• Journal of the Earthquake Engineering Society of Korea
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• v.13 no.4
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• pp.47-55
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• 2009

The purpose of this study is to verify the transfer function of input acceleration and output control force by linearizing a velocity-dependent damping term of Liquid Column Vibration Absorber (LCVA). Analytical and experimental research is conducted to identify natural frequency, damping ratio and participated mass ratio of LCVA with various section ratios of vertical and horizontal areas. Findings obtained experimentally by the shaking table test are compared with analytical findings using optimization technique with constraints. The results indicate that the level of liquid and section ratio of LCVA affect the characteristics of damping ratio and mass ratio. Damping and mass ratio increase as the section of vertical column of LCVA decreases, due to turbulence in the elbow of LCVA.

• Korean Chemical Engineering Research
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• v.52 no.4
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• pp.516-521
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• 2014

Axial and overall heat transfer coefficients were investigated in a bubble column with relatively high viscous and low surface tension media. Effects of superficial gas velocity (0.02~0.1 m/s), liquid viscosity ($0.1{\sim}0.3Pa{\cdot}s$) and surface tension ($66.1{\sim}72.9{\times}10^{-3}N/m$) on the local and overall heat transfer coefficients were examined. The heat transfer field was composed of the immersed heater and the bubble column; a vertical heater was installed at the center of the column coaxially. The heat transfer coefficient was determined by measuring the temperature differences continuously between the heater surface and the column which was bubbling in a given operating condition, with the knowledge of heat supply to the heater. The local heat transfer coefficient increased with increasing superficial gas velocity but decreased with increasing axial distance from the gas distributor and liquid surface tension. The overall heat transfer coefficient increased with increasing superficial gas velocity but decreased with increasing liquid viscosity or surface tension. The overall heat transfer coefficient was well correlated in terms of operating variables such as superficial gas velocity, liquid surface tension and liquid viscosity with a correlation coefficient of 0.91, and in terms of dimensionless groups such as Nusselt, Reynolds, Prandtl and Weber numbers with a correlation of 0.92; $$h=2502U^{0.236}_{G}{\mu}^{-0.250}_{L}{\sigma}^{-0.028}_L$$ $$Nu=325Re^{0.180}Pr^{-0.067}We^{0.028}$$.

• Journal of the Korean Chemical Society
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• v.53 no.3
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• pp.279-285
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• 2009

This paper has described about preparation of $Zr^{4+}$ affinity column based on the poly(styrene-co- gly-cidyl methacrylate) prepared by emulsion polymerization of styrene and glycidyl methacrylate in order to isolate phosphopeptide. The $Zr^{4+}$ ions were introduced after the phophonation of an epoxy group on polymeric microspheres. The successful preparation of $Zr^{4+}$-immobilized polymeric microsphere stationary phase was confirmed through Fourier transform infrared spectra, optical microscopy, scanning electron microscopy, X-ray photoelectron spectra and inductively coupled plasma-atomic emission spectrometer. The separation efficiency for $Zr^{4+}$ affinity column prepared by slurry packing was tested to phosphonated casein and dephosphonated casein. The resolution time (min) of the phosphonated casein was higher than that of dephosphated casein for $Zr^{4+}$ affinity polymeric microsphere by liquid chromatography. This $Zr^{4+}$ affinity column can be used for isolation of phosphonated casein from casein using liquid chromatography.

• Journal of the Korean Wood Science and Technology
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• v.36 no.4
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• pp.102-108
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• 2008

At the University of Maine, a hemicellulose pre-extraction technology is now being investigated to improve pulp yields, reduce the organic and inorganic load for liquor recovery, and create a feed stream for the generation of new biomaterials. It is important to understand the composition of unextracted wood, extracted wood, and pulping extracts in the design of an economically viable pilot-scale ethanol plant. For analysis of wood pulp composition, the total analytical mass balance closure was 100.6, 100.3, and 81.6% for unextracted chips, extracted chips, and pulping extracts from HPLC-H column analysis. Meanwhile, the total analytical mass balance from the HPLC-P column was 97.8, 86.3, and 80.7%, respectively. This slight variability between H- and P-column results for analytical mass balance may be within the experimental error of the measurement. The data generated by this analysis are important to further design work in commercializing this process.

• Clean Technology
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• v.26 no.2
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• pp.102-108
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• 2020

