• Title/Summary/Keyword: 순환수

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Water Quality and Hydrochemistry of Natural Springs and Community Wells in Daejeon Area (대전지역 자연샘물 및 공동우물의 수질 및 수리화학적 특성)

  • 정찬호;박충화;이광식
    • Economic and Environmental Geology
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    • v.35 no.5
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    • pp.395-406
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    • 2002
  • The sixty natural springs and community wells used as a drinking water in the Daejeon area are mainly located at the parks and the natural green districts. The purpose of this study is to investigate the characteristics of water quality and the contamination of the springs and the wells, and to suggest the management strategy for the springs and wells. For this study, we undertook water quality data from Daejeon City. According to the statistic analysis of water quality data, unacceptable rate as a drinking water was about 28 percent in 1999 and 24.5 percent in 2000, respectively. Major unacceptable factor is coliform, and others are bacteria, yersinia, color, turbidity, Fe and F. The unacceptable rate shows a roughly positive relationship with precipitation, that is, it shows highest rate during a rainy season between June and September. The major contamination source is likely to be the excrement of wild animals around natural springs and wells. Most of springs are vulnerable to the contamination of coliform and bacteria because of short residence time and shallow circulation in subsurface environment. The water samples collected from 31 springs or wells show weak acidic pHs, the electrical conductivity ranging from 63 to 357 $\mu\textrm{S}$/cm, and the hydrochemical types of Na(Ca)-HC0$_3$ and Ca-HC0$_3$. The groundwater samples of low total dissolved solid(TDS) belong to Na(Ca)-HC0$_3$. type, and the groundwater of high total dissolved solid is shifted towards Ca-HC0$_3$ type in the chemical composition. These hydrochemical characteristics indicate that most natural springs is in the early stage of geochemical evolution. The natural springs should be closed during a rainy season, which shows a high contamination rate. We suggest that a protection barrier around the springs should be built to keep wild animals away from the springs.

Air Sampling and Isotope Analyses of Water Vapor and CO2 using Multi-Level Profile System (다중연직농도시스템(Multi-Level Profile System)을 이용한 수증기와 이산화탄소 시료채취 및 안정동위원소 조성 분석)

  • Lee, Dong-Ho;Kim, Su-Jin;Cheon, Jung-Hwa;Kim, Joon
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.12 no.4
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    • pp.277-288
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    • 2010
  • The multi-level $H_2O/CO_2$ profile system has been widely used to quantify the storage and advection effects on energy and mass fluxes measured by eddy covariance systems. In this study, we expanded the utility of the profile system by accommodating air sampling devices for isotope analyses of water vapor and $CO_2$. A pre-evacuated 2L glass flask was connected to the discharge of an Infrared Gas Analyzer (IRGA) of the profile system so that airs with known concentration of $H_2O$ and $CO_2$ can be sampled. To test the performance of this sampling system, we sampled airs from 8 levels (from 0.1 to 40 m) at the KoFlux tower of Gwangneung deciduous forest, Korea. Air samples in the 2L flask were separated into its component gases and pure $H_2O$ and $CO_2$ were extracted by using a vacuum extraction line. This novel technique successfully produced vertical profiles of ${\delta}D$ of $H_2O$ and ${\delta}^{13}C$ of $CO_2$ in a mature forest, and estimated ${\delta}D$ of evapotranspiration (${\delta}D_{ET}$) and ${\delta}^{13}C$ of $CO_2$ from ecosystem respiration (${\delta}^{13}C_{resp}$) by using Keeling plots. While technical improvement is still required in various aspects, our sampling system has two major advantages over other proposed techniques. First, it is cost effective since our system uses the existing structure of the profile system. Second, both $CO_2$ and $H_2O$ can be sampled simultaneously so that net ecosystem exchange of $H_2O$ and $CO_2$ can be partitioned at the same temporal resolution, which will improve our understanding of the coupling between water and carbon cycles in terrestrial ecosystems.

Heating Efficiency of Difference Heat Collection Methods for Greenhouse (유리온실의 태양열 집열방법별 집열효과)

  • 최영하;이재한;권준국;박동금;이한철
    • Journal of Bio-Environment Control
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    • v.9 no.3
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    • pp.166-170
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    • 2000
  • Three methods for heat collection, which were the flat solar collector, two fan with radiator, and square pipe method, were studied to sue efficiently solar energy in the three different glasshouses for two years. The flat plate solar collector method was made use of the commercial solar collector with collection area of 24$m^2$, the method of two fans with radiators collected solar energy at the top of the glasshouse. An thermal storage tank was constructed underneath in teach glasshouses. When an area of 1,000$m^2$ was heated to the minimum temperature of 9$^{\circ}C$, the decrease rate of heating fuel for the flat plate solar collector, the fan attached radiator and the square pipe methods were 7%, 19% and 28% respectively. The flat plate solar collector method, which could be heated approximately 40-50$m^2$, was currently used by most of the farmer. Under the condition, the decrease rate of annual heating fuel was 14% which was not better for an economic annual heating fuel. If the fan with radiator method was operated, the use of installation and maintenance were required. So, it could not be good economic efficiency of solar heating. The heating efficiency of the square pipe method was relatively better thant those of the flat plate solar collector or the fan attached radiator. Since the cost of materials and its installation of the use of square pipe method was lower than any other method. However, corrosion of the pipe, greater shade in the greenhouse and strength against the square pipe were problems that should be overcome in the square pipe method.

