• Journal of Environmental Impact Assessment
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• v.29 no.4
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• pp.252-271
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• 2020

In this study, we investigated physical and chemical properties such as grain size, heavy metal pollution, magnetic properties, and their environmental impacts of road dusts (RD) collected from 14 sampling points in Daebul industrial Complex. Heavy metal concentrations in RD were in the order of Fe>Zn>Cu>Pb>Cr>Ni>As>Cd>Hg, and this pollution pattern was related to major industries and traffic activities in this area. The results of the correlation analysis between heavy metal elements and particle size in RD showed that Fe and all of analyzed heavy metals had a significant correlation with each other and metal concentrations had a significantly negative correlation (p<0.05). However, due to the input of large metal particles some heavy metal concentrations in the particle fraction of >1000 ㎛ were highest. Pollution load per unit area of this fraction was the highest among the grain size fractions. Cr, Ni, Cu, Zn, Cd, Pb levels in RD decreased and the levels of Cr, Ni, Cu, Zn, Cd, and Pb were reduced to 85 (As) -22 (Ni)% of the whole after removal of MFs fraction from RD. The mean heavy metal levels in the study area did not exceed the soil contamination guide value of Korea, indicating that heavy metal levels in RD were not a concern. However, at some sampling points, Zn concentrations were exceeded the soil contamination guide value for the 3rd areas of Korea and this result indicated that further studies of the impact of RD on the surrounding environment through re-suspension or non-point pollution, and of effective management methods are required.

• Journal of Korean Public Health Nursing
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• v.16 no.2
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• pp.271-284
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• 2002

This study was to provide basic materials to help reduce the fatigue by analyzing what effective factor the fatigue of hospital nurses in Gwangju and Jeonnam region. and what causes their fatigue. This descriptive research by Questionaires includes two hospitals in Gwangju. and seven hospitals in Jeonnam region, total 9 hospitals sampled at convenience sampling. The periods of collecting data was from Jul.22, 2002 to Jul. 30, 2002. Multidimensional Fatigue Scale; MFS, developed by Jang Se-Jin(2000) was taken to measure the fatigue. All collected materials were got the statistics by SAS for Windows Release 8.01. The result of this study was as follows. 1. This study included total 740 nurses, whose age ranged from 22 to 50; 30 years old by average. Nurses fatigue mean score was 90.24 (the scope by the measuring instrument is 19-133). Nurses at University Hospitals marked 92.36 and those at General Hospitals marked 87.91 in the mean score of fatigue. 2. They kept tired at work, and felt more tired while working at computer in the hospital. 3. The part of body in which they felt fatigue was the calf and $feet(36.6\%)$, the shoulders and back of the $neck(30.7\%)$, and the whole $body(10.8\%)$ and the reason that they felt tired at work was mental $stress(33.0\%)$, overworking(25.2\%)$, and irregular working $conditions(14.7\%)$ in order. 4. The solution to their fatigue at work appeared nothing by $50.1\%$, and the way of releasing fatigue after work indicated getting some $sleep(30.8\%)$, and taking a bath or a $shower(21.7\%)$ in order. 5. The degree of fatigue depending on whether they were satisfied with their pay and labor condition appeared low: and when they were satisfied with doctors. and when they were getting on well with caregivers. 6. The effective factor of the degree of fatigue appeared: the influence that fatigue in the hospital makes on daily life was $10.6\%$, the cause of fatigue at work, $9.3\%$, time of fatigue at work, $7.8\%$, the relationship with caregivers, $5.3\%$. and these explanatory$(R^2)$ variables.$33\%$. To conclude. the degree of nurses' fatigue appeared high. and it was higher in nurses at University Hospitals than in ones at General Hospitals. In addition, the influence that fatigue from the hospitals made on daily life was the most explanatory.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.319-322
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• 2003

