• 펄프종이기술
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• 제48권3호
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• pp.57-65
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• 2016

Indigo (Polygonum tinctorium L.) is a typical blue dye which had been used from ancient times. This study was going to shade the complicated traditional methods extracting indigo dye by the fermentation and producing as adsorbate on calcium hydroxide, which says so called as the 'Indigo lime'. Accordingly we were going to make indigo through the hydrolysis of the hot water extractives of indigo leaves simply. During hot-water extraction, ${\beta}$-glucosidase which required hydrolysis of the linkage between indigo and glucose was not activated. To achieve this goal, indican was acid-hydrolyzed to glucose and indigo. The acetic acid, citric acid, hydrochloric acid, and sulfuric acid were used for the hydrolysis of hot water extractives. The hydrolysis conditions of extractives performed in water bath at $80^{\circ}C$ for 120 minutes and in an autoclave for 120 minutes. In the acid hydrolysis of extracted indican by hot water, the indican yields of acetic acid and hydrochloric acid hydrolysis were higher than sulfuric acid in water bath. Also, the indican yield of hydrochloric acid hydrolysis was better than sulfuric acid in autoclave. The hot water extracted indican was confirmed by HPLC analysis and its structure was confirmed by UV-Vis and FT-IR spectroscopy, compared with isolated indigo and commercial synthesized indigo. This improved extraction and hydrolysis methods can be replace the traditional indigo making method.

• Korea Journal of Cosmetic Science
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• 제2권1호
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• pp.21-31
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• 2020

The aim of this study is to develop a sunscreen stick formulation technology with excellent water resistance and washability. Consumers' needs for sunscreen products are diversifying. Water resistance and ease of washing are both important factors in sunscreen products. However, it is difficult to develop a sunscreen formulation that satisfies these two factors at the same time, because these two elements are in conflict. Fatty acid has a hydrophobic property against the water with low or neutral pH, but when it contacts with soapy water which has high pH, saponification occurs and the fatty acids become surfactants and can be dispersed in the water. Using the reaction characteristics of fatty acids, we can make sunscreen that is highly resistant to water or sweat, but is only selectively removed from soapy water. We found that the sunscreen stick containing fatty acids had better water resistance and washability than the sunscreen sticks without fatty acid. The sunscreen stick containing fatty acids showed a tendency to improve water resistance by scattering ultraviolet rays of long wavelength area by forming insoluble precipitation with divalent ions in tap water after immersion. In addition, an increase in the fatty acid content tended to also increase the ease of cleaning the sunscreen stick. Solid fatty acid was advantageous in improving water resistance than liquid fatty acid, but there was no difference between solid fatty acids and liquid fatty acid in washability. When it comes to stability, the sunscreen stick using liquid fatty acids maintained a high hardness and melting point, and showed no sweating. Based on this study, it is possible to develop an easy washable sunscreen stick formulation technology that has excellent water resistance but is selectively removed only in soapy water.

• 한국자원식물학회지
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• 제13권2호
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• pp.131-139
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• 2000

The effects of the simulated acid rain on the growth response and water status of Glycine soja was observed in 2 months-old seedlings. The seedlings were treated with acid rain(pH 3.5), three times per week. Glycine soja showed significant reduction in the total length, total weight, dry weight, water contents and top/root ratio after treatment of simulated acid rain(pH 3.5) for 56 days. The growth of shoot was more susceptible to acid rain than that of roots. On the contray, Number of lateral roots, water saturation deficit and epidermis transpiration was higher than that of control(pH 5.6) after 56 days treatment of simulated acid rain.

