• Journal of Magnetics
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• v.5 no.4
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• pp.120-123
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• 2000

Co-Ni-Fe-N thin films were fabricated by a $N_2$ reactive rf magnetron sputtering method. The nitrogen partial pressure ($P_{N2}$) was varied in the range 0~10% . As$P_{N2}$ increases in this range, the saturation magnetization $B_s$ linearly decreases from 19.8 kG to 14 kG and the electrical resistivity ($\rho$) increases from 27 to 155 $\mu\Omegacm$. The coercivity $H_c$ exhibits the minimum value at 4% $P_{N2}$. The magnetic anisotropy fields ($H_k$) are in the range of 20$\sim$50 Oe. High frequency characteristics of $(Co_{22.2}Ni_{27.6}Fe_{50.2})_{100-x}N_x$ films are excellent in the range of 3$\sim$5% of $P_{N2}$. In particular, the effective permeability of the film fabricated at 4% $P_{N2}$ is 800, which is maintained up to 600 MHz. This film also shows Bs of 17.5 kG, $H_c$/ of 1.4 Oe, resistivity of 98$\mu\Omegacm$ and $H_k$ of about 25 Oe. Also, the corrosion resistance of $(Co_{22.2}Ni_{27.6}Fe_{50.2})_{100-x}N_x$ films was imp roved with increasing N concentration.

• Journal of Trauma and Injury
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• v.32 no.3
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• pp.136-142
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• 2019

Purpose: Near drowning refers to immediate survival after asphyxia due to submersion or immersion in water, which is a crucial public safety problem worldwide. Acute lung injury or acute respiratory distress syndrome (ARDS) is a common complication of near drowning. The purpose of this study was to investigate the feasibility and effectiveness of noninvasive nasal positive pressure ventilation (NINPPV). Methods: This retrospective study was conducted at a tertiary emergency department. NINPPV was administered for moderate ARDS caused by submersion or immersion in patients who were older than 18 years, from January 2015 to December 2018. We collected the demographic (age, sex, length of hospital stay, and outcome), laboratory (arterial blood gas, lactate, oxygen saturation, partial pressure of oxygen divided by the fraction of inspired oxygen, complete blood count, blood urea nitrogen, and creatinine), and clinical data (acute lung injury index and ventilator failure) of the patients. A statistical analysis was performed using Statistical Package for the Social Sciences version 20.0 for Windows. Results: NINPPV treatment was provided to 57 patients for near drowning, 45 of whom (78.9%) were successfully treated without complications; in 12 (21.1%), treatment was changed to invasive mechanical ventilation within 48 hours due to ARDS or acute kidney injury. NINPPV treatment was successful in 31 (75.6%) out of 41 sea-water near drowning patients. They were more difficult to treat with NINPPV compared with the fresh-water near drowning patients (p<0.05). Conclusions: NINPPV would be useful and feasible as the initial treatment of moderate ARDS caused by near drowning.

• Journal of Korean Society on Water Environment
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• v.37 no.6
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• pp.449-457
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• 2021

Photosynthesis and respiration rate of microalgae are important factors during advanced wastewater treatment research using microalgae, There are several equipments and measurement methods for measuring photosynthesis and respiration, with different challenges that occur during pretreatment and stabilization of the analysis process. Therefore, in this study, for accurate Photosynthesis and Respiration (P&R) analyzer measurement, the analysis process was divided into pre-processing, DO stabilization, and analysis stages and each was optimized to enable accurate evaluation. For this purpose, the effect of DO saturation of the sample on P&R analysis, DO stabilization according to the degassing flow rate, and photoinhibition of the OD level on photosynthesis was investigated. Based on our study results, when DO was supersaturated, photosynthetic efficiency decreased due to photorespiration, making it inappropriate as a P&R sample. In addition, 0.5 L-N2/min level was the optimal nitrogen degassing flow rate for DO desaturation. The inhibition of photosynthetic efficiency by self-shading caused by the increase in OD was observed from OD 2.0, and it was found that P& R analysis is preferably performed on samples with OD less than 2.0. In addition, based on the above three optimization results, an optimized P&R Analyzer instruction for accurate P&R analysis was also presented.

