• Journal of Radiation Protection and Research
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• v.20 no.1
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• pp.16-24
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• 1995

Assesment of dose equivalent given by inhaled $^{222}Rn$ and its progeny has been carried out based on the concentrations of $^{222}Rn$ and its daughters in indoor air, and equilibrium factor between them measured by charcoal canister method and alpha spectrometry. Assuming the occupancy factor to be 0.8, and breathing rate to be $0.75m^3\;h^{-1}$ for public and $1.2m^3\;h^{-1}$ for occupational exposure, respectively, the regional lung dose 대valent and the resulting annual effective dose equivalent due to the inhalation of $^{222}Rn$ and its daughters in indoor air were evaluated by use of three different lung models, namely, Jacobi-Eisfeld, James-Birchall and ICRP model.

• Journal of the Korean GEO-environmental Society
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• v.3 no.1
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• pp.5-12
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• 2002

The effects of ground water level, shear strength parameters of refuse, and geological condition of ground on the slope stability of uncontrolled waste landfill were studied. The Janbu method of slices based on the limit equilibrium method was used to calculate the minimum factor of safety with respect to slope stability of landfill. The analytical results showed that the factor of safety for a fully dried condition of landfill increased 2.4~2.8 times as great as that for a fully saturated condition of landfill. Under the condition of actual ground water level, the factor of safety linearly increased with increasing both cohesion and internal friction angle of refuse. Also, when the potential failure surface passed through the underlying layer, the factor of safety and shape of potential failure surface were found to depend on geological conditions of underlying layer.

• Korean Journal of Environmental Agriculture
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• v.11 no.2
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• pp.101-108
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• 1992

In order to illustrate adsorption phenomena of herbicides(alachlor and paraquat) on soils, absorption equation of herbicides and the relationships between soil properties and adsorption constants were investigated with 22 soils. The results were as follows : 1. The shaking time for approaching equillibrium reaction of herbicides(alachlor and paraquat) with woils were about 30 minutes for paraquat and 4 hours for alachlor, respectively. 2. The distribution coefficients of alachlor were inbetween 0.81-33.83 in 5 ppm and 0.09-15.52 in 50 ppm, respectively. 3. The adsorption of alachlor was positively correlated with organic matter and paraquat was with clay content of soils. 4. Both paraquat and alachlor were highly adsorbed in Chunpo series soil containing low contents of organic matter and clay on account of different mechanism from other soils, 5. Freundlich's adsorption constant(K) was greater than distribution coefficient(Kd), and the differences between K and Kd's were to be increased with increasing equillibrium concentrations.

• Membrane Journal
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• v.5 no.4
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• pp.129-136
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• 1995

This study is concerned with the treatment of dye wastewater by carrier meditated emulsion liquid membrane. Optimum conditions for the removal of anionic dye and cationic dye by the emulsion liquid membrane(ELM) containing Aliquat 336 or D2EHPA were obtained in the batch operation, an actual dye wastewater was tested under these conditions. Dye reagents used were Sirius Red(Direct dye), Reactofix Supra Blue(Reactive dye), and Apollo Blue(Basic dye). The experimental variables were surfactant(Span 80) and carrier(Aliquat 336 or D2EHPA) concentration in the membrane phase, the counter ion($Na_2SO_4$) concentration in the internal phase and the amount of emulsion. Extraction equilibrium arrived within 5 minutes after starting reaction and more than 95% of dye ion could be removed. The carrier concentration in the membrane phase was the most crucial for the removal efficiency, but other variables effected to the reaction time more than the removal efficiency. The dye wastewater was treated under the optimum conditions in two steps. The absorbance at 550nm of wastewater was decreased 0.53 to below 0.03 after 10 minutes treatment.

• Applied Chemistry for Engineering
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• v.9 no.5
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• pp.661-666
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• 1998

Liquid phase adsorption equilibria of amines in an aqueous solution onto high silica zeolite pellets (HSZ), macroreticular resin particles (MR) and granular activated carbon (GAC) were determined using a batch bottle technique at 298K. The isotherm curves of HSZ-amines and GAC-amines indicate the nonlinear relationship of unfavorable adsorption type of HSZ-amines and favourable one of GAC-amines. However the curves of MR-amines represent the linear pattern of an adsorption isotherm. Among various equilibrium isotherms, the three parameters of the Redlich-Peterson equation and the two parameters of the Freundlich equation are found to be the most satisfactory within the range of this study. The two parameters of the Langmuir isotherm were not applicable to the present adsorption systems. The amines were adsorbed on the HSZ, MR and GAC in the following sequence of adsorptivity; aromatic amines > primary amines > secondary amines. The product of the Freundlich constants, k and n, proportionally increased with the boiling point, molar volume and dissociation constants of amines adsorbed on HSZ, MR and GAC.

