• Title/Summary/Keyword: Jiho Oh

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Characteristics of White Pigments Used in Jiho Oh and Bonung Gu's Paintings Produced in Modern and Contemporary Period (근·현대 시대 오지호와 구본웅 유화작품에 사용된 백색계 안료의 특성 연구)

  • Kim, Jung Heum;Kim, Hwan Ju;Park, Hye Sun;Lim, Sung Jin
    • Journal of Conservation Science
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    • v.33 no.5
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    • pp.371-380
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    • 2017
  • To investigate the pigments used in modern and contemporary oil paintings, thirty-two paintings by Jiho Oh and Bonung Gu were selected. The white pigment found in the ground and painting layers was identified as lead white (hydrocerussite), zinc white (zinc oxide), titanium white (titanium dioxide in anatase or rutile forms), calcite (calcium carbonate), and barite (barium sulfate). Further, this indicated that pigments differ according to the artist and date of the painting's creation. However, both Oh and Gu used zinc white during the modern and contemporary period, while lead white was replaced by titanium white, barite and calcite. Compared with the overseas studies on pigments and oil paints, the change patterns of pigments were the same with them but the periods of the use were partially different. It seems to be due to the fact that South Korea is linked to the historical background of the art material which was imported from Japan instead of Western countries. Therefore, it is inevitable that any change in the white pigments used for domestic oil paintings occurred at a different time from global transitions. If the results of this study are used in the analysis of art works it is suggested that a database recording such aspects as material properties of oil paints, artistic techniques, and chronology would become important for future conservation science and the study of art history.

Growth Characteristics of Bacteriocin-Producing Lactococcus lactis subsp. hordniae JNU533 in a Glucose-Containing Skim Milk Medium

  • Jiho Shin;Subin Kim;Sejong Oh
    • Journal of Dairy Science and Biotechnology
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    • v.41 no.3
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    • pp.138-148
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    • 2023
  • In this study, Lactococcus lactis subsp. hordniae JNU533 (JNU533) was isolated from Swiss-type cheese, and the bacteriocin produced by this strain was characterized. The spot-on-lawn assay was used to determine the antimicrobial spectrum and characteristics of the JNU533-derived bacteriocin. Results confirmed that the JNU533-derived bacteriocin inhibited the growth of lactic acid bacteria. The size of the bacteriocin was approximately 4.9 kDa, and it was heat- and pH-stable under various temperature and pH conditions. Furthermore, the possibility of using JNU533 as a starter culture in the manufacturing of fermented dairy products was assessed. A single colony of JNU533 was inoculated into 10% skim milk containing 0.5% glucose to investigate its characteristics in milk culture. The decrease in the pH was similar to that elicited by Lactobacillus delbrueckii subsp. bulgaricus. Furthermore, the results confirmed that JNU533 inhibited the growth of various bacteria and could be used as a milk fermentation starter. This study highlights the characteristics of the bacteriocin produced by JNU533 and the growth features of this strain in a skim milk medium.

Lichen as Bioindicators: Assessing their Response to Heavy Metal Pollution in Their Native Ecosystem

  • Jiho Yang;Soon-Ok Oh;Jae-Seoun Hur
    • Mycobiology
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    • v.51 no.5
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    • pp.343-353
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    • 2023
  • Lichens play crucial roles in the ecosystems, contributing to soil formation and nutrient cycling, and being used in biomonitoring efforts to assess the sustainability of ecosystems including air quality. Previous studies on heavy metal accumulation in lichens have mostly relied on manipulated environments, such as transplanted lichens, leaving us with a dearth of research on how lichens physiologically respond to heavy metal exposure in their natural habitats. To fill this knowledge gap, we investigated lichens from two of South Korea's geographically distant regions, Gangwon Province and Jeju Island, and examined whether difference in ambient heavy metal concentrations could be detected through physiological variables, including chlorophyll damage, lipid oxidation, and protein content. The physiological variables of lichens in response to heavy metals differed according to the collection area: Arsenic exerted a significant impact on chlorophyll degradation and protein content. The degree of fatty acid oxidation in lichens was associated with increased Cu concentrations. Our research highlights the value of lichens as a bioindicator, as we found that even small variations in ambient heavy metal concentrations can be detected in natural lichens. Furthermore, our study sheds light on which physiology variables that can be used as indicators of specific heavy metals, underscoring the potential of lichens for future ecology studies.

Fe-rich Sepiolite from the Basalt Fault Gouge in the South of Pohang, Korea (포항시 남부 현무암체의 단층점토에서 산출되는 Fe-세피올라이트)

  • Son, Byeongseo;Hwang, Jinyeon;Lee, Jinhyun;Oh, Jiho;Son, Moon;Kim, Kwanghee
    • Journal of the Mineralogical Society of Korea
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    • v.29 no.1
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    • pp.11-22
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    • 2016
  • The black fault gouge having 5-10 cm width occurs at the center of the fault fracture zone developed at the early Miocene basaltic rocks that is located at the Geumkwang-ri area in Donghae-myeon, Pohang city. The fault gouge was analyzed with XRD, FTIR, DTA/TGA, SEM, TEM, XRF, EPMA. Analyses reveal that the fault gouge is Fe-rich sepiolite having high iron content. Alteration minerals observed in the fault fracture zone are mainly smectite. The significant amount of smectite also observed in the basaltic parent rocks. The occurrence of constituent minerals indicates that the Fe-rich sepiolite was crystallized by faulting and hydrothermal alteration after the consolidation of basaltic rock at the deep place.

