart rate was markedly decreased in all experimental groups and respiratory rate increased in detomidine-treated group and decreased in zylazine-treated group. However they were recovered rapidly after yohimbine administration In electrocardiogram, there were no significant changes except T waves and RR intervals. T waves showed negative form and RR intervals were increased but they were recovered rapidly in yohimbine-treated group compared with detomidine-treated group. Blood pressure was decreased after detomidine administration but recovered faster in yohimbine-treated group than in detomidine alone group. Blood pH was increased in detomidine-treated and yohimbine-treated groups but unchanged in xylazine-treatd group. It is considered that the effects of detomidine are similar to those of xylaxine and yohimbine is effective antagonist to detomidine in goats.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2009년도 춘계학술대회 논문집
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• pp.395-399
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• 2009

최신 엔진에 사용되는 애프터버너는 늘어난 엔진의 출력밀도(Power Density)를 감당하기 위해 기존 애프터버너와는 다른 설계 패러다임을 가지게 되었다. 가장 눈에 띄는 변화로는 애프터버너로 유입되는 공기의 온도 상승으로 인해 연료분사장치/화염안정화장치가 통합되는 설계 방식이다. 또한, 운용성을 좋게 하기 위해 Radial 형태의 형상을 사용한다. 최신예 엔진인 F414 및 F110-GE-132 엔진에는 이와같은 형태의 장치에 추가로 CMC(Ceramic Matric Composite)가 사용된 가변노즐과 ejector 노즐을 적용한 능동 냉각 개념의 가변노즐등으로 엔진 부품의 수명을 늘려서 경제성을 제고한 것으로 조사되었다. 이러한 기술 경향은 차세대 램제트 엔진이나, TBCC와 같은 복합싸이클 엔진에도 적용가능할 것으로 판단된다.

• 한국분무공학회지
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• 제12권1호
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• pp.11-17
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• 2007

The swirl spray for direct-injection spark-ignition (DISI) engines was investigated using a nozzle whose exit surface shape was cut with a certain tapered angle. The reason for the change in spray's characteristics at various tapered angles was explained by the data correlating the taper and flow angles. The spray tended to shift its characteristics from the symmetric to asymmetric when the tapered angle was increased; furthermore, the spray penetration and spray cone angle were also increased. When the tapered angle was greater than the $90^{\circ}$ minus flow angle, an opened hollow cone spray was formed because of the fuel impingement against the tapered surface area of the nozzle exit. This behavior indicates that the reduction in the air pressure difference between the inner and outer spray of the spray can be achieved. This behavior also promises the potential use of the tapered nozzle for the case where the independence of the spray performance from atmospheric pressure and fuel temperature is desired.

• 한국환경보건학회지
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• 제27권4호
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• pp.9-14
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• 2001

This study was performed to develop the modified FGD(Flue Gas Desulfurization) process which can eliminate the possibility of generating secondary pollutants. Limestone was regenerated by adding ammonium hydroxide and carbon dioxide, and reusing it as a absorbent in FGD gypsum Process. A series of the new or modified FGD process which include desulfurization and regeneration limestone from CaSO$_3$. 1/2H20 and CaSO4 . 2H2O, were carried out under various experimental conditions. The results showed that the optimum injection ratio for regeneration of limestone was 0.3 ml/min of CO2 flow rate, 2 ml of NH4OH per 0.01 M of regent grade CaSO4 . 2H20O and the optimum regeneration temperature was 50. The increaser was the number of times of limestone regeneration, the faster was the breakthrough point of desulfurization at the desulfurination process which the regenerated limestone was used. Then the efficiency of desulrurization was decreased. This study can be confirmed the possibility for reuse of regenerated limestone due to the similarity of desulfurization characteries both reagent grade calcium carbonate and regenerated calcium carbonate. Finally, it appeared that the new technology using regenerated 1imestone can be applied to the FGD process.

• Journal of Dental Anesthesia and Pain Medicine
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• 제20권4호
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• pp.187-194
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• 2020

Background: The aim of the present systematic review was to evaluate and compare the efficacy of warmed and unwarmed local anesthesia solutions in reduction of pain during intraoral injection administration. Methods: PubMed, Ovid SP, and Cochrane Central Register of Controlled Trials were searched from publication years 1990 to 2020 with relevant MeSH terms. Studies were screened by titles and abstracts, followed by full-texts evaluation of the included studies. Results: A total of four studies were included in the systematic review. Outcomes evaluated were subjective and objective pain during administration of the warmed local anesthesia solution in comparison with the unwarmed local anesthesia solution. Among the four studies that evaluated the self-reported pain score, three studies showed significantly lower pain scores associated with warmed local anesthesia. Only two studies evaluated the observed pain score, and both of them reported a significantly lower pain reaction with the warmed local anesthesia solution. Conclusion: Within the limits of this systematic review, warming the local anesthesia solution to body temperature (37℃) before administration seemed to reduce the discomfort during intraoral local anaesthesia administration, and more high-quality studies should be carried out to validate the same.

