• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.226.1-226
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• 2003

최근 쌀 소비량이 감소되고 쌀중심 식생활의 영양적 우수성을 인식하지 못하여 쌀은 주식으로서 위치가 흔들리고 있다. 그동안 쌀의 영양특성에 관한 연구로서 주로 탄수화물 급원으로서의 당질에 관한 연구와 미강을 중심으로한 식이섬유, 미강유등에 관한 연구결과들이 발표되었다. 특히 미곡 부산물인 미강으로부터 다양한 유효성분들이 확인되어 그 효능이 보고되고 있으며 일부가 기능성 소재로서 제품화되기도 하였다. 그러나 실제 우리의 식생활에서 섭취되고 있는 백미 또는 현미상태에서의 유효성분의 분포 및 함량에 대한 연구는 미진한 상태이다. 본 연구에서는 쌀의 영양적우수성을 규명하고자 유효성분 중 phenolic acid와 폴리페놀 함량을 품종 및 도정도에 따라 조사하였다. 조생종인 오대와 만생종인 남평 품종으로부터 현미와 7분도, 10분도 및 12분도로 도정도를 달리한 백미, 도정도별 미강을 각각 제조하였다. Ferulic acid 등 쌀과 미강에 존재하는 phenolic acid 는 알칼리로 추출한 후 pH를 조정하고 에틸아세테이트로 반복 추출하여 HPLC로 분석하였다. 현미에 함유된 phenolic acid는 ferulic acid가 가장 많아 50％ 내외를 차지하였으며 p-coumaric acid, benzoic acid, sinapinic acid 순으로 검출되었다. 오대 현미의 총 phenolic acid 함량은 65.9 mg%로서 남평 현미의 57.2 mg%보다 높았으며 도정도가 증가할수록 백미 중의 총 phenolic acid 함량은 감소되었다. 미강 중에는 백미의 10배 량에 해당하는 phenolic acid가 검출되었고 benzoic acid와 m-hydroxy benzoic acid는 미강 시료에서만 검출되었다. 도정한 백미 중의 phenolic acid는 28.8∼51.7 mg%, 미강에서 321.4∼438.4 mg% 범위로 나타났다. 현미, 백미 및 미강에 함유된 총 폴리페놀의 함량을 표준 페놀화합물로 카테친을 사용하고 비색법에 의하여 측정하였을 때 오대 현미의 폴리페놀 함량은 78.4 mg%, 남평 현미 88.8 mg% 였다. 도정한 백미 중의 총 폴리페놀 함량은 30.3∼56.9 mg%, 미강이 541.5∼472.6 mg%의 범위였다. 이상과 같이 쌀에는 phenolic acid 및 총 폴리페놀이 상당량 함유되어 있으며 특히 배유보다는 강층에 많이 존재하므로 이들 성분의 효율적인 이용을 위한 쌀의 섭취방안이 필요한 것으로 나타났다.

• Resources Recycling
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• v.23 no.6
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• pp.63-67
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• 2014

Gallium is an important material and is used by industry of oxide semi-conductor and LED chip. However, the most of the gallium-containing waste resources became outflow abroad and the most of which is imported from oversea by following technical problem and low circulation rate. In this research, the recovery of high purity Gallium metal from Gallium scrap, which containing about 30% of Gallium, was investigated by using hydro-metallurgical process. As pretreatment, the Gallium scrap was pulverized and leached by strong acid such as hydro chloric acid. At the leached solution, Indium was separated as an Indium sponge by substitution reaction and then Gallium and Zinc hydroxide separated and filtrated using strong alkaline solution such as sodium hydroxide by precipitation method. Also, Gallium metal and Zinc metal was recovered by electrowinning method. To make an electrolytic solution, Gallium and Zinc hydroxide was leached by strong alkaline solution. Finally, High purity Gallium metal was recovered by vacuum refining process to remove the Zinc impurity.

