• 자원리싸이클링
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• 제19권6호
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• pp.70-76
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• 2010

본 연구에서는 인산염계 모나자이트정광을 수산화나트륨 용액에 의한 분해와 영산 침출공정을 이용하여 최적의 희토류 침출조건을 확립하고자 하였다. 모나자이트정광의 hot digestion 분해 및 염산침출 실험용 수행결과 알카리 분해는 NaOH/TREO 몰비 15, 분해반응온도 $140^{\circ}C$, 분해반응시간 2시간 이상의 조건에서 분해율 90% 이상을 나타내었다. 그리고 알카리 분해 산물의 염산침출 반응 최적조건은 염산농도 6N, 침출반응 온도 $70^{\circ}C$, 침출반응시간 2시간 및 광액농도 15% 내외가 가장 효과적이었고, 이 때 회토류 침출율은 90% 이상 이었다.

• 한국산업보건학회지
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• 제11권1호
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• pp.48-55
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• 2001

The purpose of this study was to evaluate the analytical accuracy and precision of microwave oven digestion/atomi absorption spectrophotometry (AAS) for analyzing airborne chromium collected on mixed cellulose ester membrane (M filter from the work environment, and to compare the accuracy and the precision with those of the National Institute for Occupational Safety and Health (NIOSH) Method #7024 hot plate digestion/AAS method. For this study, field air sample pairs were collected from a electroplating process, and spiked samples in a laboratory were prepared and using these samples. Two digestion methods were comp; and evaluated in terms of recovery rate and bias as indices of accuracy and coefficient of variation as a index of precision. The results and conclusions are as follows. In spiked samples, the accuracies (% mean recoveries) of hot plate/AAS and microwave oven/AAS method were 97.19%, 97.1%, respectively, and the precisions (pooled respectively, and the precisions (pooled coefficient of variance, $CV_{pooled}$) 6.93% and 3.88%, respectively. The biases of hot plate ani microwave oven methods were 4.56 - 14.7% and 2.22 - 7.42% respectively. There was no statistically significant difference between hot plate and microwave oven methods recovery rates of spiked samples (p>0,05). Also, no statistically significant difference was shown among the concentrations of air samples determined by two method (p>0.05). In conclusion, microwave oven/AAS method h excellent accuracy and precision, and advantages such as time-saving and simple procedure in comparison with the classical NIOSH method. Therefore, this method can be use widely to analyze airborne chromium collected on MCE filter from the work environments.

• 대한한의학회지
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• 제29권4호
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• pp.180-193
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• 2008

Objectives: We intended to identify factors related to the severity of hot flush of climacteric women from an East-West medical point of view. Methods: We surveyed 446 climacteric women who had received Korean oriental medical questionnaires about clinical symptom patterns and health medical examinations at Kyung-Hee University Medical Center over 1 year, from June 2007 to May 2008. Then, we compared hot flush with clinical symptom pattern and health medical examination result. Results: As the severity of hot flush increased, hypnagogic disorder in sleep pattern, abdominal gaseous distention in digestion pattern, tenesmus in evacuation pattern, yellow or reddish urine in voiding pattern, spontaneous sweating in sweating pattern, chest oppression in psychologic pattern, not-pulling-bedclothes in cold-heat pattern and mouth dryness in craniocervical symptom increased (p<0.05). In relation to digestion pattern, the severity of hot flush showed statistical significance according to prevalence of gastritis diagnosed by gastroscopy and upper GI series(p<0.01). In relation to voiding pattern, the severity of hot flush showed statistical significance according to prevalence of urine protein diagnosed by urinalysis (p<0.05). In relation to sweating, psychologic & cold-heat pattern, triiodothyronine (T3) increase and thyroid stimulating hormone (TSH) decrease were significantly correlated as the severity of hot flush increased (p<0.01). Conclusions: The result showed that hot flush of climacteric women had to be considered in respect of digestion disorder related to gastritis and sweating psychologic cold-heat disorder related to thyroid hormone.

