• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.11
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• pp.41-47
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• 2011

A novel digital instrumentation amplifier(DIA) converting universal signal inputs into 5V voltage-output for industry standard sensor signal processing was designed. The circuit consists of a commercial instrumentation amplifier, seven analog switches, two voltage references of 1.0V and -10.0V, and four resistors. The converting principle is the circuit reconstruction by switches for resistor values and reference voltages according to input signals. The simulation result shows that the DIA has a good output voltage characteristics of 0~5V for the input voltage of 0V~5V, 1V~5V, -10V~+10V, and 4mA~20mA. The nonlinearity error was less than 0.1% for the four type signal inputs.

• Journal of the Korean Magnetics Society
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• v.2 no.3
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• pp.222-227
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• 1992

The effects of $V_2O_5$ addition as an additive on the densification, the microstructure and the magnetic properties of Mn-Zn ferrites were studied. The maximum density was observed at 0.1 wt% $V_2O_5$ content and it was recognized that a small content of $V_2O_5$ prohibited the discontinuous grain growth. The initial permeability showed maximum at 0.1 wt% $V_2O_5$ content and the power loss minimum at 0.03 wt% $V_2O_5$ content. It was found that a small content of $V_2O_5$ went into solid solution in the Mn-Zn ferrites, but above that extent $V_2O_5$ formed a second phase to be segregated at the grain boundaries.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.226-230
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• 2003

In this thesis I analyzed that V5.2 protocol function is effective to fulfill all of the services that are provided at the existing local exchange. I analyzed this in five methods that refer to ETSI inside patronage. I experimented turnaround time by Start-up method and verified V5.2 protocol function when Start-up. Also I confirmed stability of system by the reconstruction-ability experiment related E1 switch over. I verified V5.2 protocol function through PSTN call process that uses a special service test and local call simulator. As a result of experiment, I confirmed the best method when simultaneous Start-up. V5.2 protocol function was excellent and It becomes switch over at 1/1000 seconds when E1 is out of service. V5.2 protocol function was effective to fulfill all of the special services that are provided at local exchange and its long call process ability was superior to KT standard with 4 fails in 20000 calls. Through the experiment, it was proved that V5.2 interface will become a significant element of communication network when after LE side expanse of v5 interface ID with TDX-100 exchanger and the AN occurrences OOS by message transmission limit and call disconnect when E1 switch over are improved.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.797-800
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• 2002

Instead of a solution process producing amorphous $LiV_3O_8$ form, we prepared Lithium vanadate glass by melting $Li_2O-P_2O_5-V_2O_5$ and $Li_2O-P_2O_5-Bi_2O_3-V_2O_5$ composition in pt. crucible and by quenching on the copper plate. From the crystallization of $Li_2O-P_2O_5-V_2O_5$ and $Li_2O-P_2O_5-Bi_2O_3-V_2O_5$, we could abtain glass-ceramics having crystal phase, LiV3O8 from glass matrix. The material heat-treated at lower-temperature, $250^{\circ}C$ had less crystalline and lower capacity, But the material heat-treadted at higher-temperature, $330^{\circ}C$ had higher capacity and $Li_2O-P_2O_5-V_2O_5$ glass-ceramics had higher capacity than $Li_2O-P_2O_5-Bi_2O_3-V_2O_5$ glass-ceramics.

• Korean Chemical Engineering Research
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• v.51 no.3
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• pp.313-318
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• 2013

In order to investigate the effect of $V_2O_5$ loading of $V_2O_5-WO_3/TiO_2$ catalyst on the NO reduction and the formation of $N_2O$, the experimental study was carried out in a differential reactor using the powder catalyst. The NO reduction and the ammonia oxidation were, respectively, investigated over the catalysts compose of $V_2O_5$ content (1~8 wt%) based on the fixed composition of $WO_3$ (9 wt%) on $TiO_2$ powder. $V_2O_5-WO_3/TiO_2$ catalysts had the NO reduction activity even under the temperature of $200^{\circ}C$. However, the lowest temperature for NO reduction activity more than 99.9% to treat NO concentration of 700 ppm appeared at 340 with very limited temperature window in the case of 1 wt% $V_2O_5$ catalyst. And the temperature shifted to lower one as well as the temperature window was widen as the $V_2O_5$ content of the catalyst increased, and finally reached at the activation temperature ranged $220{\sim}340^{\circ}C$ in the case of 6 wt% $V_2O_5$ catalyst. The catalyst of 8 wt% $V_2O_5$ content presented lower activity than that of 8 wt% $V_2O_5$ content over the full temperature range. NO reduction activity decreased as the $V_2O_5$ content of the catalyst increased above $340^{\circ}C$. The active site for NO reduction over $V_2O_5-WO_3/TiO_2$ catalysts was mainly related with $V_2O_5$ particles sustained as the bare surface with relevant size which should be not so large to stimulate $N_2O$ formation at high temperature over $320^{\circ}C$ according to the ammonia oxidation. Currently, $V_2O_5-WO_3/TiO_2$ catalysts were operated in the temperature ranged $350{\sim}450^{\circ}C$ to treat NOx in the effluent gas of industrial plants. However, in order to save the energy and to reduce the secondary pollutant $N_2O$ in the high temperature process, the using of $V_2O_5-WO_3/TiO_2$ catalyst of content $V_2O_5$ was recommended as the low temperature catalyst which was suitable for low temperature operation ranged $250{\sim}320^{\circ}C$.

