• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.9
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• pp.1770-1779
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• 1992

The present study investigated dynamically and thermally interacting droplets in a closely spaced tandem array. By measuring the velocity and diameter of the droplet traveling along the isothermal vertical plate drag coefficients and vaporization rates of droplets at certain location were obtained. During the experiment initial droplet spacings were less than 5, and initial droplet diameters were ranged between 280 .mu.m and 700 .mu.m Drag coefficients on closely spaced droplets were placed far below the standard drag coefficient, for which it was caused turbulence induced from aforelocating droplets also narrow spaces among droplets restricted heat transfer to droplets from hot gas flow. In addition evaporated vapor entrapted between droplets was major factor in delaying droplet vaporization. With the experimental results the drag coefficient was correlated with respect to Reynolds number for the droplet as follows : $c_{D}$ =2.4/Red.$^{0.37}$

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.15 no.1
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• pp.219-225
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• 2002

By the treatment of herb-med, acupunture and Korean(韓方)- medicine, symptoms of nasal polyp has taken a turn for the better, but nasal polyp itself was removed in completely was imppssible. Althogh a surgical operation of western -medicine, the nasal polyp tend to recur. In China, the new treatment that Chinese(漢方)-medicine and western-medicine combined was tried. The trial was effective in decreasing recurrance rate and treatment period. But it's a case of completely removed Nasal polyp through the more vanous Korean(韓方)-medicine, The patient answered in the affinnative of electric acupunture, nasal bloodletting, vaporization, external application against the existing treatment(herb-med, acupunture, moxa). If electric acupunture, nasal bloodletting, vaporization, external application are receiving careful study, they are a help to nasal polyp and opthalmologic, otolaryngologic disease.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.5
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• pp.718-724
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• 2000

A model for depicting the rocket engine combustion process is presented and several experiments near a design point are provided with a FOOF type of unlike impinging injector for a propellant combination of Jet A-1 fuel and liquid-oxygen. The model is based on the assumption that the vaporization is the rate-controlling combustion process. The effects of initial drop size and initial drop velocity are systematically shown and discussed. It is seen that in the midst of considered parameters the change of initial drop size is more sensitive to the performance. The proposed model describes qualitative trends of combustion process well despite of its simplicity.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.6
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• pp.625-631
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• 2014

In this study, according to increase of thermoelectric power plants that use LNG, LNG-FSRU(Floating-Storage and Regasification Unit) appeared and it is installed on the Topside in order to deliver in a gaseous state to consumers who are in the shore. This study about the study on the characteristics analysis of the system depending on changes in performance with the vaporization and temperature of the heat source. For the characteristics analysis of the system, we devided vaporization method into Ethylene glycol water vaporization method and sea water as a heat source. Then the system that can vaporize 200ton per hour of LNG of $-157.9^{\circ}C$ and 10,400kPa was configured, and according to the temperature of supplied sea water, required minimum flow rate value was calculated. Also in case of using Ethylene glycol Water as a vaporization method, providing for regional and seasonal factors such as decrease of temperature of water. The system is configured by adding a steam boiler of $174.5^{\circ}C$, 775kPa as heat source. The generation amount of the steam required according to the performance of the vaporizer compared to the water temperature changes in the steam boiler and the amount of required evaporative performance due to changes in the quantity of steam and Ethylene glycol Water was confirmed.

• Safety and Health at Work
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• v.1 no.2
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• pp.175-182
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• 2010

Objectives: This study examined how ethanolamines (EAs) with the same functional alcohol group ($HOCH_2CH_2$), such as mono-EA (MEA), di-EA (DEA), and tri-EA (TEA), in water-based metalworking fluids (wbMWFs) are vaporized, condensed, and transformed by heat generated during metalworking. Methods: Two types of experimental apparatus were manufactured to achieve these objectives. Results: Vaporization tests using a water bath showed that the vaporization rate increased markedly from $0.19\;mg/m^2{\cdot}min$ at $23.5^{\circ}C$ to $8.04\;mg/m^2{\cdot}min$ at $60^{\circ}C$. Chamber tests with a heat bulb revealed that "spiked" MEA was fully recovered, while only 13.32% of DEA and no TEA were recovered. Interestingly, non-spiked types of EAs were detected, indicating that heat could convert EAs with more alcohol groups (TEA or DEA) into other EAs with fewer group(s) (DEA or MEA). The EA composition in fresh fluid was 4% DEA, 66% TEA, and 30% MEA, and in used fluids (n = 5) was 12.4% DEA, 68% TEA, and 23% MEA. Conversion from TEA into DEA may therefore contribute to the DEA increment. Airborne TEA was not detected in 13 samples taken from the central coolant system and near a conveyor belt where no machining work was performed. The DEA concentration was $0.45\;mg/m^3$ in the only two samples from those locations. In contrast, airborne MEA was found in all samples (n = 53) regardless of the operation type. Conclusion: MEAs easily evaporated even when MWFs were applied, cleaned, refilled, and when they were in fluid storage tanks without any metalworking being performed. The conversion of TEA to DEA and MEA was found in the machining operations.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.8
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• pp.134-139
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• 2000

