• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.28 no.3
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• pp.14-28
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• 2010

By philological geography method for dismantling and reconstituting Buyeo's Palkyung(扶餘 八景), which best signify the image of ancient city Buyeo's landscape, this research is to demonstrate the fact that the place's inertia of certain historic sites has been passed down as a type of geographic code. Titled poems and retrospective poems about Buyeo's Palkyung and its spectacles and landscapes reveal the fact that the splendid and glorious cultural heritage of Baekje had faded but its traces have remained in the each eight views including Nakhwa-am(落花巖), Goran-sa(皐蘭寺), and Jayong-dae(釣龍臺). In addtion, the spectacles and historic sites of Buyeo's Palkyung appear as the symbol of Baekje's fall and loss in the poems. Thus, it can be said that Buyeo's culture and civilization have never escaped from the cultural and historical scars of Baekhe's fall, being dominated by the place's inertia originated from the identity as "Baekje'slastcapital". It is ironical that Buyeo's future development and prosperity are not free from its cultural and historical spectacles which bear the image of the fall of Baekje. 'Older Buyeos' Palkyung(扶餘舊八景)' and, Prior Buyeo's Palkyung(夫餘前八景), originate from nine views of an unknown builder and after the construction of pavilions and towers, 'Subuk-jeong eight views(水北亭八景)' by Heungguk Kim(金興國) and the eight poems of the, Retrospect of Buyeo(扶餘懷古八景), were created. 'Buyeo's later Palkyung(扶餘後八景), which are especially free from the site's inertia are known to have expanded the scope of Buyeo's landscape by deliberately demonstrating spectacles and sites different from those of existing views. Nakhwa-am, Goran-sa, Joryong-dae, Songwal-dae(送月臺), Youngwal-dae(迎月臺), and Pyungje-tap(平濟塔) are all located within a one kilometer radius of Banwol-sung(半月城), Buyeo's palace and the Baekma river(白馬江), Daewang-po(大旺浦), Busan(浮山) in a two kilometers radius. Jaon-dae(自溫臺), Subuk-jeong(水北亭), and Gyuam-jin(窺岩津) are located within a three kilometers radius. Even Chunjeong-dae(天政臺), which are located within a four kilometers radius of Banwol-sung are located alongside the Baekma river. This indicates the fact that these spectacles had not been established temporarily or impromptu but for a long period time by historic retrospect and the inertia of landscape's geographic cycle. In conclusion, the geographic phenomenon of historical and cultural inertia appeared because Buyeo had the geographic message of "fallen, ancient city". Therefore, Buyeo's Palkyung which have constant retrospective inertia is clearly an geographic code effective and helpful to understand not only the characteristics of historic sites and spectacles of Buyeo in the Sabi period but also the quality of the site itself.

• Journal of Wetlands Research
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• v.24 no.2
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• pp.83-92
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• 2022

The amount of the plastic waste has been increasing according to global demand for plastic. Microplastics are the most hazardous among all plastic pollutants due to their toxicity and unknown physicochemical properties. This study investigates the optimal methodology that can be applied to sewage samples for detecting microplastics before discussing reducing microplastics in MWTPs. In this study, the effect of different pretreatment methods while detecting microplastic analysis of MWTP influent samples was investigated; the samples were collected from the J sewage treatment plant. There are many pretreatment methods but two of them are widely used: Fenton digestion and hydrogen peroxide oxidation. Although there are many pretreatment methods that can be applied to investigate microplastics, the most widely used methods for sewage treatment plant samples are Fenton digestion and H₂O₂ oxidation. For each pretreatment method, there were factors that could cause an error in the measurement. To overcome this, in the case of the Fenton digestion pretreatment, it is recommended to proceed with the analysis by filtration instead of the density separation method. In the case of the H₂O₂ oxidation method, the process of washing with distilled water after the reaction is recommended. As a result of the analysis, the concentration of microplastics was measured to be 2.75ea/L for the sample using the H₂O₂ oxidation method and 3.2ea/L for the sample using the Fenton oxidation method, and most of them were present in the form of fibers. In addition, it is difficult to guarantee the reliability of measurement results from quantitative analysis performed via microscope with eyes. A calibration curve was created for prove the reliability. A total of three calibration curves were drawn, and as a result of analysis of the calibration curves, all R² values were more than 0.9. This ensures high reliability for quantitative analysis. The qualitative analysis could determine the series of microplastics flowing into the MWTP, but could not confirm the chemical composition of each microplastic. This study can be used to confirm the chemical composition of microplastics introduced into MWTP in the future research.

