• Journal of the Korea Institute of Building Construction
• /
• v.20 no.1
• /
• pp.27-34
• /
• 2020

In the industry, due to the carbon dioxide gas produced during cement production is increasing, research on recycling by-products has been actively conducted. In the industrial by-products, the high calcium fly ash(HCFA) produced by the blast-furnace in the circulating fluidized bed combustion method has a high ratio of CaO and CaSO4. In view of this, the purpose of this is to use high calcium fly ash(HCFA) as a stimulant in blast furnace slag powder and use it as a cement substitute. As a result, it is judged that the substitution ratio of HCFA should be 15% or less. In addition, although durability and strength are relatively lower than of OPC, it is considered that it can be utilized as an environmentally building material.

• Journal of Preventive Medicine and Public Health
• /
• v.34 no.1
• /
• pp.41-46
• /
• 2001

Objectives : To investigate the effects of particulate matter (PM), a marker of environmental pollution derived from combustion sources, on lung epithelial cells (A549) and macrophage (RAW 264.7). Methods : The production of reactive radicals from lung cells, the lipid peroxidation of cell membrane, and the cytotoxicity of PM were measured using an in vitro model. The results were compared with a control group. Results : The presence of PM significantly increased the production of reactive oxygen species and reactive nitrogen species with time and in a dose dependent pattern and also increased the malondialdehyde concentration in lung epithelial cells. The cytotoxicity of PM was increased with increasing concentration of PM. Conclusions : It has been suggested that urban particulate matter causes an inflammatory reaction in lung tissue through the production of hydroxyl radicals, nitric oxides and numerous cytokines. The causal chemical determinant responsible for these biologic effects are not well understood, but the bioavailable metal in PM seems to determine the tonicity of inhaled PM.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.41 no.8
• /
• pp.553-561
• /
• 2017

The main motivation for this study was to establish a CFD-based procedure for the analysis of heating characteristics, particularly in industrial furnaces. As certain open-source software packages have gained popularity in dealing with complex industrial problems, the OpenFOAM framework was selected for further development of advanced physical models to meet industrial requirements. In this study, the newly developed comprehensive model was applied to simulate physical processes in the full-scale horizontal furnace of a continuous galvanizing line (CGL). The numerical results obtained indicate that the current approach predicts heating characteristics reasonably well. It was also found that radiative heat transfer plays a dominant role in heating the moving strip. To improve the predictability of our method, further work is required to model the turbulence-chemistry interaction realistically, as well as to impose a physically correct thermal wall boundary condition.

• Journal of Korean Institute of Fire Investigation
• /
• v.10 no.1
• /
• pp.59-75
• /
• 2007

The causes of the fire casualties were the heat burns, contacted by flame, before the period of industrialization. According to the economic has been developed drastically since 1990, residing space has been become bigger and sophistication and interior finishing materials have been diversified. Therefore, the suffocation casualties, caused by inspiration of toxic combustion gases, have been more increased than the flame casualties in recently. Also, the arson casualties have been increasing with the increasing of insurance crime to take the Insurance money. According to National Emergency Management Agency announcement, 31,778 fires was occurred nationwide in 2006 and the total casualties were 2,180 occurred. 446 persons were died among them. Because the exact investigation of fire, occurred the death, is very especially important that civil and criminal cases will be happened. Therefore, we studied about the cause of fire, the place of origin, and the group of casualties age on the axies of fires, which were occurred recently. And the identification method of fire casualties, the human behavior characteristic, the flame casualties and the suffocation casualties at fire scene.

