• Journal of Microbiology and Biotechnology
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• 제3권4호
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• pp.266-269
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• 1993

The production of free non-volatile and volatile organic acids in Kimchi during fermentations at 30, 20 and $5^{\circ}C$, were determined by gas chromatography. The order in the amount of non-volatile organic acid, soon after preparation, was malic, citric, tartaric, pyroglutamic, oxalic, lactic, succinic and ${\alpha}-ketoglutaric$ acids. The major non-volatile acids at the optimum ripening time were malic, tartaric, citric and lactic acids, and as the temperature was lowered, the amount of lactic, succinic, oxalic, pyroglutamic and fumaric acids increased, while that of malic and tartaric acids decreased. The order in the amount of volatile acids at the beginning was acetic, butyric, propionic and formic acids. Among these acids, acetic acid was significantly increased in its amount during fermentation and the Kimchi fermented at low temperature produced more acetic acid than that fermented at high temperature.

• 약학회지
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• 제39권3호
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• pp.283-288
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• 1995

Rapid gas chromatographic profiling method was applied to saliva from healthy subjects for the analysis of free organic acids. Saliva samples were first saturated with NaHCO$_{3}$ and extracted with diethyl ether. The aqueous phase was solid-phase extracted using Chromosorb P as the adsorbent and diethyl ether as the eluent after the acidification and NaCl saturation, followed by triethylamine treatment. The resulting tiiethylammonium salts of acids were directly converted into stable tert.-butyl-dimethylsflyl derivatives, with subsequent analysis by dual-capiuary column gas chromatography and gas chromatograpy -mass spectrometry. From the ten saliva samples studied, twenty eight free organic acids including various fatty acids, hydroxy acids, dicarboxylic acids, md aromatic acids were tentatively identified. Among the acids identified , the concentration of lactic acid was highest for five saliva samples while $\alpha$-hydroxyisocaproic acid was most abundant for me sample, and succinic acid and glycolic acid for two samples. respectively. When the GC profiles were simplified to the corresponding acid retention index spectra of bar graphical form, they presented characteristic patterns for each individual.

• Corrosion Science and Technology
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• 제6권2호
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• pp.68-73
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• 2007

The toxicity of chromium that is used to impart corrosion resistance to galvanized steel created environmental and health-related concerns and generated a great deal of interest in developing chrome-free treatment coatings. In the present work, organic-inorganic composite coatings were used to coat electrogalvanized steel (EG) sheets for corrosion protection without degrading its weldability property. The new coatings composed of specially modified polyurethane dispersion hybridized with silicate and unique inorganic-organic inhibitors were developed during this work. It was found that about $1{\mu}m$ thickness of coating layer is secure enough in corrosion resistance of flat and formed part even after alkaline degreasing. Overall chemical resistances including fingerprint resistance and paint adhesion property were satisfied with the test specification of Sony technical standard of SS-00260-2002. Therefore, it is concluded that the newly developed chrome-free product can replace the conventional chromated product.

• 한국유기농업학회지
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• 제25권1호
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• pp.23-35
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• 2017

The objective of this study is to analyze a price of environment-friendly and conventional rice with POS data. And we estimate the value of environment-friendly's certification with hedonic price model. In case of price level, organic and pesticide-free rice is higher than conventional rice, 22.5% and 10.6%, respectively. In contrast, price variation of conventional rice is higher environment-friendly rice. The value of organic and pesticide are 839.5 Won and 313.7 Won, respectively. As time goes by, the certification's value goes down in environment-friendly rice. In particular, price level and certification's value of pesticide-free rice is similar with conventional rice. The results of this study show that price of the environment-friendly rice is not higher than expected. Therefore it is necessary to establish a new marketing and promotion strategies for environment-friendly rice.

• 한국식품조리과학회지
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• 제19권1호
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• pp.1-10
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• 2003

자소자를 무 무게에 대해 0, 0.25, 0.5, 0.75, 1.0%의 비율로 첨가하여 담근 동치미 중 자소자를 첨가하지 않은 대조구와 전보에서 가장 기호도에서 가장 좋은 평가를 받고 이화학적으로 가장 바람직한 결과를 나타낸 0.5% 첨가한 동치미의 유리당, 유리아미노산, 휘발성 유기산 및 향기성분을 알아본 결과 다음과 같다. 1. Glucose와 fructose의 함량은 발효가 진행되면서 감소하는 반면 glycerol의 경우에는 동치미 담금직후 및 적숙기에는 존재하지 않았으나 서서히 증가하여 발효 말기인 45일에 나타나는 경향이었다. 유리당 함량은 자소자를 0.5% 첨가한 경우가 자소자를 첨가하지 않은 대조구보다 약간 많았다. 2. 유리아미노산은 대조구의 경우 저장기간이 증가함에 따라 서서히 증가하였으나 0.5%의 자소자를 첨가하여 담근 동치미의 유리아미노산은 맛이 좋아지는 시기인 발효 11일까지는 다량의 아미노산을 함유하였으나 저장기간이 증가함에 따라 감소하는 경향으로 나타났다. 3. 확인된 비휘발성 유기산은 latic acid, fumaric acid, succinic acid, malic acid, tartaric acid, citric acid 였는데, 발효가 진행됨에 따라 lactic acid와 succinic acid만이 점차로 증가하였고, 나머지는 감소하였다. 4. 동치미의 향기성분은 담금 즉시에는 0%와 0.5%를 비교한 결과 두 처리구 모두 함황 화합물이 대부분을 차지하여 동치미의 주 향기성분이었는데, 발효가 진행되면서 함황 화합물의 수나 %area가 약간 감소하였고, 산류나 알코올류 등이 증가하였다 이에 반해 자소자 처리구의 경우는 산류의 큰 증가를 보이지 않았고, 또한 함황 화합물의 변화가 두드러지지 않았고, 거의 유지하는 수준이었다. 본 실험의 결과 자소자를 첨가하지 않은 대조구보다 0.5% 처리구가 유리당, 유리아미노산, 비휘발성 유기산의 함량이 다소 높게 나타나 전보에서 가장 기호도가 높게 평가된 자소자 0.5% 첨가한 것과 일치하는 결과를 보였다.

