• Journal of The Korean Society of Clinical Toxicology
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• v.19 no.1
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• pp.8-16
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• 2021

Purpose: This study was conducted to analyze the social factors influencing the 'authenticity of suicidal ideation' based post-suicidal care programs in emergency departments (EDs). Methods: This retrospective study was an analysis using the data of patients who had attempted suicide and visited the ED in tertiary urban hospitals from January 1, 2016, to December 31, 2018. The variables examined included gender, age, history of previous psychiatric disease, suicide method, and the number of previous attempts. Univariate and multivariate logistic regression analyses were conducted to identify factors influencing the registration rate for the community-based post-suicide care program. Results: Overall,1,460 suicides were analyzed, 177 (1.16%) showed a high authenticity of suicide. The social factors influencing the authenticity of suicide intent were the unmarried status of men and women, joblessness, history of mental illnesses, more than two previous suicide attempts, the influence of alcohol, and an attempt to commit suicide after midnight more specifically between 24:00 to 6:00 hours in the morning (p<.05). The factors influencing the severity of the condition of high authenticity suicide patients were low Glasgow coma scores (12 points or less), lactate levels, and oxygen saturation observed in the patients who were admitted to the intensive care unit for treatment and died (p<.05). Conclusion: The need for evidence-based preventive measures and early assessment tools at the emergency medicine level is emphasized to reduce the rate of suicide attempts. If the results of this study are used in the management of suicide prevention, the evaluation of the authenticity of suicide intent will be more likely to be made at the emergency medicine level, allowing the severity to be assessed earlier.

• Journal of Conservation Science
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• v.37 no.6
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• pp.712-722
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• 2021

This study presents a method for conserving shamanistic spirits in Chiseonggwang Buddha. Scientific investigation has revealed that these spirits have been subject to degeneration as a result of severe exfoliation and pollution. The materials and preservation treatment techniques used in create these shamanistic spirits were identified through visual inspection and using appropriate scientific equipment. The different types of background paper, background material, and color pigments used in create the shamanistic spirits were analyzed using a colorimeter, stereoscopic microscope, and SEM-EDS techniques. The analysis revealed that the pulp paper was used as the background and synthetic fiber polyester as the background material. In addition, the study of the pigment revealed that the color components were all synthetic, except for red lead [Pb₃O₄] and oyster shell white [CaCO₃]. Moreover, it was confirmed that the green pigment, identified as emerald green [Cu(C₂H₃O₂)₂.3Cu(AsO₂)₂], was a major component of shamanistic spirits in the late 19^th century. The shamanistic spirits in Chiseonggwang Buddha were conserved by identifying raw materials and pigments through this detailed analysis.

• Journal of Conservation Science
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• v.38 no.2
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• pp.124-132
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• 2022

Through scientific analysis, this study identified the material characteristics of metal foil decorating the border line and knotting of the National Folklore Cultural Heritage 'Pouch for the Sutra Embroidered with a Sun and Moon Design'. Through Scanning Electron Microscope-Energy Dispersive Spectroscopy results, it was estimated that silver (Ag) and sulfur (S) were present in the metal foil, and silver leaf was also attached to the medium. S may discolor Ag from yellow to black depending on its concsentration and contact time. Yellow color could not be identified in metal foil at present. But there existed an example of the preparation of a gold-colored flat silver thread; therefore, further research is needed to estimate the original color. The lamella was reddish brown on the back. Aluminum, silicon, and iron were also detected and were the main components found in red soil. This is believed to be the red adhesive in traditional flat gold thread and is considered to be an adhesive-related component of the metal foil. From the gas chromatography mass spectrometry results, the adhesive component was confirmed to be animal glue.

• Journal of Conservation Science
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• v.38 no.4
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• pp.289-300
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• 2022

In the 6^th and 7^th centuries, 5 iron artifacts excavated form the Baekje Stone Tomb in Guryong-ri site, Ungcheon, Boryeong, were studied. The sample were metal microscopic observation, SEM-EDS analysis and Raman micro-spectroscopy analysis were conducted to understand the metallurgical characteristics. The microstructure observation showed the presence of ferrite and pearlite throughout, and differences in carbon content existed depending on the direction. Non-metallic inclusions were in the form of long lines, and most of them were wüstite, fayalite. It is indicated that the artifacts were forge welded using hypoeutectoid steel, with signs of carburizing and decarburizing processes. Some crystals with high P₂O₅, TiO₂, CaO content were identified as sarcopside, ulvöspinel, and perovskite, respectively, through Raman spectroscopy. A comparison of the results with previous studies on the sites of Bujang-ri site in Seosan and Bongseon-ri site in Seocheon, which are adjacent sites in the coastal area, revealed that, while heat treatment technology was available, the artifacts were not heat-treated considering the purpose for use for these artifacts. The chemical composition of the non-metallic inclusions P₂O₅, TiO₂, CaO were plotted in proportions to SiO₂ and compared with adjacent sites. Considering that the P₂O₅/SiO₂ ratio was widely distributed, the refining technology was not uniform. In addition, the TiO₂/SiO₂ ratio was found to be higher than that of other sites, meaning that a titanium-containing ore was used to manufacture the artifacts, unlike in surrounding sites, but it is not detected in all artifacts, so it may have been affected by various factors such as furnace walls in addition to raw materials. Although slag formers were used, considering the CaO/SiO₂ ratio and the (Al₂O₃/SiO₂)/(CaO/SiO₂) ratio, which appear to be similar to the surrounding sites, but it is possible that CaO containing raw ore was used because it is also affected by the components of raw ore. As a result of the study, it is highly likely that ore different from that of the surrounding sites was used for production, but a more comprehensive comparative study with the surrounding sites is needed in the future.

