• Journal of the Korean Society of Radiology
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• v.14 no.2
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• pp.85-95
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• 2020

The filtration characteristics of H₂O-C₆H₁₂O₆ solution at cell membrane model in renal tubule which irradiated by high energy x-ray(linac 6MV) was investigated. The cell membrane model used in this experiment was a polysulfonated copolymerized membrane of m-phenylene-diamine(MPD) and trimesoyl chloride(TMC)-hexane. They were used to two cell membrane models(CM-1, CM-2). The cell membrane model composed of 0.5 wt% TMC-hexane solution(CM-2) had higher permeate flux(Jv) and rejection coefficient(R) than composed of 0.1 wt% TMC-hexane solution(CM-1). The permeate flux(Jv) and rejection coefficient(R) of H₂O-C₆H₁₂O₆ solution in two cell membrane models(CM-1, CM-2) were increased with increase of pressure drop and effective pressure difference. In this experiment range(pressure 1.5-4 MPa, temperature 36.5 ℃), permeate flux(Jv) of H₂O solvent in irradiated membrane was found to be decreased about 20-30 times than non-irradiated membrane, permeate flux(Jv) and rejection coefficient(R) of H₂O-C₆H₁₂O₆ solution in irradiated membrane was found to be decreased about 2-13 times, about 4-6 times than non-irradiated membrane, respectively. The concentration increase of H₂O-C₆H₁₂O₆ solution at cell membrane model significantly was increased at rejection coefficient(R), was decreased at permeate flux(Jv). As the filtration of H₂O-C₆H₁₂O₆ solution in cell membrane model were abnormal, cell damages were appeared at cell.

• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.2
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• pp.103-113
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• 2014

Under climate change, it is likely that the suitable area for forage crop cultivation would change in Korea. The potential cultivation areas for italian ryegrass (Lolium multiflorum L.), which has been considered one of an important forage crop in Korea, were identified using the EcoCrop model. To minimize the uncertainty associated with future projection under climate change, an ensemble approach was attempted using five climate change scenarios as inputs to the EcoCrop model. Our results indicated that most districts had relatively high suitability, e.g., >80, for italian ryegrass in South Korea. Still, suitability of the crop was considerably low in mountainous areas because it was assumed that a given variety of italian ryegrass had limited cold tolerance. It was predicted that suitability of italian ryegrass would increase until 2050s but decrease in 2080s in a relatively large number of regions due to high temperature. In North Korea, suitability of italian ryegrass was considerably low, e.g., 28 on average. Under climate change, however, it was projected that suitability of italian ryegrass would increase until 2080s. For example, suitability of italian ryegrass was more than 80 in 10 districts out of 14 by 2080s. Because cold tolerance of italian ryegrass varieties has been improved, it would be preferable to optimize parameters of the EcoCrop model for those varieties. In addition, it would be possible to grow italian ryegrass as the second crop following rice in Korea in the future. Thus, it merits further study to identify suitable areas for italian ryegrass cultivation after rice using new varieties of italian ryegrass.

• Journal of fish pathology
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• v.2 no.1
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• pp.1-18
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• 1989

In Korea, studies on a Nematode, Anguillicola crassa parasitic in the air bladder of eel are not yet reported. This reason led the author to study the parasitic species, state and life history of the A. crassa parasitized in the air bladder of eel in order to take effective control measures against its damage. The size of fully developed eggs was 80 to $92(86.7){\times}62$ to $71(67.4)\;{\mu}m$, larva was 210 to $240(225){\times}18$ to $23(20.6)\;{\mu}m$. The intermediate host of A. crassa was Thermocyclops hyalinus, it was capable for parasitizing the eel after 4 days of invasion and then the size of larva was 360 to $420(390){\times}28$ to $35(31)\;{\mu}m$. Fifty days after eel had ingested the Thermocyclops hyalinus infected with larva of A. crassa, the larvae matured into adult worms in the air bladder of eel. The size of detected adult worms was 7.3 to $31.0(16.5){\times}0.5$ to 2.2(1.2) mm, 4.9 to $13.3(8.3){\times}0.3$ to 0.9(0.4) mm. Investigating the morphology of the worms, they were identified as A. crassa. Monthly the parasitic rate of the worms in the eel was high in June, September and December, but low in January to March. After the investigation on the significance between non-parasitic fish and parasitic fish, it was not significant, therefore it can be considered that there is no effect of infection in the growth of eel. Any abnormality of eels air bladder tissue was not seen by the infection of A. crassa. At 25.0 to $26.7^{\circ}C$ of water temperature the death time of Thermocyclops hyalinus by masoten treatment was 14 hours in 0.5 ppm, 20 hours in 0.4 ppm, 22 hours in 0.3 ppm, 30 hours in 0.2 ppm and 42 hours in 0.1 ppm.

