• Journal of the Korean Ceramic Society
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• v.44 no.6 s.301
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• pp.331-337
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• 2007

High temperature reaction behaviors of various oxide materials (such as bauxite, pyrophyllite, mullite and fused silica powders) used in the refractory materials for tap-hole plugging of blast furnace were investigated with varying temperature in the carbon surrounding. Kinetics of carbothermal reduction of $SiO_2$ for forming SiC with high corrosion resistance were strongly dependent on it's crystalline phase. SiC generation yield increased with increasing catalyst amount in oxide regardless of generated SiO gas amount at temperature of $<1500^{\circ}C$. However, in case of fused silica over $1500^{\circ}C$, SiC generation yield was dominantly influenced by SiO amount without catalyst effect. Bauxite showed the most effective carbothermal reduction reaction, since bauxite have a large amount of catalyst and well-dispersed $SiO_2$ phase in oxide matrix.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.27-28
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• 2019

Recently, a bed company detected a radon more than Red Politics and became a hot topic of conversation. This has led to increased interest in radon, and a number of free-of-charge bodies have also been established to recognize the dangers of radon. In addition, the Korean Institute of Geological and Resource Research is planning to assist the installation of radon alarm systems in 10,000 households nationwide, free of charge. Since radon is a colorless, odorless and tasteless gas that causes lung cancer, it aims to reduce lung cancer incidence by absorbing radon using bamboo activated carbon as a way to reduce it. Due to the use of bamboo activated carbon, radon concentration per hour tends to decrease as substitution rate increases, and table flow tends to decrease as substitution rate increases. Through this experiment, 30% of the replacement rate of bamboo activated carbon is judged to be the most suitable replacement rate.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2001.06a
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• pp.346-353
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• 2001

Zirconia powder containing 3 mol% yttria(3Y-PSZ) with and with out Fe$_2$O$_3$ addition was coated on tile cast iron substrate by plasma spraying method. The erosion experiments were performed at temperatures from $25^{\circ}C$ to $600^{\circ}C$. A gas blast type erosion tester was used to examine erosion behavior of the specimens. The results of 3Y-PSZ coatings showed that tile erosion rate had maximum value at 40$0^{\circ}C$. It coincided with tile results of phase transformation tetragonal phase to monoclinic phase caused by low temperature thermal degradation. The tensile stress relaxation and the micro-hardness improvement significantly influenced on the erosion rate at $600^{\circ}C$. In the case of Fe$_2$O$_3$ added 3Y-PSZ coatings, the erosion rate of tested at $25^{\circ}C$ showed maximum value at 5.0 mol% Fe$_2$O$_3$ added coating. This tendency is caused by the improvement of mechanical properties and the tensile residual stress. The erosion rate at 200'c and 400'L showed significantly decrease by Fe203 addition. This decrease is believed to be the stabilization of the tetragonal phase and the increase of micro-hardness.

• Journal of the Korean Society of Safety
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• v.38 no.2
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• pp.44-51
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• 2023

With the recent increase in gas energy use, risk management for explosion accidents has been emphasized. Protective walls can be used to reduce damage from explosions. The KOSHA GUIDE D-65-2018 suggests the minimum thickness and height of protective walls, minimum reinforcement diameter, and maximum spacing of reinforcements for the structural safety of the protective walls. However, no related evidence has been presented. In this study, the blast load carrying capacity of the protective wall was analyzed by the pressure-impulse diagrams while changing the yield strength of the reinforcement, concrete compressive strength, reinforcement ratio, protective wall height, and thickness, to check the adequacy of the KOSHA GUIDE. Results show that failure may occur even with design based on the criteria presented by KOSHA GUIDE. In order to achieve structural safety of protective walls, additional criteria for minimum reinforcement yield strength and maximum height of protective wall are suggested for inclusion in KOSHA GUIDE. Moreover, the existing value for minimum reinforcement ratio and the thickness of the protective wall should be increased.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.77-78
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• 2020

In Korea, more than 30,000 tons of waste Styrofoam are produced every year. Styrofoam is spent more than 500 years decomposing during the reclamation process, so it needs to be recycled. The recycling rate of waste styrofoam continues to be the third highest in the world, but it is lower than that of Germany and Japan. Therefore, measures are needed to increase the recycling rate of waste Styropol. Another problem is that cement is mainly used in existing lightweight foam concrete. However, large amounts of CO2 from cement-producing processes cause environmental pollution. Currently, Korea is increasing its greenhouse gas reduction targets to cope with energy depletion and climate change, and accelerating efforts to identify and implement reduction measures for each sector. In 2013 alone, about 600 million tons of carbon dioxide was generated in the cement industry. Therefore, this study replaces CO2 generation cement with furnace slag fine powder, uses crude steel cement for initial strength development of bubble concrete, and manufactures hardening materials to study its properties using waste styrofoam. As a result of the experiment, the hardening agent replaced by micro powder of furnace slag was less intense and more prone to absorption than cement using ordinary cement. Further experiments on the segmentation and strength replenishment of furnace slag are believed to contribute to the manufacture of environmentally friendly lightweight foam concrete.

