• Korean Journal of Soil Science and Fertilizer
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• v.36 no.5
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• pp.323-332
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• 2003

This study was carried out to provide information for the present status of soil pollution near abandoned old-zinc mining area through analysis of bound form and 0.1 N-HCl extractable concentrations of heavy metals in soils and plants. Feasibility of endemic plants for phytoremediation was evaluated by the investigation of vegetation in soils. Cd contents of the selected samples near old-zinc mining soils ranged from 0.2 to $42mg\;kg^{-1}$. Nonagricultural soils near the mining area contained great amounts of Zn, Pb, Cd, and Cu than the paddy and upland soils. Some Korean wild plants, Artemisia princeps, Artemisia montana, Erigeron canadensis, and Pueraria thunbergiana, were found to grow vigorously in the studied area. Among them, Artemisia princeps was selected as a possible phytoremediator for cleaning heavy metal contaminated soils. Artemisia princeps contained about 43 and $52mg\;kg^{-1}$ of Cd in their root and shoot as dry weight, respectively. Average contents of Cd in the rhizosphere soil, $15.68mg\;kg^{-1}$, was slightly higher than the soil-root interface soils, $14.1mg\;kg^{-1}$. Sequential extraction of Cd contaminated soils showed that average $2.4mg\;kg^{-1}$ (about 7%) of cadmium existed as exchangeable form and the average amounts increased as follows : adsorbed < organically bound < exchangeable << oxide carbonate << sulfide residual fractions. Amendment of organic by-product fertilizer in metal-contaminated soils promoted the growth of roots significantly as compared with the other treatments containing chemical fertilizer.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.611-618
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• 2020

The reliability of the results of LCC analysis is determined by accurate analytical procedures and energy data from which the uncertainty is removed. Until now, systems that can automatically measure these energy data and produce databases have not been commercialized. Therefore this paper proposes a concept model of an S-LCC platform that can automatically collect and analyze electric energy consumption data of equipment systems using the IOT, which is the core tool in the Fourth Industrial Revolution and operates the equipment system efficiently using the analyzed results. The proposed concept model was developed by the convergence of existing BLCS and IOT and was comprised of five modules: Facility Control Module, LCC Analysis Module, Energy Consumption Control Module, Efficiency Analysis Module, and Maintenance Standard Reestablishment Module. Using the results of LCC analysis deduced from this system, the deterioration condition of an equipment system can be identified in real-time. The results can be used as the baseline data to re-establish standards for the maintenance factor, replacement frequency, and lifetime of existing equipment, and establish new maintenance standards for new equipment. If the S-LCC platform is established, it would increase the reliability of LCC analysis, reduce the labor force for entering data and improve accuracy, and would also change disregarded data into big data with high potential.

• Journal of the Korea Organic Resources Recycling Association
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• v.29 no.2
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• pp.31-38
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• 2021

The aim of this study is to evaluate the possibility of treating slaughterhouse by-products using microbial electrolysis cells (MECs). The diluted pig liver was fed to MEC reactors with the influent COD concentrations of 772, 1,222, and 1,431 mg/L, and the applied voltage were 0.3, 0.6, and 0.9 V. The highest methane production of 5.9 mL was obtained at the influent COD concentration of 1,431 mg/L and applied voltage of 0.9 V. In all tested conditions, COD removal rate was increased as the influent COD concentration increased with average removal rate of 62.3~81.1%. The maximum methane yield of 129~229 mL/g COD was obtained, which is approximately 80% of theoretical maximum value. It might be due to the bioelectrochemical reaction greatly increased the biodegradability of pig liver. Future research is required to improve the methane yield and digestibility through optimizing the reactor design and operating conditions.

• Economic and Environmental Geology
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• v.56 no.3
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• pp.311-330
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• 2023

Development of Carbon Capture and Storage (CCS) technique is becoming increasingly important as a method to mitigate the strengthening effects of global warming, generated from the unprecedented increase in released anthropogenic CO₂. In the recent years, the characteristics of basaltic rocks (i.e., large volume, high reactivity and surplus of cation components) have been recognized to be potentially favorable in facilitation of CCS; based on this, research on utilization of basaltic formations for underground CO₂ storage is currently ongoing in various fields. This study investigated the feasibility of underground storage of CO₂ in basalt, based on the examination of the CO₂ storage mechanisms in subsurface, assessment of basalt characteristics, and review of the global research on basaltic CO₂ storage. The global research examined were classified into experimental/modeling/field demonstration, based on the methods utilized. Experimental conditions used in research demonstrated temperatures ranging from 20 to 250 ℃, pressure ranging from 0.1 to 30 MPa, and the rock-fluid reaction time ranging from several hours to four years. Modeling research on basalt involved construction of models similar to the potential storage sites, with examination of changes in fluid dynamics and geochemical factors before and after CO₂-fluid injection. The investigation demonstrated that basalt has large potential for CO₂ storage, along with capacity for rapid mineralization reactions; these factors lessens the environmental constraints (i.e., temperature, pressure, and geological structures) generally required for CO₂ storage. The success of major field demonstration projects, the CarbFix project and the Wallula project, indicate that basalt is promising geological formation to facilitate CCS. However, usage of basalt as storage formation requires additional conditions which must be carefully considered - mineralization mechanism can vary significantly depending on factors such as the basalt composition and injection zone properties: for instance, precipitation of carbonate and silicate minerals can reduce the injectivity into the formation. In addition, there is a risk of polluting the subsurface environment due to the combination of pressure increase and induced rock-CO₂-fluid reactions upon injection. As dissolution of CO₂ into fluids is required prior to injection, monitoring techniques different from conventional methods are needed. Hence, in order to facilitate efficient and stable underground storage of CO₂ in basalt, it is necessary to select a suitable storage formation, accumulate various database of the field, and conduct systematic research utilizing experiments/modeling/field studies to develop comprehensive understanding of the potential storage site.

