• Analytical Science and Technology
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• v.14 no.5
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• pp.432-441
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• 2001

An automated on-line portable preconcentration-short column gas chromatograph was developed, which used preconcentrator using adsorption tube with Tenax-GR and Curie-point heating. The developed system operated with 3 steps of processing, preconcentration, thermal desorption, and analysis and cleaning, and could continued operating within 1~2 min cycle. The recoveries of preconcentrator for toluene was ranged between $94.7{\pm}6.6%$ and $103.8{\pm}3.1%$ with less than 7% of RSD. For benzene, toluene and xylene(BTX) standard gas test, IDL was 41, 49, $472ng/m^3$ benzene, toluene and o-xylene, respectively. The BTX mixture was analyzed within 30 sec with baseline separation by the system equipped with 4 m long capillary column. The deficiency of separation power caused by short column was solved by the control of sample injection volume and inlet/outlet pressure ratio. The automated portable preconcentration-short column gas chromatograph system was found to be useful for the continuous air monitoring of BTX at ppb levels in ambient air.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.740-746
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• 2017

Infrared signatures emitted from hot exhaust gases generated by the internal combustion engine and generator of naval ships and from the metal surfaces of the funnel have become the targets of infrared homing missiles, which is the main cause of a reduced survivability of naval ships. The infrared signatures from the exhaust gas and the metal surface of a funnel can be reduced by installing an infrared signature suppression (IRSS) system on a ship. The IRSS system consists of three parts: an eductor that generates turbulent flow of the exhaust gas, a mixing tube that mixes the exhaust gas with ambient air, and a diffuser that forms an air film using the pressure difference between the inside and outside air. As a basic study to develop an IRSS system using domestic technology, this study analyzed the model test conditions of an IRSS system developed by an overseas engineering company and installed on a domestic naval ship, and a numerical heat-flow analysis was conducted based on the results of the aforementioned analysis. Numerical heat-flow analysis was performed using a commercial numerical-analysis application, and various turbulence models were considered. As a result, the temperature and velocity of the exhaust gas at the educator inlet and diffuser outlet and that of the metal surface of the diffuser were measured, and found to agree well with the measurement results of the model test.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.12
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• pp.7121-7126
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• 2013

Aim: To examine lymph nodes obtained after lipolysis and liposuction of subcutaneous fat of the inguinal region of female vulvar cancer patients to explore the feasibility of clinical application. Methods: The field of operation was on the basis of the range of the conventional resection of inguinal lymph nodes. We injected lipolysis liquid fanwise, started liposuction after 15-20 minutes; then the subcutaneous fatty tissue was sucked out clearly by suction tube. We selected the first puncture holes located on 2-3 cm part below anterior superior spine, the others respectively being located 3cm and 6cm below the first for puncturing into the skin, imbedding a trocar to intorduce $CO_2$ gas and the specular body, and excise the lymph nodes by ultrasonic scalpel. The surgical field chamber was set with negative pressure drainage and was pressured with a soft saline bag after surgery. Results: A lacuna emerged from subcutaneous of the inguinal region after lipolysis and liposuction, with a wide fascia easily exposed at the bottom where lymph nodes could be readily excised. The number of lymph nodes of ten patients excised within the inguinal region on each side was 4-18. The excised average number of lymph nodes was 11 when we had mature technology. Conclusion: Most of adipose tissue was removed after lipolysis and liposuction of subcutaneous tissue of inguinal region, so that the included lymph nodes were exposed and easy to excise by endoscope. This surgery avoided the large incision of regular surgery of inguinal region, the results indicating that this approach is feasible and safe for used as an alternative technology.

• Journal of the Korean Professional Engineers Association
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• v.34 no.2
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• pp.167-173
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• 2001

Through alkaline hydrothermal activation processes, Na-A type zeolite was synthesized as a single phase withfunnel-glass waste from a television tube factory. The autoclaving was performed in a closed teflon vessel in therange of 80~95"C. The silica-rich solution as a starting material was hydrothermally synthesized with quartz in INNaOH by heating 350"C under the pressure of 1,500 atm. NaA102 was made from NaOH and Al(OH)3 by heating95"c for 2~3 hours and the molar ratios of it were Na20/A1203=1.4 and H20Ha20=8. The equi-dimensional Atype zeolite (1 ~2 U) was formed by the simple mixing of'the silica-rich solution, glass waste and NaA102 for I~3hours-heating at 80"C. The characterization of the reaction product shows Na-A as a single phase. The synthesizedzeolite has cube-dodecahedral form and Ca2+ ion exchange capacity of the Na-A was in the range of 215~220mequivalent/100 g.20mequivalent/100 g.