• Journal of Nutrition and Health
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• v.9 no.2
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• pp.59-67
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• 1976

A series of experiment was carried out to study the effect of commonly used dietary fat or oils on the growth, feed efficiency, nutrient utilizability, nitrogen retention and serum cholesterol of rats and chicks fed various fat or oils at the level of 10% during 12 weeks of experimentation. Fat and oils used in this experiment were also analyzed for the composition of some fatty acids. The main observations made are as follows: 1. All groups received fat or oils gained more body weight than unsupplemented control group except chicks fed fish oil and rapeseed oil although no statistical significance was found between treatments. It was found that body weight gain achieved by the rats fed soybean oil, rapeseed oil, animal fat or corn oil was much greater than other group and that achieved by the chicks fed corn oil and animal fat was greater than other vegetable oil groups, although no statistical significance was found among treatments. 2. Feed intake data indicated that corn oil group of both rats and chicks consumed considerably more feed than other groups. Whereas feed intake of fish oil groups was the lowest among the experimental animals indicating that fish oil might contain unfavorable compound that depresses the palatability. In feed efficiency, soybean oil group of rats and corn oil group of chicks were significantly better than other experimental groups. In general, addition of fat or oils in the diet improved feed effeciency of diet. 3. Nutrient utiIizabiIity and nitrogen retention data showed that fat in the experimental diet containing 10% fat or oils was absorbed better than crude fat in control diet. It was also found that there was no significant difference in nitrogen retention among treatment. 4. Liver fat content of rapeseed oil group was much higher than that of control group and other group. It was also noticed that feeding more polyunsaturated fatty acids resulted in higher content of Iiver fat. 5. Present data indicated that serum cholesterol content of rapeseed oil and sesame oil group of rat was the higher than that of control group. Serum cholesterol content of animal fat group of chicks was higher than other group. It was interesting to note that serum cholesterol content of chicken was higher than that of rats?regardless of the kind of oils received. 6. Analytical data revealed that fatty acid composition of vegetable oil was composed mainly of oleic acid and linoleic acid, whereas animal fat and fish oil were composed of saturated fatty acid such as, myristic and palmitic acid. It should be mentionted that the perilla oil contained a very large amount of linolenic acid (58.4%) comparing with that in order vegetable oils. Little arachidonic acid was detected in vegetable oil, whereas none in animal fat and. fish oil.

• Journal of Life Science
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• v.30 no.9
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• pp.743-748
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• 2020

Sulfate is a reductant that competes for electrons and may lower CH₄ production in the rumen. This study was designed to evaluate the beneficial effect of detoxified sulfur powder supplementation on in vitro rumen fermentation and methane mitigation. A ruminally cannulated Holstein Friesian cow was used as a rumen fluid source, and commercial pelleted concentrate was used as a substrate at 1 g dry matter. Treatments included the addition of detoxified sulfur powder at the rate of 0% (Control), 0.2% (T1), 0.4% (T2), 0.6% (T3), 0.8% (T4), and 1.0% (T5) as dry matter (DM) basis. The pH, total gas (TG), methane (CH₄) production, DM digestibility, organic matter (OM) digestibility, and volatile fatty acids (VFA) production were analyzed after 12 hr of incubation. The results showed that CH₄ production was significantly lowest in T1 (13.78 ml) but highest in the control (20.16 ml). Insignificantly higher total VFA was observed in control and T1 (64.99 and 64.28 mM, respectively) compared to other treatments after 12 hr of incubation. After 12 hr of incubation, the significantly lowest acetate:propionate was observed in T1 (1.90) while the highest was observed in T4 (2.44). However, no significant differences were recorded for pH, TG, DM digestibility, OM digestibility, acetate, propionate, and butyrate between the control and T1. Total number of bacterial DNA copies was significantly lower in the treatment group than the control. Therefore, it can be concluded from this study that detoxified sulfur at 0.2% inclusion level is optimal for production performance and ruminal CH₄ mitigation.

• Journal of Soil and Groundwater Environment
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• v.9 no.2
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• pp.11-19
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• 2004

Chlorinated and nitroaromatic compounds are non-degradable substances that are extremely toxic and are known to be carcinogens and mutation causing agents. Moreover, the half-lives of substances such as carbon tetrachloride, hexachloroethane and nitroaromatic compounds are several decades. In this study, the optimal conditions to detoxify chlorinated compounds by the reductive degradation were investigated. The following results were obtained in the reductive degradation of CCl$_4$, C$_2$Cl$\_$6/, C$_2$HCl$\_$5/, C$_2$Cl$_4$, and C$_2$HCl$\_$5/ by using Fe, FeS and FeS$_2$ as mediators. CCl$_4$ was reduced to CH$_2$Cl$_3$ and CH$_2$Cl$_2$in anaerobic conditions when FeS was used as a mediator. While the reduction of CCl$_4$ to CHCl$_3$ was rapidly proceeded, the reduction of CHCl$_3$ to CH$_2$Cl$_2$ was occurred slowly. Further reduction to CH$_3$Cl was not observed. Unlike CCl$_4$, C$_2$Cl$\_$6/ was degraded to C$_2$HCl$\_$5/, C$_2$Cl$_4$. C$_2$HCl$_3$ and cis-1,2-C$_2$H$_2$Cl$_2$ by complicated pathways such as hydrogenolysis, dehalo-elimination and dehydrohalogenation. A small amount of C$_2$HCl$\_$5/ was detected only in the early stages of the reduction. However, majority of the C$_2$Cl$\_$6/ was reduced to C$_2$Cl$_4$. cis-1,2-C$_2$H$_2$C1$_2$ was the only product among other possible isomers.