• 한국세라믹학회지
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• 제53권2호
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• pp.246-252
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• 2016

Complex designed silica-based ceramic cores were fabricated by ceramic injection molding. Slow heating rate (0.2K/min) for debinding restrained bloating on the surface of ceramic cores. To investigate effect of sintering conditions on mechanical properties of ceramic cores, green bodies were sintered at temperatures in a range from $1150^{\circ}C$ to $1400^{\circ}C$ for various dwelling times (6 h to 48 h). Sintering above $1300^{\circ}C$ for 12 h and dwelling time over 24 h at $1200^{\circ}C$ reduce the flexural strength and increase the linear shrinkage of ceramic cores. Cristobalite, formed by high sintering temperature or long dwelling time, induces reduction of mechanical properties due to its phase transformation, which is accompanied by volume contraction and microcracking. Ceramic core sintered at $1200^{\circ}C$ for 12 h endured wax patterning and shell molding, and was manufactured successfully.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.59-60
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• 2008

GaN-based light-emitting diodes (LEDs) with ZnO nanorod arrays on a planar indium tin oxide (ITO) transparent electrode were demonstrated. ZnO nanorods were grown into aqueous solution at low temperature of $90^{\circ}C$. Under 20 mA current injection, the light output efficiency of the LED with ZnO nanorod arrays on ITO was remarkably increased by about 40 % of magnitude compared to the conventional LED with only planar ITO. The enhancement of light output by the ZnO nanorod arrays is due to the formation of side walls and a rough surface resulting in multiple photon scattering at the LED surface.

• Journal of Advanced Marine Engineering and Technology
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• 제33권4호
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• pp.451-458
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• 2009

This experimental study was conducted to investigate macroscopic characteristics of the flash boiling spray with tow component mixing fuel. Homogeneous Charge Compression Ignition (HCCI) is a newer combustion method for internal combustion engines to reduce nitrogen oxide and particulate matter simultaneously. But it is difficult to put this combustion method to practical use in an engine because of such problems as instability of combustion in low load operating conditions and knocking in high load operating conditions. In HCCI, combustion characteristics and exhaust emissions depend on conditions of air/fuel mixture and chemical reactions of fuel molecules. The fuel design approach is achieved by mixing two components which differ in properties such as density, viscosity, volatility, ignitability and so on. We plan to apply the fuel design approach to HCCI combustion generated in a real engine, and examine the possibility of mixture formation control using the flash boiling spray. Spray characteristics of two component fuel with a flash boiling phenomenon was investigated using Shlieren and Mie scattering photography. Test fuel was injected into a constant volume vessel at ambient conditions imitated injection timing BTDC of a real engine. As a result, it was found that a flash boiling phenomenon greatly changed spray structure, especially in the conditions of lower temperature and density. Therefore, availability of mixture formation control using flash boiling spray was suggested.

• 한국공작기계학회논문집
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• 제17권1호
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• pp.1-6
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• 2008

There are some methods that have been used to manage a degasing process in recent years, such as an injection method that uses aluminum molten metal powder and chemicals supplier and input method that supplies argon and nitrogen, or chlorine gas by using a gas blow-tube. However, these methods show some problems, and it shows that it is a difficult process to handle, pollution due to producing a lot of toxic gases like chlorine and fluoride gas, irregular effects, and lowering work efficiency due to the excessive processing time. The problems that are the most fatal are the producing a lot of sludge due to the reaction of aluminum molten metal with chemicals, loss of metals, and decreasing the life of refractory materials. In order to solve these problems, this paper develops a technology that is related to aluminum continuous casting molten metal and monolithic degasing apparatus. A degasing apparatus developed in this study improved the existing methods and prevented environmental pollution with smokeless, odorless, and harmlessness by using a new method that applies argon and nitrogen gas in which the methods used in the West and Japan are eliminated. The method developed in this study decreases the molten metal processing and settling time compared to the existing methods and improves the workers' health, safety, and environment because there is no pollution in processes.