• Journal of Korean Public Health Nursing
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• v.10 no.1
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• pp.31-38
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• 1996

Disinfection is a very important process in water plant on account of our surface water usage. Particularly. the rainfall of Korea is concentrated in summer time. it is almost carried away to ocean before our utilization as water resource. To overcome the unbalance of water resource, artificial dams and reservoirs are constructed. According to such storage of water to aggravate water pollution and make the increase of water cleaning chemicals. Chlorine, as a main traditional chemical for water treatment. is focused on account of THMS formation in recent days. In this paper. the data of a water plant located in Seoul is adopted as the foundation of water quality analysis and introduce the substitute chemicals to supplement the harmful formation. additionally. Conclusions are summarized as follows: 1. The water quality of water resource is the worst in summer time and the supply of cleaning chemical is inevitably increased on account of general bacteria increase. 2. Chlorine, as a main chemical for water cleaning, formed the cancer-causing organic THMS with water molecules. 3. One of substitute chemical. chlorine dioxids suppress the formation of THMS comparing with the case of chlorine only. Therefore. the continuous research of substitute chemicals should be activated. 4. As the supply of disinfected clean water concerned with the citizen sanitary, the cultivation of professionals and academic conference must be needed on the basis of nation

• Korean Journal of Food Science and Technology
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• v.25 no.2
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• pp.148-153
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• 1993

Composition and structure of synthetic glucitol fatty acid polyesters (GPE)-a potential fat substitute-were investigated. Also degree of substitution (D.S) of GPE was determined according to the relative ester distribution within it to evaluate the feasibility of GPE using as a fat substitute. The GPE was separated into single ester group by a normal-phase HPLC and D.S of it was identified to be 6. Absorption band at $1747\;cm^{-1}$ in the IR spectrum of GPE indicated that there were ester bonds within GPE molecules. which link fatty acid moiety to glucitol. Disappearance of the hydroxyl proton signals of glucitol in the H-NMR spectrum of GPE implied that most of hydroxyl groups in glucitol participated in the formation of ester bonds with fatty acids. In addition the D.S estimated from the quantitative proton integration of GPE coincided well with the D.S of GPE determined by hydroxyl value measurement. In conclusion, the GPE synthesized in this study was found to be a glucitol fatty acid hexaester so that it is expected to be used as a fat substitute in the near future.

• Environmental Analysis Health and Toxicology
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• v.30 no.sup
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• pp.1.1-1.5
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• 2015

Objectives Despite the great contribution made by chemical substances to the development of modern civilization, their indiscriminate use has caused various kinds of damage to the global environment and human beings. Accordingly, the major developed countries and international society have tried to ensure the safe use of chemicals and a reduction in the use of hazardous chemicals through the establishment of the United Nations Environment Programme and various international agreements. In this reason, we tried to introduce about Green Chemistry progress at the present in worldwide and Korea. Methods We checked and analyzed relative journals, reports using keyword as like Green Chemistry, alternative chemicals, eco-friendly etc. and major country's government homepage search. Results Green Chemistry theory, which argues for the reduction or removal of harmfulness in chemicals throughout their entire life-cycle, has been spreading, and major developed countries, such as the US and Denmark, have developed and operate programs to provide reliable chemical information to help replace hazardous chemicals. Korea has also been conducting studies as like eco-innovation project. Through this project the "Alternative Chemical Search program," has been developed, distributed, and operated since 2011 to provide reliable information to small and medium-sized businesses that have difficulties collecting information to ensure conformity to international regulations. The program provides information that includes the regulations of major countries and Korea, information on 340 alternative chemicals, 70 application cases, and 1:1 consulting. Conclusions The Alternative Chemical Search program is expected to contribute to the establishment of response systems for regulation of Korean small and medium-sized businesses, and it also will be used to provide basic data for Korean hazardous chemical regulation, together with the Act on the Registration and Evaluation, etc. of Chemical Substances and the Chemical Control act, making it possible to establish an infrastructure for Green Chemistry in Korea and to increase national competitiveness.

• Korean Journal of Food Science and Technology
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• v.25 no.5
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• pp.438-443
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• 1993

Physico-chemical properties of glucitol fatty acid polyesters (GPE)-one of the potential fat substitutes-were analyzed and compared with conventional edible oil. The refractive Index, apparent viscosity and melting point of S-GPE (soybean oil GPE) were 1.472, 103 cps. at $37^{circ}C\;and\;-53^{\circ}C$, respectively. S-GPE were liquid at room teperature and the Yellowness of S-GPE was slightly stronger than that of soybean oil. The acid value and smoke point of S-GPE were 0.06 and $200^{\circ}C$. To supplement the weak thermal stability of S-PEG, SP-GPE (soybean-palm blended oil GPE) was prepared with soybeanpalm blended oil (70% of soybean oil and 30% of palm oil). The appearance and color of SP-GPE was not much different from S-GPE but the smoke point of that was increased to $210^{\circ}C$. It means that thermal stability of GPE can be enhanced by increasing saturation of the fatty acid composing GPE. Because most of physico-chemical properties of S-GPE or SP-GPE were similar to conventional edible oil, they are expected to be considered as a potential fat substitute with further study for confirming the safety.