• Membrane Journal
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• v.29 no.6
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• pp.339-347
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• 2019

Forward osmosis (FO) is operated at a lower pressure than reverse osmosis (RO), which has great advantages in terms of fouling control, maintenance, membrane cleaning, and potential energy reduction. In particular, since the membrane fouling layer of the forward osmosis process has a relatively loose and dispersed property, it is possible to control the membrane fouling by physical cleaning, unlike the reverse osmosis process. However, existing studies do not apply the proper cleaning flow rate for forward osmosis physical cleaning, and thus there is a limit that the optimal operation can not be performed. Therefore, this study aims to evaluate the justification of proper flow rate that can show high efficiency cleaning with economical energy amount. The membrane fouling experiments of the forward osmosis process were maintained at a circulating flow rate of 8.54 cm/s and the recovery rates were compared with the three cleaning flow rates. As a result of this experiment, it was confirmed that the 2 × speed cleaning showed the same efficiency as the water permeability recovery rate of the 3 × speed cleaning, and it was confirmed that the 2 × speed cleaning was an appropriate flow rate with high cleaning efficiency and economical SEC.

• Journal of radiological science and technology
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• v.31 no.3
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• pp.259-266
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• 2008

Objective : The purpose of this study was to examine the relationship between bone mineral density (BMD) and the metabolic syndrome. Method : We conducted a cross-sectional study of 1204 adults(males: 364 females: 840) in a general hospital health promotion center. They were grouped into the normal and lower BMD group according to bone loss(osteopenia, osteoporosis), as determined by duel energy X-ray absorptiometery(DEXA). We analyzed the association between BMD and metabolic syndrome by multiple logistic regression analysis. After adjustment for age, weight, alcohol intake, smoking, regular exercise, regular intake of meals, and menopausal status, odds ratios for the prevalence of the metabolic syndrome by gender were calculated for lower BMD. Results : After adjustment for the effect of potential covariates, the prevalence of metabolic syndrome was associated with bone loss in men(p<0.001). If the odds ratio of normal group is 1.00, then that of the lower BMD group is 3.07(95% CI=1.83-5.16). The prevalence of metabolic alterations fitting the criteria of metabolic syndrome was significantly decreased in High BMI, Low HDL in men and in High BMI in women(p<0.05). Conclusions : This study shows that BMD was associated with metabolic syndrome. Further studies needed to obtain evidence concerning the association between BMD and metabolic syndrome.

• Journal of Sericultural and Entomological Science
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• no.12
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• pp.21-36
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• 1970

This studies have been carried out to 3nd various causes of cleanness defects on raw silk which has been increased since 1967 in Korea, so that this treatise may be a guide inform action to improve such a defect in future. The cocoon treatment for the proposed work was carried starting with in worst condition to find the critical limit of degrading through such a work. And various analysis have been also worked out using the annual silk testing data past a few years. The results obtained are as follows. 1. There was a great relationship between cleanness and neatness result. 2. Cleanness result is greatly influenced by mounting conditions and handling of cocoons, which brought 40 percent lower as cleanness result than standard ones in which caused minor defects, especially loops and split ends, so the bad mounting conditions and handling of fresh cocoons degraded raw silk from 4A grade to E. 3. The use of good water quality brought the difference of 1.04 percent in cleanness result rather than the use of bad one. 4. Well technical work brought the difference of 0.86 percent in cleanness result rather than poor technical work. 5, Satisfactory cocoon drying installation brought the difference of 1.97 percent in cleanness result rather than insufficient one. 6. Automatic reeling machine marked lower 1,55 percent in cleanness result than multi-end reeling machine. 7. The degrading of cleanness result from 1965 year silk to 1969 year silk marked 1.99 percent, which almost responds to the degrading rate from good to poor cocoon drying installed cleanness results. In view of this result, nowadays, insufficient cocoon drying installation may be main factor to be worse cleanness result of Korean raw silk. 8. The factors of cleanness defect in raw silk once supplied with cocoon into factory are water quality, technique evaluation, cocoon drying capacity and s： reeling machine. The relationship between cleanness result and above factors are as follows. cleanness result＝neatness result＋1.6－1.04(1－a)－1.97(1－b)－0.86(1-c)＋1.55${\times}$d a： The successive we ratio of water quality (0\longrightarrowl) b： The successive ratio of satisfactory cocoon drying installation (0\longrightarrowl) c： The successive ratio of well technical work (0\longrightarrowl) d： 1 in case multi-end reeling machine o in case automatic reeling machine 9, It is not admitted that there is heavy relationship between cleanness occurrence and nonbreaking reel ability. That mal$.$ be sowed with silk reeling technique. 10. The bad mounting conditions caused the worse result on the cocoon quality as much as cleanness. 11. Besides mounting conditions, there may be another factors affecting on the low reel ability of cocoons in Korea.

