• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.6
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• pp.501-506
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• 2006

Carbon nanotubes (CNTs) were grown with a microwave plasma enhanced chemical vapor deposition (MPECVD) method, which has been regarded as one of the most promising candidates for the synthesis of CNTs due to the vertical alignment, the low temperature and the large area growth. MPECVD used methane ($CH_4$) and hydrogen ($H_2$) gas for the growth of CNTs. 10 nm thick Ni catalytic layer were deposited on the Ti coated Si substrate by RF magnetron sputtering method. In this work, the pretreatment was that the Ni catalytic layer in different microwave power (600, 700, and 800 W). After that, CNTs deposited on different pressures (8, 12, 16, and 24 Torr) and grown same microwave power (800 W). SEM (Scanning electron microscopy) images showed Ni catalytic layer diameter and density variations were dependent with their pretreatment conditions. Raman spectroscopy of CNTs shows that $I_D/I_G$ ratios and G-peak positions vary with pretreatment conditions.

• Analytical Science and Technology
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• v.22 no.2
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• pp.136-140
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• 2009

To improve the carbon recovery yield of chemical pretreatment in soil and sediment for $^{14}C$ age dating using AMS (Accelerator Mass Spectrometry), we have developed ultrasonic method in chemical pretreatment to replace with stirring method which has been generally used in each step of humic acid extraction for soil and sediment samples. Extraction conditions such as ultrasonic power, temperature and reaction time have been optimized. Six times higher carbon recovery yield could be obtained from low carbon content samples using ultrasonic method. We also compared the dating results by AMS obtained using ultrasonic method with the ages of samples treated by the stirring method. It was found that this new method could be applied to the pretreatment process of low carbon content samples for AMS age dating without effects on the dated ages, and with highly improved carbon recovery yields.

• Journal of the East Asian Society of Dietary Life
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• v.3 no.2
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• pp.121-128
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• 1993

This study was intended to clarify the protective mechanism of diallyl disulfide on the carbon tetrachloride-induced hepatotoxicity in mice. It was observed that a powerfully increment of serum alanine aminotransferase activity and hepatic lipid peroxide content after carbon tetrachloride injection were markedly inhibited by the pretreatment of diallyl disulfide (20mg/kg) for 5 days. It was also observed that hepatic aminopyrine demethylase and xanthine ocidase as free radical generating enzymes as well as superoxide dismutase and catalase activities as free frdical scavenging enzymes and hepatic glutathione content were not changed by the pretreatment with diallyl disulfide. But, treatment with diallyl disulfide did signifiantly increase cytosolic glutathione S-transferase activity. However, glutathione S-transferase activity in the presence of diallyl disulfide was not affected in vitro. Therefore, it is concluded that mechanism for the observed preventive effect ofdiallyl disulfide against the carbon tetrachloride-induced hepatotoxicity can be due to the engancement of glutathione S-transferase activity.

• Korean Journal of Pharmacognosy
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• v.34 no.2 s.133
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• pp.166-171
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• 2003

The hepatoprotective effects of Liriopis tuber on carbon tetrachloride $(CCl_4)$ intoxicated rats were studied. The water extract prepared from Liriopis tuber were administrated to the pretreatment group orally once a day for successive 7 days, followed by treatment with $CCl_4$ on the seventh day. The post treatment group was treated with $CCl_4$ and then the water extract was administrated. The activities of glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), lactate dehydrogenase (LDH), and contents of total cholesterol and triglyceride in pretreatment rats serum were significantly decreased compared to the only $CCl_4$ treated rats. The level of high density lipoprotein (HDL) cholesterol was considerably increased compared to the only $CCl_4$ treated rats. In the pretreatment group with the water extract of Liriopis tuber tissue destruction was not observed in light microscopic investigation, compared to the only $CCl_4$ treated rats. These results suggest that Liriopis tuber have potent hepatoprotective effect against carbon tetrachloride intoxicated rats.

• Korean Chemical Engineering Research
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• v.44 no.6
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• pp.563-571
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• 2006

Vapor grown carbon fiber (VGCF) nano-materials such as carbon nanotubes and carbon nanofibers were directly grown on the surface of the stainless steel mesh pre-treated by reduction. The reduction of the stainless steel mesh by hydrogen formed small catalytic particles and large particles with bi-modal distribution on the metal surface. When the VGCFs were synthesized on the reduced mesh, carbon nanotubes (CNTs) were dominantly grown from the small catalytic particles without supplying hydrogen gas. However, carbon nanofibers (CNFs) were dominantly grown from the large catalytic particles with hydrogen.

