• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.6
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• pp.646-652
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• 2014

Data of pollution incidents which occurred in shipyards of South Korea for 10 years from 2004 to 2013 were collected and analyzed in order to propose the plans for the prevention of pollution incidents in shipyards. Total number of pollution incidents in shipyards was 103 cases over the nation of Korea for the recent 10 years and the average annual number was about 10 cases, and annual cases tended to increase from 8 cases in 2004 to 23 cases in 2010 and then to decrease to 9 cases in 2013. The location data of pollution incidents showed 32 cases in Busan metropolitan city (31%), 30 cases in Jeonnam (29%), 21 cases in Gyeongam (21%), 5 cases in Jeju (5%), 4 cases in Gangwon (4%), 4 cases in Gyeongbuk (4%), 3 cases in Chungnam (3%) and 3 cases in Incheon metropolitan city (3%). According to the data of work types of shipyards, 60 cases happened during the work of ship repair (58%), 25 cases during the work of ship breakup (24%), 10 cases in the course of ship building (10%) and 8 cases by others (8%). The data of pollutant type showed oil and oily mixtures to be 59 cases (57%), waste paint dust to be 22 cases (21%), iron dust and welding slag to be 13 cases (13%), wastes to be 4 cases (4%), waste FRP powder to be 3 cases (3%), and others to be 2 cases (2%). The plans for the prevention of pollution incidents in shipyards of Korea were proposed as follows; (1) Observance of the related laws and regulations, (2) Establishment and implementation of action plans to prevent areas dense with shipyards from causing pollution incidents, (3) Establishment and implementation of oil pollution prevention plans in shipyards, especially during the ship repair and breakup works, (4) Preparation of measures to solve civil complaints against pollution incidents in shipyards, and (5) Improvement in national management for the control of shipyards.

• Journal of Bio-Environment Control
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• v.31 no.2
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• pp.79-89
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• 2022

With the wide use of greenhouses, the working hours have been increasing inside the greenhouse for workers. In the closed ventilated greenhouse, the internal environment has less affected to external weather during making a suitable temperature for crop growth. Greenhouse workers are exposed to organic dust including soil dust, pollen, pesticide residues, microorganisms during tillage process, soil grading, fertilizing, and harvesting operations. Therefore, the health status and working environment exposed to workers should be considered inside the greenhouse. It is necessary to secure basic data on particulate matter (PM) concentrations in order to set up dust reduction and health safety plans. To understand the PM concentration of working environment in greenhouse, the PM concnentrations were monitored in the cut-rose and Hallabong greenhouses in terms of PM size, working type, and working period. Compare to no-work (move) period, a significant increase in PM concentration was found during tillage operation in Hallabong greenhouse by 4.94 times on TSP (total suspended particle), 2.71 times on PM-10 (particle size of 10 ㎛ or larger), and 1.53 times on PM-2.5, respectively. During pruning operation in cut-rose greenhouse, TSP concentration was 7.4 times higher and PM-10 concentration was 3.2 times higher than during no-work period. As a result of analysis of PM contribution ratio by particle sizes, it was shown that PM-10 constitute the largest percentage. There was a significant difference in the PM concentration between work and no-work periods, and the concentration of PM during work was significant higher (p < 0.001). It was found that workers were generally exposed to a high level of dust concentration from 2.5 ㎛ to 35.15 ㎛ during tillage operation.

• Korean Journal of Food Science and Technology
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• v.53 no.2
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• pp.223-229
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• 2021

To evaluate the protective effect of Codium fragile on fine dust (PM2.5)-induced cytotoxicity, we investigated its antioxidant activity and cell protective effect on PM2.5-exposed cells. The 40% ethanolic extract of C. fragile showed the highest total phenolic content, whereas the water extract of C. fragile showed the highest total polysaccharide content. The protective effect of the extracts on PM2.5-induced oxidative damage in nasal cavity (RPMI2650), lung (A549), brain (MC-IXC), hippocampus (HT-22), and microglia (BV-2) cells was evaluated by measuring the intracellular reactive oxygen species (ROS) content and cell viability. The results showed that the 40% ethanolic extract more efficiently inhibited ROS production than the water extract. In contrast, PM2.5-exposed cells treated with the water extract showed higher viability than those treated with the 40% ethanolic extract.

• Journal of the Korea Institute of Building Construction
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• v.8 no.2
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• pp.113-119
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• 2008

Recently, fiber reinforced polymers(FRP) composite materials are used extensively in the rehabilitation of concrete structural members. A main application is to wrap beams and columns using the continuous fibers sheets to improve their strength and ductility. The corner chamfering affects significantly the performance of the continuous fibers sheets, and could lead to environmental problem with waste and dust. The main purpose of this paper is to verify the effect of corner conditions on the strength of the continuous fiber sheets, and to introduce new attached components which can avoid environmental problem. A total of 15 specimens were tested and carefully checked for three types of continuous fiber sheets(carbon, glass, and aramid) and three types of corner conditions(non-chamfering, chamfering, and device attaching). It is proved that the devices proposed in this research have some capabilities to use for RC member. But additional research will be needed for commercializing.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2546-2551
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• 2007

Weather Strip(W/S) is a rubber part to proof water, sound and dust for opening and shutting devices including vehicle doors. And it requires high dimension precision and durability to proof water, noise, vibration and etc. But ironically it itself makes some wind noise because of some protuberance with glasses. The air flow analysis of door part of vehicle makes it possible to calculate and find out the cause of wind noise. In previous analysis, we focus on the numerical air flow analysis of the automobile side part. We do 2D-C.F.D first and 3D second. Through simulations, we can calculate the amount of sound pressure level at the glass run and find out the effects of glass run to make wind noise. Finally we can improve shape of glass run to reduce wind noise although it is small amounts of sound pressure reduction compared with total vehicle noise level.