• Proceedings of the Korean Magnestics Society Conference
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• 2000.09a
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• pp.492-499
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• 2000

Co-Ni-Fe-N thin films were fabricated by a N$\sub$2/ reactive rf magnetron sputtering method. The nitrogen partial pressure (P$\sub$N2/) was varied in the range of 0∼10%. As P$\sub$N2/ increases in this range, the saturation magnetization (B$\sub$s/) linearly decreases from 19.8 kG to 14 kG and the electrical resistivity ($\rho$) increased from 27 to 155 ${\mu}$$\Omega$cm. The coercivity (H$\sub$c/) exhibits the minimum value at 4% of P$\sub$N2/. The magnetic anisotropy (H$\sub$k/) are in the range of 20∼50 Oe. High frequency characteristics of (Co$\sub$22.2/Ni$\sub$27.6/Fe$\sub$50.2/)$\sub$100-x/N$\sub$x/ films are excellent in the range of 3∼5% of P$\sub$N2/. Especially the effective permeability of the film fabricated at 4% of P$\sub$N2/ is 800, which is maintained up to 600 MHz. This film also shows Bs of 17.5 kG, H$\sub$c/ of 1.4 Oe, resistivity of 98 $\Omega$cm and H$\sub$k/ of about 25 Oe. Also, the corrosion resistance of (Co$\sub$22.2/Ni$\sub$27.6/Fe$\sub$50.2/)$\sub$100-x/N$\sub$x/ were improved with the increase in N concentration.

• Journal of Korean Society for Atmospheric Environment
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• v.4 no.1
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• pp.33-44
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• 1988

For the purpose of examining the effects of simulated acid rain on the chemical properties of the experimental soil in Pinus densiflora seedlings and Forsythia koreana rooted cuttings, the experimental design of randomized block arrangement with three replications was implemented in the experimental field of Yesan National Agricultural Junior College. One-year-old Pinus densiflora seedlings and Forsythia koreana cuttings were planted in the pots filled the mixed soils (nursery soil: forest soil of siliceous sandy loam = 1 : V/V)in the early spring of 1985. The regime of artificil acid rain, in terms of spray frequency per monthly and spray amount at single treatment per plot, was simulated on the basis of climatological data averaged from 30 years records. Simulated acid rain (pH 2.0, pH4.0, and pH 5.5 as control) containing sulfuric and nitric acid in the ratio of 3:2 (chemical equivalant basis) diluted ground water, were treated on the experimental plants under condition of cutting off the natural precipitation with vinyl tunnel, during the growing season (May 1 to August 31) in 1985. THe results obtained in this study were as follows; 1. Soil acidity was dropped, and exchangeable aluminum contents in the soil was dramatically increased in both species, with decreasing pH levels of acid rain. 2. Exchangeable potassium, clacium, magnesium contents, and base saturation degree of the soil were highly drcreased in two species as the pH levels of acid rain decreased. 3. In two species, sulfate concentrations in the soil were decreased of pH 4.0 treatment, and remarkably increased at pH 2.0 treatment of acid rain in comparison with control. 4. Total nitrogen and available phosphate contents of the soil were not affected by acid rain treatment in the both species, and Fe contents at pH 2.0 treatment were highest among three acid rain treatments.

• Journal of Plant Biology
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• v.37 no.3
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• pp.387-394
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• 1994

