• Economic and Environmental Geology
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• v.51 no.1
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• pp.67-76
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• 2018

This study reviews three eco-friendly energy towns with hybrid thermal energy supply systems and borehole thermal energy storage (BTES) in Canada and Denmark. The district heating and cooling systems were designed by using multi-source energy for the higher efficiency and reliability as well as environment. ADEU (Alexandra District Energy Utility) located at the developing area in the city of Richmond, Canada was designed to supply district energy with the installation of 726 borehole heat exchangers (BHEs) and a backup boiler using natural gas. DLSC (Drake Landing Solar Community) located in the town of Okotoks, Canada is a district system to store solar thermal energy underground during the summer season by seasonal BTES with 144 BHEs. Brædstrup Solpark district heating system located in Denmark has been conducted energy supply from multiple energy sources of solar thermal, heat pump, boiler plants and seasonal BTES with 48 BHEs. These systems are designed based on social and economic benefits as well as nature-friendly living space according to the city based energy perspective. Each system has the energy center which distribute the stored thermal energy to each house for heating during the winter season. The BHE depth and ground thermal storage volume are designed by the heating and cooling load as well as the condition of ground water flow and thermophysical properties of the ground. These systems have been proved the reliance and economic benefits by providing consistent energy supply with competitive energy price for many years. In addition, the several expansions of the service area in ADEU and Brædstrup Solpark have been processed based on energy supply master plan. In order to implement this kind of project in our country, the regulation and policy support of government or related federal organization are required. As well as the government have to make a energy management agency associated with long-term supply energy plan.

• Economic and Environmental Geology
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• v.53 no.4
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• pp.383-395
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• 2020

The stratigraphical position of the Haengmae Formation can provide clues towards solving the hot issue on the Silurian formation, also known as Hoedongri Formation. Since the 2010s, there have been several reports denying the Haengmae Formation as a lithostratigraphic unit. This study aimed to clarify the lithostratigraphic and chronostratigraphic significance of the Haengmae Formation. The distribution and structural geometry of the Haengmae Formation were studied through geologic mapping, and the correlation of relative geologic age and the absolute age was performed through conodont biostratigraphy and zircon U-Pb dating respectively. The representative rock of the Haengmae Formation is massive and yellow-yellowish brown pebble-bearing carbonate rocks with a granular texture similar to sandstone. Its surface is rough with a considerable amount of pores. By studying the mineral composition, contents, and microstructure of the rocks, they have been classified as pebble-bearing clastic rocks composed of dolomite pebbles and matrix. They chiefly comprise of euhedral or subhedral dolomite, and rounded, well-sorted fine-grained quartz, which are continuously distributed in the study area from Biryong-dong to Pyeongan-ri. Bedding attitude and the thickness of the Haengmae Formation are similar to that of the Hoedongri Formation in the north-eastern area (Biryong-dong to Haengmae-dong). The dip-direction attitudes were maintained 340°/15° from Biryong-dong to Haengmae-dong with a thickness of ca. 200 m. However, around the southwest of the studied area, the attitude is suddenly changed and the stratigraphic sequence is in disorder because of fold and thrust. Consequently, the formation is exposed to a wide low-relief area of 1.5 km × 2.5 km. Zircon U-Pb age dating results ranged from 470 to 449 Ma, which indicates that the Haengmae Formation formed during the Upper Ordovician or later. The pebble-bearing carbonate rock consisted of clastic sediments, suggesting that the Middle Ordovician conodonts from the Haengmae Formation must be reworked. Therefore, the above-stated evidence supports that the geologic age of the Haengmae Formation should be Upper Ordovician or later. This study revealed that the Haengmae Formation is neither shear zone, nor an upper part of the Jeongseon Limestone, and is also not the same age as the Jeongseon Limestone. Furthermore, it was confirmed that the Haengmae Formation should be considered a unit of lithostratigraphy in accordance with the stratigraphic guide of the International Commission on Stratigraphy (ICS).

