• Clinical and Experimental Reproductive Medicine
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• v.17 no.1
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• pp.57-63
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• 1990

The purpose of this study is to improve fertilization rate in IVF-ET program of patients with male infertility used micromanipulation technique, partial zona dissection (PZD) or micro-insemination by sperm transfer (MIST). The results were as follows 1. The fertilization rate of non-micromanipulated oocytes and micromanipulated (PZD) oocytes were 12.5% (n=2) and 42.2% (n=19), respectively, and showed significant differences between two groups (p<0.05). 2. The fertilization rate of micromanipulated (MIST) oocytes was 30% (n=27). 3. The damage rate of Group 1 (PZD) and Group 2 (MIST) were 15.7% (3/19) and 29.6% (8/27), respectively. 4. One pregnancy resulted following replacement of micromanipulated (MIST) embryos in 4 patients.

• Fire Science and Engineering
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• v.16 no.1
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• pp.1-7
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• 2002

Halogen-based fire suppressing agents have environmental problems because they cause the stratospheric ozone depletion and globe warming. Hence, fire suppression system using fine water mist became the center of interest as a substitution of halon. As a study about this, it is in progress to make the optimum droplet size by using water mist nozzles and to improve the extinguishing performance of water mist by using additives. Before this study, the extinguishing time of ethanol and n-heptane pool fire was measured with changing of water mist droplet size, flow density, discharge pressure, and fire size. In this study, on adding the additives to improve physical and chemical extinguishing performance of water mist, the extinguishing performance would evaluate and the optimum condition would find out. As a result, in case of ethanol pan 1 pool fire, the extinguishing time of the water mist by adding of 2.5 wt% NaCl and 0.3% AFFF got shorter 27% and 60% than the pure water mist. Adding of AFFF was to decrease the flame temperature by forming thin film on the fuel surface and to decrease the evaporation of n-heptane fuel. In case of NaCl, alkali salt crystals showed on the flame surface.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1307-1312
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• 2007

This experiments are performed to investigate the effect of ventilation velocity on a high pressure water mist fire suppression in subway train. The experiment is conducted in half scale modeled train of a steel-welled enclosure (8.0m*2.4m*2.1m). The ventilation velocity is controlled by the ventilation duct through an inverter in the range of 0 to 2 m/s. The coverage-radius and an injection angle of an high pressure water mist system are measured. The mist nozzle with 7-injection holes is operated with pressure 80 bar. The heptane pool fires are used. The fire extinguishment times and the temperatures are measured for the ventilation velocities. In conclusion, because the momentum of injected water mist is more dominant than that of ventilation air, the characteristics of water mist, the fire extinguishment times and the temperatures are affected very little by ventilation velocity.

• Neonatal Medicine
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• v.25 no.3
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• pp.109-117
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• 2018

Purpose: Minimally invasive surfactant therapy (MIST) is currently used as a method of surfactant replacement therapy (SRT) for the treatment of respiratory distress syndrome (RDS) in preterm infants with a gestational age of less than 30 weeks. However, few studies have been conducted on MIST in neonates with a gestational age of 30 weeks or more. In this study, we compared MIST with endotracheal intubation as a rescue SRT for spontaneously breathing neonates with a gestational age of 30 weeks or more who were diagnosed with RDS. Methods: We investigated the clinical characteristics of spontaneously breathing neonates admitted to the neonatal intensive care unit of the Inje University Sanggye Paik Hospital from January 1, 2014 to December 31, 2016. These neonates were born at a gestational age of 30 weeks or more and were diagnosed with RDS. The neonates who were administered surfactant by MIST were categorized into the MIST group (n=16) and those who underwent endotracheal intubation were categorized into the control group (n=45). Thereafter, the clinical characteristics between the groups were compared. Results: Compared to the control group, the MIST group was less likely to require mechanical ventilation within 72 hours (P<0.001). The frequency of bradycardia during SRT was also low in the MIST group (P=0.033). Conclusion: MIST is considered relatively feasible and safe for treating RDS for reducing the need for mechanical ventilation and decreasing the occurrence of bradycardia during surfactant administration in neonates with a gestational age of 30 weeks or more.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.388-388
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• 2016