Effects of environmental factors of light, temperature, nitrogen sources and water stress were analyzed quantitatively on the nodule formation and nitrogen fixation activity of autumn olive plant (Elaeagnu$ umbellala Thunb.) during the seedling growth. Seedlings showed the maximum nitrogenase activity of $72.5\;\mu\textrm{M}\;C_2H_4{\cdot}g\;fr\;wt\;nodule^{-1}{\cdot}h^{-1}$ in the early nodulation stage. The relative growth rate and T/R ratio changed from $1.60%{\cdot}d^{-1}$ and 1.12 in the earlier stage to $3.75%{\cdot}d^{-1}$ and 2.31 in the later stage, respectively. light conditions of 20-25, 1015 and 4-6% resulted in decreases of 41, 54 and 71% of the nitrogenase activity, respectively. Nodules incubated in 15, 20, 25 and $30^{\circ}C$ showed the activities of 5.4, 24.7, 51.6 and $58.5\;\mu\textrm{M}\;C_2H_4{\cdot}g\;fr\;wt\;nodule^{-1}{\cdot}h^{-1}$ respectively. Pretreatment with low temperature ($15^{\circ}C$) followed incubation at $30^{\circ}C$ attained higher nitrogenase activity ($66.5\;\mu\textrm{M}\;C_2H_4{\cdot}g\;fr\;wt\;nodule^{-1}{\cdot}h^{-1}$) than that with higher temperature ($35^{\circ}C$). The oxygen pressure above 16 kPa is necessary for saturation of the nodule activity, but the activity was inhibited severely by physical impact such as the exision or isolation of nodules from the root. The relative activities of early nodules grown in pH 5.5, 6.5 and 8.0 were 89, 100 and 40% and those grown in 1 and 3 mM of $NO_3\;and\;NH_4$ were 6, 1 and 68, 50%, respectively. Watering levels of 20, 50 and 100 mL during the seedling growth resulted in 35, 120 and 8 mg of nodule formation and 33.6, 58.4 and $8.4\;\mu\textrm{M}\;C_2H_4{\cdot}g\;fr\;wt\;nodule^{-1}{\cdot}h^{-1}$ of the nitrogenase activity, respectively. Water stress with 86% decrease of soil water content caused temporary wilting point of leaf and a complete disappearance of nitrogenase activity of nodules, though the water content and transpiration rate in plant were reduced to 90 and 53%, respectively.tively.

• Journal of Korean Society of Forest Science
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• v.46 no.1
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• pp.10-20
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• 1980

This experiment was carried out to investigate the effects of physico-chemical properties of soil on the growth of Chamaecyparis obtusa and to apply the results to such rational forest management as yield forecast and selection of suitable species for a given forest stand. The soil properties observed in this experiment were soil pH, exchangeable pH organic matter, total nitrogen, available $P_2O_5$, cation exchange capacity, exchangeable $H^+$, total base and base saturation. Diameter at breast height (DBH), height and volume growth of C. obtusa were observed at 78 sampling sites. Data were processed into the following series for the analysis of multivariates : inner correlation matrix, multiple correlation coefficients, regression coefficients and partial correlation coefficients. The results are summerized as follows : 1. Multiple correlation coefficients between soil properties and DBH of C. obtusa were .364 for 20-year trees, resulting less efficient for estimating the growth of C. obtusa. However, total base, soil pH and base saturation were considerable characters for better estimation. 2. More efficient multiple correlation coefficients were observed between soil properties and height growth than those between soil properties and DBH, showing .443 for 20-year trees and factors affecting the height growth were similar to those of DBH. 3. Extremely low values of multiple correlation coefficients were estimated between physico-chemical properties of soil and volume growth of C. obtusa resulting low efficient estimation. However, total base contributed highly to volume growth of C. obtusa. Accordingly the most contributable factor for estimating the growth of C. obtusa were total base, soil pH and base saturation. Consequently, these results can be effective for selecting of the reforesting site, and less effective for estimating the growth of C. obtusa.

• Korean Journal of Soil Science and Fertilizer
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• v.2 no.1
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• pp.15-26
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• 1969

The study on physico-chemical characteristics of the acid sulfate soil present in Kimhae plain was carried out with 28 surface and subsoils from lower and higher produtive area and two representative profile samples from the areas reclaimed a few decades ago and around 10 years ago respectively. 1. There are no differences in soil texture between lower and higher productive soils being mostly silty clay loam and silty clay. 2. Very significant differences in pH, degree of base saturation and extractable aluminium content are observed; lower pH, lower degree of base saturation and higher aluminium in the lower productive soils and subsoils. The pH and degree of base saturation of these soils are extremely low whereas aluminium content is very high compared to ordinary paddy soil. 3. Cation exchange capacity of these soils are slightly higher than ordinary paddy soils. In higher productive soils, exchangeable calcium and magnesium are of same order, whereas in lower productive soils magnesium content is appreciably higher than calcium. 4. Though the soil is derived from marine and estuarine sediment, the soluble salt content is not high. There are only few lower productive surface soils and subsoils having Ec values of the saturation extracts higher than 4 mmhos but lower than 9 mmhos/cm. 5. Organic matter content of these soils is a bit higher compared to ordinary paddy soils, but, nitrogen content is comparatively low. C/N ratio of these soils is around 12. 6. Sulfur content is considerably higher but oxidizable sulfur is found to be very low. Total sulfur is generally high in subsoils and lower productive soils. 7. Active iron and available silica are slightly higher than ordinary paddy soils but easily reducible manganese is very low. Almost no differences are also observed between lower and higher productive soils. 8. Available phosphorus content is extremely low in particular, regardless of higher or lower productive soils. 9. The two representative profiles from the area of earlier reclamation and recent one show that samples from earlier reclaimed area contain less amount of free acids, sulfur compounds, toxic aluminium and soluble salts etc. than the other. This indicate greater leaching and possible addition of lime for a longer period of time. 10. From the results obtained, it can be concluded the higher productivity of group I soils is due to the greater leaching and neutralisation of acidity by liming materials, It can also be concluded that the productivity of both types can be increased by addition of liming materials and improvement of drainage facilities.