• Clean Technology
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• v.2 no.1
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• pp.96-108
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• 1996

$NO_x$ is mainly emitted from mixed acid pickling process in the stainless industry and its impact to the environment has been worried over. This study which may be considered as one of the development of clean technologies, differing from the traditional end pipe technology is about how to reduce $NO_x$ emission through the modification of corresponding process. This study consists of two parts. First, the influence of various reaction parameters in a acid pickling process on $NO_x$ emission was investigated. Second, the influence of hydrogen peroxide on $NO_x$ formation, which is known as inhibitor of $NO_x$ emission, was investigated. Major findings in this study are as follows. The important reaction parameters which have a great influence on $NO_x$ emission are the reaction temperature and the concentration of fluoric acid. The concentration of nitric acid, some of which results in $NO_x$ compound is not as important as the concentration of fluoric acid. Synthetic mixed acid of nitric acid and fluoric acid itself in absent of pickling plate contributed the $NO_x$ emission, however, its impact was negligible in terms of quantity. The addition of hydrogen peroxide to the acid pickling process significantly contributed to the reduction of $NO_x$ emission and successfully achieved 80% reduction of $NO_x$ emission at the condition of $9.51{\times}10^{-2}mole\;hydrogen\;peroxide/m^2$ pickling area. This result was compared to literature value from Avesta steel process, indicating a sixth of hydrogen peroxide addition of Avesta's in achieving a same amount of $NO_x$ reduction. The region of the economic hydrogen peroxide addition per unit area of plate to be pickled from the result of this study was established.

• Journal of the Korean Magnetics Society
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• v.22 no.3
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• pp.85-90
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• 2012

Oxidation of the $Nd_2Fe_{14}B$ compound crystal and its effect on the coercivity of the fine $Nd_2Fe_{14}B$ crystal particles were investigated. Oxidation kinetics of the $Nd_2Fe_{14}B$ compound crystal was investigated using an excessively grown $Nd_2Fe_{14}B$ grains in the $Nd_{15}Fe_{77}B_8$ alloy ingot. Oxidation of the $Nd_2Fe_{14}B$ compound crystal occurred by dissociation of the phase into multi-phase mixture of ${\alpha}$-Fe, $Fe_3B$, and Nd oxides. Oxidation rate of the $Nd_2Fe_{14}B$ compound crystal showed no dependence on the crystallographic direction. The oxidation reaction was modeled according to simple linear relationship. Activation energy for the oxidation of $Nd_2Fe_{14}B$ compound crystal was calculated to be approximately 26.8 kJ/mol. Fine $Nd_2Fe_{14}B$ crystal particles in near single domain size was prepared by ball milling of the HDDR-treated $Nd_{15}Fe_{77}B_8$ alloy, and these particles were used for investigating the effect of oxidation on the coercvity. The near single domain size $Nd_2Fe_{14}B$ crystal particles (${\fallingdotseq}0.3\;{\mu}m$) had high coercivity over 9 kOe. However, the coercivity was radically reduced as the temperature increased in air (<2 kOe at $200^{\circ}C$). This radical coercivity reduction was attributed to the soft magnetic phases, ${\alpha}$-Fe and $Fe_3B$, which were formed on the surface of the fine particles due to the oxidation.

• Journal of Korean Society of Forest Science
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• v.38 no.1
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• pp.27-32
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• 1978

The diurnal pattern of leaf water potential in cuttings by Dye Method was as follows: 1. Diurnal pattern of leaf water potential (${\psi}_l$) in Viburnum Awabuki K. Koch and Daphne odora Thunb. was shown the pattern of the curves without mutual relation with soil classes when soil water potential (${\psi}_s$) was 0 bar. When ${\psi}_s$ was above -0.01 bar, the cuttings in the loamy sand (L.S.) was shown by the maximum values than that in sandy clay (S.C.) by about -1 bar gap (Fig. 1). 2. The diurnal changes of ${\psi}_l$ was shown the most high from two to eight O'clock in the morning, the maximum value was -3 bars when ${\psi}_s$ was above -0.01 to -0.02 bar, and was -4 bars below -0.03 bar. The diurnal the lowest values of ${\psi}_l$ showed -20 to -22 bars from one to two O'clock in the afternoon. In the fifteenth day after cutting V.A., the staying time in the diurnal maximum values of ${\psi}_l$ is about half in comparison with it in the fifth day. The curves of recovery of water stress (Fig. 1), the former reached to the diurnal maximum values -1 to -2 bars lately every hours comparing with it of the latter. The general diurnal pattern of ${\psi}_l$ was most clearly related to change with air temperature and the relative humitidy. 3. Comparing the treatment block by IAA 50 ppm with controlled block in fifteenth day after V.A. cuttings, in case of treatment reached to maximum values -2 to -3 bars lately as shown Fig. 2., and also staying times was only half in comparison with controlled block. 4. The cuttings 4 leafs was much rootings than 2 leafs in V.A. (Table. 1), and the former reached maximum value -2 to -3 bars lately every hours comparing with the latter. 5. In case of Buxus microphylla var. Koreana as shown Fig. 3., comparing the pattern curves of in the cuttings 8 leafs with 4 leafs, the former reached to maximum values -2 to -3 bars lately in comparison with the latter, but reffering to the amount of rooting (Table. 2), the former is less than the latter.