• Asian Journal of Atmospheric Environment
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• v.8 no.3
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• pp.115-125
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• 2014

In this study, particle composition data for $PM_{10}$ samples were collected every 3 days at Seoul, Korea from August 2006 to November 2007, and were analyzed to provide source identification and apportionment. A total of 164 samples were collected and 21 species (15 inorganic species, 4 ionic species, OC, and EC) were analyzed by particle-induced x-ray emission, ion chromatography, and thermal optical transmittance methods. Positive matrix factorization (PMF) was used to develop source profiles and to estimate their mass contributions. The PMF modeling identified nine sources and the average mass was apportioned to secondary nitrate (9.3%), motor vehicle (16.6%), road salt (5.8%), industry (4.9%), airborne soil (17.2 %), aged sea salt (6.2%), field burning (6.0%), secondary sulfate (16.2%), and road dust (17.7%), respectively. The nonparametric regression (NPR) analysis was used to help identify local source in the vicinity of the sampling area. These results suggest the possible strategy to maintain and manage the ambient air quality of Seoul.

• Journal of environmental and Sanitary engineering
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• v.10 no.1
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• pp.35-44
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• 1995

The study was carried out to investigate on the response of environmental sanitation problems in action of the volume based waste charge system in Seoul The responses from the 346 persons who dwelled in Seoul was stimulatively answered, this system was considered as a successful on 70.5% of total answers, but little portion(29.4 % ) of those was unknown on the mean of this system. And we knew that this system was need to the communication and education through the press media about this one. After the action of the volume based waste system, the volume of refuse discharged in a day was decreased 30 ∼40% than before. In the problems of environmental sanitation after this system, the number of sanitary insect( cockroach etc ) and rat was decreased, also the production of orders and dust caused by refuse was decreased in comparison with those before. This results were considered that the Separate Collection should be perfectly performed. In response, the regular envelope of refuse was serious problems, the improvement for this one was demanded. The kind of difficult refuse treated was waste rubbers> electric products > furniture> foodstuffs> bottles, cans> papers, pulps etc, and the next proposal for this system should be prepared. Conclusively, the volume based waste charge system should be remarkable system In terms of resources recycling as well as wastes reduction. Above all in order to conform this system the separate collection system should be systematically performed, the next improvable proposal of the detailed methods in this system should be prepared.

• Publications of The Korean Astronomical Society
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• v.32 no.1
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• pp.313-315
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• 2017

We present physical properties of $24{\mu}m$ galaxies detected by AKARI and Spitzer and their evolution between redshifts 0.4 < z < 2. Using multi-wavelength data from X-ray to radio observations in NEP Deep Field (for AKARI) and Subaru/XMM-Newton Deep Field (for Spitzer), we derive photometric redshift, stellar mass, star-formation rate (SFR), dust extinction magnitude and rest-frame luminosities/colors of the $24{\mu}m$ galaxies from photometric SED fitting. We infer the SFRs from rest-frame ultraviolet luminosity and total infrared luminosity calibrated against Herschel photometric data. For both survey fields, we obtain complete samples with stellar mass of > $10^{10}M_{\odot}$ and SFR of > $30M_{\odot}/yr$ up to z = 2. We find that specific SFRs evolves with redshift at all stellar masses in NON-power-law galaxies (non-PLGs) as star-formation dominant luminous infrared galaxies (LIRGs). The correlations between specific SFR and stellar mass in the Spitzer and AKARI galaxy samples are well consistent with trends of the main sequence galaxies. We also discuss nature of PLGs and their evolution.

• Explosives and Blasting
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• v.19 no.3
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• pp.91-104
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• 2001

As in Korean environments with mountainous and hilly areas, the rock generally has to be removed in construction or civil engineering work in tunnelling or excavation for development in urban area. Explosives should be used for blasting, which may cause serious problems on local people for their claim for compensation due to ground vibration, noise. For safe and economic blasting, geology and engineering characteristics of rocks such as discontinuities of rock or weathering are very important factors, together with site characteristics for prediction of ground vibration. In this study, conducted were the detailed study for major rocks most widely distributed in the South-east area, in-situ geological survey, geological and geochemical analysis, and further laboratory uniaxial rock stress, seismic velocity of core samples together with in-situ seismic velocity measurements. Regulations on ground vibration and noise were reviewed for assessing their adaptabilities, and a total of 4,856 measured blasting vibration data were examined for enhancing the confidence level in estimating the predictive formulation using scaled distance statistically.

• The Korean Journal of Community Living Science
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• v.18 no.1
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• pp.39-53
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• 2007

The purpose of this study was to determine the characteristics of an experimental protective clothing material with regard to comfort and isolation from the hazardous heavy metals produced in municipal waste incineration. An analysis was conducted on the total concentrations of heavy metals in some parts such as surface, middle layer, and interior for the treated fabric, and the untreated one, and working clothes. We conclude that the processed fabric with charcoal for working clothes showed the least exposure to heavy metals of the three. Working clothes worn by workers during waste incineration were much more contaminated than the untreated and treated materials. The material of working clothes could be chosen according to the function with regard to its original chemical characteristics, which are the proper results of the dyeing process. The processed fabric material has high degrees of moisture regain, thermal insulation, water vapor penetration, and antibacterial function; consequently, it is much more comfortable to wear. The fabric material proposed in this research contributed much more to blocking heavy metal concentrations (such as Cd, Pb, Cu, Cr, Zn, Mn) than did the fabric of working clothes at present. Consequently, we strongly suggest that the material of working clothes be upgraded by adopting the above-mentioned charcoal-processed fabric. Materials of working clothes must be improved to increase comfort and prevent harmful gas, flying dust, and heavy metals from permeating the fabrics.