• Journal of the Korean Geographical Society
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• v.36 no.4
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• pp.474-482
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• 2001

The purpose of this study is to investigate the formation and development processes of beach resort by fabric construction in a island environment. The results are as follows. (1) The research area(Tong-ri beach, Bokil-myon, Chollanam-do)has been transformed to belch by sedimentary environmental change since latter half of 1800's. (2) The mean slope of beach face is 0.96°, and the difference of attitude between beach and mud flat face is 75cm. (3) The mean particle size of beach surface sediment is 3.53$\Phi$. This value is very finer than that of any other beach in Korea peninsula. But its value is coarser than that of mud flat surface sediment. (4) The particle size distribution of core sediment is become changed to fine particle in 70cm depth. This value is corresponded to difference of altitude between beach face and mud flat face. (5) The analysis of aerial photographs after 1970 indicates that sedimentation process was not brisked since 1970's. Consequently, the research ares has been developed by sedimentary environmental change for sea-level rise effect and wave height energy rise effect.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.317-323
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• 2017

In this study, the heating performance and the energy saving effect of the heat pump system using hot waste water(waste heat) of the thermal power plant discharged from a thermal power plant to the sea were analyzed. The greenhouse area was $5,280m^2$ and scale of the heat pump system was 120 RT(Refrigeration Ton), which was divided into 30 RT, 40 RT and 50 RT. The heat pump system consisted of the roll type heat exchangers, hot waste water transfer pipes, heat pumps(30, 40, 50 RT), a heat storage tank and fan coil units. The roll type heat exchangers was made of PE(Poly Ethylene) pipes in consideration of low cost and durability against corrosion, because hot waste water(sea water) is highly corrosive. And the heating period was 5 months from October to February. During the heating performance test(12 hours), the inlet water temperature of evaporator was changed from $32^{\circ}C$ to $26^{\circ}C$, and heat absorption of he evaporator was changed from 175 kW to 120 kW. The inlet water temperature of the condenser rose linearly from $15^{\circ}C$ to $50^{\circ}C$, and the heat release of condenser was reduced by 40 kW from 200 kW to 160 kW. And the power consumption of the heat pump system increased from 30 kW to 42 kW. When the inlet water temperature of condenser was $15^{\circ}C$, the heating COP(Coefficient Of Performance) was over 7.0. When it was $30^{\circ}C$, it dropped to 5.0, and when it was above $40^{\circ}C$, it decreased to less than 4.0. It was analyzed that the reduction of heating energy cost was 87% when compared to the duty free diesel that the carbon dioxide emission reduction effect was 62% by recycling the waste heat of the thermal power plant as a heat source of the heat pump system.

• Journal of Soil and Groundwater Environment
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• v.10 no.2
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• pp.35-43
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• 2005

Bioslurping combines the three remedial approaches of bioventing, vacuum-enhanced free-product recovery, and soil vapor extraction. Bioslurping is less effective in tight (low-permeability) soils. The greatest limitation to air permeability is excessive soil moisture. Optimum soil moisture is very soil-specific. Too much moisture can reduce air permeability of the soil and decrease its oxygen transfer capability. Too little moisture will inhibit microbial activity. So Modified Fenton reaction as chemical treatment which can overcome the weakness of Bioslurping was experimented for simultaneous treatment. Although the diesel removal efficiency of SVE process increased in proportion to applied vacuum pressure, SVE process was difficulty to remediation quickly semi- or non-volatile compounds absorbed soil strongly. And SVE process had variation of efficiency with distance from the extraction well and depth a air flow form of hemisphere centering around the well. Below 0.1 % hydrogen peroxide shows the potential of using hydrogen peroxide as oxygen source but the co-oxidation of chemical and biological treatment was impossible because of the low efficiency of Modified Fenton reaction at 0.1 % (wt) hydrogen peroxide. NTA was more efficiency than EDTA as chelating agent and diesel removal efficiency of Modified Fenton reaction increased in proportion to hydrogen peroxide concentration. Hexadecane as typical aliphatic compound was removed less than Toluene as aromatic compound because of its structural stability in Modified Fenton reaction. What minimum 10% hydrogen peroxide concentration has good remediation efficiency of diesel contaminated groundwater may show the potential use of Modified Fenton reaction after bioslurping treatment.

• Journal of Soil and Groundwater Environment
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• v.11 no.6
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• pp.8-17
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• 2006