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Clinical Observation for the 161 Cases of CVA (뇌졸중환자(腦卒中患者) 161례(例)에 대(對)한 임상적(臨床的) 고찰(考察))

  • Kang, Myeong-Seog;Jun, Chan-Yong;Park, Chong-Hyeong
    • The Journal of Korean Medicine
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    • v.16 no.2 s.30
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    • pp.17-35
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    • 1995
  • Clinical observation was made on 161 cases of CVA that were confirmed through brain CT, MRI scan and clinical observation. They were hospitalized in the oriental medical hospital of Kyung-Won University from January to December in 1994. 1. The CVA cases were classified into the following kinds: cerebral infarction, cerebral hemorrhage, subarachnoid hemorrhage(SAH), transient ischemic attack, hypertensive encephalopathy, and the greatest in number among them were the cases of cerebral infarction. 2. The frequency of strokes was much the same between male and female cases and most cases were over 50 of age. 3. In the case of cerebral infarction the place of the most frequent occurrences was in the MCA territory, and as for cerebral hemorrhage, in the basal ganglia area. 4. The most ordinary preceding disease was hypertension. The next was diabetes mellitus. 5. Generally it is thought that CVA occurs frequently in winter. But on the contrary this study of observation confirmed that it occurs mostly in summer. 6. The predisposing factors of cerebral infarction were usually initiated during the time of resting and sleeping and those of cerebral hemorrhage chiefly during the time of exercising. 7. As concerns the course of hospitalization, most patients passed through western medical hospitals or oriental medical hospitals. 8. For the patients the condition of whose consciousness was bad at the time of admission, the prognosis in most cases was bad. 9. The common symptoms were motor disability and verbal disturbance. 10. With regard to cerebral infarction, the average time to start physical theraphy was 11.4 days and with cerebral hemorrhage 22.7 days after stroke. 11. The duration of hospitalization was in most cases more than one month. 12. The main complication was urinary tract infection. The next was pneumonia. 13. At the time of admission to hospital, the blood pressure in most cases was high, but it well controlled at the time of discharge. 14. Most cases were given simultaneous treatment in both ways of western and oriental medicine.

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Performance Characteristics of Agitated Bed Manure Composting and Ammonia Removal from Composting Using Sawdust Biofiltration System (교반식 축분 퇴비화 및 톱밥 탈취처리 시스템의 퇴비화 암모니아 제거 성능)

  • Hong, J.H.;Park, K.J.
    • Journal of Animal Environmental Science
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    • v.13 no.1
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    • pp.13-20
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    • 2007
  • Sawdust biofiltration is an emerging bio-technology for control of ammonia emissions including compost odors from composting of biological wastes. Although sawdust is widely used as a medium for bulking agent in composting system and for microbial attachment in biofiltration systems, the performance of agitated bed composting and sawdust biofiltration are not well established. A pilot-scale composting of hog manure amended with sawdust and sawdust biofiltration systems for practical operation were investigated using aerated and agitated rectangular reactor with compost turner and sawdust biofilter operated under controlled conditions, each with a working capacity of approximately $40m^3\;and\;4.5m^3$ respectively. These were used to investigate the effect of compost temperature, seed germination rate and the C/N ratio of the compost on ammonia emissions, compost maturity and sawdust biofiltration performance. Temperature profiles showed that the material in three runs had been reached to temperature of 55 to $65^{\circ}C$ and above. The ammonia concentration in the exhaust gas of the sawdust biofilter media was below the maximum average value as 45 ppm. Seed germination rate levels of final compost was maintained from 70 to 93% and EC values of the finished compost varied between 2.8 and 4.8 ds/m, providing adequate conditions for plant growth.

