• Journal of ILASS-Korea
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• v.11 no.4
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• pp.205-211
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• 2006

Impinging angle, impinging distance, length eve. diameter and injection pressure of a triplet injector were tested to evaluate the spray characteristics injected by liquid/gas combinations. Two different kinds of unlike triplet sprays were produced by changing the gas and liquid feed lines. One was the G-L-G(Gas-Liquid-Gas) type, and the other was L-G-L(Liquid-Gas-Liquid) type. Spray angles were wider with the G-L-G type than with L-G-L type. Mass distributions in spray were obtained with a, mechanical patternator. Mass distributions were not circular but elliptical distributions. When the range of mechanical patternator to injector decreased, mass distributions were more concentrated in the center region.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.15 no.4
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• pp.1-8
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• 2007

Spray characteristics of a unlike triplet injector were investigated experimentally. Spray images and SMD of droplet were measured to evaluate the spray characteristics injected by liquid/gas combinations. G-L-G(Gas-Liquid-Gas), L-G-L(Liquid-Gas-Liquid) type of injector were used by changing the gas and liquid feed lines. The SMD graph shows that the droplet sizes decrease in the out of radial direction at a fixed gas Reynolds number. The SMD value of decreasing tendency shows that the more ethyl alcohol ratio increase, the more SMD value decrease.

• Korean Chemical Engineering Research
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• v.56 no.2
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• pp.186-190
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• 2018

For the first time, the characteristics of solid circulation rate ($G_S$) were investigated in a three-phase (gas-liquid-solid) viscous circulating fluidized bed (TPCFB). The solid circulation rate was controlled separately by adjusting the experimental apparatus as well as operating variables. Effects of primary and secondary liquid velocities ($U_{L1}$ and $U_{L2}$), gas velocity ($U_G$), particle size ($d_p$), height of particles piled up in the solid recycle device (h), and viscosity of continuous liquid media (${\mu}_L$) on the value of $G_S$ were determined. The experimental results showed that the value of $G_S$ increased with increases in the values of $U_{L1}$, $U_{L2}$, h and ${\mu}_L$, while it decreased with increasing $U_G$ and $d_p$ in TPCFBs with viscous liquid media. The values of $G_S$ were well correlated in terms of dimensionless groups within this experimental conditions.

• Korean Chemical Engineering Research
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• v.46 no.3
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• pp.521-528
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• 2008

The micro-porous asymmetric PVDF hollow fiber membranes for gas-liquid contactor were prepared by the dry-jet wet phase inversion process and the characteristics of hollow fiber membranes were evaluated by the gas permeation method and scanning electron microscope. The chemical absorbent for removal of $SO_2$ gas was sodium hydroxide at bench scale hollow fiber membrane contactor. The experiments were performed in a counter-current mode of operation with gas in the shell side and liquid in the fiber lumen of the module to examine the effect of various operating variables such as concentration of absorbent, gas flow rate, L/G ratio and concentration of inlet $SO_2$ gas on the $SO_2$ removal efficiency using PVDF hollow fiber membrane contactor. Membrane mass transfer coefficient($k_m$) was calculated by mathematical modeling. The volumetric overall mass transfer coefficient increased with increasing the concentration of absorbent and L/G ratio. The increase of the absorbent concentration and L/G ratio not only provides more sufficient alkalinity but also decreases liquid phase resistance. The volumetric overall mass transfer coefficient increased with increasing gas flow rate due to decreasing the gas phase resistance.

• Bulletin of the Korean Chemical Society
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• v.24 no.1
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• pp.99-105
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• 2003

A liquid-liquid extraction followed by evaporative concentration method was used to determine the concentration of normal, or straight chain, saturated hydrocarbons (NSH) $(C_{10}\;to\;C_{24})$ and polycyclic aromatic hydrocarbons (PAH) here defined as: fluorene, anthracene, pyrene, chrysene and perylene, in the Buriganga River water of Bangladesh. Samples were collected from 5 and 25 cm depth of water at the southern, middle and northern parts of the river at Postogolla, Sadarghat and Sowarighat stations. Hydrocarbons were extracted from 450 mL of water into 75 mL n-hexane and then concentrated into 1 or 2 mL solution by evaporation. These solutions were analyzed by gas chromatography. The highest and lowest concentrations were determined as $257\;{\mu}gL^{-1}\;for\;C_{13}\;and \;0.24\;{\mu}g\;L^{-1}\;for\;C_{22}$ at 5 ㎝ depth of water, at the northern part of the Sowarighat and southern part of the Postogolla, respectively. This method could allow the analysis of water for $C_{22}$ as low as $0.24\;{\mu}g\;L^{-1}$.