• Journal of Climate Change Research
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• v.5 no.2
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• pp.153-163
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• 2014

This study analyzed directions of the energy product efficiency improvement and Carbon Tax for the domestic building sector. In order to analyze GHG reduction potential and total cost, the cost optimization model MESSAGE was used. In the case of the "efficiency improvement scenario," the cumulative potential GHG reduction amount - with respect to the "Reference scenario" - from 2010 to 2030 is forecast to be $104MtCO_2eq$, with a total projected cost of 2.706 trillion KRW. In the "carbon tax scenario," a reduction effect of $74MtCO_2eq$ in cumulative potential GHG reduction occurred, with a total projected cost of 2.776 trillion KRW. The range of per-ton GHG reduction cost for each scenario was seen to be approximately $-475{\sim}272won/tCO_2eq$, and the "efficiency improvement scenario" showed as the highest in the order of priority, in terms of the GHG reduction policy direction. Regarding policies to reduce GHG emissions in the building sector, the energy efficiency improvement is deemed to deployed first in the future.

• Geophysics and Geophysical Exploration
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• v.24 no.4
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• pp.194-201
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• 2021

Induced polarization (IP) effect is known to be caused by electrochemical phenomena at interface between minerals and pore water. Spectral induced polarization (SIP) method is an electrical survey to localize subsurface IP anomalies while injecting alternating currents of multiple frequencies into the ground. This method was effectively applied to mineral exploration of various ore deposits. Titanomagnetite ores were being produced by a mining company located in Gonamsan area, Gwanin-myeon, Pocheon-si, Gyeonggi-do, South Korea. Because the ores contain more than 0.4 w% vanadium, the ore deposit is called as Gwanin vanadiferous titanomagnetite (VTM) deposit. The vanadium is the most important of materials in production of vanadium redox flow batteries, which can be appropriately used for large-scale energy storage system. Systematic mineral exploration was conducted to identify presence of hidden VTM orebodies and estimate their potential resources. In geophysical exploration, laboratory geophysical measurement of rock samples is helpful to generate reliable property models from field survey data. Therefore, we performed laboratory SIP data of the rocks from the Gwanin VTM deposit to understand SIP characteristics between ores and host rocks and then demonstrate the applicability of this method for the mineral exploration. Both phase and resistivity spectra of the ores sampled from underground outcrop and drilling cores were different of those of the host rocks consisting of monzodiorite and quartz monzodiorite. Because the phase and resistivity at frequencies below 100 Hz are mainly dependent on the SIP characteristics of the rocks, we calculated mean values of the ores and the host rocks. The average phase values at 0.1 Hz were ores: -369 mrad and host rocks: -39 mrad. The average resistivity values at 0.1 Hz were ores: 16 Ωm and host rocks: 2,623 Ωm. Because the SIP characteristics of the ores were different of those of the host rocks, we considered that the SIP survey is effective for the mineral exploration in vanadiferous titanomagnetite deposits and the SIP characteristics are useful for interpreting field survey data.

• Journal of the Korean Society for Marine Environment & Energy
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• v.11 no.3
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• pp.138-149
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• 2008

Rapid accumulation of carbon dioxide in the atmosphere for the past century leads to acidify the surface ocean and contributes to the global warming as it forms acid in the ocean and it is a green house gas. In order to curb the green house gas emissions, in particular carbon dioxide, various multilateral agreements and programs have been established including UN Convention of Climate Change and its Kyoto Protocol for the last decades. Also a number of geo-engineering projects to manipulate the radiation balance of the earth have been proposed both from the science and industrial community worldwide. One of them is ocean fertilization to sequester carbon dioxide from the atmosphere through the photosynthesis of phytoplankton in the sea. Deliberate fertilization of the ocean with iron or nitrogen to large areas of the ocean has been proposed by commercial sector recently. Unfortunately the environmental consequences of the large scale ocean iron fertilization are not known and the current scientific information is still not sufcient to predict. In 2007, the joint meeting of parties of the Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter, 1972 and 1996 Protocol (London Convention/Protocol) has started considering the purposes and circumstances of proposed large-scale ocean iron fertilization operations and examined whether these activities are compatible with the aims of the Convention and Protocol and explore the need, and the potential mechanisms for regulation of such operations. The aim of this paper is to review the current development on the commercial ocean fertilization activities and management regimes in the potential ocean fertilization activities in the territorial sea, exclusive economic zone, and high seas, respectively, and further to have a view on the emerging international management regime to be London Convention/Protocol in conjunction with a support from the United Nations General Assembly through The United Nations Open-ended Informal Consultative Process on Oceans and the Law of the Sea.