• 한국안전학회지
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• 제13권1호
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• pp.98-104
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• 1998

Recently, industrial accidents have occurred in various patterns due to the diversity of industries and the integration of facilities. Especially, the major accidents affect broad area and result in huge loss of lives and properties. Domestic researches on techniques for keeping away from such hazardous danger have been actively performed but their activities are limited in some institutes and universities. In advanced countries, integrated management systems like Seveso Directive of EU and OSHA(Occupational Safety and Health Act) of U.S.A. have been legislated along with the systematic research activities. In Korea, the integrated safety management systems called SMS(Safety Management System) and PSM(Process Safety Management) have been applied to major industries. These systems made chemical industries manage the process safety information by collecting and arranging safety data by themselves. In order to implement the system successfully, it is urgently required to prepare a tool for searching and accumulating process safety data systematically. In this study, a computerized prototype of Risk Assessment System which is essential to SMS and PSM was developed as a main system and data base as subsystem to handle safety information.

• 한국응용과학기술학회지
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• 제28권3호
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• pp.284-289
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• 2011

All spectroscopic methods used in this work indicate the instability of tungstophosphates in aqueous solutions and considerable dependence on pH with regard to the dominant species present in the solution. UV spectroscopy indicates that some changes occur in the system but they cannot be specified. IR spectroscopy gives more information on the identification of the dominant species as a function the pH of the solution. NMR spectroscopy provides unique data, which can be used for more accurate interpretation of changes in the solution of various pH values. In the case of aqueous solutions of tungstophosphates, the parent anion was present only in a very acidic solution of ca. pH 1. Some differences in interpretation of the molecular species present under various experimental conditions can be ascribed to some extent to the diversity of chemical shifts of NMR. Under physiological conditions attained with the addition of NaOH, tungstophosphates was dominantly present in the form of the lacunary monovacant anion.

• 한국해양학회지
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• 제14권1호
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• pp.6-14
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• 1979

해양 식물플랑크톤은 해양생태계에서 가장 중요한 생산자로서 해양생물 및 해양환경에 지극히 큰 영향을 미친다. 따라서 식물 플랑크톤은 해양의 생태를 연구함에 있어 중요하고도 우선되는 연구 대상이다. 한국에서는 Skvortzow(1931) 및 산전(1933)가 처음으로 해양 식물플랑크톤을 연구한 이래, 상천(1934), 소구보(1938), 창무(1943, 1944), 박(1956a,b), 최(1966, 1967, 1969, 1972), 엄 유(1967), 이 심 김 (1967), 박 김(1967), 방(1967), 최(1969, 1970), 정 심 이(1970, 1971), 정(1969), 유외(1975), 유 이(1976), 유(1977), 정 이(1977) 등으로 연구가 계속되어 오고 있다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.211-211
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• 2011

Nanostructures, with a diversity of shapes, built on substrates have been developed within many research areas. Lithography is one powerful, but complex, technique to make structures at the nanometer scale, such as platinum nanowires for studying CO catalytic reactions [1], or aluminum nanodisks for studying the plasmon effect [2]. In this work, we approach a facile method to construct nanostructures using noble metals on a titania thin film by using self-assembled structures as a pattern. Here, a large-scale silica monolayer is transferred to the titania thin film substrates using a Langmuir-Blodgett trough, followed by the deposition of a thin transition metal layer. Owing to the hexagonal close-packed structure of the silica monolayer, we would obtain a metal nanostructure that includes separated metallic triangles (islands) after removing the patterning silica beads. This nanostructure can be employed to investigate the role of metal-oxide interfaces in CO catalytic reactions by changing the patterning silica particles with different sizes or by replacing the oxide support. The morphology and chemical composition of the structure can be characterized by scanning electron microscopy, atomic force microscopy and X-ray photoelectron spectroscopy. In addition, we modify these islands to a connected island structure by reducing the silica size of the patterning monolayer, which is utilized to generating hot electron flow based on the localized surface plasmon resonance effect of the metal nanostructures.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 2000년도 Proceedings of 2000 KSAM International Symposium and Spring Meeting
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• pp.100-107
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• 2000

In a recently developed strategy for in-situ treatment of polychlorinated biphenyls (PCB), bioaugmentation was used in conjunction with a surfactant, sorbitan trioleate, as a carbon source for the degrader bacteria, along with the monoterpene, carvone, and salicylic acid as inducing substrates. Two bacteria were used for soil inoculants, including Arthrobacter sp. st. B1B and Ralstonia eutrophus H850. This methodology achieved 60% degradation of PCBs in Aroclor 1242 after 18 weeks in soils receiving 34 repeated applications of the degrader bacteria. However, an obvious limitation was the requirement for soil mixing after every soil inoculation. In the research reported here, bioaugmentation and biostimulation treatment strategies were modified by using the earthworm, Pheretima hawayana, as a vector for dispersal and mixing of surface-applied PCB-degrading bacteria and soil chemical amendments. Changes in microbial biomass and microbial community structure due to earthworm effects were examined using DNA extraction and PCR-DGGE of 16S rDNA. Results showed that earthworms effectively promoted biodegradation of PCBs in bioaugmented soils to the same extent previously achieved using physical soil mixing, and had a lesser, but significant effect in promoting PCB biodegradation in biostimulated soils treated with carvone and salicylic acid. The effects of earthworms were speculated to involve many interacting factors including increased bacterial transport to lower soil depths, improved soil aeration, and enhanced microbial activity and diversity.

