In this study, using the developed pilot device, an experiment was conducted with groundwater according to the calcium carbonate concentration and silica concentration for a certain period of time to determine the degree of RO membrane contamination according to water quality. In addition, using wastewater with severe fouling of raw water, the treatment efficiency is compared through an experiment with a pilot device, the operation progress is evaluated for the scale effect, and the stability and convenience of the developed product are considered.

PURPOSES : This paper presents the experimental results of tests conducted on concrete produced with air-cooled (AS) and water-cooled (WS) ground blast-furnace slag exposed to multi-deterioration environments of carbonation and scaling. METHODS : Carbonated and uncarbonated concrete specimens were regularly monitored according to the ASTM C 672 standard to evaluate the durability of concrete exposed to both scaling and combined carbonation and scaling conditions. Additionally, mechanical properties, such as compressive strength, flexural strength, and surface electric resistivity, were analyzed. RESULTS : It was found that concrete specimens produced with AS and WS had a beneficial effect on the mechanical properties because of the latent hydraulic properties of the AS and WS mineral admixtures. Moreover, carbonated concrete showed good scaling resistance in comparison to uncarbonated concrete, particularly for concrete produced with AS and WS. CONCLUSIONS : The improved scaling resistance of carbonated concrete showed that AS is a suitable option for binders used in cement concrete pavements subjected to combined carbonation and scaling.

In order to enhance the utilization of underground heat including underground water, the comparison between the existing high density polyethylene underground heat exchanger and the newly developed metal heat exchanger was conducted to suggest the potential use of geothermal energy corresponding to the geological characteristics of Jeju Island. When the acquired heat of the underground loop system test condition of the KS B 8292 water-water geothermal heat pump unit was compared by installing heat exchanger of HDPE material and the heat exchanger of STS material under the same bore hole condition, the total heat area of the heat exchanger of STS material was about 15% less than HDPE, but the acquired heat was estimated to be about 4 times or more.

낙동강 하구역 조간대의 보존 및 관리를 위한 기초적 연구로, 낙동강 하구 조간대를 대상으로 지하수의 물리적 특성 및 퇴적물의 성상을 조사하였다. 조간대의 지하수위 및 지하수온의 변화는 조석에 영향을 받으며, 5,000 m³/s 이상의 하천수 방류는 조간대의 지하수위를 상승시킬 뿐만 아니라 지반 내 수십 cm 깊이의 지하수 염분을 감소시키는 것으로 조사되었다. 간조 시 조간대 지하수위의 하강 형태는 조간대 퇴적물의 세립질 함량에 따른 투수도 차이에 영향을 받는 것으로 나타났다. 또한 높은 투수도의 조간대 지반에서는 활발한 지하수 흐름에 의해 세립질의 퇴적이 감소하고 재부상이 증가하여 결과적으로는 낮은 세립질 함량의 조간대 지반을 형성하였다.

PURPOSES: This study is to evaluate a ground water level effect on frost heaving in road pavements. METHODS: The effects of water table on frost heaving in pavement systems were evaluated from the mechanical analysis using FROST program. The input parameters and boundary conditions were determined by considering climates, pavement sections, and material properties specially subgrade soil types in Korea. RESULTS: When the water table located above the freezing depth, amount of frost heaving caused by freezing the water in pavement itself was big enough to damage in pavement system, although pavement system consists of fully non-frost-susceptible materials with sufficient thickness of anti-freezing layer. The amount of frost heaving was decreased rapidly with increasing the distance between the water table and freezing depth. CONCLUSIONS: It was concluded that there is no engineering problems related with frost heaving in practical sense when the distance between freezing depth and water table is over 1.5m for having subgrade soils less than 50% of #200 sieve passing to meet specification on quality control in Korea.

