• 한방안이비인후피부과학회지
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• 제19권1호
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• pp.1-10
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• 2006

This experimental study was performed to investigate the effect of herbal eye drops, Tangpo-san and Coptidis rhizoma on Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa keratitis. The following results were obtained by using Minimum inhibition Concentration(MIC) and inhibition Zone. 1. MIC on Staphylococcus aureus in Tangpo-san was 100%, in Coptidis rhizoma was 100% and in Cravit was 0.1% 2. MIC on Staphylococcus epidermidis in Tangpo-san was 100%, in Coptidis rhizoma was 10% and in Cravit was 0.1%. 3. MIC on Pseudomonas aeruginosa in Tangpo-san, Coptidis rhizoma was not showing and in Cravit was 0.1%. 4. The size of inhibition zone on Staphylococcus aureus for Tangpo-san was 13.3mm in $50{\mu}{\ell}$, for Coptidis rhizoma was 26mm in $50{\mu}{\ell}$ and for Cravit was 31mm in $50{\mu}{\ell}$, showing the highest antibacterial effect. 5. The size of inhibition zone on Staphylococcus epidermidis for Tangpo-san was 16mm in $50{\mu}{\ell}$, for Coptidis rhizoma was 25mm in $40{\mu}{\ell}$ and for Cravit was 34mm in $50{\mu}{\ell}$, showing the highest antibacterial effect. 6. The size of inhibition zone on Pseudomonas aeruginosa for Tangpo-san, Coptidis rhizoma was not and for Cravit was 24.7mm in $50{\mu}l$, showing the antibacterial effect. In addition, the results shows that the herbal eye drops, Tangpo-san and Coptidis rhizoma can be used to cure Staphylococcus aureus, Staphylococcus epidermidis keratitis and if further study is performed, the use of herbal eye drops will be valuable and beneficial in the clinical medicines.

• Journal of Dental Anesthesia and Pain Medicine
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• 제20권4호
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• pp.223-231
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• 2020

Background: The most frequent complication of nasotracheal intubation (NTI) is epistaxis. Epinephrine nasal gauze packing has been used conventionally as a pre-treatment for reducing epistaxis, but it carries a disadvantage of pain and anxiety in patients. However, xylometazoline drops are easier to administer and more convenient for patients. We aimed at comparing the effectiveness of xylometazoline drops and epinephrine merocele packing in reducing bleeding and postoperative complications in our population. Methods: Our study enrolled 120 patients in a double-blind randomized controlled trial. We randomly allocated ASA1 or 2 adult patients into 2 groups: Group X and Group E. Group X received 0.1% xylometazoline nasal drops, and epinephrine (1:10,000) merocele nasal packing was used in Group E. The primary outcome was the incidence of bleeding during NTI; the severity of bleeding, navigability, bleeding during extubation, and postoperative complications were secondary outcomes. We used IBM SPSS and Minitab software for statistical analysis, and P < 0.05 was considered statistically significant. Results: We analyzed the data of 110 patients: 55 in Group X and 55 in Group E. The two groups did not have different bleeding incidence (56.4% vs 60.0%; P = 0.70); however, the incidence of severe bleeding was less with xylometazoline than with epinephrine (3.63% vs 14.54%; P < 0.05). We also observed less bleeding during extubation (38.2% vs 68.5%; P < 0.05) with xylometazoline. Other secondary outcomes were akin to both groups. Conclusion: The incidence of severe and post-extubation bleeding was significantly less with xylometazoline. Hence, it may be an effective alternative for reducing the incidence and severity of epistaxis during NTI.

• 대한기계학회논문집B
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• 제28권12호
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• pp.1535-1548
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• 2004

Condensation heat transfer experiments were conducted with the oblong shell and plate heat exchanger without oil in a refrigerant loop using R-l34a, R-407C and R-410A. An experimental refrigerant loop has been developed to measure the condensation heat transfer coefficient h$_{r}$ and frictional pressure drop $\Delta$p$_{f}$ of the various refrigerants in a vertical oblong shell and plate heat exchanger. The effects of the refrigerant mass flux(40∼80kg/$m^2$s), average heat flux(4∼8kW/$m^2$), refrigerant saturation temperature(30∼4$0^{\circ}C$) and vapor quality of refrigerants on the measured data were explored in detail. Similar to the case of a plate heat exchanger, even at a very low Reynolds number, the flow in the oblong shell and plate heat exchanger remains turbulent. A comparison of the performance of the various refrigerants revealed that R-410A had the highest heat transfer performance followed by R-l34a, and R-407C had the lowest performance of the refrigerants tested. The pressure drops were also reported in this paper. The pressure drops for R-410A were approximately 45% lower than those of R-l34a. R-407C had 30% lower pressure drops than R-l34a. Experimental results were compared with several correlations which predicted condensation heat transfer coefficients and frictional pressure drops. Comparison with the experimental data showed that the previously proposed correlations gave unsatisfactory results. Based on the present data, empirical correlations of the condensation heat transfer coefficient and the friction factor were proposed.tor were proposed.sed.

