• Journal of Mechanical Science and Technology
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• v.18 no.9
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• pp.1493-1499
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• 2004

This paper describes the speckle shearing interferometry, a non-destructive optical method, for quantitative estimation of void defect and monitoring separation defect inside of a pneumatic tire. Previous shearing interferometry has not supplied quantitative result of inside defect, due to effective factors. In the study, factors related to the details of an inside defect are classified and optimized with pipeline simulator. The size and the shape of defect can be estimated accurately to find a critical point and also is closely related with shearing direction. The technique is applied for quantitative estimation of defects inside of a pneumatic tire. The actual traveling tire is monitored to reveal the cause of separation and the starting points. And also unknown void defects on tread are inspected and the size and shape of defects are estimated which has good agreement with the result of visual inspection.

• Membrane Journal
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• v.12 no.4
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• pp.193-206
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• 2002

Pervaporation separation is one of promising membrane technology for the energy saving processes and it has been developed to separate complex mixture systems including azeotropic mixture, close-boiling mixture, aqueous organic mixtures etc. Many researchers focused on dehydration pervaporation separation and they commercialized ethanol dehydration and isopropanol recycling processes. Nowadays, petroleum separation and volatile organic compound removal using pervaporation membranes is one of the emerging application of pervaporation separation. We reviewed the development and application of pervaporation membranes.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.336-339
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• 2006

With the steady depletion off fossil fuel reserves, hydrogen based energy sources become increasingly attractive. Therefore hydrogen production or separation technologies, such as Bas separation membrane based on adsorption technology, have received enormous attention in the industrial and academic fields. In this study, the transport mechanisms of the MTES (methyltriethoxysilane) templating silica/a-alumina composite membrane were evaluated by using unary, binary and quaternary hydrogen gas mixtures permeation experiments at unsteady- and steady-states. Since the permeation flux in the MTES membrane, through the experimental and theoretical study, was affected by molecular sieving effects as well as surface diffusion properties, the kinetic and equilibrium separation should be considered simultaneously in the membrane according to molecular properties. In order to depict the transient multi-component permeation on the templating silica membrane, the GMS (generalized Maxwell-Stefan) and DGM (dust Bas model) were adapted to unsteady-state material balance

• Membrane and Water Treatment
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• v.5 no.2
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• pp.147-170
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• 2014

This paper focuses on the study of the most recent ultra-filtration techniques, based on porous polymer membranes, used for the treatment of wastewater from oil, mine and hydrometallurgical industries. The performance of porous membranes used in separation and recovery of oil and heavy metals from wastewater, was evaluated by the polymer composition and by the membrane characteristics, as it follows: hydrophobicity or hydrophilicity, porosity, carrier (composition and concentration), selectivity, fouling, durability, separation efficiency and operating conditions. The oil/water efficient separation was observed on ultra-filtration (UF) techniques, with porous membranes, whereas heavy metals recovery from wastewater was observed using porous membranes with carrier. It can be concluded, that in the ultra-filtration wastewater treatments, a hybrid system, with porous polymer membranes with or without carrier, can be used for these two applications: oil/water separation and heavy metals recovery.

• Macromolecular Research
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• v.14 no.1
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• pp.45-51
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• 2006

We conducted simultaneous, small-angle, X-ray scattering/differential scanning calorimetry (SAXS/DSC) and simultaneous, wide-angle, X-ray scattering (WAXS)/DSC measurements for a polymer blend of poly($\varepsilon$-caprolactone)/poly(ethylene glycol)(PCL/PEG). The time-dependent SAXS/DSC and WAXS/DSC results, measured while the system was quenched below the melting temperature of PCL from a melting state, revealed the competitive behavior between liquid-liquid phase separation and crystallization in the polymer blend. The time-dependent structural evolution extracted from the SAXS/WAXS/DSC results can be characterized by the following four stages in the PCL crystallization process: the induction (I), nucleation (II), growth (III), and late (IV) stages. The influence of the liquid-liquid phase separation on the crystallization of PCL was also observed by phase-contrast microscope and polarized microscope with 1/4$\lambda$ compensator.