Chemical mist deposition (CMD) of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) was investigated with cavitation frequency f, solvent, flow rate of nitrogen, substrate temperature $T_s$, and substrate dc bias $V_s$ as variables for efficient PEDOT:PSS/crystalline (c-)Si heterojunction solar cells (Fig. 1). The high-speed camera and differential mobility analysis characterizations revealed that average size and flux of PEDOT:PSS mist depend on f, solvent, and $V_s$. The size distribution of mist particles including EG/DI water cosolvent is also shown at three different $V_s$ of 0, 1.5, and 5 kV for a f of 3 MHz (Fig. 2). The size distribution of EG/DI water mist without PEDOT:PSS is also shown at the bottom. A peak maximum shifted from 300-350 to 20-30 nm with a narrow band width of ~150 nm for PEDOT:PSS solution, whose maximum number density increased significantly up to 8000/cc with increasing $V_s$. On the other hand, for EG/water cosolvent mist alone, the peak maximum was observed at a 72.3 nm with a number density of ~700/cc and a band width of ~160 nm and it decreased markedly with increasing $V_s$. These findings were not observed for PEDOT:PSS/EG/DI water mist. In addition, the Mie scattering image of PEDOT:PSS mist under white bias light was not observed at $V_s$ above 5 kV, because the average size of mist became smaller. These results imply that most of solvent is solvated in PEDOT:PSS molecule and/or solvent is vaporized. Thus, higher f and $V_s$ generate preferentially fine mist particle with a narrower band width. Film deposition occurred when $V_s$ was impressed on positive to a c-Si substrate at a Ts of $30-40^{\circ}C$, whereas no deposition of films occurred on negative, implying that negatively charged mist mainly provide the film deposition. The uniform deposition of PEDOT:PSS films occurred on textured c-Si(100) substrate by adjusting $T_s$ and $V_s$. The adhesion of CMD PEDOT:PSS to c-Si enhanced by $V_s$ conspicuously compared to that of spin-coated film. The CMD PEDOT:PSS/c-Si solar cell devices on textured c-Si(100) exhibited a ${\eta}$ of 11.0% with the better uniformity of the solar cell parameters. Furthermore, ${\eta}$ increased to 12.5% with a $J_{sc}$ of $35.6mA/cm^2$, a $V_{oc}$ of 0.53 V, and a FF of 0.67 with an antireflection (AR) coating layer of 20-nm-thick CMD molybdenum oxide $MoO_x$ (n= 2.1) using negatively charged mist of 0.1 wt% 12 Molybdo (VI) phosphoric acid n-Hydrate) $H_3(PMo_{12}O_40){\cdot}nH_2O$ in methanol. CMD. These findings suggest that the CMD with negatively charged mist has a great potential for the uniform deposition of organic and inorganic on textured c-Si substrate by adjusting $T_s$ and $V_s$.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.17 no.1
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• pp.71-80
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• 2007

The purpose of this study was to assess the ambient level of Polynuclear aromatic hydrocarbons(PAHs), oil mist of the metalworking fluids(MWFs), especially in heat treat industry and non heat treat industry. And we assessed the relationship of the pattern of exposed PAHs with oil mist during survey day. The study population of heat treat industries contained 98 workers, non-heat treat industry contained 40 workers. Personal samples were taken for ambient monitoring of PAHs and oil mist. PAHs was to analyze the relationship of airborne oil mist. The geometric mean of airborne total PAHs was $3.44{\mu}g/m^3$ in heat treat industry and $0.13{\mu}g/m^3$ in non heat treat industry, Pyrene and Benzo(a)pyrene was detected from heat treat industry and Naphthalene in heat treat industry was significantly detected higher than in non heat treat industry. The geometric mean of airborne oil mist was $0.19{\mu}g/m^3$ in heat treat industry and $0.70{\mu}g/m^3$ in non-heat treat industry. The correlation between oil mist and total PAHs was shown below, total PAHs in workers of non heat treat industry and heat treat industry were not significantly correlated with oil mist

• Clinical and Experimental Pediatrics
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• v.65 no.4
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• pp.188-193
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• 2022

