• Proceedings of the Korean Nuclear Society Conference
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• 2005.10a
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• pp.737-738
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• 2005

• Resources Recycling
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• v.33 no.2
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• pp.73-73
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• 2024

• Journal of Soil and Groundwater Environment
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• v.25 no.2_spc
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• pp.86-100
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• 2020

Analyzing and monitoring environmental contaminants based on geophysical exploration techniques have become important and it is now widely applied to delineate spatial distribution geophysical characteristics in wide area. Among the techniques, induced polarization (IP) method, which measures polarization effects on electrical potential distribution, has drawn much attention as an effective tool for environmental monitoring since IP is sensitive to changes in biochemical reactions. However, various reactions stemming from the presence of multiple contaminants have greatly enhanced heterogeneity of polluted sites to result in highly variable electrical characteristics of the site. Those contaminants influence chemical and physical state of soil and groundwater to alter electrical double layer, which in turn influences polarization of the media. Since biochemical reactions between microbes and contaminants result in various IP effects, IP laboratory experiments were conducted to investigate IP responses of the contaminated soil samples under various conditions. Field IP surveys can delineate the spatial distribution of contamination, while providing additional information about electrical properties of a target medium, together with DC resistivity. Reviewing IP effects of contaminants as well as IP surveys can serve as a good starting point for the application of IP survey in site assessment for environmental remediation.

• 한국지구물리탐사학회:학술대회논문집
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• 2011.10a
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• pp.117-118
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• 2011

• Journal of Energy Engineering
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• v.29 no.3
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• pp.42-49
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• 2020

Precipitated Calcium Carbonate (PCC) can be utilized in energy-effective paper production. Limestone is a raw material for synthesizing PCC. Since the PCC production yield depends on the physicochemical properties of the limestone, a basic investigation of the raw limestone is required. This study provides a brief review of the origin of limestone, limestone distribution characteristics, and limestone deposits in Korea and Vietnam. Most limestones in Korea were formed in the Paleozoic era. On the other hand, limestones in Vietnam have various ages from the Precambrian to the Triassic. Limestone is the most largely produced mineral in Korea, but Vietnam has 5 times more amount of limestone reserves than Korea.

• 한국지구물리탐사학회:학술대회논문집
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• 2011.10a
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• pp.99-100
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• 2011

• Journal of Energy Engineering
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• v.26 no.1
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• pp.68-75
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• 2017

Global warming affects water supply and water resources throughout the world. In many countries, climate change affects significantly on the fresh water resources. Vietnam is exposed mainly, to landslides and floods triggered by tropical storms and monsoon rains, although storm surge, whirlwind, river bank and coastal line erosion, hail rain. In addition to the prevalent drought, there are many major water challenges, including water availability, stress, scarcity and accessibility, because of poor resource management. Fast growth of urbanization, industrialization and population growth, agricultural activities and climate change cause heavy pressure on water quality. Both domestic and industrial wastewater, as well as storm water shares the same drainage. The common facilities for wastewater treatment are not available. Therefore, wastewater is treated only superficially and then discharged directly into rivers and lakes causing serious pollution of surface water environment. In this paper, we reported the severe water crisis and massive green algal blooms formation in Vietnam rivers and lakes. This is the biggest evidence of climate change variations in Vietnam.

• Economic and Environmental Geology
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• v.49 no.3
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• pp.201-212
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• 2016

Due to growing problems securing stable mineral and energy resources with international political and economic changes, China has dedicated itself to strategies and policies to enhance its stable mineral and energy resources security. China has established a rare earth elements(REE) industry policy after the abolition of the REE exports quota system. China's six large REE companies have also been integrated into REE mining, smelting and refining companies. Efforts have been increased to enhance China's energy security through unconventional oil and gas exploration and development investment, as well as effort in R&D. The country will focus on technology development and exploration to promote commercial production of unconventional oil and gas based on countries with shale gas. China is making long-term contracts and joint ventures to ensure the acquisition of reliable mineral and energy resources from abroad. Government of China has proposed a range of initiatives, such as the integration of resources development strategies and environmental development strategies, internationalization of resource management, supply diversification and advancement, strengthening industry linking strategy, grouping and diversification strategy.

• Geomechanics and Engineering
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• v.35 no.2
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• pp.109-119
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• 2023

Ground subsidence in urban areas due to excessive development and degraded underground facilities is a serious problem. Geophysical surveys have been conducted to estimate the distribution and scale of cavities and subsidence. In this study, electrical resistivity tomography (ERT) was performed near an area of road subsidence in an urban area. The subsidence arose due to groundwater leakage that carried soil into a neighboring excavation site. The ERT survey line was located between the main subsidence area and an excavation site. Because ERT data are affected by rapid topographic changes and surrounding structures, the influence of the excavation site on the data was analyzed through field-scale numerical modeling. The effect of an excavation should be considered when interpreting ERT data because it can lead to wrong anomalous results. A method for performing 2D inversion after correcting resistivity data for the effect of the excavation site was proposed. This method was initially tested using a field-scale numerical model that included the excavation site and subsurface anomaly, which was a loosened zone, and was then applied to field data. In addition, ERT data were interpreted using an existing in-house 3D algorithm, which considered the effect of excavation sites. The inversion results demonstrated that conductive anomalies in the loosened zone were greater compared to the inversion that did not consider the effects of excavation.

• Journal of Soil and Groundwater Environment
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• v.27 no.2
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• pp.1-23
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• 2022

For its essential importance as a resource, sustainable development of groundwater has been major research interests for many decades. Conventional characterization of aquifer and groundwater has relied on borehole data from observation well. Although borehole data provide useful information on yield and flow of groundwater, it is often difficult and sometimes costly to estimate the spatial distribution of groundwater in entire aquifer. Geophysical probing is an alternative techique that provides such information due to its capability to image subsurface structures as well as to delineate spatial distribution of hydraulic parameters. This study presents various technical information about geophysical probing to estimate main characteristics of aquifer for groundwater exploitation. Subsequently, we analyzed representative cases, in which geophysical methods were applied to identify the location of the groundwater, classify freshwater and brine, derive hydraulic constants, and monitor groundwater.