• Membrane Journal
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• v.12 no.1
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• pp.21-27
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• 2002

The formation of soluble microbial products(SMP) and molecular weight distribution on loading rate were observed in batch-type culture medium, which phenol was fed as a substrate. The molecular weight destribution was obtained by using 30K, 100K dalton and $0.45{\mu}$ membrane filters. When the phenol concentrationas a substrate was 120, 230 and 440 mg/L , the specific substrate utilization rate(q) showed 0.639, 1.281 and 1.744 mgTOC/mgMLSS/day, respectively. The endogenous biomass decay rate constant($K_d$) at each substrate concentration was 0.00536, 0.0661 and 0.0749($day^1$), respectively. The $SMP_e$ product rate constant($k_{SMP}_ e$) showed 0.006, 0.0058 and 0.0057($day^1$), respectively. The initial influent substrate during the course of time degraded and produced $SMP_s$. The $SMP_s$ was converted to the $SMP_{nd}$ and endogenous phase converted to the $SMP_e$ ingredients. The molecula weight distribution on loading rate was converted to a higher MW during the course of time.

• 전자공학회논문지 IE
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• v.49 no.1
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• pp.7-11
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• 2012

In this paper, evaluation of physical properties about dielectric relaxation phenomena by the detection of the surface pressures and displacements current on the monolayer films of phospolipid monomolecular DMPC using pressure stimulus. As a result, It is found that the phospolipid monolayer of dielectric relaxation takes a little time and depend on the molecular area. When electric bias is applied across the manufactured MIM device by the deposition condition of phospolipid monomolecular, it is found that be characteristic of insulation generated it wasn't breakdown when the higher electric field to impress by increase of deposition layers.

• KSBB Journal
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• v.11 no.6
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• pp.630-635
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• 1996

Blood plasma proteins dissolved in isotonic phosphate-buffered saline were found to be adsorbed to red blood cell ghosts suspended in the solution. This was evidenced by concentration reduction of the plasma proteins in the bulk solution. For initial concentration of 0.1mg/mL immuno globulin, concentration reduction increased from 14% to 45% as the volume fraction of red blood cell ghosts in the solution increased from 5% to 45%. For initial concentration of 0.075mg/mL albumin, the concentration reduction increased from 12% to 47% as the volume fraction of red blood cell ghosts in the solution increased from 5% to 70%. The concentration reduction of plasma proteins in hardened red blood cell ghosts was higher than that in red blood cell ghosts. The number of adsorbed protein molecules per a red blood cell ghost were reduced as volume fraction of the ghosts in the solution increased.

• Membrane Journal
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• v.17 no.1
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• pp.67-79
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• 2007

Uniform microcapsules containing ionic model drugs were prepared by controlling various conditions of emulsification procedure using a lab-scale membrane emulsification system with a SPG (Shirasu porous glass) tubular membrane. We observed the effects of various emulsification parameters [concentration and molecular weight of polycaprolatone (PCL) polymer, transmembrane pressure and emulsifier concentration in disperse phase and continuous phase, stirring speed] on the mean size and size ditribution of microcapsules containing lidocaine hydrochloride (cationic drug), sodium salicylate (nonionic drug) and 4-acetaminophen (anionic drug) used as a model drugs. Also, release characteristics of a model drugs from PCL microcapsules were investigated. Controlling membrane emulsification parameters, uniform PCL microcapsules with about $5\;{\mu}m$ of the mean size were finally prepared. The release rate and the burst effect of microcapsules were decreased in condition of the acidic solution, but it was increased in condition of the base solution.

• 전자공학회논문지 IE
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• v.43 no.4
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• pp.99-104
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• 2006

The Langmuir-Blodgett(LB) technique has attracted considerable interest in the fabrication of electrical and electronic devices. Maxwell displacement current (MDC) measurement has been employed to study the dielectric property of Langmuir-films. MDC flowing across monolayers is analyzed using a rod-like molecular model. A linear relationship between the monolayer compression speed u and the molecular area Am. Compression speed a was about 30, 40, 50mm/min. Langmuir-Blodgett(LB)layers of Arachidic acid deposited by LB method were deposited onto slide glass as Y-type film. The structure of manufactured device is Au/Arachidic acid/Al, the number of accumulated layers are 9$\sim$21. Also, we then examined of the Metal-Insulator-Metal(MIM) device by means of I-V. The I-V characteristics of the device are measured from -3 to +3[V]. The insulation property of a thin film is better as the distance between electrodes is larger.