• Journal of Environmental Health Sciences
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• v.21 no.4
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• pp.17-23
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• 1995

As a basic experiment to develope biological pretreatment proces~ in water treatment, the experiments on biodegradability and isothermal adsorption of activated carbon were performed on refractories such as humic acid, $NH_3-N$, phenol and ABS which caused the problems in drinking water treatment. Also, the treatabilities on humic acid were examined in the continuous flow type reactors. The removal efficiencies of humic acid, $NH_3-N$, phenol and ABS in the biodegradable experiments for 5 days were 20.1%, 73.4%, 91.7% and 97.5%, respectively. In the isothermal adsorption test of refractories on activated carbon to be used as a media in the continuous flow type reactors, ABS and phenol are adsorbed easily, but humic acid and $NH_3-N$ are difficult to be done. The removal efficiencies of humic acid in granular activated carbon(GAC) reactor were about 7-8% higher than in biological activated carbon(BAC) reactor. The removal efficiencies of humic acid in biological fluidized bed(BFB) reactor were about 30% in GAC media, but were almost zero in sea sand media.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.1
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• pp.122-127
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• 2006

The aim of this study was to investigate the characteristics of membrane fouling caused by soluble organic materials in a membrane bioreactor process. For the removal of filterable organic materials (FOC) smaller than $1{\mu}m$, coagulants and activated carbon were added. A membrane bioreactor using a submerged $17{\mu}m$ metal sieve was operated in laboratory scale to examine the possibility of membrane fouling control. As the dosage of GAC and coagulant increased, the residual FOC concentration decreased and the permeate flow rate increased markedly. The permeate flux increased with an increased PACl addition at the range from 0 to 50 mg/l. At coagulant dosage of 27mg/l, the removal of FOC was about 46% and the flux increased to 3.5 times compared to the case without PACl addition. The permeate flux increased gradually with an increase in GAC dosage. At GAC dosage of 50mg/L, the permeate flux was about 2 times higher compared that for raw water. The particle in the range of $0.1{\sim}1.0{\mu}m$ were removed effectively by the addition of GAC and coagulant. Higher osage of GAC and coagulant, led to higher removal of FOC. A different set of experiments was also performed to investigate the effect of pretreatment on the permeation ability of MBR system using the metal sieve membrane. After 40 hours of operation, the permeate flux was about 1,000 ($L/m^2-hr$), which is 20 times higher compared to the results in literature. It is likely that combined pretreatment using coagulant and activated carbon was the most effective to resolve membrane fouling problems. Moreover, the continuous operations could be successful by applying this pretreatment method.

• Journal of Ginseng Research
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• v.27 no.1
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• pp.1-10
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• 2003

In present study, we examined whether or not the pretreatment of Korean Red Ginseng (KRG) could protect hepatotoxicity induced by carbon tetrachloride (CCl$_4$) and D-galatosamine (GalN). For this study, we not only tested activity of various plasma enzymes (AST, ALT, SDH, LDH), which are used as indicators of liver disease, but also checked the change of liver components such as lipid, glutathione and cytochromes content, and several liver enzyme activity. Pretreatment of KRG for two weeks significantly reduced the elevated plasma enzyme activities induced by CCl$_4$ and GalN. Pretreatment of KRG also restored the hepatic enzymes, malonedialdehyde formation, and depletion of reduced glutathione content induced by CCl$_4$ and GalN to near normal level. However, ${\gamma}$-glutamylcysteine synthetase activity was lot affected by KRG. These results suggest that KRG shows the hepatoprotective effect by reducing lipid peroxidation, by reducing the activity of free radical generating enzymes, and by preserving the hepatic glutathione.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.7
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• pp.1018-1023
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• 2010

This study was conducted to investigate quality changes of apple slab after pretreating with supercritical $CO_2$. L, a, b and color difference values were little changed at increasing temperature and pressure. Polyphenol oxidase was inhibited according to increment of supercritical $CO_2$ temperature and pressure. Springiness and hardness were increased at increasing pressure and temperature condition of pretreatment but hardness showed lower value than untreatment. The texture like sponge of dried apple slab was probably due to channels which were made during penetration and release of carbon dioxide.

• Biomolecules & Therapeutics
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• v.7 no.1
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• pp.35-43
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• 1999

Hepatoprotective effects of Malloti cortex extract (MCE) from Mallotus japonicus against the carbon tetrachloride (CCl$_{4}$) and galactosamine (GalN) were investigated. Whereas serum aspartate aminotransferase and alanine aminotransferase levels were markedly elevated after CCl$_{4}$ and GalN administration, pretreatment and posttreatment with MCE before and after the injection of CCl$_{4}$ and GalN resulted in decreases in elevated serum aminotransferase activities. Whereas CCl$_{4}$ and GalN treatment caused 3~7 fold increases in sorbitol dehydrogenase and ${\gamma}$-glutamyltransferase activities, pretreatment and posttreatment with MCE resulted in the blocking of CCl$_{4}$ and GalN-induced liver toxicity. The hepatoprotective effect of MCE was in part due to MCE-induced elevation of hepatic glutathione levels. Pretreatment and posttreatment with MCE also reduced increased lipid peroxidation induced by CCl$_{4}$ and GalN. These results suggest that MCE may be useful for the prevention and therapy of hepatotoxic pathogenesis. It is presumed that protective and therapeutic effects of MCE due to be inducible glutathione S-transferase and glutathione reductase activities, involving in glutathione-medicated detoxication and maintainment of glutathione content, respectively.