• Analytical Science and Technology
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• v.19 no.4
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• pp.275-279
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• 2006

A capillary electrophoresis method for the separation of carvedilol and its metabolites enantiomers using cyclodextrins as the chiral selectors was developed. The effect of several types of cyclodextrins, concentration and capillary temperature for enantiomer resolution were investigated. Best results were obtained by 15 mM carboxymethyl-${\beta}$-cyclodextrin in the run buffer. Also the effect of capillary temperature on efficiency was assessed. The optimized method was applied for separation of chiral carvedilol and its three metabolites.

• Progress in Superconductivity and Cryogenics
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• v.25 no.3
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• pp.1-6
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• 2023

We have been developing a new magnetic filter so that small sized paramagnetic substances can be separated even in a low magnetic field (lower than 2T). The developed filter is a packed ferromagnetic filament with a triangular cross section. The filament has a diameter of 120 ㎛ and a length of 3 mm, and is mechanically packed with a volume ratio of 17.6%. Using this filter, a magnetic separation experiment of hematite was carried out using a superconducting magnet at the field of 2T. Similarly, magnetic separation was performed using a conventional magnetic filter. It became clear that the separation efficiency of newly developed filter is high as that of conventional mesh filter. The smaller sized hematite (<3 ㎛) could be separated though conventional mesh filter could not separate.

• Applied Science and Convergence Technology
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• v.24 no.5
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• pp.196-202
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• 2015

Human blood consists of 55% of plasma and 45% of blood cells such as white blood cell (WBC) and red blood cell (RBC). In plasma, there are many kinds of promising biomarkers, which can be used for the diagnosis of various diseases and biological analysis. For diagnostic tools such as a lab-on-a-chip (LOC), blood plasma separation is a fundamental step for accomplishing a high performance in the detection of a disease. Highly efficient separators can increase the sensitivity and selectivity of biosensors and reduce diagnostic time. In order to achieve a higher yield in blood plasma separation, we propose a novel fluid wing structure that is optimized by COMSOL simulations by varying the fluidic channel width and the angle of the bifurcation. The fluid wing structure is inspired by the inertial particle separator system in helicopters where sand particles are prevented from following the air flow to an engine. The structure is ameliorated in order to satisfy biological and fluidic requirements at the micro scale to achieve high plasma yield and separation efficiency. In this study, we fabricated the fluid wing structure for the efficient microfluidic blood plasma separation. The high plasma yield of 67% is achieved with a channel width of $20{\mu}m$ in the fabricated fluidic chip and the result was not affected by the angle of the bifurcation.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.1
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• pp.93-98
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• 2010

An object of this study is to confirm the opening amount of the throttle valve that is begun the temperature separation of vortex tube for various engine speed and load condition in a common rail diesel engine. The vortex tube located at downstream of the exhaust manifold is a device separating the incoming exhaust gas to hot and cold stream. To find optimum separation efficiency of vortex tube, the opening amount of throttle valve has been investigated for various engine speed and load conditions. Engine speed was found that the influence of engine speed was dominant compared with that of engine load. As engine speed was increased, the throttle opening amount starting temperature separation was reduced.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.6
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• pp.787-796
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• 2012

The purpose of this study is to investigate CSOs(combined sewer overflows) control in the combined sewer with/without separation wall. There is the high correlation between sewage velocity and suspended solid(SS) loading in the sewer without it. The SS/BOD ratio was about 3 times in the area with it, while it was about 5 times in the area without it. Therefore, the accumulated deposit within the sewer has influenced high SS loading in the sewer without it. This study showed that the separation wall installed acquired an acceptable efficiency in controlling the accumulated deposit in the combined sewer. According to this study, the BOD control effect was about 38 % in the sewer with the separation wall, whereas it showed about 24 % in the sewer without it. In this case, it was anticipated that the high pollutant control effect would be expected if the separation wall was installed in the combined sewer.

