• Journal of Korean Society of Environmental Engineers
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• v.36 no.9
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• pp.641-647
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• 2014

In this study, sludge waste which has a difficulty in treating it was used to manufacture a fiber type of biosorbent. To solve the problems such as the release of organic pollutants and the difficulty in separating solid from treated water, entrapment method using Ca-alginate was used to immobilize sludge waste. Considering ease of manufacture as well as improvement of adsorptive ability, the biosorbent was manufactured in the form of fiber type. Optimum immobilization condition for minimizing the amount of alginate used and maximizing the performance of biosorbent was determined to be 10 g/L alginate concentration, 40 g/L sludge concentration, and 0.3-0.4 mm fiber diameter. The maximum Cd(II) uptake of the biosorbent was 60.73 mg/g. Pseudo-second-order kinetic model and Langmuir isotherm model adequately described the dynamic and equilibrium behaviors of Cd(II) biosorption onto the biosorbent, respectively. In conclusion, sludge waste generated from wastewater treatment process is a cheap raw material for the manufacture of biosorbent which can be used to remove toxic heavy metals from industrial wastewaters efficiently.

• Journal of Advanced Navigation Technology
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• v.17 no.4
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• pp.404-412
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• 2013

Network RTK is widely used especially for static applications so far, however, the demand for high accuracy positioning for kinetic users such as land vehicles is growing for safety and convenience reasons. Kinematic users move along the roads and the network where they receive corrections can be changed. Compact Network RTK corrections should keep consistency while network change. In this paper, we introduced a method of generating Compact Network RTK corrections considering network ambiguity level adjustment by formulation of corrections. We verified the proposed method for reference station networks across whole country. We also generated Compact Network RTK corrections using simulation and real GPS data from reference stations in South Korea and evaluated performance of users. As a result, the discontinuity between corrections from two networks reduced to 0.25 cycle from several cycles. And user could achieve less than 8 cm (2DRMS) horizontal position accuracy continuously regardless of network change.

• Korean Chemical Engineering Research
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• v.54 no.3
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• pp.380-386
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• 2016

In this study, we described a paper-based neuraminidase assay sensor (PNAS) which can be applied to detect the infection by influenza viruses. The PNAS was designed and manufactured to quantitatively identify the levels of neuraminidase in the sample, which is based on colorimetric analysis using the X-Neu5Ac substrate. The limit of detection of the PNAS was determined as 0.004 U/mL of neuraminidase. According to the amount of neuraminidase in human serum, the PNAS could monitor the enzyme activity with a good linearity ($R^2$ > 0.99). In addition, the initial performance of the PNAS has been maintained up to 70 days in the $4^{\circ}C$. Finally, we demonstrated whether the Michaelis-Menten kinetics is applied to the PNAS, which can show the reliability of the enzyme reactions. The kinetic studies indicated that the PNAS provides the good condition for enzyme reactions ($K_m=8.327{\times}10^{-3}M$), but they were performed on paper chip nonetheless. The paper-based neuraminidase assay sensor may be useful in a wide range of rapid and safe detection of influenza virus.

• Korean Journal of Applied Biomechanics
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• v.18 no.4
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• pp.31-39
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• 2008

The purposes of this study were to compare and analyze the world elite hurdler and the domestic hurdler 3-D kinematic and kinetic techniques about hurdling motion in the 110m hurdles. After analyzing variables in the 110m hurdle run the following conclusions were obtained; In a preparation phase, the domestic hurdler came out running more 0.13m then world elite hurdler from grounding to taking off in the height of center of gravity and the distance by 1.04m. In a flight phase, the domestic hurdler came out taking off 0.33m less then world elite hurdler from taking off to flight peak in the height of center of gravity and the distance by 1.63m. In a flight peak phase, domestic hurdler came out landing more 0.37m then world elite hurdler by 159m. More over, during the hurdling, the horizontal velocity of center of gravity came out decreasing from taking off to landing with domestic hurdler by 0.75m/s. the take off percentage and the landing percentage is 53:47. In a acceleration phase, domestic hurdler came out going slower 0.54m/s than world elite hurdler from landing in the horizontal velocity of center of gravity by 8.78m/s.

• Nuclear Engineering and Technology
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• v.26 no.3
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• pp.425-432
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• 1994

Voltammogram analysis of U(VI) reduction at electrochemically non-pretreated/pretreated Ti electrodes in nitric acid and hydrazine($N_2$H$_4$)/protonated hydrazine($N_2$H$_{5}$$^{＋}$) media was done in order to determine the effect of hydrazine form and Ti electrode condition on the reduction of U(VI) in nitric acid. In the case of non-pretreated Ti electrode, the reduction in nitric acid and hydrazine mono-hydrate solution needed a high activation overpotential and was affected by the ratio of hydrazine to nitric acid rather than by only absolute amount of hydrazine because of the decrease of solution conductivity and increase of iR drop, which were caused by proton consumption in the solution by the hydrazine. In the case of pretreated Ti electrode in nitric acid and protonated hydrazine solution, the reduction current peaks of U(VI) were clearer and higher enough to perform a kinetic analysis, compared with the case with the non-pretreated Ti electrode at the same potential, and the behavior was strongly affected by nitric acid. The presence of hydrazine was important in the reduction of U(VI) at the pretreated Ti electrode for preventing the reoxidation of U(IV), but the concentration of protonated hydrazine was not.t.

