• Journal of the Korean Chemical Society
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• v.54 no.1
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• pp.93-98
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• 2010

In this work, the electrochemical properties of surface treated multi-walled carbon nanotubes (MWNTs) were studied. Nitrogen and oxygen functional groups of the MWNTs were introduced by urea and acidic treatment, respectively. The surface functional groups of the MWNTs were confirmed by X-ray photoelectron spectroscopy (XPS) measurements and zeta-potential method. The characteristics of $N_2$ adsorption isotherm at 77 K, specific surface area, and total pore volumes were investigated by BET eqaution, BJH method and t-plot method. Electrochemical properties of the functionalized MWNTs were accumulated by cyclic voltammetry at the scan rates of 50 $mVs^{-1}$ and 100 $mVs^{-1}$ in 1M $H_2SO_4$ as electrolytes. As a result, the functionalized MWNTs led to an increase of capacitance as compared with pristine MWNTs. It was found that the increase of capacitance for urea treated MWNTs was attributed to the increase in density of surface functional groups, resulting in improving the wettability between electrode materials and charge species.

• Journal of the Microelectronics and Packaging Society
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• v.10 no.4
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• pp.35-38
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• 2003

Polymer light emitting diode (PLED) with an ITO/MEH-PPV/Al structure were prepared by spin coating method on the ITO (indium tin oxide)/glass substrates, using poly(2-methoxy-5-(2-ethylhexoxy)-1,4-phenylenevinylene (MEH-PPV) as the light emitting material. The dependence of heat treatment on the electrical and optical properties for the prepared PLED samples were investigated. The luminance decreased greatly from 630 cd/$\m^2$ to 280 cd/$\m^2$ at 10V input voltage as the heating temperature increased from $65^{\circ}C$ to $170^{\circ}C$. In addition, the luminance efficiency was found to be about 2 lm/W for the sample heat treated at $65^{\circ}C$. These results may be related to the interface roughness and/or the formation of an insulation layer, which is caused by the reaction between electrode and MEH-PPV organic luminescent film layer.

• Applied Chemistry for Engineering
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• v.10 no.1
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• pp.80-84
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• 1999

$Li_{4/3}Mn_{5/3}O_4$ having a defect structure was prepared by sol-gel process using lithium acetate and manganese acetate as starting materials, and their electrode characteristics in the lithium secondary battery was investigated. The reaction mole ratio was determined as $AA/Mn(OAc)_2$ of 0.2 and $NH_4OH/Mn(OAc)_2$ to $H_2O/Mn(OAc)_2$ of 0.4. The product was obtained through heat treatment at $350^{\circ}C$ for 12hrs after 1'st heat treatment at $150^{\circ}C$ of xerogel under oxygen atmosphere. When the charge and discharge cycles were performed between 2.0 V and 3.2 V, $Li/Li_{4/3}Mn_{5/3}O_4$ cell showed the dicharge capacity of 84.23 mAh/g and the good cycleability was obtained in the plateau region.

• Textile Coloration and Finishing
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• v.1 no.1
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• pp.7-18
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• 1989

The distinguishing characteristic of the glow discharge is that chemical reaction induced by partially ionized gases are limited only to the substrate surface. Most studies have been done on the plasma etching and polymerization. The graft polymerization in vapour phase by cold plasma has been rarely investigated. In this study the system of tub3ar reaction chamber with capacitively coupled electrode of alternative current of 60 Hz was employed for the graft polymerization. The graft polymerization of Acylic Acid(AA) onto the poly (ethylene terephthalate) (PET) was carried out by treatment of PET film and fabric by cold plasma (glow discharge of argon gas), followed by the supply of AA vapour. The graft yield was about 1 wt%. The surface property was determined by contact angle, the surface tension was evaluated by zisman’s plot and equation of surface tension mesurement. The results were as follows: 1. In order to obtain lower contact angle, it was effective to avoid the vicinity of electrodes for a setting position of substrate. 2. Contact angle affected on the monomer pressure and its duration of exposure to the acid vapour. 3. Polymer radical formation was influenced by the changes of the value of current density and plasma treatment time. 4. Total surface tension of plasma grafted PET film increased. With an increase in the carboxylic acid content, the dispersion force decreased, while, the polar force and hydrogen bonding force increased. 5. The contact angle decreased from $75^\circ$ to around $30^\circ$ by plasma grafting. There was no ageing effect on the contact angle after 4 months.

• Journal of Microbiology and Biotechnology
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• v.14 no.6
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• pp.1120-1128
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• 2004

The SCBFC was composed of bilayered cathode, the outside of which was modified with $Fe^{3+}$ (graphite-Fe(III) cathode) and the inside of which was porcelain membrane, and of an anode which was modified with $Mn^{4+}$ (graphite­Mn(lV) anode). The graphite-Fe(III), graphite-Mn(IV), and porcelain membrane were designed to have micropores. The outside of the cathode was exposed to the atmosphere and the inside was contacted with porcelain membrane. In all SCBFCS the graphite-Fe(III) was used as a cathode, and graphite-Mn(IV) and normal graphite were used as anodes, for comparison of the function between normal graphite and graphite-Mn(IV) anode. The potential difference between graphite-Mn(IV) anode and graphite-Fe(III) cathode was about 0.3 volt, which is the source for the electron driving force from anode to cathode. In chemical fuel cells composed of the graphite-Mn(IV) anode and graphite-Fe(III) cathode, a current of maximal 13 mA was produced coupled to oxidation of NADH to $NAD^{+}$ the current was not produced in SCBFC with normal graphite anode. When growing and resting cells of E. coli were applied to the SCBFC with graphite-Mn(IV) anode, the electricity production and substrate consumption were 6 to 7 times higher than in the SCBFC with normal graphite anode, and when we applied anaerobic sewage sludge to SCBFC with graphite-Mn(IV) anode, the electricity production and substrate consumption were 3 to 5 times higher than in the SCBFC with normal graphite anode. These results suggest that useful electric energy might possibly be produced from SCBFC without electron mediators, electrode-active bacteria, and extra energy consumption for the aeration of catholyte, but with wastewater as a fuel.

