• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.594-594
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• 2012

Al doped ZnO (AZO) thin films were deposited on textured glass substrate by magnetron sputtering method. Also, AZO films on textured glass were etched by hydrochloric acid (HCl). Average thickness of etched AZO films are 90 nm. We observed morphology of AZO film by AFM with various etchant concentration and etching time. Etched AZO films have low resistivity and high haze. The surface RMS roughness of AZO film was increased from 53.8 nm to 84.5 nm. The haze ratio was also enhanced in above 700 nm of wavelength due to light trapping effect was increased by rough AZO surface. The etched AZO films on textured glass are applicable to fabricate solar cell.

• 약학회지
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• 제45권1호
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• pp.34-38
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• 2001

The Phellodendri Cortex of Phellodendron amurense (Rutaceae) is known to contain a number of isoquinoline alkaloid, and berberine, palmatine, jateorrhizine, phellodendrine and magnoflorine are the major constituents of protoberberine alkaloids. For the determination of protoberberine alkaloids from Phellodendri Cortex and berberine chloride from the preparation, the new spectrophotometric method was developed with a simple and selective sample clean-up using thiocyanatocobaltate[II] complex ion. Samples were extracted with 0.1 mM hydrochloric acid, potassium biphthalate reagent, thiocyanatocobaltate reagent and 1.2-dichloroethane for 60 min. The absorbance of protoberberine alkaloid complexes in 1.2-dichloroethane solution was measured at 625 nm. Calibration curve for berberine was linear over the concentration range of 0.05~0.30 mg/ml 1.2-dichloroethane. The method proved to be rapid, simple and reliable for the determination of protoberberine alkaloids from Phellodendri Cortex and berberine chloride from the preparation.

• 대한화학회지
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• 제7권2호
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• pp.186-188
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• 1963

An attempt to improve the method of volumetric determination of tungsten developed by Luke has been made successfully. Using amalgam coated lead instead of pure metallic lead in the reduction procedure. W(VI)-W(III) reduction has been found to be quantitative in rather concentrated hydrochloric acid. Since there was no excessive dissolution of lead via reduction of hydrogen ion, lead surface was totally accessible for the reduction of tungsten and no trouble was caused by dereposition of $PbCl_2$ crystals at the nozzle of Jones reductor. Furthermore, it has been confirmed that almost 100 mg. of $WO_3$ can be handled easily if the chloride concentration of the HCl is increased by adding solid $NH_4Cl$.

• 한국표면공학회지
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• 제19권1호
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• pp.13-19
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• 1986

Manganese in the Anode slime and the paste-positive material of waste-dry cell was recovered by leaching with the hydrochloric acid solution. The impurities (Zn, Fe, Pb), co-leached with manganese were removed from the leached solution prior to electrolysis by hydrometallurgical techniques such as the neutralization with ammonium hydroxide and cementation on manganese powder. The electrodeposition of manganese from the purified chloride solution with sodium selenate was performed. Cathode current efficiency was found to be affected significantly by the concentration of sodium selenate and ammonium chloride salt, bath temperate, current density and PH. The current efficiency of about 88.7% was obtained by electrolysis manganese chloride solution with sodium selenate (0.1/g) at 10$^{\circ}C$.

• Corrosion Science and Technology
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• 제22권1호
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• pp.10-20
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• 2023

Because of its inexpensive cost, mild steel is frequently employed as a construction material in different industries. Unfortunately, because of its limited resistance to corrosion, a protective layer must be applied to keep it from decaying in acidic or basic environments. The presence of heteroatoms, such as nitrogen, oxygen, and pi-electrons in the Schiff base could cause effective adsorption on the mild steel surface, preventing corrosion. The weight loss method and scanning electron microscopy (SEM) were used to investigate the inhibitory effects of APIDO on mild steel in a 1 M hydrochloric acid environment. The efficiency of inhibition increased as the inhibitor concentration increased and decreased as the temperature increased. The SEM analysis confirmed that the corrosion inhibition of APIDO proceeded by the formation of an organic protective layer over the mild steel surface by the adsorption process. Simulations based on the density functional theory are used to associate inhibitory efficacy with basic molecular characteristics. The findings acquired were compatible with the experimental information provided in the research.

• Mycobiology
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• 제39권1호
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• pp.12-19
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• 2011

Cellular damage caused by reactive oxygen species has been implicated in several diseases, thus establishing a significant role for antioxidants in maintaining human health. Acetone, methanol, and hot water extracts of Pleurotus citrinopileatus were evaluated for their antioxidant activities against ${\beta}$-carotene-linoleic acid and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, reducing power, ferrous ion-chelating abilities, and xanthine oxidase inhibitory activities. In addition, the tyrosinase inhibitory effects and phenolic compound contents of the extracts were also analyzed. Methanol and acetone extracts of P. citrinopileatus showed stronger inhibition of ${\beta}$-carotene-linoleic acid compared to the hot water extract. Methanol extract (8 mg/mL) showed a significantly high reducing power of 2.92 compared to the other extracts. The hot water extract was more effective than the acetone and methanole extracts for scavenging DPPH radicals. The strongest chelating effect (92.72%) was obtained with 1.0 mg/mL of acetone extract. High performance liquid chromatography analysis detected eight phenolic compounds, including gallic acid, protocatechuic acid, chlorogenic acid, ferulic acid, naringenin, hesperetin, formononetin, and biochanin-A, in an acetonitrile and hydrochloric acid (5 : 1) solvent extract. Xanthine oxidase and tyrosinase inhibitory activities of the acetone, methanol, and hot water extracts increased with increasing concentration. This study suggests that fruiting bodies of P. citrinopileatus can potentially be used as a readily accessible source of natural antioxidants.

