• Economic and Environmental Geology
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• v.47 no.3
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• pp.291-302
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• 2014

The Chinese government and its agencies were trying in order to solve the unstability of resource supply and demand. Ministry of Land and Resources of China(MLR) carried out a lot of national-level policy and planning for estimating the domestic mineral and energy resources potential and recoverable reserves, as the Chinese land and resources survey plan(1999~2010), the Chinese mineral resource survey and exploration plan(2008~2020), announcement for shale gas industry policies of China, the Chinese shale gas resources evaluation and selection project for its development priority areas(2012), and the plan for Chinese shale gas development(2011~2015). The two large sedimentary basins of Chinese shale gas reserves are Sichuan and Tarim basins with excellent potential, accounting for majority of the estimated national reserves. Recoverable gas-bearing shale of China was surveyed to be widespread. The volume of recoverable shale gas reservoirs in China has been estimated to be around 31 trillion cubic meters(1,115 trillion cubic feet). China is one of only three countries with the US and Canada to produce shale gas in commercial quantities. China is concentrating on technology development to enhance commercial production of shale gas, and on survey and exploration activities to increase its recoverable reserves. The trends related to shale gas development and R&D activities in China to respond to changes in international oil market should be actively monitored based on analysis of Chinese policies and technology.

• Economic and Environmental Geology
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• v.53 no.2
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• pp.213-220
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• 2020

When CO₂ foam is injected into the saline aquifer, the relative permeability of CO₂ decreases and its viscosity increases, thereby reducing mobility in porous media and ultimately improving CO₂ storge with enhanced sweep efficiency. In general, surfactants were used to fabricate CO₂ foam. Recently, nanoparticles have been used to form stable foam than surfactant. This paper introduces CO₂ storage technology using nanoparticle stabilized CO₂ foam. If the surface of the hydrophilic nanoparticles is partially modified into a CO₂-philic portion, the particles have an affinity for CO₂ and water, thus forming a stable CO₂ foam even in deep saline aquifers under high temperature and high salinity conditions, thereby it can be stored in the pores of the rock. In terms of economics, injection method using nanopaticle-stabilized CO₂ foam is more expensive than the conventional CO₂ injection, but it is estimated that it will have price competitiveness because the injection efficiency is improved. From an environmental point of view, it is possible to inject chemical substances such as surfactants and nanomaterials into aquifers or reservoirs for specific purposes such as pollutant removal and oil production. However, some studies have shown that nanoparticles and surfactants are toxic to aquatic animals, so environmentally proven substances should be used. Therefore, further research and development will be needed to study the production and injection of nanoparticle-stabilized CO₂ foam that are environmentally safe and economically reasonable.

• Journal of Korean Society for Geospatial Information Science
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• v.12 no.4 s.31
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• pp.3-12
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• 2004

It is necessary to manage water resources in rural areas in order to achieve proper development of new water resources, sustainable usage and reasonable distribution. This paper aims to analyze multi-temporal Landsat-7 ETM+data for soil moisture that is essential for crops in Ahnsung area. The ETM data was also fused with KOMPSAT-1 images in order to be used as backdrop watershed maps at first. Multi-temporal Images showed also the characteristics of soil moisture distribution. Images taken in April showed that rice paddy had as low reflectance as artificial features. Compared with April scenes, those taken in Hay and June showed wetness index increased in the rice paddies. The mountainous areas have almost constant moisture index, so the difference between the dates was very low while reservoirs and livers had dramatic changes. We can calculate total potential areas of distribution of moisture content within the basin and estimate the areas being sensitive to drought. Finally we can point out the sites of small rice paddies lack of water and visualize their distribution within the same basin. It can be said that multi-temporal Landsat-7 ETM+ and KOMPSAT data can be used to show broad drought with quick and simple analysis. Drought sensitiveness maps may enable the decision makers on rural water to evaluate the risk of drought and to measure mitigation, accompanied with proper data on the hydrological and climatic drought.

• Journal of Wetlands Research
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• v.10 no.3
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• pp.57-68
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• 2008

For improving water quality and hish habitat environment the targeted instream flows added to the field measurement of low flow at each reach along Wonju Cheon are calculated by depth, velocity, and the present lower channel width with considering the landscape, aquatic environment, and natural ecological function. Target instream flow increasing ranged from $0.03m^3/s$ of upstream to $0.90m^3/s$ of downstream according to the proposed depths of 0.10m to 0.30m and velocity of 0.2m/s. The methods for target instream flow increasing are base flow increasing by watershed management, non polluted discharge inflow from valley and combined sewer by sewerage system modification, and discharges from upstream reservoirs and detention basins near-by stream. The possible increasing flow rates are $0.19m^3/s$ to $3.42m^3/s$ which are 1.4 to 2.5 times of low flow to be measured which are the equivalent targeted instream flows along Wonju Cheon. The BOD-based water quality improvement are analyzed by QUAL2E. The habitat suitability indices by PHABSIM of Zacco temmincki as target species at middle stream of Wonju Cheon improve significantly by low flow increasing, which is very important to improve water quality and fish habitat.

