• Geomechanics and Engineering
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• 제27권6호
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• pp.615-626
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• 2021

The main objective of this study is to present a fast and reliable approach to predict the swelling potential of clay-bearing rocks. Investigations showed that there is a good correlation between the swelling potential of a rock and its desire to absorb water due to its clay content which could be measured using the "Contact Angle" test as one of the most common ways to determine the wettability. In this test, the angle between a water drop and the flat rock surface on which it rests is measured. The present method is very fast and returns repeatable results and requires minimal sample preparation. Only having a saw-cut surface of a sample with any shape is all one needs to perform this test. The logic behind this approach is that the swelling potential of a rock is a function of its mineral content and molecular structure, which are not only distributed in the bulk of the sample but also reflected on its surface. Therefore, to evaluate swelling behavior, it is not necessary to wait for a sample to get wet all the way to its "internal structure" (which, due to the low permeability of clay-bearing rocks, is very slow and time-consuming). Instead, one can have a good sense of swelling potential by studying its surface. Parametric studies on the effect of moisture content, porosity, and surface roughness on the contact angle measurements showed that using a saw-cut oven-dried sample is a convenient way to evaluate the swelling potential by this method.

• 한국식생활문화학회지
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• 제17권4호
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• pp.363-376
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• 2002

In order to establish the processing conditions for salt-fermented liquefaction of anchovy(Engrulis japonica), changes in the amino acid composition from oligopeptides during fermentation periods were analyzed. Experimental sample A: chopped whole anchovy, adding 20% water, heating at $50^{\circ}C$ for 9 hrs and then adding 10% NaCl. Sample B: chopped whole anchovy, adding 20% water, heating at $50^{\circ}C$ for 9 hrs and then adding 13% NaCl. Sample C: chopped whole anchovy adding 13% NaCl. Sample D: whole anchovy adding 17% NaCl. The total amino acids from oligopeptides in fermented liquefaction of anchovy increased in early fermentation period and reached highest level, and then they declined irregularly during fermentation. Their maximum amounts were just after heating at $50^{\circ}C$ for 9 hrs in sample A, after 15 days in sample B, and after 60 days in samples C and D. The fermented liquefaction of anchovy extracts were rich in glutamic acid, aspartic acid, proline, glycine, alanine, lysine and valine. However, the contents of most amino acids fluctuated by the experimental specimens and fermenting periods. Among them glutamic acid was the most abundant amino acid which was occupied $0.6{\sim}27.7%$(average 24.0%) in the content of total amino acids from oligopeptides. The contribution of the amino acid composition from oligopeptides to extractive nitrogen was occupying average 20.8 and 17.5% in rapid- and low salt-fermented liquefaction(sample A, B and C) and traditional fermented liquefaction(sample D), respectively.

• 동의생리병리학회지
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• 제22권1호
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• pp.89-95
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• 2008

This experimental study was designed to investigate the effects of Ijin-tang add Atractylodis rhizoma and Atratcylodis macrocephalae rhizoma (IJTAA) on the change of weight and serum total cholesterol, HDL-cholesterol, LDL-cholesterol, triglyceride, free fatty acid, total lipid and phospholipid level in obese mice induced by high fat diet. Experimental groups were as follows ; Normal group was fed normal diet and administered distilled water during 7 weeks, Control group was fed high fat diet and administered distilled water during 7 weeks, Sample A group was fed high fat diet and administered IJTAA 500 ㎎/㎏/day/mouse during 7 weeks, Sample B group was fed high fat diet and administered IJTAA 700 ㎎/㎏/day/mouse during 7 weeks. The results were as follows ; 1. In Sample A group and Sample B group, There were significantly decreased in body weight, serum total cholesterol level, serum triglyceride level, serum free fatty acid level, serum total lipid level and serum phospholipid level in comparison with Control group. 2. In Sample A group and Sample B group, There were significantly increased in serum HDL-cholesterol level in comparison with Control group. 3. In Sample A group and Sample B group, There were decreased in serum LDL-cholesterol level in comparison with Control group. According to above results, I suggest IJTAA is able to be used for managing obesity by controllong body weight, serum total cholesterol level, serum triglyceride level, serum free fatty acid level, serum total lipid level and serum phospholipid level.