• Korean Journal of Environmental Agriculture
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• v.31 no.2
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• pp.185-191
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• 2012

Background: The removal of phosphate(P) in the wastewater is essential for the prevention of eutrophication in the river and stream. This study was initiated to evaluate the P removal by three strains of bacteria isolated from industrial wastewater. The three strains of bacteria, A1, A2, and A3, isolated were identified as Stenotrophomonas maltophilia strain CUPS 3, Rhodococcus erythropolis strain Sco-C01, Bacillus sp. 3434BRRJ, respectively. METHODS AND RESULTS: The experiments evaluating the effects of temperature, P concentration, aeration, and carbon sources on P removal by Bacillus sp. 3434BRRJ were performed in the following conditions: temperature, 15, 25 and $30^{\circ}C$; P concentrations, 20, 30, and 40 mg/L; oxygen condition, aerobic, anaerobic/aerobic conditions; carbon sources, glucose, acetate and mixture of glucose and acetate. As a result, the best optimum conditions for P removal by Bacillus sp. 3434BRRJ were as follows: temperature, $30^{\circ}C$; P concentration, 20 mg/L; carbon sources, mixture of glucose and acetate; oxygen concentration, anaerobic and aerobic conditions. The P removal efficiencies by Bacillus sp. 3434BRRJ, Stenotrophomonas maltophilia strain CUPS, and Rhodococcus erythropolis strain Sco-C01 were 99%, 50%, 20%, respectively. CONCLUSION: As a result, the best optimum conditions for P removal by Bacillus sp. 3434BRRJ selected and used in this study were as follows: temperature, $30^{\circ}C$; P concentration, 20 mg/L; carbon sources, mixture of glucose and acetate; oxygen concentration, anaerobic and aerobic conditions.

• Journal of Environmental Impact Assessment
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• v.26 no.6
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• pp.470-478
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• 2017

This study was classified into two groups, normal season group and drought season group, by the cluster analysis using the weather and water quality data from 2012 to 2015, using SPSS 18 version. Also each cluster was classified into three spaces, Gangcheon, Yeoju and Ipoh weir. We performed the multiple regression analysis with each monthly data that concentration of Chl-a was more than algae warming level. 6 groups classified in time and space were analyzed by the correlation analysis between concentration of Chl-a and 3 weather, 11 water quality and discharge factors. We developed Chl-a prediction equations of each group with independent variables of the multiple regression analysis applying to the correlation result. The result of cluster analysis was that the period was divided into two groups, normal group(2012-2013) that total annual precipitation rate was normal and drought group(2014-2015) that total annual precipitation rate was less than 1,000 mm/hr, in time. The months that concentration of Chl-a was more than algae warming level in each group classified by cluster analysis were that the normal group was 3~8 and drought group was 3 and 6~10. The correlation result between Chl-a and weather, water quality and discharge factors for each 6 group was that relationships between Chl-a and water, discharge factors were high in the drought group more than in normal group at all weirs. This was influenced by velocity reduction and increasing HRT according to the intense drought. Weather, water quality and discharge factors that were high correlation with Chl-a were applied to independent variables of Chl-a prediction equations and each equations were developed. Among them, Each adjusted R square of Prediction equations for Chl-a in each group at Ipoh weir where is located in Namhan river downstream and is directly connected to Paldang dam were normal group = 0.920 and drought group = 0.818. It's showed the high linear.

• Applied Microscopy
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• v.41 no.2
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• pp.109-116
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• 2011

Polycystic ovary syndrome (PCOS) is hormonal imbalance condition as the endocrine and metabolic disorder that induces the infertility and various complications in reproductive age women. Estradiol valerate (EV) is used hormone replacement therapy in menopausal women and is reported that excessive administration of EV induces the PCOS. Nerve growth factor (NGF) is the factor to regulate the survival and maturation of developing neuronal cell and is also synthesized in ovary. And NGF is overexpressed in EV-induced polycystic ovary (PCO) as previously reported. Therefore, this study examined the possibility of NGF as can be used the biological marker in diagnosis of PCOS, the hormonal imbalance condition, using PCO and CHO (chinese hamster ovarian) cell lines. The concentration of EV treatment is optimized a 1 mg as not influence on the proliferation of CHO cell but 2 mg and 3 mg of EV treatment have the inhibition effect at initial stage. The morphological change was not observed in CHO cell after dose dependent manner treatment of EV. Expression of NGF mRNA and protein is significantly increased at 30 min after EV treatment in CHO cells compared to that of control. And NGF protein expression is strongly increased in PCO tissue, which observed many follicular cysts compared to normal ovary tissue. Taken together, overexpression of NGF may be act as a molecule to induce an abnormal development of follicle, suggesting that NGF can be used as a biological marker in diagnosis of PCOS.