• Nuclear Engineering and Technology
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• v.7 no.1
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• pp.3-8
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• 1975

The quantitative analysis of various kinds of free amino acids contained in blood serum of patients with chronic mandible ostities, epidermic hemorrhagic fever, chronic renal failure and liver cirrhosis were measured with the gas-liquid chromatography (G. L. C.). The results compared with the quantity of free amino acids of healthy persons. It was found that the quantity of free amino acids were differently contained in blood serum in accordance with kinds of patients.

• Applied Chemistry for Engineering
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• v.5 no.4
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• pp.706-713
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• 1994

Isothermal vapor-Liquid equilibrium data have been measured for binary systems MTBE-methanol, MTBE-n-heptane, and methanol-n-heptane at $45^{\circ}C$ and $65^{\circ}C$ by using head space gas chromato-graphy (H.S.G.C). Among these systems a minimum azeotrope was observed in both of MTBE-methanol system and n-heptane-methanol system. Particularly n-heptane-methanol system has a heterogeneous minimum azotrope since it has an immisible region. These equilibrium data were correlated with the excess Gibbs energy model, and the thermodynamic consistency test was also carried out by using Redlich-Kister equation.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.4
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• pp.377-383
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• 2005

This paper deals with the flow characteristics of air-water two-phase flow in a vertical tube of 10mm I.D. and 600mm in length at an adiabatic condition. The obtained experimental data were covered with the liquid superficial velocity ranging from 0.095m/s to 2.56m/s. and the gas superficial velocity ranging from 0.032m/s to 21.08m/s. The effects of the gas and liquid superficial velocity on the flow pattern transitions, frictional pressure drop, and film thickness and gas-liquid interface roughness were also examined. It was found that the film thickness increased and the liquid film wave length was more longer with the liquid superficial velocity $j_L$ increasing at $j_G$ constant. It was also showed that the frictional pressure drops were experienced in three regions. namely increasing region(bubbly flow), decreasing region (Taylor bubble and slug flows) and re-increasing region (annular flow).

• Bulletin of the Korean Chemical Society
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• v.30 no.1
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• pp.61-66
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• 2009

An analytical method based on solid-phase extraction and gas chromatography / mass spectrometry has been developed for measurement of acaricides (amitraz, bromopropylate, coumaphos, cymiazole, and tetradifon) in honey sample. In the stability test of acaricides in honey, amitraz underwent a rapid degradation into 2,4-dimethylaniline (DMA), 2,4-dimethylphenylformamide (DMPF), and N-(2,4-dimethylphenyl)-N'-methylformamidine (DMPMF), whileas other acaricides were found to be stable even for over three months. Extraction of five acaricides from 5g of honey sample was carried out by liquid-liquid extraction using 20mL of ethylacetate. For purification, Florisil-SPE cartridge with elution of 5mL of n-hexane/ acetone (55:45, v/v) was found to remove interferences effectively. Quantification was performed using gas chromatography / mass spectrometry in the selected ion monitoring mode. Spiking experiments were carried out to determine the recovery, precision, and limits of detection (LODs) of the method. The overall recovery values from honey spiked at 0.02 and 0.20 ${\mu}g/g$ levels, respectively, were found to be greater than 75% for all acaricides. The method detection limits for acaricides were ranged from 0.1 to 3 ppb. The developed method in this study was applied for the monitoring of acaricides in honey products collected from urban markets in Korea.

• Environmental Analysis Health and Toxicology
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• v.16 no.3
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• pp.121-126
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• 2001

Analytical method of benzophenone (BP) in sediment and soil was developed by gas chromatography/mass selective detector/selected ion monitoring (GC/MSD/SIM). The ultrasonic extraction of US EPA (method 3550B) method and liquid-liquid extraction for sediment and soil samples were used for the analysis of BP from sediment and soil. BP was extracted with n-hexane. Organic layer was washed with 5% sodium chloride solution. 1∼2 l of the concentrated solution of organic layer was applied to GC/MSD. The retention time of BP peak was 11.10 min. Recovery (％) of BP by ultrasonication from sediment and soil samples was 96.0∼100.6％ and 40.0∼83.0％, respectively. Recovery of BP by liquid-liquid extraction was 51∼59％ in soil samples. The detection limit of BP in sediment and soil samples were determined to 0.1 ng/g.