• Food Quality and Culture
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• 제2권1호
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• pp.55-60
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• 2008

This study examined the effects of lactic acid spray, hot water spray, or their combined treatment, as well as the effects of acidified sodium chlorite (ASC), for the decontamination of Escherichia coli on beef carcass surfaces using a commercial intervention system. With this system, the effects of 2 or 4% lactic acid (v/v), hot water ($89{\pm}1^{\circ}C$), or their combined treatment, were examined in terms of reducing inoculated E. coli. ASC (266 ppm), which was adjusted to pH 2.5 using acetic acid or citric acid, was applied using a hand-held spray system. When the beef carcasses were treated with 2 or 4% lactic acid for 10.4 s, less than 1 log reductions of inoculated E. coli were observed. A hot water spray treatment for 9.8 s resulted in a 2.1 log reduction of inoculated E. coli. However, when the hot water was followed with either 2 or 4% lactic acid, no difference in E. coli reduction was found between the hot water alone or the combined treatment with lactic acid. When ASC was adjusted to pH 2.5 with acetic acid and citric acid, 3.8 and 4.1 log reductions of E. coli were observed, respectively. Overall, the lactic acid spray treatment was least effective, and the ASC treatment was most effective, for the E. coli decontamination of beef carcasses. Therefore, these data suggest that ASC would be a more effective intervention against E. coli than most of the methods currently being used. However, more research is required to evaluate the effects of ASC on other organisms, as well as to identify application methods that will not affect meat quality.

• 한국식품조리과학회지
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• 제18권5호
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• pp.487-494
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• 2002

This study was conducted to investigate the thermal stability of water-soluble and fat-soluble vitamins dissolved in water and milk by various heat treatments. Vitamin samples were prepared by dissolving them in water and milk at various concentrations, and were heat treated for 30 min at 65$\^{C}$, 15 sec at 85$\^{C}$, 5 sec at 100$\^{C}$, 121$\^{C}$ at 15 min, the levels of residual vitamin were measured by using HPLC. Milk samples were fortified with vitamins before and after UHT treatment. As heating over 100$\^{C}$, riboflavin in water were destructed more than 92% but fortified in milk showed less than 20% destruction, suggesting that riboflavin was protected by milk components. Also retinol heated ever 100$\^{C}$ was more stable in milk than in water. L-Ascorbic acid and cholecalciferol(D$_3$) showed a similar destruction rate in water and in fortified milk. L-ascorbic acid was easily destructed by UHT treatment. Destruction of thiamin and tocopherol was increased in fortified milk. Among tour capsulated water-soluble vitamins, L-ascorbic acid was much more stable compared with powder form. Nicotinic acid and folic acid either in capsule or powder form showed a slight destruction by heat treatment. The results suggested that the fortification of unstable vitamins such as L-ascorbic acid, thiamin, tocopherol and cholecalciferol(D$_3$) should be made in milk after heat treatment.

• Food Science and Biotechnology
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• 제17권3호
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• pp.637-641
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• 2008

This study investigated the heat stability of L-ascorbic acid (AA) in acetic acid solution. To analyze the degradation of AA using high performance liquid chromatography (HPLC), AA was measured at a wavelength of 244 nm in acetic acid and 265 nm in distilled water. During the storage of AA in acetic acid or distilled water at $37^{\circ}C$, degradation of AA was slower in acetic acid than in distilled water. On examining various ratios of AA to acetic acid, the stability of AA at $100^{\circ}C$ for 30 min was the highest when the concentration of acetic acid was 10 times higher than the concentration of AA. After acetic acid was added into AA degraded by heating, the AA is stabilized by reheating. Ultimately, these results indicate that degraded AA is reduced by hydrogen ions dissociated from acetic acid, and the rate of reduction of degraded AA in acetic acid solution is improved with heat processing.