• Microbiology and Biotechnology Letters
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• v.20 no.6
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• pp.655-662
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• 1992

Pectate lyase produced by recombinant strain containing pectate lyase gene from alkalitolerant Bacillus sp. YA-14 was succesively purified with 257.6 purification folds and a 10.2% yields by the affinity method, eM-cellulose column chromatography followed by gel filtration on Sephadex G-I00 column. The optimal pH and temperature for pectate lyase activity were 10.0 and $60^{\circ}C$, respectively. The enzyme was stable between pH 4.0 and 10.0, and up to $50^{\circ}C$. The molecular weight of this enzyme was estimated to be 43,000 daltons by SDS-PAGE. Amino acid analysis showed that the enzyme contained more polar and basic amino acids, especially serine, glycine and tyrosine, than that of various pectate lyase from other strains. The N-terminal amino acid sequence was Ala-Asp-Leu-Gly-His-Gln-Thr.

• KSBB Journal
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• v.22 no.4
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• pp.228-233
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• 2007

The high cost and lack of vegetable oil are limiting the expansion of biodiesel production. The purpose of research was to investigate the potential of animal fats as biodiesel feedstock. In this paper, transesterification using alkali catalyst and methanol was performed to reaction, we carried out experiments that it was changed variables as reaction temperature, methanol molar ratio, catalyst types, amount of catalyst and reaction time. The optimum reaction condition for biodiesel production was reaction temperature 65$^{\circ}C$, potassium hydroxide 1.0% (w/w), oil to methanol molar ratio 1:15 and reaction time 20 min. In this reaction condition, the contents of fatty acid methyl ester was reached to about 98.7%. Also, properties of biodiesel were measured to correspond to domestic quality standard of acid values, density and viscosity.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.6
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• pp.659-665
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• 2008

This study is about zeolite synthesis from the sewage sludge incinerator fly ash of "S" sewage treatment center located in Seoul. For this purpose, the properties of raw fly ash as starting material, the hydrothermal conditions for zeolite synthesis and the environmental applicabilities of synthesized zeolites were examined. Fly ash from sewage sludge incinerator has large quantities of SiO$_2$ and Al$_2$O$_3$ and their contents are 42.8 wt.% and 21.2 wt.% respectively. So fly ash is considered to be possible starting material for zeolite synthesis. The results from leaching test of fly ash showed that the concentration of hazardous metals were very low as compared with the Korea leaching standard of the Waste Management Law. But the concentration from total recoverable test of fly ash were higher than the fertilizer standard of Fertilizer Management Law. Major zeolite products synthesized by hydrothermal reaction are analcime in teflon vessel and zeolite P1 in borosilicate flask. Optimum conditions for the synthesis of analcime were 1 N of NaOH concentration, 16 hour of reaction time and 135$^{\circ}C$ of reaction temperature. For the zeolite P1 formation, the proper conditions were demonstrated to be 5 N of NaOH concentration, 16 hour reaction time and 130$^{\circ}C$ of reaction temperature in this study. Hazardous metal contents in the analcime product are similar with those in raw fly ash. In case of the zeolite P1, the contents are reduced to nearly a half. Raw fly ash and the analcime product showed NH$_4{^+}$ ion exchange capacity of 0$\sim$1.0 mg of NH$_4{^+}$g$^{-1}$ and 3.0$\sim$7.4 mg of NH$_4{^+}$g$^{-1}$, respectively. However, the zeolite P1 product reached exchange capacity to 14.6$\sim$17.8 mg of NH$_4{^+}$g$^{-1}$. This values are in the range of those of natural clinoptilolite and phillipsite. From this point of view, zeolite synthesis from sewage treatment sludge incinerator fly ash is a good alternative for solid waste recycling.