• Economic and Environmental Geology
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• v.56 no.4
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• pp.409-419
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• 2023

Acid mine drainage(AMD) treatment is classified as both passive and active treatment. During the treatment, about 5,000 tons of neutralization sludge is generated as a by-product per year in Korea. This study was conducted to evaluate the characteristics of sludge generated from physico·chemical treatment processes as an active treatment from 5 different sources (D, H, S, T, Y) and the possibility of the sludges being recycled. The sludges have a pH range of 5.86 ~ pH 7.89, and a water content range of 51% ~ 82%. Most of particle sizes were less than 25 ㎛. In analysis of inorganic elements, the concentration of Al, Fe, and Mn were between 1,189 mg/kg ~ 129,344 mg/kg, 106,132 mg/kg ~ 338,011 mg/kg, and 3,472 mg/kg ~ 11,743 mg/kg, respectively. The concentration of As and Zn in sludge-T, Cd in sludge-D, Ni in sludge-H, Zn in sludge-S, and Cd in sludge-Y exceeded the soil contamination standards of Korea. The results from 2 separate kinds of leaching test, the Korea Standard Leaching Test(KSLT) and Toxicity Characteristic Leaching Procedure(TCLP), showed that all the sludges met the Korea groundwater standards. From the XRD and SEM-EDS analysis, the peaks of calcite and quartz were found in the sludges. The sludge also had a high proportion of Fe and O, and the majority of the composition was amorphous iron hydroxide.

• Economic and Environmental Geology
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• v.57 no.2
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• pp.263-270
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• 2024

In this study, impact factors for dehydration with KOMIR-Tube system using flocculant and dewatering tube were evaluated for mine drainage sludges. The experiments were conducted on semi-active facility sludges with water contents above 90 % using KOMIR-Tube system. The flocculant and input amount were determined from laboratory experiment and the dewatering efficiency was verified onsite experiment. The sludge characteristics were identified by instrumental analysis such as zeta potential measurement, particle size analysis, XRD, XRF and SEM-EDS. Selection of flocculants for sludge dewatering treatment need to consider not only precipitated rate but also filterated rate. Floc size has to keep at least 0.7 mm. From on-site experiments, sludge dewatering using KOMIR-Tube system suggests to carry out April and May that is low rainfall and humidity considering to climate conditions. Also, dewatering rate depends on the crystal degree of mineral that mainly makes up sludges. Particularly, goethite of the iron hydroxides has better dewatering rate than ferrihydrite. Ferrihydrite is low degree of crystallinity and uncleared or broad shaped crystal, goethite is good crystallinity with needle shaped crystal so that the effect of flocculation and dewatering showed to depend on the crystal. In results, impact factors of dewatering for mine drainage sludges are related to flocculant, climate, crystallinity and shape of iron hydroxides.

• Korean Journal of Heritage: History & Science
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• v.57 no.1
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• pp.146-159
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• 2024

