• Korean Chemical Engineering Research
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• v.49 no.6
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• pp.704-709
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• 2011

Depolymerization of fucoidan induced by contact glow discharge electrolysis(CGDE) was investigated. To utilize fucoidan as a functional food material after CGDE, organic acids were used as a electrolyte in CGDE process. Experimental results showed that CGDE using organic acid reduced the molecular weight of fucoidan effectively. As electrolyte concentration increased, onset voltage of glow discharge decreased and onset current of glow discharge increased. From the variation of molecular weight of fucoidan with the reaction time, it was demonstrated that the degradation of fucoidan followed a first-order rate law. Molecular weight of fucoidan treated with CGDE using organic acid was about 77 times lower compared to initial fucoidan with little free sulfate.

• Journal of Sensor Science and Technology
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• v.7 no.4
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• pp.243-253
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• 1998

PVC membrane, which has been used for membrane of electrolyte sensors, shortened sensor lifetime due to poor adhesion to sensor surface and exhibited difficulty in standardization and mass-production. To overcome these problems, the membrane solution was prepared with neutral carrier, matrix(TEOS:DEDMS=1:3), solvent(ethanol), and a catalyzer(HCl). The fabricated electrolyte sensors showed typical electrical characteristics of MISFET (metal-insulator-semiconductor field-effect transistor). The K-, Ca- and Na-ISFETs showed sensitivity of 53, 25 and 50 mV/decade in wide concentration range, respectively. The response time was about 90 seconds and the drift was 0.05mV/hour. These results suggest that the sol-gel method and the lift-off technique can be applied to formation of membranes and expected to improve mass-productivity, standardzation of the sensors.

• Resources Recycling
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• v.10 no.4
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• pp.18-23
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• 2001

Air pollutants, phenol was generated in case of thermal regeneration of used activated carbon loaded with phenol and because of this problem, removal process of phenol were studied. Electrolytic oxidation of samples, used S.company granular activated carbon (WS-GAC), used C.company granular activated carbon (WC-GAC) and used L.company granular activated carbon (WL-GAC) loaded with phenol carried out by potentiostatic method in this study. In case of experiment was to come into operation in condition of samples containing 100 mg/g phenol, supporting electrolyte was 1.0% sodium chloride solution, Ti-Ir (10$\times$10$\textrm{cm}^2$) electrode and electrode distance was 2 cm, current density was $1.25 A/dm^2$, Obtained from the results of electrolytic oxidation experiments were not detected residual phenol. And then we knew about reaction time of electrolytic oxidation, current density, concentration of supporting electrolyte and electrode and electrode distance were 60 minutes, 1.25 A/dm$^2$, 1.0%, 2 cm.

• Korean Journal of Ecology and Environment
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• v.41 no.1
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• pp.66-72
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• 2008

Total metals, soluble metals, and bioavailable metals were monitored at the sediments of urban lakes located in Seoul, Korea during spring season 2006. The metals measured were zinc, arsenic, chromium, copper, nickel, and cadmium, which are known to be toxic to human health and ecosystems. The main sources of heavy metals in the lakes were urban runoff and atmospheric deposition associated with air pollution in urban areas. Extraction by using a weak electrolyte solution (0.1 M $Ca(NO_3)_2$) was used to predict bioavailability of the metals. Among the six heavy metals studied, copper was the most bioavailable, based the weak electrolyte extraction techniques. Since metal toxicity is related to metal bioavailability, the results were consistent with the high ecotoxicity of copper, compared to other heavy metals. Overall results suggest that there was no direct relationship between total and bioavailable metal concentration, although zinc, copper and cadmium show some relationships.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.2
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• pp.185-189
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• 2010

This study considered the feasibility of controlling the air concentration by oscillating flow in fuel cell channels. The fuel cell stack performance is largely influenced by the air concentration. If the air concentration is lower than 2.5 times the stoichiometric of the inlet air, the fuel cell stack performance seriously deteriorates because of air starvation. In this respect, optimizing the air concentration is crucially important to maximizing the fuel cell stack performance. In this work, the effects of oscillating actuation were studied to control the concentration. Studies have shown that there are two non-dimensional key parameters related to the frequency and oscillating amplitude. This paper presents how those parameters affect the performance of the stack.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.12
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• pp.1297-1303
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• 2015

The internal chromium plating of a long-axis tube is widely used in military and industrial application, with the thick hard plating formed using a mixed solution of Chromium acid and catalytic $H_2SO_4$. A large-caliber gun can endure a high explosive force as a result of the increased stiffness and wear resistance provided by this internal hard chromium surface. The internal chromium layer of a tube is prone to exfoliation caused by the high kinetic energy of the projectile and high pressure of the explosion. Therefore, we reviewed the plating process. Chromium plating comprises many steps, including the removal of Grease, water cleaning, electrolytic abrasion, etching, plating, water cleaning, and hydrogen brittleness removal. The exfoliated chromium plating layer is affected by the adhesion property of the plating. In particular, the Fe concentration of the electrolyte affects the adhesion property. The optimum Fe concentration for effectively suppressing the exfoliation of the plating layer was established by using a scanning electron microscope to determine the surface roughness, and the effectiveness was proved in an adhesion test, etc.