In order to understand the removal mechanism and seek the optimal conditions. KrF excimer laser ablation of Cr films on glass substrates is investigated. The surface morphology of the laser-irradiated spot is examined by SEM. The measured single-shot ablation rate is found to be about two times the result of numerical analysis based on a surface vaporization model and heat conduction theory. Surface morphology examination indicates that the Cr film is removed by the sequence of melting-surface vaporization-,melt expulsion by plasma recoil and that the outmost ripple of the diffraction pattern gives a strong effect on the morphology of molten Cr during the melting and vaporization processes. To seek the optimal process parameters for micro patterning morphological investigation is carried out experimentally on samples having different chromium film thicknesses. Optimal processing conditions are determined to enhance the accuracy and quality of thin film removal for micro patterning.

• Investigative and Clinical Urology
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• v.59 no.6
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• pp.392-398
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• 2018

Purpose: To evaluate the initial experience and outcome of photo-selective vaporization of the prostate (PVP) for benign prostatic hyperplasia (BPH) in Pakistan with the use of a 980 nm diode laser. Materials and Methods: A prospective study was performed from November 2016 to December 2017. A total of 100 patients diagnosed with bladder outlet obstruction secondary to BPH who planned for PVP were enrolled in the study. PVP was carried out with a diode laser at 980 nm (Biolitec Diode 180W laser) in a continuous wave with a 600 nm (twister) fiber. Baseline characteristics and perioperative data were compared. Postoperative outcomes were evaluated by International Prostate Symptom Score (IPSS), post void residual (PVR) and maximum urinary flow rate (Qmax) at 3 and 6 months after surgery. Results: The mean age was $65.82{\pm}10.42$, mean prostate size was $67.35{\pm}16.42$, operative time was $55.85{\pm}18.01$ and total energy was $198.68{\pm}49.12kJ$. At 3 months and 6 months, significant improvements were noted (p<0.001) in IPSS $7.04{\pm}1.69$ (-18.92), Qmax $19.22{\pm}4.75mL/s$ (+13.09) and and PVR $18.89{\pm}5.39mL$ (-112.80). Most frequent problems were burning micturition (35%) and terminal dysuria (29%). No significant difference in postoperative hemoglobin was seen in patients who were on anti-platelet drugs. Conclusions: PVP with a diode laser is a safe and effective procedure for the treatment of BPH and is also safe in patients who are on anti-platelet agents.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.8 no.2
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• pp.177-186
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• 1996

The characteristics of the flow of pure HFC refrigerants(R32, R125, and R134a) and their mixtures through capillary tubes were investigated experimentally. Two capillary tubes with 1.2mm and 1.6mm inner diameter and 1.5m length were adopted as test sections. Mass flow rates and temperatures and pressures were measured for several condensing temperatures and degrees of subcooling at capillary tube inlet. The effects of the condensing temperature, inner diameter of capillary tube, and subcooling on the mass flow rate of refrigerants were discussed, and the mass flow rates of HFC refrigerants were compared with that of R22. The pressure and temperature distributions along the capillary tube compared with that of R22. The pressure and temperature distributions along the capillary tube show that there is a metastable equilibrium state in the flow through the tube. Underpressure for vaporization increases as refrigerant mass flux increases and inlet subcooling decreases. Empirical correlation was suggested to predict underpressure for vaporization of the HFC refrigerants.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.04a
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• pp.34-37
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• 2007

Propellant filling and holding test was carried out using liquid oxygen as a working fluid. The feeding line system has a filter at propellant tank outlet. Vaporization of liquid oxygen during holding after completion of filling and effect of vaporization to recirculation performance in this system was observed. Filling rate and pressure of tank ullage had the effect on state of liquid oxygen in feeding line. There was no geysering in feeding line during holding because of the position of filter.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.5
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• pp.172-180
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• 2006

This study was to analyze the effect of mixed fuel composition and mass fraction on the characteristics of evaporating diesel spray and combustion under the various ambient conditions. The characteristics of vaporization distribution and combustion were visualized by laser induced fluorescent method and direct photography. The experiments were conducted in the constant volume vessel and rapid compression expansion machine with optical access. Multi-component fuels mixed i-octane, n-dodecane and n-hexadecane were injected the vessel and rapid compression expansion machine with electronically controlled common rail injector. Experimental results show that fuel vapor formed stratified distribution. And vaporization and diffusion are become actively increasing in mass fraction of low boiling point component. Consequently multi-component fuels were expected to control the evaporating behavior according to their suitable mass fraction.