• 한국응용곤충학회지
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• 제7권
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• pp.61-64
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• 1969

배나무 적성병균의 병자각세대에 분필하는 병자적 성분중 free sugar를 중심으로 기생엽중의 free sugar와의 상관관계를 생화학적으로 연구 고찰하여 아래와 같은 결과를 얻었다. 1. 병자각세대에 분필하는 병자적 성분중 free sugar를 paper chrmarography로 분석한 결과 fructose만이 확인되었다. 2. 기주 향나무 엽중의 free sugar는 galactose와 glucose 및 미지물질 2종임을 확인하였다. 3. 기주 배나무엽중의 free sugar로는 glucose, fructose 및 galactose를 확인하였다. 4. 배나무엽중의 arbutin-을 결정화하고 그 구조를 일반적인 방법과 paper chromatography로 분석하여 glucose와 hydroquinone의 결합체임을 확인하였다. 5. 0.05M arbutin 용액에 Emulsin을 조제하여 배양한 결과 분해 생성물로서 glucose를 확인하였고 이들 Emulsin은 모두 $\beta-glycosidase$를 함유하고 있음이 확정되었다. 이상 결과에서 보는 바와같이 병자적중의 fructose는 배나무 엽중에 있는 free sugar 및 glycoside인 arbutin이 Emulsin에 의하여 분해되어 glucose로 변화된 다음 균체내의 isomerase에 의하여 isomerization된 것이라 추측된다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.272-273
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• 2013

Some living thingsuse micro- or nano- structures for living in nature. Scientists and engineers made efforts to mimic them, and they succeeded in making new types of applications. They used 'Namib desert beetle' to self-filling device by moisture harvesting and 'lotus leaf' to self-cleaning device by water repelling. 'Namib desert beetle' and lotus leaf have micro-patterns on their surface, which consists of hydrophobic or hydrophilic materials [1]. Moreover, micro-patterns on the surface make self-filling or self-cleaning property enhanced because of the surface roughness. Surface roughness enhances wettability [2]. Micro-pattern is a significant factor to make the surface be functional, so we want to make new types of functional surface by micro-patterning. In this work,we make several functional micro-patterns (radial, line, and dot arrays) using maskless lithography and analyze the characteristics of each micro-pattern. In order to analyze and understand surface characteristics, micro-patterns with varying sizes are investigated. All experiments are proceeded on mr-DWL5 photo resists coated on silicon wafers in same condition. All the experiments have demonstrated good performances about hydrophobic or hydrophilic property corresponding to their material and structural combinations. In radial micro-pattern, although the surface is flat, water drops on hydrophilic radial pattern can be convergent to a middle point and water drops on hydrophobic radial pattern can be divergent from the middle point. In line array micro-pattern, water drops can roll off along only one direction in parallel with the line arrays. Such phenomena might be mainly caused by the local change of surface roughness. From these results, controlling the movement and direction of water drops is made feasible without introducing a slope, which can potentially be used for new types of applications.

• 한국지형학회지
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• 제23권3호
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• pp.105-122
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• 2016

To evaluate the changes in the physical characteristics of open rainfall related to canopy effects and rainfall intensity in Korea, the terminal velocity of raindrops and drop size distributions(DSD) were continuously measured by an optical-laser disdrometer in an open site(Op) and in two forest stands(Th1: Larix leptolepis, Th2: Pinus koraiensis) during five rainfall events in 2008. The terminal velocity, DSD and two forms of kinetic energy(KE, $Jm^{-2}$ $mm^{-1}$; KER, $Jm^{-2}$ $h^{-1}$) of open rainfall drops were determined and were compared with those of throughfall drops under two different canopy heights. The effects of the canopy and rainfall intensity, together with wind speed, on the changes in drop size and kinetic energy of throughfall were evaluated. Throughfall drops were larger than open rainfall drops. The distribution of terminal velocities for the drop sizes measured at Th2 was lower than that at Op; however, at Th1 the distribution was similar to that at Op. The total kinetic energy of throughfall at Th1 and Th2 was higher than the total kinetic energy of open rainfall, and the kinetic energy distribution for the drop sizes wassimilar to the drop size distribution. The observed throughfall-KER at Th1 was lower than an estimate previously produced using a model. The overestimation from the modeled value at Th1 was likely to be due to overestimated values of a square root transformation of fall height and its coefficient in the model because the distributions of terminal velocity for the drop size measured at Th1 were similar to those of open rainfall.