• Journal of the Korean Applied Science and Technology
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• v.27 no.2
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• pp.202-207
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• 2010

We investigated the electrochemical properties for Langmuir-Blodgett(LB) films mixed with l-bromotetradecane(Cl4), l-bromohexadecane(Cl6), and l-bromooctadecane(Cl8). The alkyl bromides mixture was deposited by using the Langmuir-Blodgett method on the ITO glass. The electrochemical properties measured by using cyclic voltammetry with a three-electrode system(an Ag/AgCl reference electrode, a platinum wire counter electrode and LB film-coated ITO working electrode) at various concentrations(0.5, 1.0, 1.5 and 2.0 N) of $NaClO_4$ solution. A measuring range was reduced from initial potential to -1350 m V, continuously oxidized to 1650 mV. The scan rate was 100 mV/s. As a result, LB films of Cl4, Cl6, and Cl8 mixture monolayers appeared irreversible process caused by only the oxidation current from the cyclic voltammogram. The diffusivity(D) effect of LB films decreased with increasing of alkyl bromides amount.

• Electrical & Electronic Materials
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• v.9 no.7
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• pp.674-679
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• 1996

Using the home made Kuhn type LB (Langmuir - Blodgett) film's deposition apparatus, We measured the displacement current of monolayer film on the water surface. The obtained displacement current had each different pattern by the kind of solution while varying pressure of the monolayer. Solution of 4 - octyl - 4' - (5 - carboxyl - pentamethyleneoxy ) - azobenzene (8A5H) and stearic acid (CH$_{3}$(CH$_{2}$)$_{16}$COOH) (C18) were spreaded at the air water interface respectively, and the current induced by the dynamic behavior of molecules were pressed by barrier. Displacement current of 8A5H measured small current than C18 at same condition and it was positive direction when increasing pressure but it was negative direction when decreasing pressure. Also, Two patterns of displacement current were symmetrical form and appeared repeatedly. The C18 has unsymmetrical form of displacement current and weak current when decreasing pressure (expansion). The C18 molecules have two distinct peak values of displacement current that show that the orientations of molecules were changed largely at this points. From these results, we obtained that the 8A5H has more elasticity than the C18.8.C18.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.943-946
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• 2004

We have investigated to observe the photoisomerization using the mixture solutions in chloroform and LB monolayers mixed with DPPA and BASH containing azobenzene group which has reversible to cis-trans by light irradiation.. Spreading solutions for the LB films were Prepared in chloroform($5.0{\times}10^{-5}mol/L$). We investigated the photoisomerization and property of the organic ultra thin film of fatty acid containing azobenzene was Prepared on the glass plate by LB method. As a result, the absorption spectra of 8A5H and DPPA mixture of LB films was induced to photoisomerization by alternating irradiation of ultraviolet and visible light, because the condensation of pure azobenzene monolayers was loosened by the introduction of phospholipid into the monolayers, and the molecular high aggregation in pure azobenzene monolayers is also weakened by the introduction of phospholipid. We found that it was reversibly induced to cis-trans photoisomerization in a various mixture molar ratio.

• Journal of the Korean Applied Science and Technology
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• v.29 no.3
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• pp.421-428
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• 2012

We investigated an electrochemical properties for Langmuir-Blodgett (LB) nano-films of polyimide and phospholipid mixture. LB films of polyamic acid and phospholipid monolayer were deposited by the Langmuir-Blodgett method on the indium tin oxide(ITO) glass. The electrochemical properties measured by cyclic voltammetry with three-electrode system(an Ag/AgCl reference electrode, a platinum wire counter electrode and LB film-coated ITO working electrode) in $KClO_4$ solution. The current of reduction and oxidation range was measured from 1650 mV to -1350 mV, continuously. The scan rates were 50, 100, 150, 200 and 250 mV/s, respectively. As a result, monolayer LB films of polyamic acid and phospholipid mixture was appeared on irreversible process caused by the reduction current from the cyclic voltammogram. Diffusion coefficient (D) effect in the polyamic acid and phospholipid mixture was used in the LAPC with LLPC fewer than the diffusion coefficient values.

• Journal of the Korean Applied Science and Technology
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• v.28 no.2
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• pp.213-218
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• 2011

Displacement current measuring technique has been applied on the study of polyamic acid monolayer containing p-nitroazobenzene. The displacement current was generated from monolayer on the water surface by monolayer compression and expansion. Maxwell displacement current(MDC) was generated when the area per molecule was about $200{\AA}^2$ and $70{\AA}^2$. Maxwell displacement currents were investigated in connection with monolayer compression cycles. It was found that the maximum of MDC appeared at the molecular area just before the initial rise of surface pressure in compression cycles. The monolayer surface morphology of the LB film have been measured by Atomic Force Microscope(AFM). As a result, we confirmed that the microscopic properties of LB film by AFM showed the good orientation of monolayer molecules and the thickness of monolayer was 3.5-4.1nm.