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Escape from Binary Opposition -Analysis of Performative Method in - (이항대립(二項對立)으로부터의 탈주 -<오목어>에서의 매체 수행 방식 분석-)

  • Suh, Yong-Chu
    • Cartoon and Animation Studies
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    • s.41
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    • pp.511-531
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    • 2015
  • The underlying impetus of the birth of animated film is attraction about a moving image. And the animation image occurs from the process of performative relationship between an animator and apparatus. Therefore, analysing the method how the moving image is constructed will be the focal starting point to deal with an animated film as a text. In this context, that conveys the theme in more sensuous way will be examined in a dimension of the material, technique and image-making method. KIM Jin-man's is a Stop Motion Animated Film with Noodlescreen about a journey of a fish that wishes to go outside of the water. KIM created original and friendly images out of plain thin noodle which is a common ingredient in Korea, and dealt with the ontological introspection based of the concept of Nondualism. Nondualism based on the interconnected and cyclical eastern philosophy which is different from the western dualistic theory points to the idea that the universe and all its multiplicity are ultimately expressions or appearances of one essential reality. This paper focuses on KIM's recent work and sees how Nondualism is applied throughout the animated film by analysing the performative method of mediums, technique, and structure. First of all, the form of Noodlescreen will be reviewed in Chapter Two. Pinscreen Animation which was invented by Alexander Alexeieff and Claire Parker will be also compared with Noodlescreen in the aesthetic viewpoint here. In Chapter Three, it will be analysed how the description of the image of binary opposition itself provides expanded sense and rich metaphor. Lastly, the format of Mise-en-abyme going constantly towards outer space will be dealt how it exposes the cinematic illusion and spatiality in Chapter Four. Throughout the whole chapters, it will reviewed how the concept of Nondualism relates the images of and deactivate the boundary of binary opposition in terms of both the story development and the visualization method. By this methodology, it will be confirmed that image of animated film not only explains the narrative but also activates the perception about the theme and provides integrated sensory experiences in the independent and expanded dimension.

Analysis of the Benthic Nutrient Fluxes from Sediments in Agricultural Reservoirs used as Fishing Spots (낚시터로 활용중인 농업용 저수지의 퇴적물 내 영양염류 용출 분석)

  • Joo, Jin Chul;Choi, Sunhwa;Heo, Namjoo;Liu, Zihan;Jeon, Joon Young;Hur, Jun Wook
    • Journal of Korean Society of Environmental Engineers
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    • v.39 no.11
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    • pp.613-625
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    • 2017
  • For two agricultural reservoirs that are rented for fishing spots, benthic nutrient fluxes experiment were performed two times with two sediments from fishing-effective zone and one sediment from fishing-ineffective zone using laboratory core incubation in oxic and anoxic conditions. During benthic nutrient fluxes experiment, the changes in DO, EC, pH, and ORP in the supernatant were not significantly different between fishing-effective zone and fishing-ineffective zone, and were similar to the sediment-hypolimnetic diffused boundary layer in agricultural reservoir. Except for $NO_3{^-}-N$, more benthic nutrient fluxes of $NH_4{^+}-N$, T-P, and $PO{_4}^{3-}-P$ from sediment to hypolimnetic was measured in anoxic than in oxic conditions (p<0.05). As the DO concentration in hypolimnetic decreases, the microorganism-mediated ammonification is promoted, the nitrification is suppressed, and finally the $NH_4{^+}-N$ diffuses out from sediment to hypolimnetic. Also, the diffusion of T-P and $PO{_4}^{3-}-P$ from sediments to hypolimnetic is accelerated through the dissociation of the phosphorus bound to both organic matters and metal hydroxides. The difference in the benthic nutrient diffusive fluxes between fishing-effective zone and fishing-ineffective zone was not statistically significant (p>0.05). Therefore, it was found that fishing activities did not increase the benthic nutrient diffusive fluxes to a statistically significant level. Due to the short fishing activities of 10 years and the rate-limited diffusion of the laboratory core incubation, the contribution of fishing activities on sediment pollution is estimated to be low. No significant correlation was found between the total amount of nutrients in sediment and the benthic nutrient diffusive fluxes in both aerobic and anaerobic conditions. Therefore, nutrients input from various nonpoint sources of watersheds are considered to be a more dominant factor rather than fishing activities in water quality deterioration, and both aeration and water circulation in hypolimnetic were required to suppress the anoxic environment in agricultural reservoirs.

High Density Tilapia Culture in a Recirculating Water System without Filter Bed (무여과순환수 탱크 이용 Tilapia의 고밀도 사육실험)