• Journal of the Korean Wood Science and Technology
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• v.44 no.5
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• pp.655-663
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• 2016

Increasing green house gas and it consequent climate change problems are discussed as a global issue. Accordingly, future local green house gas emission will increase up to 40% of the entire local green house gas emission and therefore, efforts to reduce the emission in construction industry is urgently required. Therefore, in this study, heating energy demand was analyzed by using the EnergyPlus simulation according to wood material finishes configuration. EnergyPlus has the entry for a variety of buildings and heating, ventilation, air conditioning (HAVC) system components, in particular buildings, air conditioning systems, and performs simultaneous integrated calculated through the feedback between the heat source unit, a verification program according to the ASHRAE Standard 140-2007 to be. The climate data for the simulation we used the data IWEC in Incheon and Gwangju provided by EnergyPlus. The analysis of simulation model was farm and fishing house standard design drawings: 2012, presented at the Korea Rural Community Corporation. The results of simulation of central region and southern region were effected by wood products of simulation model into the interior finish, exterior finish, windows, wooden structure. Also, it was confirmed that the reduced heating energy demand.

• Journal of the Korea Concrete Institute
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• v.18 no.2 s.92
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• pp.267-274
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• 2006

Greenhouse gas reduction will be highlighted as the most pending question in the cement industry in future because the production of Portland cement not only consumes limestone, clay, coal, and electricity, but also release waste gases such as $CO_2,\;SO_3$, and NOX, which can contribute to the greenhouse effect and acid rain. To meet the increase of cement demand and simultaneously comply with the Kyoto Protocol, cement that gives less $CO_2$ discharge should be urgently developed. This study aims to manufacture non-sintering cement(NSC) by adding phosphogypsum(PG) and waste lime(WL) to granulated blast furnace slag(GBFS) as sulfate and alkali activators. This study also Investigates the hydration reaction of NSC through analysis of scanning electron microscopy(SEM), X-ray diffraction(XRD), differential thermal analysis(DTA), and pH. Results obtained from analysis of the hydrate have shown that the glassy films of GBFS are destroyed by the activation of alkali and sulfate, ions eluted from the inside of GBFS react with PG and produce ettringite, and consequently the remaining component in GBFS slowly produced C-5-H(I) gel. Here, PG is considered not only to play the role of simple activator, but also to work as a binder reacting with GBFS.

• Journal of the Korea Concrete Institute
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• v.26 no.2
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• pp.117-124
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• 2014

Globally, there are environmental problems due to greenhouse gas emissions. $CO_2$ emissions rate of the cement industry is very high, but the continued demand of cement is needed in the future. In this study, in order to reduce the environmental impact of $CO_2$ emissions from cement production. The experiments were carried out for the development of non-sintered cement (have not undergone firing burning) by granulated ground blast furnace slag. In order to compare the characteristics by curing, an experiment was conducted by changing the curing conditions such as atmospheric steam curing, observe the mechanical properties for the measurement of flexural compressive strength by mortar, observe the chemical properties such as acid resistance, $Cl^-$ penetrate resistance and analyzed the mechanism of hydration by XRD, SEM experiments. From the experimental results, as compared with portland cement usually confirm the mechanical and chemical properties excellent, it is expected be possible to apply to the undersea, underwater and underground structures that require superior durability. In addition, based on the excellent compressive strength by steam curing, it is expected to be possible to utilize as a cement replacement material in the secondary product of concrete. In the future, to solve the problem through continued research, it will be expected to reduce the effect of environmental load and to be excellent economics.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.1
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• pp.50-63
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• 2007

The development of domestic plant specific emission factors is very important to estimate reliable national emissions management. This study, for the reason, was carried out to obtain advances emission factor for Carbon Dioxide ($CO_2$) by source-specific emission tests from the iron and steel industry sector which is well known as one of the major sources of greenhouse gases ($CO_2$). Emission factors estimated in this study were compared with those of IPCC for evaluation and they were found to be of similar level in the case of $CO_2$. There was no good information available on $CO_2$ plant specific emission factors from the iron and steel industry in Korea so far. The major emission sources of $CO_2$ examined from the iron and steel manufacturing precesses were a hot blast stove, coke oven, sintering furnace, electric arc furnace, heating furnace, and so on. In this study, the concentration of $CO_2$ from the hot blast stove process was the highest among all processes. The $CO_2$ emission factors for a ton of Steel and Iron products (using B-C oil) were estimated to be 0.315 $CO_2$ tonne (by Tier 3 method) and 4.89 $CO_2$ tonne. In addition, emission factor of $CO_2$ for heating furnace process was the highest among all process. Emission factors estimated in this study were compared with those of IPCC for evaluation and they were found to be of similar level in the case of $CO_2$.

• Fisheries and Aquatic Sciences
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• v.4 no.4
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• pp.201-207
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• 2001

To study the distribution of organophosphorus pesticides which are extensively used for agriculture in Korea. Sea water samples were taken from 4 coastal areas during May and August of 1997 and sediment samples were collected from two coastal areas in August of 1997. These samples were analyzed using a Gas Chromatography/Nitrogen Phosphorus Detector (GC/NPD). In August the most commonly found organophosphorus pesticides in the surface waters of Kunsan area were IBP < S-Benzyl O,O-di-isopropyl phosphorothioate > $(m=432.5ng\;L^{-1})$ and EDDP < O-ethyl S,S-diphenyl phosphorodithioate > $(m=37.4ng\;L^{-1}) $ which are largely used between June and September to prevent rice blast disease. In Danghang Bay, dry fields located near the mouth of the estuary seemed to affect the concentrations of certain organophosphorus pesticides in the surface waters. Since organophosphorus pesticides applied in the watershed are rapidly decomposed while being transported along freshwater streams, watershed size is not proportional to the concentrations of these pesticides in the coastal waters. Pesticides concentrations measured in August were compared with those in May. IBP concentrations in coastal waters were about an order of magnitude higher in August than in May. Temporal and geographical distribution of individual organophosphorus pesticides is likely to be affected by types of agricultural practices in the watershed. Chloropyrifos was the most important of the organophosphorus pesticides in the sediments of the study area because of its persistent nature and high affinity to particulates.