In recent years, packed column has been widely used in separation processes, such as absorption, desorption, distillation, and extraction, in the petrochemical, fine chemistry, and environmental industries. Packed column is used as a contacting facility for gas-liquid and liquid-liquid systems filled with random packed materials in the column. Packed column has various advantages such as low pressure drop, economical efficiency, thermally sensitive liquids, easy repairing restoration, and noxious gas treatment. The performance of a packed column is highly dependent on the maintenance of good gas and liquid distribution throughout a packed bed; thus, this is an important consideration in a design of packed column. In this study, hydraulic pressure drop, hold-up as a function of liquid load, and mass transfer in the air, air/water, and air-NH₃/water systems were studied to find the geometrical characteristic for raschig super-ring experiment dry pressure drop. Based on the results, design factors and operating conditions to handle noxious gases were obtained. The dry pressure drop of the random packing raschig super-ring was linearly increased as a function of gas capacity factor with various liquid loads in the Air/Water system. This result is lower than that of 35 mm Pall-ring, which is most commonly used in the industrial field. Also, it can be found that the hydraulic pressure drop of raschig super-ring is consistently increased by gas capacity factor with various liquid loads. When gas capacity factor with various liquid loads is increased from 1.855 to 2.323 kg^-1/2 m^-1/2 S^-1, hydraulic pressure drop increases around 17%. Finally, the liquid hold-up related to packing volume, which is a parameter of specific liquid load depending on gas capacity factor, shows consistent increase by around 3.84 kg^-1/2 m^-1/2 S^-1 of the gas capacity factor. However, liquid hold-up significantly increases above it.

• Journal of Microbiology and Biotechnology
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• v.5 no.1
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• pp.41-47
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• 1995

Biodegradation of toluene in liquid effluent stream was carried out using biofilms of Pseudomonas putida formed on celite particles in the bubble column bioreactor. Silicon rubber tubing was installed at the bottom of the bioreactor and liquid toluene was circulated within the tubing. Toluene diffused out of the tube wall and was transferred into the culture broth where degradation by biofilms occurred. The operating variables affecting the formation of biofihns on celite particles were investigated in the bubble column bioreactor, and it was found that formation of bifilm is favored by high dilution rate and supply rate of carbon source which stimulate the growth of initially attached cells. Continuous biodegradation of toluene using biofilms was stablely conducted in the bioreactor for more than one month without any significant fluctuation, showing a removal efficiency higher than 95% at the toluene transfer rate of 1.2 g/L/h.

• Journal of Power System Engineering
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• v.18 no.5
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• pp.16-21
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• 2014

The structure of the variable liquid column oscillator(VLCO) is analogous to that of the tuned liquide column damper used to suppress oscillatory motion in large structures like tall buildings and cargo ships. VLCO is the technology to absorb high potential energy made by process of accelerated motions to occur the effect of an air spring by installation of inner air chamber. So, the application of VLCO can obtain to improve efficiency of energy than wave energy converters made in Pelamis Company. In this research, the experiments were carried out for the motion characteristics of simple floating body by varying the amount of internal fluid. The experimental results were compared with the calculated results.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.14 no.1
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• pp.1-15
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• 1988

A new method for liquid chromatography with post column reaction is suggested for the separation and quantification of tertiary amines. A mixture of triethanolamine and N-ethyl diethanolamine was separated by a strong cation exchange column, followed by spectrophtometric detection of the blue colors generated from the reaction of each amine with the Folin-Ciocalteau reagent. The tertiary amines were properly separated when an eluent of pH 9.5 containing 0.5M sodium nitrate was used. Under this condition, calibration curve of triethanolamine in 2-10mg/100ml concentration range was attained. Good results were obtained when cream and shampoo preparations containing known amount of triethanolamine were analysed according to this method. In case the sample did not contain any other interfering reducing substances, the amine was quantitatively determined by the simple reaction of the samples with Folin-Ciocalteau reagent, and the subsequent spectrophotometric measurement.

• Archives of Pharmacal Research
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• v.22 no.6
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• pp.614-618
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• 1999

A reversed-phase high-performace liquid chromatographic method was developed to determine the optical purity of metoprolol enantiomers. The enantiomers were converted to diastereomeric derivatives using (-)-menthyl chloroformate reagent. Separation of the enantiomers as diastereomers was achieved by reversed-phase HPLC within 30 min using Inertsil C8 column. This method allowed determination of 0.05% of either enantiomer in the presence of its stereoisomer and method validation showed adequate linearity over the required range. Owing to the reaction condition during the derivatization with (-)-menthyl chloroformate, the possibility of racemization had to be established. Different ratios of (S)-(-)-metoprolol and (R)-(+)-metoprolol were prepared. Enantiomeric separation of these mixtures took place on a chiralcel OD column or, after derivatization with (-)-menthyl chloroformate, on a C8 column. The results form the these two independent separation systems were compared with trace racemization and were in very good agreement. No racemization was found during the experiment.

• Journal of the Korean Society of Safety
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• v.8 no.2
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• pp.44-50
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• 1993

The objective of this study was to investigate the extraction of chromium(Vl) ion in waste water through the liquid surfactant membrane with open-type Perforated Reciprocating-Plate Column. Extraction experiments were conducted to measure the effect of flow characteristics of continuous and dispersed phase and stroke velocity, sodium hydroxide concentraction in internal aqueous phase, sulfuric acid concentraction in outer phase, and residence time distribution and measured extraction velocity. The result of experiments showed that extraction velocity of chromium ion was maximum when stroke velocity was 180 1/min and dispersion phase velocity was 30m11min, continuous phase velocity was 20m1/min. Extraction velocity of chromium ion increased with increasing difference of hydrogen ion concentraction of dispersion and continuous phase and column stage decreased.