본 연구에서는 산림유역의 최상류지역에 위치한 일시하천(ephemeral stream)과 간헐천(intermittent stream)이 상존하는 수변지역을 대상으로 지하수위의 계절적인 변화 양상을 파악하였다. 3곳의 산림유역(총 12개 소유역)에서 일시하천 및 간헐천의 수변구역 보호를 위한 최적관리기법을 포함하는 4개의 처리구(BMP1, BMP2, clearcut, reference)를 적용하였다. 지하수위는 각 소유역별 25개소(총 300개소)에서 2주 간격으로 측정되었으며, 벌채 전 1년과 벌채 후 2년, 총 3년 동안 관측되었다. 전체적으로 지하수위의 반응은 강우량의 영향이 큰 것으로 관찰되었다. 또한, 산림벌채전과 비교하여, 벌채 후 2년 동안 지하수위는 유의적으로 증가하였다. 특히, 벌채 1년 후(2008) 개벌처리구에서 28.2cm, 벌채 2년 후(2009) BMP2에서 54.2cm로 가장 크게 증가하였다. 그러나, 개벌처리구와 BMP2의 지하수위 변화 특성을 비교할 때, 벌채된 목재의 재적과 지하수위의 변화는 직접적인 연관성이 없는 것으로 나타났다. 산림벌채로 인한 지하수위의 증가는 ?㎱굇璲? 보다 건조기간 동안 더 크게 나타났으며, 이러한 계절적인 추이는 산림벌채 후 식생구조의 차이에서 야기되는 증발산양의 변화에 기인하는 것으로 사료된다.

파프리카 수경재배 농가에서 사용하고 있는 지하수 수질을 조사하기 위해, 강원도(27점), 경상남도(70점), 전라남도(54점) 지역에서 채취한 지하수의 pH, EC 및 무기이온의 농도를 2008년 11월부터 2009년 9월까지 분석하였다. 평균적으로 pH 7.2(6.57~7.54), 전기전도도(EC) 0.31(0.05~0.49) dS·m-1, HCO3 97.81(35.37~161.11), T-N 5.68(0.45~15.48), P 0.67(0.15~0.70), K 2.53(0.59~6.70), Ca 35.68(4.15~80.70), Mg 7.35 (1.46~14.87), Na 17.89(3.31~34.82), Fe 0.01(0~0.05), Mn 0.09(0~0.51), Zn 0.06(0~0.07), Cu 0.03(0~0.10) mg·L-1을 나타내었다. 지역과 농가에 따라 지하수의 pH, EC, HCO3, Ca, Mg, Na 이온 특성은 차이를 나타내었다. 수경재배 전용비료로 배양액 조성이 가능한 범위 빈도율은 pH 5.0~8.0이 92.6%, EC 〈 0.5dS·m-1 미만 89.3%, Na 〈 30 미만 97.5%, Ca 〈 40 미만 88.5%, Mg 〈 20 미만 97.5%, HCO3 〈 100 미만 69.5%, Fe 〈 0.05 미만 90.1%, Mn 〈 0.6 미만 99.6%, Zn 〈 0.5mg·L-1 미만 98.3% 이었다. 이상의 측정된 전체 이온 항목이 단비 조성에 적합한 수질은 70개소로 46.3%을 나타내었다. pH는 EC, Mg, HCO3, Na, 및 Fe 이온과, EC는 T-N, K, Ca, Mg, HCO3, Na, 및 Mn과 유의한 상관을 보였다.

The indirect target strength (TS) estimation method which uses the Kirchhoff ray mode model (KRM model) was discussed to apply for a biomass estimation in the water of mixed species. TS of 25 live scorpion fishes for 120kHz were measured by a tethered method and of others dominant 5 species in the marine ranching ground of Jeju coastal water including a scorpion fish were also estimated by KRM model. The measurement TS of scorpion fish well agreed with the theoretical values and the standard formula of scorpion fish was estimated as TS120kHz=20Log (L)-72.9 (r2=0.67). TScm values estimated on trial to each sample of dominant 5 species were from -69.3dB to -75.1dB at 120kHz and they were in the general range of swimbladdered fish. It was clarified that TS by KRM model can be used to estimate fish biomass estimation by increasing a sample number and is more effective under the condition that there is rare TS information for inhabiting species in mixed-species area.

2000년부터 2002년까지 통영 바다목장 해역 5개 정점표층수와 저층수에서 종속영양세균의 개체수를 평판계수법으로 측정하여 종속영양세균군집의 계절별 변동추이를 비교 분석하고, 우점종을 선별하여 동정하였다. 7월과 8월의 하절기에 채수한 해수에는 봄 혹은 가을 및 겨울에 채수한 해수에 비하여 모든 정점에서 훨씬 더 많은 종속영양세균이 검출되었다. 저층수에 비하여 표층수에서 종속영양세균의 수가 더 많았으나 동절기(2001년 12월과 2002년 2월)에는 해