• Fire Science and Engineering
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• v.15 no.1
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• pp.23-33
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• 2001

The utility tunnels are the important facility as a mainstay of country because of the latest communication developments. However, the utilities tunnel is difficult to deal with in case of a fire accident. When a cable burns, the black smoke containing poisonous gas will be reduced. This black smoke goes into the tunnel, and makes it difficult to extinguish the fire. Therefore, when there was a fire in the utility tunnel, the central nerves of the country had been paralyzed, such as property damage, communication interruption, in addition to inconvenience for people. This paper is based on the fire occurred in the past, and reenacting the fire by making the real utilities tunnel model. The aim of this paper is the scientific analysis of the character image of the fire, and the verification of each fire protection system whether it works well after process of setting up a fire protection system in the utilities tunnel at a constant temperature. The fire experiment was equipped with the linear heat detector, the fire door, the connection water spray system and the ventilation system in the utilities tunnel. Fixed portion of an electric power supply cable was coated with a fire retardant coating, and a heating tube was covered with a fireproof. The result showed that the highest temperature was $932^{\circ}c$ and the linear heat detector was working at the constant temperature, and it pointed at the place of the fire on the receiving board, and Fixed portion of the electric power supply cable coated with the fire retardant coating did not work as the fireproof. The heating tube was covered with the fireproof about 30 minutes.

• Journal of the Society of Disaster Information
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• v.11 no.1
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• pp.135-147
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• 2015

Recent underground common utility tunnels are underground facilities for jointly accommodating more than 2 kinds of air-conditioning and heating facilities, vacuum dust collector, information processing cables as well as electricity, telecommunications, waterworks, city gas, sewerage system required when citizens live their daily lives and facilities responsible for the central function of the country but it is difficult to cope with fire accidents quickly and hard to enter into common utility tunnels to extinguish a fire due to toxic gases and smoke generated when various cables are burnt. Thus, in the event of a fire, not only the nerve center of the country is paralyzed such as significant property damage and loss of communication etc. but citizen inconveniences are caused. Therefore, noticing that most fires break out by a short circuit due to electrical works and degradation contact due to combustible cables as the main causes of fires in domestic and foreign common utility tunnels fire cases that have occurred so far, the purpose of this paper is to scientifically analyze the behavior of a fire by producing the model of actual common utility tunnels and reproducing the fire. A fire experiment was conducted in a state that line type fixed temperature detector, fire door, connection deluge set and ventilation equipment are installed in underground common utility tunnels and transmission power distribution cables are coated with fire proof paints in a certain section and heating pipes are fire proof covered. As a result, in the case of Type II, the maximum temperature was measured as $932^{\circ}C$ and line type fixed temperature detector displayed the fire location exactly in the receiver at a constant temperature. And transmission power distribution cables painted with fire proof paints in a certain section, the case of Type III, were found not to be fire resistant and fire proof covered heating pipes to be fire resistant for about 30 minutes. Also, fire simulation was carried out by entering fire load during a real fire test and as a result, the maximum temperature is $943^{\circ}C$, almost identical with $932^{\circ}C$ during a real fire test. Therefore, it is considered that fire behaviour can be predicted by conducting fire simulation only with common utility tunnels fire load and result values of heat release rate, height of the smoke layer, concentration of O2, CO, CO2 etc. obtained by simulation are determined to be applied as the values during a real fire experiment. In the future, it is expected that more reliable information on domestic underground common utility tunnels fire accidents can be provided and it will contribute to construction and maintenance repair effectively and systematically by analyzing and accumulating experimental data on domestic underground common utility tunnels fire accidents built in this study and fire cases continuously every year and complementing laws and regulations and administration manuals etc.