• 한국재료학회지
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• 제30권3호
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• pp.136-141
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• 2020

The magnetocaloric effect (MCE), which is the reversible temperature change of magnetic materials due to an applied magnetic field, occurs largely in the vicinity of the magnetic phase transition temperature. This phenomenon can be used to induce magnetic refrigeration, a viable, energy-efficient solid-state cooling technology. Recently, Metal-organic frameworks (MOFs), due to their structural diversity of tunable crystalline pore structure and chemical functionality, have been studied as good candidates for magnetic refrigeration materials in the cryogenic region. In cryogenic cooling applications, MCE using MOF can have great potential, and is even considered comparable to conventional lanthanum alloys and magnetic nanoparticles. Owing to the presence of large internal pores, however, MOF also exhibits the drawback of low magnetic density. To overcome this problem, therefore, recent reports in literature that achieve high magnetic entropy change using a dense structure formation and ligand tuning are introduced.

• 수산해양교육연구
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• 제24권6호
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• pp.920-933
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• 2012

Marine algal flora and community structure were investigated seasonally at four stations in Busan, in which coastal area and estuary affected by Nakdong river are involved, from February 2011 to October 2011. Total 78 species including 9 of cholophyta, 17 of phaeophyta and 52 of rhodophyta were found during the study period. Maximum and minimum species number were recorded at station 1(57 species) and at 3(32 species). As based on the cluster analysis, grouping pattern between the four stations was significantly affected by season and Nakdong river run off. At station 3 directly exposured on Nakdong river run off, species diversity was relatively low and dominant species were similar throughout four seasons. However, coverage at the station was relatively high because of Ulva bloom. This difference results from salinity and nitrates concentrations closely related with river runoff controlled according to precipitation. Marine algal coverage was high at lower salinity and higher nitrate concentration. In conclusion, the spatio-temporal distribution of benthic marine algae in estuary of Nakdong river was mainly determined by the precipitation and river run off with the seasons, whereas that in coastal area was seasonally affected by general physical, chemical, biological and dynamic factors.

• 한국자기공명학회논문지
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• 제23권4호
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• pp.93-97
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• 2019

Black ginger (Kaempferia parviflora) is a short-lived ginger plant with dark purple colored root and is known to be effective in treating diabetes and obesity. To find out the difference in the characteristics of the black ginger according to the variety of production, 1D proton NMR experiments were performed on 4 types of black gingers from different regions. The NMR spectra of all black ginger showed the characteristic peaks of the polymethoxy flavone compounds, and the chemical shifts and intensity of peaks showed slight differences depending of the type of black ginger implying the difference in molecular environment. These initial NMR experiments can be applied to the identification of the diversity of black ginger in physiological function according to the climate of regions using SNIF-NMR (Site-specific Natural Isotope Fractionation studied by NMR).

• ALGAE
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• 제36권3호
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• pp.195-206
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• 2021

Increasing inputs of dissolved organic matter (DOM) to northern lakes is resulting in 'lake browning.' Lake browning profoundly affects phytoplankton community composition by modifying two important environmental drivers-light and nutrients. The impact of increased DOM on native isolates of red and green-pigmented cyanobacteria identified as Pseudanabaena, which emerged from a Dolichospermum bloom (Dickson Lake, Algonquin Provincial Park, Ontario, Canada) in 2015, were examined under controlled laboratory conditions. The genomes were sequenced to identify phylogenetic relatedness and physiological similarities, and the physical and chemical effects of increased DOM on cellular performance and competitiveness were assessed. Our study findings were that the isolated red and green phenotypes are two distinct species belonging to the genus Pseudanabaena; that both isolates remained physiologically unaffected when grown independently under defined DOM regimes; and that neither red nor green phenotype achieved a competitive advantage when grown together under defined DOM regimes. While photosynthetic pigment diversity among phytoplankton offers niche-differentiation opportunities, the results of this study illustrate the coexistence of two distinct photosynthetic pigment phenotypes under increasing DOM conditions.

• Steel and Composite Structures
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• 제44권1호
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• pp.105-117
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• 2022

Impact resistance efficiency of the newly designed sandwich beam with a laterally arched core as bio-inspired by the woodpecker is numerically investigated. The principal components of the beam comprise a dual-core system sandwiched by the top and bottom laminated CFRP skins. Different materials, including hot melt adhesive, high-density polyethylene (HDPE), acrylonitrile butadiene styrene (ABS), epoxy resin (EPON862), aluminum (Al6061), and mild carbon steel (AISI1018), are considered for the side-arched core layer of the beam for impact efficiency assessment. The aluminum honeycomb takes the role of the second core. Contact force, stress, damage formation, and impact energy for beams equipped with different materials are examined. A diversity in performance superiority is noticed in each of these indicators for different core materials. Therefore, for overall performance appraisal, the impact resistance efficiency index, which covers several chief impact performance parameters, of each sandwich beam is computed and compared. The impact resistance efficiency index of the structure equipped with the AISI1018 core is found to be the highest, about 3-10 times greater than other specimens, thus demonstrating its efficacy as the optimal material for the bio-inspired dual-core sandwich beam system.