• Journal of the Geological Society of Korea
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• v.54 no.6
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• pp.587-603
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• 2018

3-D petroleum system modeling was performed on the Jeju Basin, offshore southern Korea to analyze the hydrocarbon migration and accumulation as well as the generation and expulsion of the hydrocarbon, based on subsurface structure maps of respective sedimentary formations. The lowermost formation deposited in Eocene time was assigned as a source rock, for which a mixed kerogen of type II and III was input in the modeling of oil and gas generation in consideration of the sedimentary environment of fluvio-lacustrine condition. Initial TOC was 4% as an input, based on the analysis of the well data and sedimentary environment. The modeling results show that a considerable amount of hydrocarbons was generated and expelled from the source rocks at the western Joint Development Zone (JDZ) sub-block 4, where the hydrocarbons was migrated to the above reservoir rocks at 20 Ma. The oil and gas in the reservoir rocks of the JDZ sub-block 4 are accumulated into the prospects with closure structures that has already been formed at the nearby areas. Another generation of hydrocarbon occurs from the source rock at the eastern border area of JDZ sub-block 1 and 2, where the expulsion of the hydrocarbons occurs at 10 Ma from the source rock into the above reservoir rocks, in which the accumulation also is expected. The generation, migration and accumulation were retarded at the eastern area of the JDZ sub-block 1 and 2, compared with the area of the western JDZ sub-block 4. Based on the modeling results, it is estimated that gases migrated laterally and vertically in long distance whereas oil migrated laterally in shorter distance than gases. A substantial amount of hydrocarbon could have seeped out of the reservoir formations to the surface since the migration of oil and gas actively occurred in Miocene time before the formation of seals. However, the modeling shows that the hydrocarbon could be accumulated smoothly into the closed structures that can be formed locally by alternation of sand and shale beds.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.734-744
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• 2011

A soil stabilization method is an effective and practical remediation alternative for arsenic (As) and heavy metal contaminated farmland soils nearby abandoned metal mine in Korea. This method is a technique whereby amendments are incorporated and mixed with a contaminated soil. Toxic metal bind to the amendments, which reduce their mobility in soil, so the successful stabilization of multi-element contaminated soil depends on the combination of critical elements in the soil and the type of amendments. The objective of this study is to investigate the treatment effects and applicability of limestone (LS) and steel refining slag (SRS) as the amendment for farmland soil contaminated with As and heavy metals, and a lab-column test was conducted for achieving this purpose. The result showed that soil treated with LS and SRS maintained pH buffer capacity and, as a result, the heavy metal leaching concentration was quite low below the water quality standard compared to untreated soil which leachate exceeding the water quality standard was observed, however, the arsenic concentration rather increased with increasing mixture ratio of SRS. This was believed to be related to phosphorus (P) contained in SRS, and dominancy in the competitive adsorption relation between As and P binding strongly to iron might be different according to soil characteristic. We suggested that LS is a effective amendment for reducing heavy metals in soil, and SRS should be used after investigating its applicability based on the adsorption selectivity of arsenic and phosphorus in selected soil.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.858-863
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• 2010

The blueberry farming requires the soil condition of well-drainage, pH of 4.5 to 5.2, and high in organic matters for stable growth and development. Most of soil type of cultivated land in Korea, however, belongs to alkaline soils with low organic matter content and poor drainage. Therefore, the blueberry farmers use peat moss heavily to improve the soil condition, but the guideline on the effective and economic ratio of peat moss is not established yet. This study was performed to determine the cost effective peat moss ratio for amending soils, and to investigate the feasibility of using sawdust and coco peat as soil amendments. Peat moss, coco peat and sawdust are mixed with soil at the ratio of 0, 12.5, 50 and 100% (v/v). Among 3 organic materials with various mixture ratios, the pH of soil was the lowest in 100% peat moss and sawdust mixtures (pH 3.67 and pH 3.73, respectively), followed by pH 5.30 at 50% peat moss. The soil organic matter content are directly proportional to the mixture ratios in all three organic materials and the same trend was observed in the variation of content of exchangeable potassium in the coco peat treatments. On the contrary, the content of available phosphate, exchangeable calcium and magnesium decreased with increasing the ratio of organic materials. The nitrogen content in the leaves decreased as increasing the ratio of peat moss and coco peat in soil, but not of sawdust. The content of phosphate decreased but potassium increased as the ratio of sawdust and coco peat increased. There was no clear difference in the contents of magnesium and calcium among 3 organic materials. The plant height, stem diameter and dry weight of blueberry plants were the highest in 50 % peat moss, followed by 12.5% peat moss and 12.5% coco peat. The plants in 100% peat moss showed very poor growth. It can be concluded that peatmoss, when applied and managed appropriately, will be a good material for improving soil condition as well as securing desirable growth for blueberry. Upon coupling economic aspect, the optimum mixing ratio of peatmoss for blueberry farming is approximately 25-50%.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.19-25
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• 2019