To match the charge induced by the insulators $CeO_2$ with the remanent polarization of ferro electric SBT thin films, areas of Pt/SBT/Pt (MFM) and those of $Pt/CeO_2/Si$ (MIS) capacitors were ind ependently designed. The area $S_M$ of MIS capacitors to the area $S_F$ of MFM capacitors were varied from 1 to 10, 15, and 20. Top electrode Pt and SBT layers were etched with for various area ratios of $S_M\;/\;S_F$. Bottom electrode Pt and $CeO_2$ layers were respectively deposited by do and rf sputtering in-situ process. SBT thin film were prepared by the metal orgnic decomposition (MOD) technique. $Pt(100nm)/SBT(350nm)/Pt(300nm)/CeO_2(40nm)/p-Si$ (MFMIS) gate structures have been fabricated with the various $S_M\;/\;S_F$ ratios using inductively coupled plasma reactive ion etching (ICP-RIE). The leakage current density of MFMIS gate structures were improved to $6.32{\times}10^{-7}\;A/cm^2$ at the applied gate voltage of 10 V. It is shown that in the memory window increase with the area ratio $S_M\;/\;S_F$ of the MFMIS structures and a larger memory window of 3 V can be obtained for a voltage sweep of ${\pm}9\;V$ for MFMIS structures with an area ratio $S_M\;/\;S_F\;=\;6$ than that of 0.9 V of MFS at the same applied voltage. The maximum memory windows of MFMIS structures were 2.28 V, 3.35 V, and 3.7 V with the are a ratios 1, 2, and 6 at the applied gate voltage of 11 V, respectively. It is concluded that ferroelectric gate capacitors of MFMIS are good candidates for nondestructive readout-nonvolatile memories.

• Korean journal of food and cookery science
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• v.28 no.2
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• pp.111-121
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• 2012

The purpose of this study was to investigate the quality characteristics of Garaedduk with regard to the amount of added whole soybean curd (Chun-Tofu). Whole soybean curd was added in amounts of 0, 3, 6 and 9%. Whole soybean curd Topokki dduk was stored at room temperature for 48 hours. The moisture contents had no significant difference for increases in the amount of whole soybean curd. The L value and b values of Garaedduk increased significantly with increases in the amount of whole soybean curd. Texture characteristics of Garaedduk measured with a texture analyzer revealed that hardness and cohesiveness decreased significantly for different amounts of whole soybean curd, and hardness increased significantly and cohesiveness and chewiness decreased with increase of storage time. As for sensory characteristics, samples with 9% added whole soybean curd rated higher in overall acceptability compared with other samples. In regard to cooking properties, water absorption increased and solid contents decreased with increases in the amount of whole soybean curd. Therefore, Garaedduk containing 9% whole soybean curd was most preferable.

• Journal of the Microelectronics and Packaging Society
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• v.9 no.4
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• pp.11-16
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• 2002

In this study, the dry etching characteristics of $SrBi_2Ta_2O_9$ (SBT) thin films were investigated by using ICP-RIE (inductively coupled plasma-reactive ion etching). The etching damage and degradation were analyzed with XPS (X-ray photoelectron spectroscopy) and C-V (Capacitance-Voltage) measurement. The etching rate increased with increasing the ICP power and the capacitively coupled plasma (CCP) power. The etch rate of 900$\AA$/min was obtained with 700 W of ICP power and 200 W of CCP power. The main problem of dry etching is the degradation of the ferroelectric material. The damage-free etching characteristics were obtained with the $Ar/C1_2/CHF_3$ gas mixture of 20/14/2 when the ICP power and CCP power were biased at 700 W and 200 W, respectively. The experimental results show that the dry etching process with ICP-RIE is applicable to the fabrication of the single transistor type ferroelectric memory device.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.15 no.1
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• pp.71-81
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• 2005