• 한국물환경학회지
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• 제25권1호
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• pp.151-158
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• 2009

The objective of this study was to determine on optimum ratio of oxidant and catalyst and to evaluate affecting factors such as anions and cations on persulfate oxidation of organic pollutant. Fe(II) activated the persulfate anion to produce a sulfate free radicals and thus effectively used to degrade the target organic pollutant in aqueous system. The chloride ions reacted with sulfate radical produced the $Cl^{\cdot}$ atom and had positive effects on the oxidation of organic pollutant at the initial stage. However, it was observed that chloride ions had the scavenging effects on the rate of oxidation of organic pollutant. Cations and some heavy metals were partly able to activate the persulfate anion to generate a sulfate free radical. However, high levels of cations inhibited the oxidation of organic pollutant.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.365-365
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• 2006

The wavelength dispersion of birefringence (or retardation) is very important property for optical use of polymer films. Birefringence free film and retardation film have been widely used for applications such as liquid crystal display (LCD). In this study, miscible polymer blends which consist of polymers of positive and negative birefringence were found. By operating composition and orientation of molecules in the transparent blend films, the behavior of wavelength dispersion of birefringence (retardation) was controlled. The applicability to wideband birefringence free film and quarter wave (retardation) film was discussed.

• 대한가정학회지
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• 제23권3호
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• pp.75-84
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• 1985

This studies was conducted to elucidate the taste components of shellfishes, producted in Korea. Four kinds of shellfishes including sea mussel, short-necked clam, corb shell and ark ahell were selected according to the higher sales order and cheaper retail price at 50 fish markets in Seoul in August 1982. The results are : Palatable taste of shellfishes should be caused by nucleotide related products, organic acids and free amino acids. Thus taste components found in four shellfishes were succinic, fumaric, and lactic acids as organic acids, glycine, alanine and glutamic acid as free amino acids.

• Nuclear Engineering and Technology
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• 제53권4호
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• pp.1297-1303
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• 2021

Most thickness measurement techniques using X-ray radiation are unsuitable in field processes involving fast-moving organic films. Herein, we propose a Compton scattering X-ray radiation method, which probes the light elements in organic materials, and a new simple, non-destructive, and non-contact calibration-free real-time film thickness measurement technique by setting up a bench-top X-ray thickness measurement system simulating a field process dealing with thin flexible organic films. The use of X-ray fluorescence and Compton scattering X-ray radiation reflectance signals from films in close contact with a roller produced accurate thickness measurements. In a high-thickness range, the contribution of X-ray fluorescence is negligible, whereas that of Compton scattering is negligible in a low-thickness range. X-ray fluorescence and Compton scattering show good correlations with the organic film thickness (R² = 0.997 and 0.999 for X-ray fluorescence and Compton scattering, respectively, in the thickness range 0-0.5 mm). Although the sensitivity of X-ray fluorescence is approximately 4.6 times higher than that of Compton scattering, Compton scattering signals are useful for thick films (e.g., thicker than ca. 1-5 mm under our present experiment conditions). Thus, successful calibration-free thickness monitoring is possible for fast-moving films, as demonstrated in our experiments.

• 한국식품영양학회지
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• 제28권3호
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• pp.499-506
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• 2015

The aim of this study was to investigate the changes in the taste components of cheonggukjang made with germinated soybeans, which is produced by the addition of a smoking process. The total organic acid content of smoked cheonggukjang made with germinated soybeans (SCGS) was four times higher than that of non-smoked cheonggukjang made with non-germinated soybeans (NCNS). The total organic acid content of SCGS was lower than that of non-smoked cheonggukjang made with germinated soybeans (NCGS). The total free sugar content of NCGS and SCGS was approximately three times higher than that of NCNS. The total free amino acid content of NCGS was significantly decreased compared with that of NCNS, whereas the total free amino acid content of SCGS was 1.2 times higher than that of NCGS. The essential amino acid content of SCGS was significantly increased compared with that of NCGS. The ratio of glutamic acid to the total free amino acid in NCNS and SCGS was 19.6%. Similarly, the ratio of glutamic acid to the total free amino acid in NCGS was 19.1%. There were no significant differences in the total fatty acid content of NCNS, NCGS, and SCGS. The sensory evaluation of appearance, aroma, taste, and overall quality of SCGS was significantly increased compared with that of NCNS and NCGS. These results suggest that smoked cheonggukjang made with germinated soybeans could be utilized for the development of a novel fermented food.