• 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 $491CFU/m{\ell}\;(site\;4)\;and\;217CFU/m{\ell}\;(site\;15)$.

• Korean Journal of Poultry Science
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• v.31 no.4
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• pp.221-228
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• 2004

This study was conducted to determine the effects of two chemical additives on nitrogen (N) and soluble reactive phosphorus (SRP) contents in litter (rice hull) after broiler chicks were raised for 42 days. Two different additives were applied as a top dressing to the litter at a rate of 200 g ferrous sulfate $(FeSO_4)$ or 200 g aluminum sulfate [$Al_2(SO_4)_3$ $\cdot$ $14H_2O$, Alum] per kg litter, while the control group did not have the two chemicals added to the litter. A total of 64 broiler chicks (4 treatments$\times$4 replicates$\times$4 birds) were fed the experimental diets for 6 weeks. There was no difference in pH between the two chemical treatments and control group, but SRP content was significantly affected on it (P<0.01). SRP contents from ferrous sulfate and alum treated litter at 6 weeks were reduced by $79\%$ and $60\%$, respectively, as the two chemical treatments decreased the pH compared to the control group. In the ferrous sulfate treated litter, EC, TC, $NH_4-N$, $NO_3$-N, and IN contents did not show any difference between $FeSO_4$ treatment and control. However, the differences between $FeSO_4$ treatment and control were found in moisture, TN, ON, AN, PAN, C:N, and C:ON contents (P<0.01). As seen in the alum treated litter, there were differences in moisture, TC, TN, $NH_4-N$, IN, AN, PAN, and C:N contents between alum treatment and control (P<0.05 and 0.01) but no differences in EC, $NO_3-N$, ON, and C:ON. In conclusion, the results of this research show that ferrous sulfate and alum-treatment of poultry litter has the potential to increase N and reduce SRP content by lowering litter pH and moisture content.

• Journal of Korean Society of Forest Science
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• v.89 no.3
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• pp.422-430
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• 2000

Three-year-old Pinus koraiensis seedlings, transplanted in brown forest soils originating from granite were treated with simulated acid rain of pH concentrations 5.6(control), 4.0, 3.0, 2.5 and 2.0 for 210 days from April 21 to November 17, 1999. Visible injury of the seedlings were observed at the pH 2.0 and pH 2.5 treatments. The total dry weight of the seedlings decreased at pH 2.0 treatment compared with that of the control, and T/R ratio increased at pH 2.0 treatment compared with others. The elements in each part of the seedlings, concentrations of Ca, P and content of chlorophyll in needles increased at the pH 2.0 treatment compared with the control. The concentration of N in the needles of the seedlings increased as the soil pH decreased. As the treated pH was lowered, soil pH has decreased, and concentrations of Ca, Mg, Al, and Mn increased, especially at pH 4.4. In addition, there was a strong correlation(r=0.90, p<0.05 ; r=-0.94, p<0.01) between the dry weight of the seedlings and the pH and Al concentration of the soils. Therefore, the pH and Al concentration in the soil may be useful indicator for assessing the effect of acid rain on the growth of woody plants.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.136-136
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• 2011

반도체 및 전자기기 산업에 있어서 NVM은 아주 중요한 부분을 차지하고 있다. NVM은 디스플레이 분야에 많은 기여를 하고 있는데, 측히 AMOLED에 적용이 가능하여 온도에 따라 변하는 구동 전류, 휘도, color balance에 따른 문제를 해결하는데 큰 역할을 한다. 본 연구에서는 bottom gate 구조의 nc-Si NVM 실험을 진행하였다. P-type silicon substrate (0.01~0.02 ${\Omega}-cm$) 위에 Blocking layer 층인 SiO2 (SiH4:N2O=6:30)를 12.5nm증착하였고, Charge trap layer 층인 SiNx (SiH4:NH3=6:4)를 20 nm 증착하였다. 마지막으로 Tunneling layer 층인 SiOxNy은 N2O (2.5 sccm) 플라즈마 처리를 통해 2.5 nm 증착하였다. 이러한 ONO 구조층 위에 nc-Si을 50 nm 증착후에 Source와 Drain 층을 Al 120 nm로 evaporator 이용하여 증착하였다. 제작한 샘플을 전기적 특성인 Threshold voltage, Subthreshold swing, Field effect mobility, ON/OFF current ratio, Programming & Erasing 특성, Charge retention 특성 등을 알아보았다.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.5 no.1
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• pp.30-36
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• 1999

