• Journal of Chest Surgery
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• v.36 no.3
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• pp.136-141
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• 2003

We assessed the intermediate-term result of tricuspid annuloplasty (TAP) for tricuspid valve regurgitation (TR) associated with congenital heart disease in adults. Risk factors for residual TR were also analysed. Material and Method: From August 1989 to June 2001, seventy three adult patients, 51 females and 22 males, underwent TAP for TR associated with various congenital heart disease. Their age ranged from 46 years to 73 years (mean:43). Associated heart anomalies were atrial septal defect (55), ventricular septal defect (6), partial anomalous pulmonary venous return (4) and others (8). Preoperative and post-operative TR velocities were 3.25 m/sec and 2.56 m/sec respectively, and the types of TAP were De Vega in 43, Kay in 18 and Ring annuloplasty in 12. Postoperative follow-up duration was 2,347 patient-month (mean: 32.6 months), and 134 two-dimensional echocardiographic examinations were done during this period. Residual TR greater than III/IV was considered as TAP failure. Result: TAP failure was observed in 7 patients (9.6%), and one patient among them underwent tricuspid valve replacement. Risk factors for TAP failure were diagnosis other than atrial septal defect (p=0.001), preoperative (p=0.038) and postoperative (p=0.028) high TR velocity. There was no statistical significance in terms of TAP methods. Conclusion: Careful evaluation of valve morphology and aggressive surgical intervention are mandatory for the repair of TR with preoperative or residual RV pressure overload.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.3
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• pp.155-158
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• 2003

The effects of Mn, V addition on the behavior of structure and the effects of cooling rate of S20C steel for use of Tn housing and valve for automotive parts have been investigated. Transformation start temperature measured from inflection point of cooling curves has been found out to decrease with increasing cooling rate and to be more sensitive to Mn contents when cooling rate is fast. It was therefore shown that the grain was refined. If there is a big compacting pressure, it is indicated that hardness becomes much greater at surface than inside.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.3
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• pp.230-236
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• 2012

The purpose of this research is to determine the calibration constants of the wind speed measurement systems required to calculate the wind tunnel velocity in the test section. In the present work, the aerodynamic calibration tests of the test section were conducted in the Agency for Defense Development's Low-Speed Wind Tunnel. The test speed ranged from 10 to 100 m/s with a reference pitot-static pressure probe. The validity of the calibration results was evaluated by comparing them with the previous calibration constants. The calibration results show that fair to good agreement is obtained with resonable accuracy.

• Wind and Structures
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• v.32 no.5
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• pp.439-452
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• 2021

The concept of Performance objective assessment is extended to wind engineering. This approach applies using the Database-Assisted Design technique, relying on the aerodynamic database provided by the National Institute of Standards and Technology (NIST). A structural model of a low-rise building is analyzed to obtain influence coefficients for internal forces and displacements. Combining these coefficients with time histories of pressure coefficients on the envelope produces time histories of load effects on the structure, for example knee and ridge bending moments, and eave lateral drift. The peak values of such effects are represented by an extreme-value Type I Distribution, which allows the estimation of the gust wind speed leading to the mean hourly extreme loading that cause specific performance objective compromises. Firstly a fully correlated wind field over large tributary areas is assumed and then relaxed to utilize the denser pressure tap data available but with considerably more computational effort. The performance objectives are determined in accordance with the limit state load combinations given in the ASCE 7-16 provisions, particularly the Load and Resistance Factor Design (LRFD) method. The procedure is then repeated for several wind directions and different dominant opening scenarios to determine the cases that produce performance objective criteria. Comparisons with two approaches in ASCE 7 are made.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.31 no.4
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• pp.413-422
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• 1995

Cavitation erosion-corrosion implies damage to materials due to the shock pressure or shock wave that results when bubbles form and collapse at a metal surface within a liquid. If the liquid is corrosive to the material, a condition typically encountered in industry, the component materials may suffer serious damage by a combination of mechanical and electrochemical attack. In this study, the mild steel(SS41) was tested by using the piezoelectric vibrator with 20kHz, 24$\mu$m to cavity generation apparatus. The damage behaviour of vibration cavitation erosion-corrosion and the environment characteristics were investigated in various solutions which are seawater, tap water and distilled water. The main results obtained are as follows; 1) The cavitation erosion-corrosion damage behaviour in the seawater increases to occur at the equal degree on the middle portion and the outside portion of specimen. The distilled water specimen, on other hand, occurs beginning on the outside portion across to the middle portion of specimen. 2) The cavitation erosion-corrosion damage in the tap water of low specific resistance more increases than that in the distilled water of high specific resistance at the initial testing time and more decreases than that in it by the CaCO sub(3) film with testing time. 3) Cavitation erosion-corrosion damage characteristic divides into four regions; incubation region, acceleration region, deceleration region and steady state region.