Laboratory scale experiments were performed to investigate the removal efficiency of the in-situ chemical oxidation method and the air-sparging method for diesel contaminated soil and groundwater. Two kinds of diesel contaminated soils (TPH concentration : 2,401 mg/kg and 9,551 mg/kg) and groundwater sampled at Busan railroad station were used for the experiments. For batch experiments of chemical oxidation by using 50% hydrogen peroxide solution, TPH concentration of soil decreased to 18% and 15% of initial TPH concentration. For continuous column experiments, more than 70% of initial TPH in soil was removed by using soil flushing with 20% hydrogen peroxide solution, suggesting that most of diesel in soil reacted with hydrogen peroxide and degraded into $CO_2$ or $H_2O$ gases. Batch experiment for the air-sparging method with artificially contaminated groundwater (TPH concentration : 810 mg/L) was performed to evaluate the removal efficiency of the air-sparging method and TPH concentration of groundwater decreased to lower than 5 mg/L (waste water discharge tolerance limit) within 72 hours of air-sparging. For box experiment with diesel contaminated real soil and groundwater, the removal efficiency of air-sparging was very low because of the residual diesel phase existed in soil medium, suggesting that the air-sparging method should be applied to remediate groundwater after the free phase of diesel in soil medium was removed. For the last time, the in-situ box experiment for a unit process mixed the chemical oxidation process with the air-sparging process was performed to remove diesel from soil and groundwater at a time. Soil flushing with 20% hydrogen peroxide solution was applied to diesel contaminated soils in box, and subsequently contaminated groundwater was purified by the air-sparging method. With 23 L of 20% hydrogen peroxide solution and 2,160 L of air-sparging, TPH concentration of soil decreased from 9,551 mg/kg to 390 mg/kg and TPH concentration of groundwater reduced to lower than 5 mg/L. Results suggested that the combination process of the in-situ hydrogen peroxide flushing and the air-sparging has a great possibility to simultaneously remediate fuel contaminated soil and groundwater.

• 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 the Korean Society for Marine Environment & Energy
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• v.8 no.2
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• pp.60-66
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• 2005

When external pressure higher than osmosis pressure is reversely derived into solution, its solvent is moved into the solution having lower concentration, which is called 'reverse osmosis'. We investigated the desalination application of deep ocean water using reverse osmosis pressure of $40-70\;kgf/cm^2$ We observed how to operational factor j like flow rate, water temperature and pressure have effect on efficiency of reverse osmosis membrane and salts rejection. Fluxes of reverse osmosis membrane are directly proportional to water temperature and pressure. However, salts rejection rates are positively correlated with pressure and inversely proportional to water temperature. Separation efficiencies of osmosis membrane for major elements such as $Mg^{2+},\;Ca^{+2},\;Na^+\;and\;K^+$ are as follows in a strong electrolysis solution like seawater; $Ca^{2+},\;Mg^{2+}>K^+>Na^+$. Rejection rates of $Mg^{2+}\;and\;Ca^{2+}$ that have high electric charges are over 99% and show positively correlation with water temperature. Rejection rates of $Na^+$ having low electric charge is observed to be 98%-99%, which rates is much lower than those of $2^+$ charged ions like $Ca^{2+}\;and\;Mg^{2+}$. Ion rejection rates of boron, B, are much low because boron is present il free state or gas phase in seawater. Boron concentration in desalination water is over criteria of Korean drinking water, 0.3 mg/L. However, we could satisfied with the criteria of drinking water under the operation condition like temperature $5^{\circ}C$ and pressure $70kgf/cm^2$, using the relationship that rejection rates of boron is proportional to pressure and is inversely proportional to water temperature

• Korean Journal of Environment and Ecology
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• v.26 no.4
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• pp.512-527
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• 2012

Jangdo Island (area $1.54km^2$) located in the western end of Dadohae Haesang National Park has been recognized as an prominent ecoregion possessing high moor and national biodiversity hotspot. In terms of the Z$\ddot{u}$rich-Montpellier School's phytosociology, we investigate the diversity of plant communities on the island and reevaluate the Jangdo wetland designated as Ramsar site. Ten physiognomic types of the Jangdo's vegetation were classified into 22 syntaxa (3 associations, 15 communities and 4 subcommunities). Jangdo wetland was actually denominated as 'eutrophic wetland' by Pharagmitetea and Orizetea rather than 'high moor'. Nevertheless, existence value of the Jangdo wetland is evaluated very high as a stepping stone for migratory birds and even plant dispersions. A new site of the northernmost distribution of Arachniodo-Castanopsietum sieboldii, which is a kind of cold-resistant phytocoenosis among the Camellietea japonicae of the warm-temperate broad-leaved forests, was described. Hosta yingeri-Carpinus turczaninovii var. coreana community and Carex wahuensis var. robusta-Juniperus chinensis var. procumbens community were described specifically as an endemic and an edaphic vegetation type, respectively. The unique Jangdo's vegetation reflects regional environmental conditions such as much higher frequency of frost-free days and the highest number of annual average foggy days in Korea and a well-developed aquifer in the depressed basin formed by differential erosion. We identified that human interventions (pasture, logging, forest fire, cultivation, etc.) has been involved intensively on every vegetation types, even though a rugged and inaccessible topography of the island. Particularly the Jangdo wetland has been recently threatened by fundamental distortion on hydrological system. We request an immediate establishment of the conservation prescription manual.

