• Korean Journal of Soil Science and Fertilizer
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• v.49 no.2
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• pp.132-137
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• 2016

Field monitoring was performed to evaluate the chemical properties of 260 paddy soils every 4 years from 1999 to 2015 in Gyeongnam province. Soil chemical properties, including soil pH, electrical conductivity, amount of organic matter (OM), available phosphate ($P_2O_5$), exchangeable potassium (K), calcium (Ca), magnesium (Mg) and sodium (Na), and available silicate ($SiO_2$) were analyzed. In 2015, the average values of pH, OM, available $P_2O_5$, exchangeable K, Ca, and Mg, and available $SiO_2$ was 5.8, $30g\;kg^{-1}$, $222mg\;kg^{-1}$, $0.37cmol_c\;kg^{-1}$, $6.5cmol_c\;kg^{-1}$, and $1.4cmol_c\;kg^{-1}$, $252mg\;kg^{-1}$, respectively. The frequency distribution within optimum range of paddy soils was 49.2%, 20.8%, 18.5%, and 5.8% for soil pH, OM, available $P_2O_5$, and available $SiO_2$, respectively. The available $P_2O_5$ concentrations in 2015 was excess level with portion of 58% and did not alter significantly during the experimental period. Although the average of available $SiO_2$ concentration has tended to increase with every year, the insufficient proportion of available $SiO_2$ concentration in 2015 was 48%. These results indicated that a balanced management of soil chemical properties can properly control the amount of fertilizer applied for sustainable agriculture in paddy field.

• Horticultural Science & Technology
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• v.28 no.5
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• pp.735-742
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• 2010

Objective of this research was to investigate the influence of liming fertilizers on changes in soil chemical properties and growth of pansy 'Melody Yellow' in plug production. To achieve this, dolomite (DO) with 0, 1.0, 3.5, 8.0 or $13.0g{\cdot}L^{-1}$ and calcium carbonate (CC) with 0, 2.0, 2.5, 3.0, 3.5, or $4.0g{\cdot}L^{-1}$ in application rate were incorporated into peatmoss + vermiculite (1:1, v/v) during the formulation. The treatments of $3.5g{\cdot}L^{-1}$ of DO and 2.5 or $3.0g{\cdot}L^{-1}$ of CC had acceptable range of soil solution pH such as 5.6-6.2. Faster rising of pH was observed in root media containing CC rather than those of DO, indicating higher solubility of CC. The soil Ca concentrations in all treatments of CC were 2 times as high as those of DO. The treatments of 3.5 or $8.0g{\cdot}L^{-1}$ of DO had the highest soil Mg concentrations, but all treatments of CC had lower soil Mg concentrations than control indicating that additional applications of Mg fertilizers are required. The elevated application rate of DO or CC resulted in the increase of fresh and dry weight; however, plant heights were not influenced by application of liming fertilizers. The results of tissue analysis showed that application of DO or CC influenced the Ca and Mg contents, but did not influence the contents of other nutrients such as N, P, Fe, Mn, Zn and Cu.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.3
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• pp.311-316
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• 2005

Fermentation properties and in vitro anticancer effect of young radish (YR) kimchi and young radish watery (YRW) kimchi were investigated during fermentation at 5℃. The fermentation of YR kimchi during 2-3 weeks led to the decrease of pH down to pH 4.3, increased acidity, and the highest Leuconostoc sp. counts. YR kimchi showed the acidity of 1.04-1.27% at the pH 4.3, when the kimchi was ripened properly. The fermentation of YRW kimchi during 9 days led to the decrease of pH down to pH 4.3 and the acidity of 0.20%. Inhibitory effects of the juices of YR, YR kimchi, and YRW kimchi on the growth of AGS human gastric adenocarcinoma cells in MTT assay were increased with the added concentration. The juice of YR kimchi had a higher inhibitory effect on the growth of AGS human gastric adenocarcinoma cells than that of YRW kimchi at same concentration. The juice of YR kimchi showed similar inhibitory effects on the growth of AGS human gastric and HT-29 human colon adenocarcinoma cells in MTT assay to baechu kimchi, which the inhibition rates are more than 50%.

