• Journal of the Korean Wood Science and Technology
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• v.27 no.2
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• pp.38-45
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• 1999

This study was to figure out proper Formaldehyde/Urea molar ratio of UF resin with satisfactory bonding strength of plywood and properties of particleboard. The six kinds of UF resins were manufactured with F/U molar ratio 1.0, 1.2, 1.4, 1.6, 1.8, and 2.0. The boards were made of three kinds of raw materials : Veneer, Sliver-Particle and Strand-Particle. Manufacturing condition of plywood : amount of mixing resin was 150g/$m^2$. The fourty secs/mm simple-pressing schedule in the pressure 10kgf/$m^2$ was applied for 480mm${\times}$700mm board at the temperature of $110^{\circ}C$ in a hot press. Manufacturing condition of particleboard : Target density was 0.65g/$cm^2$. The stepwise 9 minutes- multi-pressing schedule in the maximum pressure 40kgf/$cm^2$, the minimum pressure 15kgf/$cm^2$ was applied for $480mm{\times}634mm{\times}12mm$ board at the temperature of $150^{\circ}C$ in a hot press. The results are as follows : I. In bonding strength, plywood which was made by F/U molar ratio 1.2 showed the highest value. Other molar ratio resin also gave the satisfied value of KS standard, 7.5kgf/$cm^2$. 2. In internal bond strength of particleboard, Sliver-Particleboard(SLPB) and Strand-Particleboard(STPB) varied respectively from 5.9kgf/$cm^2$ to 4.8kgf/$cm^2$, from 6.7kgf/$cm^2$ to 5.4kgf/$cm^2$. SLPB with F/U=1.2 and STPB with F/U=1.6 had higher IB value. Also, both SLPB and STPB showed lower IB value in F/U molar ratio 2.0 and 1.0. 3. SLPB and STPB with six kinds of UF resin respectively satisfied bending strength of KS standard 150 Type(130kgf/$cm^2$) and 200 Type(180kgf/$cm^2$). Bending strength data for both of SLPB and STPB showed little or no loss from F/U=1.8 to F/U=1.2. Also, STPB was approximately two times higher than that of SLPB. Therefore, the raw material's shape had more effect on bending strength than the FlU molar ratio. 4. F/U=1.6 and 1.4 showed the lower thickness swelling in SLPB and STPB. All of STPBs satisfied thickness swelling of KS standard, under 12%.

• Research in Community and Public Health Nursing
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• v.11 no.2
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• pp.453-469
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• 2000

This study has a purpose to provide information to help develop nursing intervention for demented elderly staying at home. For this purpose I analysed the relationship of patients' disturbing behaviors with their demographic and social characteristics, premorbid personality, and present environmental characteristics through questionnaire survey on their family members. The survey was performed through direct interview, telephone contact. and mail in the regions of Pusan and Gyeongnam. Among family members contacted. 112 ones made an appropriate response to the survey. The statistical package SAS was utilized for descriptive statistics, correlation coefficients, stepwise multiple regression, and cluster analysis. The results of the study were as follows: 1) Demographic and social characteristics of the patients surveyed are female 81.3%, average age 81.4 years, lack of schooling 83.0%, spouse dead 73.2%, having no other disease 58.9%, average duration of dementia 3.8 years, no medical treatment for dementia 84.8%, good married life 40.2%, and primary care given by daughter-in-law 49.1%. 2) Aggressive Psychomotor Behavior(APB) was observed in a way statistically meaningful in case that primary care was given by daughter-in-law, while Nonaggressive Psychomotor Behavior(NPB) was in case of good married life and primary care given by other than daughter-in-law and spouse. Verbally aggressive behavior (VAB) was observed in groups of female, spouse dead, bad married life, and daughter-in-law's primary care. As for Passive Behavior(PB), it was observed in case that patients had educational background of not less high than middle school and that they were having medical treatment. Functionally Impaired Behavior(FIB) was observed in age group of 60-69 and more than 90, in patients' group having no other disease, and in case that the duration of dementia was not less than 5 years. 3) Premobid Neuroticism(N) showed positive correlation with APB and VAB, while Openness (O) did negative correlation with PB. Agreeableness (A) was proved to have positive correlation with PA and FIB, but to have negative correlation with APB and VAB. In addition, Conscientiousness(C) showed negative correlation with APB and VAB. 4) The worse the psychosocial environment was, the more NPB and VAB were observed. 5) APB was explained 24% by C and primary care-giver, while NPB was explained 28% by psychosocial environment, having other disease or not, and married life. VAB was explained 40% by A. sex, and married life. On the other hand PB was explained 33% by O, A. N, and having medical treatment or not. But any significant factor was not found to explain FIB. 6) A cluster analysis was performed on disturbing behaviors of demented elderly staying at home. It enabled to regroup the demented elderly in 5 patterns: high scored in NPB, high scored in FIB. high scored in NPB and VAB, moderately scored in most disturbing behaviors, and low scored in all areas. In conclusion, disturbing behaviors of demented elderly not only reflect their premorbid personality in the past, but also are affected by their present psychosocial environment. Therefore, it is necessary to encourage and respond them with understanding their disturbing behaviors in relation to their past premorbid personality. In addition, it is important to provide them better psychosocial environment in order to reduce their disturbing behaviors.