• Food Science and Preservation
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• v.14 no.4
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• pp.414-418
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• 2007

The physicochemical characteristics and sensory properties of Deodeok wine, formed by leaching of Deodeok at room temperature for 180 days, were investigated over the following range of Deodeok levels: 10, 15 and 20% (all w/v). The higher the level of Deodeok, the greater were the final values of total sugars, reducing sugars, total polyphenols, and crude saponins. The Hunter's b-value (yellowness) of Deodeok wine varied markedly with Deodeok levels, and yellowness was highest in Deodeok wine containing 20% (w/v) Deodeok. Non-volatile compounds, that form the basis of the liquor tax law, were 0.64, 1.38 and 2.11% (all w/v), respectively, at day 160. Of these values, that of 2.11% (w/v), the level of non-volatile compounds in Deodeok wine containing 20% (w/v) Deodeok, was in accord with the liquor tax law (that requires this figure to be 2.0%). Sensory evaluation showed that Deodeok wine containing 20% (w/v) Deodeok was superior to the other wines tested.

• Journal of Sensor Science and Technology
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• v.2 no.1
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• pp.101-108
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• 1993

$TiO_{2}$/Se : Te heterojunction for color sensor has been fabricated by RF reactive sputtering and thermal evaporation methods onto glass substrate. The optimum deposition condition of $TiO_{2}$ films was such that RF power was 120 W, substrate temperature was $100^{\circ}C$, oxygen concentration was 50%, working pressure was 50 mTorr for the $TiO_{2}$ film thickness of $1000{\AA}$. In this case, the optical transmittance of $TiO_{2}$ film at 550 nm-wavelength was 85%, resistivity was $2{\times}10^9{\Omega}{\cdot}cm$, refractive index was 2.3, and optical bandgap was 3.58 eV. The composition ratio of 0 to Ti by AES analysis was 1.7. When $TiO_{2}$ films were annealed at $400^{\circ}C$ for 30 min. in $O_{2}$ ambient, the optical transmittance of $TiO_{2}$ films at the wavelength range of $300{\sim}580$ nm was improved from 0 to 25%. When Se : Te films were annealed at $190^{\circ}C$ for 1 min., photosensitivity under illumination of 1000 lux was 0.75. The optical bandgap of Se : Te films was 1.7 eV. The structures of Se : Te films were the hexagonal with (100) and (110) orientation. The spectral response of a-Se was improved by the addition of Te, especially in the long wavelength region. The $TiO_{2}$/Se : Te heterojunction showed wide spectral response, and more improved one than that of a-Si film in the blue light region.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.10
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• pp.916-927
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• 2010

In general water treatment process, the disinfection process by chlorine is used to prevent water borne disease and microbial regrowth in water distribution system. Because chlorines were reacted with organic matter, carcinogens such as disinfection by-products (DBPs) were produced in drinking water. Therefore, a suitable injection of chlorine is need to decrease DBPs. Rechlorination in water pipelines or reservoirs are recently increased to secure the residual chlorine in the end of water pipelines. EPANET 2.0 developed by the U.S. Environmental Protection Agency (EPA) is used to compute the optimal chlorine injection in water treatment plant and to predict the dosage of rechlorination into water distribution system. The bulk decay constant ($k_{bulk}$) was drawn by bottle test and the wall decay constant ($k_{wall}$) was derived from using systermatic analysis method for water quality modeling in target region. In order to predict water quality based on hydraulic analysis model, residual chlorine concentration was forecasted in water distribution system. The formation of DBPs such as trihalomethanes (THMs) was verified with chlorine dosage in lab-scale test. The bulk decay constant ($k_{bulk}$) was rapidly decreased with increasing temperature in the early time. In the case of 25 degrees celsius, the bulk decay constant ($k_{bulk}$) decreased over half after 25 hours later. In this study, there were able to calculate about optimal rechlorine dosage and select on profitable sites in the network map.

• Korean Journal of Food Science and Technology
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• v.34 no.3
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• pp.449-453
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• 2002

This was studied to evaluate the quality characteristics of the bread added chitosan during storage at room temperature(Temp. $27^{\circ}C{\pm}2$, RH $75%{\pm}10$). The volume of the dough was increased depending on the larger molecular weight and the higer concentration of chitosan but was decreased at 0.50% of 120 kDa chitosan. The water activity was low depending on the larger molecular weight and the higher concentration of chitosan at the early storage, but maintained constantly during storage totally. The colors of the bread was hardly affected by 30 kDa of chitosan. Textural characteristics was improved at 30 kDa and 120 kDa of chitosan. Especially, the change of the hardness were maintained lower at 30 kDa, 120 kDa of chitosan during storage than that of standard. These results showed that the quality of the bread by added 30 kDa of chitosan was improved highly.