• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.173-179
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• 2012

Steady and unsteady three-dimensional RANS simulations have been performed on partial admission supersonic axial turbine having backward/forward sweep angles(${\pm}15^{\circ}$) and the results are compared with each other. The objective of this paper is to study the effect of unsteadiness on turbine flow characteristics and performances. The all results indicated that the losses of unsteady simulations were greater than those of steady cases. It was also shown that BSW model give the effect on the reducing of mass flow rates of tip leakage. In unsteady simulation, the increase of t-to-s efficiency at Rotor Out plane was observed more clearly.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.13 no.1
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• pp.76-84
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• 2002

Objectives：This study was conducted to investigate the effect of oxygen on attention and memory functions in healthy adolescents. Methods：The participant subjects were recruited from local advertisement. All subjects are students attending ordinary middle and high school. Their degree of achievement was average or below average. Before the study, its nature and purpose were fully explained to the patients and their parents, and a written informed consent was obtained from each child's parent and a written assent from each child for entire the procedure. The Ethics Committee and Clinical Research Committee of Gyeongsang National University Hospital approved the protocol. For baseline assessment, all subjects received tests for attention and memory. All tests were conducted by a certified psychologist. Stroop test, continuous performance test and trail making test A and B were used for evaluation of attention. As memory tests, we used memory assessment scale(MAS), standardized memory assessment tools. Ten to fourteen days after initial assessments, same tests was applied to the same subjects after prior 5 minute oxygen inhalation. Results：1) Attention test：Improved performances in trail making part B, and stroop test were found in normobaric oxygen inhalation group compared to air inhalation group. Improved reaction time in those tests seemed to reflect the enhanced executive prefrontal activity. 2) Memory test：More words and digits memorization were found in short-term memory subscale score in MAS in oxygen inhalation group compared to air inhalation group. This finding suggested the improved working memory function after oxygen inhalation. Conclusion：Though interpreted cautiously, these results suggested that normobaric oxygen inhalation could enhance executive function and working memory of prefrontal lobe. Further study, however, should be performed to investigate the mechanism of effects of oxygen on cognitive enhancement.

• Journal of Chest Surgery
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• v.31 no.6
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• pp.629-633
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• 1998

Implantation of malignant cells along the needle aspiration tract is an extremely rare potential complication following a percutaneous fine needle aspiration biopsy of a lung carcinoma. The dissemination of malignant cells by a needle aspiration biopsy may convert an operable and potentially curable lesion into a fatal disease. We report two cases of chest wall implantation of carcinoma of the lung after a thin needle aspiration biopsy. A fifty-five year old male was successfully treated by a radical full-thickness excision of the chest wall and immediate reconstruction with the latissimus dorsi musculocutaneous island flap. A sixty-eight year old female was treated with a partial-thickness excision of the chest wall and skin graft due to superimposed infection and ulceration of the metastatic chest wall carcinoma. One case lived for 31 months up to November 1994, and the other's condtion has been uneventful for 3 months up to now.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05b
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• pp.42-47
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• 1996

기존의 우회배관을 제거하고 원자로냉각재배관에 직접 RTD를 삽입하여 온도를 측정할 경우 취수부내의 유속이 기존에 비해 어떻게 변하는지 고찰하고자 한다. 이는 RTD응답시간 요건을 만족하기 위해서는 RTD SCOOP 내부유속이 3ft/sec이상이 되어야만 하기 때문에 중요하다. 이러한 유속을 계산하기 위해 취수부를 단순화하고 보수적인 가정에 의해 유체역학적으로 계산한 결과 이러한 요건을 만족하는 결과를 얻을 수 있었다. 또한 흡입구와 출구 Hole에서 차압의 대부분이 발생하므로 이부분의 부차계수가 유량계산에 절대적으로 영향을 미치고 있으며 아울러 원자로냉각재유량의 크기에 따라 미치는 영향을 계산한 결과 거의 비례적으로 증가하고 있으며 출구직경을 확대하므로 유량을 3.5 ft/sec까지 증가시킬 수 있다는 결과를 얻었다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2001.11a
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• pp.11-14
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• 2001