• 생명과학회지
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• 제14권6호
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• pp.925-930
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• 2004

양파 열수 추출물의 항산화능 및 인공소화 전과후의 항돌연변이 효과를 BHT와 ascorbic acid와 비교하여 조사하였다. 총 페놀 및 플라보노이드의 함량은 노란색 양파 추출물이 횐색 양파 추출물보다 많았으며, 양파 추출물의 과산화수소 소거능은 농도가 증가함에 따라 비례적으로 증가하였다. $\beta-carotene-linoleate\;system$에서 항산화능과 reducing power는 증가되었으나, BHT와 ascorbic acid보다는 낮았다. 양파열수 추출물의 인공소화 후에 IQ와 MNNG로 처리된 Salmonella typhimurium TA80과 TA100에 대하여 항돌연변이 효과가 나타났으며, 노란색 양파가 횐색 양파보다 높게 나타났다. 결론적으로 양파 추출물을 소화시키면 항산화 및 항돌연변이의 효과는 양파의 페놀과 플라보노이드의 성분 변화에 의한 것으로 판단된다.

• 공업화학
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• 제10권4호
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• pp.568-575
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• 1999

백금족 금소과 규산염을 포함하는 자동차 폐촉매 내의 백금족 금속과 주요 성분들을 ICP-AES로 동시에 분석하기 위한 두 종류의 전처리 방법이 비교되었다. HF, $HNO_3$, HCl, $HClO_4$, $H_2O_2$, 및 $H_3BO_3$ 등의 혼합산의 다양한 조합을 사용하여 열판(hot plate) 용해법과 밀폐용기를 사용하는 극초단파(microwave) 가압-가열법을 비교 검토하였다. 전통적인 열판 용해법보다 밀폐용기를 사용한 극초단파 가압-가열법이 화수율, 분석시간 및 사용하는 양 등의 측면에서 상대적으로 우수한 결과를 나타내었고, 0.25 g의 폐촉매 시료에 대하여 HF 2 mL, $HNO_3$2 mL, 그리고 HCl 6 mL를 사용하여 200 psi(13.79 bar), $180^{\circ}C$ 조건에서 1시간 동안 가열한 후, 5% (w/v) $H_3BO_3$ 16 mL를 사용하여 20 psi(1.38 bar), $100^{\circ}C$ 조건에서 10분간 가열한 다음, 왕수 10 mL로 열판에서 두 번 반복하여 처리하는 것이 백금족 금속의 회수율 측면에서 가장 좋은 결과를 가져왔고(XRF 분석 대비 85~110%), 이 방법은 2% 이내의 상대 표준 편차를 보임으로써, 자동차 폐촉매의 일상적인 분석기법으로서의 충분한 가능성을 보였다.

• Food Science and Biotechnology
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• 제18권2호
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• pp.317-322
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• 2009

The proteins from 15 types of cultivar of hot peppers cultivated in Korea were extracted and its allergenicity was investigated by immunoblotting and enzyme-linked immunosorbent assay (ELISA). The immunoblotting of hot pepper proteins extracts (HPEs) against serum of hot pepper sensitized patients revealed dominant IgE binding to 14, 37, and 40 kDa molecules. The specific levels of IgE to HPEs sample No. 1, 3, and 7 were much higher than the other samples in patients. Also, IgE binding capacity of HPEs were not reduced by thermal processing and digestion in ELISA using human IgE antibody acquired from hot pepper sensitized patients. By means of Western blotting using anti-thaumatin IgY, thaumatin-like protein (TLP) acting as allergen in several plants and fruits was detected in tested hot peppers. This study demonstrates that the antigenic protein in hot peppers are present but are differently contained according to cultivars.

• 한국수산과학회지
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• 제36권3호
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• pp.210-219
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• 2003

To develop natural flavoring substances, optimal two stage enzyme hydrolysis conditions and flavor compounds of short-neck clam (Tapes philippinarum) enzyme hydrolysates were examined. The optimal enzyme hydrolysis conditions for two stage enzyme hydrolysate (TSEH) of short-neck clam were revealed in temperature at $55^{\circ}C$ for 4 hours digestion with alcalase at the 1st stage and 4 hours digestion at $45^{\circ}C$ with exopeptidase type neutrase at the 2nd stage. In quality tests of hot-water extracts, steam extracts and 4 kinds of enzyme hydrolysates, TSEH processing method was superior to other methods in yield, nitrogen contents, organoleptic taste such as umami intensity and inhibition of off-flavor formation, and transparency of extract. Total free amino acid contents in hot-water extract, steam extract and TSEH were 1,352.1 mg/100 g, 1,174.1 mg/100 g and 2,122.4 mg/100 g, respectively, Major free amino acids in TSEH were glutamic acid, glycine, alanine, tyrosine, phenylalanine and arginine. As for nucleotides and other bases, betaine, TMAO and creatinine were principal components in TSEH. The major inorganic ions in TSEH were Na, K, P and Cl. TSEH also revealed very higher angiotensin-I converting enzyme inhibition effect $(70.7\%)$ than those of hot-water and steam extract. We conclude that TSEH from short-neck clam was more flavorable compared with the seasoning materials on the market, it could be utilized as the instant soup base and the seasoning substances for fisheries processing.

