• Journal of Hydrogen and New Energy
• /
• v.6 no.1
• /
• pp.35-41
• /
• 1995

The MmNi-based alloy electrode was studied for use as a negative electrode in Ni-MH battery. Alloys with $MmNi_5-_xM_x$(M=Co,Al,Mn) composition were synthesized, and their electrode charateristics of activation rate, temperature dependence, electrode capacity and cycle life were investigated. With increasing Al content and decreasing Mn content in the alloys, the discharge capacity increased while the cycle life decreased. As x in $MmNi_5-_xM_x$ increased from 1.5 to 2.0, decreasing the Ni content, the discharge capacity, the low temperature property and the rate capability decreased. However its cycle life was improved. Increasing Co content resulted in a prolonged cycle life and decrease of high rate discharge capacity. It can be concluded that the most promising alloy in view of discharge capacity and cycle life is $MmNi_{3.5}Co_{0.7}Al_{0.5}Mn_{0.3}$.

• Journal of the Korean Chemical Society
• /
• v.57 no.3
• /
• pp.322-328
• /
• 2013

Copper iodide was employed as a modifier for preparation of a new carbon ceramic electrode. For the first time, the catalytic oxidation of amoxicillin (AMX) was demonstrated by cyclic voltammetry, chronoamperometry and amperometry methods at the surface of this modified carbon ceramic electrode. The copper iodide modified sol-gel derived carbon ceramic (CIM-SGD-CC) electrode has very high catalytic ability for electrooxidation of amoxicillin. The catalytic oxidation peak current was linearly dependent on the amoxicillin concentration and the linearity range obtained was 100 to 1000 ${\mu}mol\;L^{-1}$ with a detection limit of 0.53 ${\mu}mol\;L^{-1}$. The diffusion coefficient ($D=(1.67{\pm}0.102){\times}10^{-3}\;cm^2\;s^{-1}$), and the kinetic parameter such as the electron transfer coefficient (${\alpha}$) and exchange current density ($j_0$) for the modified electrode were calculated. The advantages of the modified CCE are its good stability and reproducibility of surface renewal by simple polishing, excellent catalytic activity and simplicity of preparation.

• Journal of computational fluids engineering
• /
• v.11 no.3 s.34
• /
• pp.46-51
• /
• 2006

This paper presents the numerical results of fluid flow and mixing in a microfluidic device for electro-osmotic flow (EOF) with an trapezoidal electrode array on the bottom wall (ETZEA). Differently from previous EOF in a channel which only transports fluid in colloidal system. ETZEA can also be utilized to mix a target liquid with a reagent. In this study we propose a method of controlling fluid flow and mixing enhancement. To obtain the flow and mixing characteristics, numerical computations are performed by using a commercial code, CFX-10, and a self-made code LBM-D. It was found that the flow near the trapezoidal electrode in the ETZEA is of 3-D complex flows due to the zeta potential difference between the trapezoidal electrode and channel walls, and as a consequence the hetrogeneous zeta potential on the electrodes plays an important role in mixing the liquid.

• Applied Chemistry for Engineering
• /
• v.31 no.5
• /
• pp.539-544
• /
• 2020

A three-dimensional (3D) porous polyaniline (PANI) film was fabricated by a combined photo-and soft-lithography technique based on a large-area nanopillar array, followed by a controlled chemical dilute polymerization. The as-obtained 3D PANI film consisted of hierarchically interconnected PANI nanofibers, resulting in a 3D hierarchical nanoweb film with a large surface and open porous structure. Using electrochemical measurements, the resulting 3D PANI film was demonstrated as a flexible pH sensor electrode, exhibiting a high sensitivity of 60.3 mV/pH, which is close to the ideal Nernstian behavior. In addition, the 3D PANI electrode showed a fast response time of 10 s, good repeatability, and good selectivity. When the 3D PANI electrode was measured under a mechanically bent state, the electrode exhibited a high sensitivity of 60.4 mV/pH, demonstrating flexible pH sensor performance.

• Journal of Sensor Science and Technology
• /
• v.24 no.1
• /
• pp.15-21
• /
• 2015

Transparent and conductive multilayer thin films consisting of three alternating layers FZTO/Ag/$WO_3$ have been fabricated by radio-frequency (RF) sputtering for the applications as transparent conducting oxides and the structural and optical properties of the resulting films were carefully studied. The single layer fluorine doped zinc tin oxide (FZTO) and tungsten oxide ($WO_3$) films grown at room temperature are found to have an amorphous structure. Multilayer structured electrode with a few nm Ag layer embedded in FZTO/Ag/$WO_3$ (FAW) was fabricated and showed the optical transmittance of 87.60 % in the visible range (${\lambda}=380{\sim}770nm$), quite low electrical resistivity of ${\sim}10^{-5}{\Omega}cm$ and the corresponding figure of merit ($T^{10}/R_s$) is equivalent to $3.0{\times}10^{-2}{\Omega}^{-1}$. The resultant power conversion efficiency of 2.50% of the multilayer based OPV is lower than that of the reference commercial ITO. Asymmetric D/M/D multilayer is a promising transparent conducting electrode material due to its low resistivity, high transmittance, low temperature deposition and low cost components.