• Transactions of Materials Processing
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• v.13 no.3
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• pp.262-267
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• 2004

Ultrasonic machining has been known as one of the conventional machining methods in the glass fabrication processes. In ultrasonic machining, typically, glass is removed by the impulse energy of the abrasive generated by the ultrasonic power. However, when the machining feature decrease under hundreds of micrometers, as conventional ultrasonic machining uses only the impulse energy of the abrasive, the speed of ultrasonic machining decreases significantly and the surface roughness becomes deteriorated. To overcome this size effect, the chemicals which can erode glasses, such as HF, XF, etc, are added to the slurry. The chemical-assisted ultrasonic machining method, so called, is another alternating effective way for micro machining of glasses. In previous work, we used the hydrofluoric acid (HF) as an additive chemical. But, as the HF solution is too poisonous to be used as a ultrasonic process additive, it is needed to be substituted by other safe chemicals. As results of the machinability comparison of several chemicals, the GST-500F was selected to replace the HF. The GST-500F (pH $4.0{\pm}1.0$) is non-volatile, odorless. During experimental works, it was shown that the machining rate increases 1.5 times faster than the conventional ultrasonic machining. The machining load also decreases. However, the enlargement of the hole diameter and significant tool wear are still the problems to be solved.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.4
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• pp.46-53
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• 2015

Paper strengthening system of PVAm (polyvinylamine) has been used with strong negative charge polymer for electrostatic neutralization due to strong positive charge of PVAm. Recently, because of the controversy caused by the possibility of remaining PAM monomers in white water, a search for paper strength agent that can substitute for PAM was suggested. Therefore, this study was carried out to evaluate a dry strength polymer of PVAm. Starch and CMC were used as a substitute for PAM. The dual polymer system of PVAm and anionic charge control agent such as anionic starch or CMC (carboxy methyl cellulose) were found to be very effective as strength agent compared to the chemicals based on acrylamide.

• The Korean Journal of Mycology
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• v.6 no.1
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• pp.9-14
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• 1978

Benomyl has been used to control Mycogone perniciosa for several years, the reduced effect of Benomyl against Mycogone perniciosa has been reporteod here. These experiments were carried out to substitute Benomyl with other chemicals. The isolates of Mycogone perniciosa those Benomyl tolerant are proved to be sensitive to Vitathiram, Difolatan, Ambam and RH-2161. However, these chemicals brought undisirable effects on the cultivation. Basamid and Vapam are found not to be harmful to Agaricus bisporus' mycelial growth in casing soil, these chemicals were treated up to 100 ppm of concentration for 15days in advance of use. Although Mycogone perniciosa was tolerant to Benomyl, Basamid and Vapam were very effective and enabled it to produce higher levels of mushroom sporophores.

• Korean Journal of Food Science and Technology
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• v.24 no.3
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• pp.247-250
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• 1992

Effects of free alkali and moisture on sucrose polyesters (SPE)-possible non calorie fat substitute-synthesis were investigated using a model system composed of sodium oleate, sucrose, potassium carbonate and methyl oleate. Trace amounts of free alkali in sodium oleate were found to interefere with SPE synthesis. When free alkali content in sodium oleate was varied gradually from 0% to 5%(w/w), the yield of SPE production was reduced from 92% to 45.5%. The moisture absorbed in sodium oleate, sucrose and potassium carbonate during storage also interefered with SPE synthesis. The yield (92%) of SPE production with dried ($105^{\circ}C$.6 hrs) reactants and catalysts was higher than that (89%) of SPE production with non-dried. Soybean oil fatty acid sodium soaps (FASS) not containing free alkali could be manufactured with slightly less than molar ratio of sodium hydroxide to soybean oil fatty acid methyl esters (FAME). Practically, 91.7% yield of soybean oil SPE production was outcomed by minimizing free alkali and moisture which were remaining in sucrose, potassium carbonate, soybean oil FASS and soybean oil FAME.

• Journal of Integrative Natural Science
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• v.14 no.4
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• pp.155-158
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• 2021

To study the effects of hormones and neurotransmitters, zebrafish (Danio rerio) are a great substitute for water fleas (Daphnia). The zebrafish is an ideal vertebrate model because it has a transparent embryonic stage. It is easy to get consistent heart rate measurements in embryonic zebrafish when treating them with hormones and neurotransmitters. To observe the heart rate, two to three embryonic zebrafish are anesthetized with MS-222 and then transferred to a glass slide specifically designed for heart observation and easy application of various chemicals. After the heartbeats are counted for 2 minutes, apply either 100 µM epinephrine or 100 µM acetylcholine to the zebrafish. Wait 5, 10, and 20 minutes and count the heartbeats at each time point. All procedures are repeated three times. The final results are averaged and analyzed by using statistical methods. The above method which we have developed is practical enough for high school students to measure the heart rate in zebrafish under various conditions and to analyze the data set.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.87.1-87
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• 2003

Powdery mildew on strawberry plants, caused by Spherotheca aphanis (Wallr.) U. Braun var. aphanis, is the most serious disease for strawberry production. There is a demand to develop the substitutes for chemicals which are more environment friendly materials. Control of powdery mildew was evaluated on Akihime, Sachinoka, Dochiodome, Noyho and Redpearl varieties grown in the greenhouse. Applications of 1％, 0.5％, and 0.25％ of sodium bicarbonate (NaHCO3Nyoho in greenhouse experiments. Non-phytotoxicity was revealed on the leaves and fruits of strawberry at these concentrations. This$.$result indicates that a mixture of sodium bicarbonate and tween 20 is a useful substitute for fungicides to control powdery mildew of strawberry.