• 한국토양비료학회지
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• 제44권5호
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• pp.727-733
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• 2011

A new Korean standard for the determination of Cr(VI) in soils has been officially published as ES 07408.1 in 2009. This analytical method is based on the hot alkaline digestion and colorimetric detection prescribed by U.S. EPA method 3060A and 7196A. The hot alkaline digestion accomplished using 0.28 M $Na_2CO_3$ and 0.5 M NaOH solution (pH 13.4) at $90{\sim}95^{\circ}C$ determines total Cr(VI) in soils extracting all forms of Cr(VI), including water-soluble, adsorbed, precipitated, and mineral-bound chromates. This aggressive alkaline digestion, however, proved to be problematic for certain soils which contain large amounts of soluble humic substances or active manganese oxides. Cr(III) could be oxidized to Cr(VI) by manganese oxides during the strong alkaline extraction, resulting in overestimation (positive error) of Cr(VI). In contrast, Cr(VI) reduction by dissolved humic matter or Fe(II) could occur during the neutralization and acidic colorimetric detection procedure, resulting in underestimation (negative error) of Cr(VI). Futhermore, dissolved humic matter hampered the colorimetric detection of Cr(VI) using UV/Vis spectrophotometer due to the strong coloration of the filtrate, resulting in overestimation (positive error) of Cr(VI). Without understanding the mechanisms of Cr(VI) and Cr(III) transformation during the analysis it could be difficult to operate the experiment in laboratory and to evaluate the Cr(VI) results. For this reason, in this paper we described the theoretical principles and limitations of Cr(VI) analysis and provided useful guidelines for laboratory work and Cr(VI) data analysis.

• Preventive Nutrition and Food Science
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• 제7권3호
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• pp.317-319
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• 2002

Exo-polygalacturonase (EPG) from Rhizopus sp. was applied to the extraction of alginic acid from sea mustard to increase extraction yield. EPG digestion was examined under distinct conditions within temperatures from $25^{\circ}C$ to 5$0^{\circ}C$, pH 5 to 9, and treatment times from 0 to 36 hr. The optimal conditions fur alginic acid extraction with EPG were: pH 7.0 at 3$0^{\circ}C$ for 24 hrs. The EPG hot water extraction yield was 3.4 times higher yield than hot water extraction alone. Using EPG to extract alginic acid from sea mustard should be considered a viable alternative to conventional extraction, with the advantage of reducing hazardous wastes such as strong acid and alkali solutions.

• 한국작물학회지
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• 제44권1호
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• pp.64-69
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• 1999

Gelatinization characteristics of 111 glutinous rice varieties were evaluated by Rapid Visco Analyzer. Gelatinization viscosity of glutinous rice tested varied with ecotypes or varietal groups: indica, japonica, and Tongil type. Indica rice showed the highest average value of initial pasting temperature. The average values for peak, hot, and cool viscosities were highest in Tongil-type rice, and lowest in japonica rice. Japonica showed the lowest breakdown and consistency, but the highest setback value. Indica was lower in alkali digestion value (ADV), and shorter in gel length after gelatinization thanjaponica and Tongil-type. Glutinous rices tested could be divided into six groups by cluster analysis based on their gelatinization characteristics. Group I-A was mostly early maturing japonica varieties while I-B was mostly indica and Tongil-type rices. Groups II-A and II-B were consisted of very early maturingjaponica, and III-A and III-B included medium or medium late maturingjaponica varieties. Group III-A showed the lowest average values of peak, hot, cool, and consistency viscosities, and also in breakdown and setback ratios. Group I-B revealed the highest values in peak, hot, cool, breakdown, and consistency viscosities. ADV was low in groups I-A, I-B, and II-B, and gel consistency was not different among the six varietal groups. Principal component analysis using seven traits related with gelatinization produced four effective components, and the first and second components were highly correlated with all the gelatinization characters evaluated.