• 한국식품영양학회지
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• 제14권5호
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• pp.418-422
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• 2001

시판되는 4개 사 고춧가루를 구입하여 고춧가루의 품질에 관한 이화학적 특성을 비교 분석하였다. 고춧가루 선호도를 결정하는 것은 색상인데 C사 제품의 L값이 46.667로 가장 높았으며 a, b값도 22.738과 19.941로 제일 높게 나왔다. 고추의 적색소인 capsanthin은 D사가 80.0mg/100g으로 가장 많았으며 A, C, B사가 각각 75.0, 58.9, 51.0mg/100g 순이었고 ASTA color 도 같은 경 향을 보였다. Capsanthin 양과는 달리 L, a, b값 모두 C사가 제일 높게 나왔는데 이는 고춧가루의 입도에 의한 영향 때문으로 여겨진다 각 고춧가루의 pH 차이는 크지 않았으며 유기산은 A, B, D사 제품에서 quinic acid가 가장 많이 검출되었으며 C사 제품은citric acid가 가장 높게 검출되었다. 신미성분 가운데 capsaicin은 D사가 59.93mg/100g으로 가장 많았으며 B사가 25.87mg/100g으로 제일 적었으며 capsaicinoids는 각각 62.93, 28.20mg/100g로 나타나 2배 이상의 차이를 보였다. 미생물의 발생 가능성을 추정할 수 있는 수분활성 도는 A, B, C, D사가 각각 0.584, 0.676, 0.526 및 0.568 로 나타나 A, C, D사 제품은 문제가 없을 것으로 예측되나 B사 제품의 수분활성도가 0.676으로 곰팡이 발생 우려가 있을 것으로 예측되었다.

• 한국물환경학회지
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• 제18권3호
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• pp.283-290
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• 2002

In this study, home-made detection system by means of noble FIA is introduced on the measurement of toxic nitrite in the water samples collected from the area of Kwangju. As the standard calibration between 30 to 1000 ppb, the linearity has been shown more than 0.9999 as the correlation coefficient($R^2$) with the detection limit 1.5 ppb(S/N>2). The distribution of sample concentration was monitored as N.D. - 123 ppb which is wide span of concentrations in field water samples. The low level of nitrite is hardly detectable with other expensive sophisticated instruments including ion chromatography. Whereas the result of high concentration brings forth the necessity monitoring constantly our precious water resources. Successfully, the FIA system has played a very important role detecting wide span of nitrite in water sample. This technique can be adopted for controlling our environment in the near future.

• 대한안전경영과학회지
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• 제16권4호
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• pp.441-449
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• 2014

As people seek a healthy, wealthy, and quality life more than before, interests in mineral water are picking up and the consumption continues to increase accordingly. In an experiment to examine changes in the water quality after mineral water on the market was kept indoor and outdoor for four weeks, there seemed to be no problem in external appearance. Water kept in an outdoor storage contained more odor-savor than water kept in an indoor storage. Odor was not detected in 90% of the sample, and savor not in 80% of it. As for the mechanism of odor-savor generation, the elution of chemical substances from a container may be taken into consideration. In general, odor and savor have turned out to be in close correlation to each other. The average number of bacteria in the sample mineral water was $200{\pm}10CFU/mL$, and such factors as area of storage and ozone post-treatment did not cause significant effects on the reproduction of common microbes. Hence, it is thought that strict regulations on a production process and reduction of the period of circulation will contribute to customers consumption rates.

• 동아시아식생활학회지
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• 제13권6호
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• pp.601-607
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• 2003

This study was attempted to investigate the physicochemical changes during soybean-leaf water kimchis fermentation by adding wheat flour in cooking water. Soybean-leaf water kimchis with five different levels of wheat flour in cooking water(0%;A, 5%;B 10%;c, 15%;D, 20%;E) were tested for rhological parameters, fine structural changes, sensory evaluations and chemical analysis. The composition of the soybean-leaf was moisture (80.9%), protein(6.8%), fat(0.6%), ash(2.1%) and alkalinity (+14.9). The amount of reducing sugars of sample A and other samples were 0.75% and 1.08∼1.4% in the initial fermentation stage, but decreased to 0.3 and 0.43∼0.50% in the later fermentation stage, respectively. The pH of sample A decreased from 5.17 to 4.72 during the initial fermentation. On sample B, C, D and E, pH's decreased rapidly during the initial fermentation, but they did not change much in the later fermentation stage. The pectin contents of all samples decreased during 2nd and 4th day of fermentation, then the change was slow. The amount of hemicellulose. cellulose and lignin in terms of the DNF and ADF were varied from 4 to 33%, but the contents of them did not greatly changed during the fermentation. The sensory evaluation showed that both B and C samples had the good score in sweety taste, roasted nutty taste, and the ease of swallowing measured as chewiness. From these results, the optimum soybean-leaf water kimchis can be prepared when 200g soybean-leaf, 1000$m\ell$ water, 15g garlic, 3% red pepper powder and 5 ∼0% wheat flour were fermented at 20$^{\circ}C$ for 2 days.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2003년도 추계국제학술대회
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• pp.149-149
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• 2003

