• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.3
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• pp.400-409
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• 2000

This study used in vivo intracellular and extracellular field potential recording to evaluate the intrinsic membrane properties and connection pattern within facial nucleus. 1. There were four subdivisions of medial, intermediate, lateral, and dorsolateral in facial nucleus. 2. Principal cells in the facial nucleus was recorded from and filled with neurobiotin in anesthetized rats. The extent of their dendrites and the characteristics of cell body were examined. 3. Principal cells had a large amplitude action potential and afterhyperpolarization was followed a single action potential. 4. The response from facial motonucleus to electrical stimulation of the facial nerve was mainly a monophasic wave, with a latency of 1 msec, which was assumed to reflect antidromic activation of facial motoneurons. In some of rats the response in addition showed late components at a latency of about 7-8 msec, but its amplitude was small. 5 Most of cells exhibited accommodation of spike discharge upon depolarization of membrane by 0.8 nA for 400 ms. Our results support the hypothesis that there normally are weak connections between different parts of the facial motonucleus to explain pathophysiology of hemifacial spasm and facial naive paralysis.

• Korean Chemical Engineering Research
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• v.56 no.5
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• pp.718-724
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• 2018

In this study, the $Ni_{0.9}Co_{0.05}Ti_{0.05}(OH)_2$ precursor was prepared by the concentration gradient co-precipitation method. In order to overcome the structural change due to oxygen desorption in the cathode active material with high nickel content, the physical and electrochemical analysis of the cathode active material according to the calcination temperature were investigated. Physical properties of $Li_{1.05}Ni_{0.9}Co_{0.05}Ti_{0.05}O_2$ were analyzed by FE-SEM, XRD and TGA. The electrochemical performance of the coin cell using a cathode active material and $LiPF_6$(EC:EMC=1:2 vol%) electrolyte was evaluated by the initial charge/discharge efficiency, cycle retention, and rate capabilities. As a result, the initial capacity and initial efficiency of cathode materials were excellent with 244.5~247.9 mAh/g and 84.2~85.8% at the calcination temperature range of $750{\sim}760^{\circ}C$. Also, the capacity retention exhibited high stability of 97.8~99.1% after 50cycles.

• Membrane Journal
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• v.20 no.3
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• pp.259-266
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• 2010

Porous poly(propylene) supported gel polymer electrolytes (GPE) were synthesized by thermal polymerization of DEGDMA [Di(ethylene glycol) dimethacrylate] in electrolyte solutions (1 M solution of $LiPF_6$ in EC/DEC 1 : 1 mixture) at $70^{\circ}C$. AC impedance spectroscopy and cyclic voltammetry were used to evaluate its ionic conductivity and electrochemical stability window of the GPE membranes. Lithium ion battery (LIB) cells were also fabricated with $LiNi_{0.8}Co_{0.2}O_2$/graphite and GPE membranes via thermal polymerization process. Through the thermal polymerization, self sustaining GPE membranes with sufficient ionic conductivities (over $10^{-3}\;S/cm$) and electrochemical stabilities. The LIB cell with 5% monomer showed the best rate-capability and cycleability.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.28 no.1
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• pp.61-79
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• 2018

Objectives: The objective of this study was to examine the effect of non-thermal dielectric barrier discharge(DBD) plasma on decontamination of Staphylococcus aureus(S. aureus) and Escherichia coli(E. coli) as common pathogens. Methods: This experiment was carried out in a chamber($0.64m^3$)designed by the authors. The plasma was continuously generated by a non-thermal DBD plasma generator(Model TB-300, Shinyoung Air tech, Korea). Suspensions of S. aureus and E. coli of 0.5 McFarland standard($1.5{\times}10^8CFU/mL$) were prepared using a Densi-Check photometer(bio $M{\acute{e}}rieux$, France). The suspensions were diluted1:1000 in sterile PBS solutions(approximately$10^{4-5}CFU/mL$) and inoculated on tryptic soy agar(TSA) in Petri dishes. The Petri dishes(80mm internal diameter)were exposed to the non -thermal DBD plasma in the chamber. Results: The results showed that 95% of S. aureus colonies were killed after a six-hour exposure to the DBD plasma. In the case of E. coli, it took two hours to kill 100% of the colonies. The gram-negative E. coli had a greater reduction than the gram-positive S. aureus. This difference may be due to the structure of their cell membranes. The thickness of gram-positive bacteria is greater than that of gram-negative bacteria. The S. aureus is more resistant to DBD plasma exposures than is E. coli. It should be noted that average concentrations of ozone, a byproduct of the DBD plasma generator, were monitored throughout the experiment and the results were well below the criteria, 50 ppb, recommended by the Korean Ministry of the Environment. Thus, non-thermal DBD plasma is deemed safe for use in hospital and public facilities. Conclusions: There was evidence that non-thermal DBD plasma can effectively kill S. aureus and E. coli. The results indicate that DBD plasma technology can greatly contribute to the control of infections in hospitals and other public and private facilities.