• The Korean Journal of Pain
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• v.18 no.2
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• pp.240-245
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• 2005

Herein is described the successful treatment of complex regional pain syndrome type II with the combination treatment of spinal cord stimulation and radiofrequency thermocoagulation of the lumbar sympathetic ganglion. A 62 years old male patient, suffering from CRPS type II in his left lower extremity, visited our pain clinic. Medication and nerve blockade produced only slight improvement in his symptoms and signs. Therefore, a linear type spinal cord simulator was inserted into the thoracic epidural space, using a non-surgical percutaneous approach, with the cephalad lead located at the T11 level. Two months later, the repositioning of the electrode to the T12 level for more effective pain control, with radiofrequency thermocoagulation of lumbar sympathetic ganglion also performed at the left L2 and 3 levels for the control of trophic change. These resulted in significant pain relief and decreased trophic change, with no complications, after which the patient was able to resume a normal life.

• Journal of the Korean Society for Heat Treatment
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• v.23 no.1
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• pp.23-28
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• 2010

The cylindrical magnetron sputtering has not been widely used, although this system is useful for only certain types of applications such as fiber coatings. This paper presents electrode configurations which improved the complicacy of the target assembly by using the positive voltage power supply. It is a modified type which has a target constructed with a large cylindrical part, a conical part and a small cylindrical part. When positive voltage was applied to an anode, a stable glow discharge was established and a high deposition rate was obtained. The substrate bias current was monitored to estimate the effect of ion bombardment. As a result, it was found that the substrate current was large. With cylindrical and conical cathode magnetron sputter deposition on the surface of the substrate to prevent re-sputtering, ion impact because it can increase the effectiveness with excellent ductility and adhesion of Ti film deposition can be obtained. We board at the front end of the ground resistance of $5\;k{\Omega}$ attached to the substrate potential can be controlled easily, and Ti film deposition with excellent adhesion can be obtained. Microstructure and morphology of Ti films deposited on pure Cu wires were investigated by scanning electron microscopy in relation to preparation conditions. High level ion bombardment was found to be effective in obtaining a good adhesion for Cu wire coatings.

• Journal of Soil and Groundwater Environment
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• v.7 no.3
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• pp.79-84
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• 2002

The optimal operation conditions, including voltage applied, reaction time, distance between electrodes. and electrode material. were investigated for the treatment of soil flushing effluent using electrofloatation. When 3V was applied for 1 hour, 88% oil-water separation efficiency was achieved. In case of 6V and above, 90% efficiencies were achieved. As reaction time and distance between electrodes were longer, separation efficiencies were higher and lower, respectively. Separation efficiencies for different anode materials were copper > aluminum > iron > titanium. It might result from the differences of their electrical conductivities.

• Journal of the Korean Ceramic Society
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• v.41 no.3
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• pp.183-189
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• 2004

Cuprous oxide (Cu$_2$O) thin films are cathodically deposited on Indium Tin Oxide (ITO) substrate. The as-deposited films were heat-treated at 30$0^{\circ}C$ to obtain Cu$_2$O. After the heat treatment, the film was changed from Cu metal into Cu$_2$O phase. The phase, morphology and photocurrent density of the films were dependent on the preparation conditions of deposition time, applied voltage, and the duration of heat treatment. The Cu$_2$O films were characterized by X-Ray Diffractometer (XRD) and Scanning Electron Microscope (SEM). The apparent grain size of the films formed by the normal method was larger than those grown by the pulse method. The CU$_2$O film what was deposited at -0.7 V for 300 sec and then, calcined at 30$0^{\circ}C$ for 1 h showed the predominant photocurrent density of 1048 $\mu$A/$\textrm{cm}^2$. And the stability of Cu$_2$O electrodes were improved with chemically deposited TiO$_2$ thin films on Cu$_2$O.

• Journal of Korean Neurosurgical Society
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• v.37 no.2
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• pp.105-111
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• 2005

Objective: Tremor, either essential tremor or Parkinsonian tremor, has been effectively and safely treated by lesioning the ventral intermediate(Vim) nucleus of the thalamus with or without mircroelectrode recording. The authors evaluate the treatment outcome of sixteen tremor patients who had been treated with thalamotomy without microelectrode. Methods: Between September, 2001, and December, 2003, sixteen tremor patients were treated with thalamotomy without microelectrode recording. Twelve patients suffered from Parkinsonian tremor and four patients were essential tremor patients. The male to female ratio was 1.6 to 1 with median age of 59.6 years (range; 39-74 years). Under local anesthesia, a 3mm hole was made using a hand-held twist drill, and the dura mater was penetrated with a 1.2mm sharp drill beat. Radiofrequency(RF) electrode was placed in the Vim nucleus of thalamus. With intraoperative macrostimulation, RF lesion was made. Postoperative CT scan and/or MR imaging was performed to confirm the localization of the target lesioned. Preoperative and postoperative tremor was evaluated with simple tremor severity scale and the development of complications related with the procedure was closely reviewed at the immediate postoperative period and the last follow-up. Results: It produces immediate relief in up to 98.4% of the patients. There were no development of complications related with procedure, all patients discharged one or two days after surgery. Conclusion: Vim thalamotomy without microelectrode recording is a safe and effective procedure to control the tremor with minimal morbidity. Intraoperative macroelectrode stimulation safely localizes the Vim nucleus target of the thalamus for the treatment of patients with tremor.