A new technique is proposed for the determination of alkylphenols, chlorophenols and bisphenol A in tap water. The sample preparation consists of a solid phase extraction (SPE) of alkylphenols, chlorophenols and bisphenol A from a water sample with XAD-4 and subsequent conversion to isobutyloxycarbonyl (isoBOC) derivatives or tert.-butyldimethylsilyl (TBDMS) derivatives for sensitive analysis with the GC/MS-SIM mode. The recoveries were 86.6∼105.2 % (isoBOC derivatization) and 97.6∼484.5 % (TBDMS derivatization), respectively. The limit of quantitation of alkylphenols, chlorophenols and bisphenol A for SIM were 0.001∼0.050 $\mu\textrm{g}$/l (isoBOC derivatization) and 0.003∼0.050 $\mu\textrm{g}$/l (TBDMS derivatization). The SIM responses were linear with the correlation coefficient varying 0.9755∼0.9981 (isoBOC derivatization), and 0.9908∼0.9996 (TBDMS derivatization). The derivative methods and their application to tap water samples will be disscussed.

• 한국식생활문화학회지
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• 제17권2호
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• pp.197-213
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• 2002

In order to establish the processing condition of rapid- and low salt-fermented liquefaction of anchovy (Engrulis japonica), effect of temperature on crude enzyme activity of anchovy viscera, pretreatment conditions, and the minimum content of adding NaCl were investigated. The minimum limitation of NaCl content for anchovy liquefaction was 10%. Sample A(water adding, heating, adding 10% NaCl): chopped whole anchovy adding 20% water and then heating for 9 hrs at $50^{\circ}C$ and then adding 10% NaCl and then fermented at room temperature$(8-29^{\circ}C)$ for 180 days. Sample B(water adding, heating, adding 13% NaCl): chopped whole anchovy adding 20% water and then heating for 9 hrs at $50^{\circ}C$ and then adding 13% NaCl and then fermented at room temperature for 180 days. Sample C(adding 13% NaCl): chopped whole anchovy and then adding 13% NaCl and then fermented at room temperature for 180 days. Sample D(adding 17% NaCl): whole anchovy adding 17% NaCl and then fermented at room temperature for 180 days. The content of free amino acids such as aspartic acid, serine and threonine fluctuated severely according to the pretreatment methods. Possibly they might be recommend quality indices of standardization for salt-fermented liquefaction of anchovy. As for the relation between fermentation period(X) and individual free amino acid(Y), five kinds of free amino acids such as glutamic acid, valine, glycine, lysine, and alanine showed highly significant in their coefficient of determination in most of samples. They might be recommend as quality indices for salt-fermented liquefaction of anchovy during fermentation. The difference of taste between products of the rapid- and low salt-fermented liquefaction and the traditional salt-fermented liquefaction were caused by their composition of the free amino acids ratios, in which were umami, sweet, and bitter taste in the extracts of anchovy during fermentation. The appropriate fermentation period of the sample A was shorten 30 days than the sample B and 60 days than the samples C and 90 days than the sample D in the processing of anchovy.

• 해양환경안전학회지
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• 제25권7호
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• pp.914-919
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• 2019

알칼리성 산업부산물의 혼합에 따른 연안 오염퇴적물의 성상 변화를 평가하기 위해 해수 교환을 고려한 mesocosm 실험을 수행하였다. 실험시작 1개월 후 실험구의 인산인 농도는 대조구 대비 간극수와 직상수에서 각각 19.0, 0.4 mg/L 낮게 검출되었다. 이는 GCA에서 용출된 칼슘이온과 인산인의 흡착반응을 통한 간극수 내의 인 고정 및 직상수로의 용출 억제에 따른 결과로 판단된다. 실험구의 간극수 내 황화수소 농도는 5.0 mg/L로 112.5 mg/L인 대조구에 비해 매우 낮게 나타났으며, 실험구 직상수의 DO 농도는 대조구에 비해 3.47 mg/L 높게 나타났다. 이상의 결과로부터 알칼리성 산업부산물인 GCA는 연안 오염퇴적물의 개선에 효과적인 재료임을 확인하였다.