• Korean Journal of Environment and Ecology
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• v.30 no.5
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• pp.874-887
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• 2016

We surveyed bimonthly from April to October 2015 to understand the fish fauna and community structure in Wangpicheon. The collected species during the survey period were 40 species belonging to 15 families. Dominant species by number were Zacco koreanus (31.3%) and Rhynchocypris oxycephalus (14.7%). In biomass, the dominant species were Z. koreanus (29.2%) and Coreoperca herzi (8.6%). Also, nine endemic species (22.5%) including Squalidus multimaculatus and two endangered species (Lethenteron reissneri, Cottus koreanus) were identified. It was identified one introduced species (Oncorhynchus mykiss) from foreign countries for aquaculture. Compared with previous data, nine species were newly identified including L. reissneri, S. gracilis majimae, Pseudobagrus fulvidraco, O. mykiss, Chelon haematocheilus, Siniperca scherzeri, Acanthogobius lactipes, Luciogobius guttatus and Channa argus. Seven species (Rhodeus ocellatus, S. gracilis majimae, Hemibarbus longirostris, Pseudogobio esocinus, Microphysogobio yaluensis, Hemiculter eigenmanni and Cobitis hankugensis) introduced from other native waters in Korea were estimated. According to the analysis of the habitat characteristics of major migratory species (Tribolodon hakonensis, O. keta and Plecoglossus altivelis), O. keta was observed at station 11 and T. hakonensis at station 7, 10 and 11. These fishes have been mainly identified in the downstream. However P. altivelis was widely distributed from station 3 to 11. In the comparison of average standard length of P. altivelis at each station during the same period, populations collected from station 3 and 5 which are mid-upper area of the stream were $125.8{\pm}34.2mm$. Their growth was good compared with those collected from station 8 and 11 (mid-lower area): $80.2{\pm}16.6mm$. This difference in length comes from the artificial structures including weir, thus it is necessary to create a fishway that enables P. altivelis to pass around barriers for free movement and resource management.

• Journal of the Korean association of regional geographers
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• v.4 no.2
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• pp.49-64
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• 1998

Bing-gye valley(Kyongbuk Province, South Korea) is well known as a tourist attraction because of its meteorologic characteristics that show subzero temperature during midsummer. Also, there are some interesting geomorphic features in the valley area. Therefore, the valley is worth researching in geomorphology field. The aim of this paper is to achieve two purposes. These are to clarify geomorphic features on talus within Bing-gye valley area, and to infer the origin of Bing-gye valley. The main results are summarized as follows. 1) The formation of Bing-gye valley It would be possible to infer the following two ideas regarding the formation of Bing-gye valley. One is that the valley was formed by differential erosion of stream along fault line, and the other is that the rate of upheaval comparatively exceeded the rate of stream erosion. Especially, the latter may be associated with the fact that the width of the valley is much narrow. Judging that the fact the width of the valley is much narrow, compared with one of its upper or lower valley, it is inferred that Bing-gye valley is transverse valley. 2) The geomorphic features of talus (1) Pattern It seems to be true that the removal of matrix(finer materials) by the running water beneath the surface can result in partly collapse hollows. Taluses are tongue-shaped or cone-shaped in appearance. They are $120{\sim}200m$ in length, $30{\sim}40m$ in maximum width. and $32{\sim}33^{\circ}$ in mean slope gradient. The component blocks are mostly homogeneous in size and shape(angular), which reflect highly jointed free face produced by frost action under periglacial environment. (2) Origin On the basis of previous studies, the type of the talus is classified into rock fall talus. When considered in conjunction with the degrees of both weathering of blocks and hardness of blocks, it can be explained that the talus was formed under periglacial environment in pleistocene time. (3) The inner structure of block accumulation I recognize a three-layered structure in the talus as follows: (a) superficial layer; debris with openwork texture at the surface, 1.3m thick. (b) intermediate layer: small debris(about 5cm in diameter) with fine matrix(including humic soil), 70cm thick. (c) basal layer: over 2m beneath surface, almost pure soil horizon without debris (4) The stage of landform development Most of the blocks are now covered with lichen, and/or a mantle of weathering. It is believed that downslope movement by talus creep well explains the formation of concave slope of the talus. There is no evidence of present motion in the deposit. Judging from above-mentioned facts, the talus of this study area appears to be inactive and fossil landform.

• Journal of Animal Science and Technology
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• v.46 no.2
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• pp.193-200
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• 2004

This experiment was carried out to determine energy requirements for maintenance of Hanwoo steers. Nine Hanwoo steers weighing 376.6$\pm$12.5kg were used in this experiment and fed rice straw(44%) and concentrate (56%) at three different energy levels; 0.8 times maintenance(0.8M), 1.2 times(1.2M) and 1.6 times(1.6M), respectively. Dry matter intake was 48.5, 65.9 and 86.5g/$BW^{0.75}$ for 0.8M, 1.2M and 1.6M, respectively. Increase in energy intake with the increased DM intake did not affect digestibilities of dry matter, organic matter, crude protein, crude fiber, crude fat and nitrogen-free extract. Gross energy intake averaged 190.8, 255.8 and 340.9kcal/BW0.75 for 0.8M, 1.2M and 1.6M, respectively. Energy loss was 41% feces and 0.6${\sim}$1.5% urine of gross energy intake. Further, energy loss from methane produced during rumen fermentation was 5${\sim}$9%, while body heat loss averaged 40${\sim}$60%. Intercept of the regression equation between ME intake and retained energy indicated that energy requirement for maintenance was 124.3kcal $ME/BW^{0.75}$.