Background: Respiratory distress syndrome (RDS) is a common cause of hospitalization and death in preterm infants who require surfactant treatment and respiratory support. Purpose: This study aimed to compare the clinical outcomes of minimally invasive surfactant therapy (MIST) and the INtubation, SURfactant administration, and Extubation (INSURE) technique in preterm infants with RDS. Methods: In this clinical trial, 112 preterm infants born at 28-36 weeks of gestation and diagnosed with RDS randomly received 200-mg/kg surfactant by MIST or the INSURE method. In the MIST group, surfactant was administered using a thin catheter (5F feeding tube); in the INSURE group, surfactant was administered after intubation using a feeding tube and the tracheal tube was removed after positive pressure ventilation was started. Nasal continuous positive airway pressure was applied in both groups for respiratory support and the postprocedure clinical outcomes were compared. Results: The mean hospitalization time was shorter for infants in the MIST group than for those in the INSURE group (9.19±1.72 days vs. 10.21±2.15 days, P=0.006). Patent ductus arteriosus was less frequent in the MIST group (14.3% vs. 30.4%, P=0.041). Desaturation during surfactant administration occurred less commonly in the MIST group (19.6% vs. 39.3%, P=0.023). There were no significant intergroup differences in other early or late complications. Conclusion: These results suggest that surfactant administration using MIST could be a good replacement for INSURE in preterm infants with RDS since its use reduced the hospitalization time and the number of side effects.

• Fire Science and Engineering
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• v.15 no.4
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• pp.41-48
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• 2001

Halogen-based fire suppressing agents have been the most effective fire suppressants and widely used for flammable liquid and electric fire. However they have environmental problems causing stratospheric ozone depletion and globe warming. As a substitution of halon, fire suppression system using fine water mist is one of an effective fire suppressant. Suffocating and cooling effects of water mist are increased by the evaporation characteristics because it has droplet size less than 1,000 $\mu{m}$ and very large surface area. In this study, the extinguishing characteristics of fire was measured with changing of water mist droplet size, flow density; discharge pressure, and fire size. As a result, the extinguishing time of pool fire was shortened with the increase of flow density and in case of low flow density less than 0.5$\pm$0.05 ml/$\textrm{cm}^2$ . min, the extinguishing time was shortened with the increase of droplet size. The cycling discharge was effective for $\eta$-heptane pool fire, and total amount of water mist required to extinguish fire was reduced to a quarter compare with continuous discharge.

• Atmosphere
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• v.17 no.1
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• pp.109-114
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• 2007

The mist on the inside of an automobile windshield is not only uncomfortable but also very dangerous because it obstructs the driver's vision. However, the removal process of the mist has never been studied in detail. This study performed experiments analyzing the mechanism causes the mist in a car and investigated the appropriate removal process. The experiments were performed on two rainy days, 10 April 2006 and 26 May 2006, with temperature and relative humidity sensors of testo-175-H2 and DICKSON-TK500. We found a passenger increased water vapor by 0.2 g $min^{-1}$ through respiration and thereby relative humidity (RH) from 55% to 67% in 8 minutes. Even though RH was not saturated, misting occurred because the humid air contacted the colder surface of the window. To remove the mist, it is necessary to increase the temperature or inflow drier air in the car. Therefore, we expected that the heater would be more effective than air conditioner for this matter. However, the outcome was the other way around due to the structure of the heating and cooling system in the car. When the air-conditioner was on, colder and drier air was generated and flowed through the so-called evaporator. Droplets were produced in the evaporator due to cooling procedure. When the heater was on, the warm air evaporated the droplets and increased the water content in the air resulting in an increase of relative humidity. Consequently, the air conditioner is more effective than the heater to remove the mist.

• Journal of the Society of Disaster Information
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• v.8 no.4
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• pp.401-410
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• 2012

The study verified the extinguishing performance of the low pressure water-mist system, which is used to extinguish fire at domestic wooden architecture, through a fire test. Made of inflammable materials, a wooden house is vulnerable to fire, and the size of fire may vary from the early stage in case of arson. With the discharging pressure of 8 bar and the flow rate of 35 lpm, the low pressure water-mist nozzle used in the experiment has considerable discharging amount compared to other water-mist nozzles. The extinguishing performance was tested based on the size of fire and architecture. Test results demonstrated that the extinguishing performance was not affected by the size of a house, but decreased significantly when the size of fire was above unit 1. Taking into account that the environment of actual wooden cultural properties is more vulnerable than that of the experiment model, sufficient investigation on extinguishing performance is required to apply the water-mist extinguishing system to wooden architecture.