Physical analysis of some composite films of outer packaging at process cheeses in Korea is as following. In comparison with four composite films, tensile strength is $72.2{\mu}PET/PVDC/PE/AL-vac/PE\;film\;MD9.55kg/15mm,\;TD8.95kg/15mm>79.3{\mu}PET/PVDC/L-LDPE\;film\;MD5.37kg/15mm,\;TD5.01kg/15mm>96.9{\mu}PE/PVDC/PE\;film\;MD5.42kg/15mm,\;TD4.73kg/15mm>61.6{\mu}PVDC/PE/AL-vac/CPS\;film\;MD4.65kg/15mm,\;TD4.22kg/15mm$. Water vapor transmission is $72.2{\mu}PET/PVDC/PE/AL-vac/PE\;film\;0.41g/m^2{\cdot}24hr>79.3{\mu}PET/PVDC/L-LDPE\;film\;3.77g/m^2{\cdot}24hr>96.9{\mu}PE/PVDC/PE\;film\;3.81g/m^2{\cdot}24hr>61.6{\mu}PVDC/PE/AL-vac/4.91g/m^2{\cdot}24hr$. Gas transmission $O_2:N_2:CO_2$ is $72.2{\mu}PET/PVDC/PE/AL-vac/PE\;film\;1.81:0.74:4.2cc/m^2{\cdot}24hr{\cdot}atm>79.3{\mu}PET/PVDC/L-LDPE\;film\;13.4:6.4:34.2cc/m^2{\cdot}24hr{\cdot}atm>96.9{\mu}PE/PVDC/PE\;film\;15.3:7.1:42.0cc/m^2{\cdot}24hr{\cdot}atm>61.6{\mu}PVDC/PE/AL-vac/CPS\;film\;25.3:12.5:59.3cc/m^2{\cdot}24hr{\cdot}atm$ each other. And for preservation this were sealed to filths $N_2,\;CO_2$ gas or defilling ai (vacuum type) in the packaging and reserved less than $10^{\circ}C$ at refrigerator.

• Advanced Industrial SCIence
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• v.1 no.2
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• pp.17-23
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• 2022

The purpose of this study is to analyze the health factors of the elderly according to the region by analyzing the physical fitness and fall efficacy of the female elderly living in rural and urban areas. The subjects of this study consisted of 98 female elderly people living in rural and urban areas who exercise health and cheerleading at least twice a week at the regional center(REG; n=46, 77.53±6.37 yrs, 151.81±5.26 cm, 60.00±9.42 kg, UEG; n=53, 73.57±2.70 yrs, 154.07±3.52 cm, 57.37±2.06 kg). Physical strength was measured for muscular endurance, cardiopulmonary endurance, and flexibility. Falling efficacy was measured using 10 items of Fall Efficacy Scale developed by Tinetti et al. Significant differences in flexibility and fall efficacy were found in urban older adults (p<.01, p<.05). There was no significant difference in muscular endurance and cardiac endurance (p>.05). In the future, studies to improve the imbalance of health factors of the elderly in the region should be continuously conducted.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.59-64
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• 2002

Effects of the aging treatments on the microstructure and strength of heat affected zone(HAZ) in the welds of a age-hardened Al-Mg-Si alloy, 5N01-T5, were investigated. The base metal aging treatments before MIG welding were conducted at 423K to 473K for 28.8ks Post weld heat treatment(PWHT) to recover the HAZ strength was performed at 448K for 28.8ks. Microstructure observations, hardness measurements and tensile tests were conducted to study properties of the MIG weld joints. The position of the softest region in HAZ where the hardness insufficiently recovered after natural aging and PWHT was at a distance of approximately 15mm from the center of the fusion zone. Hardness of the softest regions after natural aging and PWHT decreased with increase in the base metal aging temperature. TEM observation clarified that strengthening ${\beta}$"(Mg$_2$Si) precipitates and coarse ${\beta}$′ precipitates affected the hardnes of HAZ. Incomplete recover of hardness in HAZ after PWHT was caused by the precipitating of non-hardening ${\beta}$′ phase during the weld thermal cycle. In order to examine the effects of weldheat input and welding speed, the laser weld joints were also investigated and compared with the MIG weld ones. Laser welding had the narrower width of the softened regions in HAZ compared with MIG welding. The hardness of the softest regions of the laser welds after PWHT was higher than that of the MIG welds. Quantitative relations between hardness of the softest region and base metal aging temperature were obtained for both welding processes. Accordingly, the equations to estimate the strength of the weld joints after PWHT with varying base metal temperatures were proposed for MIG welding and laser welding.

