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아드레날린 동작성 약물이 구강점막의 리도케인 Clearance에 미치는 영향
명재원,안명석,김중수,이종훈 대한구강생물학회 1992 International Journal of Oral Biology Vol.16 No.2
Some adrenergic drugs have been used as vasoconstrictors in local anesthetics for prolongation of acting duration and minimization of side effects. But, the exact role of vasoconstrictors on the clearance of local anesthetics in oral mucosa was not investgated. This experiment was carried out to clarify the influences of some adrenergic drugs on the clearance of lidocaine in oral mucosa. Sprague-Dawley rats were devided into control(no vasoconstrictor) group, epinephrine(1:100,000)-contained group, norepinephrine(1:30,000)-contained group and phenylephrine(1:2,500)-contained group. In urethane(1.2g/㎏) anesthetized rats, 300μl of 2% lidocaine with or without vasoconstrictor injected in the palatal mucosa. According to time schedule, they were sacrificed by exsanguination immediately, 30 and 60 minutes later after injection, respectively. The palatal mucosa was removed and homogenized by mechanical force and ultrasonicated in 0.1N HCl(500μl). The samples were centrifuged after akalization. Aliquat of the supernatant was injected into HPLC. Also, systemic effects of vasoconstrictors were evaluated with recording arterial blood pressures in common carotid artery. In control animals, lidocaine clearances reached 85.4% and 89.3% at 30 and 60 minutes after injection, respectively. At 30 minutes after injection, lidocaine clearances of vasoconstrictor contained group were different from control group significantly(p<0.01), and lidocaine clearance of phenylephrine contained group appeared higher than those of the other vasoconstrictor contained groups(p<0.05). But, at 60 minutes after injection, only epinephrine contained group had lower lidocaine clearance than control group(p<0.01). Intraperitoneal injection of the same dosage of palatal mucosa injecton of these vasoconstrictors did not elicit the change of blood pressure and heart rate.
수중 내 발포성 정제로부터 생성된 미세기포 특성에 관한 실험적 연구
명재원,맹주영,김영준,조경민,이웅희,김성호,박영철,손영구,신원규 한국가시화정보학회 2021 한국가시화정보학회지 Vol.19 No.3
Effervescent tablets generate gas bubbles when chemical reaction occurs between water and tablets. Most of previous studies have been focused on pharmaceutical characteristics of tablets. However, for their applications in disinfectants, cleaners, and pesticides, physical characteristics of bubbles released from the effervescent tablets when they are in water are important. In this study, we experimentally investigated the characteristics of microbubbles generated by an effervescent tablet made of sodium bicarbonate and tartaric acid using PDPA and high-speed camera. Microbubbles were generated using different weights of effervescent tablet as well as in different water temperature. The experimental study shows increase in reaction time, bubble concentration and rise velocity as the weight of effervescent tablet increases from 1 to 20 g. The decrease in average bubble diameter was observed when the temperature of water increased from 25 to 45 ℃. Further, reaction time varies inversely with increase in water temperature, while bubble rise velocity is directly proportional to increase in water temperature. Effervescent table continuously generates the bubble with approximately constant diameter (235 μm) in the water. However, bubble concentration and bubble rise velocity decreased over time.
명재원,Prashant.R. Deshmukh,신원규 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.120 No.-
Effective oil–water separation is necessary to cope with frequent oil spill accidents, which pose huge risksto the marine ecosystem. Among existing oil–water separation methods, gravitational filtration is themost efficient. When super-wetting materials are used for gravitational filtration, they have the meritof high efficiency but they still have the disadvantages of high price, low eco-friendliness, and complexprocedures. To overcome those problems, we fabricated a stainless steel mesh by a one-step methodvia an annealing process. The annealed mesh achieved both superhydrophilicity and superoleophilicity. For oil–water separation, the annealed mesh, which was pre-wetted by water, demonstrated underwatersuperoleophobicity. Thus, this study confirmed that the proposed system can separate various oily mixtureswith high efficiency (>99 %) and it exhibits underwater anti-oil-fouling.
The effect of the nozzle exit geometry on the flow characteristics of the free condensing jet
명재원,김승완,김대희,김종태,신원규 한국원자력학회 2024 Nuclear Engineering and Technology Vol.56 No.7
In the present study, we investigated the velocity distribution, temperature distribution and condensation characteristics of steam jet issuing from four different orifice nozzles with a Reynolds number of approximately 79,000 using the phase Doppler particle analyzer system and a K-type thermocouple. The steam jet discharged from the orifice nozzle has a wider jet width compared to pipe nozzle because of the vena-contracta which can enhance the mixing of steam jet with the ambient air. Therefore, the orifice jet showed less condensation due to its wideness, resulting in small velocity decay rate and large temperature decay rate due to momentum conservation and decreased latent heat release compared to pipe nozzle, respectively. Also, the wider jet width of the orifice jet resulted in larger velocity and temperature spread rate compared to the pipe jet. In addition, the increase in the aspect ratio of the orifice jet led to more condensation and larger velocity spread rate and temperature spread rate due to both the vena-contracta and axis-switching effect, resulting in the increase of jet entrainment.
최적 타원 생성 알고리즘 기반 2상 기포 유동 특성 분석을 위한 영상 처리 기법
명재원(Jaewon Myeong),조설희(Seolhee Cho),신원규(Weon Gyu Shin) 대한기계학회 2020 대한기계학회 춘추학술대회 Vol.2020 No.12
In this study, an image processing method for the measurement of two-phase bubbly flow was developed. Bubble shadowgraphy images were obtained using a high-speed CCD camera. Some bubbles are generated as single unit and others are overlapped or clustered. Single bubbles can be easily analyzed using parameters such as bubble shape, centroid, and area. But, overlapped bubbles have a problem of bubble segmentation. Several approaches using watershed algorithm were proposed for the bubble segmentation. However, it is difficult to transform clustered bubbles into segmented bubbles. In order to obtain the size distribution of bubbles, we present a method of splitting overlapping bubbles and approximating them to ellipse. There is only 5% error difference between manual and automatic analysis. Furthermore, the error can be reduced down to 1.2% when a correction factor is used. The ellipse fitting algorithm developed in this study can be used to measure bubble parameters accurately by reflecting the shape of the bubbles.