• Korean Chemical Engineering Research
• /
• v.57 no.3
• /
• pp.372-377
• /
• 2019

Leaching ($60^{\circ}C$, 5 min) and wet torrefaction ($200^{\circ}C$, 5 min) of empty fruit bunch (EFB) were carried out to improve the fuel properties; each liquid fraction was reused for leaching and wet torrefaction, respectively. In the leaching process, potassium was effectively removed because the leaching solution contained 707.5 ppm potassium. Inorganic compounds were accumulated in the leaching solution by increasing the reuse cycle of leaching solution. The major component of the leached biomass did not differ significantly from the raw material (p-value < 0.05). Inorganic compounds in the biomass were more effectively removed by sequential leaching and wet torrefaction (61.1%) than by only the leaching process (50.1%) at the beginning of the liquid fraction reuse. In the sequential leaching and wet torrefaction, the main hydrolysate component was xylose (2.36~4.17 g/L). This implied that hemicellulose was degraded during wet torrefaction. As in the leaching process, potassium was effectively removed and the concentration was accumulated by increasing the reuse cycle of wet torrefaction hydrolysates. There was no significant change in the chemical composition of wet torrefied biomass, which implied that fuel properties of biomass were constantly maintained by the reuse (four times) of the liquid fraction generated from leaching and wet torrefaction.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.64 no.2
• /
• pp.57-69
• /
• 2022

This study analyzes the fuel conditions and environmental effects of converting heating in rural villages that rely on fossil fuels into wood fuel. In particular, we tried to derive the most important considerations when using wooden chips as fuel in aging agricultural villages where various variables such as weather, facility characteristics, fuel quality, and maintenance capabilities work. Above all, an experiment was conducted by comparing it with oak trees to determine whether Italian poplar, a representative attribute water created to supply fuel wood in Korea, is suitable for heating fuel. Through experiments, 1) Even though the supply of poplar wood chips during 10 hours of operation was 60.74 kg less than that of hardwood chips, the production of hot water was 140 kWh higher. 2) The higher the exhaust gas temperature, the proportional (increase) oxygen concentration and inversely (decrease) PM and CO emissions. 3) Poplar has twice as much ash content as hardwood and three times more fine dust has been detected, but it meets all the standards for wood quality at the Korea Forest Science Institute. 4) Under the condition that there is a difference in water content (7.7%), hardwood cost 1.13 times more wood chips per 1 MWh than poplar, and even if the water content is corrected equally, hardwood cost 1.05 times more per 1 MWh than poplar. 5) In conclusion, it was proved that the fuel possibility, economic possibility, and environmental possibility of poplar wood chips are sufficient.

• Clean Technology
• /
• v.26 no.3
• /
• pp.221-227
• /
• 2020

When the waste solid fuel (SRF, Bio-SRF) is burnt in a boiler, a problem occurs in the combustion process involving the alkali components (Na, K) contained in large amounts in the fuel. The alkaline component has a low melting point, which usually forms low melting point salt in the temperature of the furnace, with the resulting low melting point salts attaching to the heat pipe to form a clinker. Various additives are used to suppress clinker generation, and the additive based on the kaolinite has alkali-aluminum-silica to inhibit the clinker. In this study, the reactivity of the additives based on the kaolinite was compared. The additives utilized were R-kaolinite, B-kaolinite, and A-kaolinite. Also silica and MgO were sourced as the comparison group. The experimental group was employed as a laboratory-scale batch horizontal reactor. The additive and alkaline salts were reacted at a weight ratio of 1 : 1, and the reaction temperature was performed at 900 ℃ for 10 hours. The first measurement of HCl occurring during the experiment was performed 30 minutes after the detection tube was used, and the process was repeated every hour after the experiment. After the reaction, solid residues were photographed for characterization analysis by means of an optical microscope. The reaction characteristics of the kaolinite were confirmed based on the analysis results.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.24 no.2
• /
• pp.144-151
• /
• 2016