The CleanSYS(Clean SYStem) is operated to monitor air pollutants emitted from specific industrial complexes in Korea. So the industrial complexes without the system are directly monitored by the control officers. For efficient monitoring, studies using various sensors have been conducted to monitor air pollutants emitted from industrial complex. In this study, hyperspectral sensors were used to model and verify the equations for estimating the concentration of $NO_2$(nitrogen dioxide) in air pollutants emitted. For development of the equations, spectral radiance were observed for $NO_2$ at various concentrations with different SZA(Solar Zenith Angle), VZA(Viewing Zenith Angle), and RAA(Relative Azimuth Angle). From the observed spectral radiance, the calculated value of the difference between the values of the specific wavelengths was taken as an absorption depth, and the equations were developed using the relationship between the depth and the $NO_2$ concentration. The spectral radiance mixed gas of $NO_2$ and $SO_2$(sulfur dioxide) was used to verify the equations. As a result, the $R^2$(coefficient of determination) and RMSE(Root Mean Square Error) were different from 0.71~0.88 and 72~23 ppm according to the form of the equation, and $R^2$ of the exponential form was the highest among the equations. Depending on the type of the equations, the accuracy of the estimated concentration with varying concentrations is not constant. However, if the equations are advanced in the future, hyperspectral sensors can be used to monitor the $NO_2$ emitted from the industrial complex.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.278-283
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• 2019

3 kinds of fine powder, Fe-2%Ni alloy powder(N Ltd.) and Fe+2%Ni mixed powder(B Ltd. and S Ltd.), were fabricated into sintered compacts of bending strength specimens and ring type specimens by metal injection molding, debinding and controlling sintering conditions (reduction and sintering atmospheres, sintering temperature, sintering time and cooling rates). Density and magnetic properties of the sintered compacts were evaluated with the following conclusions. (1) When each compact was hold at 1123K for 3.6ks in H2 and sintered at 1623K for 14.4ks in Ar, the density of N, B and S Ltd.'s sintered compacts were measured as 96, 99 and 99%, and oxygen/carbon contents were measured as 0.0041%O/0.0006%C, 0.0027%O/0.0022%C, and 0.160%O/0.0026%C, respectively. (2) Magnetic characteristics of B Ltd. compact in Ar with the best results showed $B_{25}=14.3KG$, $B_r=7.75KG$, and $H_c=2.1Oe$, but not enough as those made by melting process. (3) Magnetic properties of B Ltd. compact which were sintered at 1673K for 14.4ks in Ar gas, and cooled at $0.83Ks^{-1}$ to 1123K and then cooled at $0.083Ks^{-1}$ down to room temperature were measured as $B_{25}=14.8KG$, $B_r=8.3KG$, and $H_c=1.3Oe$, almost similar to those made by melting process. Objected soft magnetic materials properties were obtained through sintering process by controlling sintering conditions (reduction condition, sintering atmosphere, sintering temperature and sintering time) and cooling rates.