High-resolution Meteorological Simulation Using WRF-UCM over a Coastal Industrial Urban Area (WRF-UCM을 이용한 연안산업도시지역 고해상도 기상 모델링)

  • Bang, Jin-Hee;Hwang, Mi-Kyoung;Kim, Yangho;Lee, Jiho;Oh, Inbo
    • Journal of Environmental Science International
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    • v.29 no.1
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    • pp.45-54
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    • 2020
  • High-resolution meteorological simulations were conducted using a Weather Research and Forecasting (WRF) model with an Urban Canopy Model (UCM) in the Ulsan Metropolitan Region (UMR) where large-scale industrial facilities are located on the coast. We improved the land cover input data for the WRF-UCM by reclassifying the default urban category into four detailed areas (low and high-density residential areas, commercial areas, and industrial areas) using subdivided data (class 3) of the Environmental and Geographical Information System (EGIS). The urban area accounted for about 12% of the total UMR and the largest proportion (47.4%) was in the industrial area. Results from the WRF-UCM simulation in a summer episode with high temperatures showed that the modeled temperatures agreed greatly with the observations. Comparison with a standard WRF simulation (WRF-BASE) indicated that the temporal and spatial variations in surface air temperature in the UMR were properly captured. Specifically, the WRF-UCM reproduced daily maximum and nighttime variations in air temperature very well, indicating that our model can improve the accuracy of temperature simulation for a summer heatwave. However, the WRF-UCM somewhat overestimated wind speed in the UMR largely due to an increased air temperature gradient between land and sea.

Impact of Solvent pH on Direct Immobilization of Lysosome-Related Cell Organelle Extracts on TiO2 for Melanin Treatment

  • Bang, Seung Hyuck;Kim, Pil;Oh, Suk-Jung;Kim, Yang-Hoon;Min, Jiho
    • Journal of Microbiology and Biotechnology
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    • v.25 no.5
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    • pp.718-722
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    • 2015
  • Techniques for immobilizing effective enzymes on nanoparticles for stabilization of the activity of free enzymes have been developing as a pharmaceutical field. In this study, we examined the effect of three different pH conditions of phosphate buffer, as a dissolving solvent for lysosomal enzymes, on the direct immobilization of lysosomal enzymes extracted from Hen's egg white and Saccharomyces cerevisiae. Titanium(IV) oxide (TiO2) nanoparticles, which are extensively used in many research fields, were used in this study. The lysosomal enzymes immobilized on TiO2 under each pH condition were evaluated to maintain the specific activity of lysosomal enzymes, so that we can determine the degree of melanin treatment in lysosomal enzymes immobilized on TiO2. We found that the immobilization efficiency and melanin treatment activity in both lysosomal enzymes extracted from Hen's egg white and S. cerevisiae were the highest in an acidic condition of phosphate buffer (pH 4). However, the immobilization efficiency and melanin treatment activity were inversely proportional to the increase in pH under alkaline conditions. In addition, enhanced immobilization efficiency was shown in TiO2 pretreated with a divalent, positively charged ion, Ca2+, and the melanin treatment activity of immobilized lysosomal enzymes on TiO2 pretreated with Ca2+ was also increased. Therefore, this result suggests that the immobilization efficiency and melanin treatment activity of lysosomal enzymes can be enhanced according to the pH conditions of the dissolving solvent.

Consideration of Analysis Method of Asbestos and Existing Condition for Fibrous Materials in Domestic Air (국내 공기 중 섬유상 물질의 존재실태와 석면의 분석방법에 대한 고찰)

  • Hwang, Jinyeon;Oh, Jiho;Lee, Hyomin;Lee, Jinhyun;Son, Byeongseo
    • Journal of the Mineralogical Society of Korea
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    • v.28 no.2
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    • pp.165-171
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    • 2015
  • Dust samples collected from air in metropolitan areas of Busan and Ulsan were analyzed by phase contrast microscopy, phase contrast dispersion microscopy and SEM. Asbestos concentration in dust samples was lower than detection limit. Many fibrous materials were observed in dust samples, but most of them were organic fibers. Inorganic fibers such as rock fiber, ceramic fiber and gypsum were contained in the samples and non-fibrous minerals such as quartz, calcite and feldspar were also occasionally observed. Domestic law requires that asbestos in air dust is mainly analyzed by phase contrast microscopy. From this study, however, precise analysis of asbestos was almost impossible by this method only. As indicated in JIS method of Japan, therefore, count and identification of asbestos were more efficient by dispersion staining method after removing organic materials in samples by low temperature incinerator.

