• Membrane and Water Treatment
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• v.13 no.5
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• pp.209-217
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• 2022

In the present research, Ficus religiosa Bark (FRB) is used as an adsorbent for the removal of heavy metal Cr (VI) ions. This Ficus religiosa Bark was characterized by Scanning Electron Microscope, Fourier transform infrared Spectroscopy, Thermo Gravimetric Analyzer and the results showed that activated adsorbent have high adsorption capacity and withstand even in high temperature. Batch and Continuous experiments were conducted to determine the effect of various parameters such as pH, contact time, adsorbent dose and initial metal concentration. The biosorption followed pseudo first order kinetic model. The adsorption isotherms of Cr (VI) on Ficus religiosa fitted well with the Temkin model. In Batch study, maximum biosorption capacity of Cr (VI) was found to be 37.97 mg g^-1 (at optimal pH of 2, adsorbent dosage of 0.3 grams and concentration of Cr (VI) is100 mg L^-1). The Continuous mode of study shows that 97% of Cr (VI) ion removal at a flow rate of 15 ml min^-1. From the results, selected Ficus religiosa Bark has the higher adsorption capacity for the removal of Cr (VI) ions from wastewater.

• Journal of Sensor Science and Technology
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• v.30 no.4
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• pp.236-242
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• 2021

In this paper, we report the fabrication of the tip-on-gate of a field-effect-transistor (ToGoFET) probe using a standard complementary metal-oxide-semiconductor (CMOS) process and the performance evaluation of the fabricated probe. After the CMOS process, I-V characteristic measurement was performed on the reference MOSFET. We confirmed that the ToGoFET probe could be operated at a gate voltage of 0 V due to channel ion implantation. The transconductance at the operating point (Vg = 0 V, Vd = 2 V) was 360 ㎂/V. After the fabrication process was completed, calibration was performed using a pure metal sample. For sensitivity calibration, the relationship between the input voltage of the sample and the output current of the probe was determined and the result was consistent with the measurement result of the reference MOSFET. An oxide sample measurement was performed as an example of an application of the new ToGoFET probe. According to the measurement, the ToGoFET probe could spatially resolve a hundred nanometers with a height of a few nanometers in both the topographic image and the ToGoFET image.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.122.1-122.1
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• 2011

Phosphorus is known to pile-up at the silicon surface when it is thermally oxidized. A thin layer, about 40nm thick from the silicon surface, is created containing more phosphorus than the bulk of the emitter. This layer has a gaussian profile with the peak at the surface of the silicon. In this study the pile-up effect was studied if this layer can act as a front surface field for solar cells. The effect was also tested if its high dose of phosphorus at the silicon surface can lower the contact resistance with the front metal contact. P-type wafers were first doped with phosphorus to create an n-type emitter. The doping was done using either a furnace or ion implantation. The wafers were then oxidized using dry thermal oxidation. The effect of the pile-up as a front surface field was checked by measuring the minority carrier lifetime using a QSSPC. The contact resistance of the wafers were also measured to see if the pile-up effect can lower the series resistance.

• The Korean Journal of Mycology
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• v.19 no.3
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• pp.220-225
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• 1991

Activities of the $F_1-ATPase$ purified from Lentinus edodes were stimulated by $Fe^{3+},\;Fe^{2+},\;Cd^{2+},\;Mg^{2+},\;K^{+}\;and\;Co^{2+}$ but were inhibited by $Zn^{2+},\;Ca^{2+},\;Cu^{2+}\;and\;Ni{2+}$ ion. The enzyme activities were increased 130, 65, 65, 68, 105% and 23% by the 5mM $Fe^{3+}$, 10 mM$Fe^{2+}$, 1mM $Cd^{2+}$, 5mM $Mg^{2+}$, 5mM $K^{+}$ and 5mM$Co^{2+}$ ion addition, respectively, as compared with those not added. The enzyme activities were decreased 18, 19, 27 and 30% by 10 mM $Zn^{2+}$, 10mM $Ca^{2+}$, 0.5 mM $Cu^{2+}$ and 10 mM $Ni^{2+}$ ion, respectively. Anion effects of 10 mM ${Co_3}^{2-}$, 20 mM,$CN^{-}$ 20 mM$CH_3COO^{-}$ and 20 mM ${NO_3}^{-}$ ion were inhibited to the enzyme activities of 98, 95, 70 and 50%, respectively. As increasing of ${SO_4}^{2-}$ ion concentration, the enzyme activity was stimulated and 20 mM ${SO_4}^{2-}$ ion was shown increased of 21%.