• 유변학
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• 제11권1호
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• pp.28-33
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• 1999

붕산은 폴리비닐알코올(PVA)의 히드록시기간의 가교를 형성할 수 있기 때문에 PVA용액내에 가입되면 용액의 유변학적 특성에 큰 영향을 미친다. 본 연구에서는 양이온이 존재하지 않는 경우 PVA/디메틸술폭시드(DMSO)/물/붕산계에 있어서 물의 함량이 유변학적 특성에 미치는 영향을 조사하였다. PVA/DMSO/물계에 붕산을 1 wt.% 첨가할 경우 물 함량이 증가할 수록 점도가 급속히 감소하였다. PVA/DMSO계에 1 wt.%의 붕산이 가입된 경우 양이온이 없어도 강한 가교구조를 형성하여 탄성겔의 점탄성특성을 나타낸 반면 PVA/물계에 1 wt.%의 붕산이 가입된 경우 전형적인 점성물질의 특성을 나타냈다. 순수한 DMSO나 혼합용매중 DMSO의 함량이 높으면 양이온의 존재없이도 붕산첨가에 의해 가교구조를 형성하여 급격한 점도변화를 나타냈으나 물 함량이 풍부한 계에서는 붕산의 첨가에 따른 점도의 변화가 미약하였으며 순수한 물을 용매로 사용한 경우 붕산첨가의 영향이 거의 없었다. 저장탄성률도 PVA/DMSO계의 경우가 가장 높은 값을 보였고 혼합용매계에는 물함량이 증가할 수록 감소하였다.

• Journal of the Korean Wood Science and Technology
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• 제40권2호
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• pp.123-132
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• 2012

Pre-pulping extracts were found to contain a dilute amount of xylo-oligosaccharides and acetic acid as the major components, and many minor components including other organic acids, lignin-derived phenolics, and sugar degradation products. Once separated from the pulp, a secondary hydrolysis step was required to hydrolyze oligomeric hemicellulose sugars into monomeric sugars before fermentation. The following study detailed the extent of hemicellulose recovery by pre-pulping using hot water extraction and characterized the hydrolysis of the extract with respect to comparing acid and enzymatic hydrolysis. The secondaryhydrolysis of hot water extracts made at an H-Factor of 800 was tested for a variety of acid and enzyme loading levels using the sulfuric acid and xylanases. The maximum fermentable sugar yield from acid and enzyme hydrolysis of the extract was 18.7 g/${\ell}$ and 17.7 g/${\ell}$ representing 84.6% and 80.1% of the maximum possible yield, respectively.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2003년도 봄 학술발표회 논문집
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• pp.481-484
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• 2003

Sulfide minerals contacted with air and water in coal seam cause oxidation reactions. This oxidation reactions make low pH of groundwater and surface water(Acid Drainage). The reddish brown precipitate collected from the cut slope of the study area was estimated using the X-Ray Diffractometer(XRD). XRD results show that the cut slope was affected by Acid Drainage. The cut slope exposured to Acid Drainage become weak about chemical weathering and defile the appearance of the road. Drainage facilities are very important in Cut Slope under Acid Drainage influence. Reactions between Coal seam and water cause chemical weathering and environmental problem. Therefore It is important to control the transfer paths of groundwater and surface water and to install water collecting facilities

• 전자공학회논문지
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• 제50권7호
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• pp.269-274
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• 2013

전해 산성이온수는 알칼리성 이온수에 비해 응용분야가 음용을 목적으로 하는 알칼리이온수와 많이 다르게 이용되고 있으며 ph 농도에 따라 강산성인 경우 잔류염소에 의한 살균 목적의 소독제로 사용되고, 중산성인 경우 세척과 세안으로 사용하고, 약산성인 경우 식재료와 혼합하여 요리에 널리 사용할 수 있다. 이런 산성이온수를 생성하기 위해서는 물을 전기분해 하여 사용하는데 전기분해 하는 과정에서 염소가스와 수산화나트륨 등의 물질로 살균력을 가지며, 전기분해시 +전극 쪽으로 -이온을 띤 염소, 인, 유황 등의 유기물이 모여져 산성이온수를 만든다. 또한 산성수와 알칼리수를 분리하기 위해서 격막을 사용했다. ph 농도변화의 구현방법은 Microprocessor를 이용하여 강산성에서 약산성 사이의 ph 농도를 PWM(pulse width modulation) 제어로 3종류의 PWM 전압을 전해조 전극에 인가하여 PWM제어에 의한 연속적으로 농도가 조절된 산성수가 생성되게 구현하였다.