• Journal of Sensor Science and Technology
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• v.4 no.3
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• pp.15-21
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• 1995

In this paper, $TiO_{2}-V_{2}O_{5}$ humidity sensors are fabricated by Sol-Gel method. For the establishment of optimum processing condition which is good humidity sensitive characteristics for specimens, their microstructures and crystalline-structures are analysed. Grain size increases with substitution rate of $V^{5+}$ on $Ti^{4+}$ site. From the analysis of XRD, $V^{5+}$ peak can't confirm with $V_{2}O_{5}$ rate. Their humidity sensitive characteristics is good at 1mol% of $V_{2}O_{5}$ rate and heat-treated at $700^{\circ}C$. The capacitance of specimens decreases with frequency.

• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2459-2465
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• 2007

V2O5/TiO2-ZrO2 catalyst modified with V2O5 was prepared by adding Ti(OH)4-Zr(OH)4 powder into an aqueous solution of ammonium metavanadate followed by drying and calcining at high temperatures. The characterization of prepared catalysts was performed using XRD, DSC, solid-state 51V NMR, and FTIR. In the case of calcination temperature of 500 oC, for the catalysts containing low loading V2O5 below 25 wt % vanadium oxide was in a highly dispersed state, while for catalysts containing high loading V2O5 equal to or above 25 wt % vanadium oxide was well crystallized due to the V2O5 loading exceeding the formation of monolayer on the surface of TiO2-ZrO2. The strong acid sites were formed through the bonding between dispersed V2O5 and TiO2-ZrO2. The larger the dispersed V2O5 amount, the higher both the acidity and catalytic activities for acid catalysis.

• Applied Chemistry for Engineering
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• v.16 no.4
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• pp.491-495
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• 2005

Vanadium pentoxide xerogels with a doping ratio of $Al/V_2O_5$ ranging from 0.01 to 0.05 were synthesized by doping Al into $V_2O_5$ xerogel via the sol-gel process. By using the synthesized $Al_xV_2O_5$, the $Li/Al_xV_2O_5$ cells were assembled to investigate the chemical and electrochemical properties. Surface morphology of the $Al_xV_2O_5$ xerogel showed an anisotropic corrugated sheet-like matrix, and the interlayer distance was about $11.5{\AA}$. The IR spectra of the $Al_xV_2O_5$ revealed that the doped Al was coordinated to the vanadyl group in $V_2O_5$. The $Al_xV_2O_5$ xerogels showed enhanced reversibility and energy density compared with the $V_2O_5$ xerogel. The specific capacity of the $Al_{0.05}V_2O_5$ xerogel was more than 200 mAh/g at 10 mA/g discharge rate, and cycle efficiency was about 90% after the 31st cycling test between 1.9 V and 3.9 V.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.04b
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• pp.157-159
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• 2000

Vanadate glass in the $Li_2O-P_2O_5-V_2O_5$ system with 60mol% $V_2O_5$ was prepared by melting the bath in pt. crucible followed by quenching on the copper plate. We found that $Li_2O-P_2O_5-V_2O_5$ glass ceramics obtained from nucleation of $Li_2O-P_2O_5-V_2O_5$ glass showed significantly higher capacity and longer cycle life than conventionally made crystalline $LiV_3O_8$. In the present paper, We describe the charge/discharge properties during crystallization process and find the best crystallization condition of $Li_2O-P_2O_5-V_2O_5$ glass as cathode material. The Charge and discharge capacity of $Li_2O-P_2O_5-V_2O_5$ glass was about 220mAh/g for the cell heat-treated at $250^{\circ}C$ for 2.5hr.

• Korean Journal of Crystallography
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• v.12 no.2
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• pp.70-75
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• 2001

The purpose of this study is to investigate the effect of V₂O/sub 5/ addition on physical and magnetic properties of NiCuZn ferrite for multi-layer chip inductors. NiCuZn ferrite pastes doped with 0, 0.1, 0.3 and 0.5 wt% V₂O/sub 5/ were prepared and samples of ferrite sheets were prepared by the screen printing method. They were sintered at 870, 880, 890 and 900℃, and then their physical and magnetic properties were analyzed. After sintering at 870℃, the sintered density of the ferrite sheet doped with 0.5wt% V₂O/sub 5/ showed the highest value to 5.08g/cm³due to the best densification by the liquid phase sintering, while the microstructures of ferrite sheets doped with 0.1 and 0.3 wt% V₂O/sub 5/ showed and inhibited grain growth. Irrespective of the sintering temperature, the initial permeability of ferrite sheet doped with 0.5 wt% V₂O/sub 5/ was highest and after sintering beyond 880℃, the quality factor of 0.3 wt% V₂O/sub 5/-doped sample appeared to be highest.