• 한국환경보건학회지
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• 제21권3호
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• pp.77-86
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• 1995

Lead(II) removal efficiency by natural kaolinite was investigated through laboratory experiments. This study was conducted in two phases-sorption and desorption. In the adsorption study, the influence of sorption kinetics and sorption isotherm and various parameters such as pH, temperature, coexisting other heavy metal ions on the lead adsorption was investigated. And desorption study was carried out in order to find the re-usability of kaolinite as an adsorbent. The results of the study are as follows. 1. Sorption kinetics was investigated under the condition of 2.5 mg/l adsorbent concentration, pH 6.5$\pm$0.05, temperature $30\pm 0.5\circ$C, initial lead(II) concentration 25 mg/l. Adsorption rate was initially rapid and the extent of adsorption arrived at adsorption equilibrium with 73% adsorption efficiency in an hour. 2. The sorption isotherm experiment was made with different initial lead(II) concentration. A linearized Freundlich equation was used to fit the acquired experimental data. As a result, Freundlich constants, the sorption intensity (1/n) was 0.47 and the measure of sorption (k) was 2.44. So, it was concluded that sorption of lead(II) by kaolinite is effective. 3. The effect of pH on lead(II) sorption by kaolinite shows that at a pH of 3, only 6% of the total lead(II) was adsorbed and at a pH 9, 97% of the lead(II) was removed. And the effect of temperature on lead(II) sorption by kaolinite shows that as the temperature increased, the amount of lead(II) sorption per unit weight of kaolinite increased. But the effect was minor (p<0.05). 4. Sorption isotherm of lead coexisting cadmium (II) or zinc (II) was lower than that of lead itself. It was caused by the result of competitive sorption to adsorption site. And there was no difference between the sorption isotherm of cadmium and zinc. 5. In desorption studies, only 5.12% desorption took place in distilled water, while 52.08% in 0.1 N hydrochloric acid. Consequently used kaolinite could be regenerated by hydrochoric acid.

• 자원리싸이클링
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• 제22권2호
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• pp.3-10
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• 2013

인듐은 희유금속으로 주로 ITO제조에 사용된다. 본 총설에서는 인듐을 함유한 2차자원을 침출한 용액으로부터 인듐을 분리하기 위한 용매추출, 이온교환 및 석출법에 대한 공정 조건 및 장단점을 조사했다. 보통 정도의 산성용액에서 인듐의 추출제로 D2EHPA가 가장 많이 사용되고 있으며, 매우 강한 염산용액에서는 아민계 추출제가 사용된다. 일반적으로 이온교환수지의 인듐 흡착량이 낮으므로, 인듐의 농도가 낮은 경우에 한해 이온교환은 용매추출보다 장점이 있다.

• 한국의류학회지
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• 제26권2호
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• pp.349-354
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• 2002

In order to decolorize the reactive dye wastewater, we investigated the dye-adsorption ability of chitin, which was natural polymer obtained from shrimp shell. Chitin particle(less than 250 ${\mu}{\textrm}{m}$n) was prepared from shrimp shells in the processes of decalcification in aqueous hydrochloric acid solution and deproteination in aqueous sodium hydroxide solution. The particle size of chitin was controlled to less than 250 ${\mu}{\textrm}{m}$. Three tripes of the reactive dyes-C.I. Reactive Red 120, C.I. Reactive red 241 and C.I. Reactive Black 5-were used. Dye adsorption ability of chitin was investigated by dipping the particle in the dyebaths of concentration of 0.0l%, 0.03% and 0.05% for various periods of time(1,3,5, 10,20,40,80,160minutes). The influence of addition of salt(Na$_2$SO$_4$) and alkali to the dyebaths on dye-absorption was also investigated. We obtained the following results fur the dye-absolution ability of chitin in the dyebaths of three types of reactive dyes. 1) The amount of dye uptake by chitin was increased by addition of salt to the dyebaths. 2) As the concentration of alkali became higher than 3g/I, the amount of dye uptake by chitin was increased. Chitin showed good dye-adsorption ability, when the alkali concentration was high. 3) Chitin showed equal dye uptake in the three types of dyebaths when the dye concentration was 0.0l%. Over 90% of dyestuffs was adsorbed from the dyebaths in ten minutes. When the dye concentration was higher, better adsorption ability was showed in a dye bath of Reactive black 5 than in the others. When the dye concentration was 0.03%, 90% of Reactive red 120 and Reactive red 241 was adsorbed in 40 minutes and the same of Reactive black 5 in 10 minutes. When the dye concentration was 0.05%, 9()% of Reactive red 120 was adsorbed in 80 minutes, and Reactive black 5 in to minutes.

• Membrane and Water Treatment
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• 제3권2호
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• pp.123-131
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• 2012

This study investigated the extraction and stripping performance of PIMs consisting of PVC and Aliquat 336. Extraction and stripping of three representative heavy metals - namely $Cd^{2+}$, $Cu^{2+}$, and $Zn^{2+}$ - by the synthesized membranes were evaluated as a function of sodium chloride concentration and under different stripping solutions (0.01 M $HNO_3$, Milli-Q water, 0.01 M HCl and 0.01 M NaOH), respectively. Results reported here indicate that the formation of negatively charged metal chloride complex species was responsible for the extraction of the target metal to PIMs. Experimental results and thermodynamic modeling of the speciation of chloro metal complexes further confirm that the extraction selectivity between $Cd^{2+}$, $Cu^{2+}$ and $Zn^{2+}$ can be controlled by regulating the chloride concentration of the feed solution. An acidic solution without any chloride was the most effective stripping solution, followed by Milli-Q water, and a diluted hydrochloric acid solution. On the other hand, the stripping of metals from PIMs did not occur when a basic stripping solution was used.