• Economic and Environmental Geology
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• v.33 no.6
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• pp.519-524
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• 2000

This study has been performed to evaluate the possibility of utilizing stone powder sludges from stone quarry and manufacturing plant as adsorbents for heavy metals in industrial wastewater. The stone powder sludges from stone quarry (IS-01) have the most effective adsorption capacity (above 95％ of initial concentrations) under the given experimental conditions of reaction times (Pb : 15 min, Cu : 2 hr, Zn : 48 hr), initial acidity of solution (pH>3) and dosage (sludge/liquid ratio : 0.02). The stone powder sludges from manufacturing plant (CW-01) show relatively high adsorption capacity (about 95％ of initial concentrations) only for Pb with a reaction times of 12 hours, initial acidity of solution (pH>3) and dosage (sludge/liquid ratio : 0.02). The stone powder sludges (IS-01) from stone quarry having relatively excellent adsorption capacity under the given experimental conditions show their potential utilization as heavy metal adsorbents.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.10a
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• pp.499-504
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• 1993

To find a way for establishing work roll initial crown according to roll conditions, computer simulation for predicting plate crown in plate mill is done and effects of roll conditions on plate crown is analysed. Roll gap profile and plate crown are measured to be compared to the calculated values. As a result,a regression equation to establish work roll initial crown according to roll cooditions such as backup roll diameter, backup roll crown and work roll crown is obtained.

• Journal of KSNVE
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• v.7 no.3
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• pp.439-447
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• 1997

In this study, the dynamic instabilities of a nonlinear elastic system subjected to follower forces are investigated. The two-degree-of-freedom double pendulum model with nonlinear geometry, cubic spring, and linear viscous damping is used for the study. The constant, the initial impact forces acting at the end of the model are considered. The chaotic nature of the system is identified using the standard methods, such as time histories, power density spectrum, and Poincare maps. The responses are chaotic and unpredictable due to the sensitivity to initial conditions. The sensitivities to parameters, such as geometric initial imperfections, magnitude of follower force, direction control constant, and viscous damping, etc., are analysed. Dynamic buckling loads are computed for various parameters, where the loads are changed drastically for the small change of parameters.

• Steel and Composite Structures
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• v.47 no.6
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• pp.795-811
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• 2023

When studying the resonance problem of nanoplates, the existing papers do not consider the influences of geometric nonlinearity and initial geometric imperfection, so this paper is to fill this gap. In this paper, based on the nonlocal strain gradient theory (NSGT), the nonlinear resonances of functionally graded (FG) nanoplates with initial geometric imperfection under different boundary conditions are established. In order to consider the small size effect of plates, nonlocal parameters and strain gradient parameters are introduced to expand the assumptions of the first-order shear deformation theory. Subsequently, the equations of motion are derived using the Euler-Lagrange principle and solved with the help of perturbation method. In addition, the effects of initial geometrical imperfection, functionally graded index, strain gradient parameter, nonlocal parameter and porosity on the nonlinear forced vibration behavior of nanoplates under different boundary conditions are discussed.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.11
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• pp.761-767
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• 2019

In the present study, analyses of initial behavior of an air-launched projectile for varying initial conditions are performed by coupling computational fluid dynamics and 6 degrees of freedom calculations. Accuracy of the present numerical methods is validated by comparing the present result with the measured data. Launching safety analyses are carried out for various ejecting conditions by considering weight of the projectile and magnitude of front and rear ejector forces as the major parameters of initial behavior of the projectile. A response surface of the projectile launching safety is obtained in the range of the major parameters. In all the conditions of zero rear ejector force, unsafe launching behavior is observed. As the weight of the projectile decreases, the initial launching behavior becomes more unsafe.