1995년 경남지역에서 양액재배 원수로 사용되고 있는 77개 농가의 지하수 중의 무기성분 농도를 분석한 결과는 다음과 같다. 지하수의 깊이는 10~500m, pH는 6.2~8.4, EC는 0.11~1.44dS/m이었다. 1 liter당 무기성분의 평균함량은 N H4-N 0.3mg, N O3-N 3.1mg, P O43- 0.5mg, Ca2＋ 25.4mg, Mg2＋ 11.5mg, Na＋ 21.7mg, C l- 42.6mg, S O42- 72.5mg였다. 지하수의 pH와 Mg2＋(0.34** ), Ca2＋(0.33** ) 및 EC(0.29** ) 사이에 유의적인 정(＋)의 상관을 보였다. 또한 EC와 Na＋(0.68** ), Ca2＋(0.67** ), S O42-(0.62** ), Mg2＋(0.60** ), N H4-N(0.36** ), C l-(0.53** ) 및 K＋(0.26** ) 간에도 유의적인 정(＋)의 상관을 보였다..

This paper described on relation between the catches of tuna and the distribution of water temperature of eastern fishing ground of Tropical region in the Pacific Ocean. The data of catches and water temperature used in this paper were based log book which # 27 CHENG RONG(Gross tonnage : 399 ton) had been worked eastern fishing ground(Lat : 09˚N- 14˚S, Long : 115˚- 149˚W)from January to October, 1991. The obtained result are as follows : 1. On the relation between the catches and the geographical distribution, bigeye tuna was higher catches at Lat 4˚- 9˚N, Long 135˚- 139˚W area in the equatorial counter current region where surface water temperature was range of 27.5℃ to 27.9℃, yellowfin tuna was higher catches at Lat 4˚- 9˚S, Long 145˚- 149˚W in the south equatorial current region where surface water temperature was range of 28.0℃ to 28.4℃ and albacore tuna was higher catches at Lat 10˚- 14˚S, Long 120˚- 124˚W area in the south equatorial current region where surface temperature was range of 26.5℃ to 26.9℃ 2. On the relation between catches and distribution of vertical water temperature, bigeye tuna was higher catches at the water temperature of 10℃ to 12℃ on depth layer between 300m and 360m, yellowfin tuna was higher catches at the water temperature of 15℃ to 19℃ on depth layer between 180m and 280m and albacore tuna was higher catches at the water temperature of 12℃ to 14℃ on depth layer between 280m and 310m. Above the result, it seemed that bigeye tuna distributed deeper layer than yellowfin and albacore tuna.

In order to investigate the environmental properties of set net grounds located in the coastal waters of Yeosu. The current in the vicinity of set net grounds was observed by drogue and current meter in 1990 and 1992. The results obtained are summarized as follows: The direction of tidal current at the north enterance of Yeosu bay was southerly in ebb and northwesterly in flood without the distiction of the neap tide and the spring tide. In spring tide the maximum Velocity of the tidal current was 68 cm/sec in ebb and 66 cm/sec in flood. In neap tide the maximum velocity of the tidal current was 37 cm/sec in ebb and 35 cm/sec in flood. And so the direction of residual current was the south ward mainly and 21 cm/sec. The direction of tidal current at set net fishing grounds was southwesterly in ebb and westerly or northwesterly in flood. Regardless of the distinction of neap and spring. The maximum velocity of the current in spring tide was 50 cm/sec in ebb and 40 cm/sec in flood and that in neap was 28 cm/sec in ebb and 25 cm/sec in flood. In spring tide the speed vector along the major axis of semidiurnal tide component was three times as large as diurnal tide. In neap tide, however, the speed vector was about 50% less then that in spring tide, and the semidiurnal tide and diurnal tide were equal in the size of current ellipse and the direction of major axis. The sea area had a southwesterly residual current. 11 cm/sec in spring tide and 7 cm/sec in neap tide. According to the result of drogue tracking, the vicinity of set net fishing ground had a southerly residual current which formed in Yeosu Bay and a weak westerly residual current toward Dolsando from Namhedo. Therefore, set net fishing ground in coastal water of Yeosu was distributed in boundary of inner water which formed from Seamjin river and offshore water supplied from the vicinity of Sorido and Yochido.

Experimental and theoretical analyses were carried out to investigate the heat exchange characteristics of the nutrient solution cooling system utilizing ground water. The material of heat exchanger used in the experiment was polyethylene and the cross-flow type was adapted in which nutrient solution was mixed and ground water unmixed. For the exchanger surface area of 0.33m2 and flow rates of ground water of 1-6l/min, NTU(number of transfer units) and effectiveness of experimental heat exchanger were 0.1-0.45 and 10-35％, respectively. Therefore these results showed that the hydroponic greenhouse of 1,000m2(300 pyong) with the ground water of 10m2/day could cover about 55-70％ of maximum cooling load in summer.