• Journal of the Korean Applied Science and Technology
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• v.14 no.3
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• pp.23-28
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• 1997

The phase diagram for the surfactant mixture system of N-dodecanocyl-N-methyl amido polyolcarboxyl alkyl ether(DGC)/N-dodecanocyl-N-alkyl glucamine(DG)/water was studied usingpolarized microscopy, differential scanning calorimetry(DSC) and rheological measurements respectively. Using polarized microscopy, the textures of liquid crystal phases obtained at various surfactantconcentrations were investigated as a function of surfactant concentration and temperature, and phasetransitions between anisotropic liquid crystal phases and isotropic liquid phase were examined usingDSC measurements. Viscoelastic properties of surfactant solutions determined between hexagonal andlamellar liquid crystal phase by rheological measurements were approximately consistent with the resultsobtained by polarized microscopy and DSC. In the study for the phase of DGC/DG(5:5 mol ratio)/water system. It could be found that the hexagonal liquid crystal phase appeared at 25${\sim}$60wt％ ofsurfactant, the cubic liquid crystal phase at 50${\sim}$65wt％ and the lamellar crystal phase at above 70wt％.

• Food Science and Preservation
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• v.14 no.2
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• pp.142-147
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• 2007

We optimized braising time to improve the storage quality of braised kidney beans. The beans were prepared with different heating times between 25 and 50 min. and then stored at $10^{\circ}C$ for 20 day. Physical, chemical, microbiological, and organoleptic quality indices were monitored throughout storage. Longer braising times yielded products with lower concentrated brine coverage. Bis resulted in higher soluble contents and slightly lower water activities. Excessive heating time exposed the kidney beans to air and caused rapid microbial growth on the surfaces of the beans, which negatively affected product quality. The longest heating time of 50 min. also resulted in a large increase in product hardness. A braising time of 30 min. was best for preservation, as good sensory quality was mainatained.

• Journal of the Korean Wood Science and Technology
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• v.47 no.4
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• pp.509-518
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• 2019

This study analyzed the effect of organic solvent extractives on the classification of wood species via near-infrared spectroscopy (NIR). In our previous research, five species of Korean softwood were classified into three groups (i.e., Cryptomeria japonica (cedar)/Chamaecyparis obtuse (cypress), Pinus densiflora (red pine)/Pinus koraiensis (Korean pine), and Larix kaempferi (Larch)) using an NIR-based principal component analysis method. Similar tendencies of extractive distribution were observed among the three groups in that study. Therefore, in this study, we qualitatively analyzed extractives extracted by an organic solvent and analyzed the NIR spectra in terms of the extractives' chemical structure and band assignment to determine their effect in more detail. Cedar/cypress showed a similar NIR spectra patterns by removing the extractives at 1695, 1724, and 2291 nm. D-pinitol, which was detected in cedar, contributed to that wavelength. Red pine/Korean pine showed spectra changes at 1616, 1695, 1681, 1705, 1724, 1731, 1765, 1780, and 2300 nm. Diterpenoids and fatty acid, which have a carboxylic group and an aliphatic double bond, contributed to that wavelength. Larch showed a catechin peak in gas chromatography and mass spectroscopy analysis, but it exhibited very small NIR spectra changes. The aromatic bond in larch seemed to have low sensitivity because of the 1st overtone of the O-H bond of the sawdust cellulose. The three groups sorted via NIR spectroscopy in the previous research showed quite different compositions of extractives, in accordance with the NIR band assignment. Thus, organic solvent extractives are expected to affect the classification of wood species using NIR spectroscopy.

• Applied Chemistry for Engineering
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• v.32 no.2
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• pp.132-138
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• 2021

This review investigated the types of physiologically active substances isolated and extracted from Pinus densiflora and koraiensis native to Republic of Korea, and the current status of research on their effectiveness and industrial use. They contain various bioactive substances including essential oils, polyphenols, resins, and stilbene derivatives. In recent, physiological activities such as antioxidant, anti-inflammatory, antibacterial, cataract prevention, and neuroprotection from extracts of Pinus densiflora and koraiensis have been identified by domestic researchers. The extracts have been used in different industrial fields like food, health functional foods, cosmetics, and household goods, but the high proportion of them is industrially made from exotic species. Therefore, various studies on industrial applicability are needed due to the lack of cases in which the activity is applied to actual products, with respect to the effects that have been scientifically recognized.