• Journal of Korean Society of Forest Science
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• v.109 no.2
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• pp.157-168
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• 2020

The sensitivity of forest soil to acidification in the Republic of Korea (ROK) was evaluated based on pH_H2O, cation exchange capacity (CEC), and base saturation (BS). Sensitivity to acidification was categorized into three grades: adequate level (AL, pH ≧ 4.2, CEC ≧ 15cmol/kg, BS ≧ 15%), caution level (CL, at least one indicator is below AL), and severe Level (SL, all three indicators are below AL). Soil samples were collected from the 65 stationary monitoring plots (40 × 40 ㎢), distributed throughout ROK. Only 19% of soil samples were classified as AL, while 66% and 15% were CL and SL, respectively. The median of pH_H2O, CEC, BS, and Ca/Al indicator in AL soils was pH 4.64, 20.7cmol/kg, 29%, and 6.3, respectively. Moreover, BC_ex (K⁺, Mg²⁺, Ca²⁺) and available phosphorus (AP) concentration compared with a threshold value and molar ratio of BC_ex and AP to total nitrogen (TN) was high. This indicates that AL soils have a good nutrient condition. The molar Ca/Al ratio, an indicator for toxicity of exchangeable aluminum (Al_ex), was more than 1, indicating no negative impact of Al_ex on plant growth. On the contrary, the median of pH_H2O, CEC, and BS in SL soils was pH 4.02, 13.2cmol/kg, and 10%, respectively. The Ca/Al index was less than 0.6, which indicates that negative impacts of Al_ex on plants were high. Furthermore, both the concentration of BC_ex in SL soils and the BC_ex/TN ratio were the lowest among the three acidity degrees. This shows that SLsoils can be degraded by soil acidification compared with less acidic soils.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.5
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• pp.445-456
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• 2001

In the 1990s, Cochlodinium polykikoides red tide has been annually occurred in the southern coast of Korea and caused the mass damage to the fisheries with a huge amount of economic loss. The present study was done to establish the biological foundation for the elucidation of the mechanism of C. polykikoiaes red tide. The growth response of C. polykikoides to physico-chemical factors such as temperature, salinity, pH, and light intensity were examined using axenic cultures to evaluate the relative importance of these factors on the dynamics of natural populations, It was found that the highest growth conditions were $25^{\circ}C,\;40\%_{\circ}$, pH 7.5, and 7,500 lux, respectively. The tolerable salinity range of growth was relatively wide at an optimum temperature and was reduced to a much narrower range at a sub-optimum temperature. These findings indicate that C. polykikoides is an eurythermal and euryhaline organism. The organism demanded higher light intensity and oceanic pH narrow in its growth. C. polykikoides utilize inorganic nutrients, such as nitrate and ammonium as N, and phosphate as P. The nutritional requirements of C. polykikoides were $40{\mu}M$ for nitrate, $50{\mu}M$ for ammonium, and $5{\mu}M$ for phosphate. The half saturation constant (Ks) for growth was $2.10{\mu}M$ for nitrate, $1.03{\mu}M$ for ammonium, and $0.57{\mu}M$ for phosphate. These values were comparatively smaller than those of other dinoflagellates reported previously. We confirmed that the organism is characterized as an eutrophic species. However, ammonium Ks value is smaller than that of other eutrophic species, This result indicates that C. polykikoides red tide may outbreak in the waters which eutrophication is in progress rather than eutrophicated waters. C. polykikoides preferred ammonium better than nitrate as a nitrogen source when in a growth stage, Therefore, our results indicate that ammonium is more important nutrient on the growth of the organism in comparison with other inorganic nutrients and C. polykikoides red tide is related with the increased ammonium concentration in the coastal waters.