• Nuclear Engineering and Technology
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• v.50 no.7
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• pp.1184-1189
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• 2018

Pyroprocessing uses various molten salts during electrochemical unit processes. Reaction products after the electrochemical processes must contain a significant amount of residual salts to be separated. Vacuum distillation is a common method to separate the residual salts; however, its high operation temperature may cause side reactions. In this study, a simple rotation technique using centrifugal force was suggested to separate the residual salts from the reaction products at relatively low temperature compared to the distillation technique. When a reaction product container with porous wall rotates inside a vessel heated above the melting point of the residual salt, the residual salt in the liquid phase is separated through centrifugal force. It was shown that the $LiNO_3-Al_2O_3$ mixture can be separated by this technique to leave solid $Al_2O_3$ inside the container, with a separation efficiency of 99.4%.

• 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.

• Nuclear Engineering and Technology
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• v.45 no.5
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• pp.675-682
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• 2013

The sequential separation process, composed of an oxygen sparging process for separating lanthanides and a zone freezing process for separating Group I and II fission products, was evaluated and tested with a surrogate eutectic waste salt generated from pyroprocessing of used metal nuclear fuel. During the oxygen sparging process, the used lanthanide chlorides (Y, Ce, Pr and Nd) were converted into their sat-insoluble precipitates, over 99.5% at $800^{\circ}C$; however, Group I (Cs) and II (Sr) chlorides were not converted but remained within the eutectic salt bed. In the next process, zone freezing, both precipitation of lanthanide precipitates and concentration of Group I/II elements were preformed. The separation efficiency of Cs and Sr increased with a decrease in the crucible moving speed, and there was little effect of crucible moving speed on the separation efficiency of Cs and Sr in the range of a 3.7 - 4.8 mm/hr. When assuming a 60% eutectic salt reuse rate, over 90% separation efficiency of Cs and Sr is possible, but when increasing the eutectic salt reuse rate to 80%, a separation efficiency of about 82 - 86 % for Cs and Sr was estimated.

• Korean Chemical Engineering Research
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• v.57 no.4
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• pp.484-491
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• 2019

An efficient propylene/propane separation technology is needed to obtain high-purity propylene, which is a raw material for polypropylene synthesis. Since conventional cryogenic distillation is an energy-intensive process due to the similar physicochemical properties of propylene and propane, adsorptive separation has gained considerable interest. In this study, we have computationally investigated the changes in adsorption separation performances by arbitrarily controlling the adsorption strength of open metal sites in two different types of metal-organic frameworks (MOFs). Through the evaluation of adsorptive separation performances in terms of working capacity, selectivity, and Adsorption Figure of Merit (AFM), we have suggested proper density and strength of adsorption sites as well as appropriate temperature condition to obtain optimal propylene/propane adsorptive separation performances.

• Aerospace Engineering and Technology
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• v.2 no.1
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• pp.171-181
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• 2003

The nose fairings of KSR-III are designed to be separated from the rocket by explosive force at the mission altitude to expose the payload. Adequate amount of separation force should be imposed to allow safe separation without collision between the fairings and the rocket, and the separation device was designed for the separation at very high altitude where almost no air load was expected. As the development of KSR-III goes on, several design changes have made and lower separation altitude of 45km is expected as a result. Under these circumstances, it is required to determine if the nose fairings can be separated without collision with much severer air load than for the design condition. In this study, the 6-DOF motion analysis program, PASEM, which was developed to predict the strap-on booster separation, is modified to simulate the pivotal motion of the fairings at early stages of separation. The accuracy of pivot motion simulation is validated by comparison with the results of ground test and the accurate separation conditions are deduced from it. Trajectory simulations are performed to see if separation without collision is possible with varying angle of attack, direction of gravity, and the effect of gust. It is also found that reducing the separation angle of the clamshell hinge from 60 degrees to 40 degrees can enhance separation safety and separation at lower altitude of 40km can be done without collision.