• Korean Chemical Engineering Research
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• v.55 no.6
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• pp.861-867
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• 2017

In order to improve the capacity and cycling stability of Ni-rich NCA cathode materials for lithium ion batteries, the boron and cobalt were doped in commercial $Li_{1.06}Ni_{0.91}Co_{0.08}Al_{0.01}O_2$ (NCA) powders. Commercial NCA particles are mixed composites such as secondary particles of about $5{\mu}m$ and $12{\mu}m$, and the particle size was decreased by doping boron and cobalt. The initial discharge capacities of the boron and cobalt doped NCA-B and NCA-Co were found to be 214 mAh/g and 200 mAh/g, respectively, which are higher values than that of the raw NCA cathode material. In particular, NCA-Co exhibits the best discharge capacity of 157 mAh/g after 20 cycles, which is probably due to the enhanced diffusion of lithium ion by crystal growth along with the c-axis direction.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.9
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• pp.840-850
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• 2010

The present study was attempted to find the effects of structural properties of phosphorus on the water quality of Gyehwa reservoir in Saemangeum. Relationship of phosphorus fractions between water and sediment properties was closely examined, and a few types of phosphorus were found from the sample sediment as : Saloid-P, Al-P, Fe-P, Ca-P, Red-P and Occd-P. Saloid-P (1.4%), Al-P (0.5%), Fe-P (39.8%), Ca-P (56.6%), Red-P (0.4%), Occd-P (1.3%) were extracted in a mass basis from the sediment of Gyehwa reservoir. Approximately more than 97% of phosphorus were calcium related phosphorus (Ca-P, 56%) and iron bound phosphorus (Fe-P, 39.8%). The Fe-P closely relates with water quality of T-N (r=0.761, p<0.05), $NO_3$-N (r=0.754, p<0.05), $NH_4$-N (r=0.728, p<0.05), T-P (r=0.774, p<0.05) and $PO_4$-P (r=0.767, p<0.05) while the Ca-P did not show any consistent dependency on the water quality. On the other hand, the correlation of Ca-P with $P_2O_5$ was high with r=0.783 (p<0.05) in the sediment. The Fe-P was affected significantly on the Ignition Loss (r=0.569, p<0.05), T-N (r=0.715, p<0.05) and T-P (r=0.983, p<0.01). In the research of correlation between phosphorus fraction and heavy metals in the sediment, Ca-P did not show any specific relationships with heavy metals. The Fe-P showed a significant correlation with As (r=0.817, p<0.01), Cu (r=0.793, p<0.05), Cd (r=0.786, p<0.05), Zn (r=0.738, p<0.05), so that it can be stated that the presence of Fe-P may implicate the volume of various metallic elements.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.4 no.2
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• pp.139-147
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• 1994

Orthophosphate crystals were grown by the hydrothermal method and the properties of grown crystals were investigated by means of X-ray diffraction. Vickers hardness tester, etc. The starting powders of $AIPO_4 and GaPO_4 $were prepared as a single phase by the solid state reaction of stoichiometric mixture of $AI_2O_3 or Ga_2O_3$ and $NH_4H_2PO_4$ and the subsequently by the hydrothermal treatment. The hydrothermal conditions for high growth rates of the orthophosphate crystals are as follows: $AlPO_4$ crystal; temperature ranges, between $170$~$200^{\circ}C$; temperatures difference, $15$~$20^{\circ}C;$, hydrothermal solvent, 4m HCl, $GaPO_4 crystal; temperature ranges, between $210 and 240^{\circ}C;$; temperature difference, $25$~$30^{\circ}C; $, hydrothermal solvent, 4m HCl. Morphologies of grown crystals tended to be bounded by (1010), (1011) and (0111) faces at low temperatures, and grew with well developed (0001) faces by increasing the growth temperature. On the other hand, the properties of orthophosphate crystals $(AlPO_4/GaPO_4)$ were as follows: lattice parameters (nm); a=0.494, c=1.094/a=0.490, c=1.105, density (gcm-3); 2.62/3.56, Vickers hardness (Nm^2); $1.02{\times}10^1^0/7.06{\times}10^9$, refractive indices; $ne=1.529{\pm}0.003, no=1.519{\pm}0.003/ne=1.611{\pm}0.006, no=1.599{\pm}0.006, birefringence; {\pm}0.01/{\pm}0.012$, dielectric constant (Fm-1); 6/7.