• Journal of the Korea Concrete Institute
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• v.23 no.3
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• pp.311-320
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• 2011

Fly ash (FA), byproduct from power plant has been actively used as mineral admixture for concrete. However, since bottom ash (BA) is usually used for land reclaim or subbase material, more active reuse plan is needed. Pond ash (PA) obtained from reclaimed land is mixed with both FA and BA. In this study, 6 PA from different domestic power plant are prepared and 5 different replacement ratios (10%, 20%, 30%, 50%, and 70%) for fine aggregate substitutes are considered to evaluate engineering properties of PA as fine aggregate and durability performance of PA concrete. Tests for fine aggregate of PA for fineness modulus, density and absorption, soundness, chloride and toxicity content, and alkali aggregate reaction are performed. For PA concrete, durability tests for compressive strength, drying shrinkage, chloride penetration/diffusion, accelerated carbonation, and freezing/thawing are performed. Also, basic tests for fresh concrete like slump and air content are performed. Although PA has lower density and higher absorption, its potential as a replacement material for fine aggregate is promising. PA concrete shows a reasonable durability performance with higher strength with higher replacement ratio. Finally, best PA among 6 samples is selected through quantitative classification, and limitation of PA concrete application is understood based on the test results. Various tests for engineering properties of PA and PA concrete are discussed in this paper to evaluate its application to concrete structure.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.2
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• pp.137-143
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• 2017

There has been a number of research on concrete durability. specially, as a research on chemical ingression, the research on the degradation against acid, alkali, and sulfate has been conducted. On the other hand, for the research on oils, especially, the influence of various oils on cement mortar with Supplementary Cementitious Materials(SCMs) is not sufficiently studied. hence, in this research, the degradation of cement mortar incorporated fly ash and blast furnace slag is researched when the cement mortar is submerged in various oils. For the result of experiment, as the content of fatty acid in the oils, the degradation of cement mortar with SCMs was occurred more, and the cement mortar with SCMs suffered more degradation than the ordinary portland cement regarding the oil submerging.

• Korean Journal of Food Science and Technology
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• v.26 no.3
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• pp.288-294
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• 1994

Dietary fiber contents in brans of the two representative Korean rice varieties, Chucheong and Sucheon were measured by the AOAC method, and the composition of total dietary fiber (TDF) was analyzed with the acid detergent fiber (ADF) procedure. Rice bran contained more than 25% of TDF, most of which was insoluble dietary fiber. Hemicellulose was shown to be the major constituent and rice bran dietary fiber contained distinctive amounts of cellulose and uronic acid. Consecutive acidalkaline treatment of rice bran considerably increased soluble dietary fiber (SDF) content and water-holding capacity (WHC). WHC of wheat flour-rice bran dietary fiber mixture increased with the proportion of rice bran dietary fiber. Analysis of the differential scanning calorimetry thermograms revealed that rice bran dietary fiber effectively retarded retrogradation of wheat starch.

• Applied Chemistry for Engineering
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• v.23 no.6
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• pp.604-607
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• 2012

Solid base catalysts for biodiesel production were synthesized by impregnating basic metal species on two support materials with large specific surface area : zeolite and pyrolysis char. KL zeolite and Undaria pinnatifida char were impregnated with KOH aqueous solution and calcium nitrate solution, respectively, to enhance the basic strength. The catalysts synthesized were characterized using Hammett indicators and $CO_2$-TPD analysis. Biodiesel was produced using soybean oil and methanol over the catalysts synthesized. The content of fatty acid methyl esters was measured to evaluate the catalytic activity. Generally, the catalytic activity increased with increasing quantity of basic metal impregnated but impregnation of excessive amount of metal could cause reduction in the activity.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.1
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• pp.1-7
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• 1998

Uronate compositions and molecular weights of alginates from the four kinds of brown algae, sea mustard (Undaria pinnatifida), sea tangle (Laminaria japonica), gulf weed (Sargassum fulvellum), and seaweed fusiforme (Hizikia fusiforme), in regard with the harvesting season were investigated. Sea mustard contained the highest amount of alginates in the four kinds of brown algae. D-Mannuronic acid to L-guluronic acid (M/C) ratio of the alginates was high in order of seaweed fusiforme, gulf weed, sea mustard, and sea tangle, and especially in water-soluble alginate. Molecular weights of the alginates were greater with the growing period ranging in $4,500\~4,800\;kDa$ for sea tangle, $4,000\~4,200\;kDa$ for sea mustard, $3,300\~3,400\;kDa$ for seaweed fusiforme, and $3,000\~3,200\;kDa$ for gulfweed. In water-soluble alginate of sea mustard, M/G ratio was much higher in sporophyll than in midrib and blade.