• Applied Chemistry for Engineering
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• v.22 no.4
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• pp.395-399
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• 2011

Material of the gasket for lithium ion battery requires the chemical resistance, the electrical insulting property, the compression set, the anti-contamination level and the low temperature resistance. We compounded ethylene propylene diene monomer (EPDM), which showed widely different solubility parameter index, with adjusting the amount of metal oxide as an activator. We did long-term test and compression set against an electrolyte with consideration for operating conditions in lithium-ion battery. In these tests, we checked the physical, chemical characteristics and the effect to lithium ion battery with different kinds of activators. In case of rubber with ZnO as an activator, through 1000 h depositing test in propylene carbonate which is one of representative solvents, we could get the satisfying characteristics and result. However, $Zn^{2+}$ had eluted in the ion elution test. So, ZnO should be limited in EPDM compound for the gasket material in lithium-ion battery.

• The Korean Journal of Pharmacology
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• v.26 no.1
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• pp.35-49
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• 1990

A highly purified $(Na^+,\;K^+)-ATPase$ from the rectal gland of Squalus acanthias and from the electric organ of Electrophorus electricus has been used to raise antibodies in rabbits. The 97,000 dalton catalytic subunit and glycoprotein derived from the rectal gland of spiny shark were also used as antigens. The two $(Na^+,\;K^+)-ATPase$ holoenzymes and the two shark subunits were antigenic. In Ouchterlony double diffusion experiments, these antibodies formed precipitation bands with their antigens. Antibodies prepared against the two subunits of shark holoenzyme also formed precipitation bands with their antigens and shark holoenzyme, but not with eel holoenzyme. These observations are in good agreement with inhibitory effect of these antibodies on the catalytic activity of $(Na^+,\;K^+)-ATPase$ both from the shark and the eel, since there is very little cross-reaction between the shark anticatalytic subunit antibodies and the eel holoenzyme. The maximum antibodies titer of the anticatalytic subunit antibodies is found to be 6 weeks after the initial single exposure to this antigen. Multiple injections of the antigen increased the antibody titer. However, the time required to produce the maximum antibody titer was approximately the same. These antibodies also inhibit catalytic activity of $(Na^+,\;K^+)-ATPase$ vesicles reconstituted by a slow dialysis of cholate after solubilization of the enzyme in a presonicated mixture of cholate and phospholipid. In these reconstituted $(Na^+,\;K^+)-ATPase$ vesicles, effects of these antibodies on the fluxes of $Na^+$, $Rb^+$, and $K^+$ were investigated. Control or preimmune serum had no effect on the influx of $^{22}Na^+$ or the efflux of $^{86}Rb^+$. Immunized sera against the shark $(Na^+,\;K^+)-ATPase$ holoenzyme, its glycoprotein or catalytic subunit did inhibit the influx of $^{22}Na^+$ and the efflux of $^{86}Rb^+$. It was also demonstrated that these antibodies inhibit the coupled counter-transport of $Na^+$ and $K^+$ as studied by means of dual labeling experiments. However, this inhibitory effect of the antibodies on transport of ions in the $(Na^+,\;K^+)-ATPase$ vesicles is manifested only on the portion of energy and temperature dependent alkali metal fluxes, not on the portion of ATP and ouabain insensitive ion movement. Simultaneous determination of effects of the antibodies on ion fluxes and vesicular catalytic activity indicates that an inhibition of active ion transport in reconstituted $(Na^+,\;K^+)-ATPase$ vesicles appears to be due to the inhibitory action of the antibodies on the enzymatic activity of $(Na^+,\;K^+)-ATPase$ molecules incorporated in the vesicles. These findings that the inhibitory effects of the antibodies specific to $(Na^+,\;K^+)-ATPase$ or to its subunits on ATP and temperature sensitive monovalent cation transport in parallel with the inhibitory effect of vesicular catalytic activity by these antibodies provide direct evidence that $(Na^+,\;K^+)-ATPase$ is the molecular machinery of active cation transport in this reconstituted $(Na^+,\;K^+)-ATPase$ vesicular system.