• Journal of the Korean Wood Science and Technology
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• v.42 no.4
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• pp.450-459
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• 2014

Crushed pinewood and oakwood were studied as an adsorbent for Pb(II) removal from aqueous solution. Batch adsorption experiments were carried out to describe the effects of contact time, initial Pb(II) concentration, pH, competing cations, and adsorbent dosage on the Pb(II) adsorption process. Kinetic studies revealed that the Pb(II) adsorption process for pinewood and oakwood followed both pseudo first and pseudo second order model. The Fruendlich model best described equilibrium adsorption data with correlation coefficients ($R^2$) of 0.956 and 0.950 for pinewood and oakwood. The maximum adsorption capacity of Pb(II) onto pinewood and oakwood was found to be 16.853 and 27.989 mg/g, respectively. The Pb(II) adsorption onto both pinewood and oakwood was increased as pH increased in the pH range 3-9. The presence of cations such as $Na^+$, $Ca^{2+}$, and $Al^{3+}$ decreased Pb(II) adsorption. The Pb(II) removal was greater in seawater than deionized water, resulting from the presence of $CO{_3}^{2-}$ and $OH^-$ ions in seawater. This study showed that pinewood and oakwood have a potential application in the remediation of Pb(II) contaminated water.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.2
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• pp.230-237
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• 1996

The objective of the present study is to evaluate organic removal efficiencies, nitrogen removal efficiencies, kinetic constant, sludge production rates, oxygen requirements, and optimum treatment renditions for recycling water treatment of aquaculture by using a trickling filter process. When the loading rates were $0.500\~0.082kg\;COD/m^3/day$ and $0.271\~0.044kg\;NH_4^+-N/m^3/day$, SCOD and ammonia removal efficiencies were $74.5\~84.0\%$ and $43.7\~61.8\%$, respectively. The maximum removal rate of ammonia was 119.5 mg/L/day. Observed cell yield coefficient in the trickling filter reactor was 0.572 kg VSS/kg $BOD_{rem}$. When the hydraulic loading rate was $6.712\~40.341m^3/m^2/day$, oxygen uptake rate was $1.33\~7.22\;mg\;O_2/L/hr$.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.5
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• pp.839-846
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• 2016

Since oil leakage is one of the most common nonpoint pollution sources that contaminate soil in Korea, the capacity of soil microbial community for degrading petroleum hydrocarbons should be considered to assess the functional value of soil resource. However, conventional methods (e.g., microcosm experiments) to assess the remediation capacity of soil microbial community are costly and time-consuming to cover large area. The present study suggests a new approach to assess the toluene remediation capacity of soil microbial community using a microbial diversity index, which is a simpler detection method than measuring degradation rate. The results showed that Shannon index of microbial community were correlated with specific degradation rate ($V_{max}$), a degradation factor. Subsequently, a correlation equation was generated and applied to Michaelis-Menten kinetics. These results will be useful to conveniently assess the remediation capacity of soil microbial community and can be widely applied to diverse engineering fields including environment-friendly construction engineering fields.

• Journal of Digital Convergence
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• v.16 no.6
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• pp.407-416
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• 2018

The purpose of this study is to evaluate elite high school kayaker's iso-kinetic muscle function and provide physical training advices. Biodex system IV, Biodex stabilizer system, Inbody 3.0 and CNP-5403 are used to investigate 11 kayaker's muscle function(peak torque, average power and work fatigue), dynamic balance, body compositions, and flexibility. S4, S5, S8, S10, S11 are needed to train shoulder muscle strength and power. S5, S6, S10, S11 are needed to strengthen shoulder muscle endurance. S5, S7, S8, S10, S11 are needed to train knee muscle strength and power. S1, S4, S5, S10 are needed to strengthen knee muscle endurance. S3, S10, S11 are needed to train wrist muscle endurance. Based on these results we should establish an muscle function enhancing program with periodic inspection for elite kayakers. And standardized training program should be sublated.

• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3795-3799
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• 2013

The second-order rate constants ($k_N$) have been measured spectrophotometrically for nucleophilic substitution reactions of Y-substituted-phenyl 2-methylbenzoates (6a-e) with a series of cyclic secondary amines in MeCN at $25.0{\pm}0.1^{\circ}C$. Comparison of the $k_N$ values for the reactions of 4-nitrophenyl 2-methylbenzoate (6d) with those reported previously for the corresponding reactions of 4-nitrophenyl 2-methoxybenzoate (5) reveals that 6d is significantly less reactive than 5, indicating that modification of 2-MeO in the benzoyl moiety of 5 by 2-Me (i.e., $5{\rightarrow}6d$) causes a significant decrease in reactivity. This supports our previous report that aminolysis of 5 proceeds through a six-membered cyclic intermediate, which is highly stabilized through intramolecular H-bonding interactions. The Br${\o}$nsted-type plot for the reactions of 6d with a series of cyclic secondary amines is linear with ${\beta}_{nuc}=0.71$, which appears to be a lower limit of ${\beta}_{nuc}$ for a stepwise mechanism with breakdown of an intermediate ($T^{\pm}$) being rate-determining step (RDS). The Br${\o}$nsted-type plot for the reactions of 6a-e with piperidine is curved, i.e., the slope of Br${\o}$nsted-type plot (${\beta}_{lg}$) decreases from -1.05 to -0.41 as the leaving-group basicity decreases. The nonlinear Br${\o}$nsted-type plot has been taken as evidence for a stepwise mechanism with a change in RDS (e.g., from the $k_2$ step to the $k_1$ process as the leaving-group basicity decreases). Dissection of $k_N$ into the microscopic rate constants associated with the reactions of 6a-e with piperidine (e.g., $k_1$ and $k_2/k_{-1}$ ratio) also supports the proposed mechanism.