• Journal of Veterinary Clinics
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• v.9 no.1
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• pp.333-366
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• 1992

Safety of recombinant porcine somatotropin administration on pig was studied using 32 Landrace x Yorkshire crossbred pigs. The starting body weight ranged from 55.5kg to 65.3kg. Eight pigs were allotted to each low dose group of sustained releasing rPST(SL), high dose group of sustained releasing rPST(SH), daily injection group of rPST(DI), and control group(C). Pigs in SL group and SH group were injected subcutaneously twice in 3 week-interval with 1000$\mu\textrm{g}$ and 2000$\mu\textrm{g}$ of sustained releasing rPST per kg body weight, respectively. Pigs in DI group were injected intramuscularly with 100$\mu\textrm{g}$ of rPST everyday for 6 weeks. Blood was collected from anterior vena cava just before the first treatment, and at four weeks and six weeks of experiment. Hematological parameters and blood chemical parameters indicating liver function, kidney function, electrolyte metabolism, mineral metabolism and lipid metabolism were determined. Necropsy and urinalysis were performed after final blood collection. The results were summarized as follows, and it is concluded that rPST administration does not affect pig health negatively. 1. rPST administration did not affect kidney function as manisfested by BUN, creatinine and urinalysis. 2. rPST administration did not affect liver function as manisfested by total protein, albumin, serum AST activity serum ALT activity serum ALP activity, serum LDH activity, serum GGT activity and serum SDH activity. 3. rPST administration did not affect skeletal muscle, cardiac muscle and brain as manifasted by serum AST activity and serum LDH activity. 4. rPST administration increased blood glucose level within normal range. 5. rPST administration did not affect lipid metabolism as manisfested by triglyceride, cholesterol, and phospholipid concentrati on. 6. rPst administration dia not affect mineral metabolism as manisfested by calcium, phosphorus, magnesium and iron concentration. 7. rPST administration did not affect electrolyte metabolism as manisfested by Na, K, chloride concentration. 8. rPST administration did not affect erythrocyte count, leukocyte count, thrombocyte count, and plasma fibrinogen level.

• Membrane Journal
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• v.17 no.1
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• pp.37-43
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• 2007

The effect of anionic and cationic exchange polymer layer on the chronopotentiometry (CP) and current voltage curves (I-V) of charged composite membrane are investigated. Also, the ion transport near the interface between electrolyte and ionic exchange polymer membranes (anionic and cationic ones) and charged mosaic polymer composite membrane is studied. The results show that both anionic and cationic polymer exchange membranes exhibit lower voltage drop over range of applied current density and possess favorable industrial application potentials, especially at low KCl concentration. While the charged mosaic polymer composite membrane didn't show any current-voltage change, irrespective to the type and the concentration of used electrolyte. CP and I-V measurements are effectively used to give some fundamental understanding for ion transport behavior of ion exchange polymer membrane near the interlace.

• Polymer(Korea)
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• v.34 no.6
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• pp.511-516
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• 2010

The electrochemical coating of poly(3-octylthiophene) on carbon materials was studied in order to investigate the application possibility of the modified carbon materials in the photoelectronic devices. Commercial carbon paper and carbon fiber were used as substrate electrodes for electrochemical coating. The coating behaviors were analysed with the variation of monomer and electrolyte concentration, applied potential, and cycling number in cyclovoltammetry. The coating rate of poly(3-octylthiophene) formed on the substrate were proportional to the monomer and electrolyte concentration, applied potential, and cycling number with each independent exponent. The structure and morphology of electrochemically polymerized poly(3-octylthiophene) was investigated with scanning electron microscopy and FTIR reflectance measurement.

• Journal of the Korean Society of Industry Convergence
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• v.3 no.2
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• pp.155-166
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• 2000

In order to elucidate the interrelationship between electrolytes and exercise the investigation was undertaken to determine the electrolyte levels in young males took on varied environmental temperatures ($13^{\circ}C$, $24^{\circ}C$ or $34^{\circ}C$). 10 healthy young males were used for the experiments. Our results showed the following significant changes; 1. The raising of the environmental temperature, the weight reduction were increased due to marked sweating. 2. In the electrolytes of serum, decreased the $K^+$ concentration at $13^{\circ}C$, but increased the $Na^+$ or $Cl^-$ concentration at $24^{\circ}C$, and increased the $Na^+$ or $Cl^-$, or $Mg^{+}^{+}$ concentrations at $34^{\circ}C$. 3. The raising of environmental temperature appear to be increased PRA,Ang I, Ang II and ALD levels, whereas no changed ADH level. 4. Serum levels of PRA, Ang I, Ang II and ALD were incresed after exercise, and their increments were incresed paralel ttie incresed environmental temperature. However, there no significant change in ADH, level. In conclusion, exercise induced not only changes of serum electrolytes levels such as $Na^+$, $Cl^-$, $K^+$, $Mg^{+}^{+}$, but also serum hormonal changes such as PRA, Ang I, Ang II, ALD. However, ADH level was not changed significantly, These changes were more prominent in exercise at hot temperature than in lower temperature.