• Journal of the Korean Applied Science and Technology
• /
• v.29 no.3
• /
• pp.421-428
• /
• 2012

We investigated an electrochemical properties for Langmuir-Blodgett (LB) nano-films of polyimide and phospholipid mixture. LB films of polyamic acid and phospholipid monolayer were deposited by the Langmuir-Blodgett method on the indium tin oxide(ITO) glass. The electrochemical properties measured by cyclic voltammetry with three-electrode system(an Ag/AgCl reference electrode, a platinum wire counter electrode and LB film-coated ITO working electrode) in $KClO_4$ solution. The current of reduction and oxidation range was measured from 1650 mV to -1350 mV, continuously. The scan rates were 50, 100, 150, 200 and 250 mV/s, respectively. As a result, monolayer LB films of polyamic acid and phospholipid mixture was appeared on irreversible process caused by the reduction current from the cyclic voltammogram. Diffusion coefficient (D) effect in the polyamic acid and phospholipid mixture was used in the LAPC with LLPC fewer than the diffusion coefficient values.

• Journal of Electrochemical Science and Technology
• /
• v.7 no.1
• /
• pp.68-75
• /
• 2016

In this study a new, simple, precise, accurate and economic electrochemical method was developed and validated for the voltammetric determination of zolpidem (ZP) using disposable pencil graphite (PG) electrode. The anodic oxidation of ZP on the surface of the PG electrode was examined in a britton robinson (BR) buffer. Square wave and cyclic voltammetry were used as electrochemical techniques in the potential range of 0-1.2 V in the pH 8 BR buffer. In cyclic voltammetry studies, the diffusion coefficient of ZP oxidation was found to be 3.6×10^-6 cm² s^-1. On the other hand, the ZP has shown a well-defined irreversible anodic peak at 0.98 V in the square wave voltammetry mode. The PG electrode, primarily being graphite which has a large active surface area gives rise to increasing peak current with respect to ZP electrooxidation. PG electrode showed an electrocatalytic effect in anodic oxidation of ZP. A linear relationship between catalytic current response and ZP concentration was obtained over a concentration range of 10-30 μM with R.S.D. values ranging from 0.29-3.89. Limits of detection and quantitation were found to be 1 and 3 μM, respectively. Finally, the PG electrode was successfully used to determine ZP in standard and tablet dosage forms with a mean recovery of 100.69 %.

• Progress in Superconductivity
• /
• v.3 no.1
• /
• pp.1-4
• /
• 2001

Interface-engineered junctions with $YbBa_2$$Cu_3$$O_{7}$ as the counter electrode were demonstrated. The junctions exhibited excellent Josephson characteristics with a Josephson critical current ($I_{c}$) ranging from 0.1 mA to 8 mA and a magnetic field modulation of the $I_{c}$ exceeding 80% at 4.2 K while maintaining complete c-axis orientation of the counter-electrode layer. The$ 1\sigma$ spreads in $I_{c}$ for junctions with an average $I_{c}$ of 1-2 mA were 5-8% for 16 junctions within a chip, and 9.3% for a 100-junction array. Our dI/dV measurements suggest that a theoretical approach taking into account both a highly transparent barrier and the proximity effect is required to fully understand the Junction characteristics.ristics.

• Transactions on Electrical and Electronic Materials
• /
• v.16 no.3
• /
• pp.139-141
• /
• 2015

Contact resistance of interface between the channel layers and various S/D electrodes was investigated by transmission line method. Different electrodes such as Ti/Au, a-IZO, and multilayer of a-IGZO/Ag/a-IGZO were compared in terms of contact resistance, using the transmission line model. The a-IGZO TFTs with a-IGZO/Ag/a-IGZO of S/D electrodes showed good performance and low contact resistance due to the homo-junction with channel layer.

• Journal of Biomedical Engineering Research
• /
• v.20 no.3
• /
• pp.323-329
• /
• 1999

This paper proposed a method for the cancellation of the moving artifact which was produced during the detection of drowsiness usmg electrodermal activity signal. Two types of wrist electrode were developed to overcome the defect of the steering wheel type electrode which couldn't eliminate the moving artifacts due to driver's movements. Wrist type electrode II which has been modified from electrode type I was most effective for eliminating movmg artifacts compared to wheel type electrode and wrisL type electrode 1. The decIsion criteria(if IRI$\leq$10 and 1.1$\leq$dNz) for detecting moving artifact was determined from the virtual driving experiments. An algorithm which substituted past value of Nz for the current value of Nz whenever an EDA signal satisfied the criteria was developed. The experimental resulls of virtual driving and road test showed that the proposed algorithm had been successfully removed the most of the error due to the moving artifact Therefore, the developed system which use electrode type II and the algorithm might be less influenced by moving artifacts and could measure an accurate arousal state.