• 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.

• The Journal of Korean Medicine
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• v.30 no.3
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• pp.70-78
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• 2009

Objectives : This study was aimed at examining the effects of the application of EA (electroacupuncture) at GV20 and LI4 in the early cerebral ischemia on the size of cerebral infarction, COX-2 and IL-6. Methods : For this experiment, 21, six-week-old male S-D (Sprague - Dawley) rats weighting 160g to 200g were selected and randomly classified into 3 groups, seven rats in each group. Brain ischemia was simulated using a modified Koizumi method which was performed on each rat. In the GV20 group, the GV20 of the SD rats was stimulated for thirty minutes with acupunctural electrode low frequency stimulator five hours after inducement of ischemia. For the LI4 group, the LI4 was stimulated as above, while for the Ischemia group, no stimulation was applied. Twenty-four hours after the experiment, stained cerebral tissues were examined and an immuno-histological test was done to examine inflammatory reaction Results : Out of the three groups, the LI4 group showed the smallest size of cerebral infarction and the Ischemia group showed the highest COX-2 (cyclooxygenase-2) expression value in the cortex of the cerebrum. In addition, the LI4 group showed the lowest COX-2 expression value in unknown putamen out of the three groups. Conclusions : We infer that EA, applied at LI4 and GV20 in early ischemia, is effective in delaying the expression of IL-6 (interleukin-6) and COX-2, the inflammatory agents manifested from stroke. In addition, application at LI4, rather than GV20, can lower the expression value of the inflammatory agents. Further, EA can be an effective way to block early inflammatory reaction in stroke.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.12
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• pp.1077-1082
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• 2008

To fabricate a multi-layered piezoelectrics/electrodes structure, the piezoelectrics should be sintered at the temperature lower than $950^{\circ}C$ to use the silver electrode, which is cheaper than the electrodes containing noble metals such as Pd and Pt. Therefore, in this study, we modified the composition of $Pb(Zr,Ti)O_3$-based material as $(Pb_{0.98}Cd_{0.02})(Ni_{1/3}Nb_{2/3})_{0.25}Zr_{0.35}Ti_{0.4}O_3$ to lower the sintering temperature and to improve the piezoelectric properties. Small amount of $MnCO_3$, $SiO_2$, and $Pb_3O_4$ were also added to lower the sintering temperature of the ceramic. The prepared raw powders were mixed by using a ball mill for 24 hours. And then the mixed powders were calcinated for 2 hours at $800^{\circ}C$. The calcinated powders were again crushed with the ball mill for 72 hours. The final powders were pressed for making the shape of ${\emptyset}15\;mm$ disk. The disk-type samples were sintered at temperature range of $850{\sim}950^{\circ}C$. The crystal phases of the sintered specimens were perovskite structure without secondary phases. All of the measured electrical properties such as electromechanical coupling coefficients ($k_p$), mechanical quality factors ($Q_m$), and piezoelectric charge constants ($d_{33}$) were decreased with decreasing the sintering temperatures. The electrical properties measured at the sample sintered at $950^{\circ}C$ were 54% of $k_p$, 503 of $Q_m$, and 390 pC/N of $d_{33}$, respectively. These properties were considered to be fairly good for the application of multi-layered piezoelectric generators or actuators.

• The Korean Journal of Pain
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• v.18 no.2
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• pp.263-266
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• 2005

The ganglion impar is a solitary retroperitoneal structure at the caudal end of the paravertebral sympathetic chain. Block of this ganglion has been advocated as a means of managing intractable perineal pain. In 1990, Plancarte et al performed a neurolytic block of the ganglion impar using 4-6 ml of 10% phenol through the intergluteal skin over the anococcygeal ligament. However, technical difficulties are encountered with the placement of the needle while performing this technique, with complications from the injection of phenol also being a possibility. In 1995, a modified approach for blocking the ganglion impar through the sacrococcygeal ligament was introduced by Wemm and Saberski. We used a radiofrequency (RF) lesion generator to create a controlled and localized lesion with a lower incidence of neural damages compared to chemical neurolysis. RF thermocoagulation of the ganglion impar through the sacrococcygeal ligament was performed on a 70-year-old male patient with constant anal pain using a curved TEW electrode. The patient has been relieved of his pain, without serious complication. Therefore, this technique may be an easier and safer approach, which is associated with fewer chances of complications.