• Current Research on Agriculture and Life Sciences
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• v.6
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• pp.99-104
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• 1988

Water polution status of urban streams in Daegu city were observed to provide the basic information for the effective purification of urban sewage and the conservation of Keumho river. Periodically, pH, DO, COD, nitrate and phosphate of water were investigated at Yee cheon, B$\ddot{o}$m$\ddot{o}$ cheon, Chilsung cheon, Dalseo cheon and Kongdan cheon. The results were as follows. 1) The ranges of average values of analyzed components for 12 months at six sampling sites were pH 7.3-8.2, DO trace-6.5ppm, COD 20.4-116.9ppm, T-N 23.2-31.7ppm, $NH_4$-N 18.3-27.7ppm, $NO_2$-N 0.08-1.89ppm, $NO_3$-N 0.19-1.51ppm, $PO_4$-P 2.50-17.28ppm. 2) At Kongdan cheon, the most heavily polluted site, average values of components were pH 8.2, DO trace, COD 116.9ppm, T-N 23.2ppm, $NH_4$-N 18.3ppm, $NO_2$-N 1.89ppm, $NO_3$-N 1.51ppm, $PO_4$-P 17.28ppm. 3) The values of pH, DO, COD, T-N and $NH_4$-N at winter urban streams were higher than those at summer urban streams. And the values of $NO_2$-N and $PO_4$-P were more or less higher at summer urban streams.

• Journal of Environmental Impact Assessment
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• v.29 no.1
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• pp.61-77
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• 2020

In South Korea, major public waters have been systematic management under national level. Water environment network has been continuous monitoring for change of aquatic ecosystem, river and reservoir. In Water Quality Monitoring Networks, the data have been generally monitored Per eight days or month, while in Automatic Water Quality Monitoring Network the data have been monitored at daily intervals. Therefore, we were compared and analyzed water quality data between the networks using statistic method for same water quality item. Mann-kendall test results confirm that all points in Water Temperature (WT) and DO were not statistically significant. In particular, the result revealed that there is significant variation of TOC in the four different sites, TN in two different sites, TP in three different sites, WT in seven different sites, pH in two different sites between Water Quality Monitoring Network and Automatic Water Quality Monitoring Network. As a result firm LOWESS, TOC and pH clearly shows different trend. Among different sites, the water quality show the significantly positive correlations between at Sinam-Sangju2 and Namgang-Namgang4. Negative correlation significantly appeared in TP (ADD_Lower-AD1 site), TOC (DG-SG site), pH (GR-GR site), TP (JP-CN) and TN, TP, pH, EC, DO (GC-GC2-1 site).

• Journal of Animal Science and Technology
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• v.50 no.4
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• pp.561-572
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• 2008

Responses of real-time control parameters, such as ORP, DO and pH, to the conditions of biological animal wastewater treatment process were examined to evaluate the stability of real-time control using each parameter. Also an optimum index for supplemental carbon source addition based on NOx-N level was determined under a consideration of denitrification rate by endogenous respiration of microorganism and residual organic matter in liquor. Experiment was performed with lab-scale sequencing batch reactor(SBR) and working volume of the process was 45L. The distinctive nitrogen break point(NBP) on ORP-and DO-time profiles, which mean the termination of nitrification, started disappearing with the maintenance of low NH4-N loading rate. Also the NBP on ORP-and DO-time profiles was no longer observed when high NOx-N was loaded into the reactor, and the sensitivity of ORP became dull with the increase of NOx-N level. However, the distinctive NBP was constantly occurred on pH(mV)-time profile, maintaining unique profile patterns. This stable occurrence of NBP on pH(mV)-time profile was lasted even at very high NOx-N:NH4-N ratio(over 80:1) in reactor, and the specific point could be easily detected by tracking moving slope change(MSC) of the curve. Revelation of NBP on pH(mV)-time profile and recognition of the realtime control point using MSC were stable at a condition of over 300mg/L NOx-N level in reactor. The occurrence of distinctive NBP was persistent on pH(mV)-time profile even at a level of 10,000mg/L STOC(soluble total organic carbon) and the recognition of NBP was feasible by tracing MSC, but that point on ORP and DO-time profiles began to disappear with the increase of STOC level in reactor. The denitrfication rate by endogenous respiration and residual organic matter was about 0.4mg/L.hr., and it was found that 0.83 would be accepted as an index for supplemental carbon source addition when 0.1 of safety factor was applied.

