• Korean Journal of Agricultural Science
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• v.10 no.2
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• pp.324-333
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• 1983

Modeling of longterm runoff is theoritically based on waterbalance analysis. Simplified equation of water balance with rainfall, evapotranspiration and soil moisture storage could be formulated into regression model with variables of rainfall, pan evaporation and previous-month streamflow. The hydrologic response of water shed could be represented lumpedly, qualitatively and deductively by regression coefficients of water-balance regression model. Characteristics of regression modeling of water-balance were summarized as follows; 1. Regression coefficient $b_1$ represents the rate of direct runoff component of precipitation. The bigger the drainage area, the less $b_1$ value. This means that there are more losses of interception, surface detension and transmission in the downstream watershed. 2. Regression coefficient $b_2$ represents the rate of baseflow due to changes of soil moisture storage. The bigger the drainage area and the milder the watershed slope, the bigger b, value. This means that there are more storage capacity of watershed in mild downstream watershed. 3. Regression coefficient $b_3$ represents the rate of watershed evaporation. This depends on the s oil type, soil coverage and soil moisture status. The bigger the drainage area, the bigger $b_3$ value. This means that there are more watershed evaporation loss since more storage of surface and subsurface water would be in down stream watershed. 4. It was possible to explain the seasonal variation of streamflow reasonably through regress ion coefficients. 5. Percentages of beta coefficients what is a relative measure of the importance of rainfall, evaporation and soil moisture storage to month streamflow are approximately 89%, 9% and 11% respectively.

• Journal of Bio-Environment Control
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• v.12 no.3
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• pp.152-159
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• 2003

This study was conducted to analyze the water consumption in closed transplants production system (CTPS) for the production of quality transplants and to investigate the effect of relative humidity on the water balance in CTPS. Potato (Solanum tuberosum L. cv. Dejima) plug seedlings were grown for 15 days at air temperature of 20$^{\circ}C$, relative humidity of 70%, photoperiod of 16/8 h, and photosynthetic photon flux (PPF) of 200 ${\mu}mol{\cdot}m^{-2}{\cdot}s^{-l}$ following rooting for 5 days in CTPS. Amount of humidified, dehumidified, irrigated and evapotranspirated water were 67.9 kg${\cdot}m^{-2},\;196.9{\cdot}m^{-2},\;44.3\;kg{\cdot}m^{-2},\;33.5\;kg{\cdot}m^{-2}$, respectively. Water content of media and plants were 1.2 kg${\cdot}m^{-2},\;6.9\;kg{\cdot}m^{-2}$, respectively. Three relative humidity levels of 60, 70, and 80% were provided to analyze the effect of humidity on the water balance in CTPS. Amount of humidified, dehumidified, irrigated, evapotranspiratad water and water contents of media and plants increased with increasing relative humidity. Since the water consumption required to produce plug seedlings in CTPS dec1eased with decreasing relative humidity, the available water utilization efficiency of CTPS increased with decreasing relative humidity. CTPS showed high available water utilization efficiency of 0.92 - 0.97 if dehumidified water in CTPS was recycled. The development of CTPS with recycling system of dehumidified water will not only reduce the water consuming for the production of transplants but contribute to the establishment of plant production economizing in water consumption.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.2
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• pp.139-145
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• 1986

In order to study the influence of nitrate reduction to ionic balance in tissue of tobacco plant, differneces in amounts of those cations and anions were determined and these balances were compared with contents of organic acids and activities of nitrate reductase, while they were fertilized with different nitrogen sources ($NO_3-N$, $NH_4-N$, $NO_3+NH_4-N$) in water culture. The results of studies are summerized as follows; 1. Total uptake of inorganic cations was the highest in nitrate-fed plants, whereas that of inorganic anions showed the highest level in the plants grown with the mixture ($NO_3+NH_4$). The amounts of inorganic cations and anions were comparable in two treatments containing $NH_4-N$, but in plants treated with nitrate only had much higher level of inorganic cations than others. 2. Deficiency in the amount of inorganic anions in nitrate-fed plants was balanced with organic acids, dominantly with malic acid among them. But another two $NH_4-N$ fed plant sustained equilibrium between inorganic cations and anions. 3. Reduction of nitrate was raised in tissues of nitrate-fed plants. By the results of nitrate reduction, cations maintained equilibrium with nitrate ion were let loose. The replacement of inorganic anions with organic anions could be a compensation process for the loss of uptaken nitrate ions which must be reduced to be incorporated into organic N compounds.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.2
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• pp.78-84
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• 1994