• Korean Journal of Heritage: History & Science
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• v.46 no.4
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• pp.4-23
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• 2013

Songsalli Ancient Tombs of Gongju consists of seven tombs. King Muryeong's tomb, the seventh tomb, is a brick chamber tomb discovered during the drainage works for the fifth and the sixth tombs in 1971. The excavation at the time focused on topographic surveys of the tomb entrance and the inside of the burial chamber as well as collection of the remains. The burial mount survey confirmed the status of some stone slab remaining and lime-mixed soil layers, but the survey did not examine the exterior structure of the whole tomb as the mounds were removed even more deeply. The excavation revealed damages to the bricks and mural damages due to moisture and fungus in the sixth and the seventh tombs. Between 1996 and 1997, Gongju National University conducted a comprehensive detailed survey of Songsalli Ancient Tombs including a geophysical survey, with an aim to identify the root causes of such degradation. Based on the results, repair took place in 1999 and the fifth, sixth and seventh tombs were placed under permanent conservation to conserve the cultural assets. General public is currently denied access. The purpose of this study was to conduct a three-dimensional resistivity and GPR surveys on the ground surface of the fifth, sixth and seventh tombs of Songsalli Ancient Tombs in order to understand the underground status after repair. The study also aimed to understand the thickness of all the tomb walls and exterior structure based on GPR inside King Muryeong's tomb. The exploration on the ground surface found that the three tombs and soil adjacent to the tombs had resistivity as low as 5 to $90{\Omega}m$, which confirmed that the soil water content was still as high as that prior to the repair work. Additionally, GPR found that the wall construction of the burial chamber of King Muryeong's tomb was approximately 70cm in thickness, while the structure was of 2B with two bricks, about 35cm in length, put together longitudinally(2B brick masonry). The pathway to the burial chamber was of the 2B structure just like that of the burial chamber walls, while its thickness was 80cm with an eyebrow-type arch connected to it. Also, the ceiling exterior appears to have an arch structure, identical to the shape inside.

• Korean Journal of Psychosomatic Medicine
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• v.28 no.2
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• pp.116-125
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• 2020

Objectives : Self-poisoning is the leading cause of visits to the emergency departments after a suicide attempts. This study is aimed to compare the patient characteristics according to the category of drugs ingested by the patients who attempted suicide. Methods : All medical charts were retrospectively reviewed from patients who visited the emergency center, at Seoul Medical Center, due to intentional self-poisoning from April of 2011 to July of 2019. We investigated the information regarding the subtype and quantity of the intoxication drug, how it was obtained, suicidal history, and psychiatric history, as well as, sociodemographic information. Variables were compared between prescription drug (PD) and non-prescription drug (NPD) poisoning groups. Results : The mean age of the NPD poisoning group was significantly lower than that of the PD poisoning group. The patient ratio of those enrolled in national health insurance and living with spouses were significantly higher in the NPD poisoning group. Compared to the NPD poisoning group, the PD poisoning group had a higher incidence of mental illnesses, underlying diseases and ratio of involuntary visit to the emergency department. Among the prescription drugs, the benzodiazepine poisoning group had a higher rate of self-prescription than the non-poisoning group, while the zolpidem poisoning group had a higher rate of the using someone else's prescription than other drugs. Each single drug poisoning group (benzodiazepine, zolpidem, and antidepressant single-agent) had a higher rate of no mental illness than each of the mixed-poisoning group. Conclusions : Guidelines for regulating non-prescription drugs are needed as a matter of suicide prevention. Also, this study suggests that clinicians need to be careful when issuing prescriptions and should suicidal risk according to patients' characteristics, duration of follow-up and type of drug packaging.

• Journal of the Korean Electrochemical Society
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• v.24 no.4
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• pp.120-132
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• 2021

Although the development of high-Nickel is being actively carried out to solve the capacity limitation and the high price of raw cobalt due to the limitation of high voltage use of the existing LiCoO₂, the deterioration of the battery characteristics due to the decrease in structural stability and increase of the Ni content. It is an important cause of delaying commercialization. Therefore, in order to increase the high stability of the Ni-rich ternary cathod material LiNi_0.6Co_0.2Mn_0.2O₂, precursor Ni_0.6Co_0.2Mn_0.2-x(OH)₂/xTiO₂ was prepared using a nanosized TiO₂ suspension type source for uniform Ti substitution in the precursor. It was mixed with Li₂CO₃, and after heating, the cathode active material LiNi_0.6Co_0.2Mn_0.2-xTi_xO₂ was synthesized, and the physical properties according to the Ti content were compared. Through FE-SEM and EDS mapping analysis, it was confirmed that a positive electrode active material having a uniform particle size was prepared through Ti-substituted spherical precursor and Particle Size Analyzer and internal density and strength were increased, XRD structure analysis and ICP-MS quantitative analysis confirmed that the capacity was effectively maintained even when the Ti-substituted positive electrode active material was manufactured and charging and discharging were continued at high temperature and high voltage.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.3
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• pp.355-365
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• 2022