Weather-sensitive Diseases and Their Correlations with Meteorological Factors: Results from Academic Papers (학술논문 분석을 통한 기상민감질환 선정 및 기상인자와의 관련성고찰)

  • An, Hye Yeon;Jeong, Ju-Hee;Kim, Taehee;Yun, Jinah;Kim, Hyunsu;Oh, Inbo;Lee, Jiho;Won, Kyung-Mi;Lee, Young-Mi;Kim, Yoo-Keun
    • Journal of Environmental Science International
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    • v.25 no.6
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    • pp.839-851
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    • 2016
  • The effect of weather on disease was investigated based on results reported in academic papers. Weather-sensitive disease was selected by analyzing the frequency distributions of diseases and correlations between diseases and meteorological factors (e.g., temperature, humidity, pressure, and wind speed). Correlations between disease and meteorological factors were most frequently reported for myocardial infarction (MI) (28%) followed by chronic ischemic heart disease (CHR) (12%), stroke (STR) (10%), and angina pectoris (ANG) (5%). These four diseases had significant correlations with temperature (meaningful correlation for MI and negative correlations for CHR, STR, and ANG). Selecting MI, as a representative weather-sensitive disease, and summarizing the quantitative correlations with meteorological factors revealed that, daily hospital admissions for MI increased approximately 1.7%-2.2% with each $1^{\circ}C$ decrease in physiologically equivalent temperature. On the days when MI occurred in three or more patients larger daily temperature ranges ($2.3^{\circ}C$ increase) were reported compared with the days when MI occurred in fewer than three patients. In addition, variations in pressure (10 mbar, 1016 mbar standard) and relative humidity (10%) contributed to an 11%-12% increase in deaths from MI and an approximately 10% increase in the incidence of MI, respectively.

Growth promotion effect of red ginseng dietary fiber to probiotics and transcriptome analysis of Lactiplantibacillus plantarum

  • Hye-Young Yu;Dong-Bin Rhim;Sang-Kyu Kim;O-Hyun Ban;Sang-Ki Oh;Jiho Seo;Soon-Ki Hong
    • Journal of Ginseng Research
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    • v.47 no.1
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    • pp.159-165
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    • 2023
  • Background: Red ginseng marc, the residue of red ginseng left after water extraction, is rich in dietary fiber. Dietary fiber derived from fruits or vegetables can promote the proliferation of probiotics, and it is a key technology in the food industry to increase the productivity of probiotics by adding growth-enhancing substances such as dietary fiber. In this study, the effect of red ginseng dietary fiber (RGDF) on the growth of probiotic bacterial strains was investigated at the phenotypic and genetic levels. Methods: We performed transcriptome profiling of Lactiplantibacillus plantarum IDCC3501 in two phases of culture (logarithmic (L)-phase and stationary (S)-phase) in two culture conditions (with or without RGDF) using RNA-seq. Differentially expressed genes (DEGs) were identified and classified according to Gene Ontology terms. Results: The growth of L.plantarum IDCC3501 was enhanced in medium supplemented with RGDF up to 2%. As a result of DEG analysis, 29 genes were upregulated and 30 were downregulated in the RGDF-treated group in the L-phase. In the S-phase, 57 genes were upregulated and 126 were downregulated in the RGDF-treated group. Among the upregulated genes, 5 were upregulated only in the L-phase, 10 were upregulated only in the S-phase, and 3 were upregulated in both the L- and S-phases. Conclusions: Transcriptome analysis could be a valuable tool for elucidating the molecular mechanisms by which RGDF promotes the proliferation of L.plantarum IDCC3501. This growth-promoting effect of RGDF is important, since RGDF could be used as a prebiotic source without additional chemical or enzymatic processing.

Process window of simultaneous transfer and bonding materials using laser-assisted bonding for mini- and micro-LED display panel packaging

  • Yong-Sung Eom;Gwang-Mun Choi;Ki-Seok Jang;Jiho Joo;Chan-mi Lee;Jin-Hyuk Oh;Seok-Hwan Moon;Kwang-Seong Choi
    • ETRI Journal
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    • v.46 no.2
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    • pp.347-359
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    • 2024
  • A simultaneous transfer and bonding (SITRAB) process using areal laser irradiation is introduced for high-yield and cost-effective production of mini- or micro-light-emitting diode (LED) display panels. SITRAB materials are special epoxy-based solvent-free pastes. Three types of pot life are studied to obtain a convenient SITRAB process: Room temperature pot life (RPL), stage pot life (SPL), and laser pot life (LPL). In this study, the RPL was found to be 1.2 times the starting viscosity at 25℃, and the SPL was defined as the time the solder can be wetted by the SITRAB paste at given stage temperatures of 80℃, 90℃, and 100℃. The LPL, on the other hand, was referred to as the number of areal laser irradiations for the tiling process for red, green, and blue LEDs at the given stage temperatures. The process windows of SPL and LPL were identified based on their critical time and conversion requirements for good solder wetting. The measured RPL and SPL at the stage temperature of 80℃ were 6 days and 8 h, respectively, and the LPL was more than six at these stage temperatures.