This study effect of engine oils on regulated fuel economy and emissions including particulate matter (PM) to provide basic data for management of engine oil in vehicles. Three engine oils (Group III base oil, Group III genuine oil with additive package and synthetic oil with poly alpha olefins (PAOs)) were used in one gasoline, one LPG(liquefied petroleum gas) and two diesel vehicles. In the case of diesel vehicles, one is a diesel vehicle without DPF (diesel particulate filter) other is a diesel vehicle with DPF. In this study, the US EPA emission test cycle FTP-75, representing city driving, was used. HORIBA, PIERBURG, and AVL gas analyzers were used to measure the fuel economy and regulated emissions such as CO, NOx, and THC. The number of PM was measured using a PPS (pegasor particle sensor). And, the shape of PMs was analyzed by SEM (scanning electron microscope). The effects of oil type on fuel economy, exhaust gas, and PM were not significant because engine oil consumption by evaporation and combustion in the cylinder is very tiny. Fuel and vehicle type were dominant factors in fuel economy and emissions. HC emission from gasoline vehicles was higher than that from other vehicles and NOx emission from diesel vehicles was higher than that from other vehicles. The number of PM was not affected by the engine oil, but by the driving pattern and fuel. The shapes of the PM, sampled from each vehicle using any test engine oil, were similar.

• Polymer(Korea)
• /
• v.30 no.3
• /
• pp.238-246
• /
• 2006

The aim of this study is to enhance the flame retardancy by the synergism effect of chlorine and phosphorus groups. The flame-retardant polyurethane coatings containing chlorine and phosphorus compounds were synthesized. After synthesizing the intermediate products of tetramethylene bis (orthophosphate) (TMBO) and neohexanediol trichlorobenzoate (TBA-adduct), the condensation polymerization was performed with four different monomers of two intermediates, 1,4-butanediol, and adipic acid to obtain four-component copolymer(TTBA). The two-component flame-retardant polyurethane coatings (TTBA-10C/HDI-trimer=TTHD-10C, TTBA-20C/HDI-trimer=TTHD-20C, TTBA-30C/HDI trimer=TTHD-30C) were obtained by curing reaction at room temperature with the synthesized TTBAs and hexamethylene diisocyanate (HDI)-trimer as a curing agent. The obtained TTHDs were made into coating samples and used as test samples for various physical properties. The physical properties of the flame-retardant coatings containing chlorine and phosphorus groups were generally inferior to those containing only phosphorus group. Flame retardancy was tested by vortical and horizontal combustion method, and $45^{\circ}$ Meckel burner method. Since the retardancy of flame-retardant coatings containing chlorine and phosphorus groups was better than that containing only phosphorus group, it could be concluded that the retardancy by the synergism effect of chlorine and phosphorus groups exhibited.

• Journal of The Korean Society of Clinical Toxicology
• /
• v.10 no.2
• /
• pp.73-79
• /
• 2012

Purpose: The purpose of this study was to identify the changes in the characteristics of patients with carbon monoxide (CO) poisoning, as well as the distinctive differences in intentionally exposed patients. Methods: The medical records of CO poisoning patients, who visited nine emergency departments between January 2010 and December 2011, were reviewed retrospectively. The clinical information including age, gender, hospitalization, type of discharge, cause and location of exposure, site of onset, concentration of initial blood carboxyhemoglobin (COHb), methods of treatment and presence of neurological complications was examined. The subjects were divided into an intentional and non-intentional group and the differences between them was compared. Results: A total 209 subjects were recruited. The median age was 38 years (29~49.5 years). They frequently complained of nausea and vomiting, and the most common exposures occurred in winter, normally in the home. The cause of exposure was usually fire, followed by incomplete combustion of fuels. The median initial blood COHb was 13.15%. The proportion of intentionally exposed patients was 21%. They were significantly younger, more frequently discharged against medical advice, and showed a higher initial blood COHb level (22.85%) than the non-intentional group. Conclusion: This study suggests that those with intentional CO poisoning are normally discharged against medical advice even when they have a higher initial COHb level. An adequate explanation of the delayed neurologic sequelae and short term follow-up observation is recommended for those patients with intentional exposure.