• Journal of Environmental Health Sciences
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• v.49 no.4
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• pp.228-235
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• 2023

Background: As the public interest in chemical substances found in daily life has increased, environmental health education content has been developed and related studies have been conducted. However, there is still insufficient research on methodologies for environmental health education. Objectives: This study aimed to explore risk communication strategies by focusing on N-nitrosamines in rubber balloons. Methods: In this study, two different health messages were composed: a gain-framed message emphasizing the advantages of practicing the health behavior and a loss-framed message emphasizing the negative consequences of not practicing the health behavior. The effect of the message containing risk information was evaluated by measuring the health beliefs and health behavior potential for female caregivers. As the Environmental Health Act defines a child as "a person under the age of 13," a total of 131 women with children under the age of 13 were studied. Results: The age, awareness, and interest of the participants in the gain frame group and these in the loss frame group were similar. In terms of message framing effect, the gain-framed message was more effective in terms of health belief and potential health behavior than was the loss-framed message. As a result of an independent t-test, among the six variables of health belief model the message effect was statistically significant at the level of p<0.05 in three variables: perceived severity (t=2.287, df=129, p=0.024), self-efficacy (t=2.123, df=129, p=0.036), and health behavior potential (t=2.094, df=129, p=0.038). Conclusions: This study presented a direction for effective environmental health education by studying the effects of risk communication messages based on scientific evidence. It is necessary to extend the scope of environmental health education research by expanding research into various household products.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.110-110
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• 2022

According to the statistics of the Ministry of Environment, the amount of food waste generated in Korea is 15,903 tons, which accounts for about 30% of the daily household waste. Food waste in Korea is on the rise, and various odors, greenhouse gases, and leachate generated in the process of discharging, transporting, and processing are emerging as social problems. Accordingly, there is a need for a method for recycling food waste. Therefore, this study was carried out to establish an appropriate limiting dose by manufacturing fertilizer mixed with food waste powder and treating it on tomatoes to investigate the growth and yield of crops. The experiment was carried out with continuous cultivation in 2021 (1st year) and 2022 (2nd year), and the treatment groups were set to No Treatment (NT), Chemical Fertilizer (CF), Mixed Fertilizer (MF), and Mixed Fertilizer×2 (MF×2). As a result of the 1st year growth survey, shoot and root length did not show a significant difference between the treatment groups, and the fresh weight showed a significant difference between the MF and MF×2. As a result of the 2nd year growth survey, there was no significant difference in shoot length, root length, and dry weight between the treatment groups, and the fresh weight of the CF was significantly greater than that of the MF×2. The yield of 1st year, MF×2 increased significantly compared to other treatment groups. In the case of 2nd year, CF, and MF×2 show significantly high values compared to NT. Judging from these results, continuous cultivation using food waste powder mixed fertilizer did not have a significant effect on crop growth and yield. However, it is considered that several studies including continuous cultivation experiments are needed to accurately set the appropriate application amount and limit the application amount of the mixed fertilizer for food waste.

• Journal of Environmental Impact Assessment
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• v.28 no.2
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• pp.152-168
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• 2019

The element arsenic, which is abundant in the Earth's crust, is used for various industrial purposes including materials for disease treatment and household goods. Various human activities, such as the disposal of soil waste, metal mining and smelting, and combustion of fossil fuels, have caused the pollution of the environment with arsenic. Recently, guidelines for arsenic in rice have been adopted by the Korean ministry of food and drug safety to prevent health risks based on rice consumption. Because of the exposure to arsenic and its accumulation in the human body through various channels, such as air inhalation, skin contact, ingestion of drinking water, and food consumption, integrated multimedia risk assessment is required to adopt appropriate risk management policies. Therefore, integrated human health risk assessment was carried out in this study using integrated exposure assessment based on multimedia (e.g., air, water, and soil) and multi-route (e.g., oral, inhalation, and dermal) scenarios. The results show that oral uptake via drinking water is the most common pathway of arsenic into the human body, accounting for 57%-96% of the total arsenic exposure. Among various age groups, the highest exposures to arsenic were observed in infants because the body weight of infants is low and the surface areas of infant bodies are large. Based on the results of the exposure assessment, the cancer and non-cancer risks were calculated. The cancer risk for CTE and RME is in the range of 2.3E-05 to 6.7E-05 and thus is negligible because it does not exceed the cancer probability of 1.0E-04 for all age groups. On the other hand, the cancer risk for RME varies from 6.4E-05 to 1.8E-04 and from 1.3E-04 to 1.8E-04 for infants and preschool children, exceeding the excess cancer risk of 1.0E-04. The non-cancer risks range from 5.4E-02 to 1.9E-01 and from 1.5E-01 to 6.8E-01, respectively. They do not exceed the hazard index 1 for all scenarios and all ages.