In this study, a study on the production technology of the Buddha statue and the production of raw material origin was conducted through scientific analysis on the Bronze seated Bodhisattva Statue of Goseongsa Temple, a treasure. As a result of microstructure analysis through a metal microscope, it was confirmed that the microstructure of the Bronze seated Bodhisattva Statue of Goseongsa Temple was a process-type dendritic structure, and the casting structure of bronze was well represented, so it was manufactured through casting. Subsequently, as a result of analyzing the alloy composition ratio through SEM-EDS, it was identified as a ternary alloy with 81.26 wt% of copper (Cu) and 16.42 wt% of tin (Sn) and 1.72 wt% of lead (Pb). The results of the analysis of lead isotope ratios using a thermal ionization mass spectrometer (TIMS) were substituted into the distribution of lead isotope ratios on the Korean Peninsula, it was shown in corresponding to Jeolla-do and Chungcheong-do regions and North and South Gyeongsang Province. This suggests that the raw materials used in their production were likely sourced from the mines around Goseong Temple in Gangjin. Despite the fact that the statue is a medium and large Buddha with a total height of 51 centimeters, 1.72 wt% of lead (Pb) was found as a result of alloy composition ratio analysis, which showed a similar composition to the lead content ratio of small bronze and gilt-bronze Buddha statues. Therefore, we compared and analyzed the results of the analysis of the composition ratio of the alloys of bronze and gilt bronze statues, which has been scientifically analyzed with a compositional age similar to that of the Bronze seated Bodhisattva Statue of Goseongsa Temple. Comparison results, Various factors, such as the size of the Buddha statue as well as its stylistic characteristics and the age of composition, may exist in determining the alloy composition ratio of the bronze and gilt bronze Buddha statues, and it was confirmed that the alloy composition ratio or casting technology was properly adjusted when the Buddha statue was created. In other words, it is judged that a more comprehensive system of Buddha statue production technology should be investigated by conducting archaeological and art history studies on stylistic characteristics and age of composition, as well as scientific analysis results such as observation of internal structure, microstructure observation, and analysis of alloy composition ratio using radiation transmission irradiation.

• Korean Chemical Engineering Research
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• v.52 no.5
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• pp.667-671
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• 2014

In this study, we suggest a facile method to control conditions of single component independently when preparing consisting two-component metal oxides nanofiber by simply dispersing nanoparticles in precursor solution. The well dispersed $SiO_2$ nanoparticles in $TiO_2$ nanofibers were successfully synthesized through a simple electrospinning process. The as-synthesized nanodfibers were investigated via FE-SEM, XRD and EDS for structural studies, furthermore, the analysis of UV-VIS and photocatalytic activity were carried out for demonstrate the effect of $SiO_2$ nanoparticles dispersed in $TiO_2$ nanofibers. As a result, $TiO_2$ nanofibres dispersed with $SiO_2$ nanoparticles have enhanced photocatalytic activity than that of $TiO_2$ nanofibres only. In this strategy, the introduction of $SiO_2$ nanoparticles in $TiO_2$ nanofibers were attribute to enlarge absorption in the visible region (380~440 nm). Additionally, $Br{\o}nsted$ acid sites generated in each metal oxide of Ti and Si increase OH radicals efficiently as well as it limit recombination loss by holding photogenerated electrons for high efficient photocatalytic activity.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.3
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• pp.304-314
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• 2010

This study was carried out to find out potential use of ochre as an agent to reduce phosphorus content in water. Ochre is a by-product from treatment of acid mine drainage (AMD) which is composed mostly of $Fe_2O_3$, $Fe_2O_3{\cdot}H_2O$, $FeO{\cdot}OH$ and $Fe(OH)_3$. Three ochre samples (ochre-H, ochre-D and ochre-S) were collected from three treatment facilities in Gangwon province. Physico-chemical characteristics of three ochre samples including pH, electrical conductivity, total phosphorus, available phosphorus, particle size distribution were analyzed. Scanning electron microscopy (SEM) energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and X-ray fluorescence (XRF) analysis were also carried out. In addition, experiments for phosphorus removal from water was performed. Calcium content of ochre-H was higher than that of ochre-D and ochre-S, whereas iron content of ochre-H was lower than that of ochre-D and ochre-S. All the phosphorus in water up to maximum 191,411 mg $kg^{-1}$ per unit mass of ochre was removed with ochre-H. Ochre has immense potential as an agent to reduce phosphorus content in water.

• Journal of the Mineralogical Society of Korea
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• v.29 no.1
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• pp.1-10
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• 2016

We studied the heavy minerals in 46 surface sediments collected from the Central Yellow Sea Mud (CYSM) to characterize the type, abundance, mineralogical properties and distribution pattern using the stereo-microscopy, field-Emission scanning electron microscopy (FE SEM) and chemical analysis through the energy dispersive spectrometer (EDS). Heavy mineral assemblages are primarily composed of epidote group, amphibole group, garnet group, zircon, rutile and sphene in descending order. Epidote group and amphibole group minerals account for more than 50% of total heavy minerals. The minerals in epidote group, amphibole group and garnet group in studied area are epidote, edenite and almandine, respectively. When we divided the CYSM into two regions by $124^{\circ}E$, the eastern region contain higher contents of epidote and (zircon + rutile), which are more resistant to weathering but lower of amphibole, which is less resistant to weathering than the western region. Based on this results, it is possible to estimate that the eastern region sediments are transported for a long distance while western region sediments are transported for a short distance from the source area. In the future, the additional study on the heavy minerals in river sediments flowing into the Yellow Sea and much more samples for marine sediments must be carried out to interpret exactly the provenance and sedimentation process.