Yield response of tomato to nitrogen and potassium fertilizer and the balance of the two elements were determined in salt-accumulated greenhouse soil to improve the efficiency of fertilizer appiication. The response of tomato yield to nitrogen and potassium fertilizer application was not significant. The current parameters such as OM and $K/{\sqrt{Ca+Mg}}$ that were used to determine the level of nitrogen and potassium fertilizer in open field were not suitable in salt-accumulated greenhouse soil condition. The temporal and spatial distribution of $NO_3{^-}-N$showed the same pattern to those of $Cl^-$ ion that is non-reactive with soil, while the content of Ex. K was extraordinarily high in soil after harvesting of tomato, which had experienced relatively dry condition during harvesting time. The loss of $NO_3{^-}-N$ and Ex. K out of 28cm below the soil surface was 2~5 and 1.5~3.5 times greater than the amount of nitrogen and potassium uptake by the plant.

• Journal of Korea Water Resources Association
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• v.49 no.1
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• pp.61-72
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• 2016

In Korea, the aquifers at the coastal areas are mostly shallow alluvial unconfined aquifers. To simulate the flow and dispersion in unconfined aquifer, a FDM model has been developed to solve the nonlinear Boussinesq equation. Related analysis and verification have been executed. The iteration method is used to solve the nonlinearity, and the model shows 3-D shape because it is a 2-D y model that consider the undulation of water table and bottom. For the verification of the model, the output of flow module is compared to the 1-D analytic solution of Lee (1989) which have the drawdown or uplift boundary condition, and the two results show almost the same value. and the mass balance of dispersion module shows about 10% error. The developed model can be used for the analysis and design of the flow and dispersion in the unconfined aquifers. The model has been applied to the estuary area of Ssangcheon watershed, and the parameters have been deduced as a result : hydraulic conductivity is 90 m/day, and longitudinal dispersivity is 15 m. And the analysis with these parameters shows that the wells are situated in the influence circle of each others except for No. 7 well. Groundwater discharge to sea is $3700m^3/day$. And the chlorine ion ($cl^-$) concentration at the pumping wells increase at least 1000 mg/L if groundwater dam is not exist, so the groundwater dam plays an important role for the prevention of sea water intrusion.

• Journal of Bio-Environment Control
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• v.26 no.2
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• pp.133-139
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• 2017

This study investigated the effects of NaCl and jasmonic acid (JA) on the growth and physiological responses of spearmint (Mentha spicata L.). Spearmint was hydroponically grown for 3 weeks in modified Hoagland solution containing 0 (untreated control), JA ($20{\mu}M$ JA pretreatment), NaCl (50 mM NaCl treatment) and JA + NaCl ($20{\mu}M$ JA pretreatment + 50 mM NaCl treatment). Growth characteristics, chlorophyll, vitamin C, proline contents, DPPH scavenging activity and inorganic ion contents were evaluated. As a results, there were significant decreases in the plant height, leaf length, leaf width, and fresh weight of plants, treated with NaCl compared with control. On the other hand, the dry matters of shoot and root treated with JA + NaCl combination were better than control or NaCl treatment. Chlorophyll a and b contents in JA treatment was the highest. Vitamin C, antioxidant activity, and proline content in shoot were increased in NaCl treatment which showed low level of growth rate. The K/Na ratio, which is known to indirectly reflect the balance of ion uptake, was higher in a single treatment of JA than the control group, while lower in salt treatment (NaCl and JA + NaCl) because of high $Na^+$ absorption. In conclusion, these results showed that moderate stress treatment such as low level salt treatment and plant growth regulator jasmonic acid (JA) application would be potential strategies to improve the quality of spearmint by inducing the accumulation of secondary metabolites containing high antioxidant activity and essential oil.

• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.1
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• pp.49-54
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• 2007

The issue of acid precipitation and related environmental problems in East Asia has been emerging. To evaluate the acidity and chemical characteristics of rainwater in Korea, its chemical properties during cultivation season from April to October in 2005 were investigated at Taean. Also, to estimate the contribution of ions on acidity, ion composition characteristics and neutralization effects by cations were determined. The electrical conductivity balance between measured and estimated values showed a high correlation. Rainwater was highly distributed in the range of pH $4.5{\sim}5.0$. The acidity of rainwater was relatively low during the month of June compared with other monitored periods. $Na^+$ was the main cation, followed by $H^+>Ca^{2+}>NH_4^+>K^+>Mg^{2+}$. Among these ions, $Na^+,\;NH_4^+,\;Ca^{2+}$ and $H^+$ comprised over 94% of the total cations. Rainwater anion composition was more than 80% with $SO_4^{2-}$ and $NO_3^-$. In rainwater samples, $NH_4^+$ and $Ca^{2+}$ contributed greatly to neutralizing the rain acidity. The sulfate content decreased until September, and sea salt derivatives were higher in May and October than during other monitored periods. Also, 78% of the soluble sulfate in rainwater was nss-$SO_4^{2-}$ (non-sea salt sulfate).

• Korean Journal of Agricultural and Forest Meteorology
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• v.7 no.2
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• pp.125-131
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• 2005

This study investigated effects of acid deposition on cation contents of rinus densiflora needles. The results of the investigation were as follows: By regression the ion balance was shown to be 1.01 of slope and 0.973 of $R^2$. The volume weighted average pH measurements of wet deposition in Seoul from January to December, 2001, 2002 and 2003 were: pH 5.1, pH 5.0 and pH 4.8, respectively. The annual wet deposition ion amount was shown to gradually increase during this study period. Cation content of needles in the fall season was higher than during other seasons, but $Al^{3+}$ ion contents showed nodifferences among seasons. When ion concentrations of wet deposition were higher, cation contents of needles were generally lower.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.12
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• pp.1741-1745
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• 2005

Zinc is a trace element that is associated with a stimulation of immune function and regulation of ion balance for livestock production. In this study, the effect of zinc as inhibitor to apoptosis-induced cells was examined in vitro using mammary epithelial cell line, HC11 and macrophage cell line, NCTC3749. Cell viability, measured by MTT assay, indicated that 10 g/ml of zinc had a negative impact on cellular activity and 50 ng/ml was chosen for further testing. Apoptosis was induced in cells treated with C2-ceramide in serum-free media. DNA fragmentation and gene expression of acidic sphingomyelinase (a gene responsible for the progress of apoptosis) were distinctively low in zinc treated cells compared with those in non-treated controls. In conclusion, zinc is involved in the regulation of cell proliferation and apoptosis in mammary epithelial cells and macrophages.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.3
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• pp.357-364
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• 2007

This research is to set a direction on the recycle of Discarded Automotive tires reforming them into heavy metal adsorbents by developing a particular functional group inducing formation of Chelate complexes with heavy metal ion in the water, on the surface of the used tire conventionally turned into powdered form. For this purpose, through FT-IR, XRD, XRF, SEM, elution test we confirmed and analyzed the property of newly reformed scrapped tires, and functional group. Also, by Kinetics Study we produced an invariable value applying to absorption models. Conclusively the absorption preference of heavy metal is determined to be $Pb^{2+}>Cu^{2+}>Cd^{2+}$, and it reached absorption balance within first 30 minutes, also the absorption reaction time increased from 0.27 to $1.78\sim3.15(g/mg{\cdot}min)$, and showed more than 80% of removal efficiency. This result proved that the efficiency increased by 10 times compared with the conventional powdered Discarded Automotive tires, and the Discarded Automotive tire which implemented the Functional group can exhibit a great efficiency as heavy metal adsorbent.