• 제어로봇시스템학회:학술대회논문집
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• 1986.10a
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• pp.238-243
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• 1986

Distillation columns are widely used in almost every chemical plant. The use of multivariable control for such units is attractive because of the strong interactions exhibited between outputs and inputs and the desire to control simultaneously both top and bottom products. In this research design of a robust multivariable controller for distillation column was considered; output feedback controller with proportional and integral modes was designed using pole assignment. The transfer function matrix was obtained by fitting the step response realtions between single input double output pairs of variables. This matrix was then converted to linear time invariant state space model by multivariable realization technique. With the proposed multivariable proportional and integral controller applied to the process, the result of the digital computer simulation showed a good performance of asymtotic tracking. The limited experimental performance of this multivariable control was compared with the result from simulation. It was found that the proposed controller performed satisfactorily for the distillation column which separated binary mixture of methanol and water.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.83-86
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• 2003

Soil Aquifer Treatment (SAT) is a technique in which secondary- or tertiary-treated wastewater is infiltrated through unsaturated soil and stored in the saturated zone. In SAT, contaminants are removed by physical and biochemical reactions taking place in soils. In this study, a numerical model was developed to predict changes in water quality during SAT operations. The contaminant species considered in the model were ammonium, nitrate, dissolved organic carbon, and dissolved oxygen. The model was calibrated against experimental data obtained from one dimensional soil column tests conducted for 84 days. The calibrated model will be used to find out optimum conditions for the pilot- and regional-scale SAT operations to be scheduled for the next phase of this project.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.229-233
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• 1990

A new on-line optimization technique of a distillation column is presented. The equation decoupling method and the simultaneous solution method are combined to simulate the distillation process. The storage requirement is small enough to run on a PC. A improved successive quadratic programming is used to find the optimum operating conditions. The optimizer is intensively tested by using the dynamic simulator, SPEEDUP. After this, the technique is applied to a binary distillation column that treats methanol and water.

• Journal of Power System Engineering
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• v.18 no.3
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• pp.36-41
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• 2014

The structure of a variable liquid column oscillator(a VLCO) is analogous to that of the tuned liquid column damper used to suppress oscillatory motion in large structures like tall buildings and cargo ships. The VLCO is a system absorbing high kinetic energy of accelerated motions of the multiple floating bodies in the effect of air springs occurred by installation of inner air chambers. Thus, VLCO can improve the efficiency of energy than wave energy converters of the activating object type made in Pelamis Company. In this research, the experiment was performed in two models of same draft. The one is that weights were filled, and the other is that water was filled. The numerical results were estimated by assuming that do not exist internal flow, and the results were compared with the results of experiments.

• The Journal of Engineering Research
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• v.2 no.1
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• pp.147-149
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• 1997

Nirogen dioxide is rapidly converted to nitric oxide by the water absortbed on a Linde Molecular Sieve column. The resultant wave form is indistinguishable from that of pure nitric oxide introduced to the column. Thus, by conversion to the low boiling nitric oxide, the complication of oxidation of organic partitioning liquids is obviated.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.12
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• pp.1209-1214
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• 2006

This paper presents an application of Dividing Wall Column(DWC) to the recovery of the waste solvent from the film making processes. The waste solvent feed contains MEK(Methyl-Ethyl-Ketone), Toluene, Cyclohexanone, and water. The commercial software $HYSYS^{TM}$ was used for rigorous simulation and analysis. Sensitivity analysis for several major design variables were carried out to achieve the optimal design of the process. Distribution of the internal vapor and liquid flows to the prefractionator and main sections is shown to be the most dominant design factor for energy saving efficiency in the DWC process. The simulation results also show that the solvent recovery process using the DWC significantly improves both the energy efficiency and the compactness of the solvent recovery process.

• Journal of Mechanical Science and Technology
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• v.20 no.6
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• pp.795-805
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• 2006

Tuned Liquid damper and Tuned Liquid Column are kind of passive mechanical damper which relies on the sloshing of liquid in a rigid tank for suppressing structural vibrations. TLD and TLCD are attributable to several potential advantages - low costs ; easy to install in existing structures : effective even for small-amplitude vibrations. In this paper, the shaking table experiments were conducted to investigate the characteristics of water sloshing motion in TLD (rectangular, circular) and TLCD. The parameter obtained from the experiments were wave height, base shear force and energy dissipation. The shaking table experiments show that the liquid sloshing relies on amplitude of shaking table and frequency of tank. The TLCD was more effective control vibration than TLD.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.7
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• pp.525-531
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• 2013

In an effort to find a solution to the eutrophication of major Korean rivers, a method to utilize multi-purpose filtration pond was investigated. As literature showed that oyster shell is known to be the most adequate for the removal of dissolved phosphorus in Korean rivers, batch and column experiments were performed using oyster shell as an adsorbent in this study. The results of the batch experiment showed that the removal of dissolved phosphorus from river water through adsorption as a way of preventing algal growth was not practical. The results obtained from the column experiment, however, suggested that oyster shell may be utilized as an adsorbent under limited conditions. Based on the results of the experiments a methodology was proposed to remove algae from river water through the use of multi-purpose filtration pond. This method involves mechanically removing the accumulated algae cake from the surface of the artificial stream in the pond towards the condensing part located at the lower reach of the stream, where particles gather before the final removal. In addition, employment of oyster shell as an adsorbent in the condensing part allows prevention of phosphorus released from the dead algae re-entering the river water.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.1169-1174
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• 2001

In this study, the behavior of deteriorated concrete columns under sea-water before and after strengthening with glass fiber composite and the change of behavior by the deterioration of strengthening material are analyzed. In the analysis, the characteristics of concrete deteriorated in sea-water, preloading effect, and corrosion of steel are considered. The result of analysis is verified by the comparison with the experimental data. Using constitutive equations of the concrete and corroded steel, load-moment interaction curves of both deteriorated and strengthened concrete column are derived.

• KSBB Journal
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• v.8 no.1
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• pp.75-82
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• 1993

The inhibitory effect of cacao bean husk (CBH) extract on glucosyltransferase(GTasc) from Streptococcus mutans B13 was investigated. Water solube extract from CBH showeda sarong inhibitory effect (88-89%) on GTase from Streptococcus mutans Bl3. GTase inhibitors from sequential extraction by hot water or water-methanol had the strongest inhibition. Sources, fermentation, and types of solvents and fumigation processes did not influence the effect. These active compounds proved to be polyphones through acid hydrolytic analysis of the precipitates by ammonium sulfate or ethanol and proteinase K. It was also confirmed by additional column chromatography of Sephadex G-50, Sephadex LH-20 and DEAE-Sephdex A-50.