• Journal of the Korean Vacuum Society
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• v.12 no.2
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• pp.112-117
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• 2003

MgO films is widely used in plasma display panel (PDP) technology. In this work, structural and optical properties of the MgO films deposited by e-beam evaporation, reactive magnetron sputtering, which are commercially used, and arc deposition were compared. MgO thin films were deposited on glass substrates by vacuum arc deposition equipment using a magnesium metal target at various oxygen gas flows. In order to investigate the packing density by ellipsometer, to measure reasonable erosion-rates of the MgO protective layers, we introduced an acceleration test method, namely, Ar+ ion beam induced erosion test. Also, XPS and UV test were adopted to examine the effect of the moisture on the optical transmittance of the MgO protective layers, which showed that these of MgO films by arc deposition method sustained more 90% and were insensitive to effect of the moisture. XRD and AFM have been also used to study behaviors of the structure and surface morphology.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.8
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• pp.1318-1322
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• 2003

This study was carried out to identify the biophysical utility of bioflavonoids by the determination of their antioxidative activities, radical scavenging activity and inhibitory effect on the ACE activity. The results obtained were as follows; All flavonoids experimented greatly inhibited the linoleic acid oxidation from the early period of oxidation, and the radical scavenging ability was also greater in genistein and daidzein than other flavonoids, generally showing donating ability. Rutin has the metal-chelating ability with C $u^{2+}$ and $Mg^{2+}$, which means to have the inhibitory effect on the promotive oxidation of lipid by metal ion. All flavonoids experimented inhibited the angiotensin converting enzyme (ACE) activity, which was greater in genistein and daidzein than other flavonoids.s.

• Journal of IKEEE
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• v.21 no.1
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• pp.96-99
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• 2017

In this study the influence of the random dopant fluctuation (RDF) depending on the halo and LDD implantations for the metal-oxide-semiconductor field effect transistor is investigated through the 3D atomistic device simulation. For accuracy in calculation, the kinetic monte carlo method that models individual impurity atoms and defects in the device was applied to the atomistic simulation. It is found that halo implantation has the greater influence on RDF effects than LDD implantation; three-standard deviation of $V_{TH}$ and $I_{ON}$ induced by halo implantation is about 6.45 times and 2.46 times those of LDD implantation. The distributions of $V_{TH}$ and $I_{ON}$ are also displayed in the histograms with normal distribution curves.

• Journal of the Korean Electrochemical Society
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• v.3 no.2
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• pp.85-89
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• 2000

For replacing Li metal at Lithium ion Battery(LIB) system, we used carbon powder material which prepared by Pyrolysis of Phenol resin as starting material. It became amorphous carbon by Pyrolysis through it's self condensation by thermal treatment. Amorphous carbon can be doped with Li intercalation and deintercalation because it has wide interlayer. However, it has a problem with structural destroy due to weak carbon-carbon bond. So, we used $ZnCl_2$ as the pore-forming agent. This inorganic salt was used together with the resin serves not only as the pore-forming agent to form open pores, which grow into a three-dimensional network structure in the cured material, but also as the microstructure-controlling agent to form a loose structure doped with bulky dopants. We used SEM in order to find to difference of structure, and can calculate the distance of interlayer by XRD analysis. CV test showed oxidation and reduction.