• Journal of Digital Convergence
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• v.14 no.3
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• pp.489-497
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• 2016

The purpose of this study is to examine the effect of milk protein intake and band exercise on active fitness and metabolism risk factor of elderly women for 8 weeks. The two groups were classified into one group(TG) with milk protein intake and band exercise both, and the other group(CG) that was controled. The group of TG was applied doing milk protein intake 3 times for a day, and doing band exercise 4 times for 60 minutes a week. The intensity of the exercise was RPE<17. Each measurement variable was measured before and after 8 weeks to investigate the effect. This study got the result with this step. First, TG has shown small interaction with active fitness. Second, TG has shown small interaction with metabolism risk factor. Therefore, this study gives us the positive result of the effect of milk protein intake and band exercise on active fitness and metabolism risk factor of elderly women for 8 weeks. However, it has limitation to verify effect of milk protein intake and band exercise.

• Journal of the Korean Chemical Society
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• v.37 no.12
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• pp.1035-1046
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• 1993

Some iron(III)porphyrin complexes were prepared, and identified by the spectroscopic methods. Elution behavior of iron(III)porphyrin complexes was investigated by reversed-phase HPLC. The optimum conditions for the separation of iron(III)porphyrin complexes were examined with respect to flow rate and mobile phase strength. These complexes were successfully separated on NOVA-PAK $C_{18}$ column using methanol / water(95/5) for $[T_pCF_3PP)Fe(R)]$ and methanol / water (98/2) for $[(P)Fe(C_6F_5)]$ as a mobile phase. It was found that these complexes were largely eluted in an acceptable range of capacity factor value ($0{\leq}logk'{\leq}1$). The dependence of the capacity factor (k') on the volume fraction of water in the binary mobile phase as well as the dependence of k' on the liquid-liquid extraction distribution ratio$(D_c)$ in methanol-water / n-pentadecane extraction system showed a good linearity. It means that the retention of iron(III)porphyrin complexes on NOVA-PAK $C_{18}$ column is largely due to the solvophobic effect. Also, there was a good linear dependence of the capacity factor(k') on the column temperature and enthalpy calculated by van't Hoff plot. From these results, it was confirmed that the retention mechanism of iron(III)porphyrin complexes in reversed-phase liquid chromatography was invariant under the condition of various temperature, and the solvophobic binding process exhibited isoequilibrium behavior.

• Analytical Science and Technology
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• v.7 no.3
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• pp.379-386
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• 1994

The elution behaviors in reversed-phase liquid chromatography were investigated thermodynamically for 2-hydroxy-arylazopyrazolone chelates with Ni(II), Cu(II), Co(III), Cr(III) on Novapak $C_{18}$ column. There was a good linear dependence of the capacity factor(k') on the variations of column temperature in van't Hoff plot. From this result, it was confirmed that the retention mechanism of these chelates in the reversed phase liquid chromatography system was invariant under the condition of various temperatures. For the most cases of the chelates studied, the dependence of capacity factor(1n k') on enthalpy$(-{\Delta}H)^{\circ}$, calculated by van't Hoff plot showed a good linearity(r=0.980~0.999) except [Pm(2-OH_(5-Cl)PaPz](r=0.787) and also the compensation temperatures(${\beta}$) showed constant values. The range of compensation temperature values calculated from the slope of $-{\Delta}H^{\circ}$ vs 1n k' plots was 374.3~806.9K. It was suggested that the retention of metal-2-hydroxy-arylazopyrazolone chelates in the reversed phase liquid chromatography system was largely affected by the hydrophobic effect.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.6 no.4
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• pp.43-51
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• 2003

The purpose of this study was evaluate to the stability on cut slope of forest roads by forest environmental factors. The total of 19 environmental factors on cut slope of forest roads were investigated in about 42.74km constructed during 1987 to 1993 in Gyeongnam and Jeonnam province. The evaluation of slope stability in forest roads were conducted by the discriment analysis. The main factors influencing the stability of cut slope were significant in order of coverage, soil hardness, degree of slope, altitude, silt loam, convex(凸) and compound(凹凸). The centroids value of discriminant function in the stability and unstability area estimated to -1.194 and 1.127, respectively. The boundary value between two groups related to slope stability was -0.072. The prediction rate of discriminant function for stability evaluation of was as high as 90.4%.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.4
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• pp.659-665
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• 2016

The limit equilibrium method (LEM) is commonly used for slope design and stability analysis because it is easy to simulate slope and requires short calculating time. However, LEM cannot adequately simulate ploughing failure in a footwall slope with a joint set dipping parallel with slope, e.g. bedding joint set. This study performed parametric study to analyze the influence factors on ploughing failure using UDEC which is a commercial two-dimensional DEM (Distinct Element Method)-based numerical program. The influence of joint structure and properties on stability of a footwall slope against ploughing failure was investigated, and the factor of safety was estimated using the shear strength reduction method. It was found that the stability of footwall slope against ploughing failure strongly relies on dip angle of conjugate joint, and the critical bedding joint spacing and the critical length of slab triggering ploughing failure are also affected by dip angle of conjugate joint. The results obtained from this study can be used for effective slope design and construction including reinforcement.