• Fisheries and Aquatic Sciences
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• v.17 no.3
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• pp.385-390
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• 2014

Abalone immortal cell lines can be used to study the physiological properties and disease mechanisms of abalone at the cellular and molecular level. As a first step for the final goal to establish abalone immortal cell lines, we examined various initial culture conditions for primary cell populations derived from Haliotis discus hannai radula tissue. The survival rate after cell isolation procedures using the enzymatic method was as low as $9.95{\pm}2.37%$. Based on three different experimental conditions for H. discus hannai radula-derived cell culture, we found that the salinity of the media and the presence of growth-promoting factors were important to support radula-derived primary cell populations during the initial culture. The growth factor-containing media adjusted to 35 psu salinity could induce 100% (8 out of 8 trials) initial cell attachment, and the rate of cell attachment reached 50-70%. The data obtained from this study will provide useful information for developing immortal cell lines from abalone species.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.6
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• pp.812-817
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• 2003

In the first stage, strawberry wine was manufactured in 14$^{\circ}$Brix initial sugar content, for 50 hr at 28$^{\circ}C$ using Saccharomyces kluyeri DJ97. In the second stage, the acetic acid fermentation conditions for maximun acidity (4.60%) were 1.48% initial acidity and 195.76 rpm in agitation rate for 7.34 day. The fermentation conditions for maximun Hunter color a value were 1.78% initial acidity and 117.63 rpm in agitation rate for 7.35 day. Therefore, optimum acetic acid fermentation conditions were 1.5% initial acidity and 196 rpm in agitation rate for 176 hr using Acetobacter sp. PA97.

• Korean journal of food and cookery science
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• v.30 no.6
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• pp.792-799
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• 2014

This study was conducted to determine the optimal conditions of acetic acid fermentation of aronia using the response surface methodology (RSM). Alcohol content of aronia wine was 13.1% after alcohol fermentation of aronia fruits. The optimal conditions of acetic acid fermentation were determined by five levels of initial aronia alcohol content, initial acetic acid content, and acetic acid bacteria, using the central composite design. The acetic acid yields, residual alcohol contents, pH, and color values (L, a, b) of acetic acid fermentation products were very significantly different ($p{\leq}0.01$), and were 26.34~57.82 g/L, 0.80~1.53%, 3.19~3.43, 47.58~71.00, 31.77~51.15, and 18.45~48.57, respectively. For the results, the optimal conditions of acetic acid fermentation of aronia were 7.78% of the initial alcohol concentration, 1.58% of the initial acetic acid, and 19.39% of the acetic acid bacteria.

• Journal of Environmental Science International
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• v.17 no.7
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• pp.801-808
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• 2008

This study was investigated experimental condition which is able to evaluate photocatalytic activity of various commercial $TiO_2$. The experiments were performed for three representative substances (ethanol, phenol and methylene blue) and four kinds of commercial $TiO_2$, under the experimental conditions such as pH, reactant concentration, amount of $TiO_2$, reaction time and UV intensity. The optimum experimental conditions to evaluate photocatalytic activity were as follows : for ethanol, the initial concentration 1000 ppm, initial pH 8, $TiO_2$ loadings 0.1 wt%, and reaction time 90 minutes: for phenol, the initial concentration 200 ppm, initial pH 8, $TiO_2$ loadings 1 wt%, and reaction time 60 minutes: for methylene blue, the initial concentration 200 ppm, initial pH 4, $TiO_2$ loadings 0.5 wt%, and reaction time 30 minutes.

• Corrosion Science and Technology
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• v.21 no.2
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• pp.158-169
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• 2022

The objective of this study was to investigate the electrochemical behavior and damage degree of metal surface under different conditions by performing a potentiodynamic polarization experiment using an electropolishing solution for UNS S31603 based on initial delay time and surface roughness (parameters). A second anodic peak occurred at initial delay time of 0s and 100s. However, it was not discovered at 1000s and 3600s. This research referred to an increase in current density due to hydrogen oxidation reaction among various hypotheses for the second anodic peak. After the experiment, both critical current density and corrosion current density decreased when the initial delay time (immersion time) was longer. As a result of surface analysis, characteristics of the potentiodynamic polarization behavior were similar with roughness, although the degree of damage was clearly different. With an increase in surface roughness value, the degree of surface damage was precisely observed. As such, electrochemical properties were different according to the immersion time in the electropolishing solution. To select electropolishing conditions such as applied current density, voltage, and immersion time, 1000s for initial delay time on the potentiodynamic polarization behavior was the most appropriate in this experiment.