• Journal of Mechanical Science and Technology
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• v.16 no.10
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• pp.1336-1345
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• 2002

A triboelectrostatic separation system using a fluidized bed tribocharger for the removal of PVC material in the mixture of PVC/PS plastics is designed and evaluated as a function of electric field strength, air flow rate, and the mixing ratio of two-component mixed plastics. It consists of a fluidized-bed tribocharger, a separation chamber, a collection chamber and a controller. PVC and PS particles can be imparted negative and positive surface charges, respectively, due to the difference in the work function values of plastics suspended in the fluidized-bed tribocharger, and can be separated by passing them through an external electric field. Experimental results show that separation efficiency is strongly dependent on the electric Deld strength and particle mixing ratio. In the optimum conditions of 150 Ipm air flow rate and 2.6 kV/cm electric field strength a highly concentrated PVC (99.1%) can be recovered with a yield of more than 99.2% from the mixture of PVC and PS materials for a single stage of processing.

• International Journal of Aeronautical and Space Sciences
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• v.2 no.2
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• pp.1-18
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• 2001

A numerical technique for simulating the separation dynamics of strap-on boosters jettisoned in the dense atmosphere is presented. Six degree of freedom rigid body equations of motion are integrated into the three-dimensional unsteady Navier-Stokes solution procedure to determine the dynamic motions of strap-ons. An automated Chimera overlaid grid technique is introduced to achieve maximum efficiency for multi-body dynamic motion and a domain division technique is implemented in order to reduce the computational cost required to find interpolation points in the Chimera grids. The flow solver is validated by comparing the computed results around the Titan IV launch vehicle with experimental data. The complete analysis process is then applied to the. H-II launch vehicle, the central rocket in japans space program, the CZ-3C launch vehicle developed in China and the KSR-III, a three-stage sounding rocket being developed in Korea. From the analyses, separation trajectories of strap-on boosters are predicted and aerodynamic characteristics around the vehicles at every time interval are examined. In addition, separation-impulse devices generally introduced for safe separation of strap-ons are properly modeled in the present paper and the jettisoning force requirements are examined quantitatively.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.3
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• pp.37-43
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• 2006

Six types of hat stiffened composite panels were manufactured with different bonding methods and stiffener section shapes and compression testing of these panels were performed. The panels showed similar behaviors in bucking and postbuckling region before a skin-stiffener separation failure occurred. Although all the separation failures occurred at the same locations of stiffener flanges close by skin buckling crests, the separation loads, separation failure growth behaviors and final collapse loads were different with respect to bonding methods and stiffener section shapes. As the separation failure initiated early and propagated larger area, collapse loads and structural efficiency of the panels decreased.

• KSBB Journal
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• v.27 no.1
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• pp.40-44
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• 2012

The laboratory animal group separation is dividing animal population into subgroups, which have similar average and standard deviation values among the subgroups, based on the biological characteristics such as body weight, glucose level in blood, etc. Although group separation is very important and initial step in experimental design, it needs a labor intensive process for researchers because of making similar average and standard deviation values among the subgroups using the raw biological characteristics. To reduce the labor cost and increase the efficiency of animal grouping, we developed a web program named as laboratory animal group separation (LAGS) program. This LAGS uses biological characteristics of population, number of group, and the number of elements per each subgroup as input data. The LAGS automatically separates the population into each subgroup that has similar statistical data such as average and standard deviation values among subgroups. It also provides researchers with the extraordinary data generated in the process of grouping and the final grouping results by graphical display. Through our LAGS, researchers can validate and confirm results of laboratory animal group separation by just a few mouse clicks.

• Korean Journal of Materials Research
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• v.31 no.8
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• pp.465-470
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• 2021

Deuterium is a crucial clean energy source required for nuclear fusion and is a future resource needed in various industries and scientific fields. However, it is not easy to enrich deuterium because the proportion of deuterium in the hydrogen mixture is scarce, at approximately 0.016 %. Furthermore, the physical and chemical properties of the hydrogen mixture and deuterium are very similar. Therefore, the efficient separation of deuterium from hydrogen mixtures is often a significant challenge when using modern separation technologies. Recently, to effectively separate deuterium, studies utilizing the 'Kinetic Quantum Sieving Effect (KQS)' of porous materials are increasing. Therefore, in this review, two different strategies have been discussed for improving KQS efficiency for hydrogen isotope separation performance using nanoporous materials. One is the gating effect, which precisely controls the aperture locally by adjusting the temperature and pressure. The second is the breathing phenomenon, utilizing the volume change of the structure from closed system to open system. It has been reported that efficient hydrogen isotope separation is possible using these two methods, and each of these effects is described in detail in this review. In addition, a specific-isotope responsive system (e.g., 2nd breathing effect in MIL-53) has recently been discovered and is described here as well.