• Journal of Ocean Engineering and Technology
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• v.14 no.3
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• pp.78-83
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• 2000

In this study, CT specimens were prepared from AST SA516 Gr. 70 which was used for pressure vessel plates for room and low temperature service. And we got the following characteristics from fatigue crack growth test carried out in the environment of room and low temperature at 25$^{\circ}C $, -60$^{\circ}C $, -80$^{\circ}C $ and -100$^{\circ}C $ and in the range of stress ratio of 0.05, 0.3 by means of opening mode displacement. At the constant stress ratio, the threshold stress intensity factor range ${\delta} K_{th}$ in the early stage of fatigue crack growth (Region I) and stress intensity factor range $\delta $K in the stable of fatigue crack growth (Region II) were increased in proportion to descending temperature. It was assumed that the fatigue resistance characteristics and fracture strength at low temperature is considerable higher than that of room temperature in the early stage and stable of fatigue crack growth region. The straight line slope relation of logarithm da/dN -$\delta $K in Region II, that is, the fatigue crack growth exponent m increased with descending temperature at the constant stress ratio. It was assumed that the fatigue crack growth rate da/dN is rapid in proportion to descending temperature in Region II and the cryogenic-brittleness greatly affect a material with decreasing temperature.

• Journal of the Korean Society of Safety
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• v.16 no.3
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• pp.1-6
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• 2001

The study is to investigate the influence on the fatigue crack growth behaviors for the welded configuration in pressure vessel stiffener. In order to perform this goal, the automatic welded specimens were prepared. The material is ASTM A516 grade 60 steel used in pressure vessel mainly. In skip welding of pad-on-plate, continuous fillet welding and PWHT specimen, fatigue crack is generally initiated at the starting and end old toe zone, and ruptured at the starting old toe zone. The fatigue life of pad-on-plate of the continuous fillet welding specimen is larger than that of pad-on-plate skip fillet welding specimen about 85% under low load, about 20% under high load and less than that of two-pad continuous fillet welding specimen about 85%. In da/dN-$\Delta$K curve under low load, skip fillet welding specimen of pad-on-plate showed retardation on the initial crack, and the fatigue crack growth rate at the low region of $\Delta$K greater specimen E($3.8 {\times} 10^{-6}mm/cycle$). And the fatigue life of welding specimen was smaller than that of PWHT specimen.

• Microbiology and Biotechnology Letters
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• v.18 no.5
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• pp.511-516
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• 1990

A high-alcohol producing yeast strain had sugar and alcohol tolerance was isolated from soil and identified as Saccharomyces cerevisiae Dl according to the Lodder's yeast taxonomic studies. On investigation of the characteristics of the strain, it could grow in 60% glucose, within 15% ethanol and in the YPD medium containing 2.0 mM copper. It had 39.1% the inhibition rate of fermentation efficiency and 8% viability after 2 days in the YPD medium containing 15% ethanol. Its optimum initial pH, growth temperature, initial glucose concentration for the production of alcohol showed pH 4.5, $30^{\circ}C$, and 30%, respectively. Saa:hwomyce8 mvisiae Dl produced 14.0% (wlv) alcohol when incubated at $30^{\circ}C$, with orbital shaking 150 rpm for 72 h in a medium (pH 4.5) containing 30% (wfv) glucose.

• Journal of Life Science
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• v.18 no.12
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• pp.1712-1717
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• 2008

