• Proceedings of the IEEK Conference
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• 2003.07b
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• pp.995-998
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• 2003

This paper reports the correlation between dielectric constant and degree of amorphism of the hybrid type Si-O-C thin films. Si-O-C thin films were deposited by high density plasma chemical vapor deposition using bistrimethyl- silylmethane(BTMSM, $H_{9}$C$_3$-Si-C $H_2$-Si-C$_3$ $H_{9}$) and oxygen precursors with various flow rate ratio. As-deposited film and annealed films at 40$0^{\circ}C$ were analyzed by XRD. The Si-O-C thin films were amorphous from XRD patterns. For quantitative analysis, the diffraction pattern of the samples was transformed to radial distribution function by Fourier analysis, and then compared with each other. The degree of amorphism of annealed films was higher than that of as-deposited ones. The dielectric constant varied in accordance with flow rate ratio of precursors. The lowest dielectric constant was obtained from the as-deposited film which has the highest degree of amorphism after annealing.

• Journal of Environmental Health Sciences
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• v.21 no.4
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• pp.37-43
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• 1995

The course of biodegradation of anionic surfactants, Linear Alkylbenzene Sulfonates(LAS), Sodium Lauryl Ethoxylate Sulfonate(SLES), and Sodium Lauryl Sulfonates(SLS), which are mainly used to make detergents and shampoo, was investigated. The degree of biodegradation was studied as a function of concentration, volumetric flow rate, and temperature in Naktong River. MethyleneBlue Active Substances(MBAS), Total Dissolved Organic Carbon(TOC), and Chemical Oxygen Demand(COD) were measured to evaluate the degree of biodegradation. The degree of biodegradation of LAS was highly dependent upon the concentration and was increased as the concentration was decreased and that of SLES and SLS was almost constant at the concentration of less than 200 ppm, but was much increased as the volumetric flow rate was increased or the temperature was increased.

• Proceedings of the KIEE Conference
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• 1999.11d
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• pp.1090-1092
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• 1999

In this paper, multi discharge type ozonizer has been designed and manufactured. The of ozonizer is equipped with three electrodes(central electrode of screw shape, internal electrode and external electrode). This paper describes the following two characteristics: (1) The characteristics of discharge with variation of output voltage of AC H.V source, flow rate of oxygen supplied gas and discharge voltage. (2) The characteristics of ozone generation by varying flow rate and discharge power.

• Tribology and Lubricants
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• v.26 no.3
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• pp.157-161
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• 2010

This study investigated the effects of spray parameters on wear behavior of the Ni-based hard coatings fabricated by thermal spray process. The experiment was designed by an orthogonal array, the Ni-based hard coatings were fabricated according to this experimental design. The wear test was performed on these coatings using ball-on-disk wear tester. The ANOVA was used to analyze the effects of spray parameters on the wear rate of these coatings, as a result, oxygen gas flow and acetylene gas flow were determined as main factors effected on the wear rate. The effects of these two factors on wear behavior were observed by using SEM and EDX.

• Journal of the Semiconductor & Display Technology
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• v.6 no.1 s.18
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• pp.65-69
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• 2007

A design of experiments was applied in order to investigate the effect of processing variables in UV irradiation on the electrical/optical properties in indium-zinc oxide thin films, The processing variables, equivalently input variables are listed as UV irradiation time, oxygen flow rate, and chamber pressure. The statistical significance of Ultra Violet (UV) treatment was confirmed using a paired-t test. The full factorial $2^3$ design was employed to determine significant main and interaction effects in UV irradiation process. The chamber pressure and the interaction between UV irradiation time and $O_2$ flow rate were found to be statistically significant at the significance level of 0.1. Furthermore, the optimized approach was proposed in achieving the improved conductivity after UV irradiation.

• The KSFM Journal of Fluid Machinery
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• v.9 no.5 s.38
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• pp.28-35
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• 2006

Orbiter mechanism has been applied to vacuum pump design for small oxygen generator where low vacuum of about 200 mmHg is required. Performance of the designed vacuum pump has been numerically investigated: calculated volumetric and adiabatic efficiencies were 69.7% and 83.9%, respectively for leakage clearance of $10{\mu}m$. Total efficiency of the orbiter vacuum pump was 77.5%. At the shaft speed of 1700 rpm suction displacement volume of 6.3cc provided discharge flow at the rate of 2.3 liter/min with power consumption of 10.1Watt. Torque variation of the orbiter pump was only about 20% of that of diaphragm pump.