• Journal of Science Education
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• v.34 no.2
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• pp.225-236
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• 2010

The purpose of this study is to analyze and evaluate the Cyber Home Learning contents of Earth science area in the basic course of the $10^{th}$ grade. For this purpose, we applied the 'Cyber Home Study Content Quality Control Tool' presented in Elementary Secondary Education e-Learning Quality Management Guidelines (Ver.2.0)' of Korea Education & Research Information Service(2008). The results of Cyber home learning contents analysis are as follow: First, it was presented that the study guide introduced the contents which should be studied for one class, properly. And it was not analyzed that the diagnosis assesment was not completed in the initiative study; Second, it was possible to study choosing the contents fitting the learner's level of learning in the main study, it was comprised of about 10 minutes. Third, it was performed without feedback for incorrect answers in the learning assessment, just the number of wrong questions. And the learning arrangement present the important contents learned in that class, summarizing and arranging again. The results of evaluating the contents in Cyber Home Learning are as follows: First, in evaluation section of instructional design, many text materials which were so difficult for learners to read were explained, being provided. Besides, the systematic structures leaves much to be desired, in view of learners' learning experience, contents, and environment. And in evaluation section of learning contents, the error of contents caused the learning contents not to appear, the amount of learning in each section was found too much. Second, in evaluation section of the strategy for Teaching and Learning, when we mention the strategy of Self Directed Learning, the environment to make learners search for information free and self-study possible was not possessed well. And in evaluation section of interaction, it was found that a simple click caused the learning to go on. Third, in evaluation section of evaluating, it was evaluated that there was wanting in consistency in learning aims, contents, evaluation contents.

• Journal of Food Hygiene and Safety
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• v.13 no.2
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• pp.121-128
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• 1998

Ochratoxin A (OA) is a mycotoxin produced by Aspergillus ochraceus as well as other molds. It is a natural contaminant of mouldy food and feed. OA has a number of toxic effects, the most prominant being nephrotoxicity. Futhermore, OA is immunosuppressive, genotoxic, teratogenic and carcinogenic. OA inhibits protein synthesis by competition with phenylalanine in the phenylalanine-tRNA aminoacylation reaction. Recently, lipid peroxidation induced by OA has been reported, indicating that the lesion induced by this mycotoxin could be also related to oxidative pathway. Since it seems impossible to avoid contamination of foodstuffs by toxigenic fungi, detoxification and detoxication of OA are needed. In this study we investigated the protective effects of aspartame (Asp), phenylalanine (Phe), polyphenol 70S (PP) and aloe extract (AE) on the nephrotoxicity induced by subacute exposure to the OA. Asp and Phe are structural analogues of OA. PP, an ingredient of Green Tea and AE have been known as antioxidant and radical scavenger. Phe (40 mg/kg, i.p.) and Asp (25 mg/kg, p.o.) were administered to Sprague-Dawley rats simultaneously with OA (2.0 mg/kg, p.o.) for 2 weeks. PP (200 mg/kg, p.o.) and AE (50 mg/kg, i.v.) were pretreated before administration of OA, for 2 weeks and 3 days, respectively. Using enzymuria, BUN level, creatinemia and histophathologic examination as indices of renal damage, we observed that all of four compounds prevented the nephrotoxic effects induced by OA. It seems that structural analogues of OA such as Asp and Phe have better protective effect on the nephrotoxicity of OA than antioxidants. These results indicate that 1) formation of free radical and lipid peroxidation are likely to be involved in the nephrotoxicity of OA in vivo, 2) Asp, PP and AE might be used for prevention of renal lesions in cases of ochratoxicosis.

• Journal of The Korean Society of Grassland and Forage Science
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• v.8 no.3
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• pp.85-91
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• 1988

A field experiment was conducted to determine the effects of shading degrees (0: full sunlight, 25, 50 and 75%) on the proximate components, cell wall constituents (CWC), digestibility, water soluble carbohydrates (WSC) and nitrate nitrogen ($NO_3$-N) concentration of grasses grown in forest. For the test different artificial shading houses were established and pasture species used were orchardgrass, timothy, perennial ryegrass and ladino clover. The experiment was performed at LES in Suwon. 1985. 1. Considering proximate components, CWC and digestibility of grasses, ladino clover showed the best quality, and then perennial ryegrass. 2. The contents of crude protein, crude ash, and digestibility of grasses were increased with shading, regardless of pasture species. As the shading degrees are increased, the contents of crude fiber in orchardgrass, perennial ryegrass and timothy were decreased, while that in ladino clover was increased with shading. 3. Grasses grown in spring showed higher digestibility than those grown in summer season. 4. The content of WSC was the highest in perennial ryegrass, and then ladino clover, orchardgrass, and timothy, in that order. Also WSC was decreased as the shading degrees are increased. 5.The content of $NO_3$-N was the highest in perennial ryegrass, and then orchardgrass, ladino clover and timothy, in that order. Also the $NO_3$-N was significantly increased with higher shading level. In the regression equation between shading degrees and $NO_3$-N ($r^2$=0.90**, TEX>$r^2$=0.95**), shading degree of 43 to 44% was critical level, causing nitrate poisoning to animal. 6 Considering grass quality, dry matter yield and $NO_3$-N, less than 40% of shading degree (over 60% of full sunlight) was desirable for better grassland improvement, management and utilization in the forest.