Volatile flavor compounds of onions were analyzed and compared during storage at $0.5^{\circ}C$, which harvested in 6 regions, such as Muan, Buan, Andong and 3 regions of Changnyeong (Yueo, Jangma and Seongsan). A total of 45 compounds were detected in samples by solid phase microextraction (SPME)/GC/MSD, consisting mainly of sulfur-containing compounds (21), aldehydes (13), ketones (2) and miscellaneous compounds (9). The sulfur-containing compounds were major compounds with ranges of $66.9{\sim}86.9%$ of total volatiles in 0 day of storage as regardless of harvested regions. Three regions (Yueo, Seongsan and Muan) had high amounts of over 4,043 ng/g in 0 day of storage, whereas 2 regions (Muan and Yueo) only had amounts of over 2,400 ng/g after 60 days of storage. Five sulfur-containing compounds known as having antioxidant activity (2,4-, 2,5-dimetylthiophene, 2-vinyl-1,3-dithiane, 5-methoxy thiazole and 3,5-diethyl-1,2,4-trithiolane and isomer) were the high levels in 3 regions (Yueo, Seongsan and Muan) during 60 day of storage. These 3 regions had also the highest amounts in 5 sulfur-containing compounds known as having anticarcinogenic activity ((Z)-, (E)-methyl propenyl disulfide, (Z)-, (E)-propenyl propyl disulfide, and di-2-propenyl disulfide) and kept same trend after 60 days of storage.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.4
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• pp.7-13
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• 2001

This Study is to investigate the influence of weld residual stresses on the fatigue crack growth behaviors in pressure ves-sel reinforcement. In order to perform this study, the automatically welded specimens are prepared. The material is ASTM A516 grade 60 steel used in pressure vessel mainly. For pad-on-plate of skip welding continuous welding and PWHT specimen, fatigue crack initiation is generally initiat-ed at weld starting and end toe zone, and ruptured at weld starting toe zone, Fatigue life if pad-on-plate continuous speci-men is increased more than that of pad-on-plate skip fillet welding specimene about 85% under low load, about 20% under high load, and decreased than that of two-pad continuous welding specimen about 85%. In da/dN-$\Delta$ Κ curve under low load, pad-on-plate skip fillet welding specimen showed retardation on the initial crack, and the fatigue crack growth rate at the low region of $\Delta$Κ greater specimene E(3.8{\times}10^{-6}$mm/cycle). And the fatigue life of welding specimen was smaller than that of PWHT specimen.

• Journal of the Society of Naval Architects of Korea
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• v.47 no.4
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• pp.508-516
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• 2010

This study aims at investigating the effect of the chamfer on the liquid sloshing in the three-dimensional (3D) rectangular tank. In order to simulate the 3D incompressible viscous two-phase flow in the 3D tank with partially filled liquid, the present study has adopted the volume of fluid (VOF) method based on the finitevolume method which has been well verified by comparing with the results of the relevant previous researches. The effects of the chamfering top corners of the tank on the liquid sloshing characteristics have been investigated. The angle of the chamfering top corners (${\theta}$) has been changed in the range of $0^{\circ}{\leq}{\theta}{\leq}60^{\circ}$(${\Delta}{\theta}=15^{\circ}$) to observe the free surface behavior, and the effect on wall impact load. Generally, as the angle of the chamfering top corners increases, the impact pressure on the upper knuckle point decreases. However it seemed that a critical angle of the chamfering top corners exists to reveal the lowest impact pressure on the wall.

• Journal of Life Science
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• v.11 no.6
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• pp.509-516
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• 2001

Enzymes and non-enzymatic antioxidants are involved in defense of oxgen free radical intermediates in all aerobic cells. The non -enzymatic antioxidants and antioxidant enzyme from the extracts of Solanum nigrum L. known to be anticancer medicinal plant were examined in other to utilize the discovery in natural products as cancer chem-opereventive agents. The DPPH(1,1-diphenyl-2-picryl-hydrazyl) free radical scavening activity on plant position of Solanum nigrum L. was the highest in root, with stem, whole plant, seed, leaf and flower, at higher activities respectively. In extraction methods, the DPPH free radical scavenging activity by circulating extraction with 80 % MeOH. The DPPH activity of L6 fraction by LH-20 column chromatography showed about 6.7 times higher than that of ethyl acetate-fraction. These were identified as phenolic compounds such as 2-6-methano-3-benzazocin-11-ol, 2[1H]-phyidinethione and 2-hydroxy -5-methyl-benzaldehyde. Peroxidase(POD) and superoxide dismutase(SOD) activities of stem and root were higher than that of other plant positions and those of plant positions according to growing stage were the highest in 60 days after seeding. The numbers of isozyme pattern of POD and SOD showed 10 hands and 5 bands, respectively, especially, 8 bands of POD and 3 bands of SOC showed a difference according to plant positions.