• Korean Journal of Ecology and Environment
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• v.55 no.3
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• pp.185-200
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• 2022

The risk of various hazardous substances in aquatic environment comprises not only the concentration of substances in the environmental medium but also their accumulation in fish through complex food web and the health risks to humans through the fish. In Korea, the monitoring of residual toxicant in aquatic ecosystems began in 2016 following the enforcement of the Acts on registration and evaluation for the management of chemicals used in daily life (consumer chemical products), and attention has been paid to potentially hazardous substances attributed to them. Recently, studies have been carried out to investigate the distribution of these hazardous substances in the ecosystem and calculate their emission factors. These include the accumulation and transport of substances, such as detergents, dyes, fragrances, cosmetics, and disinfectants, within trophic levels. This study summarizes the results of recently published research on the inflow and distribution of hazardous substances from consumer chemical products to the aquatic environment and presents the scientific implication. Based on studies on aquatic environment monitoring techniques, this study suggests research directions for monitoring the residual concentration and distribution of harmful chemical substances in aquatic ecosystems. In particular, this study introduces the directions for research on trophic position analysis using compound specific isotope analysis and trophic magnification factors, which are needed to fulfill the contemporary requirements of selecting target fish based on the survey of major fish that inhabit domestic waters and assessment of associated health risk. In addition, this study provides suggestions for future biota monitoring and chemical research in Korea.

• Journal of Yeungnam Medical Science
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• v.5 no.1
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• pp.69-75
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• 1988

The drinking water in the apartment is stored in reservior tank and thereafter supplied each household. In case the drinking water is stored too long or insanitary, tap water might change in quality. This study was carried out to evaluate the physico-chemical and microbiological conditions of 36 samples of tap water of apartments compared to 18 samples of tap water of independence houses in Taegu City from May to October, 1987. Main findings are summarized as follows : PH values were within normal range in all samples. Samples less than 0.2ppm in residual chlorine accounted for 16.7% in the appartment and 5.6% in the independence house. Nitrite nitrogen was detected 2.8% of apartment samples only. Among the total of 54 samples, 11.1% of the apartment and independence samples were over the normal value in standard plate count. Samples more than 1.8 of most probable number(MPN) accounted for 27.8% in the apartment and 33.3% in the independence house. In result of test for residual chlorine, nitrite nitrogen, standard plate count, and MPN, the proportion of the samples revealed inappropriated in respect of drinking water standards. In case of all sorts of tests was 2.7% in apartment and nothing in independence houses, in case of 3 sorts of tests was 2.7% in apartment and 5.6% in independence houses, in case of 2 sorts of tests was 8.3% in apartment and 5.6% in independence houses, and in case of only 1 test was 25.0% in apartment and 22.2% in independence houses. Correlation between residual chlorine and standard plate count, and between standard plate count and MPN were observed. It was found that the more years since construction of apartment were, the worse tap water was in quality.

• 한국가스학회:학술대회논문집
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• 2005.10a
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• pp.37-43
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• 2005

The questionnaires about the safety of the urban gas have been carried out for the end users. about 8 of 10 persons said that the urban gas Is safe to use, whereas $35\%$ of them said there exists a hazard of an accident in thier residences. There cannot be found the clear evidences that the understandings on the safety of the urban gas have no relations to their ages, sex, and monthly incomes, while the safety is less confidential to the highly educated, the accident-experienced, or the mans who are poor at the safety inspections. Most of the questioned man know the inspection knacks for the gas utilities, but only $60\%$ of them carry out it. They said that they do not feel the necessity of the inspection because they are inspected routinely by the suppliers or the inspection companies. This says that the end user does not concern the safety inspections, and in order to improve the dependency of the user for the self-inspections, the inspection staff should educate the user for the necessity and the knack of inspections to encourage the self-inspection of the gas utilities.