• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.43 no.1
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• pp.29-35
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• 2011

Since the role of lignin in the wood cell wall is to keep integrity and structure rigidity of lignocellulosic substrate, lignin of the cell wall has to be destroyed before enzymatic hydrolysis of wood polysaccharides. The aspen wood meals were delignified with ozone in acidic condition. The chemical characteristics of wood meal were investigated. The 60% of lignin and almost zero % of polysaccharides in aspen wood meal was degraded with 10min. ozone treatment. The phenolic hydroxyl groups of lignin in ozonated wood meal were increased with ozonation time. The sugar composition of ozonated wood meal showed that the hemicellulose was more susceptible to ozonation than cellulose. The yield of aldehyde was increased in some degree with 10min. ozone treatment and decreased with longer ozone treatment.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.43 no.1
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• pp.23-28
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• 2011

The pine wood meal was ozonated in acidic water. A 91.3% of lignin and 13% of polysaccharides in pine wood meal were degraded with 180 min ozonation. The phenolic hydroxyl groups of lignin in ozonated wood meals were increased with ozonation time. The vanillin content in nitrobenzene oxidation products of lignin is decreased with 10 min. ozonation and it was slightly increased with ozonation time. The sugar composition of ozonated wood meals showed that the hemicellulose was more susceptible to ozonation than cellulose. The crystallinity of ozonated wood meal was increased.

• Journal of the Korean Wood Science and Technology
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• v.31 no.3
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• pp.11-16
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• 2003

On nitrobenzene oxidation of aspen, spruce, and knauf wood meals gave rise to vanilline, syrigaldehyde, p-hydroxybenzoaldehyde, vanillic acid, and other minor oxidation products. The phenolic aldehydes (p-hydroxybenzaldehyde, vanilline, and syringaldehyde) are derived from oxidative degradation of the corresponding 4-hydroxyphenylpropane units and their ethers. The lignin content of knauf wood meals was different as the concentration of NaOH solution and cooking temperature. The lignin contents of aspen, spruce, and knauf wood meals were decreased as laccase treatment. The laccase caused C-oxidation, demethylation, cleavage in phenolic groups and C-C cleavage in syrigyl structures.

• Carbon letters
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• v.4 no.1
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• pp.21-23
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• 2003

In this work, the effect of anodic oxidation treatment on Cr(VI) ion adsorption behaviors of activated carbon fibers (ACFs) was investigated. The aqueous solutions of 10 wt% $H_3PO_4$ and $NH_4OH$ were used for acidic and basic electrolytes, respectively. Surface characteristics and textural properties of ACFs were determined by XPS and $N_2$ adsorption at 77 K. The heavy metal adsorption of ACFs was conducted by ICP. As a result, the adsorption amount of the anodized ACFs was improved in order of B-ACFs > A-ACFs > pristine-ACFs. In case of the anodized treated ACFs, the specific surface area was decreased due to the pore blocking or pore destroying by acidic electrolyte. However, the anodic oxidation led to an increase of the Cr(VI) adsorption, which can be attributed to an increase of oxygen-containing functional groups, such as, carboxylic, lactonic, and phenolic groups. It was clearly found that the Cr(VI) adsorption was largely influenced by the surface functional groups, in spite of the reduced specific surface area of the ACFs.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.4
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• pp.341-349
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• 1987

Fulvic acids extracted from seven plant materials were tested. The IR spectra and the data obtained from chemical analyses in terms of oxygen-containing functional groups complemented one another. Selected samples covered straws of grain crops (rice, barley, wheat and rye), hay of wild grass, and leaves of trees (deciduous and coniferous). 1. No significant variation in IR spectra of fulvic acids was observed among samples taken from different plant residues and at different stages of humification. 2. Oxygen-containing functional goups, such as carboxyls, phenolics, alcoholics, carbonyls, and quinones were identified on IR spectra and confirmed by chemical analyses. 3. The acidity of fulvic acids was directly related with the content of carboxyl groups. 4. Alcoholic hydroxyl groups predominated over phenolic hydroxyls. 5. The major part of fulvic acid structure appeared to be strongly aliphatic in many respects of chemical characteristics.

• Food Science and Preservation
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• v.11 no.1
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• pp.79-87
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• 2004

To investigate antioxidative effects of phenolic compounds separated from persimmon leaves(PL)(Diospyros kaki Thunb.) on the ethanol-induced hepatotoxicity in rat, Sprague-Dawley rats weighing 100-150 g were divided into 5 groups; control group(CON), PL(70 mg/kg) administered group(PEl), ethanol(5 mL/kg, 25％) administered group(ETH), PL(70 mg/kg) and ethanol administered group (PE2), and PL(140 mg/kg) and ethanol administered group(PE3), respectively. The antioxidative activity of persimmon leaves decreased in order of ethylacetate>interphase materials>n-butanol>chloroform>n-hexane>water fraction. The growth rate and feed efficiency ratio decreased by ethanol were gradually increased to the adjacent level of CON by administering PL. The serum activities of ALT, alkaline phosphatase and lactic acid dehydrogenase elevated by ethanol were decreased significantly. It was also observed that the activities of SOD, catalase, and GSH-Px of rat liver increased by ethanol were markedly decreased in PL administered group as compared to ETH. The GSH content of liver was decreased by ethanol, but that was increased in PE1 and PE2 compared with ETH as a dose-dependant manner. These results suggested that phenolic compounds separated from persimmon leaves have a possible protective and relievable effect on the ethanol-induced hepatotoxicity in rats.