• Journal of Trauma and Injury
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• v.30 no.4
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• pp.113-119
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• 2017

Purpose: Despite the numerous protocols and evidence-based guidelines that have been published, application of the therapeutics to eligible patients is limited in clinical settings. Therefore, a rounding checklist was developed to reduce errors of omission and the implementation results were evaluated. Methods: A checklist consisting of 12 components (feeding, analgesia, sedation, thromboembolic prophylaxis, head elevation, stress ulcer prevention, glucose control, pressure sore prevention, removal of catheter, endotracheal tube and respiration, delirium monitoring, and infection control) was recorded by assigned nurses and then scored by the staff for traumatized, critically ill patients who were admitted in the trauma intensive care unit (ICU) of Dankook University Hospital for more than 2 days. A total of 170 patients (950 sheets) between April and October 2016 were divided into 3 periods (period 1, April to June; period 2, July to August; and period 3, September to October) for the analysis. Questionnaires regarding the satisfaction of the nurses were conducted twice during this implementation period. Results: Record omission rates decreased across periods 1, 2, and 3 (19.9%, 12.7%, and 4.2%, respectively). The overall clinical application rate of the checklist increased from 90.1% in period 1 to 93.8% in period 3. Among 776 (81.7%) scored sheets, the rates of full compliance were 30.2%, 46.2%, and 45.1% for periods 1, 2, and 3, respectively. The overall mean score of the questionnaire regarding satisfaction also increased from 61.7 to 67.6 points out of 100 points from period 1 to 3. Conclusions: An ICU rounding checklist could be an effective tool for minimizing the omission of preventative measures and evidence-based therapy for traumatized, critically-ill patients without overburdening nurses. The clinical outcomes of the ICU checklist will be evaluated and reported at an early date.

• Journal of the Korean Institute of Gas
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• v.19 no.1
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• pp.12-17
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• 2015

The core of the CNG fueling station is the compressor and most of CNG compressors in Korea require lubrication. Lubrication oil of CNG compressor that can be transferred into the pressure regulators and the engines of fueling system can cause a negative effect on NGV(Nature Gas Vehicle) performance during refueling due to oil Carry-over. In order to avoid the problem, it is necessary to enhance the quality of the compressed natural gas by measuring quantitatively the amount of the transferred oil. In this research, a sampling device and sampling tube were developed, which can be used with a gravimetric method of detection to measure CNG oil Carry-over. In addition, CNG samples were taken at 6 pre-selected CNG fueling stations and analysed for their trace oil Carry-over. The measured total oil Carry-over ranged from 2.569 to 6.509 ppm. This test measurements were compared with those of previous studies to verify the results.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.4
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• pp.426-437
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• 2005

Statement of problem : Although zirconium oxide ceramics are more and more commonly used in restorative dentistry, for many clinical applications only limited data can be found in the literature. However it is quite clear that hydrofluoric acid etching is impossible with zirconia ceramics. Therefore, other bonding techniques are required in order to lute these materials adhesively. Purpose : The purpose or this study was to evaluate the effects of surface treatments on shear bond strengths between two resin cements and a zirconia ceramic. Materials and methods : Experimental industrially manufactured yttrium-oxide-partially-stabilized zirconia ceramic discs (Adens, Korea) were used for this study. The ceramic specimens divided into five experimental groups and a control group (as received). Five surface treatments were studied 1) sandblasting with 110$\mu$m $Al_2O_3$ at 3 bars pressure 13 seconds at a distance of 10 mm, 2) flame-treated with the Silano-Pen for 5 $s/cm^3$, 3) grinding with a diamond bur. 4) sandblasting + Silano-Pen treatment, 5) diamond bur preparation + Silano-Pen treatment. Acrylic plastic tube (5 mm in height and 3 mm in diameter) were filled with composite to fabricate composite cylinders The composite cylinders were bonded to the ceramic specimens with either Superbond C&B or Panavia F resin luting agents. All cemented specimens were tested under shear loading until fracture on universal testing machine at a crosshead speed 1mm/min; the maximum load at fracture was recorded. Sheat bond strength data were analyzed with oneway analysis of variance and Tukey HSD tests (P<.05). Treated ceramic surfaces and fracture surfaces after shear testing were examined morphologically using scanning electron microscope. Results: Ceramic surface treatment with Silano-Pen after sandblasting improved the bond strength of Superbond C&B resin cement. Supevbond C& B resin cement at Silano-Pen aiker sandblasting($27.4{\pm}3.8MPa$) showed statistically higher shear bond strength than the others. Conclusion: Within the limitation of this study, Superbond C& &B resin cement are suitable for cementation of zirconia ceramics and flame-treated with the Silano-Pen after sandblasting is required to enhance the bond strength.