• Food Science and Preservation
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• v.13 no.6
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• pp.703-707
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• 2006

The propose of this study was to investigate the changes of available components in Chajogi (Perilla sikokiana B.) by different harvest periods. The Chajogi samples were divided into four groups by harvest period. The four groups were divided into I (harvesting sample at 14, July, 2005), II (harvesting sample at 25, July, 2005), III (harvesting sample at 15, Aug, 2005) and IV sample (harvesting sample at 2, Sept, 2005), and then analysed with regard to the content of proximate compositions, minerals, amino acids, perillaldehyde and anthocyanin. The contents of reducing sugar increased with increasing harvesting periods, while those of crude protein, crude lipid and total amino acids decreased for IV sample as compared to the other samples. The levels of heavy metals in all samples were not detected. The Zn, Fe and Mg contents of IV sample decreased sharply. The perilladehyde contents were 0.36%, 0.42% 0.45%, and 0.35% for I, II, III, and IV products, respectively. III sample as contented to the other samples was shown to have the highest anthocyanine content (1.21% in dry basis). In conclusion, the date of harvesting Chajogi affects the contents of available components.

• Economic and Environmental Geology
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• v.29 no.6
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• pp.725-732
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• 1996

To assess soil distribution patterns of heavy metals in agricultural environments, we have measured the concentrations of six metals from surficial soils of three different groups divided on the basis of the surrounding environment: (1) soil group I-cultivated soils within the purely agricultural regions, (2) soil group II-both cultivated and uncultivated soils near various livelihood facilities, and (3) soil group III-mainly cultivated soils near major polluting sources. The mean concentrations for the three soil groups were found in the range as follows: 0.12~0.15 (Cd), 4.94~6.08 (Pb), 0.05~0.11 (Hg), 2.82~3.50 (Cu), 4.69~7.82 (Zn), and 0.36~0.78 (As) ppm. Examination of data distribution trends indicates that the concentrations determined from the relatively unpolluted soil environs (groups I and II) were comparable not only between each other but also with those reported previously in background soil environs of Korea. The concentration data for the soil group III were however found to be much higher than the rest two groups. Unlike the direct comparison of the magnitudes of concentrations, results of a regression analysis exhibited much different patterns: it was seen that the correlation patterns for soil group I were rather analogous to those of soil group III. The similarities in correlation patterns between groups I and III along with the lack of correlations in soil group II suggest that soil characteristics such as whether being cultivated or not are important factors affecting soil distributions of heavy metals.

• Economic and Environmental Geology
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• v.21 no.3
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• pp.287-307
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• 1988