• Journal of Plant Biology
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• v.11 no.2
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• pp.1-30
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• 1968

The Han River was investigated monthly from April through September, 1967 at Chun-chon reservoir, Shin-yean, So-yang, Chung-pyong reservoir, Yang-soo-ri and Gi-doo-won to clarify the phytoplankton and to study its seasonal variation. At the same time, vertical distribution of phytoplankton was also studied from June through September at Chun-chon and Chung-pyong reservoir. The results obtained are as follows: As the environmental conditions, water temperature, dissolved oxygen, pH, and transparency were determined. The plankton samples collected from six stations were identified and classified by Engler's classification system. It resulted in 4 phyla, 4 classes, 3 subclasses, 13 orders, 27 families, 5 tribes, 71 genera, 222 species, 1 subspecies, 51 varieties and 2 forms. The total number of phytoplankton identified was 276. Of them, 84 species, 1 subspecies 26 varieties, 2 forms were recorded in this paper for the first time. Considering with the habitat of the total number of phytoplanktons, the highest percentage of Limnoplankton existed in the Chung-pyong reservoir. It suggests that hte Chung-pyong reservoir is becoming to have the character of lake. The planktons appeared commonly during six months at six station belong to Chrysophyta including 22 species in 11 genera. Among these 22 species, Navicula, consists of 6 species, was the most abundant. The number of species identified uniquely at each station were 5 species in the Chun-chon reservoir, 6 in Chung-pyong and Yang-soo-ri, 8 at Shin-yean, 11 at So-yang, and 18 at Gi-doo-won. The number of species occurred at all stations were 29 in spring, 42 in Autumn and during investigation period. The maximum production of total phytoplankton was generally shown in the late spring and the early fall with differences in quantity at six collecting statins. In the Chun-chon reservoir, the high concentration of approximately 1, 190, 000 cells per litter in the months of August and September was due to the increase of Chrysophyte genus, Melosira and the highest concentration of approximately 2, 000, 000 in July at Gi-doo-won was caused Chlorophyte genus, Secenedesmus. The Chun-chon reservoir of three years old was different from the Chung-pyong reservoir of 25 years old with respect to increase in Melosira genus in August and September. After the completion of the Ui-am reservoir, though there was an increase in total density, the number of species of phytoplankton was not changed. It suggests that Ui-am reservoir is similar to the Chun-chon reservoir under the influence of the latter. The density of total phytoplankton was generally high at the depth of 2m to 5m for the two reservoirs.

• Geophysics and Geophysical Exploration
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• v.9 no.1
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• pp.1-9
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• 2006

Geological storage of captured $CO_2$ is a new way of reducing greenhouse gas emissions to protect the climate, but is based on the established technology associated with injection of fluids underground. The geological formations of interest for this technique include operational and depleted oil and gas fields, and deep saline aquifers. Prediction of storage performance will depend on models of the behaviour of $CO_2$ in geological formations; these need to be refined and verified, and methods of monitoring developed and proved. These needs can be met through monitored demonstration and research projects. Current commercial projects that are demonstrating $CO_2$ storage include Sleipner, Weyburn, ORC, and In Salah; research projects include West Pearl Queen, Nagaoka, and Frio. In this paper, some of the monitored injection projects are described. The reservoirs employed for storing $CO_2$, and the associated monitoring techniques, are briefly reviewed. It is argued that small-scale research projects, used to develop techniques and prove models, are complementary to the large-scale monitored injections that will establish the viability of this technique for mitigating climate change.

