• Environmental Engineering Research
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• v.12 no.4
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• pp.176-193
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• 2007

The ability to measure groundwater contaminant flux is increasingly being recognized as crucial in order to prioritize contaminated site cleanups, estimate the efficiency of remediation technologies, measure rates of natural attenuation, and apply proper source terms to model groundwater contaminant transport. Recently, a number of methods have been developed and subsequently applied to measure contaminant mass flux in groundwater in the field. Flux measurement methods can be categorized as either point methods or integral methods. As the name suggests, point methods measure flux at a specific point or points in the subsurface. To increase confidence in the accuracy of the measurement, it is necessary to increase the number of points (and therefore, the cost) of the sampling network. Integral methods avoid this disadvantage by using pumping wells to interrogate large volumes of the subsurface. Unfortunately, integral methods are expensive because they require that large volumes of contaminated water be extracted and managed. Recent work has investigated the development of an integral method that does not require extraction of contaminated water from the subsurface. We begin with a review of the significance and importance of measuring groundwater contaminant mass flux. We then review groundwater contaminant flux measurement methods that are either currently in use or under development. Finally, we conclude with a qualitative comparison of the various flux measurement methods.

• International Journal of Advanced Culture Technology
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• v.9 no.3
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• pp.174-180
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• 2021

The necessity of this study is as follows. A decrease in the number of newborns, an increase in the youth unemployment rate, and a decrease in the employment rate are having a fatal impact on universities. To help increase the employment rate of universities, we intend to utilize Big Data of university public information. Big data refers to the process of collecting and analyzing data, and includes all business processes of finding data, reprocessing information in an easy-to-understand manner, and selling information to people and institutions. Big data technology can be divided into technologies for storing, refining, analyzing, and predicting big data. The purpose of this study is to find the vision and special department of a university with a high employment rate by using big data technology. As a result of the study, big data was collected from 227 universities on www.academyinfo.go.kr site, We selected 130 meaningful universities and selected 25 universities with high employment rates and 25 universities with low employment rates. In conclusion, the university with a high employment rate can first be said to have a student-centered vision and university specialization. The reason is that, for universities with a high employment rate, the vision was to foster talents and specialize, whereas for universities with a low employment rate, regional bases took precedence. Second, universities with a high employment rate have a high interest in specialized departments. This is because, as a result of checking the presence or absence of a characterization plan, universities with a high employment rate were twice as high (21/7). Third, universities with high employment rates promote social needs and characterization. This is because the characteristic departments of universities with high employment rates are in the order of future technology and nursing and health, while universities with low employment rates promoted school-centered specialization in future technology and culture, tourism and art. In summary, universities with high employment rates showed high interest in student-centered vision and development of special departments for social needs.

• The Journal of Engineering Geology
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• v.18 no.2
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• pp.127-136
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• 2008

Geophysical survey for establishing a wide site for the distribution of water content, wetting front infiltration due to the rainfall, and distribution of groundwater level has been performed by using 8round penetration radar (GPR) method, electrical resistivity method, and so on. On the other hand, a narrow area survey was performed to use a permittivity method such as time domain reflectometry, frequency domain reflectometry, and amplitude domain reflectometry methods for estimating volumetric water content, soil density, and concentration of contaminant in surface and subsurface. The permittivity methods establish more corrective physical parameters than different found survey technologies mentioned above. In this study for establishment of infiltration behaviors for wetting front in the unsaturated soil caused by an artificial rainfall, soil physical parameters for volumetric water content, pore water pressure, and pore air pressure were measured by FDR measurement device and pore water pressure meter which are installed in the unsaturated weathered granite soil with different depths. Consequently, the authors were proposed to a new establishment method for analyzing the variations of volumetric water content and wetting front infiltration from the responses of infiltrating pore water in the unsaturated soil.

• Economic and Environmental Geology
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• v.44 no.3
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• pp.203-215
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• 2011

Geochemical and mineralogical properties of a contamited soil should be taken into account to decide a remediation strategy for a given contaminant because development and optimization of soil remedial technologies are based on geochemical and mineralogical separation techniques. The objective of this study was to investigate the geochemical and mineralogical characteristics of arsenic-contaminated soils. The arsenic-contaminated soil samples were obtained from Chonam gold mine, Gwangyang, Chonnam, Particle size analysis, sequential extraction, and mineralogical analyses were used to characterize geochemical and mineralogical characteristics of the As-contaminated soils. Particle size analyses of the As-contaminated soils showed the soils contained 17-36% sand, 25-54% silt, 9-28% clay and the soil texture were sandy loam, loam, and silt loam. The soil pH ranged from 4.5 to 6.6. The amount of arsenic concentrations from the sequential soil leaching is mainly associated with iron oxides (1 to 75%) and residuals (12 to 91%). Major minerals of sand and silt fractions in the soils were feldspar, kaolinite, mica, and quartz and minor mineral of which is an iron oxide. Major minerals of clay fraction were composed of illite, kaolinite, quartz, and vermiculite. And minor minerals are iron oxide and rutile. The geochemical and mineralogical analyses indicated the arsenic is adsorbed or coprecipitated with iron oxides or phyllosilicate minerals. The results may provide understanding of geochemical and mineralogical characteristics for the site remediation of arsenic-contaminated soils.