• Journal of Soil and Groundwater Environment
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• v.11 no.6
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• pp.69-75
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• 2006

Improper disposal of petroleum and spills from underground storage tanks have created large areas with highly toxic contamination of the soil and groundwater. Methyl tert-butyl ether (MTBE) is widely used as a fuel additive because of its advantageous properties of increasing the octane value and reducing carbon monoxide and hydrocarbon exhausts. However, MTBE is categorized as a possible human carcinogen. This research investigated the Modified Photo-Fenton system which is based on the Modified Fenton reaction and UV light irradiation. The Modified Fenton reaction is effective for MTBE degradation near a neutral pH, using the ferric ion complex composed of a ferric ion and environmentally friendly organic chelating agents. This research was intended to treat high concentrations of MTBE; thus, 1,000 mg/L MTBE was chosen. The objectives of this research are to find the optimal reaction conditions and to elucidate the kinetic and mechanism of MTBE degradation by the Modified Photo-Fenton reaction. Based on the results of experiments, citrate was chosen among eight chelating agents as the candidate for the Modified Photo-Fenton reaction because it has a relatively higher final pH and MTBE removal efficiency than the others, and it has a relatively low toxicity and is rapidly biodegradable. MTBE degradation was found to follow pseudo-first-order kinetics. Under the optimum conditions, [$Fe^{3+}$] : [Citrate] = 1 mM: 4 mM, 3% $H_2O_2$, 17.4 kWh/L UV dose, and initial pH 6.0, the 1000 ppm MTBE was degraded by 86.75% within 6 hours and 99.99% within 16 hours. The final pH value was 6.02. The degradation mechanism of MTBE by the Modified Photo-Fenton Reaction included two diverse pathways and tert-butyl formate (TBF) was identified to be the major degradation intermediate. Attributed to the high solubility, stability, and reactivity of the ferric-citrate complexes in the near neutral condition, this Modified Photo-Fenton reaction is a promising treatment process for high concentrations of MTBE under or near a neutral pH.

• (The)Study of the Eastern Classic
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• no.56
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• pp.267-295
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• 2014

The purpose of this paper was to introduce the material status of women's epistolary literature published in modern study materials for writing letters in Chinese in 1920~30s and analyze gender consciousness shown in them. To this end, five kinds of representative modern study materials for writing letters in Chinese in 1920~30s were selected and 55 women's letters published in them were summarized. Through this, it was pointed out that the subjects of women's epistolary literature are mainly 'males' of families and the form of 'reply.' This implies that the authors of modern study materials for writing letters in Chinese recognized women's Chinese letters as a secondary means to prepare for inevitable communication with men rather than the leading medium of communication. The first aspect of gender consciousness shown in women's epistolary in modern study materials for writing letters in Chinese is to reaffirm the traditional gender order by calling and resetting women as the position and role in the family. The second aspect of gender consciousness is that female education materials which seemed to reflect the modern gender order are actually mentioned under the very skeptical view. The third characteristic aspect of gender consciousness is that the motif of 'discipline about economic activity' is only noticeable in women's epistolary published in modern study materials for writing letters. This setting was regarded as a means that the authors of modern study materials for writing letters in Chinese transferred the responsibilities of maintaining livelihood and managing household to women. Women's epistolary in modern study materials for writing letters in Chinese is the material which is noticeable in terms of showing the possibility of female Chinese Writing in modern times but according to the analysis of this paper, it is the text showing female form and women's writing judged within thoroughly male-centered imagination. That is, women's epistle text has a significance that allows us to read conservative reentry of modern study materials for writing letters in Chinese more clearly.

• Korean Chemical Engineering Research
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• v.54 no.5
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• pp.621-629
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• 2016

Recently, the researches on quantitative structure activity relationship (QSAR) for describing toxicities or activities of chemicals based on chemical structural characteristics have been widely carried out in order to estimate the toxicity of chemicals in multiuse facilities. Because the toxicity of chemicals are explained by various kinds of molecular descriptors, an important step for QSAR model development is how to select significant molecular descriptors. This research proposes a statistical selection of significant molecular descriptors and a new QSAR model based on partial least square (PLS). The proposed QSAR model is applied to estimate the logarithm of partition coefficients (log P) of 130 polychlorinated biphenyls (PCBs) and lethal concentration ($LC_{50}$) of 14 PCBs, where the prediction accuracies of the proposed QSAR model are compared to a conventional QSAR model provided by OECD QSAR toolbox. For the selection of significant molecular descriptors that have high correlation with molecular descriptors and activity information of the chemicals of interest, correlation coefficient (r) and variable importance of projection (VIP) are applied and then PLS model of the selected molecular descriptors and activity information is used to predict toxicities and activity information of chemicals. In the prediction results of coefficient of regression ($R^2$) and prediction residual error sum of square (PRESS), the proposed QSAR model showed improved prediction performances of log P and $LC_{50}$ by 26% and 91% than the conventional QSAR model, respectively. The proposed QSAR method based on computational toxicology can improve the prediction performance of the toxicities and the activity information of chemicals, which can contribute to the health and environmental risk assessment of toxic chemicals.