• Membrane Journal
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• v.5 no.1
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• pp.35-43
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• 1995

For several years lots of attempts have been made to establish the liquid membrane-based techniques for separations of gas mixtures especially containing carbon dioxide. A more effective system to separate $CO_{2}$ from flue gases, a circulatory hollow-fiber membrane absorber(HFMA) consisting of absorption and desorption modules with vacuum mode, has been considered in this study. Gas-liquid mass transfer has been modeled on a membrane module with non-wetted hollow-fibers in the laminar flow regime. The influence of an absorbent flow rate on the separation performance of the circulatory HFMA can be predicted quantitatively by obtaining the $CO_{2}$ concentration profile in a tube side. The system of $CO_{2}/N_{2}$ binary gas mixture has been studied using pure water as an(inert) absorbent. As the absorbent flow rate is increased, the permeation flux(i.e., defined as permeation rate/membrane contact area) also increases. The enhanced selectivity compared to the previous results, on the other hand, shows the decreasing behavior. It has been found obviously that the permeation flux depends on the variations of pressure in gas phase of desorption module. From an accurate comparison with the results of conventional flat sheet membrane module, the advantageous permeability of this circulatory HFMA can be clearly ascertained as expected. Our efforts to the theoretical model will provide the basic analysis on the circulatory HFMA technique for a better design and process.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.793-798
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• 2017

In modern naval ships, an infrared signature suppression (IRSS) system is used to reduce the metal surface temperature of the heated exhaust pipe and high-temperature exhaust gases generated from the propulsion system. Generally, the IRSS systems used in Korean naval ships consist of an eductor, mixing tube, and diffuser. The diffuser reduces the temperature of the metal surface by creating an air film due to a pressure difference between the internal gas and the external air. In this study, design variables were selected by analyzing the shapes of a diffuser designed by an advanced overseas engineering company. The characteristics of the design variables that affect the performance of the IRSS were investigated through the Taguchi experimental method. A heat flow analysis technique for IRSS systems established in previous studies was used analyze the performance of the diffuser. The performance evaluation was based on the area-averaged value of the metal surface temperature and exhaust gas temperature at the outlet of the diffuser, which are directly related to the intensity of the infrared signature. The results show that the temperature of the exhaust gas was significantly affected by changes in the diameter of the diffuser outlet, and the temperature of the diffuser's metal surface was significantly affected by changes in the number of diffuser rings.

• International Journal of Highway Engineering
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• v.8 no.2 s.28
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• pp.1-12
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• 2006

An existing Steel pipe, Cast iron pipe and Concrete pipe is can not escaped from aging, specially Metal tube is causing many problems that the quality of water worse is concerned about many rust and mike efficient use of preservation of water. The use of Glassfiber Reinforced Plastic Pipe(GRP PIPE) should be one of the possible scheme to get over these problems. The GRP PIPE has an excellent resistance power and the life is lasting from 50 to 100 years roughly. It's to be useful as a result of high durability and a good construction work also it is a light weight therefore can be expected to short the time of construction and man power. In this research, to executed the small-scaled model test, in-situ model test using CLSM of in-situ soil and to evaluated the stress - strain of the pipe also try to estimated how useful is. From the model test in laboratory, the vertical and horizontal deformation of the GRP PIPE measured in six instance using 200mm and 300mm in diameters. The value of experimentation, theory, analysis got the same results of the test, but the vertical and horizontal deformation gauged in small and the earth pressure was almost zero using CLSM of in-situ soil..