• Journal of the Korea Furniture Society
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• v.19 no.1
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• pp.83-90
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• 2008

Gypsum-wood composites were made by introducing inorganic substances into wood using calcium chloride, first treating solution, and sodium sulfate, secondary treating solution, by double diffusion process under atmospheric pressure at room temperature. The process conducted as follows: water saturated specimens were soaked in calcium chloride solutions at several concentration. Then the specimens were soaked further in saturated sodium sulfate solution, and they were leached in flowing tap water for 24h. To attain sufficient weight percent gain (WPG) values, the suitable concentration of calcium chloride and soaking time in saturated sodium sulfate solution were 20% and 48h, respectively. Inorganic substances were produced mainly in the lumina of tracheides. It was made sure that these substances were dihydrate gypsum($CaSO_4$ $2H_2O$) by X -ray microanalysis (SEM-EDX). The composites had good fire resistance due to low heat transfer rate of gypsum formed in wood. However, the composites had little decay resistances, because they showed high weight losses by test fungi attacks.

• Electrolytes & blood pressure
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• v.16 no.2
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• pp.27-29
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• 2018

Peritoneal dialysis (PD)-related peritonitis is a major cause of injury and technique failure in patients undergoing PD. Aeromonas hydrophila is ubiquitous in the environment, and is a Gram-negative rod associated with infections in fish and amphibians in most cases; however, it can also cause opportunistic infections in immunocompromised patients. We report a case of A. hydrophila peritonitis in a 56-year-old male on automated PD. Peritonitis may have been caused by contamination of the Set Plus, a component of the automated peritoneal dialysis device. Although Set Plus is disposable, the patient reused the product by cleansing with tap water. He was successfully treated with intraperitoneally-administered ceftazidime and has been well without recurrence for more than 2 years.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.317-321
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• 2022

In response to Incheon tap water accident in 2019, the Ministry of Environment has created the "Comprehensive Measures for Water Safety Management" to improve water operation management, provide systematic technical support, and respond to accidents. Accordingly, K-water is making a smart water supply management system for the entire process of tap water. In order to advance the response to water accidents, it is essential to secure the reliability of real-time water operation data such as flow rate, pressure, and water level, and to develop and apply a warning algorithm in advance using big data analysis techniques. In this paper, various statistical techniques are applied using water supply operation data (flow, pressure, water level, etc) to prepare the foundation for the selection of the optimal operating range and advancement of the monitoring and alarm system. In addition, the arrival time is analyzed through cross-correlation analysis of changes in raw water turbidity between the water intake and water treatment plants. The purpose of this paper is to study the model that predicts the raw water turbidity of a water treatment plant by applying raw water turbidity data considering the time delay according to the flow rate change.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.1
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• pp.79-82
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• 1997

The present study was aimed to explore an interaction between endothelium-derived nitric oxide (NO) and atrial natriuretic peptide (ANP) systems in normotensive and hypertensive states. Rats were made two-kidney, one clip (2K1C) hypertensive and supplemented with either $N^G-nitro-L-arginine$ methyl ester (L-NAME, 5 mg/100 ml drinking water) or L-arginine hydrochloride (400 mg/100 ml drinking water). One group supplied with normal tap water served as control. Sham-clipped rats were also divided into the L-NAME, L-arginine, and control groups. The plasma levels and atrial contents of ANP were determined at day 28 following clipping the renal artery. In 2K1C rats, the plasma level of ANP was higher and the atrial content was lower than in the sham-clipped control. L-Arginine increased the atrial content of ANP in association with a decreased plasma ANP, whereas L-NAME significantly affected neither parameter. The increase of blood pressure in 2K1C rats was not affected by L-arginine or L-NAME. In sham-clipped rats, the plasma level of ANP was significantly increased by L-NAME along with an increase in blood pressure. On the contrary, L-arginine did not affect the blood pressure or plasma ANP. The atrial content of ANP was significantly altered neither by L-arginine nor by L-NAME. These results suggest that NO plays a tonic inhibitory role on the ANP release with concomitant increases of the atrial tissue content. In addition, hypertension is suggested to modify the release and tissue storage of ANP.

• Journal of Korean Association for Spatial Structures
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• v.13 no.3
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• pp.83-90
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• 2013

A series of wind tunnel tests were conducted on 7 super-tall buildings with various polygon cross-sections, including triangle, square, pentagon, hexagon, octagon, dodecagon, and circular. The primary purpose of the present study is to investigate the effect of increasing number of sides on aerodynamic characteristics for super-tall buildings. Wind tunnel tests were conducted under the turbulent boundary layers whose power-law exponent is 0.27. Fluctuating wind pressures from more than 200 pressure taps were recorded simultaneously, and time series of overturning moments were calculated considering tributary area of each pressure tap. The results show that the overturning moment coefficients and the spectral values decrease with increasing number of sides, and the largest mean and fluctuating overturning moments were found for the triangular super-tall building, and the largest spectral values were found for the square super-tall building. The analysis should be conducted more in detail, but currently it can be roughly said that there seems to be a little differences in the aerodynamic characteristics for the super-tall buildings whose number of sides is larger than 5 or 6.