• Journal of The Korean Society of Agricultural Engineers
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• v.61 no.6
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• pp.73-79
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• 2019

Continuous and tremendous data (canopy temperature and meteorological variables) are necessary to determine Crop Water Stress Index (CWSI). This study investigated the optimal monitoring time and interval of canopy temperature and meteorological variables (air temperature, relative humidity, solar radiation and wind speed) to determine CWSIs. The Nash-Sutcliffe model efficiency coefficient (NSE) was used to quantitatively describe the accuracy of sampling method depending upon various time intervals (t=5, 10, 15, 20, 30 and 60 minutes) and CWSIs per every minute were used as a reference. The NSE coefficient of wind speed was 0.516 at the sampling time of 60 minutes, while the ones of other meteorological variables and canopy temperature were greater than 0.8. The pattern of daily CWSIs increased from 8:00 am, reached the maximum value at 12:00 pm, then decreased after 2:00 pm. The statistical analysis showed that the data collection at 11:40 am produced the closest CWSI value to the daily average of CWSI, which indicates that just one time of measurement could be representative throughout the day. Overall, the findings of this study contributes to the economical and convenient method of quantifying CWSIs and irrigation management.

• Clinical Endoscopy
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• v.56 no.2
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• pp.188-193
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• 2023

Background/Aims: Data on the incidence of adverse respiratory events during recovery from gastrointestinal endoscopy are limited. The aim of this study was to investigate the incidence of these complications. Methods: In this retrospective cohort study, data were obtained from the electronic records of 657 consecutive patients, who underwent gastroenterological procedures under sedation. Results: Pulse oximetry oxygen saturation (SpO₂) <90% for <60 seconds occurred in 82 patients (12.5%), and in 11 patients (1.7%), SpO₂ of <90% for >60 seconds occurred in 79 patients (12.0%) and in 14 patients (2.1%), and SpO₂ <75% occurred in four patients (0.6%) and in no patients during the procedure and recovery period, respectively. No major complications were noted. The occurrence of desaturation during recovery was correlated with desaturation during the procedure (p<0.001). Higher American Society of Anesthesiologists score (odds ratio [OR], 1.867; 95% confidence interval [CI], 1.008-3.458), ischemic heart disease (OR, 1.815; 95% CI, 0.649-5.080), hypertension (OR, 1.289; 95% CI, 0.472-3.516), and diabetes mellitus (OR, 2.406; 95% CI, 0.950-6.095) increased the occurrence of desaturation during recovery. Conclusions: We found no major complications during recovery after balanced propofol-based sedation administered by a gastroenterologist-nurse team. Patients with the identified risk predictors must be monitored carefully.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8728-8737
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• 2015

The purpose of this study compared the clinical features of suicidal attempters who visit in the past and present of an emergency medical center, used as a basic data for clinical severity and suicide prevention research of future patients. The author conducted a retrospective analysis of the changed characteristics of suicidal attempters who visit an emergency medical center of Wonkwang University Hospital between from January $1^{st}$, 1998 to December $31^{th}$, 1998 and from August $1^{st}$, 2013 to July $31^{th}$, 2015. Factors related to increased occurrence was changed from male(1.1:1) in 1998 to female(1.3:1) in 2013-2015, from age of $2^{nd}$, $3^{rd}$, and above $6^{th}$ decade in 1998 to $3^{rd}-5^{th}$ decade in 2013-2015. Poisoning was the most common method of suicidal attempt(90.8%;1998, 72.7%;2013-2015), Mortality rate was changed from 16.9%(male 23.1%, female 10.0%) in 1998 to 13.8%(male 18.1%, female 10.5%) in 2013-2015. Among the suicidal attempters(total=516), 37 patients has recurred. But consultant of neuropsychiatric department was 48.3%, All suicidal attempters in future were necessarily neuropsychiatric consultant and continuously follow-up because all patients had recurrent suicide attempt, psychologic disorder, suicide rates are higher than in the general population.