• Biomolecules & Therapeutics
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• v.4 no.2
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• pp.127-137
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• 1996

This study was performed to investigate the toxicity of DA-125 in beagle dogs, an anthracycline antitumor antibiotic. The dogs were administered DA-125 i.v. at 0.0023, 0.0375, 0.15 and 0.6 mg/kg/day, 6 days/week for 26 weeks. At 0.6 mg/kg, all male and female dogs were either sacrificed moribundly or dead during the 26-week treatment. The dogs revealed inactivity, salivation, dark bloody discharge, swelling of the subcutaneous injection site, abscess, and ulceration in the abdominal wall and legs. At 0.15 mg/kg, anorexia, salivation, and swelling of the injection site were observed. The food consumption was decreased with a statistical significance at 6 and 12 weeks treatment in males of 7.6 mg/kg. At 0.0375, 0.15 and 0.6 mg/kg, body weights were decreased significantly in a dose-related fashion after 17 weeks treatment. Total white blood cell counts for male dogs at 0.6 mg/kg were lower than those of control dogs after 13 weeks treatment, which appeared mainly due to decreased neutrophils. At 0.15 mg/kg, testicular atrophy was found in all males by gross pathology and the testicular weights were significantly decreased when compared to those of control males. Microscopically, the testis showed moderate atrophy of the seminiferous tubules and marked decrease in number of spermatozoa in the epididymal tubules. At 0.6 mg/kg, petechia or echymotic hemorrhage was observed in gastrointestinal tract, heart, lungs, and other organs at the necropsy, Marked atrophy of thymus were observed in both males and females. In addition, severe testicular atrophy was noted in all males. Microscopically, gastrointestinal tract showed hemorrhage, epithelial denudation, hypermucus secretion, and atrophy of intestinal villi. Seminiferous tubules of the atrophic testis were lined with Sertoli cells only and devoid of germ cells. Severe oligospermia or aspermia was present in the epididymal tubules. Bone marrow showed marked depletion of hemopoietic cells. In addition, marked atrophy was found in the lymphoid tissue of gastrointestinal tract, various Iymph nodes, and thymus. Injection sites showed marked inflammatory response with necrosis, necrotizing vasculitis, thrombus formation, and ulceration in the skin. According to the present results, no observed effect level appeared to be 0.0375 mg/kg. At 0.15 mg/kg, testis was a target organ, while at 0.6 mg/kg hemopoietic tissue, gastrointestinal tract, and testis were considered to be target organs. At 0.6 mg/kg the test compound seems to inflict a damage on the blood vessels causing hemorrhage in the various organs and tissues.

• Applied Chemistry for Engineering
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• v.25 no.3
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• pp.292-299
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• 2014

In this study, nitrogen doped carbon felt (CFt) is prepared using thermal oxidation and liquid phase ammonia treatment to improve the efficiency for vanadium redox flow batteries (VRFB). The electrochemical properties of prepared CFt electrodes are investigated using cyclic voltammetry (CV) and charge/discharge test. The XPS result shows that the increase of liquid phase ammonia treatment temperature leads to the increased nitrogen functional group on the CFt surface. Redox reaction characteristics using CV reveal that the liquid phase ammonia treated CFt electrodes are more reversible than the thermally oxidized CFt. When CFt is treated by the liquid phase ammonia at $300^{\circ}C$, VRFB cell energy efficiency, voltage efficiency, and current efficiency are increased about 6.93%, 1.0%, and 4.5%, respectively, compared to those of the thermally oxidized CFt. These results are because nitrogen functional groups on CFt help to improve the electrochemical properties of redox reaction between electrode and electrolyte interface.