The purposes of this study was to collect, analyze, and describe the MF exposure levels from subways in Korea and to measure and evaluate the MF levels generated from electric appliances used at general homes. The target subway lines were Seoul Metropolitan Line 1 to Line 8, Bundang Line, Incheon Line, Daegu Line, Gwangju Line, and Busan Line 1 and Line 2. We measured at each station in those subway lines and, all the train types (pantograph-equipped, motor-equipped, and common), and platform types(facing and isolating) were investigated by the distance(80, 200, 400 cm) from the train on 19 targeted subway lines using 3 magnetic field measuring devices (EMDEXII, Enertech Co.) during the survey from January till October, 2004. On the other hand, the levels of the 60Hz magnetic fields generated from 14 items of home electric appliances such as electric blankets, hair dryers, electric razors, etc. were measured at 10 general homes using 5 EMDEXII meters with a sampling interval of 1.5 second by the distance(surface, 30, 50, 100, 300cm ) from the target electric appliances. The survey results in the whole subway lines examined in this study were as follows; Seoul Metropolitan Line 4 using AC(alternating current) power source showed the highest mean value of $2.85{\mu}T$, followed by Seoul Metropolitan Line 1 running between Seoul and Incheon using AC($2.78{\mu}T$), Seoul Metropolitan Line 1 between Seoul and Uijongbu using AC($2.73{\mu}T$), Bundang Line using AC($1.79{\mu}T$), Seoul Metropolitan Line 1 connected from Yongsan using AC($1.67{\mu}T$), Seoul Metropolitan Line 1 between Seoul and Suwon using AC($0.79{\mu}T$), and so on. In general, the intensity of the magnetic field in the subway systems in Korea was significantly higher when using AC($2.14{\pm}0.91{\mu}T$) than when using DC($0.29{\pm}0.44{\mu}T$) power source. Among the home electric appliances examined, microwave ovens showed the highest mean value of $7.69{\mu}T$, followed by hair dryers($6.47{\mu}T$), vacuum cleaners($5.27{\mu}T$), televisions ($2.26{\mu}T$), electric blankets($1.38{\mu}T$), personal computers ($0.81{\mu}T$), and so on. Two items of electric appliances showed the excess value of $0.2{\mu}T$ at the distance of 30cm in the MF exposure level; electric razors $1.58{\pm}2.13{\mu}T$ and vacuum cleaners $0.48{\pm}0.44{\mu}T$. As a whole, this study showed a tendency that the shift of the MF levels according to the increase of distance from the electric appliances was lower than those of the results surveyed in UK and USA. As a result, this study is expected to suggest meaningful data for the future study in exposure assessment of magnetic fields and for the establishment of guidelines for subways and electric appliances in Korea. More detailed and large scaled exposure assessment studies should be performed continuously to get the various and useful information on health risk assessment of MFs in Korea.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.7
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• pp.1082-1087
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• 2003

This study was designed to investigate the effects of butanol (BuOH) fraction of pine (Pinus densiflora Sieb et Zucc) needle extract on membrane fluidity (MF), basal and induced oxygen radicals (BOR and IOR), lipid peroxide (LPO) and oxidized protein (OP) as an oxidative stress, and lipofuscin (LF) in liver membranes of Sprague-Dawley male rats. The rats were fed basic diets (control group) and experimental diets (BuOH-25, BuOH-50 and BuOH-100) prepared with 25, 50 and 100 mg added to basic diet for 45 days. MFs were significantly increased (about 16∼22%) in mitochondria of BuOH-50 and BuOH-100 groups compared with control group (p<0.01∼0.001) BOR and IOR formations in mitochondria were significantly decreased (11∼17% and 11∼28%, respectively) in these three BuOH groups (p<0.05∼0.001), while BOR and IOR formations in microsomes were significantly decreased (11∼24%) in BuOH-50 and BuOH-100 groups, and (15∼24%) in these three BuOH groups compared with control group (p<0.05∼0.001; p<0.01-0.001). LPO levels were significantly decreased (9% and 9∼13%, respectively) in mitochondria of BuOH-100 and microsomes of BuOH-50 and BuOH-100 groups (p<0.05∼0.01), whereas OP levels were significantly decreased (10∼12%) in mitochondria of BuOH-50 and BuOH-100 groups compared with control group (p<0.05). LF formations were significantly decreased (8∼9%) in BuOH-50 and BuOH-100 groups (p<0.05). These results suggest that butanol fraction of pine needle extract may playa effective role in an attenuating an oxidative stress and increasing a membrane fluidity.