• Restorative Dentistry and Endodontics
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• v.23 no.2
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• pp.537-549
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• 1998

The purpose of this study was to evaluate the influence of root resection and retrograde cavity preparation methods on the apical leakage in endodontic surgery. To investigate the effect of various root resection and retrograde cavity preparation methods on the apical leakage, 71 roots of extracted human maxillary anterior teeth and 44 mesiobuccal roots of extracted human maxillary first molars were used. Root canals of the all the specimens were prepared with step-back technique and filled with gutta-percha by lateral condensation method. Three millimeters of each root was resected at a 45 degree angle or perpendicular to the long axis of the tooth according to the groups. Retrograde cavities were prepared with ultrasonic instruments or a slow-speed round bur, and occlusal access cavities were filled with zinc oxide eugenol cement. Three coats of clear nail polish were placed on the lateral and coronal surfaces of the specimens except the apical cut one millimeter. All the specimens were immerged in 2% methylene blue solution for 7 days in an incubator at $37^{\circ}C$. The teeth were dissolved in 14 ml of 35% nitric acid solution and the dye present within the root canal system was returned to solution. The leakage of dye was quantitatively measured via spectrophotometric method. The obtained data were analysed statistically using two-way ANOVA and Duncans Multiple Range Test. The results were as follows: 1. No statistically significant difference was observed between ultrasonic retrograde cavity preparation method and slow-speed round bur technique, without apical bevel (p>0.05). 2. Ultrasonic retrograde preparation method showed significantly less apical leakage than slow-speed round bur technique, with bevel (p<0.0001). 3. No statistically significant difference was found between beveled resected root surface and non-beveled resected root surface, with ultrasonic technique (p>0.05). 4. Non-beveled resected root surface showed significantly less apical leakage than beveled resected root surface, with slow-speed round bur technique (p<0.0001). 5. No statistically significant difference in apical leakage was found between the group of retrograde cavity prepared parallel to the long axis of the tooth and the group of one prepared perpendicular to the long axis of the tooth (p>0.05). 6. Regarding isthmus preparation, ultrasonic retrograde preparation method showed significantly less apical leakage than slow-speed round bur technique, in the mesiobuccal root of maxillary molar, without bevel (p<0.0001).

• Journal of Korean Society for Geospatial Information Science
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• v.23 no.1
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• pp.101-111
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• 2015

Stream restoration projects have become threats to riparian ecosystem in Rep. of korea. Riparian wildlife becomes isolated and the animals are often experience difficulties in crossing riparian corridors. The purposes of this study is to select suitable wildlife passages for wild animals crossing riparian corridors. Maximum entropy model and snow tracking data on embankment in winter seasons were used to develop species distribution models to select suitable wildlife passages for water deer. The analysis suggests the following. Firstly, most significant factors for water deer's habitat in area nearby riparian area are shown to distance to water, age-class, land cover, slope, aspect, digital elevation model, tree density, and distance to road. For the riparian area, significant factors are shown to be land cover, size of riparian area, distance to tributary, and distance to built-up. Secondly, the suitable wildlife passages are recommended to reflect areas of high suitability with Maximum Entropy model in riparian areas and the surrounding areas and moving passages. The selected suitable areas are shown to be areas with low connectivity due to roads and vertical levee although typical habitats for water deer are forest, grassland, and farmland. In addition, the analysis of traces on snow suggests that the water deer make a detour around the artificial structures. In addition, the water deer are shown to make a detour around the fences of roads and embankment around farmland. Lastly, the water deer prefer habitats around riparian areas following tributaries. The method used in this study is expected to provide cost-efficient and functional analysis in selecting suitable areas.