3-D compressible flow analysis was conducted by using mixing plane method for turbine system which is consisted of partial admission nozzle and rotor. Computational results are shown oblique shock wave in blade leading and trailing edge and also shown flow separation along suction surface of blade due to abrupt blade curvature. But computational results are well agree with 1-D calculation results and experimental data.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.105-108
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• 2003

The intervention area located at rear hot cell can be contaminated by hot cell maintenance work. For effective decontamination of the intervention floor a wet type decontamination device was developed. The device was assembled with a brush rotating part, a washing liquid supplying part, an intake part for recovering contaminated liquid and a device moving cart part. The device was made of stainless steel for easy decontamination and corrosion resistance. The function test carried out at intervention area of the PIE facility showed good performance.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.8
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• pp.735-743
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• 2011

In this study, the distribution of surface pressure was measured in a steady state on a turbine blade which was moved the injected region and receded the stagnation region using a linear cascade apparatus. Axial-type blades were used and the blade chord was 200mm. The rectangular nozzle was applied and its size was $200mm{\times}200mm$. The experiment was done at $3{\times}10^5$ of Reynolds number based on the chord. The surface pressures on the blade were measured at three different nozzle angles of $58^{\circ}$, $65^{\circ}$ and $72^{\circ}$ for off-design performance test. In addition, three different solidities of 1.25, 1.38 and 1.67 were applied. From the results, the low solidity caused the low pressure on the blade suction surface at entering region and the reverse rotating force was generated at the low nozzle angle. The positive incidence also made the pressure lower on the suction surface at entering region.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.23 no.2
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• pp.86-94
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• 1987

In order to examine the flow motion in a combustion chamber of a motored diesel engine, the variation of instantaneous are velocity at a fixed point in combustion chamber was measured by the constant temperature hot wire anemometer, varing engine speed, shroud shape and shroud position. The results are summerized as follows: 1. The variation of air velocity in a combustion chamber is closely related with the valve timing and piston velocity. 2. The air velocity in the cylinder at suction stroke is being increased and maximized at 60$^{\circ}$ ABDC in compression stroke and then decreased at the e.v.o. in expansion stroke. 3. The mean velocity using shroud valve was less than no shroud valve. However the turbulent intensity using shroud valve was larger than no shroud valve. 4. The turbulent intensity with 90$^{\circ}$shroud valve was larger than that of 120$^{\circ}$shroud valve, and 90$^{\circ}$shroud valve at 180$^{\circ}$shroud position had the largest turbulent intensity.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.23 no.2
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• pp.40-40
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• 1987

In order to examine the flow motion in a combustion chamber of a motored diesel engine, the variation of instantaneous are velocity at a fixed point in combustion chamber was measured by the constant temperature hot wire anemometer, varing engine speed, shroud shape and shroud position. The results are summerized as follows: 1. The variation of air velocity in a combustion chamber is closely related with the valve timing and piston velocity. 2. The air velocity in the cylinder at suction stroke is being increased and maximized at 60° ABDC in compression stroke and then decreased at the e.v.o. in expansion stroke. 3. The mean velocity using shroud valve was less than no shroud valve. However the turbulent intensity using shroud valve was larger than no shroud valve. 4. The turbulent intensity with 90°shroud valve was larger than that of 120°shroud valve, and 90°shroud valve at 180°shroud position had the largest turbulent intensity.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.4
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• pp.589-594
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• 1999

There are some problems in inhalation sedation of non-cooperative pediatric patients. Usually the pediatric patients reject the nasal hood and there's no cooperation for administration of nitrous oxide gas. In mouth breathing patient, other technics of sedation such as intravenous or oral sedation or general anesthesia were recommended. Common causes of mouth breathing are common cold, allergic rhinitis, sinus problem, anatomical disorder, and habitual mouth-breathing. However in some patient not indicated the general anesthesia and high failure rate in oral and intravenous sedation. Administration of $N_2O-O_2$ with suction catheter was applied in full mouth breathing patient. Clinically effective sedation were occurred during procedure about 45 to 55 minutes. There's no any side effects by $N_2O-O_2$ inhalation sedation. The patients awoke at the end of the procedure and received 100% oxygen for 2-3 minutes. There's still some problems in use of the suction catheter such as air pollution of operation theater and elevate arterial carbon dioxide tension.