  • KIM In-Bae
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.16 no.2
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    • pp.59-67
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    • 1983
  • An experiment on the rearing of tilapia stocked in closed recirculating tanks eliminating biological filter beds was carried out at the Fish Culture Experiment Station of the National Fisheries University of Pusan, from May 18 through October 21, 1982, and the growth rates, feed conversion, water quality, spawning prevention and space utilization efficiency were discussed. Finally discussed is the feasibility on the establishment of commercial production units. On the water quality, the water temperature ranged from $22.8^{\circ}C\;to\;29.1^{\circ}C$, and total ammonia arround 10 ppm or slightly up. Maintaining phytoplankton bloom was not successful probably because of the active consumption by the heavily stocked tilapia. Several attempts were made by changing the culture water with green water from a nearby earthen pond with results of fading-away in a couple of days. Feed conversions were relatively high ranging from 0.9 to 1.2 except for experiment 1 when the fish were not fully recovered from weakened wintering state. The feed used was partly laboratory prepared $25\%$ protein diet and mostly commercially available $39\%$ protein carp feed. Spawning was completely controlled during the experiment, resulting from density effect, which ranged from 10kg to 40.7kg per square meter with water depth of 0.5 to 0.6m. Space utilization efficiency was very high. Daily net production from the experiment division 3, which showed the highest result, was 6.206 kg per tank, which is calculated 3,235 metric tons per hectare per year, This time, water temperature ranged from 27.8 to $29.1^{circ}C$, average being $28.4^{circ}C$, and total ammonia arround 10 ppm. An estimation for the commercial set-up of the production system based on the results of experiment divisions which had initial stocking rate $15\;kg/m^2$ or up, is made. If the total facility, 8 tanks comprising $56\;m^2$ in surface area, is used for the present study, the yield would become 5,639 kg from 200 day rearing, which would be possible under double sheets vinyl house without additional heating, and it is thought feasible in the economic view point, when 10 or more units are operated.

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THE EFFECT OF C-FACTOR AND VOLUME ON MICROLEAKAGE OF COMPOSITE RESIN RESTORATIONS WITH ENAMEL MARGINS (법랑질 변연으로 이루어진 복합레진 수복물의 체적과 C-factor가 미세누출에 미치는 영향)

  • Koo, Bong-Joo;Shin, Dong-Hoon
    • Restorative Dentistry and Endodontics
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    • v.31 no.6
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    • pp.452-459
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    • 2006
  • Competition will usually develop between the opposing walls as the restorative resin shrinks during polymerization. Magnitude of this phenomenon may be depended upon cavity configuration and volume. The purpose of this sturdy was to evaluate the effect of cavity configuration and volume on microleakage of composite resin restoration that has margins on the enamel site only. The labial enamel of forty bovine teeth was ground using a model trimmer to expose a flat enamel surface. Four groups with cylindrical cavities were defined, according to volume and configuration factor(Depth x Diameter / C-factor) - Group I : 1.5 mm ${\times}$ 2.0 mm / 4.0, Group II : 1.5 mm ${\times}$ 6.0 mm / 2.0, Group III : 2.Omm ${\times}$ 1.72 mm / 5.62, Group IV : 2.0 mm ${\times}$ 5.23 mm / 2.54. After treating with fifth-generation one-bottle adhesive - BC Plus$^{TM}$ (Vericom, AnYang, Korea), cavities were bulk flted with microhybrid composite resin - Denfill$^{TM}$ (Vericom). Teeth were stored in distilled water for one day at room temperature and were finished and polished with Sof-Lex system. Specimens were thermocycled 500 times between 5$^{\circ}$C and 55$^{\circ}$C for 30 second at each temperature. Teeth were isolated with two layers of nail varnish except the restoration surface and 1 mm surrounding margins. Electrical conductivity (${\mu}$A) was recorded in distilled water by electrochemical method. Microleakage scores were compared and analyzed using two-way ANOVA at 95% level. The results were as follows: 1. Small cavity volume showed lower microleakage score than large one, however, there was no statistically significant difference. 2. There was no relationship between cavity configuration and microleakage. Factors of cavity configuration and volume did not affect on microleakage of resin restorations with enamel margins only.

A COMPARATIVE STUDY ON THE MICROLEAKAGE OF PRVENTIVE RESIN RESTORATION USING FLOWABLE COMPOSITE RESIN (유동성 복합 레진을 적용한 예방적 레진 수복물의 미세 누출 양상에 관한 비교 연구)

  • Park, Heon-Jeong;Kim, Jong-Soo;Kim, Yong-Kee
    • Journal of the korean academy of Pediatric Dentistry
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    • v.27 no.3
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    • pp.419-430
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    • 2000
  • The purpose of this study was to compare the microleakage pattern of preventive resin restoration using conventional composite resin and flowable composite resin that recently developed. 60 sound premolar teeth were allocated to three groups. Flowable composite resin was used for the experimental groups(Group I and II) and conventional resin for the control group(Group III). After composite filling and sealant application, all teeth were thermocycled and evaluated for microleakage under light microscope. Additionally, a variety of voids formed inside restorations were also evaluated. Data were analyzed statistically using Kruskal-Wallis test and/or Mann-Whitney U-test. The results of the present study were as follows. 1. Microleakage found in all samples was only limited to the interface of restoration margin and enamel. 2. The flowable composite resin groups (Group I, II) generally showed less microleakage than control groups (conventional preventive resin restoration) (p<0.05) 3. Various types of voids were observed in most specimens. Especially, there was a tendency for more and larger voids to be found in group I, II than group III (p<0.05).

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