Precipitation and phase transition of iron minerals in mine drainage greatly affect the behavior of trace elements. However, the precipitation of ferrihydrite, one of the major iron minerals precipitated in drainage, and the related behavior of trace elements have hardly been studied. In this study, the effects of pH change and time on mineral precipitation characteristics in mine drainage from the Munkyeong coal mine were investigated, and the behavioral changes of trace elements related to the precipitation of these minerals were studied. In the case of precipitated mineral phases, goethite was observed at pH 4, and 2-line ferrihydrite mixed with small amount of 6-line ferrihydrite was mainly identified at pH 6 or higher. In addition, it was observed that the precipitation of calcite additionally increased as the pH increased in the samples at pH 6 or higher. The occurrence of goethite was probably due to the phase change of initially precipitated ferrihydrite within a short time under the influence of low pH. Our results showed that the concentration of trace elements was strongly influenced by pH and time. With increasing time, Fe concentration in the drainage showed a abrupt decrease due to the precipitation of iron minerals, and the concentration of As existing as oxyanions in the drainage, also decreased rapidly like Fe regardless of the pH values. This decrease in As concentration was mainly due to co-precipitation with ferrihydrite, and also partly to surface adsorption on goethite at low pH in drainage. Contrary to this observation, the concentration of other trace elements, such as Cd, Co, Zn, and Ni was greatly affected by the pH regardless of the mineral species. The lower the pH value, the higher the concentration of these trace elements were observed in the drainage, and vice versa at higher pH. These results indicate that the behavior of trace elements present as cations is more greatly affected by the mineral surface charge influenced by the pH values than the type of the precipitated mineral.

• Journal of the Daesoon Academy of Sciences
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• v.44
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• pp.141-175
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• 2023

This comparative study combines the methodologies of comparative research and literature review to examine Daesoon Thought. Comparative religious analysis in the social sciences, does not presuppose an a priori framework of the essence of religion because it targets various aspects of religion which are revealed within a historical field. However, it does not decompose and return to psychological or social phenomena like social sciences. In addition, with the emergence of religious pluralism, the climate of focusing on similarities between religions has already been accomplished to some degree. Furthermore, it is worth noting that many spiritual movements in modern spirituality reveal mixed or amorphous characteristics without being restricted by specific religious membership. It is time to overcome instrumentation and restore the transcendence of its original appearance even in secular humanist reasoning. It can be said that this reveals the perception that the ills and crises of modern civilization should be overcome in connection with the opening of the acquired world of Daesoon Thought. It could further be said that the main culprit of evil behavior is instrumental reason or degenerated reason rather than spirituality. Religion is the intellectual crystalline body of humankind and aims at human perfection and salvation. However, extremists in previous times amplified conflicts between religions and formed ideas suitable for their specific regions through different experiences. This generated mental rifts that proved greatly influential. At the time of initial inception, each religion confronted and fought other ideologies, but when the era of religious pluralism began, the necessity for inter-spiritual communication became urgent. It could be said that happiness is the realization of human spirituality by exploring the vision of humanism. In that case, the combined methodologies of comparative research and literature review reveal that the spirituality of Daesoon Thought would enable a humanism based on human dignity. This would be a path for seeking spirituality through human life and living as a true human being. Spiritual humanism as discussed through this study aims to share the problems of modern civilization and provide a critical view of modern civilization that shows the roots of prevailing thought are stuck in a Cartesian dualistic view of humanity and the world. The type of spiritual humanism to examined here focuses on a cosmotheandric vision by considering the spiritual return to Daoism via Daesoon Thought. This would treat human beings like heaven in alignment with Donghak ideology and honor the human dignity proposed by Daesoon Thought. It would also deliver sentient beings from suffering and to bliss in accordance with the aims of faith in Maitreya Buddha, and it would implement the Resolution of Grievances for Mutual Beneficence in fulfillment of Daesoon Thought.