• Proceedings of the KIEE Conference
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• 2006.10a
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• pp.192-193
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• 2006

In this paper, a co-axial type ozonizer varied with discharge gap was designed and manufactured for investigating (1) discharge characteristics with variation of output voltage power supply, flow rate and gap distance (2) ozone generation and solubility characteristics with variation of flow rate, gap distance and discharge power. Pure oxygen was used as process gas of the co-axial type ozonizer.

• Journal of Environmental Health Sciences
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• v.35 no.3
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• pp.201-208
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• 2009

Oxidation of phenol in aqueous media by electro-Fenton process using Ru-Sn-Sb/graphite electrode has been studied. Hydrogen peroxide was electrically generated by reaction of dissolved oxygen in acidic solutions containing supporting electrolyte and $Fe^{2+}$ was added in aqueous media. Phenol degradation experiments were performed in the presence of electrolyte media at pH 3. Effect of operating parameters such as current, electrolyte type (NaCl, KCl and $Na_2SO_4$) and concentration, $Fe^{2+}$ concentration, air flow rate and phenol concentration were investigated to find the best experimental conditions for achieving overall phenol removal. Results showed that current of 2 A, NaCl electrolyte concentration of 2g/l, 0.5M concentration of $Fe^{2+}$, air flow rate of 1l/min were the best conditions for mineralization of the phenol by electro-Fenton.

• Advances in materials Research
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• v.6 no.4
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• pp.343-348
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• 2017

High-pressure gas atomization was employed to prepare the Fe-based $Fe_{50}Cr_{24}Mo_{21}Si_2B_3$ alloy powder. The effect of flow rate of atomizing gas on the median powder diameter was studied. The results show that the powder size decreased with increasing the flow rate of atomizing gas. Fe-based alloy coatings with amorphous phase fraction was then prepared by high velocity oxygen fuel spraying (HVOF) of gas atomized $Fe_{50}Cr_{24}Mo_{21}Si_2B_3$ powder. Microstructural studies show that the coatings present dense layered structure and low porosity of 0.17% in about $200{\mu}m$ thickness. The Fe-based alloy coating exhibits an average hardness of about 1230 HV. Our results show that the HVOF process results in dense and well-bonded coatings, making it attractive for protective coatings applications.

• Journal of Yeungnam Medical Science
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• v.35 no.1
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• pp.84-88
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• 2018

A 33-year-old woman visited the emergency department presenting with fever and dyspnea. She was pregnant with gestational age of 31 weeks and 6 days. She had dysuria for 7 days, and fever and dyspnea for 1 day. The vital signs were as follows: blood pressure 110/70 mmHg, heart rate 118 beats/minute, respiratory rate 28/minute, body temperature $38.7^{\circ}C$, and oxygen saturation by pulse oximetry 84% during inhalation of 5 liters of oxygen by nasal prongs. Crackles were heard over both lung fields. There were no signs of uterine contractions. Chest X-ray and chest computed tomography scan showed multiple consolidations and air bronchograms in both lungs. According to urinalysis, there was pyuria and microscopic hematuria. She was diagnosed with community-acquired pneumonia and urinary tract infection (UTI) that progressed to severe sepsis and acute respiratory failure. We found extended-spectrum beta-lactamase producing Escherichia coli in the blood culture and methicillin-resistant Staphylococcus aureus in the sputum culture. The patient was transferred to the intensive care unit with administration of antibiotics and supplementation of high-flow oxygen. On hospital day 2, hypoxemia was aggravated. She underwent endotracheal intubation and mechanical ventilation. After 3 hours, fetal distress was suspected. Under 100% fraction of inspired oxygen, her oxygen partial pressure was 87 mmHg in the arterial blood. She developed acute kidney injury and thrombocytopenia. We diagnosed her with multi-organ failure due to severe sepsis. After an emergent cesarean section, pneumonia, UTI, and other organ failures gradually recovered. The patient and baby were discharged soon thereafter.