• The Journal of the Korea Contents Association
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• v.9 no.6
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• pp.256-265
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• 2009

Laser output becomes output adjustment from 20 w to 100 w consecutively and time of exposure is available adjustment through water plant in 0.01 seconds. Pulse action can intercept laser beam periodically and supermarket pulse 0.1 $\sim$ between 1ms discharge consist and momentary laser output is increased to 5 $\sim$ 10. Specially, that must remove malignancy cell in womb nine escarps in the case of uterine cancer first of all stability of tube output about pulse by weight very, stable soft switching action area is defined without high frequency transformer leakage inductance ($L_1$) increase and additional series inductor insertion to converter the first main circuit securing zero voltage and marks of switching action in this research specially, because circulation current path of inductor ($L_f$) current is intercepted, converter the first main circuit switching component and spiritual enlightenment damage of high frequency transformer take decreasing greatly and high frequency the second stoppage department ($D_5,\;D_6$) becomes soft switching, and also, switching damage absorption quantity characteristic that can come to life again as subordinate have, and to become tube stabilization design and result that manufacture and experiment, brought result that improve of 10% than existing equipment, and if supplement as systematic late, it becomes thought to get into superior result.

• Applied Chemistry for Engineering
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• v.31 no.6
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• pp.639-645
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• 2020

Among the components of redox flow battery (RFB), the electrode serves as a diffusion layer of an electrolyte and a path for electrons and also is a major component that directly affects the RFB performance. In this paper, chloric/sulfuric mixed acidwas used as a supporting electrolyte in RFB system with Fe2+/Fe3+ and V2+/V3+ as redox couple. The optimum electrode and activation temperature were suggested by comparing the capacity, coulombic efficiency and energy efficiency according to the electrode type and activation temperature. In the RFB single cell evaluation using 5 types of carbon electrodes used in the experiments, all of them showed close to the theoretical capacity to retain the reliability of the evaluation results. GFD4EA showed relatively excellent energy efficiency and charge/discharge capacity. In order to investigate the electrochemical performance according to the activation temperature, GFD4EA electrode was activated by heat treatment at different temperatures of 400, 450, 500, 600 and 700 ℃ under an air atmosphere. Changes in physical properties before and after the activation were observed using electrode mass retention, scanning electron microscope (SEM), XPS analysis, and electrochemical performance was compared by conducting RFB single evaluation using electrodes activated at each temperature given above.

• Korean Chemical Engineering Research
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• v.60 no.2
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• pp.184-192
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• 2022

Porous NiO synthesized via hydrothermal synthesis was used in the electrodes of lithium-sulfur batteries to inhibit the elution of lithium polysulfide. The electrode of the lithium-sulfur battery was manufactured as a freestanding flexible electrode using an economical and simple vacuum filtration method without a current collector and a binder. The porous NiO-added S/CNT/NiO electrode exhibited a high initial discharge capacity of 877 mA h g^-1 (0.2 C), which was 125 mA h g^-1 higher than that of S/CNT, and also showed excellent retention of 84% (S/CNT: 66%). This is the result of suppressing the dissolution of lithium polysulfide into the electrolyte by the strong chemical bond between NiO and lithium polysulfide during the charging and discharging process. In addition, for the flexibility test of the S/CNT/NiO electrode, the 1.6 × 4 cm² pouch cell was prepared and exhibited stable cycle characteristics of 620 mA h g^-1 in both the unfolded and folded state.

• Korean Chemical Engineering Research
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• v.60 no.3
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• pp.327-333
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• 2022

In this study, silicon/carbon nanotube/carbon (Si/CNT/C) composites for anode were prepared to improve the volume expansion of silicon used as a high-capacity anode material. Si/CNT were prepared by electrostatic attraction of the positively charged Si and negatively charged CNT and then hydrothermal synthesis was performed to obtain the spherical Si/CNT/C composites. Poly(vinylidene fluoride) (PVDF), polyacrylic acid (PAA), and styrene butadiene rubber (SBR) were used as binders for electrode preparation, and coin cell was assembled using 1.0 M LiPF₆ (EC:DMC:EMC = 1:1:1 vol%) electrolyte and fluoroethylene carbonate (FEC) additive. The physical properties of Si/CNT/C anode materials were analyzed using SEM, EDS, XRD and TGA, and the electrochemical performances of lithium-ion batteries were investigated by charge-discharge cycle, rate performance, dQ/dV and electrochemical impedance spectroscopy tests. Also, it was confirmed that both capacity and rate performance were significantly improved using the PAA/SBR binder and 10 wt% FEC-added electrolyte. It is found that Si/CNT/C have the reversible capacity of 914 mAh/g, the capacity retention ratio of 83% during 50 cycles and the rate performance of 70% in 2 C/0.1 C.