• Korean journal of food and cookery science
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• v.27 no.1
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• pp.43-54
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• 2011

Job's tears (Coixlachryma-jobi L.) and Chungkukjang (soybean-fermented food) were abundant source of phenolic compounds. In this study, almond cookies were prepared with different concentration(5%, 10%, 15%), of Job's tears Chungkukjang powder. The total phenolic contents were measured by the Folin-Ciocalteu method, total flavonoids contents were measured, and antioxidant activities were evaluated by DPPH assay. Antioxidative activity was highly correlated with the total phenolic and total flavonoids contents of Job's tears Chungkukjang almond cookies (r=0.867, r=0.647). In addition, the quality characteristics of the Job's tears Chungkukjang almond cookies were estimated based on the bulk density and pH of the dough, spread factor, color, texture profile analysis, proximate composition, and sensory evaluations. The spread factor, hardness, a value and b value, total polyphenolic contents, and DPPH free radical scavenging activity of cookies significantly increased with increasing content of Job's tears Chungkukjang powder (p<0.01), whereas the L values of the cookies decreased with the increasing Job's tears Chungkukjang powder content (p<0.05). The acceptability scores for the 5-15% Job's tears Chungkukjang almond cookie groups were ranked higher than those of the other groups in appearance, texture, and overall preference. The results of this study were shown that Job's tears Chungkukjang powder was a good ingredient for increasing the consumer acceptability and the functionality of cookies.

• The Korean Journal of Food And Nutrition
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• v.24 no.4
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• pp.567-576
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• 2011

A study was undertaken to examine the antioxidative activity and the quality attributes of broccoli stem powder pound cakes. Broccoli stem powder was added to the batter at a ratio of 5, 10 and 15% respectively. The antioxidant activity was estimated by DPPH free radical scavenging activity, the total phenolic compounds content and flavonoid content in Broccoli stem powder and pounds cakes. Antioxidative activity was highly correlated with the total phenolic and total flavonoids contents of broccoli stem pound cakes respectively($r$=0.937, $r$=0.981). The effect of cake improver on quality characteristics of cake broccoli stem powder and pound cakes were estimated in terms of the specific load volume, hardness, hunter value of crumb and crust and sensory quality of cakes. The specific volume were increased significantly with increasing substitution level of cake improver and broccoli stem powder($p$ <0.01). The lightness were significantly decreased with increases in broccoli stem powder of pound cake crust and crumb($p$ <0.01, $p$ <0.01). The hardness, chewiness and gumminess and cohesiveness were tended to reduce in both of powder. The consumer acceptability score for 5~10% broccoli stem pound cakes ranked significantly($p$ <0.01) higher than those of the other groups in taste, flavor and overall preference. This results showed that cake improver & broccoli stem powder are a good ingredient to increase consumer acceptability and the healthy.

• Journal of the Korean Society of Tobacco Science
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• v.31 no.1
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• pp.9-17
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• 2009

Activated carbon fiber (ACF) was surface modified by nitric acid to improve the adsorption efficiency of the propylamine. Functional groups and textural properties of modified ACF were investigated. The total surface acidity increased about 7 times to that of as-received ACF by modification with 1 M nitric acid solution, carboxylic and phenolic groups mainly increased. However, the specific surface areas and the total pore volumes of the modified ACFs were decreased by 5-8% due to the increased blocking (or demolition) of micropores in the presence of newly introduced complexes. Despite the decrease of textural properties, it was found that the amount of propylamine adsorbed by the modified ACFs was increased by approximately 17%. The oxygen and nitrogen contents on the modified ACF increased by 1.5 and 3 times compared with the as-received ACF. From the XPS results, it was observed that propylamine reacted with strong or weak acidic groups, such as -COOH or -OH on the ACF surfaces, resulting in the formation of pyrrolic-, pyridonic- or pyridine-like structures.

• Applied Chemistry for Engineering
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• v.29 no.2
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• pp.237-243
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• 2018

The surface chemistry of WCK-AC, WCN-AC and WCZ-AC which are activated carbons prepared from waste citrus peel using KOH, NaOH, and $ZnCl_2$ as activating chemicals were investigated. Also the relationships between the adsorption capacities of the target gases such as acetone, benzene and methyl mercaptan (MM) by the prepared activated carbons and the pore characteristics of each activated carbon were examined. According to XPS analysis of the prepared activated carbons, graphite and phenolic were the main surface functional groups of C1, and the sum of phenol, carbonyl and carboxyl groups increased in the order of WCK-AC > WCN-AC > WCZ-AC. The breakthrough curves obtained from the adsorption experiments for the three target gases in the fixed bed adsorption reactor were well simulated by the empirical equations proposed by Yoon and Nelson. The adsorption capacity for acetone, benzene and MM was larger for activated carbons with the larger sum of surface functional groups. The larger the specific surface area and the pore volume of activated carbons and the smaller the pore size, the better the adsorption performance. In particular, the specific surface area was the best criterion for the adsorption performance of activated carbons used in this study.