• Journal of Mushroom
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• v.11 no.1
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• pp.15-20
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• 2013

This study was performed to obtain the scientific data an artificial culture of ear mushroom(Auricularia auricula). Liquid cultural of Auricularia auricula. mycelium was characterized with respect to temperature, pH, compositions of inorganic, carbon and nitrogen. The its optimum temperature and media pH were at $25^{\circ}C$ and pH 5.0~6.0 on the mycelial growth, respectively. The optimum inorganic compositions and concentration for mycelial growth were $MgSO_4$ 0.05%(w/v) and $KH_2PO_4$ 0.1%(w/v), respectively. The optimum carbon sources and nitrogen sources were black-sugar 2%(w/v) and soybean powder at 0.3~0.5%(w/v) with7 days optimum culture time.

• Journal of Environmental Health Sciences
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• v.43 no.5
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• pp.393-400
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• 2017

This study was investigated on pH, heavy metals, oils and solvents in 34 surface soil samples and the samples are collected at two times for 17 farmland sites around 7 industrial areas in Northern Gyeonggi Province. As a result of pH for soil contamination monitoring network, the range of pH showed 4.4~8.4 and average was 6.3. The range of pH for Agricultural land around industrial area was 6.7~7.5 and average indicated 7.1 that mostly showed neutral condition in this area. he average concentrations of Cu, Pb, Ni, As and $Cr^{6+}$ are lower than Korea soil contamination worrisome levels at region 1 and the mean levels of farmland from the soil quality monitoring network. The average concentrations of Zn, Cd and Hg didn't exceed the soil contamination worrisome levels at region 1 but slightly higher than the mean levels of farmland from the soil quality monitoring network. The heavy metal levels of all samples are within Korea soil contamination worrisome levels at region 1. The results showed that the detected heavy metal concentrations ranged from N.D. to ~32.7% of Korea soil contamination worrisome levels at region 1. BTEX, TPH, TCE and PCE were not detected in all samples and thus the farmland around the industrial areas were free from oils and solvents contamination.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2006.05a
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• pp.365-369
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• 2006

[ $O_3$ ]/catalyst를 이용한 고급산화공정에서 pH변화에 따른 1,4-dioxane의 화학적 분해 특성을 알아보기 위해 이 실험을 수행하였다. 초기 pH를 6, 8, 10으로 조절하여 변화를 보면 오존의 pH 완충효과에 의해 시간이 지남에 따라 알칼리와 산의 경우 중성 쪽으로 중화되는 것을 확인하였다. 그리고 시간에 따른 1,4-dioxane의 제거율은 pH 10 > pH 8 > pH 6 의 순서로 나타는 것을 보였다. 이는 오존이 산성에서는 안정하지만 알칼리성에서는 불안정함으로 인해 자기분해를 일으켜 OH라디칼의 생성을 촉진시켜 제거율이 높게 나타났다. 초기 pH를 조절한 실험, 초기 pH를 일정하게 유지한 실험에서의 50분 후의 최종 제거율은 비슷하였지만, 초기 pH를 일정하게 유지한 실험에서 제거율이 꾸준히 감소하는 것을 알 수 있었다.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.5
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• pp.584-589
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• 2010

Sweet persimmon yield can be limited by soil pH. This study was performed to rapidly determine the optimal level of lime requirement in sweet persimmon field. Soil chemical properties such as Fe, Mn, and Zn were analyzed soil samples of 31 sweet persimmon fields at Gyeongnam Province every two months from April to October in 2008. The available Fe, Mn, and Zn content were significantly high top soil (76.5 mg $kg^{-1}$ for Fe, 46.1 mg $kg^{-1}$ for Mn, and 16.9 mg $kg^{-1}$ for Zn, respectively), and subsoil (55.5 mg $kg^{-1}$ for Fe, 35.9 mg $kg^{-1}$ for Mn, and 12.3 mg $kg^{-1}$ for Zn, respectively) in April. Furthermore, the Mn content was significantly decreased since April compared to other micronutrients. We found a significant negative correlation between soil pH and lime requirement (r=0.881, $p{\leq}0.001$ for top soil, and r=0.855, $p{\leq}0.001$ for subsoil). We suggest that a conversion factor is -171 top soil pH + 1,148 to lime requirement (kg $10a^{-1}$) for top soil, and -190 subsoil pH + 1,247 to lime requirement (kg $10a^{-1}$) for subsoil in sweet persimmon fields. These results supported that the improvement of lime requirement by soil pH value is necessary to rapidly apply to field, and prevent micronutrients over uptake by persimmon plant.