The Cheongju gold-silver mine is located at approximately $36^{\circ}28^{\prime}$north latitude and $127^{\circ}31^{\prime}$ east longitude in the Cheongju City of the Chung cheong bug Do, South Korea. Gold-Silver bearing hydrothermal quartz veins, occur in Cheongju Granit of Jurassic age. K-Ar isotope data for sericite in quartz vein indicate that the Au-Ag mineralization took place in early Cretaceous ($97.5{\pm}2.18$ MA. Park, et ai, 1986). Three stage of mineralization recognized anre, from early to later, (I) Sulide stage: pyrite, arsenopyrite, pyrrhotite (Hpo), sphalerite, chalcopyrite, electrum and quartz (II) Electrum stage: pyrite, sphalerite, galena, chalcopyrite, electrum and quartz. (III) Silver mineral stage: pyrite, marcasite, pyrrhotite (Mpo), sphalerite, galena, electrum, native silver argentite, fluorite, calcite and quartz. In this paper, mode of occurrences and chemical compositions of electum and native silver have been investigated by means of microscope and EPMA. Electron probe microanalysis shows that an individual grain of electrum is almost homogeneous in composition. Silver content of electrum ranges from 44.7-67.1 atom.%. Gold content of native silver ranges below 0.2 atom. %. Vicker's hardness number (VHN) of electrum and native silver ranges $78.2-81.8kg/mm^{2}$ respectively. The filling temperature of fluid inclusions in quartz ranges from $130-280^{\circ}C$. On the basis of arsenpyrite geothemometer, the equilibrium temperature and sulfur fugacity of the pyrite-arsenopyrite-pyrrhotite(Hpo) assemblage is assumed to be in ange from $300-310^{\circ}C$ and $10^{-10}$ to $10^{-11}$ atm. The estimated ore reserviors on Cheongju mine area are calculated to 8000 T/M, averaing 8.6g/t Au, 27.8 g/t Ag, 1.25% Pb, l.65% Zn.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.202-206
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• 2011

본 연구에서는 정체성 수역인 신갈호를 대상으로 저층 퇴적물의 오염물질에 대한 조사를 실시 하였다. 신갈호 저층 퇴적물의 분석 결과, 함수율의 범위는 49.0~68.2%로 조사되었으며, 평균 함수율은 60.8%로 나타났다. 함수비의 경우에는 지점별 96.1~214.6%의 넓은 범위를 보였으며 평균 함수비는 165.8%로 조사되었다. 퇴적물의 pH는 모든 지점에서 산성을 띄었으며, 하류부로 갈수록 더욱 낮아지는 경향을 보였다. 입도분석 결과, 토성은 SL(사양토) 및 SiL(실트질양토)로 나타났으며, 이러한 토성분포는 입자별 침강속도에 의한 것으로 퇴적물의 지점별 이 화학적 특성에 많은 영향을 줄 것으로 판단된다. 유기물 함량 분석결과, 강열감량의 경우 8.22~11.36%로 평균 10.22% 의 유기물 함량을 보였으며, COD는 24,92 mg/kg~27,38 mg/kg의 값으로 평균 26,16 mg/kg로 조사되었다. 영양물질 함량 분석결과, T-N의 경우 신갈호 저층 퇴적물 평균 2,916 mg/kg의 질소 함량을 보였으며, T-P의는 평균 710 mg/kg로 조사되었다. 영양물질 함량 분석결과 하류부로 갈수록 높아지는 경향을 보였으나 총질소의 경우 지점별 비슷한 값을 보인 반면, 총인은 지점별 큰 차이를 보였다. 퇴적물의 중금속 함량은 Cd, Cu, Zn, $Cr^{6+}$, Pb을 분석하였으며, Cd 0.10~0.12 mg/kg, Cu 18.33~20.67 mg/kg, Zn 82.73~110.15 mg/kg, $Cr^{6+}$ 0.78~0.93 mg/kg Pb 11.04~14.53 mg/kg의 범위를 보였으며, 지점별로 큰 차이를 보이지 않았다. 본 연구의 자료는 신갈호 유역의 개발계획 및 준설 검토에 대한 유용한 자료로 활용 가능할 것으로 판단된다.

• Korean Journal of Veterinary Service
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• v.29 no.4
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• pp.459-467
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• 2006

This study was designed to investigate if there were groundwater contamination in 17 landfill where slaughtered animals were buried during the crisis of 2002 foot-and-mouth-disease (FMD) outbreaks in Gyeonggi province. From March to August 2005 groundwater was collected once a month from 17 sites, and examined with potential for hydrogen (pH), colour, turbidity, lead (Pb), arsenic (As), mercury (Hg), cadmium (Cd), copper (Cu), zinc (Zn) , iron (Fe), manganese (Mn) , aluminium (Al), nitrate-nitrogen $(NO_3-N)$, ammonia-nitrogen $(NH_3-N)$, microbial pathogen and Escherichia spp. In the examination of $NH_3-N$ which of the mean concentration was from not-detected (ND) to 0.05 mg/l. The range of $NH_3-N$ level was $0.3-24.1mg/{\ell}$. However, groundwater from four sites was to go beyond the drinking water quality standard (DWQS), i.e., the mean concentration of those were $15.5mg/{\ell}\;(site\;1),\;20.7mg/{\ell}\;(site\;9),\;24.1mg/{\ell}\;(site\;13)\;and\;10.6mg/{\ell}\;(site\;17)$. In the investigation of pH, colour and turbidity, all of the pH were below of DWQS (pH 5.8-6.6), but one site in color test and four sites in turbidity test were over the standard level. Among 9 metal ions examined, Mn was in excess of DWQS, and its concentration was $2.4mg/{\ell}$. Pb, Cd, Hg and As were not traced. The contents of Cu, Zn, Fe and Al were $ND-0.22mg/{\ell},\;0.01-0.05mg/{\ell},\;ND-0.05mg/{\ell}\;and\;0.03-0.16mg/{\ell}$, respectively. Escherichiae spp were not identified, but bacterial colonies were detected at 3 groundwater including 2 sites over the DWQS at the level of $491CFU/m{\ell}\;(site\;4)\;and\;217CFU/m{\ell}\;(site\;15)$.

