• KSBB Journal
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• v.30 no.4
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• pp.197-201
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• 2015

Liquid chromatographic enantiomer separation of ${\alpha}$-amino acids and their methyl and ethyl esters as fluorenylmethoxycarbonyl (FMOC) derivatives was performed using a recently developed chiral column (Chiralpak IE) based on polysaccharide derivative under simultaneous UV detection and fluorescence detection. The degree of enantiomer separation of ${\alpha}$-amino acid esters as FMOC derivatives is generally higher than that of the corresponding ${\alpha}$-amino acids. Especially, ${\alpha}$-amino acid methyl esters showed the greatest enantioseparation. As this method developed in this study can be applied to determine the chemical and optical purity of ${\alpha}$-amino acids and esters, it is expected to be quite useful for their chiral separation using Chiralpak IE.

• Bulletin of the Korean Chemical Society
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• v.13 no.3
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• pp.280-285
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• 1992

Enantiomeric separation of free amino acids has been achieved by a reversed phase liquid chromatography with addition of a Cu(Ⅱ) complex of N-alkyl-L-proline (alkyl: propyl, pentyl or octyl) to the mobile phase. The amino acids eluted were detected by a postcolumn OPA system. N-alkyl-L-proline was prepared and used as a chiral ligand of Cu(Ⅱ) chelate for the enantiomeric separation. The concentration of the Cu(Ⅱ) chelate, the organic modifier and pH affect the enantiomeric separation of free amino acids. The retention behaviour, varied with change in pH and the concentration of the Cu(Ⅱ) chelate, was different compared with those of the derivatized amino acids. The elution orders between D- and L-forms were consistent except histidine showing that L-forms elute earlier than D-forms. The retention mechanism for the enantiomeric separation can be illustrated by the stereospecificity of the ligand exchange reaction and the hydrophobic interaction between the substituent of amino acids and reversed phase, $C_18$.

• Journal of Animal Environmental Science
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• v.6 no.3
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• pp.185-190
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• 2000

TAO system and solid-liquid separation (28mesh filter and 200mesh filter) were applied in processing piggery slurry to see the reduction of N and P and to draw the efficiency in reducing manure application area. The results are as follows; 1. The amount of N and P in slurry of $4.6m^3/day$ was 22.5kg/day ($4,893mg/{\ell}$) and 7.32kg/day ($1,592mg/{\ell}$). 2. Reduction rate of N and P by TAO reactor was 9.9 kg/day (46.0%) and 3.47kg/day(34.0%). 3. Reduction rate of N and P by Solid-liquid separation was 10.5kg/day (46.6%) and 5.12kg/day (69.8%). 4. One the basis of the amount of nitrogen composting, the square size of liquid manure sprinkled area was reduced from 74.6ha/y to 39.0ha/y in rice paddy, and from 63.2ha/y to 33.0ha/y by the treatment.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.273-276
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• 2003

Polymerization induced diffusion has been successfully applied to create new display components. Based on this principle a new technique to produce polymer covered liquid crystal layers on a single substrate, called photo-enforced stratification, allows cost-effective production of ultra-thin LCDs. The two-step photopolymerization-induced phase separation of a liquid crystal and a polymer precursor can be performed on a variety of substrates and provides freedom in display design.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.611-614
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• 2003

We have investigated electric field effect on the formation of phase separated composite organic film structure which is utilized by anisotropic phase separation from LC and prepolymer mixtures. Application of bias field resulted in a significant change in liquid crystal alignment between glass substrate and polymer layer. The liquid crystal molecules segregated into the inter-electrodes and formed twisted structure which is the result of imprinting of LC alignment by the bias field on polymer layers during polymerization process.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.166-168
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• 2009

We proposed a transflective liquid crystal display (LCD) with high aperture ratio using an electrophoretic particle layer (EPL). The transflective LCD consisted of the stacked LC layer and EPL which was acted as a switchable mirror under in-plane electrode structure. Without separation of reflective part and transmissive part in one pixel, a modeselectable display device can be obtained.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.642-644
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• 1999

We have prepared the plasma-polymerized membrane for pervaporation of organic-liquid mixtures by the plasma polymerization technique. Plasma polymerization techniques were utilized in the development of hydrophilic composite membranes having high hydrogen ion permeability and excellent dimensional stability. To develop an organic liquid permselective Membrane, suppressing membrane swearing as well as enhancing the solubility difference is impotant. the objectives of the present study are to disign a suitable membrane for an organic-mixture system by the control of the plasma-polymer solubility.

• Analytical Science and Technology
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• v.6 no.3
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• pp.267-274
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• 1993

The iterative regression optimization strategy using two parameters is described and applied to the separation of amino acids and peptides by means of micellar liquid chromatography. The parameters examined are concentration of surfactant and 2-propanol. This approach results in a efficient optimization using a small number of initial experiments.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.655-659
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• 2001

Resident time of the continuous and Instantaneous centrifugal separator using that separates the light and heavy liquids by use of density difference is the orptical factor that affects significantly the chemical metial extraction and the productivity in the chemical and mechanical process. In this paper, the overflow of the device is investigated under consideration of the relationships between inclination angle of liquid feeding screw and the centrifugal force. From the design of the length of a centrifugal separator, the radiuses of rotor and housing, theoretical formulation on the contact radius of separation weir is established through the experiments. From the experiments, it is identified that how much the capacity of inlet impeller and the emulsion phenomenon depend on the screw angle of inlet impeller. Also, we investigate the separation condition and the resident times that are functions of the phase ratio and density.

• Journal of the Korean Applied Science and Technology
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• v.6 no.1
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• pp.27-30
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• 1989

The fast separation and determination of cefatrizine${\cdot}$propylene glycol and inmpurities - TACA: 7-amino-3-(1,2,3-triazol-4-yl)thiomethyl-3-cephem-4-carboxylic acid and 7-ACA; 7-amino cephalosporanic acid - was performed by the high poerformance liquid chromatography using octadecyl siland (ODS) column. Methanol and ammonium phosphate buffer [$0.03M(NH_4)_2\;HPO_4$, (pH 7.5)] was used analyze, as eluent. The experimental value of the contents of cefatrizine${\cdot}$propylene glycol and impurities agree with the theoretical value of those.