• Geophysics and Geophysical Exploration
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• v.18 no.3
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• pp.143-153
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• 2015

Polymer flooding for enhancing hydrocarbon production injects into a reservoir polymer solution that is viscous. It is very important to monitor the behavior pattern of the polymer solution in order to evaluate the effectiveness of polymer flooding. To monitor the distribution of polymer solution and thus fluid substitution within the reservoir, we first construct seismic and resistivity rock physics models (RPMs), which are functions of reservoir parameters such as rocks and type of fluid, fluid saturation. For the seismic and resistivity RPMs, responses of seismic and electromagnetic (EM) tomography are numerically simulated as polymer injection, using two dimensional (2D) staggered-grid finite difference elastic modeling and 2.5D finite element EM modeling algorithms, respectively. In constructing RPM for EM tomography, three different reservoir rocks are considered: clean-sand, dispersed shale-sand, and sand-shale lamination rocks. The polymer solution is assumed to have 2 wt% of polymer as normally generated, while water is freshwater or saltwater. Further, neutron logging is also considered to check its sensitivity to polymer flooding. The techniques discussed in the paper are important in monitoring not only hydrocarbon but also geothermal reservoirs.

• Journal of Environmental Science International
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• v.19 no.11
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• pp.1407-1421
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• 2010

This study was carried out to elucidate the relation between water quality and structure of the aquatic ecosystem in the agriculture reservoir Otae-ji from January to December in 2009. The proportion of forest was 46.98%, which means that non-point sources are major contributor of water pollution in this area. The annual mean COD(Chemical Oxygen Demand) in Otae-ji was $3.6mgL^{-1}$, indicating, level II of environmental standards and the trophic state was mesotrophic. Although total phosporus concentration in the reservoir was high in August due to large inflow of nutrients from outside the reservoir during monsoon season, there was no break out of significant algal bloom in the summer. The seasonal succession of phytoplankton showed that the dinophyta dominated in the the spring, chlorophyta in the summer, chrysophyta and chlorophyta in the autumn and chrysophyta in the winter. In case of zooplankton, rotifers dominated in the most seasons, but cladoceran(Bosmina longirostris) dominated in June and copepod(Nauplii) in August. The macrophyte plants showed diverse species compositon consisted of 3 varieties, 24 species, 23 genera, 15 families and 14 orders. The macroinvertebrates also showed various FFG(Functional Feeding Groups) such as GC(Gathering-Collector), P(Predator), SH(Shedder), FC(Filter-Collector) and PP(Plant-Piercer). Ecosystem stability analysis using aquatic insects was classified as Group I, which has high resilience and resistance indices. A total of 14 species of fish was collected but exotic species such as Lepomis macrochirus and Micropterus salmoides were not found in Otae-ji. In conclusion, the preservation of healthy food wed in the reservoir ecosystem is closely related to water quality management as well as effective prevention of algal bloom by helping good material circulation in aquatic ecosystems.

• Geophysics and Geophysical Exploration
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• v.21 no.1
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• pp.8-14
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• 2018

For the purpose of maintenance and prevention of earth fill dams against damage from natural hazards, automatic monitoring through various measuring instruments and resistivity survey has been carried out. Reservoirs and embankments have the structural vulnerability on the agricultural usages since most of them were built more than thirty years ago. The main aim to use monitoring method is to verify the safety and integrity of the dam. Resistivity survey can detect potential weaknesses, such as defective zones, anomalous seepages or internal erosion processes. Permanent resistivity monitoring systems were installed at a reservoir, which daily measurements have been taken every 6 hour. Using monitoring data for one year, anomalous seepage and structural defects were clarified for dam safety. Annual water level fluctuations are around 10 m. During their operation, reservoir dams are subject to a never-ending hydraulic load from the reservoir, which over the years may cause changes in the properties of the inner parts of the dam construction. Detailed analysis of the monitoring results was performed and showed that resistivities at most locations have been very stable over the full monitoring period excluding the effects of water fluctuation and seasons. To investigate the detectability of weak zone using the DC resistivity monitoring, numerical modeling with a simplified model for the drainage at a reservoir dam was also performed. The results showed that the seepage zone near drainage in a reservoir dam could be detected by resistivity response change.

• Journal of Veterinary Clinics
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• v.31 no.1
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• pp.6-10
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• 2014

Siberian Roe deer which inhabits Jeju Island is unique native species. Most of all the roe deer infect a lot of ticks, which can affect its population directly and can act as a vector to spread vector-borne diseases. The purposes of this study were to identify the ticks and detect the piroplamsosis on the roe deer in Jeju island. We collected ticks and blood samples in 23 roe deer rescued and treated at the Jeju Wildlife Rescue Center. As a result, we identified the one species of ticks, Haemaphysalis longicornis in roe deer and detected the closely related to Theileria luwenshuni in all blood samples (100%) and 8 pooled ticks (34.8%). These results indicate that there may be a high prevalence particularly of T. luwenshuni infection in Jeju wild roe deer and H. longicornis is a major vector of these diseases. It suggested that Jeju roe deer may act as reservoirs for these zoonotic pathogens.