• Analytical Science and Technology
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• v.10 no.3
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• pp.187-195
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• 1997

Chemically modified electrodes(CMEs) for Ag(I) were constructed by incoporating 1,5,9,13-tetrathiacyclohexadecane([16]-ane-$S_4$) with a conventional carbon-paste mixture composed of graphite powder and nujol oil. Ag(I) ion was chemically deposited onto the surface of the modified electrode with [16]-ane-$S_4$ by immersion of the electrode in the acetate buffer solution(pH=4.5) containing $5.0{\times}10^{-4}M$ Ag(I) ion. And then the electrode deposited with Ag(I) was reduced at -0.3V vs. S.C.E. Well-defined stripping voltammetric peaks could be obtained by scanning the potential to the positive direction. The CME surface was regenerated with exposure to 0.1M $HNO_3$ solution and was reused for the determination of Ag(I) ion. When deposition/measurement/regeneration cycles were 10 times, the response could be reproduced with relative standard deviation of 6.08%. In case of differential pulse stripping voltammetry, the calibration curve for Ag(I) was linear over the range of $5.0{\times}10^{-7}{\sim}1.5{\times}10^{-6}M$. And the detection limit was $2.0{\times}10^{-7}M$. Various ions such as Cd(II), Ni(II), Pb(II), Zn(II), Mn(II), Mg(II), EDTA, and oxalate(II) did not influence the determination of Ag(I) ion, except Cu(II) ion.

• Korean Journal of Environmental Agriculture
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• v.4 no.1
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• pp.25-30
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• 1985

In order to characterize relationship between accumulation of cadmium, zinc and lead in soil and soil chemical properties and also to choose a suitable soil extractant for the prediction model of heavy metal content in brown rice, four extractants-0.1 M HCl, 0.1 M $HNO_3$, 0.1 M $NH_4-oxalate$ and 0.001 M 2Na-EDTA, were compared by analyzing 84 soil samples collected from paddy fields adjacent to five zinc-minig sites. Contents of Cd, and Pb in soil increased with Zn content and those of three elements were found to be much higher in surface soil ($0{\sim}15 cm$) than suvsqrface soil ($15{\sim}30 cm$). Contents of these elements in soil were positively correlated with soil pH, but its correlation between extractable heavy metal content and organic matter or CEC varied from region to region. These three elements were negatively correlated with Mg content of soils. The extractability of the metals was in the order 0.1 M $HCI{\geq}0.1 M$ $HNO_3>0.001 M$ 2Na-EDTA>0.1 M $NH_4-oxalate$.

• Korean Journal of Materials Research
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• v.15 no.6
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• pp.413-418
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• 2005

Perovskite $Pb(Ni_{1/3}Nb_{2/3})O_3-Pb(Zr,Ti)O_3[PNN-PZT]$ ceramics were synthesized by conventional ceramic processing technique. In order to modify piezoelectric properties for sensor application in this system, NiO addition was considered to provide $Ni^{+2}$ as an acceptor, which was known to occupy with B site in the structure. The effect of NiO addition up to $8\;mol\%$ on the following piezoelectric properties as well as sintering properties was investigated. When NiO added more than $1\;mol\%$, average grain size was decreased and second phase was found to form. Moreover, the second phase caused decrease in relative dielectric constant $(\varepsilon_{33}T/\varepsilon0)$, electro-mechanical coupling factor $(k_p)$, and piezoelectric charge constant $(d_{33})$, while increasing mechanical quality factor $(Q_m)$. When $1\;mol\%$ NiO was added, density, dielectric properties and piezoelectric properties were abruptly increased.