• 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 the Korean Crystal Growth and Crystal Technology
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• v.8 no.2
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• pp.221-226
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• 1998

Amorphous (Ba, Sr)$TiO_3$[BST] layer(30, 70 nm) was introduced between crystalline BST and $RuO_2$electrode to realize double-layered BST structure in order to improve the properties of BST film. The structure and surface morphology of double-layered BST film were modified by the application of amorphous BST layer; that is, surface became smoother and grain size increased abruptly. Amorphous layer thicker than 30 nm was effective to hinder the influence of $RuO_2$surface on the structure of as-grown BST films by in-situ process. Dielectric constant of double-layered BST film was improved dramatically from 152 to 340 and leakage current was lowered from $1.25{\times}10^{-5}A/{\textrm}{cm}^2);to;6.85{\times}10^{-7}A/{\textrm}{cm}^2$, respectively.

• Transactions of the Korean hydrogen and new energy society
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• v.7 no.1
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• pp.19-28
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• 1996

Ti-Mn based hydrogen storage alloy were modified by substituting alloying elements such as Zr, V and Ni in order to design a high capacity MH electrode for Ni/MH rechargeable battery. When V was substituted in Ti-Mn binary system, the crystal structure was maintained as $Cl_4$ Laves phase at a composition of $Ti_{0.2}V_{0.4}Mn_{0.4}$ and $Ti_{0.4}V_{0.2}Mn_{0.4}$ and equilibrium pressure decreased below 1 atm without decreasing hydrogen storage capacity considerably. It was found that Ni should be included in Ti-V-Mn alloy in order to hydrogenate it electrochemically in KOH electrolyte. But substitution of Ni for Mn in Ti-V-Mn system caused the increase of equilibrium pressure above 1atm and decrease of hydrogen storage capacity. Zr was able to increase the reversible hydrogen storage capacity of Ti-V-Mn-Ni alloy without considerable change of hydrogenation properties. The electrochemical discharge capacity of Ti-Zr-V-Mn-Ni system were in the range of 350 - 464mAh/g and among them $Ti_{0.8}Zr_{0.2}V_{0.5}Mn_{0.5}Ni_{1.0}$ alloy had $Cl_4$ Laves single phase and very high electrochemical discharge capacity of 464mAh/g.

• Journal of the korean academy of Pediatric Dentistry
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• v.43 no.3
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• pp.292-298
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• 2016

The aim of this study was to compare the compressive strength and amount of fluoride-release of recently developed giomers (Beautifil Flow Plus F00, Beautifil Flow Plus F03), conventional giomer, resin-modified glass ionomer and composite resin. Fifteen cylindrical specimens for each group were prepared to measure fluoride release. It was measured using pH/ISE meter and fluoride ion electrode every 24 hours for the first 7 days and every 72 hours until the 31st day. Also, fifteen cylindrical specimens for each group after thermocycling were prepared to measure compressive strength. The universal testing machine (Kyung-sung Testing Machine Co., Korea) was used and the crosshead speed was 1 mm/min. Recently developed giomers showed more fluoride release and higher compressive strength than conventional giomer. It would be a good alternative to composite resin.

• Korean Chemical Engineering Research
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• v.50 no.6
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• pp.1043-1048
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• 2012

In this study, activated carbons (ACs) were modified as electrode materials for an electric double layer capacitor (EDLC) by controlling oxygen- and nitrogen-containing functional groups. The morphological and chemical properties of ACs were analyzed through scanning electron microscopy (SEM), fourier transform infrared (FTIR) spectrometer, automatic elemental analyzer (EA) and Boehm titration. Also, charge/discharge tests were performed to investigate the EDLC performance. Oxygen- and nitrogen-containing functional groups were introduced on the surface of ACs through acid and urea treatments, respectively. ACs with nitrogen-containing functional groups showed 2 mA increase of gravimetric discharge capacity and quick achievement of maximum charge/discharge performance. However, ACs with oxygen-containing functional groups showed low discharge capacity and its gradual decrease during further cyclic test, since the functional groups interrupted adsorption/desorption of charges in the electrolyte on the surface of ACs.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.67-67
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• 2008

Application of organic materials with low cost, easy fabrication and advantages of flexible device are increasing attention by research work. Recently, one of them, organic solar cells were rapidly increased efficiency with regioregular poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyricacidmethylester (PCBM) used typical material. To increased efficiency of organic solar cell has tried control of domain of PCBM and crystallite of P3HT by thermal annealing and solvent vapor annealing. [4-6] In those annealing effects, be made inefficiently efficiency, which is increased fill factor (FF), and current density by phase-separated morphology with blended P3HT and PCBM. In addition, increased conductivity by modified hole transfer layer (HTL) such as Poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS), increased both optical and conducting effect by titanium oxide (TiOx), and changed cathode material for control work function were increased efficiency of Organic solar cell. In this study, we had described effect of organic photovoltaics by conductivity of interlayer such as PEDOT:PSS and TCO (Transparent conducting oxide) such as ITO, which is used P3HT and PCBM. And, we have measured with exactly defined shadow mask to study effect of solar cell efficiency according to conductivity of hole transfer layer.