• Asia-Pacific Journal of Atmospheric Sciences
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• 제54권4호
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• pp.587-598
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• 2018

The impacts of aerosol loading on surface precipitation from mid-latitude deep convective systems are examined using a bin microphysics model. For this, a precipitation case over north central Mongolia, which is a high-altitude inland region, on 21 August 2014 is simulated with aerosol number concentrations of 150, 300, 600, 1200, 2400, and $4800cm^{-3}$. The surface precipitation amount slightly decreases with increasing aerosol number concentration in the range of $150-600cm^{-3}$, while it notably increases in the range of $600-4800cm^{-3}$ (22% increase with eightfold aerosol loading). We attempt to explain why the surface precipitation amount increases with increasing aerosol number concentration in the range of $600-4800cm^{-3}$. A higher aerosol number concentration results in more drops of small sizes. More drops of small sizes grow through condensation while being transported upward and some of them freeze, thus increasing the mass content of ice crystals. The increased ice crystal mass content leads to an increase in the mass content of small-sized snow particles largely through deposition, and the increased mass content of small-sized snow particles leads to an increase in the mass content of large-sized snow particles largely through riming. In addition, more drops of small sizes increase the mass content of supercooled drops, which also leads to an increase in the mass content of large-sized snow particles through riming. The increased mass content of large-sized snow particles resulting from these pathways contributes to a larger surface precipitation amount through melting and collision-coalescence.

• Journal of Advanced Marine Engineering and Technology
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• 제28권5호
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• pp.818-826
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• 2004

The spray-induced mixing characteristics and thermal decomposition of aqueous urea solution into ammonia have been studied to design optimum sizes and geometries of the mixing chamber in SCR(Selective Catalytic Reduction) system. The cold flow tests about the urea-injection nozzle were performed to clarify the parameters of spray mixing characteristics such as mean diameter and velocity of drops and spray width determined from the interactions between incoming air and injected drops. Discrete particle model in Fluent code was adopted to simulate spray-induced mixing process and the experimental results on the spray characteristics were used as input data of numerical calculations. The simulation results on the spray-induced mixing were verified by comparing the spray width extracted from the digital images with the simulated Particle tracks of injected drops. The single kinetic model was adopted to predict thermal decomposition of urea solution into ammonia and solved simultaneously along with the verified spray model. The hot air generator was designed to match the flow rate and temperature of the exhaust gas of the real engines The measured ammonia productions in the hot air generator were compared with the numerical predictions and the comparison results showed good agreements. Finally, we concluded that the design capabilities for sizing optimum mixing chamber were established.

• 대한기계학회논문집B
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• 제24권6호
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• pp.822-833
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• 2000

This experimental study concerns the characteristics of a transitional flow in a concentric annulus with a diameter ratio of 0.52, whose outer cylinder is stationary and inner one rotating. The pressure drops and skin-friction coefficients have been measured for the fully developed flow of water and that of glycerine-water solution (44%) at a inner cylinder rotational speed of $0{\sim}600$ rpm, respectively. The transitional flow has been examined by the measurement of pressure drops and the visualization of flow field, to reveal the relation of the Reynolds and Rossby numbers with the skin-friction coefficients and to understand the flow instability mechanism. The present results show that the skin-friction coefficients have the significant relation with the Rossby numbers, only for laminar regime. The occurrence of transition has been checked by the gradient changes of pressure drops and skin-friction coefficients with respect to the Reynolds numbers. The increasing rate of skin-friction coefficient due to the rotation is uniform for laminar flow regime, whereas it is suddenly reduced for transitional flow regime and, then, it is gradually declined for turbulent flow regime. Consequently, the critical (axial-flow) Reynolds number decreases as the rotational speed increases. Thus, the rotation of inner cylinder promotes the early occurrence of transition due to the excitation of taylor vortices.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집B
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• pp.631-636
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• 2000

The experimental study concerns the characteristics of a transitional flow in a concentric annulus with a diameter ration of 0.52, whose outer cylinder is stationary and inner one rotating. The pressure drops and skin-friction coefficients have been measured for the fully developed flow of water and that of glycerine-water solution (44%) at a inner cylinder rotational speed of $0{\sim}600$ rpm, respectively. The transitional flow have been examined by the measurement of pressure drops and the visualization of flow field, to reveal the relation of the Reynolds and Rossby numbers with the skin-friction coefficients and to understand the flow instability mechanism. The present results show that the skin-friction coefficients have the significant relation with the Rossby numbers, only for laminar regime. The occurrence of transition has been checked by the gradient changes of pressure drops and skin-friction coefficients with respect to the Reynolds numbers. The increasing rate of skin-friction coefficient due to the rotation is uniform for laminar flow regime, whereas it is suddenly reduced for transitional flow regime and, then, is gradually declined for turbulent flow regime. Consequently, the critical (axial-flow) Reynolds number decreases as the rotational speed increases. Thus, the rotation of inner cylinder promotes the early occurrence of transition due to the excitation of taylor vortices.